CN105552038A - High-power crimping IGBT device - Google Patents

Abstract

The invention provides a high-power crimping type IGBT device, which includes a tube case and plate-shaped metal electrodes coaxially installed at the upper and lower ends of the tube case, and a boss is installed on the inner side of the metal electrode at the lower end, and the boss is connected to the inner side of the metal electrode. A power sub-module is crimped between the upper metal electrodes, and a cross-shaped silicon steel sheet group is vertically installed on the inner surface of the lower metal electrode to divide the inner surface of the lower metal electrode into four areas; the boss distribution In the four areas; the outside of the cross-shaped silicon steel sheet group is an insulating frame. The technical solution provided by the invention divides a large number of bosses, which reduces the mutual influence of the magnetic field generated by the bosses when passing through the transient current, thereby realizing the minimization of the stray inductance between the bosses in the local area, and improving the Device performance.

Description

A high-power crimping type IGBT device

technical field

The invention relates to a crimping-type IGBT device, in particular to a high-power crimping-type IGBT device that can balance the current distribution between bosses in the switching transient process of the IGBT device.

Background technique

Since the u-stack structure was proposed in 1993, press-connect IGBT devices have been extensively developed. The two mainstream products on the market are StakPak of ABB Company and PressPackIGBT of Westcode Company respectively. The crimp-type IGBT has the advantages of high power, short-circuit failure and easier series connection, and is very suitable for VSC-HVDC applications. Compared with the traditional soldered IGBT module, the press-fit IGBT module has small stray inductance and relatively consistent loop parameters, especially the emitter inductance has been greatly reduced.

ABB's StakPak presses the chip against the bottom plate by using a disc spring on the collector, thereby reducing the stray inductance on the emitter side, thereby reducing the stray inductance of the drive circuit, and making the chip have better turn-on consistency . Westcode's existing crimping type IGBT device, the gate is triggered by crimping the chip on the boss and using the thimble. The advantage of Westcode's PressPackIGBT is that its structure and process are relatively simple.

In Westcode's press-fit IGBT device, the boss is on the emitter side of the chip, and the auxiliary emitter is drawn out through the bottom copper plate. Since the boss has a certain height, there is self-inductance between the bosses, and there is mutual inductance between the bosses, which affects During the turn-on and turn-off process of the device, the stray inductance of the circuit where each chip is located has an impact on the turn-on and turn-off of the device.

Existing studies have shown that with the increase of the number of bosses, due to the inconsistency of the stray inductance, the current between the bosses has a problem of uneven flow during the turn-on and turn-off process, which restricts the development of high-power devices. direction of development. ,

Contents of the invention

In order to solve the above-mentioned deficiencies in the prior art, the present invention provides a high-power crimping type IGBT device with a new structure.

The technical solution provided by the present invention is: a high-power crimping type IGBT device, including a shell and plate-shaped metal electrodes coaxially installed at the upper and lower ends of the shell, and a boss is installed on the inner side of the metal electrode at the lower end. A power sub-module is crimped between the boss and the upper metal electrode, and the improvement is that: the inner surface of the lower metal electrode is vertically installed with the inner surface of the lower metal electrode into four areas A cross-shaped silicon steel sheet group; the bosses are distributed in the four areas; the outside of the cross-shaped silicon steel sheet group is an insulating frame.

Preferably, the insulating frame is a cross-shaped insulating frame whose structure is compatible with the silicon steel sheet group, the length of the insulating frame is equal to the diameter of the lower metal electrode, and its height is equal to the distance between the upper and lower metal electrodes.

Preferably, the insulating frame is composed of a cross-shaped top insulating frame and a bottom insulating frame with grooves left in the opposite direction and the opening direction of the groove is fastened; the length, width and height of the top insulating frame and the bottom insulating frame The parameters are all consistent; the grooves of the top insulation frame and the bottom insulation frame have the same size, and the groove size matches the silicon steel sheet group, so that the silicon steel sheet group is installed on the top insulation frame In the cavity formed by fastening with the bottom insulating frame.

Further, the top and side corners of the top insulating frame are rounded, the side corners of the bottom insulating frame are rounded, and the bottom corners are not chamfered.

