JP2023162086A - Touch sensor and method of manufacturing touch sensor - Google Patents

Abstract

To provide a touch sensor which can satisfy both of a flexibility requirement and a narrow bezel design requirement, and a method of manufacturing a touch sensor.SOLUTION: A touch sensor having a visible area and a peripheral area includes a substrate, a metal nanowire layer, and a silver layer. The metal nanowire layer is disposed on a main plane of the substrate to define an electrode part and a first wiring and a second wiring. The first wiring has a lead-out part connected to the electrode part, and a lead part connected to the lead-out part. The second wiring is disposed on one side of the first wiring relatively away from the visible area and adjacent to an edge portion of the main plane. The silver layer is disposed so as to be laminated on the first wiring and the second wiring and has a first side plane opposed to the visible area and a second side plane positioned at the opposite side of the visible area. The coarseness of the edge part of the first side plane is larger than the coarseness of the edge portion of the second side plane.SELECTED DRAWING: Figure 1B

Description

The present disclosure relates to a touch sensor and a method of manufacturing the touch sensor.

In recent years, touch sensors have been widely used in portable electronic devices such as mobile phones, notebook computers, satellite navigation systems, and digital AV players, and serve as an information communication channel between users and electronic devices.

As the demand for electronic devices with narrow bezels is gradually increasing, this technical field will improve the bendability of electronic devices and also reduce the size of electronic device bezels to meet the needs of users. I'm working on something. Generally, a touch sensor includes a contact electrode placed in the visible area and a peripheral circuit placed in its peripheral area, and based on the bending requirements of the touch panel, silver paste is currently preferred as the material of the peripheral circuit. It's being used. Regarding silver paste materials, it is common to perform a screen printing process to form a silver layer from the silver paste material, and it is also common to form a patterned peripheral circuit by forming a pattern on the silver layer. It is true. Additionally, the peripheral circuitry designed in the peripheral area affects the application of the touch panel to products with narrow bezels. Therefore, it is currently worth investigating how to provide a touch sensor that can meet the requirements of flexibility and narrow bezel design based on the use of silver paste as a material for the peripheral circuitry.

According to some embodiments of the present disclosure, a touch sensor having a visible region and a peripheral region adjacent to at least one side of the visible region includes a substrate, a metal nanowire layer, and a silver layer. The metal nanowire layer is disposed on the main surface of the substrate and defines an electrode portion corresponding to the visible region and a first wire and a second wire corresponding to the peripheral region. The second wiring is arranged with an interval from the first wiring. The first wiring includes a lead-out section and a lead section. The lead-out section is connected adjacent to the electrode section. The lead portion is connected to the lead-out portion, and the second wire is disposed on one side of the first wire relatively away from the visible area and adjacent an edge of the major surface. The silver layer overlaps the first wiring and the second wiring and contacts the first wiring and the second wiring. The silver layer has a first side surface on the lead-out portion facing the visible region, and a second side surface of the second wiring located on the opposite side with respect to the visible region. Here, the roughness of the edge of the first side of the silver layer is greater than the roughness of the edge of the second side of the silver layer.

In some embodiments of the present disclosure, the width of the edge roughness of the first side of the silver layer may be in the range of 10 μm or more and 50 μm or less. The width of the edge roughness of the second side surface of the silver layer may be in the range of 0.01 μm or more and 5 μm or less.

In some embodiments of the present disclosure, the metal nanowire layer may define a plurality of spaced first interconnects corresponding to the peripheral region. The silver layer may be disposed on and in contact with the top surface of the first interconnect to form a plurality of peripheral interconnects of the touch sensor.

In some embodiments of the present disclosure, the line width of the peripheral wiring may be in the range of 6 μm or more and 10 μm or less. The line spacing between any two adjacent peripheral wires may be within a range of 6 μm or more and 10 μm or less.

In some embodiments of the present disclosure, the silver layer connects the first side and the third side with a third side on the readout located opposite to the viewing area. and a fourth aspect. The lead-out, the third side of the silver layer, and the two fourth sides of the silver layer may have aligned sidewalls.

In some embodiments of the present disclosure, the lead and the silver layer laminated to and in contact with the lead can have aligned sidewalls.

In some embodiments of the present disclosure, the silver layer may have a fifth side of the second interconnect opposite the visible region. The second interconnect and the fifth side of the silver layer may have aligned sidewalls.

According to some other embodiments of the present disclosure, a method of manufacturing a touch sensor having a visible region and a peripheral region adjacent to at least one side of the visible region includes:
forming a metal nanowire material layer on a major surface of the substrate, the metal nanowire material layer corresponding to a visible region and a peripheral region;
performing a screen printing process to form a silver material layer on the metal nanowire material layer, the silver material layer corresponding to a peripheral region;
forming a photoresist layer to cover the metal nanowire material layer and the silver material layer;
A process of forming a pattern on a photoresist layer by performing exposure treatment and development treatment, and the patterned photoresist layer defines a pattern of electrode parts corresponding to the visible region and a pattern corresponding to the peripheral region. a first wiring pattern and a second wiring pattern are defined, the second wiring pattern is separated from the first wiring pattern, and the first wiring pattern is connected to a pattern of a lead-out portion and a second wiring pattern of the lead-out portion. the pattern of the lead-out section is connected adjacent to the pattern of the electrode section, the pattern of the lead section is connected to the pattern of the lead-out section, and the second wiring pattern is connected to the pattern of the lead-out section relative to the visible region. The pattern of the electrode portion and the pattern of the lead-out portion of the patterned photoresist layer are arranged on one side of the first wiring pattern separated from each other and adjacent to the edge of the main surface. a step of being a covering layer;
performing a first etching process and forming a pattern on the silver material layer using the first wiring pattern and the second wiring pattern;
performing a second etching process to form a pattern in the metal nanowire material layer using the first wiring pattern and the second wiring pattern;
and removing the photoresist layer.

In some embodiments of the present disclosure, the method for manufacturing a touch sensor may further include performing plasma treatment after the first etching process and before the second etching process. Thereby, the patterned silver material layer is processed using the first wiring pattern and the second wiring pattern.

In some embodiments of the present disclosure, the method for manufacturing a touch sensor may further include performing a chemical cleaning treatment after the first etching treatment and before the plasma treatment. Thereby, the patterned silver material layer is pretreated using the first wiring pattern and the second wiring pattern.

