| 摘要 |
PURPOSE:To increase bonding strength by composing a surface joining with an Al pad in a bump of a metallic material having the slow forming rate of an intermetallic compound with Al except Au and constituting a surface transferred onto an electrode surface in a wiring substrate of a metallic material having a low eutectic point with a metal in the electrode surface. CONSTITUTION:A transparent conductive film 42 consisting of ITO, in which Sn is doped into an In oxide, is formed onto the surface of a transparent glass plate 41, a photo-resist film is applied onto the surface of the film 42, and a mask 43 for plating is shaped through patterning. Opening sections in the mask are electroplated with Cu, and Cu bumps are formed. The surfaces of the Cu bumps are electroplated with Au. The resist film 43 is removed, thus shaping a bump substrate made up of the glass substrate 41, the transparent conductive film 42 and the bumps 2. Inner leads 3 are positioned with the bumps 2, and the bumps 2 are transferred to the leads 3. The bumps 2 transferred to the lower sections of the noses of the leads 3 and Al pads 11 for a semiconductor element 1 are positioned, and thermocompression-bonded. Accordingly, no intermetallic compound of Au and Al on joint surfaces among the pads and the bumps is formed, thus preventing the lowering of bonding strength. |
