CN104362141A - High-power crimp-connection type IGBT module - Google Patents

Abstract

The invention relates to a high-power crimping type IGBT module. The module consists of a subunit casing (1) and a subunit casing cover assembly (2) to form an airtight packaging casing. A sandwich structure formed by at least one semiconductor chip (1-1) and a first auxiliary part (1-6), at least one second auxiliary part (1-2), and at least one third auxiliary part (1-3) is arranged in the sub- In the airtight casing between the unit casing (1) and the subunit casing cover assembly (2). No less than one of the subunits is arranged in parallel in the module case (3) to form a high-power IGBT module. The IGBT module involved in the invention has the advantages of low thermal resistance, high reliability and being suitable for series use.

Description

A high-power crimping type IGBT module

technical field

The invention relates to a high-power semiconductor device, in particular to a high-power crimping type IGBT module.

Background technique

Insulated gate bipolar transistor (Insulate-Gate Bipolar Transistor—IGBT) combines the advantages of power transistor (Giant Transistor—GTR) and power field effect transistor (Power MOSFET), has good characteristics, and has a wide range of applications; IGBT is also a three-terminal device : Gate, Collector and Emitter. IGBT (Insulated Gate Bipolar Transistor) is a bipolar device with MOS structure, which belongs to the power device with high-speed performance of power MOSFET and low resistance performance of bipolar.

Due to the limit of the voltage withstand limit of silicon materials, the highest voltage of existing IGBT devices is 6500V, and in devices with voltage applications up to tens or even hundreds of kV, the application of IGBTs is mostly used in series, and each valve section requires multiple Dozens of IGBT devices are connected in series. In order to ensure the safety during installation and transportation, it is often necessary to apply a fastening force of up to 100kN. It is difficult for ordinary modules and traditional crimping devices to meet such fastening force requirements.

There are usually two types of packaging for high-power IGBTs. One is the bottom plate insulation module package, which is composed of a bottom plate, a copper-clad ceramic substrate, and an insulating shell. The back of the chip is soldered to the ceramic copper-clad surface by solder, and the front is connected by a bonding wire To the ceramic copper clad surface, the ceramic copper clad surface is etched to form different areas connecting the positive and negative electrodes. As a non-hermetic package, insulating materials such as silicone gel or epoxy resin are poured inside the module to isolate the contact between the chip and the external environment (water, air, dust), but the potting material usually also isolates the heat transfer and will last for a long time. During the working process, the isolation effect degrades.

The other is a thyristor-like, flat crimp package, which is composed of a ceramic shell and copper electrodes, and the chip and the electrodes are in contact with pressure. The full crimp IGBT package realizes full crimp contact with the silicon wafer by the upper and lower electrodes and multi-layer materials, which eliminates device failure caused by welding fatigue.

In the design of traditional press-fit power devices, in order to meet the requirements of the chip's non-solder connection, the chip is often directly connected to the electrode through pressure contact, and considering the matching of the coefficient of thermal expansion (CTE) with the silicon chip, molybdenum is selected as an auxiliary part Installed between chip and electrode. The fastening force of the device is limited by the pressure limit of the chip, and it cannot be too large, otherwise the chip will be damaged.

Contents of the invention

Aiming at the deficiencies of the prior art, the object of the present invention is to provide a high-power crimping type IGBT module, in which the semiconductor chip is protected by airtightness and inert gas in the subunit housing, so as to prevent the chip from being exposed to water vapor, dust, etc. The failure caused by the contamination of external conditions also increases the influence of the arc between the upper and lower auxiliary parts of the chip.

The object of the present invention is to adopt following technical scheme to realize:

The present invention provides a high-power crimping type IGBT module, the module is a vertical stacked packaging structure, the improvement is that: the module includes a subunit housing 1, a subunit housing cover assembly 2 and a module housing 3 ;The subunit housing 1 and the subunit housing cover assembly 2 are packaged by cold pressure welding to form a subunit, and the module housing 3 is provided with not less than one subunit along the axial direction; the subunit moves with the module housing 3 in the vertical direction Connection; the subunit casing 1 is filled with an inert gas, such as nitrogen, and is airtightly sealed by pressure welding with the subunit casing cover assembly 2 .

Further, the subunit has a relative displacement with the module casing 3 in the vertical direction, and the distance is 2-3mm.

Further, the subunit casing 1 includes a semiconductor chip 1-1, a second auxiliary part 1-2, a third auxiliary part 1-3, an electrode boss 1-4, a subunit casing 1-5 and a first auxiliary part. pieces 1-6;

The first auxiliary part 1-6, the semiconductor chip 1-1, the second auxiliary part 1-2 and the third auxiliary part 1-3 are sequentially stacked in the frame 1-8 from top to bottom, and the frame 1- 8 is installed on the electrode boss 1-4 through pressure contact; the electrode boss 1-4 is connected with the subunit shell 1-5 through the shell flange 1-7.

