JP2014124655A - Liquid dripping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid dripping device capable of dripping a liquid such as liquified solder to an object in an accurate minute amount.SOLUTION: A guiding cylindrical part for storing a liquid for dripping and having a cylindrical inner shape in a liquid reservoir communicating with a nozzle hole is arranged. A columnar reduced-diameter end part, which is coaxial with the guiding cylindrical part, is arranged at a tip of a rod drivable in a linear manner in an opening direction of the nozzle hole. Compressional waves travelling in a liquid dripping direction are generated in a stored liquid by making the reduced-diameter end part drive in a linear manner inside the guiding cylindrical part, and a predetermined amount of liquid is dripped from the nozzle hole by utilizing wave energy which the compressional waves have.

Description

  The present invention relates to a liquid dropping device that drops a small amount of liquid onto an object. More specifically, it is possible to treat a substance that maintains a liquid state under specific conditions such as molten metal exemplified by solder as a small amount of liquid and to suitably drop the substance onto a dropping object. It relates to a liquid dropping apparatus.

  For example, in the manufacturing process of a magnetic head, a conductive minute ball made of solder is arranged between a plurality of electrodes, and this is melted and further fixed to each electrode to perform electrical bonding between the electrodes. (See Patent Document 1). Here, miniaturization and high functionality of the magnetic head are being promoted at present, and the number of electrodes is increased and the electrodes themselves are reduced. As a result, the conductive balls have to be further miniaturized. When the conductive ball has a diameter of, for example, 100 μm or less, individual handling becomes difficult, and so-called contamination during handling or the price of the ball itself becomes expensive.

  Based on such a background, as disclosed in Patent Document 2 or 3, a technique for directly ejecting and adhering molten solder to an object to be bonded has been proposed. According to the technique, the problems caused by the use of the conductive ball described above are eliminated. Further, as a method for dripping a small amount of liquid, which is a related technology, for example, a technology exemplified in Patent Document 4 or 5 is known. In these techniques, a volume change is generated in a liquid reservoir in which molten metal is stored, and a predetermined amount of molten metal is discharged from the liquid reservoir using this volume change.

JP 2009-028781 A JP 2000-294591 A JP 2003-334654 A US Pat. No. 5,266,098 JP 2001-232245 A JP 2012-006076 A

  Here, Patent Document 6 discloses a liquid dropping apparatus that reduces the influence of gas intrusion on a nozzle by using a method other than the method using volume change described above. According to this apparatus, it is possible to obtain droplets having a desired diameter. However, when this is actually applied to, for example, a manufacturing process of a magnetic head, the condition range suitable for liquid generation is small, the apparatus is continuously operated, or generation conditions are appropriately set according to manufacturing conditions. The versatility in selecting was small.

  The present invention has been made in view of the above circumstances, and provides a liquid dropping device that maintains a wide range of droplet generation conditions and is excellent in continuous operability, versatility, and the like when generating liquid metal droplets. Objective.

  In order to solve the above-described problems, a liquid dropping apparatus according to the present invention is a liquid dropping apparatus that drops a predetermined amount of liquid, and stores a liquid in a liquid reservoir that forms a liquid reservoir by storing the liquid, and stores the liquid in the liquid receiver. A nozzle having a nozzle hole that communicates with the region and allows the liquid to pass therethrough, an actuator, and one end is immersed in the liquid reservoir, and the other end is supported by the actuator. A movable rod, and the rod can be linearly moved in the direction of the forming axis by an actuator, and the linear motion of the rod generates wave energy in a part of the liquid reservoir, and the liquid is driven by the wave energy. The rod is dropped from the nozzle hole, and the rod is arranged on the liquid reservoir side and has a columnar reduced diameter end portion having an axis that coincides with the forming axis. Disposed between, and having a guide tube section with columnar in shape consisting of a large cross-sectional shape perpendicular to the cross-sectional shape and the axis of the reduced diameter end portion similar and at a predetermined magnification.

