JP2004305791A - Liquid jet device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a liquid from being blocked, especially prevent clogging with an oxide film. <P>SOLUTION: This liquid jet device 100 is equipped with a tank 10 for storing molten solder S1, the pump chamber 20 provided to the lower part of the tank 10 to communicate with the tank 10 and having a wall surface comprising a diaphragm 30, the discharge nozzle 40 provided to the lower part of the pump chamber 20 to communicate with the pump chamber 20 and a piezoelectric actuator 50 for intermittently pressing the diaphragm 30 to discharge molten solder S1 downward from the discharge nozzle 40. By arranging the tank 10, the pump chamber 20 and the discharge nozzle 40 in a vertical direction, the oxide film does not enter the pump chamber and the molten solder S becomes easy to flow by its own weight to suppress clogging. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a liquid ejecting apparatus that continuously discharges a liquid such as a molten metal into fine spheres, and more particularly, to a liquid ejecting apparatus suitable for manufacturing solder bumps and solder balls.
[0002]
[Prior art]
2. Description of the Related Art In recent years, as electronic devices have become smaller and thinner, high-density mounting technology for electronic components has rapidly advanced. As a semiconductor device for realizing this high-density mounting, an FC (flip chip) or a BGA (ball grid array) having a hemispherical solder bump on a semiconductor substrate or an interposer substrate is used. Patent Documents 1 and 2 below are known as related techniques.
[0003]
Patent Document 1 discloses a method of manufacturing a three-dimensional structure by injecting molten solder from a nozzle in a horizontal direction using a piezoelectric element.
[0004]
Patent Literature 2 discloses a solder ball manufacturing apparatus in which a runner is provided in a horizontal direction of a tank for storing molten solder, a pulse pressurizing device is provided in an upper direction of the runner, and an orifice is provided in a lower direction. Have been. The molten solder travels in the runner in the horizontal direction, and is pressed from above at the tip of the runner, and is discharged from the orifice to become a solder ball.
[0005]
[Patent Document 1]
JP-A-10-156524 (FIG. 1, paragraph 0007, etc.)
[Patent Document 2]
JP-A-11-123592 (FIG. 1, paragraph 0006, etc.)
[0006]
[Problems to be solved by the invention]
However, Patent Document 1 does not disclose any specific structure of the manufacturing apparatus. Further, in Patent Literature 2, since a horizontal and long runner is provided between the tank and the pulse press device and the orifice, there is a problem that clogging of the molten solder is likely to occur. In the case of molten solder, clogging with an oxide film is particularly likely to occur.
[0007]
[Object of the invention]
Therefore, an object of the present invention is to provide a liquid ejecting apparatus that can suppress clogging of liquid and the like.
[0008]
[Means for Solving the Problems]
<< Claims 1 to 3 relate to a basic structure of a liquid ejecting apparatus. 》
[0009]
The liquid ejecting apparatus according to claim 1 includes a tank for storing the liquid, a pump chamber provided below the tank and communicating with the tank, and a pump chamber provided below the pump chamber and communicating with the pump chamber and directing the liquid downward. The apparatus includes a discharge nozzle for discharging, and an actuator that acts on the pump chamber to urge the operation of the discharge nozzle. In other words, a tank that stores the liquid, a pump chamber that is provided below the tank and communicates with the tank, a discharge nozzle that is provided below the pump chamber that communicates with the pump chamber, and discharges the liquid by acting on the pump chamber. And an actuator that discharges downward from the nozzle. Needless to say, the term “up / down” here refers to the vertical direction.
[0010]
The liquid is guided from the tank to the pump chamber, and is discharged as droplets from the discharge nozzle by the actuator. At this time, since the tank, the pump chamber, and the discharge nozzle are arranged in the vertical direction, the liquid easily flows by its own weight, so that clogging is suppressed. In addition, since the flow of the liquid is facilitated, the generation rate of droplets [pieces / second] also increases. Furthermore, even if an oxide film is formed in the tank by the liquid coming into contact with air, the oxide film remains on the surface of the liquid. Therefore, there is no possibility that the oxide film enters the pump chamber below the tank and causes clogging. In particular, when the liquid is molten solder, an oxide film is easily generated, and this effect is remarkable.
[0011]
According to a second aspect of the present invention, in the liquid ejecting apparatus according to the first aspect, the pump chamber has a wall surface formed of a diaphragm, and the actuator urges the operation of the discharge nozzle by intermittently pressing the diaphragm. That is.
[0012]
The liquid is guided from the tank to the pump chamber, and when the diaphragm in the pump chamber is pressed by the actuator, the liquid is discharged from the discharge nozzle as droplets. Also in this case, since the tank, the pump chamber, and the discharge nozzle are arranged in the vertical direction, the liquid easily flows by its own weight.
[0013]
According to a third aspect of the present invention, in the liquid ejecting apparatus of the second aspect, a pump chamber is formed in the block body, a tank is mounted on the block body, and a discharge nozzle is mounted below the block body. That is.
[0014]
Since the pump chamber, the tank, and the discharge nozzle are provided in one block, the size of the liquid ejecting apparatus is reduced. As a result, the flow path of the liquid is shortened, so that clogging is further suppressed, and the generation speed of the droplet is further increased.
