JP3772155B2 - Liquid ejector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a liquid ejecting apparatus that continuously discharges a liquid such as molten metal into a fine spherical shape, and particularly relates 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, with the miniaturization and thinning of electronic devices, high-density mounting technology for electronic components is rapidly progressing. As a semiconductor device that realizes this high-density mounting, FC (flip chip) or BGA (ball grid array) having hemispherical solder bumps on a semiconductor substrate or an interposer substrate are used. Moreover, the following patent documents 1 and 2 are known as a technique relevant to this.
[0003]
  Patent Document 1 describes a method of manufacturing a three-dimensional structure by injecting molten solder in a horizontal direction from a nozzle using a piezoelectric element.
[0004]
  Patent Document 2 describes a solder ball manufacturing apparatus in which a runner is provided in the horizontal direction of a tank for storing molten solder, a pulse pressurizing device is provided above the end of the runner, and an orifice is provided downward. Has been. The molten solder travels horizontally in the runner and is pressurized from above at the end of the runner, so that it is discharged from the orifice and becomes a solder ball.
[0005]
[Patent Document 1]
          JP-A-10-156524 (FIG. 1, paragraph 0007, etc.)
[Patent Document 2]
          Japanese Patent Laid-Open No. 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. Moreover, in patent document 2, since the horizontal and long runner was provided between the tank, the pulse pressurization apparatus, and the orifice, there existed a problem that clogging of molten solder was easy to occur. In the case of molten solder, clogging due to an oxide film is particularly likely to occur.
[0007]
OBJECT OF THE INVENTION
  Accordingly, an object of the present invention is to provide a liquid ejecting apparatus that can realize suppression of clogging of liquid and the like.
[0008]
[Means for Solving the Problems]
  << claims 1 to5IsPump roomConcerning structure. >>
[0009]
  The liquid ejecting apparatus according to claim 1 is provided in a tank that stores liquid, and is provided below the tank and communicates with the tank.Together with a diaphragm wallThe pump chamber is located below the pump chamber and communicates with the pump chamberVomitAn exit nozzle;By pressing the diaphragm, liquid is discharged downward from the discharge nozzle.And an actuator.. ThisNeedless to say, the top and bottom 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 due to its own weight, so that clogging is suppressed. In addition, since the liquid easily flows, the droplet generation speed [number / second] also increases. Furthermore, even if an oxide film is formed by contact of liquid with air in the tank, the oxide film remains on the surface of the liquid. Therefore, there is no possibility that the oxide film enters the pump chamber under the tank and clogs. In particular, when the liquid is a molten solder, an oxide film is easily generated, and this effect becomes remarkable.
[0011]
  In detailThe liquid is guided from the tank to the pump chamber, and when the diaphragm in the pump chamber is pressed by the actuator, it is discharged as droplets from the discharge nozzle. Also in this case, since the tank, the pump chamber, and the discharge nozzle are arranged in the vertical direction, the liquid easily flows due to its own weight.
[0012]
  PoThe pump chamber has a cylindrical shape having an axis in the horizontal direction and one circular wall surface is a diaphragm, an inlet pipe connected to the tank and an outlet connected to the cavity, and a cavity A discharge pipe section with an inlet connected and an outlet connected to a discharge nozzle;Has.
[0013]
  The liquid is guided from the tank to the hollow portion through the introduction pipe portion, and when the diaphragm in the hollow portion is pressed by the actuator, the liquid is discharged as a droplet from the discharge nozzle through the discharge pipe portion. Also in this case, since the tank, the pump chamber, and the discharge nozzle are arranged in the vertical direction, the liquid easily flows due to its own weight.
[0014]
  ExcretionThe entrance of the outlet is,HollowVertical directionConnected to the upper edgeing.
[0015]
  Bubbles may be generated in the cavity. Since the bubbles absorb the pressure applied to the liquid, the ejection of the droplets is hindered. Therefore, by utilizing the fact that bubbles generated in the cavity part gather at the upper edge of the cavity part by buoyancy, by providing the inlet of the discharge pipe part at the upper edge of the cavity part, the bubbles can be quickly guided to the exhaust pipe part. Discharge. This action is effective not only for bubbles that are generated later, but also for bubbles that are present in the first stage (the stage in which liquid is not filled in the pump chamber).
[0016]
  GuidanceThe exit of the immigration section,Connected to the inner circumference of the cavity along the tangential direction of the cavitying.