  In the liquid dropping apparatus described above, the condition of 90% <(SD−Sd) / Sd <110%, where Sd is the cross-sectional area of the reduced diameter end portion and SD is the inner diameter of the guide tube portion. It is preferable to satisfy. Furthermore, the liquid reservoir preferably has a predetermined space on the liquid surface of the liquid existing in the liquid reservoir. Further, it is more preferable to further include an inert gas supply / discharge path that can supply and discharge the inert gas in the predetermined space and can hold the liquid in the inert gas atmosphere. Further, in this case, the predetermined space is a sealed space, and it is further preferable to have a pressure maintaining means for holding in a state of being pressurized by 0.5 to 2.0 Pa.

  Moreover, it is preferable that the nozzle is formed of corundum in accordance with the liquid dropping apparatus described above. Further, a guide hole that is coaxial with the nozzle hole forming axis and communicates with the nozzle hole and has a predetermined length, and an inert gas supply capable of supplying an inert gas to the guide hole from the side communicating with the nozzle hole. Preferably, the liquid is guided in the dropping direction by the flow of an inert gas in the guide hole. Further, the inert gas supply system in this case further includes an inert gas heating means, and the inert gas heating means is more preferably capable of heating the temperature of the inert gas to a temperature exceeding the melting point of the liquid.

  According to the present invention, when generating liquid metal droplets, it is possible to supply suitable droplets according to the molten metal to be used, the size of the droplets, etc. by keeping the droplet generation conditions wide. . Moreover, it becomes possible to improve continuous operability, versatility, and the like by widening suitable conditions for appropriate liquid formation. Furthermore, the molten metal can be held in an inert gas, and the oxidation of the molten metal can be prevented.

It is a figure which shows typically schematic structure of the liquid dripping apparatus which concerns on 1st embodiment of this invention. It is an enlarged view which shows schematic structure of the principal part of the liquid dripping apparatus shown in FIG. It is a figure which shows typically each step in the liquid dripping process in the liquid dripping apparatus shown in FIG. In the embodiment shown in FIG. 1, the figure for demonstrating the relationship of the magnitude | size of each structure and the state by which a liquid metal is dripped are shown. It is explanatory drawing which shows the relationship of the magnitude | size of the diameter reduction end part and guide cylinder part in a rod. It is a figure which shows typically schematic structure of the liquid dripping apparatus which concerns on 2nd embodiment of this invention in the style similar to FIG. It is a figure which shows typically each step in the liquid dripping process in the liquid dripping apparatus shown in FIG.

A liquid dropping apparatus according to a first embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a conceptual diagram schematically showing a schematic configuration of a liquid dropping apparatus 100 according to the present embodiment. FIG. 2 is an enlarged view of the main part in FIG. The liquid dropping apparatus 100 includes a nozzle unit 10, an actuator system 30, and a body 50. In addition, this embodiment mainly aims at dripping a molten metal.

  The nozzle unit 10 includes a nozzle 11, a nozzle press 13, a nozzle flange 15, a disc spring 17, and a drip side atmosphere space 19. The nozzle 11 has a nozzle hole 11a through which the liquid 1 can pass and penetrates the nozzle 11 in the direction of a predetermined forming axis A. The nozzle flange 15 has an accommodating space 15a that can accommodate the nozzle retainer 13, and is disposed so as to cover the periphery of the nozzle retainer 13 and the opening of the nozzle hole 11a on the dropping side of the opening of the nozzle hole 11a. The accommodating space 15 a is a space larger than the outer shape of the nozzle retainer 13, and the nozzle retainer 17 accommodated together with the nozzle retainer 13 is biased toward the body 50. As a result, the nozzle 11 is held between the liquid receiver 51 on the body 50 side via the nozzle presser 13, and the nozzle 11 is tightly fixed to the liquid receiver 51. The nozzle holder 13 abuts and fixes the nozzle 11 to the liquid receiver 51. With the above configuration, the nozzle 11 is fixed to the liquid receiver 51 via the disc spring 17 and the nozzle holder 13 by fixing the nozzle flange 15 to the body 50 with a fixing member such as a screw (not shown). Fix in positional relationship. Further, the space in which the disc spring 17 formed between the nozzle flange 15 and the nozzle retainer 13 is arranged functions as a drip-side atmosphere space 19, covers the periphery of the opening of the nozzle 11 and surrounds the opening around the opening. It has the effect of forming an atmospheric gas.

