A power module

Abstract

The utility model relates to a kind of substrate, especially a kind of power module, including first copper plate, ceramic plate, second copper plate and copper-aluminum composite board sequentially arranged from top to bottom, the area of second copper plate is less than the area of copper-aluminum composite board;The copper-aluminum composite board includes third copper plate and aluminium plate sequentially arranged from top to bottom, and the thickness of aluminium plate is greater than the thickness of third copper plate.The utility model provides a kind of power module by copper-aluminum composite board to reduce the use amount of copper, can reduce cost, while reducing thermal resistance, improves the heat dissipation effect.

Description

Technical Field

[0001] This utility model relates to a substrate, and more particularly to a power module. Background Technology

[0002] A power module is an industrial product composed of power electronic devices combined and encapsulated according to specific functions, with its core functions being power conversion and control. Common applications include new energy vehicles, photovoltaic power generation, wind power systems, and 5G communications. IGBTs and MOSFETs are widely used semiconductor devices in these modules. A power module mainly consists of a power semiconductor chip and an insulating substrate. The insulating substrate primarily comprises a copper layer, an insulating ceramic layer, another copper layer, and a heat sink, arranged sequentially. The top copper layer is used to etch circuit patterns, and the chip is soldered onto it. The insulating ceramic layer provides insulation and thermal conductivity. Figure 3 As shown, the existing power module includes a first copper plate, a ceramic plate, a second copper plate, and a third copper plate arranged sequentially from top to bottom. The third copper plate is the substrate with the largest area and can fix multiple second copper plates. The thickness of the third copper plate is 3mm. The chip is mounted on the first copper plate. The thermal resistance of this power module is 1.164 m²k / W. This power module has problems such as poor heat dissipation performance and high cost due to the use of all copper. Utility Model Content

[0003] To solve the above problems, this utility model provides a power module, the specific technical solution of which is as follows: A power module includes a first copper plate, a ceramic plate, a second copper plate, and a copper-aluminum composite plate arranged sequentially from top to bottom, wherein the area of ​​the second copper plate is smaller than the area of ​​the copper-aluminum composite plate; the copper-aluminum composite plate includes a third copper plate and an aluminum plate arranged sequentially from top to bottom, wherein the thickness of the aluminum plate is greater than the thickness of the third copper plate.

[0004] Preferably, the thickness of the third copper plate is 5-15% of that of the copper-aluminum composite plate, and the thickness of the aluminum plate is 95-85% of that of the copper-aluminum composite plate.

[0005] Preferably, the thickness of the third copper plate is 10% of that of the copper-aluminum composite plate, and the thickness of the aluminum plate is 90% of that of the copper-aluminum composite plate.

[0006] Furthermore, the copper-aluminum composite plate has a thickness of 3mm, the third copper plate has a thickness of 0.3mm, and the aluminum plate has a thickness of 2.7mm.

[0007] Compared with the prior art, the present invention has the following beneficial effects: The power module provided by this utility model reduces the amount of copper used by using a copper-aluminum composite plate, which can reduce costs, lower thermal resistance, and improve heat dissipation. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the structure of this application; Figure 2 This is a schematic diagram of heat dissipation in this application; Figure 3 This is a schematic diagram of the structure of an existing power module. Detailed Implementation

[0009] The present invention will now be further described with reference to the accompanying drawings.

[0010] like Figure 1 and Figure 2 As shown, a power module includes a first copper plate 1, a ceramic plate 2, a second copper plate 3, and a copper-aluminum composite plate 4 arranged sequentially from top to bottom. The area of ​​the second copper plate 3 is smaller than the area of ​​the copper-aluminum composite plate 4. The copper-aluminum composite plate 4 includes a third copper plate 41 and an aluminum plate 42 arranged sequentially from top to bottom. The thickness of the aluminum plate 42 is greater than the thickness of the third copper plate 41.

[0011] Chip 6 is soldered onto the first copper plate 1.

[0012] The thickness of the third copper plate 41 is 5-15% of that of the copper-aluminum composite plate 4, and the thickness of the aluminum plate 42 is 95-85% of that of the copper-aluminum composite plate 4. Further, the thickness of the third copper plate 41 is 10% of that of the copper-aluminum composite plate 4, and the thickness of the aluminum plate 42 is 90% of that of the copper-aluminum composite plate 4.

