TWI460743B - Image display system employing a touch panel and method for fabricating the touch panel - Google Patents

Description

Image display system including touch panel and manufacturing method of touch panel

The present invention relates to an image display system, and more particularly to an image display system having a touch panel.

The touchpad has been widely used in general consumer electronic products such as mobile phone handsets, digital cameras and satellite navigators to improve the user interface and improve input efficiency; usually, the touchpad is transparent and configured The display of these electronic products is used in front of the display, so that the user can perform interactive input operations according to the indication information on the display screen, thereby greatly improving the goodwill of the communication interface between the human and the machine.

A typical touchpad structure is provided with a decorative layer on the peripheral edge of the touchpad for completely shielding the signal wires of the peripheral portion to protect the signal wires and beautify the layout. In the past, the decorative layer was generally formed by printing or lithographic etching using an ink or an organic color resist material. However, since the decorative layer formed by the ink (including the organic dye) or the organic color resist material is poor in temperature resistance, it becomes unstable at a high temperature (about 200 ° C or more) (it is easy to deform the decorative layer) It will even be decomposed by heat. Therefore, in order to avoid damage to the decorative layer composed of the organic material, it is necessary to define the highest process temperature of the subsequent process, which limits the film formation temperature of the ITO (Indium Oxide) conductive film which is subsequently formed on the surface of the touch panel. However, the lower the film formation temperature of the ITO conductive film, the higher the resistance value of the obtained ITO conductive film. For example, the ITO conductive film formed at 200 ° C has a resistance of film formation at 400 ° C. ITO conductive film resistance value is more than twice (refer to the paper "Properties of Co-deposited indium tin oxide and zinc oxide films using a bipolar pulse power supply and a dual magnetron sputter source", J. Vac. Sci. Technol. A21 ( 2003) 1399-1403, Man-Soo Hwang). In addition, even if an ink or an organic color resist material having high temperature resistance is developed, the ITO conductive film formed at a high temperature needs to be etched with a highly corrosive agent (for example, aqua regia) to achieve patterning, and the organic material is resistant. Corrosion ability is poor, so that the decorative layer of organic materials is destroyed at the same time.

Although the industry has proposed to form an ITO conductive film at a low temperature (for example, room temperature), and then crystallization of the ITO conductive film by an annealing process to reduce the resistance value, the annealing process used in the method may not be too temperature. High (avoid to affect the decorative layer of organic materials). In addition, the ITO conductive film obtained by the process has poor surface uniformity (for example, an ITO conductive film formed at room temperature and annealed at 220 ° C has a U% (uniform percentage) greater than 30%; The ITO conductive film formed at 230 ° C has a U% of about 12%, and the poor uniformity of the ITO conductive film will cause different touch sensitivity and reduce the yield of the touch panel.

In order to avoid the problems caused by the above-mentioned decorative layer of the organic material, a method uses a chromate black matrix material to form a decorative layer. Although chromate has high temperature resistance and corrosion resistance, the price of chromate is expensive, which causes the cost of the touch panel to rise, and chromium causes heavy metal pollution. Therefore, the flat panel display industry does not use this. material.

On the other hand, due to the convenience and practicality of the touch panel, in addition to small-sized portable electronic products, the demand for touch functions of large-sized flat-panel displays is increasing. When the area of the flat panel display increases, the area of the ITO conductive film of the touch panel as a whole increases. If the ITO conductive film used has a large resistance value and poor uniformity, the RC loading is increased. When the ITO conductive film's resistance load difference is too large in each area of the touch panel, the touch panel IC is difficult to interpret the signal and affects the sensitivity of the touch panel. In order to avoid the problem that the above-mentioned resistance load difference is too large, the conventional touch panel may increase the number of ICs of the touch panel or change the circuit design. However, this will increase the process cost and increase the process complexity.

Based on the above, improving the problem caused by the poor resistance and uniformity of the ITO conductive film of the large-sized touch panel is one of the most important topics in the current process of the thin film transistor liquid crystal display.

