US20150205413A1

US20150205413A1 - Touch panel and method for manufacturing a touch sensor layer of the touch panel

Info

Publication number: US20150205413A1
Application number: US14/673,610
Authority: US
Inventors: Guang-Yi Zeng; Liang-hao Kang; Yi-Cheng Tsai
Original assignee: Chunghwa Picture Tubes Ltd
Current assignee: Chunghwa Picture Tubes Ltd
Priority date: 2012-03-30
Filing date: 2015-03-30
Publication date: 2015-07-23
Also published as: US20130256008A1; US9018535B2; TW201340181A

Abstract

A touch panel includes a touch sensor layer including a first transparent electrode and a second transparent electrode, wherein an arrangement direction of the first transparent electrode can be perpendicular to that of the second transparent electrode, and both of the first and second transparent electrodes include two transparent metallic patterns which are stacked and electrically connected to each other.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Divisional of co-pending U.S. application Ser. No. 13/612,478 filed on Sep. 12, 2012, for which priority is claimed under 35 U.S.C. §120, and this application claims priority of Application No. 101111279 filed in Taiwan, R.O.C. on Mar. 30, 2012, under 35 U.S.C. §119, the entire contents of all of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of Invention
This invention relates to a touch panel and a method for manufacturing a touch sensor layer of the touch panel, and more particularly to a touch panel and a method for manufacturing a touch sensor layer of the touch panel, wherein transparent electrodes of the touch sensor layer include two transparent metallic patterns which are stacked and electrically connected to each other.
2. Related Art
Recently, the technology of a touch panel is developed quickly. For example, resistance type touch panel, capacitance type touch panel, sound wave type touch panel and optics type touch panel have been widely applied to communication products, computer devices and consumptive electronic products so as to further increase the efficiency and convenience of the applied electronic product.
Referring FIG. 1, it depicts a conventional touch panel 10 includes a touch sensor layer 12 constituted by transparently conductive wires which are disposed longitudinally and transversely, crossed and separated from each other. The touch panel detects an inference of an electric field of the transparently conductive wires generated by a finger, and then reads a sensing signal generated from the longitudinally and transversely transparently conductive wires so as to determine a touch position.
Since transparently conductive materials of transparently conductive wires of the current touch panel are amorphous indium tin oxide (ITO), the patterned ITO is formed by the etching of an oxalic acid during a patterning process (e.g. photolithography and etching process). If the film thickness of the ITO is too thick, the ITO possibly becomes a poly-ITO during a film forming process (e.g. sputtering process). When the poly-ITO is etched by the oxalic acid, some ITO can be still staying. The stayed ITO must be etched by an aqua regia (e.g. nitric acid plus hydrochloric acid). The ITO is restricted by the patterning process, and thus the film thickness of the ITO cannot be too thick.
FIG. 2 is a cross-sectional schematic view of transparent electrodes (X and Y wires along X and Y arrangement directions) of a conventional touch sensor layer. A metal connecting wire 20 is disposed on a transparent substrate 22. An insulating layer 24 is disposed on the metal connecting wire 20 and the transparent substrate 22, and exposes a part of the metal connecting wire 20. A transparent electrode 26 along X arrangement direction and a transparent electrode 28 along Y arrangement direction are disposed on the insulating layer 24, and the transparent electrode 26 along X arrangement direction is electrically connected to the exposed part of the metal connecting wire 20. A protective layer 30 covers an exposed part of the insulating layer 24, the transparent electrode 26 along X arrangement direction and the transparent electrode 28 along Y arrangement direction. However, the transparent electrode 26 along X arrangement direction and the transparent electrode 28 along Y arrangement direction are restricted by the fact that the film thickness of the ITO cannot be too thick, and thus the transparent electrode of the touch sensor layer along X and Y arrangement directions have higher resistance.
Accordingly, there exists a need for a touch panel capable of solving the above-mentioned problems.

