The present invention relates to a touch panel apparatus and a manufacturing method thereof.
Touch panel apparatuses for detecting a contact position have been widely used in recent years (see, e.g., Patent Document 1). The touch panel apparatuses are often mounted on top of display devices such as liquid crystal display panels.
The touch panel apparatuses are classified into a resistance film type, an electrostatic capacitance type (e.g., Patent Document 1), an infrared type, an ultrasonic type, an electromagnetic induction type, and the like, according to their operation principles. Among others, electrostatic capacitance type touch panel apparatuses are known to be preferably used for display devices because they are relatively less likely to degrade optical characteristics of the display devices.
An electrostatic capacitance type touch panel apparatus generally has a transparent electrode for position detection provided in a touch region, a plurality of electrode terminals provided in a peripheral region of the transparent electrode, and a current detection circuit for detecting a current flowing in the electrode terminals. The electrostatic capacitance type touch panel apparatus works as follows: when the touch region is touched, the transparent electrode is grounded at a touched position through electrostatic capacitance of an insulating material which is present between the transparent electrode and a human body. Since the resistance value between each electrode terminal and the grounded point varies depending on the position where a touch occurs, the touched position is detected by detecting a change in resistance value by the current detection circuit.
The touch panel apparatus has, for example, a rectangular touch region, and a frame region formed around the touch region. The electrode terminals and the current detection circuit are provided in the frame region, and extended wirings connecting the electrode terminals to the current detection circuit are formed in the frame region. The transparent electrode, the electrode terminals, and the extended wirings are usually formed by a printing method such as screen printing (see, e.g., Patent Document 2).
Patent Document 1: Japanese Published Patent Application No. 2003-66417
Patent Document 2: Japanese Translation of PCT International Application No. 2003-526853
Touch panel apparatuses have been required to reduce their overall size while assuring as large an area of the touch region as possible. It is therefore desirable to reduce the frame region as much as possible.
However, it is difficult to reduce the frame region of the touch panel apparatuses by the conventionally used printing method. More specifically, although the touch panel apparatuses can be relatively easily manufactured by the printing method, the printing method has problems, such as the need for a relatively large alignment margin, and print bleeding. Therefore, it is difficult to precisely form patterns of wirings, electrodes, and the like. As can been seen in, for example, mobile equipments, the size of display panels has been increasingly reduced and the frame of the display panels have been increasingly narrowed in recent years, and narrowing the frame of the touch panel apparatuses is therefore a very important issue.
The present invention was developed in view of the above-mentioned problems, and it is an object of the present invention to narrow the frame of a touch panel apparatus and to improve reliability of the touch panel apparatus.
In order to achieve the above object, a touch panel apparatus according to the present invention is a touch panel apparatus having a touch region which is a region where a position touched by a contact body is detected, and a frame region provided outside the touch region. The touch panel apparatus includes: a position detection electrode formed in the touch region and made of ITO; and a wiring portion provided in the frame region and electrically connected to the position detection electrode. The wiring portion has a first pattern film extended from the position detection electrode and made of ITO, a second pattern film laminated on the first pattern film and made of IZO, and a third pattern film laminated on the second pattern film and made of silver or a silver alloy.
A touch panel apparatus according to the present invention is a touch panel apparatus having a touch region which is a region where a position touched by a contact body is detected, and a frame region provided outside the touch region. The touch panel apparatus includes: a position detection electrode formed in the touch region and made of ITO; and a wiring portion provided in the frame region and electrically connected to the position detection electrode. The wiring portion has a first pattern film extended from the position detection electrode and made of ITO, a second pattern film laminated on the first pattern film and made of IZO, and a third pattern film laminated on the second pattern film and made of aluminum or an aluminum alloy.
Preferably, the wiring portion is formed by photolithography.
A method for manufacturing a touch panel apparatus according to the present invention is a method for manufacturing a touch panel apparatus including a position detection electrode and a wiring portion. The position detection electrode is formed in a touch region which is a region where a position touched by a contact body is detected, and the wiring portion is provided in a frame region located outside the touch region, and is electrically connected to the position detection electrode. The wiring portion has a first pattern film extended from the position detection electrode and made of ITO, a second pattern film laminated on the first pattern film and made of IZO, and a third pattern film laminated on the second pattern film and made of silver or a silver alloy. The method includes the steps of: sequentially laminating an ITO layer, an IZO layer, and a silver or silver alloy layer in this order; patterning the silver or silver alloy layer and the IZO layer by photolithography to form the third pattern film and the second pattern film; and patterning the ITO layer by photolithography to form the first pattern film.