According to the embodiment of the present disclosure described above, the touch sensor of the present disclosure includes a metal nanowire layer including an electrode portion, a first wiring, and a second wiring, and a metal nanowire layer stacked on the first wiring and the second wiring. and a contacting silver layer. The roughness (e.g., width) of the side edge of the silver layer located on the second wiring and located on the opposite side to the visible region is The edges of the outermost peripheral traces (e.g., ground wires) of the touch sensor can be made smoother (i.e. Then, the edge roughness is negligible), which is advantageous to meet the narrow bezel requirements of touch sensors. Moreover, by integrally forming the electrode portion and the first wiring to directly form an electrical connection between the contact electrode and the peripheral wiring, there is no need to design an additional overlapping structure for the touch sensor. As a result, the area occupied by the overlapping structure corresponding to the peripheral area can be omitted, and there is no need to consider overlapping, which is advantageous for narrowing the bezel of the touch sensor. Furthermore, when manufacturing a touch sensor based on the design of the laminated structure of the touch sensor of the present disclosure, the patterned photoresist layer is continuous between the pattern of the electrode part and the pattern of the readout part. The contact electrode and peripheral wiring can be formed at once by a single exposure and development process (in other words, only a single photoresist layer is used); Thereby, manufacturing steps and costs can be reduced.

The present disclosure can be more fully understood by reading the following detailed description of embodiments in conjunction with the accompanying drawings, in which: FIG.
1 is a schematic and partial top view of a touch sensor according to some embodiments of the present disclosure; FIG. 1B is a schematic cross-sectional view of the touch sensor of FIG. 1A along line AA'; FIG. 1A is a schematic and partially enlarged view showing a region R of a touch sensor in FIG. 1A. FIG. FIG. 3 is a schematic diagram illustrating a method of measuring edge roughness width according to some embodiments of the present disclosure. 1 is a flowchart illustrating a method for manufacturing a touch sensor according to some embodiments of the present disclosure. FIG. 1B is a schematic cross-sectional view showing the method of manufacturing the touch sensor of FIG. 1B in different steps; FIG. 1B is a schematic cross-sectional view showing the method of manufacturing the touch sensor of FIG. 1B in different steps; FIG. 1B is a schematic cross-sectional view showing the method of manufacturing the touch sensor of FIG. 1B in different steps; FIG. 1B is a schematic cross-sectional view showing the method of manufacturing the touch sensor of FIG. 1B in different steps; FIG. 1B is a schematic cross-sectional view showing the method of manufacturing the touch sensor of FIG. 1B in different steps; FIG. 1B is a schematic cross-sectional view showing the method of manufacturing the touch sensor of FIG. 1B in different steps; FIG. 1B is a schematic cross-sectional view showing the method of manufacturing the touch sensor of FIG. 1B in different steps; FIG. 1B is a schematic cross-sectional view showing the method of manufacturing the touch sensor of FIG. 1B in different steps; FIG. 1B is a schematic cross-sectional view showing the method of manufacturing the touch sensor of FIG. 1B in different steps;

Reference will now be made in detail to embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. However, it should be understood that these details do not limit this disclosure. Furthermore, for the convenience of the reader, the sizes of the components in the figures are not shown to their actual size. Relative terms such as "lower" or "bottom" and "upper" or "top" are used herein to describe the relationship between one component and another, as shown in the figures. It should be understood that the term ``term'' may be used in the specification. It is to be understood that relative terms include orientations of the device that are different from those shown in the figures.

Please refer to FIGS. 1A and 1B. FIG. 1A is a schematic and partial top view of a touch sensor 100 according to some embodiments of the present disclosure. FIG. 1B is a schematic cross-sectional view of the touch sensor taken along the cross-sectional line A-A' in FIG. 1A. Touch sensor 100 includes a substrate 110, a metal nanowire layer 120, and a silver layer 130. In some embodiments, touch sensor 100 has a visible area VA and a peripheral area PA. The peripheral area PA is located on multiple sides of the visible area VA. For example, the peripheral area PA may be an L-shaped area located on the left side and below the visible area VA when the touch sensor 100 is viewed from above. As another example, the peripheral area PA is a frame-shaped area located around the visible area VA, in other words, when the touch sensor 100 is viewed from above, the peripheral area PA is located on the right side, left side, upper side, and lower side of the visible area VA. It can be the area where the area is located. Substrate 110 has a major surface 111 configured to support metal nanowire layer 120 and silver layer 130. Substrate 110 may be, for example, a rigid transparent substrate or a flexible transparent substrate. In some embodiments, the material of substrate 110 is a transparent material, such as glass, acrylic, polyvinyl chloride, cycloolefin polymer, cycloolefin copolymer, polypropylene, polystyrene, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, colorless polyimide, or a combination thereof, but is not limited to these.

The metal nanowire layer 120 is arranged on the main surface 111 of the substrate 110 and corresponds to the visible area VA and the peripheral area PA. In some embodiments, metal nanowire layer 120 may include a matrix and a plurality of metal nanowires (not shown) contained within the matrix. The substrate may include an acrylic material such as poly(methyl methacrylate). The metal nanowires can include silver nanowires, gold nanowires, copper nanowires, nickel nanowires, or combinations thereof. The metal nanowire layer 120 defines an electrode portion E corresponding to the visible region VA. The electrode section E is configured to realize a touch function. In other words, the electrode portion E can constitute at least the contact electrode ET of the touch sensor 100. In some embodiments, the electrode portion E may have a single-layer structure on one side, a single-layer structure on both sides, or a double-layer structure on one side formed on the substrate 110. In the embodiment shown in FIG. 1A, the electrode portion E is an example of a single-layer electrode structure formed on one side of the substrate 110, and the plurality of electrode portions E are arranged so as not to intersect. For example, the electrode portion E may be a band-shaped electrode extending in the first direction D1 and spaced apart in the second direction D2. Here, the first direction D1 is orthogonal to the second direction D2. Further, each electrode portion E may have a plurality of electrode lines L arranged and connected in parallel. For example, in the embodiment shown in FIG. 1A, each electrode section E includes three electrode lines L arranged and connected in parallel.

