Power module heat conduction structure and power module
By setting up a raised structure of the same height between the heat sink and the ceramic substrate, the problem of uneven solder thickness was solved, the consistency of heat diffusion effect was achieved, and the performance and lifespan of the chip were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-16
- Publication Date
- 2026-04-03
AI Technical Summary
In existing technologies, the solder thickness between the heat dissipation base plate and the ceramic substrate is uneven, resulting in inconsistent heat diffusion effects, which may lead to localized high temperatures, unstable chip performance, and reduced lifespan.
By setting a raised structure of the same height between the heat sink base plate and the ceramic substrate, the raised structure can support the heat sink base plate and the ceramic substrate to maintain a relatively stable and uniform distance when solder is added. By ensuring the uniformity of solder thickness during the welding process between the heat sink and the ceramic substrate, the heat diffusion effect of different parts is consistent.
This achieves uniform solder thickness between the heat dissipation base plate and the ceramic substrate, ensuring consistent heat diffusion, avoiding localized heat accumulation, and improving chip performance and lifespan.
Smart Images
Figure CN224084051U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor heat dissipation technology, and in particular to power module thermal conductive structures and power modules. Background Technology
[0002] The main components of the power module, such as Figure 1 As shown, the power module includes a chip 1, a ceramic substrate 2, a heat sink 3, screws 4, a housing 5, and signal terminals 6. The ceramic substrate 2 can be a substrate manufactured using Direct Bonded Copper (DBC) technology. The heat sink 3 has holes through which screws connect to the heat sink 7. The bottom of the ceramic substrate 2 is in contact with the heat sink 3, and thermal paste is applied between the heat sink 3 and the heat sink 7 to ensure smooth heat transfer between them.
[0003] The function of the heat dissipation base plate 3 is to prevent the ceramic substrate 2 from directly contacting the thermal paste.
[0004] If the ceramic substrate 2 and the heat dissipation base plate 3 are connected by welding, uneven solder will cause inconsistent heat diffusion in different parts of the ceramic substrate 2, and may even lead to local high temperature.
[0005] The technical problem to be solved in this application is how to make the solder thickness between the heat dissipation base plate and the ceramic substrate uniform, so as to make the heat diffusion effect consistent in different parts. Utility Model Content
[0006] The purpose of this application is to provide a power module heat-conducting structure and a power module to solve the technical problem in the prior art of how to make the solder thickness between the heat sink base plate and the ceramic substrate uniform, so as to make the heat diffusion effect of different parts consistent.
[0007] To achieve the above objectives, one or more embodiments of this application adopt the following technical solutions.
[0008] In a first aspect, embodiments of this application provide a power module thermal conductive structure, including a ceramic substrate, a heat dissipation base plate, thermal paste, and a heat sink;
[0009] Chips and signal terminals are mounted on the upper surface of the ceramic substrate, the lower surface of the ceramic substrate is welded or sintered with metal onto the upper surface of the heat sink base plate, the lower surface of the heat sink base plate is mounted on the surface of the heat sink, and the thermal paste is disposed between the lower surface of the heat sink base plate and the surface of the heat sink.
[0010] The side of the heat dissipation base plate used for welding has at least two raised structures of the same height.
[0011] Compared with the prior art, this application has the following advantages:
[0012] The power module heat conduction structure provided in this application embodiment has raised structures of the same height. When solder is added, the raised structures can support the heat dissipation base plate and the ceramic substrate to maintain a relatively stable and uniform distance, ensuring uniform solder thickness and thus making the heat diffusion effect consistent in different parts.
[0013] Optionally, the protrusion structure is filamentous.
[0014] The advantage of choosing a filament shape as the shape of the protrusion structure is that the filament shape is simple and easy to manufacture, and two filament protrusion structures can support the space filled by solder.
[0015] Optionally, the material of the protrusion structure is metal wire.
[0016] The advantage of selecting metal wire as the protrusion structure is that metal wire is easy to manufacture, resistant to high temperatures, and prevents deformation during welding.
[0017] Optionally, the protrusion structure is a copper wire or an aluminum wire.
[0018] The advantage of selecting copper wire as the protrusion structure is that copper wire is easy to manufacture, resistant to high temperatures, and prevents deformation during welding.
[0019] The advantage of choosing aluminum wire as the protrusion structure is that aluminum wire is easy to manufacture, and aluminum has a higher melting point than tin, so it can maintain its original state during welding.
[0020] Optionally, the heat dissipation base plate is made of metal, and the protruding structure is welded to the heat dissipation base plate.
[0021] The advantage of choosing metal as the material for the heat dissipation base plate is that metal has good weldability, making it easy to weld to the ceramic substrate with solder, and it can also be used as the ground of the circuit.
