1. A cooling structure comprising; a plurality of heating elements arranged in a vertical direction, each including cooling surfaces respectively disposed on two confronting side surfaces extending in the vertical direction, and an electric terminal on 5 a side surface extending in the vertical direction and adjoining the two confronting side surfaces; a plurality of heat receiving blocks pinching the heating elements arranged in the vertical direction on the two confronting side surfaces; 10 first and second cooling devices, each including a heat pipe including a plurality of heat radiation fins; and a pressure contacting part configured to contact the heating elements and the receiving blocks with a pressure force, wherein a wind is applied to the heat radiation fins. 15

2. The cooling structure as claimed in claim 1, wherein the heat radiation fins are disposed above the heating elements and extend in a horizontal direction; and wherein the wind is applied to the heat radiation fins from a side of 20 the electric terminal.

3. The cooling structure as claimed in claim 2, wherein the cooling surfaces are electrically insulated from the electric terminal of the heating element. 25

4. The cooling structure as claimed in claim 2, wherein the first and second cooling devices extend in the vertical direction, the cooling structure further comprising a gap between a pair of adjoining heat radiation fins of the first and second cooling devices at the same 30 height in the vertical direction. - 36 -

5. The cooling structure as claimed in claim 2, wherein the heat radiation fines of the first and second cooling devices extends in a horizontal direction, wherein heat radiation fins of the first and second cooling devices are disposed at the different heights in the vertical direction an5 d interlockingly arranged.

6. The cooling structure as claimed in claim 2, wherein the first and the second cooling devices comprises the heat radiation fins which are shared 10 by heat pipes of the first and second cooling devices.

7. The cooling structure as claimed in claim 2, further comprising a waved stiffness buffering part, wherein a pair of adjoining heat radiation fins of the first and second cooling devices are connect ed with the waved 15 stiffness buffering part.

8. A power converter comprising a plurality of the cooling structures which are arranged, each of the cooling structures being defined by any one of claims 1 to 7, wherein the heating element comprises a 20 semiconductor module for a power converter .

9. The power converter as claimed in claim 8, further comprising a blower blows the heat radiation fins from a side of the electric terminal in a housing. 25

10. A power converter comprising a plurality of semiconductor modules, each comprising: cooling surfaces on two confronting side surfaces extending in the vertical direction; and 30 an electric terminal disposed on a side surface extending the vertical direction and adjoining the two confronting side surfaces; - 37 - heat receiving blocks pinching the semiconductor modules arranged in the vertical direction on the two confronting side surfaces; first and second cooling devices, each including a heat pipe mounted on the heat receiving block and a plurality of heat radiation fins, mounted on the heat pipe, disposed above the semiconductor modules an5 d horizontally extending; and a pressure contacting part configured to contact the heating elements and the receiving block with a pressure force, wherein side faces, on which the electric terminals are disposed, of the respective 10 semiconductor modules for the power converter are arranged on the same plane, and a blower blows the heat radiation fines from a side of the same plane.

11. The cooling structure as claimed in claim 1, wherein a plurality of the 15 heat radiation fins are arranged behind the heating element.

12. The cooling structure as claimed in claim 11, wherein each of the cooling surfaces comprises a plurality of protruded pin fins, wherein each of the heat receiving blocks includes: 20 a heat receiving plate having a shape corresponding to a shape of the cooling surface and holes into which the pin fins are loosely inserted, the cooling structure further comprising: a pair of pinching members configured to pinch the heating element and the heat receiving planes with a pressure force ; 25 a cooling device configured to cool the heat receiving plates, and a space reserving part configured to control a gap in a pair of the pinching members so as not to apply a pressure force by the pinching members to the heating element. 30 13. A cooling structure comprising: a heating element having at least a cooling surface including a - 38 - plurality of protruded pin fins; a heat receiving plate having a shape corresponding to a shape of the cooling surface and loose holes into which the pin fins are inserted at positions corresponding to the pin fins; a cooling device including a pair of pinching members configured t5 o pinch the heating element and the heat receiving plat e with a pressure force and cool the heat receiving plate; and a space reserving part, disposed on the heat receiving plate, configured to control an interval in a pair of the pinching members so as 10 not to apply a pressure force by the pinching members to the heating element.

14. The cooling structure as claimed in claim 13, wherein the heating element comprising cooling surfaces on two-confronting 15 side surfaces thereof, and wherein the heat receiving plate includes a shape corresponding to the two - confronting cooling surfaces and the holes formed at locations corresponding to the pin fins protruding from the two surfaces. 20 15. The cooling structure as claimed in claim 13, further comprising thermally conductive grease coated between the pin fins and the heat receiving plate.

16. The cooling structure as claimed in claim 13, wherein the interval of 25 the pinching member controlled by the space reserving part is larger than a thickness of the heating element including the pin fins.

17. The cooling structure as claimed in claim 13, wherein the hole has a circular column shape. 30

18. The cooling structure as claimed in claim 13, wherein a plurality of - 39 - the pin fins are inserted into the holes.

19. The cooling structure as claimed in claim 13, wherein the heat receiving plate includes both a loose hole into which a plurality of the pin fins are inserted and a loose hole into which one of th5 e pin fin is inserted.

20. The cooling structure as claimed in claim 13, further compri sing: heat radiation fins; and 10 a heat pipe connected to the pinching member and the heat radiation fins.

21. The cooling structure as claimed in claim 13, wherein the cooling device includes heat radiation fins connected to the 15 pinching members.

22. The cooling structure as claimed in claim 13, further composing a flow path and a heat radiation fin connected the flow path. 20 23. A cooling structure comprising: a heating element including at least a cooling surface including a plurality of pin fins; a space reserving part formed to have a thickness smaller than a thickness of the heating element including the pin fins and larger than a 25 thickness of the heating element without the pin fins; a pair of pinching members, having a shape corresponding to a shape of the cooling surface, pinching the heating element sandwiched between the space reserving parts and holding the heating elements while a pressure force is applied to heating element. 30

24. A power converter comprising: - 40 - a plurality of the cooling structures, as claimed in any one of claims 13 to 23, arranged so as to adjoin each other, wherein the heating element comprising semiconductor unit for the power converter.

25. A power converter, comprising5 : a plurality of semiconductor units for a power converter, each of the semiconductor units including cooling surfaces including a plurality of pin fines protruding from the cooling surfaces on confronting two-side surfaces thereof; and 10 an electric terminal on one of side surfaces adjoining the confronting two-side surfaces; heat receiving plates, each including a shape corresponding to a shape of the cooling surface and lose holes into which the pin fins are inserted at locations corresponding to the pin fins, wherein the heat 15 receiving plates are attached to the cooling surfaces, respectively; a plurality of cooling devices, each including: a plurality of pinching members configured to pinch the semiconductor units for the power converter and a plurality of heat receiving plates to hold the semiconductor units and the heat receiving 20 plates with a pressure force; a plurality of heat radiation fins, each extending in a horizontal direction relative to each of the semiconductor units; and heat pipes connecting the pinching members to a plurality of heat radiation fines corresponding to the pinching members, respectively; 25 space reserving parts, disposed at the heat receiving plates, controlling an interval between the pinching members so as not to apply the pressure force by the pinching member to the semiconductor units, wherein the side surfaces each having the electric terminal for the 30 semiconductor unit for the power converter are arranged on the same plane; and wherein - 41 - a blower supplies a cooling wind to a plurality of the heat radiation fins on a rear side of the same plane.

