KR20240058411A - Gravia offset device with soft blanket and sensor manufacturing method using it - Google Patents

Abstract

The present invention relates to a gravure offset device including a soft blanket and a sensor manufacturing method using the same, wherein a gravure roll with a printed pattern formed on the outer peripheral surface and a blanket roll including a soft blanket are brought into contact to transfer the printed pattern to the soft blanket. , the soft blanket is in contact with the substrate to print the printed pattern on the substrate. At this time, the soft blanket has the advantage of being able to precisely form a printed pattern by deforming its shape due to pressure when in contact with the gravure roll and the substrate, and enabling electrode printing on a substrate with a curvature.

Description

Gravia offset device with soft blanket and sensor manufacturing method using it {Gravia offset device with soft blanket and sensor manufacturing method using it}

The present invention relates to a humidity sensor and a method of manufacturing a humidity sensor, and more specifically, to a gravure offset device through pattern printing on the surface of a substrate using a gravure offset printing process and a method of manufacturing a sensor using the same.

Micropatterns are formed in various electronic devices through photolithography, but this has the disadvantage of requiring several steps to obtain precise micropatterns. To solve this problem, roll printing method

The existing grinder offset process uses steel rolls, which has the disadvantage of making it difficult to print precise and three-dimensional shapes.

Figure 1 is an example of pattern printing using a conventional gravure offset process. Referring to Figure 1, ink is injected into the pattern formed on the outer surface of the gravure roll. During injection, ink is placed in the concave part of the pattern, and ink is removed from the convex part by the blade. The ink pattern of the gravure roll is transmitted in contact with the outer surface of the blanket roll. Afterwards, the blanket roll is in contact with the upper surface of the specimen to print the pattern.

At this time, in the existing gravure offset process, steel rolls are used, which makes precise printing difficult due to separation in contact due to differences with the specimen, and has the disadvantage of making printing difficult for curved specimens.

Therefore, the present invention was made to solve the problems of the prior art as described above, and the purpose of the present invention is to manufacture a gravure offset device including a soft blanket capable of producing a humidity sensor on a curved substrate and a sensor using the same. It provides a method.

The technical challenges sought to be achieved by the embodiments of the present application are not limited to those described above, and other technical challenges may exist.

The present invention provides a gravure roll with a printing pattern formed on the outer peripheral surface; An ink injector for injecting ink into the outer peripheral surface of the gravure roll; A blanket roll including a soft blanket disposed in contact with the outer peripheral surface of the gravure roll; And a substrate on which a pattern is printed in contact with the soft blanket, wherein the soft blanket is characterized in that its shape is deformed in contact with the gravure roll and the substrate.

In addition, the ink injector includes a moving part that reciprocates toward the outer peripheral surface of the gravure roll and an ink remover that contacts the embossing of the gravure roll.

In addition, the substrate is characterized in that the upper surface in contact with the soft blanket is curved.

Additionally, the gravure offset device includes a solution injector that injects a solution onto the upper surface of a substrate on which a pattern is printed, and a blade that is spaced apart from the substrate at a predetermined distance and moves horizontally in contact with the solution.

Additionally, it is disposed below the substrate and includes a heater that applies heat to harden the solution.

In addition, the printed pattern has a plurality of electrodes, and is characterized in that it includes 40 to 60 electrodes.

In addition, in the method of manufacturing a humidity sensor using a gravure offset device, an ink injection step in which an ink injector injects ink into the outer peripheral surface of a gravure roll on which a pattern is formed; A pattern transfer step in which a blanket roll containing a soft blanket is brought into contact with a gravure roll and a printed pattern is transferred to the soft blanket; And a printing step in which the soft blanket is in contact with the substrate and a printed pattern is printed on one side of the substrate.

In addition, after the printing step, a coating step is included in which the solution is disposed on the upper side of the printed pattern and the solution is formed to a uniform thickness by blades spaced at a certain distance from the substrate.

In addition, after the coating step, a curing step is included in which a heater disposed at the bottom of the substrate cures the solution coated on the top of the substrate.

In addition, the pattern transfer step is characterized in that the gravure roll and blanket roll come into contact with a pressure of 8kgf to 12kgf.

In addition, the printing step is characterized in that the blanket roll and the substrate come into contact with a pressure of 8kgf to 12kgf.

Additionally, the pattern transfer step is characterized in that it proceeds at a speed of 1 mm/s to 3 mm/s.

The present invention includes a soft blanket and has the advantage of being able to print electrodes in precise and three-dimensional shapes.

