Development of Improved Printed Wiring Board Inner Layer Adhesion.
Abstract
Polymide multilayer printed wiring baords (MLPWB) offer much higher temperature resistance than epoxy MLPWB, however, their usage has been limited due to inner layer delamination problems. This study has determined the primary cause of delamination as adhesive failure to inner layer copper surfaces. Copper surfacd treatments based on sodium chlorite when used with a ferric chloride/hydrochloric acid pre-etch have been found to eliminate these delamination problems. A test specimen based on ASTM D2733 has been developed for measuring the inner layer adhesion of MLPWB. Also evaluated was a floating roller technique for measuring the peel strength of copper foil. This technique gave consistent, low-chatter peel strength values. Analytical techniques were also developed for characterizing polymide pre-pregs. In general, the polymide pre-pregs were of high quality and excellent consistency. MLPWB's fabricated to those materials and processes optimized per this study exhibited excellent moisture and thermal resistances when tested per applicable military specifications. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1982
- Accession Number
- ADA122067
Entities
People
- Thomas E. Baker
Organizations
- RTX