Modified Cr Dam for MC Metallurgy
Original Publication Date: 1978-Mar-01
Included in the Prior Art Database: 2005-Feb-20
The top Cr layer of metallized ceramic (MC) Cr-Cu-Cr metallurgy serves as a solder dam so that the Cu layer can be selectively tinned. Selective tinning is needed to bond devices and to interconnect substrate lands to the pins. In metallized ceramic manufacturing, it is imperative that the top Cr layer does not break down during the tinning operation since excess solder can cause rejects, such as solder bridging of closely spaced lands and shorting with devices.