Power module heat dissipation structure, vehicle and packaging equipment

Abstract

The embodiment of the utility model discloses a power module heat dissipation structure, a vehicle and packaging equipment. The power module heat dissipation structure comprises a power module, a heat dissipation layer and a welding layer, the power module comprises a chip and a lining plate; the chip is positioned on the lining plate; one side, deviating from the chip, of the lining plate is welded on the heat dissipation layer through the welding layer; the power module further comprises a packaging layer. At least part of the side wall of the lining plate is exposed out of the packaging layer, and the welding layer extends to the side wall, exposed out of the packaging layer, of the lining plate. According to the power module heat dissipation structure provided by the scheme, the generation and growth speed of weld cracks of the welding layer are inhibited, the heat dissipation capability is improved, and the reliability of weld joints of a power module system is also improved.

Description

Technical Field

[0001] The present application relates to the technical field of electronic devices, and in particular to a power module heat dissipation structure, a vehicle and a packaging device. Background Art

[0002] The power module is a key component in the electric drive system of electric vehicles. It is responsible for the high-power electric energy conversion in electric vehicles. The power module has a decisive influence on the performance, efficiency, cost, safety and reliability of the electric drive system and even the entire vehicle. The power module generates a lot of heat during operation, which causes damage to the internal components, so it needs to be cooled. In the early days, heat was mainly dissipated by setting thermal conductive silicone grease between the power module and the radiator. However, with the increase in the density of power modules, this traditional method no longer meets the heat dissipation needs.

[0003] At present, system brazing and system sintering are commonly used to weld the direct copper-clad ceramic substrate or active metal-welded ceramic substrate of the power module to the heat sink, which can achieve greater heat dissipation efficiency.

[0004] However, due to the use of system brazing and system sintering, there will be a weld at the welding position of the power module and the heat sink. There are differences in the thermal expansion coefficients of the materials on both sides of the weld. The thermal stress at the boundary and four corners of the weld is large, making it easy for cracks to initiate from the edge of the weld and expand into the weld. Therefore, the effective heat transfer area between the power module and the heat sink is reduced, and the heat dissipation capacity is reduced. Utility Model Content

[0005] In order to solve the above technical problems or at least partially solve the above technical problems, the present application provides a power module heat dissipation structure, a vehicle and a packaging device.

[0006] In a first aspect, the present application provides a power module heat dissipation structure, the method comprising:

[0007] Power module, heat dissipation layer and welding layer;

[0008] The power module comprises a chip and a liner; the chip is located on the liner;

[0009] The side of the liner facing away from the chip is welded to the heat dissipation layer through the welding layer;

[0010] The power module further includes a packaging layer; the packaging layer exposes at least a portion of a side wall of the liner, and the welding layer extends to the side wall of the liner exposed by the packaging layer.

[0011] Optionally, the power module includes a first liner and a second liner; the chip is located between the first liner and the second liner; the heat dissipation layer includes a first heat dissipation layer and a second heat dissipation layer; the welding layer includes a first welding layer and a second welding layer;

[0012] The side of the first backing plate facing away from the chip is welded to the first heat dissipation layer through the first welding layer; the side of the second backing plate facing away from the chip is welded to the second heat dissipation layer through the second welding layer;

[0013] The packaging layer exposes at least part of the side wall of the first liner and at least part of the side wall of the second liner, the first welding layer covers the side wall of the first liner exposed by the packaging layer; the second welding layer covers the side wall of the second liner exposed by the packaging layer.

[0014] Optionally, the backing plate of the power module comprises a first metal layer, an insulating layer and a second metal layer which are stacked; the second metal layer is welded on the heat dissipation layer through the welding layer; the chip is located on the first metal layer;

[0015] The packaging layer exposes at least a portion of a side wall of the second metal layer, and the welding layer extends to the side wall of the second metal layer exposed by the packaging layer.

[0016] Optionally, projections of an edge of the first metal layer and an edge of the second metal layer on the insulating layer are located within an edge of the insulating layer.

[0017] Optionally, the encapsulation layer covers an edge of the insulating layer.

[0018] Optionally, a gasket is provided between the chip and the first liner.

[0019] Optionally, the liner includes a direct copper-clad ceramic substrate or an active metal-welded ceramic substrate.

[0020] In a second aspect, the present application provides a vehicle, comprising any one of the power module heat dissipation structures described in the first aspect.

[0021] In a third aspect, the present application provides a packaging device for a power module heat dissipation structure, including:

[0022] The encapsulation layer removal device is used to remove the encapsulation layer of at least part of the side wall of the liner of the power module,

[0023] The welding device is used to weld the side of the liner away from the chip of the power module to the heat dissipation layer through the welding layer, so that the welding layer extends to the side wall of the liner exposed by the packaging layer.

[0024] Optionally, the encapsulation layer removal device comprises a laser.