SUMMARY OF THE INVENTION

The present invention provides a touch panel including a touch sensor layer. The touch sensor layer includes a first transparent electrode and a second transparent electrode. The first transparent electrode includes a first transparent metallic pattern and a second transparent metallic pattern, wherein the second transparent metallic pattern is stacked and electrically connected to the first transparent metallic pattern. The second transparent electrode includes a third transparent metallic pattern and a fourth transparent metallic pattern, wherein the fourth transparent metallic pattern is stacked and electrically connected to the third transparent metallic pattern. The first transparent metallic pattern and the third transparent metallic pattern are made of the same material in the same manufacturing process, and the second transparent metallic pattern and the fourth transparent metallic pattern are made of the same material in the same manufacturing process.
The present invention utilizes the structure of two layers of transparent metallic pattern to solve the problem that the film thickness of the amorphous ITO of the conventional touch panel cannot be too thick. Furthermore, the structure of two layers of transparent metallic patterns of the present invention can decrease the resistance of the whole transparent electrode. In addition, the present invention utilizes the film thickness of transparent metallic patterns to adjust the color shift of the touch panel.
In order to make the aforementioned and other objectives, features and advantages of the present invention comprehensible, embodiments are described in detail below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan schematic view of a conventional touch sensor layer;

FIG. 2 is a cross-sectional schematic view of a conventional touch sensor layer;

FIG. 3 is a plan schematic view of a touch sensor layer of a touch panel according to the first embodiment of the present invention, wherein a protective layer is omitted and is not shown;

FIG. 4 is a cross-sectional schematic view of a touch sensor layer of a touch panel according to the first embodiment of the present invention, showing a section along sectional line B-B′ of FIG. 3;

FIG. 5 is a cross-sectional schematic view of a touch sensor layer of a touch panel according to the first embodiment of the present invention, showing a section along sectional line C-C′ of FIG. 3;

FIG. 6 a is a plan schematic view of the first and third transparent metallic patterns according to the first embodiment of the present invention;

FIG. 6 b is a plan schematic view of the second and fourth transparent metallic patterns according to the first embodiment of the present invention;

FIG. 7 is flow diagram of a method for manufacturing a touch sensor layer of a touch panel according to an embodiment of the present invention;

FIG. 8 is a plan schematic view of the second and fourth transparent metallic patterns according to another embodiment of the present invention;

FIG. 9 is a cross-sectional schematic view of a touch sensor layer of a touch panel according to another embodiment of the present invention, showing a section along sectional line D-D′ of FIG. 8;

FIG. 10 is a cross-sectional schematic view of a touch sensor layer of a touch panel according to another embodiment of the present invention, showing a section along sectional line E-E′ of FIG. 8;

FIG. 11 is a plan schematic view of a touch sensor layer of a touch panel according to the second embodiment of the present invention, wherein a protective layer is omitted and is not shown;

FIG. 12 is a cross-sectional schematic view of a touch sensor layer of a touch panel according to the second embodiment of the present invention, showing a section along sectional line F-F′ of FIG. 11;

FIG. 13 is a cross-sectional schematic view of a touch sensor layer of a touch panel according to the second embodiment of the present invention, showing a section along sectional line G-G′ of FIG. 11;

FIG. 14 a is a plan schematic view of the first and third transparent metallic patterns according to the second embodiment of the present invention;

FIG. 14 b is a plan schematic view of the second and fourth transparent metallic patterns according to the second embodiment of the present invention;

FIG. 15 is a plan schematic view of the second and fourth transparent metallic patterns according to another embodiment of the present invention;

FIG. 16 is a cross-sectional schematic view of a touch sensor layer of a touch panel according to another embodiment of the present invention, showing a section along sectional line H-H′ of FIG. 15;

FIG. 17 is a cross-sectional schematic view of a touch sensor layer of a touch panel according to another embodiment of the present invention, showing a section along sectional line I-I′ of FIG. 15;

FIG. 18 is a plan schematic view of a touch sensor layer of a touch panel according to the third embodiment of the present invention, wherein a protective layer is omitted and is not shown;

