Reliability metal traces

• US 8,970,504 B2
• Filed: 04/25/2008
• Issued: 03/03/2015
• Est. Priority Date: 04/25/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Huang, Lili, Zhong, John Z., Hotelling, Steve Porter
• Primary Examiner(s): Leiby, Christopher E
• Application Number:
  US12/110,117
• Publication Number:
  US 20090266621A1
• Time in Patent Office: 2,503 Days
• Field of Search: 345173-178, 216/13
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• 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

Abstract

The formation of improved reliability conductive traces in touch sensor panels that are less prone to failures due to environmental effects is disclosed. Conductive traces, which can be formed from a stackup of metal layers or a single metal layer, can be protected with an additional photoimageable passivation layer of a material such as an organic polymer. This photoimageable coating can be patterned so that it does not appear in the visible area of the touch sensor panel, with much finer tolerances than conventional passivation layers to help keep product dimensions to a minimum.

Claims

1. A touch sensor panel including a viewing area and improved reliability conductive traces for carrying signals on a touch sensor panel, comprising:

a first layer of Molybdenum Niobium (Mo/Nb) formed on a substrate;

a second layer of Aluminum Neodymium (Al/Nd) formed on the first layer, the first layer for adhering the second layer to the substrate;

a third layer of the Molybdenum Niobium (Mo/Nb) formed on the second layer, the third layer for protecting the second layer; and

an organic polymer photoimageable passivation layer formed on the third layer without overlapping with the viewing area;

wherein the first, second and third layers are patterned to form the conductive traces and fully sealed over the substrate by only the organic polymer photoimageable passivation layer.

2. The improved reliability conductive traces of claim 1, further comprising a first passivation layer formed between the third layer and the organic polymer photoimageable passivation layer.

3. The improved reliability conductive traces of claim 2, the first passivation layer comprising silicon dioxide (SiO₂).

4. The improved reliability conductive traces of claim 1, the first, second and third layers patterned using photolithographic techniques having tolerances of less than +/−

10 microns to minimize an overall size of the touch sensor panel.

5. The improved reliability conductive traces of claim 1, the improved reliability conductive traces formed within a touch sensor panel.

6. The improved reliability conductive trace of claim 5, the touch sensor panel incorporated within a computing system.

7. A touch sensor panel including a viewing area and improved reliability conductive traces for carrying signals on a touch sensor panel, comprising:

a Molybdenum Niobium (Mo/Nb) layer patterned on a substrate to form the conductive traces with controlled wall angles; and

an organic polymer photoimageable passivation layer formed over the conductive traces without overlapping with the viewing area,

wherein the Mo/Nb layer is fully sealed over the substrate by only the organic polymer photoimageable passivation layer.

8. The improved reliability conductive traces of claim 7, further comprising a first passivation layer formed between the Mo/Nb layer and the organic photoimageable passivation layer.

9. The improved reliability conductive traces of claim 8, further comprising a conductive layer formed between the Mo/Nb layer and the first passivation layer.

10. The improved reliability conductive traces of claim 9, the conductive layer comprising Indium Tin Oxide (ITO).

11. The improved reliability conductive traces of claim 8, the first passivation layer comprising silicon dioxide (SiO₂).

12. The improved reliability conductive traces of claim 7, the organic photoimageable passivation layer patterned using photolithographic techniques having tolerances of less than +/−

10 microns to minimize an overall size of the touch sensor panel.

13. The improved reliability conductive traces of claim 7, the improved reliability conductive traces formed within a touch sensor panel.

14. The improved reliability conductive traces of claim 13, the touch sensor panel incorporated within a computing system.

15. A touch sensor panel including a viewing area and improved reliability conductive traces for carrying signals on a touch sensor panel, comprising:

a first layer of Molybdenum Niobium (Mo/Nb) formed on a substrate;

a second layer of a second conductive material formed on the first layer, the first and second layers configured as transparent conductive electrodes and border electrical connections; and

an organic polymer photoimageable passivation layer formed over the first and second layers without overlapping with the viewing area,

wherein the first and second layers are fully sealed over the substrate by only the organic polymer photoimageable passivation layer.

16. The improved reliability conductive traces of claim 15, the second layer formed from Indium Tin Oxide (ITO).

17. The improved reliability conductive traces of claim 15, further comprising a first passivation layer formed between the second layer and the organic photoimageable passivation layer.

18. The improved reliability conductive traces of claim 17, the first passivation layer comprising silicon dioxide (SiO₂).

19. The improved reliability conductive traces of claim 15, the organic photoimageable passivation layer patterned using photolithographic techniques having tolerances of less than +/−

10 microns to minimize an overall size of the touch sensor panel.

20. A mobile telephone including a touch sensor panel including a viewing area and containing a plurality of improved reliability conductive traces, the improved reliability conductive traces comprising:

a first layer of Molybdenum Niobium (Mo/Nb) formed on a substrate;

a second layer of Aluminum Neodymium (Al/Nd) formed on the first layer, the first layer for adhering the second layer to the substrate;

a third layer of Molybdenum Niobium (Mo/Nb) formed on the second layer, the third layer for protecting the second layer; and

an organic polymer photoimageable passivation layer formed on the third layer without overlapping with the viewing area;

wherein the first, second and third layers are patterned to form the conductive traces and fully sealed over the substrate by only the organic polymer photoimageable passivation layer.

21. A digital media player including a touch sensor panel including a viewing area and containing a plurality of improved reliability conductive traces, the improved reliability conductive traces comprising:

a Molybdenum Niobium (Mo/Nb) layer with a thickness of between 3000-5000 angstroms formed and patterned on a substrate to form the conductive traces with controlled wall angles; and

an organic polymer photoimageable passivation layer with a thickness of at least 2.0 microns formed over the conductive traces without overlapping with the viewing area,

wherein the Mo/Nb layer is fully sealed over the substrate by only the organic polymer photoimageable passivation layer.