Pad connection structure and touch sensor including the same

Patent metadata

Field	Value
Publication number	US-11249567-B2
Application number	US-201816204186-A
Country	US
Kind code	B2
Filing date	Nov 29, 2018
Priority date	Dec 12, 2017
Publication date	Feb 15, 2022
Grant date	Feb 15, 2022

Abstract

A pad connection structure includes a substrate, a lower insulation layer formed on a top surface of the substrate, a pad electrode disposed on the lower insulation layer, and an upper insulation layer including an opening through which a top surface of the pad electrode. A step height via the opening is reduced by the lower insulation layer so that connecting reliability with a conductive connection structure is improved.

First claim

What is claimed is:

1. A pad connection structure, comprising:
a substrate including a sensing region and a pad connection region;
a lower insulation layer formed only on a top surface of the pad connection region of the substrate and including a plurality of lower insulation patterns isolated from each other;
a pad electrode disposed on each of the lower insulation patterns and entirely covering each of the lower insulation patterns; and
an upper insulation layer partially covering a top surface of the pad electrode and including an opening through which a top surface of the pad electrode is exposed.

2. The pad connection structure according to claim 1 , wherein the lower insulation pattern includes a sidewall inclined by a predetermined acute angle with respect to the top surface of the substrate.

3. The pad connection structure according to claim 2 , wherein the pad electrode includes an inclined sidewall having a shape corresponding to that of the lower insulation pattern.

4. The pad connection structure according to claim 2 , wherein the upper insulation layer includes a protrusion at an overlapping region with the sidewall of the lower insulation pattern.

5. The pad connection structure according to claim 4 , wherein an upper periphery of the opening is defined by the protrusion.

6. The pad connection structure according to claim 1 , further comprising a conductive connection structure electrically connected to the pad electrode via the opening.

7. The pad connection structure according to claim 6 , wherein the conductive connection structure includes an anisotropic conductive film contacting the pad electrode via the opening.

8. The pad connection structure according to claim 7 , wherein the conductive connection structure further includes a flexible printed circuit board adhered to the anisotropic conductive film.

9. The pad connection structure according to claim 1 , wherein the upper insulation layer partially overlaps the lower insulation layer, and
a step height between top surfaces of the upper insulation layer and the pad electrode is 50% or less of a height of the upper insulation layer.

10. A touch sensor, comprising:
a substrate including a sensing region and a pad connection region;
sensing electrodes arranged on the sensing region of the substrate;
a pad connection structure disposed on the pad connection region of the substrate, wherein the pad connection structure includes:
a lower insulation layer formed only on a top surface of the pad connection region of the substrate and including a plurality of lower insulation patterns isolated from each other;
a pad electrode disposed on each of the lower insulation patterns and entirely covering each of the lower insulation patterns; and
an upper insulation layer partially covering a top surface of the pad electrode and including an opening through which a top surface of the pad electrode is exposed; and
traces connecting the sensing electrodes to the pad electrode of the pad connection structure.

11. The touch sensor according to claim 10 , wherein the sensing electrodes include first sensing electrodes and second sensing electrodes which are arranged along two directions crossing each other.

12. The touch sensor according to claim 11 , further comprising:
an insulation layer at least partially covering the first sensing electrodes; and
a bridge electrode disposed on the insulation layer to connect the second sensing electrodes neighboring each other.

13. The touch sensor according to claim 12 , wherein the lower insulation layer includes the same material as that of the insulation layer, and
the pad electrode includes the same material as that of the sensing electrodes or the bridge electrode.

14. The touch sensor according to claim 10 , wherein the upper insulation layer covers the sensing electrodes on the sensing region.

Assignees

• Dongwoo Fine Chem Co Ltd

Inventors

• Yoon Ju In
• Lee Jae Hyun
• Kim Keon

Classifications

• G06F3/0446

  using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes · CPC title

• G06F3/03547 Primary

  Touch pads, in which fingers can move on a surface · 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

• G06F3/04164 Primary

  Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads · CPC title

• G06F3/0412

  Digitisers structurally integrated in a display · CPC title