TWI751794B - Touch sensor module and method of fabricating the same - Google Patents

Abstract

A method of fabricating touch sensor module includes forming a metal layer on a substrate, forming a hydrophobic cover layer on the metal layer, patterning the cover layer and the metal layer with laser, and cleaning the cover layer after patterning with laser. A conductive trace layer is formed by patterning the metal layer.

Description

Touch sensing module and method of forming the same

The present invention is a touch sensing module and a method for forming the same.

With the high growth of the touch panel industry, the demand for touch sensing modules has increased significantly. Therefore, generating a high-quality touch sensing module is beneficial to the stability of electrical signal transmission.

One aspect of the present invention is a method of forming a touch sensing module, which includes forming a metal layer on a substrate, forming a hydrophobic protective layer on the metal layer, patterning the protective layer and the metal layer by laser to make A wire layer is formed after the metal layer is patterned by a laser, and the protective layer is cleaned after being patterned by the laser.

Another aspect of the present invention is a touch sensing module including a substrate, a wire layer on the substrate, and a protection layer on the wire layer. The wire layer includes several first inclined surfaces and several first upper surfaces, wherein the first upper surfaces are connected to the first inclined surfaces. The protective layer includes a plurality of second slopes and a plurality of second upper surfaces, wherein the first slopes and the second slopes are simultaneously formed by the same patterning process, so that the second slopes and the first slopes are continuous slopes , the second upper surface is connected to the second inclined surface.

When an element is referred to as being "on", it can generally mean that the element is directly on the other element or that the other element is present in both. Conversely, when an element is said to be "directly on" another element, it cannot have the other element intervening. As used herein, the term "and/or" includes any combination of one or more of the associated listed items.

Furthermore, for convenience in describing the relationship of one element or feature to another element or feature(s) in the figures, spatially relative terms such as "under", "under", "under" may be used , "above," "above," and similar terms. In addition to the orientation shown in the figures, spatially relative terms also encompass different orientations of the device in use or operation. When the device is turned in a different orientation (eg, rotated 90 degrees or otherwise), the spatially relative adjectives used therein will also be interpreted according to the turned orientation.

As used herein, the term "substantially" may mean that a given amount of value varies within ±5% of, for example, a target state or value (or an expected state or value).

With the high growth of the touch panel industry, the demand for touch sensing modules has increased significantly. Due to the advantages of lower cost, lower impedance, and better flexibility, metal is often used as a wire for electrical signal transmission in touch sensing modules. In order to stabilize the electrical signal transmission in the touch sensing module, high-quality wires need to be produced, and the wire area in the touch sensing module can be increased by reducing the wire spacing during the patterning process. Therefore, embodiments of the present invention provide a touch sensing module and a method for forming the touch sensing module.

Referring to FIG. 1 , a simplified structure of the touch panel 100 is shown, which includes a display module 102 , a protective cover 106 , and a touch sensing module between the display module 102 and the protective cover 106 104. In some embodiments, the display module 102 may include a liquid crystal display panel. In other embodiments, the display module 102 may include a light emitting diode (LED) display panel or an organic light emitting diode (OLED) display panel. In some embodiments, the protective cover 106 has a protective function. In some embodiments, when a conductive object (eg, a finger) touches the protective cover 106 , the capacitive coupling in the touch sensing module 104 is different to generate a signal, and the capacitive sensing signal can be calculated after being processed. Shows the relative position of the touch of the conductive object.

Referring to FIG. 2A , which is a simplified cross-sectional view of the touch sensing module 104 according to some embodiments of the present invention, the single layer presented is a simplified structure only as an example and not a limitation. In some embodiments, the touch sensing module 104 includes a substrate 200, wherein the substrate 200 includes a sensing electrode region R1 and a peripheral circuit region R2. The setting position of the sensing electrode region R1 is the operating range of the touch sensing module 104 , that is, the range where the capacitive coupling is different to generate a signal when a conductive object (eg, a finger) approaches. The peripheral circuit area R2 is disposed on the edge of the sensing electrode area R1, and the signal generated by the sensing electrode area R1 can transmit electrical signals through the peripheral circuit area R2.