In view of the above, the present invention provides an image display system having a touch panel, wherein the touch panel comprises an inorganic glaze layer as a decorative layer, and the inorganic glaze layer has high temperature resistance and high corrosion resistance. The transparent conductive layer formed later can be formed at a higher film forming temperature, improving the conductivity and uniformity of the transparent conductive layer, and avoiding excessive difference in the resistance load of each area of the large-sized touch panel.

The image display system includes a touch panel, and the touch panel includes: a substrate, wherein a transparent substrate has a sensing area and a peripheral area surrounding the sensing area; a decorative layer is disposed in the peripheral area, wherein The decorative layer is an inorganic glaze layer; and a sensing unit is disposed in the sensing area. The sensing unit includes a plurality of first sensing electrodes arranged in a row and a plurality of second sensing electrodes arranged in a row, and the first sensing electrodes are separated from each other, and the second sensing electrodes are connected to each other. a jumper wire electrically connecting any two adjacent first sensing electrodes; and a dielectric layer disposed between the second sensing electrode and the jumper wire. In addition, the touch panel further includes a protective layer covering the sensing unit.

According to an embodiment of the present invention, the image display system further includes a display panel having an image display surface, wherein the touch panel is directly disposed on the image display surface of the display panel, and a control unit coupled to the display panel The control unit receives a first signal generated by the touch panel and transmits a second signal to the display panel to cause the display panel to display an image.

The present invention also provides a method for manufacturing the touch panel, comprising: providing a transparent substrate, wherein the transparent substrate has a sensing area and a peripheral area surrounding the sensing area; forming a decorative layer in the peripheral area, wherein the decoration The layer is an inorganic glaze layer; and a sensing unit is formed in the sensing region. The process of the sensing unit includes: forming a plurality of first sensing electrodes arranged in a row, wherein the first sensing electrodes are separated from each other; forming a plurality of second sensing electrodes arranged in columns, wherein the second The sensing electrodes are connected to each other; a dielectric layer is formed between any two adjacent first sensing electrodes; and a jumper wire is formed to electrically connect any two adjacent first sensing electrodes. The dielectric layer is spaced apart from the second sensing electrode.

In order to make the above objects and features of the present invention more comprehensible, the following detailed description of the preferred embodiments and the accompanying drawings

Referring to Fig. 1, there is shown a top view of a touch panel in accordance with an embodiment of the present invention. The touch panel 50 can be, for example, a capacitive touch device having a transparent substrate 10 , and the transparent substrate 10 can be divided into a sensing area 14 and a peripheral area 12 surrounding the sensing area 14 . A decorative layer 22 is disposed within the peripheral region 12 (e.g., fills the entire peripheral region 12), which may be annular as shown in Figure 1 from the perspective of the top view. The transparent substrate 10 can be a glass substrate, preferably a tempered glass substrate, and has a strain point. It should be noted that, in order to make the transparent conductive layer formed later have a higher film forming temperature, the material used as the decorative layer 22 is an inorganic glaze layer, and the inorganic glaze layer is high. Temperature resistance (higher than 600 ° C) and corrosion resistance, allowing subsequent processes to use a temperature of more than 250 ° C to form a highly crystalline transparent conductive layer (preferably above 300 ° C), and can withstand A highly corrosive agent (such as aqua regia) that graphically crystallizes a transparent conductive layer. According to an embodiment of the invention, the inorganic glaze layer is formed on the peripheral region 12 of the transparent substrate 10 by an inorganic glaze composition and is prepared through a sintering process. Here, the temperature of the sintering process can be maintained in the range of 500-660 ° C, so that the inorganic glaze composition is melted, and the partially melted glaze can further diffuse and penetrate into the glass surface, thereby avoiding decoration The thickness of the layer is too thick, causing the problem that the subsequently formed transparent conductive layer needs to climb, and when the colored glaze penetrates into the surface of the glass, the adhesion to the glass can be increased, so that the decorative layer is not easily peeled off and scratch resistant. In addition, the process temperature of the sintering process needs to be lower than the strain point of the glass substrate, ensuring that the glass substrate begins to soften at the beginning of the sintering process (helping the color glaze penetrate into the glass) without deformation. The inorganic glaze composition can comprise a ceramic material and a colorant. The ceramic material may comprise an oxide, a carbide, a nitride, or a combination thereof, such as titanium oxide, aluminum oxide, titanium nitride, aluminum nitride, titanium carbide, titanium aluminum nitride, titanium nitride, or combinations thereof. The colorant may comprise a metal oxide, or carbon black. For example, if the color of the decorative layer to be formed is black, the coloring agent used may be carbon black; the color to be formed is green, the coloring agent used may be copper oxide; the color to be formed is yellowish yellow. The coloring agent used may be iron oxide; the color to be formed is purple, the coloring agent used may be manganese oxide; the color to be formed is blue, and the coloring agent used may be cobalt oxide; the color to be formed is Light yellow, the coloring agent used may be cerium oxide; the color to be formed is white, and the coloring agent used may be cerium oxide. Further, in order to adjust the sintering temperature of the inorganic glaze composition, a flux (which may be an alkali metal oxide such as sodium argon fluoride (Na ₂ SiF ₆ ), cryolite (Na _4A lF ₆ ), or the like) may be further added. The alkali nitrate (alkali metal)) may further comprise an adhesive (for example, an acrylate) for allowing the inorganic glaze composition to be temporarily attached to the surface of the glass.

