Die Attach of Large Dice with Ag/Glass in Multilayer Packages

Abstract

Due to oxide formation at the die backside, excessive non‐wetting and voiding can occur especially for the larger die (100K sq. mil) by gold eutectic die attach. Such voiding can cause die lift‐off and cracking. Ag/glass seems to be a promising candidate. However, it has some shortcomings. First, solder seal hermeticity reject may occur due to nickel diffusing through gold metallisation and being oxidised on the surface of the multilayer package. Secondly, for those devices requiring backside contact, gold metallisation on the die backside becomes the barrier for the reaction between the silicon and the glass. The adhesion may be degraded. The factors which may overcome these shortcomings will be discussed.

Citation

Loo, M.C. and Su, K. (1986), "Die Attach of Large Dice with Ag/Glass in Multilayer Packages", Microelectronics International, Vol. 3 No. 3, pp. 8-11. https://doi.org/10.1108/eb044239