Further, the first auxiliary part 1-6 and the third auxiliary part 1-3 are made of a metal material with a thermal expansion coefficient close to that of the silicon material; the shape of the first auxiliary part 1-6 and the third auxiliary part 1-3 All are square sheets with a thickness of 1-2mm;

The second auxiliary part 1-2 adopts a metal sheet with high ductility and high electrical conductivity;

The subunit housing 1-5 is made of insulating material.

Further, the metal material with a thermal expansion coefficient close to that of silicon material includes tungsten, molybdenum or alloy; the metal sheet with high ductility and high conductivity includes aluminum or silver; the insulating material includes ceramic or epoxy resin composite Material.

Further, the subunit cover assembly 2 includes a subunit cover boss 2-1, a heat pipe radiator 2-2, a spring assembly 2-3, a top plate electrode 2-4, a positioning frame 2-5 and a cover flange 2 -6;

The subunit boss 2-1, the spring assembly 2-3 and the top plate electrode 2-4 are assembled into one body through the positioning frame 2-5, and are arranged between the subunit boss 2-1 and the spring assembly 2-3 Heat pipe radiator 2-2;

The cover flange 2-6 is welded on the subunit boss 2-1, and the cover flange 2-6 forms an airtight subunit with the housing flange 1-7 through cold pressure welding.

Further, one end of the spring assembly 2-3 is riveted with the top plate electrode 2-4, one end is crimped with the subunit cover boss 2-1, and is positioned with the subunit boss 2-1 by the positioning frame 2-5;

The evaporating end of the heat pipe radiator 2-2 and the boss 2-1 of the subunit cover are welded and positioned through the positioning grooves on the boss.

Further, the module housing 3 is composed of the housing shell 3-1 and the housing cover 3-2 by bonding; and electrode bosses 1-4 to move in the vertical direction.

Further, no less than one subunit is installed into the housing shell 3-1 through the holes on the housing shell 3-1 and the shell cover 3-2;

The outer end surface of the electrode boss 1-4 and the outer end surface of the top plate electrode 2-4 respectively protrude from the end surface of the housing by 0.5 mm to 3 mm in the non-working state; they are horizontal to the end surface of the housing under pressure in the working state.

Further, the current path of the module flows from the subunit cover assembly 2 to the subunit housing 1 in the vertical direction; the module installation fastening force is jointly borne by the module housing 3 and the subunit cover assembly 2, and the maximum installation The fastening force is 100kN.

Compared with the closest prior art, the excellent effect of the present invention is:

1. The high-power crimping type IGBT module provided by the present invention is a full crimping contact, which eliminates the factors that cause device failure due to bonding and welding fatigue.

2. The present invention realizes double-sided heat dissipation of the chip 1-1 and pressure control of the chip by means of the subunit cover assembly 2 .

3. The present invention utilizes the assembling method of the subunit case cover assembly 2 and the module case 3 to jointly bear the external fastening force, so as to realize the requirement of large fastening force installation of the whole module.

4. In the high-power crimping type IGBT module provided by the present invention, the chip 1-1 is airtightly packaged, which avoids external water vapor, dust and other pollution, and at the same time increases the influence of the arc between the upper and lower auxiliary parts of the chip, improving the long-term reliability of the device.

5. The high-power crimping IGBT module provided by the present invention realizes crimping IGBT modules with various circuit topologies by virtue of the installation positions of different subunits in the vertical direction.

6. The IGBT module involved in the present invention has the advantages of low thermal resistance, high reliability and being suitable for series use.

Description of drawings

Fig. 1 is a cross-sectional structure diagram of a high-power crimping type IGBT module provided by the present invention, wherein: 1-subunit housing; 2-subunit housing cover assembly; 3-module housing;

Fig. 2 is a sectional view of the subunit housing of the module provided by the present invention, wherein: 1-1—IGBT or FRD chip; 1-2—second auxiliary part; 1-3—third auxiliary part; 1-4—electrode boss ; 1-5—subunit shell; 1-6—first auxiliary part; 1-7—housing flange; 1-8—frame;

Fig. 3 is a cross-sectional view of the subunit shell cover assembly of the module provided by the present invention, wherein: 2-1—subunit cover boss; 2-2—heat pipe radiator; 2-3—spring assembly; 2-4—top plate electrode; 2 -5—positioning frame; 2-6—cover flange;

Fig. 4 is a schematic diagram of the appearance of the module shell provided by the present invention;

