Method of fabricating a timepiece component and component obtained from this method

Patent metadata

Field	Value
Publication number	US-12124223-B2
Application number	US-202017121095-A
Country	US
Kind code	B2
Filing date	Dec 14, 2020
Priority date	Dec 18, 2019
Publication date	Oct 22, 2024
Grant date	Oct 22, 2024

Abstract

A method for fabricating a metallic timepiece component, wherein the method includes the steps of forming, via a UV-LIGA type process combined with hot stamping, a multi-level photosensitive resin mould and electroplating a layer of at least one metal from at least two conductive layers to form a block that substantially reaches the upper surface of the photosensitive resin.

First claim

The invention claimed is:

1. A method for the fabrication of at least one timepiece component comprising the following steps:
a) providing a substrate ( 1 ), depositing thereon a first electrically conductive layer ( 2 ) and applying a first photosensitive resin layer ( 3 );
b) hot stamping the first photosensitive resin layer ( 3 ) using a stamp, pressing the stamp ( 8 ) down to the substrate, in order to shape the first photosensitive resin layer and define a first level of the timepiece component;
c) irradiating the first shaped photosensitive resin layer ( 3 ) through a mask ( 4 ) defining at least a first level of the timepiece component and dissolving the non-irradiated areas ( 3 b ) of the photosensitive resin layer ( 3 ) to reveal, in places, the first electrically conductive layer ( 2 );
d) applying a second photosensitive resin layer ( 6 ) covering the structure resulting from step c), then irradiating the second photosensitive resin layer ( 6 ) through a mask ( 4 ″) defining a second level of the timepiece component and dissolving the non-irradiated areas ( 6 b ) of the second photosensitive resin layer ( 6 ) to form a mould comprising a first and a second level;
e) depositing by electroforming a metallic layer ( 7 ) in the mould from the first electrically conductive layer ( 2 ) to form the timepiece component, the metallic layer ( 7 ) substantially reaching the upper surface of the second photosensitive resin layer ( 6 );
f) successively removing the substrate, the first electrically conductive layer, the first photosensitive resin layer ( 3 ) and the second photosensitive resin layer ( 6 ) to release the timepiece component,
wherein, in step b) a surface of the first photosensitive resin layer ( 3 ) is formed as one of beveled and chamfered, and
in step e) a surface of the timepiece component is formed as the one of beveled and chamfered against the surface of the first photosensitive resin layer ( 3 ),
wherein the method includes a step d′), after step c), which consists in locally depositing a second electrically conductive layer ( 5 ) on the irradiated layers ( 3 a ) of the first photosensitive resin layer ( 3 ), and
wherein a second surface of the first photosensitive resin layer ( 3 ) is formed as curved and is extended from the second electrically conductive layer ( 5 ) to the first electrically conductive layer ( 2 ).

2. The method according to claim 1 , wherein step b) is carried out under vacuum.

3. The method according to claim 1 wherein during step b) or step d), the first photosensitive resin layer ( 3 ) is heated to between 70° ° C. and 150° C.

4. The method according to claim 1 , wherein the stamp has a relief print, at least one part of the relief print being arranged to be pressed directly against the surface of the substrate in step b).

5. The method according to claim 4 , wherein said relief print defines said at least a first level of the timepiece component.

6. The method according to claim 1 , wherein the second electrically conductive layer ( 5 ) is deposited through a stencil mask ( 4 ′).

7. The method according to claim 1 , wherein the second electrically conductive layer ( 5 ) is applied in a general deposition over all the exposed surfaces including sidewalls and then entirely removed except from one or more portions of the upper surface of the first photosensitive resin layer.

8. The method according to claim 1 , wherein in step d′), the second electrically conductive layer ( 5 ) is deposited by printing an ink or a conductive resin.

9. The method according to claim 1 , wherein said first electrically conductive layer ( 2 ) and said second electrically conductive layer ( 5 ) include any of Au, Ti, Pt, Ag, Cr, and Pd.

10. The method according to claim 1 , wherein the second electrically conductive layer ( 5 ) has a thickness comprised between 50 nm and 500 nm.

