Description:Technical field
[0001] The disclosed subject matter in general relates to heat sinks used for heat dissipation. The disclosed subject matter in particular relates to a heat sink comprising fins with reducing heights

Background

[0002] The heat sinks or heat dissipation devices are used in different industries like electronics, mechanical, automotive to absorb heat from heat generating components. The heat from the heat generating components need to be absorbed and dissipated into atmosphere to maintain efficiency and for smooth operation of the components/devices which generate heat.

[0003] Heat sinks come in different structures, geometries. The simple structure of a heat sink may comprises plurality of fins arranged in a straight line on a bases structure. Some heat sinks may be in the form of cylinders having fins on the outer surface.

[0004] Traditional heat sinks, such as straight fin, pin fin, and extruded types are widely used due to their simple design and low cost. However, they typically offer limited thermal efficiency. Advanced solutions like heat pipes and vapor chambers provide better thermal performance but come with challenges such as leakage risk and orientation sensitivity. Liquid cooling systems deliver excellent thermal management but increase system complexity and maintenance requirements.

[0005] One known art US 20050061478A1 discloses a circular heat sink. The heat sink comprises a plurality of streamlined curved heat dissipating fins and a conical base to constitute the circular heat sink. The shape of the heat dissipating fin is designed to have a streamlined curved surface; and the circular heat sink assembly comprises a plurality of fan-shaped heat dissipating fins stacked and encircled into a circular shape. The heat dissipating fin having a streamlined curved surface is coupled with the conical base to form a circular heat sink. When the axle fan is installed on the heat sink, the fluid is blown downwards onto the heat sink and the fluid can flow smoothly through the conical base without heating the base to rebound and lose energy,

[0006] The known art 20080024994 discloses a combination heat sink formed of a plurality of radiation fins radially fastened together to show a circular configuration having a top rounded recess that is defined by a notch on each radiation fin for gathering currents of air for enabling gathered currents of air to be guided by a curved surface portion of each radiation fin to the outside of the heat sink to carry heat away from the heat sink.

[0007] However, in the above known arts, the fins have uniform shape and size, thereby needing more material for manufacture and leading to more weight. The air is guided in a particular direction, without receiving from different directions for better cooling.

[0008] The disclosed subject matter addresses the above issues.

Summary

[0009] The subject matter is defined in the independent claims. Further details are defined in the dependent claims.

[0010] The subject matter discloses a heat sink and a method for manufacturing the heat sink.

[0011] The heat sink comprises a base and a plurality of fins protruding from the base, wherein height of the fins reduces from center of the base in at least one direction towards an outer edge of the base. The fins of the heat sink are arranged in any one of the shapes like concentric circles, concentric squares, concentric rectangles, concentric ellipses, any other enclosed shape or in straight lines.

[0012] The method of manufacturing the heat sink comprises melting Aluminum-Silicon alloy ingots and maintaining at controlled temperature; injecting molten aluminum into a die cavity, ensuring complete filling of thin fins; cooling the die, the content forming a dense microstructure with good thermal conductivity; ejecting the heat sink casting from the die using ejector pins; and trimming excess material and machining for mounting holes, flatness, or surface finish.

[0013] Molten aluminum is injected into the die cavity at very high pressure (typically 1000–2000 bar), ensuring complete filling of thin fins

[0014] Brief description of the drawings
[0015] The detailed description is described with reference to the accompanying figures. In the figures, similar reference numerals are used throughout the drawings to reference like features and components.

Figure 1 illustrates a perspective view of a heat sink according an embodiment
Figure 2A illustrates a top view of a heat sink according an embodiment
Figure 2B illustrates a cross section of a heat sink according an embodiment
Figure 3 illustrates top view of a heat sink having a round base, according an embodiment
Figure 4 illustrates a cross section of a heat sink with tapered fins, according an embodiment
Figure 5A illustrates top view of a heat sink with fins in a straight line, according an embodiment
Figure 5B illustrates a cross section of a heat sink with fins in a straight line, according an embodiment
Figure 6A illustrates top view of a heat sink with fins in a concentric square shape, according an embodiment
Figure 6B illustrates a cross section of a heat sink with fins in a concentric square shape, according an embodiment
Figure 7 illustrates a method of manufacturing the heat sink

Detailed description
[0016] The subject matter now will be described with exemplary embodiments. However, the claimed subject matter may be embodied in many different forms and should not be construed as limited to the embodiments described herein. These embodiments are provided only as examples so that this disclosure is clear and concise.

[0017] Only the details/components required to describe the claimed subject matter in specific, are disclosed in this document. The details/components which are commonly known or understood by people skilled in the art may not be covered in this document.

