薄膜基板芯片共晶焊技术研究

摘要

Eutectic is an important technology of micro-electronics assembly. It is more and more used in hybrid circuit.This paper describes briefly Principle of eutectic,and analyzes factors influencing on chip eutectic technology of thin film substrate.It uses Ti/Ni/Au film and AuSn solders, also designs fixture and studies chip eutectic technology of thin film substrate by importing nitrogen and hydrogen shielding gas in vacuum atmosphere.The test suggests void is controlled effectively below 10% when Au thickness of substrate metallization is 1.5μm, pressure is 2kPa,bonding temperature is 330℃ and bonding time is 30s. Reliablity of shear strength and contact resistance of eutectic samples were tested after 150℃ high temperature storage and -65 ℃-150℃ temperature cycling. After reliablity test, shear strength of samples can meet the requirement of GJB548B-2005 and the change of contact resistance is less than 5%.%共晶焊是微电子组装技术中的一种重要焊接工艺，在混合集成电路中得到了越来越多的应用。文章简要介绍了共晶焊接的原理，分析了影响薄膜基板与芯片共晶焊的各种因素，并且选用Ti／Ni／Au膜系和AuSn焊料，利用工装夹具在真空环境下通入氮、氢保护气体的方法进行薄膜基板芯片共晶焊技术的研究。试验证明：焊接基板金属化Au层厚度1．5μm，焊接压力为2kPa，焊接温度330℃，时间30s可有效地使空洞面积控制在10％以下。并在150℃高温贮存以及-65℃～150℃温度循环后对共晶焊接样品的剪切强度和接触电阻进行了试验。在可靠性试验后，样品的剪切强度满足GJB548B-2005的要求，接触电阻变化率小于5％。