CONFORMAL COATINGS FOR PRINTED CIRCUIT ASSEMBLIES
Quarterly rept. no. 1, 10 Jul-31 Oct 1961
MOTOROLA INC CHICAGO IL
Pagination or Media Count:
Commercially available epoxy and polyurethane resin conformal coatings were evaluated as protective coatings on glass-epoxy and paper-epoxy Cu-clad laminate printed circuit boards. All the epoxy and polyurethane coatings tested met the following characteristics 1 suitability for dip, spray on brush coat application, 2 transparency when full cured, 3 cured within 2 hr at 75 C, 4 did not support fungus, and 5 one component system preferred. No blistering, wrinkling, cracking or corrosion was observed good adhesion to test panels was obtained. The dielectric constant decreased with increasing frequency from 1 to 100 mc. The Q factor of the epox coated boards decreased as compared to the uncoated boards. All coated specimens passed the initial dielectric withstanding voltage test before thermal cycling.
- Coatings, Colorants and Finishes
- Electrical and Electronic Equipment