[0025] In a fourth aspect, the present application provides a packaging method for a power module heat dissipation structure, wherein the vehicle includes any one of the power module heat dissipation structures as described in the first aspect, and is characterized by comprising:

[0026] removing the encapsulation layer from at least part of the side wall of the backing plate of the power module,

[0027] The side of the liner facing away from the chip of the power module is welded to the heat dissipation layer through a welding layer, so that the welding layer extends to the side wall of the liner exposed by the packaging layer.

[0028] Optionally, the power module includes a first liner and a second liner; the chip is located between the first liner and the second liner; the heat dissipation layer includes a first heat dissipation layer and a second heat dissipation layer; the welding layer includes a first welding layer and a second welding layer;

[0029] The removing the encapsulation layer of at least a portion of the side wall of the liner of the power module comprises: removing the encapsulation layer of at least a portion of the side wall of the first liner and the encapsulation layer of at least a portion of the side wall of the second liner;

[0030] The step of welding the side of the liner facing away from the chip of the power module to the heat dissipation layer through a welding layer so that the welding layer extends to the side wall of the liner exposed by the packaging layer comprises: welding the side of the first liner facing away from the chip to the first heat dissipation layer through a first welding layer so that the first welding layer extends to the side wall of the first liner exposed by the packaging layer; welding the side of the second liner facing away from the chip to the second heat dissipation layer through a second welding layer so that the second welding layer extends to the side wall of the second liner exposed by the packaging layer.

[0031] Optionally, the removing the encapsulation layer of at least a portion of the side wall of the liner of the power module by using a laser etching process comprises:

[0032] The laser emission direction is controlled to be parallel to the normal line of the side wall to be etched of the liner, and the packaging layer of at least a part of the side wall of the liner of the power module is removed by a laser etching process.

[0033] Compared with the prior art, the technical solution provided by the embodiments of the present application has the following advantages:

[0034] The present solution provides a power module heat dissipation structure, which removes part of the encapsulation layer so that the encapsulation layer exposes at least part of the side wall of the liner, so that the welding layer can be extended to the side wall of the liner exposed by the encapsulation layer. Since the welding layer extends to the side wall of the liner exposed by the encapsulation layer, compared with the prior art in which the welding layer is only located at the weld between the power module and the heat sink, the present application can avoid cracks in the weld at the four corners of the liner in the prior art, and inhibit the occurrence and growth rate of weld cracks. Therefore, the effective heat transfer area between the power module and the heat sink can be maintained, the heat dissipation capacity can be improved, and the reliability of the power module can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0036] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0037] Figure 1 A schematic diagram of a power module heat dissipation structure provided by the prior art;

[0038] Figure 2 A schematic diagram of another power module heat dissipation structure provided in an embodiment of the present application;

[0039] Figure 3 A schematic diagram of another power module heat dissipation structure provided in an embodiment of the present application;

[0040] Figure 4 A schematic diagram of another power module heat dissipation structure provided in an embodiment of the present application;

[0041] Figure 5 A schematic diagram of another power module heat dissipation structure provided in an embodiment of the present application;

[0042] Figure 6 A flow chart of a packaging method for a power module heat dissipation structure provided in an embodiment of the present application;

[0043] Figure 7 A schematic diagram of a laser etching process for a power module packaging method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the scheme of the present application will be further described below. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0045] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only part of the embodiments of the present application, rather than all of the embodiments.

[0046] Before introducing a power module heat dissipation structure proposed in this solution, the problems existing in the current power module and the solutions of the prior art are first introduced so that it is easier to understand this solution later.

[0047] The power module is a key component in the electric drive system of electric vehicles. It is responsible for the high-power electric energy conversion in electric vehicles. The power module has a decisive influence on the performance, efficiency, cost, safety and reliability of the electric drive system and even the entire vehicle. The power module generates a lot of heat during operation, which causes damage to the internal components, so it needs to be cooled. In the early days, heat was mainly dissipated by setting thermal conductive silicone grease between the power module and the radiator. However, with the increase in the density of power modules, this traditional method no longer meets the heat dissipation needs.

[0048] At present, system brazing and system sintering are commonly used to weld the direct copper-clad ceramic substrate or active metal-welded ceramic substrate of the power module to the heat sink, which can achieve greater heat dissipation efficiency.

[0049] Among them, the ceramic substrate components of direct copper-clad ceramic substrates mainly include alumina, aluminum nitride, or doped zirconium oxide, which can be used as packaging substrates for power modules. As an upgraded product of direct copper-clad ceramic substrates, active metal welded ceramic substrates have more advantages in thermal conductivity and reliability. Currently, the packaging substrates of power modules mainly use active metal welded ceramic substrates.

[0050] For example, Figure 1 The schematic diagram of a power module heat dissipation structure provided by the prior art. Figure 1 As shown, a power module heat dissipation structure provided by the prior art includes a packaging layer 101 , a chip 102 , a liner 103 , a welding layer 104 and a heat dissipation layer 105 .

