The present invention relates to the technology field of touch panels, and more particularly to an alloy for making trace wires and touch panel using the same.
Nowadays, touch panel module comprising transparent conductive substrate, driving circuit and sensing circuit has been widely applied in the electronic device having small size display screen, such as smart phone and tablet PC. However, with the growing of demands made by market on All-in-One PCs, large-size laptop PCs and large-size touch displays, expensive manufacturing cost and high sheet resistance of traditional ITO transparent conductive substrate have become the major problems of large-size touch panels. Engineers skilled in development and manufacture of the transparent conductive substrate should know that, the cost of forming ITO electrode layer occupies around 40% of a total manufacturing cost of the traditional ITO transparent conductive substrate. Moreover, ITO electrode layer formed on a glass substrate of the ITO transparent conductive substrate commonly exhibits an average sheet resistance of 100-150 ohm/sq.
ITO touch panels are classified to two types including single-sided ITO touch panel and double-sided ITO touch panel.
The first extension wires 13′ and the second extension wires 14′, commonly made of silver (Ag) or copper (Cu), constitute trace wires on the transparent substrate 10′. It is worth explaining that, increasing of the manufacturing cost resulted from year to year decreasing of the indium resources has become the most important problem for the ITO transparent conductive substrate. Thus, for the purpose of manufacturing cost saving, manufacturers of the transparent conductive substrate have made great efforts to research and develop a new material of silver nanowire (AgNW) for replacing ITO so as to be used in the manufacture of the sensor units 11′ and 12′. The AgNW-made sensor units 11′ and 12′ exhibit an average sheet resistance of 30-50 ohm/sq.
After finishing the step S5′, a touch panel having MOS structure is obtained. Herein, MOS is an abbreviation of “Metal-On-Silver nanowires”. It needs to particularly explain that, during the execution of the first etching process, a first etchant comprising principle etching ingredient of HNO3 or FeCl3 is firstly applied to the copper layer CL′, and therefore a second etchant comprising principle etching ingredient of HNO3 is subsequently applied to the AgNW layer SNW′. However, inventors of the present invention find that, Galvanic displacement reaction and nucleation reaction would occur between AgNO3 and Cu element of the copper layer CL′, wherein the AgNO3 is produced during using HNO3 to etch the AgNW layer SNW′. Consequently, Galvanic displacement reaction and nucleation reaction cause that feather-like microstructures are formed between the copper layer CL′ and the first sensor units 11′. Chemical reaction equations for the feather-like microstructures are presented as follows.
3Ag+4HNO3(aq)→AgNO3(aq)+2H2O(I)+NO(g) (1)
Cu+2AgNO3(aq)→Cu(NO3)2(aq)+2Ag (2)
From the two chemical reaction equations, it is understood that the feather-like microstructures should comprise Ag contributed by AgNO3, Cu contributed by copper layer CL′, and compound of Ag and Cu. Herein, it needs to particularly emphasize that, the feather-like microstructures are found to cause a short circuit occurring between any two of the first sensor units 11′, any two of the first extension wires 13′, or the first sensor unit 11′ and the first extension wires 13′.
Steps S3a and S4a are executed to sequentially apply a photolithography process and an etching process to the AgNW layer SNW′, so as to form a plurality of first sensor units 11′ on the transparent substrate 10′.
It is worth noting that, inventors of the present invention find that HNO3 would simultaneously damage copper layer CL′ by passing through the AgNW layer SNW′ during the patterning process of the AgNW layer SNW′. Thus, it is easily extrapolated that, in the case of the fact that HNO3 are not full removed from the copper layer CL′ and the AgNW layer SNW′ after a water clean process is completed, HNO3 remaining in the copper layer CL′ and/or the AgNW layer SNW′ would continuously damage (etch) the copper layer CL′, consequently causing the trace wires (i.e., the extension wires 13′ and 14′) to be broken.
From above descriptions, the feather-like microstructures formed between the Cu-made extension wires (13′, 14′) and the AgNW-made sensor units (11′, 12′) have been found to be a serious problem on the manufacture of the touch panel having MOS structure. On the other hand, for the fabrication of the touch panel having SOM structure, there is a room for improvement in enlarging the processing window of the Cu-made extension wires (13′, 14′) during HNO3 being used to pattern the AgNW layer AgNW layer SNW′. In view of that, inventors of the present application have made great efforts to make inventive research and eventually provided an alloy for making trace wires and touch panel using the same.
