A power module

Abstract

The application relates to the field of power electronics, and provides a power module, which comprises: a heat dissipation bottom plate arranged at the bottom of the power module; an outer shell connected to the circumferential side of the heat dissipation bottom plate through sealing glue; a plurality of DBC backing plates welded on the heat dissipation bottom plate; a plurality of chips arranged on the DBC backing plates; a plurality of copper connecting sheets; the copper connecting sheet comprises a first welding part used for welding to the surface of the chip, a second welding part used for welding to the surface of the DBC backing plate, and a strip-shaped connecting section connecting the first welding part and the second welding part; and a plurality of copper connecting bridges used for connecting different DBC backing plates. The power terminal and the DBC connection of the application adopt an ultrasonic welding mode, compared with the traditional bonding wire connection power terminal, the power terminal of the ultrasonic welding has stronger overcurrent capacity and stronger anti-vibration capacity, the chip and the DBC connection adopt the copper connecting sheet, the DBC and the DBC connection adopt the copper connecting bridge, and the copper connecting sheet and the copper connecting bridge have stronger overcurrent capacity and stronger anti-vibration capacity.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, specifically to a power module. Background Technology

[0002] Power modules are a crucial component of the power electronics industry, performing functions such as power conversion, inversion, and rectification based on different circuit topologies. They are widely used in industrial control, rail transportation, consumer electronics, and new energy vehicles. As power module applications become increasingly demanding, their overcurrent capabilities face new challenges. Traditionally, the connection between the chip and the DBC (Direct Copper Ceramic Substrate) uses bonding wires. The DBC is a composite substrate made by directly sintering copper foil onto the ceramic surface at high temperatures using a thermoforming bonding method. The connection between the DBC and the power terminals also uses bonding wires. However, bonding wires generally have limited overcurrent capabilities, and under excessive current conditions, they are prone to melting. Furthermore, power modules using bonding wires are susceptible to wire detachment and breakage during vibration testing, severely impacting module reliability.

[0003] Traditional wire bonding is a common connection technology in the field of electronic packaging, mainly used to connect pads on a chip to external pins or pads on the packaging substrate. Wire bonding typically uses gold, aluminum, or copper wires as the connecting material, and the two ends of the wire are soldered to the chip pads and the packaging substrate pads respectively through processes such as thermoforming, ultrasonic bonding, or thermo-ultrasonic bonding, thereby achieving electrical connection and mechanical fixation.

[0004] When power modules connected by bond wires are subjected to vibration testing, bond wires may come loose or break, which seriously affects the reliability of the modules. Utility Model Content

[0005] To help solve the above-mentioned technical problems, this application provides a power module, which adopts the following technical solution: A power module, comprising: A heat dissipation base plate is located at the bottom of the power module to provide heat dissipation and mechanical support; The outer casing is connected to the periphery of the heat dissipation base plate by sealant to provide a sealed protection; Several DBC liners are welded to the heat dissipation base plate to provide current conduction and electrical insulation; Several chips are disposed on the DBC substrate; A plurality of copper connecting tabs are used to connect the chip and the DBC substrate; the copper connecting tabs include a first welding part for welding to the surface of the chip, a second welding part for welding to the surface of the DBC substrate, and a strip-shaped connecting segment connecting the first welding part and the second welding part; the first welding part, the second welding part and the connecting segment are integrally formed structures; Several copper connecting bridges are used to connect different DBC liners; the copper connecting bridges have a concave structure with a raised center, and flat connecting pieces extending outward on both sides, the flat connecting pieces being welded and fixed to the corresponding DBC liners respectively.

[0006] Preferably, the plurality of DBC liners include a first DBC liner, a second DBC liner, and a third DBC liner. The first DBC liner and the second DBC liner are disposed on the upper and lower sides of the third DBC liner. The first DBC liner includes a first left DBC liner and a first right DBC liner connected by a copper connecting bridge. The second DBC liner includes a second left DBC liner and a second right DBC liner connected by a copper connecting bridge.

[0007] Preferably, the third DBC substrate has a T-shaped structure, including a first connecting part and a second connecting part. The chip is disposed on both the second connecting part and the first DBC substrate. The chip on the first DBC substrate is connected to the second connecting part through a copper connecting piece. The chip on the second connecting part is connected to the second DBC substrate through a copper connecting piece. The second connecting part includes a second left connecting part and a second right connecting part connected by a copper connecting bridge.

[0008] Preferably, power terminals are provided on the inner walls of the left and right sides of the housing. The power terminals are bent structures, and the extensions of the bent structures are welded and fixed to the DBC liner.

[0009] Preferably, the power terminals on the left inner wall are welded and fixed to the first connecting part, and the power terminals on the right inner wall are welded and fixed to the second DBC liner and the third DBC liner.