[0015]
<< Claims 4 to 9 relate to the structure of the pump chamber. 》
[0016]
The liquid ejecting apparatus according to claim 4 is the liquid ejecting apparatus according to claim 2 or 3, wherein the pump chamber has a columnar shape having an axis in a horizontal direction and one of the circular wall surfaces is a diaphragm. An inlet pipe connected to the tank and an outlet connected to the cavity, and a discharge pipe connected to the cavity and the outlet connected to the discharge nozzle.
[0017]
The liquid is guided from the tank to the cavity through the introduction pipe, and when the diaphragm in the cavity is pressed by the actuator, the liquid is discharged as droplets from the discharge nozzle through the discharge pipe. Also in this case, since the tank, the pump chamber, and the discharge nozzle are arranged in the vertical direction, the liquid easily flows by its own weight.
[0018]
A liquid ejecting apparatus according to a fifth aspect is the liquid ejecting apparatus according to the fourth aspect, wherein an inlet of the discharge pipe portion is connected to an upper edge of the hollow portion.
[0019]
Bubbles may be generated in the cavity. The bubbles absorb the pressure applied to the liquid, and thus hinder the ejection of the droplet. Therefore, by utilizing the fact that bubbles generated in the cavity collect at the upper edge of the cavity by buoyancy, an inlet for the discharge pipe is provided at the upper edge of the cavity, so that the bubbles are quickly led to the discharge pipe. Discharge. This effect is effective not only for air bubbles generated later, but also for air bubbles existing in the first stage (stage where the pump chamber is filled with liquid from a state where no liquid is contained).
[0020]
According to a sixth aspect of the present invention, in the liquid ejecting apparatus according to the fifth aspect, the outlet of the introduction pipe is connected to an inner periphery of the cavity along a tangential direction of the cavity.
[0021]
Since the liquid guided from the outlet of the inlet pipe to the inner periphery of the cavity is urged in the tangential direction of the cavity, the liquid quickly advances along the inner periphery of the cavity and is discharged at the upper edge of the cavity. Reach the entrance to the tube. That is, the flow path of the liquid draws the shape of a “no”. Therefore, the liquid flows more easily and the bubbles are discharged without stagnation.
[0022]
According to a seventh aspect of the present invention, there is provided the liquid ejecting apparatus according to the sixth aspect, wherein a column having the same axis as the cavity protrudes into the cavity, and a liquid from an outlet of the introduction pipe to an entrance of the discharge pipe. Is formed around the cylinder.
[0023]
When a cylinder having the same axis as the cavity is protruded into the cavity, an annular space is formed around the cylinder. In this space, an outlet of the introduction pipe and an inlet of the discharge pipe are opened on the inner wall of the cavity. Therefore, the liquid guided from the outlet of the introduction pipe portion to the inner periphery of the hollow portion does not flow through the portion where the column is located, and therefore, concentrates on the flow path along the inner periphery of the hollow portion around the cylindrical portion. Therefore, the liquid flows more easily, and the bubbles are discharged without further stagnation.
[0024]
The liquid ejecting apparatus according to claim 8 is the liquid ejecting apparatus according to any one of claims 4 to 7, wherein the nozzle has a through hole smaller than the inner diameter of the introduction pipe section at an entrance, an exit, or in the middle of the introduction pipe section. Is provided.
[0025]
When the liquid in the cavity is pressed by the diaphragm, the liquid tends to escape from the introduction tube and the discharge tube that are open to the cavity. Of course, escaping a large amount of liquid from the introduction pipe portion is an excessive backflow of the liquid. Therefore, it is desirable to provide a check valve between the introduction pipe portion and the tank. However, when the diameter of the introduction pipe portion is extremely small, the resistance of a check valve having an ordinary complicated structure is too large and causes clogging. Therefore, a nozzle having a through hole smaller than the inner diameter of the introduction pipe is provided, for example, between the introduction pipe and the tank. The inner diameter and length of the through-hole are factors that determine the flow path resistance of the liquid. It is desirable that the size and shape of the through hole be the same as the resistance of the discharge nozzle, or have a resistance close to it. This nozzle has a function of suppressing backflow, and does not cause clogging due to its simple structure.
[0026]
A liquid ejecting apparatus according to a ninth aspect is the liquid ejecting apparatus according to any one of the fourth to seventh aspects, wherein the same thing as the discharge nozzle is connected to the entrance, the exit, or the middle of the introduction pipe portion. is there.
[0027]
For example, if the discharge nozzle is provided between the introduction pipe and the tank, the same discharge nozzle is provided in both the introduction pipe and the discharge pipe from the viewpoint of the liquid in the cavity. The resistance of the flow path is the same in the portion. On the other hand, while the liquid filled in the tank is located at the end of the introduction pipe, the end of the discharge pipe is open. Therefore, the liquid reliably escapes in the direction in which the liquid easily flows, that is, the discharge pipe portion. That is, the discharge nozzle provided between the introduction pipe section and the tank has a function of suppressing backflow. In this case, the number of types of components is one less than when a check valve is separately provided. In addition, since the discharge nozzle is designed not to cause clogging, clogging does not occur even when used as a check valve.
[0028]
<< Claims 10 to 12 relate to the structure of the actuator. 》
[0029]
In a liquid ejecting apparatus according to a tenth aspect, in the liquid ejecting apparatus according to the third aspect, the actuator is a columnar piezoelectric actuator, and the piezoelectric actuator is formed into a block by a free end that presses the diaphragm and a support member. And a fixed end on the side to be fixed.
