摘要 |
A process for producing a printed wiring board, particularly an interposer for a chip size package, which comprises the steps of (1) forming an outer insulator layer 22 having outer via-holes 24 on a substrate 32, (2) forming conducting passages 31 through the outer via-holes 24 by plating with metal up to substantially the same level as the upper surface of the outer insulator layer 22, (3) forming a thin metal film 29 on the outer insulator layer 22 and on the conducting passages 31, (4) forming a conductor layer 21 in a prescribed circuit pattern on the thin metal film 29 by plating, (5) removing the part of the thin metal film 29 on which the conductor layer 21 is not formed, (6) forming an inner insulator layer 23 on the conductor layer 21, and (7) removing the substrate 32. The outer insulator layer is formed with flatness to secure good adhesion to a semiconductor chip.
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