A method for manufacturing a touch panel apparatus according to the present invention is a method for manufacturing a touch panel apparatus including a position detection electrode and a wiring portion. The position detection electrode is formed in a touch region which is a region where a position touched by a contact body is detected, and the wiring portion is provided in a frame region located outside the touch region, and is electrically connected to the position detection electrode. The wiring portion has a first pattern film extended from the position detection electrode and made of ITO, a second pattern film laminated on the first pattern film and made of IZO, and a third pattern film laminated on the second pattern film and made of aluminum or an aluminum alloy. The method includes the steps of: sequentially laminating an ITO layer, an IZO layer, and a silver or silver alloy layer in this order; patterning the silver or silver alloy layer and the IZO layer by photolithography to form the third pattern film and the second pattern film; and patterning the ITO layer by photolithography to form the first pattern film.
Functions of the present invention will now be described.
The touch panel device described above detects a touched position when the contact body touches the touch region. More specifically, electrostatic capacitance is formed between the contact body touching the touch region and the position detection electrode. The position touched by the contact body is detected by detecting the electrostatic capacitance through the wiring portion.
In the present invention, the wiring portion is formed by a lamination of the first through third pattern films, and the third pattern film is made of silver or a silver alloy having a low electrical resistance. Therefore, electrostatic capacitance generated in the touch region can be accurately transmitted by the wiring portion. According to another invention, the third pattern film is made of aluminum or an aluminum alloy. In this case as well, electrostatic capacitance generated in the touch region can be accurately transmitted by the wiring portion.
In manufacturing of the touch panel apparatus described above, the wiring portion can be formed by photolithography. More specifically, in the case where the third pattern film is made of silver or a silver alloy, the ITO layer, the IZO layer, the silver or silver alloy layer are first sequentially laminated in this order on a transparent substrate. The silver or silver alloy layer and the IZO layer are then patterned by photolithography to form the third pattern film and the second pattern film. Thereafter, the ITO layer is patterned by photolithography to form the first pattern film.
In this case, since the second pattern film made of IZO is interposed between the third pattern film made of silver or a silver alloy and the first pattern film made of ITO, no electrolytic corrosion occurs between the first pattern film (ITO) and the third pattern film (silver or a silver alloy). Since electrolytic corrosion is prevented from occurring during etching in photolithography, the wiring portion is formed accurately and reliably, and reliability of the wiring portion is improved.
Moreover, since the wiring portion can be formed by photolithography instead of a printing method, problems such as a large alignment margin and print bleeding do not occur, and the wiring portion can be formed precisely. As a result, the frame of the touch panel apparatus can be narrowed.
Even when the third pattern film is made of aluminum or an aluminum alloy, the frame of the touch panel apparatus can be narrowed, and reliability of the touch panel apparatus can be improved, as in the case the third pattern film is made of silver or a silver alloy.
According to the present invention, since the wiring portion has the first pattern film made of ITO, the second pattern film laminated on the first pattern film and made of IZO, and the third pattern film laminated on the second pattern film and made of silver or a silver alloy, the frame region of the touch panel apparatus can be narrowed, and reliability of the touch panel apparatus can be improved.
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following embodiments.
The touch panel apparatus 1 is an electrostatic capacitance type touch panel apparatus, and is placed on the user side of a display device such as a liquid crystal display panel (not shown).
More specifically, as shown in
The touch region A is formed in a rectangular region, and is positioned in the middle in the horizontal direction and in the upper side in
The transparent conductive film 17 is made of, for example, ITO (Indium Tin Oxide). The transparent conductive film 17 has a thickness of, for example, about 5 to 25 nm. The transparent conductive film 17 is formed by a rectangular position detection electrode 17a formed over the whole touch region, a rectangular frame-shaped first conductive portion 17b formed continuously in the outer periphery of the rectangular position detection electrode 17a, and four first pattern films 17c extended from the position detection electrode 17a through the first conductive portion 17b. In other words, the position detection electrode 17a, the first conductive portion 17b, and the first pattern films 17c are formed as a single continuous ITO film as a whole. The first conductive portion 17b and the first pattern films 17c are formed in the frame region B.
The touch panel apparatus 1 further has a frame conductive portion 11 and four wiring portions 10, both in the frame region B.
The frame conductive portion 11 is formed in a rectangular frame shape along the outer periphery of the touch region A, and is formed by the first conductive portion 17b, a second conductive portion 32 laminated on the first conductive portion 17b, and a third conductive portion 33 laminated on the second conductive portion 32. The second and third conductive portions 32, 33 are formed in a rectangular frame shape so as to overlap the rectangular frame-shaped first conductive portion 17b. As shown in
The wiring portions 10 are electrically connected to the position detection electrode 17a through the frame conductive portion 11. As shown in
As shown in
More specifically, the first pattern film 17c is made of an ITO film as described above, and the second pattern film 22 made of an IZO (Indium Zinc Oxide) film is laminated on the surface of the first pattern film 17c. The second pattern film 22 has a sheet resistance of about 300Ω/□ to 1 kΩ/□ when the thickness is 10 nm. The third pattern film 23 made of silver or a silver alloy is laminated on the surface of the second pattern film 22.
