| 摘要 |
<p>PURPOSE:To form a ball bump by a method wherein a dry film resist layer, having a solder-plating hole with the diameter larger than a dam hole, on a resist layer, thick solder plating is provided on a pad through the above- mentioned holes, and a reflowing operation is conducted after the dry film resist only has been stripped. CONSTITUTION:When a ball bump is formed on a printed wiring board for IC package, circuit patterns 60 and 60 are formed on both surfaces of a both face copper clad laminated plate 50 (A) on which copper foils 54 and 54 are adhered to both surfaces of a resin insulated substrate 52 (B), then solder resist 66 is applied to a bump-formed surface 64 (C). Then, a solder plating hole 74, which is larger than a dam hole 68, is formed on the position which is overlapped on the dam hole 68 where dry film resists 70 and 72 are press-bonded on both surfaces of the printed substrate 50A, and thick solder plating is provided (D). After the prescribed solder plating has been deposited, the dry film resists 70 and 72 are stripped (E), and then the printed substrate is put in a heating device and it is heated there.</p> |