[0017]
  Since the liquid guided from the outlet of the introduction pipe portion to the inner periphery of the cavity portion is urged in the tangential direction of the cavity portion, the liquid quickly proceeds along the inner periphery of the cavity portion and is discharged at the upper edge of the cavity portion. Reach the inlet of the pipe. That is, the flow path of the liquid draws a “no” character. Therefore, the liquid easily flows and the bubbles are discharged without stagnation.
[0018]
  Claim 2The liquid ejecting apparatus described isClaim 1In the liquid ejecting apparatus described above, a pump chamber is formed in the block body, a tank is attached on the block body, and a discharge nozzle is attached below the block body.
[0019]
  Since the pump chamber, the tank, and the discharge nozzle are provided in one block body, the liquid ejecting apparatus is downsized. As a result, the liquid flow path is also shortened, so that clogging is further suppressed and the generation speed of the droplets is further increased.
[0020]
  Claim 3The liquid ejecting apparatus described isClaim 1 or 2In the liquid ejecting apparatus described above, a cylinder having the same axis as the cavity is protruded in the cavity, and a liquid flow path from the outlet of the introduction pipe to the inlet of the discharge pipe is formed around the cylinder. Is.
[0021]
  When a cylinder having the same axis as that of the cavity is projected into the cavity, an annular space is formed around the cylinder. In this space, the outlet of the introduction pipe and the inlet of the discharge pipe are open on the inner wall of the cavity. Accordingly, the liquid guided from the outlet of the introduction pipe portion to the inner periphery of the cavity portion does not flow through the portion where the cylinder is present, and thus proceeds in a concentrated manner along the flow path along the inner periphery of the cavity portion around the cylinder. Therefore, the liquid can flow more easily and the bubbles are discharged without further stagnation.
[0022]
  Claim 4The liquid ejecting apparatus described isClaims 1 to 3In the liquid ejecting apparatus according to any one of the above, a nozzle having a through-hole smaller than the inner diameter of the introduction pipe portion is provided at the inlet or the outlet of the introduction pipe portion or in the middle thereof.
[0023]
  When the liquid in the cavity is pressed by the diaphragm, the liquid tends to escape from the introduction pipe and the discharge pipe that are open to the cavity. Of course, escape of a large amount of liquid from the introduction pipe portion is an excessive backflow of the liquid, so 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 normal check valve having a complicated structure has too much resistance and clogs. Therefore, for example, a nozzle having a through hole smaller than the inner diameter of the introduction pipe portion is provided between the introduction pipe portion and the tank. The inner diameter and length of the through hole are factors that determine the flow path resistance of the liquid. The size and shape of the through holes are desirably the same as or similar to the resistance of the discharge nozzle. This nozzle has a function of suppressing backflow, and does not cause clogging due to its simple structure.
[0024]
  Claim 5The liquid ejecting apparatus described isClaims 1 to 3In the liquid ejecting apparatus according to any one of the above, the same thing as the discharge nozzle is connected to the inlet, the outlet, or the middle of the introduction pipe portion.
[0025]
  For example, when the discharge nozzle is provided between the introduction pipe portion and the tank, the same discharge nozzle is provided in both the introduction pipe portion and the discharge pipe portion when viewed from the liquid in the hollow portion. The resistance of the flow path is the same in the part. On the other hand, there is a liquid filled in the tank at the tip of the introduction pipe portion, whereas the tip of the discharge pipe portion is opened. Therefore, the liquid surely escapes in the direction in which it flows easily, that is, the discharge pipe. That is, the discharge nozzle provided between the introduction pipe portion and the tank has a function of suppressing backflow. In this case, the number of parts is reduced by one compared with the case where a check valve is separately provided. Further, since the discharge nozzle is designed not to cause clogging, clogging will not occur even if it is used like a check valve.
[0026]
  《NextRelates to the structure of the actuator. >>
[0027]
  The actuator is a columnar piezoelectric actuator, and this piezoelectric actuator has a free end on the side pressing the diaphragm and a fixed end on the side fixed to the block body by the support member.May be.
[0028]
  PressureWhen a voltage is applied, the electric actuator expands and contracts due to the piezoelectric effect. At this time, the fixed end of the piezoelectric actuator is fixed to the block body by the support member. Therefore, all the displacements of the piezoelectric actuator are reflected on the free end, and the free end expands and contracts to press the diaphragm. The piezoelectric actuator has the following features.(1). The response is fast.(2). Diaphragm amplitude can be controlled in micron order.(3). Various fluids can be discharged by adjusting electric signals such as voltage, frequency, and waveform.
