read several of the net's e-mail on cleaning and scrubbing - whole lo t of it going on. pth - usually a good acid neutralization and proper rinse after pth and an anti-tarnish within proper pH range - and no scrubbing is required - straight to the yellow room prior to soldermask - good chemical clean is all that is really required - don't forget proper rinsing this pumice - scrubbing ( actual copper grinding ) sure puts in alot of processes that don't do more than contaminate the shop or makes more work a good LPI process does not leave behind any residue on the copper surface and shouldn't cause solder skipping after HASL - just a decent chemical clean is all that is needed - maybe should look into the developing stage of the LPI now thermal cure soldermask is another story - usually on low quality boards - alot of spacing so can handle the bleed - if not - e-mail me - tell you what i've seen alot of plants doing regards richard fudalewski Atotech Canada Ltd *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************