Connection Structure of IGBT Integrated Module

Abstract

The present invention relates to a connection structure of an IGBT integrated module, comprising: a busbar, an elastic conductive connecting piece, an IGBT chip, and a housing, wherein the busbar is electrically connected to the IGBT chip through the elastic conductive connecting piece, and the housing fixes the busbar and the chip; the IGBT integrated module provided by the present invention has stable electrical performance, stable heat dissipation, anti-vibration, long product life, and good environmental adaptability. The production process of the IGBT integrated module is simple, and machine intelligent production can be adopted for mass production.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and more particularly, to a connection structure of an IGBT integrated module and the formed IGBT integrated module. Background Art

[0002] IGBT (Insulated Gate Bipolar Transistor), an insulated gate bipolar transistor, is a composite fully controlled voltage-driven power semiconductor device composed of a BJT (bipolar junction transistor) and a MOS (insulated gate field effect transistor), combining the advantages of high input impedance of MOSFET and low conduction voltage drop of GTR. GTR has a low saturation voltage drop and a large current density, but requires a large drive current; MOSFET has a very small drive power and a fast switching speed, but a large conduction voltage drop and a small current density. IGBT combines the advantages of the above two devices, with small drive power and low saturation voltage drop. It is very suitable for application in variable current systems with a DC voltage of 600V or above, such as AC motors, frequency converters, switching power supplies, lighting circuits, traction drives, etc. An IGBT module is a modular semiconductor product formed by bridging and packaging an IGBT (insulated gate bipolar transistor chip) and an FWD (freewheeling diode chip) through a specific circuit; the packaged IGBT module is directly applied to devices such as frequency converters and UPS uninterruptible power supplies.

[0003] IGBT modules are applied in a wide range of powers and industries, such as locomotive traction, electric vehicles, charging stations, wind power generation, power transmission, industrial frequency conversion, etc.; with the promotion of concepts such as electrical intelligence and energy conservation and environmental protection, their role in the market is becoming increasingly important. Currently, all IGBT modules in the world adopt the structure of traditional low-power modules. With the substantial increase in the power of IGBT modules, their electrical performance, safety, and lifespan are severely tested. In most existing IGBT modules, the electrical power terminals and the high-power semiconductor chip circuit structure are connected by welding. This connection method can achieve atomic-level close electrical contact, but problems such as low process accuracy and poor heat dissipation are obvious. Moreover, under long-term operation or environmental aging conditions, the heat stress at the welding part is prone to excessive concentration, leading to easy degradation and failure of the IGBT module. The pressure connection technology can solve this problem to a certain extent. In an IGBT module, the electrical power terminals and the high-power semiconductor chip circuit structure are connected by elastic crimping to achieve durable electrical contact, thereby avoiding heat stress accumulation. The prior Chinese patents CN205428895U and CN205428916U both propose an IGBT integrated module with a pressure connection structure, which does not require welding and solves the above problems to a certain extent. However, its conductive connection requires the connection between the busbar contact claws and the chip, and the number and method of chip connection cannot be changed. The process is complex and it is not convenient to replace and repair the IGBT chip when a failure occurs or is needed after use. Summary of the Invention

[0004] To solve the above problems, the object of the present invention is to provide a connection structure for an IGBT integrated module, including: a busbar, an elastic conductive connecting member, an IGBT chip, and a housing. It is characterized in that: the busbar is electrically connected to the IGBT chip through the elastic conductive connecting member, and the housing fixes the busbar and the chip. The material of the conductive connecting member is metal, such as copper, aluminum, iron, etc., and can also be any other substance that can conduct electricity, such as conductive polymer materials, semiconductor materials, etc.; the elasticity means that the conductive connecting member can be compressed and deformed and can still rebound after compression and deformation. In the connection structure, the busbar and the chip are electrically connected through the elastic conductive connecting member. At this time, the elastic conductive connecting member has a certain amount of compression and deformation, and the housing fixes the chip and the busbar so that the busbar and the chip cannot move relatively. Specifically, they cannot move relatively and separate along the direction of the conductive connecting member.

[0005] Further, the connection structure of the IGBT integrated module further includes an installation groove provided on the busbar for the elastic conductive connecting member to be inserted. Through the installation groove, the elastic conductive connecting member can be connected to the busbar. The installation groove accommodates the contact end of the elastic conductive connecting member and the busbar and restricts its sliding along the surface of the busbar; the elastic conductive connecting member can only move along the direction of its compression and extension, and the movement in other directions, especially the movement perpendicular to the compression and extension direction, is restricted.

