CN113325965A

CN113325965A - Electrode, method for manufacturing electrode and device thereof

Info

Publication number: CN113325965A
Application number: CN202010130421.1A
Authority: CN
Inventors: 徐维佑; 黄薇臻; 张良亦; 陈汉威
Original assignee: Chenmei Xiamen Photoelectric Co ltd
Current assignee: Chenmei Xiamen Photoelectric Co ltd
Priority date: 2020-02-28
Filing date: 2020-02-28
Publication date: 2021-08-31
Also published as: WO2021169067A1; TWM607393U; TW202132119A; TWI755023B

Abstract

An electrode and its preparation method, the electrode includes conducting the nanometer structure and a membrane layer added to said conducting nanometer structure, the interface of said conducting nanometer structure and said membrane layer has coated structure substantially.

Description

Electrode, method for manufacturing electrode and device thereof

Technical Field

The invention relates to an electrode, a method for manufacturing the electrode and a device thereof.

Background

In recent years, transparent conductors have been used in many display or touch related devices to allow light to pass through and provide appropriate electrical conductivity. Generally, the transparent conductor may be various metal oxides, such as Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), Cadmium Tin Oxide (CTO), or Aluminum-doped Zinc Oxide (AZO). However, these metal oxide thin films do not satisfy the flexibility requirements of display devices. Therefore, many flexible transparent conductors, such as those made of nanoscale materials, have been developed.

However, the process technology of nano-scale materials has many problems to be solved, such as the conventional patterning by subtractive processes, e.g. etching, to remove unwanted materials, which results in material waste and process complexity. For example, when the nanowire is used to manufacture the touch electrode, the nanowire and the lead in the peripheral region need to be overlapped, and the size of the peripheral region cannot be reduced due to the overlapped region, so that the width of the peripheral region is large, and the narrow frame requirement of the display cannot be met.

Disclosure of Invention

In some embodiments of the present invention, a coating structure is formed on a specific surface of a conductive nano-structure (such as a metal nano-wire), and the coating structure and the conductive nano-structure form a parallel connection characteristic, so as to achieve the purpose of improving electrical characteristics and satisfy the application of low resistance and flexibility.

In some embodiments of the present invention, forming the coating structure on the conductive nano-structure (e.g., metal nano-wire) is a direct-forming addition process, which is simple and can reduce material cost.

In some embodiments of the present invention, the modified conductive nano structure (e.g., metal nano wire) is directly formed by designing the peripheral lead, so as to achieve a structure without overlapping, thereby forming a peripheral region with a smaller width and further satisfying the requirement of a narrow frame.

According to some embodiments of the invention, an electrode, comprising: the conductive nano structure comprises a conductive nano structure and a film layer which is externally added to the conductive nano structure, wherein the interface of the conductive nano structure and the film layer is substantially provided with a coating structure.

In some embodiments of the present invention, the coating structure includes a plating layer, and the plating layer completely covers an interface between the conductive nano structure and the film layer. The coating structure comprises a chemical plating layer, an electroplated layer or a combination thereof.

In some embodiments of the present invention, the film has an incompletely cured state, and the coating structure is formed along the surface of the conductive nanostructure and located at the interface between the conductive nanostructure and the film.

In some embodiments of the present invention, the film has a first layer region and a second layer region, and the second layer region has a higher curing state than the first layer region; in the first layer region, a coating structure is formed along the surface of the conductive nanostructure and located at the interface of the conductive nanostructure and the film layer. In the second layer region, at least part of the surface of the conductive nanostructure has a coating structure, or the surface of the conductive nanostructure has a coating structure and has no coating structure. In the areas with a smaller degree of curing, a larger proportion of the surface of the conductive nanostructure is covered by the coating structure than in the areas with two layers.

In some embodiments of the present invention, the film is filled between adjacent conductive nanostructures, and the film has no coating structure existing separately.

In some embodiments of the present invention, the conductive nano-structure comprises a metal nanowire, and the coating structure completely covers an interface between the metal nanowire and the film layer and forms a uniform coating layer on the interface. The uniform coating layer may be a coating layer of uniform thickness.

In some embodiments of the present invention, the coating structure is a layer structure, an island-shaped protrusion structure, a dot-shaped protrusion structure or a combination thereof made of a conductive material.

In some embodiments of the present invention, the conductive material is silver, gold, platinum, iridium, rhodium, palladium, osmium, or an alloy containing the foregoing materials.

In some embodiments of the present invention, the coating structure is a single-layer structure made of a single metal material or an alloy material; or the coating structure is a two-layer or multi-layer structure made of more than two metal materials or alloy materials.

In some embodiments of the present invention, the coating structure is an electroless copper plating layer, an electrolytic copper plating layer, an electroless copper nickel plating layer, an electroless silver plating layer, or a combination thereof. The coating structure is a chemical coating which completely coats the interface of the conductive nano structure and the film layer. That is, the surface of the conductive nanostructure is separated from the film layer by an electroless plating.

According to some embodiments of the invention, the method comprises: applying a film layer on a conductive layer containing conductive nanostructures and allowing the film layer to reach a pre-cured or incompletely cured state; and performing a modification step to form a coating structure on at least a part of the surface of the conductive nanostructure, so that the interface between the conductive nanostructure and the film layer substantially has the coating structure.

In some embodiments of the present invention, the modifying step comprises immersing the film and the conductive nanostructures in an electroless plating solution, the electroless plating solution penetrating into the film and contacting the conductive nanostructures to cause metal to precipitate on the surfaces of the conductive nanostructures. The chemical plating layer completely coats the interface of the conductive nanostructure and the film layer.

In some embodiments of the present invention, a coating structure is formed along a surface of the conductive nanostructure and located at an interface between the conductive nanostructure and the film layer.

In some embodiments of the present invention, applying a film layer over a conductive layer comprising conductive nanostructures comprises coating a polymer on the conductive layer; the curing conditions are controlled to bring the polymer to a pre-cured or incompletely cured state. The polymer is photo-curable, thermal-curable or other curable.

In some embodiments of the present invention, applying a film layer over a conductive layer comprising conductive nanostructures comprises coating a polymer on the conductive layer; and controlling the curing conditions to enable the polymer to form the film layer, wherein the film layer is provided with a first layer area and a second layer area, and the curing state of the second layer area is higher than that of the first layer area.

In some embodiments of the invention, controlling the curing conditions includes introducing oxygen and controlling a concentration of oxygen in the first layer region and the second layer region.

In some embodiments of the present invention, the modifying step comprises an electroless plating step, an electroplating step, or a combination thereof

According to some embodiments of the present invention, a method for manufacturing a touch panel includes: providing a substrate with a display area and a peripheral area; arranging metal nanowires in the display area and the peripheral area to form a metal nanowire layer; additionally arranging a film layer on the metal nanowire layer, and enabling the film layer to reach a pre-curing state or an incomplete curing state; performing a patterning step comprising: patterning the metal nanowire layer and the film layer in the display area to form a touch sensing electrode and patterning the metal nanowire layer and the film layer in the peripheral area to form a peripheral lead, wherein the touch sensing electrode is electrically connected with the peripheral lead; and performing a modification step to form a coating structure on the surface of the metal nanowire of the peripheral lead, so that the interface between the metal nanowire and the film layer is substantially provided with the coating structure.

In some embodiments of the present invention, the modifying step comprises contacting the film layer of the peripheral lead with the metal nanowire layer with an electroless plating solution, wherein the electroless plating solution penetrates into the film layer and contacts the metal nanowire layer, so as to precipitate a metal on the surface of the metal nanowire.

In some embodiments, the modifying step comprises an electroless plating step, an electroplating step, or a combination thereof.

According to some embodiments of the invention, an apparatus comprises an electrode comprising: the conductive nano structure comprises a conductive nano structure and a film layer which is externally added to the conductive nano structure, wherein the interface of the conductive nano structure and the film layer is substantially provided with a coating structure.

In some embodiments of the present invention, the device includes a touch panel, an antenna structure, a coil, an electrode plate, a display, a portable phone, a tablet computer, a wearable device, a vehicle device, a notebook computer, a polarizer, or the like.

Drawings

FIG. 1A is a schematic diagram of a first step according to some embodiments of the invention.

FIG. 1B is a schematic diagram of a second step according to some embodiments of the invention.

FIG. 1C is a schematic diagram of a third step according to some embodiments of the invention.

Fig. 2 is a schematic top view of a touch panel according to some embodiments of the invention.

Fig. 2A is a schematic cross-sectional view taken along line a-a of fig. 2.

Fig. 2B is a schematic cross-sectional view taken along line B-B of fig. 2.

Fig. 3A to 3D are schematic diagrams illustrating a method for manufacturing a touch panel according to some embodiments of the invention.

