Substrate comprising a silver-plated surface protected against silver tarnishing and method for manufacturing such a substrate

Patent metadata

Field	Value
Publication number	US-2021348270-A1
Application number	US-201917278139-A
Country	US
Kind code	A1
Filing date	Sep 13, 2019
Priority date	Sep 21, 2018
Publication date	Nov 11, 2021
Grant date	—

Abstract

A substrate includes a final silver-plated surface protected against silver tarnishing by a protective coat having a thickness between 1 nm and 200 nm, the protective coat includes a first coat of Al 2 O 3 deposited on said final silver-plated surface and having a thickness between 0.5 nm and 100 nm, and on the first coat of Al 2 O 3 , a second coat of TiO 2 having a thickness between 0.5 nm and 100 nm, the substrate including a coat of a silver and copper alloy comprising between 0.1% and 10% by weight of copper with respect to the total weight of the alloy, forming said final silver-plated surface, said coat of a silver and copper alloy having a thickness between 1000 nm and 3000 nm. Embodiments also relate to a method for manufacturing such a substrate.

First claim

1 - 37 . (canceled)

38 : A substrate comprising a final silver-plated surface protected against silver tarnishing by a protective coat having a thickness between 1 nm and 200 nm, preferably between 1 nm and 100 nm, said protective coat comprises a first coat of Al 2 O 3 deposited on said final silver-plated surface and having a thickness between 0.5 nm and 100 nm, preferably between 0.5 nm and 50 nm and on the first coat of Al 2 O 3 , a second coat of TiO 2 having a thickness between 0.5 nm and 100 nm, preferably between 0.5 nm and 50 nm, the substrate being characterised in that it comprises a coat of a silver and copper alloy comprising between 0.1% and 10% by weight of copper with respect to the total weight of the alloy, forming said final silver-plated surface, said coat of a silver and copper alloy having a thickness between 1000 nm and 3000 nm.

39 : A substrate comprising a final silver-plated surface protected against silver tarnishing by a protective coat having a thickness between 1 nm and 200 nm, preferably between 1 nm and 100 nm, said protective coat comprises a first coat of Al 2 O 3 deposited on said final silver-plated surface and having a thickness between 0.5 nm and 100 nm, preferably between 0.5 nm and 50 nm and on the first coat of Al 2 O 3 , a second coat of TiO 2 having a thickness between 0.5 nm and 100 nm, preferably between 0.5 nm and 50 nm, characterised in that said substrate comprises a coat of substantially pure silver forming said final silver-plated surface, said coat of substantially pure silver having a thickness between 1000 nm and 3000 nm.

40 : The substrate according to claim 38 , wherein the first coat of Al 2 O 3 has a thickness between 30 nm and 50 nm and in that the second coat of TiO 2 has a thickness between 10 nm and 50 nm.

41 : The substrate according to claim 38 , wherein the protective coat has been deposited by ALD.

42 : The substrate according to claim 38 , wherein it is based on silver.

43 : The substrate according to claim 38 , wherein it is not based on silver.

44 : The substrate according to claim 38 , wherein said substrate has no initial silver-plated surface and in that it comprises, between said substrate and said coat of silver and copper alloy, a coat of substantially pure silver.

45 : The substrate according to claim 39 , wherein the coat of substantially pure silver has a thickness between 1500 nm and 2500 nm.

46 : The substrate according to claim 38 , wherein the silver and copper alloy comprises between 0.2% and 8% by weight, preferably between 0.5% and 7% by weight, of copper with respect to the total weight of the alloy.

47 : The substrate according to claim 38 , wherein the substrate is a horological element.

48 : The substrate according to claim 38 , wherein it has a surface structuring.

