Printed circuit board and method for producing the same

A method for producing a printed circuit board comprising the steps of:

• impregnating a base material with a solution containing ions for forming a hardly soluble metal salt by combining with metal ions free from a portion of a board and drying;
• impregnating the base material containing the ions with a resin varnish and drying so as to form a prepreg;
• laminating metal foils on the prepreg to be bonded under thermocompression;
• and forming a circuit pattern on the metal foil,
• wherein the ions are available to react with metal ions free from a portion of the printed circuit board to form a hardly soluble metal salt.

A method for producing a multilayered printed circuit board comprising the steps of:

• applying a solution containing ions onto a surface of a metal pattern of a printed circuit board including two or more layers and drying;
• laminating a prepreg on the printed circuit board;
• further laminating metal foils on the laminate to be bonded under thermocompression;
• and forming a circuit pattern on the metal foil,
• wherein the ions are available to react with metal ions free from a portion of the multilayered printed circuit board to form a hardly soluble metal salt.

A method for producing a printed circuit board comprising the steps of:

• adding a sulfur-containing organic compound to a resin vanish:
• impregnating a base material with the resin varnish and drying so as to form a prepreg;
• laminating metal foils on the prepreg to be bonded under thermocompression;
• and forming a circuit pattern on the metal foil,
• wherein the sulfur-containing compound is available to react with metal ions free from a portion of the printed circuit board.

A method for producing a printed circuit board comprising the steps of:

• impregnating a base material with a solution containing a sulfur-containing organic compound and drying;
• impregnating the sulfur compound-containing base material with a resin varnish and drying so as to form a prepreg;
• laminating metal foils on the prepreg to be bonded under thermocompression;
• and forming a circuit pattern on the metal foil,
• wherein the sulfur organic compound is available to react with metal ions free from a portion of the printed circuit board.

A method for producing a multilayered printed circuit board comprising the steps of:

• applying a solution containing a sulfur-containng organic compound onto a surface of a metal pattern of a printed circuit board including two or more layers, and drying;
• laminating a prepreg on the printed circuit board;
• further laminating metal foils on the laminate to be bonded under thermocompression;
• and forming a circuit pattern on the metal foil,
• wherein the sulfur organic compound is available to react with metal ions free from a portion of the printed circuit board.