CN106886325B - Touch panel and electronic device - Google Patents

Abstract

The invention discloses a touch panel and an electronic device, wherein the touch panel comprises: the flexible printed circuit board comprises a substrate, a transparent conductive layer, a metal layer, a covering layer, an anisotropic conductive material layer and a flexible printed circuit board. The transparent conductive layer is arranged on the substrate and comprises a touch electrode pattern and at least one joint pin. The metal layer is arranged on the substrate and comprises at least one metal lead, and the metal lead is electrically connected with the touch electrode pattern and the joint pin. The covering layer covers the touch electrode pattern and the metal wires. The anisotropic conductive material layer is disposed on the bonding pins. The flexible circuit board comprises at least one bonding pin, and the bonding pin is arranged on the anisotropic conductive material layer and is electrically connected with the bonding pin through the anisotropic conductive material layer. Therefore, the conductive block of the touch panel can provide a low-resistance conductive path.

Description

Touch panel and electronic device

Technical Field

The present invention relates to a touch panel, and more particularly, to a touch panel providing a low resistance path between a metal wire electrically connected to a touch electrode and a bonding pin of a flexible printed circuit, and an electronic device using the touch panel.

Background

A common touch panel is provided with a plurality of touch electrodes, which are made of transparent conductive material, and can detect a touch operation by changing capacitance values of the touch electrodes. The touch electrodes on the touch panel are electrically connected to bonding pins (bonding pins) through metal wires, and the bonding pins are electrically connected to a flexible circuit board (fpc) having a touch Integrated Circuit (IC) to transmit and receive driving and sensing signals of the touch electrodes. In some conventional approaches, the metal wires are made of aluminum or copper, and in order to save process steps, the bonding pins are usually fabricated in the same process as the metal wires. However, in the reliability test, the characteristics of the touch panel are affected because the metal material is easily corroded. In addition, when the touch panel suffers from static electricity, static electricity will be discharged through the electrostatic discharge path of the metal wires/bonding pins to prevent static electricity from accumulating and damaging the touch panel, so that it is an interest of those skilled in the art to find a solution for corroding the metal wires extending from the bonding pins while preventing static electricity from damaging the touch panel.

Disclosure of Invention

The present invention provides a touch panel and an electronic device, in which a conductive block can provide a low resistance conductive path, thereby improving the problem of electrostatic discharge.

The embodiment of the invention provides a touch panel, which comprises a substrate, a transparent conductive layer, a metal layer, a covering layer, an anisotropic conductive material layer and a bonding pin of a flexible circuit board. The transparent conductive layer is arranged on the substrate and comprises a touch electrode pattern and a joint pin. The metal layer is arranged on the substrate and comprises metal wires which are electrically connected with the touch electrode patterns and the joint pins. The covering layer covers the touch electrode pattern and the metal wires. The anisotropic conductive material layer is disposed on the bonding pins. The bonding pins of the flexible circuit board are arranged on the anisotropic conductive material layer and are electrically connected with the bonding pins through the anisotropic conductive material layer.

In some embodiments, the projected length of the end of the bonding pin to the side of the cover layer on the substrate is less than 200 microns.

In some embodiments, the touch panel further comprises a conductive block disposed on and electrically connected to the bonding pin, wherein a gap is formed between the conductive block and the metal wire, and a resistivity of the conductive block is smaller than a resistivity of the bonding pin.

In some embodiments, the conductive block belongs to a metal layer, and the conductive block directly contacts the bonding pin.

In some embodiments, the cover layer covers at least a portion of the conductive block.

In some embodiments, the bonding pins, the conductive blocks and the bonding pins at least partially overlap when viewed from a normal vector of the substrate.

In some embodiments, the conductive block directly contacts the bonding pins or is electrically connected to the bonding pins through the anisotropic conductive material layer.

In some embodiments, the material of the conductive block comprises aluminum or copper.

In some embodiments, the substrate includes an active region and an inactive region. The touch electrode pattern is positioned in the active area; the conductive block, the anisotropic conductive material layer and the bonding pin are located in the inactive region.