In addition, we have secured the technology to manufacture a flexible humidity sensor through a gravure offset device including a soft blanket, and will be able to produce electrodes in various precise patterns and three-dimensional shapes in the future. It can be widely applied in device manufacturing.

Figure 1 is an example of a conventional gravure offset process.
Figure 2 is an exemplary gravure offset process of the present invention.
Figure 3 is an enlarged view of the pattern printing step.
Figure 4 is a coating step of the present invention.
Figure 5 is a print pattern result according to the pressure of the blanket roll.
Figure 6 shows the resulting printing pattern according to the speed of the blanket roll.
Figure 7 shows the surface analysis results of the manufactured sensor.
Figure 8 is a cross-sectional view of the manufactured sensor.
Figure 9 is an example diagram according to the width of the sensor.
10 to 12 are comparison tables of sensor response speeds.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all changes included in the spirit and technical scope of the present invention.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the present invention pertains.

Terms defined in commonly used dictionaries should be interpreted as having meanings consistent with the meanings they have in the context of the related technology, and unless clearly defined in the present application, should not be interpreted in an ideal or excessively formal sense. It shouldn't be.

Hereinafter, a gravure offset device including a soft blanket and a sensor manufacturing method using the same according to an embodiment of the present invention will be described in detail with reference to the attached drawings.

Figure 2 is an exemplary process diagram using the gravure offset device of the present invention. Figure 2(a) is an example diagram showing the order of processes sequentially from left to right. Referring to Figure 2 (a), a gravure roll 200 with a printing pattern formed on the outer peripheral surface, an ink injector 100 for injecting ink into the outer surface of the gravure roll 200, a soft blanket is disposed on the outer surface, and the gravure roll 200 It includes a blanket roll 300 in contact with the outer surface of the roll 200, and a substrate 400 on which a pattern is printed in contact with the soft blanket.

The gravure roll 200 has a printed pattern engraved on its outer surface. The ink injector 100 injects ink into the outer peripheral surface of the rotating gravure roll 200. The ink injector 100 includes a moving part (not shown) that moves back and forth toward the outer peripheral surface of the gravure roll and injects ink into the engraved pattern. The ink injector includes an ink remover at the bottom. The ink remover contacts the embossed portion of the printing pattern to remove ink. Through this, the desired printing pattern can be formed.

The blanket roll 300 rotates in contact with the gravure roll 200. The blanket roll 300 and the gravure roll 200 rotate at the same rotation speed. At this time, the ink injected into the outer peripheral surface of the gravure roll (200) by rotating in opposite directions is printed on the outer peripheral surface of the blanket roll (300).

A soft blanket is placed on the outer peripheral surface of the blanket roll, and the soft blanket is in contact with the gravure roll 200 at a certain pressure, so that the ink pattern of the gravure roll is transferred to the outer surface of the soft blanket. At this time, the shape of the soft blanket is deformed by the pressure of the gravure roll, and the ink in the intaglio is transferred. The process in which the gravure roll 200 and the blanket roll 200 come into contact and ink is transferred to the outer peripheral surface of the blanket roll 300 is called an off process, and in the off process, differences in printing quality occur depending on pressure and speed.

The blanket roll 300 is in contact with the substrate 400 and moves the printed pattern to the upper surface of the specimen. The soft blanket's shape is deformed by pressure with the substrate and the printed pattern is printed in close contact even if the substrate is curved. The process in which the outer peripheral surface of the blanket roll 300 comes into contact with the substrate 400 is called a set process. A soft blanket is disposed on the outer peripheral surface of the blanket roll 300, which increases adhesion to the substrate 400, forming a pattern with precision, and has the advantage of being able to form a pattern on the curved substrate 400. When the substrate is formed in the form of a film, it has the advantage of being sufficiently closely adhered by a soft blanket and causing less damage due to contact. Afterwards, a cleaning process is performed to remove residual ink from the gravure roll 200, and the printing process is repeated.

Figure 2(b) is an example of a sensing layer formed on a substrate. Referring to Figure 2(b), the printed sensing layer (A) is identical to the engraved pattern of the gravure roll. Even if the upper surface of the substrate 400 is convex or concave, the ink pattern is printed by being pressed by the soft blanket. This has the advantage of being able to form a sensing layer in configurations with various shapes, unlike the existing method where the sensing layer is limited to a flat configuration.