Continuing to refer to FIG. 2A, the touch sensing module 104 includes a wire structure 202 disposed in the sensing electrode region R1, a protective layer 204 disposed on the wire structure 202 in the sensing electrode region R1, and a peripheral circuit region R2 The wire structure 206 . The wire structures 202 disposed in the sensing electrode region R1 and the wire structures 206 disposed in the peripheral circuit region R2 are disposed on the substrate 200 . The protective layer 204 is only distributed on the wire structure 202 of the sensing electrode region R1. The protective layer 204 and the wire structure 202 of the sensing electrode region R1 are fabricated by the same patterning process, so that the protective layer 204 has a pattern corresponding to the wire structure 202 of the sensing electrode region R1.

Referring to FIG. 2B , which is a simplified cross-sectional view of the touch sensing module 104 according to other embodiments of the present invention, the single-layer structure is shown for simplicity only as an example and not a limitation. In some embodiments, the touch sensing module 104 includes a substrate 200, wherein the substrate 200 includes a sensing electrode region R1 and a peripheral circuit region R2. The touch sensing module 104 includes a wire structure 202 disposed in the sensing electrode region R1, a protective layer 204 disposed on the wire structure 202 in the sensing electrode region R1, a wire structure 206 disposed in the peripheral circuit region R2, and The protective layer 208 on the wire structure 206 in the peripheral circuit region R2. The wire structures 202 disposed in the sensing electrode region R1 and the wire structures 206 disposed in the peripheral circuit region R2 are disposed on the substrate 200 . The protective layer 204 and the wire structure 202 of the sensing electrode region R1 are fabricated by the same patterning process, so that the protective layer 204 has a pattern corresponding to the wire structure 202 of the sensing electrode region R1. The protective layer 208 and the conductive structure 206 of the peripheral circuit region R2 are fabricated by the same patterning process, so that the protective layer 208 has a pattern corresponding to the conductive structure 206 of the peripheral circuit region R2.

2A and 2B can also be a double-layer structure (not shown here). and protective layer on the conductor structure. The protective layer may be disposed only on the wire structure of the sensing electrode area, or the protective layer may be disposed on the wire structure of the sensing electrode area and the wire structure of the peripheral circuit area at the same time. The protective layer has the same pattern as the wire structure due to the same patterning process.

The above-mentioned wire structure can be achieved by patterning the metal layer of the sensing electrode region and/or the peripheral circuit region, wherein the patterning method includes exposure and development, masking, laser, or other suitable techniques. For example, in the exposure and development process, after the photoresist is coated on the metal layer and subjected to the yellow light process, the blank area is removed with an etching solution to leave the wires. However, a large amount of waste liquid is generated during the process. In another example, the mask technology is to hollow out the part defined as the wire in the mask. Then, according to the hollow part of the mask, the wire is plated on the substrate. However, after the process, there will be residual metal on the mask, which needs to be treated with chemicals. clean. In another example, using a laser to etch the blank areas of the conductive layer to leave wires, a large amount of waste liquid will not be generated during the process, and the laser patterning process has high directionality and high power compared to the exposure and development patterning process. It is easy to simplify the process operation. However, the slag in the laser process may adhere to the wire and cause contamination, which affects the processing quality of the wire. Therefore, the embodiments of the present invention provide an apparatus for the touch sensing module 104 and a method for forming the touch sensing module 104 , especially a structure and method of wires formed by a laser patterning process.

FIGS. 3 to 7 are simplified cross-sectional views of various process stages of the method of forming the touch sensing module 104 , and the process sequences presented in the figures are merely examples and are not intended to limit the present invention. Furthermore, there may be other process operations between the various process stages of forming the touch sensing module 104 , and for the purpose of simplifying the description, the description of the other process operations may be omitted. Likewise, in the drawings, in addition to the devices or systems mentioned in the present invention, other devices or systems may also be included. To simplify the description, the above devices or systems are not shown in FIGS. 3 to 7 .

The flowcharts shown in FIGS. 3 to 7 are not limited to be applied to the wire structures 202 disposed in the sensing electrode region R1 and the wire structures 206 disposed in the peripheral circuit region R2 as shown in FIGS. 2A and 2B . In other words, as long as the structure is made by patterning the metal layer, it is suitable to be made with the third to the seventh drawings.

