TWI569883B - Electrostatic coating method and electrostatic coating device - Google Patents

Description

Electrostatic coating method and electrostatic coating device

The present invention relates to an electrostatic coating method in which various liquids are stretched by electric power at a tip end of a nozzle to form a fine pattern on a substrate.

For example, a method using electrostatic attraction described in Patent Document 1 has been known as a method of applying a fine pattern on a substrate as a minute droplet.

Fig. 12 shows the method of Patent Document 1.

In this method, the nozzle 2 is placed facing the surface of the object 4 to be coated, and a pulse voltage is applied between the application target 4 and the nozzle 2 by the power supply unit 30, and the liquid 1 of the nozzle tip 3 is attracted to the electrostatic force to On the side of the object 4 to be coated, the droplet 31 is dropped onto the object 4 to be coated.

Although Patent Document 2 is not a coating object to be coated, a method of discharging fine droplets having a uniform particle diameter into a solution by a needle is also known. In Patent Document 2, the electrostatic force as shown in Patent Document 1 is not used.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2001-038911

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2006-320795

When the solution adhering to the tip of the needle is applied to the object to be coated by the technique of Patent Document 2, it is as follows.

As shown in Fig. 13 (a), the needle 32 placed in the nozzle 2 is lowered as shown in Fig. 13 (b) until the tip end 3 of the nozzle protrudes. At this time, at the tip end of the needle 32, the droplets 33 of the liquid 1 in the nozzle 2 are formed in a state in which a small amount is adhered. Thereafter, as shown in FIG. 13( c ), the needle 32 is lowered until the liquid droplet 33 adhering to the tip end comes into contact with the object 4 to be coated. Thereby, the liquid droplet 33 adhering to the tip end of the needle 32 can be applied to the object 4 to be coated.

However, in the method shown in FIG. 12 as a conventional method and the method shown in FIG. 13 as considered, when a fine linear pattern is formed by coating on the surface of the object 4 to be coated, there is a coating result. The linearity of the edges is poor, and the problem of uniform coating of a wide pattern cannot be achieved.

The coating state at this time is shown in FIG.

Fig. 14 (a) shows a state in which the droplets are continuously coated with a small amount of droplets. The state after the completion of drying of the applied droplets is shown in Fig. 14 (b). As described above, in the drying stage after coating, the leveling of adjacent droplets is performed, but since the trace applied as the droplet remains, it is difficult to obtain the linearity of the edge. This is based on The surface area of the fine droplets to be discharged is large, and is promoted to be dried before being discharged by the nozzle 2 and reaching the object 4 to be coated. Therefore, the leveling after reaching the object 4 to be coated becomes difficult.

In the case of the above, in order to achieve high linearity of the edge and uniform coating of the pattern, it is preferable not to bond the liquid droplets, but to continuously coat the liquid droplets without interrupting the liquid droplets.

Therefore, in consideration of the principle of droplet suction by electrostatic force, the liquid reservoir 34 is formed at the tip end of the nozzle 2 shown in FIG. 15, and the liquid 1 is continuously applied to the surface of the object 4 to be coated. When the liquid storage unit 34 is continuously applied, it takes a long time to form the coating end of the coating with the expansion and contraction of the liquid reservoir 34 by the electrostatic force, and thus the flow time (tact time) increases, and The problem of messy coating conditions.

The formation state of the liquid storage portion 34 in the coating start end when the liquid 1 is continuously applied by the liquid storage portion is shown in Figs. 16(a) to 16(d).

Fig. 16 (a) shows a state before a voltage is applied to the nozzle 2 into which the liquid 1 has been placed.

Next, when a voltage is applied between the nozzle 2 and the object 4 to be coated, as shown in FIGS. 16(b) and 16(c), the liquid reservoir 34 is elongated toward the side of the object 4 by electrostatic force, such as As shown in FIG. 16( d ), as shown in FIG. 16( d ), the liquid storage unit 34 reaches the object 4 to be coated, as shown in FIG. 16( c ).

In the suction by the electrostatic force as shown above, it is necessary to move from the unstable state of Fig. 16 (c) to the stable state of Fig. 16 (d). Therefore, the timing control for starting the relative movement of the nozzle 2 for coating and the application target 4 is extremely difficult, and the position at which the liquid reservoir 34 reaches the application target 4 is different from the target. situation. As a result, as shown in Fig. 17 (a), when the liquid 1 of the above amount is applied at the beginning of the coating, the line width is increased by 35, or conversely, as shown in Fig. 17 (b), the liquid 1 is The problem of the interruption 36 is caused by insufficient coating amount.

18(a) to (d) show the reduced state of the liquid reservoir 34 in the coating terminal.

As described above, before the application of the voltage to the nozzle 2 in which the liquid 1 has been placed is stopped (Fig. 18 (a)), after the application of the voltage is stopped (Fig. 18 (b)), the liquid storage portion 34 is also held. The influence of the residual charge is not immediately cut off from the object 4 to be coated, and the final reservoir portion 34 is cut away as shown in Fig. 18 (c) and (d) via the state of being unstable.

In the suction by the electrostatic force as described above, after the application of the stop voltage, the unstable state of FIG. 18(b) is continued, so that the nozzle 2 for coating and the coating object 4 are stopped. The timing control of the relative movement becomes extremely difficult, and the situation in which the position where the liquid reservoir 34 and the coating object 4 are cut away is different from the target is generated. As a result, as shown in Fig. 19 (a), when the liquid 1 required for coating is applied to the coating terminal, the line width is increased by 35, or conversely, as shown in Fig. 19 (b), the coating of the liquid 1 is performed. The problem is insufficient to generate an interruption 36.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrostatic coating method which does not have a time required for forming at the permanent end, and which does not have a disordered shape, and which has high linearity of the edge and uniform pattern width.

