JP2019063698A - Liquid discharge nozzle - Google Patents

Abstract

To provide a liquid discharge nozzle which easily changes a line width without changing a coating condition at the time of coating.SOLUTION: A liquid discharge nozzle continuously discharges liquid from a discharge port to an object to be coated. A tip end portion of the liquid discharge nozzle has a body portion, and a projecting portion which is connected to a tip end surface of the body portion and projects out from a tip end surface of the body portion in a discharging direction of the liquid. At a tip end of the projecting portion, the tip end surface generally vertical to the discharging direction of the liquid is formed. If it is assumed that a virtual surface is obtained by rotating the tip end surface of the projecting portion around a line passing through the center of the discharge port and parallel to the discharging direction as a rotation axis, when the tip end surface of the projecting portion and the virtual surface are projected from any direction vertical to the discharging direction, the minimum value of projected dimensions of the tip end surface of the projecting portion is smaller than the minimum value of projected dimensions of the virtual surface.SELECTED DRAWING: Figure 1A

Description

  The present invention relates to a liquid discharge nozzle. In particular, the present invention relates to a liquid discharge nozzle that discharges liquid continuously.

  In order to form a predetermined pattern or the like on a coating object such as a substrate without using a mask, various liquid coating apparatuses are used which eject a liquid from a nozzle or a slit and apply the liquid to the coating object and draw a predetermined pattern directly. . As such a liquid application apparatus, a dispenser, an inkjet apparatus, etc. are illustrated, for example.

  When manufacturing an organic EL, a display device such as liquid crystal, a semiconductor device, a solar cell, an electronic component such as a coil or a capacitor, or an electronic device such as a touch panel, various kinds of wiring, electrodes, solder regions, adhesion regions, resist regions, etc. Pattern is formed on the substrate. The liquid coating apparatus used to form these patterns is required to form the patterns in a short time and with high accuracy.

  Since the inkjet apparatus can precisely control the discharge of the liquid, it is widely used as a liquid application apparatus for forming the above pattern. In the case of applying a liquid by inkjet, as a mechanism for discharging the liquid, a piezoelectric type, a heating type, an electrostatic suction type and the like are exemplified.

  Among these mechanisms, the electrostatic suction type ink jet device is known to have high landing accuracy. As such an electrostatic suction type inkjet device, for example, the electrostatic suction type inkjet devices described in Patent Documents 1 to 4 are exemplified.

  In the electrostatic suction type inkjet apparatus, first, a voltage is applied between the nozzle and the application target to charge the ink supplied to the nozzle. A meniscus of ink is formed at the discharge port of the nozzle, and the meniscus is pulled by electrostatic attraction, and a part of the ink is separated from the meniscus to form a droplet. The droplets to be formed are applied by flying and landing toward the application target by electrostatic attraction.

  The droplet spreads in the form of dots after landing on the application target, and the size (dot diameter) of the coated area corresponds to the size of the droplet. The application area formed by the impact of the droplets is the smallest unit constituting the pattern formed by the application of the ink. Therefore, the size of the dot diameter greatly affects the formation accuracy of the pattern.

  On the other hand, the shape and dimensions of the pattern vary depending on the application and the like. Therefore, it is preferable to change the dot diameter at the time of application according to the shape and dimensions of the pattern.

  Since the droplets are formed separately from the meniscus as described above, the factors that affect the dot diameter include the size of the electrostatic attraction, that is, the size of the applied voltage, the diameter of the nozzle tip, and the nozzle The distance between the tip end and the application target is exemplified. However, since the diameter of the nozzle tip can not be changed at the time of coating, when changing the dot diameter at the time of coating, it is conceivable to change the applied voltage or to change the distance between the nozzle tip and the coating target.

  However, when the above conditions are changed, the conditions after the change are deviated from the optimum conditions for performing the application, and the problems such as the ink discharge amount becoming unstable and the landing position of the droplets being shifted occur. There is. Therefore, there is a problem that the degree of freedom in controlling the size of the dot diameter is low at the time of coating.

  On the other hand, Patent Document 5 discloses an electrostatic suction type ink jet device having a method different from the electrostatic suction type ink jet device for causing ink to fly as droplets. In the device, the ink is continuously discharged from the discharge port of the nozzle so that a liquid column of the ink is formed between the discharge port of the nozzle and the application target. In this case, the applied ink is drawn as a line segment.

Patent No. 3661350 Patent No. 3340378 Patent No. 3367840 Patent No. 3916184 gazette JP 2001-88306 A

  Patent Document 5 describes changing the applied voltage and changing the pressure on the ink when changing the line width at the time of application. However, when changing the applied voltage, as described above, there is a problem that the degree of freedom in controlling the line width is low.

  In addition, in the case of changing the pressure on the ink, it is necessary to add a member such as a pump for applying pressure to the ink to the electrostatic suction type ink jet apparatus, which causes problems such as cost.

  Furthermore, in Patent Document 5, the electric conductivity of the ink used for the electrostatic suction type ink jet apparatus is limited to a predetermined range, and there is a problem that the line width is not constant when using the ink outside the range.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a liquid discharge nozzle in which the line width can be easily changed without changing the application conditions at the time of application.

