Power module based on copper clamp and lead bonding and electronic equipment

Abstract

The power module mounting substrate based on bonding of the copper clamp and the lead comprises a chip, the copper clamp and the lead, the chip is mounted on the mounting substrate, the copper clamp comprises a chip connecting part and a substrate connecting part which are integrally formed, the substrate connecting part is connected with the mounting substrate, and the chip connecting part is connected with the chip. The lead comprises a copper clamp lead, a substrate lead and a chip lead, the copper clamp lead is connected with the chip connecting part, two ends of the substrate lead are respectively bonded with the substrate connecting parts of two different copper clamps, and the chip lead is connected with the chip. The power module and the electronic equipment based on bonding of the copper clamp and the lead solve the problems that the bonding point is easy to fall off and the falling off or pseudo soldering of the bonding point cannot be found even.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, in particular to a power module and electronic equipment based on copper clip and wire bonding. Background Art

[0002] Inverter power modules are developing towards high power density and high efficiency. This requires the power module to be smaller in size, with lower losses, with higher current carrying capacity, and with lower parasitic inductance ESL. The wire bonding process has the advantages of low cost, wide application, and mature technology, and is widely used in power device packaging. The stable and reliable use of power modules requires not only high reliability and durability, but also higher and higher requirements for their size, weight, and power. These requirements pose challenges to the chip-substrate connection and chip-chip connection.

[0003] Existing power modules mostly use wire bonding technology to achieve electrical interconnection and form a circuit, such as Figure 2 As shown, the electrical connection between the chips of the device power circuit is connected by bonding wires. The traditional wire bonding process usually requires multiple thick wire bonding (Wire Bond) on the power circuit during the packaging process of high-power devices, but the more wire bonding is used, the lower the production efficiency. The more bonding points there are, each bonding point is a potential failure risk point. Under the influence of the thermal stress of the switching cycle, the bonding point is prone to fall off, causing the entire device to fail. In addition, multiple bonding will also cover up the problem of bonding quality. When a bonding point falls off or is poorly soldered, it is usually not discovered immediately, but the fault will often spread secretly, and other bonding wires will be overloaded and overheated, causing other wires to fail in turn. In addition, wire bonding often requires a relatively high wire arc height to circulate between the chip and the substrate or between the chip and the chip, which will bring about problems related to the packaging space. Finally, the use of wire bonding technology to achieve electrical connections for power device packages will bring about larger parasitic inductance (ESL) and parasitic resistance (ESR) problems. In particular, larger parasitic inductance is an important factor affecting the switching performance of the device. Larger parasitic inductance not only limits the switching speed of the power device, but also causes greater losses together with the parasitic resistance effect. Utility Model Content

[0004] In view of the above shortcomings of the prior art, the purpose of the utility model is to provide a power module and electronic equipment based on copper clips and wire bonding, which are used to solve the problems in the prior art that bonding points are easy to fall off and it is impossible to timely detect the falling off of bonding points or cold soldering. The electrical connection of the module power circuit is achieved by bonding wires on the copper clip to connect the various sub-chips of the chip, and at the same time, the copper clip is used as a medium to connect the chip and the substrate respectively.

[0005] The utility model provides a power module based on copper clip and wire bonding, comprising:

[0006] Install the base plate;

[0007] Chip, the chip is mounted on a mounting substrate;

[0008] A copper clip, the copper clip comprising an integrally formed chip connection portion and a substrate connection portion, the substrate connection portion being connected to the mounting substrate, and the chip connection portion being connected to the chip;

[0009] Leads include copper clip leads, substrate leads and chip leads. The copper clip leads are bonded to the chip connection part of the copper clip. Both ends of the substrate lead are respectively bonded to the substrate connection parts of two different copper clips. The chip leads are connected to the chip.

[0010] In one embodiment of the present invention, each chip includes a gate portion and a source portion, and the source portion is connected to the chip connection portion of the copper clip.

[0011] In one embodiment of the present invention, within the same half bridge, the copper clip leads are respectively bonded to the chip connection portion of the copper clip corresponding to each chip.

[0012] In one embodiment of the present invention, in the same half bridge, all chips are connected in series through the same chip lead.

[0013] In one embodiment of the present invention, the gate portion of the chip is wire-bonded to the chip.

[0014] In an embodiment of the present invention, in the same half bridge, the chip leads are bonded to each chip in sequence.

[0015] In one embodiment of the present invention, the lower surface of the substrate connection part of the copper clip is sintered with the mounting substrate, and the upper surface of the substrate connection part is bonded with the substrate wire.

