We provide primarily surface finishing services to the printed circuit board industry so about 80% of our business is deep tank nickel gold plating. We pumice scrub all panels prior to resist lamination unless the panels have already been through a solder mask operation. Our preplate cleaning steps consist of a 15% sulfuric clean followed by a 25 microinch etch with sodium persulfate based etchant. In the 5 years that I have been the engineer for the nickel/gold plating operation we have never had one defect due to poor adhesion to the copper. Michael Holan Process Engineer Radian International, LLC Electronics Div. 512.310.4209 [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: FAB: Manual Scrubbing prior to NiAu Author: [log in to unmask] at INTERNET Date: 6/6/96 11:09 AM Address, EXPLANATION: I have been conducting some experiments on the use of mechanical and chemical scrubbing on panels prior to resist lamination. We currently perform a mechanical scrub to all panels prior to resist lamination. Based on minimal testing, we are successful in chemical cleaning panels prior to resist lamination with no resist breakdown in deep electrolytic Ni and Au. However, in the test process we conducted a tape test and discovered NiAu peel from the base copper (no electrolytic copper applied due to reason of test). The NiAu peel from the copper occurs on mechanical scrubbed and chemical clean sample panels, but on different sides. The mechanical scrubbed panel has peel on the component side and the chemical clean panel has peel on the solder side. So the problem now points to the method in which we prepare panels prior to Ni and Au plating. To insure good adhesion between Ni-copper and Au-Ni, panels are manually scrubbed with an abrasive pad. Recent observation shows there is a large variable associated with this type of method. QUESTION: -I would like to discuss with other manufacturers who use deep Ni and Au plating? -What types of methods are others using to prep panels prior to Ni and Au plating? -Is the method chemical or mechanical and if mechanical how are variables minimized? Please advise. Thank you.