JP5553795B2 - Liquid dripping device - Google Patents

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.

  On the basis of such a background, as disclosed in Patent Documents 2 to 5, techniques for ejecting and adhering molten solder directly to an object to be bonded have been proposed. According to the technique, the problems caused by the use of the conductive ball described above are eliminated. 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 10-137930 A JP 2003-334654 A JP 2006-075781 A Japanese Patent Laid-Open No. 02-175254 JP 2001-232245 A JP 2009-000719 A

  Here, as a method for dropping or discharging a small amount of liquid, a technique disclosed in Patent Document 6 or 7 is also known. Also in these methods, basically, a predetermined amount of liquid is dropped using a change in volume of the liquid, which is the same as in the above-described prior art. However, when volume change is used, when gas is mixed in the liquid, the relationship between the volume change and the pressure change applied for the volume change does not become a linear curve. For this reason, as the amount of liquid dropped becomes smaller, the influence of gas mixture into the liquid on the accuracy of dropping becomes larger. From the above, in the techniques disclosed in Patent Documents 2 to 7, a liquid reservoir is formed in a sealed space where no gas exists, and a volume change in the space is performed to change a predetermined amount of liquid. Allows dripping.

  For example, in the configuration disclosed in Patent Document 8, gas penetration into the nozzle is prevented by configuring the inner wall of the space in consideration of so-called wettability with the liquid to be stored. It can be said that this document paradoxically shows that mixing a gas into the nozzle can be a serious problem when a small amount of liquid is dropped. Further, in the case of the nozzle having such a structure, when the liquid is made of resin, it is possible to perform maintenance by disassembling the nozzle and cleaning each component. However, if the liquid is a molten metal, the solidified metal must be removed.

  The present invention has been made in view of the above situation, and by adopting a method other than the volume change described above, it is possible to eliminate the influence of gas intrusion and the like on the nozzle, and it is simple with excellent maintainability. An object of the present invention is to provide a liquid dropping device that can drop a small amount of liquid with a simple structure.

  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. It is dripped from a nozzle hole.

In addition, it is preferable that the liquid dropping apparatus described above further includes a heating unit that heats the liquid present in the liquid reservoir. The liquid reservoir preferably has a space on the liquid surface of the liquid existing in the liquid reservoir. Further, in this case, it is more preferable to further have an inert gas supply / discharge path that can supply and discharge the inert gas in the space and can hold the liquid in the inert gas atmosphere. In addition, the liquid receiving path further includes a liquid supply path capable of supplying a liquid to the liquid receiver. More preferably, it is formed. Also, a nozzle flange that is disposed on the liquid dropping side of the opening of the nozzle hole so as to cover the periphery of the opening of the nozzle hole and make the periphery of the opening an inert gas atmosphere; It is preferable to further have a dripping side atmosphere space formed between the nozzle presser that is in contact with and fixed to the nozzle. The actuator is more preferably a piezo element. Further, it is more preferable that the atmosphere in the space on the liquid dropping side in the nozzle hole can be maintained at a temperature equal to or higher than the melting point of the liquid. Furthermore, the nozzle is more preferably formed from corundum.
Further, in the liquid dropping apparatus described above, a guide hole that is coaxial with the formation axis of the nozzle hole and communicates with the nozzle hole and has a predetermined length, and an inert gas from the side communicating with the nozzle hole to the guide hole. More preferably, the liquid is guided in the dropping direction by the flow of the inert gas in the guide hole.
Furthermore, it is preferable that the inert gas supply system can temporarily increase the supply amount of the inert gas according to the linear motion of the rod by the actuator.
Furthermore, it is preferable that the inert gas supply system further includes an inert gas heating unit, and the inert gas heating unit can heat the temperature of the inert gas to a temperature exceeding the melting point of the liquid.
Furthermore, it is more preferable that the guide hole further has a release opening that allows the guide hole to communicate with the external space of the guard nozzle constituting the guide hole together with the opening provided in the liquid dropping direction.

