JP2010000442A - Liquid discharge device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid discharge device which discharges steadily a trifling amount of liquid materials with little fluctuation in discahrge quanity. <P>SOLUTION: The liquid discharge device 100 discharging a trifling amount of liquid drops includes a pushing out needle 120 which moves the inside of a taper-shaped liquid holding pipe 10 charged with the liquid materials 30 and of which the end part moves in and out through an opening 11 formed at the distal end of the liquid holding pipe 10, and a plurality of minute recesses 123 (dimple-shaped convex and concave) are formed, in a jig jag arrangement, on the side face part 122 of the distal end side in the pushing out needle 120. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid discharge apparatus that discharges a liquid material, and more particularly, to a liquid discharge apparatus that discharges a small amount of a liquid material stably with little variation in discharge amount.

  In recent years, there is an increasing need in various fields to discharge a small amount of liquid material. On the other hand, various techniques such as a micro droplet discharge device have been proposed (for example, see Patent Document 1).

  For example, in an electronic device that is becoming smaller and lighter, a semiconductor in which minute electrodes are formed at a narrow pitch and a printed wiring board in which a minute wiring pattern is formed are used. Furthermore, progress such as miniaturization of electrodes and miniaturization of wiring patterns is remarkable. Then, how to quantitatively discharge the liquid material used when connecting a minute electrode and a minute wiring pattern is a point in ensuring quality.

  In general, a dispensing method is known as a method for discharging a liquid material. In the dispensing method, air is used as a drive source for discharging the liquid material filled in the syringe. For this reason, the discharge amount depends on the volume of the material filled in the syringe, and as the material decreases due to discharge, the water head difference cannot follow the fluctuation of the material decrease, and it becomes difficult to discharge in a fixed amount.

  Here, the water head difference means a change in the discharge amount generated due to a change in the liquid amount in the syringe. When the space volume in the syringe increases, a time lag occurs when air is sent in, and the discharge amount changes. In particular, when a small amount of liquid material is discharged, the variation in the discharge amount appears remarkably.

  In addition, for example, when a filler is contained in the liquid material, such as a solder adhesive containing solder powder, the dispersibility of the filler contained in the liquid material is broken by the air pressure and included in a part of the discharged liquid material. There is a problem that the amount of filler to be fixed is not constant.

<Liquid ejection device>
Here, a conventional liquid ejection apparatus will be described.
As shown in FIG. 6, the liquid ejection device 1 is a device that ejects a small amount of the liquid material 30 from the opening 11 formed at the tip of the tapered liquid holding tube 10. A rod-shaped extrusion needle 20 is provided that moves inside the liquid holding tube 10 in which the liquid material 30 is placed and the tip 21 enters and exits from the opening 11. Here, the liquid holding tube 10 is disposed with the opening 11 on the lower side, and the plate-like discharged object 40 is disposed with a slight gap below the opening 11. The liquid material 30 is discharged to the discharge target body 40 by a small amount by manually or automatically moving the extrusion needle 20 in the vertical direction.

  Here, the side surface of the extrusion needle 20 is smooth. Further, the outer diameter C3 is smaller than the inner diameter C1 of the opening 11 of the liquid holding tube 10 and is disposed inside the liquid holding tube 10 so as to be able to enter and leave the opening 11 of the liquid holding tube 10.

<Discharge process>
Next, a discharge process for discharging a small amount of liquid droplets onto the discharge target body 40 using the liquid discharge apparatus 1 will be described.

  First, as shown in FIGS. 7A to 7B, the extrusion needle 20 descends, passes through the opening 11 of the liquid holding tube 10, and the tip 21 of the extrusion needle 20 from the inside of the liquid holding tube 10. coming out. Further, the push-out needle 20 is lowered until the tip 21 of the push-out needle 20 comes into contact with the discharged body 40. At this time, the liquid material 31 that is a part of the liquid material 30 adheres to the tip 21 and the side surface portion 22 of the extrusion needle 20.

  Thereafter, as shown in FIG. 7C, when the tip 21 of the extrusion needle 20 comes into contact with the discharge target body 40, the liquid material 31 attached to the tip 21 and the side surface portion 22 through the tip 21 of the extrusion needle 20. Part of the fluid flows to the discharge target body 40.

