Method for fabricating thin touch sensor panels

• US 7,918,019 B2
• Filed: 01/09/2009
• Issued: 04/05/2011
• Est. Priority Date: 01/09/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Zhong, John Z., Youngs, Lynn, Chang, Shih Chang, Huang, Lili, Hong, Seung Jae
• Primary Examiner(s): Banks; Derris H
• Assistant Examiner(s): PARVEZ, AZM A
• Application Number:
  US12/351,767
• Publication Number:
  US 20100175249A1
• Time in Patent Office: 816 Days
• Field of Search: 298/30, 298/31, 298/42, 298/46, 427/466, 427/469, 156/247
• US Class Current: 29/846
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 2201/0317 Thin film conductor layer; Thin film passive component
• CPC Class Codes: H05K 2201/0326 Inorganic, non-metallic conductor, e.g. indium-tin oxide [ITO]
• CPC Class Codes: H05K 2203/1536 Temporarily stacked PCBs
• CPC Class Codes: H05K 3/0097 Processing two or more printed circuits simultaneously, e.g. made from a common substrate, or temporarily stacked circuit boards H05K3/0052 takes precedence
• CPC Class Codes: Y10T 29/49126 Assembling bases
• CPC Class Codes: Y10T 29/49128 Assembling formed circuit to base
• CPC Class Codes: Y10T 29/49147 Assembling terminal to base
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49156 with selective destruction of conductive paths

Abstract

A method for fabricating thin DITO or SITO touch sensor panels with a thickness less than a minimum thickness tolerance of existing manufacturing equipment. In one embodiment, a sandwich of two thin glass sheets is formed such that the combined thickness of the glass sheets does not drop below the minimum thickness tolerance of existing manufacturing equipment when thin film process is performed on the surfaces of the sandwich during fabrication. The sandwich may eventually be separated to form two thin SITO/DITO panels. In another embodiment, the fabrication process involves laminating two patterned thick substrates, each having at least the minimum thickness tolerance of existing manufacturing equipment. One or both of the sides of the laminated substrates are then thinned so that when the substrates are separated, each is a thin DITO/SITO panel having a thickness less than the minimum thickness tolerance of existing manufacturing equipment.

Claims

1. A method for fabricating a thin printed circuit, comprising:

providing a first substrate having a first thickness, a first surface, and a second surface;

providing a second substrate having a second thickness, a third surface, and a fourth surface;

joining the first and second substrates together to form a first sandwich, the first surface of the first substrate being a first outer surface of the first sandwich and the third surface of the second glass sheet being a second outer surface of the first sandwich;

forming thin film patterns on the first outer surface of the first sandwich;

forming thin film patterns on the second outer surface of the first sandwich; and

separating the first and second substrates of the first sandwich from each other.

2. The method of claim 1, wherein the first substrate is a first glass sheet and the second substrate is a second glass sheet.

3. The method of claim 2, further comprising:

coating each of the second surface and the fourth surface with a layer of shielding.

4. The method of claim 3, wherein coating is performed before the first glass sheet and the second sheet are joined together.

5. The method of claim 3, wherein the layer of shielding is ITO.

6. The method of claim 2, further comprising:

coating an ITO layer on each of the first surface and the third surface before the first glass sheet and the second glass sheet are joined together.

7. The method of claim 6, further comprising:

coating a metal layer on top of the ITO layers on the first surface and the third surface before the first glass sheet and the second glass sheet are joined together.

8. The method of claim 2, wherein neither the first glass sheet nor the second glass sheet has a thickness greater than a minimum thickness tolerance of existing touch sensor panel manufacturing equipment, and wherein the combined thickness of the first glass sheet and the second glass sheet is at least greater than the minimum thickness tolerance.

9. The method of claim 2, wherein joining comprises sealing the edges of the first glass sheet and the second glass sheet together.

10. The method of claim 9, wherein separating comprises unsealing sealed-together edges of the first glass sheet and the second glass sheet.

11. The method of claim 2, wherein joining comprises inserting at least one separator between the first glass sheet and the second glass sheet to prevent the first glass sheet and the second glass sheet from contacting each other.

12. The method of claim 11, wherein separating comprises detaching the separators from the first glass sheet and the second glass sheet.

13. The method of claim 2, further comprising:

joining the first glass sheet and the second glass sheet together to form a second sandwich, the second surface and the fourth surface being outer surfaces of the second sandwich, respectively;

forming thin film patterns on the outer surfaces of the second sandwich; and

separating the first glass sheet and the second glass sheet of the second sandwich from each other.

14. The method of claim 13, further comprising:

coating an ITO layer on both surfaces of the first glass sheet and the second glass sheet before the first glass sheet and the second glass sheet are joined together to form the first sandwich.

15. The method of claim 14, further comprising:

coating a metal layer on top of the ITO layers on both surfaces of the first glass sheet and the second glass sheet before the first glass sheet and the second glass sheet are jointed together to form the first sandwich.

16. The method of claim 13, wherein neither the first glass sheet nor the second glass sheet has a thickness greater than a minimum thickness tolerance of existing touch sensor panel manufacturing equipment, and wherein the combined thickness of the first glass sheet and the second glass sheet is at least the minimum thickness tolerance.

17. The method of claim 1, wherein the first substrate is a first glass sheet, and the second substrate is a carrier substrate.

18. The method of claim 17, further comprising:

coating the second surface of the first glass sheet with a layer of shielding.

19. The method of claim 18, wherein coating is performed before the first glass sheet and the carrier substrate are joined together.

20. The method of claim 19, wherein the layer of shielding is ITO.

21. The method of claim 17, further comprising:

coating an ITO layer on the first surface of the first glass sheet before the first glass sheet and the carrier substrate are joined together.

22. The method of claim 21, further comprising:

coating a metal layer on top of the ITO layers on the first surface of the first glass sheet before the first glass sheet and the carrier substrate are joined together.

23. The method of claim 17, wherein the first glass sheet has a thickness less than a minimum thickness tolerance of existing touch sensor panel manufacturing equipment, and wherein the combined thickness of the first glass sheet and the carrier substrate is at least the minimum thickness tolerance.

24. The method of claim 17, wherein joining comprises sealing the edges of the first glass sheet and the carrier substrate together.

25. The method of claim 24, wherein separating comprises unsealing sealed-together edges of the first glass sheet and the carrier substrate.

26. The method of claim 17, wherein joining comprises inserting at least one separator between the first glass sheet and the carrier substrate to prevent the first glass sheet and the carrier substrate from contacting each other.

27. The method of claim 26, wherein separating comprises detaching the separators from the first glass sheet and the carrier substrate.

28. The method of claim 17, further comprising:

joining the first glass sheet and the carrier substrate together to form a second sandwich, the second surface of the first glass sheet being an outer surface of the second sandwich;

forming thin film patterns on the outer surface of the second sandwich, the outer surface is the second surface of the first glass sheet; and

separating the first glass sheet and the carrier substrate of the second sandwich from each other.

29. The method of claim 28, further comprising:

coating an ITO layer on both surfaces of the first glass sheet before the first glass sheet and the carrier substrate are joined together to form the first sandwich.

30. The method of claim 29, further comprising:

coating a metal layer on top of the ITO layers on both surfaces of the first glass sheet before the first glass sheet and the carrier substrate are joined together to form the first sandwich.

31. The method of claim 28, wherein the first glass sheet has a thickness less than a minimum thickness tolerance of existing touch sensor panel manufacturing equipment, and wherein the combined thickness of the first glass sheet and the carrier substrate is at least the minimum thickness tolerance.

32. The method of claim 1 further comprising:

providing at least one separator between the first and second substrates.