Method for fabricating thin touch sensor panels

• US 8,997,339 B2
• Filed: 10/20/2010
• Issued: 04/07/2015
• Est. Priority Date: 01/09/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Chang, Shih Chang, Zhong, John Z., Huang, Lili, Hong, Seung Jae, Youngs, Lynn
• Primary Examiner(s): Vo, Peter DungBa
• Assistant Examiner(s): PARVEZ, AZM A
• Application Number:
  US12/908,763
• Publication Number:
  US 20110030209A1
• Time in Patent Office: 1,630 Days
• Field of Search: 298/47, 298/46, 298/29, 298/25, 295/921, 298/44, 298/42, 427/466, 427/496, 427/331, 156/247, 216/23, 216/31, 216/83, 216/88, 249/156
• US Class Current: 29/831
• 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 substrate being a second outer surface of the first sandwich;

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

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

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

2. The method of claim 1, further comprising:

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

3. The method of claim 2, wherein coating is performed before the glass sheet and the carrier substrate are joined together.

4. The method of claim 3, wherein the layer of shielding is indium tin oxide.

5. The method of claim 1, further comprising:

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

6. The method of claim 5, further comprising:

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

7. The method of claim 1, 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.

8. The method of claim 1, wherein joining comprises sealing the edges of the first glass sheet and the carrier substrate together.

9. The method of claim 8, wherein separating comprises unsealing sealed-together edges of the first glass sheet and the carrier substrate.

10. The method of claim 1, 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.

11. The method of claim 10, wherein separating comprises detaching the separators from the first glass sheet and the carrier substrate.

12. The method of claim 1, further comprising:

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.

13. The method of claim 12, further comprising:

coating an indium tin oxide 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.

14. The method of claim 13, further comprising:

coating a metal layer on top of the indium tin oxide 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.

15. The method of claim 12, 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.