EMC材料特性对SCSP器件应力及层裂的影响

利用动态机械分析仪测定环氧模塑封(EMC)材料的粘弹特性数据,使用有限元软件MSCMarc分别模拟了EMC材料粘弹性、随温度变化的弹性以及恒弹性三种情况下,SCSP器件在–55～+125℃的等效应力分布及界面层裂。结果表明:125℃和–55℃时最大等效应力分别出现在恒弹性模型、粘弹性模型顶层芯片的悬置区域;将EMC材料视为恒弹性性质时等效应力比粘弹性时大了15.10MPa;–55℃时EMC材料粘弹性模型中裂纹尖端的J积分值比恒弹性模型增长了45%左右,容易引起分层裂纹扩展。

Influence of EMC material property on stress and interfacial delamination of SCSP device

The dynamic mechanical analyzer was employed to determine the viscoelastic properties data of epoxy molding compound (EMC material).Based on the EMC material viscoelastic model,temperature-dependent elastic model and constant elastic model,finite element software MSC Marc was used to investigate the distribution of maximum equivalent stress and interfacial delamination of SCSP device during temperature cycling (-55～+125 ℃),respectively.The results show that the maximum equivalent stress at 125 ℃ and -55 ℃ are present to the overhang of top chip in constant elastic model and viscoelastic model,respectively;the equivalent stress of EMC material as constant elastic material is 15.10 MPa higher than viscoelastic model;the J-integral value at crack tip in viscoelastic model is increased by about 45% compared with constant elastic model at -55 ℃,and the cracks in viscoelastic model easy to cause propagation.