Fig. 5 is a sectional view of the module housing provided by the present invention, wherein: 3-1—the housing shell; 3-2—the housing cover.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

The present invention provides a high-power crimping type IGBT module, the module is a vertical laminated packaging structure, the cross-sectional structure diagram of the high-power crimping IGBT module is shown in Figure 1, including a subunit housing 1, a subunit The shell cover assembly 2 and the module shell 3; the subunit shell 1 and the subunit shell cover assembly 2 are encapsulated by cold pressure welding to form a subunit, and no less than one subunit is arranged and assembled in the module shell 3 in sequence, and the subunit is in There is a relative displacement with the module shell 3 in the vertical direction, and the distance is 2-3mm

The current path of the module flows from the subunit case cover assembly 2 to the subunit case 1 in the vertical direction; the module installation fastening force is jointly borne by the module case 3 and the subunit case cover assembly 2, and the maximum installation fastening force is 100kN .

The subunit housing 1 includes a semiconductor chip 1-1, a second auxiliary part 1-2, a third auxiliary part 1-3, an electrode boss 1-4, a subunit housing 1-5 and a first auxiliary part 1- 6; The sandwich structure formed by at least one semiconductor chip 1-1 and the first auxiliary part 1-6, at least one second auxiliary part 1-2, and at least one third auxiliary part 1-3 is arranged between the subunit housing 1 and the subunit housing 1. In the airtight casing between the unit case cover assembly 2. The sectional view of the subunit housing is shown in Figure 2.

The first auxiliary part 1-6, the semiconductor chip 1-1, the second auxiliary part 1-2 and the third auxiliary part 1-3 are sequentially stacked in the frame 1-8 from top to bottom, and the frame 1- 8 is installed on the electrode boss 1-4 through pressure contact; the electrode boss 1-4 is connected with the subunit shell 1-5 through the shell flange 1-7.

The first auxiliary part 1-6 and the third auxiliary part 1-3 are made of a metal material with a thermal expansion coefficient close to that of silicon material, including tungsten, molybdenum or other alloys; the first auxiliary part 1-6 and the third auxiliary part The shapes of 1-3 are all square sheets, and the thickness is 1-2mm;

The second auxiliary part 1-2 adopts a metal sheet with high ductility and high electrical conductivity, including aluminum or silver;

The subunit shells 1-5 are made of insulating materials, such as ceramics or epoxy resin composite materials.

The subunit cover assembly 2 includes a subunit cover boss 2-1, a heat pipe radiator 2-2, a spring assembly 2-3, a top plate electrode 2-4, a positioning frame 2-5 and a cover flange 2-6; The cross-sectional view of the subunit shell cover assembly is shown in Figure 3.

The subunit boss 2-1, the spring assembly 2-3 and the top plate electrode 2-4 are assembled into one body through the positioning frame 2-5, and are arranged between the subunit boss 2-1 and the spring assembly 2-3 At least 6 heat pipe radiators 2-2;

The cover flange 2-6 is welded on the subunit boss 2-1, and the cover flange 2-6 forms an airtight subunit with the shell flange 1-7 through cold pressure welding, that is, the subunit shell 1 and the subunit shell cover assembly 2 realize the airtight packaging of the subunit through cold pressure welding between the shell flange 1-7 and the cover flange 2-6.

One end of the spring component 2-3 is riveted with the top plate electrode 2-4, one end is crimped with the subunit cover boss 2-1, and is positioned with the subunit boss 2-1 by the positioning frame 2-5;

The evaporating end of the heat pipe radiator 2-2 and the boss 2-1 of the subunit cover are welded and positioned through the positioning grooves on the boss.

The module shell 3 is composed of the shell shell 3-1 and the shell cover 3-2 through bonding; the end faces of the shell shell 3-1 and the shell cover 3-2 are provided so that the top plate electrode 2-4 and the electrode boss 1 -4 holes that move in the vertical direction. The schematic diagram of the module shell and its cross-sectional view are shown in Figures 4 and 5, respectively.

No less than one subunit is installed on the shell shell 3-1 through the holes on the shell shell 3-1 and the shell cover 3-2;

The outer end surface of the electrode boss 1-4 and the outer end surface of the top plate electrode 2-4 respectively protrude from the end surface of the housing by 0.5 mm to 3 mm in the non-working state; they are horizontal to the end surface of the housing under pressure in the working state.

The subunit casing 1 is filled with an inert gas, such as nitrogen, and is airtightly sealed by pressure welding with the subunit casing cover assembly 2 .

The invention makes the semiconductor chip work in the airtight and inert gas-protected space, and at the same time, the spring component and the module shell jointly bear the fastening force of up to 100kN from the user.

