光电耦合器封装及相关失效机理

与一般的半导体器件相比,光电耦合器的工作原理、结构和封装设计独具特色。光耦的失效机理除与单独的LED、三极管相同外,还有它独有的失效机理。在简单介绍光耦的工作原理与封装结构的基础上,重点分析了几种与光耦封装有关的失效机理:导光胶或反射胶工艺控制不佳导致胶开裂、起皮;光耦内部材料间热膨胀系数不匹配,内部电连接开路;内部沾污产生腐蚀;塑料和内部有机胶吸潮发生"爆米花效应";外部电路异常导致光耦失效。并针对各种失效机理提出了改进措施。

Package and Corresponding Failure Mechanism of Optical Couplers

Comparing to normal semiconductor devices,the operating principle,structure,and package design of optical coupler(OC) are quite different.Failure mechnisms of OC is unique,besides the failure mechnism of LED and triode.After the operating principle,structure,and package is introduced,sevaral failure mechnisms of OC are analyzed include the glue splited and peeled because of poor process control,the open circuit happened because of dismatch of coefficient of thermal expansion(CTE).Corrosion is caused by inte...