  In addition, it is preferable that at least the surface of the region that contacts the liquid to be dropped, such as the inside of the nozzle 11, particularly the nozzle hole 11a, is covered with a liquid repellent material. Accordingly, it is preferable that these regions are covered with Teflon (registered trademark), DLC (Diamond-like-Carbon), or the like, or the nozzle 11 is made of these materials. Further, as in this embodiment, when the dropping target is a molten metal, it is more preferable to form the nozzle 11 by corundum such as ruby or sapphire. The dripping side atmosphere space 19 is used to promote suitable dripping of the liquid by suppressing oxidation of the liquid to be used, suppressing temperature change, and the like. When the object to be dropped is a molten metal as in the present embodiment, the dropping side atmosphere space 19 is preferably filled with an inert gas such as nitrogen, and further constitutes an atmosphere having a temperature equal to or higher than the melting temperature of the metal. It is preferred that Therefore, it is preferable to add a configuration that enables supply and discharge of a high-temperature inert gas at a predetermined pressure, or a configuration that enables heating of the gas present in the space.

  The actuator system 30 includes an actuator 31, a rod 33, a joint 35, a heat insulating part 37, and a plate 39. The actuator 31 is supported by the plate 39. The rod 33 enters the body internal space 57 through a through-hole 55a of the body side flange 55 described later, and one end thereof is immersed in the liquid reservoir 53 of the liquid receiver 51. The rod 33 is supported by the actuator 31 via the joint 35 and the heat insulating portion 37 at the other end, and is driven coaxially with the predetermined forming axis A of the nozzle hole 11a described above by the actuator 31. That is, the rod 33 is supported by the actuator 31 so as to be linearly movable in the direction of the predetermined forming axis A. In this embodiment, the tip of the rod 33 on the liquid reservoir 53 side has a cylindrical shape, and further has a cylindrical reduced diameter end portion 33a that is coaxial and has a reduced outer diameter. In this embodiment, the energy of the wave generated in the liquid reservoir 53 around one end of the rod 33 when the rod 33 is linearly moved by the actuator 31 is used. Therefore, it is desirable to construct the actuator 31 with a piezo element having a high operating speed and high response.

  The rod 33, at least one end immersed in the liquid in the liquid reservoir 53, particularly the aforementioned reduced diameter end 33a, is formed from a material having liquid repellency with respect to the liquid to be dropped, or The surface is preferably covered with such a material. Therefore, it is preferable that these regions are covered with Teflon, DLC (Diamond-like-Carbon), titanium, or the like, or the rod 33 or the reduced diameter end portion 33a as a part thereof is formed of these materials. In addition, as in this embodiment, when the dropping target is a molten metal, it is more preferable to form the rod 33 or a part thereof with Hastelloy, titanium or the like. Further, as in the present embodiment, when the object to be dropped is a molten metal, it is preferable to thermally shut off the rod 33 and the actuator 31 that receive the heat because the liquid or the like is heated. For this reason, in this embodiment, the heat insulating portion 37 is disposed between the rod 33 and the joint 35. However, depending on the melting temperature of the liquid, the heat resistance of the actuator, the use conditions of the liquid, etc., the heat insulating part 37 can eliminate this. Alternatively, it is also preferable that the rod 33 is made of a heat insulating ceramic. Since the rod 33 is made of ceramic, in addition to its own hardness, it is not necessary to consider the heat insulating properties of the structure in the vicinity of the heat insulating portion 37, so that this can be made a simpler structure. As a result, the stroke operation of the actuator propagates directly to the tip (reduced diameter end portion 33a) of the rod 33, and it becomes possible to set the conditions for dropping the metal more easily.

  The body 50 includes a liquid receiver 51, a liquid reservoir 53, a body side flange 55, a body inner space 57, a heater 59, a body body 61, a liquid supply path 63, and an inert gas supply / discharge path 65. The body internal space 57 is a space arranged on the predetermined forming axis A described above, and the actuator system 30 side is closed by the body side flange 55, and the nozzle unit 10 side is closed by the liquid receiver 51. A through-hole 55a is formed in the body-side flange 55 in the direction of a predetermined forming axis A, and the rod 33 described above penetrates the inside of the body internal space 57. The liquid receiver 51 has a bowl shape, and forms a liquid pool 53 by storing liquid in the recess. The nozzle hole 11a communicates with the liquid reservoir 53 to allow the liquid in the liquid reservoir 53 to flow out to the liquid dropping side at the opening of the nozzle hole 11a. In addition, a liquid supply path 63 communicates with the body internal space 57 so that the liquid can be supplied into the body internal space 57.