Aspects of the invention are:
[1] A liquid discharge nozzle for continuously discharging a liquid from a discharge port to a coating target,
A tip end portion of the liquid discharge nozzle has a body portion, and a projecting portion connected to a tip end surface of the body portion and projecting from the tip end surface of the body portion in a liquid discharge direction;
A tip surface substantially perpendicular to the liquid discharge direction is formed at the tip of the projection,
Assuming that a virtual surface obtained by rotating the tip end face of the projecting portion with a line passing through the center of the discharge port and being parallel to the discharge direction as a rotation axis,
When projecting the tip end surface and the virtual surface of the protrusion from any direction perpendicular to the ejection direction, the minimum value of the projection dimension of the tip surface of the protrusion is smaller than the minimum value of the projection dimension of the virtual surface It is a liquid discharge nozzle to be used.

  [2] The liquid discharge nozzle according to [1], wherein the liquid is discharged by electrostatic attraction.

  [3] In the projection shape of the trunk obtained by projecting the trunk from any direction perpendicular to the discharge direction, the length of the trunk in the direction perpendicular to the discharge direction is the discharge direction from the tip end face of the trunk And the liquid discharge nozzle according to [1] or [2], which gradually increases in the opposite direction.

  [4] Assuming that the minimum value of the projection dimension of the tip end face of the protrusion is cmin and the minimum value of the projection dimension of the virtual surface is dmin, cmin is 0.2 dmin or more and 0.8 dmin or less. It is a liquid discharge nozzle in any one of [1] to [3].

  [5] h is 0.1 dmin or more, where h is the distance between the tip end face of the body and the tip end face of the protrusion in the discharge direction, and dmin is the minimum projected size of the virtual face. The liquid discharge nozzle according to any one of [1] to [4].

FIG. 1A is a perspective view of a liquid discharge nozzle according to the present embodiment. FIG. 1B is a projection view of the liquid discharge nozzle projected from the B direction in FIG. 1A. FIG. 1C is a projection view of the liquid discharge nozzle projected from the C direction in FIG. 1A. FIG. 1D is a projection view of the liquid discharge nozzle projected from direction D in FIG. 1A. FIG. 2 is a plan view of the liquid discharge nozzle as viewed from the Z-axis direction in FIG. 1A. FIG. 3 is a projection view of the liquid discharge nozzle projected from the B direction in FIG. 1A. FIG. 4A is a schematic view showing a liquid discharge nozzle and a liquid column viewed from the Y-axis direction. FIG. 4B is a schematic view showing the liquid discharge nozzle and the liquid column viewed from the X-axis direction. FIG. 5 is a projection view of a liquid discharge nozzle having an outer peripheral shape different from the liquid discharge nozzle shown in FIG. 1A projected from the Y-axis direction. FIG. 6A is a cross-sectional schematic view of the relevant part of the liquid application device according to the present embodiment. FIG. 6B is a schematic cross-sectional view for explaining the formation of a liquid column between the discharge port of the nozzle and the application target shown in FIG. 6A. FIG. 7 is a view for explaining that line segments having different line widths can be formed using the liquid discharge nozzle according to the present embodiment. FIG. 8 is a view for explaining that, by using the liquid discharge nozzle according to the present embodiment, line segments having different line widths can be connected to form an area of the same shape.

Hereinafter, the present invention will be described in detail in the following order based on the embodiments shown in the drawings.
1. Liquid discharge nozzle 1.1. Configuration of liquid discharge nozzle 1.2. Shape of liquid column 1.3. Other shapes of liquid discharge nozzles Liquid application device 2.1. Configuration of Liquid Application Device 2.2. Operation of liquid application device Liquid application method 3.1. Liquid 3.2. Coating step 4 Effects of this embodiment Modified example

(1. Liquid discharge nozzle)
The liquid discharge nozzle according to the present embodiment is a nozzle that is used to discharge a liquid to a coating target, and that discharges the liquid continuously. When the liquid is applied to the application target using the liquid discharge nozzle according to the present embodiment, the liquid is applied to the application target so that the discharge surface of the liquid discharge nozzle and the application target are connected by the liquid column. The liquid discharge nozzle according to the present embodiment constitutes a liquid discharge portion in a liquid application device described later.

  In the present embodiment, the liquid column is formed by the action of electrostatic attraction on the charged liquid. That is, the liquid discharge nozzle according to the present embodiment is suitably used for an electrostatic suction type liquid application device that discharges a liquid using an electrostatic suction force and applies the liquid to an application target.

(1.1. Configuration of liquid discharge nozzle)
FIG. 1A shows the tip of the liquid discharge nozzle 1. The liquid discharge nozzle 1 is hollow. The hollow portion is a flow path of the liquid to be discharged, and the liquid is discharged from the discharge port 30 at the tip. In the present embodiment, the cross section of the hollow portion is circular. In FIG. 1A, the discharge direction of the liquid is the direction indicated by the arrow O (the negative direction of the Z axis).

  The tip end portion of the liquid discharge nozzle 1 has a body portion 20 and a projecting portion 10 connected to the tip end surface of the body portion 20 and projecting from the body portion 20 in the liquid discharge direction O. In the present embodiment, the trunk portion 20 and the projection portion are such that the inner wall surface of the trunk portion 20 and the inner wall surface of the projection portion 10 are continuous, and the outer wall surface of the trunk portion 20 and the outer wall surface of the projection portion 10 are continuous. 10 are integrally formed. In other words, the end portion shown in FIG. 1A is an end portion of the cylinder, a plane which is parallel to the discharge direction O and passes through the center of the hollow portion (the discharge direction O in FIG. 1A) and a plane perpendicular to the discharge direction O It has a cutout shape.