[0022] Optionally, the heat dissipation base plate is made of metal, and the raised structure of the heat dissipation base plate is a raised structure made by a stamping process.
[0023] The advantage of choosing metal as the material for the heat dissipation base plate is that metal has good ductility, which facilitates the implementation of stamping processes. Stamping processes can easily achieve raised structures, and the resulting raised structures are uniform and dimensionally stable.
[0024] Optionally, the heat dissipation base plate has four protrusions, which are located at the four corners of the rectangle.
[0025] The advantage of this raised structure is that the distribution of the four corners is symmetrical and has good support. The ceramic substrate placed on top of the raised structure is not easy to tip over, and it is easy to fill the center with solder.
[0026] Optionally, the power module thermal structure includes a housing that covers the chip and a portion of the signal terminals are located inside the housing, the inside of which is encapsulated with epoxy resin.
[0027] The inner side of the outer shell is encapsulated with epoxy resin. Compared with the traditional method of using silicone, the advantages are that silicone is a soft material with low mechanical support and protective performance, and it is difficult to resist external impact. In contrast, epoxy resin encapsulation, after curing, is as hard as stone, with better mechanical support and protective performance, and it is easier to resist external impact. Moreover, it is difficult to remove and has a good confidentiality function.
[0028] Optionally, the height of the protrusion structure is in the range of 0.10-0.25mm.
[0029] The advantage of this height is that it allows for the formation of a solder layer with a height of 0.10-0.25mm, resulting in sufficient welding strength without taking up too much volume.
[0030] Secondly, embodiments of this application provide a power module, the power module including the power module heat-conducting structure described in the first aspect.
[0031] The optional implementation of the power module is consistent with the heat-conducting structure of the power module described in the first aspect, and the beneficial effects of each implementation are consistent with the heat-conducting structure of the power module described in the first aspect. Attached Figure Description
[0032] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0033] Figure 1 A schematic diagram of a power module provided in an embodiment of this application;
[0034] Figure 2 A schematic diagram of a power module without a heat sink base plate 3;
[0035] Figure 3 This is a schematic diagram of a heat dissipation base plate provided in an embodiment of this application;
[0036] Figure 4 A schematic diagram of a heat dissipation base plate with a strip-shaped protrusion structure 31 provided in an embodiment of this application;
[0037] Figure 5A schematic diagram showing that the number of protrusions 31 of a heat dissipation base plate 3 provided in this application embodiment is 4 and located at the four corners of a rectangle;
[0038] Figure 6 A schematic diagram showing the portion of a heat dissipation base plate 3 with holes on both sides, provided in an embodiment of this application;
[0039] Figure 7 This is a schematic diagram of a stepped heat dissipation base plate provided in an embodiment of this application.
[0040] Explanation of reference numerals in the attached figures:
[0041] 1 chip
[0042] 2 Ceramic substrate
[0043] 3 Heat dissipation base plate
[0044] 31. Protruding structure
[0045] 4 screws
[0046] 5. Outer shell
[0047] 6 signal terminals
[0048] 7 Radiator
[0049] 8 Thermal paste
[0050] 9 Cracks Detailed Implementation
[0051] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of this application, not all embodiments. The components of the embodiments of this application described in the accompanying drawings can generally be arranged and designed in various different configurations.
[0052] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0053] In the description of this application, it should be noted that:
[0054] Relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations;
[0055] "Connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.
[0056] like Figure 1 , Figure 1 In the power module shown, the bottom of the ceramic substrate 2 is in contact with the heat sink 3. Thermal paste is applied between the heat sink 3 and the heatsink 7 to ensure smooth heat transfer between them. The function of the heat sink 3 is to prevent the ceramic substrate 2 from directly contacting the thermal paste.
[0057] like Figure 2 If there is no heat dissipation base plate 3 and thermal paste 8 is directly placed between the ceramic substrate 2 and the heat sink 7, then if the thermal paste 8 is uneven, the ceramic substrate 2 may become uneven in height, and then the ceramic substrate 2 will be cracked as the outer shell 5 presses down, resulting in crack 9.
[0058] Therefore, a heat dissipation base plate 3 was added so that the ceramic substrate 2 does not need to directly contact the thermal paste, thus avoiding the cracking of the ceramic substrate 2 caused by uneven thermal paste 8.
[0059] In assembly such as Figure 1 When installing power modules, the ceramic substrate 2 and the heat sink 3 can be pre-installed and fixed to each other, which facilitates the installation of other components.
[0060] The ceramic substrate 2 and the heat dissipation base plate 3 can be fixed by welding.