Fig. 4 is a schematic cross-sectional view of a touch panel according to another embodiment of the invention.

Fig. 5 is a schematic view of a touch panel according to another embodiment of the invention.

Fig. 5A is a schematic cross-sectional view taken along line a-a of fig. 5.

Fig. 6 is a schematic view of a touch panel according to another embodiment of the invention.

Fig. 7 is a schematic view of a touch panel according to another embodiment of the invention.

FIG. 8 is a graph showing the total thickness of the first region and the second region after 20% oxygen is introduced into the film layer, and the thickness of the second region after etching with alkali solution.

Fig. 9 shows SEM images of metal nanowires electroless plated without a film layer.

Fig. 10 is an SEM image of metal nanowires evolving into silver nanowires with a coating structure over time of electroless plating.

Description of reference numerals:

100: touch panel

110: substrate

120: peripheral lead wire

140: marking

130: film layer

136: non-conductive region

190: metal nanowire

150: protective layer

160: shielded conductor

180: coating structure

VA: display area

PA: peripheral zone

BA: bonding region

TE 1: first touch electrode

TE 2: second touch electrode

TE: touch control induction electrode

NWL: metal nanowire layer

D1: a first direction

D2: second direction

Detailed Description

In the following description, for purposes of explanation, numerous implementation details are set forth in order to provide a thorough understanding of the various embodiments of the present invention. It should be understood, however, that these implementation details are not to be interpreted as limiting the invention. That is, in some embodiments of the invention, such implementation details are not necessary. In addition, some conventional structures and components are shown in simplified schematic form in the drawings.

As used herein, "about" or "approximately" generally means that the numerical value has an error or range within twenty percent, preferably within ten percent, and more preferably within five percent. Unless expressly stated otherwise, all numerical values mentioned are approximate, i.e., have an error or range as indicated by the term "about", "approximately" or "approximately".

As used herein, "conductive nanostructures" generally means that the layer (layer)/film (film) of nanostructures has a sheet resistance of less than 500 ohms/square, preferably less than 200 ohms/square, and more preferably less than 100 ohms/square; while nanostructures generally refer to structures of nanometer dimensions, such as, but not limited to, structures having at least one dimension (e.g., diameter, length, width, thickness, etc.) of 10^-9Linear structures at the meter scale, columnar structures, lamellar structures, lattice structures, tubular structures, and the like.

Some embodiments of the present invention provide a method for modifying conductive nanostructures (e.g., nanowires), which may include the steps of:

referring to fig. 1A, metal nanowires 190 are first disposed on a substrate 110 to form a metal nanowire layer NWL, such as a nano-silver wire layer, a nano-gold wire layer, or a nano-copper wire layer coating. The embodiment is specifically as follows: a dispersion or slurry having metal nanowires 190: (ink) is formed on the substrate 110 by a coating method, and is dried to make the metal nanowires 190 cover the surface of the substrate 110, thereby forming a metal nanowire layer NWL disposed on the substrate 110. After the curing/drying step, the solvent and other substances are volatilized, and the metal nanowires 190 are randomly distributed on the surface of the substrate 110; preferably, the metal nanowires 190 are fixed on the surface of the substrate 110 without falling off to form the metal nanowire layer NWL, and the metal nanowires 190 can contact each other to provide a continuous current path, thereby forming a conductive network (conductive network), in other words, the metal nanowires 190 contact each other at the crossing position to form a path for transferring electrons. Taking silver nanowires as an example, one silver nanowire and another silver nanowire form a direct contact state at the crossing position, so that a low-resistance electron transfer path is formed. In one embodiment, when the sheet resistance of a region or a structure is higher than 10⁸Ohm/square (ohm/square) may be considered as electrical insulation, preferably above 10⁴Ohm/square (ohm/square),3000 ohm/square (ohm/square),1000 ohm/square (ohm/square), 350 ohm/square (ohm/square), or 100 ohm/square (ohm/square). In one embodiment, the sheet resistance of a silver nanowire layer comprised of silver nanowires is less than 100 ohms/square.

Next, as shown in fig. 1B, the film 130 is disposed such that the film 130 covers the metal nanowires 190, and the curing degree of the film 130 is controlled. In a specific embodiment, a proper polymer is coated on the metal nanowires 190, the polymer with flowing state/property can penetrate into the metal nanowires 190 to form a filler, and the metal nanowires 190 can be embedded into the film layer 130 to form a composite structure CS; and controlling the conditions of polymer coating and curing, such as controlling the temperature, light curing parameters and the like, so that the polymer is pre-cured or not fully cured; alternatively, the layer 130 may have different degrees of curing, such as a lower region (i.e., a region close to the substrate 110) being cured to a greater degree than an upper region (i.e., a region away from the substrate 110), which is in the pre-cured or incompletely cured state. That is, in this step, the polymer is coated to externally add the film 130 to the metal nanowire 190, and the metal nanowire 190 is embedded in the pre-cured or incompletely cured film 130 to form the composite structure CS. In some embodiments of the present invention, the film 130 is formed of an insulating material. For example, the material of the film layer 130 may be non-conductive resin or other organic material, such as polyacrylate, epoxy resin, polyurethane, polysilane, polysiloxane, poly (silicon-acrylic acid), polyethylene (polyethylene; PE), Polypropylene (PP), Polyvinyl butyral (PVB), Polycarbonate (PC), Acrylonitrile butadiene styrene (Acrylonitrile butadiene styrene; ABS), poly (3, 4-ethylenedioxythiophene) (PEDOT), poly (styrenesulfonic acid) (PSS), ceramic material, or the like. In some embodiments of the present invention, the film 130 may be formed by spin coating, spray coating, printing, or the like. In some embodiments, the thickness of the film 130 is about 20 nm to 10 μm, or 50nm to 200 nm, or 30 to 100nm, for example, the thickness of the film 130 may be about 90 nm or 100 nm. For simplicity, in fig. 1B, the metal nanowire 190 and the film 130 are drawn as an integral structural layer, but the invention is not limited thereto, and the metal nanowire 190 and the film 130 may form other types of structural layers, such as an upper-lower stacked structure, and the like.

In one embodiment, the curing state of the film 130 is controlled by curing the film using different energy curing conditions to achieve a non-complete curing level. The curing behavior of the film is based on the bonding change of the film during curing, so the curing degree of a certain film can be defined as the ratio (expressed in percentage in the present embodiment) of the bonding strength of the film to the bonding strength of a completely cured film. For example, for a commercially available film material, it is originally required to irradiate 500mJ light energy under a low oxygen atmosphere for 4 minutes to achieve complete curing, and in this embodiment, 500mJ light energy is used to irradiate under a low oxygen atmosphere for 2 minutes to achieve a cured state with 95% of total curing amount, that is, the bonding strength measured by IR spectroscopy under the curing condition is 95% of that of the completely cured layer, so that the cured film obtained under the curing condition is defined as a cured state with 95% of total curing amount.

In one embodiment, the film 130 can be controlled to have different curing states at different depths (i.e., thicknesses), and gas can be introduced during curing of the film to make the gas concentrations at the surface and the bottom of the film different, so as to promote the curing reaction at the surface of the film to generate a gas blocking curing phenomenon, thereby causing the film to have a first layer region and a second layer region with different curing degrees, for example, the curing state of the second layer region belongs to the bottom of the film, which is a region with a higher curing degree, while the curing state of the first layer region belongs to the surface of the film, which is a region with a lower curing degree. The specific method is to control the concentration of gas (such as oxygen) and/or curing energy under the curing condition, the gas concentration can be 20% oxygen, 10% oxygen, 3% oxygen or < 1% oxygen, etc., and the curing energy is selected according to the material of the film layer, such as the UV light energy with a range of 250mJ to 1000 mJ. In the embodiment, the higher the oxygen concentration, the more remarkable the phenomenon of promoting the oxygen-blocking curing of the film surface, the thicker the first region with the lower curing degree, and the thinner the second region with the higher curing degree, so that the thickness of the first region is 20% oxygen, 10% oxygen, 3% oxygen or < 1% oxygen in order from the thicker to the thinner. In one embodiment, the degree of curing in the first region is about 60% and the thickness of the first region is about 23.4nm (or 12% of the total film thickness) with 20% oxygen at 500mJ of curing energy; while the second region has a degree of cure of about 99-100% (near full cure) and a thickness of about 168.1nm (or 88% of the total film thickness). FIG. 8 shows the total thickness of the first (uncured) and second (nearly fully cured or fully cured) regions formed by irradiation with curing energies of 250mJ, 500mJ and 1000mJ, respectively, and the thickness of the remaining second region after etching the film with alkali solution, under the condition of 20% oxygen gas. It is observed that as the curing energy increases, the thickness of the first region will be reduced (i.e., reduced thickness after etching). The thickness of the first region is about 8.8nm (or 5% of the total film thickness) at a curing energy of 1000 mJ; and the second region has a thickness of about 195.9nm (or 95% of the total film thickness).