Still referring to FIG. 1 , a sensing unit 30 is disposed in the sensing region 14 of the transparent substrate 10 . The sensing unit 30 includes a patterned transparent conductive layer 16 , a jumper 20 , and a dielectric layer 18 . The transparent conductive layer 16 includes a plurality of first sensing electrodes 16Y arranged in a row, and a plurality of second sensing electrodes 16X arranged in a row. The first sensing electrodes 16Y arranged in a row are separated from each other, and the second sensing electrodes 16X arranged in a row are connected to each other, and any two adjacent first sensing electrodes 16Y are connected by a jumper 20 (for example, A metal layer) is electrically connected. The dielectric layer 18 is used to prevent the second sensing electrode 16X from being electrically connected to the jumper wire 20 . The material of the transparent conductive layer 16 may include indium tin oxide (ITO), indium zinc oxide (IZO), zinc aluminum oxide (AZO), zinc oxide (ZnO), or a combination thereof. It should be noted that in order to make the first sensing electrode 16Y and the second sensing electrode have a lower resistance value and higher uniformity, the film forming temperature of the transparent conductive layer 16 must be greater than 250 ° C, and the film forming method is adopted. It can be sputtering, electron beam evaporation, thermal evaporation, or chemical vapor deposition. The signal transmission line 24 is disposed on the decorative layer 22 and is extendable to the first sensing electrode 16Y and the second sensing electrode 16X.

It should be noted that the touch panel 50 of the present invention is different from the conventional two-substrate bonding type touch panel, and only includes a transparent substrate 10, and all components are formed on the transparent substrate to reduce the overall The thickness of the touch panel 50 is reduced and the process steps and costs are reduced. The touch panel of the present invention can be further disposed on an image display surface of a display panel (not shown), and the display panel can be coupled to a control unit (not shown). The first sensing electrode 16Y and the second sensing electrode 16X of the touch panel can transmit the induced electrical changes to a control unit to perform calculation of the touch signal, and transmit the touch signal to the display panel to display The panel displays images according to the touch signal.