An embodiment of the invention provides an electronic device, which includes the touch panel.

In the electronic device and the touch panel, the conductive block provides a conductive path with a low resistivity, so that the problem of electrostatic discharge can be improved.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1 is a schematic top view of a touch panel according to a first embodiment of the invention.

FIG. 2 is a cross-sectional view of the present invention taken along line AA' of FIG. 1.

Fig. 3a to 3d are electrostatic discharge path diagrams of different embodiments of the first embodiment of the present invention.

Fig. 4 is a schematic top view of a touch panel according to a second embodiment of the invention.

Fig. 5 is a cross-sectional view of the invention taken along line AA' of fig. 4.

FIGS. 6a and 6b are electrostatic discharge path diagrams without conductive blocks and with conductive blocks according to the present invention.

Fig. 7a, 7b, 7c are cross-sectional views of different cover layer embodiments in a second embodiment of the invention.

Fig. 8 is a schematic top view of a touch panel according to another embodiment of the present invention.

FIGS. 9a and 9b are electrostatic discharge path diagrams of different embodiments of the second embodiment of the present invention.

Fig. 10a and 10b are electrostatic discharge path diagrams of different embodiments of the second embodiment of the present invention.

FIGS. 11a, 11b, 11c, 11d are cross-sectional views of different embodiments of the cover layer in a second embodiment of the present invention.

Detailed Description

Embodiments of the invention are best understood from the following detailed description when read with the accompanying drawing figures. It should be emphasized that, in accordance with the standard practice in the industry, the features in the figures are not necessarily drawn to scale, and that, in fact, various features may be arbitrarily increased or reduced. In addition, other features may be added from feature to feature, unless direct contact is specifically noted below.

