Patent Application
20160004344
This application claims priority of the People's Republic of China Patent Application No. CN201310271872.7, filed on Jul. 1, 2013, the entirety of which is incorporated by reference herein.
1. Field of the Invention
The present invention relates to touch device technology, and in particular to touch devices and fabrication methods thereof.
2. Description of the Related Art
Recently, touch devices have been popularly applied in various electronic products, such as mobile phones, personal digital assistants (PDA), and handheld personal computers. One kind of conventional touch panels is fabricated by forming a sensing electrode layer directly on strengthened glass. This kind of touch panels has a single-sheet substrate structure using the strengthened glass as a substrate for forming the sensing electrode layer thereon. When the strengthened glass of the touch panels is broken or cracked due to an external force, the sensing electrode layer formed on the strengthened glass easily fails in broken circuit by losing the stability and support of the strengthened glass. Furthermore, the touch-sensing function of the touch panels also fails.
Therefore, it is desired to improve the reliability of the touch panels with the single-sheet substrate structure for increasing the practicability of the touch panels.
According to embodiments of the disclosure, a functional protection layer is provided in touch panels with a sensing electrode layer formed on a strengthened substrate. The functional protection layer is a clad layer or a coating layer formed of a tough, heat-resistant, and transparent material. Further, the functional protection layer is disposed between the strengthened substrate and the sensing electrode layer. According to the disposition of the functional protection layer in the embodiments of the disclosure, when the strengthened glass of the touch panels is broken or cracked due to an external force, the functional protection layer can prevent the sensing electrode layer of the touch panel from failing. Thus, the reliability of touch panels is thereby enhanced. Moreover, the touch panels of the embodiments of the disclosure can also have the advantages of light weight, low thickness and high transparency due to the touch panels having a single-sheet substrate structure.
According to embodiments of the disclosure, a touch panel is provided. The touch panel is defined as having a viewable area and a non-viewable area corresponding to the viewable area. The touch panel includes a protection cover and a sensing electrode layer, wherein the protection cover further includes a strengthened substrate and a functional protection layer formed on the surface of the strengthened substrate in the viewable area. The sensing electrode layer is formed on the surface of the functional protection layer in the viewable area. The protection cover is used as a carrier substrate for the sensing electrode layer, and the functional protection layer of the protection cover is used as a toughness substrate between the sensing electrode layer and the strengthened substrate.
According to embodiments of the disclosure, a method for fabricating a touch panel is also provided. The touch panel is defined as having a viewable area and a non-viewable area corresponding to the viewable area. The method includes providing a protection cover, wherein the protection cover comprises a strengthened substrate and a functional protection layer formed on the surface of the strengthened substrate and located in the viewable area; and forming a sensing electrode layer on the surface of the functional protection layer and located in the viewable area. The protection cover is used as a carrier substrate for the sensing electrode layer, and the functional protection layer of the protection cover is used as a toughness substrate between the sensing electrode layer and the strengthened substrate.
Using the touch panels of the disclosure, the functional protection layer disposed between the strengthened substrate and the sensing electrode layer can prevent the sensing electrode layer from failing in an open circuit due to the strengthened substrate breaking or cracking. Further, the reliability of the touch panels is thereby enhanced.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
In the accompanying drawings, in order to clearly illustrate the characteristics of embodiments of the disclosure, each element in the touch panels may not be drawn to scale. Moreover, in the descriptions that follow, the orientations of “on”, “over”, “above”, “under” and “below” are used for representing the relationship between the relative positions of each element in the touch panels, and are not used to limit the disclosure. However, in an actual application of the touch panels, the protection cover 100 is disposed at the top of the touch device for users.
In
Referring to
The touch panel of the embodiment includes a protection cover 100 and a sensing electrode layer 120, wherein the protection cover 100 includes a strengthened substrate 101 and a functional protection layer 102. The functional protection layer 102 is formed on a lower surface of the strengthened substrate 101 in the viewable area 100V. The sensing electrode layer 120 is formed on a lower surface of the functional protection layer 102 in the viewable area 100V. As such, the protection cover 100 of the embodiment can be used as a carrier substrate for the sensing electrode layer 120. The functional protection layer 102 of the protection cover 100 is used as a toughness substrate between the sensing electrode layer 120 and the strengthened substrate 101. The functional protection layer 102 is a clad layer or a coating layer formed of a transparent heat-resistant material, preferably a high-toughness, transparent and heat-resistant layer. The transparent heat-resistant material is for example polyimide resin, a low-viscosity resin, titanium dioxide, etc.
