Search

CN-121985825-A - Bottom plate structure for power module

CN121985825ACN 121985825 ACN121985825 ACN 121985825ACN-121985825-A

Abstract

The invention discloses a bottom plate structure for a power module, which comprises a bottom heat conduction bottom plate, wherein the bottom heat conduction bottom plate comprises a heat dissipation channel region and a peripheral region positioned at the peripheral side of the heat dissipation channel region. The heat dissipation channel region is provided with a heat dissipation channel bottom plate, and the heat dissipation channel bottom plate comprises a first composite material layer and surface metal layers formed on the top surface and the bottom surface of the first composite material layer. The peripheral zone has a peripheral metal floor therein. The surface metal layer and the peripheral metal bottom plate are both made of aluminum or aluminum alloy. The heat dissipation channel bottom plate and the peripheral metal bottom plate form an integrally formed bottom heat conduction bottom plate. The first composite material layer is an aluminum and diamond composite material layer, and the heat conductivity of the first composite material layer is adjusted by adjusting the consumption of diamond particles and is higher than that of copper, so that the heat resistance is reduced, and meanwhile, the cost is reduced. The invention can realize high heat dissipation performance, maintain good mechanical performance, reduce cost and improve reliability.

Inventors

  • Request for anonymity

Assignees

  • 海南亿塔科技有限公司

Dates

Publication Date
20260505
Application Date
20260209

Claims (15)

  1. 1. The bottom plate structure for the power module is characterized by comprising a bottom heat conduction bottom plate, wherein the bottom heat conduction bottom plate comprises a heat dissipation channel region and a peripheral region positioned at the peripheral side of the heat dissipation channel region; the heat dissipation channel area is provided with a heat dissipation channel bottom plate, and the heat dissipation channel bottom plate comprises a first composite material layer and surface metal layers formed on the top surface and the bottom surface of the first composite material layer; The peripheral zone is provided with a peripheral metal bottom plate; The surface metal layer and the peripheral metal bottom plate are both made of aluminum or aluminum alloy; the heat dissipation channel bottom plate and the peripheral metal bottom plate form the bottom heat conduction bottom plate which is integrally formed; the first composite material layer is an aluminum and diamond composite material layer, and the heat conductivity of the first composite material layer is adjusted by adjusting the using amount of diamond particles and is higher than that of copper, so that the heat resistance is reduced, and meanwhile, the cost is reduced.
  2. 2. The base plate structure for a power module according to claim 1, wherein an intermediate insulating heat conductive layer is formed on a top surface of the base heat conductive base plate, a top copper layer is formed on a top surface of the intermediate insulating heat conductive layer, the top copper layer has a pattern structure of chip mounting areas arranged according to a circuit topology, and an insulating heat conductive base plate is formed by laminating the base heat conductive base plate, the intermediate insulating heat conductive layer, and the top copper layer.
  3. 3. The backplane structure for a power module of claim 2, wherein the surface metal layer has a thickness of 0.1 mm to 0.5mm.
  4. 4. The backplane structure for a power module of claim 1 wherein the aluminum or aluminum alloy used for the surface metal layer comprises 1050 pure aluminum and the aluminum alloy comprises 6061 or 6063 aluminum alloy.
  5. 5. The backplane structure for a power module of claim 4, wherein the peripheral metal backplane has a thickness of 2mm to 5 mm.
  6. 6. The base plate structure for a power module according to claim 1, wherein the volume fraction of diamond particles of the first composite layer is 40% or more.
  7. 7. The backplane structure for a power module of claim 2, wherein the number of heat dissipation channel regions is 1 or more.
  8. 8. The backplane structure for a power module of claim 7, wherein the number of heat dissipation channel regions is arranged according to the dimensions of the bottom thermally conductive backplane and the circuit topology.
  9. 9. The base plate structure for a power module of claim 8, wherein the chip mounting areas are used for mounting power chips, the number of the power chips mounted in each chip mounting area is more than one, the number of the chip mounting areas is more than one, and the heat dissipation channel area is located in the chip mounting area.
  10. 10. The backplane structure for a power module of claim 9, wherein the heat dissipation channel region and the die attach region are the same size and edge aligned, or the heat dissipation channel region is larger in size than the die attach region and the edge of the heat dissipation channel region extends outside the edge of the die attach region.
  11. 11. The base plate structure for a power module according to claim 2, wherein the thickness of the intermediate insulating heat conductive layer is 0.1 mm to 0.3mm, and the thermal conductivity is 15W/(m.K) to 30W/(m.K).
  12. 12. The backplane structure for a power module of claim 2 wherein said top copper layer is C10300 pure copper and has a thickness of 0.2 mm to 0.5mm.
  13. 13. The base plate structure for a power module according to claim 1, wherein in the bottom heat conductive base plate, the first composite material layer and the peripheral metal base plate of the surface metal layer bottom are integrally formed by a vacuum pressure impregnation method.
  14. 14. The backplane structure for a power module of claim 2, wherein said middle insulating and thermally conductive layer is secured to a top surface of said bottom thermally conductive backplane using a thermal compression process, said middle insulating and thermally conductive layer having a peel strength determined by said thermal compression process.
  15. 15. The backplane structure for a power module of claim 2 wherein said top copper layer is secured to a top surface of said intermediate insulating thermally conductive layer by a crimping process.

