ELECTRODE JUNCTION PART CONSTRUCTION OF SEMICONDUCTOR DEVICE

摘要

PURPOSE:To delay the increment rate of electrical resistance between copper ball and Al electrode and to extend the life of device by constituting the electrode junction construction so that the Cu.Al alloy layer and Al layer continue in vertical direction to the electrode surface. CONSTITUTION:A copper ball 1 which was formed by heating the tip of copper wire is joined to an Al electrode 2 on an insulator 4 by the supersonic thermocompression bonding method. In this case, a Cu.Al alloy layer 3 is generated directly below the copper ball 1 but an Al layer 21 should remain over the entire surface below the alloy layer 3. A junction consisting of Cu ball- Cu.Al alloy layer-Al layer is formed on the entire surface of junction and this Al layer is in a construction to continue to the surrounding Al layer so that the increment rate of electrical resistance due to deterioration of the alloy layer 3 is delayed and the life of device is long.