Heat dissipation structure of power module
By setting a thermally conductive copper layer on the aluminum radiator and canceling the contact layer and thermal grease, the problem of poor heat dissipation effect of the power module is solved, achieving more efficient heat dissipation and production efficiency improvement, while reducing costs.
Patent Information
- Application Number
- CN202420460050.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-11
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2034-03-11
AI Technical Summary
The existing power modules have poor heat dissipation effects, resulting in reduced working performance, complex production processes and high cost.
The thermally conductive copper layer is installed on the aluminum radiator, and the chip is directly or indirectly welded on the thermally conductive copper layer through DBC ceramic copper clad plate, eliminating the contact layer and thermally conductive silicon grease, and using electroless plating, mechanical spraying or plasma spraying technology to set thermally conductive copper layer.
Improves heat dissipation effect, simplifies production processes, reduces production costs, and enhances compatibility and heat transfer efficiency, reducing the risk of product damage.
Smart Images
Figure CN222261034U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of semiconductors, in particular to a heat dissipation structure of a power module. Background Art
[0002] Semiconductor power modules are mainly composed of power metal oxide semiconductor field effect transistors (MOS), insulated gate bipolar transistors (IGBT) and power integrated circuits (power IC). These devices and integrated circuits can work at very high frequencies, and the circuits can save more energy and materials when working at high frequencies, which can greatly reduce the size and weight of the equipment. In particular, the highly integrated monolithic power system on chip (PSOC) can integrate sensor devices and circuits, signal processing circuits, interface circuits, power devices and circuits on a silicon chip, so that it has the intelligent function of precisely adjusting the output according to the load requirements and self-protecting according to overheating, overvoltage, overcurrent and other conditions.
[0003] High efficiency, high power density and high reliability are important performance indicators of power modules, but the heat dissipation effect of power modules directly affects these performance indicators. If the heat dissipation effect of the power module is poor, its working performance will decline. Conversely, its working performance will be improved and its application space will be expanded.
[0004] In order to improve the heat dissipation effect of the power module, many related technologies have been proposed in the prior art. For example, the patent document with the announcement number CN217822764U discloses a new IGBT module with heat dissipation function, which includes a ceramic substrate, a contact layer is fixedly installed at the bottom of the ceramic substrate, a silicone grease layer is provided at the bottom of the contact layer, a copper clad layer is fixedly installed at the top of the ceramic substrate, a plurality of chips are welded on the top of the copper clad layer, and two insertion holes are also provided on the top of the copper clad layer, and auxiliary components are provided on the inner walls of the two insertion holes. Although this technology has a certain heat dissipation effect, it still has the following technical problems:
[0005] 1. This technology dissipates heat through the cooperation of the contact layer and the silicone grease layer, but since the thermal conductivity of silicone grease is only 0.8-5.0W / m·K, its heat dissipation effect is still poor.
[0006] 2. The contact layer is usually a copper plate. Setting a copper plate alone as the contact layer not only complicates the production process but also increases the cost. Utility Model Content
[0007] The purpose of the utility model is to overcome the above-mentioned technical problems existing in the prior art, and provide a heat dissipation structure of a power module. The utility model can utilize the thermally conductive copper layer arranged on the aluminum radiator for direct heat dissipation. Compared with the prior art, the contact layer and thermally conductive silicone grease are eliminated, which not only reduces the intermediate heat transfer structure and process, improves the heat dissipation effect, but also simplifies the production process and reduces the production cost, thereby solving the technical problems of poor heat dissipation effect, complex production process and high cost of the prior art power module.
[0008] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:
[0009] A heat dissipation structure of a power module, characterized in that it comprises a chip and an aluminum heat sink, the aluminum heat sink is provided with a thermally conductive copper layer, and the chip is directly and / or indirectly welded to the thermally conductive copper layer through a DBC ceramic copper clad plate.
[0010] The number of the chips is at least one. When the number of the chips is one, the chip is directly soldered on the thermally conductive copper layer, or the chip is indirectly soldered on the thermally conductive copper layer through a DBC ceramic copper clad laminate; when the number of the chips is multiple, all the chips are directly soldered on the thermally conductive copper layer, or all the chips are indirectly soldered on the thermally conductive copper layer through a DBC ceramic copper clad laminate, or a part of the chips are directly soldered on the thermally conductive copper layer, and the other part of the chips are indirectly soldered on the thermally conductive copper layer through a DBC ceramic copper clad laminate.
[0011] When the chip is directly soldered on the thermally conductive copper layer, the chip and the thermally conductive copper layer are fixed by soldering with solder paste; when the chip is indirectly soldered on the thermally conductive copper layer through the DBC ceramic copper clad laminate, the chip and the DBC ceramic copper clad laminate and the DBC ceramic copper clad laminate and the thermally conductive copper layer are fixed by soldering with solder paste.
