表面镀层对封帽质量的影响

Effect of Surface Plating Layer on Encapsulation Quality

气密封装工艺技术是混合电路制造的关键技术。在可靠性要求较高的场合,对混合电路产品提出了水汽含量、漏气率和粒子碰撞噪声检测(PIND)合格率的指标要求。封装内部的多余物对电子器件的可靠性带来严重影响。主要从盒体的表面镀层方面进行讨论,分析了不同的金属化结构和不同的镀层厚度对气密封装的影响。实验表明,当封装使用的压力较大时,化学镀镍外壳的镀层容易出现裂纹,造成外壳锈蚀。外壳使用化学镀镍、电镀金结构时,其PIND不合格率较高。当镀层厚度超标时,不仅PIND不合格率较高,也会出现漏气问题。

Hermetic packaging process is one of the key technologies in microwave hybrid IC manufacturing.There are many constraint limitations to hybrid circuits used in the application of higher reliability requirements,such as inner moisture content,leakage rate and particle impact noise detection（PIND） reject ratio.Particles in hermetic packaging device cavities bring the serious influence on thereliability of electron devices.The surface plating layer of the box was discussed.The different effects ofcoating thickness and metallization structures on hermetic packaging were analyzed.The tests show that when the package pressure is larger,the crack occurs easily at the plating layer of the case usingelectroless nickel,resulting in the package corrosion.With electroless nickel and gold plating structure,PIND reject ratio is higher.When the plating thickness is higher（out of limits）,the PIND reject ratio ishigher and the leakage can occur.