1. A cooling structure of a heating element, comprising: the heating element having at least one cooling surface from 5 which a plurality of pin fins project; a heat receiving plate which has a shape complying with the cooling surface and in which holes are formed at positions facing each of the pin fins, each of the pin fins being movably inserted into the holes; 10 a cooler which has a pair of clamping members that sandwich therebetween the heating element and the heat receiving plate while pressing the heating element and the heat receiving plate, and which cools the heat receiving plate; and a space securing part which is provided on the heat receiving 15 plate and suppresses a distance between the pair of clamping members so as not to apply a pressing force by the clamping members to the heating element.

2. The cooling structure of the heating element, according to claim 1, wherein 20 the- heating element has the cooling surface on two opposite surfaces thereof, and the heat receiving plate has a shape complying with the cooling surface on the two surfaces, the holes being formed at the positions facing each of the pin fins which project from the cooling surface 25 on the two surfaces.

3. The cooling structure of the heating element, according to claim 1, further comprising a heat conducting agent provided between the pin fins and the heat receiving plate.

4. The cooling structure of the heating element, according to 30 claim 1, wherein the distance between the pair of clamping members suppressed by the space securing part is greater than a thickness of the heating element inclusive of the pin fins. 26

5. The cooling structure of the heating element, according to claim 1, wherein each of the holes has a columnar shape.

6. The cooling structure of the heating element, according to claim 1, wherein some of the plurality of pin fins are movably 5 inserted into one of the holes.

7. The cooling structure of the heating element, according to claim 1, wherein in the heat receiving plate, both of a hole into which some of the plurality of pin fins are movably inserted, and a hole into which one pin fin is movably inserted, are formed. 10 8. The cooling structure of the heating element, according to claim 1, wherein the cooler includes heat dissipating fins and heat pipes connected to the clamping members and the heat dissipating fins .

9. The cooling structure of the heating element, according to 15 claim 1, wherein the cooler includes heat dissipating fins joined to the clamping members.

10. The cooling structure of the heating element, according to claim 1, wherein the cooler includes distribution channels for refrigerant joined to the clamping members, and heat dissipating 20 fins joined to the distribution channels.

11. A cooling structure of a heating element, comprising: the heating element having at least one cooling surface from which a plurality of pin fins project; space securing parts each of which is formed to be smaller 25 than a thickness of the heating element inclusive of the pin fins and to be greater than a thickness of the heating element except for the pin fins; and a pair of clamping members each of which has a shape complying with the cooling surface and in each of which holes are formed at 30 positions facing each of the pin fins, each of the pin fins being movably inserted into the holes, the clamping members sandwiching therebetween the heating element sandwiched by the space securing 27 parts while applying a pressing force to the heating element.

12. A power conversion device comprising a plurality of cooling structures, each being the cooling structure of the heating element, according to claim 1, wherein 5 the plurality of cooling structures are arranged side by side to allow respective coolers to lie next to each other, and the heating element is a semiconductor device for the power conversion device.

13. A power conversion device comprising: 10 a plurality of semiconductor devices for the power conversion device, each semiconductor device having cooling surfaces from which a plurality of pin fins project, on both opposite surfaces thereof, and having electric terminals on one side surface which abuts on the cooling surfaces; 15 a plurality of heat receiving plates each of which has a shape complying with a corresponding one of the cooling surfaces, in each of which holes are formed at positions facing each pin fin, each pin fin being movably inserted into the holes, and each of which is attached to the corresponding cooling surface; 20 a plurality of coolers including a plurality of clamping members that sandwich therebetween the plurality of semiconductor devices for the power conversion device and the plurality of heat receiving plates while pressing the semiconductor devices and the heat receiving plates, a plurality of heat dissipating fins that 25 lie next to each other in a horizontal direction relative to each of the semiconductor devices for the power conversion device, and at least one heat pipe that connects each of the clamping members with a corresponding plurality of heat dissipating fins, the plurality of coolers cooling the plurality of heat receiving plates, 30 respectively; and a plurality of space securing parts which are provided for each of the plurality of heat receiving plates and suppress distances 28 between the clamping members so as not to apply a pressing force by the clamping members to the semiconductor devices for the power conversion device, wherein the side surfaces on which the plurality of semiconductor 5 devices for the power conversion device have the electric terminals are arranged on the same plane, and cooling wind is fed by a blower to the plurality of heat dissipating fins from a reverse side of the same plane.

