Cooling plate, power module and inverter

Abstract

The embodiment of the utility model discloses a cooling plate, a power module and an inverter, and relates to the technical field of heat dissipation structures. The cooling plate comprises a cooling plate body, a sintering layer for sintering is arranged on one side of the cooling plate body, and an anti-corrosion layer is arranged on the other side of the cooling plate body; wherein the cooling plate body is made of copper or copper alloy, and the sintering layer and the anti-corrosion layer are mutually independent. The structural arrangement of the cooling plate can enable the cooling plate and the power module to have a more reliable connection interface, the connection strength and the structural reliability are greatly improved, and the phenomenon of coating interface cracking is avoided, so that the problem that heat dissipation of a chip in the power module is blocked and the chip is overheated finally is solved, and the service life of the power module is prolonged. And the use effects of the power module and the inverter are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of heat dissipation structures, in particular to a cooling plate, a power module and an inverter. Background Art

[0002] The heat dissipation structure of the power module usually consists of an independent module with a power interface and a cooling plate. During use, the cooling plate and other parts of the cooling water channel form a sealed water channel. The heat generated by the module operation enters the cooling plate through the interface between the module and the cooling plate, and is finally transferred to the circulating cooling water.

[0003] Existing cooling plates can be roughly divided into two categories. One is connected to the power module by welding or thermal grease. This type of connection between the cooling plate and the power module has the problem of poor connection performance. The other type is to set a silver plating layer on the cooling plate to meet the adaptation conditions for silver sintering between the cooling plate and the power module. This type of cooling plate is divided into two types. One type of cooling plate is selectively silver-plated on the surface nickel layer of the copper substrate, but the selective silver plating on nickel also has defects. The main problem is that the bonding force between nickel and silver is low. Due to the alternating load during long-term use, the interface between nickel and silver often cracks, resulting in chip heat dissipation being blocked and eventually chip overheating; the other is to use aluminum as the substrate and directly silver-plated on the surface, but the thermal conductivity of aluminum is 40% lower than that of copper, and the bonding force between aluminum and silver is also low, and there is also the problem of cracking at the coating interface.

[0004] Therefore, the inventors have found that the existing cooling plates have at least the following problems:

[0005] The coating interface between the silver coating and the substrate is prone to cracking. Summary of the invention

[0006] In view of the above shortcomings of the prior art, the purpose of the present invention is to provide a cooling plate, a power module and an inverter, which can avoid the defect of easy cracking of the coating interface between the sintered layer and the substrate.

[0007] The utility model provides a cooling plate, comprising:

[0008] cooling plate body,

[0009] The cooling plate body has a sintering layer for sintering on one side and an anti-corrosion layer on the other side;

[0010] Wherein, the cooling plate body is made of copper or copper alloy, and the sintered layer and the anti-corrosion layer are independent of each other.

[0011] Specifically, the structural setting of the cooling plate can provide a more reliable connection interface with the power module, greatly improving the connection strength and structural reliability, and avoiding the phenomenon of cracking of the coating interface.

[0012] Further, the cooling plate body comprises pin fins.

[0013] Further, the anti-corrosion layer includes one or a combination of a nickel layer, a tin layer, a chromium layer, a silver layer, a gold layer, an aluminum layer, a stainless steel layer and a tungsten layer.

[0014] Further, the sintered layer includes a silver-plated layer.

[0015] Furthermore, the thickness of the silver-plated layer is α, 0.03um≤α≤10um.

[0016] Furthermore, an intermediate layer is provided between the silver-plated layer and the cooling plate body.

[0017] Further, the intermediate layer is made of copper, zinc, gold or tin.

[0018] Furthermore, the thickness of the intermediate layer is β, 0.1um≤β≤5um.

[0019] Furthermore, the substrate and the heat sink are integrally formed.

[0020] Furthermore, the substrate and the heat sink are separately provided, and the substrate and the heat sink are fixedly connected.

[0021] Furthermore, the heat sink is entirely encapsulated in the anti-corrosion layer, and the substrate is entirely encapsulated in the sintering layer.

[0022] The utility model also provides a power module, which comprises the above-mentioned cooling plate. The power module also comprises a module body, and the module body is sintered and combined with the cooling plate through a sintering layer.

[0023] The utility model also provides an inverter, which comprises the cooling plate mentioned above and / or the power module mentioned above.