The metal nanowire layer 120 defines a wiring T corresponding to the peripheral area PA. The wiring T includes a first wiring T1 and a second wiring T2 that are spaced apart from each other. The second wiring T2 is arranged on one side of the first wiring T1 relatively away from the visible area VA, and is adjacent to and parallel to the edge 112 of the main surface 111 of the substrate 110. The first wiring T1 includes a lead-out portion T11 and a lead portion T12. The lead-out portion T11 is connected adjacent to the electrode portion E. Lead portion T12 is connected to lead-out portion T11. In other words, the electrode portion E, the lead-out portion T11, and the lead portion T12 extend continuously from the visible area VA toward the peripheral area PA, and form a signal transmission path spanning the visible area VA and the peripheral area PA. In some embodiments, the lead-out portion T11 can be a component configured to connect a plurality of parallel electrode lines L of the electrode portion E, and the area occupied by the lead-out portion T11 allows the silver A region is provided for layer 130 to stably electrically connect with metal nanowire layer 120. In this embodiment, regarding the first wiring T1 and the second wiring T2 arranged on the same side as the visible area VA, the second wiring T2 is parallel to the boundary B between the visible area VA and the peripheral area PA, Further, it is arranged parallel to and spaced apart from the lead portion T12 of the first wiring T1 extending in the extending direction of the boundary B (for example, the second direction D2).

The silver layer 130 is disposed on the main surface 111 of the substrate 110, and is laminated and in contact with the first wiring T1 and the second wiring T2. Specifically, in the present embodiment, the first wiring T1 of the present disclosure is configured to form a signal line ST of the touch sensor 100 in order to transmit a touch signal to, for example, an external electronic component. obtain. Therefore, the number of first wirings T1 is usually designed to be a plurality so as to correspond to the number of electrode parts E. On the other hand, the second wiring T2 may be configured to, for example, form a ground line GT of the touch sensor 100 to prevent interference of electrostatic waves or electromagnetic waves. Further, in some embodiments, the peripheral area PA is a frame-shaped area arranged around the visible area VA, and the second wiring T2 is arranged along the four sides of the main surface 111 of the substrate 110. The first wiring T1 is arranged to surround the entire visible area VA and the first wiring T1. In other embodiments, when designing the ground line GT is not required, the second wiring T2 may be configured to form the signal line ST furthest from the visible area VA among all the signal lines ST. Therefore, regardless of the function provided by the second wiring T2, the silver layer 130 of the present disclosure is laminated and in contact with the upper surface TS of the first wiring T1 and the second wiring T2, and A peripheral wiring PT is formed. In other words, the peripheral wiring PT of the present disclosure has a two-layer structure, in which the metal nanowire layer 120 is located relatively close to the substrate 110, and the silver layer 130 is located on the opposite side of the substrate 110. The metal nanowire layer 120 is layered on the surface of the metal nanowire layer 120.

Further, the silver layer 130 according to the present embodiment at least partially overlaps the lead-out portion T11 of the first wiring T1, and completely overlaps the lead-out portion T12 of the first wiring T1 and the second wiring T2. may overlap. In other words, the vertical protrusion of the silver layer 130 laminated and in contact with the lead-out portion T11 of the substrate 110 may at least partially overlap the vertical protrusion of the lead-out portion T11 of the substrate 110. . Further, the vertical protrusion of the silver layer 130 stacked and in contact with the lead portion T12 of the substrate 110 and the second wiring T2 is connected to the vertical protrusion of the lead portion T12 of the substrate 110 and the second wiring T2. May overlap completely. Based on the configuration of the metal nanowire layer 120 and the silver layer 130, by integrally forming the electrode part E and the first wiring T1 belonging to the metal nanowire layer 120, the electrical connection between the contact electrode ET and the peripheral wiring PT is Connections can be made directly. Therefore, there is no need to design an additional overlapping structure for realizing electrical connection between the contact electrode ET and the peripheral wiring PT, and as a result, the area occupied by the overlapping structure corresponding to the peripheral area PA can be omitted, and the overlapping structure can be omitted. This is advantageous to meet the narrow bezel requirements of the touch sensor 100 as there is no need to take this into consideration.

As a supplement, since the plurality of peripheral wirings PT are insulated from each other and arranged at intervals, the silver layer 130 of the present disclosure is arranged only on the upper surface TS of the first wiring T1 and the second wiring T2. Thus, it overlaps with the first wiring T1 and the second wiring T2. As a result, the silver layer 130 and the first wiring T1/second wiring T2 have aligned sidewalls 134. In other words, when the silver layer 130 is overlapped with the first wiring T1 and the second wiring T2, the silver layer 130 does not cover the side walls of the first wiring T1 and the second wiring T2, so that the silver layer 130 does not cover the side walls of the first wiring T1 and the second wiring T2. It is possible to prevent the line width of the wiring PT from increasing. When viewed from another perspective (for example, from above or from the side), the silver layer 130 and the first wiring T1/second wiring T2 have substantially the same pattern.

FIG. 1C is a schematic and partially enlarged view showing region R of the touch sensor 100 of FIG. 1A. See FIGS. 1B and 1C. The silver layer 130 is laminated and in contact with the first wiring T1 and the second wiring T2. Silver layer 130 has a first side surface 131 and a second side surface 133. The first side surface 131 faces the visible area VA and is arranged on the lead-out portion T11 of the first wiring T1. The second side surface 133 is located on the opposite side to the visible area VA, and is arranged on the second wiring T2. A single mask etching process of the present disclosure performed to manufacture the touch sensor 100 (see the following paragraphs for details) can form a specific shape in the silver layer 130. Specifically, the first side surface 131 of the silver layer 130 has a continuously extending edge roughness SE1. The second side surface 133 of the silver layer 130 also has a continuously extending edge roughness SE2. The magnitude of the edge roughness SE1 of the first side surface 131 of the silver layer 130 (e.g., width W _SE1 ) is equal to the magnitude of the edge roughness SE2 of the second side surface 133 of the silver layer 130 (e.g., width W SE1 ). width W _SE2 ). Additionally, it should be noted that the term "edge roughness" as used in this disclosure may be the term "serrated edge" meaning that the edge is uneven and uneven. In other words, the edge roughness may include any number of depressions and protrusions. The contour shape of each concave portion and each convex portion is not limited to the present disclosure, and may be regular or irregular. The term "edge roughness" may be the term "serrated edge," although edge roughness does not necessarily imply the sharp shape of the serrations. Note that when the touch sensor 100 is viewed from one side (in other words, when viewed from the viewpoint of FIG. 1B), the specific positions of the edge roughness SE1 and SE2 are the upper surface 132 and the outer side of the silver layer 130. It should be noted that it is located at the turning point C with the wall 136.