This application is based upon and claims the benefit of
priority to the Japanese Patent Application No.2014-198049, filed
on September 29, 2014, the entire contents of which are incorporated
herein by reference.
BACKGROUND OF THE INVENTION
10 1. Field of the Invention
The present invention relates to a cooling structure of a
heating element and a power conversion device.
2. Description of the Related Art
Patent Document 1 (Japanese Patent Application Publication
15 No.2013-073964) discloses in paragraph [0001] "The invention
relates to a power module that has good heat dissipation and
reliability", and in paragraph [0011] "A heat dissipating portion
307A is provided on one of two surfaces of the flat case that have
wide areas and face each other, and a heat dissipating portion 307B
20 is provided on the other surface. The heat dissipating portion 307A
and the heat dissipating portion 307B function as heat dissipating
walls of the module case 304, and two or more fins 305 are uniformly
formed on the outer circumferential surfaces".
Meanwhile, there is a desire to use a heating element such
25 as a semiconductor module that has been originally designed as a
water-cooled one, as an air-cooled one. This is for reasons that
adoption of an air-cooled one makes piping for refrigerant and the
like unnecessary, thereby having an advantage in maintenance. On
the other hand, adoption of the air-cooled one requires attachment
30 of an external cooling fin having a certain degree of size and the
like to the heating element. However, a heating element that has
been originally designed as a water-cooled one does not assume
1
application of a strong pressing force thereto because the heating
element does not assume attachment of an external cooling fin thereto
while having small pin fins (fins each projecting in the form of
a pin) or the like. Accordingly, when attempting to simply attach
5 an external cooling fin to the heating element by bolting or the
like, there is a possibility that the heating element is broken.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above
circumstances, and an object of the invention is to provide a cooling
10 structure of a heating element and a power conversion device that
are capable of cooling the heating element such as a semiconductor
module having pin fins while preventing breakage of the heating
element.
In order to solve the above problems, the present invention
15 provides, as one aspect thereof, a cooling structure of a heating
element, including: the heating element having at least one cooling
surface from which a plurality of pin fins project; a heat receiving
plate which has a shape complying with the cooling surface and in
which holes are formed at positions facing each of the pin fins,
20 each of the pin fins being movably inserted into the holes; a cooler
which has a pair of clamping members that sandwich therebetween the
heating element and the heat receiving plate while pressing the
heating element and the heat receiving plate, and which cools the
heat receiving plate; and a space securing part which is provided
25 on the heat receiving plate and suppresses a distance between the
pair of clamping members so as not to apply a pressing force by the
clamping members to the heating element.
Moreover, the present invention provides, as another aspect
thereof, a power conversion device including: a plurality of
30 semiconductor devices for the power conversion device, each
semiconductor device having cooling surfaces from which a plurality
of pin fins project, on both opposite surfaces thereof, and having
2
electric terminals on one side surface which abuts on the cooling
surfaces; a plurality of heat receiving plates each of which has
a shape complying with a corresponding one of the cooling surfaces,
in each of which holes are formed at positions facing each pin fin,
5 each pin fin being movably inserted into the holes, and each of which
is attached to the corresponding cooling surface; a plurality of
coolers including a plurality of clamping members that sandwich
therebetween the plurality of semiconductor devices for the power
conversion device and the plurality of heat receiving plates while
10 pressing the semiconductor devices and the heat receiving plates,
a plurality of heat dissipating fins that lie next to each other
in a horizontal direction relative to each of the semiconductor
devices for the power conversion device, and at least one heat pipe
that connects each of the clamping members with a corresponding
15 plurality of heat dissipating fins, the plurality of coolers cooling
the plurality of heat receiving plates, respectively; and a
plurality of space securing parts which are provided for each of
the plurality of heat receiving plates and suppress distances
between the clamping members so as not to apply a pressing force
20 by the clamping members to the semiconductor devices for the power
conversion device, wherein the side surfaces on which the plurality
of semiconductor devices for the power conversion device have the
electric terminals are arranged on the same plane, and cooling wind
is fed by a blower to the plurality of heat dissipating fins from
25 a reverse side of the same plane.
According to the present invention, the heating element having
pin fins can be cooled while preventing breakage thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG.l is a circuit diagram of a power conversion device
30 according to an embodiment of the present invention.
FIG. 2 is a circuit diagram of a converter in the power
conversion device.
3
FIG. 3 is a circuit diagram of an inverter in the power
conversion device.
FIG. 4 is a circuit diagram of a chopper in the power conversion
device.
5 FIG.5A is an appearance view of a double-sided cooling power
module, and FIG.5B is a circuit diagram of the power module.
FIGS.6A and 6B are perspective views of heat receiving
spacers.
FIG. 7 is a perspective view showing a state in which the heat
10 receiving spacers are attached to the power module.
FIG.8 is an enlarged view of a portion B in FIG.7.
FIG.9 is a cross-sectional view taken along a line A-A' in
FIG.7.
FIG.10 is a perspective view of an air-cooled double-sided
15 cooling power unit.
FIG.11 is an exploded view of a portion C in FIG.10.
FIG.12 is a perspective view of a basic converter unit.
FIG.13 is an exploded view of the basic converter unit.
FIG.14 is an exploded view of a laminate bus bar.
20 FIG.15 is a circuit diagram of the basic converter unit.
FIG.16 is an appearance view of a power conversion device in
which two or more basic converter units are installed.
FIG.17 is an exploded view of a phase-to-phase laminate bus
bar.
25 FIG.18 is a view corresponding to the enlarged view of the
portion B, in one modified example of the heat receiving spacer.
FIG.19 is a view corresponding to the enlarged view of the
portion B, in another modified example of the heat receiving spacer.
FIG.20 is a view corresponding to the enlarged view of the
30 portion B, in still another modified example of the heat receiving
spacer.
FIG.21 is a view corresponding to the exploded view of the
4
portion C in FIG.10, in further another modified example of the heat
receiving spacer.
DETAILED DESCRIPTION OF THE INVENTION

