IGBT module

Abstract

The utility model relates to the technical field of IGBT (Insulated Gate Bipolar Translator) modules, in particular to an IGBT module. The IGBT module comprises a shell, an IGBT chip and an aluminum-based copper-clad plate; the aluminum-based copper-clad plate comprises an aluminum plate, an oxidation film layer, a silicon carbide layer, a nickel-copper alloy layer and a first copper layer, the oxidation film layers are formed on the two sides of the aluminum plate, the silicon carbide layers are formed on the oxidation film layers on the two sides of the aluminum plate, the nickel-copper alloy layers are formed on the silicon carbide layers on the two sides of the aluminum plate, and the first copper layers are formed on the nickel-copper alloy layers on the two sides of the aluminum plate. The IGBT chip is fixedly arranged on the first copper layer of the aluminum-based copper-clad plate, and the shell is fixedly arranged on the aluminum-based copper-clad plate and covers the IGBT chip. The IGBT chip is fixedly arranged on the first copper layer of the aluminum-based copper-clad plate, a ceramic substrate and a copper heat conduction block are not used, a copper layer and a soldering tin layer between the ceramic substrate and the copper heat conduction block are omitted, the cost of the ceramic substrate, the copper heat conduction block and the attaching technology is saved, the cost is low, the technology is simple, the production yield is improved, heat conduction resistance caused by a multi-layer structure is avoided, and the heat conduction efficiency is high.

Description

Technical Field

[0001] The utility model relates to the technical field of IGBT modules, in particular to an IGBT module. Background Art

[0002] IGBT module (Insulated Gate Bipolar Transistor) is a high-performance power semiconductor device that combines the high input impedance of MOSFET (metal-oxide-semiconductor field-effect transistor) and the low on-state voltage drop of bipolar transistor (BJT). IGBT is particularly suitable for power electronics that require high voltage and high current. The IGBT module structure mainly includes IGBT chip, wire bonding, packaging structure, drive and protection circuits, etc.

[0003] like Figure 1 As shown, the current traditional IGBT module packaging structure is: the power chip (IGBT chip) is fixed on the ceramic substrate by a die bonder, and then the ceramic substrate is soldered to the copper heat conductive block with nickel plated surface by a solder sheet.

[0004] Such an IGBT module packaging structure has a complex process flow, high cost, low yield, and low thermal conductivity efficiency. Utility Model Content

[0005] The embodiment of the utility model provides an IGBT module to solve the problems of complex process flow, high cost, low yield and low thermal conductivity efficiency of the IGBT module packaging structure in the prior art.

[0006] The utility model discloses an IGBT module, comprising a housing, an IGBT chip and an aluminum-based copper-clad plate; the aluminum-based copper-clad plate comprises an aluminum plate, an oxide film layer, a silicon carbide layer, a nickel-copper alloy layer and a first copper layer; the oxide film layer is formed on both sides of the aluminum plate, the silicon carbide layer is formed on the oxide film layer on both sides of the aluminum plate, the nickel-copper alloy layer is formed on the silicon carbide layer on both sides of the aluminum plate, and the first copper layer is formed on the nickel-copper alloy layer on both sides of the aluminum plate;

[0007] The IGBT chip is fixed on the first copper layer of the aluminum-based copper-clad plate, and the shell is fixed on the aluminum-based copper-clad plate and covers the IGBT chip.

[0008] Optionally, a second copper layer and a first solder layer are arranged between the IGBT chip and the first copper layer, the second copper layer is fixed on the first copper layer, the first solder layer is fixed on the second copper layer, and the IGBT chip is fixed on the first solder layer.

[0009] Optionally, the IGBT module further includes a heat sink, which is fixedly arranged on a side of the aluminum-based copper-clad laminate facing away from the housing.

[0010] Optionally, the heat dissipation member is made of aluminum, and multiple rows of heat dissipation fins are provided on the side of the heat dissipation member facing away from the aluminum-based copper clad laminate.

[0011] Optionally, the heat dissipation member is fixedly arranged on the aluminum-based copper clad laminate through fasteners.