[0051] In order to allow the power module to dissipate heat more effectively, the backing plate 103 of the power module is connected to the heat dissipation layer 105 through the welding layer 104, and the heat dissipation plate has a water cooling system inside to dissipate heat.

[0052] However, the power module heat dissipation structure of the prior art has problems with the reliability of the weld because of the difference in the thermal expansion coefficient system on both sides of the weld formed by the welding layer 104 .

[0053] The power module is made of a variety of materials. The thermal expansion coefficient at the interface where the power module is connected to the welding layer 104 is about 6 to 8. The weld formed by the welding layer 104 is usually a tin-based metal alloy, and the thermal expansion coefficient of the welding layer 104 is about 20. The material of the heat dissipation layer 105 is usually copper or aluminum, and the thermal expansion coefficient of the heat dissipation layer 105 is about 18 to 23. Due to the different thermal expansion coefficients of objects, the thermal stress they are subjected to when the temperature changes will also be different. Therefore, the interface where the power module is connected to the welding layer 104 is the area with the highest thermal stress. When the heat dissipation structure of the power module is subjected to a temperature cycle test, the weld formed by the welding layer 104 will be subjected to cyclically changing thermal stress due to the influence of temperature. The thermal stress borne by the interface between the power module and the welding layer 104 is the greatest. Because the weld formed by the welding layer 104 is usually a tin-based metal alloy, the material strength at the welding layer 104 is the lowest. As the temperature rises, the strength of the welding layer 104 will decrease by half or more. Therefore, cracks are likely to initiate at the edge of the welding layer 104 and expand into the interior of the welding layer 104, resulting in a reduction in the effective heat transfer area between the power module and the heat dissipation layer 105 and a decrease in the heat dissipation capacity.

[0054] In order to solve the problem in the prior art that the welding layer of the power module is prone to cracks, resulting in the inability of the power module heat dissipation structure to effectively dissipate heat, this solution provides a power module heat dissipation structure, packaging method and vehicle that can effectively solve the problem in the prior art. The following article first introduces the power module heat dissipation structure provided by this solution.

[0055] For example, Figure 2 A schematic diagram of a power module heat dissipation structure provided in an embodiment of the present application. Figure 2 As shown, the power module heat dissipation structure provided in the embodiment of the present application includes a power module 20 , a heat dissipation layer 201 and a welding layer 202 .

[0056] The positional relationship between the various parts in the heat dissipation structure of the power module 20 is as follows:

[0057] The power module 20 includes a chip 203 and a backing plate 204 . The chip 203 is located on the backing plate 204 . The side of the backing plate 204 facing away from the chip 203 is welded to the heat dissipation layer 201 through the welding layer 202 .

[0058] Optionally, the liner 204 includes a direct copper-clad ceramic substrate or an active metal-welded ceramic substrate. Specifically, the active metal-welded ceramic substrate is a ceramic substrate in which a small amount of active elements are added to the brazing electronic paste, which is printed on the ceramic substrate using silk screen technology, covered with oxygen-free copper and placed in a vacuum brazing furnace for sintering, and then a pattern is etched to make a circuit, and finally the surface pattern is chemically plated. The direct copper-clad ceramic substrate has excellent thermal cycling, shape stability, good rigidity, high thermal conductivity, high reliability, and the copper-clad surface can be etched with various patterns. It should be noted that the selection of the liner 204 is not limited to the above two substrates, and can also be other substrates with good thermal conductivity, which is not specifically limited here. After providing the liner 204, the chip 203 is attached to the liner 204 and connected to the pin. The connection method includes but is not limited to welding, gold wire bonding or ball pressure bonding. In this embodiment, the chip 203 can be a SiC chip, an IGBT chip, etc.

[0059] Optionally, the heat dissipation layer 201 may use a radiator based on a water cooling system. Specifically, the water in the radiator lowers its temperature after passing through the cooling device, and the water flows along the corresponding channels to take away the heat, so that the power module is kept at a relatively low temperature to ensure its normal operation. It should be noted that the choice of the heat dissipation layer 201 is not limited to the above-mentioned radiator based on a water cooling system, and can also be other radiators with better heat dissipation performance, which is not specifically limited here.

[0060] Optionally, the welding layer 202 can be formed by system brazing. Specifically, system brazing uses a brazing material with a much lower melting point than the base material, and heats the weldment and the brazing material to a temperature slightly higher than the melting point of the brazing material but lower than the melting temperature of the base material, so that the liquid brazing material can wet the surface of the base material and finally solidify to form a tightly connected joint. It should be noted that the formation method of the welding layer 202 is not limited to the above-mentioned system brazing, and other welding methods can also be used, which are not specifically limited here.

[0061] The power module further includes a packaging layer 205. In order to protect the chip from damage by environmental factors, such as moisture or dust, the packaging layer 205 is usually used for packaging. After the power module is packaged, the side of the liner 204 facing away from the chip 203 is welded to the heat dissipation layer 201 through the welding layer 202. The welding layer 202, for example, welds the side of the liner 204 facing away from the chip 203 to the heat dissipation layer 201 through a brazing process.