It should be noted that the present invention focuses on discussing the film 130 applied to the metal nanowire 190, and the curing degree or the curing depth applied to the film 130 is controlled to enable the coating structure 180 to grow along the surface of the metal nanowire 190 to form the modified structure at the interface between the metal nanowire 190 and the film 130. In the step of coating the metal nanowire 190 dispersion liquid or slurry (ink), the dispersion liquid or slurry may also contain a polymer or the like, but it is not the focus of the present invention. The curing degree of the film layer 130 can be controlled to be 0%, 20%, 30%, 60%, 75%, 95%, 98%, 0% -95%, 0% -98%, 95% -98%, 60% -75% and the like. As mentioned above, the incomplete curing or only the pre-curing of the embodiments of the present invention may be defined as the bonding strength of the film being different from the bonding strength of the fully cured film, i.e., the ratio of the two is not 100%.

Next, as shown in fig. 1C, a modification step is performed to form a metal nanowire layer NWL composed of a plurality of modified metal nanowires 190. That is, after the modification, at least a portion of the initial metal nanowire 190 is modified to form a coating structure 180 on the surface thereof to form the modified metal nanowire 190. In fig. 1B and 1C, the metal nanowires 190 before and after modification are denoted by the symbols "v" and "o", respectively. In one embodiment, the coating structure 180 may be formed by electroless plating/electrolytic method, and the coating structure 180 may be a layer structure, an island-like protrusion structure, a dot-like protrusion structure or a combination thereof made of conductive material, and the coating rate accounts for about 80% or more, 90-95%, 90-99%, or 90-100% of the total surface area (the coating rate 100% means that no surface of the original metal nanowire 190 is exposed); the conductive material may be silver, gold, platinum, nickel, copper, iridium, rhodium, palladium, osmium, an alloy containing the foregoing material, an alloy containing no the foregoing material, or the like. In one embodiment, the coating structure 180 is a single layer structure made of a single conductive material, such as forming an electroless copper plating layer, an electrolytic copper plating layer, or an electroless copper nickel plating alloy layer; alternatively, the coating structure 180 may be a two-layer or multi-layer structure made of more than two conductive materials, such as an electroless copper layer and an electroless silver layer.

In one embodiment, the following electroless copper plating solutions (copper ion-containing solutions, chelating agents, alkaline agents, reducing agents, buffers, stabilizers, etc.) may be prepared; the metal nanowire 190 and the film 130 are immersed in an electroless copper plating solution, the electroless copper plating solution can penetrate into the pre-cured or incompletely cured film 130 and contact the surface of the metal nanowire 190 by using the capillary phenomenon and the like, the metal nanowire 190 is used as a catalytic point or a nucleation point to facilitate the precipitation of copper, and an electroless copper plating layer is deposited on the metal nanowire 190 to form the coating structure 180. The coating structure 180 is grown substantially according to the initial state of the metal nanowire 190, and forms a structure coating the metal nanowire 190 with the modification time; in contrast, there is no copper precipitation at the position where the metal nanowire 190 is not present in the original composite structure CS, in other words, through good control, the coating structures 180 are all formed on the interface between the metal nanowire 190 and the film layer 130, and there is no coating structure 180 present alone in the film layer 130 without contacting the surface of the metal nanowire 190. Therefore, after the modification step, the metal nanowires 190 in the conductive network are covered by the covering structure 180, and the covering structure 180 is located between the interface formed by the metal nanowires 190 and the film layer 130; the coating structure 180 and the metal nanowires 190 coated by the coating structure can be regarded as a whole, and the gaps between the nanowires are still occupied by the material of the film 130.

In one embodiment, the film 130 and the electroless plating solution/electrolytic solution may be matched materials, such as a polymer with poor alkali resistance may be selected to make the film 130, and an alkaline solution may be selected as the electroless plating solution, so that in this step, the incompletely cured film 130 may be attacked (etched) by the electroless plating solution to facilitate the above-mentioned modification reaction, in addition to the incompletely cured state of the film.

The principle is explained below, but not limited thereto. At the beginning of the immersion of the metal nanowires 190 and the film 130 into the electroless/electrolytic solution, the solution will attack the incompletely cured film 130, and when the solution contacts the metal nanowires 190, metal ions (e.g., copper ions) will start to grow on the surface of the metal nanowires 190 with the immersion time, such as the batch structure 180 mentioned above. On the other hand, the film 130 serves as a control layer or a limiting layer in the above reaction process, which limits the growth reaction of the cladding structure 180 at the interface between the metal nanowire 190 and the film 130, so that the cladding structure 180 can be controlled and uniformly grown. Fig. 9 shows that when the metal nanowires 190 are subjected to the electroless plating without the protection of the film 130, it can be seen that the copper layer grows randomly and uncontrollably, some metal nanowires 190 grow a thick copper layer, and some metal nanowires 190 do not have a copper layer; that is, the film 130 can limit the position of copper deposition to the interface between the metal nanowire 190 and the film 130, so that the present invention has better consistency when applied to sensing/transmitting signals.

A curing step may be included to fully cure the film layer 130. Full curing of the film layer 130 may be performed using light, heat, or other means.

The following table shows an embodiment of the present invention, and it can be found that the surface resistance (or sheet resistance) of the film layer can be effectively reduced by performing copper plating on the film layer 130 under the conditions of 0%, 95%, 98%, 0% -95%, 0% -98%, 95% -98%, and the like. The degree of cure can be measured in a number of ways other than the above calculation of bond strength, such as by solvent extraction of the polymer film, measuring the weight of uncured polymer dissolved in the solvent, and calculating the percent solubility (% Sol) compared to the total weight of cured and uncured polymer; for example, the degree of cure can be measured by a thermal analysis technique for thermosetting polymer materials.

In the foregoing method, the coating structure 180 is formed on the surface of each metal nanowire 190, covers the entire surface of the metal nanowire 190, and grows outward. In one embodiment, the coating structure 180 may be made of a highly conductive material, such as copper, as the coating structure 180 covering the surface of the silver nanowires and located at the interface between the silver nanowires and the film layer. It should be noted that although the conductivity of the silver material is higher than that of the copper material, due to the size of the silver nanowires and the mutual contact state, the overall conductivity of the silver nanowire layer is lower (but the resistance is still low enough to transmit electrical signals), and after modification, the conductivity of the silver nanowires 190 with the coating structure 180 is higher than that of the unmodified silver nanowires 190, that is, the modified metal nanowire layer NWL can form a low-resistance conductive layer (the surface resistance can be reduced by about 100 to 10000 times compared with the unmodified metal nanowire layer NWL); the conductive layer can be used to fabricate electrode structures for various applications, such as conductive substrates, wireless charging coils, antenna structures, etc. in flexible applications. Specifically, the electrode structure may at least include a metal nanowire and a film layer additionally coated on the metal nanowire, at least a portion or all of the surface of the metal nanowire (i.e., the interface between the metal nanowire 190 and the film layer 130) has a coating layer, and the conductivity of the metal nanowire layer NWL may be improved by introducing the coating layer. Fig. 10 is an SEM evolution of the metal nanowires 190 into nanosilver wires with the coating structure 180 as the electroless plating time progresses. Since the copper layer is along the surface of the metal nanowire (i.e., the interface between the metal nanowire 190 and the film 130), the observed copper morphology after plating is relatively similar to the original morphology of the metal nanowire (e.g., all linear structures), and the copper grows uniformly to form an outer layer structure with similar dimensions (e.g., thickness).

The touch panel 100 in some embodiments includes a substrate 110, a peripheral lead 120, and a touch sensing electrode TE, wherein the touch sensing electrode TE includes a plurality of unmodified initial conductive nanostructures, the peripheral lead 120 includes a plurality of modified conductive nanostructures, the modified conductive nanostructures include a coating structure 180 (see fig. 1C), and the conductive nanostructures may be metal nanowires 190. Fig. 2 is a schematic top view of a touch panel 100 according to some embodiments of the invention. Referring to fig. 2, the touch panel 100 may include a substrate 110, a peripheral lead 120, a mark 140, and a touch sensing electrode TE substantially located in a display area VA, which is patterned by a metal nanowire layer NWL composed of a plurality of unmodified initial metal nanowires 190; the modified metal nanowire 190 has a coating structure 180 thereon, and the modified metal nanowire 190 is patterned to form the peripheral lead 120 and/or the mark 140. By forming the coating structure 180 at the interface between the metal nanowire 190 and the film layer 130, the conductivity can be increased, so as to fabricate the peripheral lead 120; in addition, in the display area VA, the metal nanowires 190 are in direct contact with the additional film layer 130 (i.e., the metal nanowires 190 in the display area VA are unmodified), in other words, the coating structure 180 is not formed on the surface of the metal nanowires 190 in the display area VA, so that the good optical characteristics of the conductive network formed by the metal nanowires 190 in the display area VA can be maintained.