  In the present embodiment, the tip end surface of the body portion 20 is a surface perpendicular to the discharge direction O, and the protrusion 10 is a portion that protrudes from the tip end surface. The tip end surface of the body portion 20 is configured of a surface connected to the protrusion 10 and a surface exposed to the outside. A distal end surface 10 a is formed in the protrusion 10, and the distal end surface 10 a is a surface substantially perpendicular to the discharge direction O. The end surface 10a and the end surface 20a have a step in the Z-axis direction.

  Further, as shown in FIG. 1A, the discharge surface of the liquid discharge nozzle 1 is composed of the tip end surface 10 a and the step surface 10 b of the protrusion 10 and the tip end surface of the body 20.

  In the present embodiment, a virtual surface with respect to the tip end surface 10 a of the protrusion 10 is assumed at the tip end of the liquid discharge nozzle 1. Specifically, the virtual surface is a surface obtained by rotating the protrusion 10 with the axis parallel to the discharge direction O passing through the center of the discharge port 30 as the rotation axis.

  In the liquid discharge nozzle 1 shown in FIG. 1A, an axis passing through the center of the discharge port 30 and parallel to the discharge direction O coincides with a line indicating the discharge direction O. Therefore, the virtual surface obtained by rotating the tip end surface 10a of the protrusion 10 is the end surface 40 of the cylinder without a notch in FIG. 1A.

  From the virtual surface 40 thus obtained and the tip end surface 10a of the protrusion 10 from an arbitrary direction perpendicular to the discharge direction O of the liquid (a direction parallel to the XY plane including the X axis and the Y axis in FIG. 1A) When projected, the minimum value cmin of the projection dimension c of the tip end face 10a of the protrusion 10 is smaller than the minimum value dmin of the projection dimension d of the virtual surface 40.

  For example, when each projected dimension is calculated at the tip portion of the liquid discharge nozzle 1 shown in FIG. 1A, the projected dimension d of the virtual surface 40 is determined as shown in FIG. Although the same value is obtained when viewed from the direction, the projection dimension c of the tip surface 10 a of the protrusion 10 changes depending on the direction of projection, and has a minimum value and a maximum value.

  In FIG. 1A, when the tip of the liquid discharge nozzle 1 is projected from the B direction (Y-axis direction), the projected shape of the tip of the liquid discharge nozzle 1 is as shown in FIG. 1B. The said shape corresponds with the side surface shape of the front-end | tip part of the liquid discharge nozzle 1 seen from the B direction. As apparent from FIG. 1B, the projection dimension c of the tip end face 10a of the protrusion 10 is smaller than the projection dimension d of the virtual surface 40, and c is half the value of d.

  On the other hand, in FIG. 1A, when the tip of the liquid discharge nozzle 1 is projected from the C direction (X-axis direction), the projected shape of the tip of the liquid discharge nozzle 1 is as shown in FIG. 1C. The said shape corresponds with the side surface shape of the front-end | tip part of the liquid discharge nozzle 1 seen from the C direction. As apparent from FIG. 1C, the projection dimension c of the tip end face 10a of the protrusion 10 is the same as the projection dimension d of the virtual surface 40.

  Further, in FIG. 1A, when the tip of the liquid discharge nozzle 1 is projected from the D direction (direction inclined 45 ° to both the X axis and the Y axis), the projection shape of the tip of the liquid discharge nozzle 1 is shown in FIG. It has the shape shown in. The said shape corresponds with the side surface shape of the front-end | tip part of the liquid discharge nozzle 1 seen from the D direction. As apparent from FIG. 1D, the projection dimension c of the tip end face 10a of the protrusion 10 is smaller than the projection dimension d of the virtual surface 40. However, it is larger than the projection dimension c of the tip end face 10 a of the protrusion 10 viewed from the B direction shown in FIG. 1B.

  Therefore, when the shape of the tip portion of the liquid discharge nozzle 1 is the shape shown in FIG. 1A, the projection dimension d of the virtual surface 40 has the same value regardless of the projection direction, so d = dmin = dmax. On the other hand, the projection size c of the tip end face 10a of the protrusion 10 changes depending on the projection direction, and the projection size c projected from the B direction becomes the minimum value cmin. Further, the projected dimension c projected from the C direction is the maximum value cmax, and cmax is equal to d.

  A line formed by applying the liquid without changing the discharge condition of the liquid while changing the discharge condition of the liquid while the minimum value of the projection dimension satisfies the above relationship at the tip of the liquid discharge nozzle 1 The line width of the minute can be easily changed.

  FIG. 2 is a plan view of the liquid discharge nozzle 1 shown in FIG. 1A as viewed from the discharge direction O. As shown in FIG. In FIG. 2, the minimum value cmin of the projection dimension of the tip end face 10 a of the protrusion 10 corresponds to the length of the protrusion 10 in the X-axis direction. In addition, the minimum value dmin of the projection dimension of the virtual surface 40 matches the outer diameter of the virtual surface 40, and is the same value in any projection direction.