[0018] In this document some terms may be used interchangeably. Some examples are given below:

[0019] The terms ‘heat dissipating device’ and ‘heat sink’ may be used interchangeably.

[0020] The subject matter discloses a heat sink comprising a base and a plurality of fins. The fins are arranged in straight lines or concentric shapes. The concentric shapes may include, concentric circles, concentric squares, concentric rectangles, concentric ellipses or any other shape which is closed by its sides. The fins are designed in such a way that the height of the fins reduces from center of the base towards the edge of the base at least in one direction. In some embodiments the fins may comprises at least on groove.

[0021] The structure of the heat sink is described below with respect to figures.

[0022] Figure 1 illustrates a perspective view of the heat sink 100 according to an embodiment. The heat sink 100 comprises the base 102 and fins 104. The heat sink 100 may be an extruded heat sink, a stamped heat sink, bonded heat sink, forged heat sink or a die cast heat sink. Different processes may be used to manufacture the heat sink 100.

[0023] In figure 1, in an embodiment of the heat sink 100, the fins 104 are arranged in concentric circles. The base 102 is shown as rectangle in shape. However, the base 102 and the fins 104 can be in different shapes, as shown in other figures.

[0024] The fins 104 comprise grooves 106. The grooves 106 are from top surface of the fins 104 till the base 100. The grooves 106 divide the fins into smaller sub-fins. There are eight grooves shown in figure 1. However, the number of grooves may vary. The grooves 106 are shown in radial direction. However, the grooves may be in other directions dividing the fins 100 in different geometries.

[0025] The height of the fins 104 is reduced for each concentric circle. The fins 100 which are closest to the center of the base have maximum height and the fins 100 which are closest to the edge of the base have minimum height. The height of each fin 104 is decided on how closer the fin is from the center of the base. The closer the fin from the center, the height is larger and gradually the height reduces for the fins 104 which are away from the center of the base 102.

[0026] The maximum and minimum heights of the fins 104 may be decided on different factors like available space for the heat sink 100 to be fitted on a component, available air flow for the heat sinks, accessibility of the heat sink etc. Similarly the height of each concentric circle of fins 104 may be decided.

[0027] Figure 2A illustrates a top view of the heat sink 100 shown in figure 1. The fins 104 are arranged concentrically and the grooves 106 arranged in radial directions, divide the concentric circled fins 100 into smaller sub-fins.

[0028] Figure 2B illustrates a cross section of the heat sink 100 along the line A-A shown in figure 2A. The cross section illustrates the fins 104 whose height is decreasing for each concentric circle from the center of the base 102 towards the edge of the base 102. The height of the fins 104 is reduced gradually from the center of the base 102 in radial directions. In an embodiment the shape of the fins 100 is in the form of steps. The top surface 105 of the fins 100 is flat.

[0029] Figure 3 illustrates another embodiment of the heat sink 100. The heat sink shown in figure 3 comprises a circular base 102.

[0030] Figure 4 illustrates another embodiment of the heat sink 100. The top surface 400 of each fins 100 is tapered. The tapering is from the center of the base 100 in radial directions. In this embodiment, the height of the fins 100 is reduced for every concentric circle in radial direction as well as the top surface of the fins 100 is tapered. This geometry provides increased efficiency for air circulation by eliminating any obstruction to the air circulation by the fins 104.

[0031] Figure 5A illustrates a top view of another embodiment of the heat sink 100. The embodiment illustrates the heat sink 100 where the fins 100 are arranged in straight lines from a first edge 100 to a second edge 502 of the base 102.

[0032] Figure 5B illustrates a cross section of the heat sink 100 along with the line B-B shown in figure 5A. The height of the fins 104 reduces from the center of the base 102 towards the edges of the base 102.

[0033] Figure 6A illustrates a top view of another embodiment of the heat sink 100. The embodiment illustrates the heat sink 100 where the fins 100 are arranged in concentric squares. There is a single groove 106 shown. However there may be multiple groves 106.

[0034] Figure 6B illustrates a cross section of the heat sink 100 along with the line C-C shown in figure 6A. The height of the fins 104 reduces from the center of the base 102 towards the edges of the base 102.

[0035] The heat sink 100 is manufactured using an aluminum-silicon (AlSi) casting alloy by the High Pressure Die Casting (HPDC) method. In this process, molten alloy is injected into a precision steel die under very high pressure, ensuring thin fins and complex shapes are accurately formed. After rapid solidification, the heat sink 100 is ejected, trimmed, machined where required, and finally surface treated for improved thermal performance and corrosion resistance.

