Fabrication of Touch Sensor Panel Using Laser Ablation

• US 20120026099A1
• Filed: 07/30/2010
• Published: 02/02/2012
• Est. Priority Date: 07/30/2010
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: HARLEY, Jonah A.
• Granted Patent: US 9,652,088 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• 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

Abstract

Fabrication of a touch sensor panel using laser ablation is disclosed. The fabricated touch sensor panel can have its touch sensors formed from conductive layers disposed on a surface such as an undersurface of the panel'"'"'s cover substrate. A fabrication method can include ablating a first conductive layer to define the first part of the touch sensors and then ablating a second conductive layer proximate to the first conductive layer to define the second part of the touch sensors. The touch sensor panel can be incorporated into a mobile telephone, a digital media player, or a personal computer.

Claims

1. A method comprising:

depositing a first conductive layer onto a substrate;

ablating the first conductive layer to define a first touch sensing pattern;

depositing a dielectric layer onto the first conductive layer;

depositing a second conductive layer onto the dielectric layer; and

ablating the second conductive layer to define a second touch sensing pattern.

2. The method of claim 1, wherein ablating the first conductive layer comprises making gaps in the first conductive layer to define the first touch sensing pattern.

3. The method of claim 1, wherein the first touch sensing pattern comprises conductive rows for touch sensors.

4. The method of claim 1, wherein ablating the second conductive layer comprises making gaps in the second conductive layer to define the second touch sensing pattern.

5. The method of claim 1, wherein the second touch sensing pattern comprises conductive columns for touch sensors.

6. The method of claim 1, wherein the dielectric layer electrically separates the first and second touch sensing patterns.

7. The method of claim 1, wherein the first and second touch sensing patterns cross over each other to form touch sensors configured to sense a touch on a surface of the substrate that is opposite a surface having the first and second conductive layers and the dielectric layer deposited thereon.

8. A method comprising:

depositing a first conductive layer onto a substrate;

ablating the first conductive layer at a first set of discrete locations to define a first portion of a first touch sensing pattern;

depositing a dielectric layer onto the first conductive layer;

depositing a second conductive layer onto the dielectric layer;

ablating the first conductive layer, the dielectric layer, and the second conductive layer at a second set of discrete locations to define a second portion of the first touch sensing pattern connecting with the first portion of the first touch sensing pattern on the first conductive layer and to define a first portion of a second touch sensing pattern on the second conductive layer; and

ablating the second conductive layer at a third set of discrete locations to define a second portion of the second touch sensing pattern connecting with the first portion of the second touch sensing pattern on the second conductive layer.

9. The method of claim 8, wherein ablating the first conductive layer comprises removing pairs of horizontal strips of the first conductive layer at the first set of discrete locations to form gaps in the first conductive layer to define the first portion of the first touch sensing pattern.

10. The method of claim 8, wherein ablating the first conductive layer, the dielectric layer, and the second conductive layer comprises concurrently removing strips of the first conductive layer, the dielectric layer, and the second conductive layer at the second set of discrete locations to form gaps in the first conductive layer, the dielectric layer, and the second conductive layer to define the second portion of the first touch sensing pattern on the first conductive layer and to define the first portion of the second touch sensing pattern on the second conductive layer.

11. The method of claim 8, wherein ablating the second conductive layer comprises removing pairs of vertical strips of the second conductive layer at the third set of discrete locations to form gaps in the second conductive layer to define the second portion of the second touch sensing pattern.

12. The method of claim 8, wherein the first and second touch sensing patterns cross over each other at the first and third sets of discrete locations to form touch sensors configured to sense a touch on a surface of the substrate that is opposite a surface having the first and second conductive layers and the dielectric layer deposited thereon.

13. The method of claim 8, comprising ablating the second conductive layer to remove strips at regular intervals across the second conductive layer so as to reduce visual sensitivity to the second touch sensing pattern.

14. A method comprising:

ablating a first conductive layer to define first portions of touch sensors, the first portions having multiple narrowing regions; and

ablating a second conductive layer proximate to the first conductive layer to define second portions of the touch sensors, the second portions having multiple narrowing regions,

wherein the first and second portions cross over at the respective narrowing regions.

15. The method of claim 14, wherein ablating the first conductive layer comprises defining either drive lines or sense lines of the touch sensors.

16. The method of claim 14, wherein ablating the second conductive layer comprises defining either drive lines or sense lines of the touch sensors.

17. The method of claim 14, wherein ablating the first conductive layer comprises separating the first conductive layer into electrically connected regions and electrically disconnected regions, the electrically connected regions comprising the first portions of the touch sensors.

18. The method of claim 14, wherein ablating the second conductive layer comprises separating the second conductive layer into electrically connected regions and electrically disconnected regions, the electrically connected regions comprising the second portions of the touch sensors.

19. The method of claim 14, comprising depositing a mask around a boundary of at least one of the first and second conductive layers.

20. The method of claim 14, comprising forming a first set of contacts on the first portions of the touch sensors and a second set of contacts on the second portions of the touch sensors to electrically contact touch circuitry.

21. The method of claim 14, wherein the narrowing regions of the first and second portions are so narrowed to reduce unwanted capacitive coupling between the first and second portions.

22. A touch sensor panel comprising:

a cover substrate having a touchable surface; and

multiple touch sensors formed on a surface of the cover substrate opposite the touchable surface, the touch sensors including first and second conductive layers having ablated gaps, the first conductive layer being deposited over the opposite surface of the cover substrate and the second conductive layer being deposited over a dielectric layer disposed over the first conductive layer.

23. The panel of claim 22, wherein the ablating comprises laser ablating.

24. The panel of claim 22 incorporated into at least one of a mobile telephone, a digital media player, or a personal computer.

25. A touch sensor panel comprising:

a substrate having a touchable surface;

a first conductive pattern formed on the substrate into a first portion of touch sensors, the first conductive pattern having been ablated;

a dielectric layer disposed on the first conductive pattern;

a second conductive pattern formed on the dielectric layer into a second portion of the touch sensors, the second conductive pattern having been ablated; and

a mask formed on the second conductive pattern, the mask having been printed.