CN106339132A - Touch panel - Google Patents

Abstract

The present invention relates to a touch panel, including a substrate, a touch sensing layer formed on the substrate, and an electrostatic protection ring. The touch panel also includes: the electrostatic protection ring also includes an extension; a spare connection pad, the spare connection pad stacked on the extension part, and the spare connection pad is grounded through the static protection ring and the extension part. In the present invention, by changing the structure of the static protection ring, the spare connection pad is electrically connected to the extension of the static protection ring and grounded, which effectively prevents the static charge accumulated on the spare connection pad from being attracted and conducted to the touch area, causing damage to the touch electrodes and traces.

Description

touch panel

technical field

The invention belongs to touch display technology, in particular to a touch panel.

Background technique

With the wide application of smart phones, tablet computers and other electronic products and the development of touch display technology, it has become a popular trend in current electronic products to apply touch display screens to smart phones, tablet computers and other electronic products to realize human-computer interaction. trend of development.

One of the currently existing capacitive touch screens includes an insulator such as glass coated with a transparent conductor (such as a sensing electrode made of indium tin oxide (ITO)), and a sensing electrode. electrically connected touch sensor integrated circuit (IC). Since the human body is also a conductor, touching the surface of the screen will cause a change in the electric field of the screen and a change in the capacitance on the sensing electrodes. This capacitance variation can be converted into a sensing signal. Then, the touch sensor IC can receive the sensing signal and mark the location of the touch. However, electrostatic charge (ESD) is often generated due to friction or other factors during the process or use of the capacitive touch panel, and excessive electrostatic charge may cause damage to the touch sensing unit, thereby reducing the Yield and reliability of capacitive touch panels.

FIG. 1 is a schematic diagram of a conventional capacitive touch panel. As shown in FIG. 1 , the touch panel 10 includes a substrate 11 on which a sensing electrode layer 12 is arranged. The sensing electrode layer 12 includes a plurality of horizontally arranged first sensing electrodes 12a, a plurality of vertically arranged second sensing electrodes 12a, and a plurality of vertically arranged second sensing electrodes. The sensing electrodes 12b and the bridging layer 12c, the bridging layer 12c is, for example, ITO, and the bridging layer 12c can be used for bridging between a plurality of first sensing electrodes 12a, or bridging between a plurality of second sensing electrodes 12b. The first sensing electrodes 12 a and the second sensing electrodes 12 b are, for example, metal wires or ITO.

Continuing to refer to FIG. 1, the substrate 11 is provided with an electrostatic protection ring 13 on the periphery of the plurality of first sensing electrodes 12a and the plurality of second sensing electrodes 12b. The electrostatic protection ring 13 preferably forms a closed ring, and is used to The static electricity accumulated on the substrate 11 is grounded to prevent the sensing electrodes from being damaged by static electricity.

The edge of the substrate 11 is also provided with a connection pad 14, the connection pad 14 is used to bond with the gold finger of the FPC ((FlexiblePrintedCircuit), so that the electrical conduction between the substrate 11 and the FPC. The other end of the FPC needs to be bonded with the connector of the display module, and in order to adapt to different types of display modules, a spare connection pad 15 will also be provided on the substrate 11 .

FIG. 2 is a schematic cross-sectional view along the dotted line a of the spare connection pad 15 in FIG. 1 . As shown in Figure 1 and Figure 2, the spare connection pad 15 is arranged on the outside of the electrostatic protection ring 13, the spare connection pad 15 includes a first insulating layer 16 formed on the substrate 11, a conductive layer 17 and a second insulating layer 18, the second An insulating layer 16 has a first opening 16A, the conductive layer 17 fills the first opening 16A, a second insulating layer 18 covers the conductive layer 17, and the second insulating layer 18A has a second opening 18A to expose part of the conductive layer 17.

In addition, in order to effectively improve the uniformity of light transmission and the visual effect of the existing touch panel, reduce the crosstalk phenomenon (crosstalk) between adjacent electrodes, and improve the sensitivity of operation, the first sensing electrode 12a and the first sensing electrode 12a The periphery of the second sensing electrode 12b is provided with a floating electrode (not shown). When the floating electrode is located at the periphery of the static protection ring 13 and it is in an ungrounded state, the floating electrode and the spare connection pad 15 are easily attracted. The electrostatic charge moves toward the touch area, and then causes the traces or the sensing electrodes of the touch area of the substrate 11 to be damaged by static electricity.

