Method for connecting a cooler module to a metal plate, and component

Abstract

The present invention relates to a method for connecting a cooler module (4) to a metal plate by means of a sintering method, wherein the cooler module (4) comprises a metallic housing (5) having a coolant inlet (7), a coolant outlet (8) and a first housing side (9) and, in the housing (5), a coolant flow structure (6), and wherein the method comprises the following steps: introducing at least one glycol between the coolant flow structure (6), applying a sintering paste and sintering for the purpose of connecting the metal plate and the first housing side (9) under pressure and temperature.

Description

[0001] Description

[0002] title

[0003] Method for connecting a cooler module to a metal plate and component

[0004] State of the art

[0005] The present invention relates to a method for connecting a cooler module to a metal plate and to a component comprising a cooler module and an electronic power module.

[0006] Power semiconductors in power electronics conduct high electrical currents. This results in high temperatures during operation, which lead to conduction losses and, subsequently, heat dissipation. To prevent this, a power electronics module is connected to a high-performance cooler. This cooler is made of aluminum, AlSiC, or copper alloys. The power module can be directly joined to a surface plate of the high-performance cooler, for example, by soldering or sintering.

[0007] Sintered joints have the advantage over soldered joints in that they have higher thermal conductivity, allowing the cooling capacity of the high-performance cooler to be used more effectively to cool the power electronics module, and the heat from the power electronics module can be dissipated more effectively. However, in addition to high temperatures, high pressures are also applied to form sintered joints. These can damage the often delicate flow structures inside the high-performance cooler. To prevent this, the flow structure can be supported by a suitable component against the applied pressure. However, this only works for coolers whose flow structures are exposed, i.e., coolers that are not completely enclosed.This process is therefore very complex, since, on the one hand, the support must be adapted to the respective flow structure, and, on the other hand, the cooler must be closed before commissioning. Disclosure of the invention.

[0008] The inventive method according to claim 1 represents a significantly simplified process compared to the methods known from the prior art, enabling both the formation of a stable sintered joint and the use of closed coolers. The provision of a support structure specifically designed to support the flow structure of the cooler is not required, so that both time and costs can be saved by applying the inventive method.

[0009] The method according to the invention is provided for connecting a cooler module to a metal plate by a sintering process. The cooler module comprises a metallic housing with a coolant inlet and a coolant outlet. The housing further comprises a first housing side, which is to be connected to the metal plate according to the invention. A coolant flow structure is located inside the housing. The coolant flow structure is not specifically limited and generally serves to generate turbulence in the coolant flowing through the coolant flow structure, so that the coolant can absorb a particularly large amount of heat. The coolant flow structure also enlarges the surface area of ​​the coolant. This likewise contributes to particularly effective heat absorption by the coolant. For example, the coolant flow structure can be a lattice structure.

[0010] The size, shape, and type of cooler are adapted to the structure to be cooled. The structure to be cooled is symbolized here by a metal plate. The metal plate can, for example, incorporate electronic power modules on its surface, such as those used in power electronics.

[0011] The process comprises the following steps: First, at least one glycol is introduced into the coolant flow structure. This is achieved by filling the glycol through the coolant inlet. The coolant outlet is closed so that the glycol remains inside the housing. After the coolant has been filled through the coolant inlet, the coolant inlet is also closed. The cooler is then a closed system. In other words, a conventional cooler intended for cooling power electronics can already be used to create the sintered connection without the need for an open cooler. Rather, the cooler is used in its ready-to-use state for the process.It is therefore closed except for the coolant inlet and the coolant outlet, whereby the coolant inlet and the coolant outlet are closed during the process according to the invention, after the introduction of the glycol.

[0012] The process also includes a step of applying a sintering paste. However, the two aforementioned process steps can also be carried out in reverse order.

[0013] Commercially available sintering pastes are used to bond the corresponding metals of the first housing side and the metal plate. The sintering paste can be applied to the first housing side and / or to the surface of the metal plate intended for connection to the first housing side. This typically corresponds to the side opposite the power electronics, and thus to the underside of the power electronics.

[0014] In a further process step, sintering is performed to bond the metal plate and the first housing side. This is done using pressure and, if necessary, heating, depending on the sintering paste used. Suitable pressure ranges are, for example, 10 to 20 MPa, and suitable temperature ranges are 180 °C to 230 °C.

[0015] It is important for the process that the glycol is essentially water-free, ie apart from technically unavoidable residues, since otherwise, for example at the temperatures used, air bubbles would be formed which would not allow for uniform support, so that the sintered connection would not be formed homogeneously.

[0016] The process according to the invention allows conventional coolers, which usually have a very thin metallic casing due to the high thermal conductivity required, to be directly bonded to a metal plate using a sintered joint. The glycol introduced into the coolant flow structure provides excellent support without requiring significant technical or costly effort.

[0017] The subclaims show preferred developments of the invention.

[0018] According to an advantageous development, the glycol is selected from ethylene glycol, propylene glycol, butylene glycol, and mixtures thereof. The aforementioned glycols have proven particularly stable at the applicable sintering temperatures and pressures and are also very easy to fill and rinse.

[0019] As already stated above, the structure, dimensions, and shape of the cooler module are essentially unlimited. Advantageously, the housing of the cooler module comprises two half-shells connected by solder joints. The half-shells can be designed as a lower shell and an upper shell of the cooler module, for example, as deep-drawn parts, and enclose the coolant flow structure between them. Designing the cooler module with two half-shells is cost-effective, and additional weight can be saved through additional components. One of the half-shells comprises the first housing side, which is connected to the metal plate by a sintered joint.

