引线尺寸对CPGA翼形引线焊点可靠性的影响

Effect of CPGA gull wing lead size on reliability of soldered joints

关键词:  有限元  陶瓷针型棚格阵列翼形引线  焊点  应力

Key words:  finite element method  gull wing lead  soldered joint  stress

摘要:

采用有限元法对陶瓷针型棚格阵列(CPGA)翼形引线焊点的应力分布进行了研究,发现在焊点最内侧底面处应力集中较大,是整个焊点最脆弱的部位,易发生破坏;分析了不同尺寸翼形引线与焊点最大应力之间的关系,得到了不同外观形状的翼形引线焊点在受交变热作用时焊点热应力的分布情况。结果表明,翼形引线厚度增加,焊点应力增大;翼形引线高度增加,焊点应力有一个最大值;翼形引线与陶瓷基板接触长度增加,焊点应力减小;翼形引线与焊盘接触长度增加,焊点应力有一个最小值。

Abstract:

Finite element method was used to study the stress distribution in soldered joints of CPGA gull wing lead.Results indicate that the innerside of soldered joint underside is the weakest position where the stress is relatively concentrated,so it is easily to be destroyed.The relationships between different sizes of gull wing lead and the max-stress in soldered joints were calculated and the thermal stress distribution in soldered joints was analyzed with different sizes of gull wing lead experienced alternating thermal effects.Results show that the stress distribution is affected by the size of gull wing lead.With the increasing of lead's thickness,the stress will increase in soldered joints;With the increasing of lead's hight,the stress in soldered joints will increase firstly and then decrease,which has a maximum value.With the increasing of lead's length contacted with solder pad,the stress in soldered joints will decrease firstly and then increase,which has a minimum value.