Figure 3 is an exemplary diagram of the coating step of the present invention. Referring to FIG. 3, a sensor is formed by applying a solution 510 to the upper surface of the substrate 400 on which the sensing layer (A) is printed. A solution is injected into the upper surface of the substrate on which the pattern is printed through a solution injector (not shown), and the blades 500, spaced at a certain angle and a certain distance from the substrate 400, come into contact with the solution and move horizontally in one direction to create a layer of a certain thickness. This is formed. A heater that generates heat is placed at the bottom of the substrate 400 on which the solution is placed, and the humidity sensor is completed by curing the solution by heat. At this time, the solution is formed of a material that can maintain a flexible state even when hardened. Figure 3(b) is a perspective view showing a cross section of the sensor. Referring to FIG. 3(b), the solution 510 is injected and disposed between patterns of the sensing layer.

The present invention includes a method for manufacturing a humidity sensor. An ink injection step in which an ink injector injects ink into the outer peripheral surface of a gravure roll on which a pattern is formed, a pattern transfer step in which a blanket roll including a soft blanket is in contact with the gravure roll and a printing pattern is transferred to the soft blanket, and the soft blanket It includes a printing step in which the cat is in contact with the substrate and a printed pattern is printed on one side of the substrate, and a coating step in which a solution is coated on the upper surface of the specimen on which the pattern is formed.

In the ink injection step, an ink injector injects ink into the outer peripheral surface of the gravure roll. The ink injector includes a blade, and the ink placed on the positive side of the gravure roll is removed through the blade, leaving ink on the negative side.

In the pattern transfer step, the printed pattern is transferred to the outer peripheral surface of the blanket roll by contacting the outer peripheral surface of the gravure roll and the outer peripheral surface of the blanket roll. The outer peripheral surface of the blanket roll includes a soft blanket that can be deformed by pressure, so the ink placed on the intaglio of the gravure roll is easily transferred to the outer peripheral surface of the blanket roll.

In the printing step, the outer peripheral surface of the blanket roll is in contact with the upper surface of the substrate, and a pattern is printed on the upper surface of the substrate. At this time, the blanket roll moves horizontally with respect to the upper surface of the worktable on which the substrate is placed, and even if the upper surface of the substrate has a curvature, the pattern is printed without being separated by the soft blanket of the blanket roll.

This has the advantage of being able to print on substrates and configurations with various shapes. The printing pattern formed on the substrate is based on the printing pattern of the gravure roll, and the pattern is designed to reflect the deformation caused by the curvature and bending of the substrate.

In the coating step, the solution is placed on the upper side of the printed pattern, and the solution is formed to a uniform thickness by blades spaced at a certain distance from the substrate. A certain amount of solution is placed on the substrate by a solution injector, and a coating layer of a certain thickness is formed through a blade. The blade moves parallel to the top surface of the substrate, and the empty spaces in the pattern are filled with solution.

After the coating step, a curing step is performed in which a heater disposed at the bottom of the substrate cures the solution coated on the top of the substrate. Curing is not limited to a hard solid state, and the solution is cured by heat. However, when manufacturing a flexible humidity sensor, the solution can be formed of components that can maintain a flexible state.

The present invention proposes process conditions suitable for manufacturing a flexible humidity sensor using a blanket roll. Unlike existing blanket rolls, the blanket roll of the present invention contains a soft blanket, so there is a difference in the quality of pattern printing depending on the process speed and pressure during the off process and set process. If the pressure is too low or the speed is too fast, the pattern becomes sticky, and if the pressure is too strong, the pattern becomes connected to each other. Accordingly, the present invention provides a preferred embodiment for manufacturing a flexible humidity sensor.

Figures 4 and 5 show the printing pattern results according to contact pressure. Referring to Figure 4, this is an example in which the off pressure, which is the contact pressure between the gravure roll and the blanket roll, is modified. If the off pressure is weak, a problem occurs in which the ink on the gravure roll is not transferred 100%. Through this, it is difficult to manufacture a precise sensor due to the problem of sensor disconnection and the uneven thickness of the sensor. The present invention seeks to provide a desirable off pressure through testing.

The test examples in FIGS. 4 and 5 are the results of the same test speed of 2 mm/s. This refers to the speed at which a pattern is printed, and the printing speed can be controlled by controlling the rotation speed of the gravure roll and blanket roll.

Referring to Figure 4, Example 1(a) is the result when the off pressure is 1kgf and the set pressure is 1kgf. In Example 1, the pattern was not 100% transferred, so the middle was sticky or the thickness was uneven. This means that at least one of the off pressure and set pressure is weak.

Example 2(b) is the result when the off pressure is 10kgf and the set pressure is 1kgf. In Example 2, the off pressure was increased, so the pattern was not sticky, but the thickness of the pattern was not uniform. If the off pressure is low, the ink on the gravure roll will not transfer well. By comparing Example 1 and Example 2, it is a preferred embodiment that the off pressure is performed at a pressure of 8kgf to 12kgf.

