KR20130007947A - Transparent circuit substrate for touchscreen and method for fabricating the same - Google Patents

Abstract

PURPOSE: A transparent PCB for a touch screen and a manufacturing method thereof are provided to suppress the increase of the linear resistance of an electrode layer by suppressing interfacial de-adhesion of the electrode layer caused by the rough surface of a light blocking layer. CONSTITUTION: A light blocking layer(120) is laminated on the peripheral part of a transparent PCB. A sensor layer(160a) is laminated on the central part of the transparent PCB. An insulating protection layer(170) is laminated on the light blocking layer. An electrode layer(180a) is laminated on the insulating protection layer in a way to be connected to the sensor layer. The sensor layer includes a first conductive pattern laminated on the central part of the transparent PCB and a second conductive pattern laminated on the transparent PCB in a way to cross the first conductive pattern, with an insulating layer in between. A non-reflective layer(130) is laminated between the transparent PCB and the sensor layer.

Description

Transparent circuit board for touch screen and manufacturing method therefor {TRANSPARENT CIRCUIT SUBSTRATE FOR TOUCHSCREEN AND METHOD FOR FABRICATING THE SAME}

The present invention relates to a touch screen, and more particularly, to a transparent circuit board for a touch screen having a sensor layer and forming a front surface of the touch screen, and a manufacturing method thereof.

In general, a touch screen refers to a device incorporating an input detecting means into a display means, and includes a display unit such as a liquid crystal display (LCD) and a touch panel disposed above the display unit. ).

The touch screen receives a user's input through the screen contact by detecting the position of a person's fingertip or other object on a character or a specific position displayed on the screen without using a mechanical keypad. .

Although the touch screen is not highly accurate, it does not require a mechanical keypad and is simple to operate, and thus is widely used as a display device for guidance in public places such as subways, department stores, banks, and various stores. In addition to being widely applied to sales terminals, recently, they are widely used in portable terminals such as mobile phones, digital multimedia broadcasting (DMB) receivers, and vehicle navigation systems.

Types of touch panels (or touch screens) include resistive overlay, capacitive, surface acoustic wave, and infrared beam.

In the conventional capacitive touch panel, first and second conductive layers are formed on the first and second films, respectively, and the first and second conductive layers are connected to the controller through the electrode layers. do. The controller detects a change in capacitance of a corresponding portion of the touch panel according to the contact of an input means (for example, a finger, a stylus pen, etc.), and determines the position of the contact portion.

However, in a conventional capacitive touch screen, a phenomenon in which a metal electrode is formed on a light blocking layer and the metal electrode is partially open or short often occurs. In addition, there is a problem that the wire resistance of the metal electrode is increased, thereby delaying the transmission of a signal applied to or output from the sensor layer, which adversely affects touch sensitivity and operation speed. In addition, there is a problem that it is difficult to form a fine electrode on the light blocking layer.

In addition, in the conventional capacitive touch screen, there is a problem that a phenomenon in which the pattern of the sensor layer is partially open or short due to the step between the bridge and the insulating layer often occurs.

Therefore, the present invention can prevent the metal electrode stacked on the light blocking layer from being partially opened or shorted, and can easily form a fine electrode on the light blocking layer, and the pattern of the sensor layer is partially opened or shorted. Provided are a transparent circuit board for a touch screen capable of preventing a phenomenon, a manufacturing method thereof, and a touch screen using the same.

Transparent circuit board for a touch screen according to an aspect of the present invention, the transparent substrate; A light blocking layer laminated on the periphery of the transparent substrate; A sensor layer laminated on a central portion of the transparent substrate; An insulating protective layer laminated on the light blocking layer; And an electrode layer stacked on the insulating protective layer so as to be connected to the sensor layer.

According to another aspect of the present invention, there is provided a method of manufacturing a transparent circuit board for a touch screen, the method including: stacking a light blocking layer on a periphery of a transparent substrate; Stacking an insulating protective layer on the light blocking layer; Stacking an electrode layer on the insulating protective layer.