The subunit shell cover assembly 2 of the present invention provides elastic crimping force for the semiconductor chip, and conducts heat from the subunit cover boss 2-1 to the top plate electrode 2-4 by the heat pipe structure, and finally conducts heat to the heat sink to realize Double-sided cooling of semiconductor chips.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still implement the present invention Any modification or equivalent replacement that does not deviate from the spirit and scope of the present invention is within the protection scope of the claims of the pending application of the present invention.

Claims (10)

1. A high-power crimping type IGBT module, the module is a vertical stacked package structure, characterized in that: the module includes a subunit housing (1), a subunit housing cover assembly (2) and a module housing (3); the subunit housing (1) and the subunit housing cover assembly (2) are encapsulated by cold pressure welding to form a subunit, and the module housing (3) is provided with not less than one subunit along the axial direction; The unit is movably connected with the module shell (3) in the vertical direction; The subunit housing (1) is filled with inert gas. 2. The high-power crimping type IGBT module according to claim 1, characterized in that, said subunit is displaced relative to the module case (3) in the vertical direction, and the distance is 2-3mm. 3. The high-power crimping type IGBT module according to claim 1, characterized in that, the subunit housing (1) comprises a semiconductor chip (1-1), a second auxiliary part (1-2), a second Three auxiliary parts (1-3), electrode bosses (1-4), subunit shells (1-5) and first auxiliary parts (1-6); The first auxiliary part (1-6), the semiconductor chip (1-1), the second auxiliary part (1-2) and the third auxiliary part (1-3) are sequentially stacked on the frame (1) from top to bottom -8), the frame (1-8) is mounted on the electrode boss (1-4) through pressure contact; the electrode boss (1-4) and the subunit casing (1-5) pass through the housing Flange (1-7) connection. 4. The high-power crimping type IGBT module according to claim 3, characterized in that, the first auxiliary part (1-6) and the third auxiliary part (1-3) adopt a material with a thermal expansion coefficient close to that of silicon material Metal material; the shape of the first auxiliary part (1-6) and the third auxiliary part (1-3) are both square sheets, and the thickness is 1-2mm; The second auxiliary part (1-2) adopts a metal sheet with high ductility and high electrical conductivity; The subunit housing (1-5) is made of insulating material. 5. The high-power crimping type IGBT module as claimed in claim 4, wherein the metal material having a thermal expansion coefficient close to that of the silicon material comprises tungsten, molybdenum or an alloy; the metal material having high ductility and high electrical conductivity Metal sheets include aluminum or silver; the insulating material includes ceramic or epoxy composite materials. 6. The high-power crimping type IGBT module according to claim 1, characterized in that, the subunit case cover assembly (2) comprises a subunit cover boss (2-1), a heat pipe radiator (2-2 ), spring assembly (2-3), top plate electrode (2-4), positioning frame (2-5) and cover flange (2-6); The subunit boss (2-1), the spring assembly (2-3) and the top plate electrode (2-4) are assembled into one body through the positioning frame (2-5), and the subunit boss (2-1 ) and the spring assembly (2-3) are provided with a heat pipe radiator (2-2); The cover flange (2-6) is welded on the subunit boss (2-1), and the cover flange (2-6) forms an airtight seal with the shell flange (1-7) through cold pressure welding gender subunit. 7. The high-power crimping type IGBT module according to claim 6, characterized in that one end of the spring assembly (2-3) is riveted with the top plate electrode (2-4), and one end is connected with the subunit cover boss (2-4). -1) crimping, and positioning with the subunit boss (2-1) through the positioning frame (2-5); The evaporating end of the heat pipe radiator (2-2) and the subunit cover boss (2-1) are welded and positioned through the positioning grooves on the boss. 8. The high-power crimping type IGBT module according to claim 1, characterized in that, the module casing (3) is composed of a casing shell (3-1) and a casing cover (3-2) by bonding; Both the shell shell (3-1) and the shell cover (3-2) have holes on the end faces that allow the top plate electrode (2-4) and the electrode boss (1-4) to move in the vertical direction. 9. The high-power crimping type IGBT module according to claim 8, characterized in that no less than one subunit is installed into the housing through the holes on the housing shell (3-1) and the housing cover (3-2) housing (3-1); The outer end surface of the electrode boss (1-4) and the outer end surface of the top plate electrode (2-4) respectively protrude from the end surface of the housing by 0.5 mm to 3 mm in the non-working state; level. 10. The high-power crimping type IGBT module as claimed in claim 1, wherein the current path of the module flows in the vertical direction from the subunit housing cover assembly (2) to the subunit housing (1); The installation fastening force of the above modules is jointly borne by the module casing (3) and the subunit case cover assembly (2), and the maximum installation fastening force is 100kN.