[0012] Optionally, a thermal conductive silica gel is coated between the heat dissipation member and the aluminum-based copper clad laminate.

[0013] Optionally, the interior of the housing is filled with a silicone material, and the silicone material encapsulates and fixes the IGBT chip.

[0014] Optionally, the interior of the housing is filled with epoxy resin, and the epoxy resin is filled between the silicone material and the top of the housing.

[0015] Optionally, the thickness range of the oxide film layer is 12 μm to 25 μm; and / or, the thickness range of the silicon carbide layer is 500 nm to 1000 nm.

[0016] Optionally, the thickness range of the nickel-copper alloy layer is 70 nm to 100 nm; and / or, the thickness range of the first copper layer is 0.2 mm to 0.5 mm.

[0017] Compared with the prior art, the beneficial effects of the IGBT module provided by the embodiment of the present utility model are as follows: The IGBT module in the present utility model uses an aluminum-based copper clad laminate as the encapsulation carrier board, and the IGBT chip is fixedly arranged on the first copper layer of the aluminum-based copper clad laminate, without using a ceramic substrate and a copper heat sink, and omitting the copper layer and the solder layer between the ceramic substrate and the copper heat sink, saving the costs of the ceramic substrate, the copper heat sink and the bonding process, with low cost, simple process, improving the production yield, simpler structure, eliminating the thermal conduction resistance caused by the multi-layer structure, and having high thermal conduction efficiency. Description of the Drawings

[0018] The technical solutions of the present utility model will be further described in detail below in conjunction with the drawings. In the drawings:

[0019] Figure 1 is a schematic diagram of the encapsulation structure of a traditional IGBT module;

[0020] Figure 2 is a schematic diagram of the IGBT module of the embodiment of the present utility model;

[0021] Figure 3 is a schematic diagram of the aluminum-based copper clad laminate of the embodiment of the present utility model.

[0022] The reference numerals in the drawings are as follows:

[0023] 1. Housing; 2. IGBT chip; 3. Aluminum-based copper clad laminate; 31. Aluminum sheet; 32. Oxide film layer; 33. Silicon carbide layer; 34. Nickel-copper alloy layer; 35. First copper layer; 4. Second copper layer; 5. First solder layer; 6. Heat sink; 61. Heat dissipation fins; 7. Fastener; 8. Thermal conductive silicone; 9. Organosilicon material; 10. Epoxy resin; 20. Metal bonding wire; 30. Busbar terminal; 40. Copper layer; 50. Solder layer; 60. Ceramic substrate; 70. Copper heat conduction block. Detailed implementation manners

[0024] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Now, in combination with the drawings, the preferred embodiments of the present utility model will be described in detail.

[0025] An embodiment of the present utility model provides an IGBT module, as Figure 2 shown, the IGBT module includes a housing 1, an IGBT chip 2 and an aluminum-based copper clad laminate 3. The aluminum-based copper clad laminate 3 includes an aluminum sheet 31, an oxide film layer 32, a silicon carbide layer 33, a nickel-copper alloy layer 34 and a first copper layer 40; the oxide film layer 32 is formed on both sides of the aluminum sheet 31, the silicon carbide layer 33 is formed on the oxide film layer 32 on both sides of the aluminum sheet 31, the nickel-copper alloy layer 34 is formed on the silicon carbide layer 33 on both sides of the aluminum sheet 31, and the first copper layer 40 is formed on the nickel-copper alloy layer 34 on both sides of the aluminum sheet 31.

[0026] The IGBT chip 2 is fixedly arranged on the first copper layer 40 of the aluminum-based copper clad laminate 3, and the housing 1 is fixedly arranged on the aluminum-based copper clad laminate 3 and covers the IGBT chip 2.

[0027] In the IGBT module of the present utility model, the aluminum-based copper clad laminate 3 is used as the packaging carrier board, the IGBT chip 2 is fixedly arranged on the first copper layer 40 of the aluminum-based copper clad laminate 3, the ceramic substrate 60 and the copper heat conduction block 70 are not used, and the copper layer 40 and the solder layer 50 between the ceramic substrate 60 and the copper heat conduction block 70 are omitted, saving the costs of the ceramic substrate 60, the copper heat conduction block 70 and the bonding process, having low cost, simple process, improving the production yield, having a simpler structure, eliminating the heat conduction resistance caused by the multi-layer structure, and having high heat conduction efficiency.