In the electrostatic coating method of the present invention, the nozzle tip of the nozzle in which the liquid is accommodated is disposed to face the object to be coated, and a potential difference is applied between the liquid and the object to be coated during the application. The tip end of the nozzle forms a liquid storage portion that is elongated toward the side of the object to be coated, and at the time of the application, the tip end of the needle disposed in the nozzle protrudes from the liquid storage portion, and the front end of the liquid storage portion is formed. The object to be coated is contacted.

In the electrostatic coating apparatus of the present invention, an electrostatic coating apparatus that applies a potential difference between a liquid in a nozzle and an object to be coated, thereby extracting the liquid from the nozzle and applying the coating object, is characterized in that: a power supply unit that applies a predetermined voltage between the liquid and the object to be coated; a needle that moves up and down among the nozzles; a needle driving unit that drives the needle up and down; and a control unit At the time of coating, the power supply unit is controlled such that the tip end of the needle protrudes from the liquid storage portion so that the liquid storage portion of the liquid elongated toward the object to be coated is formed at the tip end of the nozzle. In the method, the needle driving unit is operated to bring the tip end of the liquid storage unit into contact with the object to be coated.

According to the electrostatic coating method of the present invention, a liquid level portion that is elongated toward the object to be coated is formed at the tip end of the nozzle by applying a potential difference, and the tip end of the needle disposed in the nozzle protrudes from the liquid storage portion to allow the liquid to be stored. Since the distal end of the portion contacts the object to be coated, the responsiveness of the liquid reservoir at the tip end of the nozzle can be improved. Moreover, the confusing end of the coating can be prevented, and the shortening of the tact time can be achieved. Further, since the liquid can be continuously applied, a pattern having high linearity can be precisely formed.

1‧‧‧Liquid

2‧‧‧ nozzle

3‧‧‧Nozzle front end

4‧‧‧Applying object

5‧‧‧Power Supply Department

6‧‧‧ needle

7‧‧‧Liquid supply department

8‧‧‧Electrode plate

9‧‧‧Nozzle Drive Department

10‧‧‧needle drive department

11‧‧‧ stage

12‧‧‧Motor Station Drive Department

13‧‧‧Control Department

14‧‧‧Liquid reservoir at the front end of the nozzle

15‧‧‧The inner diameter of the nozzle at the front end of the nozzle

16‧‧‧Neon Ag ink

17‧‧‧ Needle diameter at the front end of the nozzle

18‧‧‧Nozzle front face

19‧‧‧ needle front end face

20‧‧‧ needle side

21‧‧‧The gap between the inner wall of the nozzle and the side of the needle in the front end face of the nozzle

22‧‧‧A region of contact angle θ 4 in the side of the needle that protrudes more than the front end of the nozzle

23‧‧‧A region of contact angle θ 5 in the side of the needle that protrudes more than the front end face of the nozzle

24‧‧‧ needle taper

25‧‧‧The area of the contact angle θ 6 of the nozzle side in the side portion of the tapered portion of the needle

26‧‧‧A region of the contact angle θ 7 of the front end side of the side portion of the tapered portion of the needle

30‧‧‧Power Supply Department

31‧‧‧ droplets

32‧‧‧ needle

33‧‧‧ droplets

34‧‧‧Liquid Department

35‧‧‧ Thickening

36‧‧‧Interruption

Fig. 1 is a schematic view showing an electrostatic coating apparatus according to an embodiment of the present invention.

Fig. 2 (a) to (c) are flow charts showing the application of the coating start end in the same embodiment.

3(a) to (c) are flowcharts showing the application of the coating terminal in the same embodiment.

Fig. 4 is an enlarged cross-sectional view showing the condition 1 of the nozzle tip of the electrostatic coating apparatus of the embodiment.

Fig. 5 is an enlarged view showing the contact angles θ 1 to θ 3 of the needle in Condition 1.

Fig. 6 is an explanatory view showing the results of coating of Conditions 1 to 8 of the present invention.

Fig. 7 is an enlarged cross-sectional view showing the condition 3 of the nozzle tip of the electrostatic coating apparatus of the embodiment.

Fig. 8 is an enlarged view showing the contact angles θ 4 and θ 5 of the needle in Condition 3.

Fig. 9 is an enlarged cross-sectional view showing the condition 5 of the nozzle tip of the electrostatic coating apparatus of the embodiment.

Figure 10 is a front end of the nozzle of the electrostatic coating device of the same embodiment. An enlarged cross-sectional view in the case of Condition 7.

Fig. 11 is an enlarged view showing the contact angles θ 6 and θ 7 of the needle in the case of Condition 7.

Fig. 12 is an explanatory diagram of Patent Document 1 obtained by electrostatic attraction by a pulse voltage.

13(a) to (c) are coating flow charts when referring to Patent Document 2.

Fig. 14 (a) and (b) are explanatory views of problems at the time of application in the coating flow of Fig. 13.

Fig. 15 is a view showing a continuous application state of a liquid storage portion which is extended by an electrostatic force according to Patent Document 1.

(a) to (d) of FIG. 16 are views showing a state in which a liquid storage portion at the beginning of coating is formed by the liquid storage portion of Patent Document 1.