The number of the peripheral leads 120, the marks 140 and the touch sensing electrodes TE may be one or more, and the numbers shown in the following embodiments and drawings are only for illustrative purposes and do not limit the present invention. Referring to fig. 2, the substrate 110 has a display area VA and a peripheral area PA disposed at a side of the display area VA, for example, the peripheral area PA may be a frame-shaped area disposed at a periphery (i.e. covering a right side, a left side, an upper side and a lower side) of the display area VA, but in other embodiments, the peripheral area PA may be an L-shaped area disposed at the left side and the lower side of the display area VA. As shown in fig. 2, the embodiment has eight sets of peripheral leads 120, all disposed in the peripheral area PA of the substrate 110; the touch sensing electrode TE is disposed in the display area VA of the substrate 110 and electrically connected to the peripheral lead 120. In the present embodiment, two sets of marks 140 are disposed in the peripheral area PA of the substrate 110.

Referring to fig. 3A to 3D, the manufacturing method of the touch panel 100 is shown: first, a substrate 110 having a peripheral area PA and a display area VA defined in advance is provided. Next, disposing unmodified metal nanowires 190 on the substrate 110 to form a metal nanowire layer NWL in the peripheral region PA and the display region VA (see fig. 3A); then, a film 130 is disposed on the unmodified metal nanowires 190, such that the film 130 covers the unmodified metal nanowires 190, and the film 130 is in a pre-cured or incompletely cured state (as shown in fig. 3B); then, patterning is performed to form a patterned metal nanowire layer NWL (as shown in fig. 3C), wherein the metal nanowire layer NWL in the display area VA is patterned to form a touch sensing electrode TE (as shown in fig. 2), and the metal nanowire layer NWL in the peripheral area PA is patterned to form a peripheral lead 120 (as shown in fig. 2); next, a modification step is performed to form a coating structure 180 on the metal nanowires 190 (as shown in fig. 3D), wherein the metal nanowire layer NWL in the display area VA is not modified, and the metal nanowire layer NWL in the peripheral area PA is modified, that is, the peripheral lead 120 is formed by the modified metal nanowires 190 due to the modification step.

The above steps are explained in more detail below.

Referring to fig. 3A, first, a metal nanowire layer NWL, such as a nano-silver wire layer, a nano-gold wire layer, or a nano-copper wire layer, including at least metal nanowires 190 is coated on the peripheral area PA and the display area VA on the substrate 110; the first portion of the metal nanowire layer NWL is mainly located at the display area VA, and the second portion is mainly formed at the peripheral area PA. The embodiment is embodied as follows: the dispersion or slurry (ink) having the metal nanowires 190 is formed on the substrate 110 by a coating method, and dried to allow the metal nanowires 190 to cover the surface of the substrate 110, thereby forming a metal nanowire layer NWL disposed on the substrate 110. After the curing/drying step, the solvent and other substances are volatilized, and the metal nanowires 190 are randomly distributed on the surface of the substrate 110; preferably, the metal nanowires 190 are fixed on the surface of the substrate 110 without falling off to form a metal nanowire layer NWL, and the metal nanowires 190 can contact each other to provide a continuous current path, thereby forming a conductive network (conductive network), in other words, the metal nanowires 190 contact each other at crossing positions to form a path for transferring electrons. Taking silver nanowires as an example, a state of direct contact (i.e., a silver-silver contact interface) is formed at the intersection of one silver nanowire and another silver nanowire, so that a low-resistance electron transfer path is formed, and subsequent modification operations do not affect or change the low-resistance structure of the silver-silver contact, and the surface of the metal nanowire 190 is further coated with the coating structure 180 with high conductivity, so that an effect of improving the electrical characteristics of the terminal product is generated.

In embodiments of the present invention, the dispersion may be water, alcohol, ketone, ether, hydrocarbon or aromatic solvent (benzene, toluene, xylene, etc.); the dispersion may also contain additives, surfactants or binders such as carboxymethylcellulose (CMC), 2-Hydroxyethylcellulose (HEC), Hydroxypropylmethylcellulose (HPMC), sulfonates, sulfates, disulfonates, sulfosuccinates, phosphates or fluorosurfactants, and the like. The dispersion or slurry containing the metal nanowires 190 can be formed on the surface of the substrate 110 and the metal layer ML by any method, such as but not limited to: screen printing, nozzle coating, roller coating and other processes; in one embodiment, the dispersion or slurry containing the metal nanowires 190 can be applied to the surface of the continuously supplied substrate 110 and the metal layer ML by a roll-to-roll (RTR) process.

As used herein, "metal nanowires (metal nanowires)" is a collective term referring to a collection of metal wires comprising a plurality of elemental metals, metal alloys or metal compounds (including metal oxides), wherein the number of metal nanowires contained therein does not affect the scope of the claimed invention; and at least one cross-sectional dimension (i.e., cross-sectional diameter) of the single metal nanowire is less than about 500nm, preferably less than about 100nm, and more preferably less than about 50 nm; the metal nanostructures referred to herein as "wires" have a high aspect ratio, such as between about 10 and 100,000, and more particularly, the metal nanowires may have an aspect ratio (length: diameter of cross section) of greater than about 10, preferably greater than about 50, and more preferably greater than about 100; the metal nanowires can be any metal including, but not limited to, silver, gold, copper, nickel, and gold-plated silver. Other terms such as silk (silk), fiber (fiber), tube (tube), etc. having the same dimensions and high aspect ratios are also within the scope of the present invention.

Referring to fig. 3B, a step of coating the film layer 130 is performed. In one embodiment, the film 130 is disposed on the unmodified metal nanowire 190, such that the film 130 covers the unmodified metal nanowire 190, and then the patterning step and the modifying step are sequentially performed. In an embodiment, the polymer of the film layer 130 after coating may penetrate between the metal nanowires 190 to form a filler, and the metal nanowires 190 may be embedded in the film layer 130 to form a composite structure CS. That is, the unmodified metal nanowire 190 is embedded in the film 130 to form the composite structure CS. In some embodiments of the present invention, the film 130 is formed of an insulating material. For example, the material of the film 130 may be a non-conductive resin or other organic material. In some embodiments of the present invention, the film 130 may be formed by spin coating, spray coating, printing, or the like. In some embodiments, the thickness of the film 130 is about 20 nm to 10 μm, or 50nm to 200 nm, or 30 to 100nm, for example, the thickness of the film 130 may be about 90 nm or 100 nm. For efficient modification, the polymer (i.e., the film layer 130) may be in an incompletely cured or pre-cured state, which is specifically referred to above.

Patterning is then performed as shown in fig. 3C. After the patterning step, the metal nanowire layer NWL and the film layer 130 formed by the unmodified metal nanowires 190 in the display area VA are patterned to form an electrode structure; similarly, the metal nanowire layer NWL and the film layer 130 formed by the unmodified metal nanowires 190 in the peripheral area PA are also patterned to form an electrode structure, and the electrode structures in the two areas constitute an electrode group applicable to touch sensing.

In one embodiment, the metal nanowire layer NWL containing the unmodified metal nanowires 190 in the display area VA and the peripheral area PA can be etched simultaneously, and an etching mask (such as a photoresist) is used to fabricate the patterned metal nanowire layer NWL in the display area VA and the peripheral area PA at one time in the same process. According to one embodiment, when the metal nanowire layer NWL is made of silver nanowires, the etching solution can be used for etching silverComponent, e.g. etching liquid, having H as main component₃PO₄(ratio of about 55% to 70%) and HNO₃(in a ratio of about 5% to 15%) to remove the silver material in the same process. In another specific embodiment, the main component of the etching solution is ferric chloride/nitric acid or phosphoric acid/hydrogen peroxide.

As shown in fig. 3C, the patterned metal nanowire layer NWL fabricated on the peripheral region PA is the peripheral lead 120. In another embodiment, the peripheral leads 120 and the marks 140 (refer to fig. 2) formed by the second portions of the metal nanowire layers NWL can be fabricated on the peripheral region PA. In the embodiment, the mark 140 can be widely interpreted as a pattern with a non-electrical function, but not limited thereto. In some embodiments of the present invention, the peripheral wires 120 and the mark 140 may be fabricated from the same metal nanowire layer NWL.