5 Description will be hereinafter given of a configuration of
a power conversion device 150 according to an embodiment of the
present invention.
FIG.l is a circuit diagram of the power conversion device 150
according to the present embodiment. As shown in FIG. 1, alternating
10 current (AC) power is supplied to the power conversion device 150,
which is regulated to a proper voltage through a transformer 105
from a power receiving point 107 in a power system. The AC power
supplied is input to a converter 152 to be converted into direct
current (DC) power. The DC power is input to an inverter 153 to
15 be converted into AC power. This AC power is consumed in a
three-phase AC load 108.
On the other hand, where power is not supplied to the converter
152 due to failure or the like in the power system, a superordinate
control circuit 109 detects non-supply of the power to activate a
20 chopper 154. DC power input to the chopper 154 from a storage cell
106 is regulated to a proper power through the chopper 154 and then
input to the inverter 153. The DC power input to the inverter 153
is converted into AC power, which is consumed in the three-phase
AC load 108.
25 The operation described above is regulated by an instruction
signal HOC to the converter 152, an instruction signal 1101 to the
inverter 153, and an instruction signal 110X to the chopper 154,
which are output depending on an intended operation determined by
the superordinate control circuit 109. The converter 152, the
30 inverter 153 and the chopper 154 generate heat in the respective
operations to increase temperatures thereof. In order to suppress
the temperature increase, cooling wind 111 generated by a cooling
5
fan 101 (blower) is fed into the converter 152, the inverter 153
and the chopper 154 for cooling. Of the electric system configured
as described above, the cooling fan 101, the converter 152, the
inverter 153, the chopper 154 and the superordinate control circuit
5 109 are provided in the power conversion device 150 in the present
embodiment. Moreover, a filter circuit may be arranged between the
converter 152 and transformer 105, or between the inverter 153 and
the AC load 108, if necessary.
FIG.2 is a circuit diagram of the converter 152 in the power
10 conversion device 150; FIG.3 is a circuit diagram of the inverter
153 in the power conversion device 150; and FIG. 4 is a circuit diagram
of the chopper 154 in the power conversion device 150. Circuits
of the converter 152, the inverter 153 and the chopper 154 will be
hereinafter described with reference to FIGS.2 to 4.
15 The converter 152 shown in FIG.2 is constituted by legs 253
(253R, 253S, 253T) each comprised of a plurality of semiconductor
elements, and each leg 253 is constituted by a plurality of switching
elements 204 (e.g., 204RH, 204RL) and a plurality of diode elements
205 (e.g., 205RH, 205RL). In the description below, the leg 253,
20 the switching element 204 and the diode element 205 are used
collectively as representing the entirety of respective components.
Both ends of the leg 253 are connected to a capacitor 201.
An upper side arm of the leg 253R is constituted by a switching
element 204RH and a diode element 205RH for return current. Also,
25 a lower side arm of the leg 253R is constituted by a switching element
204RL and a diode element 205RL for return current. In the same
manner, an upper side arm of the leg 253S is constituted by a
switching element 204SH and a diode element 205SH for return current.
Also, a lower side arm of the leg 253S is constituted by a switching
30 element 204SL and a diode element 205SL for return current.
Moreover, an upper side arm of the leg 253T is constituted by a
switching element 204TH and a diode element 205TH for return current.
6
Also, a lower side arm of the leg 253T is constituted by a switching
element 204TL and a diode element 205TL for return current.
Switching signals to the switching elements 204RH, 204RL, 204SH,
204SL, 204TH and 204TL are controlled by a converter gate controller
5 202 which is a subordinate controller.
Note that any device as long as it is an element capable of
switching between conduction (ON) and blocking (OFF) of current can
be used as the switching element in the present embodiment. For
example, an IGBT (Insulated Gate Bipolar Transistor) , a power MOSFET
10 (Metal Oxide Semiconductor Field Effect Transistor) and the like
can be used.
The inverter 153 shown in FIG.3 is constituted by legs 253
(253U, 253V, 253W) each comprised of a plurality of semiconductor
elements, and both ends of the leg 253 are connected to a capacitor
15 301. An upper side arm of the leg 253U is constituted by a switching
element 204UH and a diode element 205UH for return current. Also,
a lower side arm of the leg 253U is constituted by a switching element
204UL and a diode element 205UL for return current. In the same
manner, an upper side arm of the leg 253V is constituted by a
20 switching element 204VH and a diode element 205VH for return current.
Also, a lower side arm of the leg 253V is constituted by a switching
element 204VL and a diode element 205VL for return current.
Moreover, an upper side arm of the leg 253W is constituted by a
switching element 204WH and a diode element 205WH for return current.
25 Also, a lower side arm of the leg 253W is constituted by a switching
element 204WL and a diode element 205WL for return current.
Switching signals to the switching elements 204UH, 204UL, 204VH,
204VL, 204WH and 204WL are controlled by an inverter gate controller
302 which is a subordinate controller.
30 The chopper 154 shown in FIG.4 is constituted by one leg 253
(253X) comprised of a plurality of semiconductor elements, and both
ends of the leg 253 are connected to a capacitor 401. An upper side
7
arm of the leg 253X is constituted by a switching element 204XH and
a diode element 205XH for return current. Also, a lower side arm
of the leg 253X is constituted by a switching element 204XL and a
diode element 205XL for return current. An interconnected point
5 of the switching elements 204XH and 204XL is connected via a reactor
403 to the storage cell 106 (see FIG.l). Switching signals to the
switching elements 204XH and 204XL are controlled by a chopper gate
controller 402 which is a subordinate controller.
By way of example of the control operation, description will
10 be given of an example of the chopper gate controller 402.
Switching signals to be given to the chopper 154 are given
through a step-up/down switching circuit (not shown). Selection
of the switching signals depends on the magnitude relation between
a DC voltage value appearing between the chopper 154 and the inverter
15 153, and an output voltage value of the converter 152 (rectifying
function). More specifically, when the output of the chopper 154
is higher than the output voltage of the converter 152, a PWM (Pulse
Width Modulation) signal is transmitted to the switching element
204XL, and in the reverse case, a PWM signal is transmitted to the
20 switching element 204XH.
Where power is discharged from the storage cell 106, the
switching element 204XL is allowed to switch between on and off in
response to the PWM signal. When the switching element 204XL is
turned on, energy is accumulated in the reactor 403. On the other
25 hand, when the switching element 204XL is turned off, the voltage
of the storage cell 106 and the energy in the reactor 403 cause a
higher voltage than the voltage of the storage cell 106 to be charged
into the capacitor 401 via the diode element 205XH which is connected
across the switching element 204XH.
30 Where power is charged into the storage cell 106, the switching
element 204XH is allowed to switch between on and off in response
to the PWM signal. When the switching element 204XH is turned on,
8
power accumulated in the capacitor 401 is charged into the storage
cell 106 via the reactor 403. When the switching element 204XH is
turned off, the energy accumulated in the reactor 403 is allowed
to circulate via the diode element 205XL which is connected across
5 the switching element 204XL. These operations enable power to be
charged into and discharged from the storage cell 106.
Note that, although in a commonly-used power conversion device,
capacitors are collectively arranged in some cases, the capacitors
201, 301 and 401 in the present embodiment are separately arranged
10 from a standpoint of standardization of the configuration of a basic
converter unit 960 (see FIG. 12) which will be described later. More
specifically, the capacitors 201 and 301 are further separated for
each leg 253.
Conduction and blocking of current by the switching elements
15 204 and the diode elements 205 of the legs 253 shown in FIGS.2 to
4 are carried out to allow the converter 152 to perform AC to DC
conversion and to allow the inverter 153 to perform DC to AC
conversion. At the conduction, loss is generated in resistances
included in the switching elements 204 and the diode elements 205.
20 Moreover, loss is generated also in switching the state from
conduction to blocking. Consequently, the operation of the power
conversion device 150 is accompanied by heat generation.