Contents of the invention

The purpose of the present invention is to provide a new touch panel for more effectively grounding the static electricity accumulated around the static protection ring, so as to avoid the damage caused by the static electricity conduction to the touch area.

The touch panel provided by the present invention includes a substrate, a touch sensing layer formed on the substrate, and an electrostatic protection ring. The touch panel also includes: the electrostatic protection ring also includes an extension; a spare connection pad, and the spare connection pad stacked on the extension part, and the spare connection pad is grounded through the static protection ring and the extension part.

Optionally, the extension is formed on the substrate, the spare connection pad includes a first insulating layer and a first conductive layer, the first insulating layer is formed on the extension, the first insulating layer has a first opening to The extension part is exposed, the first conductive layer is formed on the first insulating layer, and the first conductive layer is electrically connected to the extension part through the first opening.

Optionally, the spare connection pad further includes a second insulating layer, the second insulating layer is formed on the first conductive layer, and the second insulating layer has a second opening to expose part of the first conductive layer.

Optionally, the static protection ring is disposed around the touch area of the touch sensing layer, and the static protection ring is disposed on the edge of the substrate.

Optionally, the extension part forms a closed ring structure with one side of the static protection ring.

Optionally, the extensions have a grid-like pattern.

Optionally, the extension part has a notch, and the notch makes the extension part and one side of the electrostatic protection ring form an unclosed annular structure.

Optionally, a third insulating layer and a second conductive layer are also included, the third insulating layer is formed on the extension portion and the notch, the third insulating layer has a through hole, and the extension portion is exposed through the through hole The second conductive layer is electrically connected with the through hole and the extension part.

Optionally, a fourth insulating layer is further included, and the fourth insulating layer is formed on the second conductive layer.

Optionally, the material of the extension part is metal.

Compared with the prior art, in the present invention, by changing the structure of the static protection ring, the spare connection pad is electrically connected to the extension of the static protection ring and grounded, effectively avoiding the electrostatic charge accumulated on the backup connection pad from being attracted and conducted to the touch area, causing damage to the touch electrodes and traces.

Description of drawings

FIG. 1 is a schematic diagram of a conventional capacitive touch panel.

FIG. 2 is a schematic cross-sectional view of the spare connection pad in FIG. 1 along the dotted line a.

FIG. 3 is a schematic diagram of a capacitive touch panel according to a first embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view of the spare connection pad stacked on the extension of the ESD protection ring along the dotted line b in FIG. 3 .

FIG. 5 is a schematic diagram of a capacitive touch panel according to a second embodiment of the present invention.

FIG. 6 is a schematic diagram of a capacitive touch panel according to a third embodiment of the present invention.

FIG. 7 is a schematic cross-sectional view of the connecting hole in FIG. 6 .

detailed description

In order to have a clearer and more accurate understanding of the content of the present invention, it will now be described in detail with reference to the accompanying drawings, which show examples of embodiments of the present invention, wherein the same reference numerals represent the same elements. It can be understood that the proportions shown in the drawings of the description are not the proportions of the actual implementation of the present invention, which are for illustrative purposes only, and are not drawn according to the original scale.

FIG. 3 is a schematic diagram of a capacitive touch display panel according to a first embodiment of the present invention.

As shown in FIG. 3 , the touch panel 20 includes a substrate 21, a touch sensing layer 22 is disposed on the substrate 21, an electrostatic protection ring 23 surrounds the touch area of the touch sensing layer 22, and the electrostatic protection ring 23 is disposed on the substrate 21. and is electrically connected to the ground potential. The ESD protection ring 23 has an extension portion 23A, and the spare connection pad 25 is stacked on the extension portion 23A, so that the spare connection pad 25 is grounded through the extension portion 23A. Wherein, two ends of the extension part 23A are respectively connected to one side of the ESD protection ring 23 , so that the extension part 23A and one side of the ESD protection ring 23 form a closed ring structure.