Fig. 17 (a) and (b) are plan views showing the coating failure at the beginning of the coating by Patent Document 1.

18(a) to (d) are views showing a state in which the liquid storage portion of the coating terminal is formed by Patent Document 1.

19(a) and (b) are plan views showing the coating failure of the coating terminal by Patent Document 1.

Hereinafter, the electrostatic coating method of the present invention will be described based on the electrostatic coating apparatus of the embodiment.

1 to 3 show static electricity for realizing the electrostatic coating method of the present invention. Coating device.

In Fig. 1, the electrostatic coating apparatus is configured as follows.

The nozzle 2 in which the liquid 1 has been placed is disposed such that the nozzle tip end 3 faces the object 4 to be coated. A voltage is applied between the liquid 1 and the object 4 to be coated by the power supply unit 5. A needle 6 that can move up and down is disposed inside the nozzle 2. The liquid 1 is supplied from the liquid supply unit 7 inside the nozzle 2.

However, when the nozzle 2 formed of an insulating material is used, since the voltage cannot be applied through the nozzle 2, the electrode plate 8 that contacts the liquid 1 inside the nozzle 2 is provided, and the voltage is applied from the power source unit 5 through the electrode plate 8. When the nozzle 2 is formed of a conductive material, a voltage can be applied through the nozzle 2, and thus the electrode plate 8 may not be provided.

The nozzle 2 is held by the nozzle driving unit 9, and the movement control of the upper and lower positions of the object 4 is performed.

The needle 6 is held by the needle driving unit 10 to control the vertical position.

The stage 11 adsorbs and holds the object 4 to be coated, and is position-controlled by the stage driving unit 12 that moves the object 4 in the horizontal direction at the time of coating.

A voltage is applied between the application target 4 and the liquid 1 accommodated in the nozzle 2 by the power supply unit 5. The nozzle drive unit 9, the needle drive unit 10, and the stage drive unit 12 are controlled by the control unit 13.

In order to move the nozzle 2 and the application target 4 in the horizontal direction during the application, the stage driving unit 12 is provided. However, a nozzle horizontal driving unit that moves the nozzle 2 in the horizontal direction may be provided (not shown). ),and At least one of the stage driving units 12 relatively moves the nozzle 2 and the object 4 to be coated in the horizontal direction during coating.

2(a) to (c) show a coating flow chart at the beginning of the coating. Fig. 2(a) shows the application of the voltage at the beginning of the coating, Fig. 2(b) shows the voltage application at the beginning of the coating, and Fig. 2(c) shows the coating of the liquid at the beginning of the coating. When the object arrives. Fig. 3(a) shows the steady coating of the coating terminal, Fig. 3(b) shows the needle rising at the coating end, and Fig. 3(c) shows the completion of the needle movement at the coating terminal.

This coating process is explained below.

In FIG. 2(a), the object 4 to be coated is placed on the stage 11, and the nozzle 2 is aligned at the application start position. At this time, the front end of the needle 6 is positionally controlled by the needle driving unit 10 so as to be located inside the nozzle 2 more than the nozzle tip end 3.

Next, the height of the nozzle 2 is controlled by the nozzle driving unit 9 so that the gap between the nozzle tip end 3 and the application target 4 becomes a desired distance.

In FIGS. 2(b) and 2(c), a voltage is applied between the liquid 1 and the object 4 to be coated by the power supply unit 5, and the needle 6 is lowered to the object to be coated by the needle driving unit 10. The object 4 side to the front end reach a desired position on the side closer to the object 4 to be coated than the nozzle tip end 3 .

Thereby, the liquid 1 is attracted to the side of the object to be coated 4 by the electrostatic force, and the center portion of the liquid reservoir 14 of the nozzle tip 3 can be selectively applied to the object to be coated as the needle 6 is lowered. 4 side elongation, can be greatly shortened The time during which the liquid storage portion 14 reaches the object to be coated 4 is in an unstable state before reaching the object 4 to be coated.

As a result, the timing control for starting the relative movement of the nozzle 2 for coating and the application target 4 is facilitated, and the position at which the liquid reservoir 14 reaches the application target 4 can be bounced as desired. Thereby, at the beginning of the coating, there is no case where the line width is thickened or interrupted, and the effect of precise coating can be obtained. Further, since the time required for coating of the start end can be shortened, it is possible to achieve a shortening effect of the production process time.

After that, the liquid storage unit 14 that has been narrowly extended reaches the application target 4, and the nozzle 2 and the application target 4 are relatively moved in the horizontal direction at a desired timing and applied.

The timing of the relative movement of the nozzle 2 and the application target 4 at the beginning of this time is confirmed by an experiment beforehand, whereby the stable coating can be easily reproduced. By the lowering of the needle 6, the central portion of the reservoir portion 14 of the nozzle tip end 3 is selectively extended toward the object to be coated 4, whereby the reservoir portion 14 can be greatly shortened toward the object to be coated 4 The effect of the time when the object 4 is in an unstable state before reaching the object 4 in the process.

In the state of FIG. 3(a) which is applied in the steady state, at the coating end position, as shown in FIG. 3(b) and (c), the application to the liquid by the power supply unit 5 is stopped at a desired timing. 1 and the voltage between the application object 4, and the needle 6 is raised until the nozzle 2 side to the front end reach a desired position further inside than the nozzle front end 3.