Next, a double-sided cooling power module 600 (heating element,
25 or a semiconductor device for the power conversion device) used in
the present embodiment will be described with reference to an
appearance view shown in FIG.5A and a circuit diagram shown in FIG. 5B.
In FIG.5B, the double-sided cooling power module 600 includes
switching elements 204MH, 204ML and diode elements 205MH, 205ML which
30 are mounted on an insulator 753. Connection between the respective
semiconductor elements is made so as to constitute the leg 253 (e.g.,
see FIG.2). Moreover, attached to the insulator 753 are a
9
P-terminal 754P (DC positive terminal), an N-terminal 754N (DC
negative terminal), an AC-terminal 754AC (AC-terminal), and gate
terminals 751 for controlling on and off of each switching element.
Next, in FIG.5A, the double-sided cooling power module 600
5 is consliluled by a body pari 710 which has the form of a nearly
rectangular parallelepiped, a flange part 720 which has the form
of a nearly rectangular parallelepiped and is formed to spread one
side surface of the body part 710, and a terminal part 730 composed
of a plurality of terminals which project from a surface opposite
10 to the body part 710 on the flange part 720 and is composed of a
plurality of terminals. The terminals constituting the terminal
part 730 include the P-terminal 754P, the N-terminal 754N, the
AC-terminal 754AC and the gate terminals 751 shown in FIG.5B.
A number of (200 or more in total) pin fins 762A, each being
15 a projection having the form of a minute column, are provided to
project from one principal surface 760A of the body part 710. Also,
the same number of pin fins 762B (not shown) as the pin fins 762A
are formed on the other principal surface 760B opposite to the
surface 760A of the body part 710. In the description below, the
20 pin fins 762A, 762B are collectively referred to merely as "pin fins
762" in some cases. The double-sided cooling power module 600 has
originally assumed water-cooled cooling and thus is adapted to
immerse the body part 710 in a refrigerant basin with the terminal
part 730 directed upward and the body part 710 directed downward
25 and to allow refrigerant to pass between the pin fins 762. In view
of this, the surface 760A, 760B is hereinafter referred to as a
"cooling surface". A thickness of the body part 710 exclusive of
each pin fin 762, namely a distance between the cooling surfaces
760A, 760B, is defined as dl.
30 When the semiconductor elements described above are operated,
they exhaust heat by way of the cooling surfaces 760A, 760B while
obtaining electric conduction with the outside by way of the terminal
10
part 730. More specifically, since the terminal part 730 is formed
on one side surface which abuts on the cooling surfaces 760A, 760B
and thus is electrically isolated from the cooling surfaces 760A,
760B, the heat transport pathway and the electric pathway are
5 independent of each other.

One pair of heat receiving spacers 630A, 630B shown in FIGS.6A
and 6B are allowed to come face-to-face with the cooling surfaces
10 760A, 760B of the double-sided cooling power module 600. The heat
receiving spacer 630A is constituted by a heat receiving part 631A
(heat receiving plate) having the form of a nearly rectangular plate
and one pair of space securing parts 632A each having the form of
a nearly rectangular parallelepiped and projecting from both ends
15 of the heat receiving part 631A toward the heat receiving spacer
630B. Also, a number of columnar through-holes 633A (holes) are
formed in the heat receiving part 631A. These through-holes 633A
are formed at positions on the heat receiving part 631A which face
each pin fin 762A on the cooling surface 760A, and have a slightly
20 greater diameter than a diameter of each pin fin 762A. It is normally
desirable to allow the pin fin 762A to fit into the through-hole
633A without any space, but since the diameter and/or position of
the pin fin 762A involve a slight manufacturing error, the diameter
of the through-hole 633A is enlarged to such an extent that the
25 manufacturing error can be absorbed.
Moreover, the heat receiving spacer 630B is constituted by
a heat receiving part 631B having the form of a nearly rectangular
plate and one pair of space securing parts 632B each having the form
of a nearly rectangular parallelepiped and projecting from both ends
30 of the heat receiving part 631B toward the heat receiving spacer
630A. The heat receiving spacer 630B has a vertically symmetrical
shape as a whole to the heat receiving spacer 630A, and through-holes
11
633B are formed in the heat receiving part 631B, at positions which
face each pin fin 762B projecting from the cooling surface 760B of
the double-sided cooling power module 600.
When attaching the heat receiving spacers 630A, 630B to the
5 double-sided cooling power module 600, heat conducting grease is
sufficiently coated on the cooling surfaces 760A, 760B and the space
securing parts 632A, 632B are then allowed to come face-to-face with
each other while aligning the positions of the through-holes 633A,
633B with each pin fin 762. FIG.7 shows a state in which the heat
10 receiving spacers 630A, 630B are thus attached to the double-sided
cooling power module 600. As shown in FIG.7, an end face 710a of
the body part 710 is exposed to the outside, but the cooling surfaces
760A, 760B are mostly covered by the heat receiving spacers 630A,
630B.
15 FIG.8 shows an enlarged plan view of a portion B surrounded
by a dashed line in FIG.7.
As described above, since the diameter of each through-hole
633A is slightly greater than the diameter of each pin fin 762A,
each pin fin 762A is movably inserted into a gap 635 while securing
20 the gap 635 between each pin fin 762A and each through-hole 633A.
In the event of insertion, the heat conducting grease coated on each
pin fin 762A penetrates to be pushed into the gap 635 and thus the
gap 635 is filled with the heat conducting grease without any space.
Next, FIG. 9 shows an enlarged view of a major part (end
25 portion) on the cross-section surface along a line A-A' in FIG. 7.
When the space securing parts 632A, 632B are allowed to come
face-to-face with each other, the heat receiving parts 631A, 631B
face each other at a predetermined distance. This distance is
defined as d2. The heat receiving spacers 630A, 630B are formed
30 to allow the distance d2 to be slightly greater than the thickness
dl of the body part 710 of the double-sided cooling power module
600. As a result, gaps 637A, 637B are formed between the heat
12
receiving part 631A and the body part 710, and between the heat
receiving part 631b and the body part 710, respectively. Since the
double-sided cooling power module 600 has looseness for the heat
receiving spacers 630A, 630B, widths of the gaps 637A, 637B are not
5 necessarily equal Lo each other.
When the space securing parts 632A, 632B are allowed to come
face-to-face with each other, the heat conducting grease coated on
each pin fin 762 also penetrates to be pushed into the gaps 637A,
637B and thus the gaps 637A, 637B are also filled with the heat
10 conducting grease without any space. Also, when a thickness of the
body part 710 inclusive of a distance from a tip of the pin fin 762A
to a tip of the pin fin 762B is defined as d4 and the entire width
obtained when the heat receiving spacers 630A, 630B are allowed to
come face-to-face with each other is defined as d5, the heat
15 receiving spacers 630A, 630B are formed to allow the width d5 to
be slightly greater than the thickness d4 . Consequently, gaps 639A,
639B are formed between an upper surface of the heat receiving spacer
630A in the illustration and the tip of the pin fin 762A, and between
a lower surface of the heat receiving spacer 630B and the tip of
20 the pin fin 762B, respectively. As described above, since the
double-sided cooling power module 600 has looseness for the heat
receiving spacers 630A, 630B, widths of the gaps 639A, 639B are not
necessarily equal to each other.
When the heat receiving spacers 630A, 630B are attached to
25 a cooler 610 (details will be described later), a pressing force
such as indicated by hatched arrows is applied to the heat receiving
spacers. This pressing force is applied to the portions at which
the space securing parts 632A, 632B are allowed to come face-to-face
with each other. In the present embodiment, since the gaps 637A,
30 637B are formed between the body part 710 and the heat receiving
spacers 630A, 630B and further the gaps 639A, 639B are formed between
each tip of the pin fins 762A, 762B and the heat receiving spacers
13
630A, 630B, application of the above pressing force to the body part
710 can be prevented, thereby making it possible to prevent breakage
of the double-sided cooling power module 600 before something
happens.
5 NexL, FIG.10 shows a perspective view of a state in which two
double-sided cooling power modules 600 are installed on the cooler
610. The cooler 610 is constituted by a pair of coolers 610A, 610B.
The coolers 610A, 610B have heat receiving blocks 601A, 601B each
of which is in the form of a nearly rectangular parallelepiped block,
10 and the heat receiving blocks 601A, 601B sandwich therebetween the
two double-sided cooling power modules 600 on each of which the heat
receiving spacers 630A, 630B are installed.
The heat receiving blocks 601A, 601B are secured by a plurality
of securing members 604 to each other and thus a pressing force is
15 applied to the heat receiving blocks 601A, 601B in directions
indicated by hatched arrows. Note that, as described above with
respect to FIG. 9, the pressing force is applied to the heat receiving
spacers 630A, 630B, but not applied to the double-sided cooling power
modules 600. As for the securing member 604, a general bolt and
20 a nut can be used.
In FIG. 10, four heat pipes 602 project from the heat receiving
block 601A in the y-axis direction, with an inclination of about
10 degrees to the x-y plane (horizontal plane) formed by the x-axis
and the y-axis. Also, a plurality of plate-like heat dissipating
25 fins 603 are attached by welding to the heat pipes 602 in a radial
direction of the heat pipes 602. Accordingly, each of the heat
dissipating fins 603 is inclined at about 10 degrees to the x-z plane
(vertical plane) formed by the x-axis and the z-axis. The cooler
610B is also configured in the same manner as the cooler 610A. As
30 described above, the two double-sided cooling power modules 600 are
installed on the cooler 610, thereby constituting one air-cooled
double-sided cooling power unit 620.
14
When the double-sided cooling power modules 600 generate heat,
the heat is propagated via the heat receiving spacers 630A, 630B
to the heat receiving blocks 601A, 601B and further propagated via
the heat pipes 602 backward (in the y-axis direction) . Then, when
5 cooling wind 853 directed upward from bottom (directed in the z-axis
direction) is fed to the air-cooled double-sided cooling power unit
620, the cooling wind 853 goes through the heat dissipating fins
603 toward the upper direction while cooling the fins 603, and thus
the heat is rapidly emitted to the outside. Such heat propagation
10 pathways are indicated by arrows 851 in the illustration. Note that
heat propagation in a direction perpendicular to the cooling wind
853 is propagation caused mainly by the heat pipes 602.
FIG.11 shows an exploded view of a portion C surrounded by
a dashed line in FIG.10.
15 In FIG. 11, heat conducting grease 606 is provided between the
heat receiving spacer 630A and the heat receiving block 601A, and
between the heat receiving spacer 630B and the heat receiving block
601B, respectively. When the heat receiving blocks 601A, 601B are
secured by the securing members 604 to each other, the heat
20 conducting grease 606 spreads along and over opposed surfaces of
the heat receiving spacer 630A and the heat receiving block 601A,
and opposed surfaces of the heat receiving spacer 630B and the heat
receiving block 6-0IB, to become the form of a thin film layer as
shown in the figure. In the process, the heat conducting grease
25 606 penetrates into the gaps 639A, 639B (see FIG.9) on the tips of
each pin fin 762A, 762B and thus the heat conducting grease 606
spreads over outsides of each pin fin 762A, 762B without any space.