[0012] The thermal conductive copper layer is arranged on the aluminum radiator by chemical plating, mechanical spraying or plasma spraying.
[0013] The aluminum heat sink has a mounting surface, and the heat-conducting copper layer covers the mounting surface.
[0014] The thickness of the thermal conductive copper layer is 10 um to 2000 um.
[0015] The aluminum radiator is a fin-type structure.
[0016] The advantages of adopting the utility model are:
[0017] 1. The key improvement of the utility model is that a thermally conductive copper layer is provided on the aluminum radiator. The thermally conductive copper layer is directly provided on the aluminum radiator. According to the actual product needs, the chip can be directly soldered to the thermally conductive copper layer, or indirectly soldered to the thermally conductive copper layer through the DBC ceramic copper clad plate. Since the thermal conductivity of the thermally conductive copper layer is 401W / mk, which is much larger than the thermal conductivity of silicone grease, its thermal conductivity is better. Compared with the prior art, since the contact layer and thermally conductive silicone grease are eliminated, on the one hand, it can not only reduce the intermediate heat transfer structure and process, but also improve the heat dissipation effect; on the other hand, it can also simplify the production process and reduce the production cost, and has better practicality.
[0018] 2. In the heat dissipation structure of the utility model, the chip in the power module can be directly soldered to the thermal conductive copper layer, or indirectly soldered to the thermal conductive copper layer through the DBC ceramic copper clad plate, or soldered to the thermal conductive copper layer in a combination of direct and indirect methods, which is suitable for different products and has stronger compatibility.
[0019] 3. The thermally conductive copper layer in the utility model can be arranged on the aluminum radiator by chemical plating, mechanical spraying or plasma spraying. On the one hand, it can make the thermally conductive copper layer and the aluminum radiator form an integrated structure, thereby achieving a better heat dissipation effect. On the other hand, it also makes the arrangement of the thermally conductive copper layer simpler.
[0020] 4. The utility model adopts a 10um to 2000um thermal conductive copper layer, which, on the one hand, is conducive to greatly improving the heat transfer efficiency. On the other hand, when the thermal conductive silicone grease process is used for filling, if air is contained in the thermal conductive silicone grease or at the connection, it is difficult to remove, and irregular and randomly located voids will be formed, which may cause product damage. The use of a thermal conductive copper layer can effectively eliminate voids, which is conducive to reducing the risk of product damage.
[0021] 5. The utility model directly covers the thermal conductive copper layer on the mounting surface, which is beneficial to further improve the heat transfer effect between the chip and the aluminum heat sink. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 It is a schematic diagram of the structure in which the chip is directly soldered on the thermal conductive copper layer;
[0023] Figure 2 It is a schematic diagram of the structure in which the chip is indirectly soldered to the thermal conductive copper layer through the DBC ceramic copper clad plate;
[0024] Figure 3 It is a schematic diagram of the structure of the chip being directly and indirectly soldered to the thermal conductive copper layer;
[0025] Figure 4 for Figure 3 Schematic diagram of the enlarged structure at I in the middle.
[0026] The markings in the figure are: 1. Chip, 2. Aluminum radiator, 3. Thermal conductive copper layer, 4. DBC ceramic copper clad board. DETAILED DESCRIPTION
[0027] The heat dissipation structure of the power module described in the utility model has been prepared into actual samples, and the applicant has tried it and found it to have a good heat dissipation effect, so it is ready for actual production and sales. In order to better protect this technology, the applicant has applied for a utility model patent for this technology. The utility model is described in detail below in conjunction with specific embodiments.
[0028] A heat dissipation structure of a power module includes a chip 1 and an aluminum heat sink 2. The number of chips 1 is at least one, and can be set to multiple according to design requirements. The aluminum heat sink 2 is preferably a fin-type structure with a smooth mounting surface and heat dissipation fins, but can also be other structures commonly used in the prior art. A heat-conducting copper layer 3 is provided on the aluminum heat sink 2, and the chip 1 is directly and / or indirectly soldered to the heat-conducting copper layer 3 through a DBC ceramic copper-clad plate 4.
[0029] like Figure 1-4 As shown, the chip 1 and the thermal conductive copper layer 3 in the present invention include the following three connection structures:
[0030] The first type: when the number of the chip 1 is one, the chip 1 is directly soldered on the thermal conductive copper layer 3 , or the chip 1 is indirectly soldered on the thermal conductive copper layer 3 through the DBC ceramic copper clad plate 4 .
[0031] The second type: when there are multiple chips 1 (including two), all chips 1 are directly soldered to the thermal conductive copper layer 3, or all chips 1 are indirectly soldered to the thermal conductive copper layer 3 through the DBC ceramic copper clad laminate 4.
[0032] The third type: when there are multiple chips 1 , some of the chips 1 are directly soldered to the thermal conductive copper layer 3 , and the other chips 1 are indirectly soldered to the thermal conductive copper layer 3 through the DBC ceramic copper clad plate 4 .
