| 摘要 |
<p>PROBLEM TO BE SOLVED: To make it possible to enhance the connecting strength of a solder bump electrode by a method wherein a bump substrate conductor layer which comes into contact with the solder bump electrode is formed of a conductor layer which contains Pb. SOLUTION: An opening part 4 by which a part of a derivation electrode 3 is exposed is formed in a part of a lower-layer surface protective film 4a, and a bump electrode 7 is formed on an exposed region via respective bump substrate metal layers 6a, 6b. The bump substrate metal layer 6a is composed of Ti, and it has a function or the like which enhances the bonding property of the derivation electrode 3 to the bump electrode 7. The upper-layer substrate metal layer 6b is composed of a conductor layer composed of, e.g. Pd and of an alloy layer which is formed in such a way that Pd is diffused to the lower part of the bump electrode 7 and which contains Pd. The bump substrate metal layer 5b prevents the oxidation on the surface of the lower-layer bump substrate metal layer 6a which is composed of Ti or the like, it is diffused to the lower part of the bump electrode 7, and it has an action to enhance the connecting strength of the bump electrode 7.</p> |