[0028] And because the aluminum-based copper clad laminate 3 includes an aluminum sheet 31, an oxide film layer 32, a silicon carbide layer 33, a nickel-copper alloy layer 34 and a first copper layer 40, it can greatly improve the heat conduction rate, and the coefficient of thermal expansion (CTE) on the surface of the aluminum-based copper clad laminate 3 is small, the thermal expansion performance is good, and it has better thermal stability; and the adhesion between the layers of the aluminum-based copper clad laminate 3 is better, and the surface insulation and high-voltage resistance performance are excellent.

[0029] Specifically, in the aluminum-based copper clad laminate 3 of the present utility model, the thermal conductivity of the silicon carbide layer 33 can reach up to 400 W / m·K, increasing the infrared emissivity of the aluminum-based copper clad laminate 3 and improving the overall heat dissipation effect of the aluminum-based copper clad laminate 3. Therefore, plating the silicon carbide layer on the aluminum sheet 31 can improve the thermal conductivity of the aluminum-based copper clad laminate 3; the CTE value of the aluminum sheet 31 itself is very large, 26 times that of ceramics, and plating the silicon carbide layer on the aluminum sheet 31 can reduce the CTE value.

[0030] The structure of the aluminum sheet 31 itself is relatively soft and the structural strength is low, making it difficult to firmly bond with the silicon carbide layer 33. Therefore, delamination is likely to occur between the silicon carbide layer 33 and the aluminum sheet 31, while the oxide film layer 32 can increase the adhesion between the silicon carbide layer 33 and the aluminum sheet 31, improve the adhesion of the silicon carbide layer 33 and increase the content of the silicon carbide layer. The aluminum sheet 31 itself is not insulated. In the present utility model, after forming the oxide film layer 32 on the surface of the aluminum sheet 31, the silicon carbide layer 33 is plated, which can improve the insulation of the aluminum-based copper clad laminate 3. That is, the silicon carbide layer 33 can enhance the surface hardness of the aluminum sheet 31 and improve the impact resistance, and can also make the aluminum sheet 31 become insulated.

[0031] Using the nickel-copper alloy layer 34 as the transition layer between the silicon carbide layer 33 and the first copper layer 40 can solve the problem that pure copper is too soft to form good adhesion with the silicon carbide layer, and at the same time solve the problem that the etching of the etched circuit is not easy due to using titanium metal as the transition layer between copper and ceramics in the ceramic substrate 60.

[0032] Therefore, for the aluminum-based copper clad laminate 3 of the present utility model, forming the oxide film layer 32 on the surface of the aluminum sheet 31 and plating the silicon carbide layer on the surface can solve the insulation and withstand voltage problems. After treatment, the withstand voltage can reach more than 2000 volts, and after plating the silicon carbide layer, the withstand voltage can be increased to more than 7000 volts. The thermal conductivity of the aluminum-based copper clad laminate 3 can reach 280 W / m·K, and the thermal conductivity is more than 8 times that of the current ceramic substrate 60.

[0033] Specifically, the aluminum sheet 31 can be a pure aluminum sheet 31 or an aluminum alloy sheet. When the aluminum-based copper clad laminate 3 is used as a packaging carrier board, the first copper layer 40 conducts electricity as a conductor, and conductive circuits can be prepared thereon.

[0034] The thickness range of the oxide film layer 32 is 12 μm to 25 μm, the thickness range of the silicon carbide layer 33 is 500 nm to 1000 nm, the thickness range of the nickel-copper alloy layer 34 is 70 nm to 100 nm, and the thickness range of the first copper layer 40 is 0.2 mm to 0.5 mm.

[0035] Specifically, the aluminum-based copper clad laminate 3 can be prepared by the following preparation method:

[0036] S100: Clean the oxide on the surface of the aluminum sheet 31 with dilute sulfuric acid at a concentration of 2% - 5%.

