大腔体陶瓷封装中平行缝焊的密封可靠性设计

Sealing Reliability Design of Parallel Seam Welding in Large Cavity Ceramic Package

随着平行缝焊腔体尺寸的增大,尤其在中温共烧陶瓷封装和薄型高温共烧陶瓷封装中,常常存在平行缝焊的密封成品率相对较低和气密性可靠性相对较差的问题。通过分析氧化铝陶瓷封装的密封失效原因,提出优化平行缝焊可伐焊框和盖板的结构设计来提升密封可靠性。以采用FC-CPGA570封装形式的某型DSP电路为例进行仿真和验证,通过降低钎焊残余热应力、增加缓冲结构、采用盖板轻量化设计,实现了很好的密封成品率及好的密封可靠性,为同类产品乃至低温共烧陶瓷封装的气密性设计、可靠性提升提供参考。

With the increase of the size of the parallel seam welding cavity,especially in the medium temperature co-fired ceramic package and thin high temperature co-fired ceramic package,the sealing yield of parallel seam welding is relatively low and the reliability of air tightness is relatively poor.By analyzing the reasons of sealing failure of alumina ceramic package,an optimized structure design of kovar frame and lid of parallel seam welding is proposed to improve sealing reliability.A certain type of DSP circuit using FC-CPGA570 package is taken as an example for simulation and verification.By reducing the residual thermal stress of brazing,increasing the buffer structure,and adopting the lightweight design of lid,very good sealing yield and good sealing reliability are achieved,thus providing a reference for the air tightness design and reliability improvement of similar products and even low temperature co-fired ceramic package.