Description

Bottom plate structure for power module Technical Field The present invention relates to the field of semiconductor devices, and in particular, to a bottom plate structure for a power module. Background A power module is the core semiconductor device for all electrical systems, power transmission and control. Power chips are the key to make up a power module and consume a portion of their energy during the transfer of electrical energy due to their voltage drop and switching losses, and are converted to thermal energy, resulting in an increase in the chip junction temperature. Excessive chip junction temperature can lead to further increase of loss, and finally damage of the power module is caused by the fact that the chip junction temperature exceeds the maximum working junction temperature. Therefore, the power module must have extremely low thermal resistance, while the electrical system must have good heat dissipation to ensure reliable operation of the power chip. With the rapid development of 5G, new energy and artificial intelligence, the electric system is also continuously developed towards high integration, small volume, high power and the like. Therefore, the power density of the power device is also continuously improved, and the heat dissipation requirement of an application end on the power device is continuously improved in order to ensure the stable operation of the device and prolong the service life of the device. Copper and its alloy materials are important packaging materials for power modules due to their excellent electrical and thermal conductivity. The bottom plate of the power module and the power terminal are usually made of pure copper, and the ceramic copper-clad substrate in the module is also made of oxygen-free copper. Copper is an important strategic metal, and the price of the copper continuously rises along with the explosive growth demands of new energy sources, artificial intelligence, robots and other emerging industries, so that the cost of power devices is also continuously increased. On the other hand, as the power density of the system is improved, the area of the power chip is continuously reduced under the same current output capacity, and further, higher requirements are put on the heat dissipation capacity of the power device, so that materials with higher heat conductivity than pure copper are obtained, and more application opportunities are obtained. New heat conductive materials typified by aluminum nitride, silicon nitride, and diamond have been attracting attention. The diamond has extremely high heat conductivity, can reach more than 2000W/(m.K) theoretically, is five times that of copper at room temperature, and has the advantages of small specific heat capacity, small thermal expansion coefficient and the like, so that the diamond has great application potential in the aspect of heat dissipation of high-power devices. But the single diamond thermally conductive back plane is difficult to manufacture and difficult to use directly for the back plane of the power module due to its brittleness. Disclosure of Invention The invention aims to solve the technical problem of providing a bottom plate structure for a power module, which can realize high heat dissipation performance, simultaneously maintain good mechanical performance, reduce cost and improve reliability. In order to solve the technical problems, the bottom plate structure for the power module comprises a bottom heat conduction bottom plate, wherein the bottom heat conduction bottom plate comprises a heat dissipation channel area and a peripheral area positioned on the peripheral side of the heat dissipation channel area. The heat dissipation channel region is provided with a heat dissipation channel bottom plate, and the heat dissipation channel bottom plate comprises a first composite material layer and surface metal layers formed on the top surface and the bottom surface of the first composite material layer. The peripheral zone has a peripheral metal floor therein. The surface metal layer and the peripheral metal bottom plate are both made of aluminum or aluminum alloy. The heat dissipation channel bottom plate and the peripheral metal bottom plate form the bottom heat conduction bottom plate which is integrally formed. The first composite material layer is an aluminum and diamond composite material layer, and the heat conductivity of the first composite material layer is adjusted by adjusting the using amount of diamond particles and is higher than that of copper, so that the heat resistance is reduced, and meanwhile, the cost is reduced. A middle insulating heat conducting layer is formed on the top surface of the bottom heat conducting bottom plate, a top copper layer is formed on the top surface of the middle insulating heat conducting layer, and the top copper layer is provided with a pattern structure of a chip mounting area arranged according to circuit topology; and the insulating heat co