  According to the present invention, wave energy applied from the rod is used to discharge the liquid from the nozzle. Therefore, it is not necessary to completely remove the gas from the liquid reservoir, and the configuration of the nozzle can be simplified by removing the configuration for removing the gas. Further, unlike the configuration in which the volume change is caused, it is possible to introduce the gas into the nozzle without any problem. 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 a figure which shows the initial stage in the liquid dripping process in the liquid dripping apparatus shown in FIG. It is a figure which shows the state which moved the rod linearly in the liquid dripping apparatus shown in FIG. It is a figure which shows the state which produced the close-packed wave with respect to the liquid of the rod front-end | tip part periphery in the liquid dripping apparatus shown in FIG. It is a figure which shows the dropping step of a liquid in the liquid dripping apparatus shown in FIG. In the embodiment shown in FIG. 1, it is a figure which expands and shows the nozzle vicinity regarding a structure suitable when a molten metal is made into object further. It is a figure which shows the state by which a liquid metal is dripped in the structure shown to FIG. 3A. It is a further form of this invention, Comprising: It is a figure which shows typically the case where a dripping direction differs from the form shown in FIG. It is a figure which shows typically the shape of the electronic component manufactured with the manufacturing apparatus of the electronic component using the liquid dripping apparatus which concerns on this invention. It is a figure which shows typically the structure of the manufacturing apparatus of the electronic component using the liquid dripping apparatus which concerns on this invention. It is a figure which shows typically the case where it is a case where electrode joining is performed by a prior art, and this is seen from the electrode front about the electronic component at the time of producing a bridge | bridging. It is a figure which shows the case where the structure shown to FIG. 7A is seen from the electrode side surface. It is a figure which shows the state which looked at the initial stage in the electrode joining process at the time of using the liquid dripping apparatus concerning this invention from the electrode front regarding the electronic component shown to FIG. 7A and 7B. It is a figure which shows the case where the structure shown to FIG. 8A is seen from the electrode side surface. It is a next stage of the process shown in FIG. 8A, and shows a state where metal particles are dropped on the electrode. It is a figure which shows the case where the structure shown to FIG. 9A is seen from the electrode side surface. It is a next stage of the process shown in FIG. 9A and shows a state in which metal particles are remelted and solidified. It is a figure which shows the case where the structure shown to FIG. 10A is seen from the electrode side surface. 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 the initial stage in the liquid dripping process in the liquid dripping apparatus shown in FIG. It is a figure which shows the state which moved the rod linearly in the liquid dripping apparatus shown in FIG. It is a figure which shows the state which produced the close-packed wave with respect to the liquid of the rod front-end | tip part periphery in the liquid dripping apparatus shown in FIG. It is a figure which shows the dripping step of the liquid in the liquid dripping apparatus shown in FIG. It is a figure which shows the further aspect of the liquid dripping apparatus which concerns on 2nd embodiment. It is a figure which shows the further aspect of the liquid dripping apparatus which concerns on 2nd embodiment. It is a figure which shows the further aspect of the liquid dripping apparatus which concerns on 2nd embodiment.

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. 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, 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 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.

  Note that at least one end of the rod 33 immersed in the liquid in the liquid reservoir 53 is formed of a material having liquid repellency with respect to the liquid to be dropped, or the surface is covered with such a material. It is preferable. Therefore, it is preferable that these regions are covered with Teflon, DLC (Diamond-like-Carbon), titanium, or the like, or the rod 33 or 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.

  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.

  Similar to one end 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 liquid repellent with respect to the liquid to be dropped. It is preferable that the material is made of a material having a property 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. 2A to 2D respectively show the operation states of the liquid dropping apparatus 100 shown in FIG. FIG. 2A shows a state before the liquid is dropped, and a state where the liquid has been replenished to the liquid reservoir 53 via the liquid supply path 63. When the liquid is dropped, as shown in FIG. 2B, 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 a movement stroke, is 20 to 40 μm, and the time required for movement is 300 to 500 μsec. Due to the movement of the rod 33, a dense wave w is formed in the liquid at the tip of the rod 33 as shown in FIG. 2C. Wave energy is present in this dense wave. For example, submerged ultrasonic cleaning uses this wave energy. The liquid 1 to which the wave energy is given is discharged into the external space as a droplet 1 as shown in FIG. 2D 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 30 to 200 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 using FIGS. 3A and 3B showing the nozzle unit 10 in an enlarged manner in the same manner as FIG. In this embodiment, the periphery of the dropping side opening of the nozzle hole 11a is set to an atmosphere of 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 a corundum or the like. 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. 3B.

  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 the above embodiment, the case where the predetermined forming axis direction A, which is the liquid dropping direction, coincides with the vertical direction has been described. However, the usage mode of the liquid dropping apparatus according to the present invention is not limited to this. Other usage patterns will be described with reference to the usage pattern shown in FIG. Since each component is the same as the above-described embodiment, the description is omitted using the same reference numerals and the like. For example, it may be more convenient if the dropping trajectory of the droplet 1 has a predetermined angle with respect to the vertical direction. FIG. 4 illustrates such a case.

