Manufacture of semiconductor element

Abstract

Abstract PURPOSE:To augment the adhesive strength to a mounted substrate wiring metal by a method wherein Sn/Pb composition is changed continuously or discontinuously in the direction of bump thickness. CONSTITUTION:Firstly a Cr/Cu layer (d) is formed on the Al pad opening. Sec ondly an Ni layer (c) is formed on the Cr/Au layer (d) to be the core of a solder bump. Thirdly an Sn/Pb solder bump layer (a) is formed on the Ni layer (c). Fourthly another Sn/Pb bump layer (b) as the second layer is formed on the solder bump layer (a). Finally the Cr/Au layer (d) is physically etched using the bump layer (b) as a mask. Through these procedures, in case a solder bump is bonded on a mounted substrate, the adhesive strength to the mounted substrate wiring metal may be augmented avoiding any defect such as peeled adhesive and the like.

Inventors

• 👤 Minoru Yokozawa
• 👤 横澤　実

Bibliographic Details