[0006] Further, the housing further includes mounting holes, and the chip is mounted in the mounting holes. Further, the connection structure of the IGBT integrated module further includes a chip substrate. The chip is fixed on the chip substrate, and the chip substrate is mounted in the mounting holes. The mounting holes accommodate the chip substrate and define its position, so that it is in a fixed position on the lower surface of the housing and cannot slide randomly on the lower surface of the housing. Further, the mounting holes also have a certain depth, which can accommodate the contact end of the elastic conductive connecting member and the chip and make the contact end in a fixed position; make the contact end can only move along the direction of compression and extension of the elastic conductive connecting member on the contact surface, and the movement in other directions, especially the movement perpendicular to the compression and extension direction, is restricted.

[0007] Further, the installation grooves on the busbar are one or more, and can connect one or more of the elastic conductive connecting members. The mounting holes on the housing are one or more, and can mount one or more of the IGBT chips. The one or more IGBT chips are correspondingly connected to the one or more elastic conductive connecting members;

[0008] Further, according to the integrated modules with different power ratings, that is, according to different numbers and positions of the chips, elastic conductive connectors with different numbers, positions, directions, and / or current-carrying capacities can be selected to connect the bus bar and the chips. When one or more of the elastic conductive connectors are connected to one or more of the chips, they can be correspondingly inserted into one or more of the mounting grooves;

[0009] Further, the elastic conductive connector is generally in the shape of a calabash-shaped conductor. The width of the middle part is relatively large, and the widths of the upper and lower connecting ends are relatively small. The connecting end connected to the bus bar is two wound contacts, which can be inserted into the mounting groove of the bus bar. The connecting end connected to the chip is a flat contact, which can be connected to the chip;

[0010] Further, the connection structure further includes a radiator. The frame is connected to the radiator by bolts, so that the integrated module is locked on the radiator;

[0011] Further, the bus bar includes a positive plate, a negative plate, and a series connection plate, and each is insulated once by powder coating, and the three plates are bonded into a whole by a polymer sheet.

[0012] For the powder coating used for insulation, the insulating material used is an epoxy resin material or a synthetic material of epoxy resin plus glass fiber. In the embodiments of the present invention, the insulating material, insulating pad, or insulating powder used is an epoxy resin material without special instructions.

[0013] The polymer sheet can be, for example, made of polyethylene terephthalate (PET) material. The polymer sheet mainly plays the following several roles: one is insulation, the second is bonding to bond the positive plate, the negative plate, and the series connection plate together, and the third is anti-oxidation. After bonding, the positive plate, the negative plate, and the series connection plate are partially or completely coated by the polymer material, playing an anti-oxidation role.

[0014] Further, the bus bar is an integrally formed bus bar, and mounting grooves are formed on the bus bar. One end of the elastic conductive connector is inserted into the mounting groove to be connected to the bus bar, and the other end of the elastic conductive connector is connected to the chip. The chip is fixed on the chip substrate, and the chip substrate is installed in the mounting hole of the frame. The frame is used to fix the bus bar and the chip substrate to form an integrated module. Preferably, the integrally formed method is injection molding or molding. The bus bar is integrally formed into one body by injection molding and molding, and a whole plastic shell is formed on the outside of the bus bar, and one or more mounting grooves for the elastic conductive connectors to be inserted are formed on the plastic shell.

[0015] In addition, the present invention also provides a method for assembling or connecting the connection structures of the above-mentioned IGBT integrated modules. According to the integrated modules with different power levels, that is, according to the different numbers and different positions of the chips, elastic conductive connectors with different numbers, positions, directions, and / or current-carrying capacities can be selected to connect the bus bar and the chips. That is, when one or more of the elastic conductive connectors are connected to one or more of the chips, they can be correspondingly inserted into one or more of the mounting grooves.

[0016] In addition, the present invention also provides an IGBT integrated module, including: a bus bar, an elastic conductive connector, a chip, a chip substrate, and a frame. It is characterized in that one end of the elastic conductive connector is connected to the bus bar, and the other end is connected to the chip. The chip is fixed on the chip substrate, and the frame fixes the bus bar and the chip substrate;

[0017] Furthermore, for the IGBT integrated module, mounting grooves for inserting the elastic conductive connectors are formed on the bus bar. Through the mounting grooves, the elastic conductive connectors can be connected to the bus bar;

[0018] Furthermore, for the IGBT integrated module, there are mounting holes on the frame. The chip substrate can be placed in the mounting holes to fix the chip substrate;