  The form shown in FIG. 4 shows a case where a predetermined forming axis A, which is an axis connecting the center of the nozzle hole 11a and the central axis of the rod 33, is inclined by a predetermined angle α with respect to the vertical direction. In this case, if the tip of the rod 33 is immersed in the liquid pool 53, it is possible to generate and transmit wave energy to the liquid. Therefore, liquid can be extracted from the opening of the nozzle hole 11a. In addition, although the dripping locus | trajectory of a liquid does not become a straight line, it becomes what approximated the quadratic curve started at a predetermined angle from the opening part of the nozzle hole 11a. Therefore, by assuming this dropping trajectory in advance, it is possible to drop the liquid in a direction different from the vertical direction and supply the droplet to a desired dropping position.

Next, a specific example of an electronic component manufacturing apparatus constructed using the liquid dropping apparatus according to the present invention will be described. FIG. 4 schematically shows a cross section of an electronic component in which resin is sealed by the manufacturing apparatus. In the electronic component 3, a chip-shaped electronic component 5 is disposed in a cavity 4 a provided in the substrate 4 and sealed with a resin filler 6. In the electronic component 3, for example, the recess is assumed to have a diameter of 2.7 mm and a depth of 0.85 mm. The liquid level is recognized to have a tolerance of Δd in the range of 10 μm. Here, assuming that there is no shape change due to surface tension, the volume corresponding to the allowable error of the resin filler 6 is (2.7 / 2) ² × π × 0.010 = 0.057 mm ³ . Assuming that the discharge accuracy of a general air dispenser is 0.1 mg and the specific gravity ρ of the liquid is 1, 1 g = ρcm ³ and cm3 = mm ³ × 10 ³ , so the previous discharge accuracy is 0.1 ρcm ³ × 10 ^{− 3} = 0.1 mm ³ It is understood that it is difficult to manage the volume corresponding to the previous tolerance.

  Therefore, according to such a problem, the electronic device manufacturing apparatus shown in FIG. 5 can be constructed using the present invention. The manufacturing apparatus 200 includes a substrate transport system 201, a dispenser 207 included in the substrate transport system 201, a preheating stage 203, a coating stage 205, a measurement stage 209, a replenishment stage 213, a dispenser 207, a measurement device 211, a dispenser controller 215, It has the calculating part 217, the controller 219, the monitor 221, and the liquid dripping apparatus 100 which concerns on this invention. The substrate 4 is first preheated on the substrate transport system 201 by the preheating stage 203, and the resin filler 6 is injected by the dispenser 207 controlled by the dispenser controller 215 at the coating stage 205. At this time, the filling amount of the liquid is set in advance as an amount smaller than a predetermined value.

Subsequently, at the measurement stage 209, the liquid level of the resin filler 6 is measured by the measurement device 211, and the suitability and the deficiency are measured by the calculation unit 217. The measurement result and the like are displayed on the monitor 221 and sent to the controller 219, and the controller 219 instructs the liquid dropping device 100 to supply the replenishment amount. The substrate sent to the replenishment stage 213 is dripped and replenished with liquid from the liquid dripping device 100 in accordance with a command from the controller 219 to obtain an appropriate sealed state. The liquid dropping apparatus 100 according to the present invention can drop a droplet having a diameter of about 100 μm, and its volume is (4/3) × π × r3 = 0.004 mm ³ , so that the number of dropped droplets is controlled. This makes it possible to adjust the amount of liquid for the number of drops with a resolution of 0.004 mm ³ .

  Next, a specific example of an electronic component manufacturing apparatus constructed using the liquid dropping apparatus according to the present invention will be described. FIG. 7A shows a state in which the electrodes of the electronic parts to be joined are viewed from the front, and FIG. 7B shows a state in which the electrodes are seen from the side, where these electrodes are joined by a conventional method. Each is schematically shown. The electronic component 7 is provided with electrodes 7 a, and these electrodes 7 a are joined to the substrate-side electrode 4 b provided on the substrate 4 by solder 8. At that time, for example, when the electrode pitch is less than 100 μm, the gap between the pitches is too narrow, so that there is a high risk that the solder paste or the like causes a so-called bridge (short circuit) as shown in the figure.

