초록 ▼

In order to enable fine traces to be obtained on printed circuit boards without excessive undercutting, while maintaining a high degree of adhesion, an unclad FRA board is provided with a surface butter coat which is etched to form a microporous surface layer. This layer is subjected to treatment in

In order to enable fine traces to be obtained on printed circuit boards without excessive undercutting, while maintaining a high degree of adhesion, an unclad FRA board is provided with a surface butter coat which is etched to form a microporous surface layer. This layer is subjected to treatment in a plasma additively reactive with surface groups of the butter coat resin to provide modified groups promoting adherence to a thin metallization layer of vacuum deposited copper. The metallization layer is selectively electroplated to form the desired circuit pattern, and the unplated areas of the metallization layer are etched away.

대표청구항 ▼

A method of preparing a printed circuit board comprising etching the external surface of a synthetic resin substrate board without metal cladding to provide a microporous structure in surface layers of the board which are free of fibrous reinforcement, freeing said surface layers of etchant residues

A method of preparing a printed circuit board comprising etching the external surface of a synthetic resin substrate board without metal cladding to provide a microporous structure in surface layers of the board which are free of fibrous reinforcement, freeing said surface layers of etchant residues, subjecting said surface to a plasma treatment in a plasma additively reactive with surface groups of the resin to provide modified surface groups promoting adherence to a metallization layer, metallizing the plasma treated surfaces by vacuum deposition or sputtering to provide a thin layer of copper, selectively electroplating the copper layer with a much thicker layer of copper in accordance with a desired circuit pattern, and etching away unplated areas of the metallization layer.