Method of forming insulating layer and touchscreen manufactured using the same

Patent metadata

Field	Value
Publication number	US-9655250-B2
Application number	US-201414381498-A
Country	US
Kind code	B2
Filing date	Jun 3, 2014
Priority date	Jun 18, 2013
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

A method of forming an insulating layer and a touchscreen including the insulating layer formed using the same are provided. The method of forming an insulating layer insulating a conductive pattern of a touchscreen from a bridge electrode thereof includes heating a substrate provided with the conductive pattern formed on the substrate, sequentially forming a first pattern and a second pattern on the heated substrate using an insulating composition, and curing the first pattern and the second pattern. The first pattern includes a groove portion to prevent adjacent patterns from overlapping each other and the second pattern is formed in the groove portion of the first pattern.

First claim

The invention claimed is:

1. A method of forming an insulating layer insulating a conductive pattern of a touchscreen from a bridge electrode of the touchscreen, the method comprising:
heating a substrate provided with the conductive pattern formed on the substrate;
sequentially forming a first pattern and a second pattern on the heated substrate using an insulating composition; and
curing the first pattern and the second pattern,
wherein the first pattern includes a groove portion to prevent adjacent patterns from overlapping each other and the second pattern is formed in the groove portion of the first pattern.

2. The method of claim 1 , wherein the heating of the substrate is performed at a temperature of 40° C. to 80° C.

3. The method of claim 1 , wherein a pitch of the first pattern ranges from 200 μm to 400 μm.

4. The method of claim 1 , wherein a pitch of the second pattern is in a range of 0.5 to 1 times that of the first pattern.

5. The method of claim 1 , wherein the forming of the first pattern and the second pattern is performed using a scheme of ejecting droplets of the insulating composition through inkjet printing.

6. The method of claim 5 , wherein the first pattern and the second pattern formed using the ejected droplets have a dot shape or a linear shape.

7. The method of claim 6 , wherein when the first pattern has the dot shape, a size of dots of the first pattern is in a range of 0.8 to 1 times the pitch of the first pattern.

8. The method of claim 7 , wherein when the second pattern has the dot shape, a size of dots of the second pattern is in a range of 0.5 to 1 times the size of the dots of the first pattern.

9. The method of claim 6 , wherein when the first pattern has the linear shape, a line width of the first pattern is in a range of 0.8 to 1 times the pitch of the first pattern.

10. The method of claim 9 , wherein when the second pattern has the linear shape, a line width of the second pattern is in a range of 0.5 to 1 times the line width of the first pattern.

11. The method of claim 1 , wherein the conductive pattern is formed using a metal mesh.

12. The method of claim 1 , wherein the insulating composition comprises a novolac-type epoxy resin, a high boiling point solvent having a boiling point of 170° C. or higher, a low boiling point solvent having a boiling point ranging from 100° C. or higher to less than 170° C., and a curing agent.

13. The method of claim 12 , wherein the insulating composition comprises:
100 parts by weight of a novolac-type epoxy resin;
80 to 570 parts by weight of a solvent; and
1 to 10 parts by weight of a curing agent,
wherein a weight ratio of the high boiling point solvent to the low boiling point solvent is within a range of 85 to 99:1 to 15.

14. The method of claim 12 , wherein the novolac-type epoxy resin is a phenol novolac-type epoxy resin, a cresol novolac-type epoxy resin, or a bisphenol A (BPA)-novolac type epoxy resin.

15. The method of claim 12 , wherein the curing agent is an imidazole-based curing agent.

16. An insulating layer formed using the method of forming an insulating layer of claim 1 has a convex shape in a vertical cross section.

17. The insulating layer of claim 16 , wherein in the insulating layer, a difference in a thickness between a central portion of the vertical cross section and an edge portion
of the vertical cross section is within a range of 50 nm to 150 nm.

18. The insulating layer of claim 16 , wherein the thickness of the insulating layer is within a range of 100 nm to 2 μm.

19. A touchscreen including a substrate, a conductive pattern formed on the substrate, a bridge electrode formed on the conductive pattern, and an insulating layer interposed between the conductive pattern and the bridge electrode to insulate the conductive pattern from the bridge electrode, the touchscreen being characterized in that the insulating layer is formed using the method of forming an insulating layer of claim 1 and has a convex shape in a vertical cross section.

20. The touchscreen of claim 19 , wherein in the vertical cross section of the insulating layer, a difference in a thickness between a central portion and an edge portion of the vertical cross section is within a range of 50 nm to 150 nm.

21. The insulating layer of claim 19 , wherein the thickness of the insulating layer is in a range of 100 nm to 2 μm.

Assignees

• Lg Chemical Ltd

Inventors

• Yoo Jae-Hyun
• Kim Mi-Kyoung
• Kim Joon-Hyung

Classifications

• H05K3/0011 Primary

  Working of insulating substrates or insulating layers · CPC title

• H05K2201/10128

  Display · CPC title

• G06F2203/04111

  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 title

• H05K3/381

  by special treatment of the substrate · CPC title

• G06F2203/04103

  Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices · CPC title