TWI439901B - Method for manufacturing touch panel - Google Patents

Description

Touch panel manufacturing method

The present invention relates to a touch panel and a method of fabricating the same.

The touch interface is more and more diversified because it allows users to easily input data and click functions. According to different sensing principles, touch panels can be classified into Resistive, Capacitive, Surface Acoustic Wave, and Optics. The capacitive touch panel can be further divided into a surface capacitive type and a projected capacitive type (Projected Capacitive). In recent years, projected capacitive touch technology with multi-touch function has attracted the most attention.

The general projected capacitive technology utilizes the capacitive coupling between the electrodes and the touch object, and measures the capacitance change of the electrodes to determine the touch position. This is because a single-layer or multi-layer patterned transparent electrode can be used as the sensing unit in the projected capacitive touch panel, so that an accurate touch position can be obtained.

If the above-mentioned projected capacitive panel adopts a single-layer patterned transparent electrode, the manufacturing process usually requires four mask processes. The four mask processes are used to form patterned metal lines, insulating layers, transparent electrodes, and protective layers, respectively. If a double-layer patterned transparent electrode is used, a five-mask process is required.

The more masks are required for the process, the longer the manufacturing time. Therefore, there is a need for a novel manufacturing method that reduces process steps to reduce process time and process cost.

One aspect of the present invention provides a method of manufacturing a touch panel comprising the following steps. A metal layer is formed on the substrate. A patterned photoresist layer is formed on the metal layer and a portion of the metal layer is exposed. The patterned photoresist layer has a first region and a second region, and the thickness of the patterned photoresist layer of the first region is greater than the thickness of the patterned photoresist layer of the second region. The exposed portion of the metal layer is removed to form a metal wire and expose a portion of the substrate. The patterned photoresist layer is thinned to remove the patterned photoresist layer of the second region to expose the metal wires underneath. An insulating layer is formed on the exposed metal wires, the exposed portion of the substrate, and the patterned photoresist layer of the first region. The patterned photoresist layer of the first region and the insulating layer thereon are removed to form a contact window in the insulating layer. A patterned transparent conductive layer is formed in the contact window and on the insulating layer. A protective layer is formed on the patterned transparent conductive layer.

In one embodiment, the step of forming the patterned photoresist layer comprises using a gray scale mask.

In one embodiment, the patterned photoresist layer is used to define metal wires.

In one embodiment, the patterned photoresist layer of the first region is used to define a contact window.

In one embodiment, after thinning the patterned photoresist layer, the thickness of the patterned photoresist layer of the first region is greater than the thickness of the insulating layer.

In one embodiment, the ratio of the thickness of the patterned photoresist layer of the first region to the thickness of the insulating layer is about 3:1 to 5:1.

In one embodiment, the step of removing the patterned photoresist layer of the first region and the insulating layer thereon comprises dissolving the patterned photoresist layer of the first region using a solution.

In one embodiment, the transparent conductive layer comprises indium tin oxide.

In one embodiment, the step of thinning the patterned photoresist layer comprises treating the patterned photoresist layer with oxygen plasma.

In one embodiment, the step of forming a protective layer includes forming an opening in the protective layer to expose the patterned transparent conductive layer.

As can be seen from the above, the manufacturing method can manufacture the touch panel by using three mask processes, thereby shortening the processing time and reducing the production cost.

The Summary of the Invention is intended to provide a simplified summary of the present disclosure in order to provide a basic understanding of the disclosure. This Summary is not an extensive overview of the disclosure, and is not intended to be an The basic spirit and other objects of the present invention, as well as the technical means and implementations of the present invention, will be readily apparent to those skilled in the art of the invention.

The embodiments of the present invention are disclosed in the following drawings, and the details of However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not necessary. In addition, some of the conventional structures and elements are shown in the drawings in a simplified schematic manner in order to simplify the drawings.

FIG. 1 is a schematic top plan view of a touch panel according to an embodiment of the invention. 2A-2F is a cross-sectional view showing each process stage in the method of manufacturing the touch panel according to the embodiment of the present invention, which is a section along the line A-A' in Fig. 1. The various process steps will be described in detail below.

First, a metal layer 120 is formed on the substrate 110 as shown in FIG. 2A. The material of the substrate may be, for example, glass. The material of the metal layer 120 may be aluminum, Chromium, nickel (nickel), molybdenum or neodymium. For example, the metal layer 120 can be formed using a sputtering process.