49 : A method for manufacturing a substrate comprising a final silver-plated surface protected against silver tarnishing by a protective coat, wherein said method comprises the following steps:
a) obtaining a substrate having a final silver-plated surface b) depositing on at least a part of said final silver-plated surface from step a) at least one protective coat against silver tarnishing having a thickness between 1 nm and 200 nm, preferably between 1 nm and 100 nm, said step b) comprising a first step b1) of depositing, on at least a part of said final silver-plated surface from step a), a first coat of Al2O3 having a thickness between 0.5 nm and 100 nm, preferably between 0.5 nm and 50 nm, and a second step b2) of depositing, on the first coat of Al 2 O 3 obtained in step b1), a second coat of TiO2 having a thickness between 0.5 nm and 100 nm, preferably between 0.5 nm and 50 nm, characterised in that the method comprises a step a1) of depositing on said substrate a coat of a silver and copper alloy comprising between 0.1% and 10% by weight of copper with respect to the total weight of the alloy to obtain said final silver-plated surface, said coat of a silver and copper alloy having a thickness between 1000 nm and 3000 nm.

50 : A method for manufacturing a substrate comprising a final silver-plated surface protected against silver tarnishing by a protective coat, wherein said method comprises the following steps:
a) obtaining a substrate having a final silver-plated surface b) depositing on at least a part of said final silver-plated surface from step a) at least one protective coat against silver tarnishing having a thickness between 1 nm and 200 nm, preferably between 1 nm and 100 nm, said step b) comprising a first step b1) of depositing, on at least a part of said final silver-plated surface from step a), a first coat of Al 2 O 3 having a thickness between 0.5 nm and 100 nm, preferably between 0.5 nm and 50 nm, and a second step b2) of depositing, on the first coat of Al 2 O 3 obtained in step b1), a second coat of TiO 2 having a thickness between 0.5 nm and 100 nm, preferably between 0.5 nm and 50 nm, characterised in that the method comprises a step a3) of depositing a coat of substantially pure silver on said substrate to obtain said final silver-plated surface, the coat of substantially pure silver having a thickness between 1000 nm and 3000 nm.

51 : The method according to claim 49 , wherein the first coat of Al 2 O 3 has a thickness between 30 nm and 50 nm and in that the second coat of TiO 2 has a thickness between 10 nm and 50 nm.

52 : The method according to claim 49 , wherein step b) is carried out by means of a method selected from the group comprising an ALD, PVD, CVD, and sol-gel deposition.

53 : The method according to claim 52 , wherein step b) is carried out by ALD deposition.

54 : The method according to claim 49 , wherein it comprises, before and/or after step b2), a plasma treatment step.

55 : The method according to claim 49 , wherein it comprises, between step a) and step b), at least one plasma pre-treatment step c) of the final silver-plated surface of the substrate obtained in step a)

56 : The method according to claim 55 , wherein the plasma pre-treatment step c) consists of an Ar plasma or Ar/H 2 plasma pre-treatment.

57 : The method according to claim 55 , wherein step c) is carried out without venting the final silver-plated surface of the substrate between step c) and said step b).

58 : The method according to claim 55 , wherein it comprises, between step c) and step b), an oxidising pre-treatment step d).

59 : The method according to claim 58 , wherein the oxidising pre-treatment step d) consists of a plasma pre-treatment with an oxidising agent.

60 : The method according to claim 58 , wherein the oxidising pre-treatment step d) consists of injecting water or hydrogen peroxide, in liquid form, into a pre-treatment chamber in a vacuum.

61 : The method according to claim 58 , wherein step d) is carried out without venting the final silver-plated surface of the substrate between step c) and said step d).

62 : The method according to claim 58 , wherein step b) is carried out without venting the final silver-plated surface of the substrate between step d) and said step b).

63 : The method according to claim 62 , wherein steps c), d) and b) are implemented in the same overall treatment machine.

64 : The method according to claim 49 , wherein the substrate from step a) has no initial silver-plated surface, and in that said method comprises

Assignees

• Swatch Group Res & Dev Ltd

Inventors

• Manasterski Christian
• Spassov Vladislav
• Faure Cédric

Classifications

• C25D5/627

  Electroplating characterised by the visual appearance of the layers, e.g. colour, brightness or mat appearance · CPC title

• C25D5/10

  Electroplating with more than one layer of the same or of different metals (for bearings C25D7/10) · CPC title

• C23C28/32

  including at least one pure metallic layer · CPC title

• C23C16/45555

  applied in non-semiconductor technology · CPC title

• C23C16/0245

  by etching with a plasma · CPC title