In the transparent circuit board for a touch screen and a method of manufacturing the same according to the present invention, since the electrode layer is formed on the insulating protective layer, the interface separation phenomenon of the electrode layer due to the rough surface of the light blocking layer can be suppressed, and thus the electrode layer There is an advantage that the increase in the line resistance can be suppressed.

Accordingly, the transparent circuit board for a touch screen and the method of manufacturing the same according to the present invention can prevent a phenomenon in which the metal electrodes stacked on the light blocking layer are partially opened or shorted, and can easily form fine electrodes on the light blocking layer. And, there is an advantage in that the pattern of the sensor layer can be prevented from being partially opened or shorted.

1 is a flowchart illustrating a method of manufacturing a transparent circuit board for a touch screen according to a first embodiment of the present invention;
2 to 15 are views for explaining the detailed steps of the manufacturing method of the transparent circuit board for a touch screen,
16 illustrates a touch screen according to an exemplary embodiment of the present invention.
17 to 23 are views for explaining detailed steps of a method of manufacturing a transparent circuit board for a touch screen according to a second embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus and an operation method of the present invention will be described in detail with reference to the accompanying drawings. In the following description, specific matters such as specific elements are shown, which are provided to help a more general understanding of the present invention. It is self-evident to those of ordinary knowledge in Esau. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

For convenience of explanation, a conventional capacitive touch screen has a structure in which a conductive layer is formed on a film and the film is adhered to a glass substrate, but the transparent circuit board for a touch screen according to the present invention is an example. For example, it has a structure in which a sensor layer is directly formed on a glass substrate.

Hereinafter, a method of manufacturing a transparent circuit board for a touch screen according to the present invention will be described, and a touch screen to which the transparent circuit board for the touch screen is applied will be described.

1 is a flowchart illustrating a method of manufacturing a transparent circuit board for a touch screen according to a first embodiment of the present invention, Figures 2 to 15 are views for explaining the detailed steps of the manufacturing method of a transparent circuit board for a touch screen admit.

The manufacturing method of the transparent circuit board for the touch screen includes a light blocking layer stacking step (S10), an antireflective layer stacking step (S20), a first conductive layer stacking step (S30), a bridge layer forming step (S40), Insulating layer forming step (S50), second conductive layer stacking step (S60), sensor layer forming step (S70), first insulating protective layer stacking step (S80), and third conductive layer stacking step (S90) And an electrode layer forming step S100 and a second insulating protective layer stacking step S110.

Referring to FIG. 2, in the light blocking layer stacking step (S10), the light blocking layer 120 is laminated on a peripheral portion (or an edge portion) of the upper surface of the transparent substrate 110. The light blocking layer 120 is stacked around the upper surface of the transparent substrate 110 to have a rectangular band shape. The bottom surface of the transparent substrate 110 forms at least a portion of the front surface of the touch screen exposed to the outside. The transparent substrate 110 is formed of an insulating material that is transparent to visible light. Examples of the insulating material include glass, polyethylene terephthalate (PET), polycarbonate (PC), and the like. Since the bottom surface of the transparent substrate 110 is exposed to the outside, visible light is visible at the periphery of the bottom surface of the transparent substrate 110 in order to prevent the periphery outside the central portion included in the effective display area displayed to the viewer from being seen from the outside. The light blocking layer 120 to block the stacked. The light blocking layer 120 may be formed through a process such as black ink printing. As the material of the light blocking layer 120, an ink for screen printing containing a resin such as polyethylene (PE), acrylic, polyurethane (PU), or the like may be used.

Referring to FIG. 3, in the step of stacking the anti-reflective layer (S20), the anti-reflective layer 130 is stacked on the center of the upper surface of the transparent substrate 110. In the present exemplary embodiment, the antireflective layer 130 is illustrated as including an Nb ₂ O ₅ layer 132 and an SiO ₂ layer 134, but the antireflective layer 130 reflects light incident on the surface thereof. Configured to minimize, subject to layers of any material, subject to a configuration in which a high refractive index layer (eg, an Nb ₂ O ₅ layer) and a low refractive index layer (eg, an SiO ₂ layer) are alternately stacked Can be configured. In the transparent substrate 110 having the antireflective layer 130, the color difference value is a * is 1.5 or less, b * is 1.5 or less, transmittance is 91% or more, and reflectance is 5-10% or less. In addition, the touch screen including the transparent substrate 120 having the antireflective layer 130 has a transmittance of 88% or more. Herein, a * and b * are components of the CIE coordinate system representing color, and the stronger the color is, the farther from 0 is.