  In the present embodiment, cmin is preferably 0.3 dmin or more and 0.7 dmin or less. Further, it is more preferable that cmin be 0.4 d or more. On the other hand, the cmin is more preferably 0.6 d or less. If cmin is too small, the thickness of the protrusion 10 becomes very thin, and the strength of the protrusion 10 tends to be insufficient. If c is too large, the difference in the formed line width tends to be small, and the range in which the line width can be changed tends to be narrow. In addition, it is preferable to set cmin such that the path of the liquid formed in the liquid discharge nozzle is exposed to the outside at the protrusion 10.

  FIG. 3 is a side view of the tip of the liquid discharge nozzle as viewed from the B direction in FIG. 1A. Thus, FIG. 3 is equivalent to FIG. 1B. In FIG. 3, assuming that the distance between the front end surface 10a of the protrusion 10 and the front end surface 20a of the trunk 20 in the discharge direction O is h, in this embodiment, h is preferably 0.1 dmin or more. If h is too small, the difference in the formed line width tends to be small, and the range in which the line width can be changed tends to be narrow.

  The upper limit of h is not particularly limited in terms of the effect that the line width can be changed. However, if h is too large, the amount of the liquid exposed to the outside increases until the liquid forms a meniscus on the tip surface 10 a of the protrusion 10, so drying of the liquid, overflow of the liquid from the nozzle, and the like easily occur. It is not preferable. From such a viewpoint, the upper limit of h is about 2.0 dmin.

(1.2. Shape of liquid column)
FIGS. 4A and 4B show that the liquid discharge nozzle 1 shown in FIG. 1A discharges the liquid onto the application target 70. FIG. When the liquid is discharged from the liquid discharge nozzle 1, a meniscus of the liquid is formed at the discharge port of the liquid discharge nozzle 1 by the electrostatic suction force. Then, the meniscus is further pulled by the electrostatic attraction force, extends in the discharge direction, and finally reaches the application target 70 to form the liquid column LC of the liquid.

  In this embodiment, the tip of the liquid discharge nozzle 1 has the above-described shape, thereby forcibly changing the shape of the liquid column in a specific direction, and the shape of the liquid column viewed from the direction perpendicular to the discharge direction O Is anisotropic. The anisotropy of the shape of the liquid column will be described in detail with reference to FIGS. 4A and 4B.

  FIG. 4A shows the liquid discharge nozzle 1 and the liquid column LC viewed from the Y-axis direction shown in FIG. 1A. As shown in FIG. 4A, since the length in the X-axis direction of the tip surface 10a of the protrusion 10 is the minimum value cmin of the projection dimension of the tip surface 10a, the length in the X-axis direction of the tip surface of the trunk portion 20 Since the discharge surface is smaller than (which corresponds to the projection dimension of the virtual surface 40 in FIG. 4A), the discharge surface has a step in the Z-axis direction.

  On such a discharge surface, the liquid reaching the vicinity of the end surface 20a of the body 20 wets and spreads on the end surface 20a to form a meniscus, but the liquid present on the inner wall surface side of the protrusion 10 It tries to move to the tip surface 10a of the protrusion 10 without forming it. Therefore, the meniscus to be formed on the tip end surface 20 a is pulled by the liquid to move to the tip end surface 10 a of the protrusion 10 and moves to the inner wall surface side of the protrusion 10.

  As a result, the length in the X-axis direction (the width of the liquid) of the liquid reaching the tip surface 10 a of the protrusion 10 is the length of the liquid in the X-axis direction when reaching the vicinity of the tip surface 20 a of the barrel 20 It becomes smaller than (the width of the liquid). Then, as shown in FIG. 4A, the liquid reaching the end surface 10a of the protrusion 10 wets and spreads on the end surface 10a to form a meniscus, and further corresponds to the size of the meniscus formed on the end surface 10a. Liquid column LC is formed.

  On the other hand, FIG. 4B shows the liquid discharge nozzle 1 and the liquid column LC viewed from the X-axis direction shown in FIG. 1A. As shown in FIG. 4B, the length in the Y-axis direction of the tip surface 10a of the protrusion 10 is the maximum value cmax of the projection dimension of the tip surface 10a, and the length in the Y-axis direction of the tip surface of the body 20 In FIG. 4B, which is the same as the projection dimension of the virtual surface 40, the liquid hardly forms a meniscus even when it reaches the end surface 20a of the barrel 20, and moves as it is to the end surface 10a of the protrusion 10. Then, the liquid that has reached the front end surface 10 a of the protrusion 10 wets and spreads on the front end surface 10 a to form a meniscus.

  In FIG. 4B, the length in the Y-axis direction (the width of the liquid) of the liquid reaching the tip surface 10a of the protrusion 10 is the length of the liquid in the Y-axis direction when reaching the vicinity of the tip surface 20a of the barrel 20. Since it is about the same as the length (the width of the liquid), a liquid column LC corresponding to the size of the meniscus about the same as the diameter of the tip end face of the body portion 20 is formed.

