CN210073809U

CN210073809U - Crimping type IGBT internal packaging structure

Info

Publication number: CN210073809U
Application number: CN201822222979.3U
Authority: CN
Inventors: 王豹子; 屈斌; 叶娜; 黄小娟
Original assignee: Xi'an Zhongche Yongji Electric Co Ltd
Current assignee: Xi'an Zhongche Yongji Electric Co Ltd
Priority date: 2018-12-27
Filing date: 2018-12-27
Publication date: 2020-02-14
Anticipated expiration: 2028-12-27

Abstract

The utility model provides an inside packaging structure of crimping formula IGBT, this structure include IGBT FRD chip and carborundum aluminium lamination, the carborundum aluminium lamination is located the upper and lower both sides of IGBT FRD chip to be provided with the welding layer between IGBT FRD chip and the carborundum aluminium lamination, the upper and lower surface of IGBT FRD chip all is equipped with the metal level. The utility model provides a ceramic tube encapsulation crimping formula IGBT's carborundum-silicon carbide-welded layer-IGBT FRD chip-welded layer-carborundum inner structure has simplified ceramic tube encapsulation crimping formula IGBT's encapsulation technology operation greatly, has guaranteed crimping formula IGBT's two-sided heat dissipation, satisfies heavy current through-flow and high reliability requirement.

Description

Crimping type IGBT internal packaging structure

Technical Field

The utility model belongs to the technical field of the IGBT packaging structure, concretely relates to inside packaging structure of crimping formula IGBT.

Background

The IGBT is a composite device of the MOSFET and the bipolar transistor, has the characteristic of easy driving of the MOSFET and the characteristics of high voltage, large current and the like of a power transistor, and is a representative product of the third technical revolution of power electronics recognized in the world.

Compared with a welding type IGBT, the crimping type IGBT has the advantages of double-sided heat dissipation, wider safe working area (SOA), higher working junction temperature, no lead, high reliability, special failure short circuit characteristics and the like, and has very obvious competitive advantages in the application fields of direct series connection of devices in a flexible direct current transmission converter valve, harsh application environment and high reliability requirements.

Most of crimping formula IGBT's structural design is similar with conventional power devices such as thyristor, GTO, IGCT, and the outside adopts ceramic tube shell encapsulation, and inside packaging structure is different because of manufacturing enterprise's difference, and crimping formula IGBT inside packaging structure is each manufacturing enterprise technical protection restriction.

At present, the internal structure of the ceramic tube package crimping type IGBT sold in the market mainly comprises a molybdenum sheet-IGBT/FRD chip-molybdenum sheet structure (as shown in fig. 1), a molybdenum sheet-IGBT/FRD chip-molybdenum sheet-silver sheet structure (as shown in fig. 2), and a molybdenum sheet-silver sintered layer-IGBT/FRD chip-molybdenum sheet-silver sheet structure (as shown in fig. 3). The three ceramic tube shell packaging crimping type IGBT internal structures have special requirements on the thickness of a metal layer on the surface of an emitting electrode of a packaged IGBT/FRD chip. As shown in fig. 4 and 5, the internal structure of the above three ceramic case packaged crimping type IGBT requires that the surface metal layer of the emitter of the IGBT/FRD chip is thicker than the surface AlSi1 metal layer of the emitter of the IGBT/FRD chip for packaging the common welding type IGBT, so as to realize the pressure buffering in the crimping type packaging structure and meet the short circuit connection in the short circuit mode of the crimping type IGBT failure. The internal structure of the ceramic tube shell packaging crimping type IGBT module disclosed in the market has the problem that the assembly process is difficult to operate. The crimping type IGBT device with the structure of the molybdenum sheet-IGBT/FRD chip-molybdenum sheet and the structure of the molybdenum sheet-IGBT/FRD chip-molybdenum sheet-silver sheet has more assembly components, the thickness of the chip and the silver sheet is thinner, the material of the chip is brittle, the material of the silver sheet is soft, mutual positioning is difficult to realize, the packaging process is more complex, and the loss rate of the chip in the assembly process is higher. The molybdenum sheet-silver sintering layer-IGBT/FRD chip-molybdenum sheet-silver sheet structure firstly adopts nano silver solder to realize sintering and fixing of a chip collector electrode and a molybdenum sheet, and the silver sintering layer is introduced to serve as a compression joint buffer layer.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that not enough to above-mentioned prior art provides an inside packaging structure of crimping formula IGBT, and this structure can be encapsulated in ceramic tube, and it adopts silicon aluminium carbide (AlSiC) layer, welding layer, IGBT FRD chip, welding layer, silicon aluminium carbide (AlSiC) layer structural design, can simplify ceramic tube encapsulation crimping formula IGBT's encapsulation operation technology, can satisfy the requirement that ceramic tube encapsulation crimping formula IGBT encapsulation assembly process is simple, chip fragment rate is low.