Also, in the patterning step, the metal nanowire layer NWL of the display area VA is patterned. In other words, the etching mask (e.g., photoresist) may be used to pattern the first portion of the metal nanowire layer NWL of the display area VA with the etching solution to form the touch sensing electrode TE of the present embodiment in the display area VA (as shown in fig. 3C), and the touch sensing electrode TE may be electrically connected to the peripheral lead 120. Specifically, the touch sensing electrode TE may be a metal nanowire layer NWL including at least unmodified metal nanowires 190. In general, the patterned metal nanowire layer NWL forms the touch sensing electrode TE in the display area VA and the peripheral lead 120 in the peripheral area PA, so that the electrodes in the two areas are made of the same layer of material to be electrically connected to transmit signals in the display area VA and the peripheral area PA. In another embodiment, the metal nanowire layer NWL and the film layer 130 may also form the mark 140 in the peripheral region PA, and the mark 140 can be widely interpreted as a pattern with a non-electrical function, but not limited thereto. In some embodiments of the present invention, the peripheral wires 120 and the mark 140 may be fabricated from the same metal nanowire layer NWL.

Referring to fig. 3D, a modification step is performed to form a metal nanowire layer NWL composed of a plurality of modified metal nanowires 190. That is, after the modification, at least a portion of the initial metal nanowires 190 in the metal nanowire layer NWL is modified to form the coating structure 180 on the surface thereof to form the modified metal nanowires 190. In one embodiment, the coating structure 180 may be formed by a chemical plating method, and the chemical plating solution is used to permeate into the incompletely cured film layer 130, so that the reactive metal ions in the chemical plating solution are deposited on the surface of the metal nanowire 190 to form the coating structure 180, which may be a layer structure, an island-shaped protrusion structure, a point-shaped protrusion structure or a combination thereof made of a conductive material; the coating structure 180 may also be a single-layer or multi-layer structure made of a single material or an alloy material, or a single-layer or multi-layer structure made of multiple materials or alloy materials.

It is noted that the modification step is performed along the surface of the metal nanowire 190, so that the shape of the coating structure 180 is substantially the same as the shape of the metal nanowire 190. In the modification step, the growth conditions (such as chemical plating time, chemical plating solution composition concentration, etc.) of the coating structure 180 can be controlled, so that the coating structure 180 is not excessively grown, and only coats the surface of the metal nanowire 190; in addition, as mentioned above, the incompletely cured film 130 also plays a role of limiting and controlling. Accordingly, the coating structure 180 formed in the modification step does not separate out or grow on the film layer 130 and does not contact the metal nanowire 190, and the coating structure 180 is formed between the surface of the metal nanowire 190 and the film layer 130; in one embodiment, the film 130 is filled between adjacent metal nanowires 190. On the other hand, the coating structure 180 formed by the chemical plating/electrolytic plating has high density, and compared with the size (e.g. 10um line width) of the peripheral lead 120, the defect size of the coating structure 180 is 0.01-0.001 times of the size of the peripheral lead 120, so even if the coating structure 180 has defects, the problems of wire breakage and the like of the peripheral lead 120 are not caused.

Referring to fig. 3D, in some embodiments of the present invention, the modification step is performed only in the peripheral region PA, and a "v" symbol is drawn in the touch sensing electrode TE shown in fig. 3D to represent that the touch sensing electrode TE includes the unmodified initial metal nanowire 190; while the "o" symbol is drawn in the peripheral wire 120 shown in fig. 3D to represent that the peripheral wire 120 is composed of the modified metal nanowire 190, the coating structure 180 is not drawn in fig. 3D for simplicity of illustration. In detail, after the patterning step, a photoresist or the like is covered on the display area VA to shield the touch sensing electrode TE, so that the chemical plating solution permeates into the incompletely cured film layer 130 in the peripheral area PA, and the reactive metal ions are precipitated on the surface of the metal nanowire 190 in the peripheral area PA by the redox reaction to form the coating structure 180, so as to form the modified metal nanowire 190. Since the touch sensing electrode TE is still formed by the metal nanowire 190 before modification, it has good light transmittance, for example, the light transmittance (Transmission) of visible light (e.g. wavelength between 400nm and 700nm) is greater than about 90%, 91%, 92%, 93% or more.

A curing step may be further included to bring the pre-cured or incompletely cured film 130 to a fully cured state.

Through the above steps, the touch panel 100 shown in fig. 2 can be manufactured, for example, the patterned metal nanowire layer NWL in the display area VA constitutes the touch sensing electrode TE of the touch panel 100; the patterned metal nanowire layer NWL in the peripheral area PA forms the peripheral lead 120 of the touch panel 100, and the metal nanowires 190 in the peripheral lead 120 have a coating structure 180 (the modified metal nanowires 190 are denoted by "o" symbols in the drawings), and the peripheral lead 120 can be connected to an external controller for performing touch control or other signal transmission. As described above, the coating structure 180 may have the same or similar structural appearance as the metal nanowires 190, and the film 130 is filled between the adjacent metal nanowires 190.

In an alternative embodiment, the touch panel 100 of the present invention can be manufactured by different process sequences, for example, first providing the substrate 110 having the predefined peripheral area PA and the predefined display area VA thereon. Then, disposing the unmodified metal nanowires 190 on the substrate 110 to form a metal nanowire layer NWL in the peripheral area PA and the display area VA; then, a film 130 is arranged on the unmodified metal nanowires 190, so that the film 130 covers the unmodified metal nanowires 190, and the film 130 is in a pre-cured or incompletely cured state; then, a modification step is performed, in which a coating structure 180 is formed on the metal nanowires 190, wherein the metal nanowires 190 located in the display area VA are not modified, and the metal nanowires 190 located in the peripheral area PA are modified; then, patterning is performed to form a patterned metal nanowire layer NWL, wherein the metal nanowire layer NWL before modification in the display area VA is patterned to form the touch sensing electrode TE, and the metal nanowire layer NWL after modification in the peripheral area PA is patterned to form the peripheral lead 120, that is, the peripheral lead 120 is formed by the modified metal nanowires 190 due to the above-mentioned modification step.

Hereinafter, only the adjusted steps will be described, and the remaining omitted portions can be referred to the description of the foregoing embodiments.

In the modification step of this embodiment, a photoresist or the like may be covered on the display area VA to shield the first portion of the metal nanowire layer NWL of the display area VA, and only the second portion of the metal nanowire layer NWL of the peripheral area PA is modified, so that the reactive metal ions in the electroless plating solution are separated out on the surface of the metal nanowires 190 of the peripheral area PA to form the coating structure 180, so as to form the modified metal nanowires 190.

In the patterning step of the present embodiment, an etching solution capable of simultaneously etching the pre-modified metal nanowire 190 and the post-modified metal nanowire 190 may be used in conjunction with an etching mask (such as a photoresist) to fabricate the patterned metal nanowire layer NWL in the display area VA and the peripheral area PA at one time in the same process. In one embodiment, the etching of the pre-modified metal nanowire 190 and the post-modified metal nanowire 190 may be performed simultaneously, which means that the etching rate ratio of the etching medium to the pre-modified metal nanowire 190 and the post-modified metal nanowire 190 is about 0.1-10 or 0.01-100.

According to one embodiment, the metal nanowire layer NWL is made of silver nanowires, and with a copper coating structure 180 on the surface, the etching solution can be used for etching copper and silver components, for example, the etching solution has a main component H₃PO₄(ratio of about 55% to 70%) and HNO₃(in a ratio of about 5% to 15%) to remove the copper material and the silver material in the same process. In a further embodiment of the method according to the invention,the main component of the etching solution is ferric chloride/nitric acid or phosphoric acid/hydrogen peroxide.

In the patterning step, an etching mask (e.g., photoresist) may be used to pattern the first portion of the metal nanowire layer NWL of the display area VA with the etching solution to form the touch sensing electrode TE of the present embodiment in the display area VA, and the touch sensing electrode TE may be electrically connected to the peripheral lead 120. Specifically, the touch sensing electrode TE may be a metal nanowire layer NWL including at least the pre-modified metal nanowires 190. In the peripheral area PA, the modified metal nanowires 190 form the peripheral lead 120, so that the touch sensing electrode TE is electrically connected to the peripheral lead 120 for signal transmission. In the embodiment, the mark 140 may also be formed on the metal nanowire layer NWL in the peripheral region PA, and the mark 140 may be widely interpreted as a pattern with a non-electrical function, but not limited thereto. In some embodiments of the present invention, the peripheral lead 120 and the mark 140 may be fabricated by using the modified metal nanowire 190 in the same layer.