  Therefore, as shown in FIG. 4A, when viewed from the Y-axis direction, the width of the liquid column LC corresponds to the minimum value cmin of the projection dimension of the tip surface 10 a of the protrusion 10. On the other hand, as shown in FIG. 4B, when viewed in the X-axis direction, the width of the liquid column LC corresponds to the diameter of the tip surface of the trunk portion 20 (projected dimension of the virtual surface 40). That is, the shape of the liquid column LC viewed from the Y-axis direction is different from the shape of the liquid column LC viewed from the X-axis direction, and the shape of the liquid column viewed from the direction perpendicular to the ejection direction O is anisotropic have.

  Since the shape of the liquid column seen from the direction perpendicular to the discharge direction O is anisotropic, in FIG. 4A, when the liquid discharge nozzle 1 is swept in the Y-axis positive / negative direction, the line whose line width is LW1 A minute is formed.

  On the other hand, in FIG. 4B, when the liquid discharge nozzle 1 is swept in the positive and negative directions of the X-axis, line segments having a line width of LW2 are formed.

  Making the line width LW1 of the line segment formed along the Y-axis direction smaller than the line width LW2 of the line segment formed along the X-axis direction by using the liquid discharge nozzle 1 shown in FIG. 1A Can. Therefore, only by changing the sweep direction of the liquid discharge nozzle 1, the line width of the line segment formed by applying the liquid to the application target can be changed without changing the application conditions at the time of application.

  LW1 is a substantially minimum value of the line width of the line segment which can be drawn by the liquid discharge nozzle 1 shown in FIG. 1A, and LW2 is a substantially maximum line width of the line segment which can be drawn by the liquid discharge nozzle 1 shown in FIG. It is a value. Therefore, for example, when it is desired to form a line segment having a line width between LW1 and LW2, the liquid discharge nozzle may be swept in a direction having a predetermined angle with respect to the X axis or the Y axis.

(1.3. Other shapes of liquid discharge nozzles)
In the above, the case where the shape of the tip of the liquid discharge nozzle is a shape in which a part is cut out from the end of the cylinder has been described, but in the present embodiment, the shape of the tip of the liquid discharge nozzle is the above It is not limited to the shape of. In the present embodiment, it is preferable that at the tip of the liquid discharge nozzle, at least the outer periphery of the body gradually widens in the direction opposite to the discharge direction.

  FIG. 5 shows a body 20 obtained by projecting the body 20 of a liquid discharge nozzle having an outer peripheral shape different from the liquid discharge nozzle shown in FIG. 1A from the direction (Y-axis direction) perpendicular to the discharge direction O of the liquid. And the projected shape of the protrusion 10 is shown. In addition, in FIG. 5, the protrusion part 10 is arrange | positioned on the trunk | drum 20 so that the projection dimension of the front end surface 10a may become minimum value cmin. The outer peripheral shape of the projecting portion 10 is formed so as to be continuous with the outer peripheral shape of the trunk portion 20 on the tip end surface of the trunk portion 20, and the projection dimension of the projection 10 is large in the direction opposite to the discharge direction O. It is formed to be

As apparent from FIG. 5, the outer peripheral shapes of the body portion 20 and the projecting portion 10 are only the taper shapes of the outer peripheral shape of the liquid discharge nozzle 1 shown in FIG. . As described above, the factors (cmin, dmin, h, etc.) giving anisotropy to the shape of the liquid column hardly affect the outer peripheral shape of the tip portion of the liquid discharge nozzle. Therefore, the items described above can be applied to the liquid discharge nozzle 1 shown in FIG. 5, and the same effect can be obtained.
Further, in the present embodiment, the outer peripheral shape of the distal end surface 10 a is not particularly limited as long as the projected dimension of the distal end surface 10 a of the protrusion 10 and the projected dimension of the virtual surface 40 satisfy the above-described relationship. In the liquid discharge nozzle 1 shown in FIGS. 1A and 5, the outer peripheral shape of the tip surface 10a is a semicircular shape, but for example, even if the outer periphery of the tip surface 10a is a polygonal shape composed of a plurality of sides Good.

(2. Liquid application device)
The liquid application apparatus according to the present embodiment is a liquid application apparatus that uses electrostatic attraction, and during liquid application, liquid is continuously supplied from a nozzle that discharges the liquid, and between the nozzle and an application target A liquid column is formed. Therefore, even in a liquid coating apparatus using electrostatic attraction, part of the liquid is separated from the meniscus formed at the discharge port of the nozzle to form a droplet, and the droplet is ejected to the application target. It is different from the coating device.

(2.1. Configuration of liquid application device)
In the present embodiment, as shown in FIG. 6A, the liquid application device 50 includes a plurality of nozzles 1 as a liquid discharge unit, a voltage application unit 52, and a support 53 on which an application target is placed. There is. The nozzle 1 is disposed such that the discharge port 30 faces the support 53 and the application target 70. The nozzle 1 is the liquid discharge nozzle 1 according to the above-described embodiment.

  6A, the liquid application device 50 has a plurality of nozzles, but the liquid application device 50 may have only one nozzle.

  The voltage application means 52 is connected to the nozzle 1 and the support 53, and can apply a voltage between the nozzle 1 and the support 53. Thus, the liquid 60 supplied from the liquid supply unit (not shown) into the nozzle can be charged. The applied voltage is a high voltage of about several hundred volts to several thousand volts. In the present embodiment, the respective nozzles are connected in parallel, and the same voltage can be applied to the respective nozzles.