FIG. 19 is a cross-sectional schematic view of a touch sensor layer of a touch panel according to the third embodiment of the present invention, showing a section along sectional line J-J′ of FIG. 18;

FIG. 20 is a cross-sectional schematic view of a touch sensor layer of a touch panel according to the third embodiment of the present invention, showing a section along sectional line K-K′ of FIG. 18;

FIG. 21 is a cross-sectional schematic view of a touch sensor layer of a touch panel according to the fourth embodiment of the present invention; and

FIGS. 22 and 23 are across-sectional schematic views of a touch sensor layer of a touch panel according to another embodiment of the present invention.

The present invention will become more fully understood from the detailed description given herein below for illustration only, and thus are not limitative of the present invention, and wherein:

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 3, 4, 5, 6 a and 6 b, they depict a touch sensor layer 112 of a touch panel according to the first embodiment of the present invention. Referring to FIGS. 3, 4 and 5, the touch sensor layer 112 is constituted by transparently conductive wires which are interlaced longitudinally and transversely and separated from each other. The touch sensor layer 112 can disposed above a liquid crystal display module (not shown). The touch panel detects an inference of an electric field of the transparently conductive wires generated by a finger, and then reads a sensing signal generated from the longitudinal and transverse coordinates so as to determine a touch position.
The touch sensor layer 112 includes a first transparent electrode 128 (i.e., transparent electrode along Y arrangement direction) and a second transparent electrode 126 (i.e., transparent electrode along X arrangement direction), wherein the arrangement direction of the first transparent electrode 128 can be perpendicular to that of the second transparent electrode 126, and both of the first and second transparent electrodes 128, 126 include two transparent metallic patterns which are stacked and electrically connected to each other. The transparent metallic pattern is made of material being indium tin oxide (ITO) or indium zinc oxide (IZO). Generally, the transparent metallic pattern is formed by a film forming process and a patterning process.
After the second transparent metallic pattern 128 b and the fourth transparent metallic pattern 126 b shown in FIG. 6 b are stacked to the first transparent metallic pattern 128 a and the third transparent metallic pattern 126 a shown in FIG. 6 a, the first and second transparent electrodes 128, 126 shown in FIG. 3 are formed accordingly. In other words, the first transparent electrode 128 includes a first transparent metallic pattern 128 a (e.g., transparent metallic pattern along Y arrangement direction) and a second transparent metallic pattern 128 b (e.g., floating transparent metallic pattern along Y arrangement direction), and the second transparent metallic pattern 128 b is stacked and electrically connected to the first transparent metallic pattern 128 a. The second transparent electrode 126 includes a third transparent metallic pattern 126 a (e.g., transparent metallic pattern along X arrangement direction) and a fourth transparent metallic pattern 126 b (e.g., floating transparent metallic pattern along X arrangement direction), and the fourth transparent metallic pattern 126 b is stacked and electrically connected to the third transparent metallic pattern 126 a. The first transparent metallic pattern 128 a and the third transparent metallic pattern 126 a are made of the same material in the same manufacturing process, and the second transparent metallic pattern 128 b and the fourth transparent metallic pattern 126 b are made of the same material in the same manufacturing process.
Referring FIGS. 6 a and 6 b again, the first transparent metallic pattern 128 a includes a left portion 140, a crossing portion 142 and a right portion 144, and the crossing portion 142 is physically connected to the left portion 140 and the right portion 144. Also, the fourth transparent metallic pattern 126 b includes a front portion 150, a crossing portion 152 and a rear portion 154, and the crossing portion 152 is physically connected to the front portion 150 and the rear portion 154.
Referring FIGS. 4 and 5 again, the first transparent metallic pattern 128 a and the third transparent metallic pattern 126 a are formed on a transparent substrate 122 respectively. An insulating layer 124 (which is island-shaped) is formed on the transparent substrate 122, whereby the crossing portion 142 of the first transparent metallic pattern 128 a is electrically isolated from the crossing portion 152 of the fourth transparent metallic pattern 126 b, and further the first transparent electrode 128 is electrically isolated from the second transparent electrode 126. A protective layer 130 covers the first transparent electrode 128, the second transparent electrode 126 and the insulating layer 124.