Next, the basic converter unit 960 in the present embodiment
30 will be described with reference to FIG.12 to FIG.15. FIG.12 is
a perspective view of the basic converter unit 960; FIG.13 is an
exploded view of the basic converter unit 960; FIG. 14 is an exploded
15
view of a P-N-AC-layer laminate bus bar 955; and FIG. 15 is a circuit
diagram of the basic converter unit 960.
In the basic converter unit 960 shown in FIG. 12, the P-terminal
754P (see FIGS. 5A, 5B) , the N-terminal 754N and the AC-terminal 754AC
5 of electric terminals in the air-cooled double-sided cooling power
unit 620 described above are connected to the P-layer, the N-layer
and the AC-layer of the P-N-AC-layer laminate bus bar 955,
respectively. Moreover, the gate terminals 751 of the electric
terminals are connected to a gate driver substrate 954. Also, each
10 positive terminal 952P and each negative terminal 952N of a plurality
of capacitors 951 are connected to the P-layer and the N-layer of
the P-N-AC-layer laminate bus bar 955, respectively. Furthermore,
a positive fuse 953P and a negative fuse 953N are connected to the
P-layer and the N-layer of the P-N-AC-layer laminate bus bar 955,
15 respectively. Note that the positive fuse 953P and the negative
fuse 953N shown herein have a function of breaking circuits so as
to protect the device when current of a specified level or more flows
through the circuits, and thus if such a protective function is not
required, the fuses can also be omitted.
20 FIG. 13 is an exploded view for FIG. 12. FIG. 14 is an exploded
view of the P-N-AC-layer laminate bus bar 955. As shown in FIG. 14,
the bus bar 955 is constituted by a P-layer bus bar 955P, an N-layer
bus bar 955N and an AC-layer bus bar 955AC, and the bus bars are
insulated by an insulating layer 955S from one another. Moreover,
25 in the basic converter unit 960, the P-terminal 754P, the N-terminal
754N and the AC-terminal 754AC of the double-sided cooling power
module are connected to the P-layer bus bar 955P, the N-layer bus
bar 955N and the AC-layer bus bar 955AC, respectively. Also, each
P-terminal and each N-terminal of the capacitors 951 are connected
30 to the P-layer bus bar 955P and the N-layer bus bar 955N, respectively.
An electric circuit diagram for the above configuration is shown
in FIG.15.
16

