X射线在陶瓷气密封装空洞检查中的不足

The Limitation of X-ray Inspection in Voids Detecting of Hermetic Ceramic Packaging

在集成电路的陶瓷气密封装中,往往使用X射线照相技术来检查密封区的空洞情况并由此判断密封质量的好坏。通常情况下,X射线的检测结果是可信的,但是也存在由于某种原因导致焊接空洞无法为X射线所探测的情形。此外,部分具有底部热沉的陶瓷外壳,其热沉材料本身对X射线的吸收很大,会对焊接区存在的空洞的成像进行覆盖,并造成漏判。另外,X射线对于不同层面的空洞会进行图像叠加,从而无法对空洞部位进行准确定位。文中从X射线照相的原理上对此类X射线照相中的空洞漏判等现象进行了分析和探讨。

X-ray radiography is commonly used to detect the voids of lid sealing area in micro-electronics hermetic ceramic packaging. In general, the result of X-ray radiography is reliable, however, there are some exceptions that X-ray radiography could not detect the voids formed in the sealing area for some reasons, also, the heat sink material on the bottom side of some ceramic packages could absorb most of X-ray dose and results in screening of void image which causing fault negatives. In addition, as X-ray radiography will overlap all the voids images formed in different layers in one picture, it is hard to identify the locations of these voids. The phenomenon of such kind of false negative is analyzed and discussed from the principle of X-ray radiography in this paper.