论影响银合金线电性迁移的因素

The factors that affect the electrical migration of Ag Alloy

目前电子行业主要的键合线材有金线、纯铜线、镀钯铜线、银合金线等。金线由于成本太高已经不能适应市场发展需求;纯铜线容易氧化、加工难度高、可靠性低等因素只能占据低端产品市场;镀钯铜线材质太硬,在焊接过程中对产品铝垫损伤较大,容易产生裂纹和弹坑。银合金线材质比镀钯铜线软,加工稳定性高,所以被得到了较大的推广和使用。但是银合金线的主要成分为银,它是一种很活跃的带电离子,将会造成电性迁移现象;本论文通过两组试验论证,银合金线在特殊温度、电流密度、电场方向的影响下[1],它的中值失效时间(median time of failure简称MTF)会随着温度和电流密度的影响而变化,产生电性迁移,最终影响产品可靠性。

At present,the main bonding wire of electronics industry is gold wire,copper wire,PdCu wire Ag alloy wire,Because costing gold wire is too high,so it’s cannot meet the market development.Copper wire is easy to oxidize,low reliability and other factors,only occupy the low-end market;PdCu wire is too hard,in the welding process for pad damage is bigger,processing easy to produce cracks and crater.Ag alloy wire is more flexible than the PdCu wire.However the main component is Ag,it’s a very active charged particles,There will be an electrical transfer.This thesis is proved by two groups of experiments,in special temperature,current density,the influence of field direction and induction,The median time of failure(MTF)varies with temperature and current density,the particle migration happens,Ultimately it affects product reliability.