[0024] The utility model proposes a cooling plate, a power module and an inverter. By setting a substrate made of copper or a copper alloy, the bonding force of the substrate when combined with the sintered layer can be improved. At the same time, the sintered layer and the anti-corrosion layer are independent of each other, thereby avoiding the bonding of the sintered layer and the anti-corrosion layer, and further avoiding the cracking of the coating interface, thereby solving the problem of chip heat dissipation being blocked and eventually chip overheating. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0026] Figure 1 It is a structural schematic diagram of a power module in the prior art;

[0027] Figure 2 It is one of the structural schematic diagrams of the cooling plate in the prior art;

[0028] Figure 3 This is the second structural schematic diagram of a cooling plate in the prior art;

[0029] Figure 4 The third schematic diagram of the structure of the cooling plate in the prior art;

[0030] Figure 5 A schematic diagram of the structure of a cooling plate provided in an embodiment of the utility model;

[0031] Figure 6 Another structural schematic diagram of a cooling plate provided in an embodiment of the utility model.

[0032] Icon: 100-cooling plate; 10-substrate; 101-silver plating layer; 11-heat sink; 111-anti-corrosion layer; 200-power module; 21-module body; 22-power interface. DETAILED DESCRIPTION

[0033] The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0034] It should be noted that the illustrations provided in the following embodiments are only used to schematically illustrate the basic concept of the present invention, and thus the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0035] like Figure 1As shown, the heat dissipation structure of the power module 200 is usually composed of a module body 21 and a cooling plate that are independently packaged and have a power interface 22. In the prior art, a typical cooling plate is designed as a pin-fin heat sink (Pinfin). During use, the cooling plate and other parts of the cooling water channel form a sealed water channel. The heat generated by the operation of the power module 200 enters the cooling plate through the interface between the module body 21 and the cooling plate, and is finally transferred to the circulating cooling water. Improving the heat dissipation efficiency can effectively reduce the operating temperature of the chip in the module, so that it can withstand a larger current and have a longer life cycle. The material of the cooling plate is usually made of copper or aluminum. Both have their own advantages and disadvantages. The copper cooling plate has a high thermal conductivity, but is not resistant to coolant corrosion. Although the aluminum cooling plate is corrosion-resistant, its thermal conductivity is not as good as copper, and the aluminum surface cannot be directly welded or sintered, requiring complex surface treatment.

[0036] Existing cooling plates can be roughly divided into two categories.

[0037] One type can be Figure 2 As shown, the nickel plating on the surface of the cooling plate can prevent the copper cooling plate from corroding, allowing the product to be immersed in the coolant for a long time, and the upper surface can be connected to the module by welding or thermal grease. This design has the lowest production cost and is the most widely used, but the connection performance between the cooling plate and the module is poor. First, the welding layer has a high porosity and low thermal conductivity. Secondly, during long-term use, the solder has the problem of brittle intermetallic compound growth, resulting in its low durability. If the solder is replaced with silicone grease, it is difficult to meet the heat dissipation requirements of high-performance modules because the thermal conductivity of silicone grease is much lower than that of metal.

[0038] Another type of cooling plate is to provide a silver-plated layer on the substrate of the cooling plate to meet the adaptation conditions for silver sintering of the cooling plate and the power module 200 .

[0039] This type of cooling plate is divided into two types, one of which is Figure 3 As shown, silver plating makes it possible to sinter silver on the surface of the copper cooling plate. Compared with solder, sintered silver has high thermal conductivity and strong durability, and is the best choice for assembling the current power module 200. However, selective silver plating on nickel also has defects. The main problem is that the bonding strength between nickel and silver is low. Due to the alternating load during long-term use, cracks often occur at the interface between nickel and silver, resulting in chip heat dissipation being blocked, and eventually the chip overheating occurs.

[0040] Another cooling plate is Figure 4 The cooling plate shown is an aluminum cooling plate. The corrosion resistance of aluminum eliminates a series of problems caused by copper nickel plating. The surface silver plating is suitable for silver sintering process, which is a more reasonable design. However, the thermal conductivity of aluminum is 40% lower than that of copper, and the bonding strength between aluminum and silver is also low, and there is also the problem of cracking at the coating interface.

[0041] Please refer to Figure 5 and Figure 6 The utility model provides a cooling plate 100. The cooling plate 100 comprises a cooling plate body, one side of the cooling plate body has a sintering layer for sintering, and the other side has an anti-corrosion layer 111. The cooling plate body is made of copper or copper alloy, and the sintering layer and the anti-corrosion layer 111 are independent of each other.

[0042] It is worth mentioning that by providing a cooling plate body made of copper or copper alloy, the bonding strength of the cooling plate body when combined with the sintered layer can be improved. At the same time, the sintered layer and the anti-corrosion layer 111 are independent of each other, avoiding the bonding of the sintered layer and the anti-corrosion layer 111, and further avoiding the cracking of the coating interface, thereby solving the problem of chip heat dissipation being blocked and ultimately chip overheating.

