METHOD OF DESMEARING HOLES

摘要

METHOD OF DESMEARING HOLES The invention relates to a process of desmearing drilled holes in PCBs with a high aspect ratio through plasma cleaning. The plasma processing is carried out with a CF4/O2 gas mixture. By a respective selection of the CF4 contents, the method can be optimized with respect to the etching speed and uniformity through the individual drilled hole, across each individual panel and with respect to the entire panel set of the plasma reactor. It was found that an optimum is reached for these parameters with a CF4 contents of 60 Vol.% and the remainder oxygen.