Power semiconductor module and related method

Abstract

The present disclosure relates to power semiconductor modules and related methods. A particular implementation of a cooler for power semiconductor devices can include a top portion including a first maximum planar surface configured to receive one or more power semiconductor devices coupled thereon, the top portion having a second maximum planar surface opposite the first maximum planar surface, the second maximum planar surface including a plurality of spike fins extending therefrom; and a bottom portion including a planar surface facing the plurality of spike fins. A length of each spike of the plurality of spike fins can be long enough for a tip of each spike to overtravel into a material of the planar surface when the top portion and the bottom portion are couplable together.

Description

Technical Field

[0001] This document generally relates to cooling systems, such as systems used to cool semiconductor dies during operation. Background Technology

[0002] Various semiconductor packages are designed to protect semiconductor dies from moisture or electrostatic discharge. Other semiconductor packages are designed to prevent damage to semiconductor dies from shock or vibration. Various other semiconductor packages allow for the formation of various electrical connections between the semiconductor die and the circuit board or motherboard to which the semiconductor package is attached. Summary of the Invention

[0003] A specific implementation of a cooler for power semiconductor devices may include: a top portion including a first maximum planar surface configured to receive one or more power semiconductor devices coupled thereto, the top portion having a second maximum planar surface opposite to the first maximum planar surface, the second maximum planar surface including a plurality of stud-shaped fins extending therefrom; and a bottom portion including a planar surface facing the plurality of stud-shaped fins. Each stud of the plurality of stud-shaped fins may be long enough to allow the tip of each stud to extend into the material of the planar surface when the top and bottom portions can be coupled together.

[0004] Specific implementations of coolers for power semiconductor devices may include one, all, or any of the following:

[0005] One or more power semiconductor devices can be sintered to the first maximum planar surface.

[0006] The overtravel at the tip of each nail-shaped fin prevents warping of the top and bottom portions during sintering.

[0007] The tip of each of the multiple stud fins may include a cone.

[0008] The tip of each of the multiple nail-shaped fins may include a truncated cone.

[0009] The truncated cone may have a diameter at its base that is smaller than the diameter of the longest portion of each nail-shaped fin.

[0010] The overtravel distance of each stud fin can be a predetermined distance based on the average length of each stud fin.

[0011] The bottom portion may also include two ports configured to allow coolant to enter and exit the enclosed space between the top and bottom portions, with multiple spike-shaped fins extending into the enclosed space.

[0012] A specific implementation of a cooler for a power semiconductor device may include: a top portion having a first maximum planar surface and a second maximum planar surface opposite to the first maximum planar surface, the second maximum planar surface including a plurality of fins extending therefrom; and a bottom portion including a planar surface facing the plurality of fins. Each of the plurality of fins may be long enough to allow the tip of each fin to extend into the material of the planar surface when the top portion and the bottom portion are coupled together.

[0013] Specific implementations of coolers for power semiconductor devices may include one, all, or any of the following:

[0014] One or more power semiconductor devices can be sintered to the first maximum planar surface.

[0015] The overtravel at the tip of each fin prevents warping of the top and bottom portions during sintering.

[0016] The cross-sectional shape of each of the multiple fins can be a square, rectangle, ellipse, triangle, hexagon, or any closed shape.

[0017] The cross-sectional shape of the tip of each of the multiple fins can be a square, rectangle, ellipse, triangle, hexagon or any closed shape.

[0018] The overtravel distance for each fin can be based on a predetermined distance of the average length of each of the multiple fins.

[0019] The bottom section also includes two ports configured to allow coolant to enter and exit the space between the top and bottom sections, with multiple fins extending into the space.

[0020] A specific implementation of a method for assembling a power semiconductor module may include: providing a top portion having a first maximum planar surface, the top portion having a second maximum planar surface opposite to the first maximum planar surface, the second maximum planar surface including a plurality of fins extending therefrom; and using sintering paste to couple one or more semiconductor packages to the first maximum planar surface. The method may include: fastening a bottom portion including a planar surface facing the plurality of fins; driving the tip of each fin into the material of the planar surface by an overtravel distance during the coupling of the top portion and the bottom portion; and sintering the top portion, the bottom portion, and the one or more semiconductor packages.