Referring to FIG. 7, it depicts a method for manufacturing a touch sensor layer 112 of the touch panel of the present invention. In step S900, a first transparent metallic pattern 128 a and a third transparent metallic pattern 126 a are formed on a transparent substrate 122 respectively. In step S902, an insulating layer 124 is formed on the transparent substrate 122 and covers a part of the first transparent metallic pattern 128 a (e.g., the crossing portion 142 of the first transparent metallic pattern 128 a). In step S904, a second transparent metallic pattern 128 b is stacked and electrically connected to the first transparent metallic pattern 128 a so as to form a first transparent electrode 128; and simultaneously a fourth transparent metallic pattern 126 b is stacked and electrically connected to the third transparent metallic pattern 126 a so as to form a second transparent electrode 126, wherein a part of the fourth transparent metallic pattern 126 b (e.g., the crossing portion 152 of the fourth transparent metallic pattern 126 b) covers the insulating layer 124, and the arrangement direction of the first transparent electrode 128 can be perpendicular to that of the second transparent electrode 126. In step S906, the first and second transparent electrodes 128, 126 and the insulating layer 124 are covered by a protective layer 130, thereby finishing the touch sensor layer 112, shown in FIGS. 3, 4, 5, 6 a and 6 b.
More detailed, the metal conductive wire, the first transparent electrode, the insulating layer, the second transparent electrode and the protective layer are five processes in this embodiment, and two photo masks of transparent electrodes in the five processes are used, i.e., the first transparent electrode 128 and the second transparent electrode 126 are designed in different photo masks of transparent electrodes respectively. When the first transparent metallic pattern 128 a of the first transparent electrode 128 is designed, the third transparent metallic pattern 126 a of the second transparent electrode 126 is designed simultaneously; and when the fourth transparent metallic pattern 126 b of the second transparent electrode 126 is designed, the second transparent metallic pattern 128 b of the first transparent electrode 128 is designed simultaneously. Thus, the first transparent metallic pattern 128 a in the second process can be electrically connected to the second transparent metallic pattern 128 b in the fourth process, and the third transparent metallic pattern 126 a in the second process can be electrically connected to the fourth transparent metallic pattern 126 b in the fourth process. The island-shaped insulating layer 124 is located between the first and second transparent electrodes 128, 126, and thus the first and second transparent electrodes 128, 126 are not electrically connected to each other.
FIG. 8 is a plan view of the second transparent metallic pattern 128 b and the fourth transparent metallic pattern 126 b according to another embodiment of the present invention. Referring to FIGS. 8 to 10, in another embodiment, an insulating layer 124 of a touch sensor layer 112 covers the whole first transparent metallic pattern 128 a. The insulating layer 124 includes a plurality of first plated through holes 124 a and second plated through holes 124 b, the first plated through holes 124 a are adapted to electrically connect the second transparent metallic pattern 128 b to the first transparent metallic pattern 128 a, and the second plated through holes 124 b are adapted to electrically connect the fourth transparent metallic pattern 126 b to the third transparent metallic pattern 126 a.
Referring to FIGS. 11, 12, 13, 14 a and 14 b, they depict a touch sensor layer 212 of a touch panel according to the second embodiment of the present invention. The touch sensor layer 212 in the second embodiment is substantially similar to the touch sensor layer 112 in the first embodiment, wherein the similar elements are designated with the same reference numerals. Referring to FIGS. 11, 12, 13, the difference between the touch sensor layers of the touch panels in the second and first embodiments is that: a metal connecting wire 220 is formed on the transparent substrate 222, wherein the first transparent metallic pattern 228 a includes a left portion 240 and a right portion 244, and the metal connecting wire 220 is physically connected to the left portion 240 and the right portion 244 of the first transparent metallic pattern 228 a (shown in FIG. 12). The metal connecting wire 220 can be made of non-transparent material.
