| 摘要 |
<p>PURPOSE:To make the thickness of solder uniform so as to prevent the occurrence of tilting or insufficient continuity of surface-mounted parts by selectively removing the solder so that the solder can be left at necessary parts only. CONSTITUTION:A photoresist 3 is formed on the upper surface of a plated layer except pads 1 for mounting electronic parts, parts of the surrounding areas of through holes 5, and wiring layer forming areas 2 and, at the same time, a thick copper layer is stuck to the part of the plated layer exposed through the resist layer 3. Then, after forming a solder layer on the surface of the copper, the resist 3 is removed and the plated layer is etched off except the pads 1, the internal surfaces and parts of the surrounding areas of the holes 5, and the parts 2 and an outer wiring layer is formed. Then a dry film is vacuum-laminated on the wiring board and a resist 6 is formed on the pads 1 and in the surrounding areas of the holes 5. When the resist 6 is removed thereafter, the solder remains on the pads 1 and internal surfaces and surrounding areas of the holes 5 and a printed wiring board on which the copper of wiring pattern is exposed is obtained.</p> |