Then, a patterned photoresist layer 130 is formed on the metal layer 120, and a portion of the metal layer 120 is exposed, as shown in FIG. 2A. The patterned photoresist layer 130 can be divided into a first region 130a and a second region 130b, and the thickness of the patterned photoresist layer 130 of the first region 130a is greater than the thickness of the patterned photoresist layer 130 of the second region 130b. In an embodiment, a gray scale mask can be used to form the first region 130a and the second region 130b of the patterned photoresist layer 130. For example, a photoresist layer may be formed first, and then the pattern of the first region 130a and the second region 130b of the photoresist layer is defined by a gray scale mask. Subsequently, through the development process, the patterned photoresist layer 130 having different thicknesses at different positions can be obtained. The photoresist layer may be a positive photoresist or a negative photoresist. This is because the light transmittance at each position on the gray scale mask is different, so that the patterned photoresist layer 130 after the lithography has a different thickness. It can be fabricated using a high contrast photoresist, and a patterned photoresist layer 130 with a steeper sidewall can be obtained after the development process.

Then, the exposed portion of the metal layer 120 is removed according to the patterned photoresist layer 130 to form the metal wires 122 and expose a portion of the substrate 110 as shown in FIG. 2B. For example, a wet etch process can be used to remove the exposed metal layer 120. Thus, the first region 130a and the second region 130b of the patterned photoresist layer 130 can be used to define a pattern of metal lines 122.

Next, the patterned photoresist layer 130 is thinned to remove the patterned photoresist layer of the second region 130b to expose the metal wires 122 under the patterned photoresist layer 130 of the second region 130b, as shown in FIG. 2B. . For example, oxygen plasma can be used to remove the patterned photoresist layer 130 of a certain thickness until the patterned photoresist layer 130 of the second region 130b is completely removed. Therefore, the metal wires 122 under the patterned photoresist layer 130 of the second region 130b can be exposed. Also, the thickness of the patterned photoresist layer 130 of the first region 130a is also reduced. The thickness of the patterned photoresist layer 130 of the remaining first region 130a may be, for example, 1.0 to 1.5 μm. Next, the related process can be designed according to the patterned photoresist layer 130 of the remaining first region 130a to fabricate the structure of the other layers.

Subsequently, an insulating layer 140 is formed on the exposed metal wires 122, the exposed portion of the substrate 110, and the patterned photoresist layer 130 of the first region 130a, as shown in FIG. 2C. The material of the insulating layer 140 may be yttrium oxide. The insulating layer 140 can be formed, for example, using a chemical vapor deposition method. In the process of depositing the insulating layer 140, the thickness of the insulating layer 140 deposited on the side of the patterned photoresist layer 130 of the first region 130a may be thin or expose a portion of the patterned photoresist layer 130.

In an embodiment, the thickness of the patterned photoresist layer 130 of the first region 130a is greater than the thickness of the insulating layer 140. For example, the thickness of the insulating layer 140 over the patterned photoresist layer 130 of the first region 130a may be, for example, 0.2 to 0.3 μm.

In one embodiment, the ratio of the thickness of the patterned photoresist layer 130 of the first region 130a to the thickness of the insulating layer 140 is about 3:1 to 5:1. If the thickness ratio is larger, the area of the patterned photoresist layer 130 that is exposed may be larger.

Then, the patterned photoresist layer 130 of the first region 130a and the insulating layer 140 thereon are removed to form a contact window 140a in the insulating layer 140, as shown in FIG. 2D. The method of removal can utilize a lift-off method. In detail, a solution can be used first to dissolve the photoresist layer. The solution can be, for example, an alkaline solution. The exposed patterned photoresist layer 130 is dissolved by contact with the exposed patterned photoresist layer 130. Therefore, the insulating layer 140 above the patterned photoresist layer 130 can be peeled off, and the contact window 140a can be formed in the insulating layer 140. The contact window 140 exposes a portion of the metal wire 122. It can be seen that the patterned photoresist layer 130 of the first region 130a can be used to define the contact window 140a. Therefore, in addition to the patterned photoresist layer 130, the patterned photoresist layer 130 of the first region 130a left after thinning can be used to define the contact window 140a in the insulating layer 140. In summary, the structure of the metal wire 122 and the insulating layer 140 can be formed by a gray scale mask and a lift-off method.