  In the present invention, a cylindrical guide cylinder portion 51 a having an inner diameter into which the reduced diameter end portion 33 a disposed coaxially with the reduced diameter end portion 33 a is disposed with respect to the liquid receiver 51. The inner surface of the liquid receiver 51 has a shape similar to the inner surface of a funnel, and has an effect of causing the liquid to flow toward the axis. The distal end portion of the conventional rod 33 has a partial conical shape corresponding to this funnel-like inner surface because it must be ensured to some extent with the operating range. However, when the droplet diameter to be obtained is small and the operating range of the rod 33 is small, it is difficult to keep the distance between each part of the funnel-like inner surface and the tip of the rod 33 within an allowable error according to this operating range. Become. For this reason, the wave formed by the rod 33 to be described later cannot be evenly applied in the axial direction, which may affect the ejection direction of the droplet. In the present invention, the columnar diameter-reduced end portion 33a whose interval is easily regulated is operated in the cylindrical guide tube portion 51a to obtain a wave. Thereby, the wave propagates in the axial direction and the horizontal direction, and propagation in an unnecessary direction is suppressed. Therefore, according to the present invention, even if the droplet has a small diameter, the wave can be supplied and propagated along the axis of the rod 33 that coincides with the ejection direction, and the ejection of the droplet in a desired direction can be performed. It becomes possible.

  Similar to the reduced diameter end portion 33a of the rod 33, the inner wall of the body inner space 57 that may come into contact with the liquid, the liquid receiver 51, and the inner wall of the liquid supply path 63 are repellent to the liquid to be dropped. It is preferable that the material is made of a liquid material or the surface is covered with such a material. Therefore, it is preferable that these regions are covered with Teflon, DLC, titanium, or the like, or these structures are formed of these materials. Further, as in the present embodiment, when the dropping target is a molten metal, it is more preferable to form the liquid receiver 51 or the body main body 61 with Hastelloy, titanium, or the like. Furthermore, in order to suppress the oxidation of the molten metal, the space inside the liquid surface formed above the liquid reservoir 53 in the body internal space 57 is preferably filled with an inert gas such as nitrogen. The supply / discharge path 65 is used to supply and discharge these inert gases. However, when the dropping target is other than these, the inert gas supply / discharge path 65 can be removed. Since the metal present in the liquid reservoir 53 stored in the liquid receiver 51 is in a molten state or needs to be maintained in a molten state, the heater 59 heats the body main body 61, the liquid receiver 51, and the nozzle 11. To do.

  Next, the operation principle of the liquid dropping apparatus according to this embodiment will be described. 3 (a) to 3 (d) show respective operation states of the liquid dropping apparatus 100 shown in FIGS. FIG. 3A shows a state before the liquid is dropped, and a state in which the liquid supply to the liquid reservoir 53 is completed through the liquid supply path 63. When the liquid is dropped, as shown in FIG. 3B, the actuator 33 moves the rod 33 in the arrow B direction (the direction toward one on the predetermined forming axis A) by the distance s. In the present embodiment, the distance s, which is the movement stroke, is 8 to 48 μm, and the time required for the movement is 300 to 420 μsec. By this movement of the rod 33, a dense wave is formed in the liquid at the tip of the rod 33 as shown in FIG. Wave energy is present in this dense wave. For example, submerged ultrasonic cleaning uses this wave energy. The liquid 1 given the wave energy is discharged into the external space as a droplet 1 as shown in FIG. 3D through a part of the nozzle holes 11a. In the above configuration, the droplet diameter can be arbitrarily set by a combination of the inner diameter of the nozzle hole 11a and the movement stroke s of the rod 33. Specifically, a droplet diameter of 60 to 150 μm is obtained. It has been.

