There is another item to consider in determining the cause of adhesion problems. You might want to investigate the need to use a primer prior to applying the conformal coating. Again, as mentioned by Mr. Fisher below, contact the technical people at the coating manufacturer for recommendations. Art Perez Woodward Governor Co. ---------- From: [log in to unmask] To: [log in to unmask] Subject: Re: ASSY: CONFORMAL COATING ADHESION Date: Wednesday, March 19, 1997 6:50AM It is possible that the conformal coating you want to use is not compatible with the particular solder mask on the boards you have. To check for this, may ZI suggest: 1. Take a small section of a board and clean it thoroughly with an alkaline cleaner (Joy dishwasher miracle can work), rinse, clean with isopropyl alchohol, rinse and dry thoroughly. 2. Dip the cleaned board sample in the conformal coating to be tested and dry/cure according to the manufacturers spec sheet. 3. Look for a smooth, continuous coating of the conformal coating over the entire surface of the sample board and conduct a cross hatch adhesion test, For this, take a razor blade, cut 6 parrallel lines about 1/8" apart, cut 6 more parallel lines (perpendicular to the 1st 6 lines) about 1/8" apart and then apply a strip of 1" Scotch transparent tape to the grid pattern you have made. Pull the tape up sharply and look for any lifting of the conformal coating. 4. If everything looks okay, you can say that the conformal coating is compatible with the solder mask. If there is adhesion loss, then the conformal coating is not compatible and either the conformal coating or the solder mask must be changed. Since most conformal coating manufacturers offer many different types (acrylics, epoxies, urethanes, silicones, etc.) of conformal coatings and different formulas in each type range, I.m sure that if you contact the specific conformal coating manufacturer, they would be able to give you the right direction to go. Hope this information helps. Larry Fisher Dexter Electronic Materials [log in to unmask] ************************************************************************ *** * 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] * ************************************************************************ *** *************************************************************************** * 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] * ***************************************************************************