[0061] However, the soldering method may have problems: if the solder between the ceramic substrate 2 and the heat sink 3 is not uniform, the distance between the ceramic substrate 2 and the heat sink 3 will be different, the solder thickness will be different, the thermal conductivity will be different, and the thermal conductivity will be uneven. In severe cases, it may lead to local heat accumulation, which is not conducive to the performance of the chip and also to the lifespan of the chip.
[0062] A heat dissipation base plate 3 such as Figure 3 , Figure 3 The heat dissipation base plate 3 shown has at least two protrusions 31. These protrusions 31 are not shown to scale; the actual protrusions 31 can be very small.
[0063] Install this heat sink 3 on Figure 1The power module shown includes a ceramic substrate 2, a heat sink 3, thermal paste, and a heat sink 7. The upper surface of the ceramic substrate 2 is equipped with a chip 1 and a signal terminal 6. The lower surface of the ceramic substrate 2 is welded or sintered onto the upper surface of the heat sink 3. The lower surface of the heat sink 3 is mounted on the surface of the heat sink 7. Thermal paste is disposed between the lower surface of the heat sink 3 and the surface of the heat sink 7. The side of the heat sink 3 used for welding is provided with at least two protrusions 31 of the same height.
[0064] If there are two protrusions 31, the two protrusions can be filamentous or strip-shaped and spaced a certain distance apart, so that they can support the ceramic substrate 2 in parallel. Figure 4 An embodiment of a circular cross-section filament as a protruding structure 31 is shown. Figure 3 The protruding structure 31 in the middle can be a strip-shaped protruding structure 31 with a square cross section.
[0065] Because of the raised structures of uniform height, when solder is added, the raised structures can support the heat dissipation base plate and the ceramic substrate to maintain a relatively stable and uniform distance, ensuring uniform solder thickness and thus consistent heat diffusion effect in different parts.
[0066] Regarding the material of the protruding structure, metal can be selected as the material of the protruding structure. The advantage of selecting metal as the material of the protruding structure is that metal has good weldability and is easy to weld.
[0067] When metal is used as the material of the protruding structure, copper can be selected as the material of the protruding structure. The advantages of selecting copper as the material of the protruding structure are that it is resistant to high temperature, prevents deformation during welding, and copper has good electrical conductivity. When the heat dissipation base plate 3 is used as the ground in the circuit, the protruding structure 31 can be used as a grounding connection method.
[0068] When metal is used as the material for the protrusion structure, aluminum can be selected as the material for the protrusion structure. The advantage of selecting aluminum as the material for the protrusion structure is that aluminum has a lower cost and a higher melting point than tin, and it can maintain its original state during welding.
[0069] Regarding the shape of the protrusion structure, the advantage of choosing a filament shape is that the filament shape is simple and easy to manufacture, and two filament protrusion structures can support the space filled by the solder.
[0070] When the protrusion structure 31 is filamentous, it can be a metal wire. The advantage of choosing a metal wire as the protrusion structure is that it is easy to manufacture, resistant to high temperatures, and prevents deformation during welding.
[0071] When the protruding structure 31 is made of metal wire, copper can be further used as the material for the protruding structure 31. The advantages of using copper wire as the protruding structure are that copper is resistant to high temperatures, preventing deformation during welding, and copper has good electrical conductivity. When the heat dissipation base plate 3 is used as the ground in the circuit, the protruding structure 31 can be used as a grounding connection.
[0072] When the protrusion structure 31 is made of metal wire, aluminum can be further used as the material for the protrusion structure 31. The advantage of using aluminum wire as the protrusion structure is that aluminum wire is easy to manufacture, and aluminum has a higher melting point than tin, so it can maintain its original state during welding.
[0073] When tin sheets are used as solder between the lower surface of the ceramic substrate and the upper surface of the heat dissipation base plate, copper wires can be embedded between the tin sheets. The copper wires serve as the raised structure, and the thickness of the copper wires is used to control the thickness of the solder.
[0074] Aluminum wire, copper wire, or aluminum strip can also be used as the protruding structure. The aluminum wire, copper wire, or aluminum strip can be ultrasonically welded onto the copper base plate, which can also be used to control the solder height.
[0075] Regarding the material of the heat dissipation base plate 3, the material of the heat dissipation base plate 3 can be metal. The advantage of choosing metal as the material of the heat dissipation base plate 3 is that metal has good welding performance, is easy to weld, and can be used as ground in the circuit.
[0076] If the heat dissipation base plate 3 is made of metal, the protruding structure 31 can be welded to the heat dissipation base plate 3 first, and then the ceramic substrate 2 can be welded.
[0077] Another advantage of choosing metal as the material for the heat dissipation base plate 3 is that metal has good ductility, which is beneficial for stamping processes. The raised structure 31 of the heat dissipation base plate 3 can be a raised structure 31 manufactured by a stamping process.