The method for measuring the width W _SE2 of the edge roughness SE2 on the second side surface 133 of the silver layer 130 will be further supplemented. See FIGS. 1C and 2. FIG. 2 is a schematic diagram illustrating a method of measuring edge roughness width according to some embodiments of the present disclosure. FIG. 2 shows a rectangular touch sensor 100 as an example. The electrode portion E of the touch sensor 100 in FIG. 2 is a band-shaped electrode that extends in the first direction D1 and is arranged at intervals in the second direction D2. The width W _SE2 of the edge roughness SE2 on the second side surface 133 of the silver layer 130 can be obtained by specifically measuring the silver layer 130 of the ground line GT. The measurement method may include the following steps. In step S1, the length L2 of the ground line GT is divided into five equal length sections at four points O1 to O4. Here, the ground line GT is arranged on one side of the touch sensor 100 and extends in the second direction D2. In step S2, point O1 is set as the center point of observation range R1 of the Olympus optical microscope (observation range R1 is 10 times the objective lens and 10 times the eyepiece). Next, the first measurement line M1 extending in the second direction D2 is adjusted so as to touch the most concave point P1 of the most concave portion of the edge roughness SE2. Then, the second measurement line M2, which similarly extends in the second direction D2, is adjusted so that it touches the most protruding point P2 of the most protruding part of the edge roughness SE2 (for clear understanding, See Figure 1C). In step S3, the vertical distance between the first measurement line M1 and the second measurement line M2 is measured to obtain the width of the edge roughness SE2 in the observation range R1. In step S4, points O2 to O4 are set as the center points of observation ranges R2 to R4 of the same Olympus optical microscope (observation ranges R2 to R4 are 10 times the objective lens and 10 times the eyepiece), and By repeating S3, the width of the edge roughness SE2 in the observation ranges R2 to R4 is obtained. In step S5, the average value of the widths (total of 4 pieces) of the edge roughness SE2 in the observation ranges R1 to R4 obtained in the preceding step is calculated, and the average value is applied to the second side surface of the silver layer 130. The width W SE2 of the edge roughness SE2 at 133 is assumed to be W _SE2 . By performing steps S1 to S5, a width W _SE2 of the edge roughness SE2 on the second side surface 133 of the silver layer 130 is obtained. In addition, in FIG. 1C, the vertical distance between the first measurement line M1 and the second measurement line M2 in the observation range R1 is directly defined as the width W _SE2 of the edge roughness SE2. It should be noted that the width W SE2 of the edge roughness _SE2 is actually the average value of the widths of the edge roughness SE2 obtained in the observation ranges R1 to R4.

The method for measuring the width W _SE1 of the edge roughness SE1 on the first side surface 131 of the silver layer 130 will be further supplemented. Referring again to FIGS. 1C and 2. The method for measuring the width W _SE1 of the edge roughness SE1 on the first side surface 131 of the silver layer 130 may include the following steps. In step S1', the total length L1 of all the electrode parts E arranged at intervals in the second direction D2 is divided into sections of equal length at four points O1' to O4'. Here, the total length L1 extends in the second direction D2. In step S2, point O1' is set as the center point of the observation range R1' of the Olympus optical microscope (observation range R1' is 10 times the objective lens and 10 times the eyepiece), and the above process is performed for the edge roughness SE1. Perform S2. In step S3', the above step S3 is performed. Here, details of step S3 are omitted. In step S4', points O2' to O4' are set to the centers of observation ranges R2' to R4' (observation ranges R2' to R4' are 10 times the objective lens and 10 times the eyepiece) of the same Olympus optical microscope, respectively. The above step S4 is performed for the edge roughness SE1. In step S5', the average value of the widths of the edge roughness SE1 (total of 4) in the observation range R1' to R4' obtained in the preceding step is calculated, and The width of the edge roughness SE1 is assumed to be W _SE1 . By performing steps S1' to S5', the width W _SE1 of the edge roughness SE1 on the first side surface 131 of the silver layer 130 can be determined. In addition, in FIG. 1C, the vertical distance between the first measurement line M1 and the second measurement line M2 in the observation range R1' is directly defined as the width W _SE1 of the edge roughness SE1. , it should be noted that the width W SE1 of the edge roughness _SE1 is actually the average value of the width of the edge roughness SE1 obtained in the observation range R1' to R4'.

See FIGS. 1B and 1C. In some embodiments, the width W _SE1 of the edge roughness SE1 of the first side surface 131 of the silver layer 130 may be in the range of 10 μm or more and 50 μm or less. Further, the width W _SE2 of the edge roughness SE2 of the second side surface 133 of the silver layer 130 may be within the range of 0.01 μm or more and 5 μm or less. In the present disclosure, since mask etching is performed once, the silver layer 130 is It is possible to prevent the lead-out portion T11 located below from being etched at the same time. As a result, it is possible to prevent the electrical connection between the electrode portion E and the lead portion T12 from being interrupted. Therefore, the edge roughness SE1 caused by the screen printing process of the silver layer 130 remains on the first side 131 of the silver layer 130. In other words, other side surfaces of the silver layer 130 in the first wiring T1 and the second wiring T2 other than the first side surface 131 of the silver layer 130 can be etched and trimmed. The wiring T1 and the second wiring T2 can have aligned sidewalls. Therefore, the side surfaces of the silver layer 130 including the second side surface 133 have relatively low edge roughness. Specifically, regarding the first wiring T1 and the silver layer 130 disposed on the first wiring T1, the silver layer 130 is relatively far away from the visible area VA (compared to the first side surface 131). It also has a third side surface 135 on the lead-out portion T11 and two fourth side surfaces 137 that connect the first side surface 131 and the third side surface 135. The lead-out portion T11, the third side surface 135 of the silver layer 130, and the two fourth side surfaces 137 of the silver layer 130 have aligned sidewalls 134. Further, the lead portion T12 and the silver layer 130 stacked on and in contact with the lead portion T12 also have aligned side walls 134. Regarding the second wiring T2 and the silver layer 130 disposed on the second wiring T2, the silver layer 130 is connected to the second wiring which is relatively away from the visible area VA (compared to the second side surface 133). It has a fifth side 139 on T2. The second wiring T2 and the fifth side surface 139 of the silver layer 130 have aligned sidewalls 134. Note that in the present disclosure, first, a material layer forming the metal nanowire layer 120 is formed on the entire surface of the peripheral area PA, and then a material layer forming the silver layer 130 is formed on the entire surface of the peripheral area PA. A corresponding pattern is formed, and a mask etching process is performed once to form a pattern in the above-mentioned material layer and further form a peripheral wiring PT. Accordingly, the lead-out portion T11, the third side 135 of the silver layer 130, and the fourth side 137 of the silver layer 130 on the lead-out portion T11 may have aligned sidewalls 134. Therefore, there is no need to consider the overlap due to the overlapping structure of the silver layer 130 and the lead-out portion T11, which is advantageous in satisfying the narrow bezel requirement of the touch sensor 100.