Preferably, the group of silicon steel sheets is composed of several silicon steel sheets insulated from each other, laminated and compacted, and the overall thickness of the group of silicon steel sheets is 0.5-2 mm.

Preferably, the distance between two bosses with an insulating frame between them on the lower metal electrode is greater than the distance between two bosses without an insulating frame therebetween, and the difference in distance is the width of the insulating frame.

Preferably, the distance between the power sub-modules on the two bosses on the lower metal electrode with the insulating frame between them is equal to the width of the insulating frame.

Further, grooves are distributed on the inner surface of the lower metal electrode, and a boss is fixed in each groove;

The two sides of the boss are provided with columns parallel to the axial direction of the shell, and the two sides of the groove are provided with grooves suitable for the columns; the columns are accommodated in the grooves to The boss is confined within the groove.

Further, the surface of the boss in contact with the bottom of the groove is an upwardly concave concave surface; the concave surface is a curved surface or an inclined surface;

The groove is rectangular, and the width of the groove is equal to the corresponding side length of the boss, so as to limit the boss in the groove; the length of the groove is slightly longer than the corresponding bottom length of the boss; The cross section of the concave surface is arched; the symmetry line of the cross section of the concave surface is perpendicular to the length of the groove.

Further, the insulating frame is made of insulating material with high thermal conductivity.

Compared with the closest prior art, the present invention has following remarkable progress:

1) The high-power crimping type IGBT device provided by the present invention is vertically installed on the inner surface of the lower metal electrode with a cross-shaped silicon steel sheet group that divides the inner surface of the lower metal electrode into four regions. The silicon steel sheet group can reduce the The mutual influence of the magnetic field generated by the boss when the current passes improves the consistency of the stray inductance of the main power circuit and the consistency of the stray inductance of the gate drive circuit of the power sub-module.

2) The edges and corners of the insulating frame used to install the silicon steel sheet group are rounded, which can improve the insulating properties of the insulating frame and improve the overall performance of the device.

3) The insulating frame used to install the silicon steel sheet group is made of high thermal conductivity insulating material, which can ensure that the heat generated by the silicon steel sheet is transferred to the outside through the insulating frame, improving the overall performance of the device.

4) The boss of the crimping type IGBT module is installed in the groove on the inner surface of the lower metal electrode, and the bottom of the boss is provided with an upward concave surface, which improves the consistency of heat dissipation of each chip in the power sub-module and improves the crimping type. The performance of IGBT devices.

Description of drawings

Fig. 1 is a schematic diagram of the relative position between the frame and the boss in the present invention;

Fig. 2 is a schematic diagram of silicon steel sheet and frame shape used in the present invention;

Fig. 3 is the structural detail schematic diagram that silicon steel sheet is placed in the frame among the present invention;

Fig. 4 is the structural representation of boss among the present invention;

Fig. 5 is a schematic diagram of the longitudinal section structure when the boss and the groove are installed together in the present invention;

Among them: 1. Top insulating frame; 2. Silicon steel sheet group; 3. Bottom insulating frame; 4. Partition plate composed of silicon steel sheet group and frame; 5. Boss; 6. Lower metal electrode; 7. Notch; 8. Bar shaped pillars.

detailed description

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

In order to thoroughly understand the embodiments of the present invention, the detailed structure will be set forth in the following description. Obviously, the practice of the embodiments of the invention is not limited to specific details familiar to those skilled in the art. Preferred embodiments of the present invention are described in detail below, however, the present invention may have other embodiments besides these detailed descriptions.

The outside of the high-power crimping type IGBT module provided by the present invention is composed of a tube case and two plate-shaped metal electrodes arranged at the upper and lower ends of the tube case, and the inside is a power sub-module and the corresponding boss 5 .

As shown in Figure 1, the key point of the present invention is: in order to reduce the mutual influence of the magnetic field generated by the bosses 5 when passing through the transient current, and realize the minimization of the stray inductance between the bosses 5, the crimping type provided by the present invention The IGBT module is equipped with a cross-shaped silicon steel sheet group 2 on the inner surface of the lower metal electrode 6; it is used to divide a large number of bosses 5 on the lower end surface.