First embodiment

Fig. 1 is a schematic top view of a touch panel 100 according to a first embodiment of the invention, and fig. 2 is a cross-sectional view corresponding to a cut line AA' in fig. 1. Referring to fig. 1 and fig. 2, the touch panel 100 includes a substrate 210, and the substrate 210 includes an active region (active region)110 (also referred to as a touch region) and a non-active region (non-active region)112 (also referred to as a peripheral region). Touch electrodes 121a and 122a (also called touch electrode patterns) and metal wires 131 and 132 are formed in the active area 110 and the inactive area 112, respectively, wherein the touch electrodes 121a form a first touch electrode row 121 extending along the Y direction via bridge portions 121b, and the touch electrodes 122a form a second touch electrode row 122 extending along the X direction via connecting portions 122 b. The first touch electrode rows 121 and the second touch electrode columns 122 are spatially insulated (spatially isolated) from each other. In the embodiment, the touch electrode 121a is a driving electrode, and the touch electrode 122a is a sensing electrode, but the invention is not limited thereto, and in other embodiments, the touch electrode 121a may also be a sensing electrode, and the touch electrode 122a is a driving electrode. The first touch electrode row 121 and the second touch electrode row 122 are electrically connected to one end of the metal wires 131 and 132, respectively. The other ends of the metal wires 131, 132 are electrically connected to Bonding pins (Bonding pins) 140, and the Bonding pins 140 are electrically connected to a plurality of Bonding pins 160a (commonly referred to as gold fingers) of the flexible circuit board 160 through Anisotropic Conductive Film (ACF) 150. As shown in fig. 2, the flexible circuit board 160 includes a flexible substrate 160b and a plurality of bonding pins 160a disposed on the flexible substrate 160 b. Although fig. 2 only shows a cross-sectional view of the metal wire 132 electrically connected to the bonding pin 140, the cross-sectional view of the metal wire 131 electrically connected to the bonding pin 140 is the same as that in fig. 2, and therefore the same description is not repeated. It should be noted that, although not shown in fig. 1, the bonding pins 160a of the flexible circuit board 160 are electrically connected to a touch circuit element (e.g., a touch IC) (not shown) disposed on the flexible circuit board 160 or a touch circuit element disposed on a printed circuit board (not shown) electrically connected to the flexible circuit board 160 via a conductive trace (not shown) of the flexible circuit board 160, which is only conventional in the art and therefore will not be described herein again. As shown in the cross-sectional view of fig. 2, an Anisotropic Conductive Film (ACF) 150 is disposed between the bonding pins 160a of the flexible circuit board 160 and the bonding pins 140 in the Z-direction for electrically connecting the bonding pins 160a of the flexible circuit board 160 and the bonding pins 140. The touch panel 100 further includes an over coating layer (over coating layer)240 formed on the touch electrodes 121a and 122a and the metal wires 131 and 132, and having a function of protecting the touch electrodes and the metal wires. The cover layer 240 covers the active area 110 and a portion of the inactive area 112, and has an opening 240a exposing the bonding pin 140, so that the anisotropic conductive material layer 150 can be disposed above the bonding pin 140, and the bonding pin 160a of the flexible circuit 160 can be pressed against the anisotropic conductive material layer 150 to electrically connect the bonding pin 160a to the bonding pin 140. In the present embodiment, the thickness of the capping layer 240 is between 1 micron and 2 microns, and the distance OV1 that the capping layer 240 extends beyond the metal wires 131 and 132 in fig. 2 is between 10 microns and 50 microns, and preferably between 20 microns and 30 microns, but the thickness of the capping layer 240 and the distance that the capping layer 240 extends beyond the metal wires 131 and 132 are not limited thereto in the present invention. Although fig. 1 and 2 illustrate the side 150s of the anisotropic conductive material layer 150 contacting the side 240s of the cover layer 240, the invention is not limited thereto, since the anisotropic conductive material layer 150 is used for electrically connecting the bonding pins 160a and the bonding pins 140 in the Z direction, the disposition position of the anisotropic conductive material layer 150 may not contact the side 240s of the cover layer 240, and the distance from the side 150s of the anisotropic conductive material layer 150 to the side 240s of the cover layer 240 may be adjusted according to actual requirements without affecting the electrical connection between the bonding pins 160a and the bonding pins 140. With the above configuration, and the touch circuit device (e.g., the touch IC) is disposed on the flexible circuit board 160 or the printed circuit board (not shown) electrically connected to the flexible circuit board 160, the touch driving signal and the sensing signal can be transmitted through the paths of the bonding pins 160a, the anisotropic conductive material layer 150, the bonding pins 140, the metal wires 131, 132, and the touch electrodes 121a, 122a of the flexible circuit board 160, so as to sense the coordinates of the touch points of the user on the touch panel 100.

In this embodiment, the touch electrodes 121a and 122a are formed of a transparent conductive material, such as Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), or other conductive and transparent materials, the metal wires 131 and 132 may be made of aluminum, copper, or other suitable metals or alloys, and the bonding pins 140 are made of a material different from the metal wires 131 and 132, and preferably the same as the touch electrodes 121a and 122a and formed in the same process step, so as to save cost. In the prior art, the bonding pins 140 are made of the same material as the metal wires 131 and 132, so that corrosion (e.g., aluminum corrosion) of the bonding pins 140 may extend to the metal wires 131 and 132 during the reliability test, resulting in abnormal performance of the touch panel 100. By arranging the bonding pins 140 made of a material different from that of the metal wires 131 and 132 in the transmission paths of the touch driving signals and the sensing signals, the performance abnormality of the touch panel 100 caused by the corrosion of the bonding pins 140 during the reliability test of the touch display device 100 can be avoided.

It should be noted that, in the present embodiment, the metal wires 131 and 132 are directly contacted with the bonding pin 140 to electrically connect with each other, but the electrical connection manner of the metal wires 131 and 132 and the bonding pin 140 is not limited thereto in the present invention. For example, in other embodiments, an insulating layer may be disposed between the bonding pin 140 and the metal wires 131 and 132 thereon, and the insulating layer has conductive vias for electrically connecting the bonding pin 140 and the metal wires 131 and 132 thereon.