As described above, as the needle 6 is raised, the central portion of the reservoir portion 14 in the nozzle tip 3 can be selectively pulled back to the side of the nozzle 2, and the application is stopped. Even after the voltage is applied, the object to be coated 4 is not cut off due to the influence of the residual electric charge held by the liquid storage unit 14, and the time during which the temperature is unstable can be greatly shortened. As a result, it is easier to stop the timing control of the relative movement of the nozzle 2 for coating and the application object 4, and the position where the liquid storage portion 14 is cut away from the application object 4 is as shown in the object. .

Thereby, in the coating terminal, there is no case where the line width is thickened or interrupted, and the effect of precise coating can be obtained. In addition, since the time required for coating of the terminal can be shortened, it is possible to achieve a shortening effect of the production process time.

The timing at which the power supply unit 5 at this time is stopped and the needle 6 is raised is confirmed by an experiment in advance, whereby the stable coating can be easily reproduced. By the rise of the needle 6, the central portion of the liquid reservoir 14 in the nozzle tip 3 can be selectively pulled back to the side of the nozzle 2, and the liquid storage portion 14 is maintained after the application of the voltage is stopped. The influence of the residual charge is not cut off by the object 4 to be coated, and the effect of the time of being unstable can be greatly shortened.

As described above, according to the present invention, the responsiveness of the liquid reservoir at the tip end of the nozzle can be improved by the vertical movement of the needle 6, and the confusion of the coating end can be prevented, and the flow time can be shortened. Further, since the liquid can be continuously applied, a pattern having high linearity can be formed with precision.

The above-described electrostatic coating apparatus will be described in detail based on Conditions 1 to 8.

- Condition 1

Performing a fine linear pattern using the electrostatic coating device shown in FIG. Coating. The details of Condition 1 are as follows.

Here, the nozzle 2 is made of glass, and as shown in FIG. 4, the front end inner diameter 15 is 200 μm. In the liquid 1 system, a nano Ag ink 16 having a center particle diameter of 200 nm was used. The nano-Ag ink was used in a solid concentration of 80% by weight and an ink viscosity of 1,500 mPa‧s. The needle 6 was made of tungsten, and a round rod having a diameter of 17 μm and a constant diameter was used. A glass substrate having a thickness of 1.7 mm was used for the object to be coated 4 . The distance between the nozzle front end surface 18 and the object 4 to be coated was set to 400 μm. As shown in FIG. 5, the contact angle θ 1 of the nano-Ag ink 16 in the nozzle front end surface 18 is set to 20°, and the contact angle θ 2 of the nano-Ag ink 16 in the needle side surface 16 is set to 15°, and the needle front end is set to 15°. The contact angle θ 3 of the nano-Ag ink 16 in 19 was set to 15°.

At the time of non-coating, the needle tip end surface 19 is held at a position of 500 μm from the nozzle tip end surface 18 toward the inside of the nozzle 2, and at the time of coating, the nozzle tip end surface 18 faces the object to be coated 4 at a position of 200 μm. The needle front end face 19 is held. Here, the gap 21 between the inner wall of the nozzle 2 and the needle side surface 20 in the nozzle tip end surface 18 is 75 μm, and is formed to be larger than 50 μm of the diameter 17 of the needle 6. Further, the moving speed of the needle 6 was set to 15 mm/s, and the power supply unit 5 was applied with a DC voltage of 1.5 kV. At this time, the nozzle 2 side is set to +.

At the beginning of the coating, the pressure of the needle 6 was started while the voltage was applied, and after the applied voltage was 100 ms, the relative movement of the nozzle 2 and the object 4 to be coated (speed 50 mm/s) was started. At the coating terminal, the application of the voltage is stopped 100 ms before reaching the coating end position, and the rise of the needle 6 is started. The rate of rise at this time was set to 15 mm/s.

As described above, 30 coatings having a line width of 8 μm, a coating thickness of 0.5 μm, and a coating length of 100 mm were formed, and the state of the coating start end and the coating terminal in the range of 20 mm from the coating end was evaluated. The result is shown in Fig. 6.

In addition, the evaluation index of the line width of the start/end of FIG. 6 is set to ○ when all the samples are in the range of 8 μm ± 3%, and if there is a sample which is not within the range even if one part is present, ×. Regarding the interruption, if all the samples are not interrupted, it is set to ○, and if there is an interruption of one part, it is set to ×. Regarding the coating position accuracy at the end, the amount of shift with respect to the position of the target position is set to ○ when all the samples are within 100 μm, and is set to × even if one portion exceeds 100 μm. Regarding the line width of the start/end, it is set to:

If all the samples are in the range of 8 μm ± 2.8%, it is ○ ○

If all the samples are in the range of 8 μm ± 2.5%, it is ○ ○ ○

If all the samples are in the range of 8 μm ± 2.3%, it is ○ ○ ○ ○

If all the samples are in the range of 8 μm ± 2.0%, it is ○ ○ ○ ○ ○

. The conditions 2 to 8 and the comparative example 1 described later are also collectively shown in Fig. 6 as a result of evaluation based on the same criteria as the condition 1.

-Comparative Example 1

In the case of Comparative Example 1, the coating was carried out by the method of stretching and contracting only the liquid storage portion by electrostatic force caused by the conventional method shown in FIG.