The boss 5 in Fig. 1 omits the strip-shaped pillars 8 on both sides, and there is a notch 7 on the side diagonal of the boss 5, which is flush with the inner surface of the lower metal plate for installation The PCB board, the upper surface of the PCB board is coated with copper, and the grid of the power sub-module above the boss 5 is electrically connected to the upper surface of the PCB board through ejector pins.

As shown in Figure 2, the cross-shaped silicon steel sheet group 2 is installed on the insulating frame; the insulating frame is a cross-shaped insulating frame whose structure is compatible with the silicon steel sheet group 2, and the length of the insulating frame is approximately equal to the lower end The diameter and height of the metal electrodes 6 are equal to the distance between the metal electrodes at the upper and lower ends, so that the insulating frame can be fixed between the metal electrodes at the upper and lower ends.

The insulating frame has a certain thickness and has good insulating properties, so as to ensure electrical insulation between the silicon steel sheet group 2 and the upper and lower metal electrodes.

As shown in Figure 3, the insulating frame is composed of a cross-shaped top insulating frame 1 and a bottom insulating frame 3 that have a groove inside and the opening direction of the groove is opposite to each other; the top insulating frame 1 and the bottom insulating frame The sum of the heights of 3 is the distance between the metal electrodes at the upper and lower ends of the press-fit IGBT device. The length, width and height parameters of the top insulating frame 1 and the bottom insulating frame 3 are all consistent; the grooves of the top insulating frame 1 and the bottom insulating frame 3 have the same size, and the groove size is the same as The silicon steel sheet group 2 is adapted so that the silicon steel sheet group 2 is installed in the cavity formed by the fastening of the top insulating frame 1 and the bottom insulating frame 3 .

The top and side corners of the top insulating frame 1 are rounded chamfers, and the side corners of the bottom insulating frame 3 are rounded chamfers, which can be used to improve the characteristics of the insulating frame, and the bottom corners have no chamfers.

The silicon steel sheet group 2 is composed of several silicon steel sheets insulated from each other, laminated and compacted, and the overall thickness of the silicon steel sheet group 2 is 0.5-2 mm.

In the place where the insulating frame is placed, the distance between the bosses 5 is relatively large, and the difference between the distance between the two bosses 5 with the insulating frame and the distance between the two bosses 5 without the insulating frame is The width of the insulating frame.

The distance between the power sub-modules on the two bosses 5 with the insulating frame in between is equal to the width of the insulating frame.

As shown in Figure 4-5, there are grooves distributed on the inner surface of the lower metal electrode 6, and a boss 5 is fixed in each groove; the surface of the boss 5 in contact with the bottom of the groove is upward. a depressed concave surface; said concave surface is a curved or inclined surface;

The groove is a rectangular groove with a certain depth, and the width of the groove is the same as the corresponding side length of the boss 5, so as to play the role of fixing the boss 5, but the length is slightly longer than the length of the bottom of the boss 5, which is convenient When the boss 5 is pressed and deformed, the bottom edge of the boss 5 has a certain displacement space; the cross-sectional symmetry line of the concave surface is perpendicular to the length of the groove.

Both sides of the boss 5 are provided with bar-shaped pillars 8 parallel to the axial direction of the shell, and both sides of the groove are provided with grooves compatible with the bar-shaped pillars 8; the bar-shaped pillars 8 is accommodated in the groove to confine the boss 5 in the groove.

The insulating frame outside the silicon steel sheet group 2 is made of high thermal conductivity insulating material, and its insulating properties meet the insulation requirements between the silicon steel sheet group 2 and the upper and lower metal electrodes. The heat inside is diffused to the outside.

In order to improve the thermal conductivity of the insulating frame, the insulating frame is made of the following components by weight: silicone rubber 60-80, polyimide 20-40, benzoyl peroxide 3-5, acetylene carbon black 30-50, AlN20~30, glass fiber 5~8, silane coupling agent 5~10.

