Method for manufacturing wiring board

Patent metadata

Field	Value
Publication number	US-11903141-B2
Application number	US-202117400715-A
Country	US
Kind code	B2
Filing date	Aug 12, 2021
Priority date	Aug 21, 2020
Publication date	Feb 13, 2024
Grant date	Feb 13, 2024

Abstract

A method for manufacturing a wiring board in which the adhesion between an underlayer and a seed layer is improved. A diffusion layer in which an element forming the underlayer and an element forming a coating layer are mutually diffused is formed between the underlayer and a wiring portion of the coating layer by irradiating the wiring portion with a laser beam. A seed layer is formed by removing a portion excluding the wiring portion of the coating layer from the underlayer. A metal layer is formed by disposing a solid electrolyte membrane between an anode and the seed layer and applying voltage between the anode and the underlayer. An exposed portion without the seed layer of the underlayer is removed from an insulating substrate.

First claim

What is claimed is:

1. A method for manufacturing a wiring board, the wiring board including an insulating substrate and a wiring layer disposed on a surface of the insulating substrate, and the wiring board having a predetermined wiring pattern, the method comprising:
providing:
an insulating substrate,
an underlayer, which is electrically-conductive, disposed on a surface of the insulating substrate, wherein the underlayer includes an oxide film formed on a surface thereof, the providing the underlayer comprising vapor deposition of the oxide film, and
a coating layer, which is electrically-conductive, disposed so as to coat the oxide film;

forming a diffusion layer, in which an element forming the underlayer and an element forming the coating layer are mutually diffused, between the underlayer and a first portion of the coating layer, the forming the diffusion layer comprising irradiating the first portion of the coating layer corresponding to the predetermined wiring pattern with a laser beam;
forming a seed layer from the first portion of the coating layer by removing a second portion of the coating layer, thereby leaving the first portion of the coating layer, disposed on the diffusion layer, as the seed layer;
forming a metal layer on a surface of the seed layer by disposing a solid electrolyte membrane between an anode and the seed layer as a cathode, pressing the solid electrolyte membrane against at least the seed layer, and applying a voltage between the anode and the underlayer, to thereby reduce metal ions contained in the solid electrolyte membrane; and
forming the wiring layer by removing, from the insulating substrate, a portion of the underlayer not covered by the seed layer.

2. The method for manufacturing the wiring board according to claim 1 , wherein
the forming the diffusion layer further comprises, causing a permeable member, permeable to the laser beam, to adhere to a surface of the coating layer, and irradiating the first portion of the coating layer with the laser beam via the permeable member, thereby forming the diffusion layer, and
the forming the seed layer further comprises, removing the second portion of the coating layer such that the permeable member is removed together with the second portion of the coating layer.

3. The method for manufacturing the wiring board according to claim 1 , wherein
an element forming the coating layer is a noble metal element, and
the irradiating the first portion of the coating layer with the laser beam comprises diffusing oxygen, originating from the oxide film, into the diffusion layer.

4. The method for manufacturing the wiring board according to claim 1 , wherein the coating layer contains metallic nanoparticles.

Assignees

• Toyota Motor Co Ltd

Inventors

• Kuroda Keiji
• Mori Rentaro
• Yanagimoto Hiroshi
• Kondoh Haruki
• Okamoto Kazuaki
• Kato Akira

Classifications

• H05K3/242 Primary

  characterised by using temporary conductors on the printed circuit for electrically connecting areas which are to be electroplated · CPC title

• C25D3/38

  of copper · CPC title

• C25D17/002

  Cell separation, e.g. membranes, diaphragms · CPC title

• C25D17/005

  Contacting devices · CPC title

• H05K2203/0723

  Electroplating, e.g. finish plating · CPC title