摘要
功率循环中表面安装器件（ＳＭＤ）的热应变是影响ＳＭＤ焊点可靠性的重要因素之一．本文采用实时全息干涉度量法对一个具有１００条引线的塑料四边引线封装器件（ＰＱＦＰ）在功率循环中的热－力耦合离面变形场进行了测量，获得了分别位于ＰＱＦＰ和印制电路版（ＰＣＢ）表面的离面变形数值，并根据两者之间的离变形失配，精确地计算出了引线和焊点的变形，为全面了解ＳＭＤ在功率循环条件下的热力学行为及分析ＳＭＤ焊点的疲劳失效机理提供了精确可靠的实验数据．
Abstract This study is directed toward an investigation of thermo mechanical behaviour of a plastic leaded surface mount assembly under a complete power cycle by means of real time holographic interferometry (RTHI). The specimen is a 100 leads plastic quad flat pack (PQFP) assembled to an FR 4 printed circuit board (PCB). The deformation types and magnitudes of whole assembly, including the PQFP, the PCB, the lead and solder joints, are obtained. Deformation responses with different power levels are measured. Then the thermal fatigue mechanism of the lesd of PQFP and solder joints is discussed based on the experimental results.