As a supplement, the differences between the one-time mask etching process of the present disclosure and the laser process will be described. The laser treatment is, for example, irradiating a laser beam from a direction perpendicular to the main surface 111 of the substrate 110. The laser beam scans and etches linearly in the first direction D1 or the second direction D2. Therefore, the laser treatment may not be able to etch and trim the edge roughness SE2 of the second side 133 of the silver layer 130. For example, when the position of the laser beam for trimming is adjusted to the most protruding part of the edge roughness SE2, the silver layer 130 to be etched is placed in the recessed part of the relatively concave edge roughness SE2. Because it is not present, the laser beam may damage the substrate 110. Therefore, when laser processing is performed to form the pattern, the edge roughness SE2 of the second side 133 of the silver layer 130 cannot be trimmed, and as a result, the edge roughness SE2 (e.g. , 10 μm or more and 50 μm or less), a relatively large width W _SE2 remains.

Further, by one mask etching process of the present disclosure, the line width W1 of the plurality of peripheral wirings PT arranged in parallel corresponding to the peripheral area PA can be set within the range of 6 μm or more and 10 μm or less. Further, the line spacing D between two adjacent peripheral wirings PT can be within the range of 6 μm or more and 10 μm or less. Those skilled in the art will understand that the line width W1 and the line spacing D are the line widths of the peripheral wirings PT that are on the same side of the touch sensor 100 and extend in parallel in the same direction (for example, the second direction D2). It can be understood that W1 and line spacing D can be used. The line width W1 and the line spacing D of the two-layered peripheral wiring PT of the present disclosure are within a specific range that has a certain effect on the size of the peripheral area PA (for example, the width W of the peripheral area PA) of the touch sensor 100. It can be done. Since the size of the peripheral area PA further influences the size of the bezel of the terminal product, the touch sensor 100 of the present disclosure can meet the requirements of electrical specifications and the requirements of products with narrow bezels. In some embodiments, if the second wiring T2 is designed to function as a grounding line GT, it is necessary to Accordingly, the line width W1 of the ground line GT can be made larger than the line width W1 of the signal line ST. However, such adjustment does not prevent the peripheral area PA of the touch sensor 100 of the present disclosure from meeting the requirements of narrow bezel products.

In some embodiments, the touch sensor 100 may further include a protective layer 140 disposed on the main surface 111 of the substrate 110 and covering the entirety of the metal nanowire layer 120 and the silver layer 130. Protective layer 140 may include an insulating resin, an organic material, or an inorganic material. For example, the protective layer 140 may include materials such as polyethylene, polypropylene, polycarbonate, polyvinyl butyral, polystyrene sulfonic acid, acrylonitrile-butadiene-styrene copolymer, poly(3,4-ethylenedioxythiophene), ceramic, or combinations thereof. obtain.

It should be noted that the connections and functions of the described components will not be repeated in the following description. Reference is made to FIG. 3, which shows a flowchart illustrating a method of manufacturing a touch sensor 100 according to some embodiments of the present disclosure. In the following description, the steps shown in FIGS. 4A to 4I are examples for explaining the method for manufacturing the touch sensor 100. 4A to 4I are schematic cross-sectional views showing a method for manufacturing the touch sensor 100 of FIG. 1B through different steps. The method for manufacturing the touch sensor 100 includes steps S10 to S18. Further, steps S10 to S18 may be performed sequentially.

First, refer to FIG. 4A. In step S10, a metal nanowire material layer 220 is formed on the main surface 111 of the substrate 110. Here, the metal nanowire material layer 220 corresponds to the visible region VA and the peripheral region PA. Specifically, a dispersion or slurry containing at least metal nanowires and a substrate can be formed on the main surface 111 of the substrate 110 using a process such as screen printing, nozzle coating, or roller coating. . The dispersion or slurry is then cured or dried to form a layer of metal nanowire material 220 disposed on the major surface 111 of the substrate 110. In some embodiments, a roll-to-roll process can be performed to coat the major surface 111 of the substrate 110 in a continuous manner with a dispersion or slurry. In some embodiments, the major surface 111 of the substrate 110 can be pretreated before the metal nanowire material layer 220 is formed. For example, a surface modification treatment may be performed or an additional layer of adhesive or resin may be applied to the major surface 111 of the substrate 110 to enhance adhesion between the substrate 110 and other layers.