The nozzle 2 of Comparative Example 1 was made of glass and had an inner diameter of the nozzle tip of 200 μm. For the liquid 1, a nano Ag ink having a center particle diameter of 200 nm was used. The nano-Ag ink was used in a solid concentration of 80% by weight and an ink viscosity of 1,500 mPa‧s. A coating substrate 4 was a glass substrate having a thickness of 1.7 mm. The distance between the nozzle tip end surface and the object 4 to be coated was set to 400 μm. The contact angle θ 1 of the nano-Ag ink on the tip end surface of the nozzle was set to 20°. The power supply unit 5 applies a DC voltage of 1.5 kV (+ on the nozzle side). At the beginning of the coating, the relative movement of the nozzle 2 and the object 4 to be coated (speed 50 mm/s) was started after the applied voltage was 100 ms. At the coating terminal, the application of the voltage is stopped 100 ms before reaching the coating end position.

In the electrostatic coating of Comparative Example 1 by the conventional method, the liquid storage portion 14 is extended toward the object 4 to be coated by the electrostatic force immediately before the application of the voltage, and the pressure is applied to the object to be coated 4 by the electrostatic force. The liquid reservoir 14 before the application of the object 4 is in an unstable state, and the final reservoir 14 reaches the object 4 to be coated. In the suction by the conventional electrostatic force, it takes time to move from the unstable state to the stable state before the liquid storage portion 14 reaches the object 4 to be coated, so that the nozzle 2 for coating and coating are started. The timing control of the relative movement of the object 4 becomes extremely difficult, and the situation where the liquid reservoir 14 reaches the position to be coated 4 is different from the target. As a result, a desired amount or more is applied at the beginning of the coating, resulting in a problem that the line width is thickened, or conversely, the coating amount is insufficient and interrupted.

At the application end, the application target 4 is not immediately affected by the residual charge held by the reservoir portion 14 after the application of the voltage is stopped. After being cut away, the liquid storage portion 14 is finally cut away by the state of being held unsteadily. As described above, in the suction by the conventional electrostatic force, the state of the unsteady state is continued after the application of the voltage is stopped, so that the timing control of the relative movement of the nozzle 2 for coating and the object 4 to be coated is stopped. It is very difficult to produce a situation in which the position where the liquid reservoir 14 is separated from the object to be coated 4 is different from the target. As a result, the amount required for coating at the coating terminal is increased, resulting in a problem that the line width is thickened, or conversely, the coating amount is insufficient to cause interruption.

On the other hand, in the condition 1, the center portion of the liquid storage portion 14 at the tip end of the nozzle can be selectively extended toward the object to be coated 4 at the beginning of the coating as the needle 6 is lowered, and the liquid storage portion can be greatly shortened. When the object 4 is stretched toward the side of the object to be coated 4, the unstable state before reaching the object 4 is also the time. As a result, the timing control for starting the relative movement of the nozzle 2 for coating and the application target 4 is facilitated, and the position at which the liquid reservoir 14 reaches the application target 4 can be played as a target. . Thereby, at the beginning of the coating, there is no case where the line width is thickened or interrupted, and precise coating can be achieved.

In addition, since the time required for coating of the start end can be shortened, the production process time can be shortened.

Further, since the contact angle θ 1 of the nano-Ag ink 16 in the nozzle front end surface 18 is larger than the contact angle θ 2 in the needle side surface 20 and the contact angle θ 3 in the needle front end surface 19, the electrostatic force and the needle 6 can be prevented. The liquid storage portion 14 led out by the nozzle 2 is wetly spread on the nozzle front end surface 18, and the liquid storage portion 14 can be held on the needle front end surface 19. As a result, the liquid reservoir 14 can be realized The expansion and contraction speed is increased, and the liquid storage portion 14 is not interrupted, and stable continuous coating can be realized.

Further, at the coating terminal, as the needle 6 is raised, the central portion of the liquid reservoir 14 at the tip end of the nozzle can be selectively pulled back to the nozzle side, and after the application of the voltage is stopped, it is also retained by the reservoir portion 14. The influence of the residual charge is not cut off by the object 4 to be coated, and the time during which it is unstable can be greatly shortened. As a result, it is easier to stop the timing control of the relative movement of the nozzle 2 for coating and the application object 4, and the position where the liquid storage portion 14 is cut away from the application object 4 is as shown in the object. . Thereby, in the coating terminal, there is no case where the line width is thickened or interrupted, and precise coating can be realized. In addition, since the time required for coating of the terminal can be shortened, the production process time can be shortened.

- Condition 2

In Condition 1, θ 1 = 20°, θ 2 = 15°, and θ 3 = 15°. Under the condition 2, only θ 3 = 10° is changed, and the other conditions are the same as Condition 1. In addition, the evaluation result of the state of the application end of the same index as the condition 1 is shown in FIG.

In the condition 2, θ 1 > θ 2 > θ 3 , since the contact angle of the needle distal end surface 19 is the lowest, the speed of expansion and contraction of the reservoir portion 14 in the needle distal end surface 19 is higher than that of the condition 1 It is possible to achieve high speed, and there is no case where the liquid storage portion 14 is interrupted, and stable continuous coating can be realized.

Further, since the needle front end surface 19 has the lowest contact angle, at the coating end, the liquid storage portion 14 can be lifted by the needle front end surface 19 as compared with the condition 1. Responsiveness when cutting away. As a result, it is easier to stop the timing control of the relative movement of the nozzle 2 for coating and the application object 4, and the position where the liquid storage portion 14 is cut away from the application object 4 is as shown in the object. . Thereby, in the coating terminal, there is no case where the line width is thickened or interrupted, and precise coating can be realized. In addition, since the time required for coating of the terminal can be shortened, the production process time can be shortened.