[0033] According to a preferred embodiment of the present invention, when the chip 1 is directly soldered to the thermally conductive copper layer 3, the chip 1 and the thermally conductive copper layer 3 are fixed by soldering with solder paste; when the chip 1 is indirectly soldered to the thermally conductive copper layer 3 through the DBC ceramic copper clad board 4, the chip 1 and the DBC ceramic copper clad board 4 and the DBC ceramic copper clad board 4 and the thermally conductive copper layer 3 are fixed by soldering with solder paste. Optionally, the solder paste can be melted by a sintering furnace in actual application.
[0034] According to a preferred embodiment of the present invention, the thermal conductive copper layer 3 can be disposed on the aluminum heat sink 2 by chemical plating, mechanical spraying or plasma spraying.
[0035] It should be noted that when the thermal conductive copper layer 3 is set by the above-mentioned process in the present invention, the thermal conductive copper layer 3 is limited to forming a copper plating layer or a copper clad layer on the aluminum radiator 2, and it does not include a structure in which a copper plate is separately set. At the same time, the copper plating layer or the copper clad layer is not equivalent to the structure of a separate copper plate, that is, the structure and effect are not the same or the same.
[0036] According to a preferred embodiment of the present invention, the thickness of the thermal conductive copper layer 3 is 10um to 2000um. It should be noted that the difference in the thickness of the thermal conductive copper layer 3 is closely related to the heat dissipation effect, but its specific processing thickness needs to be calculated in combination with the power size / circuit structure / layout differences of the power components inside the module, that is, the thermal conductive copper layer 3 can be adjusted accordingly within this range according to design requirements to achieve the best heat dissipation effect.
[0037] According to a preferred embodiment of the present invention, the thermally conductive copper layer 3 covers the mounting surface. According to design requirements, the area of the thermally conductive copper layer 3 can be the same as or smaller than the area of the mounting surface in the aluminum heat sink 2, that is, the thermally conductive copper layer 3 can cover the entire mounting surface or partially cover the mounting surface.
[0038] The production process of the utility model is as follows: firstly, a thermally conductive copper layer 3 is formed on the mounting surface of the aluminum radiator 2 by chemical plating, mechanical spraying or plasma spraying, and then a tin brushing / silk screen steel mesh is made according to the actual component layout, and the solder paste is evenly filled to the calibrated position. After the lower surface of the component and the upper surface of the solder paste are assembled and combined, the solder paste is melted by a sintering furnace, and the chip 1 and / or the DBC ceramic copper clad board 4 can be fixed to the thermally conductive copper layer 3.
[0039] Compared with the heat dissipation structure using thermal conductive silicone grease and copper plate in the prior art, the utility model has a higher cost performance as follows:
[0040] Taking the 400A welding machine module produced by the applicant company as an example, according to the design requirements, the size of the bottom copper plate will not be less than 110*80*3mm, and the amount of thermal grease used will not be less than 3g. Through actual measurements by the procurement, engineering, production and packaging departments, the main process materials and comparisons are as follows:
[0041]
[0042] After auditing and financial accounting, the use of this utility model can increase production efficiency by 30%, but the comprehensive cost can be reduced by 27%. Compared with the existing technology, it has better thermal conductivity, improves production efficiency and reduces production costs, and is more innovative.
[0043] The above description is only a specific implementation method of the present utility model. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes; all disclosed features, or all methods or steps in the process, except for mutually exclusive features and / or steps, can be combined in any way.
Claims
1. A heat dissipation structure of a power module, characterized in that: It comprises a chip (1) and an aluminum heat sink (2), wherein a heat-conducting copper layer (3) is provided on the aluminum heat sink (2), and the chip (1) is directly soldered to the heat-conducting copper layer (3).
2. The heat dissipation structure of a power module according to claim 1, characterized in that: The number of the chip (1) is at least one, and all the chips (1) are directly soldered onto the heat-conducting copper layer (3).
3. A heat dissipation structure of a power module according to claim 1 or 2, characterized in that: When the chip (1) is directly soldered onto the thermally conductive copper layer (3), the chip (1) and the thermally conductive copper layer (3) are fixed by soldering with solder paste.
4. The heat dissipation structure of a power module according to claim 1, characterized in that: The thermally conductive copper layer (3) is disposed on the aluminum heat sink (2) by chemical plating, mechanical spraying or plasma spraying.
5. The heat dissipation structure of a power module according to claim 1, characterized in that: The thickness of the thermally conductive copper layer (3) is 10 um to 2000 um.
6. The heat dissipation structure of a power module according to claim 1, characterized in that: The aluminum heat sink (2) has a mounting surface, and the heat-conducting copper layer (3) covers the mounting surface.
7. A heat dissipation structure of a power module according to any one of claims 1, 2, 4, 5 or 6, characterized in that: The aluminum heat sink (2) is a fin-type structure.