[0029]
  BranchAn actuator holder fixed to the holding member and fixing the free end of the piezoelectric actuator via an elastic member;May be.
[0030]
  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 body via a support member. Therefore, the piezoelectric actuator can be made robust while the free end of the piezoelectric actuator can be extended and contracted.
[0031]
  BulletThe sex member is a part of the actuator holder processed into an annular shape.May be.
[0032]
  When a part of the actuator holder is processed into an annular shape, this part has elasticity. Therefore, an elastic member can be obtained without increasing the number of parts.
[0033]
  《NextRelates to the structure of the heater and the structure of its heat insulation. >>
[0034]
  PoA heater for heating the pump chamber, tank and discharge nozzle is embedded in the block body.May be.
[0035]
  Since the pump chamber, the tank, the discharge nozzle, and the heater are provided in one block body, 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.
[0036]
  AThe actuator is a columnar piezoelectric actuator.May be.
[0037]
  The fixed end of the piezoelectric actuator is fixed to the block body by a support member. On the other hand, since the block body is heated by the heater, it becomes high temperature. Since the piezoelectric actuator has a problem in operation at a high temperature, heat conduction from the block body to the fixed end is prevented by using a support member having heat insulation properties.
[0038]
  TheBetween the lock body and the piezoelectric actuator, a heat insulating sheet for blocking radiant heat from the block body was provided,May be.
[0039]
  The heat affecting the piezoelectric actuator from the block body is not only due to heat conduction but also due to 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.
[0040]
  RefusalThe heat sheet separates the block body side from the piezoelectric actuator side, and a fan for cooling the piezoelectric actuator is provided on the piezoelectric actuator side.May be.
[0041]
  Since the block body side and the piezoelectric actuator side are separated from each other by the heat insulating sheet and the fan is provided on the piezoelectric actuator side, the wind of the fan only hits the piezoelectric actuator. Therefore, wind does not strike the block body that must maintain a high temperature, and only the piezoelectric actuator is efficiently cooled.
[0042]
  《Claim 6Relates to the type of liquid. >>
[0043]
  Claim 6The liquid ejecting apparatus described isClaims 1 to 5In the liquid ejecting apparatus according to any one of the above, the liquid is a molten solder.
[0044]
  In the liquid ejecting apparatus according to the present invention, since the weight of the liquid is positively used, a liquid having a higher specific gravity such as a molten metal is more effective. Among molten metals, molten solder is most effective because the heater can be simple due to its low melting point.
[0045]
DETAILED DESCRIPTION OF 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 a block body is stainless steel unless otherwise specified. A sign is abbreviated about a washer used with a cap screw. The illustration of the washer made of a fluororesin inserted into the contact surface by screwing is omitted.
[0046]
  1 to 4 show an embodiment of a liquid ejecting apparatus according to the present invention, and FIG. 1 is a longitudinal sectional view taken along line II in FIG. 3 (a tank portion includes a center line of the tank), FIG. 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 line IV-IV in FIG. The basic structure of the liquid ejecting apparatus according to the invention will be described below with reference to these drawings.
[0047]
  The liquid ejecting apparatus 100 of the present embodiment includes a tank 10 that stores molten solder S1, a pump chamber 20 that is provided below the tank 10 and that communicates with the tank 10 and has a wall surface that includes a diaphragm 30. And a discharge nozzle 40 that communicates with the pump chamber 20 and discharges the molten solder S1 downward, and a piezoelectric actuator 50 that 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 attached on the block body 60, and the discharge nozzle 40 is attached 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.
[0048]
  The tank 10 has a cylindrical shape and is screwed into a recess 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 to become molten solder S1.
[0049]
  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 in the pump chamber 20 is pressed by the piezoelectric actuator 50, the molten solder S1 is discharged as droplets S2 from the discharge nozzle 40. 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 easily flows due to its own weight, so that clogging is suppressed. In addition, since the molten solder S1 easily flows, the generation rate [number / second] of the droplet S2 also increases. Further, in the tank 10, even if the molten solder S1 comes into contact with air and an oxide film is generated, 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 clogs. Furthermore, since the tank 10, the pump chamber 20, and the discharge nozzle 40 are provided in one block body 60, the liquid ejecting apparatus 100 is reduced in size. Thereby, since the flow path of the molten solder 1 is shortened, clogging is further suppressed, and the generation rate of the droplet S2 is further increased.