- Condition 3

Under the condition 2, the portion of the needle 6 which is located inside the nozzle 2 or the portion which protrudes outside the nozzle 2 as shown in FIG. 4 has a contact angle of 15° with respect to the nano-Ag ink 16 of the needle side 20 In the case of the condition 3, as shown in FIG. 7 and FIG. 8, the contact angles of the side faces of the needles 6 projecting toward the side of the object 4 to be coated from the nozzle tip end surface 18 are different. Areas 22, 23. The contact angle θ 4 of the region 22 on the nozzle side is set to 15°, and the contact angle θ 5 of the region 23 on the tip end side of the needle 6 is set to 13°. Other conditions are formed in the same manner as Condition 2. The evaluation result of the state of the application end of the same index as the condition 1 is shown in FIG.

Under the condition 3, since the needle distal end surface 19 has the lowest contact angle, the effect of holding the liquid reservoir 14 on the needle distal end surface 19 can be improved as compared with the condition 1. In addition, the contact surface angle θ 4 of the nozzle-side region 22 is formed as the region 23 on the distal end side of the needle 6 at the side surface portion of the needle 6 that protrudes toward the application target 4 side from the nozzle distal end surface 18 at the time of application. The contact angle θ 5 or more is compared with the case of Condition 2. Can be raised to maintain the nanometer at the front end of the nozzle The effect of Ag ink 16. As a result, the speed of expansion and contraction of the liquid reservoir 14 can be increased, and the liquid storage portion 14 can be prevented from being interrupted, and stable continuous coating can be realized.

Further, since the needle distal end surface 19 has the lowest contact angle, the effect of holding the liquid reservoir portion 14 on the needle distal end surface 19 is improved as compared with the condition 1, and therefore, when the liquid storage portion 14 is cut off at the coating terminal Responsiveness will increase.

In the region 22 on the nozzle side of the needle side surface portion that protrudes toward the application target 4 side from the nozzle distal end surface 18 at the time of application, the contact angle θ 4 of the nozzle-side region 22 is formed as the distal end side. The contact angle θ 5 or more of the region 23 can improve the effect of maintaining the nano Ag ink 16 on the needle front end surface 19 as compared with the case of the condition 2. As a result, it is easier to stop the timing control of the relative movement of the nozzle 2 for coating and the application object 4, and the position where the liquid storage portion 14 is cut away from the application object 4 is as shown in the object. . Thereby, in the coating terminal, there is no case where the line width is thickened or interrupted, and precise coating can be realized. In addition, since the time required for coating of the terminal can be shortened, the production process time can be shortened.

In the condition 3, θ 2 = θ 4 , but by setting θ 2 > θ 4 , the liquid storage portion 14 formed at the tip end of the nozzle can be stabilized by the inside of the nozzle as compared with the case of θ 2 = θ 4 . Supply liquid. As a result, there is no case where the liquid reservoir 14 is interrupted, and stable continuous coating can be achieved.

- Condition 4

Under condition 3, the needle 6 is θ 4 = 15°, θ 5 = 13°, θ 3 = 10°, θ 5 > θ 3, but under the condition 4, θ 5 = θ 3 is set. Other conditions are set to be the same as condition 3.

Here, the contact angle θ 4 of the region 22 on the nozzle side of the needle side surface portion that protrudes toward the application target 4 side from the nozzle tip end surface 18 at the time of liquid application is 15°, and the region on the distal end side of the needle 6 The contact angle θ 5 of 23 is set such that the contact angle is 10° smaller than the contact angle θ 4 . In addition, the evaluation result of the state of the application end of the same index as the condition 1 is shown in FIG.

In the electrostatic coating of the condition 4, since the needle distal end surface 19 has the lowest contact angle, the effect of holding the liquid reservoir 14 on the needle distal end surface 19 can be improved as compared with the condition 1. In addition, the contact angle θ 5 of the region 23 on the distal end side of the needle side surface portion that protrudes toward the application target 4 side at the time of application from the nozzle distal end surface 18 is equal to the contact angle θ 3 of the needle distal end surface. Compared with Condition 3, the effect of maintaining the nano Ag ink 16 at the tip end of the nozzle can be improved. As a result, the speed of expansion and contraction of the liquid reservoir 14 can be increased, and the liquid storage portion 14 can be prevented from being interrupted, and stable continuous coating can be realized.

Further, in the coating terminal, since the needle tip end surface 19 has the lowest contact angle, the effect of holding the liquid reservoir portion 14 on the needle tip end surface 19 can be improved as compared with the condition 1, so that the liquid reservoir portion 14 can be cut away. The responsiveness of the time increases. In addition, the contact angle θ 5 of the region 23 on the distal end side of the needle side surface portion that protrudes toward the application target 4 side at the time of application from the nozzle distal end surface 15 is equal to the contact angle θ 3 of the needle distal end surface. Compared with Condition 3, the effect of maintaining the nano Ag ink 16 at the tip end of the nozzle can be improved. As a result, it is easier to stop the timing control of the relative movement of the nozzle 2 for coating and the application object 4, and the liquid storage portion 14 is coated with the object to be coated. 4 The position to be cut off is as shown in the target. Thereby, in the coating terminal, there is no case where the line width is thickened or interrupted, and precise coating can be realized. In addition, since the time required for coating of the terminal can be shortened, the production process time can be shortened.

- Condition 5-

In the needle 6 of each of the above conditions, a round rod having a constant diameter to the tip end is used. However, under the condition 5, as shown in FIG. 9, the tip end portion of the needle 6 is formed into a tapered shape. The situation is different.

