Patent Application
20160103508
The subject matter herein generally relates to transparent conductive films, and more particularly, to a transparent conductive film, a touch-sensitive device using the same, and a method for making the same.
Many electronic devices, such as mobile phones, tablet computers, and multimedia players, employ touch-sensitive screens as input interfaces. Typically, the touch-sensitive screen includes a substrate and a transparent conductive film formed on at least one surface of the substrate. The transparent conductive film functions as sensing electrodes capable of identifying touch operations on the touch-sensitive screen, and is usually made of indium tin oxide (ITO).
Implementations of the present technology will now be described, by way of example only, with reference to the attached figures.
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of the present disclosure.
Several definitions that apply throughout this disclosure will now be presented.
The term “substantially” is defined to be essentially conforming to the particular dimension, shape, or other feature that the term modifies, such that the component need not be exact. For example, substantially cylindrical means that the object resembles a cylinder, but can have one or more deviations from a true cylinder. The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series and the like.
A support layer 30 is formed on at least one surface of the substrate 10. A surface of the support layer 30 away from the substrate 10 defines a number of grooves 31 formed in a mesh pattern. Each groove 31 has a width of about 0.5 μm to about 10 μm. In at least one embodiment, the support layer 30 is made of a material selected from a group consisting of thermoplastic polymer, thermosetting polymer, and UV curable polymer. The support layer 30 has a thickness of about 1 μm to about 50 μm.
An ink layer 60 is formed at a bottom of the grooves 31. As such, the ink layer 60 is also formed in a mesh pattern. At least one embodiment, the ink layer 60 includes metallic ions selected from a group consisting of palladium (Pd), silver (Ag), titanium (Ti), copper (Cu), zirconium (Zr), or any combination thereof.
A conductive layer 50 is formed on the ink layer 60. As such, the conductive layer 50 is also formed in a mesh pattern. A height of the conductive layer 50 and the ink layer 60 is greater than a depth of the grooves 31; namely, a top of the conductive layer 50 protrudes out of the first groove portion 311. In at least one embodiment, the conductive layer 50 protrudes out of the first groove portion 311 by about 0.01 μm to about 2 μm. In at least one embodiment, the conductive layer 50 is made of metal or alloy. The metal is selected from a group consisting of copper (Cu), aluminum (Al), gold (Au), silver (Ag), titanium (Ti), palladium (Pd), chrome (Cr), or any combination thereof.
The conductive layer 50 functions as sensing electrodes capable of identifying touch operation on the touch-sensitive screen 100 and generating corresponding touch signals. First, the conductive layer 50 can be cost effective compared to the sensing electrode formed of high-price ITO. Second, the sheet resistance of the conductive layer 50 is increased since the height of the conductive layer 50 and the ink layer 60 is greater than a depth of the grooves 31, thereby allowing the touch-sensitive screen 1 to have an improved touch sensitivity.
In block 51, the transparent substrate 10 is provided.
In block 52, at least one surface of the substrate 10 is coated with a wet transparent resin material (not shown).
In block 53, a mold core 200 (shown in
In block 54, the substrate 10 coated with the transparent resin material is loaded into the mold core 200, and the ribs 210 formed at the mold core 200 are impressed into the transparent resin material at a selected temperature. Then, the grooves 31 having a width of about 0.5 μm to about 10 μm are formed on the transparent resin material.
In block 55, the transparent resin material after impression is solidified to form the support layer 30 on at least one surface of the substrate 10.
In block 56, an ink material is formed at a bottom of the grooves 31, and is further solidified to form the ink layer 60. In at least one embodiment, this step may be carried out by printing the ink material on the surface of the support layer 30 defining the grooves 31, followed by removing the ink material formed outside the grooves 31 by using a scraper for example, and solidifying the remaining ink material to obtain an intermediate product with the ink layer 60 formed at a bottom of the grooves 31.
In block 57, The intermediate product is immersed in an aqueous solution including a reducing agent, and the reducing agent can reduce the metallic ions in the ink layer 60 to metal atoms which then function as an accelerant during a subsequent chemical plating reaction. In at least one embodiment, the ink layer 60 includes palladium ions, and the aqueous solution includes sodium hydroxide or sodium pentaborate which reduces the palladium ions to palladium atoms.
In block 58, The intermediate product after being immersed in the aqueous solution is further immersed in a chemical plating solution with metal ions. Then, a chemical plating reaction happens which causes the metal ions in the chemical plating solution to be deposited to form the conductive layer 50 on the ink layer 60. At the same time, the time period for the chemical plating reaction is controlled to cause the conductive layer 50 to protrude out of the grooves 31 by about 0.01 μm to about 2 μm.
It is to be understood, even though information and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the present embodiments, the disclosure is illustrative only; changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the present embodiments to the full extent indicated by the plain meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201410540569.7 | Oct 2014 | CN | national |
This application is related to co-pending U.S. patent application entitled, “TRANSPARENT CONDUCTIVE FILM, METHOD FOR MAKING THE SAME, AND TOUCH-SENSITIVE SCREEN USING THE SAME”, filed ______ (Atty. Docket No. US56454). The application has the same assignee as the present application. The above-indentified application is incorporated herein by reference.