[0021] Specific implementations of the method for assembling power semiconductor modules may include one, all, or any of the following:

[0022] This method may include performing an X-ray inspection to determine the degree of warping of the top and bottom portions.

[0023] This method may include reducing the warpage of the power semiconductor module by extending the overtravel distance at the tip of each fin.

[0024] The bottom portion may include two ports configured to receive coolant flowing around multiple fins.

[0025] The method may include forming multiple fins on the second largest planar surface by one of machining or casting.

[0026] The foregoing and other aspects, features and advantages will become apparent to those skilled in the art through the detailed description and accompanying drawings, as well as through the claims. Attached Figure Description

[0027] Specific embodiments will be described below in conjunction with the accompanying drawings, in which similar reference numerals denote similar elements, and:

[0028] Figure 1 This is a side sectional view of a specific implementation of the power semiconductor module;

[0029] Figure 2 It is a detailed cross-sectional view of the specific implementation of the power semiconductor module;

[0030] Figure 3 It is a detailed cross-sectional view of the specific implementation of the power semiconductor module;

[0031] Figure 4 These are detailed views of two specific embodiments of the nail-shaped fins;

[0032] Figure 5 This is a top view of a specific implementation of the top portion of the cooler;

[0033] Figure 6 This is a side view of a specific implementation of the top portion of the cooler;

[0034] Figure 7 This is an end view of a specific implementation of the top portion of the cooler;

[0035] Figure 8 This is a bottom view of a specific implementation of the top portion of the cooler, showing various spiked fins;

[0036] Figure 9 yes Figure 8 Detailed view of the spiked fins;

[0037] Figure 10 This is a side view of the specific implementation of the bottom part of the cooler;

[0038] Figure 11 This is an end view of a specific implementation of the bottom portion of the cooler;

[0039] Figure 12 It is a side sectional view of the implementation of the top portion coupled to the implementation of the bottom portion;

[0040] Figure 13 yes Figure 12 Detailed view of the nail-shaped fins of the cooler implementation;

[0041] Figure 14 yes Figure 12 An end perspective view of the specific implementation of the cooler;

[0042] Figure 15 It is a perspective view of a specific implementation of the top portion, in which sintering paste is applied to the first maximum planar surface;

[0043] Figure 16 This is a perspective view of the bottom surface of a specific implementation of the bottom portion of the cooler;

[0044] Figure 17 It is a view of a specific implementation of a semiconductor package, coupled to Figure 15 Top perspective view and bottom perspective view of a specific embodiment of a cooler for multiple semiconductor packages above the sintered paste portion;

[0045] Figure 18 It is after the sintering process. Figure 17 Various views of the specific implementation of the cooler. Detailed Implementation

[0046] This disclosure, its aspects, and specific embodiments are not limited to the specific components, assembly steps, or method elements disclosed herein. Many additional components, assembly steps, and / or method elements known in the art, consistent with the intended cooler for a semiconductor device, will be readily apparent for use with specific embodiments of this disclosure. Therefore, for example, although a specific embodiment is disclosed, such embodiments and implementation components may include any shape, size, style, type, model, version, measure, concentration, material, quantity, method element, step, etc., of such coolers and implementation components and methods known in the art for semiconductor devices, consistent with the intended operation and method.

[0047] refer to Figure 1The diagram illustrates a side sectional view of a specific embodiment of a cooler 2 for a semiconductor device. The cooler 2 includes a top portion 4 and a bottom portion 6. While the terms "top portion" and "bottom portion" are used for ease of description in this document, the top portion is also the part of the cooler 2 to which multiple semiconductor packages / devices 6 are attached, while the bottom portion 6 is the part facing multiple stud fins 8 and helps to form a casing for allowing coolant to flow around the stud fins. In various embodiments, the coolant may be a liquid or a gas.

