JP2000189874A - Method and apparatus for controlling discharge of high viscosity substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make controllable the discharge of a high viscosity substance simply and surely. SOLUTION: In the method for discharging a high viscosity substance, electrodes are arranged in a part or the whole of a container which has a circular or polygonal orifice in the lower part and is filled with the high viscosity substance. With the meniscus of the substance protruded from the orifice, a high voltage pulse is applied between the electrodes to pull out the substance, and part of the substance is separated/cut to stick it on a catalyst. In this process, the amplitude of the pulse is controlled to control the discharge amount of the substance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling a discharge amount of a high-viscosity substance when a high-viscosity substance is discharged in a dot form according to an electric signal.

[0002]

BACKGROUND OF THE INVENTION It is well known as dispensers to press a liquid from behind and push it out of a container to form it on a medium. The conventionally proposed dispenser can discharge a substance having a low viscosity to a high viscosity and form it on a medium, but it takes time for pressure to be transmitted, and a sufficient response cannot be obtained. Also, the lines or dots to be formed are determined by the outer diameter of the nozzle, and thus are not suitable for high-definition patterning. In addition, a method is known in which a liquid droplet is formed by vibrating the vicinity of an outlet in addition to pressure from behind to form a liquid droplet and ejecting the liquid droplet to deposit the liquid droplet on a medium. Cannot be discharged.

On the other hand, a method of forming ink on a medium by discharging ink from an orifice is widely known as ink jet technology. As the ink-jet technology, a method of extruding ink by heating a part of a nozzle to generate air bubbles and a method of extruding ink with the pressure by vibrating a piezoelectric ceramic are known. In the above method, too, the force for pushing out the ink is very weak, and a high-viscosity substance cannot be ejected. Also,
In the inkjet method, the size of the ejected ink droplet is several times as large as the diameter of the orifice.

This point will be described with reference to FIG. 11. As shown in the drawing, the high viscosity substance 2 in the nozzle 1 is extruded from the tip opening by suction or electromechanical pressure by electrostatic force, and the extruded swelling. When the protrusion 3 reaches a certain length,
It is cut from the root (nozzle opening) and then becomes a spherical droplet 4 due to surface tension, which adheres to the medium 5. Therefore, the size of the dot adhering to the medium 5 is about 5 to 6 times larger than the nozzle opening diameter.

In order to form small droplets, it is necessary to reduce the diameter of the orifice. Therefore, when attempting to discharge ink containing particles having a large particle diameter, clogging occurs, and the orifice is caused by the particles. There is a problem that the life of the discharge device is shortened due to wear. Further, even in the case of the electrostatic suction type ink jet, a high viscosity substance cannot be discharged similarly.

In the conventional ink jet system, the amount of dots formed is controlled by discharging ink droplets at a predetermined frequency, charging the ink droplets, causing the charged ink droplets to fly between deflection electrodes, and applying a deflection voltage applied to the deflection electrodes. Therefore, the ink droplets that are not used need to be collected by a collecting device, which makes the device complicated and large. In addition, there is no specific proposal for control of the discharge amount of a device that discharges a high-viscosity substance by an electrostatic suction method.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to make it possible to easily and reliably control the discharge amount of a high-viscosity substance.

[0008]

According to a control method of the present invention, an electrode is arranged on a part or the whole of a container filled with a high-viscosity material having a circular or polygonal orifice at a lower portion, and a high viscosity material is supplied from the orifice. In a state in which the meniscus of the substance is extended and formed, a high-voltage substance is applied to the electrode, a high-viscosity substance is drawn out, and a part of the substance is separated and cut, so that a high-viscosity substance discharge method is applied to adhere to the medium. The discharge amount of the high-viscosity substance is controlled by controlling the amplitude of the high-voltage pulse. Further, the present invention is further characterized in that the discharge amount is controlled by changing the pressure of the high-viscosity substance in the container to the back surface. Further, the control device of the present invention arranges an electrode on a part or the whole of a container filled with a high-viscosity material having a circular or polygonal orifice at a lower portion, and protrudes a meniscus of the high-viscosity material from the orifice. A high-viscosity substance ejecting apparatus that applies a high-voltage pulse to the electrode to draw out a high-viscosity substance in the formed state, and separates and cuts a part of the high-viscosity substance to adhere to a medium; Control means for controlling the amplitude of the high-voltage substance by controlling the amplitude of the high-voltage pulse by the control means.
Further, the present invention is characterized in that it further comprises a pressure control means for controlling the pressure of the high-viscosity substance in the container on the back surface.

