TWI693684B - Igbt module with improved heat dissipation structure - Google Patents

Abstract

An IGBT module with an improved heat dissipation structure includes a layer of IGBT chips, a bonding layer, a thick copper layer, a thermally-conductive and electrically-insulating layer, and a heat dissipation layer. The thermally-conductive and electrically-insulating layer is disposed on the heat dissipation layer. The thick copper layer is disposed on the thermally-conductive and electrically-insulating layer. The bonding layer is disposed on the thick copper layer, and the layer of IGBT chips is disposed on the bonding layer for bonding to the thick copper layer.

Description

IGBT module heat dissipation structure improvement

The invention relates to an IGBT module, in particular to an improvement of the heat dissipation structure of the IGBT module.

At present, high-power rectifiers (Inverters) used in electric vehicles/hybrid vehicles mostly use IGBT (Insulated Gate Bipolar Transistor: Insulated Gate Bipolar Transistor) chips. Therefore, the heat generated during the operation of the high-power rectifier will cause the temperature of the IGBT wafer to rise. Without proper heat dissipation measures, the temperature of the IGBT wafer may exceed the allowable temperature, resulting in deterioration of performance and damage. Therefore, IGBT heat dissipation technology has become a problem that relevant technicians are eager to solve.

At present, DBC (Direct Bonding Copper: ceramic-metal composite board structure) board has become the first choice for the heat dissipation structure of IGBT modules. Please refer to FIG. 1 and FIG. 2, which is a conventional IGBT module heat dissipation structure, which mainly includes an IGBT chip layer 11A, an upper solder layer 12A, a DBC board 13A, a lower solder layer 14A, and a heat dissipation layer 15A. The DBC board 13A includes an upper thin copper layer 131A, a ceramic layer 132A, and a lower thin copper layer 133A in order from top to bottom. However, the DBC board 13A is a multi-layer structure and has limited thermal conductivity. When the IGBT wafer 111A of the IGBT wafer layer 11A generates heat, it cannot be transferred to the heat dissipation layer 15A through the DBC board 13A in time, and the DBC board 13A and the heat dissipation layer 15A must pass through Only the lower solder layer 14A can form a connection, and a whole piece of lower solder layer 14A will be prone to empty soldering, and will increase the interface resistance, which will affect the Sound thermal conductivity.

Therefore, the inventor feels that the above-mentioned deficiency can be improved, and is dedicated to study and cooperate with the application of the theory, and finally proposes a reasonable design and effectively improves the above-mentioned deficiency of the present invention.

The main purpose of the present invention is to provide an improved IGBT module heat dissipation structure to solve the above problems.

An embodiment of the present invention is to provide an improved IGBT module heat dissipation structure, including: an IGBT chip layer, a bonding layer, a thick copper layer, a thermally conductive insulating layer, and a heat dissipating layer. The thermally conductive insulating layer is disposed on the heat dissipating layer. The thick copper layer is disposed on the thermally conductive insulating layer, the bonding layer is disposed on the thick copper layer, and the IGBT wafer layer is disposed on the bonding layer.

Preferably, the thermally conductive insulating layer includes a first polymer composite layer and a second polymer composite layer, the first polymer composite layer is screen printed on the heat dissipation layer, and the second polymer composite layer The screen is printed on the first polymer composite layer, and the thick copper layer is thermocompression bonded on the second polymer composite layer.

Preferably, the first polymer composite layer is one of an epoxy resin layer, a polyimide layer, and a polypropylene layer.

Preferably, the first polymer composite layer includes a filler, and the filler is at least one selected from alumina, aluminum nitride, silicon nitride, silicon carbide, and boron nitride.

Preferably, the second polymer composite layer is one of an epoxy resin layer, a polyimide layer, and a polypropylene layer.

Preferably, the second polymer composite layer includes a filler, and the filler is selected from at least one of aluminum oxide, aluminum nitride, silicon nitride, silicon carbide, and boron nitride.

Preferably, the thickness of the first polymer composite layer is 20-200 μm, and the thickness of the second polymer composite layer is 20-200 μm.

Preferably, the thickness of the thick copper layer is greater than or equal to 1000 μm.

Preferably, the thermally conductive insulating layer includes a first polymer composite layer, a second polymer composite layer, a third polymer composite layer, and a fourth polymer composite layer, and the first polymer composite layer is screen printed on The heat dissipation layer, the second polymer composite layer is screen printed on the first polymer composite layer, and the third polymer composite layer is screen printed on the second polymer composite layer The fourth polymer composite layer is screen printed on the third polymer composite layer, and the thick copper layer is thermocompression bonded on the fourth polymer composite layer.

