| 摘要 |
PROBLEM TO BE SOLVED: To prevent diffusion of Au into a solder bump from an upper electrode layer by forming a lower electrode layer, a dielectric thin-layer, an upper electrode layer sequentially on a substrate, and forming a diffusion preventive layer of Pt and/or Pd on the upper electrode layer, and then forming a solder bump on the diffusion preventive layer. SOLUTION: A lower electrode layer 2 of Au is formed on an alumina substrate 1, and a dielectric thin film 3 is formed on the lower electrode layer 2. Then an upper electrode layer 4 of Au is formed on the upper surface of the dielectric thin film 3, and a diffusion preventive layer 5 of Pt is formed only on a part of the upper electrode layer 4 where a solder bump is formed. Then a protective film 8 of a photosensitive polyimide resin is formed on the surface of the upper part electrode layer 4 and the diffusion preventive layer 5, and a via hole is worked at a part of the protective film 8 where a solder bump 7 is formed, for the diffusion preventive layer 5 to be exposed. Then, a solder ball is mounted on the diffusion preventive layer 5 for reflow process, so that a thin film capacitor comprising a solder bump is provided.
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