FIG.16 is an appearance view of the power conversion device
150 in which two or more basic converter units 960 are installed.
In the power conversion device 150, the converter 152, the
5 inverter 153 and the chopper 154 are arranged side by side in this
order. The converter 152 is constituted by the basic converter
units 960 which correspond to three legs 253R, 253S and 253T shown
in FIG.2. The inverter 153 is constituted by the basic converter
units 960 which correspond to three legs 253U, 253V and 253W shown
10 in FIG.3. The chopper 154 is constituted by one basic converter
unit 960. Note that the converter 152, the inverter 153 and the
chopper 154 may be arranged in a different order from that in the
present embodiment, and the legs in each of the converter 152, the
inverter 153 and the chopper 154 may be arranged in a different order
15 of phases.
As described above with respect to FIG.10, the air-cooled
double-sided cooling power unit 620 in the present embodiment allows
the heat generated by the double-sided cooling power modules 600
to be propagated via the heat pipes 602 backward (in the y-direction)
20 to be emitted via the heat dissipating fins 603 provided backward
to the outside. According to the configuration shown in FIG.16,
convenience of maintenance can be increased because multiple basic
converter units 960 each attaching the air-cooled double-sided
cooling power unit 620 thereon are laterally arranged. When any
25 of the basic converter units 960 fails to operate properly, the
failed unit is generally pull out from the power conversion device
150 and a spare unit is instead inserted into the power conversion
device 150. In the process, pulling out the failed unit and
inserting the spare unit can be realized by simply moving the
30 respective units in the y-direction, and thus the failure can be
rapidly coped with.
The converter 152 is constituted so as to connect a P-N-layer
17
phase-to-phase laminate bus bar 1053 to positive terminals 1051 and
negative terminals 1052, respectively, of three basic converter
units 960. The inverter 153 is also constituted in the same manner
as the converter 152. The chopper 154 is constituted by one basic
5 converter unit 960 and thus is not necessarily connected to the
P-N-layer phase-to-phase laminate bus bar 1053. Note that, in the
present embodiment in which the capacitance of the chopper 154 is
increased, and the converter 152, the inverter 153 and the chopper
154 are unified as one system, it is desirable to connect the chopper
10 154 together with the converter 152 and the inverter 153 to the
P-N-layer phase-to-phase laminate bus bar 1053. Herein, as shown
in FIG.17, the P-N-layer phase-to-phase laminate bus bar 1053
includes a phase-to-phase P-bus bar 1053P and a phase-to-phase N-bus
bar 1053N, and the bus bars are insulated by an insulating layer
15 1053S from each other.
In the converter 152, the inverter 153 and the chopper 154
which are provided with the above configurations, a plurality of
basic converter units 960 can also be connected in parallel with
each other for one leg. This makes it possible to increase the rated
20 output capacity of the power conversion device.
In a cooling method for the basic converter units 960 in the
power conversion device shown in FIG.16, in the same manner as in
FIG.10, the cooling wind 853 is fed to the heat dissipating fins
603 upward from bottom. Accordingly, even if the basic converter
25 units 960 are densely installed side by side in the power conversion
device 150, an advantage of not decreasing a cooling effect of each
basic converter unit 960 can be obtained. Also, where temperatures
of the respective semiconductor elements in the converter 152, the
inverter 153 and the chopper 154 are different from each other, wind
30 speeds of cooling winds 853A, 853B, 853C or the like may be changed.
Advantageous Effects of Embodiments>
As described above, the cooling structure according to the
18
present embodiment includes: a heating element (600) having at least
one cooling surface (760A, 760B) from which a plurality of pin fins
(762) project; a heat receiving plate (631A, 631B) which has a shape
complying with the cooling surface (760, 760B) and in which holes
5 (633A, 633B) are formed at positions facing each pin fin (762) , each
pin fin (762) being movably inserted into the holes; a cooler (610)
which has a pair of clamping members (601A, 601B) that sandwich
therebetween the heating element (600) and the heat receiving plate
(631A, 631B) while pressing the heating element and the heat
10 receiving plate, and which cools the heat receiving plate (631A,
631B); and a space securing part (632A, 632B) which is provided on
the heat receiving plate (631A, 631B) and suppresses a distance
between the pair of clamping members (601A, 601B) so as not to apply
a pressing force by the clamping members (601A, 601B) to the heating
15 element (600).
This allows the cooling structure according to the present
embodiment to make it possible to propagate heat of the heating
element (600) via the heat receiving plate (631A, 631B) and the
clamping members (601A, 601B) for cooling the heating element.
20 Also, in the present embodiment, the heating element (600)
has the cooling surface (760A, 760B) on two opposite surfaces thereof,
and the heat receiving plate (631A, 631B) has a shape complying with
the cooling surf ace (760A, 760B) on the two surfaces, the holes (633A,
633B) being formed at the positions facing each of the pin fins (762)
25 which project from the cooling surface (760A, 760B) on the two
surfaces. This makes it possible to propagate heat from the cooling
surface on the two surfaces and to further enhance a heat conduction
effect.
Moreover, in the present embodiment, since a heat conducting
30 agent (606) is provided between the pin fins (762) and the heat
receiving plate (631A, 631B) , thermal resistance between the heating
element (600) and the heat receiving plate (631A, 631B) can be
19
reduced to downsize the cooler (610).
Furthermore, in the present embodiment, the distance (d5 +
the thickness of the heat conducting grease 606) between the pair
of clamping members (601A, 601B) suppressed by the space securing
5 part (632A, 632B) is greater than the thickness (d4) of the heating
element (600) inclusive of the pin fins (762) . Consequently, when
the heating element (600), the heat receiving plate (631A, 631B)
and the space securing part (632A, 632B) are clamped by the clamping
members (601A, 601B), application of a pressing force to each pin
10 fin (762) can be prevented to prevent breakage of the heating element
(600) .
In addition, in the power conversion device 150 according to
the present embodiment, the side surfaces (terminal part 730) on
which the plurality of semiconductor devices (600) for the power
15 conversion device have the electric terminals are arranged on the
same plane, and cooling wind is fed by a blower (101) to the plurality
of heat dissipating fins (603) from the reverse side of the same
plane. Accordingly, wiring between the semiconductor devices (600)
for the power conversion device can be easily realized by the
20 P-N-layer phase-to-phase laminate bus bar 1053.