[0010] Preferably, the heat sink base plate is connected to the DBC substrate, the DBC substrate to the chip, and the chip to the copper connecting piece by welding or sintering, and the power terminal is connected to the DBC substrate by ultrasonic welding.

[0011] Preferably, the connection between the DBC backing plate and the power terminal is made of bare copper material to improve the quality of ultrasonic welding.

[0012] Preferably, the DBC liner is used to set circuits corresponding to the application conditions of the power module, the power module is filled with silicone gel or epoxy resin, and the outer shell is connected to the heat dissipation base plate through silicone rubber.

[0013] In summary, this application has the following beneficial effects: 1. The power terminals of this power module are connected to the DBC using ultrasonic welding. Compared with the traditional bonding wire connection of power terminals, the power terminals of ultrasonic welding have stronger overcurrent capacity and stronger vibration resistance.

[0014] 2. The chip is connected to the DBC using copper connecting pieces, and the DBCs are connected to each other using copper connecting bridges. Compared with traditional bonding wires, copper connecting pieces and copper connecting bridges have stronger current carrying capacity and stronger vibration resistance. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of one embodiment of a power module according to this application; Figure 2 for Figure 1 Top view of the embodiment shown.

[0016] Reference numerals: 10-Heat dissipation base plate; 20-House casing; 21-Power terminal; 30-DBC liner; 31-First left DBC liner; 32-First right DBC liner; 33-Second left DBC liner; 34-Second right DBC liner; 35-First connecting part; 36-Second left connecting part; 37-Second right connecting part; 40-Chip; 50-Copper connecting bridge; 51-Planar connecting piece; 60-Copper connecting piece; 61-First welding part; 62-Second welding part; 63-Strip connecting segment. Detailed Implementation

[0017] The present application will be further described below with reference to the accompanying drawings. The structure and principle of the present application are very clear to those skilled in the art. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

[0018] Figure 1 This is a schematic diagram of the structure of one embodiment of a power module according to this application. Figure 2 for Figure 1 Top view of the embodiment shown.

[0019] The power module proposed in this application includes: A heat dissipation base plate 10 is disposed at the bottom of the power module to provide heat dissipation and mechanical support; The outer casing 20 is connected to the periphery of the heat dissipation base plate 10 by sealant to provide a sealed protection; Several DBC liners 30 are welded onto the heat dissipation base plate 10 to provide current conduction and electrical insulation; Several chips 40 are disposed on the DBC substrate 30; A plurality of copper connecting pieces 60 are used to connect the chip 40 and the DBC substrate 30; the copper connecting piece 60 includes a first welding part 61 for welding to the surface of the chip 40, a second welding part 62 for welding to the surface of the DBC substrate 30, and a strip-shaped connecting segment 63 connecting the first welding part 61 and the second welding part 62; the first welding part 61, the second welding part 62 and the connecting segment 63 are integrally formed structures; Several copper connecting bridges 50 are used to connect different DBC liners 30; the copper connecting bridges 50 have a concave structure with a raised middle, and flat connecting pieces 51 extending outward on both sides, and the flat connecting pieces 51 are welded and fixed to the corresponding DBC liners 30 respectively.

[0020] It should be noted that in the embodiments of this application, both the first welding part 61 and the second welding part 62 are connecting pieces made of copper.

[0021] Specifically, the heat sink 10 is located at the bottom of the power module, providing heat dissipation and mechanical support; the housing 20 is connected to the heat sink 10 via silicone rubber, providing sealed protection for the power module; the DBC liner 30 is welded to the heat sink 10, providing a current path and insulation for the power module; the chip 40 is welded or sintered to the DBC liner 30, providing electrical characteristics for the power module. The DBC liner 30 is used to install circuits corresponding to the application conditions of the power module.

[0022] The plurality of DBC liners 30 include a first DBC liner, a second DBC liner, and a third DBC liner. The first DBC liner and the second DBC liner are disposed on the upper and lower sides of the third DBC liner. The first DBC liner includes a first left DBC liner 31 and a first right DBC liner 32 connected by a copper connecting bridge 50. The second DBC liner includes a second left DBC liner 33 and a second right DBC liner 34 connected by a copper connecting bridge 50.

[0023] It should be noted that in this article, "up," "down," "left," and "right" refer to... Figure 2 The top, bottom, left, and right sides are used as the standard.

[0024] from Figure 2 As can be seen, the third DBC backing plate has a T-shaped structure. The third DBC backing plate includes a first connecting part 35 and a second connecting part. The chip 40 is provided on both the second connecting part and the first DBC backing plate. The chip 40 on the first DBC backing plate is connected to the second connecting part through a copper connecting piece 60. The chip 40 on the second connecting part is connected to the second DBC backing plate through a copper connecting piece 60. The second connecting part includes a second left connecting part 36 and a second right connecting part 37 connected by a copper connecting bridge 50.

