| 摘要 |
PROBLEM TO BE SOLVED: To form via-filling efficiently with simple operation by first forming metal film in the via hole by the use of electroless plating, and then subjecting the resulting via hole to electrical metal-plating by PR-electrolysis. SOLUTION: This method can be applied to the via hole having a diameter of about 10-1000μm and a hole depth of about 10-1000μm. The via hole is treated by conventional method to make its bottom part and side surface electro-conductive, and then these parts are subjected to electroless metal plating and PR-electrolysis. Though the conditions suitable for PR-electrolysis depend on a kind of metal to be deposited, bath components, the shape of the via hole, etc., PR-electrolysis is generally carried out under following conditions. The ratio of time kept as cathode to time kept as anode is preferably in a range of about 2:1-5:1. PR-period is preferably about 10-100 sec., and total electrolysis time is in the range of about 0.1-10 hrs. The bath capable of giving Cu, Ni, Au, Ag, Pd and Sn films or alloy films of these metals is selected as the metal plating bath capable of being applied. |