  As described above, the present embodiment is intended to drop molten metal such as solder. A configuration suitable for molten metal will be described below with reference to FIGS. 4A and 4B showing the nozzle unit 10 in an enlarged manner in the same manner as FIG. Here, D is the inner diameter of the guide cylinder portion 51a, d is the outer diameter of the reduced diameter end portion 33a, Dn is the inner diameter of the nozzle hole 11a, and d2 is the reduced diameter end portion 33a provided in this embodiment. The outer diameter of the connecting portion 33c, which has an outer diameter larger than the outer diameter and smaller than the outer diameter of the rod 33 and connects the reduced diameter end portion 33a to the rod 33, g is below the cylindrical reduced diameter end portion 33a. The gaps in the state where the end surface 33b and the bottom surface of the guide cylinder portion 51a having the cylindrical inner shape are closest to each other are shown. In addition to these conditions, a molten metal having a desired outer diameter can be obtained by appropriately setting the stroke s, which is the movement distance of the rod 33 during the wave formation, and the movement time t required for the movement of the stroke s. For example, when obtaining a molten metal having a droplet diameter of 60 to 150 μm as described above, the nozzle hole diameter Dn is preferably 15 to 70 μm. The moving stroke s is preferably 8 to 48 μm, and the moving time t is preferably 300 to 420 μsec as described above.

  Next, these conditions will be described in more detail. FIG. 5 is a diagram showing only the reduced diameter end portion 33a, the guide tube portion 51a, and the nozzle hole 11a, and is a diagram for explaining the subsequent conditions. The bottom surface 33b of the reduced diameter end portion 33a is always located inside the guide tube portion 51a so that the wave generated by this operation stays inside the guide tube portion 51a without unevenly spreading. A gap g and a moving stroke s are set in advance. Under these conditions, the area ratio of the area Sd of the diameter-reduced end bottom surface 33b and the area SD of the guide cylinder bottom surface 51b is (SD−Sd) and Sd, and whether or not a suitable droplet is ejected. I confirmed the relationship. As a result, when this ratio is in the range of 1 ± 10%, suitable droplet ejection was obtained. This is mainly due to the wave propagating around the reduced diameter end portion 33a when the ratio is large, and when the ratio is small, favorable propagation of the wave itself is hindered by the influence from the inner surface of the guide tube portion 51b. it is conceivable that. In this embodiment, a connecting portion 33c is also provided. By arranging the connecting portion 33c, an effect of suppressing a reduction in the proportion of the wave that propagates effectively to the information of the guide tube portion 51b and acts effectively can be obtained.

  Further, in this embodiment, the periphery of the dropping side opening of the nozzle hole 11a is set to an atmosphere of a high-temperature inert gas, and the dropping side atmosphere space 19 is filled with heated nitrogen. Accordingly, the molten metal dropped from the nozzle hole 11a is exposed to a high temperature atmosphere, so that the viscosity does not increase, and so-called cracking of the droplet is improved. Accordingly, it is possible to obtain smaller droplets and to suppress variations in the shape of the molten metal that has been dropped. In addition, an effect of reducing the adhesion of metal around the opening of the nozzle hole 11a can be expected. In particular, as described above, this effect becomes more conspicuous if the nozzle 11 and the like are made of a material having liquid repellency, preferably corundum. Therefore, it is preferable to use this for bump formation for electronic parts, for example. As described above, the temperature of the atmosphere is preferably equal to or higher than the melting point of the molten metal. For example, in the case of solder, a nitrogen gas of 300 ° C. is preferable. By driving the actuator 31 under this condition, it is possible to drop the molten metal droplet 1 from the nozzle 11 as shown in FIG.

  In this embodiment, it is also easy to clean the apparatus by removing the nozzle unit 10 and the liquid receiver 51 from the body 50 and removing the liquid reservoir 53 by this. In this embodiment, by removing the nozzle flange 15 from the body main body 61, the nozzle presser 13 and the nozzle 11 that are pressed and fixed to the body main body 61 by the disc spring 17 can also be removed from the body main body 61. At the same time, the liquid receiver 51 can be removed from the body main body 61. In this embodiment, the portion of the liquid reservoir 53 that comes into contact with the liquid is a liquid-repellent surface, so that the liquid or the solidified molten metal is not fixed to the surroundings and can be easily removed. After these steps are performed and the interior of the body space 57 is cleaned, the components are combined in the reverse order to the above, and finally the nozzle flange 15 is fixed to the body body 61 to complete the assembly of the apparatus again. To do.