In addition, the shape and arrangement of the touch electrodes 121a and 122a in fig. 1 are only examples, and the invention is not limited to the shape, arrangement and forming method of the touch electrode pattern. For example, although the touch electrode pattern in the embodiment of fig. 1 is a conventional single-Sided Indium Tin Oxide (SITO) structure, the invention is not limited thereto. In other embodiments, the touch electrode pattern may be a single layer solution (OLS) structure or a double-sided indium tin oxide (DITO) structure. In addition, although the touch electrode of the touch panel 100 in fig. 1 is designed in the form of mutual-capacitance (mutual-capacitance), the invention is not limited thereto, and in other embodiments, the touch electrode of the touch panel may also be designed in the form of self-capacitance (self-capacitance).

In practical applications, the touch panel 100 may be formed separately and then attached to the display panel to form a touch display screen, or the touch panel and the display panel may be integrated into an On-cell or In-cell type touch display screen. In the On-cell or In-cell type touch display screen embodiment, the substrate 210 of FIG. 2 corresponds to a color filter substrate or a TFT array substrate. In addition, the touch panel 100 is included in an electronic device, which may be a television, a smart phone, a tablet computer, a notebook computer, or any device with a touch function, but not limited thereto.

Please continue with fig. 2. The material of the substrate 210 includes, for example, glass, polymer, composite material, or a combination thereof. Examples of materials that can be used include, but are not limited to, polyethylene terephthalate (PET), Polycarbonate (PC), Polyethersulfone (PES), triacetyl cellulose (TAC), polymethyl methacrylate (PMMA), polyethylene (pe), cycloolefin polymer (COP), Polyimide (PI), and a composite material of Polycarbonate (PC) and polymethyl methacrylate (PMMA).

The substrate 210 has a transparent conductive layer 230 thereon, and the transparent conductive layer 230 includes touch electrode patterns (i.e., touch electrodes 121a and 122a) in the active area 110 and bonding pins 140 in the inactive area 112. The material of the transparent conductive layer 230 includes indium tin oxide, indium zinc oxide, or other conductive and transparent material. The substrate 210 also has a metal layer 220 thereon, the metal layer 220 includes metal wires 131 and 132, and the material of the metal layer 220 includes copper, aluminum, or other suitable metals or alloys. The cover layer 240 covers the touch electrode pattern and the metal wires 131 and 132, and has an opening 240a exposing the bonding pad 140, and the cover layer 240 may be made of any suitable insulating material. By electrically connecting the metal wires 131 and 132 to the bonding pins 140, the bonding pins 140 are provided with the anisotropic conductive material layer 150, and the anisotropic conductive material layer 150 is provided with the bonding pins 160a of the flexible circuit board 160, so that the metal wires 131 and 132 are electrically connected to the flexible circuit board 160, and the material of the bonding pins 160a of the flexible circuit board 160 includes, for example, copper or gold, but not limited thereto.

In this embodiment, the distance between the end 160a1 of the bonding pin 160a and the side 240s of the covering layer 240 is D1. When the touch panel 100 suffers from static electricity, the static electricity is discharged through the metal wires 131, 132, the bonding pins 140, the anisotropic conductive material layer 150, and the discharge path 280 of the bonding pin 160a of the flexible circuit board 160 (as shown by the arrow in fig. 2). Although the present invention provides the bonding pins 140 with different materials from the metal wires 131 and 132 in the transmission paths of the touch driving signals and the sensing signals, so as to avoid corrosion of the metal wires 131 and 132 during the reliability test of the touch display device 100, however, since the resistance of the bonding pin 140 formed of the transparent conductive material of the present invention is larger than that of the bonding pin of the same material as the metal wire in the prior art (generally, the sheet resistance of the transparent conductive material is about 18ohm/sq, the resistivity is about-4 times ohm cm of 10, while the sheet resistance of the metal wire containing aluminum or copper is about 0.5ohm/sq, the resistivity is about-8 times ohm cm of 10), static electricity is likely to accumulate to a high potential in a short time, and thus the static electricity is likely to accumulate on the touch panel 100 and damage the touch panel because the static electricity is not released in time due to the large impedance of the discharge path 280. In addition, because the resistance of the bonding pin 140 formed of the transparent conductive material is large, the bonding pin 140 also bears high power during discharging, so that the bonding pin 140 is easily melted down when encountering the electrostatic problem. Therefore, the present invention sets the distance D1 to be less than 200 μm to reduce the impedance of the discharge path 280 (i.e., the short bonding pin 140 path can be released upward to the bonding pin 160a of the flexible circuit board 160 through the anisotropic conductive material layer 150 during the electrostatic discharge). Thus, the electrostatic discharge problem caused by the large resistance of the bonding pin 140 can be solved.