[0019] Furthermore, for the IGBT integrated module, the mounting grooves on the bus bar are one or more, which can connect one or more of the elastic conductive connectors. The mounting holes on the frame are one or more, which can fix one or more of the chip substrates. Each of the chip substrates can further include one or more of the chips, and the one or more chips are correspondingly connected to the one or more elastic conductive connectors;

[0020] Furthermore, for the IGBT integrated module, according to the integrated modules with different power levels, that is, according to the different numbers and different positions of the chips, elastic conductive connectors with different numbers, positions, directions, and / or current-carrying capacities can be selected to connect the bus bar and the chips. When one or more of the elastic conductive connectors are connected to one or more of the chips, they can be correspondingly inserted into one or more of the mounting grooves;

[0021] Furthermore, for the IGBT integrated module, the shape of the elastic conductive connector is generally gourd-shaped. The width of the middle part is relatively large, and the widths of the upper and lower connection ends are relatively small. The connection end connected to the bus bar is two wound contacts, which can be inserted into the mounting grooves on the bus bar. The connection end connected to the chip is a flat contact, which can be connected to the chip;

[0022] Further, for the IGBT integrated module, the frame is connected to the radiator by bolts, so that the integrated module is locked on the radiator;

[0023] Further, for the IGBT integrated module, the bus bar includes a positive plate, a negative plate and a series connection plate, and each is insulated once by powder coating, and the three plates are bonded into a whole by a polymer sheet;

[0024] Further, a method for connecting an IGBT integrated module uses an integrally formed bus bar, and an installation groove is formed on the bus bar. One end of an elastic conductive connector is inserted into the installation groove to be connected to the bus bar, and the other end of the elastic conductive connector is connected to a chip. The chip is fixed on a chip substrate, and the chip substrate is installed in an installation hole of a frame, and the frame is used to fix the bus bar and the chip substrate to form an integrated module;

[0025] Further, for the method for connecting an IGBT integrated module, according to the integrated modules with different power ratings, that is, according to different numbers and positions of the chips, elastic conductive connectors with different numbers, positions, directions and / or current-carrying capacities can be selected to be connected to the bus bar and the chip, that is, when one or more elastic conductive connectors are connected to one or more chips, they can be correspondingly inserted into one or more of the installation grooves.

[0026] The electrical connection described in the present invention means that this connection method is conductive and its conductivity is reliable. The polymer sheet can be made of, for example, polyethylene terephthalate (PET) material. The polymer sheet mainly plays the following several roles: one is insulation, the second is bonding to bond the positive plate, the negative plate and the series connection plate together, and the third is anti-oxidation. After bonding, the positive plate, the negative plate and the series connection plate are partially or completely coated by the polymer material, playing an anti-oxidation role.

[0027] Compared with the prior art: the IGBT integrated module provided by the present invention has stable electrical performance, stable heat dissipation, anti-vibration, long product life and good environmental adaptability. The production process of this IGBT integrated module is simple, and machine intelligent production can be adopted for mass production, greatly reducing the production cost; this IGBT integrated module can easily change the product model and technical requirements according to different powers and structures, reducing the development cost and shortening the development cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a front view (excluding the frame) of the integrated module of the present invention.

[0029] Figure 2 is a top view (including the frame) of the integrated module of the present invention.

[0030] Figure 3It is a schematic diagram of the slotting on the busbar of the integrated module of the present invention.

[0031] Figure 4 It is a structural diagram of the elastic conductive connector of the integrated module of the present invention.

[0032] Figure 5 It is a schematic diagram of the housing of the integrated module of the present invention.

[0033] Figure 6 It is a three-dimensional schematic diagram of the integrated module of the present invention (excluding the housing). Detailed implementation mode

[0034] The following is further illustrated by examples:

[0035] As Figure 1-6 shown, an IGBT integrated module 1 includes: a busbar 2, an elastic conductive connector 3, a chip 4, a chip substrate 5, and a housing 6. The busbar 2 is at the top, the elastic conductive connector 3 is in the middle, its upper end is connected to the busbar 2, and its lower end is connected to the chip 4. The chip 4 is fixed on the chip substrate 5. There are mounting holes 7 at the lower part of the housing 6. The chip substrate is mounted on the housing 6 through the mounting holes 7, so that the chip substrate 2 can be horizontally fixed. The housing 6 fixes the busbar 2 and the chip substrate 5 integrally from top to bottom. The housing 6 is connected to a radiator (not shown) through bolts, so that the integrated module 1 is locked on the radiator. That is, while the elastic conductive connector 3 flexibly connects the busbar 2 and the chip 4, it flexibly presses the chip substrate 5 and the radiator.