  In addition, when the desired droplet diameter is further smaller, or when the allowable stroke of the rod 33 is very small because the viscosity of the liquid is small, it is conceivable that the conditions for suitably ejecting the droplet are very limited. In this case, for example, a sealing member such as a so-called O-ring is disposed on the body-side flange 55 so that the body inner space 57 is hermetically sealed, and an inert gas is supplied thereto using the inert gas supply / discharge path 65. It is also conceivable to pressurize the interior of the space. By constantly applying the pressure to the liquid in an auxiliary manner, it is possible to suitably obtain a small-diameter droplet even with a very small stroke.

  In the above-described embodiment, the reduced diameter end portion has a cylindrical shape, and the guide tube portion is described as having a cylindrical inner shape. However, the present invention is not limited to this form, and from the viewpoint of preventing wave diffusion, the reduced diameter end portion is disposed at the side end portion of the liquid reservoir of the rod and has a columnar shape having an axis that coincides with a predetermined forming axis A. In this case, the guide tube portion is located on the nozzle hole side of the liquid reservoir and is disposed between them, and is similar to the cross-sectional shape perpendicular to the axis of the reduced diameter end portion and large at a predetermined magnification. It may have a columnar inner shape having a cross-sectional shape. The predetermined magnification in this case satisfies the condition of 90% <(SD−Sd) / Sd <110%, where Sd is the cross-sectional area of the reduced diameter end portion and SD is the inner diameter of the guide tube portion. Anything is fine.

  Next, a second embodiment of the present invention will be described below with reference to FIG. 6 showing this embodiment in the same manner as FIG. Note that the same reference numerals are used for the same components in the embodiment described below and the first embodiment described above, and the description thereof will be omitted hereinafter. As shown in FIG. 6, the liquid dropping apparatus 101 according to the present embodiment differs from the first embodiment in that it includes a guard nozzle 21 fixed to the nozzle flange 15 and a second inert gas supply path 23. Is different. When the guard nozzle 21 is fixed to the nozzle flange 15, the guard nozzle 21 has a guide hole 21 a that is coaxial with the nozzle hole 11 a, the presser through hole 13 a of the nozzle presser 13, and the flange through hole 15 b of the nozzle flange 15. The tip of the guard nozzle 21 (the portion facing the substrate) has a pointed shape so that the portion facing the substrate is small.

  In order to increase the landing accuracy of the droplet 1, it is preferable to bring the opening of the nozzle hole 11a close to the adherend of the droplet 1. In the case of the first embodiment, the inert gas supplied from the dropping-side atmosphere space 19 flows to another space through a gap between the substrate facing surface of the nozzle flange 15 and the substrate. Here, when the lower surface of the nozzle flange 15 becomes a substrate facing surface having an area of a certain extent or more, as the gap becomes narrower than necessary, the increase in the wind pressure of the inert gas here and the turbulence of the air flow become remarkable, Conversely, the landing accuracy of the droplet 1 may be reduced. By disposing the guard nozzle 21 having a pointed shape as in the present embodiment, the inert gas released from the tip of the nozzle easily flows to another space. Therefore, an event such as an extreme increase in the wind pressure and turbulence of the airflow does not occur, and an effect that the landing accuracy is improved can be obtained. Further, by sharpening the tip portion of the guard nozzle 21, even when an object that can be an obstacle on the substrate at the time of landing of the droplet already exists, the droplet 1 is supplied while suppressing these influences. The effect that it becomes possible is also acquired.

  The structure of the guide nozzle 21 varies depending on the size or material of the droplet used, but is preferably set based on the inner diameter Dn of the nozzle hole 11a. In the present invention, the liquid discharged from the nozzle hole 11a is spheroidized by surface tension after discharge, so that the outer diameter increases from the liquid outer diameter at the time of discharge. Further, although the droplet 1 is formed by wave motion, it is preferable to give a certain amount of kinetic energy to the droplet 1 in order to bring the droplet 1 to the landing position. It is considered that it is preferable in terms of the structure of the liquid dropping device. From the above viewpoint, considering the relationship with the outer diameter of the droplet 1 and the flow of the inert gas, the inner diameter Dg of the guide hole 21a is preferably designed to satisfy the relationship of Dn × 2 ≦ Dg. . Further, in order to suppress the retention of heated nitrogen in the gap between the tip of the guard nozzle 21 and the substrate surface, the outer diameter De of the guard nozzle 21 has a relationship of De ≦ Dg × 2 and the gap between the tip and the substrate. Da preferably satisfies the relationship 0.2 mm <Da ≦ De.

