焊盘阵列陶瓷封装外壳手动搪锡方法研究

Study on Manual Tinning Method for Ceramic Land Grid Array Package

针对某型号陶瓷封装DC-DC电源稳压器手动搪锡过程中的瓷裂现象,通过失效分析发现其失效原因为300℃搪锡条件下陶瓷局部热应力过大。通过有限元分析,发现塘锡前增加预热工艺可将陶瓷局部应力降低到安全范围。采用预热方案(140℃预热,烙铁温度设置为260℃)对该陶瓷封装产品进行验证,搪锡后无瓷裂现象,且产品满足200次温循(-65℃~150℃)、10000g恒定加速度的可靠性要求,解决了300℃手动搪锡条件导致的瓷裂问题。

In accordance with the phenomenon of ceramic cracking in manual tinning of a certain type of ceramic-packed DC-DC power regulator,through failure analysis,it was found that the failure reason is the excessive local stress of the ceramic under 300℃tinning.Through finite element simulation,it was found that preheating can reduce the local stress of ceramic to a safe range.The ceramic-packed product with preheating(140℃preheating,iron temperature set to 260℃)was verified,there was no ceramic cracking and the product can meet the reliability requirements of 200 temperature cycles(-65℃~150℃)and 10000 g constant ac celeration.The problem of ceramic cracking caused by manual tinning at 300℃was solved.