[0030]
The piezoelectric actuator expands and contracts by a piezoelectric effect when a voltage is applied. At this time, the fixed end of the piezoelectric actuator is fixed to the block body by the support member. Therefore, all displacements of the piezoelectric actuator are reflected on the free end, and the free end expands and contracts and presses the diaphragm. The piezoelectric actuator has the following features. ▲ 1 ▼. Response is fast. ▲ 2 ▼. The amplitude of the diaphragm can be controlled on the order of microns. (3). By adjusting electric signals such as voltage, frequency, and waveform, various fluid discharges can be performed.
[0031]
The liquid ejecting apparatus according to an eleventh aspect is the liquid ejecting apparatus according to the tenth aspect, further comprising an actuator holder fixed to the support member and fixing a free end of the piezoelectric actuator via an elastic member. .
[0032]
The free end of the piezoelectric actuator is fixed to the actuator holder via an elastic member. The actuator holder is fixed to the block via a support member. Therefore, the stiffness of the piezoelectric actuator can be improved while the free end of the piezoelectric actuator can be extended and contracted.
[0033]
A liquid ejecting apparatus according to a twelfth aspect is the liquid ejecting apparatus according to the eleventh aspect, wherein the elastic member is formed by processing a part of the actuator holder into an annular shape.
[0034]
When a part of the actuator holder is machined into an annular shape, this part has elasticity. Therefore, an elastic member can be obtained without increasing the number of parts.
[0035]
<< Claims 13 to 16 relate to a structure of a heater and a structure of heat insulation thereof. 》
[0036]
A liquid ejecting apparatus according to a thirteenth aspect is the liquid ejecting apparatus according to the third aspect, wherein a heater for heating the pump chamber, the tank, and the discharge nozzle is embedded in the block body.
[0037]
Since the pump chamber, the tank, the discharge nozzle, and the heater are provided in one block, the liquid ejecting apparatus is reduced in size, and the heat generated from the heater is efficiently transmitted to the pump chamber, the tank, and the discharge nozzle.
[0038]
According to a fourteenth aspect of the present invention, in the liquid ejecting apparatus according to the thirteenth aspect, the actuator is a columnar piezoelectric actuator, and the piezoelectric actuator includes a free end on the side that presses the diaphragm and a supporting member having heat insulation. And a fixed end on the side fixed to the block body.
[0039]
The fixed end of the piezoelectric actuator is fixed to the block by a support member. On the other hand, since the block body is heated by the heater, the temperature of the block body becomes high. Since the operation of the piezoelectric actuator is hindered at high temperatures, the use of a heat-insulating support member prevents heat conduction from the block body to the fixed end.
[0040]
A liquid ejecting apparatus according to a fifteenth aspect is the liquid ejecting apparatus according to the fourteenth aspect, wherein a heat insulating sheet for blocking radiant heat from the block body is provided between the block body and the piezoelectric actuator.
[0041]
The heat which affects the piezoelectric actuator from the block body includes not only heat conduction but also heat radiation. Therefore, a heat insulating sheet is provided between the block body and the piezoelectric actuator to prevent radiant heat from the block body.
[0042]
The liquid ejecting apparatus according to claim 16 is the liquid ejecting apparatus according to claim 15, wherein the block body side and the piezoelectric actuator side are separated by a heat insulating sheet, and a fan for cooling the piezoelectric actuator is provided on the piezoelectric actuator side. Things.
[0043]
Since the block body side and the piezoelectric actuator side are separated by the heat insulating sheet and the fan is provided on the piezoelectric actuator side, the wind of the fan hits only the piezoelectric actuator. Therefore, the block body that needs to maintain a high temperature does not hit the wind, and only the piezoelectric actuator is efficiently cooled.
[0044]
<< Claim 17 relates to the type of liquid. 》
[0045]
A liquid ejecting apparatus according to a seventeenth aspect is the liquid ejecting apparatus according to any one of the first to sixteenth aspects, wherein the liquid is molten solder.
[0046]
In the liquid ejecting apparatus according to the present invention, since the own weight of the liquid is positively used, a liquid having a higher specific gravity such as a molten metal is more effective. Among the molten metals, the molten solder is most effective because the heater is simple and good due to its low melting point.
[0047]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a liquid ejecting apparatus using molten solder as a liquid will be described with reference to the drawings. The material of each component such as the block body is stainless steel unless otherwise specified. The symbols for washers used with the cap screw are omitted. The illustration of a fluorine resin washer inserted into the contact surface by screwing is omitted.
[0048]
1 to 4 show one embodiment of the liquid ejecting apparatus according to the present invention. FIG. 1 is a vertical sectional view taken along line II of FIG. 3 (a sectional view of the tank includes a center line of the tank). 3 is a front view, FIG. 3 is a plan view, FIG. 4 [1] is a left side view, and FIG. 4 [2] is a vertical sectional view taken along the line IV-IV in FIG. 3 (partly different from FIG. 3). Hereinafter, the basic structure of the liquid ejecting apparatus according to the present invention will be described with reference to these drawings.