Referring to Fig. 2, the touch panel 50 is further assembled with a display panel 40 to form an image display system 100, which is a cross-sectional view taken along line Y-Y' of Fig. 1. The display panel 40 can be, for example, a liquid crystal display panel, an organic light emitting diode panel, or other display elements. The touch panel 50 can be attached to the display surface of the display panel 40 by an adhesive layer (not shown). The transparent substrate 10 of the touch panel 50 has a sensing area 14 and a peripheral area 12, and a decorative layer (inorganic glaze layer) 22 is disposed in the peripheral area 12, and the first sensing electrode 16Y and the second sensing electrode 16X are formed in the transparent On the sensing region 14 of the substrate 10, the dielectric layer 18 includes the second sensing electrode 16X to prevent the second sensing electrode 16X from being in electrical contact with the jumper wire 20. A jumper 20 is formed on the dielectric layer 18 for electrically connecting the separated first sensing electrodes 16Y. The signal transmission line 24 is disposed on the decorative layer 22 and can be connected to the first sensing electrode 16Y. The signal transmission line 24 can be made of the same material (conductive metal) as the jumper 20 and in the same step. form. It should be noted that, in addition to the peripheral area 12, the decorative layer 22 may also be disposed in the sensing area 14 for use as a design pattern (for example, a function key pattern such as a keyboard). Please refer to FIG. For example, the decorative layer 22 may include a first decorative layer 22a disposed in the peripheral region 12, and a second decorative layer 22b disposed in the sensing region 14. In addition, the first decorative layer 22a and the second decorative layer 22b disposed in the peripheral region 12 and the sensing region 14 are formed of the same material and formed in the same process, and then the sensing electrodes are formed on the decorative layer. In addition, the touch panel 50 can include a protective layer 26 that comprehensively covers all of the components disposed on the transparent substrate 10 to protect the components and provide a flat surface for the display panel 40 to attach.

According to other embodiments of the present invention, the jumper wire may be formed directly on the transparent substrate, the dielectric layer is formed on the jumper, and the first sensing electrode and the second sensing electrode are formed on the dielectric layer. However, the second sensing electrode still needs to utilize a dielectric layer to avoid electrical contact with the jumper, and the jumper is still used to connect the first sensing electrode in a continuous manner.

Please refer to FIG. 4A to FIG. 4E for explaining the manufacturing process of the touch panel of the present invention.

First, as shown in FIG. 4A, a transparent substrate 10 is provided. The transparent substrate 10 has a first surface 11 and an opposite second surface 13. The first surface 11 serves as a touch surface of the touch panel. A sensing area 14 and a peripheral area 12 are defined on the two surfaces 13. After the second surface 13 is cleaned, an inorganic glaze composition (composed as described above) is formed and filled in by screen printing, transfer (hot pressing or water pressure), or ink jet. In the peripheral region 12, the transparent substrate 10 is then subjected to a sintering process using a strengthening furnace to form an inorganic glaze layer having high temperature resistance and corrosion resistance as the decorative layer 22. The decorative layer 22 can be black, white, or other color, and a desired color can be achieved by adding a colorant to the inorganic glaze composition. It should be noted that the decorative layer can also be disposed in the sensing area as a design pattern (for example, a function key pattern such as a keyboard), and the decorative layer disposed in the peripheral area and the sensing area is formed by the same material and in the same process. . Further, in order to allow the inorganic glaze composition to be temporarily attached to the surface of the glass to be sintered, an adhesive may be further added to the inorganic glaze composition. The sintering process can have a temperature between 500 and 660 ° C and a sintering time of between 1 and 60 minutes. The upper limit of the sintering temperature is lower than the strain point of the transparent glass substrate, so that the transparent glass substrate is softened but not deformed, and the sintering temperature required for the inorganic glaze composition can be adjusted by adding a flux. . Please refer to Table 1 for a series of temperature characteristics of glass substrates commonly used in flat panel displays in the industry, all having strain points higher than 500 °C.

