Diffusion Process for Improved Ceramic-To-Metal Bond
Original Publication Date: 1984-Jan-01
Included in the Prior Art Database: 2005-Feb-02
A variety of semiconductor packaging technologies utilize ceramic substrates that must have attached to them metallic mounting pins. Often as well, plated through holes or metallic composition filled holes (vias) extend through a ceramic layer so that metallic contacts can be made at both sides of the substrate. Currently, the contact pins attached to the substrate are brazed on the bottom surface for attachment to a printed circuit board, for example. The pins are normally brazed with an 80% gold/20% tin eutectic alloy. This is a very expensive alloy, and copper and silver eutectics are often employed to avoid some of the expense. However, the copper/silver eutectic is expensive as well and must be brazed at temperatures of 900ŒC or higher.