Thereafter, as shown in FIGS. 7D to 7E, the push-out needle 20 rises, passes through the opening 11 of the liquid holding tube 10, and the tip 21 of the push-out needle 20 enters the liquid holding tube 10. Enters.
Then, by repeating this series of steps while changing the discharge position, droplets 51, 52,... Are discharged to the discharge target body 40 as shown in FIG.
JP 2006-320795 A

  However, the liquid ejection apparatus 1 according to the conventional technique has a problem that even if a small amount of liquid material can be ejected, the ejection amount varies. As shown in FIG. 8, this point can be easily recognized from the variation in the diameter E1 of the droplet 51, the diameter E2 of the droplet 52, and the like. This is because, as shown in FIG. 6, when the droplet 50 is discharged onto the discharge target body 40, the liquid material 31 spreads and spreads on the surface of the discharge target body 40.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid discharge apparatus that discharges a small amount of a liquid material stably with little variation in discharge amount.

In order to achieve the above object, a coating apparatus according to the present invention has the following characteristics.
(CL1) The liquid discharge device is (a) a liquid discharge device that discharges a small amount of liquid droplets, and (b) moves inside a tapered liquid holding tube containing a liquid material to hold the liquid. An extrusion needle having a tip entering and exiting from an opening formed at the tip of the tube is provided, and (c) an unevenness is formed on the side surface portion on the tip side of the extrusion needle.

Thereby, the adhesion state of the liquid material which is a part of the liquid material adhering to the side surface portion of the extrusion needle can be maintained, and the liquid material can be prevented from flowing downward.
This is because an extruded needle with a concavo-convex portion on the side surface has a larger area in contact with the liquid material than an extruded needle with a smooth side surface, so the surface tension and friction resistance increase, and the liquid material is discharged. This is because it becomes difficult to flow in the direction.

  As a result, using the liquid discharge device of the present invention over the conventional liquid discharge device has less variation in discharge amount and can discharge minute droplets in a fixed amount, which is optimal for discharging a small amount of liquid material. is there.

Furthermore, the coating apparatus according to the present invention may have the following features.
(CL2) In the liquid ejecting apparatus according to (CL1), the unevenness formed on the side surface portion may be any of a plurality of minute convex portions formed in a staggered arrangement and a plurality of minute concave portions formed in a staggered arrangement. It may be.

  (CL3) In the liquid ejection device according to (CL1), the unevenness formed on the side surface portion is recessed along the outer periphery of the protruding needle and the outer periphery of the pressing needle. It may be either an annular recess.

  (CL4) In the liquid ejection device according to (CL1), (a) the liquid material includes a filler, and (b) the depth of the concave portion or the height of the convex portion in the unevenness formed on the side surface portion. The average filler particle diameter may be greater than or equal to twice the average filler particle diameter.

  (CL5) In the liquid ejection device according to (CL1), (a) the liquid material includes a filler, and (b) an interval between adjacent concave portions in the concave and convex portions formed on the side surface portion or an adjacent convex portion. The interval may be greater than or equal to the average filler particle size.

  Note that the present invention is not limited to being realized as a liquid discharge apparatus, but may be realized as a liquid discharge method for discharging a minute amount of liquid droplets using the liquid discharge apparatus.

  According to this invention, the unevenness | corrugation is formed in the side part of the extrusion needle. Thereby, the adhesion state of the liquid material which is a part of the liquid material adhering to the side surface portion can be maintained, and the liquid material can be prevented from flowing downward.

  This is because an extruded needle with a concavo-convex portion on the side surface has a larger area in contact with the liquid material than an extruded needle with a smooth side surface, so the surface tension and friction resistance increase, and the liquid material is discharged. This is because it becomes difficult to flow in the direction.

  As a result, using the liquid discharge device of the present invention over the conventional liquid discharge device has less variation in discharge amount and can discharge minute droplets in a fixed amount, which is optimal for discharging a small amount of liquid material. is there. For example, it is suitable for applications that require fine droplets and discharge accuracy so as to connect a minute electrode and a fine wiring pattern, and contributes to an improvement in connection quality.

(Embodiment)
Embodiments according to the present invention will be described below.
<Configuration>
First, the configuration of the liquid ejection apparatus in the present embodiment will be described.