[0050]
  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.
[0051]
  The pump chamber 20 has a flat cylindrical shape having an axis L in the horizontal direction, and one circular wall surface is a diaphragm 30, and 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 having an inlet 23 a connected to the cavity portion 21 and an outlet 23 b connected to the discharge nozzle 40. The inlet 23 a of the discharge pipe part 23 is connected to the upper edge of the cavity part 21, and the outlet 22 b of the introduction pipe part 22 is connected to the inner periphery of the cavity part 21 along the vertically downward direction and the tangential direction of the cavity part 21. . Further, a flat cylinder 31 (FIG. 5) having the same axis L as that of the hollow portion 21 is projected into the hollow portion 21, and the molten solder S 1 from the outlet 22 b of the introduction pipe portion 22 to the inlet 23 a of the discharge pipe portion 23 is projected. A flow path S3 (FIG. 6) is formed around the cylinder 31.
[0052]
  The diaphragm 30 is a disk having a hole in the center, and is supported by a short rod-shaped diaphragm retainer 32 and a long rod-shaped diaphragm joint 33. The head of the diaphragm presser 32 is a cylinder 31. The diaphragm presser 32 is press-fitted into the diaphragm joint 33 in a state where the diaphragm 30 is sandwiched, and is soldered 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 accommodated in the recess 34.
[0053]
  Next, the operation of the pump chamber 20 will be described.
[0054]
  The molten solder S1 is guided from the tank 10 through the introduction tube portion 22 to the cavity portion 21, and when the diaphragm 30 of the cavity portion 21 is pressed by the piezoelectric actuator 50, the liquid solder S1 passes through the discharge tube portion 23 and is discharged from the discharge nozzle 40. A droplet S2 is discharged. 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 due to its own weight.
[0055]
  Here, bubbles (not shown) may be generated in the cavity 21. The bubbles absorb the pressure applied to the molten solder S1 by the diaphragm 30 and prevent the droplet S1 from being discharged. Therefore, by utilizing the fact that bubbles generated in the cavity portion 21 gather at the upper edge of the cavity portion 21 by buoyancy, by providing the inlet 23a of the discharge pipe portion 23 at the upper edge of the cavity portion 21, the bubbles are quickly discharged. To do.
[0056]
  Moreover, since the molten solder S1 guided to the inner periphery of the cavity portion 21 from the outlet 22b of the introduction tube portion 22 is urged in the tangential direction of the cavity portion 21, the molten solder S1 quickly proceeds along the inner periphery of the cavity portion 21, It reaches the inlet 23 a of the discharge pipe portion 23 located at the upper edge of the cavity portion 21. That is, the flow path S3 of the molten solder S1 draws a “no” character. Strictly speaking, it is the character of the reverse “NO” that traces the character of “NO” in reverse. Accordingly, the molten solder S1 can easily flow and the bubbles are discharged without stagnation.
[0057]
  Furthermore, when a cylinder 31 having the same axis L as the cavity 21 is projected into the cavity 21, an annular space is formed around the cylinder 31. In this space, an outlet 22 b of the introduction pipe part 22 and an inlet 23 a of the discharge pipe part 23 are opened on the inner wall of the cavity part 21. Accordingly, the molten solder S1 guided from the outlet 22b of the introduction pipe portion 22 to the inner periphery of the cavity portion 21 does not flow through the portion where the column 31 is present, so that the flow along the inner periphery of the cavity portion 21 around the column 31 is avoided. Concentrate on road S3. Therefore, the molten solder S1 becomes easier to flow and the bubbles are discharged without further stagnation.
[0058]
  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]. It is a -VIIa line longitudinal cross-sectional view. Hereinafter, the flat plate nozzle will be described with reference to FIGS. 1, 5 and 7 [1A] and [2A].
[0059]
  A disc-shaped flat plate nozzle 45 is provided between the inlet 22 a of the introduction pipe portion 22 and the tank 11. The flat plate nozzle 45 is formed with a conical through hole 46 to suppress backflow.likeFunction. That is, the flat plate nozzle 45 is installed with the tip of the through-hole 46 (the one with the smaller diameter) 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 pipe part 22 and the discharge pipe part 23 that are open to the cavity part 21. Of course, it is not preferable that a lot of molten solder S1 escapes from the introduction pipe portion 22 because it is an excessive backflow of the molten solder S1. Therefore, a flat plate nozzle 45 is provided between the introduction pipe portion 22 and the tank 10. Since the flat nozzle 45 has a simple structure, it does not clog. Note that there is no particular problem with the molten solder S1 as long as it is about the same as the discharge amount even if it escapes by flowing backward.