[0016] In an embodiment of the present invention, in the same half bridge, substrate connection parts of two adjacent copper clips are connected via substrate leads.

[0017] In one embodiment of the present utility model, the power module further comprises a heat dissipation substrate, the heat dissipation substrate and the mounting substrate are sintered, and the mounting substrate and the chip are sintered.

[0018] The utility model also provides an electronic device, which comprises any one of the above-mentioned packaging structures.

[0019] The utility model provides a power module and electronic device based on copper clip and wire bonding, wherein the copper clip is used as a medium to connect the chip and the substrate respectively, and then the corresponding wires are bonded, thereby realizing the electrical connection of the module power circuit. Specifically, the utility model connects the chip and the substrate through the copper clip, each copper clip includes a chip connection part and a substrate connection part, and then the current of the chip is led out to form a loop through the copper clip bonded copper clip wire welded on the chip source, and then the substrate connection parts of different copper clips welded on the substrate are bonded together through the substrate wire, and finally the chip wire is bonded to the chip, and the signal loop is derived through the chip wire. At the same time, in the utility model, any copper clip wire that completes the bonding has the same length, and the length of any substrate wire is also equal to each other, so that the current path length of each chip in the power circuit is as consistent as possible, so that the parasitic inductance and parasitic resistance of each chip caused by the electrical connection are close, thereby improving the current sharing degree of the parallel chips of the power module. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 It is a partial schematic diagram of the power module of the utility model;

[0022] Figure 2 A schematic diagram of a power module in the prior art;

[0023] Figure 3 It is a schematic diagram of the position layout of the power modules in one embodiment of the utility model.

[0024] Component number

[0025] Mounting substrate 10 , heat dissipation substrate 20 , chip 30 , gate portion 31 , source portion 32 , copper clip 40 , chip connection portion 41 , substrate connection portion 42 , lead 50 , copper clip lead 51 , substrate lead 52 , chip lead 53 . DETAILED DESCRIPTION

[0026] The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0027] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0028] In the following description, a large number of details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0029] Inverter power modules are developing towards high power density and high efficiency. This requires the power module to be smaller in size, with lower losses, with higher current carrying capacity, and with lower parasitic inductance ESL. The wire bonding process has the advantages of low cost, wide application, and mature technology, and is widely used in power device packaging. The stable and reliable use of power modules requires not only high reliability and durability, but also higher and higher requirements for their size, weight, and power. These requirements pose challenges to the chip-substrate connection and chip-chip connection.

[0030] like Figure 2As shown, the existing power modules mostly use wire bonding technology to achieve electrical interconnection to form a loop, and the electrical connection between the chips in the device power loop is connected by bonding wires. In the prior art, a wire 50 is generally used to directly bond with the chip 30 and the substrate 10. This connection method easily leads to the breakage of the bonding point and the problem of being unable to detect the breakage of the bonding point in time. The utility model uses a copper clip as a medium to connect the chip and the substrate respectively, thereby realizing the electrical connection of the module power loop, and the source signal of the chip is led out through the wire bonding above the copper clip to form a signal loop of the power module. At the same time, the distance between the bonding leads is ensured to be consistent, so that the parasitic inductance and parasitic resistance of each chip caused by the electrical connection are close, thereby improving the current sharing degree of the parallel chips in the power module. The structure of the power module is described in detail below.

[0031] Combination Figure 1 As shown, a power module based on copper clip and wire bonding of the utility model is shown. The power module based on copper clip and wire bonding of the utility model comprises a mounting substrate 10, a chip 30, a copper clip 40 and a lead 50, wherein the chip 30 is mounted on the mounting substrate 10. The copper clip 40 comprises an integrally formed chip connection portion 41 and a substrate connection portion 42, wherein the substrate connection portion 42 is connected to the mounting substrate 10, and the chip connection portion 41 is connected to the chip 30. The lead 50 comprises a copper clip lead 51, a substrate lead 52 and a chip lead 53, wherein the copper clip lead 51 is connected to the chip connection portion 41, and both ends of the substrate lead 52 are respectively bonded to the substrate connection portions 42 of two different copper clips 40, and the chip lead 53 is connected to the chip 30.