  As shown in FIG. 1, the liquid ejection device 100 is a device that ejects a small amount of a liquid material 30 from an opening 11 formed at the tip of a tapered liquid holding tube 10. A rod-shaped push-out needle 120 that moves inside the liquid holding tube 10 in which the liquid material 30 is placed and the tip 121 enters and exits from the opening 11 is provided. Here, the liquid holding tube 10 is disposed with the opening 11 on the lower side, and the plate-like discharged object 40 is disposed with a slight gap below the opening 11. The liquid material 30 is discharged to the discharge target body 40 by a small amount by manually or automatically moving the extrusion needle 120 in the vertical direction.

<Extruded needle 120>
Here, the extrusion needle 120 has a plurality of minute concave portions 123 (dimple-shaped irregularities) formed on the side surface portion 122 in a staggered arrangement. The minute concave portion 123 is an elliptical hole portion that narrows inward on the side surface of the push-out needle 120. Further, the outer diameter C <b> 2 is smaller than the inner diameter C <b> 1 of the opening 11 of the liquid holding tube 10, and the liquid holding tube 10 is disposed inside the liquid holding tube 10 so as to freely enter and leave the opening 11.

<Liquid material 30>
In addition, the liquid material 30 is widely used from those composed of a single resin such as epoxy or acrylic resin to those in which a filler is mixed with the resin, such as a solder adhesive containing solder powder in the resin. Is possible. Moreover, what mixed metal fillers, such as silver particle, and what mixed inorganic fillers, such as a silica, can be used. A material having a viscosity of 100 Pa · s or less is suitable.

<Subject 40>
In addition, as the material 40 to be ejected, a glass plate, a glass fiber-containing epoxy resin plate, a ceramic plate, a polymer resin plate such as polyethylene terephthalate (PET) or acrylonitrile butadiene styrene (ABS), and various other materials can be used. It is. Also, a circuit board on which a conductive circuit pattern is formed by copper foil, plating, or the like can be used.

<Discharge process>
Next, a discharge process for discharging a small amount of liquid droplets onto the discharge target body 40 using the liquid discharge apparatus 100 will be described.

  First, as shown in FIGS. 2A to 2B, the extrusion needle 120 descends, passes through the opening 11 of the liquid holding tube 10, and the tip 121 of the extrusion needle 120 from the inside of the liquid holding tube 10. coming out. Further, the push-out needle 120 is lowered until the tip 121 of the push-out needle 120 contacts the discharged body 40. At this time, the liquid material 131 that is a part of the liquid material 30 adheres to the tip 121 and the side surface portion 122 of the extrusion needle 120.

  Thereafter, as shown in FIG. 2C, when the tip 121 of the extrusion needle 120 comes into contact with the discharge target body 40, the liquid material 131 attached to the tip 121 and the side surface portion 122 through the tip 121 of the extrusion needle 120. Part of the fluid flows to the discharge target body 40.

Thereafter, as shown in FIGS. 2D to 2E, the push-out needle 120 rises, passes through the opening 11 of the liquid holding tube 10, and the tip 121 of the push-out needle 120 enters the liquid holding tube 10. Enters.
Then, by repeating this series of ejection steps while changing the ejection position, as shown in FIG. 3, droplets 151, 152,...

  Note that the liquid material 131 that is a part of the liquid material 30 is attached to the side surface portion 122 of the extrusion needle 120 without dripping down until the tip 121 of the extrusion needle 120 contacts the discharged body 40. . For example, as shown in FIG. 4A, surface tension and friction resistance corresponding to the shape, size, and pitch of the minute recesses 123a are generated in the side surface portion 122 of the extrusion needle 120, and the surface tension and friction resistance cause This is because the generated force F acts toward maintaining the attached state of the liquid material 131a. For this reason, in the liquid ejection device 100, the liquid material 131 is ejected in a stable amount without drooping to the ejection position of the body 40 to be ejected.

<Dimensions and spacing>
Here, the dimension of the micro recessed part 123 and the space | interval of the adjacent micro recessed part 123 are demonstrated.

  For example, when the liquid material 30 includes a filler, the size of the minute recesses 123 and the interval between adjacent minute recesses 123 are limited. Here, as an example, it is assumed that the liquid material 30 is a solder paste. In this case, in order for solder particles (filler particles) to enter the minute recesses 123, the diameter and depth of the minute recesses 123 need to be equal to or larger than the size of the solder particles (filler particle diameter). For this reason, at least the length corresponding to the average solder particle diameter (average filler particle diameter) is required as the diameter and depth of the minute recesses 123.

