A press-fit IGBT module

Abstract

The present invention discloses a press-fit IGBT module. In the present invention, a conductive liquid structure is arranged in an inner cavity between an emitter electrode and a collector electrode. When any chip fails, an arc is generated between the failure point of the chip and the upper molybdenum sheet of the failed chip, which burns through the shell. The conductive liquid flows out from the burn-through point, covering all chips in the inner cavity and the space around the chips, thereby short-circuiting the covered conductive structure and achieving a good and stable short circuit between the emitter electrode and the collector electrode, so that the press-fit IGBT module has a stable long-term short-circuit failure function.

Description

Technical Field

[0001] The invention relates to a press-connected IGBT module, belonging to the field of power semiconductor device packaging. Background Art

[0002] Developed to meet the needs of high-voltage flexible power transmission applications, the press-fit IGBT module is a new type of IGBT module designed for easy series connection to increase switching voltage. It is a core component for high-voltage, high-current power conversion in power grids, and its long-term reliability and stability are crucial to the long-term operation of the power grid. However, when a press-fit IGBT module fails in high-voltage, high-current applications, it will cause a short circuit due to overcurrent heating, melting, or arc erosion within a limited timeframe of one minute or one hour. Therefore, when designing power grid switching valve groups, redundant designs and bypass short-circuit systems are necessary to ensure the long-term safety of the valve group. Although internationally renowned press-fit IGBT module suppliers have all adopted different design structures to improve the short-circuit failure resistance of IGBT modules, these structures only provide safe short-circuit bypass when the press-fit IGBT device fails, and are insufficient to ensure long-term short-circuit resistance. Summary of the Invention

[0003] The present invention provides a press-fit IGBT module, which solves the problems disclosed in the background technology.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A press-fit IGBT module comprises an emitter electrode and a collector electrode arranged opposite to each other, a conductive liquid structure and several chip structures being arranged in an inner cavity between the emitter electrode and the collector electrode, the chip structure comprising a press-fit conductive structure, an upper molybdenum sheet, a chip and a lower molybdenum sheet stacked in sequence, the upper end of the press-fit conductive structure being connected to the emitter electrode, and the bottom surface of the lower molybdenum sheet being connected to the collector electrode, the conductive liquid structure comprising a shell and a conductive liquid enclosed in the shell; when any chip fails, an arc is generated between the chip failure point and the upper molybdenum sheet of the failed chip, burning through the shell, and the conductive liquid flows out from the burn-through point, covering all chips in the inner cavity and the space around the chips.

[0006] The cross section of the pressure member in the pressure conductive structure is smaller than the top surface area of ​​the upper molybdenum sheet.

[0007] The bottom surface of the conductive liquid structure is flush with the top surface of the upper molybdenum sheet, and the outflowing conductive liquid covers the space below the conductive liquid structure.

[0008] The conductive liquid is gallium-indium alloy liquid or mercury liquid.

[0009] If the press-fit IGBT module is a rigid press-fit IGBT module, the press-fit conductive structure is a rigid press-fit conductive metal.

[0010] If the press-fit IGBT module is an elastic press-fit IGBT module, the press-fit conductive structure includes an elastic press-fit structure provided between the emitter electrode and the upper molybdenum sheet, and a bypass metal conductive sheet connecting the emitter electrode and the upper molybdenum sheet.

[0011] The beneficial effects achieved by the present invention are as follows: the present invention sets a conductive liquid structure in the inner cavity between the emitter electrode and the collector electrode. When any chip fails, an arc is generated between the chip failure point and the upper molybdenum sheet of the failed chip to burn through the shell. The conductive liquid flows out from the burn-through point, covering all chips in the inner cavity and the space around the chip, thereby short-circuiting the covered conductive structure, achieving a good and stable short circuit between the emitter electrode and the collector electrode, and making the press-fit IGBT module have a stable long-term short-circuit failure function. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a structural diagram of a first embodiment of a press-fit IGBT module;

[0013] Figure 2 This is a structural diagram of the second embodiment of the press-fit IGBT module. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0015] like Figure 1 As shown, a press-fit IGBT module, specifically a rigid press-fit IGBT module, includes an emitter electrode 1 and a collector electrode 2 arranged opposite to each other, and a conductive liquid structure and a plurality of chip structures are arranged in the inner cavity between the emitter electrode 1 and the collector electrode 2.

[0016] The chip structure is a centrally symmetrical structure, including a pressure-applying conductive structure 3, an upper molybdenum sheet 6, a chip 7 and a lower molybdenum sheet 8 stacked in sequence. The upper end of the pressure-applying conductive structure 3 is connected to the emitter electrode 1, and the bottom surface of the lower molybdenum sheet 8 is connected to the collector electrode 2.

[0017] The pressure-applying conductive structure 3 passes through the conductive liquid structure. The cross-section of the pressure piece in the pressure-applying conductive structure 3 is smaller than the top surface area of ​​the upper molybdenum sheet 6. The area reduction is mainly to provide mechanical support for the conductive liquid structure. The area reduction needs to be compromised with the flow area. The cross-section of the pressure piece can be determined specifically in combination with the flow requirements of the single chip 7.

[0018] The pressure-applying conductive structure 3 is a rigid pressure-applying conductive metal, and the pressure-applying part is also a conductive part, that is, the emitter electrode 1 and the upper molybdenum sheet 6 are directly connected through the rigid pressure-applying conductive metal, and the connection surface of the chip 7 is directly pressure-applied and contacted through the rigid pressure-applying conductive metal, and the current flows directly through the rigid pressure-applying conductive metal.