  Further, the support 53 is held on a table 54 movable in each direction of the X-axis, Y-axis and Z-axis in response to an electric signal from a control unit (not shown), corresponding to the movement of the table 54 The support 53 is also movable. The nozzle may move or the table may move as long as the nozzle and the application target can move relative to each other.

(2.2. Operation of liquid application device)
In the liquid application device 50, when a control unit (not shown) sends an electric signal to the voltage application means 52, the voltage application means 52 applies a voltage corresponding to the electric signal to the nozzle 1. By performing such control, as shown in FIG. 6B, the charged liquid 60 moves to the discharge port 30 of the nozzle 1 through the flow path in the nozzle 1, and the liquid 60 is formed on the tip surface of the nozzle 1. The meniscus of the wetting and spreading liquid 60 is formed. The formed meniscus is further drawn by electrostatic attraction and extends to the application object 70 (the support or the application body formed on the support) to connect the discharge port 30 of the nozzle 1 and the application object 70. A liquid column LC is formed. The nozzle 1 can continuously supply the liquid 60 to the application target 70 via the liquid column LC.

  Simultaneously with the discharge of the liquid 60, the control unit also sends an electrical signal to the nozzle moving unit (not shown) or the table moving unit (not shown) to maintain the distance between the nozzle 1 and the table 54 constant. The table 54 can be moved on the XY plane. Therefore, since the nozzle and the table move relative to each other on the XY plane in a state where the liquid 60 is discharged to the application object 70, the liquid is applied to the application object 70 placed on the table along the moving direction And a predetermined pattern is drawn.

  At this time, since the tip of the nozzle 1 has the above-described shape, the line width of the pattern to be drawn can be freely set within a predetermined range by controlling the sweeping direction of the nozzle or the moving direction of the table. It can be set.

  When the control unit stops transmission of the electric signal, the voltage application unit 52 sets the voltage applied to the nozzle 1 to zero. As a result, since the electrostatic attraction does not act on the liquid 60, the liquid 60 constituting the liquid column LC is separated from the application target 70 by the effect of surface tension and pulled back to the meniscus formed on the discharge surface of the nozzle 1. Thus, the application to the application target 70 is completed. By this series of operations, a predetermined pattern can be formed on the application target 70.

  In the liquid application apparatus according to the present embodiment, since the liquid is charged, and the discharge start and discharge stop of the charged liquid are controlled by the electrostatic suction force, the discharge start and discharge stop of the liquid are performed in response to the voltage application. Respond very quickly and accurately. Therefore, when the voltage is applied, the liquid is immediately discharged to the application target, and when the voltage application is stopped, the discharge of the liquid is immediately stopped without liquid dripping, so that the predetermined pattern can be repeatedly drawn with high reproducibility.

  The distance between the discharge port of the nozzle and the application target may be appropriately set in consideration of the shape of the tip of the nozzle 1, the component and viscosity of the liquid, the applied voltage, and the like.

  In the present embodiment, as described above, by making the shape of the tip of the nozzle 1 a specific shape, the shape of the liquid column formed by drawing the liquid from the meniscus is forcibly changed. Therefore, it is preferable to set the distance to such an extent that the changed shape can be maintained.

  If the distance is too long, the shape of the liquid column at the time of reaching the application target tends to change from the shape of the liquid column immediately after being pulled out from the meniscus by the surface tension of the liquid and to be close to a cylindrical shape. .

  Further, in the present embodiment, the same voltage can be applied to a plurality of nozzles provided in the liquid application device. By doing this, the same pattern can be formed simultaneously. In this case, a single power supply may be used to apply a voltage to the plurality of nozzles, and it is not necessary to configure the voltage application means to simultaneously apply different voltages to the plurality of nozzles to simultaneously form different patterns. In addition, since the same voltage is applied to a plurality of nozzles forming the same pattern, the insulating process between the adjacent nozzles is not necessary. As a result, the configuration of the liquid application device according to the present embodiment can be simplified.

  Furthermore, the liquid application apparatus can apply an application target using a plurality of liquids. In this case, the liquid discharger may be configured with a plurality of nozzles according to the number of liquids used. For example, the liquid discharge unit may be configured of a first head unit including a plurality of nozzles to which a first liquid is supplied, and a second head unit including a plurality of nozzles to which a second liquid is supplied. Can.

(3. Method of applying liquid)
The method of applying a liquid according to the present embodiment is a method of applying a liquid using a liquid applying apparatus that utilizes the above-described electrostatic suction force.

(3.1. Liquid)
The liquid to be applied in the application method of the liquid according to the present embodiment is not particularly limited as long as it is a liquid that can be applied to an application target by electrostatic attraction. In the present embodiment, the liquid is preferably an ink containing functional particles and a solvent, and the functional particles are dispersed in the solvent.

  The functional particle is composed of a material exhibiting a predetermined property such as a predetermined electrical property, a predetermined optical property, a predetermined magnetic property, or a compound serving as the material in the formed pattern. In the present embodiment, metal materials, ceramic materials and the like are exemplified. In addition, the particle diameter of the functional particles can also be appropriately selected according to the application of the pattern to be formed.

  The solvent is not particularly limited as long as the solvent can disperse the functional particles, and examples thereof include known aqueous solvents, organic solvents and the like.