Referring to FIG. 3, a simplified cross-sectional view of one of the process stages of the touch sensing module 104 is shown: a metal layer 302A and a protective layer 304A are sequentially formed on the substrate 300, wherein the protective layer 304A covers the exposed metal layer 302A external surfaces, such as the top and/or side surfaces. The substrate 300 includes a transparent glass substrate, a transparent plastic film, a metal substrate, or other suitable materials. As an example and not a limitation, the material of the light-transmitting plastic film may include polyethylene terephthalate (PET), polyimide (PI), polymethylmethacrylate (PMMA) , Polycarbonate (PC), Triacetate cellulose (TAC), or polyethylene naphthalate (PEN). In some embodiments, the thickness of the substrate 300 is 50µm to 125µm, such as 60µm, 70µm, 80µm, 90µm, 100µm, 110µm, or 120µm.

The material of the metal layer 302A may include gold, silver, aluminum, copper, tungsten, iron, tin, platinum, other materials with conductive properties, or any combination thereof. In some embodiments, the material of the metal layer 302A may be copper. In some embodiments, the metal layer 302A may be a nano-copper layer. In some embodiments, the technique of forming the metal layer 302A on the substrate 300 may include sputtering, physical vapor deposition (PVD), chemical vapor deposition (CVD), other suitable technology, or any combination of the above. In some other embodiments, the metal layer 302 may be formed using screen printing techniques. Also, in some embodiments, after the metal layer 302 is formed using a screen printing technique, a laser patterning process can be used for processing.

The protective layer 304A covering the metal layer 302A has hydrophobicity. The hydrophobicity of the protective layer 304A may come from the hydrophobicity of the material itself, the hydrophobicity generated by pretreatment, or a combination of the above. In some embodiments, the material of the protective layer 304A includes an organic polymer. In some embodiments, the material of the protective layer 304A further includes an organic polymer containing fluorine functional groups, for example, carbon tetrafluoromethane (Tetrafluoromethane), perfluorooctanesulfonic acid (PFOS), perfluoroisohexane Perfluoro(2-methylpentane), or Perfluoro-1,3-dimethyl cyclohexane (Perfluoro-1,3-dimethyl cyclohexane), such organofluorine compounds are incorporated into organic polymers. It should be noted that the selection of the organofluorine compound is not limited to this. In some embodiments, in addition to the protection layer 304A having hydrophobicity, the material of the protection layer 304A may include a material that does not contain acidic chemical substances, that is, the hydrogen ion concentration that can be dissociated from the material is less than 1×10 ⁻⁷ vol moles Concentration (mol/L). Therefore, when physically contacting the metal layer 302A, the protective layer 304A will not substantially adversely affect (eg, oxidize) the metal layer 302A. In addition, the protective layer 304A can also serve as an anti-corrosion layer to protect the metal layer 302A.

In one embodiment, the protective layer 304A may be made hydrophobic using a pre-treatment, which may include first depositing a film compatible with the metal layer 302A (ie, without adversely affecting the metal layer 302A), and then The film is subjected to material treatment to produce a hydrophobic effect, wherein the material treatment includes forming a hydrophobic material on the film. The hydrophobic material itself has hydrophobic properties, but may have an adverse effect on the metal layer 302A or interact with the metal layer 302A. The adhesion between them is not ideal, so a thin film needs to be formed on the metal layer 302A first, and then the hydrophobic material is formed. In another embodiment, a film that is compatible with the metal layer 302A (ie, does not adversely affect the metal layer 302A) may be deposited first, and then the film may be laser processed to produce a hydrophobic effect. In one embodiment, the use of laser processing to produce the hydrophobic effect includes the use of high-power, high-frequency pulsed lasers to form microstructures on the surface of the film.

The material of the protective layer 304A, in some embodiments, may be a liquid material. When using the liquid material as the protective layer 304A, a screen printing or spraying technique may be used to cover the entire surface of the metal layer 302A with the liquid material, or even cover the substrate 300 at the same time. Next, a curing process is performed on the liquid material, and the curing technique includes room temperature moisture curing, ultraviolet (ultraviolet, UV) curing, thermal curing, other suitable curing techniques, or a combination thereof. In other embodiments, when the material of the protective layer 304A is a solid material, the solid material may be a sheet material. In some embodiments, solid state material is placed and adhered to the surface of metal layer 302A.

