Conductive silver paste for LTCC ceramic substrate and preparation method thereof

Abstract

The present invention provides a conductive silver paste for LTCC (Low Temperature Co-fired Ceramic) ceramic substrate. According to the mass percent, the conductive silver paste is formed by 82%-86%of silver powder, 3%-4% of polymer resin, 0.2%-1.1% of glass powder and 10%-15% of solvent. The polymer resin is formed by ethyecellulose, carboxymethylcellulose and polyaspartic acid. The conductivesilver paste obtained by employing the preparation method provided by the invention is good in conductivity, high in adhesive force, and smooth and dense in appearance. The bonding force of the sliverlayer and the ceramic interface is high, and the internal portion of the device cannot generate cracking and delamination.

Description

technical field [0001] The invention relates to the technical field of conductive paste, in particular to a conductive silver paste suitable for LTCC ceramic substrates and a preparation method thereof. Background technique [0002] Communication, automotive, medical, military, aerospace and other applications require high performance, high density, and high reliability of electronic systems are and will continue to pose new challenges to electronic packaging. LTCC (Low Temperature Co-fired Ceramic) technology, low temperature co-fired ceramic technology, is an advanced passive integration and hybrid circuit packaging technology, which can integrate three passive components (including resistors, capacitors and inductors) And its various passive components (such as filters, transformers, etc.) are packaged in multilayer wiring substrates, and are integrated with active devices (such as: power MOS, transistors, IC circuit modules, etc.) into a complete circuit system. Low-tem...

AI Technical Summary

Problems solved by technology

This not only leads to the high cost of LTCC devices developed and produced in my country, but more importantly, the core key technologies and products are controlled by others, which seriously hinders the upgrading and development of my country's electronic paste technology and industry

[0004] LTCC technology In order to reduce the sintering temperature, LTCC ceramics are usually realized by doping low-melting point oxides or low-melting point glass. The complex system makes it difficult for traditional silver paste to match it, and even cannot meet the basic requirements for use.

During the co-firing process of traditional conductive silver paste and LTCC ceramic substrate, due to the differences in the affinity between ceramics and silver powder and between silver powder and silver powder, the excessive diffusion of silver powder to the ceramic body causes the insulation resistance to decrease, and there is a risk of electrical breakdown of the circuit. The silver electrode layer is prone to more voids after sintering; the insufficient bonding force between the silver layer and the ceramic interface will lead to serious consequences of cracking and delamination inside the device

In addition, due to the different diffusion coefficients of metals and ceramics, the difference in diffusion speed leads to unevenness on both sides of the interface, resulting in a decrease in the flatness of the substrate

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