Touch device and manufacturing method thereof

The present disclosure provides a touch device and a manufacturing method thereof. The touch device includes a substrate, a touch electrode layer, a protective layer, and a plurality of wires. The substrate includes a first region and a second region, in which the second region is adjacent to the first region. The touch electrode layer is disposed in the first region and is completely covered by the protective layer. The protective layer has a plurality of openings. The openings expose a portion of the touch electrode layer and extend from the first region to the second region. Each wire is formed in the corresponding openings and extends from the portion of the touch electrode layer to the second region, in which each opening is partially filled with one of the wires, and thereby a recess is defined in each opening.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to China Application Serial Number 201910450935.2, filed May 28, 2019, which is herein incorporated by reference.

BACKGROUND

Field of Invention

The present disclosure relates to a touch device and a manufacturing method thereof.

Description of Related Art

At present, silver nanowires have been widely adopted as electrode material for touch devices. However, during the etching process of forming traces, silver nanowires are prone to be attacked by the etching liquid if the material of trace is copper and the trace is in direct contact with the silver nanowires. This is due to the low selectivity of the etching liquid to copper and silver nanowires. In addition, the etching liquid remained at the interface between copper and silver after the etching process can render the formation of copper-silver crystals, thereby causing short circuit issue of the traces. Furthermore, the interface adhesion between copper and silver nanowires is poor. Therefore, a new design is needed to solve the foregoing problems.

SUMMARY

One aspect of the present disclosure is to provide a touch device. The touch device comprises a substrate, a touch electrode layer, a protective layer, and a plurality of lead wires. The substrate comprises a first region and a second region. The second region is adjacent to the first region. The touch electrode layer is disposed in the first region. The touch electrode layer in the first region is covered by the protective layer. The protective layer has a plurality of openings exposing a portion of the touch electrode layer, and the openings extend from the first region to the second region. Each lead wire is formed in corresponding one of the openings and extends from the portion of the touch electrode layer to the second region. Each opening is partially filled with one of the lead wire, and thereby a recess is defined in each opening.

In one embodiment of the present disclosure, the touch electrode layer comprises silver nanowires, gold nanowires, copper nanowires, carbon nanotubes, or a combination thereof.

In one embodiment of the present disclosure, a thickness of the protective layer ranges from 1 μm to 15 μm.

In one embodiment of the present disclosure, a depth of each recess ranges from 1 μm to 15 μm, and the depth of each recess is less than the thickness of the protective layer.

In one embodiment of the present disclosure, the depth of each recess is less than the thickness of the protective layer.

In one embodiment of the present disclosure, the lead wires comprise gold, silver, copper, molybdenum, titanium, aluminium, nickel, or a combination thereof.

In one embodiment of the present disclosure, each of the lead wires is conformally formed in the openings.

In one embodiment of the present disclosure, the lead wires in the openings are in direct contact with the substrate.

Another aspect of the present disclosure is to provide a method of manufacturing touch device. The method comprises the steps of providing a substrate comprising a first region and a second region adjacent to the first region; forming a touch electrode layer in the first region; forming a protective layer covering the touch electrode layer, in which the protective layer has a plurality of openings exposing a portion of the touch electrode layer, and the openings extend from the first region to the second region; and forming a plurality of lead wires, in which each lead wire is formed in a corresponding one of the openings and extend from the portion of the touch electrode layer to the second region, each opening is partially filled with one of the lead wire, and thereby a recess is defined in each opening.

In one embodiment of the present disclosure, the step of forming the lead wires in the openings comprises conformally forming the lead wires in the openings.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. The embodiments disclosed herein may be combined or substituted with each other in an advantageous manner, and other embodiments may be added to an embodiment without further description or description.

In the following description, numerous specific details are set forth in the following detailed description. However, embodiments of the present disclosure may be practiced without such specific details. In order to simplify the drawings, well-known structures and devices are only schematically shown in the figure.

One aspect of the present disclosure is to provide a touch device and a manufacturing method thereof. The touch device can avoid short circuit problem of traces.FIG. 1illustrates a flow chart of a method100of manufacturing a touch device according to one embodiment of the present disclosure. Referring toFIG. 1, method100includes step S110to step S140. Step S110includes providing a substrate110.

Reference is made toFIG. 2AandFIG. 2B.FIG. 2Aillustrates a top view during one stage of the method of manufacturing the touch device according to one embodiment of the present disclosure.FIG. 2Billustrates a schematic sectional view along line A-A′ inFIG. 2A. As shown inFIG. 2B, the substrate110comprises a first region R1and a second region R2. The second region R2is adjacent to the first region R1. In one embodiment, the substrate110may be a rigid transparent substrate or a flexible transparent substrate, such as glass, polymethylmethacrylate (PMMA), polyvinyl chloride (PVC), polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polystyrene, (PS), and the like, but is not limited thereto.

