Preparation process of single-layer nano silver conductive film touch sensor based on printing technology and single-layer nano silver conductive film touch sensor
Technical Field
The invention relates to the field of nano-silver conductive films, in particular to a single-layer nano-silver conductive film touch sensor and a preparation process thereof based on a printing technology.
Background
With the development of science and technology, touch screens are widely applied to various fields of daily life as a simple and convenient human-computer interaction mode, and meanwhile, with the continuous improvement of requirements of people, the touch screens are developing towards light, thin, low-cost and the like. The silver nanowire has high conductivity and excellent flexibility of metal silver, so that the silver nanowire is the best choice for the transparent electrode material of the flexible touch screen.
At present, in the existing capacitive screen, TX and RX are respectively prepared by two conductive films, which not only wastes much material and makes the thickness control of the sensor difficult, but also needs to be coated with photoresist, exposed, developed, etched, sputtered and the like for many times in the existing process, so that the process is very complex and not environment-friendly.
The american apple company discloses an invention patent relating to a Method for making thin touch sensor panels (US7918019B2), and more particularly to the preparation of a thin double-sided and single-sided touch sensor panel, which can be manufactured with a minimum thickness, but has a complicated manufacturing process and cannot meet the processing requirements of most of the existing production equipment.
Disclosure of Invention
In order to solve the technical problems, the invention provides a preparation process of a single-layer nano silver conductive film touch sensor based on a printing technology and the single-layer nano silver conductive film touch sensor.
In a first aspect, the invention provides a process for preparing a single-layer nano silver conductive film touch sensor based on a printing technology, which comprises the following specific steps:
(1) simultaneously etching an RX direction laser pattern and a TX direction laser pattern on the single-layer nano silver conductive film;
(2) cutting the single-layer nano silver conductive film along the TX direction to form a grid structure comprising a first unit, a second unit, a third unit and a fourth unit, wherein the second unit and the third unit are communicated through a connecting part;
(3) printing an insulating layer extending in a TX direction between the first unit and the fourth unit;
(4) printing a conductive layer extending along both ends of the insulating layer at a middle position on the insulating layer.
It should be noted that the pitch width of the conductive film of the present invention is 2-20mm, and the pitch width means, for example, as shown in fig. 1, the second unit and the third unit are one channel unit of RX, and the distance from the next channel unit parallel to the second unit is the pitch width.
In some embodiments of the invention, the length of the insulating layer is greater than the width of the connecting portion, the thickness of the insulating layer is 100nm-100um to prevent short circuit between an RX channel and a TX channel, and the width of the insulating layer is 50um-1 mm; the width of the connecting part is 0.2mm-2 mm.
In some embodiments of the present invention, the insulating layer is a photo-or thermal-curable transparent resin having a thickness of 200nm to 500 nm.
In some embodiments of the present invention, the length of the conductive layer is greater than the length of the insulating layer to ensure that the first unit and the fourth unit are conducted, and the width of the conductive layer is smaller than the width of the insulating layer.
In certain embodiments of the invention, the conductive layer has a width of 40um to 100 um.
In some embodiments of the invention, the conductive ink component in the conductive layer is a nano-silver wire having a diameter of less than 100nm and a length of less than 10 um; preferably, the diameter of the nano silver wire is less than 30nm, and the length of the nano silver wire is less than or equal to 3 um.
It should be noted that, the conductive layer adopts the conductive ink containing the silver nanowires, which has the advantages that the conductive layer can be transparent, so as to obtain better appearance, and in order to avoid printing the plugged holes, the length of the silver nanowires is required to be less than or equal to 3 um.
In some embodiments of the present invention, the conductive ink in the conductive layer is a silver paste ink, and the silver paste ink has a solid content of 5-60% and a viscosity of 1000cps or less.
It should be noted that the silver paste ink has good adhesion to the nano silver conductive layer, and the Baige test of the silver paste ink can reach the 5B standard.
In certain embodiments of the present invention, after step (4), further comprising: and heating and curing after printing, wherein the heating temperature range is 70-150 ℃, the preferred heating temperature range is 90-130 ℃, and the curing time is less than or equal to 15 minutes, so as to ensure good conductivity.