[0049]
The liquid ejecting apparatus 100 according to the present embodiment includes a tank 10 that stores the molten solder S1, a pump chamber 20 that is provided below the tank 10, communicates with the tank 10, and has a wall surface including the diaphragm 30. And a piezoelectric actuator 50 which communicates with the pump chamber 20 and discharges the molten solder S1 downward, and a piezoelectric actuator 50 which urges the operation of the discharge nozzle 40 by intermittently pressing the diaphragm 30. It is provided. The pump chamber 20 is formed in the block body 60, the tank 10 is mounted on the block body 60, and the discharge nozzle 40 is mounted below the block body 60. Further, a heater 80 for heating the tank 10, the pump chamber 20, and the discharge nozzle 40 is embedded in the block body 60.
[0050]
The tank 10 has a cylindrical shape and is screwed into a concave portion 11 formed in the block body 60. A joint 12 is screwed onto the tank 10 as necessary, and a tube (not shown) is inserted into the joint 12. The solder particles supplied to the tank 10 are heated by the heater 80 and become molten solder S1.
[0051]
Next, the operation of the liquid ejecting apparatus 100 will be described. The molten solder S1 is guided from the tank 10 to the pump chamber 20, and when the diaphragm 30 of the pump chamber 20 is pressed by the piezoelectric actuator 50, the molten solder S1 is discharged from the discharge nozzle 40 as a droplet S2. At this time, since the tank 10, the pump chamber 20, and the discharge nozzle 40 are arranged in the vertical direction, the molten solder S1 can easily flow by its own weight, so that clogging is suppressed. Further, since the molten solder S1 flows more easily, the generation rate [pieces / second] of the droplet S2 also increases. Furthermore, even if the molten solder S1 comes into contact with air in the tank 10 to form an oxide film, the oxide film remains on the surface of the molten solder S1. Therefore, there is no possibility that the oxide film enters the pump chamber 20 below the tank 10 and causes clogging. Furthermore, since the tank 10, the pump chamber 20, and the discharge nozzle 40 are provided in one block body 60, the size of the liquid ejecting apparatus 100 is reduced. Thereby, the flow path of the molten solder 1 is shortened, so that clogging is further suppressed and the generation speed of the droplet S2 is further increased.
[0052]
5 and 6 show a pump chamber in the liquid ejecting apparatus of FIG. 1, FIG. 5 is an enlarged sectional view, and FIG. 6 is a perspective view. Hereinafter, the pump chamber 20 will be described with reference to FIGS. 1, 5 and 6.
[0053]
The pump chamber 20 has a flat cylindrical shape having an axis L in the horizontal direction, and one circular wall has a diaphragm 30 as a diaphragm 30, an inlet 22 a is connected to the tank 10, and an outlet 22 b is connected to the cavity 21. And a discharge pipe portion 23 in which an inlet 23a is connected to the hollow portion 21 and an outlet 23b is connected to the discharge nozzle 40. The inlet 23a of the discharge pipe portion 23 is connected to the upper edge of the hollow portion 21, and the outlet 22b of the inlet pipe portion 22 is connected to the inner periphery of the hollow portion 21 vertically downward and along the tangential direction of the hollow portion 21. . Further, a flat column 31 (FIG. 5) having the same axis L as the cavity 21 is protruded into the cavity 21, and the molten solder S1 from the outlet 22b of the inlet tube 22 to the inlet 23a of the outlet tube 23 is formed. A channel S3 (FIG. 6) is formed around the column 31.
[0054]
The diaphragm 30 is a disk with a hole in the center, and is supported by a short rod-shaped diaphragm holder 32 and a long rod-shaped diaphragm joint 33. The head of the diaphragm holder 32 is a column 31. The diaphragm retainer 32 is pressed into the diaphragm joint 33 with the diaphragm 30 sandwiched therebetween, and is brazed with silver. A concave portion 34 is formed in the block body 60, and a cylindrical diaphragm fixing ring 35 is screwed into the concave portion 34. The diaphragm 30 is fixed by a diaphragm fixing ring 35 while being housed in the concave portion 34.
[0055]
Next, the operation of the pump chamber 20 will be described.
[0056]
The molten solder S <b> 1 is guided from the tank 10 to the cavity 21 through the introduction pipe 22, and when the diaphragm 30 in the cavity 21 is pressed by the piezoelectric actuator 50, the molten solder S <b> 1 passes from the discharge nozzle 40 through the discharge pipe 23. The droplet S2 is ejected. Also in this case, since the tank 10, the pump chamber 20, and the discharge nozzle 30 are arranged in the vertical direction, the molten solder S1 can easily flow by its own weight.
[0057]
Here, air bubbles (not shown) may be generated in the hollow portion 21. The bubbles absorb the pressure applied to the molten solder S1 by the diaphragm 30, and thus hinder the ejection of the droplet S1. Therefore, by utilizing the fact that bubbles generated in the hollow portion 21 gather at the upper edge of the hollow portion 21 by buoyancy, the inlet 23a of the discharge pipe portion 23 is provided at the upper edge of the hollow portion 21 to quickly discharge the bubbles. I do.
[0058]
Further, since the molten solder S1 guided from the outlet 22b of the introduction pipe portion 22 to the inner periphery of the hollow portion 21 is urged in the tangential direction of the hollow portion 21, the molten solder S1 quickly advances along the inner circumference of the hollow portion 21, It reaches the inlet 23a of the discharge pipe 23 located at the upper edge of the cavity 21. That is, the flow path S3 of the molten solder S1 draws the shape of "". Strictly speaking, it is an inverted "no" character that traces the "no" character in reverse. Therefore, the molten solder S1 flows more easily and the bubbles are discharged without delay.
