Process for producing printed circuit board

A process for producing printed circuit boards which comprises the steps of

• (a) roughening of a copper layer formed on an insulating board, and covering the roughened surface with a thin film of metal having a more negative reduction potential of oxide than that of copper,
• (b) coating the thin metal film surface with a photo-resist layer containing a sublimable copper-corrosion inhibitor, exposing the resist layer selectively to actinic rays according to a circuit pattern to form, and developing the resulting resist, thereby forming plating-resist coats on circuit-negative pattern portions of the thin metal film,
• (c) heat-treating the plating-resist coats,
• (d) plating chemically the circuit-corresponding portion with copper,
• (e) removing the plating-resist coats, and
• (f) removing the thin metal film and the copper layer except their circuit-corresponding portion.

A process for producing printed circuit boards which comprises the steps of

• (a) roughening a surface of a copper layer formed on an insulating board, and oxidizing and then reducing the roughened surface of copper layer,
• (b) coating the treated surface of copper layer with a photo-resist layer containing a sublimable copper-corrosion inhibitor, exposing the resist layer selectively to actinic rays according to the circuit pattern to form, and developing the resulting resist, thereby forming plating-resist coats on circuit-negative pattern portion of the copper layer,
• (c) heat-treating the plating-resist coats,
• (d) plating chemically the circuit-corresponding portion with copper,
• (e) removing the plating-resist coats, and
• (f) removing the copper layer except the circuit-corresponding portion thereof.

A process for producing printed circuit boards which comprises the steps of

• (a) Roughening a surface of a copper layer formed on an insulating board, oxidizing and then reducing the roughened surface of copper layer, and covering the treated surface with a thin film of metal having a normal negative reduction potential of oxide than that of copper,
• (b) coating the thin metal film surface with a photo-resist layer containing a sublimable copper-corrosion inhibitor, exposing the resist layer selectively to actinic rays according to a circuit pattern to form, and developing the resulting resist, thereby forming plating-resist coats on circuit-negative pattern portions of the thin metal film,
• (c) heat-treating the plating-resist coats, (d) plating chemically the circuit-corresponding portion with copper,
• (e) removing the plating-resist coats, and
• (f) removing the thin metal film and the copper layer except their circuit-corresponding portions.