[0062] In order to eliminate the stress concentration phenomenon at the edge of the welding layer, before the side of the liner 204 facing away from the chip 203 is welded to the heat dissipation layer 201 through the welding layer 202, the packaging layer 205 is arranged to expose at least part of the side wall of the liner 204, so that the welding layer 202 extends to the side wall of the liner 202 exposed by the packaging layer 205. Figure 2In the embodiment of the present application, part of the encapsulation layer 205 is removed to expose at least part of the side wall of the liner 204, for example Figure 2 The position is shown in the dotted box. Since at least part of the side wall of the liner 204 is exposed, during the process of soldering the side of the liner 204 away from the chip 203 to the heat dissipation layer 201, the soldering layer 202 can extend to the side wall of the liner 204 exposed by the packaging layer 205, that is, the soldering layer 202 can climb longitudinally on the exposed side wall of the liner 204, eliminating the stress concentration problem of the soldering layer at the four sides of the bottom surface of the liner in the prior art, thereby reducing the risk of cracking of the soldering layer and inhibiting the occurrence and growth rate of cracks in the soldering layer. Therefore, the effective heat transfer area between the power module and the heat dissipation layer can be maintained, the heat dissipation capacity can be improved, and the reliability of the power module system weld is also improved.

[0063] In some embodiments, the composition of the welding layer mainly includes a tin-based metal alloy, and the bottom lining plate and the heat dissipation layer of the power module are directly combined together through the metallurgical bonding principle of the metal by means of system brazing and system sintering. The heat dissipation layer can use a radiator with a water-cooled heat dissipation system. Therefore, by using the power module heat dissipation structure provided in the embodiment of the present application, it is not easy to generate cracks from the outside to the inside at the weld at the welding position between the power module and the radiator, and the occurrence and growth rate of weld cracks are suppressed. Therefore, the effective heat transfer area between the power module and the radiator can be maintained, the heat dissipation capacity can be improved, and the reliability of the power module system weld is also improved.

[0064] For example, Figure 3 This is a schematic diagram of another power module heat dissipation structure provided in an embodiment of the present application. Figure 3 As shown, the power module of the power module heat dissipation structure provided in the embodiment of the present application includes a first lining plate 301 and a second lining plate 302; the chip 303 is located between the first lining plate 301 and the second lining plate 302; the heat dissipation layer includes a first heat dissipation layer 304 and a second heat dissipation layer 305; the welding layer includes a first welding layer 306 and a second welding layer 307.

[0065] The side of the first liner 301 facing away from the chip 303 is welded to the first heat dissipation layer 304 through the first welding layer 306 ; the side of the second liner 302 facing away from the chip 303 is welded to the second heat dissipation layer 305 through the second welding layer 307 .

[0066] The packaging layer 308 exposes at least part of the sidewalls of the first liner 301 and at least part of the sidewalls of the second liner 302 . The first welding layer 306 covers the sidewalls of the first liner 301 exposed by the packaging layer 308 . The second welding layer 307 covers the sidewalls of the second liner 302 exposed by the packaging layer 308 .

[0067] After providing the first backing plate 301 and the second backing plate 302, the chip 303 is attached between the first backing plate 301 and the second backing plate 302, and connected to the pins. In order to achieve greater heat dissipation efficiency, the embodiment of the present application welds the power module to the two heat sinks on both sides, and in order to eliminate the stress concentration phenomenon at the edges of the first heat dissipation layer 304 and the second heat dissipation layer 305, before welding the side of the first backing plate 301 away from the chip 303 to the first heat dissipation layer 304 through the first welding layer 306, the embodiment of the present application sets the packaging layer 308 to expose at least part of the side wall of the first backing plate 301, so that the first welding layer 306 extends to the side wall of the first backing plate 301 exposed by the packaging layer 308. See Figure 3 In the embodiment of the present application, part of the encapsulation layer 308 is removed to expose at least part of the side wall of the first liner 301, for example Figure 3 Before the second substrate 302 is welded to the second heat dissipation layer 305 on the side facing away from the chip 303 by the second welding layer 307, the packaging layer 308 is provided to expose at least part of the side wall of the second substrate 302, so that the second welding layer 307 extends to the side wall of the second substrate 302 exposed by the packaging layer 308. Figure 3 In the embodiment of the present application, part of the encapsulation layer 308 is removed to expose at least part of the side wall of the second liner 302, for example Figure 3 The position is shown in the dotted box 310.