[0048] Although Figure 6 The various semiconductor packages 6 illustrated herein are power semiconductor packages containing various power semiconductor dies, but other types of semiconductor devices may be attached to the top portion 4 in package form. As non-limiting examples, these include metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistors (IGBTs), diodes, rectifiers, thyristors, microprocessors, graphics processors, or any other type of semiconductor device. The various semiconductor dies included in the multiple packages may be formed on / from any of a wide variety of semiconductor substrate types, as non-limiting examples, including silicon, silicon carbide, gallium nitride, gallium arsenide, silicon-on-insulator, sapphire, ruby, or any other semiconductor material type. The various semiconductor packages may include molding compounds / electrically insulating sealants, or may include various layers exposed through molding compounds / electrically insulating sealants. Various electrical connectors (pins, clips, wire bonds, etc.) may be employed, and various lead frames and / or substrates may be included in the semiconductor packages. Embedded semiconductor dies may be included in various semiconductor package implementations. In some implementations, the semiconductor packages may be identical, but in other implementations, one or more semiconductor packages may differ by their structure, by including different semiconductor dies, or both.

[0049] Figure 1This illustrates how conductive heat transfer can be used to transfer heat generated during the operation of a semiconductor package downwards from the package through the sintered layer 10, through the thickness of the top portion 4, and along the length of each stud fin in the stud fins 8. Then, convective heat transfer from the stud fins 8 transfers heat to the coolant as it flows through the enclosed space 12 between the top portion 4 and the bottom portion 6. Because the electrical connectors 14 of the multiple semiconductor packages 6 are in the form of pin / press-fit pins in various specific embodiments, tolerances between the electrical connectors 14 and the pin receivers on the circuitry or motherboard to which the cooler 2 is coupled are important. In cases where sintering is used to attach / couple multiple semiconductor packages 6 to portion 4, it has been observed that the top portion, bottom portion, or both the top and bottom portions may warp to unpredictable degrees during high-temperature processes. This deformation of the cooler structure results in different thermal properties for one or more semiconductor packages of the multiple semiconductor packages 6 attached to the top portion 4 of the cooler. After analysis, the main cause of the deformation / warping was observed to be the change in the length of each of the multiple nail-shaped fins / fins coupled to the bottom maximum planar surface 16 of the top portion. Figure 1 Examples of various nail-shaped fins / blades with different lengths are shown.

[0050] refer to Figure 2A detailed view of the semiconductor package 6 attached to the top portion 4 via the sintering layer 10 is illustrated here. Three spiked fins 18, 20, and 22 are shown, each with a different length. Spiked fin 20 is the shortest, followed by spiked fin 22. None of these spiked fins reach the surface 24 of the bottom portion 6 opposite to the spiked fins 18, 20, and 22. Due to this remaining space between the ends of the spiked fins 20 and 22, the top portion 4, bottom portion 6, or both the top and bottom portions, can freely move mechanically relative to each other during the sintering process. The resulting warping / displacement causes the electrical connector 26 of the semiconductor package 6 to shift, which may result in the inability to insert the electrical connector 26 into the corresponding receiver or socket. If the stud fins 20, 22 have the same length as the stud fin 18 with its tip 28 just touching the surface 24, then the stud fins 18, 20, 22 will collectively mechanically reinforce the top portion 4 and the bottom portion 6 and prevent mechanical movement of these portions relative to each other during sintering. Achieving such dimensional tolerances for all or even substantially all stud fins across the entire second maximum planar surface 30 of the top portion 4 is challenging. This is especially true when the various stud fins are screwed, welded, brazed, friction-fitted, or otherwise mechanically coupled to the second maximum planar surface 30. Even when the stud fins are integrally formed from the material of the top portion by machining processes (milling, etc.), achieving the degree of dimensional tolerance for each stud fin across the entire maximum planar surface is challenging. Machining all stud fins is also a time-consuming process, which may be more expensive than for simply mechanically coupled stud fins. Finally, when using fin structures other than stud fins, the ability to control dimensional tolerances may be further reduced. As a non-limiting example, alternative fin structures that can be utilized in various specific implementations include row structures, column structures, interconnected structures, alternating fin structures, and other three-dimensional structures that can extend away from the second maximum planar surface 30.