[0037] S200: After cleaning the aluminum sheet 31 with the acid solution, use a corona equipment to bombard the surface electrode of the aluminum sheet 31 to form an oxide film layer 32 with a thickness of 12um - 25um.

[0038] S300: Use a magnetron physical vapor deposition equipment (PVD), with the target material being silicon carbide with a purity of 99.9%, and deposit a silicon carbide layer 33 with a thickness of 500nm - 1000nm on the oxide film layer 32.

[0039] S400: After the aluminum sheet 31 is coated with the silicon carbide layer 33, transfer it to another PVD equipment, with the target material being a nickel - copper alloy (alloy ratio: nickel: copper = 7:3), and deposit a nickel - copper alloy layer 34 on the silicon carbide layer 33, and the thickness range of the nickel - copper alloy layer 34 is 70nm - 100nm.

[0040] S500: Sputter a first copper layer 40 with a thickness of 1000nm - 2000nm on the nickel - copper alloy, and then electroplate the first copper layer 40 with a thickness of 1000nm - 2000nm to a thickness of 0.2mm - 0.5mm to obtain the aluminum - based copper - clad laminate 3, as Figure 3 shown.

[0041] Specifically, a first copper layer 40 with a thickness of 1000nm - 2000nm can be sputtered on the nickel - copper alloy through vacuum nano - coating technology, and then the first copper layer 40 with a thickness of 1000nm - 2000nm can be electroplated to a thickness of 0.2mm - 0.5mm through vertical copper - plating wire (VCP). Vacuum nano - coating is a surface treatment technology that deposits materials (such as copper) in the form of nano - scale particles onto the substrate material in a vacuum environment. Vertical copper - plating wire is an electroplating equipment used in the manufacture of electronic packaging materials, which allows the material to be vertically suspended in the electroplating bath, and deposits the first copper layer 40 on the material surface through electroplating. The VCP technology can provide a uniform coating and can control the thickness of the coating. Further, after the step of depositing the first copper layer 40 on the nickel - copper alloy layer 34, an antioxidant treatment, that is, corona treatment, is performed on the first copper layer 40.

[0042] Specifically, a second copper layer 4 and a first solder layer 5 are provided between the IGBT chip 2 and the first copper layer 40, the second copper layer 4 is fixed on the first copper layer 40, the first solder layer 5 is fixed on the second copper layer 4, and the IGBT chip 2 is fixed on the first solder layer 5. The first solder layer 5 firmly fixes the IGBT chip 2 on the second copper layer 4 during the welding process. The first solder layer 5 has good ductility and toughness under thermal cycles and mechanical stress, which helps to improve the reliability of the module. Each electrode (such as the emitter, collector and gate) of the IGBT chip 2 adopts a metal bonding wire 20, which is electrically connected to the second copper layer 4 through a wire bonding technology, and transmits current from the IGBT chip 2 to an external circuit through a busbar terminal 30, thereby achieving electrical connection with the external circuit. The metal bonding wire 20 can be a gold wire, an aluminum wire or a copper wire.

[0043] The IGBT module also includes a heat sink 6, which is fixed on the side of the aluminum-based copper-clad laminate 3 facing away from the housing 1. The provision of the heat sink 6 can significantly improve the heat dissipation capacity of the IGBT module. Since the IGBT module generates a large amount of heat when working, an effective heat dissipation design is essential to maintaining the stable operation and extending the service life of the IGBT module. Specifically, the heat sink 6 is made of aluminum, and a plurality of rows of heat sink fins 61 are provided on the side of the heat sink 6 facing away from the aluminum-based copper-clad laminate 3. The plurality of rows of heat sink fins 61 increase the surface area of ​​the heat sink 6, thereby improving the heat dissipation efficiency and allowing more heat to be dissipated through air convection. The heat sink 6 is fixed on the aluminum-based copper-clad laminate 3 by fasteners 7. The use of fasteners 7 can ensure that a stable mechanical connection is formed between the heat sink 6 and the aluminum-based copper-clad laminate 3, reducing displacement or falling off due to vibration or thermal expansion. The fasteners 7 can be rivets, screws, etc.