Next, as shown in FIG. 4B, a highly crystalline transparent conductive layer (for example, ITO) is formed in the sensing region 14 of the transparent substrate 10 at a film forming temperature of 250 ° C or higher (preferably, 300 ° C or higher). And patterning the highly crystalline transparent conductive layer with a highly corrosive agent such as aqua regia to obtain a patterned transparent conductive layer 16. The patterned transparent conductive layer 16 includes a first first sensing electrode 16Y and a second sensing electrode 16X, wherein the first sensing electrode 16Y and the second sensing electrode 16X are not in contact with each other. In other words, the first sensing electrode 16Y and the second sensing electrode 16X are formed of the same material and in the same process, wherein the process has a process temperature greater than 250 ° C. It is worth noting that since the inorganic glaze layer as the decorative layer 22 has high heat resistance, it is not necessary to limit the maximum process temperature of the subsequent process, so that the film formation temperature of the transparent conductive layer can be increased to 250 ° C or higher in this step (No Will damage the decorative layer), the transparent conductive layer can have better conductivity and uniformity. In addition, the decorative layer 22 of the present invention has high corrosion resistance, so that when the highly crystalline transparent conductive layer is patterned with a highly corrosive agent, the decorative layer is not damaged. Furthermore, the present invention directly forms a transparent conductive layer by using a film forming temperature higher than 250 ° C. Compared with the prior art, the transparent conductive layer is not crystallized by an annealing process, which saves the process steps.

Next, as shown in FIG. 4C, a dielectric layer 18 is formed to cover the second sensing electrode 16X to prevent the second sensing electrode 16X from being electrically connected to the subsequently formed jumper wire 20. The dielectric layer can be, for example, hafnium oxide, tantalum nitride, hafnium oxynitride, or a combination thereof.

Next, as shown in FIG. 4D, a metal conductive layer is formed on the decorative layer 22, the first sensing electrode 16Y, and the dielectric layer 18, and a patterned process is performed on the metal conductive layer. For example, a lithography process) to simultaneously form the jumper 20 and the signal transmission line 24. Suitable materials for the metal conductive layer may be molybdenum (Mo), tungsten (W), aluminum (Al), titanium (Ti), chromium (Cr) or alloys thereof.

Finally, as shown in FIG. 4E, a protective layer 26 is formed to cover all of the elements on the second surface 13 (including the first sensing electrode 16Y, the second sensing electrode 16X, the dielectric layer 18, the jumper 20, and the signal). Transfer line 24) and provide a substantially flat surface. After the touch panel 50 is completed, a display panel 40 can be placed on the protective layer 26 in an attached manner to form the image display system 100 according to the second embodiment of the present invention.

FIG. 5 is a schematic diagram of a configuration of an image display system 100 including a touch display panel according to the present invention. The image display system 100 includes a display panel 40 and a touch panel 50 disposed on the display panel 40. on. In general, the image display system 100 further includes a control unit 200 coupled to the display panel 40. In addition to transmitting the signal to the display panel, the control unit 200 can display the image, and can receive the first signal generated by the touch panel and transmit the second signal corresponding to the first signal to the display panel for display. The panel displays images according to the touch action. The image display system 100 described above can be a mobile phone, a digital camera, a personal digital assistant (PDA), a notebook computer, a desktop computer, a television, a car display, or a portable DVD player.

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

10. . . Transparent substrate

11. . . First surface

12. . . Surrounding area

13. . . Second surface

14. . . Sensing area

16. . . Transparent conductive layer

16X. . . Second sensing electrode

16Y. . . First sensing electrode

18. . . Dielectric layer

20. . . Jumper

twenty two. . . Decorative layer

twenty four. . . Signal transmission line

26. . . The protective layer

30. . . Sensing unit

40. . . Display panel

50. . . Touch panel

100. . . Image display system

200. . . control unit

as well as

Y-Y’. . . Tangent

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

Fig. 2 is a cross-sectional view showing the touch panel of Fig. 1 further assembled with a display panel to form an image display system, taken along the line Y-Y' of Fig. 1.

FIG. 3 is a schematic view showing a touch panel according to an embodiment of the invention, showing that the decorative layer is simultaneously formed in the peripheral area and the sensing area.

4A to 4E are a series of schematic cross-sectional views for explaining a manufacturing process of the touch panel according to an embodiment of the present invention.