In the first conductive layer stacking step (S30), the first conductive layer 140 is laminated on the entire surface (that is, the upper surface) of the antireflective layer 130. The first conductive layer 140 is formed of a conductive material that is transparent to visible light, and examples of the conductive material include indium tin oxide (ITO) and PEDOT (poly (3,4-ethylenedioxythiophene)). Can be. The first conductive layer 140 may be formed by a vacuum deposition process. Examples of the vacuum deposition process may include an electron beam (E-beam), sputtering, and the like.

Referring to FIG. 4, in the bridge layer forming step (S40), the first conductive layer 140 is partially (or selectively) etched to form a bridge layer 140a having a predetermined pattern. The bridge layer 140a is formed of conductive strips positioned at points where the first conductive patterns and the second conductive patterns constituting the sensor layer intersect.

The bridge layer 140a may be formed by patterning by a photolithography process.

In the photolithography process, a photoresist having a uniform thickness is laminated on the entire upper surface of the first conductive layer 140, and the photoresist is partially (or selectively) irradiated with ultraviolet rays to cure the photoresist. By removing the uncured portion of the resist using an etching solution, a photoresist mask having a plurality of slits is formed, and the portion of the first conductive layer 140 exposed through the slits of the photoresist mask is exposed. The bridge layer 140a may be formed by etching them.

Referring to FIG. 5, in the insulating layer forming step (S50), an insulating layer 150 is stacked on the bridge layer 140a. In order to electrically insulate the first conductive patterns and the second conductive patterns, the insulating layer 150 is formed of a plurality of insulating strips, and the plurality of insulating strips are stacked one-to-one on the conductive strips. The conductive strips and the insulating strips corresponding to each other cross each other (for example, in the form of a cross).

It is preferable that side ends of each of the insulating strips in the longitudinal direction of the first conductive pattern are inclined, respectively.

12 and 13 are views for explaining an insulating strip having an inclined side end.

FIG. 12 illustrates a case where the insulating strip 320 stacked on the conductive strip 310 does not have sloped side ends. When the conductive layer 330 is stacked on the conductive strip 310 and the insulating strip 320, the conductive layer 330 is opened or shorted due to the step between the insulating strip 320 and the conductive strip 310. Parts are formed.

13 illustrates a case in which the insulating strip 320a stacked on the conductive strip 310a has sloped side ends 322. Referring to FIG. 13A, the insulating strip 320a has side ends 322 that are inclined on a cross section along the length direction of the first conductive pattern.

Referring to FIG. 13B, in the exposure step, the photoresist 320b corresponding to the insulating strip and the gap G of the mask 350 are appropriately maintained so that the photoresist portion cured by the exposure is inclined. Have them listen. That is, when the mask 350 and the photoresist 320b are spaced apart by an appropriate gap, the light 340 incident on the slit 352 of the mask 350 is the wavelength and the slit of the light 340. It is diffracted according to the width, and inclined side ends are formed by this diffracted light 342. In this case, ultraviolet light is used, and the width of the slit 352 of the mask 350 may be several tens to several hundred μm.

Referring to FIG. 6, in the second conductive layer stacking step (S60), an upper surface of the anti-reflective layer 130, the light blocking layer 120, the bridge layer 140a, and the insulating layer 150 are disposed on the exposed surface. The second conductive layer 160 is laminated on the substrate. That is, the second conductive layer 160 is stacked on the entire upper end of the structure shown in FIG. 5. The second conductive layer 160 may be formed of the same material and method as that of the first conductive layer 140.