[0051] Due to the challenges posed by the dimensional tolerance variations of the spiked fins 18, 20, and 22, attempts to rely on these spiked fins to help prevent mechanical deformation of the cooler during the sintering process are unlikely to yield consistent results. Figure 3 Different methods are illustrated below. Here, a detailed view of another specific embodiment of the cooler 32 includes a top portion 34 coupled to the bottom portion 36. Spike-shaped fins 38, 40, 42 extend from a second maximum planar surface 44 opposite to the first maximum planar surface 46, to which the semiconductor package 48 is coupled via a sintered layer 50. The semiconductor package 48 also includes an electrical connector 52 extending away from the semiconductor package.

[0052] exist Figure 3In the illustrated cooler embodiment 34, the stud fins 38, 40, and 42 still have different lengths, reflecting that they are manufactured using a process with dimensional variations. However, the tips 54, 56, and 58 of each stud fin 38, 40, and 42 extend beyond the planar surface 60 of the bottom portion 36 into the material of the bottom portion 36. This is because the design / nominal length of each stud fin 38, 40, and 42 is set longer than the width 62 of the housing between the top portion 34 and the bottom portion 36. Therefore, despite the normal dimensional variations involved in the specific process of manufacturing the stud fins 38, 40, and 42, the tips 54, 56, and 58 of all the studs will still contact and drive into the material of the bottom portion 36. The distance by which the tips 54, 56, and 58 of the stud fins travel into or overshoot into the material of the bottom portion 36 is referred to herein as overshoot or overshoot distances 64, 66, and 68. This overtravel capability, which relies on the stud fins, means that the expected average overtravel distance for each stud fin is a predetermined distance based on the average length of each stud fin. This average length of the stud fin can be calculated using actual measurements of the manufactured stud fins or through cumulative dimensional tolerance analysis based on the specific manufacturing and assembly processes of the stud fins.

[0053] In some cooler embodiments, the shape / cross-sectional shape of each stud fin 38, 40, 42 remains the same along its entire length (constant cross-section), and the tips of the stud fins then penetrate into the material of the bottom portion by a distance corresponding to the extent that the length of each stud fin is longer than the width 62. In this embodiment, while the tips 54, 56, 58 penetrate into the material, in some embodiments, because the tips are substantially flat, the material of one or more stud fins 38, 40, 42 may impinge on or compress the surface 60. This would typically be expected to provide similar mechanical reinforcement to prevent warping, but due to the lack of a uniform mechanical interface between the stud fins 38, 40, 42 and the material of the bottom portion 36, stress between the top and bottom portions may tend to increase during cooler heating and cooling. Figure 3 This design is illustrated in cooler 32.

[0054] However, in other embodiments, to facilitate a smoother mechanical process during the coupling of the top portion 34 and the bottom portion 36, the shapes of the tips 54, 56, and 58 may be modified to help ensure they penetrate the material of the bottom portion. (Reference) Figure 4Specific embodiments of the two spiked fins 70, 72 include tips 74, 76 having a cross-sectional shape different from the main body of the spiked fins 70, 72. Tip 74 has a truncated cone shape, wherein the cross-section of the tip portion of the spiked fin 70 varies linearly along the length 78 of the tip portion of the spiked fin 70. Tip 76 exemplifies a different design, wherein the shape of the tip has a constant or substantially constant cross-sectional shape along the length 80 of the tip portion of the spiked fin 72. The size of the cross-sectional shape of tip 76 is smaller than the cross-sectional shape of the main portion of the spiked fin 76. This gradual reduction in size can help the tip portion penetrate the material of the bottom portion or impact the surface of the bottom portion firmly to provide the desired mechanical stability.

[0055] In various embodiments, the tips of the studded fins can take a wide variety of shapes, including, as non-limiting examples, conical, pyramidal, cylindrical, elliptical, cubic, spherical, or any other regular or irregular closed shape. In various embodiments, as non-limiting examples, the cross-sectional shape of the studded fin can be square, rectangular, elliptical, triangular, hexagonal, or any other closed shape. For the tip of the studded fin, as a non-limiting example, the cross-sectional shape of the tip portion can be square, rectangular, elliptical, triangular, hexagonal, or any other closed shape. In various embodiments, the cross-section of the tip portion of the studded fin can also vary linearly or non-linearly along the length of the tip. A wide variety of combinations of studded fins, tips, and the cross-sectional shapes of the tip portion can be constructed using the principles disclosed herein.