The present invention is not limited to the above embodiments,
and can be variously modified, for example, as follows.
(1) Through-holes to be formed in the heat receiving spacers
25 630A, 630B are not limited to ones in the embodiments, and can be
changed to ones having various shapes and sizes as long as they are,
in short, through-holes to allow the pin fins 762 to be movably
inserted thereinto. For example, as shown in FIG.18, rectangular
through-holes 640Amay be formed at positions corresponding to each
30 pin fin 762A, in the heat receiving spacers 630A. In this case,
even if a length of one side of the rectangular through-hole 640A
is the same as the diameter of the circular through-hole 633A (see
20
FIG.8) in the above embodiments, an area of the through-hole 640A
can be increased resulting in an advantage of further facilitating
work to attach the heat receiving spacer 630A to the double-sided
cooling power module 600.
5 (2) Moreover, each of through-holes to be formed in the heat
receiving spacers 630A, 630B is not limited to one into which one
pin fin 762 is movably inserted. For example, as shown in FIG.19,
a through-hole 642A into which four pin fins 762 are movably inserted
may be formed. Thus, when the through-hole 642A is formed to allow
10 a plurality of pin fins 762 to be movably inserted thereinto, the
number of through-holes to be formed can be reduced resulting in
advantages of being able to loosen the dimensional precision and
reduce the manufacturing process. Note that although in the example
of FIG. 19, four pin fins 762 are movably inserted into one
15 through-hole 642A which has the form of a nearly parallelogram, the
number of the pin fins 762 to be movably inserted into the one
through-hole may be two, three, or five or more. Moreover, with
this modification, the shape of each through-hole may be a shape
other than the nearly parallelogram.
20 (3) Further, the shape of each of through-holes to be formed
in the heat receiving spacers 630A, 630B, and the number of the pin
fins 762 to be movably inserted into the through-holes, may be
changed for every region on the heat receiving spacers 630A, 630B.
For example, as shown in FIG.20, the through-hole 642A into which
25 four pin fins 762 are movably inserted, and the through-hole 633A
into which one pin fin 762 is movably inserted, may be formed in
the heat receiving spacer 630A. The former through-hole 642A has
an advantage over the through-hole 633A in that the manufacturing
process can be reduced, while the latter through-hole 633A has an
30 advantage over the through-hole 642A in that the thermal resistance
can be less reduced. In view of this, it is desirable for a region
having less heat discharge in the double-sided cooling power module
21
600 to adopt the through-hole 642A into which a plurality of pin
fins 762 are movably inserted, and for a region having more heat
discharge to adopt the through-hole 633A into which a single pin
fin 762 is movably inserted. This makes it possible to balance ease
5 of manufacturing with thermal performance.
(4) Although in the above embodiments, the heat receiving
spacers 630A, 630B and the coolers 610A, 610B are separate members,
heat receiving spacers and coolers may be configured integral with
each other. For example, the heat receiving blocks 601A, 601B and
10 the heat receiving spacers 630A, 630B shown in FIG. 11 may be replaced
with heat receiving blocks 650A, 650B shown in FIG.21. The heat
receiving block 650B is provided with a plurality of columnar
depressed portions 654B which are formed at places facing the pin
fins 762 of the double-sided cooling power module 600. In the same
15 manner, the heat receiving block 650A is also provided with a
plurality of columnar depressed portions (not shown) which are
formed at places facing the pin fins 762.
Moreover, on the heat receiving block 650B, a pair of space
securing parts 652 each being in the form of a nearly rectangular
20 parallelepiped is formed to surround a region in which the depressed
portions 654B are formed. Note that in this modified example, what
are equivalent to the space securing parts 652 are not formed at
the corresponding places on the heat receiving block 650A. Each
of the space securing parts 652 is set to be smaller than the
25 thickness d4 (see FIG.9) of the body part 710 inclusive of the pin
fins 762, and to be slightly greater than the thickness dl (see FIG. 9)
of the body part 710 except for the pin fins 762. Moreover, the
depth of each of the depressed portions 654B formed in the heat
receiving block 650B, and the depth of each of the depressed portions
30 (not shown) formed in the heat receiving block 650A, are set to be
slightly greater than the height of each pin fin 762. Accordingly,
even where the double-sided cooling power module 600 is sandwiched
22
between the heat receiving blocks 650A, 650B as shown in FIG.21 and
the heat receiving blocks 650A, 650B are then secured by the securing
members 604 to each other, no pressing force is applied to the
double-sided cooling power module 600.
5 In the present modified example, the heat receiving blocks
650A, 650B combine the respective functions of the heat receiving
spacers 630A, 630B and the heat receiving blocks 601A, 601B in the
above embodiments, thereby making it possible to further suppress
the entire thermal resistance. Also, since the number of components
10 can be reduced, an advantage that manufacturing management becomes
easier is also obtained. Note that, the space securing parts 652
in the present modified example are not necessarily formed integral
with the heat receiving block 650B, and may be formed as separate
members.
15 (5) Although in the above embodiments, the through-holes 633A,
633B are formed in the heat receiving spacers 630A, 630B, depressed
portions similar to the depressed portions 654B such as shown in
FIG.21 may be formed in place of the through-holes. In this case
too, the depth of each depressed portion is set to be greater than
20 the height of each pin fin 762.
(6) The heat receiving spacers 630A, 630B are preferably
comprised of highly heat-conductive metal such as aluminum or copper
from the standpoint of heat dissipation characteristics. However,
where the double-sided cooling power module 600 and the cooler 610
25 need to be isolated from each other, material such as resin or
ceramics may be used as the heat receiving spacers 630A, 630.B.
(7) In the above embodiments, a flexible member such as a
rubber plate may be inserted between the abutting faces of the space
securing parts 632A, 632B. This also makes it possible to perform
30 a minute height adjustment and a lessening in pressing.
(8) Although in the above embodiments, the heat pipes 602 and
the heat dissipating fins 603 are used in the coolers 610A, 610B,
23
a cooler may be used which does not include the heat pipes 602 and
in which heat dissipating fins are directly joined to the heat
receiving blocks 601A, 601B. Moreover, a liquid-cooled cooler may
be adopted which allows refrigerant to flow through the inside
5 thereof. More specifically, distribution channels for refrigerant
joined to the heat receiving blocks 601A, 601B may be formed and
heat dissipating fins may be joined to the distribution channels.
(9) Although in the above embodiments, the bolt and the nut
are used as the securing member 604, a spring member or the like
10 may be used.
(10) In the above embodiments, a heat conducting sheet may
be used in place of the heat conducting grease 606.
(11) Although in the above embodiments, the cooling surfaces
760A, 760B of the double-sided cooling power module 600 are flat
15 surfaces and the heat receiving parts 631A, 631B are in the form
of a flat plate, the cooling surfaces 760A, 760B are not necessarily
flat surfaces. More specifically, the shapes of the heat receiving
parts 631A, 631B can be made the shapes complying with the cooling
surf aces 760A, 760B, thereby obtaining the same advantageous effects
20 as in the above embodiments.
(12) Although in the above embodiment in FIG. 10, the heat pipes
602 are inclined at about 10 degrees to the x-y plane (horizontal
plane), the heat pipes 602 may be made flat with no inclination.
[Description of Reference Signs]
25 101: Cooling fan, 105: Transformer, 106: Storage cell, 107:
Power receiving point, 108: Alternating current (AC) load, 109:
Superordinate control circuit, HOC: Instruction signal to
converter, 1101: Instruction signal to inverter, 110X: Instruction
signal to chopper, 111: Cooling wind, 150: Power conversion device,
30 152: Converter, 153: Inverter, 154: Chopper, 201: Capacitor, 202:
Converter gate controller, 204: Switching element, 205: Diode
element, 253: Leg, 600: Double-sided cooling power module (Heating
24
element), 601: Heat receiving block, 601A, 601B: Heat receiving
block (Clamping member) , 602: Heat pipe, 603: Heat dissipating fin,
604: Securing member, 606: Heat conducting grease, 610, 610A, 610B:
Cooler, 620 : Air-cooled double-sided cooling power unit, 630A, 630B:
Heat receiving spacer, 631A, 631B: Heat receiving part (Heat
receiving plate) , 632A, 632B: Space securing part, 633A, 633B, 640A,
642A: Through-hole (Hole), 635, 637A, 637B, 639A, 639B: Gap, 650A,
650B: Heat receiving block (Clamping member), 652: Space securing
part, 654B: Depressed portion, 710: Body part, 710a: End face, 720:
Flange part, 730: Terminal part, 751: Gate terminal, 753: Insulator,
754N: N-terminal, 754P: P-terminal, 754AC: AC-terminal, 760A, 760B:
Cooling surface, 762, 762A, 762B: Pin fin, 853: Cooling wind, 951:
Capacitor, 952N: Negative terminal, 952P: Positive terminal, 953N:
Negative fuse, 953P: Positive fuse, 954: Gate driver substrate, 955:
P-N-AC-layer laminate bus bar, 955N: N-layer bus bar, 955P: P-layer
busbar, 955S: Insulating layer, 955AC: AC-layer bus bar, 960: Basic
converter unit, 1051: Positive terminal, 1052: Negative terminal,
1053: P-N-layer phase-to-phase laminate bus bar