Next, a patterned transparent conductive layer 150 is formed in the contact window 140a and on the insulating layer 140 as shown in FIG. 2E. Therefore, the metal wires 122 and the patterned transparent conductive layer 150 can be electrically connected by contacting the contact window 140a. The patterned transparent conductive layer 150 may contain indium tin oxide. For example, a transparent conductive layer can be formed by physical vapor deposition or chemical vapor deposition. Then, a pattern of the transparent conductive layer is defined by a mask, and then a lithography process is performed to form the patterned transparent conductive layer 150. For example, the patterned transparent conductive layer 150 as shown in FIG. 1 can be formed. Each of the transparent conductive layer blocks may be separated by a slit 150a.

Then, a protective layer 160 is formed on the patterned transparent conductive layer 150 as shown in FIG. 2F. After the protective layer 160 is formed, the touch panel shown in FIG. 1 is formed. The material of the protective layer 160 may be ruthenium oxide. For example, a protective layer 160 may be formed first by chemical vapor deposition. Then, the pattern of the protective layer 160 is defined by a mask, and then a photolithography process is performed to form the patterned protective layer 160. In addition, the patterned protective layer 160 may have an opening 160a to expose a portion of the patterned transparent conductive layer 150. The exposed patterned transparent conductive layer 150 can be used to connect other electronic components or to test the electrical characteristics of the touch panel.

As can be seen from the above, the structure of the metal wires and the insulating layer can be formed by a gray scale mask and a lift-off method. Then, the patterned transparent conductive layer and the protective layer are respectively formed by two masks and related processes, and the touch panel can be completed. Therefore, the manufacturing method can manufacture a touch panel by using three mask processes, which can shorten the processing time and reduce the production cost.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention can be modified and modified without departing from the spirit and scope of the present invention. The scope is subject to the definition of the scope of the patent application attached.

110. . . Substrate

120. . . Metal layer

122. . . Metal wire

130. . . Patterned photoresist layer

130a. . . First district

130b. . . Second district

140. . . Insulation

140a. . . Contact window

150. . . Patterned transparent conductive layer

150a. . . Slit

160. . . The protective layer

160a. . . Opening

The above and other objects, features, advantages and embodiments of the present invention will become more apparent and understood.

FIG. 1 is a schematic top plan view of a touch panel according to an embodiment of the invention.

2A-2F are schematic cross-sectional views showing respective process stages of a method of manufacturing a touch panel according to an embodiment of the present invention.

110. . . Substrate

122. . . Metal wire

140. . . Insulation

150. . . Patterned transparent conductive layer

160. . . The protective layer

160a. . . Opening

Claims (10)

A method for manufacturing a touch panel, comprising: forming a metal layer on a substrate; forming a patterned photoresist layer on the metal layer, and exposing a portion of the metal layer, wherein the patterned photoresist layer has a first a region and a second region, wherein a thickness of one of the patterned photoresist layers of the first region is greater than a thickness of the patterned photoresist layer of the second region; removing the metal layer of the exposed portion to form a metal wire And exposing a portion of the substrate; thinning the patterned photoresist layer to remove the patterned photoresist layer of the second region to expose the metal wire underneath; forming an insulating layer on the exposed metal wire, Exposing a portion of the substrate and the patterned photoresist layer of the first region; removing the patterned photoresist layer of the first region and the insulating layer thereon to form a contact window in the insulating layer; Forming a patterned transparent conductive layer in the contact window and the insulating layer; and forming a protective layer on the patterned transparent conductive layer. The method of claim 1, wherein the step of forming the patterned photoresist layer comprises using a gray scale mask. The method of claim 1, wherein the patterned photoresist layer is used to define the metal wire. The method of claim 1, wherein the patterned photoresist layer of the first region is used to define the contact window. The method of claim 1, wherein after thinning the patterned photoresist layer, one of the patterned photoresist layers of the first region has a thickness greater than a thickness of the insulating layer. The method of claim 5, wherein the ratio of the thickness of the patterned photoresist layer of the first region to the thickness of the insulating layer is about 3:1 to 5:1. The method of claim 1, wherein the step of removing the patterned photoresist layer of the first region and the insulating layer thereon comprises dissolving the patterned photoresist layer of the first region using a solution. The method of claim 1, wherein the transparent conductive layer comprises indium tin oxide. The method of claim 1, wherein thinning the patterned photoresist layer comprises treating the patterned photoresist layer with oxygen plasma. The method of claim 1, wherein forming the protective layer comprises forming an opening in the protective layer to expose the patterned transparent conductive layer.