[0013] Preferably, the copper-aluminum composite plate 4 has a thickness of 3mm, the third copper plate 41 has a thickness of 0.3mm, and the aluminum plate 42 has a thickness of 2.7mm.

[0014] The sampling copper-aluminum composite plate 4 enables products to be lighter, achieving weight reduction, and can effectively reduce manufacturing costs and shorten the process recovery time.

[0015] The present application enables the power module to release the temperature of the chip rising in real time and efficiently through the copper-aluminum composite plate 4 downwards. Since the heat diffusion angle at the junction of aluminum and copper is 1.028°, the heat is dissipated from the entire area of ​​aluminum, thus releasing heat more efficiently.

[0016] Thermal conductivity: Solder 49 W / mK; Copper (C1100) 388 W / mK; Ceramic 30 W / mK; Aluminum (1060) 234 W / mK. Comparison of heat dissipation area based on diffusion, such as... Figure 3 As shown, the thermal resistance of the existing power module is: α1 = tan -1 (49 / 388) = 0.1256° α2=tan -1 (388 / 30) = 1.4936° α3=tan-1 (30 / 388) = 0.077° α4=tan -1 (388 / 49) = 1.445° α5=tan -1 (49 / 388) = 0.125° α is the thermal diffusion angle.

[0017] The existing power module substrate is a pure copper plate with a thickness of 3mm and a thermal resistance of 388W / mK × 0.003 = 1.164m²k / W.

[0018] The thermal resistance of the power module in this application is: α1 = tan -1 (49 / 388) = 0.1256° α2=tan -1 (388 / 30) = 1.4936° α3=tan -1 (30 / 388) = 0.077° α4=tan -1 (388 / 49) = 1.445° α5=tan -1 (49 / 388) = 0.125° α6=tan -1 (388 / 234) = 1.028° Thermal resistance = (388W / mK × 0.0003) + (234W / mK × 0.0027) = (0.1164 + 0.6318) m²k / W = 0.7482 m²k / W.

[0019] Lower thermal resistance results in better heat dissipation. The thermal resistance of the copper-aluminum composite plate 4 in this application is 1.56 times lower than that of a pure copper substrate. Therefore, the heat dissipation effect of the copper-aluminum composite plate 4 in this application is 1.56 times better than that of a pure copper plate, resulting in a lower junction temperature inside the package and thus improving chip efficiency. The technical principles of this utility model have been described above in conjunction with specific embodiments. These descriptions are only for explaining the principles of this utility model and should not be construed as limiting the scope of protection of this utility model in any way. Based on the explanation herein, those skilled in the art can conceive of other specific embodiments of this utility model without creative effort, and these embodiments will all fall within the protection scope of the claims of this utility model.

Claims

1. A power module, characterized in that, It includes a first copper plate (1), a ceramic plate (2), a second copper plate (3) and a copper-aluminum composite plate (4) arranged from top to bottom, wherein the area of ​​the second copper plate (3) is smaller than the area of ​​the copper-aluminum composite plate (4); The copper-aluminum composite plate (4) includes a third copper plate (41) and an aluminum plate (42) arranged sequentially from top to bottom, wherein the thickness of the aluminum plate (42) is greater than the thickness of the third copper plate (41).

2. A power module according to claim 1, characterized in that, The thickness of the third copper plate (41) is 5-15% of that of the copper-aluminum composite plate (4), and the thickness of the aluminum plate (42) is 95-85% of that of the copper-aluminum composite plate (4).

3. A power module according to claim 2, characterized in that, The thickness of the third copper plate (41) is 10% of that of the copper-aluminum composite plate (4), and the thickness of the aluminum plate (42) is 90% of that of the copper-aluminum composite plate (4).

4. A power module according to claim 3, characterized in that, The copper-aluminum composite plate (4) has a thickness of 3 mm, the third copper plate (41) has a thickness of 0.3 mm, and the aluminum plate (42) has a thickness of 2.7 mm.

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