Similarly, after the second transparent metallic pattern 228 b and the fourth transparent metallic pattern 226 b shown in FIG. 14 a are stacked to the first transparent metallic pattern 228 a and the third transparent metallic pattern 226 a shown in FIG. 14 a, the first and second transparent electrodes 228, 226 shown in FIG. 11 are formed accordingly. In other words, the first transparent electrode 228 includes a first transparent metallic pattern 228 a (e.g., transparent metallic pattern along Y arrangement direction) and a second transparent metallic pattern 228 b (e.g., floating transparent metallic pattern along Y arrangement direction), and the second transparent metallic pattern 228 b is stacked and electrically connected to the first transparent metallic pattern 228 a. The second transparent electrode 226 includes a third transparent metallic pattern 226 a (e.g., transparent metallic pattern along X arrangement direction) and a fourth transparent metallic pattern 226 b (e.g., floating transparent metallic pattern along X arrangement direction), and the fourth transparent metallic pattern 226 b is stacked and electrically connected to the third transparent metallic pattern 226 a. The first transparent metallic pattern 228 a and the third transparent metallic pattern 226 a are made of the same material in the same manufacturing process, and the second transparent metallic pattern 228 b and the fourth transparent metallic pattern 226 b are made of the same material in the same manufacturing process.
Referring FIGS. 14 a and 14 b again, the third transparent metallic pattern 226 a includes a front portion 260, a crossing portion 262 and a rear portion 264, and the crossing portion 262 is physically connected to the front portion 260 and the rear portion 264. Also, the fourth transparent metallic pattern 226 b includes a front portion 250, a crossing portion 252 and a rear portion 254, and the crossing portion 252 is physically connected to the front portion 250 and the rear portion 254.
Referring FIGS. 12 and 13 again, the first transparent metallic pattern 228 a and the third transparent metallic pattern 226 a are formed on a transparent substrate 222 respectively. An insulating layer 224 (which is island-shaped) is formed on the transparent substrate 222, whereby the metal connecting wire 220 is electrically isolated from the crossing portion 262 of the third transparent metallic pattern 226 a, and further the first transparent electrode 228 is electrically isolated from the second transparent electrode 226. A protective layer 230 covers the first transparent electrode 228, the second transparent electrode 226 and the insulating layer 224.
FIG. 15 is a plan view of the second transparent metallic pattern 228 b and the fourth transparent metallic pattern 226 b according to another embodiment of the present invention. Referring to FIGS. 15 to 17, in another embodiment, an insulating layer 224 of a touch sensor layer 212 covers the whole metal connecting wire 220. The insulating layer 224 includes a plurality of plated through holes 224 a, and the plated through holes 224 a is adapted to electrically connect the first transparent metallic pattern 228 a to electrically connect to the metal connecting wire 220.
Referring to FIGS. 18 to 20, they depict a touch sensor layer 312 of a touch panel according to the third embodiment of the present invention. The touch sensor layer 312 in the third embodiment is substantially similar to the touch sensor layer 112 in the first embodiment, wherein the similar elements are designated with the same reference numerals. The first transparent metallic pattern 328 a and the third transparent metallic pattern 326 a are formed on a transparent substrate 322 respectively. An insulating layer 324 (which is island-shaped) is formed on the transparent substrate 322, whereby the first transparent electrode 328 is electrically isolated from the second transparent electrode 326. A protective layer 330 covers the first transparent electrode 328, the second transparent electrode 326 and the insulating layer 324.
The difference between the touch panels in the third and first embodiments is that: the touch sensor layer 312 further includes a metal conductive wire 314, wherein the metal conductive wire 314 and the first transparent metallic pattern 328 a are made of different material by the same gray-level photo mask, and simultaneously the metal conductive wire 314 and the third transparent metallic pattern 326 a are made of different material by the same gray-level photo mask. The metal conductive wire 314 can be made of non-transparent material. In this embodiment, the metal conductive wire 314 can be located in a non-display area 316, and the first transparent metallic pattern 328 a and the third transparent metallic pattern 326 a can be located in a display area 318.
