The Effects of Moisture on Multilayered Ceramic Top Brazed Flat Packs

Recent moisture resistance tests of various multilayer top brazed ceramic flat packs have revealed a serious design deficiency. These flat packs which utilize a tungsten interconnect system, in the presence of high humidity, suffer a galvanic corrosion which anodically consumes the tungsten. This may ultimately produce an open circuit. The results indicate that the lead plating system does not adequately seal off the interface area where the tungsten stripe gresses from the inside of the package.