[0043] In this embodiment, the heat sink 11 includes pin fins. It can be understood that the pin fins are heat dissipation structures with discontinuous fin ribs, which are not only simple in structure and easy to process, but also enable the heat sink 11 to obtain a larger heat transfer surface and improve the heat exchange efficiency. Depending on the specific implementation environment, the heat sink 11 can be a circular pin fin, a square pin fin, a diamond pin fin, or a fin structure. This embodiment does not constitute a specific limitation on the structural shape of the heat sink 11, but is only an example of its structural shape.

[0044] like Figure 5 As shown, the anti-corrosion layer 111 includes one or a combination of a nickel layer, a tin layer, a chromium layer, a silver layer, a gold layer, an aluminum layer, a stainless steel layer and a tungsten layer.

[0045] It is worth noting that the anti-corrosion layer 111 can preferably be made of metal nickel, which serves to provide a certain anti-corrosion effect in the area where the surface of the heat sink 11 contacts the coolant. Nickel has a certain strength and good ductility. When used as the anti-corrosion layer 111, it can enhance the corrosion resistance of the heat sink 11 while having the advantage of low cost. Other plating layers, such as tin, chromium, silver, gold, aluminum, stainless steel or tungsten, can also play the same role. This embodiment does not constitute a limitation on the material of the anti-corrosion layer, but is merely an example thereof.

[0046] In this embodiment, the sintered layer includes a silver-plated layer 101 .

[0047] It is worth noting that the silver-plated layer 101 is provided on the upper surface where the substrate 10 and the module body 21 are connected, which can bear the function of sintering. The silver-plated cooling plate 100 and the module can be combined together by sintering. The feasible sintering processes include silver sintering, palladium sintering, copper sintering, etc.

[0048] It is also worth noting that the thickness of the silver-plated layer 101 is α, 0.03um≤α≤10um, and the silver-plated layer 101 can be directly made on the copper surface. It is understandable that the silver-plated layer 101 within this thickness range can save raw materials while making the substrate 10 have a sufficient thickness to achieve a good sintering effect.

[0049] In one implementation of this embodiment, there is an intermediate layer (not shown in the figure) between the silver-plated layer 101 and the substrate 10 .

[0050] It is worth noting that one or more intermediate layers can be added between the silver-plated layer 101 and the substrate 10 by chemical plating, electroplating, vapor deposition, etc., and then the silver-plated layer 101 is plated. The purpose is to enhance the bonding force, bonding strength and bonding reliability between the layers, and also to prevent oxygen from penetrating the silver-plated layer 101 to oxidize the substrate. The intermediate layer can be selected from materials including but not limited to copper, gold, tin, etc. Depending on the specific implementation environment, the copper intermediate layer, the gold intermediate layer and the tin intermediate layer have the characteristics of high bonding force when they are combined with the silver-plated layer, thereby avoiding the occurrence of cracking at the interface between the intermediate layer and the silver-plated layer, and preventing oxygen from penetrating the silver-plated layer 101 to oxidize the substrate. That is, the intermediate layer should have a high bonding force with the silver-plated layer to avoid cracking of the intermediate layer and the silver-plated layer. In this embodiment, the thickness of the intermediate layer is β, 0.1um≤β≤5um. It is understandable that an intermediate layer with a thickness of at least 0.1um can better prevent oxygen from penetrating the silver-plated layer 101 to oxidize the substrate. At the same time, if its thickness is controlled within 5um, it can save costs and avoid the phenomenon of the joint surface between the module body 21 and the cooling plate 100 being too thick.

[0051] Please refer again Figure 5 In one implementation of this embodiment, the substrate 10 and the heat sink 11 are integrally formed.

[0052] In this embodiment, in order to directly plate silver on the surface of the copper substrate 10, the original plating layer (nickel layer) can be removed, and then silver is plated locally to form a structure of local nickel plating + local silver plating. It is also possible to use tooling or glue to shield the silver-plated area during nickel plating, and then silver is plated locally. The available methods for removing the original plating layer include milling, local chemical corrosion, grinding, plasma treatment, etc.

[0053] Please refer again Figure 6 In one implementation of the present embodiment, the substrate 10 and the heat sink 11 are separately provided, and the substrate 10 and the heat sink 11 are fixedly connected.

[0054] In this embodiment, the heat sink 11 is entirely coated in the anti-corrosion layer 111, and the substrate 10 is entirely coated in the sintered layer. During the manufacturing process, the heat sink 11 entirely coated in the anti-corrosion layer 111 and the substrate 10 entirely coated in the sintered layer can be manufactured separately, and then the two are fixedly connected by welding. Depending on the specific implementation environment, the connection method between the substrate 10 and the heat sink 11 can also be splicing, direct metal bonding, sintering, etc. This embodiment does not constitute a limitation on the method of fixed connection between the two, but is only an example thereof.