The present invention relates to a cooling structure for a heating
element and a power converter.
2. Description of the Related Art
A power converter includes a circuit using semiconductor devices
10 for performing current conduction and current blocking and provides
functions of AC-DC conversion, frequency conversion, etc by controlling
switching operations of the semiconductor devices. In the semiconductor
devices in the power converter, losses are generated upon current
conduction and switching during turning on and off. When a temperature
15 of the semiconductor devices exceeds an operating limit point due to heat
caused by the loss, current interruption cannot be done, so that the power
converter cannot provide a desired operation. Accordingly, a cooling
device for cooling the semiconductor devices is required in the power
converter.
20 There are various types of semiconductor devices depending on an
exterior, an electric characteristic, etc. Accordingly the cooling device is
designed in accordance with respective characteristics. For example, JP
2013-73964 A discloses a semiconductor unit including a cooling device
having two cooling surfaces, an electric terminal part, and a cooling unit
25 with protrusions has a pin-shape.
JP 2000-060106 A discloses, similarly to JP 2013-73964 A, a cooling
device including a high heat conductor, and an air-cooling fins on two
cooling surfaces.
In addition, JP 2013-73964 A discloses, at a paragraph 0001,"the
30 document relates to a power module having a high heat radiation
characteristic and a high reliability and, at a paragraph 0011, "On one of
- 3 -
the two confronting surfaces with larger area, is provided with a heat
radiation part, and another surface has a heat radiation part". The heat
radiation parts function as heat radiation walls for a module case 304. On
an outer circumferential surface, a plurality of fins are uniformly formed.
In JP 2013-73964 A, a cooling water is used for cooling th5 e
semiconductor devices. However, it is necessary to additionally provide a
water channel, a pump, and a heat radiator separately. In addition, the
power module housing the semiconductors therein has two surfaces for
cooling the heat from their inside, each having a heat radiation part having
10 a lot of fins on each of the surfaces, which may cause the structure to be
complicated.
In JP 2000-060106 A, an increase in the cooling characteristic has
been tried by arranging a heat radiator near the semiconductor devices, etc.
However, the structure becomes complicated. Accordingly, when this
15 structure is applied to a power converter requiring a lot of power modules,
a size of the power converter becomes large.
On the other hand, there is a need to use as an air -cooling type one
the heating element such as the semiconductor module having originally
designed as a water-cooling type. This is because the use of the air -
20 cooling type one eliminates necessity of piping for the coolant, which is
advantageous to maintenance. When the air -cooling type is adopted, it
becomes necessary to provide cooling fins, etc. having a certain size on the
heating element. However, the heating element, originally having
designed as a water-cooling type one, has small pin fines (fins protruding
25 in a pin shape), etc. However, such a heating element is designed without
assumption that a large pressurizing force is applicable, so that there is no
assumption that a strong pressure force is applied. Accordingly, when an
external cooling fin is simply mounted by fastening bolts, the heating
element may be damaged.
30 An aspect of the present invention is to provide a cooling structure
for a heating element or a plurality of power modules with extensibility in
- 4 -
arranging the heating elements such as a power module and with downsizing
a device for power converters, etc., using the heating elements such
as a plurality of power modules.
An aspect of the present invention is to provide a cooling structure
for a heating element, having pin fins and being capable of cooling th5 e
heating element for a semiconductor module, etc with avoidance of
damage and a power converter.
SUMMARY OF THE INVENTION
10 A first aspect of the present invention provides a cooling structure
comprising;
a plurality of heating elements arranged in a vertical direction, each
including cooling surfaces respectively disposed on two confronting side
surfaces extending in the vertical direction, and an electric terminal on a
15 side surface extending the vertical direction and adjoining the two
confronting side surfaces;
a plurality of heat receiving blocks pinching the heating elements
arranged in the vertical direction on the two confronting s ide surfaces;
first and second cooling devices, each including a heat pipe
20 including a plurality of heat radiation fins;
a pressure contacting part configured to contact the heating
elements and the receiving block with a pressure force; and
a blower configured to apply a wind to the heat radiation fins.
A second aspect of the present invention provides a cooling
25 structure comprising:
a heating element having at least a cooling surface including a
plurality of protruded pin fins;
a heat receiving plate having loose holes into which the pin fins are
inserted at positions corresponding to the pin fins;
30 a cooling device including pair of pinching members configured to pinch
the heating element and the heat receiving plate with a pressure force and
- 5 -
cool the heat receiving plate; and
a space reserving part, disposed on the heat receiving plate,
configured to control a gap (interval) in a pair of the pinching members so
as not to apply a pressure force by the pinching members to the heating
element5 .
In the first aspect, a cooling structure for a heating element has
extensibility in arranging the heating element such as a power module and
capability of down-sizing a device such as a power converters, etc., using
the heating elements such as a plurality of power modules.
10 In the second aspect, the heating element can be cooled with
avoidance of damage.
BRIEF DESCRIPTION OF THE DRAWINGS
The object and features of the present invention will become more
15 readily apparent from the following detai led description taken in
conjunction with the accompanying drawings in which:
Fig. 1 is a circuit diagram of a power converter according to a first
embodiment of the present invention.
Fig. 2 is a circuit diagram of a converter of the power converter
20 Fig. 3 is a circuit diagram of an inverter for the power converter.
Fig. 4 is a circuit diagram of a chopper for the power converter.
Fig. 5 is a perspective view of an air-cooling type of power unit
Fig. 6 is an exploded drawing showing arrangement of power
module having two face cooling in the
25 Fig. 7A is a perspective view of the double-sided-cooling power
module, and Fig. 7B is a schematic circuit diagram.
Fig. 8 is an illustration showing heat transferring path of an air -
cooling type of double-sided-cooling power unit.
Fig. 9 is a perspective view of the single converter unit.
30 Fig. 10 is an exploded view showing an arrangement of the single
converter unit.
- 6 -
Fig. 11 is a schematic circuit diagram of the single converter unit.
Fig. 12 is an illustration showing the power converter in which a
plurality of the single converter units are arranged.
Fig. 13 is an illustration for illustrating a method of cooling the
single converter unit in the power converter5 .
Fig. 14A and 14B are perspective views in which the heat radiation
fins of the first and second cooling devices are interlockingly arranged, in
which Fig. 14A shows the whole view and Fig. 14B is an enlarged view.
Fig. 15A is a perspective view of the radiation fins in the case where
10 the same radiation fins are installed at the heat pipes of the first and
second cooling devices in which Fig. 15A shows the whole view and Fig.
15B is an enlarged view.
Figs. 16A and 16B are perspective views in a case where the
radiation fins of the first and second cooling devices are connected with
15 waved rigid buffering parts in which Fig. 16A shows the whole view and
Fig. 16B is an enlarged view.
Fig. 17 is a schematic circuit diagram of the power converter
according to the second embodiment .
Fig. 18 is a schematic circuit diagram of the converter.
20 Fig. 19 is a schematic circuit diagram of the inverter
Fig. 20 is a schematic circuit diagram of the chopper.
Fig. 21A is a perspective view of double-sided-cooling power
module, and Fig. 21B is a circuit diagram the double-sided-cooling power
module.
25 Fig. 22A and 22B are perspective views of the heat receiving spacer.
Fig. 23 is a perspective view illustrating a mounting state in which
the heat receiving spacer is mounted.
Fig. 24 is an enlarged view of a B part in Fig. 23.
Fig. 25 shows a cross section taken along line A - A' in Fig. 23.
30 Fig. 26 shows a perspective view of the air -cooling type of doublesided-
cooling power unit according to the second embodiment .
- 7 -
Fig. 27 is a perspective view of a C part in Fig. 26.
Fig. 28 is a perspective view of the single converter unit.
Fig. 29 is an exploded view of the single converter unit.
Fig. 30 is an exploded view of a laminated bus bar.
Fig. 31 is a schematic circuit diagram of the singl e converter unit5 .
Fig. 32 is a perspective view of the power converter in which a
plurality of the single converter units are arranged.
Fig. 33 is an exploded view of an interphase laminated bus bar.
Fig. 34 is an enlarged view corresponding to a B part in Fig. 23
10 according to one modification of the heat receiving spacer.
Fig. 35 is an enlarged view corresponding to the B part in Fig. 23
according to another modification of the heat receiving spacer.
Fig. 36 is an enlarged view corresponding to the B part in Fig. 23
according to another modification of the heat receiving spacer.
15 Fig. 37 is an exploded perspective view corresponding to a C part in
Fig. 26 according to another modification of the heat receiving spacer.
Fig. 38 is a perspective view of the liquid-cooling type of doublesided-
cooling power unit according to a modification.
The same or corresponding elements or parts are designated with
20 like references throughout the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[First embodiment]
A first embodiment of the present invention is described blow with
25 reference to the drawings.
A power converter 100 (see Figs. 1, 12, 13) includes a plurality of
single converter units 910 (see Figs. 9 and 12). The single converter unit
910 includes a double-sided-cooling power unit 520 (see Fig. 5,
semiconductor unit for the power converter) including a plurality of
30 double-sided-cooling power modules 500 (semiconductor module, see Fig.
7). Respective components in the power converter 100 are described
- 8 -
below.
Fig 1 is a schematic circuit showing the power converter according
to the first embodiment. As shown in Fig. 1, the power converter 100 is
supplied with an AC power having a voltage which is appropriately
adjusted through a transformer 105 from a power receiving point 107 of 5 a
power grid. The supplied AC power is inputted into a converter 102
which converts the supplied AC power into a DC power. The DC power
is inputted into the inverter 103 to convert the DC power into an AC powe r.
The AC power is consumed by a three-phase AC load 108.
10 On the other hand, when the power is not supplied to the converter
102 due to a trouble, etc. in the power grid, an upper control circuit 109
detects this and controls a chopper 104 to operate. A DC power supplied
from a battery 106 to the chopper 104 is adjusted to an appropriate power
and inputted into an inverter 103. The DC power inputted into the
15 inverter 103 is converted into an AC power which is consumed by the
three-phase AC load 108.
The operation described above is judged by the upper control
circuit 109 as to whether the operation is a desired operation or not. The
converter 102, the inverter 103, and the chopper 104 generate heat during
20 their operations, so that temperatures increase. To suppress the
temperature increase, a cooling wind 111 is supplied to the converter 102,
the inverter 103, and the chopper 104 by a cooling fan (blower) 101. Out
of the electric systems as described above, the cooling fan 101, the
converter 102, the inverter 103, the chopper 104, the upper control circuit
25 109, etc. are housed in the power converter 100 according to the
embodiments.
Fig. 2 is a circuit diagram of the converter in the power converter.
Fig. 3 is a circuit diagram of the inverter in the power converter. Fig. 4 is
a circuit diagram showing the chopper in the power converter. With
30 reference to Figs. 2 to Fig. 4, circuits of the converter 102, the inverter 103,
and the chopper 104 are described.
- 9 -
The converter 102 shown in Fig. 2 includes leg 203s (203R, 203S,
203T) each configured with a plurality of semiconductor devices. The leg
203 includes a plurality of switching devices 204 (for example, 204RH,
204RL) and a plurality of diode devices 205 (for example, 205RH, 205RL).
Hereinafter, in the case where a whole of components are generall5 y
referred, the leg 203, the switching device 204, and the diode device 205
are used.
Both ends of the leg 203 are connected to a capacitor 201. An
upper arm of the leg 203R includes a switching device 204RH and a
10 refluxing diode device 205RH. A lower arm of a leg 203R includes a
switching device 204RL and a refluxing diode device 205RL. Similarly, an
upper arm of the leg 203S includes a switching device 204SH and a
refluxing diode device 205RH. Further, a lower arm of the leg 203S
includes a switching device 204SL and a refluxing diode device 205SL.
15 An upper arm of a leg 203T includes a switching device 204TH and a
refluxing diode device 205TH. A lower arm of the leg 203T includes a
switching device 204TL and a refluxing diode device 205TL.
Switching signals to the switching devices 204RH, 204RL, 204SH,
204SL, 204TH, 204TL are controlled by a converter gate controller 202,
20 which is a lower control unit.
Further, in the switching device according to the present invention,
any devices capable of turning on and off can be used. For example, there
are an IGBT (Insulated Gate Bipolar Transistor), and a power MOSFET
(Metal Oxide Semiconductor Field Effect Transistor).
25 The inverter 103 shown in Fig. 3 includes a plurality of the legs 203
(203U, 203V, 203W) configured with a plurality of semiconductor devices
and both ends of the leg 203 are connected to a capacitor 301. The upper
arm of the leg 203U includes a switching device 204UH and a re fluxing
diode 205UH. A lower arm of the leg 203U includes a switching device
30 204UL and a refluxing diode 205UL. Similarly, an upper arm of a leg
203V includes a switching device 204VH and a refluxing diode 205VH. A
- 10 -
lower arm of the leg 203V includes a switching device 204VL and a
refluxing diode 205VL. An upper arm of a leg 203W includes a switching
device 204WH and a refluxing diode 205WH. A lower arm of the leg
203W includes a switching device 204WL and a refluxing diode 205WL.
Switching signal applied to the switching devices 204UH, 204UL, 204VH5 ,
204VL, 204WH, 204WL are controlled by an inverter gate control unit 302
as a lower control part.
The chopper 104 includes the leg 203 configured with
semiconductor devices (203X). The both ends of the leg 203 are connected
10 to a capacitor 401. An upper arm of a leg 203X includes a switching
device 204XH and a refluxing diode 205XH. A lower arm of the leg 203
includes a switching device 204XL and a refluxing diode 205XL. A
junction point between the swi tching devices 204XH and 204XL is
connected to the battery 106 through a reactor 403 (see Fig. 1). The
15 switching signals to the switching devices 204XH, 204XL are controlled by
a chopper gate control unit 402.
As an example of the control operation, the chopper gate control
unit 402 is amplified.
The switching signals are applied to the chopper 104 through a
20 boosting and stepping-down switching circuit (not shown). These
selections depend on a larger-smaller relation in the output voltage of the
converter 102 (commutation function). When an output of the chopper
104 is greater than an output voltage of the converter 102, a PWM (Pulse
Width Modulation) signal is transmitted to the switching device 204XL.
25 In a reverse case, the PWM signal is transmit ted to the switching device
204XH. When an electric power of the battery 106 is discharged, the
switching device 204XL is switched in accordance with the PWM signal.
When the switching device turns on, an energy is stored in the reactor 403.
On the other hand, the switching device turns off, due to the energy from
30 the voltage of the battery 106 and the reactor 403, a voltage higher than the
voltage of the battery 106 is charged in the capacitor 401 through the
- 11 -
refluxing diode 205XH connected to the switching device 204XH.
When the battery 106 is charged with an electric power, the
switching device 204XH is switched in accordance with the PWM signal, so
that an electric power in the capacitor 401 is charged in the battery 106
through the reactor 403 when the switching device 204XH is turned on5 .
When the switching device 204XH is turned off, the energy stored in the
reactor 403 is circulated through the diode 205XL connected to the
switching device 204XL. The electric power in the battery 106 is charged
and discharged by these operations.
10 In addition, there may be a case where the capacitor s may be
arranged integrally． However, in this embodiment, the capacitors 201,
301, 401 are divided from a point of view of standardizing the
configuration of the single converter unit 910 (see Fig. 9) described later.
More specifically, the capacitors 201, 301 are further divided for each of
15 the legs 203.
In the converter 102, AC to DC conversion is performed and in the
inverter 103, DC to AC conversion is performed by conducting and
blocking of current by the switching device 204 and a diode 205 in the leg
203 shown in Figs. 2 to 4. During conduction, a loss is generated by the
20 resistor in the switching device 204 and the diode device 205. Further,
when switching is made from the conduction state to the blocking state, a
loss is generated. Accordingly, heat generation is caused by the operation
of the power converter 100.
(Air-cooling type of double-sided-cooling power unit)
25 Next, a cooling structure in the air -cooling type of double-sided
(two confronting side surfaces) -cooling power unit 520 is described with
reference to Fig. 8.
Fig. 5 is a perspective view of the air -cooling type of double-sidedcooling
power module in which a plurality of the double-sided-cooling
30 power modules are disposed.
Fig. 6 is an exploded view showing arrangement of the double-
12 -
sided-cooling power modules in the air -cooling type of double-sidedcooling
power unit.
The air-cooling type of double-sided-cooling power unit 520 is
configured to basically include a cooling device 510 (a first cooling device
510A, a second cooling device 510B) and a plurality of the double -sided5 -
cooling power modules 500. The cooling device 510 includes a heat
receiving block 501, a heat pipe 502, and a heat radiating fin 503. The first
cooling device 510A includes a heat receiving block 501A, a heat pipe 502A,
and a heat radiation fin 503A. The second cooling device 510B includes a
10 heat receiving block 501B, a heat pipe 502B, and a heat radiation fin 503B.
The air-cooling type of double-sided-cooling power unit 520 has a slim and
simple structure with such expandability that a plurality of power modules
can be arranged in the actual structure of the double -sided-cooling power
module 500.
15 When the air-cooling type of double-sided-cooling power unit 520 is
assembled, more than one double-sided-cooling power modules 500
including semiconductor devices therein as a heat source, are sandwiched
between the heat receiving blocks 501. After sandwiching, the double -
sided-cooling power module 500 and the heat receiving block 501 are fixed
20 with bolts 504 and nuts 505 as a pressure-contacting means for providing
pressure-contact therebeween. Inside of the heat receiving block 501, one
end of more than one heat pipe 502 are connected. The other ends of the
heat pipe 502 extend upwardly and are connected to a plurality of the heat
radiating fins 503 at parts protruding from the heat receiving blocks 501.
25 Between the double-sided-cooling power module 500 and the heat
receiving blocks 501A, 510B, a soft thermally conductive grease 506
(thermal conductive agent) having a high thermal conductivity is coated to
reduce a poor heat contact caused by a roughness of respective surfaces
and tolerance.
30 Fig. 7A is a perspective view of the double-sided-cooling power
module, and Fig. 7B is a schematic circuit diagram. As shown in Fig. 7B,
- 13 -
the double-sided-cooling power module 500 includes a switching devices
204MH, 204ML, and diodes 205MH, 205ML. Respective semiconductors
are connected to each other to form the leg 203 (for example, see Fig. 2).
As shown in Fig. 7A, a P terminal 704P (DC positive terminal), an
N-terminal 704N (DC negative terminal), an AC terminal 704AC, and 5 a
gate terminal 701 are exposed at a top surface thereof to be connectable
with an External with electrical insulation. When the semiconductor
device described above is operating, electrical conduction to the external
via these electric terminals. On the other hand, heat simultaneously
10 generated is exhausted vie a cooling surface 702 being connected to an
insulator 703. More specifically, the gate terminal 701 is electrically
insulated from the cooling surface 702, and the heat transferring paths are
independent from the electric path.
The double-sided-cooling power module 500 according to the
15 embodiment includes: the cooling surfaces 702 on two confronting side
surfaces and the P terminal 704P, a N terminal 704N, the AC terminal
704AC, and the gate terminal 701, which are electric terminals on one of
the vertically extending side surfaces adjoining the cooling surface 702.
Fig. 8 is an illustration showing a heat transferring path of the air -
20 cooling type of double-sided-cooling power unit. Fig. 8 shows a cross
section of a part in Fig. 5. In a plurality of the double -sided-cooling
power modules 500 arranged in vertical direction, heat generated by
semiconductor devices 802 included therein transfers to the heat pipe 502
through the heat receiving block 501, which rapidly transfers a heat 801 in
25 the vertical direction. The heat 801 is transferred to the heat radiating
fins 503 and exhausted by a cooling wind 803 flowing between the heat
radiating fins 503.
(Single converter unit)
A single converter unit 910 in the power converter 100 according to
30 the embodiment of the present invention is described with reference to
Figs. 9 to 11. Fig. 9 is a perspective view of the single converter unit.
- 14 -
Fig. 10 is an exploded view showing an arrangement of the single
converter unit. Fig. 11 is a schematic circuit diagram of the single
converter unit.
In the single converter unit 910 shown in Fig. 9, the P terminal 704P,
the N terminal 704N, the AC terminal 704AC, which are electric terminal5 s
of the air-cooling type of double-sided-cooling power unit 520 (see Fig. 7),
are connected to a P layer, an N layer, and an AC layer of a P･N･AC
laminated bus bar 905, respectively. Further, the gate terminal 701, which
is an electric terminal, is connected to a gate driver circuit board 904.
10 Positive terminals 902P and negative terminals 902N of a plurality of a
capacitors 901 are connected to the P layer and the N layer of the P･N･AC
laminated bus bar 905, respectively. Further, a positive phase 903P and a
negative phase 903N are connected to the P layer and the N layer of the P･
N･AC laminated bus bar 905, respectively.
15 Fig. 10 is an exploded view of the single converter unit 910 Fig. 9.
The P･N･AC laminated bus bar 905 includes a P bus bar 905P, an N bus bar
905N, and an AC bus bar 905AC which are electrically insulated each other
with insulation layers (not shown). In the single converter unit 910, the P
terminal 704P, the N terminal 704N, and the AC terminal 704AC of the
20 double-sided-cooling power module are connected to the P bus bar 905P,
the N bus bar 905N, and the AC bus bar 905AC, respectively. The gate
terminal 701 of the double-sided-cooling power module 500 is connected to
the gate driver circuit board 904. Further, the P terminal and the N
terminal of the capacitor 901 are connected to the P bus bar 905P and the N
25 bus bar 905N, respectively. The structure described above is shown in an
electric circuit diagram as shown Fig. 11.
In the first embodiment, as shown in Fig. 9, the cooling wind 803 is
caused to flow to the heat radiating fin 503 from the side at which the
electric terminals are installed. This structure provides such an
30 advantageous effect that a cooling effect does not decrease among the
single converter units 910 though the single converter unit s 910 are
- 15 -
laterally arranged in the power converter 100 at a high density. In the
present embodiment, the cooling wind comes from the side at which the
terminals are installed. However, the present invention is not limited to
this. For example, the cooling wind may be caused to flow from a side
opposite to the electric terminals to the heat radiating fins 5035 .
(Power converter)
Fig. 12 is an illustration showing the power converter in which a
plurality of the single converter units are arranged. Fig. 13 is an
illustration for illustrating a method of cooling the single converter units
10 in the power converter.
The converter 102, the inverter 103, and the chopper 104 are
laterally arranged in the power converter 100. The converter 102 includes
the single converter units 910 corresponding to the three legs 203R, 203S,
203T shown in Fig. 2. The inverter 103 includes the single converter units
15 910 corresponding to three the legs 203U, 203V, 203V shown in Fig. 3.
Though the chopper 104 is shown in Fig. 4 with one of the legs 203X.
However, actually, the single converter unit 910 includes a circuit
corresponding to the two legs 203X shown in Fig. 4.
The converter 102 is configured by connecting the three single
20 converter units 910 by connecting a P･N interphase lamination bus bar
1003 to positive terminals 1001 and negative terminal 1002. The inverter
103 is configured similarly to the converter 102. The chopper 104 is
configured by connecting the two single converter units 910 in parallel.
In the converter 102, the inverter 103, and the chopper 104 having
25 the configurations described above, a plurality of single converter units
907 may be connected in parallel for one leg. This can increase a rated
output capacity of the power converter.
In the method of cooling the single converter units 910 in the power
converter shown in Fig. 13, similar to Fig. 9, the cooling wind 803 is caused
30 to flow from the side of the electric terminals to the heat radiating fin 503.
This provides such an advantageous effect that the cooling effect among
- 16 -
the single converter units 910 is not decreased through the single converter
units 910 are laterally arranged in the power converter 100 at a high
density. Further, in the case where calorific values of of the converter 102,
the inverter 103, and the chopper 104 are different from each other,
velocities of cooling winds 803A, 803B, and 803C may be changed5 .
(Structure of the heat radiation fin)
Next, a structure of the heat radiation fin is described with
reference to Figs. 14 to 16.
Fig. 14A and 14B are perspective views in which the heat radiation
10 fins of the first and second cooling devices are interlockingly arranged, in
which Fig. 14A shows the whole view and Fig. 14B is an enlarged view.
In the heat radiating fin 503 shown in Fig. 14, a heat radiating fin 1401A
and a heat radiating fin 1401B are different in height from the heat
receiving blocks 501A, 501B and arranged interlockingly in which one fin
15 of one of the first and second cooling device 510A and 510B is inserted into
a space between the adjoining radiation fins of another of the first and
second cooling device 510A and 510B. This is a difference of the heat
radiating fin 503 shown in Fig. 14 from the heat radiating fin 503 shown in
Fig. 5. This structure has an advantageous effect in that heat radiation
20 areas of the heat radiating fin 1401A and the heat radiating fin 1401B are
increased.
Fig. 15A is a perspective view of the radiation fins in the case where
the same radiation fins are installed at the heat pipes of the first and
second cooling devices in which Fig. 15A shows the whole view and Fig.
25 15B is an enlarged view. A radiation fin 1501 in Fig. 15 is different from
the heat radiating fin 503 shown in Fig. 5 in that the same heat radiation
fins are used for both of the first cooling device 510A and the second
cooling device 510B. Even in a case where calorific values are different
from each other between a side of the first and second cooling devices
30 510A, 510B. This provides an advantageous effect in that the calorific
values can be equalized with the same radiation fins.
- 17 -
Fig. 16A is a perspective view in a case where the radiation fins of
the first and second cooling devices are connected with a waved rigid
buffering part in which Fig. 16A shows the whole view and Fig. 16B is an
enlarged view. In heat radiating fins 1601 shown in Fig. 16 are conne cted
between the first cooling device 510A and the second cooling device 5105 B
with waved stiffness buffering parts 1602. This is a difference from the
heat radiating fin 503 shown in Fig. 5. This provides an advantageous
effect in that the air-cooling type of double-sided-cooling power unit 520
configured to include the first cooling device 510A and the second cooling
10 device 510B can increase a mechanical strength of the air-cooling type of
double-sided-cooling power unit 520.
A semiconductor unit for a power converter according to the
embodiment (for example, the air-cooling type of double-sided-cooling
power unit 520) includes:
15 a double-sided cooling semiconductor module (for example, the
double-sided-cooling power module 500) including a first cool ing surface
(for example, the cooling surface 702) electrically insulated from an electric
terminal and a second cooling surface (for example the cooling surface 702)
confronting the first cooling surface; a heat receiving block (for example,
20 the heat receiving block 501A) being in contact with the first cooling
surface of a plurality of the double-sided cooling semiconductor modules;
a first heat pipe (for example, the heat pipe 502A) of which one end is
thermally coupled to the first heat receiving block thereinside; more than
one heat radiation fins (for example, the heat radiation fin 503A) thermally
25 coupled to another end of the first heat pipe; a second heat receiving
block (for example, the heat receiving block 501B) being in contact with the
second cooling surface of a plurality of the double-sided cooling
semiconductor modules; a second heat pipe (for example, the heat pipe
502B) of which one end is thermally coupled to the second heat receiving
30 block thereinside; more than one heat radiation fins (for example, the heat
radiation fin 503B) thermally coupled to another end of the second heat
- 18 -
pipe; a fixing device configured to fix the first and second heat receiving
blocks (for example, the bolt 504 and the nut 505).
[0047]
This provides an advantageous effect in expandability of
arrangement of the double-sided-cooling power module 500 and down5 -
sizing the air-cooling type of double-sided-cooling power unit 520 using a
plurality of the air-cooling type of double-sided-cooling power unit 520.
The air-cooling type of double-sided-cooling power unit 520 shown in Fig 5
has been described about assembling the two double-sided-cooling power
10 modules 500. However, the present invention is not limited to this. For
example, in Fig. 5, the double-sided-cooling power modules 500 are
arranged in a vertical direction. However, more than two double -sidedcooling
power modules 500 may be arranged.
In summary, the semiconductor unit for the power converter
15 includes cooling surface confronting each other, more than one doublesided-
cooling semiconductor modules having electric terminal part
electrically insulated therein, and the cooling device 510 (heat radiator)
sandwiching the double-sided-cooling semiconductor modules from both
sides thereof. The cooling device 510 includes a member called the heat
20 receiving block 501 having flat surfaces, the heat pipe 502, and the heat
radiating fin 503.
Semiconductor unit for the power converter is characterized by
having expandability of arrangement of the double-sided-cooling power
module, and a slim and simple structure.
25 Contacting cooling surfaces of the double-sided-cooling power
module to the flat surfaces of the heat receiving block 501 enable to
transmit the heat generated by the semiconductor device 802 in the doublesided-
cooling power module to the heat receiving block 501. Inside the
heat receiving block 501, the heat pipe 502 straightly extends in a direction
30 in parallel to the flat surface of the heat receiving block 501. One end of
the heat pipe 502 is embedded in the heat receiving block 501 and the other
- 19 -
end extends outwardly from the heat receiving block 501. The heat pipe
502 extending from the heat receiving block 501 is connected to the heat
radiating fin 503. When the cooling wind 803 is brown between the heat
radiating fins 503, heat exchange between the heat radiating fin 503 and
the cooling wind 803 is provided. As the result, the semiconductor devic5 e
802 in the double-sided-cooling semiconductor module is cooled.
According to the cooling structure configured as described above,
the heat generated by the semiconductor device 802 can be rapidly
dispersed via the heat pipe 502 and transmitted to the heat radiating fin
10 503 , so that an efficiency of the heat radiation fin can be increased.
Further, connection between the cooling device 510 and the double -sidedcooling
semiconductor module is made through the heat receiving block
501. Accordingly, for example, this allows a defected double -sidedcooling
semiconductor module to be easily replaced.
15 [Second embodiment]