The primary objective of the present invention is to provide an alloy for making trace wires and touch panel using the same. The alloy mainly comprises a first clapping layer, a second clapping layer, and a copper layer disposed between the first clapping layer and the second clapping layer. By applying the alloy as the trace wires of the touch panel, feather-like microstructures are effectively prevented from forming between the trace wires and sensor units of the touch panel. On the other hand, because this novel alloy is able to completely defense the corrosion attack coming from HNO3-based etchant, the trace wires made of the alloy exhibits an outstanding corrosion resistant during the patterning process of the AgNW-made sensor units. Therefore, during patterning the AgNW-made sensor units, the touch panel has a good manufacturing yield rate since the processing window of the trace wires is enlarged. Moreover, the end product of the touch panel using this alloy as its trace wires also possesses an outstanding reliability.
In order to achieve the primary objective of the present invention, the inventor of the present invention provides an embodiment for the alloy for making trace wires, comprising:
Moreover, the inventor of the present invention also provides one embodiment for the touch panel, comprising:
In the embodiment of the alloy and the embodiment of the touch panel, metal material is selected from the group consisting of silver (Ag), gold (Au), platinum (Pt), palladium (Pd), iridium (Ir), iron (Fe), tin (Sn), lead (Pb), tungsten (W), nickel (Ni), chromium (Cr), zinc (Zn), aluminum (Al), magnesium (Mg), and a combination of two or more of the foregoing materials.
In the embodiment of the alloy and the embodiment of the touch panel, both the first clapping layer and the second clapping layer have a thickness in a range between 1 nm and 5 μm.
In the embodiment of the alloy and the embodiment of the touch panel, the copper layer has a thickness in a range between 1 nm and 5 μm.
In the embodiment of the alloy and the embodiment of the touch panel, the copper layer and the first clapping layer have a first thickness ratio in a range between 1:5000 and 5000:1, and the copper layer and the second clapping layer have a second thickness ratio in a range from 1:5000 to 5000:1. Moreover, there is a resistance difference ratio of the surface resistance of the first clapping layer and that of the second clapping layer, and the resistance difference ratio is less than 10%. Therefore, the copper layer disposed between the first clapping layer and the second clapping layer is able to withstand the corrosion attack coming from an etchant comprising principle etching ingredient of 50% HNO3 for at least 20 seconds.
The invention as well as a preferred mode of use and advantages thereof will be best understood by referring to the following detailed description of an illustrative embodiment in conjunction with the accompanying drawings, wherein:
To more clearly describe an alloy for making trace wires and touch panel having traces wire made of the alloy according to the present invention, embodiments of the present invention will be described in detail with reference to the attached drawings hereinafter.
Embodiment of the Alloy for Making Trace Wires of a Touch Panel
With reference to
Foregoing
For effectively preventing the production of the said feather-like microstructures, the present invention particularly adopts a metal material to make both the first clapping layer 11 and the second clapping layer 13, wherein the electrode potential of the is lower than that of the copper layer CL′. Exemplary material for making the two clapping layers 11 and 13 are summarized and listed in following Table (1).
From above-presented Table (1), it is understood that the metal material for making the first clapping layer 11 and the second clapping layer 13 is selected from the group consisting of silver (Ag), gold (Au), platinum (Pt), palladium (Pd), iridium (Ir), iron (Fe), tin (Sn), lead (Pb), tungsten (W), nickel (Ni), chromium (Cr), zinc (Zn), aluminum (Al), magnesium (Mg), and a combination of two or more of the foregoing materials. For example, the metal material can be Ni—Cr compound, Ni—W compound, or Ni—Co compound, such that the alloy 1 of the present invention has a sandwich structure of Ni—Cr/Cu/Ni—Cr, Ni—W/Cu/Ni—W, or Ni—Co/Cu/Ni—Co, correspondingly. Of course, the manufacturing material of the first clapping layer 11 can be different from that of the second clapping layer 13. Moreover, according to the particular design of the present invention, the copper layer 12 and the first clapping layer 11 have a first thickness ratio in a range between 1:5000 and 5000:1, and the copper layer 12 and the second clapping layer 13 have a second thickness ratio in a range from 1:5000 to 5000:1. In a practical application, both the first clapping layer 11 and the second clapping layer 13 are set to have a thickness in a range between 1 nm and 5 μm, and the copper layer 12 has a thickness in a range between 1 nm and 5 μm.