  In the first embodiment, an inert gas such as high-temperature nitrogen is supplied into the dripping side space 19, and the inert gas is supplied to the adherend together with the droplet 1 through the flange through hole 15b. In this embodiment, as an inert gas supply system for introducing an inert gas into the dropping side space 19, in addition to the inert gas supply path 22 arranged in the first embodiment, a second inert gas supply path 23 is provided. Is provided. In the present embodiment, nitrogen is used as an inert gas, as in the first embodiment. Moreover, the dropping side space 19 described above constitutes a part of this inert gas supply system. In this embodiment, the nitrogen supplied from the nitrogen supply source 25 is heated to a predetermined temperature through the gas heating region 26 and then into the first inert gas supply path 22 and the second inert gas supply path 23. To be separated. The gas heating region 26 is constructed as an inert gas heating means comprising a known heating source, and can heat nitrogen until the temperature exceeds the melting point of the droplet 1. The first inert gas supply path 22 has a first flow rate control valve 22a, and a constant amount of heated nitrogen is always supplied to the dripping side space 19 through the path. The heated nitrogen supplied to the dripping side space 19 guides the droplet 1 toward the deposition position through the guide hole 21a and is sprayed onto the substrate surface together with the droplet 1.

  The second inert gas supply path 23 includes a second flow rate adjustment valve 23a and a solenoid valve 23b that opens and closes instantaneously, and allows heated nitrogen to flow intermittently. By opening and closing the solenoid valve 23b, the supply amount of heated nitrogen supplied to the guide hole 21a via the dropping side space 19 can be temporarily or instantaneously increased. By temporarily increasing the amount of heated nitrogen blown using the solenoid valve 23b, an air flow is generated in the guide hole 21a, and the droplet 1 is pointed out without contacting the inner wall of the guide hole 21a. It can be conveyed to a part. By maintaining an inert atmosphere at a high temperature as in the present embodiment, the droplet 1 can be transferred into the guide hole 21a to prevent the droplet 1 from solidifying or oxidizing. The operation time of the solenoid valve 23b is preferably synchronized with or in accordance with the operation timing of the linear motion of the rod 33 by the actuator 31, and is preferably around 10 msec.

  Next, the operation principle of the liquid dropping apparatus according to this embodiment will be described. FIGS. 7A to 7D show the respective operation states of the liquid dropping apparatus 101 shown in FIG. FIG. 7A shows a state before the liquid is dropped, and a state in which the liquid supply to the liquid reservoir 53 is completed through the liquid supply path 63. When the liquid is dropped, as shown in FIG. 7B, the actuator 33 moves the rod 33 by a distance s in the arrow B direction (the direction toward one on the predetermined forming axis A). Further, as indicated by an arrow in the figure, heated nitrogen is supplied into the dropping side space 19 through the first inert gas supply path 22 described above, and flows out of the guard nozzle 21 through the guide hole 21a. ing. In this embodiment, as in the first embodiment, the distance s, which is the movement stroke, is 8 to 48 μm, and the time required for movement is 300 to 420 μsec.

  Due to the movement of the rod 33, a dense wave is formed in the liquid at the tip of the rod 33 as shown in FIG. Wave energy is present in this dense wave. For example, submerged ultrasonic cleaning uses this wave energy. The liquid 1 given the wave energy is discharged into the external space as a droplet 1 as shown in FIG. 7D through a part of the nozzle holes 11a. Along with the operation of the rod 33, the solenoid valve 23b can temporarily supply heated nitrogen from the second inert gas supply path 23, and the movement of the droplet 1 in the guide hole 21a is easier. And The operation timing of the rod 33 and the solenoid valve 23b is the same or adjusted as an operation timing within a range with a deviation of several milliseconds, but the rod 33 and the solenoid valve 23b are substantially the same operation timing including these. You can think that is driven. In the above configuration, the droplet diameter can be arbitrarily set by a combination of the inner diameter of the nozzle hole 11a and the movement stroke s of the rod 33. Specifically, a droplet diameter of 50 to 100 μm is obtained. It has been.

