| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily remove electric parts from a printed wiring board and, at the same time, to obtain sufficiently high soldering strength, by partially applying a solder resist to a land formed on the surface of the wiring board and the internal surface of a through hole. SOLUTION: A solder resist 8 is partially applied to the surface-side land of a through hole 2 and the internal surface of the hole 2 so that copper can be partially exposed on the rear-side land and an internal surface 5 of the hole 2. When leads 6 of electric parts 9 are soldered after the leads 6 are inserted into the hole 2, the soldered area becomes larger and the solder strength is also increased, because the solder covers part of the internal surface 5. The Fig. shows an example in which the through hole 2 is applied to a double-sided printed wiring board having wide copper patterns on both surfaces. The copper patterns 11 are connected to each other through the hole 2. In this example, the solder flows to the part of the internal surface 5 where te solder resist 8 is not applied, but the solder does not reach the surface layer.</p> |