More detailed, in this embodiment, a transparent metal layer is firstly formed, and a metal layer is formed. Then, a first transparent metallic pattern 328 a, a third transparent metallic pattern 326 a and a metal conductive wire 314 are manufactured by a gray-level photo mask. Then, an island-shaped insulating layer 324 is manufactured so as to prevent the first transparent electrode 328 from electrically connecting to the second transparent electrode 326. Finally, a second transparent metallic pattern 328 b and a fourth transparent metallic pattern 326 b are manufactured, wherein the second transparent metallic pattern 328 b can be physically connected to the first transparent metallic pattern 328 a, and the fourth transparent metallic pattern 326 b can be physically connected to the third transparent metallic pattern 326 a.
Referring to FIGS. 21 to 23, they depict a touch sensor layer 412 of a touch panel according to the third embodiment of the present invention. The touch sensor layer 412 further includes a metal conductive wire 414, a fifth transparent metallic pattern 428 and a sixth transparent metallic pattern 426. The metal conductive wire 414 can be located in a non-display area. In this embodiment, the fifth transparent metallic pattern 428 and the sixth transparent metallic pattern 426 are stacked to different sides of the metal conductive wire 414 respectively, thereby decreasing the resistance of the metal conductive wire 414. For example, the fifth transparent metallic pattern 428, the metal conductive wire 414, the sixth transparent metallic pattern 426 and the protective layer 430 are disposed on the transparent substrate 422 in order, shown in FIG. 21. In another embodiment, the fifth transparent metallic pattern 428 and the sixth transparent metallic pattern 426 are stacked to the same side of the metal conductive wire 414 in order, thereby decreasing the resistance of the metal conductive wire 414. For example, the sixth transparent metallic pattern 426, the fifth transparent metallic pattern 428, the metal conductive wire 414, and the protective layer 430 are disposed on the transparent substrate 422 in order, shown in FIG. 22; or, the metal conductive wire 414, the fifth transparent metallic pattern 428, the sixth transparent metallic pattern 426, and the protective layer 430 are disposed on the transparent substrate 422 in order, shown in FIG. 23. The fifth transparent metallic pattern 428 in the fourth embodiment and the first transparent metallic pattern 128 a and the third transparent metallic pattern 126 a in the first embodiment can be made of the same material in the same manufacturing process; and the sixth transparent metallic pattern 426 in the fourth embodiment and the second transparent metallic pattern 128 b and the fourth transparent metallic pattern 126 b in the first embodiment can be made of the same material in the same manufacturing process.
The present invention utilizes the structure of two layers of transparent metallic pattern to solve the problem that the film thickness of the amorphous ITO of the conventional touch panel cannot be too thick. Furthermore, the structure of two layers of transparent metallic patterns of the present invention can decrease the resistance of the whole transparent electrode. In addition, the present invention utilizes the film thickness of transparent metallic patterns to adjust the color shift of the touch panel.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Claims

1. A method for manufacturing a touch sensor layer of a touch panel comprising the following steps of:

respectively forming a first transparent metallic pattern and a third transparent metallic pattern on a transparent substrate;

forming an insulating layer on the transparent substrate and covering a part of the first transparent metallic pattern;

stacking and electrically connecting a second transparent metallic pattern to the first transparent metallic pattern so as to form a first transparent electrode, and simultaneously stacking and electrically connecting a fourth transparent metallic pattern to the third transparent metallic pattern so as to form a second transparent electrode, wherein a part of the fourth transparent metallic pattern covers the insulating layer; and

covering the first and second transparent electrodes and the insulating layer by a protective layer, thereby finishing the touch sensor layer.