[0068] Since at least part of the side walls of the first liner 301 and the second liner 302 are exposed, when the side of the first liner 301 facing away from the chip 303 is welded and connected to the first heat dissipation layer 304 by the brazing process, the first welding layer 306 can extend to the side wall of the first liner 301 exposed by the encapsulation layer 308, that is, the first welding layer 306 can climb vertically on the exposed side wall of the first liner 301. Similarly, when the side of the second liner 302 facing away from the chip 303 is welded and connected to the second heat dissipation layer 305 by the brazing process, the second welding layer 307 can extend to the side wall of the second liner 302 exposed by the encapsulation layer 308, that is, the second welding layer 307 can climb vertically on the exposed side wall of the second liner 302, eliminating the stress concentration problem of the welding layer at the four sides of the bottom surface of the liner in the prior art, thereby reducing the risk of cracking of the welding layer, inhibiting the occurrence and growth rate of cracks in the welding layer, and adopting the double-sided welding of the power module and the two heat sinks to achieve greater heat dissipation efficiency. Therefore, the effective heat transfer area between the power module and the heat dissipation layer can be maintained, the heat dissipation capacity can be improved, and the reliability of the power module system weld is also improved.

[0069] The power module heat dissipation structure provided in the embodiment of the present application achieves greater heat dissipation efficiency by respectively arranging heat dissipation layers on the upper and lower surfaces of the power module and connecting the heat dissipation layers to the power module through welding layers. Since both welding layers can climb on the side walls of the exposed liner, the effective heat transfer area between the power module and the heat dissipation layer can be maintained, thereby improving the reliability of the weld of the power module system.

[0070] In some embodiments, a gasket may be disposed between the chip and the first backing plate.

[0071] Figure 4 This is a schematic diagram of another power module heat dissipation structure provided in an embodiment of the present application. Figure 4 As shown, the power module of the power module heat dissipation structure provided in the embodiment of the present application includes a first liner 401 and a second liner 402; the chip 403 is located between the first liner 401 and the second liner 402, and a gasket 404 is provided between the chip 403 and the first liner 401, and the chip 403 is connected to the gasket 404; the heat dissipation layer includes a first heat dissipation layer 405 and a second heat dissipation layer 406; the welding layer includes a first welding layer 407 and a second welding layer 408.

[0072] The side of the first liner 401 facing away from the chip 403 is welded to the first heat dissipation layer 405 through the first welding layer 407 ; the side of the second liner 402 facing away from the chip 403 is welded to the second heat dissipation layer 406 through the second welding layer 408 .

[0073] The packaging layer 409 exposes at least part of the sidewalls of the first liner 401 and at least part of the sidewalls of the second liner 402 . The first welding layer 407 covers the sidewalls of the first liner 401 exposed by the packaging layer 409 . The second welding layer 408 covers the sidewalls of the second liner 402 exposed by the packaging layer 409 .

[0074] When the power module is double-sidedly welded to two heat sinks to achieve greater heat dissipation efficiency, and in order to eliminate stress concentration at the edges of the first heat dissipation layer 405 and the second heat dissipation layer 406, before the first liner 401 is welded to the first heat dissipation layer 405 on the side facing away from the chip 403 through the first welding layer 407, the embodiment of the present application sets a packaging layer 409 to expose at least part of the side wall of the first liner 401, so that the first welding layer 407 extends to the side wall of the first liner 401 exposed by the packaging layer 409. Figure 4 In the embodiment of the present application, part of the encapsulation layer 409 is removed to expose at least part of the side wall of the first liner 401, for example Figure 4 The position is shown in the dotted box 410.

[0075] Before the second soldering layer 408 is used to solder the side of the second substrate 402 facing away from the chip 403 to the second heat dissipation layer 406, a packaging layer 409 is provided to expose at least part of the side wall of the second substrate 402, so that the second soldering layer 408 extends to the side wall of the second substrate 402 exposed by the packaging layer 409. Figure 4 In the embodiment of the present application, part of the encapsulation layer 409 is removed to expose at least part of the side wall of the second liner 402, for example Figure 4 The position is shown in the dotted box 411.

[0076] Since at least part of the side walls of the first liner 401 and the second liner 402 are exposed, during the process of welding and connecting the first liner 401 and the second liner 402 on the side away from the chip 403 with the first heat dissipation layer 405 and the second heat dissipation layer 406 through the brazing process, the first welding layer 407 and the second welding layer 408 can extend to the side walls of the first liner 401 and the second liner 402 exposed by the packaging layer 409, that is, the first welding layer 407 and the second welding layer 408 can climb longitudinally on the exposed side walls of the first liner 401 and the second liner 402, thereby eliminating the stress concentration problem of the welding layer at the four sides of the bottom surface of the liner in the prior art, thereby reducing the risk of cracking of the welding layer, inhibiting the occurrence and growth rate of cracks in the welding layer, and adopting the double-sided welding of the power module and the two heat sinks to achieve greater heat dissipation efficiency. Therefore, the effective heat transfer area between the power module and the heat dissipation layer can be maintained, the heat dissipation capacity can be improved, and the reliability of the weld of the power module system is also improved.

[0077] Since the first liner 401 and the second liner 402 have a very high potential difference, and the chip 403 is relatively thin, it is easy to cause a short circuit between the first liner 401 and the second liner 402. Therefore, in the power module heat dissipation structure provided in the embodiment of the application, a gasket 404 is arranged between the chip 403 and the first liner 401 to increase the distance between the first liner 401 and the second liner 402, so as to ensure electrical insulation between the first liner 401 and the second liner, so that the chip 403 can maintain normal operation.