  Therefore, the electrodes are joined by using the apparatus of the present invention to drop droplets 1 as molten metal particles a plurality of times within the range of the electrode width and temporarily fix them, followed by reflow or the like. 8A, 8B, 9A, 9B, 10A and 10B illustrate this process step by step. 8A, 9A, and 10A show the electronic components in the same manner as in FIG. 7A, and FIGS. 8B, 9B, and 10B show the electronic components in the same manner as in FIG. 7B. is there. As shown in FIG. 8A, this embodiment assumes a case where the electrode pitch is 60 to 80 μm. As shown in FIGS. 9A and 9B, molten metal particles (droplet 1) are dropped a plurality of times on the butt portion between the electrode 7a and the substrate side electrode 4b, and these are temporarily fixed between the individual electrodes. . Subsequently, as shown in FIG. 10B, a heat ray is irradiated onto the bonding region D (FIG. 10A) by a heat ray irradiator 9 such as a laser to remelt the metal particles 1. When the remelted metal particles are solidified, the electrode 7a and the substrate side electrode 4b can be electrically joined. According to the present invention, metal particles having a diameter of less than 50 μm can be formed, and silver, gold (gold solder), copper, etc. can be considered in addition to solder as the metal used for the bonding shown here.

  Next, a second embodiment of the present invention will be described below with reference to FIG. 11 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. 11, the liquid dropping apparatus 101 according to this embodiment is different 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. 12A to 12D respectively show the operation states of the liquid dropping apparatus 101 shown in FIG. FIG. 12A shows a state before the liquid is dropped, and a state where the liquid has been replenished to the liquid reservoir 53 via the liquid supply path 63. When the liquid is dropped, as shown in FIG. 12B, 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. 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 the present embodiment, the distance s, which is a movement stroke, is 20 to 40 μm, and the time required for movement is 300 to 500 μsec.

  Due to the movement of the rod 33, a dense wave w is formed in the liquid at the tip of the rod 33 as shown in FIG. 12C. 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 as a droplet 1 to the external space through a part of the nozzle holes 11a as shown in FIG. 12D. 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 30 to 200 μm is obtained. It has been.

  Next, further aspects of the second embodiment will be described with reference to the drawings. For example, when the outer diameter of the droplet 1 to be used becomes smaller, the amount of heated nitrogen required to transfer the droplet 1 in the guide hole 21a is the wind pressure between the tip of the guard nozzle 21 and the substrate. There are cases where the impact cannot be ignored. Even in such a case, there may be a case where it is not appropriate to greatly reduce the amount of heated nitrogen required at the time of supplying the droplet 1 by the inner diameter of the guide hole 21a. In the form shown in FIG. 13, as a countermeasure to such a case, a release hole 21 b extending from the outside of the guard nozzle 21 to the guide hole 21 a is added before reaching the opening of the guide hole 21 a. The release hole 21 b extends in a direction different from the extending direction of the guide hole 21 a and communicates with the space around the guide hole 21 a and the guard nozzle 21. By providing such a release hole 21b, heated nitrogen flowing out from the release hole 21 is generated, and the amount of heated nitrogen reaching the opening of the guide hole 21a is suppressed, so that the liquid droplet 1 can be supplied accurately. And

  When the amount of heated nitrogen reaching the substrate surface is insufficient with only this release hole 21b, a slit-like release groove 21c extending along the guide hole 21a is provided as shown in FIG. You may aim at expansion of the route for the outflow of heating nitrogen. The release groove 21c extends in a direction different from the extending direction of the guide hole 21a, particularly in a direction perpendicular thereto, and communicates with the guide hole 21a and the space around the guard nozzle 21. From the above, the release holes 21b and the release grooves 21c are grasped in the present invention as release openings through which excess inert gas can flow out. Moreover, in the aspect shown as 2nd embodiment, it is also considered that the front-end | tip part of the guide nozzle 21 which produces the residence space of heated nitrogen facing the substrate surface is made small. The further aspect shown in FIG. 15 shows a case where the outer diameter Dg of the tip portion of the guide nozzle 21 is further reduced in this way. Specifically, a predetermined range from the tip of the guard nozzle 21 is tubular. In the above-described embodiment, the second inert gas supply path is opened and closed by a solenoid valve. However, any valve device that can synchronize with the piezo element that discharges the droplet 1 is known. Various types of valves can be used. In addition, the guard nozzle 21 may not be configured independently, but may perform the role of the guard nozzle 21 in the present embodiment by performing various processes on the nozzle flange 15. The second inert gas supply path 23 may be arranged as necessary, and can be eliminated depending on the characteristics of the droplet 1 to be used. The length of the guide hole 21a is affected by the flow rate of the inert gas supplied to the guide hole 21a, the ejection speed of the droplet 1 when it exits the nozzle hole 11a, and the like. Therefore, it is preferable to grasp the predetermined length required to give the momentum that the droplet 1 has a predetermined directionality and can be discharged from the guide hole 21a in consideration of these various conditions.