In order to solve the technical problem, the utility model discloses a technical scheme is: the utility model provides an inside packaging structure of crimping formula IGBT, this structure encapsulates in ceramic tube, its characterized in that: including IGBT/FRD chip and carborundum aluminium lamination, the carborundum aluminium lamination is located the upper and lower both sides of IGBT/FRD chip to be provided with the welding layer between IGBT/FRD chip and the carborundum aluminium lamination, the upper and lower surface of IGBT/FRD chip all is equipped with the metal level.

Foretell inside packaging structure of crimping formula IGBT which characterized in that: the metal layer is an Al/Ti/Ni/Ag four-layer integrated metal layer.

Foretell inside packaging structure of crimping formula IGBT which characterized in that: the thickness of the metal layer is 2um ~ 5 um.

Foretell inside packaging structure of crimping formula IGBT which characterized in that: the IGBT/FRD chip is a Si-based IGBT/FRD chip.

Foretell inside packaging structure of crimping formula IGBT which characterized in that: the solder of the welding layer is tin-lead-silver or nano-silver.

Foretell inside packaging structure of crimping formula IGBT which characterized in that: the welding surface of the silicon carbide aluminum layer is plated with metal Ni.

Compared with the prior art, the utility model has the following advantage:

1. the utility model discloses consider, because silicon aluminium carbide (AlSiC) material is compared with molybdenum, the coefficient of expansion CTE of silicon aluminium carbide (AlSiC) material and molybdenum all is close with the silicon chip, but AlSiC purchasing cost is low, and the thin layer of covering aluminium on AlSiC self surface is softer because of the material, can be better act as the buffer layer at crimping interface, realize the good connection with ceramic tube shell copper contact electrode. Meanwhile, the silicon aluminum carbide (AlSiC) has good heat conducting performance and good conducting performance, and can meet the requirements of double-sided heat dissipation and electric connection through-flow performance of the crimping type IGBT. In addition, AlSiC is easy to realize welding with a collector and an emitter of the IGBT/FRD chip, an integrated internal structure of silicon aluminum carbide (AlSiC) -welding layer-IGBT/FRD chip-welding layer-silicon aluminum carbide (AlSiC) can be formed, the compression joint type IGBT is convenient to modularize and assemble, and the packaging process is simplified.

2. In combination with the requirement of the novel ceramic tube shell packaging crimping type IGBT internal structure provided by the utility model, in order to realize the welding of the emitting electrode and the collecting electrode of the chip and the AlSiC, the upper and lower surface metal layers of the IGBT/FRD chip preferably adopt Al/Ti/Ni/Ag four-layer integrated metal layers with the thickness of about 2-5 um, so that the through-flow path and the heat dissipation path of the crimping type IGBT formed by welding with the AlSiC are easier to realize; and the welding layer forms a buffer layer which bears pressure deformation between the AlSiC chip and the IGBT/FRD chip, and the welding layer is remelted to realize the special failure short-circuit mode of the crimping IGBT under the condition of short circuit of the crimping IGBT.