[0019] The bottom surface of the conductive liquid structure is flush with the top surface of the upper molybdenum sheet 6. The conductive liquid structure includes a shell 4 and a conductive liquid 5 enclosed in the shell 4. The shell 4 is made of an organic plastic material or a thin metal material with a melting point higher than 150°C and is easily melted. The conductive liquid 5 is a gallium-indium alloy liquid.

[0020] When any chip 7 fails, the module current is concentrated through the failed chip 7, so that an arc is generated between the failure point of the chip 7 and the upper molybdenum sheet 6 of the failed chip 7. The arc will burn through the shell 4. At this time, the conductive liquid 5 will flow out from the burn-through point, and the flowing liquid will cover all the chips 7 in the inner cavity and the space around the chip 7, specifically covering the space under the conductive liquid structure, thereby short-circuiting the covered conductive structure, achieving a good and stable short circuit between the emitter electrode 1 and the collector electrode 2, so that the press-fit IGBT module has a stable long-term short-circuit failure function.

[0021] like Figure 2 As shown, a press-fit IGBT module, specifically an elastic press-fit IGBT module, includes an emitter electrode 1 and a collector electrode 2 arranged opposite to each other, and a conductive liquid structure and a plurality of chip structures are arranged in the inner cavity between the emitter electrode 1 and the collector electrode 2.

[0022] The chip structure is a centrally symmetrical structure, including a pressure-applying conductive structure 3, an upper molybdenum sheet 6, a chip 7 and a lower molybdenum sheet 8 stacked in sequence. The upper end of the pressure-applying conductive structure 3 is connected to the emitter electrode 1, and the bottom surface of the lower molybdenum sheet 8 is connected to the collector electrode 2.

[0023] The pressure conductive structure 3 passes through the conductive liquid structure. The cross-section of the pressure part in the pressure conductive structure 3 is smaller than the top surface area of ​​the upper molybdenum sheet 6. The area reduction is mainly to provide mechanical support for the conductive liquid structure. The area reduction needs to be compromised with the flow area. The cross-section of the pressure conductive structure 3 can be determined in combination with the flow requirements of the single chip 7.

[0024] The pressure conductive structure 3 includes an elastic pressure structure 10 arranged between the emitter electrode 1 and the upper molybdenum sheet 6, and a bypass metal conductive sheet 9 connecting the emitter electrode 1 and the upper molybdenum sheet 6. The elastic pressure structure 10 is a pressure part, which can be a flexible pressure component such as a spring or a butterfly spring. The elastic pressure structure 10 is used to apply pressure to the connection surface of the chip 7. The bypass metal conductive sheet 9 is a conductive part, and current flows through the bypass metal conductive sheet 9.

[0025] The bottom surface of the conductive liquid structure is flush with the top surface of the upper molybdenum sheet 6. The conductive liquid structure includes a shell 4 and a conductive liquid 5 enclosed in the shell 4. The shell 4 is made of an organic plastic material or a thin metal material with a melting point higher than 150°C and is easily melted. The conductive liquid 5 is a gallium-indium alloy liquid.

[0026] When any chip 7 fails, the module current is concentrated through the failed chip 7, so that an arc is generated between the failure point of the chip 7 and the upper molybdenum sheet 6 of the failed chip 7. The arc will burn through the shell 4. At this time, the conductive liquid 5 will flow out from the burn-through point, and the flowing liquid will cover all the chips 7 in the inner cavity and the space around the chip 7, specifically covering the space under the conductive liquid structure, thereby short-circuiting the covered conductive structure, achieving a good and stable short circuit between the emitter electrode 1 and the collector electrode 2, so that the press-fit IGBT module has a stable long-term short-circuit failure function.

[0027] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A press-fit IGBT module, characterized in that: It includes an emitter electrode and a collector electrode arranged opposite to each other, and a conductive liquid structure and several chip structures are arranged in the inner cavity between the emitter electrode and the collector electrode. The chip structure includes a pressure-applying conductive structure, an upper molybdenum sheet, a chip and a lower molybdenum sheet stacked in sequence. The upper end of the pressure-applying conductive structure is connected to the emitter electrode, and the bottom surface of the lower molybdenum sheet is connected to the collector electrode. The conductive liquid structure includes a shell and a conductive liquid coated in the shell; when any chip fails, the chip failure point and the upper molybdenum sheet of the failed chip generate an arc that burns through the shell, and the conductive liquid flows out from the burn-through point, covering all chips in the inner cavity and the space around the chip.

2. A press-fit IGBT module according to claim 1, characterized in that: The cross section of the pressure member in the pressure conductive structure is smaller than the top surface area of ​​the upper molybdenum sheet.

3. The press-fit IGBT module according to claim 1, characterized in that: The bottom surface of the conductive liquid structure is flush with the top surface of the upper molybdenum sheet, and the outflowing conductive liquid covers the space below the conductive liquid structure.

4. A press-fit IGBT module according to claim 1 or 3, characterized in that: The conductive liquid is gallium-indium alloy liquid or mercury liquid.

5. The press-fit IGBT module according to claim 1, characterized in that: If the press-fit IGBT module is a rigid press-fit IGBT module, the press-fit conductive structure is a rigid press-fit conductive metal.

6. The press-fit IGBT module according to claim 1, characterized in that: If the press-fit IGBT module is an elastic press-fit IGBT module, the press-fit conductive structure includes an elastic press-fit structure provided between the emitter electrode and the upper molybdenum sheet, and a bypass metal conductive sheet connecting the emitter electrode and the upper molybdenum sheet.

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