[0060]
  7 [1B] and [2B] show discharge nozzles used in place of the flat plate nozzle, 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 based on FIG. 4 [2] and FIGS. 7 [1B] and [2B].
[0061]
  In the example shown in FIG. 4 [2], instead of the flat plate nozzle 45, a discharge nozzle 41 that is reversed is used. The discharge nozzle 41 is the same as the discharge nozzle 40. At this time, since the same discharge nozzles 40 and 41 are provided in both the introduction pipe part 22 and the discharge pipe part 23 as viewed from the molten solder S1 of the cavity part 21, the flow is made in both the introduction pipe part 22 and the discharge pipe part 23. The road resistance will be the same. On the other hand, there is molten solder S1 filled in the tank 10 at the tip of the introduction tube portion 22, whereas the tip of the discharge tube portion 23 is opened. Accordingly, the molten solder S1 surely escapes to the direction in which it flows easily, that is, the discharge pipe portion 23. That is, the discharge nozzle 41 provided between the introduction pipe portion 22 and the tank 10 has a function of suppressing backflow. In this case, the number of parts is reduced by one compared with the case where a check valve is separately provided. Further, since the discharge nozzle 41 is designed not to cause clogging, clogging will not occur even if it is used like a check valve. The reason why the discharge nozzle 41 is reversed is that it is easy to attach to the block body 60.
[0062]
  8 shows an actuator holder that holds the piezoelectric actuator 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]. FIG. Hereinafter, the piezoelectric actuator will be described with reference to FIGS. 1 to 3 and FIG.
[0063]
  The piezoelectric actuator 50 has a columnar shape in which a large number of piezoelectric ceramics are stacked, and includes 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. Yes. The piezoelectric actuator 50 is held by the actuator holder 70.
[0064]
  The actuator holder 70 includes a diaphragm support portion 71 that supports the diaphragm joint 33, an actuator storage portion 72 that stores the piezoelectric actuator 50, a fixed portion 73 that is fixed to the support member 53, a diaphragm support portion 71, and a fixed portion 73. It is comprised by the elastic coupling part 74 which couple | bonds with elasticity. A part of the elastic coupling portion 74 is an elastic member 75a, 75b processed into an annular shape. The actuator holder 70 has a substantially rectangular frame shape. The two opposing short sides are the diaphragm support portion 71 and the fixing portion 73, the remaining two long sides are the elastic coupling portions 74, and the four sides are the actuator accommodating portions 72. ing.
[0065]
  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. The actuator accommodating portion 72 has the piezoelectric actuator 50 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 housing portion 72 while resisting the restoring force of the elastic members 75a and 75b.
[0066]
  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 support members 53a and 53b are made of titanium that is excellent in heat insulation and heat resistance and is lightweight. The spacers 55a and 55b are made of synthetic resin because they are used at positions that do not require much heat resistance.
[0067]
  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 the 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 fixed to the block body 60 so as to be extendable and contractable as a result of the elastic members 75a and 75b being interposed therebetween. Therefore, all the displacements of the piezoelectric actuator 50 are reflected on the diaphragm support 71 including the free end 51 by the elastic members 75a and 75b, and the diaphragm support 71 expands and contracts to press the diaphragm 30. As a result, the free end 51 of the piezoelectric actuator 50 can be fixed to the block body 60 while allowing it to expand and contract, so that the piezoelectric actuator 50 can be made robust.
[0068]
  Hereinafter, the structure of the heater and the heat insulation structure in the liquid ejecting apparatus of FIG. 1 will be described with reference to FIGS. 1 to 4.
[0069]
  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. 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 that uses Joule heat of a resistor, and the temperature sensor 81 is a thermocouple.
[0070]
  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 is reduced in size and the heat generated from the heater 80 is efficiently transferred to the tank 10, the pump chamber 20, It is transmitted to the discharge nozzle 40.
[0071]
  Next, the heat insulation structure of the heater 80 will be described.
[0072]
  Since the block body 60 is heated by the heater 80, it becomes high temperature. On the other hand, the operation of the piezoelectric actuator 50 is hindered at a high temperature. 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.
