Archive for the ‘03 Inner Layer Pre-Clean’ Category

Inner Layer Pre-Clean

Sunday, May 15th, 2011

Inner layer processing requires Dry Film Photo Resist to be laminated onto the copper surface. The dry film is resolved into a circuit pattern. Copper we want to keep is protected by the circuit pattern from the etchants used to remove the copper. The bond of the dry film to the copper surface must be strong enough so that the film does not come of when in the etchant chemistry. Copper foil such as RTF, Reverse Treated Foil, are rough enough so that the dry film forms a good bond to the copper as is. Many copper foils are not rough enough or are supplied with a contaminated surface. In these cases the foil must be (more…)