  In addition, the ink may contain a resin component to firmly form a pattern. The ink may also contain components (dispersants, plasticizers, etc.) other than the components described above.

(3.2. Coating process)
Subsequently, in the coating step of the liquid coating method according to the present embodiment, the above liquid is coated on a support or a coated body formed on a support using the above liquid coating device, and a predetermined pattern is formed. Draw Hereinafter, the application process will be described in detail.

  In this process, a liquid discharge nozzle shown in FIG. 1A is used as a nozzle provided in the liquid application apparatus. As shown in FIGS. 4A and 4B, the liquid discharge nozzle is disposed such that the discharge port 30 of the nozzle faces the support. The projection dimension of the tip surface 10a of the protrusion 10 projected from the Y-axis direction is the minimum value cmin, and the projection dimension of the tip surface 10a of the protrusion 10 projected from the X-axis direction is the maximum value cmax. ing. In FIGS. 4A and 4B, the liquid application devices other than the tip of the nozzle are not shown.

  4A and 4B show that the liquid supplied in the nozzle is charged by applying a voltage, and the electrostatic attraction force causes the liquid column drawn from the meniscus to reach the application target 70. There is.

  In FIGS. 4A and 4B, the projected dimension of the tip end surface of the protrusion and the projected dimension of the virtual surface of the tip end surface have the relationship described above, so the width LW1 of the liquid column seen from the Y-axis direction The (length in the X-axis direction) is smaller than the width LW2 (length in the Y-axis direction) of the liquid column as viewed from the X-axis direction.

  When the nozzle 1 is moved by sweeping or moving the table such that the nozzle shown in FIGS. 4A and 4B and the application target 70 move relative to each other in the Y-axis direction, a line along the Y-axis direction as shown in FIG. A line segment L1 having a width of LW1 is drawn. On the other hand, if the nozzle is moved by sweeping or moving the table so that the nozzle and the application target move relative to each other in the X-axis direction, as shown in FIG. 7, a line L2 having a line width of LW2 along the X-axis direction Is drawn.

  Therefore, it is possible to draw line segments having different line widths while using the same nozzle. Moreover, since the line width of the formed line segment can be changed without changing the application condition of the liquid, even if the line widths are different, drawing can be performed while maintaining drawing stability.

  In addition, by repeatedly forming the line segment L1 at a predetermined number of times in a direction parallel to the Y-axis direction so that the line segments L1 are continuous at a predetermined length, the line segments L1 are formed to be continuous and have a predetermined area The rectangular region S1 can be formed. Similarly, line segments L2 are formed continuously by forming line segments L2 repeatedly by a predetermined number of times in a direction parallel to the X-axis direction so that line segments L2 are continuous with a predetermined length. A rectangular area S2 can be formed.

  Here, by adjusting the formation length of the line segment L1, the formation length of the line segment L2, the number of times of forming the line segment L1, and the number of times of forming the line segment L2, the rectangular area S1 and the rectangular area S2 can have the same shape.

  That is, as shown in FIG. 8, the length in the Y-axis direction of the rectangular area S1 (formation length a1 of the line segment L1) and the length in the Y axis direction of the rectangular area S2 (the line segment L2 is in the width direction And the length b2) formed in succession to the same length, and the length in the X-axis direction of the rectangular area S1 (the length b1 formed by connecting the line segment L1 continuously in the width direction), and The length in the X-axis direction of the shape region S2 (the formed length a2 of the line segment L2) is the same length.

  For example, when the dimension of the rectangular area is large and the formation accuracy is not required so much, the line segments L2 having a large line width are formed to form a rectangular area S2, and the line segments L1 having a narrow line width are formed. The rectangular region S2 having the same shape as that of the rectangular region S1 can be formed in a shorter time than forming the rectangular region S1. Therefore, the productivity at the time of drawing a predetermined pattern can be improved.

  On the other hand, when the dimension of the rectangular area is small and the formation accuracy is required, the rectangular area S1 is formed by connecting the line segments L1 having a narrow line width, as compared with the rectangular area S2. S1 can be formed with high resolution and accuracy.

  That is, by using the liquid application apparatus including the liquid discharge nozzle according to the present embodiment, the line width at the time of forming the pattern can be flexibly changed according to the dimension and the formation accuracy of the pattern to be drawn. As it can, both productivity and formation accuracy can be achieved.

(4. Effects in the present embodiment)
In the present embodiment described in the above (1) to (3), a liquid application device including the liquid discharge nozzle having the above-described shape is used to form a liquid column connecting the discharge port of the nozzle and the application target The liquid is applied to the application object.

  The liquid discharge nozzle according to the present embodiment can change the width of the liquid column in the sweep direction of the nozzle by having the above-described shape. The width of the liquid column corresponds to the line width of the line segment formed by the application of the liquid.

  Therefore, by changing the width of the liquid column, the line width of the formed line segment can be changed according to the sweep direction of the nozzle. In addition, the line width can be made within a predetermined range simply by changing the sweep direction of the nozzle without changing the liquid application conditions (component of the liquid, viscosity, applied voltage, distance between the discharge port and the application target, etc.). You can control it freely.

  That is, the quality of the formed line segment is the same even if the line widths are different, and excellent drawing stability can be ensured.