Referring to FIG. 4 , a simplified cross-sectional view of one of the process stages of the touch sensing module 104 is shown: a patterning process is performed on the metal layer 302A and the protective layer 304A using the laser 306 . In some embodiments, the laser 306 is focused to actually cut the metal layer 302A to form the conductive layer 302 , and at the same time, the protective layer 304A is also formed into a patterned protective layer 304 . In some embodiments, a pulsed laser 306 may be used. Generally speaking, during the patterning process using the laser 306, the high energy density laser 306 continuously irradiates a specific position of the metal layer 302A, so that the temperature of the material of the metal layer 302A at this position increases and reaches the melting point or boiling point , thereby removing the material of the metal layer 302A at this position to achieve the function of cutting and patterning the metal layer 302A. Therefore, foreign matter 308, such as slag, may be generated on the protective layer 304A due to high temperature during the laser patterning process.

Referring to FIG. 5 , a cleaning step 310 is performed to remove foreign matter 308 remaining on the protective layer 304 . Since the material of the protective layer 304 has been selected or pre-treated, it has hydrophobicity, so that the foreign matter 308 adheres to the protective layer 304 with weak viscosity and is easy to remove. Therefore, in some embodiments, the cleaning step 310 may be performed by washing with water to remove the foreign matter 308 , and then combined with a gas to remove the foreign matter 308 and dry the touch sensing module 104 , wherein the gas may be a high-pressure gas.

Referring to FIG. 6A , a simplified cross-sectional view of the touch sensing module 104 after the conductive layer 302 is formed is shown. After the touch sensing module 104 is subjected to a patterning process, a plurality of slopes S are generated. In some embodiments, the extension of these slopes S includes the protective layer 304 and the wire layer 302 . The part encircled by the dotted box in Fig. 6A is a partial enlargement M, which is shown in Fig. 6B.

Referring to FIG. 6B , the slope S of the touch sensing module 104 can be further classified into a first slope S1 located on the wire layer 302 and a second slope S2 located on the protective layer 304 . Since the first slope S1 on the wire layer 302 and the second slope S2 on the protective layer 304 are simultaneously formed by the same laser patterning process, the first slope S1 on the wire layer 302 and the second slope S2 on the protective layer 304 are formed simultaneously by the same laser patterning process. Both the second slopes S2 appear as continuous slopes and have the same slope. The first upper surface U1 of the wire layer 302 has an edge A and an edge A', and the second upper surface U2 of the protective layer 304 has an edge B and an edge B'. In the laser patterning process, since the energy of the laser 306 exhibits a Gaussian distribution, the protective layer 304 can absorb most of the energy of the laser 306 , and only the higher-energy laser 306 located in the center of the laser 306 can penetrate the protective layer _{304 and the wire layer 302, so that the distance S A-A'} from the edge A to the edge A' on the wire layer 302 is _{smaller than the distance S B-B'} from the edge B to the edge B' on the protective layer 304. In this way, the laser patterning can generate scribe lines with smaller widths on the wire layer 302 , thereby increasing the area available for the wires, such as the length of the first upper surface U1 .

In addition, the protective layer 304 can absorb part of the energy of the laser 306, so as to avoid excessive cutting of the substrate caused by the laser patterning process. In some embodiments, after the laser patterning process, there is no cutting on the substrate 300 caused by the laser patterning process, which means that the sloped surfaces S terminate on the substrate surface, which is ideal. In some embodiments, in order to ensure that the adjacent wires in the wire layer 302 are reliably separated to avoid short circuit, there may be cuts on the substrate 300 caused by the laser patterning process, which means that the extension of the slopes S includes the protective layer 304 , the wire layer 302 and part of the substrate 300 , wherein the depth of the slopes S extending to the substrate 300 should be less than about 10% of the thickness of the substrate 300 to avoid affecting the function of the touch sensing module 104 .