Next, a power converter 150 according to a second embodiment of
the present invention is explained.
Fig. 17 is a schematic circuit diagram of the power converter 150
20 according to the second embodiment. The power converter 150 is
different from the power converter 100 in the first embodiment (see Fig. 1)
in that a converter 152, an inverter 153, a chopper 154 are used in place of
the converter 102, the inverter 103, and the chopper 104. Other parts are
similarly configured.
25 In addition, a filter circuit may be disposed between the converter
152 and the transformer 105 or between the inverter 153 and the three -
phase AC load 108.
Fig. 18 is a schematic circuit diagram of the converter 152. Fig. 19
is a schematic circuit diagram of the inverter 153. Fig. 20 is a schematic
30 circuit diagram of the chopper 154. The converter 152, the inverter 153,
and the chopper 154 have the same circuit structure as the converter 102,
- 20 -
the inverter 103, and the chopper 104 (see Figs. 2 to 4), respectively except
that a leg 253 is used in place of the leg 203. The circuit structure of the
leg 253 is similar to the leg 203. However, an exterior appearance of the
leg 253 is different from that of the leg 203, and exterior appearances of the
converter 152, the inverter 153, and the chopper 154 are different fro5 m
those of the converter 102, the inverter 103, and the chopper 104 in the first
embodiment, respectively. These differences are described la ter.

