Metallic keys

• US 6,321,441 B1
• Filed: 10/27/1999
• Issued: 11/27/2001
• Est. Priority Date: 12/22/1998
• Status: Active Grant

• Current Assignee: Ironworks Patents LLC
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Davidson, Brian, Mabbot, Jeff
• Primary Examiner(s): Bryant, David P.
• Assistant Examiner(s): SMITH, SEAN PRENTISS
• Application Number:
  US09/427,622
• Time in Patent Office: 762 Days
• Field of Search: 296/22, 298/25, 298/27, 298/29, 298/31, 200/512, 200/268, 200/269, 200/292
• US Class Current: 29/622
• CPC Class Codes: H01H 13/705 characterised by construction, mounting or arrangement of operating parts, e.g. push-buttons or keys
• CPC Class Codes: H01H 2209/0021 with metallic appearance, e.g. polymers with dispersed particles to produce a metallic appearance
• CPC Class Codes: H01H 2209/07 metallic
• CPC Class Codes: H01H 2219/03 in transparent keyboard
• CPC Class Codes: H01H 2221/006 Adhesive
• CPC Class Codes: H01H 2221/07 transparent
• CPC Class Codes: H01H 2229/014 Electro deposition
• CPC Class Codes: H01H 2229/016 Selective etching
• CPC Class Codes: H01H 2231/022 Telephone handset
• CPC Class Codes: Y10T 29/49105 Switch making

Abstract

A method of forming a key comprising the steps of: depositing an electroless metallic layer on an upper surface of a substrate; removing the metallic layer from selected portions to expose the substrate, said exposed portions of the substrate defining the image of an indicia; depositing a second metallic layer on the remaining portions of the first metallic layer by electrolysis; and coupling a lower surface of the substrate to an element for actuating a switch. A device for tactile actuation by a user, having an element, for activating a switch, coupled to a body supporting a metallic layer for tactile actuation by a user, wherein the metallic layer extends over an upper surface of the body and wherein at least one aperture extends through the metallic layer to said upper surface thereby defining at least one visible indicia.

Claims

1. A method of forming a key for tactile activation by a user comprising the steps of:

a) depositing a first metallic layer on an upper surface of a substrate;

b) removing the metallic layer from selected portions to expose the substrate, said exposed portions of the substrate defining the image of an indicia;

c) depositing a second metallic layer on the remaining portions of the first metallic layer; and

d) coupling a lower surface of the substrate to an element for actuating a switch such that, in use, tactile actuation of the key through the second metallic layer activates the switch.

2. A method according to claim 1 wherein the first metallic layer is formed by electroless plating.

3. A method according to claim 2 wherein the first metallic layer is formed by reducing copper salts.

4. A method as claimed in claim 1 wherein step b) comprises the masked etch back of the first metallic layer.

5. A method as claimed in claim 4 comprising the steps of:

forming a mask layer having an aperture or apertures exposing portions of the first metallic layer overlying said selected portions of the substrate and etching the first metallic layer through said aperture or apertures to expose said substrate.

6. A method as claimed in claim 5 wherein the step of forming a mask layer comprises depositing a photoresist layer, selectively exposing portions of the photoresist layer,

removing either the exposed or unexposed portions of the photoresist layer to define a mask layer comprising photoresist extending over the first metallic layer and having apertures therein exposing the portions of said first metallic layer overlying said selected portions of the substrate.

7. A method as claimed in claim 1 wherein the step of depositing a second metallic layer involves depositing the second metallic layer by electrolysis.