In an alternative embodiment, the metal nanowire layer NWL in the display area VA and the peripheral area PA may be patterned by different etching steps (i.e. different etching solutions are used), for example, in the case that the metal nanowire layer NWL is a nano-silver layer and the coating structure 180 is a copper layer, the etching solution used in the display area VA may be an etching solution having an etching capability only for silver, and the etching solution used in the peripheral area PA may be an etching solution having an etching capability for silver/copper.

The touch panel 100 of the present invention can be manufactured by the above steps, and the specific structure is as described above, which is not described herein again.

Referring back to fig. 2, fig. 2A and fig. 2B, for convenience of description, the cross section of the peripheral leads 120 and the marks 140 is a quadrilateral (e.g., a rectangle drawn in fig. 2A), but the structural types or the number of the peripheral leads 120 and the marks may vary according to practical applications and is not limited by the text and the drawings herein.

In the present embodiment, the mark 140 is a bonding area BA (see fig. 2 and fig. 2A) disposed in the peripheral area PA, which can be a butt alignment mark, i.e., a mark for aligning a flexible circuit board (not shown) with the touch panel 100 in a step of connecting an external circuit board, such as a flexible circuit board, to the touch panel 100 (i.e., a bonding step). However, the present invention is not limited to the placement or function of the mark 140, for example, the mark 140 may be any inspection mark, pattern or label required in the manufacturing process, and all such features are within the scope of the present invention. The indicia 140 may have any possible shape, such as a circle, a quadrilateral, a cross, an L-shape, a T-shape, and so forth.

As shown in fig. 2A, in the peripheral region PA, a non-conductive region 136 is disposed between adjacent peripheral wires 120 to electrically isolate the adjacent peripheral wires 120 and avoid short circuit. In the present embodiment, the non-conductive region 136 is a gap to isolate the adjacent peripheral wires 120.

As shown in fig. 2B, in the display area VA, a non-conductive area 136 is disposed between the adjacent touch sensing electrodes TE to electrically block the adjacent touch sensing electrodes TE and thus avoid short circuit. That is, the non-conductive region 136 is disposed between the side surfaces of the adjacent touch sensing electrodes TE, and in the present embodiment, the non-conductive region 136 is a gap to isolate the adjacent touch sensing electrodes TE; in one embodiment, the above-mentioned etching method can be used to fabricate the gap between the adjacent touch sensing electrodes TE. In the present embodiment, the touch sensing electrode TE and the first middle layer M1 can be fabricated by using the same metal nanowire layer NWL (e.g. a nano silver wire layer), so that the metal nanowire layer forms the touch sensing electrode TE in the display area VA and the peripheral lead 120 in the peripheral area PA, and the touch sensing electrode TE and the peripheral lead 120 form a connection structure at the boundary between the display area VA and the peripheral area PA, so as to form a conductive circuit between the touch sensing electrode TE and the peripheral lead 120.

In some embodiments of the present invention, the peripheral lead 120 of the touch panel 100 can be formed by a direct yellow light and etching process, which is a high precision process and does not need to be aligned, so that an alignment error space does not need to be reserved in the peripheral region, thereby reducing the width of the peripheral region PA and further achieving the narrow frame requirement of the display. Specifically, the width of the peripheral leads 120 of the touch panel 100 according to some embodiments of the present invention is about 5um to 30um, the distance between adjacent peripheral leads 120 is about 5um to 30um, or the width of the peripheral leads 120 of the touch panel 100 is about 3um to 20um, the distance between adjacent peripheral leads 120 is about 3um to 20um, and the width of the peripheral area PA can also reach a size smaller than about 2mm, which is reduced by about 20% or more compared with the conventional touch panel product.

As shown in fig. 2, the touch sensing electrodes TE are arranged in a non-staggered manner. For example, the touch sensing electrode TE is a strip-shaped electrode extending along the first direction D1 and having a width varying along the second direction D2, and the touch sensing electrode TE is not staggered with each other. In the present embodiment, the touch sensing electrodes TE are configured in a single layer, wherein the touch position can be obtained by detecting the capacitance change of each touch sensing electrode TE.

In the present embodiment, the composite structure CS (i.e., the combination of the unmodified metal nanowires 190 and the film layer 130) of the display area VA may have conductivity and light transmittance, for example, the light transmittance (Transmission) of visible light (e.g., wavelength between about 400nm-700nm) of the touch sensing electrode TE may be greater than about 80%, and the surface resistivity (surface resistance) is between about 10 to 1000 ohm/square (ohm/square); alternatively, the transmittance (Transmission) of visible light (e.g., wavelength between about 400nm-700nm) of the touch sensing electrode TE is greater than about 85%, and the surface resistivity (surface resistance) is between about 50-500 ohm/square (ohm/square). In one embodiment, the transmittance (Transmission) of visible light (e.g., having a wavelength between about 400nm and 700nm) of the touch sensing electrode TE is greater than about 88% or greater than about 90%. In an embodiment, the haze of the touch sensing electrode TE is less than 3.0, 2.5, 2.0, or 1.5.

In some embodiments, the metal nanowires 190 may be further post-treated to improve the contact characteristics of the metal nanowires 190 at the crossing points, such as increasing the contact area and thus the conductivity, and the post-treatment may be a process step including heating, plasma, corona discharge, UV ozone, pressure, or a combination thereof. For example, after the step of curing to form the metal nanowire layer, the metal nanowire layer may be formedApplying pressure thereto using rollers, in one embodiment, a pressure of 50 to 3400psi, preferably 100 to 1000psi, 200 to 800psi, or 300 to 500psi may be applied to the metal nanowire layer by one or more rollers; the step of applying pressure is preferably performed before the step of coating the film layer 130. In some embodiments, the post-treatment with heat and pressure may be performed simultaneously; in particular, the metal nanowires 190 may be formed by applying pressure via one or more rollers as described above while heating, for example, the pressure applied by the rollers is 10 to 500psi, preferably 40 to 100 psi; simultaneously, the roller is heated to a temperature between about 70 ℃ and 200 ℃, preferably between about 100 ℃ and 175 ℃, which improves the conductivity of the metal nanowires 190. In some embodiments, the metal nanowires 190 may preferably be exposed to a reducing agent for post-treatment, for example, the metal nanowires 190 comprising nano-silver wires may preferably be exposed to a silver reducing agent for post-treatment, the silver reducing agent comprising a borohydride, such as sodium borohydride; boron nitrogen compounds such as Dimethylaminoborane (DMAB); or gaseous reducing agents, such as hydrogen (H)₂) (ii) a And the exposure time is from about 10 seconds to about 30 minutes, preferably from about 1 minute to about 10 minutes. Through the post-treatment step, the contact strength or area of the metal nanowire 190 at the intersection point can be enhanced, and the contact surface (i.e., the first surface 191) of the metal nanowire 190 at the intersection point can be further ensured not to be affected by the modification treatment.

In an embodiment, the touch panel 100 further includes a protection layer 150, which can be applied to various embodiments, and the embodiment of fig. 2B is merely used as an example. FIG. 4 shows a cross-sectional view of a protective layer 150 formed on the embodiment of FIG. 2B. It is noted that the material of the protection layer 150 can refer to the exemplary material of the film layer 130 described above. In one embodiment, the passivation layer 150 covers the touch panel 100 in a full-face manner, that is, the passivation layer 150 covers the touch sensing electrodes TE, the peripheral leads 120 and the marks 140. The passivation layer 150 may fill the non-conductive region 136 between the adjacent peripheral wires 120 to isolate the adjacent peripheral wires 120, or the passivation layer 150 may fill the non-conductive region 136 between the adjacent touch sensing electrodes TE to isolate the adjacent touch sensing electrodes TE.

Fig. 5 is a schematic top view of a touch panel 100 according to some embodiments of the present invention, in which the touch sensing electrode TE of the present embodiment adopts a double-layer configuration; FIG. 5A is a cross-sectional view taken along line A-A of FIG. 5.

For convenience of description, the configuration adopted in the present embodiment is described with reference to the first touch electrode TE1 and the second touch electrode TE 2. The first touch electrode TE1 is formed on one surface (such as the upper surface) of the substrate 110, and the second touch electrode TE2 is formed on the other surface (such as the lower surface) of the substrate 110, so that the first touch electrode TE1 and the second touch electrode TE2 are electrically insulated from each other; the first touch electrode TE1 is electrically connected to its corresponding peripheral lead 120; similarly, the second touch electrode TE2 is connected to its corresponding peripheral lead 120. The first touch electrode TE1 is a plurality of strip electrodes arranged along the first direction D1, and the second touch electrode TE2 is a plurality of strip electrodes arranged along the second direction D2. As shown in the figure, the extending directions of the elongated touch sensing electrodes TE1 and the elongated touch sensing electrodes TE2 are different and are staggered with each other. The first touch sensing electrode TE1 and the second touch sensing electrode TE2 can be used for transmitting a control signal and receiving a touch sensing signal, respectively. From this, the touch position can be obtained by detecting the signal change (e.g. capacitance change) between the first touch sensing electrode TE1 and the second touch sensing electrode TE 2. With this arrangement, a user can perform touch sensing at each point on the substrate 110. As in the foregoing embodiments, the first touch sensing electrode TE1 and/or the second touch sensing electrode TE2 can be made of at least unmodified metal nanowires 190 and film 130, and the peripheral leads 120 and/or marks 140 (fig. 5 and 5A do not depict the marks 140, but do not affect the description of the embodiment) on both sides of the substrate 110 can be made of modified metal nanowires 190 and film 130, that is, the peripheral leads 120 and/or marks 140 on both sides of the substrate 110 can be formed by molding the coating structure 180 on the surface of the metal nanowires 190 according to the foregoing method.

