1. Field of the Disclosure
The present disclosure relates to a conductive plate and a touch panel including the same, and more particularly to a conductive plate including a patterned conductive film bonded to a substrate through an adhesive layer.
2. Description of Related Art
Touch panels are commonly used in electronic devices, such as Global Positioning Systems (GPSs), personal digital assistants (PDAs), cellular phones, and hand-held personal computers, and include two overlapped conductive plates. Conventional conductive plates normally include a transparent substrate and a transparent conductive film coated on the substrate. The substrate can be made from glass or a plastic material. The conductive film can be made from indium tin oxide (ITO), tin oxide, or zinc oxide. Among them, ITO exhibits the best transparency and excellent conductivity. However, the ITO film formed on the substrate tends to be deformed and damaged when the substrate is bent. In addition, formation of the ITO film on the substrate is complicated and the control of forming a uniform ITO film is difficult to achieve. Moreover, indium is harmful to the environment and shortage of indium raw material will be getting worse in the future, which can result in an increase in the manufacturing costs of the conductive plate.
Other objects and advantages of the present disclosure can be further illustrated by the technical features broadly embodied and described as follows.
According to one aspect of the present disclosure, there is provided a conductive plate that comprises a substrate and a patterned conductive film bonded to the substrate through an adhesive layer. The conductive film has a pattern of conductive traces.
According to another aspect of the present disclosure, there is provided a touch panel that comprises a first conductive plate and a second conductive plate juxtaposed with the first conductive plate in a face-to-face manner. The first conductive plate includes a first substrate and a patterned first conductive film bonded to the first substrate through a first adhesive layer. The patterned first conductive film includes a pattern of first conductive traces. The second conductive plate includes a second substrate and a patterned second conductive film bonded to the second substrate through a second adhesive layer. The patterned second conductive film includes a pattern of second conductive traces.
Other objects and advantages of the disclosure can be further illustrated by the technical features broadly embodied and described as follows.
The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of at least one embodiment. In the drawings, like reference numerals designate corresponding parts throughout the various views.
Reference will now be made to the drawings to describe various embodiments in detail.
Referring to
The substrate 100 can be a transparent substrate or an opaque substrate. Examples of the transparent substrate include glass board, polymethylmethacrylate (PMMA) board, polyethylene terephthalate (PET) board, and polycarbonate (PC) board. Examples of the opaque substrate include metal plates, semiconductor boards, printed circuit boards, and plastic boards. The plastic boards can be made from a colored plastic material or coated with a colored coating.
The adhesive layer 20 can be applied to the substrate 100 through printing, spin coating or liquid drop coating techniques. The adhesive layer 20 can be selected from the group consisting of a light curable adhesive layer (such as an ultraviolet glue), a heat curable adhesive layer (which is cured at an elevated temperature), and a light-heat curable adhesive layer (which is cured at an elevated temperature under a ultraviolet light). In addition, the adhesive layer 20 can be made from a conductive polymer.
The conductive film 30 exhibits electric anisotropy, which is a property having different conductivities or resistivities in different directions. For example, the conductive film 30 is formed by stretching a conductive nanomaterial along a predetermined direction so as to exhibit electric anisotropy. Examples of the nanomaterial are nanotubes and nano-particles. An example of the nanomaterial includes strings of interconnected nanounits extending in a predetermined direction along which the nanomaterial is stretched. The nanounits may be carbon nanotubes, carbon nanotube bundles, or conductive nanoparticles exhibiting electric anisotropy.
The patterning of the conductive film 30 to form the conductive traces 300 can be performed by emboss transferring, wet etching, dry etching, laser patterning, scraping, or adhesive tape removing techniques. The scraping techniques involves removing undesired portions of the conductive film 30 from the adhesive layer 20 by scraping through the use of a tool so as to form the conductive traces 300 on the adhesive layer 20. The adhesive tape removing techniques involves attaching an adhesive tape to undesired portions of the conductive film 30 to be removed, followed by removing the adhesive tape together with the undesired portions of the conductive film 30 so as to form the conductive traces 300. The laser patterning techniques involves radiating a laser light onto undesired portions of the conductive film 30 to be removed, followed by removing the irradiated portions of the conductive film 30 so as to form the conductive traces 300. Dry or wet etching involves forming a patterned photoresist on the conductive film 30 through photolithographic techniques, followed by etching with a plasma gas or a liquid etchant to remove the undesired portions of the conductive film 30 so as to form the conductive traces 300. The emboss transferring techniques involves transferring an insulator on a mold having a pattern of protrusions onto the undesired portions of the conductive film 30 so as to form the conductive traces 300. In addition, the conductive film 30 can be patterned prior to attachment to the adhesive layer 20, followed by attaching or transferring the patterned conductive film 30 to the adhesive layer 20.
In this exemplary embodiment, the adhesive layer 20 is not patterned.
Each of the conductive connecting lines 400 extends along a surface of the adhesive layer 20, and has one end connected to an end of the respective one of the conductive traces 300, and the other end disposed on an edge of the adhesive layer 20 for connecting the respective conductive trace 300 to a circuit (not shown). The conductive connecting lines 400 can be made from a material including conductive pastes, conductive wires, metal lines, etc.
In this exemplary embodiment, the pattern of the conductive traces 300 is in the form of parallel lines, and has a distance (D) between adjacent said conductive traces ranging from about 1 to about 1000 microns, and a line width (d) ranging from about 1 to about 1000 microns.
The patterning of the adhesive layer 20 can be conducted by one of the emboss transferring, wet etching, dry etching, laser patterning, scraping, or adhesive layer tape removing techniques.
In this exemplary embodiment, the adhesive layer 20 is first patterned to form into the pattern of the adhesive traces 200, followed by attaching a non-patterned conductive film 30 to the patterned adhesive traces 200 and subsequently removing undesired portions of the conductive film 30 that are not bonded to the adhesive traces 200, thereby forming a patterned conductive film 30 that has a pattern of conductive traces 300 the same as that of the adhesive traces 200. Removal of the undesired portions of the conductive film 30 can be performed by peeling or cutting methods.
Comparing to the previous exemplary embodiment, each of the conductive connecting lines 400 of this exemplary embodiment extends along the surface of the substrate 100 instead.
Referring to
In operation, when the second conductive plate 700 of the touch panel of the present disclosure is depressed, the second conductive plate 700 is brought into contact with the first conductive plate 600 at the pressed spot of the second conducted plate 700, which turns on a circuit and generates a voltage potential drop that is detected by a scanner (not shown) and that is used to calculate the coordinate of the pressed spot for generating a control signal to for performing a desired function.
In summary, by forming a patterned conductive film and attaching it to a substrate through an adhesive layer which is patterned or non-patterned, the manufacturing costs of the conductive plate can be reduced.
It is to be understood that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only; and that changes may be made in detail, especially in matters of shape, size, and arrangement of parts, within the principles of the embodiments, to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
Number | Date | Country | Kind |
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200910304132.2 | Jul 2009 | CN | national |