| 摘要 |
PURPOSE:To simplify the steps of treating a substrate on which an IC with a bump is carried by employing a bump coated with a tin coating by an electroless plating process on the copper bump as a bump when bonding the IC on the substrate, thereby eliminating shortcircuit or the like thereat. CONSTITUTION:An aluminum wiring layer 1 is formed on the substrate, and is surrounded by an insulating protective film 2, and a barrier metallic film 3 of Cr of the like is coated from the surface of the layer 1 over the end of the film 2. Then, a plating metallic film 4 is laminated thereon, the thick copper bump 5 is precipitated thereon by plating, and the exposed surface of the bump 5 is electrolessly plated while coating other portion with positive type photoresist to thus form the tin coating 6 thereon. In this manner, there can be used a substrate plated by Au as the substrate, the wire may not be shortcircuited due to tin whisker when using a tin- plated substrate, the treatment thereafter may also be eliminated, and the reliability of the IC may be consequently improved. |
