| 摘要 |
PURPOSE:To make use of the gold layer of an electrode in forming an area for preventing solder flow with the simpler stage than in the prior art by depositing and oxidizing Cr on the surface of the electrode gold layer by a heat treatment thereby forming the area for preventing solder flow. CONSTITUTION:A laminated electrode of a nichrome layer 12 and a gold layer 13 is formed on the surface of a base plate 1 of alumina, etc., and a resist pattern 17 is formed in the part of the metal 13 where an area for preventing solder flow is to be formed. The plate 11 in this state is heated to, for example, about 300 deg.C to form an oxide layer 18 of nichrome on the surface layer of the layer 13 including the lower part of its pattern 17. The exposed part of the layer 18 is etched off to form the remaining layer (layer for preventing solder flow) 14 of the layer 18 in a patterned shape on the lower part of the pattern 17. The pattern 17 atop the layer 14 is then removed and the remaining layer 14 of the same pattern as the pattern 17, i.e. the remaining layer 14 consisting of the oxide of nichrome having poor wettability with molten solder and converting the area for preventing solder flow exposed with the layer 14, is formed on the surface of the layer 13. The layer 14 suppresses the spread of the molten solder and prevents the short circuit diffusion of the layer 13 and the solder 16. |