The touch panel 20 of this embodiment includes an externally attached touch panel and a touch panel integrated in a display device (not shown). The display device can be, for example, a liquid crystal display (Liquid Crystal Display, LCD), a Organic Electro Luminescence Display (OEL), Organic Light Emission Diode Display (OLED), Light Emission Diode Display (Light Emission Diode Display, LED), Plasma Display Panel (PDP), field Field Emission Display, Carbon Nanotube Display, Electronic Ink (E-ink) Display.

FIG. 4 is a schematic cross-sectional view of the spare connection pads stacked on the extension portion along the dotted line b in FIG. 3 .

As shown in FIG. 4 , the substrate 21 includes an extension 23A, a first insulating layer 26 , a first conductive layer 27 and a second insulating layer 28 in sequence, wherein the first insulating layer 26 covers the surface of the extension 23A, And the first insulating layer has a plurality of first openings 26A, and the extension part 23A can be exposed from the first openings 26A; the first conductive layer 27 is formed on the first insulating layer 26, and the first conductive layer 27 passes through the first openings 26A and The extension portion 23A is electrically connected; the second insulating layer 28 is formed on the first conductive layer 27 , the second insulating layer 28 has a plurality of second openings 28A, and the first conductive layer 27 is exposed from the plurality of second openings 28A.

In this embodiment, the ESD protection ring 23 and the extension part 23A are, for example, metal, and the static charge accumulated on the spare connection pad 25 can be grounded through the extension part 23A and the ESD protection ring 23, so as to protect other signal lines and wires in the touch area. The sensing electrodes are damaged by static electricity.

Continuing to refer to FIG. 3 , the touch sensing layer 22 further includes a plurality of first sensing electrodes 22a, a plurality of second sensing electrodes 22b and a plurality of bridging portions 22c, and the plurality of bridging portions 22c are used for a plurality of first sensing electrodes 22a. The bridge between electrodes 22a, or the bridge between multiple second sensing electrodes 22b. The first sensing electrodes 22 a are arranged at equal intervals along the first axis and parallel to each other, and the second sensing electrodes 22 b are arranged at equal intervals along the second axis and are arranged parallel to each other. The first axis is perpendicular to the second axis, and the first sensing electrodes 22a and the second sensing electrodes 22b are alternately arranged in a matrix. The first sensing electrodes 22a on each first axis are connected to each other, and the second sensing electrodes 22b on each second axis are not connected to each other. In this embodiment, as shown in FIG. 3 , the plurality of second sensing electrodes 22 b on the second axis are bridged by a plurality of bridging portions 22 c to form an electrical connection. The bridging portion 22c can be metal material (such as gold wire or silver wire) or screen printing silver paste.

The peripheral wires 22d are connected between the plurality of first sensing electrodes 22a, the plurality of second sensing electrodes 22b and the FPC connection pad 24 for transmitting sensing signals. The peripheral wires 22d are preferably made of low-resistance materials, such as gold wires or silver wires. The FPC connection pad 24 is used to transmit the sensing signal obtained by the sensing electrodes to a subsequent signal processing circuit (not shown), and the signal processing circuit can be formed on a flexible printed circuit board (or tape). Wherein, the flexible printed circuit board is bonded to the FPC connection pad 24 by using conductive adhesive, such as anisotropic conductive film (ACF).

In the above-mentioned substrate 21, an equivalent capacitance can be formed between the sensing electrode and the peripheral wire 22d, so when the user's finger or conductor touches or lightly slides over the surface of the substrate 21, the signal processing circuit can see through the change in capacitance , to determine the touch position of the conductor or the user's finger.

In the present invention, the spare connection pads 25 are relative to the FPC connection pads 24 . Specifically, an electrical connection is required between the touch sensing layer 22 and the display panel in the touch panel 20 to transmit electrical signals. One end of the flexible printed circuit board connected to the touch sensing layer 22 is connected to the substrate 21. The FPC connection pad 24 is electrically connected, and the other end of the flexible circuit board needs to be connected to the display panel through a connector. Therefore, in order to adapt to different display panels, it is often necessary to set spare FPC connection pads on the substrate of the touch panel, that is, the spare connection pads 25 of the present invention, and the setting of the spare connection pads 25 can avoid encountering different display panels. When using a touch panel, it is necessary to re-layout the FPC connection pads on the touch panel, resulting in prolongation of the manufacturing process, thereby reducing manufacturing costs.