Next, an air-cooling type of double-sided-cooling power unit 600
10 (heating body, a semiconductor unit for the power converter) used in the
second embodiment is described with reference to the perspective view in
Fig. 21A and a schematic circuit diagram in Fig. 21B. Each of the
semiconductor devices is connected to configure the leg 253 (for example,
see Fig. 18). Attached to an insulation body 753 are a P terminal 754P (DC
15 positive terminal), an N terminal 754N (DC negative terminal), an AC
terminal 754AC (AC terminal), and a gate terminal 751 for controlling
switching between tuning-on and turning off.
Next, in Fig. 21A, the air-cooling type of double-sided-cooling
power unit 600 includes a cooling body 710 having a substantially
20 rectangular parallelepiped, a flange 720, and on the flange 720, a terminal
part 730 having a plurality of terminals extending from a surface opposite
to the cooling body 710. The terminals in the terminal part 730 includes
the P terminal 754P, the N terminal 754N, the AC terminal 754AC, and the
gate terminal 751 which are shown in Fig. 21B.
25 Protruding from a one surface 760A of the cooling body 710 are a lot
of (a total is not smaller than 200) pin fins 762 each having a small column
shape. Further, formed on the other surface 760B opposite to the surface
760A are the same number of pin fins 762B (see Fig. 25). Hereinafter, the
pin fins 762A and the pin fins 762B may be integrally referred to simply as
30 "pin fin 762". The air-cooling type of double-sided-cooling power unit 600
is assumed to be cooled by a water cooling system. Accordingly, the
- 21 -
terminal part 730 is directed upwardly and the cooling body 710 is directed
downwardly, so that the cooling body 710 can be immersed into a cooling
vessel to allow a coolant to flow between the pin fins 762. Accordingly,
the surfaces 760A, 760B are called "cooling surface". It is assumed that a
thickness of the cooling body 710, i.e., a distance between the surface 7605 A
d the the other surface 760B, is "d1".
When the semiconductor devices operate, electric connection to the
external is provided via the terminal part 730. On the other hand, heat
exhausting is provided via the surface 760A, 760B. More specifically, the
10 terminal part 730 is formed on one of the side surface adjoi ning to the
surfaces 760A, 760B and is electrically insulated from the surfaces 760A,
760B. Accordingly, the heat transfer path is independent from the electric
paths.

