BLISTER Elimination in RISTON T168
Original Publication Date: 1987-Nov-01
Included in the Prior Art Database: 2005-Feb-02
Printed circuit panels that are manufactured using a method involving the additive plating of circuit lines on a prepreg surface occasionally experience blisters which become visible only after the electroless deposition of the copper-plated circuits. The blisters are seen as small round areas of resist poor adhesion along the plated copper lines and are related to functional defects, including copper spots and insulation/resistance failure. Following hot roll lamination of RISTON * T168 onto the seeded prepreg surface, micro-voids/micro-capillaries are formed between the resist and the prepreg. The minute channels function as a semi-permeable membrane between the bulk additive bath solution and the sandwiched Reten/seed mixture.