[0078] In some embodiments, the backing plate of the power module includes a first metal layer, an insulating layer, and a second metal layer which are stacked; the second metal layer is welded to the heat dissipation layer through a welding layer; the chip is located on the first metal layer; the packaging layer exposes at least part of the side wall of the second metal layer, and the welding layer extends to the side wall of the second metal layer exposed by the packaging layer.

[0079] See for example Figure 2The backing plate 204 includes a first metal layer 2041, an insulating layer 2042, and a second metal layer 2043 which are stacked. The chip 203 is disposed on the first metal layer 2041, and after being packaged by the packaging layer 205, the packaging layer 205 at at least a portion of the sidewall of the second metal layer 2043 is removed to expose at least a portion of the sidewall of the second metal layer 2043, and then the second metal layer 2043 is welded to the heat dissipation layer 201 through the welding layer 202. Since the solder can wet the sidewall of the second metal layer 2043, the welding layer 202 can extend to the sidewall of the second metal layer 2043 exposed by the packaging layer 205 during the formation of the welding layer 202.

[0080] It should be noted that Figure 2 The encapsulation layer is exemplarily configured to expose part of the side wall of the second metal layer. In other embodiments, the size of the side wall of the second metal layer exposed by the encapsulation layer can be set according to actual conditions. For example, the encapsulation layer can be configured to expose the entire side wall of the second metal layer.

[0081] For a power module that needs heat dissipation on both sides, the first backing plate and the second backing plate may also include a first metal layer, an insulating layer, and a second metal layer that are stacked. Figure 5 , the first liner 501 and the second liner 502 of the power module both include a first metal layer, an insulating layer, and a second metal layer that are stacked. For the convenience of description, the first metal layer, the insulating layer, and the second metal layer in the first liner 501 are marked as a first film layer 5011, a second film layer 5012, and a third film layer 5013, respectively. The first metal layer, the insulating layer, and the second metal layer in the second liner 502 are marked as a fourth film layer 5023, a fifth film layer 5022, and a sixth film layer 5021, respectively. The third film layer 5013 is welded on the first heat dissipation layer 505 through the first welding layer 504. The sixth film layer 5021 is welded on the second heat dissipation layer 512 through the second welding layer 511. The gasket 506 is located between the chip 513 and the first liner 501, and the chip 513 is arranged on the first metal layer 5023. The encapsulation layer 507 exposes at least part of the sidewalls of the third film layer 5013 of the first liner 501 and the sixth film layer 5021 of the second liner 502. The first welding layer 504 extends to the sidewalls of the third film layer 5013 exposed by the encapsulation layer 507. The second welding layer 511 extends to the sidewalls of the sixth film layer 5021 exposed by the encapsulation layer 507.

[0082] In some embodiments, projections of an edge of the first metal layer and an edge of the second metal layer on the insulating layer are located inside an edge of the insulating layer.

[0083] Since there is a relatively large voltage difference between the first metal layer and the second metal layer when the power module is working, in order to prevent the current from flowing from one metal layer through the insulating layer to the other metal layer, thereby causing the creepage effect on the liner of the power module, this embodiment arranges the projection of the edge of the first metal layer and the edge of the second metal layer on the insulating layer within the edge of the insulating layer, that is, the edge of the insulating layer exceeds the edge of the first metal layer and the edge of the second metal layer, so that the creepage path is increased, thereby effectively suppressing the creepage effect.

[0084] In some embodiments, the encapsulation layer covers edges of the insulating layer.

[0085] Since there is a relatively large voltage difference between the first metal layer and the second metal layer when the power module is working, when removing the packaging layer, only the packaging layer on the side wall of the second metal layer is removed so that the packaging layer covers the edge of the insulating layer, so that the subsequent solder can climb to the insulating layer, causing the liner of the power module to produce a creepage effect.

[0086] The embodiment of the present application also provides a vehicle, in which the power module heat dissipation structure in the vehicle can adopt any one of the power module heat dissipation structures described above. Therefore, the vehicle has the technical features of the power module heat dissipation structure provided by the embodiment of the present application, and can achieve the beneficial effects of the power module heat dissipation structure provided by the embodiment of the present application. The similarities can be referred to the above description of the power module heat dissipation structure provided by the embodiment of the present application, and will not be repeated here.

[0087] The present application also provides a packaging device for a power module heat dissipation structure, including:

[0088] The encapsulation layer removal device is used to remove the encapsulation layer of at least part of the side wall of the liner of the power module,

[0089] The welding device is used to weld the side of the liner away from the chip of the power module to the heat dissipation layer through the welding layer, so that the welding layer extends to the side wall of the liner exposed by the packaging layer.

[0090] The packaging device of the power module heat dissipation structure provided in the embodiment of the present application can be packaged to form the power module heat dissipation structure described in any of the above embodiments.