[0078] like Figure 5 ,and Figure 3 , Figure 4 The side views shown are different. Figure 5 A top view was shown. Figure 5 In the middle, the number of protruding structures 31 of the heat dissipation base plate 3 is 4, and they are located at the four corners of the rectangle.
[0079] Figure 5 In the figure, the protruding structure 31 is circular. The protruding structure 31 can be a circular protrusion or a circular boss. The top of the protruding structure 31 can be a regular symmetrical sphere or a flat platform. The protruding structure 31 can also be square.
[0080] Regarding the height of the protrusion 31, the height of the protrusion 31 can be in the range of 0.10-0.25mm. The advantage of this height is that it can form a solder layer with a height of 0.10-0.25mm, achieving sufficient welding strength without occupying too much volume.
[0081] like Figure 6 The heat dissipation base plate 3 can be provided with holes on both sides for screws to pass through. The screws are connected to the heat sink 7 through these holes, thereby better securing the heat dissipation base plate 3 to the heat sink 7. Figure 7 The holes on both sides of the heatsink base plate 3 can be arranged in a stepped shape: the left and right sides are higher, as shown in the enlarged image, which is a through hole for the screw to pass through; the middle is lower, and is the position where it fits against the chip and heatsink. This ensures that the bottom surface in the middle is in close contact with the heatsink: excess thermal paste can be squeezed out to both sides, thus preventing excessive thermal paste on the bottom surface from causing unevenness or gaps.
[0082] like Figure 1 The power module thermal structure may include a housing 5, which covers the chip 1 and a portion of the signal terminal 6 is located inside the housing 5.
[0083] In one embodiment, the inner side of the outer shell 5 is encapsulated with epoxy resin. Compared with the traditional method of using silicone, the advantages are that silicone is a soft material with low mechanical support and protective performance, and it is difficult to resist external impact. In contrast, epoxy resin encapsulation, after curing, is as hard as stone, with better mechanical support and protective performance, and it is easier to resist external impact. Moreover, it is difficult to remove and has a good confidentiality function.
[0084] Based on the above-described power module heat-conducting structure, this application embodiment also provides a power module, the power module including the above-described power module heat-conducting structure, such as... Figure 1 The power module includes a chip 1, a ceramic substrate 2, a heat sink 3, screws 4, a housing 5, signal terminals 6, and a heat sink 7.
[0085] In summary, this application proposes a power module heat-conducting structure and a power module. Due to the presence of raised structures of uniform height, the raised structures can maintain a relatively stable and uniform distance between the heat sink and the ceramic substrate when solder is added, ensuring uniform solder thickness and thus consistent heat diffusion across different areas.
[0086] The apparatus and system embodiments described above are merely illustrative. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement these embodiments without any creative effort.
[0087] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A power module heat conducting structure, characterized by, The ceramic substrate, the heat dissipation base plate, the heat conductive paste and the heat sink; The upper surface of the ceramic substrate is mounted with a chip and signal terminals, the lower surface of the ceramic substrate is welded or sintered with metal on the upper surface of the heat dissipation base plate, the lower surface of the heat dissipation base plate is mounted on the surface of the heat sink, and the heat conductive paste is arranged between the lower surface of the heat dissipation base plate and the surface of the heat sink. The side of the heat dissipation base plate for welding is provided with at least two protruding structures with the same height.
2. The power module thermally conductive structure of claim 1, wherein, The protruding structure is in a wire shape.
3. The power module thermally conductive structure of claim 2, wherein, The material of the protruding structure is metal wire.
4. The power module thermally conductive structure of claim 3, wherein, The protruding structure is copper wire or aluminum wire.
5. The power module thermally conductive structure of claim 3, wherein, The material of the heat dissipation base plate is metal, and the protruding structure is welded with the heat dissipation base plate.
6. The power module thermally conductive structure of claim 1, wherein, The material of the heat dissipation base plate is metal, and the protruding structure of the heat dissipation base plate is a protruding structure made by a stamping process.
7. The power module thermally conductive structure of claim 1, wherein, The number of the protruding structures of the heat dissipation base plate is four, and the protruding structures are located at four corners of a rectangle.
8. The power module thermally conductive structure of claim 1, wherein, The power module heat conductive structure includes a shell, the shell covers the chip, and a part of the signal terminals is located inside the shell, and the inside of the shell is filled with epoxy resin.
9. The power module thermally conductive structure of claim 1, wherein, The height of the protruding structure is in the range of 0.10-0.25 mm.
10. A power module, characterized by The power module includes the power module heat conductive structure according to any one of claims 1 to 9.