In the distal end portion of the needle 6 of the condition 5, a needle tapered portion 24 having a needle diameter of 50 μm to 25 μm was formed in a range of 20 mm from the tip end of the needle. The evaluation result of the state of the application end of the same index as the condition 1 is shown in FIG.

In this condition 5, since the needle tapered portion 24 is provided, the flow resistance of the nano-Ag ink 16 at the tip end of the nozzle can be suppressed from being increased as compared with the case of the condition 1, and the inner pair of the nozzle can be formed at the time of coating. The liquid is stably supplied to the liquid reservoir 14 at the tip end of the nozzle. As a result, the speed of expansion and contraction of the liquid reservoir 14 can be increased, and the liquid storage portion 14 can be prevented from being interrupted, and stable continuous coating can be realized.

Further, since the needle tapered portion 24 is provided, at the coating end, the flow resistance of the nano-Ag ink 16 at the tip end of the nozzle can be suppressed from increasing as compared with the case of the condition 1, and the needle is tapered at the time of non-coating. The start position P1 of the portion 24 is located on the inner side of the tip end of the nozzle 2, and the needle drive unit 10 is operated by the control unit 13, whereby the liquid storage unit 14 can be realized. Increased responsiveness when cutting away. As a result, it is easier to stop the timing control of the relative movement of the nozzle 2 for coating and the application object 4, and the position where the liquid storage portion 14 is cut away from the application object 4 is as shown in the object. . Thereby, in the coating terminal, there is no case where the line width is thickened or interrupted, and precise coating can be realized. In addition, since the time required for coating of the terminal can be shortened, the production process time can be shortened.

- Condition 6-

Under the condition 5, the contact angle of the nano-Ag ink on the side surface of the needle 6 is θ 2 = 15°, and the contact angle of the nano-Ag ink on the needle front end surface 19 is θ 3 = 15°, but under the condition 6 The contact angle θ 3 of the needle tip end surface 19 is set to 10°. Other conditions are set to be the same as condition 5. In addition, the evaluation result of the state of the application end of the same index as the condition 1 is shown in FIG.

Under the condition 6, since the needle distal end surface 19 has the lowest contact angle, the effect of holding the liquid reservoir 14 on the needle distal end surface 19 can be improved as compared with the case of the condition 5. As a result, the speed of expansion and contraction of the liquid reservoir 14 can be increased, and the liquid storage portion 14 can be prevented from being interrupted, and stable continuous coating can be realized.

Further, since the needle distal end surface 19 has the lowest contact angle, the effect of maintaining the liquid reservoir portion 14 at the needle distal end surface 19 at the coating terminal can be improved as compared with the case of the condition 5, so that the liquid reservoir portion 14 can be achieved. Increased responsiveness when cutting away. As a result, it is easier to stop the timing control of the relative movement of the nozzle 2 for coating and the application object 4, and the liquid storage portion The position at which the object to be coated 4 is cut off is as shown in the object. Thereby, in the coating terminal, there is no case where the line width is thickened or interrupted, and precise coating can be realized. In addition, since the time required for coating of the terminal can be shortened, the production process time can be shortened.

- Condition 7-

Under the conditions 5 and 6, the contact angle of the nano-Ag ink of the needle tapered portion 24 is single, but under the condition 7, as shown in Fig. 10, it is more than the nozzle front end surface 18 only when the liquid is applied. The side surface portion of the needle 6 that protrudes toward the application target 4 side is different in the regions 25 and 26 in which the contact angle of the nano Ag ink is different, and the other conditions are the same as the condition 6.

Here, as shown in Fig. 11, the contact angle of the region 25 on the nozzle side is θ 6 = 15°, and the contact angle of the region 26 on the needle tip side is θ 7 = 13°. The evaluation result of the state of the application end of the same index as the condition 1 is shown in FIG.

Under this condition 7, since the needle distal end surface 19 has the lowest contact angle, the effect of holding the liquid reservoir 14 at the needle tip end can be improved as compared with the case of the condition 5. Further, in the needle taper portion 24 that protrudes toward the object 4 to be coated from the nozzle tip end surface 18 at the time of coating, the contact angle θ 6 of the region 25 on the nozzle side is formed as the contact of the region 26 on the distal end side. The angle θ 7 or more can improve the effect of holding the nano Ag ink 16 on the needle front end surface 19 as compared with the case of the condition 6. As a result, the speed of expansion and contraction of the liquid reservoir 14 can be increased, and the liquid storage portion 14 can be prevented from being interrupted, and stable continuous coating can be realized.

Further, since the needle distal end surface 19 has the lowest contact angle, at the coating terminal, the effect of holding the liquid reservoir portion 14 at the needle distal end surface 19 can be improved as compared with the case of the condition 5, so that the liquid reservoir portion 14 can be achieved. Increased responsiveness when cutting away. In the needle taper portion 24 that protrudes toward the object to be coated 4 from the nozzle tip end surface 15 during coating, the contact angle θ 6 of the region 25 on the nozzle side is formed as the contact of the region 26 on the distal end side. The angle θ 7 or more can improve the effect of holding the nano Ag ink 16 on the needle front end surface 19 as compared with the case of the condition 6. As a result, it is easier to stop the timing control of the relative movement of the nozzle 2 for coating and the application object 4, and the position where the liquid storage portion 14 is cut away from the application object 4 is as shown in the object. . Thereby, in the coating terminal, there is no case where the line width is thickened or interrupted, and precise coating can be realized. In addition, since the time required for coating of the terminal can be shortened, the production process time can be shortened.