Next, refer to FIG. 4B. In step S11, a screen printing process is performed to form a silver material layer 230 on the metal nanowire material layer 220. Here, the silver material layer 230 corresponds to the peripheral area PA. Specifically, silver paste material may be formed on the substrate 110 through a screen printing process. Here, the silver material layer 230 corresponds to the peripheral area PA and covers the metal nanowire material layer 220 corresponding to the peripheral area PA. The silver paste material is then cured or dried to form the silver material layer 230. The screen has multiple mesh holes on all its sides. Commonly used screens are, for example, screens with two intersecting angles, so the arrangement of mesh holes in the screen allows non-linear edges, including serrations, recesses, and protrusions, to be produced in the screen printing process. Formed at the edges of the entire applied layer. As a result, the formed silver material layer 230 may have edge roughness (here, the edge refers to the turning point C between the top surface 231 and the side wall 233 of the silver material layer 230). ). As shown in FIG. 4B, edge roughness is formed on the edges of the entire silver material layer 230 facing the visible area VA. The edge roughness is also formed at the edge of the entire silver material layer 230 located on the opposite side to the visible region VA and adjacent to the edge of the main surface 111 of the substrate 110. Those skilled in the art will appreciate that factors that influence the amount (e.g., width) of the edge roughness formed by screen printing include, for example, the number of screen meshes, the distance between the screen and the squeegee, the Parameters include squeegee pressure, squeegee speed for screen printing, distance between the screen and the surface to be printed, level characteristics of the silver paste material (the level characteristics of the silver paste material can be influenced by the viscosity of the silver paste material), etc. You will be able to understand that. In some embodiments, the number of screen meshes is 640, the distance between the screen and the squeegee is 3 mm, the squeegee speed for screen printing is 50 m/min, and the distance between the screen and the surface to be printed is is 2.5 mm, and the viscosity of the silver paste material is 1000 cp or more and 5000 cp or less. In this regard, the width of the edge roughness of the silver material layer 230 formed by the screen printing process of the present disclosure can be adjusted to a range of 10 μm or more and 50 μm or less.

Different types of silver paste materials may also be used to form the silver material layer 230 of the present disclosure. Specifically, the first type of silver paste material may include a solvent, an acrylic material (eg, poly(methyl methacrylate)), and silver particles. A second type of silver paste material can produce elemental silver by a silver mirror reaction involving the reaction of an aldehyde functional group (eg, the aldehyde functional group of acetaldehyde) with a silver ammonia complex. The reaction formula is as follows.

In some embodiments, with respect to the thickness H of the silver material layer 230 formed by a single screen printing process, the thickness H of the silver material layer 230 formed using the first type of silver paste material is , may be about 1 μm to 1.5 μm. Further, the thickness H of the silver material layer 230 formed using the second type of silver paste material may be in the range of 500 nm to 600 nm.

Next, refer to FIG. 4C. In step S12, a photoresist layer 240 is formed on the main surface 111 of the substrate 110, completely covering the metal nanowire material layer 220 and the silver material layer 230. Refer now to FIG. 4D. In step S13, exposure processing and development processing are performed, and as a result, a pattern is formed in the photoresist layer 240. The desired patterns formed in the metal nanowire material layer 220 and the silver material layer 230 are formed at once in a single photoresist layer 240 through a single exposure and development process, resulting in reduced manufacturing steps and costs. Reduce. In some embodiments, the photoresist layer 240 defines a pattern PE of the electrode portion corresponding to the visible area VA, and also defines a first wiring pattern PT1 and a second wiring pattern PT2 corresponding to the peripheral area PA. Here, the first wiring pattern PT1 is separated from and insulated from the second wiring pattern PT2. The first wiring pattern PT1 includes a lead-out pattern PT11 connected adjacent to the electrode pattern PE, and a lead-out pattern PT12 connected to the lead-out pattern PT11. The second wiring pattern PT2 is arranged on one side of the first wiring pattern PT1 relatively away from the visible area VA, and is adjacent to the edge 112 of the main surface 111. The pattern PE of the electrode portion of the patterned photoresist layer 240, the first wiring pattern PT1, and the second wiring pattern PT2 are transferred to the metal nanowire material layer 220 and the silver material layer 230 in a subsequent etching process. . Then, when the photoresist layer 240 is removed, a metal nanowire layer 120 including the electrode portion E, the first wiring T1, and the second wiring T2 is laminated on the first wiring T1 and the second wiring T2. A contacting silver layer 130 is formed (see FIG. 1B for a specific configuration).

Referring now to FIG. 4E. In step S14, a first etching process is performed to form a desired pattern in the silver material layer 230 corresponding to the peripheral area PA. Specifically, a pattern is formed in the silver material layer 230 using the first wiring pattern PT1 and the second wiring pattern PT2, and the pattern PT12 of the lead portion of the first wiring pattern PT1 is formed along with the equiangular pattern. , and a pattern of the second wiring pattern PT2 are formed. In step S13 (FIG. 4D) described above, the patterned photoresist layer 240 has a surface that continuously covers the pattern PE of the electrode part and the pattern PT11 of the lead-out part. In other words, the patterned photoresist layer 240 continuously extends the pattern PE of the electrode portion and the pattern PT11 of the lead-out portion. Therefore, the rough edges formed by the screen printing process on the silver material layer 230 facing the visible area VA and located in the non-etched area are covered by the photoresist layer 240, so the first etching process There will be no etching or trimming. Therefore, it should be understood that the width of the edge roughness of the silver material layer 230 facing the visible region VA and located in the non-etched region is maintained in a range of 10 μm or more and 50 μm or less. On the other hand, in step S13 (FIG. 4D) described above, the roughness of the edge formed on the silver material layer 230 located on the opposite side to the visible region VA and located in the non-etched region is reduced by the photoresist layer 240. Since it is not covered, the edge roughness of the silver material layer 230 located opposite to the visible area VA can be etched and trimmed in the first etching process. Therefore, the width of the roughness of the edge of the silver material layer 230 located on the opposite side to the visible region VA can be reduced to a range of 0.01 μm or more and 5 μm or less. In some embodiments, the main components of the etchant for etching the silver material layer 230 may include, for example, nitric acid and iron nitrate. These can selectively etch the silver material layer 230 without etching the metal nanowire material layer 220 below the silver material layer 230. In some embodiments, the etch depth of silver material layer 230 can be adjusted, for example, by adjusting the etch time.

Note that, as shown in FIG. 4E, after etching the silver material layer 230, a residue 250 such as a resin usually remains in the etched region S. This residue 250 affects the etching accuracy of the metal nanowire material layer 220, and furthermore, it may be difficult to reduce the line width W1 and line spacing D of the peripheral wiring PT to meet the requirements. In this regard, reference is made to FIG. 4F for step S15. In some embodiments, a chemical cleaning process is performed and the patterned silver material layer 230 is pretreated using a first wiring pattern PT1 and a second wiring pattern PT2. Specifically, the residue 250 in the etched region S is pretreated. In some embodiments, during the chemical cleaning process, a chemical cleaning agent capable of removing the resin of the silver material layer 230 is used at an air temperature of about 45° C. and a showerhead pressure of about 0.2 MPa, at a temperature of about 40° C. A surface treatment is performed for 2 seconds, so that the residue 250 in the etched area S is removed.

