可伐合金与玻璃封接工艺的优化

Process optimization for glass to Kovar sealing

研究了熔封气氛、熔封温度和熔封时间对玻璃与可伐合金封接件的外观、气密性、结合强度、弯曲次数和玻璃沿引线的爬坡高度的影响.结果表明:熔封气氛的影响很大,随着熔封气氛氧化性的增强,玻璃飞溅程度越来越严重.随着熔封时间的延长或者熔封温度的升高,可伐合金表面为单一FeO或单一Fe3O4氧化膜时与玻璃的结合强度缓慢增加且弯曲次数基本保持不变,双层氧化膜(FeO+Fe3O4或Fe3O4+Fe2O3)与玻璃的结合强度虽然较高,但弯曲次数却明显下降.可伐合金表面氧化膜类型与玻璃沿引线的爬坡高度关系不大,随着熔封温度的升高,玻璃沿引线的爬坡高度下降;而随着熔封时间的延长,玻璃沿引线的爬坡高度急剧下降,当降至140μm后逐渐趋于稳定.推荐的优化工艺条件是:熔封气氛为弱还原气氛,熔封温度在980℃左右,熔封时间为20～30 min.

The effects of sealing atmosphere, sealing temperature, and sealing time on the surface appearance, leakage rate, bonding strength, bending frequency, and height of glass along the pins were investigated for glass to Kovar sealing. The results indi- cated that sealing atmosphere had an important impact on the surface appearance, and the extent of glass spattering was more serious as increasing the oxidizability of sealing atmosphere. With the extending of sealing time or the increasing of sealing temperature, the bonding strength between single oxide film （single FeO or single Fe304） and glass gradually increased, and the bending frequency almost maintained. The bonding strength between hilayer oxide film （FeO ＋ Fe3O4 or Fe3O4 ＋ Fe2O3） and glass was relatively higher and increased more quickly, however the bending frequency sharply decreased. The height of glass along the pins was not related to the type of the oxide; it reduced gradually with increasing sealing temperature, and also decreased rapidly with increasing sealing time until 140μm. The recommended sealing conditions included that the sealing atmosphere was weak reductive gas, the sealing temperature was about 980℃ and the sealing time was between 20 and 30 min.