  Further, when the line width of the formed line segment is large, a pattern having a predetermined area can be formed in a shorter time than in the case where the line width is small. On the other hand, in the case of forming a minute pattern, the formation accuracy of the minute pattern is improved by forming the line segment with a smaller line width than in the case of forming the line width with a large line segment. Can.

  Therefore, by changing the line width in accordance with the pattern to be formed, it is possible to achieve both the formation speed and the formation accuracy of the pattern.

(5. Modification)
In the embodiment described above, the liquid discharge nozzle is a nozzle used for a liquid application device that utilizes electrostatic attraction. However, the present invention is not limited to a liquid application device that utilizes electrostatic attraction, and may be, for example, a liquid discharge nozzle used for an air pressure dispenser. In this case, the description in the above-described embodiment can be applied except that the movement of the liquid in the nozzle is caused by pressure, and similar effects can be obtained.

  Moreover, in embodiment mentioned above, the structure by which the level | step difference is formed between the front end surface 10a of the protrusion part 10 and the front end surface 20a which the trunk | drum 20 exposed is employ | adopted. However, the entire front end surface of the body 20 may be connected to the protrusion 10 by forming the stepped surface 10 b of the protrusion 10 at a predetermined angle with respect to the discharge direction O. In this case, the step surface 10b may be a flat surface or a curved surface.

  Further, in the embodiment described above, the tip end surface 10 a of the protrusion 10 is configured as a flat surface. However, as long as the liquid wets and spreads on the tip surface 10a to form a meniscus, the tip surface 10a of the protrusion 10 may be formed of a curved surface.

  Further, in the embodiment described above, a line segment having a wide line width is formed along the X-axis direction, and a line segment having a narrow line width is formed along the Y-axis direction. However, after one of the line segments is formed, the nozzle or table is rotated at a predetermined angle with respect to the Z axis, and then the other line segment is formed, whereby the line segment with a large line width and the line width are small. The line segment may be formed along the same direction.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and may be modified in various aspects within the scope of the present invention.

  The present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

(Experimental example 1)
As a liquid discharge nozzle, a nozzle shown in FIG. 1A was used. In the nozzle, the minimum value cmin of the projection dimension of the tip end face of the protrusion and the minimum value dmin of the projection dimension of the virtual surface were the values shown in Table 1.

  The liquid coating apparatus equipped with these nozzles was filled with the ink in which the ceramic particles were dispersed, and was supplied into the nozzles. In the liquid application apparatus, a voltage of 1000 V is applied between the nozzle and the support in Examples 1 and 3, and a voltage of 500 V is applied in Example 2 to connect the nozzle and the support. Formed. With the liquid column formed, the projection direction (B direction in FIG. 1A) in which the projection dimension of the tip end face of the projection shows the minimum value and the projection direction (C direction in FIG. 1A) the projection dimension shows the maximum value And the nozzle was swept to form a line segment on the support, and the line width was measured. The results are shown in Table 1.

  From Table 1, it was confirmed that the difference in the formed line width can be increased simply by changing the sweep direction of the nozzle without changing the application conditions by setting the shape of the nozzle tip as described above.

DESCRIPTION OF SYMBOLS 1 ... Liquid discharge nozzle 10 ... Protrusion part 10a ... Tip surface 10b ... Step surface 20 ... Body part 20a ... Tip surface 50 exposed to the outside Discharge device 1 ... Nozzle 52 ... Voltage application means 53 ... Support 54 ... Table 54 60 ... Ink 70 ... Application target

Claims (5)

A liquid discharge nozzle for continuously discharging a liquid from a discharge port to a coating target,
The tip portion of the liquid discharge nozzle has a body portion, and a projecting portion connected to a tip end surface of the body portion and protruding in the discharge direction of the liquid from the tip end surface of the body portion,
A tip surface substantially perpendicular to the discharge direction of the liquid is formed at the tip of the projecting portion,
In a case where a virtual surface obtained by rotating the tip end surface of the protrusion with the line passing through the center of the discharge port and being parallel to the discharge direction as a rotation axis,
When the tip end surface of the protrusion and the virtual surface are projected from any direction perpendicular to the ejection direction, the minimum value of the projection dimension of the tip surface of the protrusion is from the minimum value of the projection dimension of the virtual surface A liquid discharge nozzle characterized by having a small size.   The liquid discharge nozzle according to claim 1, wherein the liquid is discharged by electrostatic attraction.   In the projection shape of the body obtained by projecting the body from any direction perpendicular to the discharge direction, the length of the body in the direction perpendicular to the discharge direction is the tip of the body. The liquid discharge nozzle according to claim 1, wherein the liquid discharge nozzle gradually increases in the direction opposite to the discharge direction from the surface.   Assuming that the minimum value of the projection dimension of the end face of the protrusion is cmin and the minimum value of the projection dimension of the virtual surface is dmin, the cmin is 0.2 dmin or more and 0.8 dmin or less. The liquid discharge nozzle according to any one of Items 1 to 3.   Assuming that the distance between the tip end surface of the body and the tip end surface of the protrusion in the discharge direction is h, and the minimum value of the projection dimension of the virtual surface is dmin, the h is 0.1 dmin or more The liquid discharge nozzle according to any one of claims 1 to 4, characterized in that:

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