Referring to FIG. 7, in the sensor layer forming step (S70), the second conductive layer 160 is partially (or selectively) etched to form a sensor layer 160a having a predetermined pattern. The sensor layer 160a is formed such that its end 162 overlaps with the light blocking layer 120 so as to be connected to the electrode layer on the light blocking layer 120.

The sensor layer 160a may have various patterns such as a linear lattice pattern and a diamond pattern. Hereinafter, a diamond pattern will be described below.

FIG. 14 is a plan view illustrating the sensor layer 160a, and FIG. 15 is an enlarged view of one crossing portion 168 of the sensor layer 160a.

The sensor layer 160a may include first conductive patterns 164 extending along a first direction (for example, the X axis), and a second direction (perpendicular to the first direction) (for example, Y). Axis) along the second conductive patterns 166.

The first conductive patterns 164 and the second conductive patterns 166 intersect at a plurality of points on the transparent substrate 130. The bridge layer 140a allows each of the second conductive patterns 166 to be electrically connected to each other without being disconnected at such intersections, and the insulating layer 150 is connected to the first conductive patterns 164 and the second. The conductive patterns 166 are insulated from each other at these intersections. Each of the second conductive patterns 166 includes a plurality of second sections 166a separated from each other with the first conductive patterns 164 interposed therebetween, and the plurality of second sections 166a. ) Is electrically connected by the conductive strips 142 of the bridge layer 140a. Each of the first conductive patterns 164 is composed of a plurality of first sections 164a electrically connected to each other, and the connecting portions 164b between the plurality of first sections are each an insulating strip 152. Are stacked on.

Referring to FIG. 8, in the stacking of the first insulating protective layer (S80), a first insulating protective layer may be disposed on the exposed upper surface of the anti-reflective layer 130, the light blocking layer 120, and the sensor layer 160a. 170) are stacked. That is, the first insulating protective layer 170 is stacked on most of the upper end of the structure shown in FIG. 7. In this case, the first insulating protective layer 170 is not stacked on the end portions 162 of the sensor layer positioned on the light blocking layer 120, and the end portions 162 of the sensor layer are still exposed to the outside. It is. An insulating dielectric material such as SiO ₂ may be used as a material of the first insulating protective layer 170.

Referring to FIG. 9, in the third conductive layer stacking step S90, a third conductive layer may be disposed on the exposed ends 162 of the sensor layers 140a and 160a and the first insulating protective layer 170. 180) are stacked. That is, the third conductive layer 180 is stacked on the entire upper end of the structure shown in FIG. 8.

Referring to FIG. 10, in the forming of the electrode layer (S100), the third conductive layer 180 is partially (or selectively) etched to form an electrode layer 180a having a predetermined pattern.

The electrode layer 180a is stacked on the periphery 174 of the first insulating protective layer 170 to be positioned outside the sensor layer 160a, and the first insulating protective layer is formed on the third conductive layer 180. The part which was laminated | stacked on the center part 172 of 170 is removed.

For the electrical connection with the sensor layer 160a, the electrode layer 180a is formed to partially overlap the ends 162 of the sensor layer 160a. The electrode layer 180a may include connection terminals 182 for applying a current to the sensor layer 160a, and first and second conductive patterns of the connection terminals 182 and the sensor layer 160a. Consisting of connecting lines 184 connecting 164 and 166. The connection terminals 182 are disposed outside the sensor layer 160a to facilitate access from the outside.

The electrode layer 180a may be formed of the same material as that of the sensor layer 160a or may be formed of another material (for example, an opaque conductive material such as silver). The connection terminals 182 of the electrode layer 180a may be connected to each other in a manner of directly contacting a flexible printed circuit board (FPCB) (not shown) connected to a controller (not shown).

Referring to FIG. 11, in the stacking of the second insulating protective layer S110, the second insulating protective layer 190 is stacked on the central portion 172 of the first insulating protective layer 170. An insulating dielectric material such as SiO ₂ may be used as the material of the second insulating protective layer 190.