In a second aspect, the invention further provides a single-layer nano silver conductive film touch sensor, which is prepared by the preparation process of the single-layer nano silver conductive film touch sensor based on the printing technology.
Compared with the prior art, the invention has the following advantages:
according to the preparation process of the single-layer nano silver conductive film based on the printing technology, the single-layer nano silver conductive film is cut into a grid structure comprising a first unit, a second unit, a third unit and a fourth unit, the second unit is communicated with the third unit through a connecting part, an insulating layer and a conductive layer are sequentially printed between the first unit and the fourth unit, the length of the conductive layer is larger than that of the insulating layer and is arranged on the insulating layer, and the first unit and the fourth unit are communicated through the conductive layer, so that the obtained single-layer nano silver conductive film is excellent in performance when applied to a capacitive screen, has good conductive performance and achieves expected effects; meanwhile, the preparation process for preparing the single-layer nano silver conductive film is simple, complex processes of multiple photoresist coating, exposure, development, etching, sputtering and the like in the prior art are avoided, the operation is simple, the pollution is less, the environment is protected, and the market prospect is good.
Drawings
FIG. 1 is a flow chart of a process for preparing a single-layer nano silver conductive film based on printing technology;
FIG. 2 is a schematic structural diagram of a single-layer nano-silver conductive film according to the present invention;
fig. 3 is a schematic diagram of a grid structure formed by cutting the single-layer nano silver conductive film along the TX direction according to the present invention.
In the figure: 1. a single-layer nano silver conductive film; 11. a first unit; 12. a second unit; 13. a third unit; 14. a fourth unit; 2. a connecting portion; 3. an insulating layer; 4. and a conductive layer.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
The first embodiment of the invention provides a preparation process of a single-layer nano silver conductive film based on a printing technology, which comprises the following specific steps:
(1) simultaneously etching an RX direction laser pattern and a TX direction laser pattern on the single-layer nano silver conductive film 1;
(2) cutting the single-layer nano silver conductive film 1 along the TX direction to form a grid structure comprising a first unit 11, a second unit 12, a third unit 13 and a fourth unit 14, wherein the second unit 12 and the third unit 13 are communicated through a connecting part 2 of 0.2 mm; as shown in figure 3 of the drawings,
(3) an insulating layer 3 which is 0.3mm long, 50um wide, 200nm thick and extends along the TX direction is printed between the first unit 11 and the fourth unit 14, and the material of the insulating layer 3 is specifically light-cured transparent resin; after the curing, the mixture is cured,
(4) printing a conductive layer 4 with the length of 0.4mm and the width of 40um at the middle position on the insulating layer 3 and extending along the two ends of the insulating layer, wherein the two ends of the conductive layer 4 are respectively communicated with the first unit 11 and the fourth unit 14; the conducting layer 4 is made of conducting ink prepared from nano silver wires with the length of 3um and the diameter of 20 nm;
after printing, heating and curing for 15 minutes at 130 ℃ to obtain a single-layer nano silver conductive film touch sensor, and attaching the single-layer nano silver conductive film touch sensor to a cover plate through OCA to obtain the capacitive screen. The obtained capacitive screen was subjected to performance tests, and the results of the analyses are shown in table 1.
Example 2
The second embodiment of the invention provides a preparation process of a single-layer nano silver conductive film based on a printing technology, which comprises the following specific steps:
(1) simultaneously etching an RX direction laser pattern and a TX direction laser pattern on the single-layer nano silver conductive film 1;
(2) cutting the single-layer nano silver conductive film 1 along the TX direction to form a grid structure comprising a first unit 11, a second unit 12, a third unit 13 and a fourth unit 14, wherein the second unit 12 and the third unit 13 are communicated through a connecting part 2 of 1 mm;
(3) the insulating layer 3 which is 1.2mm long, 100um wide, 300nm thick and extends along the TX direction is printed between the first unit 11 and the fourth unit 14, and the material of the insulating layer 3 is specifically light-cured transparent resin; after the curing, the mixture is cured,
(4) printing a conductive layer 4 with the length of 1.5mm and the width of 60um at the middle position on the insulating layer 3 and extending along the two ends of the insulating layer, wherein the two ends of the conductive layer 4 are respectively communicated with the first unit 11 and the fourth unit 14; the conductive layer 4 is made of conductive ink prepared from nano silver wires with the length of 3um and the width of 20 nm;
after printing, heating and curing for 15 minutes at 130 ℃ to obtain a single-layer nano silver conductive film touch sensor, and attaching the single-layer nano silver conductive film touch sensor to a cover plate through OCA to obtain the capacitive screen. The obtained capacitive screen was subjected to performance tests, and the results of the analyses are shown in table 1.