[0009]

Embodiments of the present invention will be described below. FIG. 1 is a view showing a schematic configuration of a high-viscosity substance discharging apparatus used in the present invention. In FIG. 1, a syringe 12 is filled with a high-viscosity ink 11 in which particles such as phosphors are dispersed. At the bottom of the syringe, the inner diameter is 50
A Teflon or polypropylene nozzle 13 of μm to 1 mm is provided. The inner diameter is selected according to various conditions such as the viscosity of the substance, the discharge speed, and the particle diameter. An electrode 14 is formed on the nozzle 13, and a pulse voltage of 1 kV to 10 kV can be applied by a power supply 15 controlled by a controller 30. Here, an insulating nozzle is used, but in this case, the electrode does not necessarily need to be formed in the nozzle, and may be provided at a position lower than the ink surface of the syringe 12. Further, the nozzle 13 is not necessarily required to be insulative, but may be made of metal. In this case, it is not necessary to newly provide an electrode, and the nozzle functions as an electrode. Also, the orifice does not necessarily need to be at the tip of the nozzle.
One in which one or a plurality of holes are formed in the bottom surface of the ink or in a container filled with ink can also be used. From the upper part of the syringe, a predetermined pressure can be applied by a pressurizing device (not shown) driven by being controlled by the controller 30 as needed. Also, depending on the nature of the high-viscosity substance to be discharged,
You may heat to 50 degreeC-150 degreeC with a heating apparatus. The medium 16 does not necessarily need to constitute a counter electrode, but may be paper,
Film, glass and the like can be used. Further, the medium does not necessarily need to be flat, and may have a curved surface or irregularities. The distance between the orifice and the medium is 0.1 to 10 mm
It is about.

Next, the ejection of a high-viscosity substance according to the present invention will be described in detail with reference to FIGS. FIG. 2 is a diagram illustrating a state in which a high-viscosity substance is discharged, FIG. 3 is a diagram illustrating an applied pulse voltage, and FIG. 4 is a diagram illustrating a meniscus. High viscosity material filled in syringe 12 (Fig. 1)
Is gradually extruded by its own weight to form a meniscus 17 at the nozzle tip (orifice) (FIG. 2A). Depending on the diameter of the orifice and the nature of the highly viscous substance, the meniscus may take time to form under its own weight or may not form at all. In such a case, as described in FIG. By applying pressure from above, a meniscus is forcibly formed. By heating as needed, the formation of a meniscus can be promoted. In such a state, for example, when a pulse-like voltage as shown in FIG. 3 is applied, the tip of the meniscus 17 is pulled out and deformed into an elongated conical shape ((stretch in FIGS. 2 (b) and 2 (c)). Part 1
8), the meniscus is separated at the tip (FIG. 2 (d)),
It adheres to the medium (dot 19 in FIG. 2 (e)).

The pulse-like voltage is, for example, a rectangular voltage from 0 to 5 kV as shown in FIG.
Although a frequency of 0 Hz to 100 kHz can be used, the present invention is not limited to this. For example, a rectangular pulse of −5 kV to 0 V as shown in FIG. Further, as shown in FIG. 3C, a rectangular voltage pulse of -2.5 kV to 2.5 kV may be used. The offset voltage does not necessarily need to be 0,
As long as the amplitude is equal to or larger than a predetermined value, ejection is possible regardless of the setting.

The shape of the meniscus extended in a conical shape changes depending on the amplitude of the pulse voltage and the rheological characteristics of the highly viscous substance. For example, when the amplitude of the pulse voltage is large,
The shape of the meniscus sharply narrows from the orifice as shown in FIG. Conversely, when the amplitude is reduced, FIG.
As shown in (b), it gradually narrows from the orifice. When the high-viscosity substance ejection apparatus has a thin nozzle as shown in FIG. 1, when the voltage of the voltage pulse is high (the amplitude is large), the meniscus is located at the orifice position at the nozzle inner diameter, that is, the orifice. It is equal to the diameter (Fig. 4
(A)) When the amplitude is small, it becomes equal to the outer diameter of the nozzle (FIG. 4 (b)). If the amplitude of the pulse voltage is too large, the tip of the meniscus becomes thinner at a position distant from the medium, and when the medium is flat, the line of electric force from the nozzle to the medium is widened, so that it extends over a certain range from the center. Attaches on media. As the distance between the tip of the meniscus and the medium increases, the high-viscosity substance particles adhere to a wider area. Therefore, when it is desired to form a high-viscosity substance in the form of fine dots on the medium or in the form of a thin line while changing the position of the orifice and the medium relatively, the amplitude of the voltage pulse should be reduced, or the orifice and the orifice should be reduced. The distance between the medium and the tip of the meniscus may be reduced by reducing the distance of the medium or using any method. Also, before the meniscus is completely thinned, a portion of the high-viscosity material adheres to the medium at the portion where the meniscus is in contact with the medium, so that the line width is controlled by changing the amplitude of the voltage pal. A high viscosity substance can be formed in a line shape. The line width or dot diameter of the formed high viscosity substance is 1
/ 2 or less.