Figure 5 is an example in which the set pressure, which is the contact pressure between the blanket roll and the specimen, is modified. Referring to Figure 5, Example 3(c) is the result when the off pressure is 1kgf and the set pressure is 10kgf. In Example 3, the off pressure was weak, so it was not 100% transferred, and it was confirmed that the middle of the pattern was sticky or not printed.

Example 4(d) is the result when the off pressure is 10kgf and the set pressure is 10kgf. In Example 4, compared to other Examples, it was confirmed that the pattern was not sticky and the thickness of the pattern was generally uniform.

Through this, the gravure offset process including the soft blanket is an embodiment in which the process conditions of Example 4 are preferable, and through the above test, the device with the soft blanket roll was used to transfer ink to the blanket roll through high off pressure and then set pressure. It can be seen that the higher the value, the more ink transfer occurs by more than 90%, and the ideal embodiment is to set the off pressure to a pressure of 8kgf to 12kgf.

Figures 6 and 7 show printing pattern results according to process speed. Since process speed directly affects production per hour, production efficiency can be increased by suggesting a process speed that prints quickly without damaging the pattern. Examples 5 to 8 below were conducted with an off pressure of 10 kgf and a set pressure of 10 kgf obtained through Examples 1 to 4. Figure 6 is an example according to the off process speed, and the effect on pattern printing can be confirmed depending on the off process speed. Referring to Figure 6, Example 5(e) is the result when the off speed is 2mm/s and the set speed is 2mm/s, and Example 6(f) is the result when the off speed is 10mm/s and the set speed is 2mm. This is the result when /s.

When comparing Example 5(e) with Example 6(e), the pattern of Example 5(e) is good, and Example 6(f), which has a fast off speed, confirms that the pattern transfer is torn. You can.

Figure 7 is an example according to set process speed. Example 7(g) is the same result as Example 5 when the off speed is 2mm/s and the set speed is 2mm/s, and Example 8(h) is the result when the off speed is 2mm/s and the set speed is 10mm/s. This is the result when s. Comparing Example 7(g) and Example 8(h), it can be seen that Examples 7 and 8 printed patterns well and did not significantly affect pattern printing depending on the set speed.

Therefore, through the examples, the off speed is preferably 1 mm/s to 3 mm/s to prevent the ink transfer from tearing, and the set speed is preferably 10 mm/s or more to increase the process speed.

In order to be applicable to the roll-to-roll process, it has a high-speed process of 10mm/s without pattern distortion, and by measuring the optimal process speed, production time can be planned to improve production efficiency.

Figure 8 shows the surface analysis results of the manufactured sensor. This is an example of measuring the thickness of the manufactured flexible sensor. The thickness of the printed pattern was measured using the optimal process method derived through Examples 1 to 8.

Figure 8(a) is a diagram showing the height of the pattern viewed from above, and Figure 8(b) is a distance-height graph. It can be seen that the thickness (D) of the produced pattern is printed consistently, and the height of the pattern is also printed consistently.

Figure 9 is a cross-sectional view of the manufactured sensor. Figure 9(a) is a side cross-sectional view of the printed pattern, and Figure 9(b) is a side cross-sectional view of the product with the coating layer formed. The printed pattern in one embodiment has a thickness of 1.0 to 1.50 um. At this time, the printed pattern is an electrode containing silver (Ag) (IDE, An interdigitated electrode). A coating solution is placed on the printed pattern, and a blade passes at a certain distance from the pattern to form a uniform coating layer on the pattern.

The coating process of the present invention will be described with reference to an embodiment of the coating process. The coating solution is used by mixing CNF (Cellulose Nanofiber) solution and DI water (Deionized water) in a ratio of 1:4 to 5. The blade is spaced 50um away from the substrate and passes at a speed of 10mm/s to form a constant coating layer.

It is necessary to control various process conditions so that the pattern is not exposed to the outside and the coating layer is formed uniformly and thinly, and a coating layer with a thickness of 170 nm to 200 nm is formed through the described process.

Figure 10 is an example diagram according to the number of electrodes. We aim to provide a desirable pattern width by comparing the performance of humidity sensors through several examples with different pattern widths. Figure 10(a) is Sample 1 with 30 electrodes formed within the same length, and Figure 10(b) is Sample 2 with 50 electrodes formed within the same length. Figure 10(c) is Sample 3 in which 100 electrodes were formed within the same length.

When relative humidity increases and decreases, the example with a small error rate in the impedance value has excellent hysteresis and is therefore judged to be the best example.