[0059]
Further, when a column 31 having the same axis L as the cavity 21 is protruded into the cavity 21, an annular space is formed around the column 31. In this space, an outlet 22 b of the introduction pipe 22 and an inlet 23 a of the discharge pipe 23 are opened on the inner wall of the cavity 21. Therefore, the molten solder S1 guided from the outlet 22b of the introduction pipe portion 22 to the inner periphery of the hollow portion 21 does not flow through the portion where the column 31 exists, and therefore flows along the inner periphery of the hollow portion 21 around the column 31. Proceed intensively on road S3. Therefore, the molten solder S1 becomes easier to flow, and the bubbles are discharged without further stagnation.
[0060]
7 [1A] and [2A] show a flat plate nozzle provided between the inlet of the introduction pipe section and the tank, FIG. 7 [1A] is a plan view, and FIG. 7 [2A] is VIIa in FIG. 7 [1A]. FIG. 7 is a vertical sectional view taken along line -VIIa. Hereinafter, the flat nozzle will be described with reference to FIGS. 1, 5, and 7 [1A] and [2A].
[0061]
A disc-shaped flat plate nozzle 45 is provided between the inlet 22 a of the introduction pipe section 22 and the tank 11. The flat plate nozzle 45 has a conical through-hole 46 formed therein, and functions to suppress backflow. That is, the flat plate nozzle 45 is installed with the tip (the smaller diameter) of the through hole 46 facing the cavity 21. When the molten solder S <b> 1 in the cavity 21 is pressed by the diaphragm 30, the molten solder S <b> 1 tends to escape from the introduction tube 22 and the discharge tube 23 opened in the cavity 21. Of course, the escape of a large amount of the molten solder S1 from the introduction pipe portion 22 is not preferable because the molten solder S1 is excessively backflowed. Therefore, a flat plate nozzle 45 is provided between the introduction pipe section 22 and the tank 10. The flat nozzle 45 has a simple structure and does not cause clogging. It should be noted that there is no particular problem as long as the amount of the molten solder S1 is about the same as the ejection amount even if the molten solder S1 escapes by flowing backward.
[0062]
7 [1B] and [2B] show discharge nozzles used in place of the flat nozzles, FIG. 7 [1B] is a plan view, and FIG. 7 [2B] is a vertical sectional view taken along the line VIIb-VIIb in FIG. 7 [1B]. It is. Hereinafter, the discharge nozzle will be described with reference to FIG. 4 [2] and FIGS. 7 [1B] and [2B].
[0063]
In the example shown in FIG. 4 [2], the discharge nozzle 41 turned in the opposite direction is used instead of the flat plate nozzle 45. The discharge nozzle 41 is the same as the discharge nozzle 40. At this time, from the viewpoint of the molten solder S1 in the hollow portion 21, the same discharge nozzles 40 and 41 are provided in both the introduction tube portion 22 and the discharge tube portion 23. The resistance of the road will be the same. On the other hand, while the molten solder S1 filled in the tank 10 is located at the end of the introduction tube 22, the end of the discharge tube 23 is open. Therefore, the molten solder S <b> 1 reliably escapes in the direction in which it is easy to flow, that is, in the discharge pipe 23. That is, the discharge nozzle 41 provided between the introduction pipe section 22 and the tank 10 has a function of suppressing backflow. In this case, the number of types of components is one less than when a check valve is separately provided. Further, since the discharge nozzle 41 is designed not to cause clogging, clogging does not occur even when used as a check valve. The reason why the discharge nozzle 41 is reversed is that the discharge nozzle 41 is easily attached to the block body 60.
[0064]
8 shows an actuator holder for holding the piezoelectric actuator shown in FIG. 1. FIG. 8 [1] is a front view, FIG. 8 [2] is a plan view, and FIG. 8 [3] is VIII-VIII in FIG. 8 [2]. It is a line longitudinal cross-sectional view. Hereinafter, the piezoelectric actuator will be described with reference to FIGS. 1 to 3 and FIG.
[0065]
The piezoelectric actuator 50 has a columnar shape in which a large number of piezoelectric ceramics are laminated, and has a free end 51 on the side pressing the diaphragm 30 and a fixed end 52 on the side fixed to the block body 60 by the support members 53a and 53b. I have. Further, the piezoelectric actuator 50 is held by an actuator holder 70.
[0066]
The actuator holder 70 includes a diaphragm supporting portion 71 that supports the diaphragm joint 33, an actuator housing portion 72 that houses the piezoelectric actuator 50, a fixing portion 73 that is fixed to the supporting member 53, a diaphragm supporting portion 71, and a fixing portion 73. And an elastic coupling portion 74 that elastically couples them. A part of the elastic coupling portion 74 is formed into elastic members 75a and 75b which are processed into an annular shape. The actuator holder 70 has a substantially rectangular frame shape, two short sides facing each other are a diaphragm support part 71 and a fixing part 73, the other two long sides are an elastic coupling part 74, and the four sides are actuator storage parts 72. ing.
