KEYBOARD ASSEMBLIES HAVING REDUCED THICKNESS AND METHOD OF FORMING KEYBOARD ASSEMBLIES

• US 20160336128A1
• Filed: 05/13/2016
• Published: 11/17/2016
• Est. Priority Date: 05/13/2015
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: La, Thai Q., Lehmann, Alex J., Leong, Craig C., Zercoe, Bradford J., Cao, Robert Y., Mathew, Dinesh C.
• Granted Patent: US 10,424,446 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 1/1662 Details related to the integrated keyboard
• CPC Class Codes: H01H 13/10 Bases; Stationary contacts mounted thereon
• CPC Class Codes: H01H 13/702 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
• CPC Class Codes: H01H 13/7065 characterised by the mechanism between keys and layered keyboards
• CPC Class Codes: H01H 13/807 characterised by the spatial arrangement of the contact sites, e.g. superimposed sites
• CPC Class Codes: H01H 13/88 Processes specially adapted for manufacture of rectilinearly movable switches having a plurality of operating members associated with different sets of contacts, e.g. keyboards
• CPC Class Codes: H01H 2203/028 embedded in layer material
• CPC Class Codes: H01H 2205/026 Adhesive sheet
• CPC Class Codes: H01H 2215/006 Only mechanical function
• CPC Class Codes: H01H 2231/002 Calculator, computer
• CPC Class Codes: H01H 3/125 using a scissor mechanism as stabiliser

Abstract

Keyboard assemblies having reduced thicknesses and methods of forming the same. A keyboard assembly may include a printed circuit board (PCB) and a single membrane sheet adhered directly to the PCB. The single membrane sheet may substantially cover the PCB. The keyboard assembly may also include a group of dome switches coupled directly to the single membrane sheet. Another keyboard assembly may include a group of conductive pads and a group of membrane pads. Each of the group of membrane pads may be adhered directly to a corresponding one of the group of conductive pads. The keyboard assembly may also include a group of dome switches coupled directly to the membrane pads. Each of the group of dome switches may be coupled directly to a corresponding one of the group of membrane pads.

Claims

1. An electronic device comprising:

a casing; and

a keyboard assembly housed at least partially within the casing, the keyboard assembly comprising;

a printed circuit board (PCB) positioned within the casing;

a membrane layer affixed directly to the PCB; and

a dome switch coupled directly to the membrane layer.

2. The electronic device of claim 1, further comprising an anisotropic conductive film bonded to both the PCB and the membrane layer;

wherein

the anisotropic conductive film directly affixes the membrane layer to the PCB.

3. The electronic device of claim 2, wherein the anisotropic conductive film electrically couples the PCB and the membrane layer.

4. The electronic device of claim 1, wherein the membrane layer comprises one of:

a single membrane sheet substantially covering the PCB; and

a group of membrane pads directly coupled to the PCB.

5. The electronic device of claim 1, wherein the membrane layer is formed from a substantially flexible, electrically conductive material.

6. The electronic device of claim 1, wherein the keyboard assembly further comprises a switch housing affixed directly to one of:

the membrane layer; and

the PCB.

7. A keyboard assembly comprising:

a printed circuit board (PCB);

a single membrane sheet adhered directly to and substantially covering the PCB; and

a group of dome switches coupled directly to the single membrane sheet.

8. The keyboard assembly of claim 7, wherein:

the single membrane sheet comprises a group of electrical contacts in electrical communication with the PCB; and

a set of two distinct electrical contacts of the group of electrical contacts are formed below each of the group of dome switches.

9. The keyboard assembly of claim 8, wherein a single dome switch of the group of dome switches contacts one of the set of two distinct electrical contacts when the single dome switch is in a compressed state.

10. The keyboard assembly of claim 7, further comprising a pressure sensitive adhesive positioned between the single membrane sheet and the PCB, the pressure sensitive adhesive adhering the single membrane sheet to the PCB.

11. The keyboard assembly of claim 7, wherein the group of dome switches is one of adhered or laminated to the single membrane sheet.

12. A keyboard assembly comprising:

a group of conductive pads;

a group of membrane pads, each of the group of membrane pads adhered directly to a corresponding one of the group of conductive pads; and

a group of dome switches, each of the group of dome switches coupled directly to a corresponding one of the group of membrane pads.

13. The keyboard assembly of claim 12, wherein each of the group of membrane pads comprises:

an outer conductive ring;

an intermediate conductive spacer concentric with and surrounded by the outer conductive ring; and

an inner conductive ring concentric with and surrounded by the intermediate conductive spacer.

14. The keyboard assembly of claim 13, wherein each of the group of conductive pads comprises:

an outer conductive portion in contact with the outer conductive ring of a corresponding one of the membrane pads; and

an inner conductive portion spaced apart from and surrounded by the outer conductive portion, the inner conductive portion separated from the inner conductive ring and the intermediate conductive spacer of the membrane pad when a corresponding dome switch of the group of dome switches is in an uncompressed state.

15. The keyboard assembly of claim 14, wherein the intermediate conductive spacer of the membrane pad is in electrical communication with the outer conductive portion and the inner conductive portion of the conductive pad when the corresponding dome switch is in a compressed state.

16. The keyboard assembly of claim 12, wherein each of the group of membrane pads further comprises:

an upper portion comprising a first electrical contact; and

a lower portion comprising two distinct electrical contacts;

wherein

the lower portion is spaced apart from the upper portion when a corresponding dome switch of the group of dome switches is in an uncompressed state.

17. The keyboard assembly of claim 16, wherein the first electrical contact of the upper portion is displaced toward and contacts the two distinct electrical contacts of the lower portion when the corresponding dome switch is compressed.

18. The keyboard assembly of claim 16, wherein each upper portion is sealed to each corresponding lower portion at a perimeter of each of the group of membrane pads.

19. A method for assembling a keyboard, the method comprising:

coupling a dome switch directly to a membrane layer;

affixing the membrane layer directly to a printed circuit board (PCB);

positioning a switch housing over the PCB to surround the dome switch; and

coupling a keycap to a hinge mechanism positioned adjacent the switch housing, the keycap positioned above the dome switch.

20. The method of claim 19, wherein coupling the dome switch directly to the membrane layer further comprises one of:

adhering the dome switch to the membrane layer; and

laminating the dome switch to the membrane layer.

21. The method of claim 20, wherein coupling the dome switch to the membrane layer further comprises:

depositing an ultraviolet (UV) glue between the dome switch and the membrane layer; and

curing the UV glue.

22. The method of claim 19, wherein coupling the dome switch directly to the membrane layer further comprises one of:

affixing the dome switch to a single membrane sheet, the single membrane sheet substantially covering the PCB; and

affixing the dome switch to a membrane pad.

23. The method of claim 19, wherein positioning the switch housing over the PCB to surround the dome switch further comprises one of:

adhering the switch housing directly to a single membrane sheet; and

adhering the switch housing directly to the PCB such that the switch housing substantially surrounds a membrane pad.

24. The method of claim 19, wherein affixing the membrane layer directly to the PCB further comprises bonding the membrane layer to the PCB with an anisotropic conductive film.