Method for producing a metal decoration on a dial and dial obtained according to this method

Patent metadata

Field	Value
Publication number	US-11499242-B2
Application number	US-201917052376-A
Country	US
Kind code	B2
Filing date	May 23, 2019
Priority date	May 28, 2018
Publication date	Nov 15, 2022
Grant date	Nov 15, 2022

Abstract

A method for producing metal decorations on a curved dial made of insulating material includes forming, by a method of the LIGA-UV type, a mould made of photosensitive resin and of galvanically depositing a layer of at least one metal from the conductive layer in order to form a block substantially reaching the upper surface of the photosensitive resin.

First claim

The invention claimed is:

1. A method of producing at least one metal decoration on a substrate made of insulating material having a curved upper surface, the method comprising:
a) providing the substrate and depositing a photosensitive resin layer directly on the curved upper surface of the insulating material of the substrate;
b) irradiating the photosensitive resin layer through a mask defining a contour of desired decorations as well as of photopolymerised areas and of non-photopolymerised areas;
c) dissolving non-irradiated areas of the photosensitive resin layer in order to show in places the substrate at the location of the decorations;
d) depositing a first adhesion layer and a second electrically conductive layer via a vapour deposition on the substrate and the photopolymerised areas;
e) galvanically depositing a layer of a first metal or of a metal alloy from said second electrically conductive layer in order to form at least one block substantially reaching the upper surface of the photosensitive resin layer;
f) performing surfacing and polishing in order to remove surplus of the galvanically deposited layer;
g) eliminating a remaining resin layer by plasma etching; and
h) eliminating the first and second layers by a wet etching.

2. The method according to claim 1 , wherein said first adhesion layer is Ti, Ta, Cr or Th.

3. The method according to claim 1 , wherein said second electrically conductive layer is chosen from: Au, Pt, Ag, Cr, Pd, TiN, CrN, ZrN or Ni.

4. The method according to claim 1 , wherein the first adhesion layer has a thickness between 30 nm and 80 nm.

5. The method according to claim 1 , wherein the second electrically conductive layer has a thickness between 30 nm and 80 nm.

6. The method according to claim 1 , wherein:
during step e), depositing a second metal or metal alloy covering the layer of the first metal or of the metal alloy.

7. The method according to claim 1 , wherein the substrate made of insulating material, is a substrate made of ceramic, sapphire, mother-of-pearl, glass, quartz, diamond, mineral material, polymers, composites, or enamel.

8. The method according to claim 1 , wherein the substrate is a dial of a watch case.

9. The method according to claim 8 , wherein, at the conclusion of step h), electrodeposited blocks are fixed to the watch case via the first adhesion layer and the second electrically conductive layer to form a decoration on the watch case.

10. The method according to claim 1 , wherein, at the conclusion of step g), all of the photosensitive resin layer, including the remaining resin layer, is removed from the substrate.

Assignees

• Swatch Group Res & Dev Ltd

Inventors

• Laforge Elias
• Springer Simon

Classifications

• G03F7/24

  Curved surfaces {(G03F7/70 takes precedence)} · CPC title

• G04B19/10

  Ornamental shape of the graduations or the surface of the dial; Attachment of the graduations to the dial {(cases for special purposes, e.g. ring or button watches G04B37/12; indicating means with special effects G04B45/00)} · CPC title

• C25D5/022 Primary

  using masking means · CPC title

• C23C28/3225

  with at least one zinc-based layer · CPC title

• C25D5/02 Primary

  Electroplating of selected surface areas · CPC title