Abstract: A method for depositing a conductive metal onto a dielectric substrate is provided. The method includes obtaining a metal sheet having a roughened surface that has the following parameters:R.sub.a =0.05-0.08 mil,R.sub.max =0.20-0.55 mil,S.sub.m =1.00-3.00 mil,R.sub.p =0.20-0.35 mil, andsurface area=0.90-1.20 square milswherein R.sub.a is the average roughness and the arithmetic mean of the departures from horizontal mean line profile;R.sub.max is the maximum peak-to-valley height;S.sub.m is the mean spacing between high spots at the mean line;R.sub.p is the maximum profile height from the mean line; andsurface area is the area under the surface profile from each measurement using a Talysurf S-120 profilometer;The sheet is laminated to the dielectric substrate surface by pressing the roughened surface of the metal sheet against the surface of the substrate and then removed from the substrate.

Abstract: Disclosed is a method of fabricating a multilayer electronic circuit package. The multilayer circuit package has at least one layer that is a circuitized, polymer encapsulated metal core. According to the method of the invention a metal foil is provided for the metal core of the layer. This metal core foil may be provided as a single unit or in a continuous, roll to roll, process. The vias and through holes are drilled, etched, or punched through the metal foil. An adhesion promoter is then applied to the perforate metal foil for subsequent adhesion of polymer to the foil. The dielectric polymer is then applied to the perforate metal foil core by vapor depositing, chemical vapor depositing, spraying or electrophoretically depositing, a thermally processable dielectric polymer or precursor thereof onto exposed surfaces of the perforate metal foil including the walls of the through holes and vias.

Abstract: Photocurable compositions with, as photoinitiator, sulfonium salts of the formula: ##STR1## wherein Ar is a fused aromatic radical; R.sub.1 is a divalent organic bridge; each R.sub.2 and R.sub.3 individually is an alkyl, aryl, alkaryl, aralkyl or substituted aryl, provided that not more than one of R.sub.2 and R.sub.3 is alkyl; and A is a non-nucleophilic anion; use thereof and preparation thereof.

Abstract: Sulfonium salts of the formula: ##STR1## wherein Ar is a fused aromatic radical; R.sub.1 is a divalent organic bridge; each R.sub.2 and R.sub.3 individually is an alkyl, aryl, alkaryl, aralkyl or substituted aryl, provided thatn not more than one of R.sub.2 and R.sub.3 is alkyl; and A is a non-nucleophilic anion; use thereof and preparation thereof.

Abstract: A non-conductive substrate is conditioned for subsequent selective deposition of a metal thereon by providing at least one of the major surfaces of the substrate in roughened form, contacting that surface(s) with a palladium/tin catalyst, activating the catalyst by employing an alkali hydroxide solution, laminating a photosensitive composition to the major surface(s), and exposing the photosensitive composition to actinic light in a predetermined pattern and then developing to provide the predetermined pattern.

Abstract: Cationic curable photoresists are patterned by exposing such to a laser beam in a pattern, followed by developing.

Abstract: The surface of a substrate is roughened by providing a substrate which comprises a resinous material and an inorganic particulate material; and etching a surface of the substrate to selectively etch the resinous material and thereby produce the roughened surface.