[0073]
  Further, the heat affecting the piezoelectric actuator 50 from the block body 60 is not only due to heat conduction but also due to 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 ceramics, and is not limited to cloth but may be plate.
[0074]
  Further, as shown in FIG. 2 (not shown in FIGS. 1 and 3), a fan 83 that cools the piezoelectric actuator 50 is provided on the piezoelectric actuator 50 side, separated 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 only hits the piezoelectric actuator 50 side. Therefore, the wind W does not hit the block body 60 that must maintain a high temperature, and only the piezoelectric actuator 50 is efficiently cooled.
[0075]
  As shown in FIG. 2, the fan 83 is fixed to the fan metal fitting 84, and the fan metal fitting 84 is fixed to the spacers 55a and 55b by cap screws 54a and 54b. A wiring board 85 for supplying electric power to the fan 83 and the piezoelectric actuator 50 is attached to the fan metal fitting 84 by a cap screw 86 and a nut 87.
[0076]
  Needless to say, 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.
[0077]
【The invention's effect】
  According to the liquid ejecting apparatus of the invention, the tank that stores the liquid and the tank that is provided under the tank and communicates with the tank.Together with a diaphragm wallThe pump room is located below the pump room and communicates with the pump roomVomitAn exit nozzle;By pressing the diaphragm, liquid is discharged downward from the discharge nozzle.By providing the actuator, the tank, the pump chamber, and the discharge nozzle are arranged in the vertical direction, so that the liquid can easily flow due to its own weight, thereby suppressing clogging. In addition, since the liquid easily flows, the generation speed [number / second] of the droplets can be increased. Moreover, even if the liquid comes into contact with air in the tank and an oxide film is formed, the oxide film stays 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. .
[0078]
  AndWhen 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 this case as well, the tank, the pump chamber and the discharge nozzle are arranged in the vertical direction. , Liquid can flow quickly.
[0079]
  Also,When the liquid is guided from the tank to the cavity through the introduction pipe and the diaphragm in the cavity is pressed by the actuator, the droplet is ejected from the ejection nozzle through the discharge pipe. In addition, since the discharge nozzle is disposed in the vertical direction, the liquid can flow quickly.
[0080]
  In addition,The inlet of the discharge pipeVertical directionBy connecting to the upper edge, bubbles generated in the cavity can be quickly discharged.
[0081]
  In addition to this,By connecting the outlet of the introduction pipe part to the inner periphery of the cavity part along the tangential direction of the cavity part, the liquid flow path can be made into the shape of "", so that the liquid can flow quickly and the bubbles Can be easily discharged.According to the liquid ejecting apparatus of the present invention, the following effects are also obtained for each claim.
[0082]
  Claim 2According to the described liquid ejecting apparatus, since the pump chamber, the tank, and the discharge nozzle are provided in one block body, the liquid ejecting apparatus can be reduced in size. Thereby, since the flow path of the liquid can be shortened, clogging can be further suppressed, and the generation speed of the droplets can be further increased.
[0083]
  Claim 3According to the liquid ejecting apparatus described above, a cylinder having the same axis as the cavity is projected into the cavity, and a liquid flow path from the inlet of the introduction pipe to the inlet of the discharge pipe is formed around the cylinder. As a result, the liquid can be concentrated and advanced in the flow path along the circumference of the cylinder, so that the liquid can flow more quickly and the bubbles can be discharged more easily.
[0084]
  Claim 4According to the described liquid ejecting apparatus, a nozzle having a through hole can be provided in the introduction pipe portion to function like a check valve, and clogging can be prevented because the nozzle structure is simple.
[0085]
  Claim 5According to the described liquid ejecting apparatus, the same thing as the discharge nozzle can be provided in the introduction pipe portion to function like a check valve, and the discharge nozzle is designed not to cause clogging. Even if the discharge nozzle is used like a check valve, clogging can be prevented.
[0086]
  DaBy using a piezoelectric actuator that has a free end that presses the diaphragm and a fixed end that is fixed to the block body, the displacement of the piezoelectric actuator can be reflected only on the free end. Displacement can be used effectively.
[0087]
  PressureBy providing an actuator holder that fixes the free end of the electric actuator via an elastic member, the piezoelectric actuator can be made robust while the free end of the piezoelectric actuator is stretchable.
[0088]
  ABy processing a part of the actuator holder into an annular shape, an elastic member can be obtained without increasing the number of parts.
