Warpage control structure for metal base plate, semiconductor module, and inverter device

Abstract

The purpose of the present invention is to provide a technology that controls the warpage of a metal base plate generated while the temperature changes from a high temperature to room temperature, by providing the warpage to the metal base plate in a temperature change from room temperature to the high temperature. This warpage control structure for a metal base plate 1 comprises a metal base plate 1, a dissimilar metal layer 2, and an insulation substrate 4. The dissimilar metal layer was formed on the surface of the metal base plate 1. The insulation substrate 4 has metal plates 42a, 42b bonded to the surface of the dissimilar metal layer 2 via a bonding material 3 and arranged on both surfaces thereof. When the linear expansion coefficient of the metal base plate 1 is alpha1, the linear expansion coefficient of the dissimilar metal layer 2 is alpha2, and the linear expansion coefficient of the metal plates 42a, 42b is alpha3, alpha1>alpha3>alpha2 is satisfied.

Description

technical field [0001] The present invention relates to a technique for controlling warpage that occurs when an insulating substrate is bonded to a metal base plate at a high temperature. Background technique [0002] A semiconductor module employs a structure and a method of bonding an insulating substrate to a metal base plate. Inexpensive welding is often used as a common joining method. However, when the insulating substrate is welded to the metal base plate, the metal base plate warps after joining. The reason is that although the metal base plate does not warp when the temperature changes from normal temperature to high temperature when the solder melts, when the temperature changes from high temperature to normal temperature when the solder solidifies, due to the metal base plate and the insulation The difference in the linear expansion coefficient of the substrate causes large warpage in the metal base plate. At this time, when the initial warp of the metal base p...

AI Technical Summary

Problems solved by technology

[0010] However, as shown in the technology described in Patent Document 1, if only the same type of metal as the insulating substrate is pasted on the metal base plate, when the temperature of the metal pasted on the metal base plate changes from normal temperature to high temperature The amount of warpage is larger when the temperature changes from high temperature to normal temperature after the insulating substrate is bonded to the metal base plate in a high temperature state.

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