FIG. 5 is a schematic diagram of a touch panel according to a second embodiment of the present invention. As shown in FIG. 5 , the only difference between the touch panel 30 and the touch panel 20 is that the extension portion 33A of the ESD protection ring 33 has a grid pattern structure. The spare connection pad 25 is stacked on the extension part 33A, and the static charge accumulated on the spare connection pad 25 can also be grounded through the extension part 33A and the static protection ring 33, preventing the electrostatic charge from being released by the charge on the spare connection pad 25. Attracted and conducted to the touch area, causing electrostatic damage.

FIG. 6 is a schematic diagram of a touch panel according to a third embodiment of the present invention, and FIG. 7 is a cross-sectional view of a connection hole on an extension portion of the static protection ring in FIG. 6 . As shown in FIG. 6 , the only difference between the touch panel 40 and the touch panel 20 is that a connection hole 44 is disposed above the extension portion 43A of the ESD protection ring 43 .

As shown in FIG. 7 , the extension portion 43A is formed on the substrate 21 , and the extension portion 43A has a notch 43B. The notch 43B forms an unclosed annular structure between the extension portion 43A and one side of the ESD protection ring 43 . The third insulating layer 46 is formed on the extension portion 43A and covers the gap 43B, and the third insulating layer 46 has connection holes 44 (the number of connection holes 44 shown in FIG. 7 is two, but not limited thereto) to expose the Part of the extension portion 43A; the second conductive layer 45 is formed on the third insulating layer 46, and the second conductive layer 45 is respectively connected to the extension portion 43A through the connection hole 44; the fourth insulating layer 47 is formed on the second conductive layer 45 , used to block the influence of the environment on the second conductive layer 45 and the extension portion 43A. The second conductive layer 45 is preferably ITO. The fourth insulating layer 47 is, for example, polycarbonate (Polycarbonate, PC), polyester (Polythylene terephthalate, PET), polymethylmethacrylate (polymethylmethacrylate, PMMA) or cyclic olefin copolymer (Cyclic Olefin Copolymer).

To sum up, in the present invention, by changing the structure of the static protection ring, the spare connection pad is electrically connected to the extension of the static protection ring and grounded, which effectively prevents the static charge accumulated on the backup connection pad from being attracted and conducted to the contactor. In the control area, the damage to the touch electrodes and wiring is caused.

Certainly, the present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes All changes and modifications should belong to the scope of protection of the appended claims of the present invention.

Claims (10)

1. A touch panel, comprising a substrate, a touch sensing layer and an electrostatic protection ring formed on the substrate, characterized in that the touch panel also includes: The electrostatic protection ring also includes an extension; The spare connection pad is stacked on the extension part, and the spare connection pad is grounded through the static protection ring and the extension part. 2. The touch panel according to claim 1, wherein the extension portion is formed on the substrate, the spare connection pad comprises a first insulating layer and a first conductive layer, and the first insulating layer is formed on the extension portion Above, the first insulating layer has a first opening to expose the extension, the first conductive layer is formed on the first insulating layer, and the first conductive layer is electrically connected to the extension through the first opening. 3. The touch panel according to claim 2, wherein the spare connection pad further comprises a second insulating layer, the second insulating layer is formed on the first conductive layer, and the second insulating layer has The second opening exposes part of the first conductive layer. 4 . The touch panel according to claim 1 , wherein the static protection ring is disposed around the touch area of the touch sensing layer, and the static protection ring is disposed on an edge of the substrate. 5 . The touch panel as claimed in claim 1 , wherein the extension part and one side of the static protection ring form a closed ring structure. 6 . 6. The touch panel as claimed in claim 1, wherein the extension portion has a grid pattern. 7 . The touch panel according to claim 1 , wherein the extension part has a notch, and the notch makes the extension part and one side of the static protection ring form an unclosed ring structure. 8. The touch panel according to claim 7, further comprising a third insulating layer and a second conductive layer, the third insulating layer is formed on the extension portion and the gap, the third insulating layer There is a through hole, the extension part is exposed from the through hole, and the second conductive layer is electrically connected with the extension part through the through hole. 9. The touch panel as claimed in claim 8, further comprising a fourth insulating layer formed on the second conductive layer. 10. The touch panel as claimed in claim 1, wherein a material of the extension part is metal.