3. The utility model provides a ceramic tube encapsulation crimping formula IGBT's carborundum aluminium (AlSiC) -welded layer-IGBT FRD chip-welded layer-carborundum aluminium (AlSiC) inner structure has simplified ceramic tube encapsulation crimping formula IGBT's packaging technology operation greatly, has guaranteed crimping formula IGBT's two-sided heat dissipation, satisfies heavy current through-flow and high reliability requirement.

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Drawings

FIG. 1 is a schematic diagram of a molybdenum sheet-IGBT/FRD chip-molybdenum sheet structure.

FIG. 2 is a schematic diagram of a conventional molybdenum sheet-IGBT/FRD chip-molybdenum sheet-silver sheet structure.

Fig. 3 is a schematic structural diagram of a conventional molybdenum sheet-silver sintered layer-IGBT/FRD chip-molybdenum sheet-silver sheet.

Fig. 4 is a schematic structural diagram of a conventional press-contact IGBT/FRD chip provided with a surface metal layer.

FIG. 5 is a schematic structural diagram of a conventional welded IGBT/FRD chip with a surface metal layer.

Fig. 6 is the utility model discloses the inside packaging structure schematic diagram of crimping formula IGBT.

Fig. 7 is the utility model discloses crimping formula IGBT/FRD chip structure sketch map for IGBT with surface metal layer.

Fig. 8 is a schematic structural diagram of the ceramic tube package crimping type IGBT made by the internal packaging structure of the crimping type IGBT of the present invention.

Description of reference numerals:

1-molybdenum sheet;	2-IGBT/FRD chip;	3-silver flake;
			4-silver sintered layer;	5-metal layer with thickened emitter;	6-a collector metal layer;
7-emitter AlSi1, a metal layer;	8-ceramic tube shell;	9—AlSiC；
			10-a solder layer;	11-metal layer.

Detailed Description

The utility model discloses a simplify ceramic tube crimping formula IGBT packaging technology, realize crimping formula IGBT's development, through bitter technique attack the customs, designed a crimping formula IGBT inner structure finally. As shown in fig. 6, the structure specifically includes an IGBT/FRD chip 2 and a silicon carbide aluminum layer 9, the silicon carbide aluminum layer 9 is located above and below the IGBT/FRD chip 2, a welding layer 10 is provided between the IGBT/FRD chip 2 and the silicon carbide aluminum layer 9, and metal layers 11 are provided on both upper and lower surfaces of the IGBT/FRD chip 2.

The utility model discloses an it reachs to test several times, and the preferred four layers of integration metal levels of Al/Ti Ni/Ag of the material of metal level 11, and the preferred 2um ~ 5um of thickness. Wherein the four integrated metal layers of Al/Ti/Ni/Ag are the existing materials. The IGBT/FRD chip 2 is preferably a Si-based IGBT/FRD chip. The solder used for the soldering layer 10 is preferably tin-lead-silver or nano-silver. The welding surface of the silicon carbide aluminum layer 9 is plated with metal Ni.

The utility model discloses consider, because silicon aluminium carbide (AlSiC) material is compared with molybdenum, the coefficient of expansion CTE of silicon aluminium carbide (AlSiC) material and molybdenum all is close with the silicon chip, but AlSiC purchasing cost is low, and the thin layer of covering aluminium on AlSiC self surface is softer because of the material, can be better act as the buffer layer at crimping interface, realize the good connection with ceramic tube shell copper contact electrode. Meanwhile, the silicon aluminum carbide (AlSiC) has good heat conducting performance and good conducting performance, and can meet the requirements of double-sided heat dissipation and electric connection through-flow performance of the crimping type IGBT. In addition, the surface of the AlSiC can be plated with a nickel layer, so that the welding with a collector and an emitter of the IGBT/FRD chip can be realized more easily, and an integrated internal structure of silicon aluminum carbide (AlSiC) -welding layer-IGBT/FRD chip-welding layer-silicon aluminum carbide (AlSiC) can be formed, thereby facilitating the modularized assembly of the crimping type IGBT and simplifying the packaging process.