In addition to the possibility of generating foreign objects 308 due to high temperature during the laser patterning process, some defects (eg, crater defects) may also be generated in the patterned target material using the laser patterning process. In some embodiments, after the laser patterning process, the second upper surface U2 of the protective layer 304 cannot maintain the flatness of the original parallel substrate 300 , for example, the protrusions 312 are formed on the protective layer 304 , more precisely, the protrusions are formed 312 is on the second upper surface U2 of the protective layer 304 and close to the edges B and B', as shown in FIG. 6B. However, in some embodiments, the protective layer 304 acts as a buffer, so that defects generated by the laser patterning process occur on the second upper surface U2 of the protective layer 304 and are close to the edges B and B′, and maintain the second upper surface U2 of the conductive layer 302 An upper surface U1 is substantially parallel to the plane of the substrate 300 . More precisely, the first upper surface U1 of the wire layer 302 and close to the edges A and A′ can still substantially maintain the flatness originally parallel to the substrate 300 . The flatness of the first upper surface U1 of the wire layer 302 will facilitate stable performance of electrical signals in the touch sensing module 104 .

Referring to FIG. 7 , a transparent insulating layer 314 and a protective cover 316 (ie, the protective cover 106 in FIG. 1 ) are formed on the touch sensing module 104 , and the transparent insulating layer 314 is disposed between the touch sensing mold The group 104 and the protective cover plate 316 have the function of bonding. In some embodiments, the material of the transparent insulating layer 314 may include, but is not limited to, solid optical clear adhesive (OCA), liquid optical clear adhesive (LOCA), or other materials with high transparency Light rate adhesive, so as not to affect the display effect. The transparent insulating layer 314 covers the touch sensing module 104 and contacts the slope S or a part of the slope S, which means that the transparent insulating layer 314 contacts the first slope S1 on the wire layer 302 and the second slope on the protective layer 304 S2, or a combination of the above.

In some embodiments, the material of the protective cover plate 316 may be glass, by way of example and not limitation, such as soda glass, aluminosilicate glass, alkali-free glass, or other suitable glass materials. In other embodiments, the material of the protective cover plate 316 may be transparent plastic, or any other material that has a certain degree of light transmittance and can protect the structure attached thereto.

Based on the above, the protective layer formed on the wire layer can provide the following functions: (1) the anti-corrosion layer of the wire layer; (2) the protective layer with hydrophobicity makes the foreign matter attached to the wire layer show weak adhesion, so Foreign matter (for example, molten slag) generated in the laser patterning process can be easily removed by the process of water washing and gas blowing; (3) During the laser patterning process, the protective layer absorbs most of the energy of the laser and has high energy The center of the laser can penetrate into the metal layer to produce a smaller width of the dicing line, which increases the available area of the wire; (4) In the laser patterning process, the protective layer can prevent the laser patterning process from causing excessive cutting of the substrate ; and (5) the protective layer can be used as a buffer layer, so that defects (such as crater defects) generated by the laser patterning process occur on the protective layer, the upper surface of the wire layer can be kept flat, and the improvement of processing quality helps electrical performance.

The features of several embodiments of the present invention are briefly described above, so that those skilled in the art can more easily understand the present invention. Anyone with ordinary knowledge in the art should understand that this specification can easily be used as a basis for modification or design of other structures or processes to achieve the same purpose and/or obtain the same advantages of the embodiments of the present invention. Anyone with ordinary knowledge in the technical field can also understand that the structures equivalent to the above do not depart from the spirit and protection scope of the present invention, and can make changes, substitutions and modifications without departing from the spirit and scope of the present invention.