[0067]
The diaphragm support portion 71 supports the diaphragm joint 33 in the groove by the joint retainer 76 and the cap screws 77a and 77b. In the actuator accommodating portion 72, the piezoelectric actuator 50 is fitted into the frame together with the spacers 78 and 79. This is one in which the piezoelectric actuator 50 and the spacers 78 and 79 are pushed into the actuator accommodating section 72 while resisting the restoring force of the elastic members 75a and 75b.
[0068]
The fixing portion 73 is fixed to the support members 53a and 53b by cap screws 54a and 54b and spacers 55a and 55b. The support members 53a and 53b are fixed to the block body 60 by cap screws 56a and 56b. The supporting members 53a and 53b are made of titanium, which is excellent in heat insulation and heat resistance and is lightweight. The spacers 55a and 55b are made of a synthetic resin because they are used at positions that do not require much heat resistance.
[0069]
Next, the operation of the piezoelectric actuator 50 will be described. When a voltage is applied, the piezoelectric actuator 50 expands and contracts due to a piezoelectric effect. At this time, the fixed end 52 of the piezoelectric actuator 50 is firmly fixed to the block body 60 via the fixing portion 73 of the actuator holder 70 and the support members 53a and 53b. On the other hand, the free end 51 of the piezoelectric actuator 50 is elastically fixed to the block body 60 as a result through the elastic members 75a and 75b. Therefore, all the displacements of the piezoelectric actuator 50 are reflected on the diaphragm supporting portion 71 including the free end 51 by the elastic members 75a and 75b, and the diaphragm supporting portion 71 expands and contracts and presses the diaphragm 30. Thereby, the piezoelectric actuator 50 can be fixed to the block body 60 while the free end 51 is stretchable, so that the piezoelectric actuator 50 can be made robust.
[0070]
Hereinafter, the structure of the heater and its heat insulating structure in the liquid ejecting apparatus of FIG. 1 will be described with reference to FIGS.
[0071]
As shown in FIG. 1, a heater 80 for heating the tank 10, the pump chamber 20, and the discharge nozzle 40 is embedded in the block body 60. Further, a temperature sensor 81 for use in feedback control is also embedded in the block body 60. For example, the heater 80 is a general one using Joule heat of a resistor, and the temperature sensor 81 is a thermocouple.
[0072]
Next, the operation of the heater 80 will be described. Since the tank 10, the pump chamber 20, the discharge nozzle 40, and the heater 80 are provided in one block body 60, the liquid ejecting apparatus 100 can be reduced in size, and the heat generated from the heater 80 can efficiently use the tank 10, the pump chamber 20, It is transmitted to the discharge nozzle 40.
[0073]
Next, the heat insulation structure of the heater 80 will be described.
[0074]
Since the block body 60 is heated by the heater 80, the temperature of the block body 60 becomes high. On the other hand, when the temperature of the piezoelectric actuator 50 becomes high, the operation is hindered. Therefore, heat conduction from the block body 60 to the piezoelectric actuator 50 is prevented by using titanium having excellent heat insulation and heat resistance for the support members 53a and 53b for fixing the piezoelectric actuator 50 to the block body 60.
[0075]
Further, the heat affecting the piezoelectric actuator 50 from the block body 60 includes not only heat conduction but also heat radiation. Therefore, a heat insulating sheet 82 is provided between the block body 60 and the piezoelectric actuator 50 to prevent radiant heat from the block body 60. The heat insulating sheet 82 has a cloth shape made of a fluorine resin such as polytetrafluoroethylene. The heat insulating sheet 82 is not limited to resin but may be metal or ceramic, and may be not only cloth but also plate.
[0076]
Further, as shown in FIG. 2 (not shown in FIGS. 1 and 3), a fan 83 for cooling the piezoelectric actuator 50 is provided on the piezoelectric actuator 50 side by a heat insulating sheet 82 between the block body 60 side and the piezoelectric actuator 50 side. Provided. Due to the heat insulating sheet 84, the wind W of the fan 83 hits only the piezoelectric actuator 50 side. Therefore, the wind W does not hit the block body 60 that needs to maintain a high temperature, and only the piezoelectric actuator 50 is efficiently cooled.
[0077]
As shown in FIG. 2, the fan 83 is fixed to a fan fitting 84, and the fan fitting 84 is fixed to the spacers 55a and 55b by cap screws 54a and 54b. Further, a wiring board 85 for supplying electric power to the fan 83 and the piezoelectric actuator 50 is attached to the fan fitting 84 by a cap screw 86 and a nut 87.
[0078]
It is needless to say that the present invention is not limited to the above embodiment. For example, a flux or the like may be used as the liquid instead of the molten solder. The block body is not limited to a metal such as stainless steel, but may be a synthetic resin or ceramics.
[0079]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the liquid ejecting apparatus which concerns on this invention, the tank which stores a liquid, the pump room provided under a tank, and communicates with a tank, and it communicates with the pump room provided under a pump room, and discharges a liquid downward. Since the tank, the pump chamber, and the discharge nozzle are disposed in the vertical direction by providing the discharge nozzle to perform and the actuator that urges the operation of the discharge nozzle by acting on the pump chamber, the liquid flows by its own weight. This facilitates clogging. In addition, since the flow of the liquid is facilitated, the generation rate of droplets [pieces / second] can be increased. Moreover, even if the liquid contacts the air in the tank to form an oxide film, the oxide film remains on the surface of the liquid, so that the oxide film can be prevented from entering the pump chamber below the tank and causing clogging. . According to the liquid ejecting apparatus of the present invention, the following effects are also obtained for each claim.