[0089]
  PoBy embedding a heater for heating the pump chamber, the tank, and the discharge nozzle in the block body, the liquid ejecting apparatus can be reduced in size, and the heat generated from the heater can be efficiently transmitted to the pump chamber, the tank, and the discharge nozzle.
[0090]
  RefusalBy fixing the piezoelectric actuator to the block body with a support member having thermal properties, heat conduction from the block body to the piezoelectric actuator can be effectively prevented.
[0091]
  TheBy providing the heat insulating sheet between the lock body and the piezoelectric actuator, heat radiation from the block body to the piezoelectric actuator can be effectively prevented.
[0092]
  RefusalBy providing a fan on the side of the piezoelectric actuator separated by the heat sheet, it is possible to apply air only to the piezoelectric actuator without applying air to the block body that must maintain high temperature. Cools well.
[0093]
  Claim 6According to the described liquid ejecting apparatus, the use of the molten solder, which is a liquid having a large specific gravity and a low melting point, can effectively use the weight of the liquid and can simplify the heater. Can be exhibited most. In particular, even if molten solder comes into contact with air in the tank and forms an oxide film, the oxide film stays on the liquid surface, preventing the oxide film from entering the pump chamber under the tank and causing clogging. it can.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view taken along the line II in FIG. 3 (a tank portion includes a center line of a tank) showing an embodiment of a liquid ejecting apparatus according to the invention.
FIG. 2 is a front view showing an embodiment of a liquid ejecting apparatus according to the invention.
FIG. 3 is a plan view illustrating an embodiment of a liquid ejecting apparatus according to the invention.
4 shows an embodiment of a liquid ejecting apparatus according to the invention, FIG. 4 [1] is a left side view, and FIG. 4 [2] is a vertical sectional view taken along line IV-IV in FIG. Different).
FIG. 5 is an enlarged cross-sectional view showing a pump chamber in the liquid ejecting apparatus of FIG. 1;
6 is a perspective view showing a pump chamber in the liquid ejecting apparatus of FIG. 1. FIG.
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 FIG. It is a VIIa-VIIa line longitudinal section in 1A]. 7 [1B] and [2B] show discharge nozzles used in place of the flat plate nozzle, 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 that holds the piezoelectric actuator 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. FIG.
[Explanation of symbols]
  10 tanks
  20 Pump room
  21 Cavity
  22 Introduction pipe section
  22a Inlet pipe inlet
  22b Outlet of inlet pipe
  23 Discharge pipe section
  23a Exhaust pipe entrance
  23b Exhaust pipe outlet
  30 Diaphragm
  31 cylinder
  40, 41 Discharge nozzle
  45 Flat 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 Molten solder droplets
  S3 Flow path of molten solder

Claims (6)

A tank for storing the liquid, a pump chamber having a wall consisting of the diaphragm as well as the tank and communicating provided below the tank, and the ejection exit nozzle that through communication with the pump chamber is provided below the pump chamber, An actuator for discharging the liquid downward from the discharge nozzle by pressing the diaphragm , and a liquid ejecting apparatus comprising :
The pump chamber has a columnar shape having an axis in the horizontal direction and one circular wall surface is the diaphragm, and an introduction pipe portion having an inlet connected to the tank and an outlet connected to the cavity. A discharge pipe part having an inlet connected to the cavity and an outlet connected to the discharge nozzle;
The inlet of the discharge pipe is connected to the uppermost edge in the vertical direction of the cavity, and the outlet of the introduction pipe is connected to the inner periphery of the cavity along the tangential direction of the cavity,
A liquid ejecting apparatus. The pump chamber is formed in the block body, the tank is attached on the block body, and the discharge nozzle is attached below the block body,
The liquid ejecting apparatus according to claim 1 . A cylinder having the same axis as that of the hollow part is projected in the hollow part, and the flow path of the liquid from the outlet of the introduction pipe part to the inlet of the discharge pipe part is formed around the cylinder.
The liquid ejecting apparatus according to claim 1 or 2 . A nozzle having a through-hole smaller than the inner diameter of the introduction tube portion was provided at the entrance or exit of the introduction tube portion or in the middle thereof.
The liquid ejecting apparatus according to claim 1 . The same thing as the discharge nozzle was connected to the inlet or outlet of the introduction pipe part or in the middle,
The liquid ejecting apparatus according to claim 1 . The liquid is a molten solder;
The liquid ejecting apparatus according to claim 1 .

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