JP2018069206A - Droplet jet apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a droplet injection device in which an actuator and wiring connected to the actuator are not damaged in storage in a storage case, removal work, attachment to a dropping device, removal work, and the like. The droplet injection device of the embodiment includes a droplet injection unit, a solution holding container, an actuator, an electrical substrate, and a base member. The droplet injection unit communicates with the nozzle that discharges the solution, and a pressure chamber filled with the solution is formed inside. The first surface on the side that discharges the solution from the nozzle and the side that supplies the solution to the pressure chamber It has a second surface. The electrical board has wiring that is connected to the actuator. The base member holds the droplet injection portion. The base member is formed with a recessed portion for the electrical substrate for mounting the electrical substrate and an opening for mounting the droplet injection portion. The first distance in the solution discharge direction from the first surface to the wiring is shorter than the second distance from the first surface to the end surface of the base member in the solution discharge direction. [Selection diagram] Fig. 4

Description

  Embodiments described herein relate generally to a droplet ejecting apparatus.

  In research and development in fields such as biology and pharmaceutics, medical diagnosis and inspection, and agricultural tests, an operation of dispensing a microliter (μL) liquid from a picoliter (pL) may be performed. For example, in the stage of determining the concentration of a compound required to effectively attack cancer cells, dispensing a low volume of liquid is an important task.

  These are commonly referred to as dose response experiments, and many different concentrations of compound are made in a container such as a well of a microplate to determine the effective concentration of the compound. There is an on-demand type droplet ejecting apparatus used for such an application. This droplet ejecting apparatus controls, for example, a solution holding container that holds a solution, a nozzle that discharges the solution, a pressure chamber that is disposed between the solution holding container and the nozzle, and a pressure of the solution in the pressure chamber. An actuator.

  In this droplet ejecting apparatus, the amount of one droplet discharged from the nozzle is in the order of pL, and by controlling the number of times of dropping, it is possible to drop liquid in the order of pL to μL into each well. Therefore, it is an apparatus suitable for the operation of dispensing many compounds typified by dose response experiments at different concentrations and for the operation of dispensing a very small amount from pL to nanoliter (nL).

  Multiple dose solutions are used in dose response experiments. In medical and bio applications, it is desirable that the droplet ejection device is disposable in order to prevent contamination. Therefore, the on-demand type droplet ejecting apparatus has a shape that can be exchanged with the dropping apparatus.

  As an actuator provided in this droplet ejecting apparatus, a structure in which a piezoelectric actuator is formed on a surface having a nozzle is also possible. For example, Patent Document 2 is disclosed as an inkjet head application.

US Patent Publication US2014 / 0193309 JP2015-009448A

  Since this prior art actuator is formed on a surface having a nozzle, a part of wiring for sending a control signal connected to the actuator of the droplet ejecting apparatus and the actuator is a surface for ejecting a solution (droplet ejecting). It will be placed on the back side of the device.

  For this reason, when the droplet ejection device is taken out of the storage case, the actuator or the wiring may be damaged if the actuator or the wiring comes in contact with a part of the storage case. Further, when replacing the used droplet ejecting device mounted on the dropping device with the unused droplet ejecting device, the unused droplet ejecting device is replaced with the table on which the dropping device is installed. May be temporarily placed on top. In such a case, if the solution discharge surface side of the unused droplet ejecting apparatus is placed facing down, the actuator or wiring may come into contact with the table and the actuator or wiring may be damaged. .

  The problem of the present embodiment is to provide a droplet ejecting device in which the actuator and the wiring connected to the actuator are not damaged in the storing and taking out operation in the storage case, the mounting operation to the dropping device, and the like. .

  The liquid droplet ejecting apparatus according to the embodiment includes a liquid droplet ejecting unit, a solution holding container, an actuator, an electrical board, and a base member. The liquid droplet ejecting unit communicates with a nozzle that discharges the solution, and a pressure chamber that is filled with the solution is formed. The solution is supplied to the first surface on the side from which the solution is discharged from the nozzle and the pressure chamber. And a second surface on the side to be operated. The solution holding container is attached to the second surface and has a solution receiving port for receiving the solution and a solution outlet communicating with the pressure chamber. The actuator changes the pressure in the pressure chamber and discharges the solution in the pressure chamber from the nozzle. The electrical board has wiring connected to the actuator. The base member holds the droplet ejecting unit. The base member is formed with an electrical substrate recess for mounting the electrical substrate and an opening for mounting the droplet ejecting portion communicating with the electrical substrate recess. A distance L1 in the solution discharge direction from the first surface to the wiring is shorter than a distance L2 from the first surface to an end surface in the solution discharge direction of the base member.