The second pattern film 22 has a thickness of, for example, about 10 to 30 nm, and the third pattern film 23 has a thickness of, for example, about 100 to 300 nm. As shown in
The wiring portions 10, the frame conductive portion 11, and the position detection electrode 17a are covered by a transparent insulating film 18 as a protective layer. The insulating film 18 has a thickness of, for example, about 50 to 700 nm. A contact hole 26 is formed in the insulating film 18 at a position above the end of each wiring portion 10 in the mount region 13. Each terminal 25 formed on the insulating film 18 is connected to the third pattern film 23 of a corresponding one of the wiring portions 10 through a corresponding one of the contact holes 26. The terminals 25 are arranged in line in the horizontal direction in
When the contact body such as a stylus touches the surface of the insulating film 18, electrostatic capacitance formed between the contact body and a part of the opposing position detection electrode 17a is detected by a detection circuit such as the FPC. The position touched by the contact body is detected in this manner.
[Manufacturing Method]
Hereinafter, a manufacturing method of the touch panel apparatus 1 will be described.
First, as shown in
The silver or silver alloy layer 43 and the IZO layer 42 are then patterned by photolithography to form the third pattern films 23 and the second pattern films 22.
More specifically, as shown in
As shown in
The ITO layer 41 is then patterned by photolithography to form the first pattern films 17c.
More specifically, as shown in
A transparent insulating film 18 is then deposited over the glass substrate 16 so as to cover the position detection electrode 17a, the wiring portions 10, and the frame conductive portion 11. The thickness of the insulating film 18 is, for example, about 50 to 700 nm.
Thereafter, the terminals 25 are formed. More specifically, as shown in
As described above, according to the first embodiment, each wiring portion 10 is formed by the first pattern film 17c made of ITO, the second pattern film 22 laminated on the first pattern film 17c and made of IZO, and the third pattern film 23 laminated on the second pattern film 22 and made of silver or a silver alloy. Accordingly, the frame region of the touch panel apparatus 1 can be narrowed, and reliability of the touch panel apparatus 1 can be improved.
In other words, since the third pattern film 23 is made of silver or a silver alloy having a low electrical resistance, electrostatic capacitance generated in the touch region A can be accurately transmitted by the wiring portions 10.
Moreover, since the wiring portions 10 can be formed by photolithography instead of a printing method, problems such as a large alignment margin and print bleeding do not occur, and the wiring portions 10 can be formed precisely. As a result, the frame of the touch panel apparatus 1 can be narrowed. In other words, the area of the frame region B can be reduced while maintaining a relatively large area of the touch region A.
In addition, since the second pattern film made of IZO is interposed between the third pattern film made of silver or a silver alloy and the first pattern film made of ITO, electrolytic corrosion can be prevented from occurring between the first pattern film (ITO) and the third pattern film (silver or a silver alloy) during formation of the wiring portions 10 by photolithography. In other words, electrolytic corrosion can be prevented from occurring during etching in photolithography. Therefore, the wiring portions 10 can be reliably and precisely formed, and reliability of the wiring portions 10 can be improved.
The first embodiment was described with respect to the case where the respective third pattern films 23 of the wiring portions 10 and the third conductive portion 33 of the frame conductive portion II are made of silver or a silver alloy. However, the present invention is not limited to this, and the third pattern films 23 and the third conductive portion 33 may be made of aluminum or an aluminum alloy (e.g., AlNb).
In this case as well, electrolytic corrosion between the first pattern film 17c made of ITO and the third pattern film 23 made of aluminum or an aluminum alloy can be prevented. In other words, since the wiring portions 10 can be formed by photolithography, the frame of the touch panel apparatus 1 can be narrowed, and reliability of the touch panel apparatus 1 can be improved, as described in the first embodiment.
The first embodiment was described with respect to an example in which the transparent conductive film 17 made of ITO is formed on the surface of the glass substrate 16. However, the present invention is not limited to this. An insulating layer such as SiO2 may be uniformly formed on the surface of the glass substrate 16, and the transparent conductive film 17 may be formed on the surface of the insulating layer. This insulating layer is preferably formed with a thickness of, for example, about several tens of nanometers. This enables the transparent conductive film 17 to be improved in adhesion property to the glass substrate 16.
As has been described above, the present invention is useful for a touch panel apparatus and a manufacturing method thereof, and is suitable especially for narrowing the frame of the touch panel apparatus and for improving reliability of the touch panel apparatus.
Number | Date | Country | Kind |
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2007-028812 | Feb 2007 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2007/071219 | 10/31/2007 | WO | 00 | 4/29/2009 |