摘要 |
A process for bonding a silicon die to a package. This process comprises the following steps: (a) providing to the back surface of the die a barrier layer which is impervious to silicon; (b) providing to the barrier layer a layer of gold; and (c) bonding the die to the package by activating a binder composition disposed at the interface of the package and the layer of gold. The barrier layer prevents the migration of silicon to the gold layer, both at the time of application of the gold layer to the die and at the time of bonding the die to the package. Titanium and tungsten are preferred barrier layer materials, while the preferred binder composition is a gold-/<.>tin alloy solder. The prevention of silicon migration into the gold produces highly reliable bonds. |