Method of forming wiring pattern and etching apparatus for forming wiring pattern
A method of forming a wiring pattern includes: a) forming a metal underlayer including a first underlying wiring layer which is in contact with an electrode, a second underlying wiring layer which is not in contact with the electrode, and an underlying connection layer which connects the first underlying wiring layer to the second underlying wiring layer; b) forming a metal plating layer on the metal underlayer through electroplating; and c) removing a metal connection portion through etching. The metal connection portion is the underlying connection layer covered with the metal plating layer. The etching includes bringing a solid electrolyte material that contains a solution into which metal of the metal connection portion is dissolved, into contact with the metal connection portion and applying a voltage between the metal connection portion and the solid electrolyte material.
1. A method of forming a wiring pattern, comprising:
a) forming a metal underlayer on a surface of a resin substrate, the metal underlayer including
a first underlying wiring layer which is in contact with an electrode during electroplating,
a second underlying wiring layer which is not in contact with the electrode during the electroplating, and
an underlying connection layer which partially connects the first underlying wiring layer to the second underlying wiring layer;
b) forming a metal plating layer on a surface of the metal underlayer through the electroplating; and
c) removing at least a portion of a metal connection portion through etching, the metal connection portion being the portion of the underlying connection layer covered with a portion of the metal plating layer, wherein
the step of c) includes impregnating a solid electrolyte material with a solution for dissolving metal of the underlying connection layer and metal of the metal plating layer, and
the etching includes
bringing the solid electrolyte material, which has the solution impregnated therein, into contact with the portion of the metal connection portion, and
applying a voltage between an anode and a cathode, the cathode being the solid electrolyte material and the anode being the portion of the metal connection portion, wherein the solution dissolves metal of the underlying connection layer and metal of the metal plating layer.
2. The method of forming a wiring pattern according to claim 1 , wherein
the solid electrolyte material is a first solid electrolyte membrane,
a first surface of the first solid electrolyte membrane has a protrusion to contact with a surface of the portion of the metal connection portion, and
the etching is performed in a state where a first conductive member is arranged on a second surface of the first solid electrolyte membrane, the electrode is in contact with the metal plating layer formed on the first underlying wiring layer, and a surface of the portion of the metal connection layer is in contact with the protrusion.
3. The method of forming a wiring pattern according to claim 2 , wherein
the step of b) includes
bringing a first surface of a second solid electrolyte membrane containing metal ions into contact with the metal underlayer,
arranging a second conductive member on a second surface of the second solid electrolyte membrane, and
forming the metal plating layer on the surface of the metal underlayer by setting the second conductive member as an anode, setting the metal underlayer as a cathode, and applying a voltage between the anode and the cathode.
4. The method of forming a wiring pattern according to claim 3 , wherein
the wiring pattern include a first metal wiring and a second metal wiring,
the first metal wiring includes the first underlying wiring layer, a first end portion, and a second end portion,
the first end portion is positioned near a first edge portion of the surface of the resin substrate,
the second end portion is positioned near a second edge portion of the surface of the resin substrate,
the first metal wiring is provided in a region from the first edge portion to the second edge portion,
the second metal wiring includes the second underlying wiring layer,
opposite end portions of the second metal wiring are provided further inward from the first edge portion and the second edge portion on the resin substrate as compared to the first end portion and the second end portion,
in the step of a), the metal underlayer is formed on the surface of the resin substrate, the metal underlayer including the first underlying wiring layer which is formed to conform to a shape of the first metal wiring, the second underlying wiring layer which is formed to conform to a shape of the second metal wiring, and the underlying connection layer which connects the second underlying wiring layer to the first underlying wiring layer, and
in the step of b), the metal plating layer is formed on the surface of the metal underlayer after arranging the electrode on at least one of the first edge portion and the second edge portion so as to come into contact with at least one of the first end portion and the second end portion.
5. The method of forming a wiring pattern according to claim 1 , wherein
the solution for dissolving metal of the underlying connection layer and metal of the metal plating layer comprises at least one of hydrogen ions, hydroxide ions, or chloride ions.
6. The method of forming a wiring pattern according to claim 1 , wherein
the solution for dissolving metal of the underlying connection layer and metal of the metal plating layer is selected from the group consisting of a potassium hydroxide aqueous solution, a ferric chloride aqueous solution, nitric acid aqueous solution, and a sulfuric acid aqueous solution.
7. The method of forming a wiring pattern according to claim 1 , wherein
the metal of the underlying connection layer and the metal of the metal plating layer comprises at least one of copper (Cu), nickel (Ni), or silver (Ag).