| 摘要 |
PURPOSE:To ensure cleanness at the wire bonding pad part by removing the deposited solder together by forming a second solder resist layer which covers the wire bonding pad part and has a different etching property from that of a first solder resist. CONSTITUTION:For example on a substrate 10 made of an aluminum plate coated with an insulating resin, a conductive paste of copper group is printed so as to form predetermined wirings 11, wire bonding pad parts 12, and part land parts 13. Next, a first solder resist layer 14 as a first solder resist is formed in the region among these wirings 11, wire bonding pad parts 12, and part land parts 13. Next, the surface of the wire bonding pad part 12 is coated with a second solder resist layer 15 as a second solder resist. This second solder resist layer 15 comprises a selection ratio comparable with the first solder resist layer 14. Subsequently, solder printing is applied to predetermined positions and a circuit part 16 is put on the part land 13 followed by soldering. Next, the second solder resist layer 15 is cleaned with a fluorine- or chlorine-group solvent and is removed. |
