| 摘要 |
<p>PURPOSE:To enable junction strength of soldering to be improved by forming a structure where a recessed part with a U-shaped vertical section shape and a circular horizontal section shape is provided at a pad for surface mount. CONSTITUTION:A multilayer body is dipped into a soda lye solution and resin is dissolved and eliminated, thus enabling a recessed part 21 to be formed. Then, a hole is opened at a specified part and a penetration hole is provided and an entire surface of the multilayer body including an inner wall of a penetration hole and a bottom surface of the recessed part 21 is made conductive by electroless plating. Then, etching resist is laminated and a specified circuit pattern is exposed and developed, and then etching treatment is performed, copper is eliminated, thus forming a through-hole 24, a conductive circuit 26, and a pad for surface mount 27. Then, an etching resist is eliminated and a solder resist 28 is coated at a specified part. Then, a ring-shaped solder is fit into a lead 41 of a surface mount component 40, is inserted into a recessed part 21, and then is soldered, thus enabling a proper positioning of joint parts to be made and obtaining a high junction strength as compared with a normal and flat pad for surface mounting.</p> |