  However, if the depth of the minute concave portion 123 is too large, the amount of the liquid coating 131b attached to the side surface portion 122 is excessively large, and the variation in the discharge amount is not preferable. As shown in FIG. 4B, the surface tension and the frictional resistance increase as the depth of the minute concave portion 123b increases, and the force F generated by the surface tension and the frictional resistance also increases. This is because the adhesion state of many liquid substances 131b is maintained by the increased force F. For this reason, it is preferable that the depth of the minute recesses 123b is not less than the average solder particle diameter (average filler particle diameter) and not more than twice the average solder particle diameter (average filler particle diameter).

  Further, as shown in FIG. 4C, the narrower the interval between the adjacent minute recesses 123c, the more uniform the surface of the liquid 131c, but the diameter of the minute recesses 123c is the average solder particle diameter (average filler particle diameter). It is necessary to be above. For this reason, at least the length corresponding to the average solder particle diameter (average filler particle diameter) is necessary as the interval between the adjacent minute recesses 123c.

  That is, the depth of the minute recesses 123 is equal to or greater than the average solder particle diameter (average filler particle diameter) and equal to or less than twice the average solder particle diameter (average filler particle diameter). The interval between adjacent minute recesses 123c is equal to or greater than the average solder particle diameter (average filler particle diameter). The diameter of the minute recess 123 is equal to or larger than the average solder particle diameter (average filler particle diameter).

<Case>
Next, specific examples will be described. Here, with respect to the case where the liquid ejection device 100 shown in FIG. 1 is used, variation measurement and flow observation were performed.

  Here, as an example, the inner diameter C1 of the opening 11 formed at the tip of the liquid holding tube 10 is set to 350 μm. The outer diameter C2 of the extrusion needle 120 was set to φ300 μm. Further, the depth of the minute recess 123 was 75 μm, and the diameter of the minute recess 123 was 150 μm. The interval between adjacent minute recesses 123 was set to 500 μm.

  As the liquid material 30, a thermosetting epoxy resin made of bisphenol A was mixed with solder particles having an average solder particle diameter of 40 μm, and the viscosity at normal temperature was 20 Pa · s. A glass plate was used as the discharge target 40.

It should be noted that the condition that the depth of the minute recess 123 is not more than twice the average solder particle diameter is satisfied.
<Measurement of variation>
First, the variation measurement was performed according to the following (Procedure 1) to (Procedure 3).

  (Procedure 1) First, by using the liquid ejection device 100 shown in FIG. At this time, as shown in FIG. 3, the droplets 151, 152,.

  (Procedure 2) Next, the diameter of 500 droplets attached to the discharge target body 40 was measured. Specifically, the diameters D1, D2,... Of the droplets 151, 152,.

  (Procedure 3) Next, an average value and a standard deviation were calculated for the diameter of the droplets from the measurement results. As a result of calculation, the average value of the diameters was 380 μm, and the standard deviation of the diameters was 10.

<Flow observation>
Next, regarding the flow observation, in the step shown in FIG. 2C, the flow behavior of the liquid 131 was observed using a microscope. As a result of the observation, it was not observed that the liquid 131 hangs down to the discharge position of the discharge target body 40 without tightening.

<Comparative example>
Further, as a comparative example, variation measurement and flow observation were performed even when the liquid ejection apparatus 1 shown in FIG. 6 was used.

  Here, as an example, the outer diameter C3 of the extrusion needle 20 is set to φ300 μm. Moreover, the unevenness | corrugation is not formed in the side part 22 of the extrusion needle 20. Except for these points, the conditions were the same as the above examples.

<Measurement of variation>
First, the variation measurement was performed according to the following (Procedure 1) to (Procedure 3).
(Procedure 1) First, using the liquid discharge apparatus 1 shown in FIG. At this time, as shown in FIG. 8, the droplets 51, 52,.

  (Procedure 2) Next, the diameter of 500 droplets attached to the discharge target body 40 was measured. Specifically, the diameters E1, E2,... Of the droplets 51, 52,.

  (Procedure 3) Next, an average value and a standard deviation were calculated for the diameter of the droplets from the measurement results. As a result of the calculation, the average diameter was φ430 μm, and the standard deviation of the diameter was 27.

<Flow observation>
Next, regarding the flow observation, in the process shown in FIG. 7C, the flow behavior of the liquid material 31 was observed using a microscope. As a result of observation, as shown in FIG. 6, it was observed that the liquid material 31 hangs down to the discharge position of the discharge target body 40 without tightening.