[0080]
According to the liquid ejecting apparatus of the second aspect, when the liquid is guided from the tank to the pump chamber and the diaphragm of the pump chamber is pressed by the actuator, the droplet is discharged from the discharge nozzle. In addition, since the discharge nozzle is disposed in the vertical direction, the liquid can be quickly flowed.
[0081]
According to the liquid ejecting apparatus of the third aspect, the pump chamber, the tank, and the discharge nozzle are provided in one block, so that the liquid ejecting apparatus can be downsized. Thereby, the flow path of the liquid can be shortened, so that the clogging can be further suppressed and the generation speed of the droplet can be further increased.
[0082]
According to the liquid ejecting apparatus of the fourth aspect, the liquid is guided from the tank through the introduction pipe to the cavity, and when the diaphragm in the cavity is pressed by the actuator, the liquid is discharged from the discharge nozzle through the discharge pipe. Drops are ejected, and in this case also, the tank, the pump chamber, and the ejection nozzle are arranged in the vertical direction, so that the liquid can flow quickly.
[0083]
According to the liquid ejecting apparatus of the fifth aspect, by connecting the inlet of the discharge pipe to the upper edge of the cavity, the air bubbles generated in the cavity can be quickly discharged.
[0084]
According to the liquid ejecting apparatus according to the sixth aspect, by connecting the outlet of the introduction pipe portion to the inner periphery of the hollow portion along the tangential direction of the hollow portion, the liquid flow path can be formed in the shape of a "". Therefore, the liquid can flow quickly, and the bubbles can be easily discharged.
[0085]
According to the liquid ejecting apparatus of the seventh aspect, a cylinder having the same axis as the cavity is protruded into the cavity, and a liquid flow path from the outlet of the introduction pipe to the entrance of the discharge pipe is formed around the cylinder. By forming the liquid, the liquid can be intensively advanced in the flow path along the circumference of the cylinder, so that the liquid can flow more quickly and the bubbles can be more easily discharged.
[0086]
According to the liquid ejecting apparatus of the eighth aspect, a nozzle having a through-hole can be provided in the introduction pipe portion to function as a check valve, and clogging can be prevented because the structure of the nozzle is simple. .
[0087]
According to the liquid ejecting apparatus of the ninth aspect, the same as the discharge nozzle can be provided in the introduction pipe portion to function as a check valve, and the discharge nozzle is designed so as not to cause clogging. Therefore, clogging can be prevented even if the discharge nozzle is used like a check valve.
[0088]
According to the liquid ejecting apparatus of the tenth aspect, by using the piezoelectric actuator having the free end that presses the diaphragm and the fixed end that is fixed to the block body, the displacement of the piezoelectric actuator is reduced to the free end side. , The displacement of the piezoelectric actuator can be effectively used.
[0089]
According to the liquid ejecting apparatus of the eleventh aspect, by providing the actuator holder for fixing the free end of the piezoelectric actuator via the elastic member, the robustness of the piezoelectric actuator can be maintained while the free end of the piezoelectric actuator can be extended and contracted. Can be achieved.
[0090]
According to the liquid ejecting apparatus of the twelfth aspect, by processing a part of the actuator holder into an annular shape, it is possible to obtain an elastic member without increasing the number of parts.
[0091]
According to the liquid ejecting apparatus of the thirteenth aspect, by embedding the heater for heating the pump chamber, the tank, and the discharge nozzle in the block, the liquid ejecting apparatus can be downsized, and the heat generated from the heater can be efficiently pumped. It can communicate to chambers, tanks and discharge nozzles.
[0092]
According to the liquid ejecting apparatus of the fourteenth aspect, by fixing the piezoelectric actuator to the block by the support member having heat insulation, heat conduction from the block to the piezoelectric actuator can be effectively prevented.
[0093]
According to the liquid ejecting apparatus of the fifteenth aspect, since the heat insulating sheet is provided between the block body and the piezoelectric actuator, heat radiation from the block body to the piezoelectric actuator can be effectively prevented.
[0094]
According to the liquid ejecting apparatus of the present invention, the fan is provided on the piezoelectric actuator side separated by the heat insulating sheet, so that the block body that needs to maintain a high temperature is not exposed to wind, and only the piezoelectric actuator is exposed. Since the wind can be applied, the piezoelectric actuator can be efficiently cooled.
[0095]
According to the liquid ejecting apparatus of the seventeenth aspect, since the molten solder which is a liquid having a large specific gravity and a low melting point is used, the self-weight of the liquid can be effectively used, and the heater can be simplified. The effects of the invention can be exhibited most. In particular, even if molten solder comes into contact with air in the tank and an oxide film is formed, the oxide film remains on the surface of the liquid, preventing the oxide film from entering the pump chamber below the tank and causing clogging. it can.
[Brief description of the drawings]
FIG. 1 is a vertical sectional view taken along line II of FIG. 3 (a sectional view of a tank including a center line of the tank), showing one embodiment of a liquid ejecting apparatus according to the present invention.
FIG. 2 is a front view illustrating an embodiment of the liquid ejecting apparatus according to the present invention.