[0036] The busbar plates are made of semi-hard high-conductivity copper alloy. The positive and negative plates of the busbar and the series connection plates are each insulated and oxidized by powder coating. At the overlapping joints of each plate for incoming and outgoing, the busbar 2 is integrally formed and bonded with a low-water-absorbing and high-voltage-resistant polymer sheet, and at the same time, a second voltage withstand treatment is carried out. The thickness of the insulating layer coated on each side of each plate of the busbar 2 is 0.3 mm - 0.5 mm, and the voltage withstand reaches 20 KV / mm. The thickness of the polymer sheet bonding layer is 0.2 mm, and the voltage withstand reaches 25 KV / mm. The three plates are insulated for the first time by coating, and then the three plates are bonded into a whole by the polymer sheet for the second insulation. The busbar 2 is integrally plasticized to ensure that the IGBT integrated module has a good anti-vibration effect; through integral plasticization and forming, a plurality of mounting grooves 8 are formed. Specifically, the mounting grooves 8 are on the outer layer of the busbar after plasticization, as Figure 3As shown, there are 14 mounting slots 8 on the bus bar, which are the placement areas and spare placement areas for the elastic conductive connectors 3. According to the power of the IGBT integrated module 1 or different structures, the number, position, direction and current-carrying capacity of the elastic conductive connectors 3 can be arbitrarily changed. At this time, according to needs, the elastic conductive connectors 3 can be inserted into one or more of the mounting slots 8 of the bus bar 2 as corresponding, which can be flexibly applied. Different structural layouts can be carried out according to different product structures, and different specifications of products can be flexibly developed and designed according to the needs of customer products, reducing the development cost.

[0037] As Figure 4 shown, the elastic conductive connector 3 is a flexible metal connector and is treated with silver plating for anti-oxidation. Its shape is roughly a gourd-shaped frame. The width of the middle part is relatively large, and the contact widths of the upper and lower parts are relatively small. The connection end 9 with the bus bar is two wound contacts, which can be inserted into the mounting slot 8 of the bus bar. The corresponding position at the mounting slot 8 of the bus bar is not insulated and coated, so as to form an electrical connection. The connection end 10 with the chip is a flat contact, which can be crimped with the antenna of the chip 4 to form an electrical connection. The height of the elastic conductive connector is 20 mm, the length is 12 mm, and the width is 5 mm.

[0038] As Figure 5-6 shown, 2 mounting holes 7 are formed on the frame 6. The 2 nickel-based chip substrates 5 are crimped in the mounting holes 7 by the elastic conductive connectors 3. There are 6 groups of chips 4 on each chip substrate 5. The lower ends of the 12 elastic conductive connectors 3 are respectively crimped with the 12 chips 4, and the upper ends are respectively inserted into the mounting slots 8 of the bus bar 2. The frame 6 further fixes the bus bar 2 and the chip substrate 5 as a whole. There is also a pressing plate 11 between the frame 6 and the bus bar 2. The bus bar 2 is pressed by the pressing plate 11. The pressing plate can also be omitted, and the unslotted side of the integrally plasticized bus bar is set as the pressed surface. The frame 6 integrally encapsulates the bus bar 2, the elastic conductive connectors 3 and the chip substrate 5 to form the integrated module 1, and then is locked on the radiator (not shown) by bolts. The chip substrate 5 is directly crimped in the mounting hole 7 and contacts with the radiator for heat dissipation.

[0039] When the IGBT integrated module 1 is assembled, there is a certain amount of overlapping dimension in the vertical direction between the bus bar 2, the elastic conductive connecting piece 3, and the chip substrate 5. When tightened by bolts, the elastic conductive connecting piece 3 flexibly connects the chip 4 and the bus bar 2, and the contact force generated by the overlapping dimension also reduces the thermal resistance between the chip substrate 4 and the heat dissipation module. The elastic conductive connection 3 of this module 1 does not need to be welded and is directly assembled into the required installation groove 8 to conduct electricity between the bus bar 2 and the chip 4 without damaging the flexible electric connection piece material and affecting the stability of the product, solving the problem of electrical instability caused by thermal expansion and contraction of the product. It can also provide good contact force to effectively fit the radiator, provide good heat dissipation performance without affecting the performance of the chip, prevent mechanical force from damaging the chip, and protect the uniform contact between the chip substrate and the radiator plane. At the same time, the flexible connection can effectively compensate for the overall fitting error of the module. At the same time, external structural components such as the pressure plate and the frame body are made of high thermal conductivity molecular materials, which not only solves the heat dissipation of the chip by the radiator but also achieves the overall heat dissipation of the IGBT integrated module, reducing the power consumption of the module and improving the life and safety of the module at the same time.