FIG. 5 is a block diagram showing an image display system according to an embodiment of the invention.

10. . . Transparent substrate

12. . . Surrounding area

14. . . Sensing area

16. . . Transparent conductive layer

16X. . . Second sensing electrode

16Y. . . First sensing electrode

18. . . Dielectric layer

20. . . Jumper

twenty two. . . Decorative layer

twenty four. . . Signal transmission line

30. . . Sensing unit

50. . . Touch panel

Claims (18)

An image display system including a touch panel includes: a touch panel comprising: a transparent substrate having a sensing area and a peripheral area surrounding the sensing area; a first decorative layer disposed in the peripheral area and a a second decorative layer is disposed in the sensing area, wherein the first decorative layer and the second decorative layer are an inorganic glaze layer; and a sensing unit is disposed in the sensing area, wherein the sensing unit comprises a a first sensing electrode and a second sensing electrode, and the first sensing electrode and the second sensing electrode are located above the second decorative layer. The image display system including the touch panel according to claim 1, wherein the transparent substrate is a glass substrate. The image display system comprising the touch panel according to claim 1, wherein the inorganic glaze layer is prepared by a sintering process of an inorganic glaze composition. An image display system comprising a touch panel according to claim 3, wherein the inorganic glaze composition comprises a ceramic material and a colorant. An image display system comprising a touch panel according to claim 4, wherein the ceramic material comprises an oxide, a carbide, a nitride, or a combination thereof. An image display system comprising a touch panel according to claim 4, wherein the ceramic material comprises titanium oxide, aluminum oxide, and nitride. Titanium, aluminum nitride, titanium carbide, titanium aluminum nitride, titanium nitride, or a combination thereof. An image display system comprising a touch panel according to claim 4, wherein the colorant comprises a metal oxide or carbon black. An image display system comprising a touch panel according to claim 4, wherein the colorant comprises copper oxide, iron oxide, manganese oxide, cobalt oxide, cerium oxide, cerium oxide, or a mixture thereof. An image display system comprising a touch panel according to claim 4, wherein the inorganic glaze composition further comprises a flux or an adhesive. The image display system including the touch panel of claim 1, further comprising: a display panel having an image display surface, wherein the touch panel is directly disposed on the image display surface of the display panel. The image display system including the touch panel of claim 10, further comprising: a control unit coupled to the display panel, wherein the control unit receives a first signal generated by the touch panel and transmits A second signal is sent to the display panel to cause the display panel to display an image. A method for manufacturing a touch panel, comprising: providing a transparent substrate, wherein the transparent substrate has a sensing area and surrounding a peripheral area of the sensing area; forming a first decorative layer in the peripheral area and forming a second a decorative layer in the sensing region, wherein the first decorative layer and the second decorative layer are an inorganic glaze layer; Forming a sensing unit in the sensing region, wherein the sensing unit includes a first sensing electrode and a second sensing electrode, and the first sensing electrode and the second sensing electrode are located in the second decorative layer Above. The method of manufacturing a touch panel according to claim 12, wherein the first decorative layer and the second decorative layer are formed of the same material and in the same process. The method for manufacturing a touch panel according to claim 12, wherein the inorganic glaze layer is prepared by a sintering process of an inorganic glaze composition. The method of manufacturing a touch panel according to claim 14, wherein the temperature of the sintering process is between 500 and 660 °C. The method of manufacturing a touch panel according to claim 15, wherein the temperature of the sintering process is smaller than a strain point of the transparent substrate. The method of manufacturing a touch panel according to claim 12, wherein the forming the sensing unit comprises forming a plurality of first sensing electrodes arranged in a row and a plurality of second sensing electrodes arranged in a row. In the sensing region, the first sensing electrodes are separated from each other, and the second sensing electrodes are connected to each other. The method of manufacturing a touch panel according to claim 17, wherein the first sensing electrode and the second sensing electrode are formed of the same material and formed in the same process, wherein the process has a process temperature greater than 250 ° C.