THROUGH HOLE FILLING AND PLATING METHOD APPLIED TO OPTICAL MODULE HIGH DENSITY INTERCONNECT HDI BOARD

摘要

A through hole filling and plating method applied to an optical module high density interconnect (HDI) board, comprising sequentially performing copper reduction, forward and reverse drilling, trepanning drilling, degumming copper precipitation, first time exposure development, through hole electroplating, film stripping, plate grinding, second time exposure development, and hole filling and electroplating. In the through hole filling and plating method applied to an optical module HDI board, drilling is performed twice so that the cross section of the through hole appears to be a stepped shape the center portion of which is small and the two ends of which are large, and the two drilling steps match the two hole filling steps for the center portion and two ends of the through hole respectively, thereby implementing the step-by-step filling and plating of the through hole. Thus, the phenomenon of core covering is prevented from occurring during the filling and plating process, and the signal transmission stability of a circuit board is effectively improved.