[0036] Figure 7 illustrates a method of manufacturing the heat sink 100. The method starts with step 702. The step 702 discloses melting Aluminum-Silicon alloy ingots and maintaining at controlled temperature. The step 702 discloses injecting molten aluminum into a die cavity, ensuring complete filling of thin fins. Molten aluminum is injected into the die cavity at very high pressure (typically 1000–2000 bar), ensuring complete filling of thin fins. The step 706 discloses cooling the die, the content forming a dense microstructure with good thermal conductivity. The step 708 discloses ejecting the heat sink casting from the die using ejector pins. The step 710 discloses trimming excess material and machining for mounting holes, flatness, or surface finish.

[0037] The method 700 further discloses surface treatment by anodizing the heat sink 100 for corrosion protection and better heat dissipation.

[0038] The disclosed subject matter provides various technical advantages. Some are described below as examples.

[0039] The design of the heat sink 100 is suited for low-airflow applications. Traditional heat sinks usually feature equal fin height and uniform shapes, which limit the airflow and the direction of air flow. However, the new design disclosed, provides bidirectional and even 360 degree airflow, making it highly effective even with limited airflow. The subject matter incorporates round step fins 104 that help maintain airflow dynamics and enhance heat absorption from the heat sink body. The tapered fins 104 allow air to approach from all directions, not just in one or two directions. This innovative structure improves thermal performance significantly under low-airflow conditions.

[0040] The tapering of the top surface of the fins 100 provides better air flow without obstructing any incoming air. The reduction of height of fins 104 and tapering of the top surface of the fins 104 together give maximum efficiency for heat dissipation.

[0041] The different shapes of bases 102, like circular, square, rectangular etc. provide suitable options for fixing the heat sink 100 to different heat generating components which may be in different shapes.

[0042] The grooves 106 in the fins 100 provide better paths for efficient air circulation thereby absorbing the heat efficiently.

[0043] The subject matter provides fins 100 in the form of reduced step, tapered fins, grooves etc. for efficient air circulation, thereby providing more cooling effect for a given surface and weight of the heat sinks 100.

 
Reference numerals and their description:

100 Heat sink
102 Base
104 Fins
105 Flat top surface of the fins
106 Grooves
400 Tapered top surface of the fins
500 First edge of the base
502 Second edge of the base
, C , Claims:1. A heat sink (100) for dissipating heat, the heat sink (100) comprising:
a base (102);
a plurality of fins (104) protruding from the base (102), wherein height of the fins (104) reduces from center of the base (102) in at least one direction towards an outer edge of the base (102).

2. The heat sink (100) as claimed in claim 1 wherein the plurality of fins (104) are arranged as one of:
concentric circles; or
concentric squares; or
concentric rectangles; or
concentric ellipses;
any enclosed shape; or
straight lines.

3. The heat sink (100) as claimed in claim 1 wherein the plurality of fins (104) are arranged as straight lines from a first edge (500) of the base (102) to a second edge (502) of the base 102.

4. The heat sink (100) as claimed in claim 1 wherein, the height of the fins (104) closer to the center of the base (102) being larger compared to the fins (104) closer to the outer edge of the base (102).

5. The heat sink (100) as claimed in claim 1 wherein, a fin (104) whose distance from the center of the base (102) is lesser, is taller compared to a fin (104) whose distance from the center of the base (102) is more.

6. The heat sink (100) as claimed in claim 1 wherein the fins (104) comprise at least one grove (106) from top surface of the fin (104) till the base (102), in at least one direction from the center of the base (102), thereby dividing the fins (104) into multiple parts.

7. The heat sink (100) as claimed in claim 1 wherein top surface of the fins (104) comprises tapered shape (400) in the direction from center of the base (102) towards an edge of the base (102).

8. The heat sink (100) as claimed in claim 1 wherein top surface of the fins (104) is a flat surface (105).

9. The heat sink (100) as claimed in claim 1 wherein the shape of the base (102) is:
a circle; or
a square; or
a rectangle; or
an ellipse; or
any enclosed shape.

10. A method (700) of manufacturing a heat sink (100), the method comprising:
melting (702) Aluminum-Silicon alloy ingots and maintaining at controlled temperature;
injecting (704) molten aluminum into a die cavity, the die cavity having a cavity for a base (102) and cavities for fins (104) wherein height of the fins (104) reduces from center of the base (102) in at least one direction towards an outer edge of the base (102);
cooling (706) the die, the content forming a dense microstructure with good thermal conductivity;
ejecting (708) the heat sink casting from the die using ejector pins; and
trimming (710) excess material and machining for mounting holes, flatness, or surface finish.
11. The method (700) as claimed in claim 10 comprising surface treatment by anodizing the heat sink (100) for corrosion protection and better heat dissipation.

12. The method (700) as claimed in claim 10 wherein injecting the molten aluminum into the die cavity comprises injecting the molten aluminum into the die cavity at a pressure of 1000–2000 bar.