Semiconductor integrated circuit device and fabrication method thereof

摘要

A semiconductor device is fabricated by forming first metal balls on electrode pads of a semiconductor chip. The first metal balls each can have a sharp tipped anchor. All of the anchors simultaneously flattened slightly only to the extent of equalizing the height thereof. The first metal balls are bonded to electrodes formed on a substrate with wirings by embedding the anchors into the electrodes. Alternatively, second metal balls can be formed on the electrodes which are then flattened to equalize the height thereof. The first metal balls, either with or without the anchors, are bonded to the second metal balls. The first and second metal balls are preferably heated during the bonding step to soften the second metal balls.