  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 as shown in FIG. 5, the present invention can also be used as a dropping device for a liquid such as a resin.

1: droplet (molten metal particle), 3: electronic component, 4: substrate, 4a: cavity, 4b: substrate side electrode, 5: chip-shaped electronic component, 6: resin filler, 7: electronic component, 7a: electrode 8: Solder, 9: Heat beam irradiator, 10: Nozzle unit, 11: Nozzle, 11a: Nozzle hole, 13: Nozzle presser, 13a: Presser through hole, 15: Nozzle flange, 15a: Housing space, 51b: Flange through Hole: 17: disc spring; 19: drip side atmosphere space; 21: guard nozzle; 21a: guide hole; 22: first inert gas supply path; 22a: first flow control valve; Active gas supply path, 23a: second flow control valve, 23b: solenoid valve, 25: nitrogen supply source, 26: gas heating area, 30: actuator system, 31: actuator 33: Rod, 35: Joint, 37: Thermal insulation part, 39: Plate, 50: Body, 51: Liquid receptacle, 53: Liquid reservoir, 55: Body side flange, 55a: Through hole, 57: Space in the body, 59: heater, 61: body main body, 63: liquid supply path, 65: inert gas supply / discharge path, 100, 101: liquid dropping apparatus, 200: electronic component manufacturing apparatus, 201: substrate transport system, 203: preheating stage, 205: Application stage, 207: Dispenser, 209: Measurement stage, 211: Measuring instrument, 213: Replenishment stage, 215: Dispenser controller, 217: Calculation unit, 219: Controller, 221: Monitor, A: Forming axis, B: Arrow, s: moving distance, w: close-packed wave, Δd: tolerance, D: junction area , Α: predetermined tilt angle, Da: gap, Dg: guide hole inner diameter, De: guard nozzle tip outer diameter

Claims (11)

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 a rod that is movable in the formation axis direction of the nozzle hole,
A guide hole that is coaxial with the forming axis of the nozzle hole and has a predetermined length in communication with the nozzle hole;
An inert gas supply system capable of supplying an inert gas to the guide hole from the side communicating with 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 liquid is guided in the dropping direction by the flow of the inert gas in the guide hole,
A nozzle flange which is disposed on the liquid dropping side of the opening of the nozzle hole, covers the periphery of the opening of the nozzle hole, and allows the periphery of the opening to be an inert gas atmosphere; and the nozzle A nozzle holding member that is fixed in contact with the liquid receiver, and a dropping side atmosphere space formed between the nozzle holder and the nozzle flange disposed in the dropping side atmosphere space and biased by the nozzle flange through the nozzle holding member. And a disc spring that presses the liquid receiver to form the liquid reservoir. 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 a rod that is movable in the formation axis direction of the nozzle hole,
A nozzle presser that presses and fixes the nozzle to the liquid receiver, a disc spring that biases the nozzle press toward the liquid receiver, and the liquid receiver, the nozzle, and the nozzle presser via the disc spring. A nozzle flange that is integrally fixed so that a liquid receiver forms the liquid reservoir,
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. A liquid dropping device, wherein the liquid dropping device is dropped from a hole.   The liquid dropping apparatus according to claim 1, further comprising a heating unit that heats the liquid present in the liquid reservoir. The reservoir fluid is above the liquid surface of the liquid present in the collecting the liquid, and having a space, the liquid dropping device according to claim 1 or 3. The liquid dropping apparatus according to claim 4 , further comprising an inert gas supply / discharge path capable of supplying and discharging an inert gas in the space and allowing the liquid to be held in an inert gas atmosphere. A liquid supply path capable of supplying the liquid to the liquid receiver is further provided, and the liquid receiver, the liquid supply path, an inner wall of the space, and a region where the nozzle can come into contact with the liquid are liquid repellent. The liquid dripping device according to claim 4 , wherein the liquid dropping device is formed by a surface of It said actuator liquid dropping device according to any one of claims 1 and 3 to 6, characterized by using a piezoelectric element. The liquid dropping apparatus according to any one of claims 1 and 3 to 7 , wherein an atmosphere in a space on the liquid dropping side in the nozzle hole can be maintained at a temperature equal to or higher than a melting point of the liquid. The nozzle liquid dropping device according to any one of claims 1 and 3 to 8, characterized in that it is formed from corundum. 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 any one of 1 and 3 to 9 . The guide hole further includes an opening provided in the liquid dropping direction, and a release opening that communicates the guide hole with the external space of the guard nozzle that forms the guide hole at a position different from the opening. The liquid dropping apparatus according to any one of claims 1 and 3 to 10 .

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