Method for manufacturing wiring board

Patent metadata

Field	Value
Publication number	US-2022061165-A1
Application number	US-202117400715-A
Country	US
Kind code	A1
Filing date	Aug 12, 2021
Priority date	Aug 21, 2020
Publication date	Feb 24, 2022
Grant date	—

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 including an insulating substrate, and a wiring layer disposed on a surface of the insulating substrate and having a predetermined wiring pattern, the method comprising:
preparing a substrate with coating-layer including the insulating substrate, an electrically conductive underlayer disposed on the surface of the insulating substrate, and an electrically conductive coating layer disposed so as to coat a surface of the underlayer; 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 wiring portion of the coating layer, by irradiating the wiring portion of the coating layer corresponding to the predetermined wiring pattern with a laser beam; forming a seed layer on the underlayer via the diffusion layer by removing a portion excluding the wiring portion of the coating layer, as a removing portion, from the underlayer of the substrate with coating-layer in which the diffusion layer is formed; 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 voltage between the anode and the underlayer to reduce metal ions contained in the solid electrolyte membrane; and forming the wiring layer by removing, from the insulating substrate, an exposed portion without the seed layer of the underlayer.

2 . The method for manufacturing the wiring board according to claim 1 , wherein
in forming the diffusion layer, a permeable member permeable to the laser beam is made to adhere to the surface of the coating layer, and with the permeable member kept adhering to the surface of the coating layer, the wiring portion of the coating layer is irradiated with the laser beam via the permeable member, so that the diffusion layer is formed, and in forming the seed layer, the removing portion of the coating layer is removed from the underlayer such that the permeable member is peeled off from the substrate with coating-layer, together with the removing 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, the underlayer of the prepared substrate with coating-layer contains an oxide at an interface with the coating layer, and in forming the diffusion layer, a diffusion layer in which oxygen originating from the oxide is diffused is formed as the diffusion layer by irradiating the wiring portion of the coating layer with the laser beam.

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

• C25D5/06

  Brush or pad plating · CPC title

• H05K2203/107

  Using laser light · CPC title

• C25D17/005

  Contacting devices · CPC title

• C25D5/024

  using locally applied electromagnetic radiation, e.g. lasers · CPC title

• H05K2203/0723

  Electroplating, e.g. finish plating · CPC title