- Condition 8-

Under the condition 7, θ 6 = 15° and θ 7 = 13°, but under the condition 8, θ 6 = 15° and θ 7 = 10°. Other conditions are set to be the same as condition 7. In addition, the evaluation result of the state of the application end of the same index as the condition 1 is shown in FIG.

Under the condition 8, since the needle distal end surface 19 has the lowest contact angle, the effect of holding the liquid reservoir 14 at the tip end of the needle can be improved as compared with the condition 5. In addition, the contact angle θ 3 of the region 26 on the distal end side of the needle tapered portion that protrudes toward the application target 4 side from the nozzle distal end surface 18 at the time of application is the contact angle θ 3 with the needle distal end surface 19 Equal, as in condition 7 The effect of maintaining the nano Ag ink 16 at the tip end of the nozzle can be improved. As a result, the speed of expansion and contraction of the liquid reservoir 14 can be increased, and the liquid storage portion 14 can be prevented from being interrupted, and stable continuous coating can be realized.

Further, since the needle distal end surface 19 has the lowest contact angle, at the coating terminal, the effect of holding the liquid reservoir portion 14 at the needle tip end can be improved as compared with the case of the condition 5. In addition, the contact angle θ 7 of the region 26 on the distal end side of the needle-cone portion 24 that protrudes toward the object to be coated 4 from the nozzle distal end surface 18 at the time of coating and the contact angle θ 3 of the needle distal end surface 19 To be equal, the effect of maintaining the nano Ag ink 16 at the tip end of the nozzle can be improved as compared with the case of Condition 7. As a result, it is easier to stop the timing control of the relative movement of the nozzle 2 for coating and the application object 4, and the position where the liquid storage portion 14 is cut away from the application object 4 is as shown in the object. . Thereby, in the coating terminal, there is no case where the line width is thickened or interrupted, and precise coating can be realized. In addition, since the time required for coating of the terminal can be shortened, the production process time can be shortened.

[Industrial availability]

The present invention can form a pattern with high linearity at a high speed and continuously, and thus can be suitably used for producing components such as an organic EL or plasma display, a liquid crystal display, a touch panel, a circuit substrate, a semiconductor, a solar cell, a lithium secondary battery, and the like. Printing manufacturing engineering.

1‧‧‧Liquid

2‧‧‧ nozzle

3‧‧‧Nozzle front end

4‧‧‧Applying object

5‧‧‧Power Supply Department

6‧‧‧ needle

7‧‧‧Liquid supply department

8‧‧‧Electrode plate

9‧‧‧Nozzle Drive Department

10‧‧‧needle drive department

11‧‧‧ stage

12‧‧‧Motor Station Drive Department

13‧‧‧Control Department

Claims (9)

An electrostatic coating method in which a nozzle tip of a nozzle in which a liquid is accommodated is disposed to face an object to be coated, and a potential difference is applied between the liquid and the object to be coated to form a tip of the nozzle. a liquid storage portion that is elongated toward the side of the object to be coated, and at the time of the coating, the tip end of the needle disposed in the nozzle protrudes from the liquid storage portion, and the front end of the liquid storage portion contacts the coating In the object to be coated, the object to be coated is moved relative to the nozzle, and the liquid is continuously applied to the object to be coated in a line shape. The electrostatic coating method according to claim 1, wherein, at the end of the coating, the potential difference is made smaller than the coating time, and the tip end of the needle is moved back to the inside of the nozzle more than the nozzle tip. An electrostatic coating apparatus that applies a potential difference between a liquid in a nozzle and an object to be coated, thereby extracting the liquid from the nozzle and applying the coating material to an electrostatic coating apparatus, which has: a power supply unit that applies a predetermined voltage between the liquid and the object to be coated; a needle that moves up and down among the nozzles; a needle driving unit that drives the needle up and down; and a control unit that controls At the time of coating, the power supply unit is controlled such that the tip end of the needle protrudes from the liquid storage portion so that the liquid storage portion of the liquid elongated toward the object to be coated is formed at the tip end of the nozzle. The needle driving unit is operated to bring the distal end of the liquid storage unit into contact with the object to be coated, and the object to be coated is moved relative to the nozzle. The liquid is continuously applied to the object to be coated in a line shape. The electrostatic coating apparatus according to claim 3, wherein the control unit is configured to raise the needle until the tip end is located inside the nozzle when the liquid is not applied. The electrostatic coating apparatus of claim 3, wherein the needle system has a tapered portion that tapers toward the front end. The electrostatic coating apparatus according to claim 5, wherein the control unit is configured such that a start position of the tapered portion of the needle is located more than a front end of the nozzle when the liquid is not applied The needle drive unit is operated in the manner of the inner side. The electrostatic coating apparatus according to claim 5, wherein a contact angle of the liquid in an end surface of the front end of the nozzle is θ 1 , and a contact angle of the liquid in a side surface of the needle is θ 2 When the contact angle of the liquid in the front end of the needle is θ 3 , θ 1 > θ 2 and θ 1 > θ 3 . The electrostatic coating apparatus according to the seventh aspect of the invention, wherein the portion of the nozzle that protrudes toward the side of the object to be coated is larger than the side of the needle as described above The region where the contact angle of the liquid is θ 2 has a region where the contact angle of the liquid is θ 4 on the side of the tip end of the needle, and is θ 2 ≧ θ 4 . The electrostatic coating apparatus according to any one of claims 3 to 8, wherein in the front end of the nozzle at the time of liquid application, a gap between an inner wall of the nozzle and an outer wall of the needle is larger than the foregoing The diameter of the needle.