  As described above, the present invention relates to a liquid dropping apparatus suitable for generating and dropping liquid metal microdroplets. However, the application target of the present invention is not limited to this, and the present invention can also be used as a dropping device for a liquid such as a resin.

DESCRIPTION OF SYMBOLS 1: Droplet (molten metal particle), 10: Nozzle unit, 11: Nozzle, 11a: Nozzle hole, 13: Nozzle pressing, 13a: Pressing through-hole, 15: Nozzle flange, 15a: Storage space, 51b: Flange through-hole 17: Belleville spring, 19: Drip side atmosphere space, 21: Guard nozzle, 21a: Guide hole, 22: First inert gas supply path, 22a: First flow control valve, 23: Second inert Gas supply path, 23a: second flow control valve, 23b: solenoid valve, 25: nitrogen supply source, 26: gas heating region, 30: actuator system, 31: actuator, 33: rod, 33a: reduced diameter end, 33b: Reduced diameter end portion bottom surface, 33c: connecting portion, 35: joint, 37: heat insulating portion, 39: plate, 50: body, 51: liquid 51a: guide tube portion, 51b: bottom surface of guide tube portion, 53: liquid reservoir, 55: body side flange, 55a: through-hole, 57: space in the body, 59: heater, 61: body body, 63: liquid supply Path: 65: inert gas supply / discharge path, A: forming axis, B: arrow, s: movement distance, D: guide cylinder inner shape, Da: gap, Dg: guide hole inner diameter, De: guard nozzle tip outer diameter D: Outer diameter of the reduced-diameter end, d2: Outer diameter of the connecting part, g: Gap guide part-reduced-end end gap

Claims (9)

A liquid dropping device for dropping a predetermined amount of liquid,
A liquid receiver for storing the liquid to form a liquid reservoir;
A nozzle having a nozzle hole through which the liquid can pass in communication with a region where the liquid is stored in the liquid receiver;
An actuator,
One end is immersed in the liquid reservoir, the other end is supported by the actuator, and has a rod movable in the direction of the formation axis of the nozzle hole,
The rod can be linearly moved in the direction of the forming axis by the actuator, and wave energy is generated in a part of the liquid reservoir by the linear movement of the rod, and the liquid is moved to the nozzle by the wave energy. Dripped from the hole,
The rod has a columnar reduced diameter end portion disposed on the liquid reservoir side and having an axis that coincides with the forming axis;
The liquid reservoir is disposed between the nozzle hole and a guide cylinder portion having a columnar inner shape that is similar to the cross-sectional shape perpendicular to the axis of the reduced diameter end portion and has a large cross-sectional shape at a predetermined magnification. A liquid dropping apparatus comprising:   The condition of 90% <(SD−Sd) / Sd <110% is satisfied, where Sd is an area of the cross section of the reduced diameter end portion and SD is an inner diameter of the guide tube portion. The liquid dropping apparatus according to 1.   The liquid dripping device according to claim 1, wherein the liquid reservoir has a predetermined space on a liquid surface of the liquid existing in the liquid reservoir.   The liquid dripping according to claim 3, further comprising an inert gas supply / discharge path capable of supplying and discharging an inert gas in the predetermined space and allowing the liquid to be held in an inert gas atmosphere. apparatus.   5. The liquid dropping apparatus according to claim 3, wherein the predetermined space is a sealed space and has pressure maintaining means for holding the pressurized space in a state of being pressurized by 0.5 to 2.0 Pa.   The liquid dripping device according to claim 1, wherein the nozzle is formed of corundum.   A guide hole that is coaxial with the axis of formation of the nozzle hole and communicates with the nozzle hole and has a predetermined length, and an inert gas that can be supplied to the guide hole from the side that communicates with the nozzle hole. The liquid dropping apparatus according to claim 1, further comprising an active gas supply system, wherein the liquid is guided in a dropping direction by the flow of the inert gas in the guide hole. .   The liquid dropping apparatus according to claim 7, wherein the inert gas supply system can temporarily increase the supply amount of the inert gas according to a linear motion of the rod by the actuator.   The inert gas supply system further includes an inert gas heating unit, and the inert gas heating unit is capable of heating the temperature of the inert gas to a temperature exceeding the melting point of the liquid. The liquid dropping apparatus according to 7 or 8.

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