In the method for manufacturing the transparent circuit board 100 for a touch screen according to the preferred embodiment of the present invention as described above, since the electrode layer (180a) is formed on the first insulating protective layer 170, the light blocking layer An interface separation phenomenon of the electrode layer 180a due to the rough surface of 120 may be suppressed, and thus an increase in the line resistance of the electrode layer 180a may be suppressed. Due to differences in materials and manufacturing methods, the light blocking layer 120 usually has a surface roughness of 2000 kPa to 3000 kPa, while the first insulating protective layer 170 may have a surface roughness of 200 kPa to 400 kPa. Therefore, the electrode layer 180a formed on the first insulating protective layer 170 may have a finer pattern than the conventional one.

Hereinafter, a touch screen to which the transparent circuit board 100 for the touch screen is applied will be exemplified, and the touch screen transparent circuit board 100 and its manufacturing method may be applied to various touch screens. It should be noted that is merely an example.

16 is a diagram illustrating a touch screen according to an exemplary embodiment of the present invention. In the touch screen 200 illustrated in FIG. 16, it should be noted that the transparent circuit board 100 illustrated in FIG. 11 is applied in an inverted state. In addition, overlapping descriptions of the description of the transparent circuit board 100 will be omitted.

The touch screen 200 includes a display unit 210, the transparent circuit board 100, and an adhesive member 120.

The display unit 210 includes a plurality of pixels and displays an image through the pixels. A portion (center portion) of the upper surface of the display unit 210 may be included in the effective display area of the touch screen 100 displayed to the observer, but for the sake of understanding, in the present embodiment, the display unit 210 The entire top surface of is included in the effective display area. As the display unit 210, a liquid crystal display (LCD), organic light emitting diodes (OLED), or the like may be used.

The LCD displays an image under control of a controller (not shown). A typical liquid crystal display device includes a liquid crystal display panel having a liquid crystal layer and displaying an image, and a back light unit (BLU) for providing light to the liquid crystal display panel. The liquid crystal display panel includes the liquid crystal layer and upper and lower glass substrates disposed above and below the liquid crystal layer to control the arrangement of liquid crystal molecules. The lower glass substrate includes thin film transistors and pixel electrodes, and the upper glass substrate includes a common electrode. The liquid crystal display panel further includes upper and lower polarization plates disposed above and below the liquid crystal layer and linearly polarize the input light. In this case, polarization directions of the upper and lower polarizers are perpendicular to each other.

The transparent circuit board 100 is attached (that is, bonded) to the display unit 210 using the adhesive member 220. That is, a part of the lower end (ie, the lower surface) of the transparent circuit board 100 (that is, the second insulating protective layer 190) is formed on the upper end of the display unit 210 using the adhesive member 220. That is, the upper surface) is attached to the whole. The adhesive member 220 is formed of an insulating material that is transparent to visible light. As the adhesive member 220, an optical clear adhesive tape (OCA tape), an adhesive (or an adhesive), an ultraviolet curable resin, or the like, which is transparent to visible light, may be used. The OCA tape may be double-sided adhesive, and may be formed of acrylic, silicon, or the like material.

17 to 23 are views for explaining detailed steps of a method of manufacturing a transparent circuit board for a touch screen according to a second embodiment of the present invention. Since the manufacturing method according to the second embodiment is similar to the manufacturing method according to the first embodiment, a redundant description will be omitted.

Referring to FIG. 17, the light blocking layer 420 is stacked on the upper periphery (or the edge) of the transparent substrate 410, and the anti-reflective layer 430 is stacked on the center of the upper surface of the transparent substrate 410. On the surface (ie, the upper surface) of the antireflection layer 430, a bridge layer 440 made of conductive strips positioned at points where the first conductive patterns and the second conductive patterns constituting the sensor layer intersect are stacked. The insulating layer 450 is stacked on the bridge layer 440. In order to electrically insulate the first conductive patterns and the second conductive patterns, the insulating layer 450 is composed of a plurality of insulating strips, and the plurality of insulating strips are stacked one-to-one on the conductive strips. The conductive strips and the insulating strips corresponding to each other cross each other (for example, in the form of a cross).

It is preferable that side ends of each of the insulating strips in the longitudinal direction of the first conductive pattern are inclined, respectively.