It should be noted that, although the discharge path 280 in the anisotropic conductive material layer 150 is shown as being inclined and forming an angle with the Z-axis in fig. 2, it is only an example. Since the bonding pins 160a and the bonding pins 140 are vertically conducted by pressing conductive particles (not shown) in the anisotropic conductive material layer 150, and the conductive particles are uniformly dispersed in the anisotropic conductive material layer 150, the actual discharge path between the bonding pins 140 and the bonding pins 160a is determined according to the positions of the pressed conductive particles in the anisotropic conductive material layer 150, and thus, in some embodiments, the discharge path in the anisotropic conductive material layer 150 may be substantially parallel to the Z-axis.

In addition, since the end 160a1 of the bonding pin 160a shown in fig. 2 overlaps the projection of the side 240s of the cover 240 in the Z-axis direction (i.e., the height of the bonding pin 160a in the Z-axis overlaps the height of the cover 240 in the Z-axis), the distance D1 between the end 160a1 of the bonding pin 160a and the side 240s of the cover 240 shown in fig. 2 is parallel to the X-Y plane. In other embodiments of the present invention, if the projection of the end 160a1 of the bonding pin 160a and the side 240s of the cover 240 in the Z-axis direction does not overlap due to the thickness of the anisotropic conductive material layer 150 (i.e., the lower surface of the bonding pin 160a is higher than the upper surface of the cover 240 in the Z-axis), the distance D1 between the end 160a1 of the bonding pin 160a and the side 240s of the cover 240 is not parallel to the X-Y plane and forms an angle with the X-Y plane. Since the impedance of the discharge path 280 is proportional to the projected length of the distance D1 between the end 160a1 of the bonding pin 160a and the side 240s of the cover 240 on the substrate 210, the present invention sets the projected length of the distance D1 on the substrate 210 to be less than 200 μm to reduce the impedance of the discharge path 280. In the embodiment of FIG. 2, because the distance D1 is parallel to the X-Y plane, the projected length of the distance D1 on the substrate 210 is equal to D1.

Referring to fig. 3a to 3D, fig. 3a is a schematic diagram illustrating that a distance D1 between the end 160a1 of the bonding pin 160a of the flexible circuit board 160 and the side 240s of the cover layer is greater than 200 micrometers, fig. 3b is a schematic diagram illustrating that the distance D1 is less than 200 micrometers and greater than 0 micrometer, fig. 3c is a schematic diagram illustrating that the distance D1 is equal to 0 micrometer, and fig. 3D is a schematic diagram illustrating that the end 160a1 of the bonding pin 160a is located above the cover layer 240. As shown in fig. 3a to 3d, in the event of electrostatic discharge, compared to the arrangement of the bonding pins 160a in fig. 3a, the paths of the bonding pins 140 in fig. 3b to 3d are shorter than those of the bonding pins 160a in fig. 3a, and the bonding pins 160a in the flexible circuit board 160 can be discharged upwards through the anisotropic conductive material layer 150, so that the risk of electrostatic damage to the touch panel 100 or the bonding pins 140 being melted during electrostatic discharge can be reduced, and the electrostatic protection capability of the touch panel 100 can be improved.