Although the present invention can be applied to a substance having a low viscosity to a substance having a very high viscosity, it is not preferable to use a material having a viscosity of 1000 cps or less because the shape of the material attached to the medium cannot be maintained. Since it is difficult to fill the discharge section with a high viscosity substance, 1000 cps
Application to high viscosity materials of ~ 1,000,000 cps is preferred. The high-viscosity substance can be used as long as it contains particles having a particle diameter of 1/10 or less of the orifice diameter.
0 μm is preferred.

The high-viscosity substances to which the present invention can be applied include, for example, instant adhesives, paints, inks, high-viscosity one-part epoxies, two-part RTV rubbers, silver pastes, cream solders, industrial greases, phosphors In addition to the above, application to formation of a spacer by mixing and attaching glass beads to a resin is also possible.

[0015]

Next, an embodiment of the present invention will be described. <Adjustment of phosphor paste> ・ Phosphor Green K1-P1G1S (Red KX-5
04A, Blue KX-501A) 65wt% ・ Acrylic resin MP-4009 (Soken Chemical) 100wt% ・ Solvent butyl carbitol acetate: butyl carbitol = 1: 1 And

When the viscosity of the obtained paste was measured, it was 70000 cps.

<Ejecting Apparatus for High-Viscosity Substance> FIG. 5 is a view showing the schematic arrangement of an apparatus for ejecting a high-viscosity substance according to an embodiment of the present invention. Here, a type using an insulating ejection section will be described. In FIG. 5, a Teflon discharge part (nozzle 1) having an inner diameter of about 270 μm is provided below the syringe 12.
3). An electrode 14 for applying a high voltage is formed near the discharge port of the discharge unit. Medium 2
0 is an XY stage movable in the horizontal direction (not shown)
It is installed on the top, and the relative position in the horizontal direction with respect to the discharge part of the syringe can be arbitrarily changed. The pressure in the syringe can be arbitrarily adjusted by the nitrogen cylinder 40 and the pressure controller 41. In addition, if necessary, the temperature of the syringe and the paste in the syringe can be controlled by the heating device 60. All these controls are performed by the controller 30 and the controller 3
0 controls the power supply 31, the pressure controller 41, the XY stage, controls the pressure in the syringe, controls the amplitude and timing of the voltage pulse, controls the discharge position and the discharge amount,
A high-viscosity substance filled in a syringe can be attached to a medium. The state of ejection is photographed by the CCD camera 50 and observed on the monitor 51.

Next, a description will be given of the result of examining the state of ejection of a high-viscosity substance using the apparatus shown in FIG. The ejection conditions are as follows. Discharge member material: Teflon Discharge portion inner diameter (orifice diameter): 270 μm Substrate (medium): glass Orifice-substrate distance: 0.75 mm Pressure: 3 atm Temperature: room temperature (25 ° C.) Voltage (amplitude): 2 kV to 15 kV Offset: -2.5 kV to 2.5 kV (amplitude: 5 kV) Frequency: 10 Hz to 1 kHz Waveform: rectangular wave Under the above ejection conditions, the amplitude of the voltage pulse is 2 kV to 1
5 kV (offset 0 V, frequency 1 kHz)
z) When the shape of the meniscus was observed with a CCD camera, the meniscus was pulled out in a conical shape with an amplitude of 3 kV or more, and discharge of the paste was confirmed. Also, when the diameter of the meniscus at a position 0.25 mm from the orifice was measured, as shown in FIG. 6, the larger the amplitude of the voltage pulse, the smaller the meniscus diameter (one-third of the length from the root to the tip of the cone). (The diameter at the position) tended to be smaller. At an amplitude of 10 kV or more, it was observed that the length of the meniscus was shorter than the distance between the orifice and the substrate, and the paste was separated and discharged at a position away from the substrate.

Next, the amplitude was fixed at 5 kV and the frequency was fixed at 1 kHz, and the offset was changed between -2.5 kV and 2.5 kV. Observation with a CCD camera similarly revealed differences in the shape of the meniscus and the ejection state. Was not seen.

Further, while the amplitude was fixed at 5 kV and the offset was 0 V, the ejection state was observed in the same manner while changing the frequency from 10 Hz to 1 kHz. In the case of a high frequency of 1 kHz, a meniscus having a shape as shown in FIG. 7A was immediately drawn out from the start of voltage application, and discharge of the paste was confirmed. However, as the frequency became smaller, the reaction became slower. The shape of the meniscus also became a bulging shape as shown in FIG. 7 (b), and the ejection stability was poor.

