In a message dated 97-04-01 15:07:01 EST, you write: << A while back someone asked about enhancing peel strength for built-up multilayer (BUM) boards. It is possible that a process being investigated at Sandia for polyimides could be applied to BUM fabrication. Anyone interested in discussing detailed requirements can contact me off-line. I would be interested in knowing which solder-mask materials you are using for the dielectric layers and the suppliers and chemical makeup of the materials. Perhaps some samples could be provided to Sandia for experiments and evaluation if there is enough interest in the industry.>> 1. You may want to read a paper by Peter Gabriele and others at MacDermid about an infrared spectroscopy technique to study the metal/polymer adhesion process on Build-Up Interconnects. The paper was just presented at IPC Expo, and is available in the proceedings, or by contacting me. 2. I know of no supplier who is just shipping "solder mask" for the dielectric of Build Up Interconnects. We all work to improve the adhesion of the metallization, take out any plating poisons, and run about twice as many tests on the dielectric as on a solder mask. Any shop who thinks that simply plating over their present solder mask is just starting the journey to making HDI boards. Denny Fritz MacDermid, Inc Waterbury, CT [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] * ***************************************************************************