FIG. 1 is a perspective view showing an overall schematic configuration of a solution dropping apparatus on which the droplet ejecting apparatus according to the first embodiment is mounted. FIG. 2 is a plan view of the upper surface (solution holding container side) showing the droplet ejecting apparatus of the first embodiment. FIG. 3 is a plan view of the lower surface (droplet ejection side) showing the droplet ejecting apparatus of the first embodiment. 4 is a cross-sectional view taken along line F4-F4 of FIG. FIG. 5 is a plan view showing a droplet ejection array of the droplet ejection device according to the first embodiment. 6 is a cross-sectional view taken along line F6-F6 of FIG. FIG. 7 is a longitudinal sectional view showing a peripheral structure of a nozzle of the droplet ejecting apparatus according to the first embodiment. FIG. 8 is a longitudinal sectional view showing the main structure of the droplet ejecting apparatus according to the second embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. Each figure is a schematic diagram for promoting the embodiment and understanding thereof, and there are places where the shape, dimensions, ratios, and the like are different from the actual ones, but these can be appropriately changed in design.

(First embodiment)
An example of the liquid droplet ejecting apparatus according to the first embodiment will be described with reference to FIGS. FIG. 1 is a perspective view showing an example of use of a liquid droplet ejecting apparatus 2 of the present embodiment used in a solution dropping apparatus 1. FIG. 2 is a top view of the droplet ejecting apparatus 2, and FIG. 3 is a bottom view showing a surface of the droplet ejecting apparatus 2 that ejects droplets. 4 shows a cross-sectional view taken along line F4-F4 of FIG. FIG. 5 is a plan view showing the droplet ejection array 27 of the droplet ejection device 2 according to the first embodiment. 6 is a cross-sectional view taken along line F6-F6 of FIG. FIG. 7 is a longitudinal sectional view showing the peripheral structure of the nozzle 110 of the droplet ejecting apparatus 2.

  The solution dripping device 1 includes a rectangular flat base 3 and a droplet ejection device mounting module 5. In this embodiment, an embodiment in which a solution is dropped onto a 96-hole microplate 4 will be described. Here, the front-rear direction of the base 3 is referred to as the X direction, and the left-right direction of the base 3 is referred to as the Y direction. The X direction and the Y direction are orthogonal to each other.

  The microplate 4 is fixed at the center position of the base 3. On the base 3, a pair of left and right X direction guide rails 6 a and 6 b extending in the X direction are provided on both sides of the microplate 4. Both end portions of the X-direction guide rails 6 a and 6 b are fixed to fixed bases 7 a and 7 b that protrude from the base 3.

  Between the X direction guide rails 6a and 6b, a Y direction guide rail 8 extending in the Y direction is installed. Both ends of the Y-direction guide rail 8 are fixed to X-direction moving bases 9 that can slide in the X-direction along the X-direction guide rails 6a and 6b.

  The Y-direction guide rail 8 is provided with a Y-direction moving table 10 on which the droplet ejecting device mounting module 5 can move along the Y-direction guide rail 8 in the Y direction. A droplet ejection device mounting module 5 is mounted on the Y-direction moving table 10. The droplet ejection device 2 of this embodiment is fixed to the droplet ejection device mounting module 5. Thus, a combination of an operation in which the Y-direction moving table 10 moves in the Y direction along the Y-direction guide rail 8 and an operation in which the X-direction moving table 9 moves in the X direction along the X-direction guide rails 6a and 6b. Thus, the droplet ejecting apparatus 2 is supported so as to be movable to an arbitrary position in the orthogonal XY directions.

  The droplet ejecting apparatus 2 according to the first embodiment includes a flat base member 21. As shown in FIG. 2, on the surface (upper surface) side of the base member 21, a plurality of, in the present embodiment, eight solution holding containers 22 are arranged in a line in the Y direction. The solution holding container 22 is a bottomed cylindrical container having an upper surface opened as shown in FIG. On the surface side of the base member 21, a cylindrical recess 21 a is formed at a position corresponding to each solution holding container 22. The bottom of the solution holding container 22 is bonded and fixed to the recess 21a. Furthermore, an opening 22 a serving as a solution outlet is formed at the center of the bottom of the solution holding container 22. The opening area of the upper opening 22b is larger than the opening area of the solution outlet opening 22a.

  As shown in FIG. 3, on the back surface (lower surface) side of the base member 21, the same number as the solution holding containers 22, in this embodiment, eight electrical boards 23 are arranged in parallel in the Y direction. The electrical board 23 is a rectangular flat plate member. On the back surface side of the base member 21, as shown in FIG. 4, a rectangular recess 21b for mounting the electrical board 23 and a droplet ejection array portion opening 21d communicating with the recess 21b are formed. . The base end portion of the recessed portion 21b extends to a position near the upper end portion in FIG. 3 of the base member 21 (a position near the right end portion in FIG. 4). As shown in FIG. 4, the tip of the recessed portion 21 b extends to a position where it overlaps with a part of the solution holding container 22. The electrical board 23 is bonded and fixed to the inner bottom surface 21b1 of the recessed portion 21b.

  On the electrical board 23, an electrical board wiring 24 is formed by patterning on the surface opposite to the adhesive fixing surface with the inner bottom surface 21b1 of the recessed portion 21b. The wiring board 24 is formed with two wiring patterns 24a and 24b that are respectively connected to the terminal portion 131c of the lower electrode 131 and the terminal portion 133c of the upper electrode 133 formed in the droplet ejection array 27 described later. Yes.