Preferably, the thicknesses of the first polymer composite layer, the second polymer composite layer, the third polymer composite layer, and the fourth polymer composite layer are 20-200 μm, respectively.

Therefore, in the present invention, a heat conductive insulating layer is provided between the thick copper layer and the heat dissipation layer, so that the heat of the IGBT chip is quickly and uniformly conducted to the heat dissipation fins of the entire heat dissipation layer through the thick copper layer and the heat dissipation layer. Compared with the existing DBC board of the IGBT module heat dissipation structure, the present invention can have both the heat dissipation uniformity of the thick copper layer and the insulation and thermal conductivity of the thermally conductive insulation layer, and it is directly formed on the surface of the heat dissipation layer without passing through the welding layer The thermally conductive insulating layer will not affect the thermal conductivity due to the voiding problem and the interface impedance problem caused by the solder layer, nor will it affect the thermal conductivity due to the multilayer structure of the DBC board, so that the heat dissipation layer of the present invention can maximize heat absorption and Cooling efficiency.

[current technology]

11A‧‧‧IGBT chip layer

12A‧‧‧Upper welding layer

13A‧‧‧DBC board

131A‧‧‧upper thin copper layer

132A‧‧‧Ceramic layer

133A‧‧‧Lower copper layer

14A‧‧‧Lower welding layer

15A‧‧‧radiation layer

[this invention]

11‧‧‧IGBT layer

111‧‧‧IGBT chip

12‧‧‧Joint layer

13‧‧‧ thick copper layer

14‧‧‧ thermal insulation layer

141‧‧‧The first polymer composite layer

142‧‧‧The second polymer composite layer

143‧‧‧The third polymer composite layer

144‧‧‧The fourth polymer composite layer

15‧‧‧radiation layer

FIG. 1 is an exploded schematic side view of a heat dissipation structure of an IGBT module in the prior art.

2 is a schematic side view of a heat dissipation structure of an IGBT module in the prior art.

FIG. 3 is a schematic exploded side view of the improved IGBT module heat dissipation structure of the present invention.

4 is a schematic side view of the improved IGBT module heat dissipation structure of the present invention.

FIG. 5 is an enlarged schematic view of part V of FIG. 4.

6 is a schematic side view of another improved IGBT module heat dissipation structure of the present invention.

7 is an enlarged schematic view of part VII of FIG. 6.

The following is a specific specific example to illustrate the implementation of the "IGBT module heat dissipation structure improvement" disclosed by the present invention. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments. Various details in this specification can also be based on different viewpoints and applications, and various modifications and changes can be made without departing from the spirit of the present invention. In addition, the drawings of the present invention are for illustrative purposes only, and are not depicted according to actual dimensions. The following embodiments will further describe the related technical content of the present invention in detail, but the disclosed content is not intended to limit the technical scope of the present invention.

Please refer to FIG. 3, FIG. 4, and FIG. 5 for an improved IGBT module heat dissipation structure provided by the present invention. As shown in FIGS. 3 and 4, according to the improvement of the heat dissipation structure of the IGBT module provided by the present invention, from top to bottom, the IGBT chip layer 11, the bonding layer 12, the thick copper layer 13, the thermally conductive insulating layer 14, and the heat dissipation layer 15.

A thermally-conductive and electrically-insulating layer 14 is disposed on the heat dissipation layer 15. The heat dissipation layer 15 may be an aluminum heat sink or a metal plate with heat dissipation effect. In addition, the thermally conductive insulating layer 14 is composed of a polymer composite, which can achieve the purposes of insulation, thermal conduction, and bonding. Therefore, compared with the existing IGBT module heat dissipation structure, the DBC board and the heat dissipation layer must be connected through a solder layer to form a connection. The present invention directly forms a thermally conductive insulating layer 14 on the surface of the heat dissipation layer 15 without a solder layer. It will not affect the thermal conductivity due to the problem of empty soldering and interface impedance caused by the solder layer, nor will it affect the thermal conductivity due to the multilayer structure of the DBC board.