[0032] like Figure 1 The figure shows a partial schematic diagram of the technical solution of the utility model. The power module provided by the utility model includes a mounting substrate 10, a chip 30, a copper clip 40 and a lead 50. The mounting substrate 10 is mounted on the heat dissipation substrate 20, and a welding layer is sandwiched between the mounting substrate 10 and the heat dissipation substrate 20 for welding the mounting substrate 10 and the heat dissipation substrate 20. The heat dissipation substrate 20 is generally made of an insulating material with high thermal conductivity, so that the heat dissipation effect of the mounting substrate 10 can be guaranteed without affecting the signal circuit. A plurality of chips 30 are mounted on the mounting substrate 10, and the chips 30 are welded to the mounting substrate 10, and the chips 30 are insulated from the mounting substrate 10. The copper clip lead 51 is bonded to the chip connection part 41 in the same half bridge, and the substrate lead 52 is bonded to the copper clip body 41 on different copper clips 40.

[0033] Figure 3An embodiment of the utility model is shown. Each chip 30 provided by the utility model includes a gate part 31 and a source part 32. In this embodiment, three chips 30 form a group. Two groups of chips are arranged in a chip half-bridge structure. Adjacent chips 30 in the same group are arranged in parallel and at equal distances. They are all arranged in parallel on the mounting substrate 10. A copper clip 40 is installed on the chip 30. One end of the copper clip 40 is welded to the chip 30 and the other end is welded to the mounting substrate 10. A welding layer is provided between the copper clip 40, the chip 30 and the mounting substrate 10. The copper clip 40 includes an integrally formed chip connection part 41 and a substrate connection part 42. The substrate connection part 42 is connected to the mounting substrate 10, and the chip connection part 41 is connected to the chip 30. In this embodiment, one copper clip 40 corresponds to a group of chips 30, and one copper clip 40 includes three chip connection parts 41 and one substrate connection part 42. The function of the copper clip 40 is to electrically connect the mounting substrate 10 and the chip 30, thereby realizing the electrical connection of the power module circuit. It should be noted that the utility model does not limit the number of chips 30 in each group and the number of chip connection parts 41, and it is only necessary that the number of chip connection parts 41 is consistent with the number of chips 30 in the chipset. The material of the copper clip 40 is not limited, and it only needs to be a metal conductive material. In this embodiment, a copper clip is used, and a silver-plated copper clip, a silver clip, and an iron-nickel alloy stamping clip can also be used. The lead 50 includes a copper clip lead 51, a substrate lead 52, and a chip lead 53. The copper clip lead 51 is connected to the chip connection part 41, and the two ends of the substrate lead 52 are respectively bonded to the substrate connection parts 42 of two different copper clips 40, and the chip lead 53 is connected to the chip 30. One end of the copper clip lead 51 and the chip lead 53 are respectively connected to the fixing member 60, and the fixing member 60 is an insulating structure, which fixes the lead 50. The chip connection part 41 in the same half bridge is bonded to the copper clip lead 51, the chip 30 in the same half bridge is connected in series through the chip lead 53, and the gate part 31 of the chip 30 is bonded to the chip lead 53. The substrate lead 52 is used to connect the copper clip body 41 of two different copper clips 40, and the two ends of the substrate lead 52 are respectively bonded to the end of the copper clip body 41 away from the copper clip lead 51, and the lengths of different substrate leads 52 are also equal. This connection relationship generally occurs between two copper clips 40 in a half bridge structure. When the circuit between the substrate connection parts 42 of the two copper clips 40 cannot be directly connected in a straight line due to reasons such as insulation parts and discontinuous parts, and needs to be arranged in a bypass, and cannot be directly connected through the mounting substrate 10, it is necessary to connect through the substrate lead 52. There is no limitation on the material of the lead 50, including but not limited to copper wire, aluminum wire, palladium-plated copper, aluminum-magnesium wire and aluminum-nickel wire. The copper clip lead 51 and the substrate lead 52 realize the electrical connection of the loop, and the chip lead 53 realizes the signal connection of the loop.

[0034] like Figure 3As shown, in order to ensure the current equalization degree of the parallel chips of the power module, the chip layout structure is improved in this embodiment, including four groups of chips 30, and two adjacent chips 30 are connected by substrate leads 52. By adjusting the shape of the copper clip and the connection layout of the chip, the current path length of each chip in the power circuit is made as consistent as possible, which can improve the current equalization degree of the parallel chips of the power module. In this embodiment, by designing the shape structure of the copper clip and arranging the position of the connection bonding points of the copper clip 40 and each sub-chip of the chip 30, the distance between the bonding point of the copper clip lead 51 on the chip connection part 41 and the bonding point of the substrate lead 52 on the substrate connection part 42 is equal, and the length of the substrate lead 52 connecting different substrate connection parts 42 is also equal. The power module structure adopted in this embodiment uses a copper clip 40 to connect the mounting substrate 10 and the chip 30 respectively. The contact area of ​​the copper clip 40 is large, which greatly reduces the probability of bonding point falling off and cold soldering. At the same time, it effectively reduces the total parasitic resistance and parasitic inductance of the power circuit, significantly improves the thermal conductivity and heat dissipation performance of the power module, improves the switching characteristics of the power module, and thus improves the current capacity and power density of the power module. In addition, the chip and the substrate are connected by a copper clip, which avoids the bonding weak points caused by wire bonding, improves the ability to withstand power cycles, and enhances the reliability of the module. When the power module is packaged, the first step is to print silver paste on the mounting substrate 10, the second step is to place the chip 30 on the mounting substrate 10 and sinter it, the third step is to place the copper clip 40 on the chip and sinter it, the fourth step is to perform wire bonding on the copper clip 40 to lead out the signal current, the fifth step is to perform plastic packaging, and the sixth step is to punch and cut to form the power module.