We claim:
1. A cooling structure of a heating element, comprising:
the heating element having at least one cooling surface from
5 which a plurality of pin fins project;
a heat receiving plate which has a shape complying with the
cooling surface and in which holes are formed at positions facing
each of the pin fins, each of the pin fins being movably inserted
into the holes;
10 a cooler which has a pair of clamping members that sandwich
therebetween the heating element and the heat receiving plate while
pressing the heating element and the heat receiving plate, and which
cools the heat receiving plate; and
a space securing part which is provided on the heat receiving
15 plate and suppresses a distance between the pair of clamping members
so as not to apply a pressing force by the clamping members to the
heating element.
2. The cooling structure of the heating element, according to
claim 1, wherein
20 the- heating element has the cooling surface on two opposite
surfaces thereof, and
the heat receiving plate has a shape complying with the cooling
surface on the two surfaces, the holes being formed at the positions
facing each of the pin fins which project from the cooling surface
25 on the two surfaces.
3. The cooling structure of the heating element, according to
claim 1, further comprising a heat conducting agent provided between
the pin fins and the heat receiving plate.
4. The cooling structure of the heating element, according to
30 claim 1, wherein the distance between the pair of clamping members
suppressed by the space securing part is greater than a thickness
of the heating element inclusive of the pin fins.
26
5. The cooling structure of the heating element, according to
claim 1, wherein each of the holes has a columnar shape.
6. The cooling structure of the heating element, according to
claim 1, wherein some of the plurality of pin fins are movably
5 inserted into one of the holes.
7. The cooling structure of the heating element, according to
claim 1, wherein in the heat receiving plate, both of a hole into
which some of the plurality of pin fins are movably inserted, and
a hole into which one pin fin is movably inserted, are formed.
10 8. The cooling structure of the heating element, according to
claim 1, wherein the cooler includes heat dissipating fins and heat
pipes connected to the clamping members and the heat dissipating
fins .
9. The cooling structure of the heating element, according to
15 claim 1, wherein the cooler includes heat dissipating fins joined
to the clamping members.
10. The cooling structure of the heating element, according to
claim 1, wherein the cooler includes distribution channels for
refrigerant joined to the clamping members, and heat dissipating
20 fins joined to the distribution channels.
11. A cooling structure of a heating element, comprising:
the heating element having at least one cooling surface from
which a plurality of pin fins project;
space securing parts each of which is formed to be smaller
25 than a thickness of the heating element inclusive of the pin fins
and to be greater than a thickness of the heating element except
for the pin fins; and
a pair of clamping members each of which has a shape complying
with the cooling surface and in each of which holes are formed at
30 positions facing each of the pin fins, each of the pin fins being
movably inserted into the holes, the clamping members sandwiching
therebetween the heating element sandwiched by the space securing
27
parts while applying a pressing force to the heating element.
12. A power conversion device comprising a plurality of cooling
structures, each being the cooling structure of the heating element,
according to claim 1, wherein
5 the plurality of cooling structures are arranged side by side
to allow respective coolers to lie next to each other, and
the heating element is a semiconductor device for the power
conversion device.
13. A power conversion device comprising:
10 a plurality of semiconductor devices for the power conversion
device, each semiconductor device having cooling surfaces from which
a plurality of pin fins project, on both opposite surfaces thereof,
and having electric terminals on one side surface which abuts on
the cooling surfaces;
15 a plurality of heat receiving plates each of which has a shape
complying with a corresponding one of the cooling surfaces, in each
of which holes are formed at positions facing each pin fin, each
pin fin being movably inserted into the holes, and each of which
is attached to the corresponding cooling surface;
20 a plurality of coolers including a plurality of clamping
members that sandwich therebetween the plurality of semiconductor
devices for the power conversion device and the plurality of heat
receiving plates while pressing the semiconductor devices and the
heat receiving plates, a plurality of heat dissipating fins that
25 lie next to each other in a horizontal direction relative to each
of the semiconductor devices for the power conversion device, and
at least one heat pipe that connects each of the clamping members
with a corresponding plurality of heat dissipating fins, the
plurality of coolers cooling the plurality of heat receiving plates,
30 respectively; and
a plurality of space securing parts which are provided for
each of the plurality of heat receiving plates and suppress distances
28
between the clamping members so as not to apply a pressing force
by the clamping members to the semiconductor devices for the power
conversion device, wherein
the side surfaces on which the plurality of semiconductor
5 devices for the power conversion device have the electric terminals
are arranged on the same plane, and cooling wind is fed by a blower
to the plurality of heat dissipating fins from a reverse side of
the same plane.