[0056] In various embodiments, the materials of the stud fins / fins and the bottom portion can be selected, in combination with the specific shape of the stud fins and their tips, to facilitate overtravel into the bottom portion. For example, in some embodiments, the same metallic material with the same material properties can be used for both the stud fins and the bottom portion, such as aluminum and aluminum or copper and copper as non-limiting examples. In other embodiments, the same metal or metal alloy as the bottom portion can be used for the stud fins, but the stud fins are made of a version of the metal / metal alloy with higher mechanical strength than that of the bottom portion. For example, high-strength aluminum would be used for the stud fins, while lower-strength aluminum would be used for the bottom portion. In still other embodiments, different metal / metal alloys can be used for both the stud fins and the bottom portion to achieve a desired contrast in mechanical material properties. For example, the stud fins could be made of copper, while the bottom portion could be made of aluminum, or vice versa. Those skilled in the art will be able to use the principles disclosed herein to select an appropriate combination of materials for the stud fins and the bottom portion to achieve the desired overtravel of the stud fins.

[0057] The specific shapes of the top and bottom portions of the cooler are typically determined by the size and desired configuration of the semiconductor package, as well as any constraints related to the mounting location. In some implementations, the cooler and semiconductor package form a power semiconductor module that collectively performs a specific function. For example, in some implementations, the power semiconductor module may be used as a liquid-cooled traction inverter. Figure 5 This is a top view of a specific embodiment of the top portion 82, showing that the top portion may be symmetrical about one axis rather than two axes in a particular embodiment. In this view, a first maximum planar surface 84 is illustrated, to which one or more semiconductor packages will be attached.

[0058] Figure 6 This is a side view of the top portion 82, showing multiple nail-shaped fins 86 extending from the second largest planar surface 88. Although Figure 6 In some embodiments, the array of stud fins 86 is illustrated as being uniformly distributed within the periphery of the housing that will be formed when the bottom portion is attached. However, in other embodiments, the stud fins may be centered or otherwise distributed only around the mounting / coupling location of the semiconductor package, thus creating gaps in the array. Furthermore, the stud fin array may be non-uniformly patterned but may be concentrated near the mounting / coupling location of the semiconductor package. In still other embodiments, the stud fin array may use a random pattern to achieve the desired heat transfer coefficient / transmission distribution. Figure 7 This is an end view of the top portion 82 and the array of nail-shaped fins 86. Note that in this view, the nail-shaped fins appear narrower because the nail-shaped fins in this embodiment do not have a uniform cross-sectional shape like a square, circle, or triangle, but are elliptical.

[0059] Figure 8 This is a bottom view of the second largest planar surface 88 of the top portion 82. In this view, the alternating pattern of the stud fins 86 is organized in rows along the largest dimension of the top portion. Although this alternating row pattern is used, in various specific embodiments, any of a wide variety of other regular, irregular, targeted, or random patterns can be used for various stud fin arrays. Figure 9 It shows Figure 8 A detailed view of the array of nail-shaped fins is shown, illustrating the cross-sectional shape of each nail-shaped fin in the array 86, since the tip 90 of each nail-shaped fin in the array 86 is flat and does not include any of the aforementioned three-dimensional or cross-sectional shapes. In this specific embodiment, the cross-sectional shape of the nail-shaped fins is oval or elliptical.

[0060] refer to Figure 10 An example is given of a specific implementation of the bottom portion 92. In this specific implementation, the main body includes a cavity 94, which includes a cavity facing from... Figures 6 to 9 The top portion 82, illustrated in the diagram, embodies a recessed surface of a stud-fin array. A cavity 94 receives the studs and forms a remaining surface that forms a casing, through which coolant 96 flows into the casing through inlet 98, around the stud-fin array, and then out through outlet 100. Each of inlet 98 and outlet 100 is designed such that a specific hose or other mechanism for delivering coolant to it can be structurally and securely coupled to the external portions of inlet 98 and outlet 100. Figure 11 This is an end view of the bottom portion 92, showing that in this embodiment, the inlet 98 and outlet 100 are arranged on a straight line aligned with the longest dimension of the bottom portion. In various embodiments, the inlet and outlet may take many different shapes and positions depending on how the power semiconductor module will be attached to the coolant lines and mounted.

