Copper paste capable of achieving low-temperature high-density sintering

Abstract

The invention relates to the field of metal composite materials, in particular to copper paste capable of achieving low-temperature high-density sintering. The copper paste comprises spherical copperparticles, flake copper particles, flake indium particles and high-link resin; and the ratio of the two kinds of copper particles is more than 80%, the ratio of the indium particles is 10%-20%, and the ratio of the high-link resin is 0-10%. According to the copper paste body, under the non-pressure condition, the sintering temperature can be as low as about 180 DEG C to 250 DEG C, and the densityis more than 95% after sintering.

Description

technical field [0001] The present application relates to the field of metal composite materials, in particular to the preparation of a copper paste that can be used for low-temperature and low-pressure sintering. Background technique [0002] A new generation of power modules for electric vehicles, aviation, and other industries requires high power and high service temperature. It has been demonstrated in the past 10 years that wide bandgap semiconductors can withstand high operating temperatures above 300°C. However, traditional packaging materials, such as tin-based solders and conductive adhesives, are limited to operation below 200°C. Researchers have been looking for ways to achieve high reliability at high temperature and high power. In past explorations, the sintering of highly conductive and conductive silver or copper among metals has been found to be a promising approach. For cost considerations, copper sintering is a technology that has been tried in recent ye...

AI Technical Summary

Problems solved by technology

At present, many nano-copper particles are mostly spherical, and some of them are difficult to achieve mutual fusion and sintering even below 30 nanometers. The main problem is that the oxidation problem of copper surface has always existed. As the surface energy increases, the chance of interdiffusion of metal atoms increases, but the oxidation tendency is also more intensified. Therefore, it is a great challenge to reduce the temperature of copper sintering

At the same time, sinter porosity is also a problem to be considered, because the porosity will reduce the thermal conductivity and the reliability of the sintering point

[0003] The document "Development of Die Attachment Technology for Power IC Module yIntroducing Indium into Sintered Nano-Silver Joint", 2017IEEE67th Electronic Component and Technology Conference records that adding indium foil to silver sintered materials will reduce the oxidation of copper matrix in use and service, while The reliability of the device has also been greatly improved, probably because of the barrier of the Cu-In intermetallic compound

Images