The first insulating protective layer 460 is stacked on the light blocking layer 420. An insulating dielectric material such as SiO ₂ may be used as a material of the first insulating protective layer 460.

Referring to FIG. 18, a mask 470 covering an inner portion of the first insulating protective layer 460 and the entire upper end of the structure surrounded by the light blocking layer 460 is stacked.

Optionally, the mask 470 may be stacked to cover only the entire upper end of the structure surrounded by the light blocking layer 460.

The mask 470 may be formed by printing a peelable ink for preventing plating (peelable ink) that can be easily removed without a separate peeling process or attaching an adhesive tape. The filler ink is printed in a liquid state, and then dried and cured. The cured peelable ink is then peeled off and removed.

Referring to FIG. 19, a first conductive layer 480 is stacked on an upper surface of the mask 470 and the first insulating protective layer 460.

Referring to FIG. 20, the mask 470 and a part of the first conductive layer 480 stacked on the mask 470 are removed.

Referring to FIG. 21, a second conductive layer 490 is disposed on the exposed upper surface of the antireflective layer 430, the first insulating protective layer 460, the bridge layer 440, and the insulating layer 450. Laminated. That is, the second conductive layer 490 is stacked on the entire upper end of the structure surrounded by the first conductive layer 480a.

Referring to FIG. 22, the second conductive layer 490 is partially (or selectively) etched to form a sensor layer 490a having a predetermined pattern, and the first conductive layer 480a is partially ( Or optionally) to form an electrode layer 480b having a predetermined pattern.

 The sensor layer 490a is formed such that an end portion 492 of the sensor layer 490a overlaps the first insulating protective layer 460 so as to be connected to the electrode layer 480b on the first insulating protective layer 460.

Referring to FIG. 23, a second insulating protective layer 500 is stacked on the antireflective layer 430 and the sensor layer 490a. An insulating dielectric material such as SiO ₂ may be used as a material of the second insulating protective layer 500.

110: transparent substrate, 120: light blocking layer, 130: antireflective layer, 140a: bridge layer, 150: insulating layer, 160a: sensor layer, 170: first insulating protective layer, 180a: electrode layer, 190: second insulating protective layer

Claims (8)

In the transparent circuit board for touch screen,
A transparent substrate;
A light blocking layer laminated on the periphery of the transparent substrate;
A sensor layer laminated on a central portion of the transparent substrate;
An insulating protective layer laminated on the light blocking layer;
And an electrode layer laminated on the insulating protective layer so as to be connected to the sensor layer. The method of claim 1, wherein the sensor layer,
A first conductive pattern laminated on a central portion of the transparent substrate;
And a second conductive pattern laminated on the transparent substrate so as to intersect the first conductive pattern with an insulating layer interposed therebetween. The method of claim 1,
And a non-reflective layer laminated between the transparent substrate and the sensor layer. In the method of manufacturing a transparent circuit board for a touch screen,
Stacking a light blocking layer on the periphery of the transparent substrate;
Stacking an insulating protective layer on the light blocking layer;
The method of manufacturing a transparent circuit board for a touch screen, comprising the step of laminating an electrode layer on the insulating protective layer. The method of claim 4, further comprising: stacking a sensor layer on a central portion of the transparent substrate before the stacking of the electrode layer.
The electrode layer is a method of manufacturing a transparent circuit board for a touch screen, characterized in that stacked to be connected to the sensor layer. The method of claim 4, further comprising, after the stacking of the electrode layer, stacking a sensor layer on a central portion of the transparent substrate.
The sensor layer is a method of manufacturing a transparent circuit board for a touch screen, characterized in that stacked to be connected to the electrode layer. The method according to claim 5 or 6,
Stacking a bridge layer on a central portion of the transparent substrate;
Stacking an insulating layer on the bridge layer;
And the sensor layer includes first and second conductive patterns intersecting the insulating layer therebetween. 5. The method of claim 4,
The method of manufacturing a transparent circuit board for a touch screen further comprising the step of laminating an antireflection layer between the transparent substrate and the sensor layer.

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