Second embodiment

Referring to fig. 4 to 5, fig. 4 is a schematic top view of a touch panel 200 according to a second embodiment of the invention, and fig. 5 is a cross-sectional view corresponding to a cut line AA' in fig. 4. The difference between fig. 4-5 and fig. 1-2 is that fig. 4-5 form a conductive block 310 on the upper surface of the bonding pin 140, and the rest is similar to the first embodiment, and the same description is not repeated here. In the embodiment, the conductive block 310 and the metal wires 131 and 132 belong to the same metal layer 220, so the conductive block 310 and the metal wires 131 and 132 can be formed in the same process step to save cost. However, the invention is not limited thereto, and the material of the conductive block 310 may be different from the metal wires 131 and 132. As shown in fig. 5, the length of the conductive block 310 extending toward the X direction is L, and in the distance of the length L, as long as the resistance of the conductive block 310 is lower than that of the lower bonding pin 140 in the distance of the length L, the charges will move upward toward the conductive block 310 with lower resistance during the electrostatic discharge, so as to rapidly discharge the electrostatic. Therefore, the material of the conductive block 310 is preferably a metal material or other conductive material with a lower resistivity than the bonding pin 140, but the invention is not limited thereto. The conductive block 310 is disposed between the covering layer 240 and the bonding pin 160a of the flexible circuit board 160 in the X direction and electrically connected to the bonding pin 140. In the embodiment of fig. 5, the conductive block 310 directly contacts the bonding pin 140, but the invention is not limited thereto. For example, in other embodiments, when the conductive block 310 and the metal wires 131 and 132 belong to the metal layer 220, and the bonding pin 140, the metal wires 131 and 132 thereon and the conductive block 310 have an insulating layer therebetween, and the insulating layer has a conductive via for electrically connecting the bonding pin 140, the metal wires 131 and 132 thereon and the conductive block 310, because the conductive via is usually formed of a metal material having a much lower resistivity than the transparent conductive material, the charges move upward from the bonding pin 140 to the conductive block 310 having a lower resistivity through the conductive via during the electrostatic discharge.

Therefore, the electrostatic discharge path 280 of the present embodiment includes the conductive block 310 with a low resistance, that is, compared to the first embodiment without the conductive block 310, the present embodiment replaces a section of the bonding pin 140 with a higher resistance in the electrostatic discharge path 280 with the conductive block 310 with a lower resistance, so that the static electricity encountered by the touch panel 200 can be rapidly released through the discharge path 280 to avoid the touch panel 200 from being damaged by the static electricity (see the discharge path without the conductive block 310 in fig. 6a and the discharge path with the conductive block 310 in fig. 6 b). It should be noted that, in the present invention, the conductive block 310 may be disposed between the end 160a1 of the bonding pin 160a and the side 240s of the cover 240 in combination with the embodiment shown in fig. 3a and 3b, and the anisotropic conductive material layer 150 is not disposed between the conductive block 310 and the bonding pin 140, i.e., the distance D1 from the end 160a1 of the bonding pin 160a to the side 240s of the cover is not limited in this embodiment. For example, in embodiments where the distance D1 is less than 200 μm, the conductive bumps 310 may be formed on the top surfaces of the bonding pins 140 to further reduce the impedance of the esd paths and improve esd protection. Alternatively, the distance D1 cannot be reduced to less than 200 μm due to the length of the bonding pad 160, the width of the anisotropic conductive material layer 150, and the size of the opening 240a of the cover 240, and the like, the conductive bump 310 may be formed on the top surface of the bonding pad 140 to improve the esd protection. In addition, as shown in fig. 4 and 5, since the conductive block 310 does not directly contact the metal wires 131 and 132 and has a gap G with the metal wires 131 and 132, the conductive block 310 is electrically connected to the metal wires 131 and 132 by the bonding pin 140. With the above configuration, even if the conductive block 310 is corroded, the corrosion will not extend to the metal wires 131 and 132, so that the touch panel can still operate normally (even if the conductive block 310 is corroded seriously to cause resistance increase or disconnection, the touch driving signal and the sensing signal can still be transmitted through the paths of the bonding pin 160a, the anisotropic conductive material layer 150, the bonding pin 140, and the metal wires 131 and 132 of the flexible circuit board 160).