<Conclusion>
From these results, the following can be obtained.
(1) When the liquid ejection device 100 was used, the average value of the diameters was 380 μm. When the liquid ejection apparatus 1 was used, the average value of the diameter was φ430 μm. From this, it is possible to eject droplets having a smaller average diameter when the liquid ejection device 100 is used than when the liquid ejection device 1 is used.

  (2) When the liquid ejection apparatus 100 was used, the standard deviation of the diameter was 10. This corresponds to 2.6% of the average diameter. When the liquid ejection device 1 was used, the standard deviation of the diameter was 27. This corresponds to 6.2% of the average diameter. When the liquid ejection device 100 was used, the standard deviation of the diameter was suppressed to ½ or less when the liquid ejection device 1 was used. From this, it is possible to discharge liquid droplets stably by using the liquid discharge apparatus 100 rather than the liquid discharge apparatus 1 with less variation in the discharge amount.

  (3) When the liquid ejection device 100 was used, it was not observed that the liquid material 131 drooped without being tightened to the ejection position of the body 40 to be ejected. In the case of using the liquid ejection device 1, it was observed that the liquid material 31 hangs down without being tightened to the ejection position of the body 40 to be ejected. Since the liquid material 30 is less likely to flow in the discharge direction when the liquid discharge device 100 is used than the liquid discharge device 1, the liquid material 30 can be prevented from flowing out to the discharge target body 40 and stably. Droplets can be ejected.

<Summary>
As described above, according to the present embodiment, the dimple-shaped irregularities are formed on the side surface portion 122 of the extrusion needle 120. Thereby, the adhesion state of the liquid material 131 which is a part of the liquid material 30 adhered to the side surface portion 122 can be maintained, and the liquid material 131 can be prevented from flowing downward.

  This is because the surface of the extruded needle 120 in which the dimple-shaped irregularities are formed on the side surface portion 122 is larger than the surface of the extruded needle 20 having a smooth side surface portion 22. This is because the liquid material 30 becomes difficult to flow in the discharge direction.

  As a result, the use of the liquid discharge device 100 rather than the liquid discharge device 1 can discharge a small amount of liquid droplets with a small amount of discharge and is optimal for discharging a small amount of liquid material. For example, it is suitable for applications that require fine droplets and discharge accuracy so as to connect a minute electrode and a fine wiring pattern, and contributes to an improvement in connection quality.

(Other)
<Modification 1>
Instead of the pushing needle 120, an pushing needle 160a shown in FIG. 5A may be used. Here, in order to make it easy to understand the shape of the unevenness formed on the side surface portion 162a, the tip 161a side of the pushing needle 160a is partially removed.

  Here, the extrusion needle 160a has a plurality of annular recesses 163a formed on the side surface portion 162a so as to be aligned in the axial direction of the extrusion needle 160a. The annular recess 163a is a groove portion that is recessed along the outer periphery of the extrusion needle 160c on the side surface of the extrusion needle 160a. The depth of the annular recess 163a is not less than the average filler particle diameter and not more than twice the average filler particle diameter. The interval between adjacent annular recesses 163a is equal to or greater than the average filler particle diameter. Further, since the filler particles enter the annular recess 163a, the groove width of the annular recess 163a is equal to or larger than the average filler particle diameter.

<Modification 2>
Instead of the push needle 120, a push needle 160b shown in FIG. 5B may be used. Here, in order to make it easy to understand the shape of the unevenness formed on the side surface portion 162b, the tip 161b side of the extrusion needle 160b is partially removed.

  Here, the extrusion needle 160b has a plurality of minute convex portions 163b formed in a staggered arrangement on the side surface portion 162b. The minute convex portion 163b is a rectangular parallelepiped portion protruding outward on the side surface of the extrusion needle 160b. The height of the minute projections 163b is equal to or greater than the average filler particle size and is equal to or less than twice the average filler particle size. The interval between adjacent minute convex portions 163b is equal to or larger than the average filler particle diameter. Further, since the filler particles enter the gap between the adjacent minute convex portions 163b, the gap between the adjacent minute convex portions 163b is equal to or larger than the average filler particle diameter.