[0020] Further advantageous in terms of high thermal conductivity, the cooler module is made of aluminum, copper, or stainless steel, and is particularly made of aluminum. To improve conductivity and bonding to the metal plate, the aluminum or stainless steel can have a copper or silver coating, and the copper can have a silver coating.

[0021] In order to provide particularly efficient cooling, the cooler module advantageously includes a turbocharger.

[0022] For reasons of excellent connection to power electronics and also due to its very high thermal conductivity, the metal plate is a copper plate. Accordingly, it is further advantageous for the metal plate to be part of an electronic power module.

[0023] According to the present invention, a component is also described which comprises an electronic power module and a cooler module which are connected to one another by means of a sintered connection.

[0024] The cooler module comprises a closed metallic housing with a coolant inlet and a coolant outlet. A coolant flow structure is present in the housing. The housing is formed from one or more housing parts, with two or more housing parts each connected to one another by a soldered joint. The coolant flow structure can also be connected to the housing by one or more soldered joints. In other words, the cooler module according to the invention can also be described as a soldered cooler.

[0025] The electronic power module is directly connected to a first housing side of the cooler module via a sintered connection. According to the invention, an electronic power module is understood to be at least one semiconductor structure (made of Si / SiC in particular) which comprises a metal plate, and in particular a copper plate, on the underside connected to the first housing side. The copper plate can be silver-plated and of any desired thinness. The metal plate, or rather the copper plate, serves to form the sintered connection. If a sintered paste were to be directly bonded to the semiconductor structure of the electronic power module, the semiconductor structure would be damaged and the performance of the electronic power module would be impaired.

[0026] The component according to the invention is very lightweight and simply structured due to the use of a soldered cooler. In particular, the first housing side connected to the electronic power module is relatively thin, so that very good heat transfer to the coolant contained in the cooler module is ensured. The sintered connection additionally supports high heat transfer. Further advantageous in light of very good thermal conductivity for transporting heat from the electronic power module to the coolant in the cooler module, the housing and / or the coolant flow structure of the cooler module are made of aluminum, copper or stainless steel. Aluminum is used as the material, or metal (e.g. steel) that is coated with aluminum or copper.

[0027] For particularly efficient cooling of the electronic power module, the cooler module includes a turbocharger.

[0028] Short description of the drawing

[0029] An embodiment of the invention will be described in detail below with reference to the accompanying drawings. In the drawing:

[0030] Figure 1 is a schematic view of a component according to an advantageous further development in section.

[0031] Embodiment of the invention

[0032] The present invention is illustrated using an exemplary embodiment. Only the essential components are shown; all other components are omitted for clarity.

[0033] In detail, Fig. 1 shows a component 1 according to an advantageous development, schematically in section. The component 1 comprises an electronic power module 2, which includes at least one power semiconductor. A bottom side 3 of the electronic power module 2 is formed from a metal plate made of copper.

[0034] The component 1 further comprises a cooler module 4 with a housing 5 and a coolant flow structure 6 located in the housing 5. The cooler module 4 has a closed metallic housing 5 with a coolant inlet 7 and a coolant outlet 8. The housing 5 here has, for example, two housing parts 5a and 5b, which are each connected to one another by a soldered connection. A first housing part 5a is aligned with the electronic power module 2. A first housing side 9 of the first housing part 5a is connected to the underside 3 of the electronic power module 2 by means of a sintered connection 10. The underside 3 of the electronic power module comprises a metal plate or is designed in particular as a metal plate, such as a copper plate.

[0035] The cooler module 4 is designed as a solder cooler. To form the sintered joint 10, the housing interior 11 can be filled with one or more glycols, so that the first housing part 5a is supported against the electronic power module 2 and the coolant flow structure 6 is stabilized, preventing any deformation of the component or further damage due to the pressure applied during the sintering process. The sintered joint 10 can be obtained by applying and sintering a sintering paste.

Claims

Claims 1. A method for connecting a cooler module (4) to a metal plate by a sintering process, wherein the cooler module (4) comprises a metallic housing (5) with a coolant inlet (7), a coolant outlet (8) and a first housing side (9) and a coolant flow structure (6) in the housing (5), the method comprising: Introducing at least one glycol between the coolant flow structure (6), Applying a sintering paste and Sintering to join the metal plate and the first housing side (9) under pressure and temperature.

2. The process of claim 1, wherein the glycol is selected from ethylene glycol, propylene glycol, butylene glycol, and mixtures thereof.

3. Method according to claim 1 or 2, wherein the housing (5) of the cooler module (4) comprises two half-shells connected by solder joints.

4. Method according to one of the preceding claims, wherein the cooler module (4) consists of aluminum, copper or stainless steel and in particular of aluminum.

5. Method according to one of the preceding claims, wherein the cooler module (4) comprises a turbocharger.

6. A method according to any one of the preceding claims, wherein the metal plate is a copper plate.

7. Method according to one of the preceding claims, wherein the metal plate is part of an electronic power module (2). Component comprising an electronic power module (2) and a cooler module (4), which are connected to one another by means of a sintered connection (10), wherein the cooler module (4) comprises a closed metallic housing (5) with a coolant inlet (7) and a coolant outlet (8) and a coolant flow structure (6) in the housing (5), wherein the housing comprises housing parts (5a, 5b) which are each connected to one another by a soldered connection. Component according to claim 8, wherein the housing (5) and / or the coolant flow structure (6) of the cooler module (4) consists of aluminum, copper or stainless steel and in particular of aluminum and / or is coated with aluminum or copper. Component according to claim 8 or 9, wherein the cooler module (4) comprises a turbocharger.

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