An improved Coffin-Manson model for mid-power LED wire-bonding reliability

Abstract

Thermal shock is usually used for LED wire-bonding accelerated life testing, and the failure is commonly treated as a low-cycle fatigue problem. The lifetime analyses which base on the Coffin-Manson model never consider the modulus saltation of silicone enclosure with the temperature changing. With an extensive DOE, an improved Coffin-Manson model is proposed, which also copes with the glass transition of silicone encapsolent. With this improved model, a more accurate prediction of wire-bonding reliability can be made.