<Modification 3>
Instead of the push needle 120, a push needle 160c shown in FIG. 5C may be used. Here, in order to make it easy to understand the shape of the unevenness formed on the side surface portion 162c, the tip 161c side of the extrusion needle 160c is partially removed.

  Here, the extrusion needle 160c has a plurality of annular convex portions 163c formed on the side surface portion 162c so as to be aligned in the axial direction of the extrusion needle 160c. The annular convex portion 163c is a band portion protruding along the outer periphery of the extrusion needle 160c on the side surface of the extrusion needle 160c. The height of the annular convex part 163c is not less than the average filler particle diameter and not more than twice the average filler particle diameter. The space | interval of the adjacent cyclic | annular convex part 163c is more than an average filler particle diameter. Further, since the filler particles enter the gap between the adjacent annular protrusions 163c, the gap between the adjacent annular protrusions 163c is equal to or larger than the average filler particle diameter.

  If the extrusion needle 120 is made of resin, it may be formed by injection molding, machining, or the like, and if it is made of metal, it is formed by die casting, pressing, machining, or the like. It may be done. Further, the extrusion needles 160a to 160c may be formed in the same manner as the extrusion needle 120.

  In addition, this invention is not limited to said content, A various change is possible in the range which does not deviate from the summary of invention.

  INDUSTRIAL APPLICABILITY The present invention can be used as a liquid discharge device that discharges a liquid material, and particularly as a liquid discharge device that discharges a small amount of liquid material stably with little variation in discharge amount.

It is sectional drawing which shows the principal part of the liquid discharge apparatus in embodiment. (A)-(E) are figures which show the discharge process by the liquid discharge apparatus in embodiment. It is a top view which shows the to-be-discharged body after discharging a liquid material using the liquid discharge apparatus in embodiment. (A)-(C) is a figure which shows the mode of the liquid substance at the time of changing the dimension of the micro recessed part formed in the side part of the extrusion needle in embodiment, and the space | interval of an adjacent micro recessed part. . (A)-(C) are figures which show the modification of the extrusion needle with which the liquid discharge apparatus in embodiment is equipped. It is sectional drawing which shows the principal part of the liquid discharge apparatus in a prior art. (A)-(E) are figures which show the discharge process by the liquid discharge apparatus in a prior art. It is a top view which shows the to-be-discharged body after discharging a liquid material using the liquid discharge apparatus in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid discharge apparatus 10 Liquid holding tube 20 Extrusion needle 21 Tip 22 Side surface part 30 Liquid material 31 Liquid substance 40 To-be-discharged body 50,51,52 Droplet 100 Liquid discharge apparatus 120 Extrusion needle 121 Tip 122 Side surface part 123,123a, 123b , 123c Micro recesses 131, 131a, 131b, 131c Liquid material 150, 151, 152 Droplet 160a Extrusion needle 161a Tip portion 162a Side surface portion 163a Annular recess 160b Extrusion needle 161b Tip portion 162b Side surface portion 163b Micro projection portion 160c Extrusion needle 161c Tip Part 162c side part 163c annular convex part

Claims (6)

A liquid ejection device that ejects a small amount of liquid droplets,
It moves inside the tapered liquid holding tube containing the liquid material, and includes an extrusion needle whose tip moves in and out of the opening formed at the tip of the liquid holding tube,
The liquid ejecting apparatus is characterized in that an unevenness is formed on a side surface portion on the tip side of the extrusion needle. 2. The liquid according to claim 1, wherein the unevenness formed on the side surface portion is any one of a plurality of minute convex portions formed in a staggered arrangement and a plurality of minute concave portions formed in a staggered arrangement. Discharge device. The unevenness formed on the side surface portion is one of an annular convex portion protruding along the outer periphery of the extrusion needle and an annular concave portion recessed along the outer periphery of the extrusion needle. The liquid discharge apparatus according to 1. The liquid material contains a filler,
The depth of the concave portion or the height of the convex portion in the unevenness formed on the side surface portion is equal to or larger than the average filler particle diameter and equal to or smaller than twice the average filler particle diameter. Liquid ejection device. The liquid material contains a filler,
The liquid ejection device according to claim 1, wherein an interval between adjacent concave portions or an interval between adjacent convex portions in the unevenness formed on the side surface portion is equal to or larger than an average filler particle diameter. A liquid discharge method comprising: a discharge step of discharging a very small amount of liquid droplets onto a discharge target body using the liquid discharge apparatus according to claim 1.

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