[0055] This embodiment further provides a power module 200, which includes the above-mentioned cooling plate 100. The power module 200 also includes a module body 21. The module body 21 is sintered and combined with the cooling plate 100 through a sintering layer, and has all its beneficial effects.

[0056] This embodiment further provides an inverter, which includes the cooling plate 100 described above, and / or the power module 200 described above, and has all the beneficial effects thereof.

[0057] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed in the present invention shall still be covered by the claims of the present invention.

[0058] In the description herein, many specific details, such as examples of components and / or methods, are provided to provide a complete understanding of the embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more specific details or by other devices, systems, components, methods, components, materials, parts, etc. In other cases, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of the embodiments of the present invention.

[0059] References throughout the specification to "one embodiment," "an embodiment," or "a specific embodiment" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present invention, and not necessarily in all embodiments. Thus, various appearances of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. In addition, the particular features, structures, or characteristics of any specific embodiment of the present invention may be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the present invention described herein and shown may be based on the teachings herein and will be considered part of the spirit and scope of the present invention.

[0060] It should also be understood that one or more of the elements shown in the figures may also be implemented in a more separate or more integrated manner, or even removed because they are inoperable in certain circumstances or provided because they may be useful depending on the application.

[0061] In addition, unless otherwise explicitly indicated, any marking arrows in the drawings should be regarded as exemplary only and not limiting. In addition, unless otherwise indicated, the term "or" used herein is generally intended to mean "and / or". In the case where the term is not clear because it is anticipated that the ability to separate or combine is provided, the combination of components or steps will also be regarded as indicated.

[0062] As used in the description herein and throughout the claims that follow, "a", "an", and "the" include plural references unless otherwise indicated. Likewise, as used in the description herein and throughout the claims that follow, the meaning of "in" includes "in" and "on" unless otherwise indicated.

[0063] The above description of the illustrated embodiments of the present invention (including the contents in the abstract of the specification) is not intended to be an exhaustive list or to limit the present invention to the precise form disclosed herein. Although specific embodiments of the present invention and examples of the present invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the present invention as will be recognized and understood by those skilled in the art. As noted, these modifications may be made to the present invention in accordance with the above description of the embodiments of the present invention, and these modifications will be within the spirit and scope of the present invention.

[0064] Systems and methods have been generally described herein as details that are helpful for understanding the present invention. In addition, various specific details have been given to provide an overall understanding of the embodiments of the present invention. However, those skilled in the relevant art will recognize that the embodiments of the present invention can be practiced without one or more specific details, or practiced using other devices, systems, accessories, methods, components, materials, parts, etc. In other cases, well-known structures, materials, and / or operations are not specifically shown or described in detail to avoid confusion with various aspects of the embodiments of the present invention.

Claims

1. A cooling plate, characterized in that: include: cooling plate body, The cooling plate body has a sintering layer for sintering on one side and an anti-corrosion layer on the other side; Wherein, the cooling plate body is made of copper or copper alloy, and the sintered layer and the anti-corrosion layer are independent of each other.

2. The cooling plate according to claim 1, characterized in that The cooling plate body includes pin fins.

3. The cooling plate according to claim 1, characterized in that The anti-corrosion layer includes one or a combination of a nickel layer, a tin layer, a chromium layer, a silver layer, a gold layer, an aluminum layer, a stainless steel layer and a tungsten layer.

4. The cooling plate according to claim 1, characterized in that The sintered layer includes a silver-plated layer.

5. The cooling plate according to claim 4, characterized in that The thickness of the silver-plated layer is α, 0.03um≤α≤10um.

6. The cooling plate according to claim 4, characterized in that An intermediate layer is provided between the silver-plated layer and the cooling plate body.

7. The cooling plate according to claim 6, characterized in that The intermediate layer is made of copper, gold or tin.

8. The cooling plate according to claim 7, characterized in that The thickness of the intermediate layer is β, 0.1um≤β≤5um.

9. The cooling plate according to any one of claims 1 to 8, characterized in that: The cooling plate body comprises a base plate and a heat sink which are separately arranged, and the base plate is fixedly connected to the heat sink.

10. The cooling plate according to claim 9, characterized in that The heat sink is entirely covered in the anti-corrosion layer, and the substrate is entirely covered in the sintering layer.

11. A power module, comprising the cooling plate according to any one of claims 1 to 10, characterized in that: The power module further includes a module body, and the module body is sintered and combined with the cooling plate through the sintering layer.

12. An inverter, characterized in that: It comprises the cooling plate according to any one of claims 1 to 10, and / or the power module according to claim 11.

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