In detail, as shown in FIG. 5, the thermally conductive insulating layer 14 of this embodiment includes a first polymer composite layer 141 and a second polymer composite layer 142. The first polymer composite layer 141 is bonded to the heat dissipation layer 15, and the second polymer composite layer 142 is bonded to the first high Above the molecular composite layer 141. In more detail, the first polymer composite layer 141 can be bonded to the heat dissipation layer 15 by screen printing or hot pressing, and the second polymer composite layer 142 can be bonded to the first polymer composite by screen printing or hot pressing. Above layer 141.

The first polymer composite layer 141 may be an epoxy-based composite for forming insulation and heat conduction. Moreover, the first polymer composite layer 141 may include a filler, such as at least one of aluminum oxide, aluminum nitride, silicon nitride, silicon carbide, and boron nitride. The second polymer composite layer 142 may also be an epoxy resin layer for bonding to the thick copper layer 13. The second polymer composite layer 141 may also contain fillers.

In other embodiments, the first polymer composite layer 141 may be a polyimide-based composite layer or a polypropylene-based composite layer. In addition, the second polymer composite layer 142 may be a polyimide layer or a polypropylene layer. Therefore, the configurations of the first polymer composite layer 141 and the second polymer composite layer 142 may be the same or different.

In this embodiment, the thickness of the first polymer composite layer 141 is 20-200 μm (micrometer), preferably 100 μm, which can achieve better insulation and thermal conductivity. The thickness of the second polymer composite layer 142 is 20-200 μm (micrometer), preferably 100 μm.

The thick copper layer 13 is disposed on the thermally conductive insulating layer 14 to insulate the thick copper layer 13 and the heat dissipation layer 15 through the thermally conductive insulating layer 14, and the thick copper layer 13 conducts heat to the heat dissipation layer 15 through the thermally conductive insulating layer 14.

In detail, the thick copper layer 13 is a second polymer composite layer 142 bonded to the thermally conductive insulating layer 14 by thermocompression bonding. Moreover, since the thick copper layer 13 is the second polymer composite layer 142 bonded to the thermally conductive insulating layer 14 by thermocompression bonding, only the second polymer composite layer 142 may be deformed by hot pressing, and the first polymer composite The layer 141 can maintain the original predetermined thickness without affecting the insulation and thermal conductivity.

Furthermore, since the thick copper layer 13 is the second polymer composite layer 142 bonded to the thermally conductive insulating layer 14 by thermocompression bonding, the thick copper layer 13 can reach a relatively thick thickness. in In this embodiment, the thickness of the thick copper layer 13 may be at least greater than 1000 μm. Therefore, compared with the thin copper layer of the existing DBC board of the IGBT module heat dissipation structure of about 300 μm, the IGBT module heat dissipation structure of the present invention can increase heat dissipation uniformity and overall heat conduction efficiency through the thick copper layer 13. In addition, the thick copper layer 13 of this embodiment may be composed of a thick copper plate.

The bonding layer 12 is provided on the thick copper layer 13, and the IGBT wafer layer 11 is provided on the bonding layer 12. The bonding layer 12 may be a tin bonding layer, but may also be a silver sintered layer. The IGBT wafer layer 11 may be composed of at least one IGBT wafer 111. In addition, the IGBT wafer layer 11 is connected to the thick copper layer 13 through the bonding layer 12. When the IGBT chip 111 generates heat, the thick copper layer 13 and the thermally conductive insulating layer 14 can conduct heat to the heat dissipation layer 15 to dissipate heat outward.

Please refer to FIG. 6 and FIG. 7 for another IGBT module heat dissipation structure improvement provided by the present invention. As shown in FIGS. 6 and 7, the heat dissipation structure of the IGBT module provided by the present invention is improved. The IGBT chip layer 11, the bonding layer 12, the thick copper layer 13, the thermally conductive insulating layer 14, and the heat dissipation layer are in order from top to bottom. 15.

In detail, as shown in FIG. 7, the thermally conductive insulating layer 14 of this embodiment includes a first polymer composite layer 141, a second polymer composite layer 142, a third polymer composite layer 143, and a fourth polymer composite Layer 144. It can also be said that the first polymer composite layer 141 is a base and the second polymer composite layer 142 is a multilayer structure. In more detail, the first polymer composite layer 141 is screen printed on the heat dissipation layer 15, the second polymer composite layer 142 is screen printed on the first polymer composite layer 141, and the third polymer composite layer 143 is screen printed On the second polymer composite layer 142, the fourth polymer composite layer 143 is screen printed on the third polymer composite layer 143, and the thick copper layer 13 is thermocompression bonded on the fourth polymer composite layer 144. Therefore, the thermally conductive insulating layer 14 of this embodiment has at least two or more polymer composite layers, and the thickness of each polymer composite layer is 20-200 μm (micrometers), so that the thick copper layer 13 can better Bonding to thermally conductive insulating layer by thermocompression bonding 14, and the thermally conductive insulating layer 14 can better achieve insulation and thermal conductivity.