Example 3
The third embodiment of the invention provides a preparation process of a single-layer nano silver conductive film based on a printing technology, which comprises the following specific steps:
(1) simultaneously etching an RX direction laser pattern and a TX direction laser pattern on the single-layer nano silver conductive film 1;
(2) cutting the single-layer nano silver conductive film 1 along the TX direction to form a grid structure comprising a first unit 11, a second unit 12, a third unit 13 and a fourth unit 14, wherein the second unit 12 and the third unit 13 are communicated through a connecting part 2 of 2 mm;
(3) the insulating layer 3 which is 2.5mm in length, 1mm in width, 500nm in thickness and extends along the TX direction is printed between the first unit 11 and the fourth unit 14, and the material of the insulating layer 3 is specifically light-cured transparent resin; after the curing, the mixture is cured,
(4) printing a conductive layer 4 with the length of 3mm and the width of 100um at the middle position on the insulating layer 3 and extending along two ends of the insulating layer, wherein two ends of the conductive layer 4 are respectively communicated with the first unit 11 and the fourth unit 14; the conductive layer 4 is made of conductive ink prepared from nano silver wires with the length of 3um and the width of 20 nm;
after printing, heating and curing for 15 minutes at 130 ℃ to obtain a single-layer nano silver conductive film touch sensor, and attaching the single-layer nano silver conductive film touch sensor to a cover plate through OCA to obtain the capacitive screen. The obtained capacitive screen was subjected to performance tests, and the results of the analyses are shown in table 1.
Example 4
The fourth embodiment of the invention provides a preparation process of a single-layer nano silver conductive film based on a printing technology, which comprises the following specific steps:
(1) simultaneously etching an RX direction laser pattern and a TX direction laser pattern on the single-layer nano silver conductive film 1;
(2) cutting the single-layer nano silver conductive film 1 along the TX direction to form a grid structure comprising a first unit 11, a second unit 12, a third unit 13 and a fourth unit 14, wherein the second unit 12 and the third unit 13 are communicated through a connecting part 2 of 0.2 mm;
(3) an insulating layer 3 which is 0.3mm long, 50um wide, 200nm thick and extends along the TX direction is printed between the first unit 11 and the fourth unit 14, and the material of the insulating layer 3 is specifically light-cured transparent resin; after the curing, the mixture is cured,
(4) printing a conductive layer 4 with the length of 0.4mm and the width of 40um at the middle position on the insulating layer 3 and extending along the two ends of the insulating layer, wherein the two ends of the conductive layer 4 are respectively communicated with the first unit 11 and the fourth unit 14; the conductive layer 4 is made of silver paste ink, the solid content of the silver paste ink is 30%, and the viscosity of the silver paste ink is 80 cps;
after printing, heating and curing for 15 minutes at 130 ℃ to obtain a single-layer nano silver conductive film touch sensor, and attaching the single-layer nano silver conductive film touch sensor to a cover plate through OCA to obtain the capacitive screen. The obtained capacitive screen was subjected to performance tests, and the results of the analyses are shown in table 1.
TABLE 1
The result analysis is performed by combining table 1, and it can be seen that the wider the width of the RX direction connection (i.e., the connection part 2) is, the lower the resistance is, the wider the connection width of the conductive layer 4 printed along the TX direction is, the lower the resistance is, and the resistance is higher when the conductive ink containing the nano silver wire is printed, compared with the silver paste ink prepared from nano silver particles, but the optical index is better.
The present invention has been further described with reference to specific embodiments, but it should be understood that the detailed description should not be construed as limiting the spirit and scope of the present invention, and various modifications made to the above-described embodiments by those of ordinary skill in the art after reading this specification are within the scope of the present invention.