[0061] refer to Figure 12 The diagram illustrates the top portion 82 when it is fully and securely coupled to the bottom portion 92. As illustrated, a cavity 94 receives an array of stud-like fins 86 and forms a housing 102 around which coolant flows in and out. In this cross-sectional view, a recess 104 in the first largest planar surface 104 of the top portion 82 is illustrated, designed to facilitate the placement and retention of the semiconductor package during the sintering bonding process. A wide variety of methods designed to achieve a fixed coupling relationship can be used to couple the top portion 82 and the bottom portion 92, including, as non-limiting examples, screwing, bolting, clamping, welding, brazing, or any other method that securely holds these portions together and forms a coolant-resistant seal. In some specific implementations, one or more O-rings, gaskets, or other sealing structures / systems may be employed to ensure that coolant does not leak from the joint between the top portion 82 and the bottom portion 92.

[0062] Figure 13 It comes from Figure 12 A detailed view of the array of studded fins 86 is provided, illustrating how each studded fin 86 embeds / inserts / overtravels into the material of the bottom portion 92 because the length of each studded fin is longer than the width of the housing 102. Here, because each studded fin 86 overtravels into the material of the bottom portion 92, the tip 106 of each studded fin 86 rests below the surface 108 of the bottom portion 92. It should be noted that the desired mechanical stability from the overtravel of the studded fins 86 can be achieved without the studded fins needing to travel a long distance into the material of the bottom portion 92 relative to the length of each studded fin 86. Figure 15 This is an end perspective view of the top portion 82 and the bottom portion 92 coupled together, showing the orientation of the spiked fins 86 relative to the coolant.

[0063] Various specific implementations of the methods for assembling power semiconductor modules can be used to construct the various coolers and power semiconductor modules disclosed herein. References Figure 15 A perspective view illustrates a specific embodiment of the top portion 110, where portions of the sintering paste 112, 114 are located within the recess 116. A wide variety of techniques can be used to apply the sintering paste, including, as non-limiting examples, screen printing, dispensing, stencil printing, or any other technique to achieve a layer of desired uniform height in a desired area. In some embodiments, a drying operation / process may be employed after the application of the sintering paste to help stabilize the sintering paste portions 112, 114, making them ready for the application of semiconductor packages. In some embodiments, the sintering paste may contain silver. Figure 15 In the middle, the top portion 110 is illustrated as coupled to Figure 16 In the bottom portion 118 illustrated in the diagram. As part of the coupling, the desired overtravel of the pin entering the material of the bottom portion 118 has been completed. Figure 16 The corresponding bottom portion 118 is shown in a bottom view / surface perspective view, which shows the inlets 120, 122 for coolant.

[0064] refer to Figure 17 The illustration shows the top portion 110 after a semiconductor package 124 has been placed onto sintering pastes 112, 114. In this embodiment, each semiconductor package 124 includes press-fit leads 126 extending upward therefrom. Once the semiconductor package 124 has been placed therein, the top portion 110 and the bottom portion 118 are now ready for a sintering operation that forms a bond between the semiconductor package 124 and the material of the top portion 110 of the cooler. In various embodiments consistent with the specific sintering system / materials used to form a bond between the specific material of the semiconductor package and the top portion 110, any of a variety of sintering processes can be utilized. Figure 17 A bottom view of the bottom portion 118 cooler is also shown, which shows the position of the semiconductor package 124 after it is placed on the top portion 110.

[0065] refer to Figure 18 The diagram illustrates four different views of the cooler after the sintering process is complete (top-bottom view 126, end view 128, side view 130, and bottom view 132). These views illustrate how the use of stud fins ensures that mechanical displacement and / or warpage are minimized / eliminated after sintering to allow pins and other electrical connectors to remain in the desired positions. At this point, the power semiconductor module 134 is ready to be assembled with coolant lines and sockets / receivers at the point of use.