11. The method according to claim 1 , wherein substrate ( 1 ) is made of silicon.

12. The method according to claim 1 , wherein the first electrically conductive layer ( 2 ) has a thickness comprised between 50 nm and 500 nm.

13. The method according to claim 1 ,
wherein, in step b) the surface of the second photosensitive resin layer ( 6 ) is formed on an outer surface of the first photosensitive resin layer ( 3 ) by the hot stamping using the stamp of step b), and
wherein step e) comprises the depositing by electroforming the metallic layer ( 7 ) against the least the surface of the first photosensitive resin layer ( 3 ), and thereby forming the surface of the timepiece component along the at least one surface and in a manner such that the surface of the timepiece component is formed as curved.

14. The method according to claim 1 , wherein the timepiece component comprises at least one of a pallet fork and an escape wheel.

15. A method for the fabrication of at least one timepiece component comprising the following steps:
a′) providing a substrate ( 1 ), depositing thereon a first electrically conductive layer ( 2 ) and applying a first photosensitive resin (3) layer;
b′) irradiating the first photosensitive resin layer ( 3 ) through a mask ( 4 ) defining at least a first level of the timepiece component and dissolving the non-irradiated areas ( 3 b ) of the first photosensitive resin layer ( 3 ) to reveal, in places, the first electrically conductive layer ( 2 );
c′) applying a second photosensitive resin layer ( 6 ) covering the structure resulting from step b′),
d′) hot stamping the second photosensitive resin layer ( 6 ) using a stamp to shape the second photosensitive resin layer and define a second level of the timepiece component;
e′) irradiating the second shaped photosensitive resin layer ( 6 ) through a mask ( 4 ″) defining a second level of the timepiece component and dissolving the non-irradiated areas ( 6 b ) of the second photosensitive resin layer ( 6 ) to form a mould comprising a first and a second level;
f) depositing a metallic layer ( 7 ) by electroforming in the mould from the first electrically conductive layer ( 2 ) to form the timepiece component, the metallic layer ( 7 ) substantially reaching the upper surface of the second photosensitive resin layer ( 6 );
g′) successively removing the substrate, the first electrically conductive layer, the first photosensitive resin layer ( 3 ) and the second photosensitive resin layer ( 6 ) to release the timepiece component,
wherein in step d′) a surface of the second photosensitive resin layer ( 6 ) is formed as at least one of beveled and chamfered, and
wherein in step f′) a surface of the timepiece component is formed as the one of beveled and chamfered against the surface of the second photosensitive resin layer ( 6 ),
wherein the method includes a step d″), after step c′), which consists in locally depositing a second electrically conductive layer ( 5 ) on irradiated layers ( 3 a ) of the first photosensitive resin layer ( 3 ), and
wherein a second surface of the first photosensitive resin layer ( 3 ) is formed as curved and is extended from the second electrically conductive layer ( 5 ) to the first electrically conductive layer ( 2 ).

16. The method according to claim 15 , wherein step d′) is carried out under vacuum.

17. The method according to claim 15 wherein during step d′), the first photosensitive resin layer ( 3 ) is heated to between 70° C. and 150° C.

Assignees

• Nivarox Far Sa

Inventors

• Cusin Pierre
• Gandelhman Alex
• Musy Michel
• Golfier Clare

Classifications

• G03F7/20

  Exposure; Apparatus therefor (photographic printing apparatus for making copies G03B27/00) · CPC title

• C25D1/00

  Electroforming · CPC title

• B29C59/02

  by mechanical means, e.g. pressing {(B29C59/007 takes precedence; embossing expanded porous articles B29C44/5627)} · CPC title

• G04B15/14

  Component parts or constructional details, e.g. construction of the lever or the escape wheel {(assembly and manufacture of the spring G04B1/145; assembly and manufacture of components, e.g. pinions, spindles G04B13/02; lubrication of clockwork bearings G04B31/008; oils for clockwork bearings in general G04B31/08)} · CPC title

• G04B13/02

  Wheels; Pinions; Spindles; Pivots (bearings G04B31/00 {; chain wheels, spindles for chain wheels, also chains and driving weights G04B1/08}) · CPC title