Experiment I
In order to prove that the use of the first clapping layer 11 and the second clapping layer 13 is help for preventing Galvanic displacement reaction from occurring between AgNO3 and Cu element of copper layer CL′, inventors of the present invention complete experiment I. In the experiment I, alloy 1 having sandwich structure as shown in
Microstructures of sample 1 are presented by two images as shown in
On the other hand, microstructures of sample 2 are presented by two images as shown in
Experiment II
Inventors of the present invention further complete experiment II. In the experiment II, alloy 1 having sandwich structure as shown in
Microstructures of sample 3 are presented by the image as shown in
On the other hand, microstructures of sample 4 are presented by the image as shown in
Based on the supports of experimental data, it is believable that the alloy 1 of the present invention can fully defense the corrosion attack coming from HNO3-based etchant during the patterning process of the AgNW layer (i.e., the sensor units of the touch panel). Therefore, it is extrapolated that, the width and the pitch of the trace wires and/or the sensor units of the touch panel can be precisely controlled by etching process, in the case of the alloy 1 of the present invention being adopted for the manufacture of the trace wires. Therefore, during patterning the AgNW-made sensor units, the touch panel has a good manufacturing yield rate since the processing window of the trace wires is enlarged. Moreover, the end product of the touch panel using this alloy as its trace wires also possesses an outstanding reliability because there is no HNO3-based etchant remaining the trace wires and/or the sensor units.
Embodiment of the Touch Panel Having Traces Wire Made of the Alloy
The first extension wires 22 and the second extension wires 24 constituted the trace wires of the touch panel 2. Particularly, both the first extension wires 22 and the second extension wires 24 are made of the above-introduced alloy 1, comprising: a first clapping layer 11, a second clapping layer 13, and a copper layer 12 disposed between the first clapping layer 11 and the second clapping layer 13.
In a practical application, the touch display panel 2 may further comprises: a first optical adhesive layer 25, a second optical adhesive layer 26 and a protection glass 27. The first optical adhesive layer 25 is coated onto the transparent substrate 20, and covers the first sensor units 21 and the first extension wires 22. Moreover, the second optical adhesive layer 26 is coated onto the transparent, and covers the second sensor units 23 and the second extension wires 24. In addition, the protection glass 27 is attached onto the transparent substrate 20 via the first optical adhesive layer 25, and the LCM 28 is attached onto the transparent substrate 20 through the second optical adhesive layer 26. From
Therefore, through above descriptions, the alloy for making trace wires and touch panel using the alloy have been introduced completely and clearly; in summary, the present invention includes the advantages of:
(1) The present invention provides an alloy 1 for making trace wires of a touch panel 2. The alloy 1 mainly comprises a first clapping layer 11, a second clapping layer 13, and a copper layer 12 disposed between the first clapping layer 11 and the second clapping layer 13. By applying the alloy 1 as the trace wires of the touch panel, feather-like microstructures are effectively prevented from forming between the trace wires and sensor units of the touch panel. On the other hand, because this novel alloy 1 is able to completely defense the corrosion attack coming from HNO3-based etchant, the trace wires made of the alloy 1 exhibits an outstanding corrosion resistant during the patterning process of the AgNW-made sensor units. Therefore, during patterning the AgNW-made sensor units, the touch panel has a good manufacturing yield rate since the processing window of the trace wires is enlarged. Moreover, the end product of the touch panel using this 1 alloy as its trace wires also possesses an outstanding reliability because there is no HNO3-based etchant remaining the trace wires and/or the sensor units.
The above description is made on embodiments of the present invention. However, the embodiments are not intended to limit scope of the present invention, and all equivalent implementations or alterations within the spirit of the present invention still fall within the scope of the present invention.
Number | Date | Country | Kind |
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107133443 | Sep 2018 | TW | national |