From the above-mentioned structure, when the protection cover 100 of the embodiment is damaged by an external force to cause the strengthened substrate 101 to break or crack, the functional protection layer 102 would not fail due to the damage of the strengthened substrate 101 because the functional protection layer 102 has a toughness character. Conversely, the functional protection layer 102 can further be used as a carrier base for the sensing electrode layer 120 to maintain the touch-sensing function of the sensing electrode layer 120. Indeed, the functional protection layer 102 can protect the sensing electrode layer 120.
The functional protection layer 102 of the embodiment can further extend to at least a part of the non-viewable area 100B and be formed on the lower surface of the strengthened substrate 101. In other words, the functional protection layer 102 of the embodiment is formed to completely cover the lower surface of the strengthened substrate 101. In addition, the decorative layer 104 is formed on a lower surface of the functional protection layer 102. The decorative layer 104 can be formed from printing ink by a printing process, in which case the decorative layer 104 has a thickness of about 5 μm to about 10 μm. The decorative layer 104 can also be formed from an opaque photoresist material by a photolithography process, in which case the decorative layer 104 has a thickness of about 1 μm to about 2 μm.
The sensing electrode layer 120 of the embodiment is illustrated by a single-layered transparent conductive structure. In the other embodiment, the sensing electrode layer 120 can be designed as a two-layered transparent conductive structure. It is not used to limit the scope of the disclosure. In an embodiment, the single-layered transparent conductive structure of the sensing electrode layer 120 includes a plurality of first sensing electrodes formed of indium tin oxide (ITO) arranged along a first-axial direction, for example the X-axis, wherein each of the first sensing electrodes includes a plurality of first conductive units 106X separated from each other and a plurality of jumpers 106X′ for electrically connecting any two adjacent first conductive units 106X in the first-axial direction. The sensing electrode layer 120 further includes a plurality of second sensing electrodes arranged along a second-axial direction, for example the Y-axis, wherein each of the second sensing electrodes includes a plurality of second conductive units (not shown) and a plurality of connection lines 106Y′ for electrically connecting any two adjacent second conductive units in the second-axial direction. The jumpers 106X′ and the connection lines 106Y′ crisscross.
The sensing electrode layer 120 further includes a plurality of electrical isolation structures 108. The electrical isolation structures 108 are individually disposed between each of the connection lines 106Y′ and each of the jumpers 106X′ which are crisscrossed to prevent a short circuit from occurring between the first sensing electrodes arranged along the first-axial direction, for example the X-axis, and the second sensing electrodes arranged along the second-axial direction, for example the Y-axis. In an embodiment, the structure and pattern of each element of the sensing electrode layer 120 can be formed by a deposition, photolithography and etching process.
Next, as shown in
According to the structure of the embodiment, the functional protection layer 102 extends from the viewable area 100V of the touch panel to at least a part of the non-viewable area 100B, or to cover all of the non-viewable area 100B. When the strengthened substrate 101 is broken or cracked, the functional protection layer 102 not only can protect the sensing electrode layer 120 in the viewable area 100V, but it also can be used as a toughness substrate between the wiring layer 112 and the strengthened substrate 101. The functional protection layer 102 can be used as a carrier base for continuously supporting the wiring layer 112. The signal-transmitting function of the wiring layer 112 is maintained by the functional protection layer 102 to protect the wiring layer 112.
Moreover, the functional protection layer 102 is formed of a tough, transparent, heat-resistant material. The tough, transparent, heat-resistant material has a good adhesion to the strengthened substrate 101 and the adhesion of the sensing electrode layer 120 to the tough material is higher than the adhesion of the sensing electrode layer 120 to the strengthened substrate 101. Therefore, it can effectively prevent the sensing electrode layer 120 from peeling. The reliability of the sensing electrode layer 120 is thereby enhanced. In addition, the high-toughness, transparent and heat-resistant material has a heat-resistant temperature of higher than about 240° C., such that the functional protection layer 102 can resist the processing temperature when subsequently forming the sensing electrode layer 120 and the wiring layer 112.