The double-sided touch panel manufactured in the embodiment of the invention can be manufactured as follows: first, a substrate 110 having a peripheral area PA and a display area VA defined in advance is provided. Then, forming metal nanowire layers NWL on the peripheral regions PA and the display regions VA of the first and second surfaces (e.g., the upper surface and the lower surface) of the substrate 110 respectively; then, forming a film layer 130 which is not completely cured on the metal nanowire layer NWL; then, performing a double-sided patterning step, such as double-sided photolithography, etching, etc., to form a patterned metal nanowire layer NWL on the first and second surfaces of the substrate 110; then, a double-sided modification step is performed to form a coating structure 180 on the metal nanowires 190 on the upper and lower surfaces of the substrate 110, for example, a modification step is performed on the peripheral regions PA on the upper and lower surfaces of the substrate 110, and the modified metal nanowires 190 constitute the peripheral leads 120.

In one embodiment, the patterned product may be immersed in a plating solution while modifying the upper and lower surfaces of the substrate 110.

Like the previous embodiment, any side (such as the upper surface or the lower surface) of the substrate 110 may further include a mark 140, which is also composed of the modified metal nanowires 190.

It should be noted that, the above embodiments applied to the double-sided touch panel can refer to the above description of the single-sided touch panel, and the implementation methods illustrated in the foregoing paragraphs are only exemplary and are not intended to limit the present invention.

The method for manufacturing the double-sided touch panel according to the embodiment of the invention may be formed by laminating two sets of single-sided touch panels in the same direction or in opposite directions. For example, the touch electrodes of the first set of single-sided touch panels are disposed upward (e.g., closest to the user, but not limited thereto), the touch electrodes of the second set of single-sided touch panels are disposed downward (e.g., farthest from the user, but not limited thereto), and the substrates of the two sets of touch panels are fixed by an optical adhesive or other similar adhesive, thereby forming a double-sided touch panel.

Fig. 6 is a schematic top view of a touch panel 100 according to a portion of the present embodiment, in which the touch panel 100 further includes shielding wires 160 disposed in the peripheral area PA. The shielding wire 160 mainly surrounds the touch sensing electrode TE and the peripheral lead 120, and the shielding wire 160 extends to the bonding area and is electrically connected to the ground terminal of the flexible circuit board, so that the shielding wire 160 can shield or eliminate signal interference or Electrostatic Discharge (ESD) protection, especially small current change caused by touching the connecting wire around the touch device by a human hand.

The shielding wire 160 may be made of modified metal nanowires 190, which may be referred to the description of the peripheral lead 120 or the mark 140. In some embodiments of the present invention, the shielding wire 160, the peripheral lead 120 and the mark 140 may be fabricated by using the modified metal nanowire 190 and the film layer 130 in the same layer, and the metal nanowire 190 (e.g., a nano-silver wire layer) may be modified to have the coating structure 180 according to the above-mentioned process, which may be referred to the above-mentioned implementation methods; the touch sensing electrode TE is made of an unmodified metal nanowire layer NWL.

Fig. 7 shows another embodiment of the single-sided touch panel 100 according to the present invention, which is a single-sided bridge type touch panel. This embodiment is different from the above embodiments at least in that the touch sensing electrode TE formed by the transparent conductive layer (i.e., the metal nanowire layer NWL) formed on the substrate 110 after the patterning step may include: the first touch sensing electrode TE1 arranged along the first direction D1, the second touch sensing electrode TE2 arranged along the second direction D2, and the connecting electrode CE electrically connecting two adjacent first touch sensing electrodes TE1, that is, the first touch sensing electrode TE1, the second touch sensing electrode TE2, and the connecting electrode CE are made of unmodified metal nanowires 190 and the film layer 130; in addition, the insulating block 164 may be disposed on the connection electrode CE, for example, the insulating block 164 is formed of silicon dioxide; the bridging wires 162 are disposed on the insulating block 164, for example, the bridging wires 162 are formed by copper/ITO/metal nanowires, and the bridging wires 162 are connected to two adjacent second touch sensing electrodes TE2 in the second direction D2, and the insulating block 164 is disposed between the connecting electrode CE and the bridging wires 162 to electrically isolate the connecting electrode CE and the bridging wires 162, so that the touch sensing electrodes in the first direction D1 and the second direction D2 are electrically isolated from each other.

In addition, after the metal nanowire layer NWL in the peripheral area PA is subjected to the patterning and modifying steps, the modified metal nanowires 190 and the film layer 130 can be used to manufacture the peripheral lead 120, which is electrically connected to the first touch sensing electrode TE1 and the second touch sensing electrode TE2, so as to transmit signals.

For the specific implementation, reference is made to the foregoing description, which is not repeated herein.

The metal nanowire modification method of the present invention can be applied to the fabrication of sensing electrodes without considering transmittance, such as a touch panel (but not limited thereto) of a notebook computer, an antenna structure, a wireless charging coil, and the like. Specifically, the method for fabricating the sensing electrode includes disposing unmodified metal nanowires 190 on the substrate 110 to form a metal nanowire layer NWL on the substrate 110; then, arranging a film layer 130 on the unmodified metal nanowire 190, so that the film layer 130 covers the unmodified metal nanowire 190, and the film layer 130 is in a pre-cured or incompletely cured state; patterning to form a metal nanowire layer NWL with patterns so as to manufacture an induction electrode for sensing a touch position/a touch gesture; then, a modification step is performed to form a coating structure 180 on the metal nanowire 190, so that the patterned metal nanowire layer NWL is modified, that is, due to the modification step, the sensing electrode for sensing the touch position/touch gesture is formed by the modified metal nanowire 190. As in the previous embodiments, the coating structure 180 may have the same or similar structural appearance as the metal nanowires 190, and the film layer 130 is filled between the adjacent metal nanowires 190. Since the objects such as a touch panel, an antenna structure, and a wirelessly charged coil of a notebook computer do not need to transmit light, the modified metal nanowire 190 may be used to fabricate an inductive electrode.

The sensing electrode of the present embodiment can be connected to the trace for connecting with the external circuit to transmit signals. The routing of the present embodiment can be equivalent to the peripheral lead 120, and is also composed of the modified metal nanowire 190; in another embodiment, the traces can be made of other conductive materials, such as silver traces, copper traces, and the like.

In another embodiment, the modifying step and the patterning step may be mutually adjusted in order.

The specific implementation method of the above steps can be referred to the above.

The method for modifying metal nanowires of the present invention can be applied to manufacture electrode plates without patterns, such as a cathode plate/an anode plate of a battery (but not limited thereto). Specifically, the method of fabricating the electrode plate includes disposing unmodified metal nanowires 190 on the substrate 110 to form a metal nanowire layer NWL on the substrate 110; then, arranging a film layer 130 on the unmodified metal nanowire 190, so that the film layer 130 covers the unmodified metal nanowire 190, and the film layer 130 is in a pre-cured or incompletely cured state; then, a modification step is performed to form a coating structure 180 on the metal nanowire 190, so that the metal nanowire layer NWL is modified, that is, due to the modification step, the electrode plate on the whole surface of the substrate is formed by the modified metal nanowire 190. As in the previous embodiments, the coating structure 180 may have the same or similar structural appearance as the metal nanowires 190, and the film layer 130 is filled between the adjacent metal nanowires 190.

The electrode plate of the present embodiment can be connected to the trace for connecting with the external circuit to transmit signals. The routing of the present embodiment can be equivalent to the peripheral lead 120, and is also composed of the modified metal nanowire 190; in another embodiment, the traces can be made of other conductive materials, such as silver traces, copper traces, and the like.