15 Attached to the surfaces 760A, 760B of the air -cooling type of
double-sided-cooling power unit 600 are a pair of heat receiving spacers
630A, 630B shown in Fig. 22. The heat receiving spacer 630A includes a
heat receiving part 631A (heat receiving plate) and a pair of space abutting
parts 632A, having a substantially rectangular parallelepiped, protruding
20 from the both ends of the heat receiving part 631A toward a heat receiving
spacer 630B. Further, the heat receiving part 631A has a lot of loose
through holes 633A having a circular column shape. These loose through
holes 633A are formed at corresponding positions facing a cooling surface
pin fins 762A on the surface 760A and have a diameter which is slightly
25 greater than a diameter of the pin fins 762A. Essentially, it is ideal that
the loose through holes 633A fit into the pin fins 762A tightly without any
gap. However, there are slight errors caused during manufacturing
regarding a diameter and a position of the pin fin 762A. Accordingly, a
diameter of the through hole 633A is expanded to such an extent that the
30 manufacturing error can be absorbed.
In addition, the heat receiving spacer 630B includes the heat
- 22 -
receiving part 631B having a substantially rectangular parallelepiped
shape and a space reserving part 632B having a substantially rectangular
parallelepiped extends from both ends of a heat receiving part 631B having
a substantially rectangular parallelepiped. The heat receiving spacer 630B
has a symmetrical shape about the heat receiving spacer 630A. The hea5 t
receiving part 631B has loose through holes 633B at position corresponding
to the pin fins 762 protruding from the the other surface 760B of the aircooling
type of double-sided-cooling power unit 600, respectively.
When the heat receiving spacers 630A, 630B are attached to the air -
10 cooling type of double-sided-cooling power unit 600, the thermally
conductive grease is sufficiently coated on the surface 760A, 760B, and the
space reserving part 632A is abutted on the space reserving part 632B
while the positions of the loose through hole 633A, 633B are aligned with
the pin fins 762, respectively. Fig. 25 shows the state in which the heat
15 receiving spacer 630A, 630B are attached, as des cribed above, to the aircooling
type of double-sided-cooling power unit 600. As shown, an end
surface 710a thereof of the cooling body 710 is exposed. However, large
parts of the surfaces 760A, 760B are covered by the heat receiving spacers
630A, 630B.
20 An enlarged plan view of a part B in Fig. 23, which is enclosed with
a broken line is shown in Fig. 24.
As described above, a diameter of the loose through hole 633A is
slightly greater than that of the pin fin 762A, so that the pin fin 762A is
inserted into the gap 635 the pin fin 762A provide a gap 635 with the loose
25 through hole 633A During this, the thermally conductive grease coated
on the pin fin 762A is pushed into and penetrates into the gap 635, so that
the gap 635 is filled with the thermal ly conductive grease.
Fig. 25 shows an enlarged view of a main part (end part) taken
along line A -A' in Fig. 23. When the space reserving part 632A is abutted
30 on the space reserving part 632B, the heat receiving part 631A faces the
heat receiving part 631B through a predetermined distance. This distance
- 23 -
is d2 (see Fig. 25). The heat receiving spacer 630A, 630B are formed so
that a distance d2 is greater than a thickness d1 of the cooling body 710 of
the air-cooling type of double-sided-cooling power unit 600. As the result,
gaps 637A, 637B are formed between the heat receiving part 631A and the
cooling body 710 and between the heat receiving part 631B and the coolin5 g
body 710. Because the air-cooling type of double-sided-cooling power
unit 600 has play with the heat receiving spacer 630A, 630B, widths of the
gap 637A 637B are not the same.
When the space reserving part 632A is abutted on the space
10 reserving part 632B, the thermally conductive grease coated on the pin fin
762 is pushed and penetrates into the gap 637A, 837B, so that the gap 637A,
637B are also filled with the thermally conductive grease without
generation of gaps.
If it is assumed that a thickness of the cooling body 710 including a
15 tip of the pin fin 762A to the tip of the pin f in 762B is d4, and a width of
the whole body when the heat receiving spacer 630A is abutted on the heat
receiving spacer 630B is d5, the heat receiving spacers 630A, 630B are
formed such that the width d5 is slightly greater than a thickness d4.
Accordingly, gaps 639A, 639B are formed between the an upper surface of
20 the heat receiving spacer 630A and the tip of the pin fin 762A, and between
a lower surface of the heat receiving spacer 630B and the tip of the pin fin
762B. As described above, the air -cooling type of double-sided-cooling
power unit 600 has play on the heat receiving spacers 630A, 630B, so that
widths of the gap 637A, 637B are not the same.
25 When the heat receiving spacer 630A, 630B are attached to a cooling
device 610 (details are described later), a pressure force as shown by an
arrow with hatching is applied. The pressure force is applied to the
abutting part between the space reserving part 632A, 632B. In this
embodiment, the gaps 637A, 637B are formed between the cooling body 710
30 and the heat receiving spacers 630A, 630B and the gaps 639A, 639B are
formed at tips of the pin fins 762A, 762B. This prevents that the pressure
- 24 -
force is applied to the cooling body 710. This can previously prevents the
air-cooling type of double-sided-cooling power unit 600 from being
defected.
Next, Fig. 26 shows a perspective view in which the the air -cooling
type of double-sided-cooling power unit 600 is attached to the coolin5 g
device 610. The cooling device 610 includes a pair of cooling devices
610A, 610B. The cooling device 610A, 610B includes heat receiving blocks
601A, 601B, each being formed in a block in a substantially rectangular
parallelepiped. The air-cooling type of double-sided-cooling power unit
10 600 is sandwiched.
The heat receiving blocks 601A, 601B are fastened by a plurality of
fixing members 604 each other. The pressure forces indicated with
hatched arrows are applied to the heat receiving blocks 601A, 601B.
However, as described with reference to Fig. 25, the pressure force is
15 applied to the heat receiving spacers 630A, 630B, but not applied to the air -
cooling type of double-sided-cooling power unit 600. Further, as the
fixing member 604, well-known bolts and nuts are usable.
In Fig. 26, four heat pipes 602 protrude in a y-axis direction from
the heat receiving block 601A with inclination of about 10 degrees from the
20 xy plane (horizontal plane) defined by the X, y axes. Further, a plurality
of a heat radiation fins 603 having plate shapes are welded thereon in a
radial direction of the heat pipe 602. Accordingly, the heat radiation fins
603 are inclined from the xz plane (vertical plane) defined by the x axis and
the z axis. A cooling device 610B is also configured similarly to the
25 cooling device 610A. As described above, the two air-cooling type of
double-sided-cooling power units 600 are attached to the cooling device
610, so that the air-cooling type of double-sided-cooling power unit 620 is
configured.
When the air-cooling type of double-sided-cooling power unit 600
30 generates heat, the heat is transferred to the heat receiving blocks 601A,
601B and further transferred to a rear part (in a direction of y-axis) by the
- 25 -
heat pipe 602. When a cooling wind 853 is applied to the air -cooling type
of double-sided-cooling power unit 620 so as to flow upwardly (in the zaxis
direction) from a lower part of the air -cooling type of double-sidedcooling
power unit 620, the cooling wind 853 cools the heat radiation fins
603 and passes there upwardly, so that the heat is rapidly exhausted. Th5 e
heat transferring path is shown with arrows 851 in Fig. 26. Further, heat
transferring in a direction orthogonal with the cooling wind 853 is mainly
generated by the heat pipe 602.
In Fig. 26, an exploded view of the region C encircled with a broken
10 line is shown in Fig. 27.
In Fig. 27, the a conductive grease 606 is coated between the heat
receiving spacer 630A and the heat receiving block 601A and between the
heat receiving spacer 630B and the heat receiving spacer 630B, respectively.
When the heat receiving block 601A, 601B are fastened with the fixing
15 members 604, the thermally conductive grease 606 spreads along
confronting surfaces between the heat receiving spacer 630A and the heat
receiving block 601A and surfaces between the heat receiving spacer 630B
and a heat receiving block 601B so as to be in a thin film state. During
this, the thermally conductive grease 606 also penetrates into the gaps
20 639A, 639B (see Fig. 25) and penetrates on outer surface of the pin fins
762A, 762B without any gap.

