Capacitive touch panel unit

A capacitive touch panel unit includes a transparent substrate, a conductive layer and a protection layer. The transparent substrate has a first side and a second side opposite to the first side. The conductive layer is disposed on the second side. The protection layer is correspondingly attached to one side of the conductive layer, which side is opposite to the transparent substrate. By means of the design of the capacitive touch panel unit, the number of the conductive layer is reduced to lower the manufacturing cost and reduce the total thickness.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a capacitive touch panel unit, and more particularly to a capacitive touch panel unit, which has greatly reduced thickness and is manufactured at lower cost.

2. Description of the Related Art

Along with the rapid development of information techniques and communication networks, various personal electronic information products have been more and more popularly used. To go with the tide, various touch panels have bee rapidly developed and applied to the electronic products. According to the sensing principle, the current touch panels can be mainly classified into resistive touch panels, capacitive touch panels, electromagnetic touch panels and optical touch panels. The capacitive touch panel structures have the advantages of dustproof, fireproof and high-resolution performances and are thus widely used. The working principle of the capacitive touch panel is that the touch point position is identified according to the change of capacitance. When a conductive touch article (such as a finger) gets close to the touch panel, the capacitance between the electrodes changes to identify the coordinates of the touch point.

The capacitive touch panels have gradually become the mainstream of touch techniques and are widely applied to various electronic information products nowadays, such as cellular phones, tablets, walkmans, handheld electronic devices, displays and monitors. The capacitive touch panel can detect the capacitance change caused by the weak current of human body to identify the positions of the finger and touch selection conditions so as to achieve the object of touch control.

Most of the conventional capacitive touch panels are double-board touch panels. The double-board touch panel is made of transparent conductive substrates by means of several times of halftone printing processes or lithography processes. The transparent conductive substrate are generally made of glass and coated with indium tin oxide (ITO) coatings. The unit price of the transparent conductive substrate is quite high. Moreover, in manufacturing, much material is wasted. In case that a defective product is produced in the manufacturing process, it is necessary to discard the entire touch panel without possibility of recovery. This results in waste of cost. Moreover, the touch panel is made of the transparent conductive substrates by means of several times of halftone printing processes or lithography processes. The transparent conductive substrates are respectively coated with the indium tin oxide (ITO) coatings. Such processes are complicated so that the manufacturing cost is greatly increased. Moreover, the double-board touch panel will increase the total thickness of the electronic device. This fails to meet the requirement for lightweight, slim and miniaturized structure of portable electronic device.

According to the above, the conventional touch panel has the following shortcomings:

1. The conventional touch panel has a larger thickness.

2. The manufacturing processes of the conventional touch panel are complicated.

3. The manufacturing cost of the conventional touch panel is higher.

SUMMARY OF THE INVENTION

It is therefore a primary object of the present invention to provide a capacitive touch panel unit, which can reduce the total thickness of the electronic device.

It is a further object of the present invention to provide the above capacitive touch panel unit the manufacturing cost of which is greatly lowered.

To achieve the above and other objects, the capacitive touch panel unit of the present invention includes a transparent substrate, a conductive layer and a protection layer.

The transparent substrate has a first side and a second side opposite to the first side. The conductive layer is coated on the second side. The protection layer is attached to one side of the conductive layer, which side is opposite to the transparent substrate. By means of the design of the capacitive touch panel unit, the number of the conductive layer is reduced to lower the manufacturing cost and reduce the total thickness of the electronic device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer toFIGS. 1 and 2.FIG. 1is a sectional exploded view of a preferred embodiment of the capacitive touch panel unit of the present invention.FIG. 2is a sectional assembled view of the preferred embodiment of the capacitive touch panel unit of the present invention. According to the preferred embodiment, the capacitive touch panel unit1of the present invention includes a transparent substrate10, a conductive layer11and a protection layer12. In this embodiment, the material of the transparent substrate10is, but not limited to, glass for illustration purposes only. Alternatively, the material of the transparent substrate10can be selected from a group consisting of polyethylene terephthalate (PET), polycarbonate (PC), polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), polymethylmethacrylate (PMMA) and cyclo olefin copolymer (COC).

The transparent substrate10has a first side101and a second side102opposite to the first side101. The conductive layer11is disposed on the second side102. The conductive layer11is selected from a group consisting of indium tin oxide (ITO) coating, antimony tin oxide (ATO) coating and indium zinc oxide (IZO) coating. In this embodiment, the conductive layer11is disposed on the second side102by means of, but not limited to, sputtering deposition. In practice, the conductive layer11can be alternatively disposed on the second side102by means of gelatinization, electroplating or evaporation.