The preparation method of the insulating material with high thermal conductivity comprises the following steps:

(1) Surface treatment of AlN: put AlN in an electric stirrer, add the silane coupling agent according to the formula at a speed of 200 rpm, after the dropwise addition, adjust the speed to 2000 rpm, Stirring at a temperature of ℃ for 30 minutes to obtain surface-modified AlN;

(2) Mixing: Add polyimide, acetylene carbon black, glass fiber and surface-modified AlN in step (1) to the internal mixer according to the formula, stir for 15 minutes until uniform, then add silicone rubber, and continue stirring Discharge after 15 minutes;

(3) Place the mixture obtained in step (2) on a two-roller mill, add benzoyl peroxide after wrapping the rolls, mix for 3 to 5 minutes, remove the sheet and park at room temperature for 24 hours;

(4) Vulcanize the film obtained in step (3) on a flat vulcanizer under the conditions of 140° C., 15 MPa, and 30 min.

The thermal conductivity of the insulating material prepared by the above method can reach above 2.70w/(m·K).

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 pending claims.

Claims (10)

1. a high-power compression joint type IGBT device, comprise shell and be coaxially arranged on the plate-shape metal electrode at the upper and lower two ends of described shell, the medial surface of lower end metal electrode is provided with boss, be crimped with power modules between described boss and upper end metal electrode, it is characterized in that: the medial surface of described lower end metal electrode is vertically installed with the cross silicon steel sheet group medial surface of described lower end metal electrode being separated into four regions; Described boss is distributed in described four regions; Described cross silicon steel sheet group outside is Insulating frame.

2. the high-power compression joint type IGBT device of one according to claim 1, it is characterized in that: described Insulating frame is the cross Insulating frame that structure and described silicon steel sheet group adapt, the length of described Insulating frame equals the diameter of lower end metal electrode, and it highly equals the distance between the metal electrode of upper and lower two ends.

3. the high-power compression joint type IGBT device of one according to claim 1, is characterized in that: described Insulating frame leaves groove by inside and the contrary cross-shaped top Insulating frame in slot opening direction and bottom insulation framework fasten and form; Length, the width of described top Insulating frame and described bottom insulation framework are all consistent with height parameter; The groove size of described top Insulating frame and described bottom insulation framework is in the same size, described groove size size and described silicon steel sheet group match, and be arranged on fastened in the cavity that formed by top Insulating frame and bottom insulation framework to make described silicon steel sheet group.

4. the high-power compression joint type IGBT device of one according to claim 3, is characterized in that:

The top of described top Insulating frame and sidepiece corner angle are rounded corners, and the sidepiece corner angle of described bottom insulation framework are rounded corners, and bottom it, corner angle are without chamfering.

5. the high-power compression joint type IGBT device of one according to claim 1, is characterized in that:

Described silicon steel sheet group is made up of some pieces of stacked compressions of silicon steel sheet insulated from each other, and the integral thickness of described silicon steel sheet group is 0.5-2mm.

6. the high-power compression joint type IGBT device of one according to claim 1, is characterized in that:

Distance between two boss of the large therebetween naked framework of the distance between two boss described lower end metal electrode having Insulating frame therebetween, and the difference of distance is the width of described Insulating frame.

7. the high-power compression joint type IGBT device of one according to claim 1, is characterized in that:

Described lower end metal electrode there is the distance between the power modules on two of Insulating frame boss equal the width of described Insulating frame therebetween.

8., according to the compression joint type IGBT device of a kind of improvement in claim 1-7 described in any one, it is characterized in that:

The medial surface of lower end metal electrode is distributed with groove, and each groove internal fixtion has a boss;

The both sides of described boss are provided with the pillar be parallel on shell axis direction, and the both sides of described groove are provided with the groove adapted with described pillar; Described pillar is contained in described groove, to be limited in described groove by described boss.

9. the compression joint type IGBT device of a kind of improvement according to claim 8, is characterized in that:

The face that described boss contacts with described bottom portion of groove is the concave surface upwards caved in; Described concave surface is curved surface or inclined-plane;

Described groove is rectangle, and the width of described groove equals the corresponding length of side of boss, to be limited in described groove by described boss; The length of described groove is slightly larger than the corresponding bottom lengths of boss; The cross section of described concave surface is arch; The cross section line of symmetry of described concave surface is perpendicular to the length of described groove.

10., according to the high-power compression joint type IGBT device of the one in claim 1-7 described in any one, it is characterized in that:

Described Insulating frame high thermal conductivity insulating material makes.