As a comparative example, a currently common welded IGBT/FRD chip structure with a surface metal layer is shown in fig. 5, where the surface metal layer of the IGBT emitter/FRD collector is an Al/Ti/Ni/Ag four-layer integrated metal layer, and the thickness of the metal layer is about 2-5 um, so that the metal layer is easily welded with solders such as tin, lead, silver, and nano silver; and IGBT collecting electrode/FRD emitter surface coating is AlSi1, and thickness is about 4 ~ 5um, mainly carries out the electricity through the aluminium wire bonding mode and connects, can't realize welded connection through the solder.

Combine the utility model provides a novel ceramic tube encapsulation crimping formula IGBT inner structure demand, in order to realize chip projecting pole, collecting electrode and AlSiC's welding, the preferred four layers of integration metal levels that adopt Al/Ti Ni/Ag of surface metal level about IGBT FRD chip, thickness is about 2um-5um, as shown in figure 7, changes the realization and forms crimping formula IGBT's through-flow path and heat dissipation path with AlSiC welding. And the welding layer forms a buffer layer which bears pressure deformation between the AlSiC chip and the IGBT/FRD chip, and the welding layer is remelted to realize the special failure short-circuit mode of the crimping IGBT under the condition of short circuit of the crimping IGBT.

The utility model relates to a preparation method of the crimping formula IGBT inner structure of encapsulating in ceramic tube does: firstly, producing a novel ceramic tube shell packaging crimping type IGBT required IGBT/FRD chip with a special metal layer structure through an IGBT/FRD chip surface metallization process, wherein the specific structure is shown in figure 7; then, welding between silicon aluminum carbide (AlSiC) and the IGBT/FRD chip is realized by adopting a universal tin-lead-silver or nano-silver solder, and an integrated internal structure of silicon aluminum carbide (AlSiC) -welding layer-IGBT/FRD chip-welding layer-silicon aluminum carbide (AlSiC) is formed, as shown in fig. 6 specifically; and finally, assembling the silicon aluminum carbide (AlSiC) -welding layer-IGBT/FRD chip-welding layer-silicon aluminum carbide (AlSiC) internal structure formed by the welding process with the ceramic tube shell to form the novel ceramic tube shell packaging crimping type IGBT, wherein the structure is shown in figure 8.

To sum up, the utility model provides a ceramic tube encapsulation crimping formula IGBT's carborundum aluminium (AlSiC) -welding layer-IGBT FRD chip-welding layer-carborundum aluminium (AlSiC) inner structure has simplified ceramic tube encapsulation crimping formula IGBT's packaging technology operation greatly, has guaranteed crimping formula IGBT's two-sided heat dissipation, satisfies heavy current through-flow and high reliability requirement.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention in any way. Any simple modifications, changes and equivalent changes made to the above embodiments according to the technical spirit of the present invention all fall within the protection scope of the technical solution of the present invention.

Claims

1. The utility model provides an inside packaging structure of crimping formula IGBT, this structure encapsulates in ceramic tube shell (8), its characterized in that: including IGBT/FRD chip (2) and carborundum aluminium lamination (9), carborundum aluminium lamination (9) are located the upper and lower both sides of IGBT/FRD chip (2) to be provided with between IGBT/FRD chip (2) and carborundum aluminium lamination (9) welding layer (10), the upper and lower surface of IGBT/FRD chip (2) all is equipped with metal level (11).

2. The internal packaging structure of the crimp type IGBT according to claim 1, wherein: the metal layer (11) is an Al/Ti/Ni/Ag four-layer integrated metal layer.

3. The internal packaging structure of the crimp type IGBT according to claim 1, wherein: the thickness of the metal layer (11) is 2um-5 um.

4. The internal packaging structure of the crimp type IGBT according to claim 1, 2 or 3, wherein: the IGBT/FRD chip (2) is a Si-based IGBT/FRD chip.

5. The internal packaging structure of the crimp type IGBT according to claim 1, 2 or 3, wherein: the solder of the welding layer (10) is tin-lead-silver or nano-silver.

6. The internal packaging structure of the crimp type IGBT according to claim 1, 2 or 3, wherein: the welding surface of the silicon carbide aluminum layer (9) is plated with metal Ni.