As shown in FIG. 4F, after the chemical cleaning process, the residue 250 in the etched area S can be substantially removed. However, since the chemical cleaning process removes the residue 250 through a chemical reaction, the residue 250 cannot be removed after reaching chemical equilibrium, and the residue 250 in the etched region S may not be completely removed. For example, when forming the silver material layer 230 using the first type of silver paste material in step S11, the silver material layer 230 having a thickness of about 1.5 μm is subjected to the first etching process (see FIG. After performing step 4E), the thickness of the residue 250 remaining in the etched region S may be about 300 nm. Further, after the chemical cleaning treatment (FIG. 4F) of step S15 is performed, the thickness of the residue 250 remaining in the etched region S may be about 50 nm.

Furthermore, if the residue 250 needs to be completely removed to further improve the etching precision of the metal nanowire material layer 220, refer to FIG. 4G for step S16. In some embodiments, a plasma treatment step is performed such that the patterned silver material layer 230 is further processed using the first wiring pattern PT1 and the second wiring pattern PT2. Specifically, the residue 250 in the etched region S is further processed. Because plasma treatment is non-selective, all surfaces exposed to the treatment environment are physically removed, resulting in complete removal of residue 250. In some embodiments, plasma treatment is performed on silver material layer 230 for about 4.5 minutes. Here, the plasma treatment uses argon plasma with a minimum vacuum of about 20 mTorr, an operating vacuum of about 200 mTorr, an output of about 8 kW, a helium flow rate of 1000 sccm (standard cubic centimeters per minute), an oxygen flow rate of 1000 sccm, This is performed on the silver material layer 230 for approximately 4.5 minutes. In some embodiments, the plasma treatment can further remove the substrate above the metal nanowire material layer 220 to facilitate a subsequent second etching process.

As a supplement, the chemical cleaning treatment in step S15 and the plasma treatment in step S16 can be performed selectively or adjusted according to the actual requirements of etching precision.

Next, refer to FIG. 4H. In step S17, a second etching process is performed to form a pattern in the metal nanowire material layer 220 corresponding to the peripheral area PA and visible area VA. Specifically, since the photoresist used in the second etching process and the photoresist used in the first etching process are the same photoresist layer 240, the peripheral area PA is covered by the second etching process. The pattern formed in the metal nanowire material layer 220 is the same as the pattern of the silver material layer 230 in which the pattern corresponding to the peripheral area PA is formed. In addition, other expected patterns (for example, the pattern PE of the electrode part) are formed in the metal nanowire material layer 220 corresponding to the visible region VA by the second etching process. Overall, the pattern PE of the electrode portion of the photoresist layer 240, the first wiring pattern PT1, and the second wiring pattern PT2 are transferred to the metal nanowire material layer 220 in the second etching process. As a result, a pattern is formed in the metal nanowire material layer 220, and includes an electrode portion E corresponding to the visible region VA, a first wiring T1 corresponding to the peripheral region PA, and a peripheral region insulated from the first wiring T1. A second wiring T2 corresponding to PA is formed. Here, the first wiring T1 includes a lead-out part T11 adjacent to the electrode part E, and a lead part T12 connected to the lead-out part T11, and the second wiring T2 extends from the visible area VA. It is arranged on one side of the relatively distant first wiring T1 and is adjacent to and parallel to the edge 112 of the main surface 111 of the substrate 110. For the specific location of T2, see FIG. 1B). In some embodiments, the main components of the etching solution for etching the metal nanowire material layer 220 can include, for example, ferric chloride and hydrochloric acid. In some embodiments, the etch depth of the metal nanowire material layer 220 can be adjusted, for example, by adjusting the etch time.

See FIGS. 4I and 1C. In step S18, photoresist layer 240 is removed. Regarding the silver material layer 230, in particular, after removing the photoresist layer 240, the silver layer 130 formed by the patterned silver material layer 230 can be seen. Here, the silver layer 130 has a first side surface 131 facing the visible region VA, and a second side surface 133 located on the opposite side to the visible region VA. Due to the arrangement of the photoresist layer 240 and the design of the first etching process, the first side surface 131 and the second side surface 133 of the silver layer 130 have an edge roughness SE1 and an edge roughness SE2, respectively. . The width W _SE1 of the edge roughness SE1 of the first side surface 131 is larger than the width W _SE2 of the edge roughness SE2 of the second side surface 133 .

Regarding the metal nanowire material layer 220, after removing the photoresist layer 240, the metal nanowire layer 120 formed by the patterned metal nanowire material layer 220 can be seen. Here, the electrode portion E of the metal nanowire layer 120 can constitute at least the contact electrode ET of the touch sensor 100 and the first wiring T1 and the second wiring T2 of the metal nanowire layer 120. Furthermore, the silver layer 130 that is laminated and in contact with the first wiring T1 and the second wiring T2 can constitute at least the peripheral wiring PT of the touch sensor 100.

To summarize the above steps S13 to S18, between the two etching treatments (in other words, the first etching treatment and the second etching treatment), chemical cleaning treatment and plasma treatment are selectively performed to improve etching accuracy. can be improved. This entire process includes "development", "first etching (of the silver material layer 230)", "chemical cleaning", "plasma treatment", "second etching (of the metal nanowire material layer 220)", and " These are further referred to as "DECEPS processing" for short.

In the embodiment of the present disclosure described above, the touch sensor of the present disclosure includes a metal nanowire layer that includes an electrode portion, a first wiring, and a second wiring, and is stacked on and in contact with the first wiring and the second wiring. and a silver layer. The roughness (e.g., width) of the edge of the side surface of the silver layer located on the second wiring and located on the opposite side to the visible region is the same as that of the first wiring, and Since the magnitude of the roughness is smaller than that of the edge of the side of the silver layer facing the visible region, the outermost peripheral wiring (eg, ground line) of the touch sensor is formed with a smoother edge. In other words, edge roughness can be ignored. This is advantageous to meet the narrow bezel requirements of touch sensors. Moreover, by integrally forming the electrode portion and the first wiring to directly form an electrical connection between the contact electrode and the peripheral wiring, there is no need to design an additional overlapping structure for the touch sensor. As a result, the area occupied by the overlapping structure corresponding to the peripheral area can be omitted, and there is no need to consider overlapping, which is advantageous for realizing a narrow bezel for the touch sensor. Further, based on the laminated structure design of the touch sensor of the present disclosure, during the manufacture of the touch sensor, the patterned photoresist layer continuously extends the pattern of the electrode part and the pattern of the readout part. designed to. As a result, contact electrodes and peripheral wiring can be formed at once through a single exposure and development process (in other words, only a single photoresist layer is used), reducing manufacturing process steps and costs. can.