In some embodiments, the touch panel 100/sensing electrodes/electrode plates described herein can be manufactured by a Roll-to-Roll (Roll to Roll) process, which uses conventional equipment and can be fully automated, thereby significantly reducing the cost of manufacturing the touch panel. The roll-to-roll coating process comprises selecting a flexible substrate 110, mounting the substrate 110 between two rollers, and driving the rollers by a motor to make the substrate 110 continuously move along the movement path between the two rollers. For example, a slurry containing the metal nanowires 190 is deposited on the surface of the substrate 110 using a storage tank, a spraying device, a brushing device, and the like to form the metal nanowires 190; using a spray head to deposit the polymer on the surface of the substrate 110, and curing the polymer into the film 130, patterning and modifying. Subsequently, the completed touch panel 100 is rolled out by a roller at the rearmost end of the production line to form a touch sensor roll tape.

The touch sensor tape of the present embodiment may further include the protection layer 150, which covers the uncut touch panel 100 on the touch sensor roll in a full-scale manner, that is, the protection layer 150 may cover the uncut touch panels 100 on the touch sensor roll, and then be cut and separated into the individual touch panels 100.

In some embodiments of the present invention, the substrate 110 is preferably a transparent substrate, and more particularly, may be a rigid transparent substrate or a flexible transparent substrate, and the material thereof may be selected from transparent materials such as glass, acryl (PMMA), polyvinyl Chloride (PVC), polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), Polycarbonate (PC), Polystyrene (PS), Cyclic Olefin Polymers (COP), Colorless Polyimide (CPI), Cyclic Olefin Copolymers (COC), and the like. In order to improve the adhesion between the substrate 110 and the metal nanowires 190, a pretreatment process, such as a surface modification process, may be preferably performed on the substrate 110, or an adhesive layer or a resin layer may be additionally coated on the surface of the substrate 110.

In some embodiments of the present invention, the metal nanowires 190 may be silver nanowires or silver nanofibers (silver nanofibers) that may have an average diameter of about 20 to 100 nanometers, an average length of about 20 to 100 micrometers, preferably an average diameter of about 20 to 70 nanometers, and an average length of about 20 to 70 micrometers (i.e., an aspect ratio of 1000). In some embodiments, the metal nanowires 190 can have a diameter of 70 nm to 80 nm and a length of about 8 μm.

The roll-to-roll line may adjust the sequence of multiple coating steps as desired along the path of motion of the substrate or may incorporate any number of additional stations as desired. For example, pressure rollers or plasma equipment may be installed in the production line to achieve proper post-processing.

The touch panel of the embodiment of the invention can be assembled with other electronic devices, such as a display with touch function, for example, the substrate 110 can be attached to a display module, such as a liquid crystal display module or an Organic Light Emitting Diode (OLED) display module, and the two can be attached by an optical adhesive or other similar adhesives; the touch sensing electrode TE can be bonded to an outer cover layer (e.g., a protective glass) by using an optical adhesive. The touch panel, the antenna and the like in the embodiment of the invention can be applied to electronic equipment such as a portable phone, a tablet computer, a notebook computer and the like, and can also be applied to flexible products. The electrodes of the embodiments of the invention can also be fabricated on a polarizer. The electrode of the embodiment of the invention can also be manufactured on wearable devices (such as watches, glasses, intelligent clothes, intelligent shoes and the like) and vehicle devices (such as instrument panels, driving recorders, vehicle rearview mirrors, vehicle windows and the like).

Other details of this embodiment are substantially as described above, and will not be further described herein.

The structures of the different embodiments of the present invention may be cited with each other, and are not intended to be limited to the specific embodiments described above.

In some embodiments of the present invention, the metal nanowire 190 is modified, so that the modified metal nanowire 190 has better conductive characteristics than before the modification.

In some embodiments of the present invention, the modified metal nanowires 190 are directly fabricated into the peripheral leads and/or marks, so that the error space reserved in the alignment process can be eliminated, and the width of the peripheral region can be effectively reduced.

In some embodiments of the present invention, the modification may be performed on conductive nanostructures on one or both sides of the substrate.

In some embodiments of the present invention, an additive process (i.e., a process is performed directly on the conductive nano-structure) is used instead of a subtractive process, thereby increasing the process efficiency and reducing the material cost.

Some embodiments of the present invention can be applied to a flexible conductive substrate.

In some embodiments of the present invention, the exposed surface of the metal nanowire 190 is entirely covered by the coating structure, that is, the coating structure is spaced between the metal nanowire and the film layer.

In some embodiments of the present invention, the coating structure is not layered or stacked on the metal nanowire layer in a block-like manner, but is affected by the initial form of the metal nanowires, and the metal nanowires are used as seed crystals and limited by the film layer to uniformly grow along the interface between the metal nanowires and the film layer.

In some embodiments of the present invention, the film layer serves as a limiting layer to limit/control the growth of the coating structure along the exposed surface of the metal nanowire 190. Due to the spacing layer, the coating structure can be uniformly grown on the exposed surface of the metal nanowire 190.

In some embodiments of the present invention, the growth of the coating structure is controlled and uniform.

While the invention has been described with respect to various embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. An electrode, comprising: the conductive nano structure comprises a conductive nano structure and a film layer which is externally added to the conductive nano structure, wherein the interface of the conductive nano structure and the film layer is substantially provided with a coating structure.

2. The electrode of claim 1, wherein the coating structure comprises a plating layer that completely covers an interface between the conductive nanostructure and the film layer.

3. The electrode of claim 1, wherein the film has an incompletely cured state, and the coating structure is formed along a surface of the conductive nanostructure and at an interface between the conductive nanostructure and the film.

4. The electrode of claim 3, wherein in the incompletely cured state, the layer has a first layer region and a second layer region, the second layer region having a higher cured state than the first layer region; in the first layer region, the coating structure is formed along the surface of the conductive nanostructure and located at the interface between the conductive nanostructure and the film layer.

5. The electrode of claim 1, wherein the film is filled between adjacent conductive nanostructures, and the coating structure is absent in the film.

6. The electrode of claim 1, wherein the conductive nanostructures comprise metal nanowires, and the coating completely covers the interface between the metal nanowires and the film layer, and forms a uniform coating layer at the interface.

7. The electrode of claim 1, wherein the coating structure is a layer structure, an island-like protrusion structure, a dot-like protrusion structure or a combination thereof made of a conductive material.

8. The electrode of claim 7, wherein the conductive material is silver, gold, copper, nickel, platinum, iridium, rhodium, palladium, osmium, or an alloy comprising the foregoing.

9. The electrode of claim 1, wherein the coating structure is a single layer structure made of a single metal material or an alloy material; or the coating structure is a two-layer or multi-layer structure made of more than two metal materials or alloy materials.

10. The electrode of claim 1, wherein the coating structure is an electroless copper plating layer, an electrolytic copper plating layer, an electroless copper nickel plating layer, an electroless silver plating layer, or a combination thereof.

11. A method of making an electrode, comprising:

applying a film layer on a conductive layer containing conductive nanostructures and allowing the film layer to reach a pre-cured or incompletely cured state; and

and performing a modification step to form a coating structure on at least a part of the surface of the conductive nanostructure, so that the interface between the conductive nanostructure and the film layer substantially has the coating structure.

12. The method of claim 11, wherein the step of modifying comprises immersing the film and the conductive nanostructures in an electroless plating solution, the electroless plating solution penetrating into the film and contacting the conductive nanostructures to deposit metal on the surfaces of the conductive nanostructures.

13. The method of claim 12, wherein the coating structure is formed along a surface of the conductive nanostructure at an interface between the conductive nanostructure and the film.

14. The method of claim 11, wherein applying a film layer over a conductive layer comprising conductive nanostructures comprises:

coating a polymer on the conductive layer;

the curing conditions are controlled to bring the polymer to a pre-cured or incompletely cured state.

15. The method of claim 11, wherein applying a film layer over a conductive layer comprising conductive nanostructures comprises:

coating a polymer on the conductive layer;

controlling the curing conditions to enable the polymer to reach a pre-curing state or an incomplete curing state, wherein the pre-curing state or the incomplete curing state of the film layer is provided with a first layer area and a second layer area, and the curing state of the second layer area is higher than that of the first layer area.

16. The method of claim 15, wherein the coating structure is formed along the surface of the conductive nanostructure and at the interface between the conductive nanostructure and the film layer in the first layer region.

17. The method of claim 15, wherein controlling the curing conditions comprises introducing a gas and controlling the concentration of the gas in the first layer region and the second layer region.

18. The method of claim 11, wherein the modifying step comprises an electroless plating step, an electroplating step, or a combination thereof.

19. A device comprising the electrode of claim 1.

20. The device of claim 19, wherein the device comprises a touch panel, a touch pad, an antenna structure, a coil, an electrode plate, a display, a portable phone, a tablet computer, a wearable device, a vehicular device, a notebook computer, or a polarizer.