Comparing samples 1 to 3, the conductivity increases as the sensor electrodes become closer. Looking at the impedance between 70% and 90% relative humidity, a difference occurs from about 70%. Sample 1 has a large difference at 80%, and Sample 2 has a large difference at 90%. Through this, it is judged that Sample 3, which showed small differences, is excellent.

Figures 11 and 12 are comparison tables of sensor response speeds. Figure 11 shows the response speed of the humidity sensor by measuring the cap value over time. It is carried out under the same conditions, with the humidity gradually increased over time. For samples 1 to 3, the cap value increases as the humidity increases, but in the case of sample 1, the graph is very unstable due to the measurement width being very shaky.

When comparing Sample 2 and Sample 3, the difference in cap value according to humidity is small in Sample 2 (h1) and large in Sample 3 (h3). This shows that the closer the electrode gap is, the greater the change in cap value and the faster the recovery time.

Figure 12 is a graph measuring the response and recovery time of the sensor. Referring to Figure 12, this is a graph measuring response and recovery time within the range of 10%RH to 90%RH. Sample 1's response time is 30s and recovery time is 17s. The response time of Sample 2 is 17s and the recovery time is 7s. The response time of Sample 3 is 50s and the recovery time is 5s.

Sample 2 had the fastest response speed, and sample 3 had the fastest recovery speed. Through this, the closer the electrode gap is, the more stably the cap value is recovered.

Figure 13 is an experimental graph of Sample 2. Referring to Figure 13, the stability of Sample 2, which had relatively satisfactory response and recovery time, was measured for change in cap value according to humidity in a stepwise manner. We checked the humidity change at relative humidity above 50%RH and conducted a sensor stability test at above 50%. We can confirm that the sensor cap value is stable over time.

The present invention is not limited to the above-described embodiments, and the scope of application is diverse. Of course, various modifications and implementations are possible without departing from the gist of the present invention as claimed in the claims.

1: Blade 2: Gravure Roll
3: Blanket roll 4: Sheet
4: Stage
100: Ink injector
200: Gravure roll
300: Blanket roll
400: substrate
500: blade
510: solution
A: Sensing layer

Claims (12)

A gravure roll with a printed pattern formed on the outer circumference;
An ink injector for injecting ink into the outer peripheral surface of the gravure roll;
A blanket roll including a soft blanket disposed in contact with the outer peripheral surface of the gravure roll; and
It includes a substrate on which a pattern is printed in contact with the soft blanket;
The soft blanket is a gravure offset device, characterized in that the shape is deformed in contact with the gravure roll and the substrate.
According to paragraph 1,
The ink injector is a gravure offset device including a moving part that reciprocates toward the outer peripheral surface of the gravure roll and an ink remover that contacts the embossing of the gravure roll.
According to paragraph 1,
A gravure offset device, wherein the substrate has a curved upper surface in contact with the soft blanket.
According to paragraph 1,
The gravure offset device is
A solution injector that injects a solution into the upper surface of the pattern printed board and
A gravure offset device comprising a blade that is spaced apart from the substrate at a predetermined distance and moves horizontally in contact with a solution.
According to paragraph 1,
A gravure offset device disposed below the substrate and including a heater that applies heat to harden the solution.
According to paragraph 1,
The printed pattern has a plurality of electrodes, and is a gravure offset device characterized in that it includes 40 to 60 electrodes.
In the method of manufacturing a humidity sensor using the gravure offset device of claim 1,
An ink injection step in which an ink injector injects ink into the outer peripheral surface of the gravure roll on which the pattern is formed;
A pattern transfer step in which a blanket roll containing a soft blanket is brought into contact with a gravure roll and a printed pattern is transferred to the soft blanket; and
A method of manufacturing a humidity sensor comprising a printing step in which the soft blanket is in contact with the substrate and a printed pattern is printed on one side of the substrate.
In clause 7,
After the printing step, the solution is disposed on the upper side of the printed pattern, and a coating step in which the solution is formed to a uniform thickness by blades spaced at a certain distance from the substrate.
According to clause 8,
After the coating step, a humidity sensor manufacturing method including a curing step in which a heater disposed at the bottom of the substrate cures the solution coated on the top of the substrate.
In clause 7,
The pattern transfer step is a humidity sensor manufacturing method characterized in that the gravure roll and blanket roll are brought into contact with a pressure of 8kgf to 12kgf.
In clause 7,
The printing step is a humidity sensor manufacturing method characterized in that the blanket roll and the substrate come into contact with a pressure of 8kgf to 12kgf.
In clause 7,
A humidity sensor manufacturing method, characterized in that the pattern transfer step is performed at a speed of 1 mm/s to 3 mm/s.

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