[0035] The utility model also provides an electronic device, including the above-mentioned power module.

[0036] The utility model discloses a power module and electronic device based on copper clip and wire bonding, wherein the copper clip is used as a medium to connect the chip and the substrate respectively, and then the corresponding wires are bonded, thereby realizing the electrical connection of the module power circuit. Specifically, the utility model connects the chip and the substrate through the copper clip, each copper clip includes a chip connection part and a substrate connection part, and then the circuit signal of the chip is led out through the copper clip bonding copper clip wire welded on the chip source, and then the substrate connection parts of different copper clips welded on the substrate are bonded together through the substrate wire, and finally the chip wire is bonded to the gate part of the chip, and the signal circuit is derived through the chip wire. At the same time, in the utility model, any copper clip wire that completes the bonding has the same length, and the length of any substrate wire is also equal to each other, so that the current path length of each chip in the power circuit is as consistent as possible, so that the parasitic inductance and parasitic resistance of each chip caused by the electrical connection are close, thereby improving the current sharing degree of the parallel chips of the power module.

[0037] Therefore, the power module and electronic device based on copper clip and wire bonding of the utility model can solve the problems of the prior art that the bonding points are easy to fall off and the bonding point fall off or cold solder joint cannot be discovered immediately.

[0038] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed in the present invention shall still be covered by the claims of the present invention.

Claims

1. A power module based on copper clip and wire bonding, characterized in that: include: Mounting substrate (10); A chip (30), wherein the chip (30) is mounted on the mounting substrate (10); A copper clip (40), the copper clip (40) comprising a chip connection portion (41) and a substrate connection portion (42) formed integrally, the substrate connection portion (42) being connected to the mounting substrate (10), and the chip connection portion (41) being connected to the chip (30); A lead (50), the lead (50) comprising a copper clip lead (51), a substrate lead (52) and a chip lead (53), the copper clip lead (51) being bonded to the chip connection portion (41) of the copper clip (40), two ends of the substrate lead (52) being respectively bonded to the substrate connection portions (42) of two different copper clips (40), and the chip lead (53) being connected to the chip (30).

2. The power module based on copper clip and wire bonding according to claim 1, characterized in that: Each of the chips (30) comprises a gate portion (31) and a source portion (32), and the source portion (32) is connected to the chip connection portion (41) of the copper clip (40).

3. The power module based on copper clip and wire bonding according to claim 2, characterized in that: In the same half bridge, the copper clip lead (51) is respectively bonded to the chip connection portion (41) of the copper clip (40) corresponding to each chip (30).

4. The power module based on copper clip and wire bonding according to claim 3, characterized in that: In the same half bridge, all the chips (30) are connected in series via the same chip lead (53).

5. The power module based on copper clip and wire bonding according to claim 4, characterized in that: The gate portion (31) of the chip (30) is bonded to the chip lead (53).

6. The power module based on copper clip and wire bonding according to claim 5, characterized in that: In the same half bridge, the chip leads (53) are respectively bonded to each chip (30) in sequence.

7. The power module based on copper clip and wire bonding according to claim 1, characterized in that: The lower surface of the substrate connection part (42) of the copper clip (40) is sintered with the mounting substrate (10), and the upper surface of the substrate connection part (42) is bonded to the substrate lead (52).

8. The power module based on copper clip and wire bonding according to claim 7, characterized in that: In the same half bridge, the substrate connection parts (42) of two adjacent copper clips (40) are connected via the substrate lead wire (52).

9. The power module based on copper clip and wire bonding according to claim 1, characterized in that: The power module further comprises a heat dissipation substrate (20), wherein the heat dissipation substrate (20) and the mounting substrate (10) are sintered, and the mounting substrate (10) and the chip (30) are sintered.

10. An electronic device, comprising the power module according to any one of claims 1 to 9.

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