Next the single converter unit 960 in the first embodiment is
described with reference to Figs. 28 to 31. Fig. 28 is a perspective view of
25 the single converter unit 960. Fig. 29 is an exploded view of the single
converter unit 960. Fig. 30 is an exploded view of a P･N･AC laminated
bus bar 955. Fig. 31 is a schematic circuit diagram of the single converter
unit 960.
In the single converter unit 960 shown in Fig. 28, the P terminal
30 754P (see Fig. 21), the N terminal 754N, and the AC terminal 754AC, being
electric terminals of the air-cooling type of double-sided-cooling power
- 26 -
unit 620 described above, are connected to the P layer, the N layer, and the
AC layer of the P･N･AC laminated bus bar 955, respectively. Further, the
gate terminal 751 of an electric terminal is connected to a gate driver
circuit board 954. Further, positive terminals 952P and negative terminals
952 of a plurality of capacitors 951 are connected to the P layer and the 5 N
layer of the P･N･AC laminated bus bar 955, respectively. In addition,
positive fuses 953P and negative fuses 953N are connected to the P layer
and the N layer of the P･N･AC laminated bus bar 955, respectively. The
positive fuse 953P and the negative fuse 953N have functions for cutting
10 off the circuits to protect devices which an over current flows therethrough.
If such a protection function is unnecessary, it is possible to omit the fuses.
Fig. 29 is an exploded view of Fig. 28. Fig. 30 is an exploded view
of the P･N･AC laminated bus bar 955. As shown in Fig. 30, the P･N･AC
laminated bus bar 955 includes a P layer bus bar 955P, the P layer bus bar
15 955P, an N layer bus bar 955N, an N･AC layer bus bar 955C. In the single
converter unit 960, the P terminal 754P, the N terminal 754N, the AC
terminal 754AC are connected to the P layer bus bar 955P, the N layer bus
bar 955N, and an AC bus bar 955AC, and the AC bus bar 955AC,
respectively. Further, the P terminal and the N terminal of the capacitor
20 951 are connected to the P layer bus bar 955P and the N layer bus bar 955N,
respectively. The configuration in a circuit diagram described above is as
shown in Fig. 31.

Fig. 32 is a perspective view of the power converter 150 in which a
25 plurality of the single converter units 960 are arranged.
Inside the power converter 150, the converter 152, the inverter 153,
and the chopper 154 are arranged laterally. The converter 152 includes
the single converter units 960 corresponding to the three legs 253R, 253S,
and 253T shown in Fig. 18. The inverter 153 includes the single converter
30 units 960 corresponding to the three legs 253U, 253V, and 253W, as shown
in Fig. 19. The chopper 154 includes the one single converter unit 960.
- 27 -
However, the converter 152, the inverter 153, the chopper 154 can be
arranged in an order which is different from the embodiment of the
present invention, and the converters 152, the inverters 153, and the
choppers 154 may be arranged thereamong in a different phase order.
As described in Fig. 26, in the air -cooling type of double-sided5 -
cooling power unit 620 in the second embodiment, the heat generated by
the air-cooling type of double-sided-cooling power unit 600 is transferred
to a rear side (in the y direction) with the heat pipe 602 and exhausted
through the heat radiation fins 603 provided at a rear part. In the
10 structure shown in Fig. 32, a plurality of the single converter units 960 in
which the air-cooling type of double-sided-cooling power units 620 are
installed are arranged in a lateral direction, so that maintainability can be
increased. When any one of the single converter units 960 is troubled,
generally, the unit in traveling is drawn out from the power converter 150
15 and a spare unit is inserted. During this, drawing out the traveled unit
and inserting a spare unit can be provided by moving these units simply in
the y direction, so that a rapid maintain ace operation can be provided.
The converter 152 is configured by connecting the three single
converter units 960 by connecting the P･N interphase lamination bus bar
20 1053 to corresponding positive terminals 1051 and negative terminals 1052.
The inverter 153 and the converter 152 are similarly configured. Because
the chopper 154 includes the one single converter unit 960, it is not always
necessary that the chopper 154 is connected to the P･N interphase
lamination bus bar 1053. However, if a capacity of the chopper 154 is
25 increased or in a case where the converter 152 and the inverter 153 are
configured as an integrated system as describe in the second embodiment,
it is desirable to connect the converter 152 and the inverter 153 at the same
time. The P･N interphase lamination bus bar 1053 includes, as shown in
Fig. 33, an interphase P bus bar 1053P and an interphase N bus bar 1053N,
30 in which a insulating layer 105S provides insulation between respective
bus bars.
- 28 -
In the converter 152, the inverter 153, and the chopper 154, it is also
possible to connect a plurality of the single converter units 960 in parallel
for each leg. Accordingly, the rated output capacity of the power
converter can be increased.
In the cooling method of the single converter unit 960 in the powe5 r
converter shown in Fig. 32, the cooling wind 853 i s applied to the heat
radiation fins 603 from a lower side to upper side. Accordingly, through
the single converter unit 960s are arranged in the power converter 150 in
lateral direction at a high density, the cooling efficiency between
10 respective the single converter unit 960 cannot be decreased as an
advantageous effect. In a case where temperatures of semiconductor
devices in the converter 152, the inverter 153, and the chopper 154 are
different, velocity of cooling winds 853A, 853B, 853C may be changed.