It should be noted that the length, width, thickness or aspect ratio of the conductive block 310 is not limited in the present invention, and the width of the conductive block 310 is not limited to be wider than the width of the bonding pin 140 as shown in fig. 4. For example, referring to fig. 5, the length of the conductive block 310 extending toward the X direction is L, and in the distance of the length L, as long as the resistance of the conductive block 310 is lower than that of the lower bonding pin 140 in the distance of the length L, the charges move upward toward the conductive block 310 with the lower resistance during the electrostatic discharge, so as to rapidly discharge the electrostatic. Therefore, one of ordinary skill in the art can adjust the position, shape, thickness, length, or width of the conductive block according to the design requirement and process capability of the touch panel.

In the embodiment of fig. 5, the conductive bumps 310 are not directly contacted to the covering layer 240, and are disposed between the ends 160a1 of the bonding pins 160a and the side 240s of the covering layer 240, but the invention is not limited thereto. Referring to fig. 7a to 7c, in the embodiment of fig. 7a, the side 310s of the conductive block 310 directly contacts the side 240s of the covering layer 240, and in the embodiments of fig. 7b and 7c, the covering layer 240 respectively partially covers and completely covers the conductive block 310, which can also achieve the effect of improving the electrostatic protection capability. That is, whether the cover layer 240 directly contacts or covers the conductive block 310 does not affect the electrostatic protection capability, so a person skilled in the art can determine whether the cover layer 240 contacts or covers the conductive block 310 according to the process capability and the design requirement of the touch panel. In addition, since at least a portion of the conductive block 310 in the embodiments of fig. 5, 7a and 7b is exposed in the air and is prone to moisture corrosion, the covering layer 240 completely covers the conductive block 310 in the embodiment of fig. 7c can avoid the above problem of moisture corrosion of the conductive block 310.

In the embodiments of fig. 5 and 7a to 7c, the conductive bumps 310 do not directly contact the bonding pins 160a of the flexible circuit board 160. However, referring to fig. 8 and 9a, fig. 8 is a schematic top view of the touch panel 300 of the present invention, and fig. 9a is a cross-sectional view corresponding to a cut line AA' of fig. 8. As shown in fig. 8 and 9a, the conductive block 310, the bonding pin 140 and the bonding pin 160a of the flexible circuit board 160 are at least partially overlapped in the vertical direction (Z direction) (when viewed from the normal vector of the substrate 210). In the embodiment of fig. 8 and 9a, the conductive bumps 310 directly contact the bonding pins 160a of the flexible circuit board 160, and in practice, the conductive bumps 310 are formed longer. The present invention is not limited to the embodiments shown in fig. 8 and 9a, but the bonding wires 160a of the flexible circuit board 160 can be designed to have a longer length as shown in fig. 9b, and the conductive bumps 310 can also directly contact the bonding pins 160a of the flexible circuit board 160. The invention does not limit the length of the conductive block 310 and the bonding pin 160a of the flexible circuit board 160. Referring to fig. 6b, 7a to 7c, and 9a to 9b, the electrostatic discharge path 280 of fig. 6b and 7a to 7c is the metal wires 131, 132, the bonding pin 140, the conductive block 310, the bonding pin 140, the anisotropic conductive material layer 150, the bonding pin 160a of the flexible circuit board 160, and the electrostatic discharge path 280 of fig. 9a to 9b is the metal wires 131, 132, the bonding pin 140, the conductive block 310, the bonding pin 160a of the flexible circuit board 160, so that compared with the embodiments of fig. 6b and 7a to 7c, the embodiments of fig. 9a and 9b provide a lower impedance electrostatic discharge path 280, which can further improve the electrostatic protection capability of the touch panel.