FIG. 3 is a plan view illustrating an embodiment of the liquid ejecting apparatus according to the present invention.
4 shows an embodiment of the liquid ejecting apparatus according to the present invention, wherein FIG. 4 [1] is a left side view, and FIG. 4 [2] is a vertical sectional view taken along the line IV-IV in FIG. Is different).
FIG. 5 is an enlarged sectional view showing a pump chamber in the liquid ejecting apparatus of FIG.
FIG. 6 is a perspective view showing a pump chamber in the liquid ejecting apparatus of FIG. 1;
7 [1A] and [2A] show a flat plate nozzle provided between the inlet of the introduction pipe portion and the tank, FIG. 7 [1A] is a plan view, and FIG. 7 [2A] is FIG. 7 [ 1A] is a vertical sectional view taken along line VIIa-VIIa. 7 [1B] and [2B] show discharge nozzles used in place of the flat nozzles, FIG. 7 [1B] is a plan view, and FIG. 7 [2B] is a vertical sectional view taken along the line VIIb-VIIb in FIG. 7 [1B]. It is.
8 shows an actuator holder for holding the piezoelectric actuator in FIG. 1, wherein FIG. 8 [1] is a front view, FIG. 8 [2] is a plan view, and FIG. 8 [3] is VIII-VIII in FIG. 8 [2]. It is a line longitudinal cross-sectional view.
[Explanation of symbols]
10 tanks
20 pump room
21 cavity
22 Introduction pipe section
22a Entrance of introduction pipe
22b Outlet of the inlet pipe
23 Discharge pipe section
23a Inlet of discharge pipe
23b Exit of discharge pipe
30 diaphragm
31 cylinder
40, 41 discharge nozzle
45 Flat plate nozzle
46 through hole
50 Piezoelectric actuator
51 Free end of piezoelectric actuator
52 Fixed end of piezoelectric actuator
53a, 53b support member
60 blocks
70 Actuator holder
80 heater
82 Insulation sheet
83 fans
100 liquid ejector
L axis
S1 molten solder
S2 Drop of molten solder
S3 Flow path of molten solder

Claims (17)

A tank for storing the liquid, a pump chamber provided below the tank and communicating with the tank, and a discharge nozzle provided below the pump chamber and communicating with the pump chamber and discharging the liquid downward. An actuator that acts on the pump chamber to urge the operation of the discharge nozzle;
A liquid ejecting apparatus comprising: The pump chamber has a wall surface composed of a diaphragm, and the actuator biases the operation of the discharge nozzle by intermittently pressing the diaphragm.
The liquid ejecting apparatus according to claim 1. The pump chamber was formed in the block body, the tank was mounted on the block body, the discharge nozzle was mounted under the block body,
The liquid ejecting apparatus according to claim 2. The pump chamber has a cylindrical shape having a columnar shape having an axis in the horizontal direction and one circular wall surface is the diaphragm, and an inlet pipe portion having an inlet connected to the tank and an outlet connected to the hollow portion. An outlet connected to the cavity and an outlet connected to the discharge nozzle,
The liquid ejecting apparatus according to claim 2. An inlet of the discharge pipe portion is connected to an upper edge of the hollow portion,
The liquid ejecting apparatus according to claim 4. An outlet of the introduction pipe portion is connected to an inner periphery of the hollow portion along a tangential direction of the hollow portion,
The liquid ejecting apparatus according to claim 5. A cylinder having the same axis as the cavity is protruded into the cavity, and a liquid flow path from an outlet of the introduction pipe to an entrance of the discharge pipe is formed around the cylinder.
The liquid ejecting apparatus according to claim 6. Provided with a nozzle having a through hole smaller than the inner diameter of the introduction pipe portion, at the entrance or exit or in the middle of the introduction pipe portion,
The liquid ejecting apparatus according to claim 4. The same as the discharge nozzle was connected to the inlet or outlet or in the middle of the introduction pipe portion,
The liquid ejecting apparatus according to claim 4. The actuator is a columnar piezoelectric actuator,
The piezoelectric actuator has a free end on the side that presses the diaphragm and a fixed end on the side fixed to the block body by a support member.
The liquid ejecting apparatus according to claim 3. An actuator holder fixed to the support member and fixing a free end of the piezoelectric actuator via an elastic member,
The liquid ejecting apparatus according to claim 10. The elastic member is formed by processing a part of the actuator holder into an annular shape.
The liquid ejecting apparatus according to claim 11. A heater for heating the pump chamber, the tank and the discharge nozzle was embedded in the block body,
The liquid ejecting apparatus according to claim 3. The actuator is a columnar piezoelectric actuator,
The piezoelectric actuator has a free end on the side that presses the diaphragm, and a fixed end on the side that is fixed to the block body by a support member having heat insulation.
The liquid ejecting apparatus according to claim 13. Between the block body and the piezoelectric actuator, a heat insulating sheet for blocking radiant heat from the block body was provided,
The liquid ejecting apparatus according to claim 14. The block body side and the piezoelectric actuator side are separated by the heat insulating sheet, and a fan for cooling the piezoelectric actuator is provided on the piezoelectric actuator side,
The liquid ejecting apparatus according to claim 15. The liquid is molten solder,
The liquid ejecting apparatus according to claim 1.

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