| 摘要 |
PROBLEM TO BE SOLVED: To form a chip-scale package which is superior in heat resistance, electric insulation after absorbing moisture, anti-migration characteristic and the like by improving the peeling strength of a solder ball. SOLUTION: This printed wiring board uses a double-sided copper-clad board, having at least 2 or more copper layers with a thickness of 0.2 mm or less as a substrate of a semiconductor chip scale package. At least 2 or more blind holes (b) are formed in a ball pad on the lower surface connected to an upper- surface copper pad by a through-hole conductor, so that a pad (e) for fixing a solder ball on the lower surface connected to the rear side of the upper-surface copper pad by the conductor is electrically connected by a swollen solder ball (c) which is melted and filled in the blind hole. Consequently, the peeling strength of the solder ball is improved by several levels and a printed wiring board for chip-scale package superior in electrical insulation, anti-migration characteristic and the like after subjecting it to pressure cooker treatment is obtained.
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