Although the present disclosure has been described in great detail with reference to particular embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments set forth herein.

It will be apparent to those skilled in the art that various modifications and changes can be made to the structure of the present disclosure without departing from the scope or spirit of the disclosure. In this regard, the present disclosure is intended to include modifications and variations thereof provided they come within the scope of the following claims.

100 Touch sensor 110 Substrate 111 Main surface 112 Edge 120 Metal nanowire layer 130 Silver layer 131 First side surface 132 Top surface 133 Second side surface 134 Side wall 135 Third side surface 136 Outer wall 137 Fourth side surface 139 Fifth side surface 140 Protective layer 220 Metal nanowire material layer 230 Silver material layer 231 Top surface 233 Side wall 240 Photoresist layer 250 Residue AA' Section line B Boundary C Turning point D Line spacing D1 First direction D2 Second direction E Electrode section ET Contact electrode GT Ground wire H Thickness L Electrode wire L1 Total length of electrode section L2 Length of ground wire M1 First measurement line M2 Second measurement line PA Peripheral area PE Pattern of electrode section PT Peripheral wiring PT1 First Wiring pattern PT11 Pattern of lead-out part PT12 Pattern of lead part PT2 Second wiring pattern R Regions R1 to R4 Observation range R1' to R4' Observation range S Etching region ST Signal line T Wiring T1 First wiring T11 Lead-out part T12 Lead part T2 Second wiring TS Upper surface VA Visible area

Claims (10)

A touch sensor having a visible region and a peripheral region adjacent to at least one side of the visible region,
A substrate and
A metal nanowire layer disposed on a main surface of the substrate, the metal nanowire layer defining an electrode portion corresponding to the visible region, and defining a first wiring and a second wiring corresponding to the peripheral region. a wiring is defined, the second wiring is placed apart from the first wiring, the first wiring includes a lead-out portion, and the lead-out portion is connected to the electrode portion. , the lead portion is connected to the lead-out portion, the second wiring is located on one side of the first wiring relatively distant from the visible area, and , a metal nanowire layer adjacent to an edge of the main surface;
a silver layer laminated and in contact with the first wiring and the second wiring; and a second side surface located on the opposite side to the visible area of the wiring, and the roughness of the edge of the first side surface of the silver layer is such that the roughness of the edge of the first side surface of the silver layer is such that the roughness of the edge of the first side surface of the silver layer is Touch sensor with silver layer and which is larger than the edge roughness. the metal nanowire layer defines a plurality of spaced first interconnects corresponding to the peripheral region;
The touch sensor according to claim 1, wherein the silver layer is disposed on and contacts the upper surface of the first wiring to form a plurality of peripheral wirings of the touch sensor. The silver layer includes a third side surface on the lead-out part located on the opposite side with respect to the visible region, and two fourth side surfaces connecting the first side surface and the third side surface. It has
The touch sensor according to claim 1 or 2, wherein the lead-out portion, the third side surface of the silver layer, and the two fourth side surfaces of the silver layer have aligned sidewalls. The touch sensor according to claim 1, wherein the lead portion and the silver layer laminated on and in contact with the lead portion have aligned sidewalls. The silver layer has a fifth side surface facing the visible region of the second wiring,
The touch sensor of claim 1, wherein the second wiring and the fifth side of the silver layer have aligned sidewalls. The width of the roughness of the edge of the first side surface of the silver layer is in the range of 10 μm or more and 50 μm or less,
The touch sensor according to claim 1, wherein the width of the roughness of the edge of the second side surface of the silver layer is within a range of 0.01 μm or more and 5 μm or less. The line width of the peripheral wiring is within a range of 6 μm or more and 10 μm or less,
The touch sensor according to claim 2, wherein a line interval between two adjacent peripheral wirings of the peripheral wiring is within a range of 6 μm or more and 10 μm or less. A method for manufacturing a touch sensor having a visible region and a peripheral region adjacent to at least one side of the visible region, the method comprising:
forming a metal nanowire material layer corresponding to the visible region and the peripheral region on the main surface of the substrate;
performing a screen printing process to form a silver material layer corresponding to the peripheral region on the metal nanowire material layer;
forming a photoresist layer covering the metal nanowire material layer and the silver material layer;
A pattern is formed in the photoresist layer by performing an exposure process and a development process, and the patterned photoresist layer defines an electrode portion corresponding to the visible region and corresponds to the peripheral region. a first wiring pattern and a second wiring pattern are defined, the second wiring pattern is arranged apart from the first wiring pattern, and the first wiring pattern is separated from a pattern of a lead-out portion. , a pattern of a lead part, the pattern of the lead-out part is connected adjacent to the pattern of the electrode part, the pattern of the lead part is connected to the pattern of the lead-out part, and the pattern of the lead-out part is connected to the pattern of the lead-out part, and the pattern of the lead-out part is connected to the pattern of the second lead-out part. A wiring pattern is disposed on one side of the first wiring pattern relatively away from the visible region, adjacent to an edge of the main surface, and adjacent to the patterned photoresist layer. The pattern of the electrode part and the pattern of the lead-out part are continuous coating layers,
Performing a first etching process, forming a pattern on the silver material layer using the first wiring pattern and the second wiring pattern,
performing a second etching process to form a pattern in the metal nanowire material layer using the first wiring pattern and the second wiring pattern;
removing the photoresist layer;
A method of manufacturing a touch sensor. After the first etching process and before the second etching process, plasma treatment is performed to remove the patterned silver using the first wiring pattern and the second wiring pattern. 9. The method of manufacturing a touch sensor according to claim 8, wherein the material layer is treated. After the first etching treatment and before the plasma treatment, a chemical cleaning treatment is performed, and the patterned silver material layer is cleaned using the first wiring pattern and the second wiring pattern. The method for manufacturing a touch sensor according to claim 9, wherein the touch sensor is pretreated.

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