摘要
研究了具有Gent-Thomas特征的热超弹性材料构成的高聚物电子封装件在回流焊过程中由于吸湿所引发的蒸汽压力以及由于材料的热失配引发的热应力共同作用下而导致的"爆米花"式的分层失效问题.利用超弹性材料空穴生成和增长的理论给出了此类封装材料在回流焊过程中孔穴的生成及增长与蒸汽压力和热应力之间的解析关系.分析结果表明,当高聚物电子封装件吸湿较少、回流焊过程中孔穴中的潮完全汽化时,单纯的蒸汽压力不足以导致"爆米花"式的分层失效.当高聚物电子封装件吸湿较多、回流焊过程中孔穴内压保持饱和蒸汽压时,单纯的蒸汽压力将使孔穴产生不稳定的增长行为,从而导致封装件发生"爆米花"式的分层失效.
Popcorn delamination failure of electronic packages made of thermohyperelastic material with Gent-Thomas feature under the joint effects of vapor pressure induced by the moisture and thermal stress by heat mismatch was studied. Using the theory of cavity formation and unstable void growth in incompressible hyper-elastic material, an analytical solution relating the void growth to the vapor pressure and thermal stress is obtained. Numerical analysis shows that when thermohyperelastic electronic packages absorb little moisture, the moisture in voids becomes single vapor phase during the solder-reflow process, as a result,no popcorn failure occur. On the contrary,when the thermohyperelastic electronic packages absorb more moisture, the vapor pressure in voids always maintains saturation state during the solder-reflow process; as a result,the voids grow unstably and the popcorn failure appears.
出处
《固体力学学报》
CAS
CSCD
北大核心
2011年第5期459-464,共6页
Chinese Journal of Solid Mechanics
基金
山西省科技攻关项目(2010081016)
太原市科技明星项目(10011607)
2008山西省回国留学人员科研资助项目(2008.30)
太原理工大学校青年基金资助