[0040] At the same time, a connection method corresponding to this module is as follows: First, a bus bar formed by integral plastic molding is used, and one or more installation grooves are formed on the bus bar. One end of the elastic conductive connecting piece is inserted into the installation groove to be electrically connected to the bus bar, and the other end of the elastic conductive connecting piece is connected to the chip. The chip is fixed on the chip substrate, and the chip substrate is installed in the installation hole of the frame body. The bus bar and the chip substrate are fixed by the frame body to form an integrated module. Finally, the frame body is connected to the radiator by bolts, so that the integrated module is locked on the radiator. According to the different numbers and positions of the chips, elastic conductive connecting pieces with different numbers, positions, directions, and / or current-carrying capacities can be selected to be connected to the bus bar and the chip, that is, when one or more elastic conductive connecting pieces are connected to one or more chips, they can be correspondingly inserted into one or more of the installation grooves.

[0041] The electrical connection described in the present invention means that this connection method is conductive and its conductivity is reliable. The polymer sheet material can be, for example, polyethylene terephthalate PET material. The polymer sheet material mainly plays the following several roles: First, it is insulating; second, it bonds the positive plate, the negative plate, and the series connection plate together; third, it is anti-oxidation. After bonding, the positive plate, the negative plate, and the series connection plate are partially or completely coated by the polymer material to play an anti-oxidation role. The insulating material is an epoxy resin material or a synthetic material of epoxy resin plus glass fiber. In the embodiments of the present invention, the insulating material, insulating pad, or insulating powder used is epoxy resin material without special instructions.

[0042] It is understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims

1. A connection structure of an IGBT integrated module, comprising: Bus bar, elastic conductive connector, IGBT chip, and housing, characterized in that: the bus bar is electrically connected to the IGBT chip through the elastic conductive connector, the housing fixes the bus bar and the chip, and further includes an installation groove provided on the bus bar for inserting the elastic conductive connector. Through the installation groove, the elastic conductive connector can be connected to the bus bar. The housing further includes installation holes, and the chip is installed in the installation holes. There are multiple installation grooves on the bus bar, which can connect one or more elastic conductive connectors. There are one or more installation holes on the housing, which can install one or more IGBT chips. The one or more IGBT chips are correspondingly connected to the one or more elastic conductive connectors. According to the integrated module of different power ratings, that is, according to the different numbers and positions of the chips, elastic conductive connectors with different numbers, positions, directions, and / or current-carrying capacities can be selected to be connected to the bus bar and the chip. When one or more elastic conductive connectors are connected to one or more chips, they can be correspondingly inserted into one or more of the installation grooves.

2. The connection structure according to claim 1, wherein, The elastic conductive connector is a conductive body with a generally gourd-like shape. The width of the middle part is relatively large, and the widths of the upper and lower connecting ends are relatively small. The connecting end connected to the bus bar is two wound contacts, which can be inserted into the installation groove of the bus bar. The connecting end connected to the chip is a flat contact, which can be connected to the chip.

3. The connection structure according to any one of claims 1-2, characterized in that, The connection structure further includes a radiator. The housing is connected to the radiator by bolts, so that the integrated module is locked on the radiator.

4. The connection structure according to any one of claims 1-3, characterized in that, The bus bar includes a positive plate, a negative plate, and a series connection plate, and each is insulated once by powder coating, and the three plates are bonded into a whole by a polymer sheet.

5. The connection structure according to any one of claims 1-4, characterized in that, The bus bar is an integrally formed bus bar, and an installation groove is formed on the bus bar. One end of the elastic conductive connector is inserted into the installation groove to be connected to the bus bar, and the other end of the elastic conductive connector is connected to the chip. The chip is fixed on a chip substrate, and the chip substrate is installed in the installation hole of the housing. The housing fixes the bus bar and the chip substrate to form an integrated module.

6. The assembly method of the connection structure according to any one of claims 1-5. According to the integrated module of different power ratings, that is, according to the different numbers and positions of the chips, elastic conductive connectors with different numbers, positions, directions, and / or current-carrying capacities can be selected to be connected to the bus bar and the chip. That is, when one or more elastic conductive connectors are connected to one or more chips, they can be correspondingly inserted into one or more of the installation grooves.

Images