[0066] Where the above description refers to specific embodiments of coolers for semiconductor devices, as well as implementation components, sub-components, methods, and sub-methods, it should be apparent that various modifications can be made without departing from the substance, and that these embodiments, implementation components, sub-components, methods, and sub-methods can be applied to other coolers for semiconductor devices.

Claims

1. A cooler for a power semiconductor device, the cooler comprising: The top portion includes a first maximum planar surface configured to receive one or more power semiconductor devices coupled thereto, and the top portion has a second maximum planar surface opposite to the first maximum planar surface, the second maximum planar surface including a plurality of nail-shaped fins extending therefrom; and The bottom portion includes a planar surface facing the plurality of nail-shaped fins; The length of each of the plurality of nail-shaped fins is long enough that the tip of each nail extends into the material of the planar surface when the top portion and the bottom portion are coupled together.

2. The cooler of claim 1, wherein the one or more power semiconductor devices are sintered to the first maximum planar surface.

3. The cooler of claim 2, wherein the overtravel of the tip of each nail-shaped fin prevents warping of the top and bottom portions during the sintering process.

4. The cooler of claim 1, wherein the tip of each of the plurality of stud fins comprises a cone.

5. The cooler of claim 1, wherein the tip of each of the plurality of stud fins comprises a truncated cone.

6. The cooler according to claim 5, wherein the truncated cone has a diameter at its base that is smaller than the diameter of the longest portion of each nail-shaped fin.

7. The cooler of claim 1, wherein the overtravel distance of each stud fin is a predetermined distance based on the average length of each stud fin.

8. The cooler of claim 1, wherein the bottom portion further comprises two ports configured to allow coolant to enter and exit an enclosed space between the top portion and the bottom portion, the plurality of stud fins extending into the enclosed space.

9. A cooler for a power semiconductor device, the cooler comprising: The top portion has a first maximum planar surface and a second maximum planar surface opposite to the first maximum planar surface, the second maximum planar surface including a plurality of fins extending therefrom; and The bottom portion includes a planar surface facing the plurality of fins; Each of the plurality of fins is long enough that the tip of each fin extends beyond the material of the planar surface when the top portion and the bottom portion are coupled together.

10. The cooler of claim 9, wherein one or more power semiconductor devices are sintered to the first maximum planar surface.

11. The cooler of claim 10, wherein the overtravel of the tip of each fin prevents warping of the top and bottom portions during the sintering process.

12. The cooler of claim 9, wherein the cross-sectional shape of each of the plurality of fins is one of a square, rectangle, ellipse, triangle, hexagon or any closed shape.

13. The cooler of claim 9, wherein the cross-sectional shape of the tip of each of the plurality of fins is one of a square, rectangle, ellipse, triangle, hexagon or any closed shape.

14. The cooler of claim 9, wherein the overtravel distance of each fin is a predetermined distance based on the average length of each of the plurality of fins.

15. The cooler of claim 9, wherein the bottom portion further comprises two ports configured to allow coolant to enter and exit the space between the top portion and the bottom portion, the plurality of fins extending into the space.

16. A method for assembling a power semiconductor module, the method comprising: A top portion is provided, the top portion having a first maximum planar surface, the top portion having a second maximum planar surface opposite to the first maximum planar surface, the second maximum planar surface including a plurality of fins extending therefrom; Sintering paste is used to couple one or more semiconductor packages onto the first maximum planar surface; Secure the bottom portion, the bottom portion including a planar surface facing the plurality of fins; During the coupling of the top and bottom portions, the tip of each fin is driven into the material of the planar surface by an overtravel distance; as well as Sintering the top portion, the bottom portion, and the one or more semiconductor packages.

17. The method of claim 16, further comprising performing an X-ray inspection to determine the degree of warping of the top portion and the bottom portion.

18. The method of claim 17, further comprising reducing the warpage of the power semiconductor module by means of the overtravel distance of the tip of each fin.

19. The method of claim 16, wherein the bottom portion includes two ports configured to receive coolant flowing around the plurality of fins.

20. The method of claim 16, further comprising forming the plurality of fins on the second maximum planar surface by one of machining or casting.

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