4 BARRIER LAYERS FOR ELECTROPLATED SNPB EUTECTIC SOLDER JOINTS

摘要

The present invention relates to a method for producing a reliable low-temperature flip chip C4 bonding (flip-chip) structure for (low-temperature joining), which. Includes a barrier layer between the C4 interconnections produced electrochemically it includes a solder bump plating electrolyte containing a lot of tin (solder bump) and the ball limiting metal (ball-limiting metallurgy), the barrier layer limits seen by Sn in the solder It prevents the metal in the metal terminal damage. The barrier layer does not require a separate patterned (patterning) step since the electrolytic plating using the same photoresist mask, and the solder. Electroplating a thin nickel layer is a reliable barrier layer with a copper-based (copper-based) ball limiting metal layer and the tin-is provided between the lead (Sn-Pb) eutectic (eutectic) C4 ball.