Method of manufacturing bonded body for insulating circuit board, and bonded body for insulating circuit board

Abstract

This method of manufacturing a bonded body for an insulating circuit board comprises: an aluminum circuit layer forming step of forming, on one surface of a ceramics board, a plurality of aluminum circuit layers; and a copper circuit layer forming step in which a circuit layer copper plate is individually stacked on each of the aluminum circuit layers, the stack is arranged between a pair of backing plates each of which have a convex surface on at least one surface thereof and which are arranged with the convex surfaces opposing each other, and the backing plates are moved in opposing directions to thereby pressurize the stack in the stacking direction and heated in the pressurized state, thereby forming a copper circuit layer in which the circuit layer copper plate is bonded to the aluminum circuit layers by solid-phase diffusion bonding. In the copper circuit layer forming step, the backing plates are arranged such that any of the convex surfaces spans across and abuts against a plurality of circuit layer copper plates adjacent to each other in the stack.

Description

technical field [0001] The present invention relates to a method for manufacturing an insulating circuit board assembly such as a power module substrate used in a semiconductor device that controls large current and high voltage, and the insulating circuit board assembly. This application claims priority based on Japanese Patent Application No. 2018-58136 filed on March 26, 2018, and uses the content thereof here. Background technique [0002] As a substrate for a power module, there is known a substrate in which a circuit layer is bonded to one surface of an insulating layer composed of a ceramic substrate represented by aluminum nitride, and a metal layer for heat dissipation is bonded to the other surface. The layers are bonded with heat sinks. [0003] For example, in the substrate for a power module with a heat sink disclosed in Patent Document 1, a circuit layer with a double-layer structure of an aluminum layer and a copper layer is formed on one surface of an insula...

AI Technical Summary

Problems solved by technology

[0007] However, since the guide post cannot be installed directly above the laminated body, it tends to be difficult to apply a load inside the outer periphery of the ceramic substrate.

The bonding between the ceramic substrate and the aluminum plate is substantially uniform over the entire surface due to the liquid phase generated by brazing, but since the aluminum layer and the copper layer are bonded in the solid phase, the contact state has a great influence on the bonding

In the bonding using the above-mentioned pressure plate, the load tends to concentrate on the outer periphery of the circuit layer, conversely, it is difficult to apply the load on the inner side of the outer periphery, and bonding failure may occur outside the outer periphery of the metal layer.

In particular, when the circuit layer is separated into a plurality of circuit layers, a sufficient intermetallic compound layer due to solid-phase diffusion bonding is not formed at the end of the adjacent copper plate for circuit layer facing the inside of the gap, which is likely to occur. Poor joint

Images