Next, step S120is performed to form a touch electrode layer in the first region.FIG. 2A,FIG. 3A,FIG. 4A, andFIG. 5Aare top views during various process stages for implementing step S120.FIG. 2B,FIG. 3B,FIG. 4B, andFIG. 5Bare respectively schematic cross-sectional view along line A-A′ inFIG. 2AtoFIG. 5A.

As shown inFIG. 2AandFIG. 2B, in one embodiment, an electrode material layer120is formed on the substrate110. The formation technique of the electrode material layer120includes but not limited to forming a layer of dispersion liquid containing nanowires on the substrate110by a screen printing process, a spray coating process, or a roller coating process, and then drying the same to form the electrode material layer120. In one example, the nanowires include silver nanowires, gold nanowires, copper nanowires, carbon nanotubes, or a combination thereof. The dispersion may include additives, surfactants or adhesives, such as carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), hydroxypropyl methylcellulose (HPMC), sulfonate ester, organosulfate, disulfonate, sulfosuccinic acid ester, organophosphate, or a fluorine-containing surfactant, and the like.

Next, as shown inFIG. 3AandFIG. 3B, a first photoresist layer130is formed on the electrode material layer120. The first region R1and the second region R2are entirely covered by the first photoresist layer130. Next, as shown inFIG. 4AandFIG. 4B, using a mask having a predetermined pattern, the first photoresist layer130is exposed and developed to form a first patterned photoresist layer132. It is noted that in the embodiment shown inFIG. 4AandFIG. 4B, the first patterned photoresist layer132is formed only in the first region R1, but the present disclosure is not limited thereto. Thereafter, as shown inFIG. 5AandFIG. 5B, using the first patterned photoresist layer132as a mask, the electrode material layer120is etched to form the touch electrode layer122in the first region R1. The first patterned photoresist layer132is then removed. It is noted that in the embodiment shown inFIG. 5AandFIG. 5B, the touch electrode layer122is formed only in the first region R1, but the present disclosure is not limited thereto. In one embodiment, the first photoresist layer130may be a dry film, and the removal of the first patterned photoresist layer132may include stripping off the dry film.

Next, step S130is performed. Step S130includes forming a protective layer covering the touch electrode layer and having a plurality of openings in the second region.FIG. 6AandFIG. 7Aare top views during various process stages for implementing step S130.FIG. 6BandFIG. 7Bare respectively schematic cross-sectional views along line A-A′ inFIG. 6AandFIG. 7A.

Reference is made toFIG. 6AandFIG. 6B. In one embodiment, a protective material layer140is formed over the substrate110. It is noted that the touch electrode layer122and the substrate110are completely covered by the protective material layer140. In one embodiment, the protective material layer140comprises a transparent resin and a photosensitive material. The transparent resin comprises polymethacrylate, polyvinyl alcohol, polyester, aromatic polymer, polyurethane, epoxy resin, polyolefin, cellulose, vinyl chloride, polyacetate, fluorine-containing polymer, and silicon-containing polymer, but is not limited thereto.

Next, as shown inFIG. 7AandFIG. 7B, the protective material layer140is patterned to form a protective layer142having a plurality of openings144. In one embodiment, the patterning process includes using an exposure and developing step. The developer may be KOH solution, Na2CO3solution, tetramethylamine hydroxide, xylene, and the like. Reference is made toFIG. 7A. It is noted that the protective layer142has a plurality of openings144, and each opening144exposes a portion122aof the touch electrode layer122and a portion of the substrate110. Furthermore, still referring toFIG. 7A, each opening144extends from the first region R1to the second region R2.

Step S140is performed to form a plurality of lead wires. Each lead wire is formed in corresponding one of the openings and extends from a portion of the touch electrode layer to the second region. Each opening is partially filled with one of the lead wire, such that a recess is defined in each opening.FIG. 8A,FIG. 9A,FIG. 10A, andFIG. 11Aare top views during various process stages for implementing step S140.FIG. 8B,FIG. 9B,FIG. 10B, andFIG. 11Bare respectively schematic cross-sectional views along line A-A′ inFIG. 8AtoFIG. 11A.

Referring toFIG. 8AandFIG. 8B, a metal layer150is conformally formed on the protective layer142and inside the openings144. In other words, the metal layer150is conformally located on the bottom and sidewalls of the openings144, and thereby a recess154is defined in each opening144. It is noted that in the second region R2, the metal layer150at the bottom of the openings144is in direct contact with the substrate110. In one embodiment, the metal layer150comprises gold, silver, copper, molybdenum, titanium, aluminium, nickel, or a combination thereof. The metal layer150is conformally formed by the following process, including but not limited to a sputtering process, an evaporation process, a sol-gel process, a spraying process, a pulsed laser deposition (PLD) process, a chemical vapor deposition (CVD) process, or other suitable processes.

Referring toFIG. 9AandFIG. 9B, a second photoresist layer160is formed covering the metal layer150. The material and forming technique of the second photoresist layer160is similar to those of the first photoresist layer130, and therefore are not repeated herein. It is noted that referring toFIG. 9B, each recess154is completely filled with the second photoresist layer160.