Please further refer toFIGS. 1 and 2. The protection layer12is correspondingly attached to one side of the conductive layer11, which side is opposite to the transparent substrate10. The material of the protection layer12is selected from a group consisting of silicon nitride (SiNx), silicon dioxide (SiO2) and silicon carbide (SiC). In this embodiment, the protection layer12is a coating coated on the side of the conductive layer11, which side is opposite to the transparent substrate10by means of gelatinization, electroplating, evaporation, deposition or sputtering deposition for providing protection effect for the conductive layer11.

Please now refer toFIG. 3, which is a sectional assembled view of a second embodiment of the capacitive touch panel unit of the present invention. According to the second embodiment, the capacitive touch panel unit1of the present invention includes a transparent substrate10, a shield layer103, a conductive layer11, a lead layer104, a flexible circuit board105and a protection layer12.

The transparent substrate10has a first side101and a second side102. A central section of the transparent substrate10is defined with a touch section2, while a peripheral section of the transparent substrate10is defined with a non-touch section3. The material of the transparent substrate10is selected from a group consisting of glass, polyethylene terephthalate (PET), polycarbonate (PC), polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), polymethylmethacrylate (PMMA), and cycloolefin copolymer (COC). In this embodiment, the material of the transparent substrate10is, but not limited to, glass for illustration purposes only.

The shield layer103is disposed on the second side102of the transparent substrate10correspondingly on the non-touch section3. A section of the transparent substrate10that is coated with the shield layer103is defined as the non-touch section3. A section of the transparent substrate10that is free from the shield layer103is defined as the touch section2. In this embodiment, the shield layer103is made of such as a nontransparent insulation material by means of printing or coating.

The conductive layer11is coated on the second side102of the transparent substrate10on the touch section2. The conductive layer11partially extends from the touch section2to the other side of the shield layer103, which side is distal from the transparent substrate10. The conductive layer11is selected from a group consisting of indium tin oxide (ITO) coating, antimony tin oxide (ATO) coating and indium zinc oxide (IZO) coating. In this embodiment, the conductive layer11is disposed on the second side102by means of, but not limited to, sputtering deposition. In practice, the conductive layer11can be alternatively disposed on the second side102by means of gelatinization, electroplating or evaporation.

The lead layer104is disposed on one side of the shield layer103on the non-touch section3, which side is distal from the second side102. The lead layer104partially extends to the other side of the conductive layer11, which side is distal from the shield layer103. The lead layer104is electrically connected with the conductive layer11. The lead layer104is formed of a metal material selected from a group consisting of silver paste, copper and molybdenum.

The flexible circuit board105is disposed on the non-touch section3. A conductive adhesive106is disposed between the flexible circuit board105and the lead layer104. The flexible circuit board105is attached to one side of the conductive adhesive106, while the lead layer104is attached to the other side of the conductive adhesive106. The flexible circuit board105is electrically connected with the lead layer104via the conductive adhesive106. The conductive adhesive106is an anisotropic conductive film (ACF) or an anisotropic conductive paste (ACP).

The protection layer12is correspondingly attached to the other side of the conductive layer11, which side is distal from the transparent substrate10. The material of the protection layer12is selected from a group consisting of silicon nitride (SiNx), silicon dioxide (SiO2) and silicon carbide (SiC). In this embodiment, the protection layer12is a coating coated on the side of the conductive layer11, which side is distal from the transparent substrate10by means of gelatinization, electroplating, evaporation, deposition or sputtering deposition for providing protection effect for the conductive layer11. The protection layer12is also coated on the flexible circuit board105and the other side of the lead layer104, which side is distal from the transparent substrate10to provide protection effect.

Therefore, the capacitive touch panel unit1of the present invention only includes one single conductive layer11to achieve the object of detection and touch control. In this case, the number of the conductive layer11is reduced to lower the manufacturing cost. Also, the total thickness of the electronic device is reduced.

According to the above arrangement, in comparison with the conventional touch panel, the present invention has the following advantages:

1. The total thickness is reduced.

2. The manufacturing process is simplified.

3. The manufacturing cost is lowered.

The present invention has been described with the above embodiments thereof and it is understood that many changes and modifications in the above embodiments can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.