[0091] In some embodiments, the encapsulation layer removal device includes a laser.

[0092] When removing the packaging layer at the corresponding position of the power module, if the mechanical method in the prior art is used, it is easy to cause the insulation layer to crack, and if the corrosion process in the prior art is used, it is easy to cause the metal layer to be corroded, thereby reducing the insulation of the module. The embodiment of the present application uses a laser to remove the packaging layer of at least part of the side wall of the liner of the power module, which can ensure the integrity of the insulation layer and ensure that the metal layer is not corroded, thereby ensuring good insulation.

[0093] The present application also provides a packaging method for a power module heat dissipation structure, which is applicable to the power module heat dissipation structure described in any of the above embodiments. Figure 6 A flow chart of a packaging method for a power module heat dissipation structure provided in an embodiment of the present application. Figure 6 As shown, a packaging method of a power module heat dissipation structure provided in an embodiment of the present application includes S601-S602:

[0094] S601: removing the encapsulation layer of at least a portion of the side wall of the liner of the power module.

[0095] S602: Welding the side of the liner away from the chip of the power module to the heat dissipation layer through a welding layer, so that the welding layer extends to the side wall of the liner exposed by the packaging layer.

[0096] The packaging method of the power module heat dissipation structure provided in this solution can expose part of the side wall of the power module liner, and then extend the welding layer to the side wall of the liner exposed by the packaging layer. This structure can eliminate the problem of excessive thermal stress around the welding layer, thereby reducing the risk of cracking of the welding layer and inhibiting the occurrence and growth rate of cracks in the welding layer. Therefore, the effective heat transfer area between the power module and the heat dissipation layer can be maintained, and the heat dissipation capacity can be improved.

[0097] In some embodiments, the backing plate of the power module heat dissipation structure includes a first metal layer, an insulating layer, and a second metal layer which are stacked; the second metal layer is welded on the heat dissipation layer through a welding layer; and the chip is located on the first metal layer.

[0098] Accordingly, removing the encapsulation layer from at least a portion of the sidewall of the liner of the power module includes: removing the encapsulation layer from at least a portion of the sidewall of the second metal layer.

[0099] The side of the liner facing away from the chip of the power module is welded to the heat dissipation layer through a welding layer so that the welding layer extends to the side wall of the liner exposed by the packaging layer, which includes: welding the second metal layer to the heat dissipation layer through a welding layer so that the welding layer extends to the side wall of the second metal layer.

[0100] In some embodiments, the power module includes a first liner and a second liner; the chip is located between the first liner and the second liner; the heat dissipation layer includes a first heat dissipation layer and a second heat dissipation layer; and the welding layer includes a first welding layer and a second welding layer.

[0101] Accordingly, removing the encapsulation layer from at least part of the side wall of the liner of the power module includes: removing the encapsulation layer from at least part of the side wall of the first liner and the encapsulation layer from at least part of the side wall of the second liner.

[0102] The side of the liner facing away from the chip of the power module is welded to the heat dissipation layer through a welding layer so that the welding layer extends to the side wall of the liner exposed by the packaging layer, including: welding the side of the first liner facing away from the chip to the first heat dissipation layer through a first welding layer so that the first welding layer extends to the side wall of the first liner exposed by the packaging layer; welding the side of the second liner facing away from the chip to the second heat dissipation layer through a second welding layer so that the second welding layer extends to the side wall of the second liner exposed by the packaging layer.

[0103] In some embodiments, removing the encapsulation layer from at least a portion of the sidewall of the liner of the power module includes: removing the encapsulation layer from at least a portion of the sidewall of the liner of the power module using a laser etching process.

[0104] When removing the packaging layer at the corresponding position of the power module, if the mechanical method in the prior art is used, it is easy to cause the insulation layer to crack, and if the corrosion process in the prior art is used, it is easy to cause the metal layer to be corroded, thereby reducing the insulation of the module. The embodiment of the present application uses a laser etching process to remove the packaging layer of at least part of the side wall of the liner of the power module, which can ensure the integrity of the insulation layer and ensure that the metal layer is not corroded, so as to ensure good insulation.

[0105] In some embodiments, a laser etching process is used to remove the packaging layer of at least a portion of the side wall of the liner of the power module, including: controlling the laser emission direction to be parallel to the normal line of the side wall to be etched of the liner, and using the laser etching process to remove the packaging layer of at least a portion of the side wall of the liner of the power module.

[0106] For example, Figure 7 A schematic diagram of a laser etching process for a power module packaging method provided in an embodiment of the present application. Figure 7 As shown, the schematic diagram of the laser etching process of a packaging method for a power module heat dissipation structure provided in an embodiment of the present application includes a laser 701 , a liner 702 , a chip 703 and a packaging layer 704 .

[0107] The chip 703 is located on the backing plate 702 , and is packaged with a packaging layer 704 to protect the chip from damage by environmental factors.

