Method of forming metal plate pattern and circuit board

A method of forming a circuit board, comprising the steps of:

• coating a resist on one or two surfaces of an insulating base member and forming a resist pattern by patterning;
• forming by pattern plating a metal layer of a metal of a different type from the metal foil at a portion of the resist pattern not masked;
• removing the resist;
• half etching the metal foil with the metal plating layer as a first mask;
• coating a positive resist on the half etched surface from the upper portion of the first mask and by exposure and development from the upper portion of the first mask, forming a positive resist as a second mask on the side etching layer formed under the first mask;
• half etching the metal foil again through the first and second masks;
• and
• removing the first and second masks.

A method of forming a metal plate pattern, comprising the steps of:

• coating a resist on one or two surfaces of a metal plate and forming a resist pattern by patterning the resist;
• forming by pattern plating a metal layer of a metal of a different type from the metal plate at a portion of the resist pattern not masked;
• removing the resist;
• half etching the metal plate with the metal plating layer as a first mask;
• coating a positive resist on the half etched surface from the upper portion of the first mask and by exposure and development from the upper portion of the first mask, forming a positive resist as a second mask on the side etching layer formed under the first mask;
• half etching the metal plate again through the first and second masks;
• removing the first and second masks;
• dipping the metal plate and a metal of different type from the metal plate in an electrolytic solution;
• and
• applying a voltage between the metal plate pattern in the electrolytic solution as a positive electrode and the metal of different type from the metal plate as a negative electrode and electrolytically polishing by preferentially eluting the protrusions on the surface of the metal plate pattern.

A method of forming a metal plate pattern, comprising the steps of:

• coating a resist on one or two surfaces of a metal plate and forming a resist pattern by patterning the resist;
• forming by pattern plating a metal layer of a metal of a different type from the metal plate at a portion of the resist pattern not masked;
• removing the resist;
• half etching the metal plate with the metal plating layer as a first mask;
• coating a positive resist on the half etched surface from the upper portion of the first mask and by exposure and development from the upper portion of the first mask, forming a positive resist as a second mask on the side etching layer formed under the first mask;
• half etching the metal plate again through the first and second masks;
• removing the first and second masks;
• dipping the metal plate and a metal of the same type as the metal plate in an electrolytic solution;
• and
• applying a voltage between the metal plate pattern in the electrolytic solution as a positive electrode and a metal of the same type as the metal plate as a negative electrode and electrolytically polishing by preferentially eluting the protrusions on the surface of the metal plate pattern.

A method of forming a circuit board device, comprising the steps of:

• coating a resist on one or two surfaces of an insulating base member and forming a resist pattern by patterning;
• forming by pattern plating a metal layer of a metal of a different type from the metal foil at a portion of the resist pattern not masked;
• removing the resist;
• half etching the metal foil with the metal plating layer as a first mask;
• coating a positive resist on the half etched surface from the upper portion of the first mask and by exposure and development from the upper portion of the first mask, forming a positive resist as a second mask on the side etching layer formed under the first mask;
• half etching the metal foil again through the first and second masks, and removing the first and second masks;
• removing the first and second masks to form a circuit board;
• dipping the circuit board and a metal in an electrolytic solution;
• and
• applying a voltage between the circuit board in the electrolytic solution as a positive electrode and the metal as a negative electrode and electrolytically polishing by preferentially eluting the protrusions on the surface of the circuit board.

A method of forming a circuit board device, comprising the steps of:

• coating a resist on one or two surfaces of an insulating base member and forming a resist pattern by patterning;
• forming by pattern plating a metal layer of a metal of a different type from the metal foil at a portion of the resist pattern not masked;
• removing the resist;
• half etching the metal foil with the metal plating layer as a first mask;
• coating a positive resist on the half etched surface from the upper portion of the first mask and by exposure and development from the upper portion of the first mask, forming a positive resist as a second mask on the side etching layer formed under the first mask;
• half etching the metal foil again through the first and second masks, and removing the first and second masks;
• removing the first and second masks to form a circuit board;
• dipping the and a metal of the same type as the metal foil forming the circuit board in an electrolytic solution;
• and
• applying a voltage between the circuit board in the electrolytic solution as a positive electrode and the metal of the same type as the metal foil as a negative electrode and electrolytically polishing, by preferentially elution, the protrusions on the surface of the circuit board.