In summary, according to the present invention, the heat conductive insulating layer 14 is provided between the thick copper layer 13 and the heat dissipation layer 15 to quickly and uniformly conduct the heat of the IGBT chip 111 through the thick copper layer 13 and the heat conductive insulating layer 14 to the whole Compared with the DBC board of the heat dissipation structure of the IGBT module on the heat dissipation fins of the heat dissipation layer 15, the present invention can simultaneously have the heat dissipation uniformity of the thick copper layer 13 and the insulation and thermal conductivity of the heat conduction insulation layer 14 without passing through The solder layer forms the thermally conductive insulating layer 14 directly on the surface of the heat dissipation layer 15. It will not affect the thermal conductivity due to the soldering layer and the problem of interface soldering and interface resistance, nor will it affect the thermal conductivity due to the multilayer structure of the DBC board. The performance enables the heat dissipation layer 15 of the present invention to exert maximum heat absorption and heat dissipation efficiency.

The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Therefore, any equivalent changes in the description and drawings of the present invention are included in the rights of the present invention. Within the scope of protection, Chen Ming.

11‧‧‧IGBT layer

111‧‧‧IGBT chip

12‧‧‧Joint layer

13‧‧‧ thick copper layer

14‧‧‧ thermal insulation layer

15‧‧‧radiation layer

Claims (10)

An improved IGBT module heat dissipation structure includes: an IGBT chip layer, a bonding layer, a thick copper layer, a thermally conductive insulating layer, and a heat dissipating layer. The thermally conductive insulating layer is disposed above the heat dissipating layer, and the thick copper layer is disposed at On the thermally conductive insulating layer, the bonding layer is disposed on the thick copper layer, and the IGBT wafer layer is disposed on the bonding layer, wherein the thermally conductive insulating layer has a height of at least two layers The molecular composite layers are joined. The improvement of the heat dissipation structure of the IGBT module according to claim 1, wherein the at least two or more polymer composite layers include a first polymer composite layer and a second polymer composite layer, the first polymer composite layer One of them is bonded to the heat dissipation layer by screen printing and hot pressing, the second polymer composite layer is bonded to the first polymer composite layer by screen printing and hot pressing, and the thick The copper layer is thermocompression bonded on the second polymer composite layer. The improvement of the heat dissipation structure of the IGBT module according to claim 2, wherein the first polymer composite layer is one of an epoxy resin layer, a polyimide layer, and a polypropylene layer. The improvement of the heat dissipation structure of the IGBT module according to claim 3, wherein the first polymer composite layer contains a filler selected from alumina, aluminum nitride, silicon nitride, silicon carbide, and boron nitride At least one. The improvement of the heat dissipation structure of the IGBT module according to claim 3, wherein the second polymer composite layer is one of an epoxy resin layer, a polyimide layer, and a polypropylene layer. The improvement of the heat dissipation structure of the IGBT module according to claim 5, wherein the second polymer composite layer contains a filler selected from alumina, aluminum nitride, silicon nitride, silicon carbide, and boron nitride At least one. The improvement of the heat dissipation structure of the IGBT module according to claim 5, wherein the thickness of the first polymer composite layer is 20-200 μm, and the thickness of the second polymer composite layer is 20-200 μm. The improvement of the heat dissipation structure of the IGBT module according to claim 1, wherein the thickness of the thick copper layer is greater than or equal to 1000 μm. The improvement of the heat dissipation structure of the IGBT module according to claim 1, wherein the at least two or more polymer composite layers include a first polymer composite layer, a second polymer composite layer, a third polymer composite layer, and A fourth polymer composite layer, the first polymer composite layer is screen-bonded on the heat dissipation layer, and the second polymer composite layer is screen-bonded on the first polymer composite layer. The third polymer composite layer is screen-bonded on the second polymer composite layer, the fourth polymer composite layer is screen-bonded on the third polymer composite layer, and the thick copper layer Hot press bonding on the fourth polymer composite layer. The improvement of the heat dissipation structure of the IGBT module according to claim 9, wherein the first polymer composite layer, the second polymer composite layer, the third polymer composite layer, and the fourth polymer composite The thickness of the layer is 20~200μm.

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