[0025] Power terminals 21 are provided on the inner walls of the left and right sides of the outer casing 20. The power terminals 21 have a bent structure, and the extension of the bent structure is welded and fixed to the DBC liner 30.

[0026] The power terminal 21 on the left inner wall is welded and fixed to the first connecting part 35, and the power terminal 21 on the right inner wall is welded and fixed to the second DBC liner and the third DBC liner.

[0027] The heat dissipation base plate 10 is connected to the DBC liner plate 30, the DBC liner plate 30 is connected to the chip 40, and the chip 40 is connected to the copper connecting piece 60 by welding or sintering. The power terminal 21 is connected to the DBC liner plate 30 by ultrasonic welding to improve the quality of ultrasonic welding.

[0028] The connection points between the DBC backing plate 30 and the power terminals 21 are made of bare copper to improve the quality of ultrasonic welding. The DBC backing plate 30 is used to install circuitry corresponding to the operating conditions of the power module. The power module is filled with silicone gel or epoxy resin, and the outer casing 20 is connected to the heat dissipation base plate 10 via silicone rubber. Ultrasonic welding of the power terminals 21, the copper connecting bridge 50, and the copper connecting piece 60 replace traditional bonding wire connections, improving the power module's overcurrent capacity and vibration resistance, preventing melting, detachment, and breakage, and enhancing the reliability of the power module.

[0029] In summary, the power terminals and DBCs of this application are connected by ultrasonic welding. Compared with traditional wire bonding, ultrasonically welded power terminals have stronger current carrying capacity and vibration resistance. The connection between chip 40 and DBC uses copper connecting piece 60, and the connection between DBCs uses copper connecting bridge 50. Compared with traditional wire bonding, copper connecting piece and copper connecting bridge have stronger current carrying capacity and vibration resistance.

Claims

1. A power module, characterized in that, include: A heat dissipation base plate is located at the bottom of the power module to provide heat dissipation and mechanical support; The outer casing is connected to the periphery of the heat dissipation base plate by sealant to provide a sealed protection; Several DBC liners are welded to the heat dissipation base plate to provide current conduction and electrical insulation; Several chips are disposed on the DBC substrate; A plurality of copper connecting tabs are used to connect the chip and the DBC substrate; the copper connecting tabs include a first welding part for welding to the surface of the chip, a second welding part for welding to the surface of the DBC substrate, and a strip-shaped connecting segment connecting the first welding part and the second welding part; the first welding part, the second welding part and the connecting segment are integrally formed structures; Several copper connecting bridges are used to connect different DBC liners; the copper connecting bridges have a concave structure with a raised center, and flat connecting pieces extending outward on both sides, the flat connecting pieces being welded and fixed to the corresponding DBC liners respectively.

2. The power module according to claim 1, characterized in that, The plurality of DBC liners include a first DBC liner, a second DBC liner, and a third DBC liner. The first DBC liner and the second DBC liner are disposed on the upper and lower sides of the third DBC liner. The first DBC liner includes a first left DBC liner and a first right DBC liner connected by a copper connecting bridge. The second DBC liner includes a second left DBC liner and a second right DBC liner connected by a copper connecting bridge.

3. The power module according to claim 2, characterized in that, The third DBC substrate has a T-shaped structure, including a first connecting part and a second connecting part. The chip is provided on both the second connecting part and the first DBC substrate. The chip on the first DBC substrate is connected to the second connecting part through a copper connecting piece. The chip on the second connecting part is connected to the second DBC substrate through a copper connecting piece. The second connecting part includes a second left connecting part and a second right connecting part connected by a copper connecting bridge.

4. The power module according to claim 3, characterized in that, Power terminals are provided on the inner walls of the left and right sides of the outer casing. The power terminals are bent structures, and the extensions of the bent structures are welded and fixed to the DBC liner.

5. The power module according to claim 4, characterized in that, The power terminals on the left inner wall are welded and fixed to the first connection part, and the power terminals on the right inner wall are welded and fixed to the second DBC liner and the third DBC liner.

6. The power module according to claim 1, characterized in that, The heat sink base plate is connected to the DBC substrate, the DBC substrate to the chip, and the chip to the copper connector by welding or sintering. The power terminals are connected to the DBC substrate by ultrasonic welding.

7. The power module according to claim 1, characterized in that, The connections between the DBC backing plate and the power terminals are made of bare copper to improve the quality of ultrasonic welding.

8. The power module according to claim 1, characterized in that, The DBC liner is used to set up circuits corresponding to the application conditions of the power module. The power module is filled with silicone gel or epoxy resin, and the outer shell is connected to the heat dissipation base plate through silicone rubber.

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