ZHANG Dong-mei, DING Gui-fu, WANG Hong, et al. Study of low temperature eutectic bonding process for MEMS hermetic package[J]. 2006, (1): 82-84. DOI: 10.13873/j.1000-97872006.01.029.
MEMS器件气密性封装的低温共晶键合工艺研究
摘要
介绍了一种采用Pb-Sn共晶合金作为中间层的键合封装技术
通过电镀的方法在芯片与基片上形成Cr/N i/Cu/Pb-Sn多金属层
在温度为190℃、压强为150 Pa的真空中进行键合
键合过程不需使用助焊剂
避免了助焊剂对微器件的污染。试验表明:这种键合工艺具有较好的气密性
键合区合金分布均匀、无缝隙、气泡等脱焊区
键合强度较高
能够满足电子元器件和微机电系统(MEMS)可动部件低温气密性封装的要求。
Abstract
A fluxless bonding technique using eutectic Pb-Sn alloy as joint is presented.Cr/Ni/Cu/Pb-Sn multilayer on substrate and chip is electroplated
then bonded at 190 ℃ and 150 Pa in vacuum.This fluxless bonding process can prevent micro device being polluted.This bonding process is hermetic.The thickness of the joint is found to be very uniform along the entire cross section.The strength of the joint is high
it can meet the requirement of hermetic packaging of electronic device and MEMS movable parts at low temperature.