[0044] Furthermore, a thermally conductive silicone 8 is coated between the heat sink 6 and the aluminum-based copper-clad laminate 3. As a thermally conductive material, the thermally conductive silicone 8 can effectively fill the micro gap between the heat sink 6 and the aluminum-based copper-clad laminate 3 to form a thin and uniform heat conduction layer, improve the thermal interface, reduce thermal resistance, and improve the efficiency of heat transfer from the IGBT chip 2 to the heat sink 6.

[0045] Furthermore, the interior of the housing 1 is filled with a silicone material 9, and the silicone material 9 encapsulates and fixes the IGBT chip 2. The filling of the silicone material 9 can provide a stable support for the IGBT chip 2, reducing displacement or damage caused by vibration or shock. The filled silicone material 9 can protect the IGBT chip 2 from moisture, dust, and other environmental factors, extending the service life of the IGBT chip 2. The interior of the housing 1 is filled with an epoxy resin 10, and the epoxy resin 10 is filled between the silicone material 9 and the top of the housing 1. The epoxy resin 10 has high mechanical strength and can provide additional physical protection for the IGBT chip 2 against external shocks and vibrations. The filling of the epoxy resin 10 can reduce the noise caused by vibration of the internal components of the IGBT module and improve the working stability of the module.

[0046] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. For those skilled in the art, the technical solutions described in the above embodiments can be modified, or some of the technical features can be equivalently replaced; and all such modifications and replacements should fall within the protection scope of the appended claims of the present invention.

Claims

1. An IGBT module, characterized in that, The invention comprises a housing, an IGBT chip and an aluminum-based copper-clad laminate; the aluminum-based copper-clad laminate comprises an aluminum plate, an oxide film layer, a silicon carbide layer, a nickel-copper alloy layer and a first copper layer; the oxide film layer is formed on both sides of the aluminum plate, the silicon carbide layer is formed on the oxide film layer on both sides of the aluminum plate, the nickel-copper alloy layer is formed on the silicon carbide layer on both sides of the aluminum plate, and the first copper layer is formed on the nickel-copper alloy layer on both sides of the aluminum plate; The IGBT chip is fixed on the first copper layer of the aluminum-based copper-clad laminate, and the housing is fixed on the aluminum-based copper-clad laminate and covers the IGBT chip.

2. The IGBT module according to claim 1, characterized in that, A second copper layer and a first solder layer are arranged between the IGBT chip and the first copper layer, the second copper layer is fixed on the first copper layer, the first solder layer is fixed on the second copper layer, and the IGBT chip is fixed on the first solder layer.

3. The IGBT module according to claim 1, characterized in that, The IGBT module further comprises a heat sink, which is fixedly arranged on a side of the aluminum-based copper-clad laminate facing away from the housing.

4. The IGBT module according to claim 3, characterized in that, The heat sink is made of aluminum, and a plurality of rows of heat sink fins are arranged on a side of the heat sink facing away from the aluminum-based copper-clad laminate.

5. The IGBT module according to claim 3, wherein, The heat sink is fixed on the aluminum-based copper-clad plate by fasteners.

6. The IGBT module according to claim 3, characterized in that Thermally conductive silica gel is coated between the heat sink and the aluminum-based copper-clad laminate.

7. The IGBT module according to claim 1, characterized in that, The shell is filled with organic silicon material, and the organic silicon material encapsulates and fixes the IGBT chip.

8. The IGBT module according to claim 7, characterized in that, The inside of the shell is filled with epoxy resin, and the epoxy resin is filled between the organic silicon material and the top of the shell.

9. The IGBT module according to any one of claims 1 to 8, characterized in that, The thickness of the oxide film layer ranges from 12um to 25um; and / or the thickness of the silicon carbide layer ranges from 500nm to 1000nm.

10. The IGBT module according to any one of claims 1 to 8, characterized in that, The thickness of the nickel-copper alloy layer is in the range of 70 nm to 100 nm; and / or the thickness of the first copper layer is in the range of 0.2 mm to 0.5 mm.

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