15 As described above, according to the embodiments of the present
invention provides a cooling structure including:
a heating element 600 having at least a cooling surface 760A, 760B
including a plurality of protruded pin fins 762;
a heat receiving plate 631A, 631B having loose holes 633A, 633B into
20 which the pin fins 762 are inserted at positions corresponding to the pin
fins 762;
a cooling device 610 including pair of pinching members 601A, 601B
configured to pinch the heating element 600 and the heat receiving plate
631A, 631B with a pressure force and cool the heat receiving plate 631A,
25 631B; and
a space reserving part 632A, 632B, disposed on the heat receiving
plate 631A, 631B, configured to control a gap (interval) in a pa ir of the
pinching members 601A, 601B so as not to apply a pressure force by the
pinching members 601A, 601B to the heating element 600.
30 Accordingly, the heat in the air -cooling type of double-sidedcooling
power unit 600 can be transferred and cooled through the heat
- 29 -
receiving parts 631A, 631B and the heat receiving blocks 601A, 601B.
In the second embodiment, the air -cooling type of double-sidedcooling
power unit 600 as the heating element includes cooling surfaces
760A, 760B on two confronting surfaces. The heat receiving plates 631A,
631B have a shape corresponding to the cooling surfaces 760A, 760B an5 d
loose holes at positions corresponding to the pin fins 762. This provides
transferring the heat from the double-sided cooling surfaces, so that the
heat transferring effect can be further increased.
Further, in this embodiment thermally conductive grease 606 is
10 coated between the pin fins 762 and a heat receiving plates 631A, 631B.
Accordingly, a thermal resistance between the heating element and the
heat receiving parts 631A, 631B can be reduced, so that the cooling device
610 can be down-sized.
In the second embodiment, the space reserving part 632A, 632B
15 control the interval (d5 + width of the thermally conductive grease 606)
between a pair of pinching members (the heat receiving blocks 601A, 601B)
is larger than a thickness d4 of the heating element including the pin fins
762. Accordingly, when the pinching members pinch the heating element,
application of the pressure force to the pin fins 762 and defection of the
20 heating elements is prevented.
Further, in the power converter 150, side surfaces of a plurality of
semiconductor units for the power converter are arranged on the same
plane, and a cooling wind is supplied by the cooling fan 101 to a plurality
of heat radiation fins 603 from a rear side of the same plane. Accordingly,
25 wiring between the air-cooling type of double-sided-cooling power unit
600 can be provided by the P･N interphase lamination bus bar 1053.

The present invention is not limited to the above-described
embodiments. For example, there are various modifications as follows.
30 (1) The loose through holes formed in the heat receiving spacer
630A, 630B are not limited to those described in the second embodiment.
- 30 -
As long as the loose through hole can be inserted into the pin fin 762 with
a gap therebetween, a pin fin loose through hole can be modified in
various shapes and sizes. For example, as shown in Fig 34, a loose
through hole 640A having an opening of a rectangular shape may be
formed at a position corresponding to the pin fin 762A. In this case5 ,
though a length of a side of the loose through hole 640A in the rectangular
shape is equivalent to a diameter of the loose through hole 633A having a
circle shape in the second embodiment as described above, an area of the
loose through hole can be increased, so that there is an advantageous effect
10 in that an operation for attaching the heat receiving spacer 630A to the air -
cooling type of double-sided-cooling power unit 600 can be facilitated.
(2) One loose through hole formed in the heat receiving spacer 630A,
630B is not limited to the loose through hole inserted into one pin fin 762.
For example, as shown in Fig. 35, it is also possible to form a loose through
15 hole 642A into which the four pin fins 762A can be loosely inserted. As
described above, when the loose through hole 642A is formed so that a
plurality of the pin fin 762 is inserted, the number of the loose through
holes to be formed can be decreased. This looses an accuracy in size and
decreases the manufacturing process. In the example in Fig. 35, the four
20 pin fins 762A are inserted into the loose through holes 642A having a
substantially parallelogram shape with a gap. However, the number of
the pin fins 762 inserted into the two, three, or more than four loose
through holes may be applicable. Accordingly, the shape of the loose
through hole may be changed to a shape other than the substantially
25 parallelogram.
(3) Shapes of the loose through holes formed in the heat receiving
spacer 630A, 630B and the number of the pin fin 762 inserted into the loose
through holes with gap may be changed in each region in the heat
receiving spacer 630A, 630B. For example, as shown in Fig. 36, the four
30 pin fins 762A inserted into loose through holes 642 and the loose through
hole 633A into which the one pin fin 762A is inserted with a gap may be
- 31 -
formed in the heat receiving spacer 630A. The former, i.e., loose through
hole 642A, is more advantageous than the loose through hole 633A because
the manufacturing process can be decreased. The latter, i.e., the loose
through hole 633A is more advantageous than the loose through hole 642A
in capability of decreasing the thermal resistance. Accordingly, in th5 e
region of which a heat radiation quantity is little in the air-cooling type of
double-sided-cooling power unit 600, the loose through hole 642A allowing
a plurality of the pin fins 762A to insert therethrough together is adopted.
On the other hand, at a location having a larger quantity of heat radiation,
10 the loose through hole 633A into which each of the pin fins 762 is inserted
is adopted. This provides both a manufacturing easiness and a high heat
performance.
(4) In the second embodiment described above, the heat receiving
spacers 630A 630B are separated from the cooling devices 610A, 610B.
15 However the heat receiving spacer can be formed integrally with the
cooling device. For example, a heat receiving blocks 650A, 650B shown in
Fig. 37 are applicable in place of the the heat receiving block 601A, 601B
and the heat receiving spacers 630A, 630B. In the heat receiving blocks
650B, a plurality of hollow parts 654B having a column shape are formed at
20 locations corresponding to the pin fins 762 of the air-cooling type of
double-sided-cooling power unit 600. Similarly, in the heat receiving
block 650A, a plurality of hollow parts in a column shape are formed at
locations corresponding to the pin fins 762.
Further, in the heat receiving block 650B, a pair of a space reserving
25 part 652 having a rectangular parallelepiped are formed so as pinch the
region where the hollow part 654B is formed. In the modification, at
corresponding locations of the heat receiving block 650A, parts
corresponding to the space reserving part 652 are not formed. The space
reserving part 652 are formed to be lower than the thickness d4 (see Fig.
30 25) of the cooling body 710 including the pin fin 762 and slightly higher
than the thickness d1 of the cooling body 710 except the pin fin 762 (see Fig.
- 32 -
25). Further, a depth of the hollow part 654B formed in the heat receiving
block 650B and a depth of the hollow part (not shown) formed in the heat
receiving block 650A are slightly deeper than a height of the pin fin 762.
Accordingly, in Fig. 37, though the air -cooling type of double-sidedcooling
power unit 600 is pinched between the heat receiving blocks 6505 A
650B and the heat receiving blocks 650A, 650B are fasten with the fixing
members 604, a pressure force is not applied to the air-cooling type of
double-sided-cooling power units 600.
In the modification of the present invention, it is possible to further
10 suppress the heat resistance of the hole of the device because the the heat
receiving blocks 650A, 650B have the functions of the heat receiving
spacers 630A, 630B and the heat receiving blocks 601A, 601B together.
Further, the number of the components can be reduced, so that there are
advantageous effects in that the manufacturing control can be easily
15 provided. In addition, there is not always to form the the space reserving
part 652 in the modification together with the heat receiving block 650B
but may be formed separately.
(5) In the second embodiment, the loose through holes 633A, 633B
are formed in the heat receiving spacers 630A, 630B. However, in place of
20 the loose through hole, it is also possible to form the hollow part similar to
the hollow part 654B shown in Fig. 37. During the formation, the abovedescribed
configuration is allowed as long as the depth of the hollow part
is deeper than the height of the pin fin 762.
(6) It is desirable that the heat receiving spacers 630A, 630B are
25 formed with high heat transferring metal such as aluminum or copper in
view of heat radiation. However, it is also possible to use a resin or
ceramic as the heat receiving spacers 630A, 630B when it is necessary to
insulate the air-cooling type of double-sided-cooling power unit 600 from
the cooling device 610.
30 (7) In the second embodiment, an elastic member such as a rubber
plate may be inserted into the abutting surfaces of the space abutting parts
- 33 -
632A, 632B. This enables a slight height adjustment and relaxation of the
pressure force.
(8) In the second embodiment, the heat pipe 602 and the heat
radiation fin 603 are used for the cooling devices 610A, 610B. However, it
is also possible to use a cooling device in which a heat radiation fins ar5 e
directly joined with the heat receiving blocks 601A, 601B. Further, a
cooling device of a liquid cooling type in which a coolant is flow
thereinside can be used.
Fig. 38 shows an example of this structure as a modification. Flow
10 channels 1601 are formed in the heat receiving block 601B. One end of a
forward pipe 1602A is connected to one end of each of the flow channels
1601. On a side of the cooling device 610A opposite to the heat receiving
block 601B the forward pipe 1602A is connected to one end of a return pipe
1603. The other end of the return pipe 1603 is connected to one end of the
15 backward pipe 1602B. The other end of the backward pipe 1602B is
connected to the other end of the flow channels 1601 to form a flow path
1604. The heat of the heating element is transferred to a liquid coolant
(not shown) in the flow channel 1601 in the heat receiving block 60 1B.
The liquid coolant flows and circulates through the flow path 1604, so that
20 the heat in the liquid coolant is radiated by the heat radiation fins 603.
The heat receiving block 601B has a pair of this structure. The heat
receiving block 601A also has a pair of this structure. The air-cooling
type of double-sided-cooling power unit 520 in the first embodiment also
can have this structure.
25 (9) In the second embodiment, as the fixing member 604, the bolts
and nuts are used. However, a spring may be used.
(10) In the second embodiment, a heat conductive sheet may be used
in place of the thermally conductive grease 606.
(11) In the second embodiment, the surfaces 760A, 760B of the air -
30 cooling type of double-sided-cooling power unit 600 are flat, and the heat
receiving parts 631A, 631B are planer shapes. However, the surfaces 760A,
- 34 -
760B are not always flat. More specifically, the same advantageous effect
similar to the above-described embodiment can be provided by equalizing
the the shapes of the heat receiving parts 631A, 631B to shapes extending
along the surfaces 760A, 760B.
(12) In Fig. 26 of the second embodiment, the heat pipe 602 i5 s
inclined by about 10 degrees to the xy plane (horizontal plane), the heat
pipe 602 may arranged horizontal without the inclination.