In another embodiment, the sensing electrode layer 120 further extends to at least a part of the non-viewable area 100B. The sensing electrode layer 120 in the non-viewable area 100B is formed on the lower surface of the decorative layer 104. Therefore, the wiring layer 112 of the embodiment is completely located in the non-viewable area 100B and formed on the lower surface of the decorative layer 104 for electrically connecting to the sensing electrode layer 120.
Referring to
In addition, the functional protection layer 102 of the embodiment is formed after forming the decorative layer 104, such that the wiring layer 112, which is subsequently disposed in the non-viewable area 100B, is formed on a lower surface of the functional protection layer 102 and further extends to the viewable area 100V for electrically connecting to the sensing electrode layer 120. Moreover, although a detailed structure of the sensing electrode layer 120 is not shown in the embodiment of
Referring to
Furthermore, the wiring layer 112 of the embodiment is further formed on a lower surface of the decorative layer 104. In other words, the insulating decorative layer 104 is disposed between the wiring layer 112 and the sensing electrode layer 120. Therefore, the decorative layer 104 of the embodiment further includes a conductive part 118 disposed for corresponding to each of the sensing electrodes of the sensing electrode layer 120. The conductive part 118 can be formed by filling a through hole in the decorative layer 104 with a conductive material, for example conductive glue. The wiring layer 112 can be electrically connected to the sensing electrode layer 120 through the conductive part 118. In another embodiment, the conductive part 118 can be directly formed of the wiring layer 112 combined with the through hole. In other words, the conductive material filling in the through hole can be directly obtained from the material of the wiring layer 112. As such, when the wiring layer 112 is formed on the surface of the decorative layer 104, the wiring layer also fills in the through hole to form the conductive part 118.
In the above-mentioned embodiments, the functional protection layer 102 can extend from the viewable area 100V to at least a part of the non-viewable area 100B, or cover all of the non-viewable area 100B. Thus, the functional protection layer 102 can completely cover the sensing electrode layer 120 and the wiring layer 112 in their relative position. As such, when the strengthened substrate 101 is broken or cracked, the functional protection layer 102 can continuously provide a complete carrier base for supporting the sensing electrode layer 120 and the wiring layer 112. It can prevent the sensing electrode layer 120 and the wiring layer 112 from breaking or peeling to lose the functions thereof. Thus, the reliability of the touch panel is thereby enhanced.
In addition, the touch panels of the embodiments of the disclosure can be capacitive touch panels. All elements of the touch panel are formed on the surface of one side of the strengthened substrate 101 in sequence to form a single-sheet substrate structure. The surface of the other side of the strengthened substrate 101 is used as the touch side of the touch panel.
Moreover, the material of the functional protection layer 102 can be a low viscosity resin. The low viscosity resin is different from the optical clear adhesive (OCA) used in conventional touch panels for bonding a touch-function substrate with a cover plate. The optical clear adhesive (OCA) is a viscolloid and usually made of silicone or acrylic resin. However, the functional protection layer 102 of the embodiments is a clad layer or a coating layer of a high-toughness, transparent and heat-resistant material, not a glue for bonding.
In another embodiment, the material of the functional protection layer 102 can be titanium dioxide, which can be formed by a sputtering method. The titanium dioxide material has several advantages of low thickness, good optical character, high transparency, etc. Moreover, titanium dioxide has a good UV-resistant ability. As such, the touch panels using titanium dioxide have a long lifetime. In addition, titanium dioxide is dense. When titanium dioxide is firstly formed on the strengthened glass substrate 101 and then other touch elements are subsequently formed thereon, it can prevent the surface of the strengthened glass substrate 101 from being etched by an acid or a base solution used in the fabrication process of the touch panel. The strength of all structures of the touch panels is thereby enhanced.
Moreover, the material of the functional protection layer 102 of the embodiment can resist a high-temperature of a subsequent process for forming the sensing electrode layer 120. In an embodiment, a heat-resistant temperature of the material of the functional protection layer 102 is more than about 240° C.