100: touch panel

102: Display module

104: Touch Sensing Module

106: Protective cover

200: Substrate

202: Wire Structure

204: Protective Layer

206: Wire Structure

208: Protective Layer

300: Substrate

302: Conductor layer

302A: Metal Layer

304: Protective Layer

304A: Protective layer

306: Laser

308: Foreign body

310: Cleaning Steps

312: Overhang

314: Transparent insulating layer

316: Protective cover

A: Edge

A': edge

B: edge

B': edge

M: Partial magnification

R1: Sensing electrode area

R2: Peripheral line area

S: Bevel

S1: The first slope

S2: Second slope

S _A-A' : distance

S _B-B' : distance

U1: first upper surface

U2: Second upper surface

The following embodiments are read in conjunction with the accompanying drawings for a clear understanding of the concepts of the present invention. It should be noted that, in accordance with standard industry practice, the various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily enlarged or reduced for clarity of discussion. FIG. 1 shows a simplified schematic diagram of a touch panel according to some embodiments of the present invention. FIG. 2A illustrates a simplified cross-sectional view of a touch sensing module according to some embodiments of the present invention. FIG. 2B illustrates a simplified cross-sectional view of a touch sensing module according to some embodiments of the present invention. FIG. 3 is a simplified cross-sectional view of one of the process stages of a method of forming a touch sensing module according to some embodiments of the present invention. FIG. 4 is a simplified cross-sectional view of one of the process stages of a method of forming a touch sensing module according to some embodiments of the present invention. 5 is a simplified cross-sectional view of one of the process stages of a method of forming a touch sensing module according to some embodiments of the present invention. 6A illustrates a simplified cross-sectional view of one of the process stages of a method of forming a touch sensing module according to some embodiments of the present invention. FIG. 6B shows a simplified cross-sectional view of the enlarged partial view of FIG. 6A. FIG. 7 is a simplified cross-sectional view of a portion of a touch panel according to some embodiments of the present invention.

Domestic storage information (please note in the order of storage institution, date and number) none Foreign deposit information (please note in the order of deposit country, institution, date and number) none

104: Touch Sensing Module

300: Substrate

302: Conductor layer

302A: Metal Layer

304: Protective Layer

304A: Protective layer

306: Laser

308: Foreign body

Claims (13)

A method of forming a touch sensing module, comprising: forming a metal layer on a substrate; forming a protective layer with hydrophobicity on the metal layer; patterning the protective layer and the metal simultaneously by a laser layer, so that the patterned metal layer forms a wire layer; and after the laser patterning, cleaning the protective layer. The method for forming a touch sensing module as claimed in claim 1, wherein forming the protective layer with hydrophobicity comprises using an organic polymer material containing a fluorine functional group. The method for forming a touch sensing module as claimed in claim 1, wherein forming the protective layer having hydrophobicity comprises using a material, wherein the dissociable hydrogen ion concentration of the material is less than 1×10 ^-7 vol mol concentration. The method for forming a touch sensing module as claimed in claim 1, wherein forming the protective layer having hydrophobicity comprises forming a liquid material having hydrophobicity on the metal layer and curing the liquid material on the metal layer . The method for forming a touch sensing module as claimed in claim 1, wherein forming the protective layer with hydrophobicity comprises forming a solid material with hydrophobicity on the metal layer. The method for forming a touch sensing module according to claim 1, wherein forming the protective layer with hydrophobicity includes performing a hydrophobic pretreatment on the protective layer. The method for forming a touch sensing module as claimed in claim 1, wherein the laser patterning the protective layer and the metal layer comprises patterning the protective layer and the metal layer in a sensing electrode region, patterning a The protective layer and the metal layer in the peripheral circuit area, or the protective layer and the metal layer of the combination of the above-mentioned positions are patterned. The method for forming a touch sensing module as claimed in claim 1, wherein cleaning the protective layer comprises cleaning the protective layer with water and gas. A touch sensing module includes: a substrate; a wire layer on the substrate, comprising: a plurality of first slopes; and a plurality of first upper surfaces connected to the first slopes; and a protective layer , located on the wire layer, comprising: a plurality of second slopes, wherein the first slopes and the second slopes are simultaneously formed by the same patterning process, so that the second slopes and the first slopes are a continuous inclined surface; and a plurality of second upper surfaces connected to the second inclined surfaces. The touch sensing module of claim 9, wherein the protective layer comprises a hydrophobic material. The touch sensing module of claim 9, wherein the wire layer comprises the wire layer located in a sensing electrode area, the wire layer located in a peripheral circuit area, or a combination of the above-mentioned positions the wire layer. The touch sensing module of claim 9, wherein the first upper surfaces are substantially a plane parallel to the substrate. The touch sensing module as claimed in claim 9, further comprising a plurality of protrusions located on the second upper surfaces of the protective layer.

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