Please refer to fig. 10a and 10 b. The difference between fig. 10a and 10b and fig. 9a and 9b is that the anisotropic conductive material layer 150 is disposed between the conductive block 310 and the bonding pin 160a of the flexible circuit board 160. When the thickness difference between the conductive block 310 and the anisotropic conductive material layer 150 (for example, if the thickness of the conductive block 310 is much smaller than the thickness of the anisotropic conductive material layer 150) makes the conductive block 310 unable to directly contact the bonding pin 160a of the flexible circuit board 160 as shown in fig. 9a and 9b, the anisotropic conductive material layer 150 is disposed on the bonding pin 140 and the conductive block 310, and then the bonding pin 160a of the flexible circuit board 160 is pressed on the anisotropic conductive material layer 150, so that the bonding pin 160a of the flexible circuit board 160 can simultaneously electrically connect the bonding pin 140 and the conductive block 310 through the anisotropic conductive material layer 150. Referring to fig. 6b, fig. 7a to fig. 7c, and fig. 10a to fig. 10b, the electrostatic discharge path 280 of fig. 6b and fig. 7a to fig. 7c is the metal wires 131, 132, the bonding pin 140, the conductive block 310, the bonding pin 140, the anisotropic conductive material layer 150, and the bonding pin 160a of the flexible circuit board 160, and the electrostatic discharge path 280 of fig. 10a and fig. 10b is the metal wires 131, 132, the bonding pin 140, the conductive block 310, the anisotropic conductive material layer 150, and the bonding pin 160a of the flexible circuit board 160, so that the low impedance electrostatic discharge path 280 is provided in the low impedance embodiment of fig. 10a and fig. 10b compared to the embodiment of fig. 6b and fig. 7a to fig. 7 c.

Please refer to fig. 11a to 11 d. In the embodiments of fig. 9a to 9b and 10a to 10b, although the covering layer 240 does not cover the conductive block 310, other embodiments of the present invention may be modified to cover the covering layer 240 partially on the conductive block 310 as shown in fig. 11a to 11d to avoid the problem of the conductive block 310 being corroded by moisture. It should be noted that, although the right side of the covering layer 240 in fig. 11a to 11d is not contacted with the bonding pins 160a of the flexible circuit board 160 or the anisotropic conductive material layer 150, the invention is not limited thereto, and in other embodiments, the side of the covering layer 240 may be contacted with the bonding pins 160a of the flexible circuit board 160 or the anisotropic conductive material layer 150 to completely cover the conductive blocks 310 with the bonding pins 160a of the flexible circuit board 160 or the anisotropic conductive material layer 150.

It is within the scope of the present invention that one skilled in the art can modify or modify the embodiments of fig. 4, fig. 5, fig. 7a to fig. 7c, fig. 8, fig. 9a to fig. 9b, fig. 10a to fig. 10b, and fig. 11a to fig. 11d to implement other types of conductive blocks, as long as a conductive block with a smaller resistance (compared to the resistance of the bonding pin 140 at the same length L) is provided in the discharge path 280 between the electrical connection of the metal wires 131, 132 and the bonding pin 140 and the bonding pin 160a of the flexible circuit board 160.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.

Claims (2)

1. A touch panel, comprising:

a substrate;

a transparent conductive layer disposed on the substrate, the transparent conductive layer including a touch electrode pattern and at least one bonding pin;

a metal layer disposed on the substrate and including at least one metal wire electrically connected to the touch electrode pattern and the bonding pin;

a cover layer covering the touch electrode pattern and the metal wire;

a layer of anisotropic conductive material disposed over the bond pins; and

a flexible circuit board including at least one bonding pin disposed on the anisotropic conductive material layer and electrically connected to the bonding pin via the anisotropic conductive material layer,

the projection length of the distance from the end of the bonding pin to the side edge of the covering layer on the substrate is less than 200 microns.

2. An electronic device, comprising:

a touch panel, the touch panel comprising:

a substrate;

a transparent conductive layer disposed on the substrate, the transparent conductive layer including a touch electrode pattern and at least one bonding pin;

a metal layer disposed on the substrate and including at least one metal wire electrically connected to the touch electrode pattern and the bonding pin;

a cover layer covering the touch electrode pattern and the metal wire;

a layer of anisotropic conductive material disposed over the bond pins; and

a flexible circuit board including at least one bonding pin disposed on the anisotropic conductive material layer and electrically connected to the bonding pin via the anisotropic conductive material layer,

the projection length of the distance from the end of the bonding pin to the side edge of the covering layer on the substrate is less than 200 microns.

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