| 摘要 |
<p>PURPOSE:To eliminate dimensional defect and flaw on the surface layer copper foil by removing resin drained out through a through hole for connecting the surface layer copper foil with the inner layer circuit in next layer without requiring mechanical polishing. CONSTITUTION:A prepreg 3 is sandwiched by inner layer printed wiring boards 2 having through holes 1 produced by a well known method and then subjected to hot press to produce a multilayer copper clad laminate. Resin 4 drained out through the through holes in the multilayer copper clad laminate is removed through irradiation with excimer laser beam having wavelength in the range of 230-270nm.</p> |