Referring to
Referring to
Referring to
Referring to
Moreover, after the sensing electrode layer 120 is completed, a wiring layer 112 is further formed on the decorative layer 104 for electrically connecting to the sensing electrode layer 120. The wiring layer 112 of the embodiment extends to the viewable area 100V for electrically connecting to the sensing electrode layer 120. In an embodiment, the jumpers 106X′ and the wiring layer 112 can be formed by a deposition, a photolithography and an etching process at the same time. The materials for forming the jumpers 106X′ and the wiring layer 112 are for example a metal. Next, the wiring layer 112 is bonded to a flexible printed circuit (FPC) 114 as shown in
In the touch panel fabricated by the embodiment, the functional protection layer 102 in the non-viewable area 100B is formed before the decorative layer 104 and the wiring layer 112 are formed. The protection cover 100 of the touch panel is used as a carrier substrate for supporting the sensing electrode layer 120. The functional protection layer 102 of the protection cover 100 is used as a toughness substrate between the sensing electrode layer 120, the wiring layer 112 and the strengthened substrate 101 for protecting the sensing electrode layer 120 and the wiring layer 112.
In the following embodiments, different process sequences corresponding to different structures of touch panels are illustrated. The materials, the sizes and the technologies used in the following embodiments can be the same as those of the above-mentioned embodiments, and are not repeated again to simplify the illustration.
Next, as shown in
In the touch panel fabricated by the embodiment, the functional protection layer 102 in the non-viewable area 100B is formed after the decorative layer 104 is formed and before forming the wiring layer 112. The functional protection layer 102 of the protection cover 100 can be used as a toughness substrate between the sensing electrode layer 120, the wiring layer 112 and the strengthened substrate 101 to achieve an effect of protecting the sensing electrode layer 120 and the wiring layer 112.
As shown in
Referring to
Referring to
Referring to
In the touch panel fabricated by the embodiment, the functional protection layer 102 in the non-viewable area 100B is formed before forming the sensing electrode layer 120, the decorative layer 104 and the wiring layer 112. The functional protection layer 102 of the protection cover 100 can be used as a toughness substrate between the sensing electrode layer 120, the wiring layer 112 and the strengthened substrate 101 to achieve an effect of protecting the sensing electrode layer 120 and the wiring layer 112.
As per the above description, and according to the embodiments of the disclosure, the functional protection layer is disposed between the strengthened substrate of the protection cover and the sensing electrode layer in the touch panels having the single-sheet substrate structure with the sensing electrode layer formed on the protection cover. The functional protection layer can extend from an active area having the sensing electrode layer to a trace area at the periphery of the active area. As such, the functional protection layer can completely cover the areas of the sensing electrode layer and the wiring layer.
The functional protection layer of the disclosure is a clad layer or a coating layer formed of a high-toughness, transparent and heat-resistant material. The high-toughness, transparent and heat-resistant material has good adhesion to the protection cover made of glass. Moreover, the adhesion of the sensing electrode layer to the high-toughness, transparent and heat-resistant material is higher than that to the glass protection cover. Therefore, when the strengthened substrate is broken or cracked, the functional protection layer of the disclosure can prevent the sensing electrode layer and the wiring layer from breaking or peeling, i.e. make sure the sensing electrode layer and the wiring layer are not affected by the strengthened substrate. Thus, the disposition of the functional protection layer can effectively prevent the touch-function of the touch panels from failing. The reliability of the touch panels is thereby enhanced. Moreover, the touch panels of the embodiments of the disclosure can also keep the advantages of the touch panels with the single-sheet substrate structure, i.e. light weight, low thickness and high transmission of light.
Referring to Table 1 and Table 2, according to an analysis of the results of a Drop Ball Test, the functional protection layer disposed between the strengthened substrate and the sensing electrode layer can increase the strength of the strengthened substrate. As shown in Table 1 and Table 2, the functional protection layer is titanium dioxide, for example. With the same test conditions, the average height in the Drop Ball Test needed to break the strengthened substrate of Example 1 without a functional protection layer is 17.9 cm, and the average height in the Drop Ball Test needed to break the strengthened substrate of Example 2 with a functional protection layer of titanium dioxide is 34.6 cm. From the results in Table 1 and Table 2, touch panels using the strengthened substrate with the functional protection layer can have a better mechanical strength.
While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201310271872.7 | Jul 2014 | CN | national |