Next, under the condition of a frequency of 1 kHz and an offset of 0 V, an amplitude of 2 kV and 5 kV were alternately applied, and the state of ejection was observed. As shown in FIG. 8, when a voltage of 2 kV and a voltage of 5 kV were alternately applied for 2 seconds, when 5 kV was applied, ejection of the paste was observed, and when 2 kV was applied, no ejection was observed. The shape of the meniscus maintained the same shape as when 5 kV was applied.

Next, control of the discharge amount of the high-viscosity substance will be described. FIG. 9 is a diagram showing an example of a voltage application and a discharge state. In the example shown in FIG. 9, ink ejection is observed when the amplitude of the pulse voltage is 3 kV or more. As shown, 3-5
When the voltage was applied while changing the amplitude in the range of kV, the ejection amount could be controlled in accordance with the amplitude.

FIG. 10 is a diagram showing another example of voltage application. In this example, by changing the amplitude in the range of −2.5 kV− + 2.5 kV, the ink ejection amount could be controlled. Also in this example, when the amplitude was 3 kV or less, no ink ejection was observed.

Next, while a pulse-like voltage having a constant amplitude is applied, the controller 30 shown in FIG. 1 and FIG. There was a change. When it is not necessary to adjust the ink discharge amount for each pulse, the adjustment of the ink discharge amount by the back pressure is effective. The pulse voltage to be applied is not limited to a rectangular wave, and a voltage having a triangular waveform may be applied.

The high-viscosity substance discharge control device of the present invention has a function of controlling an applied voltage by a controller to adjust the amount of ink discharged, and a function of controlling the amount of ink consumed.
It has a function to adjust the amount of ink to be ejected to a desired amount by adjusting the pressure from the back, and when the amount of ink consumption is large, increase the back pressure to increase the amount of ink supply Thus, it has a function corresponding to this.

The above-described voltage application condition is an example of the present invention, and the present invention is not limited to this. The condition under which a high-viscosity substance is discharged is not limited to the high-viscosity substance. However, it is not limited to this, because it changes depending on conditions such as viscosity, surface tension, and orifice diameter.

[0027]

As described above, according to the present invention, the discharge amount of a high-viscosity substance can be easily and accurately controlled only by changing the amplitude and the back pressure of the pulse voltage. Application of a high-viscosity substance having a desired pattern can be extremely easily performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a high-viscosity substance discharging apparatus used in the present invention.

FIG. 2 is a diagram illustrating a state in which a high-viscosity substance is discharged.

FIG. 3 is a diagram illustrating a pulse voltage to be applied.

FIG. 4 is a diagram illustrating a meniscus.

FIG. 5 is a diagram illustrating a high-viscosity substance ejection device of the present invention.

FIG. 6 is a diagram showing a relationship between the amplitude of a pulse voltage to be applied and a meniscus diameter.

FIG. 7 is a view showing a meniscus.

FIG. 8 is a diagram illustrating an example of a pulse voltage to be applied.

FIG. 9 is a diagram illustrating an example of a voltage application and a discharge state.

FIG. 10 is a diagram showing another example of voltage application.

FIG. 11 is a diagram illustrating a conventional phosphor screen forming method.

[Explanation of symbols]

11 high viscosity substance, 12 container, 13 nozzle, 14
Electrode, 15 power supply, 16 medium, 17 meniscus, 1
8. Extension unit, 19 dot, 20 medium, 30 controller, 31 power supply, 40 cylinder, 41 pressure controller, 50 CCD camera, 51 monitor, 60 heating device.

Claims (4)

[Claims] 1. A state in which an electrode is arranged on a part or the whole of a container filled with a high-viscosity material having a circular or polygonal orifice at a lower portion, and a meniscus of the high-viscosity material is projected from the orifice. A high-viscosity substance is ejected by applying a high-voltage pulse to the electrode to extract a high-viscosity substance, and a part of the substance is separated and cut, whereby a high-viscosity substance is ejected onto a medium. Controlling the discharge amount of the high-viscosity substance by controlling the discharge amount of the high-viscosity substance. 2. The control method according to claim 1, further comprising controlling a discharge amount by changing a pressure applied to a back surface of the high-viscosity substance in the container. 3. A state in which an electrode is arranged on a part or the whole of a container filled with a high-viscosity material having a circular or polygonal orifice at a lower portion, and a meniscus of the high-viscosity material is projected from the orifice. A high-viscosity substance ejection device that applies a high-voltage pulse to the electrode to draw out a high-viscosity substance, and separates and cuts a part of the high-viscosity substance to adhere on a medium, and controls an amplitude of the high-voltage pulse. A high-viscosity substance ejection amount control apparatus, comprising: a control unit for controlling the amplitude of a high-voltage pulse to control an ejection amount of a high-viscosity substance. 4. The control device according to claim 3, further comprising pressure control means for controlling the pressure of the high-viscosity substance in the container on the back surface.