Experience has shown that LPI soldermask over pre-conditioned bare copper has worked the best. BW ______________________________ Reply Separator _________________________________ Subject: Re: Unidentified subject! Author: [log in to unmask] at uucpmail Date: 11/19/96 05:31 We do copper pours on FR-4 boards and have run into similar problems. With a dry film type of mask you will get peeling unless you hatch the copper. LPI works great, so that's what we use now. If you absolutely have to have solid copper pours, you'll probably have to pay the higher price for the LPI. Andy Buonviri ([log in to unmask]) >We recently completed a single sided FR-4 design with a large area that we "poured" copper into. Two of our three high volume board shops said no problem >when they reviewd this design. However our third house said that it there is a possibility of a problem because we use a screenable solder mask and they have a >worry about possible flaking of the mask on the large copper area. They recommended two ideads: > 1. Hatch the copper pour instead of leaving it solid. >Our answer to this? (Ameritech Commercial guy) ....MMMMM.......NO. We need it there for RF and ESD reasons I can't discuss. 2. Hatch the solder mask every 1/8 of an inch. >Again our answer to this is .....MMMMMM.......No. This would gobble solder out of our wave machines for no good reason. > >So we said how about LPI and they said sure for a significant price increase. Out of the three board houses this is the one who always gives us the best product >at the cheapest price with the least amount of rejects. > >SO WHAT DO WE DO NOW ? We want to continue to use the solid copper pour feature on future products. > >Your thoughts would be appreciated. *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************