PARTIAL LASER ABLATION SENSOR PROCESS

• US 20130228442A1
• Filed: 03/04/2013
• Published: 09/05/2013
• Est. Priority Date: 03/05/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Kang, Sunggu, Zhong, John Z., Mohaptatra, Siddharth
• Granted Patent: US 9,911,550 B2
• Time in Patent Office: Days
• US Class Current: 200/600
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• 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: H01H 11/00 Apparatus or processes specially adapted for the manufacture of electric switches processes specially adapted for manufacture of rectilinearly movable switches having a plurality of operating members associated with different sets of contacts, e.g. keyboards, H01H13/88
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: Y10T 29/49105 Switch making

Abstract

Processes for fabricating compact touch sensors for touch sensitive devices are disclosed. A process can include providing a touch sensor structure having a substrate, a first layer disposed on the substrate, and a second layer disposed on the first layer. The second layer can have an ablation fluence value that is lower than an ablation fluence value of the first layer. The process can include patterning the second layer with a laser emitting energy having a fluence value greater than or equal to the ablation fluence value of the second layer and less than the ablation fluence value of the first layer. The process can further include etching at least a portion of the first layer that was exposed during the patterning of the second layer. At least a portion of the second layer can then be removed by etching or laser ablation.

Claims

1. A method comprising:

providing a touch sensor structure comprising;

a substrate;

a first layer disposed on a surface of the substrate, the first layer having an associated first ablation fluence value; and

a second layer disposed on a surface of the first layer opposite the substrate, the second layer having an associated second ablation fluence value that is less than the first ablation fluence value;

ablating the second layer using a laser emitting energy having a fluence value that is greater than or equal to the second ablation fluence value and less than the first ablation fluence value;

removing at least a portion of the first layer exposed after ablating the second layer; and

removing at least a portion of the second layer after removing the portion of the first layer.

2. The method of claim 1, wherein removing the portion of the first layer exposed after ablating the second layer comprises etching the portion of the first layer.

3. The method of claim 1, wherein removing the portion of the second layer after removing the portion of the first layer comprises ablating the portion of the second layer.

4. The method of claim 1, wherein removing the portion of the second layer after removing the portion of the first layer comprises etching the portion of the second layer.

5. The method of claim 1, wherein the substrate below the portion of the first layer is exposed after removing the portion of the first layer.

6. A method comprising:

depositing a first layer onto a substrate, the first layer having an associated first ablation fluence value;

depositing a second layer on the first layer, the second layer having an associated second ablation fluence value that is less than the first ablation fluence value;

patterning the second layer using a laser emitting energy having a fluence value greater than or equal to the second ablation fluence value and less than the first ablation fluence value;

removing at least a portion of the first layer exposed after patterning the second layer; and

removing at least a portion of the second layer after removing the portion of the first layer.

7. The method of claim 6, wherein removing the portion of the second layer comprises etching the portion of the second layer using an etchant configured to etch the second layer without etching the first layer and the substrate.

8. The method of claim 6, wherein removing the portion of the second layer comprises ablating the portion of the second layer using the laser emitting energy having the fluence value that is greater than or equal to the second ablation fluence value and less than the first ablation fluence value.

9. The method of claim 6, wherein the first layer comprises indium tin oxide and the second layer comprises Ti, and wherein the fluence value of the energy emitted by the laser used to pattern the second layer is between 20-300 mJ/cm².

10. The method of claim 6, wherein patterning the second layer comprises ablating the second layer to form:

a plurality of rows; and

a plurality of strips along edges of the substrate that are connected to the plurality of rows.

11. A method comprising:

providing a touch sensor structure comprising;

a substrate;

a first layer disposed on a surface of the substrate, the first layer having an associated first ablation fluence value; and

a second layer disposed on a surface of the first layer opposite the substrate, the second layer having an associated second ablation fluence value that is less than the first ablation fluence value;

ablating the second layer using a laser emitting energy having a fluence value that is greater than or equal to the second ablation fluence value and less than the first ablation fluence value; and

removing at least a portion of the first layer exposed after ablating the second layer.

12. The method of claim 11 further comprising removing at least a portion of the second layer after removing the portion of the first layer.

13. The method of claim 11, wherein the substrate further comprises:

a third layer disposed on a surface of the substrate opposite the first layer, the third layer having an associated third ablation fluence value; and

a fourth layer disposed on a surface of the third layer opposite the substrate, the further layer having an associated fourth ablation fluence value that is less than the third ablation fluence value.

14. The method of claim 13 further comprising:

ablating the fourth layer using a laser emitting energy having a fluence value that is greater than or equal to the fourth ablation fluence value and less than the third ablation fluence value; and

removing at least a portion of the third layer exposed after ablating the fourth layer.

15. The method of claim 14 further comprising removing at least a portion of the fourth layer after removing the portion of the third layer.

16. A method comprising:

depositing a first layer onto a surface of a substrate, the first layer having an associated first ablation fluence value;

depositing a second layer on a surface of the first layer opposite the substrate, the second layer having an associated second ablation fluence value that is less than the first ablation fluence value;

patterning the second layer using a laser emitting energy having a fluence value greater than or equal to the second ablation fluence value and less than the first ablation fluence value; and

removing at least a portion of the first layer exposed after patterning the second layer.

17. The method of claim 16 further comprising removing at least a portion of the second layer after removing the portion of the first layer.

18. The method of claim 16 further comprising:

depositing a third layer onto a surface of the substrate opposite the first layer, the third layer having an associated third ablation fluence value;

depositing a fourth layer on a surface of the third layer opposite the substrate, the fourth layer having an associated fourth ablation fluence value that is less than the third ablation fluence value;

patterning the fourth layer using a laser emitting energy having a fluence value greater than or equal to the fourth ablation fluence value and less than the third ablation fluence value; and

removing at least a portion of the third layer exposed after patterning the fourth layer.

19. The method of claim 18 further comprising removing at least a portion of the fourth layer after removing the portion of the third layer.

20. The method of claim 18, wherein removing the portion of the fourth layer after removing the portion of the third layer comprises ablating the portion of the fourth layer.

21. The method of claim 18, wherein removing the portion of the fourth layer after removing the portion of the third layer comprises etching the portion of the fourth layer.

22. The method of claim 16, wherein patterning the second layer comprises patterning the second layer to form a plurality of columns, and wherein patterning the fourth layer comprises patterning the fourth layer to form a plurality of rows that are at least substantially perpendicular to the plurality of columns.

23. A touch sensitive device comprising:

a plurality of conductive traces formed by ablating a first layer according to a first fluence value so as to form a pattern for the plurality of conductive traces and etching a second layer to match the pattern, the etched second layer being the conductive traces.

24. The touch sensitive device of claim 23, wherein the first fluence value is greater than or equal to an ablation fluence value of the second layer and less than an ablation fluence value of the first layer.

25. The touch sensitive device of claim 23, wherein the second layer comprises indium tin oxide and the first layer comprises Ti, and wherein the first fluence value is between 20-300 mJ/cm².