Next, referring toFIG. 10AandFIG. 10B, the second photoresist layer160is exposed and developed using a second predetermined mask pattern to form a second patterned photoresist layer162, and a portion of the metal layer150is exposed. The forming technique of the second patterned photoresist layer162is similar to that of the first patterned photoresist layer132, and therefore is not repeated herein. It is noted that with reference toFIG. 10B, the second patterned photoresist layer162remains in each recess154.

Next, referring toFIG. 11AandFIG. 11B, the metal layer150is etched to form a plurality of lead wires152, and then the second patterned photoresist layer162is removed. In one embodiment, by selecting an appropriate etchant and controlling the etching time, portions of the metal layer150on the horizontal direction are removed, thereby forming the lead wires152shown inFIG. 11AandFIG. 11B. As shown inFIG. 11A, the portion122aof the touch electrode layer122is covered by each lead wire152, and each lead wire152extends from the portion122aof the touch electrode layer122to the second region R2. Referring toFIG. 11B, each lead wire152is formed in corresponding one of the openings144. Each opening144is partially filled with one of the lead wire152, and thereby the recess154is defined in each opening144.

Another aspect of the present disclosure is to provide a touch device. The touch device can avoid short circuit problem of traces. Reference is made toFIG. 11AandFIG. 11B. In one embodiment, a touch device200comprises a substrate110, a touch electrode layer122, a protective layer142, and a plurality of lead wires152. The material of the substrate110, the touch electrode layer122, the protective layer142, and the lead wires152have been described above, and therefore are not repeated herein.

As shown inFIG. 11B, the substrate110includes a first region R1and a second region R2. The second region R2is adjacent to the first region R1. The touch electrode layer122is disposed in the first region R1. The touch electrode layer122in the first region R1is covered by the protective layer142. In one embodiment, the protective layer142in the first region R1has a first thickness t1ranged from 1 μm to 15 μm. In one embodiment, the protective layer142in the second region R2has a second thickness t2ranged from 1 μm to 15 μm. In one embodiment, the second thickness t2is equal to the first thickness t1. The protective layer142has a plurality of openings144. It is noted that as shown inFIG. 11AandFIG. 11B, the openings144extend from the first region R1to the second region R2.

As shown inFIG. 11B, each lead wire152is formed in corresponding one of the openings144. In one embodiment, each lead wire152is conformally formed in the openings144. Specifically, each opening144is partially filled with one of the lead wire152, and thereby the recess154is defined in each opening144. In one embodiment, the recess154has a depth ranged from 1 μm to 15 μm. It is noted that the depth d1of each recess154is less than the first thickness t1and the second thickness t2of the protective layer142. In other words, the depth d1of the recess154depends on the difference between the first thickness t1or the second thickness t2of the protective layer142and the thickness of each lead wire152. In one embodiment, in the second region R2, the metal layer150in the openings144is in direct contact with the substrate110.

It is noted that as shown inFIG. 11AandFIG. 11B, the portion122aof the touch electrode layer122is covered by the lead wires152, and each lead wire152extends from the portion122aof the touch electrode layer122to the second region R2.

FIG. 11Cillustrates a schematic sectional view along line B-B′ inFIG. 11Aaccording to one embodiment of the present disclosure. It is noted that inFIG. 11C, the touch electrode layer122and the lead wire152are located between the adjacent protective layer142, and the lead wire152is disposed on the touch electrode layer122. In other words, the touch electrode layer122is located between the substrate110and the lead wire152. In one embodiment, a first height difference H1between the protective layer142and the lead wire152ranges from 1 μm to 15 μm.

FIG. 11Dillustrates a schematic sectional view along line C-C′ inFIG. 11Aaccording to one embodiment of the present disclosure. It is noted that in the embodiment shown inFIG. 11D, the lead wire152is in direct contact with the substrate110. In one embodiment, a second height difference H2between the protective layer142and the lead wire152ranges from 1 μm to 15 μm.

FIG. 11Eillustrates a schematic sectional view along line C-C′ inFIG. 11Aaccording to another embodiment of the present disclosure. It is noted that in the embodiment shown inFIG. 11E, the lead wire152is disposed on the touch electrode layer122. In other words, the touch electrode layer122is located between the substrate110and the lead wire152. In one embodiment, a third height difference H3between the protective layer142and the lead wire152ranges from 1 μm to 15 μm.

In summary, the present disclosure provides a touch device which is capable of avoiding short circuit and a manufacturing method thereof. When copper is etched during the process, the silver nanowire in the touch device is not susceptible to the copper etching liquid, thereby avoiding the formation of copper-silver crystals, and thus avoiding the problem of short circuit. In addition, the present disclosure is applicable to various designs of touch device, such as single-layer multi-point, double-sided bonding (FF), single-sided or double-sided touch devices.