WE CLAIM:-
1. A cooling structure comprising;
a plurality of heating elements arranged in a vertical direction, each
including cooling surfaces respectively disposed on two confronting side
surfaces extending in the vertical direction, and an electric terminal on 5 a
side surface extending in the vertical direction and adjoining the two
confronting side surfaces;
a plurality of heat receiving blocks pinching the heating elements
arranged in the vertical direction on the two confronting side surfaces;
10 first and second cooling devices, each including a heat pipe
including a plurality of heat radiation fins; and
a pressure contacting part configured to contact the heating
elements and the receiving blocks with a pressure force, wherein
a wind is applied to the heat radiation fins.
15
2. The cooling structure as claimed in claim 1, wherein
the heat radiation fins are disposed above the heating elements and
extend in a horizontal direction; and
wherein the wind is applied to the heat radiation fins from a side of
20 the electric terminal.
3. The cooling structure as claimed in claim 2, wherein
the cooling surfaces are electrically insulated from the electric
terminal of the heating element.
25
4. The cooling structure as claimed in claim 2, wherein
the first and second cooling devices extend in the vertical direction,
the cooling structure further comprising a gap between a pair of adjoining
heat radiation fins of the first and second cooling devices at the same
30 height in the vertical direction.
- 36 -
5. The cooling structure as claimed in claim 2, wherein
the heat radiation fines of the first and second cooling devices
extends in a horizontal direction, wherein
heat radiation fins of the first and second cooling devices are
disposed at the different heights in the vertical direction an5 d
interlockingly arranged.
6. The cooling structure as claimed in claim 2, wherein the first and the
second cooling devices comprises the heat radiation fins which are shared
10 by heat pipes of the first and second cooling devices.
7. The cooling structure as claimed in claim 2, further comprising a
waved stiffness buffering part, wherein a pair of adjoining heat radiation
fins of the first and second cooling devices are connect ed with the waved
15 stiffness buffering part.
8. A power converter comprising a plurality of the cooling structures
which are arranged, each of the cooling structures being defined by any
one of claims 1 to 7, wherein the heating element comprises a
20 semiconductor module for a power converter .
9. The power converter as claimed in claim 8, further comprising a
blower blows the heat radiation fins from a side of the electric terminal in
a housing.
25
10. A power converter comprising
a plurality of semiconductor modules, each comprising:
cooling surfaces on two confronting side surfaces extending
in the vertical direction; and
30 an electric terminal disposed on a side surface extending the
vertical direction and adjoining the two confronting side surfaces;
- 37 -
heat receiving blocks pinching the semiconductor modules arranged
in the vertical direction on the two confronting side surfaces;
first and second cooling devices, each including a heat pipe
mounted on the heat receiving block and a plurality of heat radiation fins,
mounted on the heat pipe, disposed above the semiconductor modules an5 d
horizontally extending; and
a pressure contacting part configured to contact the heating
elements and the receiving block with a pressure force, wherein
side faces, on which the electric terminals are disposed, of the respective
10 semiconductor modules for the power converter are arranged on the same
plane, and a blower blows the heat radiation fines from a side of the same
plane.
11. The cooling structure as claimed in claim 1, wherein a plurality of the
15 heat radiation fins are arranged behind the heating element.
12. The cooling structure as claimed in claim 11, wherein
each of the cooling surfaces comprises a plurality of protruded pin
fins, wherein each of the heat receiving blocks includes:
20 a heat receiving plate having a shape corresponding to a shape of
the cooling surface and holes into which the pin fins are loosely inserted,
the cooling structure further comprising:
a pair of pinching members configured to pinch the heating
element and the heat receiving planes with a pressure force ;
25 a cooling device configured to cool the heat receiving plates, and
a space reserving part configured to control a gap in a pair of the
pinching members so as not to apply a pressure force by the pinching
members to the heating element.
30 13. A cooling structure comprising:
a heating element having at least a cooling surface including a
- 38 -
plurality of protruded pin fins;
a heat receiving plate having a shape corresponding to a shape of
the cooling surface and loose holes into which the pin fins are inserted at
positions corresponding to the pin fins;
a cooling device including a pair of pinching members configured t5 o
pinch the heating element and the heat receiving plat e with a pressure
force and cool the heat receiving plate; and
a space reserving part, disposed on the heat receiving plate,
configured to control an interval in a pair of the pinching members so as
10 not to apply a pressure force by the pinching members to the heating
element.
14. The cooling structure as claimed in claim 13, wherein
the heating element comprising cooling surfaces on two-confronting
15 side surfaces thereof, and wherein
the heat receiving plate includes a shape corresponding to the two -
confronting cooling surfaces and the holes formed at locations
corresponding to the pin fins protruding from the two surfaces.
20 15. The cooling structure as claimed in claim 13, further comprising
thermally conductive grease coated between the pin fins and the heat
receiving plate.
16. The cooling structure as claimed in claim 13, wherein the interval of
25 the pinching member controlled by the space reserving part is larger than a
thickness of the heating element including the pin fins.
17. The cooling structure as claimed in claim 13, wherein
the hole has a circular column shape.
30
18. The cooling structure as claimed in claim 13, wherein a plurality of
- 39 -
the pin fins are inserted into the holes.
19. The cooling structure as claimed in claim 13, wherein
the heat receiving plate includes both a loose hole into which a
plurality of the pin fins are inserted and a loose hole into which one of th5 e
pin fin is inserted.
20. The cooling structure as claimed in claim 13, further compri sing:
heat radiation fins; and
10 a heat pipe connected to the pinching member and the heat
radiation fins.
21. The cooling structure as claimed in claim 13, wherein
the cooling device includes heat radiation fins connected to the
15 pinching members.
22. The cooling structure as claimed in claim 13, further composing a
flow path and a heat radiation fin connected the flow path.
20 23. A cooling structure comprising:
a heating element including at least a cooling surface including a
plurality of pin fins;
a space reserving part formed to have a thickness smaller than a
thickness of the heating element including the pin fins and larger than a
25 thickness of the heating element without the pin fins;
a pair of pinching members, having a shape corresponding to a
shape of the cooling surface, pinching the heating element sandwiched
between the space reserving parts and holding the heating elements while
a pressure force is applied to heating element.
30
24. A power converter comprising:
- 40 -
a plurality of the cooling structures, as claimed in any one of claims
13 to 23, arranged so as to adjoin each other, wherein the heating element
comprising semiconductor unit for the power converter.
25. A power converter, comprising5 :
a plurality of semiconductor units for a power converter,
each of the semiconductor units including cooling surfaces
including a plurality of pin fines protruding from the cooling surfaces on
confronting two-side surfaces thereof; and
10 an electric terminal on one of side surfaces adjoining the
confronting two-side surfaces;
heat receiving plates, each including a shape corresponding to a
shape of the cooling surface and lose holes into which the pin fins are
inserted at locations corresponding to the pin fins, wherein the heat
15 receiving plates are attached to the cooling surfaces, respectively;
a plurality of cooling devices, each including:
a plurality of pinching members configured to pinch the
semiconductor units for the power converter and a plurality of heat
receiving plates to hold the semiconductor units and the heat receiving
20 plates with a pressure force;
a plurality of heat radiation fins, each extending in a
horizontal direction relative to each of the semiconductor units; and
heat pipes connecting the pinching members to a plurality of
heat radiation fines corresponding to the pinching members, respectively;
25 space reserving parts, disposed at the heat receiving plates,
controlling an interval between the pinching members so as not to apply
the pressure force by the pinching member to the semiconductor units,
wherein
the side surfaces each having the electric terminal for the
30 semiconductor unit for the power converter are arranged on the same
plane; and wherein
- 41 -
a blower supplies a cooling wind to a plurality of the heat radiation
fins on a rear side of the same plane.