[0108] Specifically, due to process reasons, the side wall of the liner 702 is arc-shaped. When using a laser etching process to remove the packaging layer of at least part of the side wall of the liner of the power module, the power module is tilted and fixed at a certain angle so that the laser emission direction of the laser is parallel to the normal of the side wall to be etched of the liner. Figure 7 The dotted line 705 in the figure represents the normal line of the side wall to be etched. For example, the laser can be controlled to swing through the galvanometer so that the laser emission direction is always kept in a position parallel to the normal line of the side wall to be etched of the liner, and the irradiated packaging layer is slowly removed by the laser until at least part of the side wall of the liner is exposed. By adopting the above-mentioned laser etching process method, the laser emission direction of the laser is always controlled to be parallel to the normal line of the side wall to be etched of the liner, so that the laser can be focused on the side wall surface, and the packaging glue on the side wall can be removed cleanly, avoiding the problem that the packaging layer of the side wall of the liner cannot be removed cleanly due to the failure of the laser to focus.

[0109] For a rectangular liner including four sides, the power module can be rotated 90 degrees, 180 degrees and 270 degrees in sequence, and the above-mentioned laser etching process can be used to remove the packaging layer of at least part of the side walls of the four sides of the liner of the power module.

[0110] In some embodiments, see, for example, Figure 7 , the liner 702 includes a first metal layer 7021, an insulating layer 7022 and a second metal layer 7023 which are stacked. Among them, the chip 703 is arranged on the first metal layer 7021 and is encapsulated by using an encapsulation layer 704. Due to process reasons, the side walls of the first metal layer 7021 and the second metal layer 7023 are arc-shaped. When using a laser etching process to remove the encapsulation layer of at least part of the side wall of the second metal layer 7023, the power module can be tilted and fixed at a certain angle, and the laser emission direction of the laser is parallel to the normal line of the side wall to be etched of the second metal layer of the liner, and the laser is controlled to swing through the galvanometer so that the laser is always kept in a position parallel to the normal line of the side wall to be etched of the second metal layer of the liner, and the irradiated encapsulation layer is slowly removed by the laser emission direction until the side wall of the second metal layer of the liner is exposed.

[0111] It should be noted that, in this article, relational terms such as "first" and "second" are only used 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. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0112] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power module heat dissipation structure, characterized in that: include: Power module, heat dissipation layer and welding layer; The power module comprises a chip and a liner; the chip is located on the liner; The side of the liner facing away from the chip is welded to the heat dissipation layer through the welding layer; The power module further includes a packaging layer; the packaging layer exposes at least a portion of a side wall of the liner, and the welding layer extends to the side wall of the liner exposed by the packaging layer.

2. The power module heat dissipation structure according to claim 1, characterized in that: The power module comprises a first liner and a second liner; the chip is located between the first liner and the second liner; the heat dissipation layer comprises a first heat dissipation layer and a second heat dissipation layer; the welding layer comprises a first welding layer and a second welding layer; The side of the first backing plate facing away from the chip is welded to the first heat dissipation layer through the first welding layer; the side of the second backing plate facing away from the chip is welded to the second heat dissipation layer through the second welding layer; The packaging layer exposes at least part of the side wall of the first liner and at least part of the side wall of the second liner, the first welding layer covers the side wall of the first liner exposed by the packaging layer; the second welding layer covers the side wall of the second liner exposed by the packaging layer.

3. The power module heat dissipation structure according to claim 1, characterized in that: The backing plate of the power module comprises a first metal layer, an insulating layer and a second metal layer which are stacked; the second metal layer is welded on the heat dissipation layer through the welding layer; the chip is located on the first metal layer; The packaging layer exposes at least a portion of a side wall of the second metal layer, and the welding layer extends to the side wall of the second metal layer exposed by the packaging layer.

4. The power module heat dissipation structure according to claim 3, characterized in that: Projections of the edge of the first metal layer and the edge of the second metal layer on the insulating layer are located within the edge of the insulating layer.

5. The power module heat dissipation structure according to claim 3, characterized in that: The encapsulation layer covers the edge of the insulating layer.

6. The power module heat dissipation structure according to claim 2, characterized in that: A gasket is arranged between the chip and the first liner.

7. The power module heat dissipation structure according to any one of claims 1 to 6, characterized in that: The liner includes a direct copper-clad ceramic substrate or an active metal-welded ceramic substrate.

8. A vehicle, characterized in that: It comprises a power module heat dissipation structure as described in any one of claims 1 to 7.

9. A packaging device for a power module heat dissipation structure, characterized in that: include: The encapsulation layer removal device is used to remove the encapsulation layer of at least part of the side wall of the liner of the power module, The welding device is used to weld the side of the liner away from the chip of the power module to the heat dissipation layer through the welding layer, so that the welding layer extends to the side wall of the liner exposed by the packaging layer.

10. The packaging device of the power module heat dissipation structure according to claim 9, characterized in that: The encapsulation layer removal device includes a laser.

Images