  A control signal input terminal 25 for inputting a control signal from the outside is formed at one end of the electrical board wiring 24. An electrode terminal connection portion 26 is provided at the other end portion of the electrical board wiring 24. The electrode terminal connection part 26 is a connection part for connecting to the lower electrode terminal part 131c and the upper electrode terminal part 133c formed in the droplet ejection array 27 described later shown in FIG.

  The base member 21 is provided with a through hole for the droplet ejection array portion opening 21d. As shown in FIG. 3, the droplet ejection array portion opening 21 d is a rectangular opening, and is formed at a position overlapping the recessed portion 21 a on the back surface side of the base member 21.

  A droplet ejection array (droplet ejection unit) 27 shown in FIG. 5 is bonded and fixed to the lower surface of the solution holding container 22 so as to cover the openings 22a of the eight solution holding containers 22, respectively. The droplet ejection array 27 is disposed at a position corresponding to the droplet ejection array portion opening 21 d of the base member 21.

  As shown in FIG. 6, the droplet ejection array 27 is formed by laminating a nozzle plate 100 and a pressure chamber structure 200. As shown in FIG. 7, the nozzle plate 100 includes a nozzle 110 that discharges a solution, a diaphragm 120, a driving element 130 that is a driving unit, a protective film 150 that is a protective layer, and a liquid repellent film 160. The vibration plate 120 and the drive element 130 constitute an actuator 170. In the present embodiment, as shown in FIG. 5, the plurality of nozzles 110 are arranged in, for example, 3 × 3 rows.

The diaphragm 120 is formed integrally with the pressure chamber structure 200, for example. When the silicon wafer 201 for manufacturing the pressure chamber structure 200 is heat-treated in an oxygen atmosphere, a SiO ₂ (silicon oxide) film is formed on the surface of the silicon wafer 201. The vibration plate 120 uses a SiO ₂ (silicon oxide) film on the surface of the silicon wafer 201 formed by heat treatment in an oxygen atmosphere. The diaphragm 120 may be formed by forming a SiO ₂ (silicon oxide) film on the surface of the silicon wafer 201 by a CVD method (chemical vapor deposition method).

The film thickness of the diaphragm 120 is preferably in the range of 1 to 30 μm. The diaphragm 120 may be made of a semiconductor material such as SiN (silicon nitride) or Al ₂ O ₃ (aluminum oxide) instead of the SiO ₂ (silicon oxide) film.

  The drive element 130 is formed for each nozzle 110. The drive element 130 has an annular shape surrounding the nozzle 110. The shape of the drive element 130 is not limited, and for example, a C shape in which a part of the ring is cut out may be used. As shown in FIG. 7, the drive element 130 includes an electrode portion 131 a of the lower electrode 131 and an electrode portion 133 a of the upper electrode 133 with a piezoelectric film 132 that is a piezoelectric body interposed therebetween. The electrode part 131a, the piezoelectric film 132, and the electrode part 133a are coaxial with the nozzle 110 and have a circular pattern of the same size.

  The lower electrode 131 includes a plurality of circular electrode portions 131a coaxial with the plurality of circular nozzles 110, respectively. For example, the diameter of the nozzle 110 is 20 μm, the outer diameter of the electrode portion 131a is 133 μm, and the inner diameter is 42 μm. Further, as shown in FIG. 7, the lower electrode 131 includes a wiring part 131b for connecting a plurality of electrode parts 131a, and a terminal part 131c (see FIG. 5) at the end of the wiring part 131b. In FIG. 5, the driving element 130 is shown in a state where the electrode portion 131 a of the lower electrode 131 and the electrode portion 133 a of the upper electrode 133 overlap each other.

The drive element 130 includes a piezoelectric film 132 made of a piezoelectric material having a thickness of 2 μm, for example, on the electrode portion 131 a of the lower electrode 131. The piezoelectric film 132 is made of PZT (Pb (Zr, Ti) O ₃ : lead zirconate titanate). The piezoelectric film 132 is, for example, coaxial with the nozzle 110 and has an annular shape having the same shape as the electrode portion 131a and an outer diameter of 133 μm and an inner diameter of 42 μm. The film thickness of the piezoelectric film 132 is generally in the range of 1 to 30 μm. The piezoelectric film 132 is made of, for example, PTO (PbTiO ₃ : lead titanate), PMNT (Pb (Mg _1/3 Nb _2/3 ) O ₃ -PbTiO ₃ ), PZNT (Pb (Zn _1/3 Nb _2/3 )). A piezoelectric material such as O ₃ —PbTiO ₃ ), ZnO, or AlN can also be used.

  The piezoelectric film 132 generates polarization in the thickness direction. When an electric field in the same direction as the polarization is applied to the piezoelectric film 132, the piezoelectric film 132 expands and contracts in a direction orthogonal to the electric field direction. In other words, the piezoelectric film 132 contracts or expands in a direction orthogonal to the film thickness.

  The upper electrode 133 of the drive element 130 is coaxial with the nozzle 110 on the piezoelectric film 132 and has an annular shape having the same outer shape as the piezoelectric film 132, an outer diameter of 133 μm, and an inner diameter of 42 μm. As shown in FIG. 5, the upper electrode 133 includes a wiring portion 133b that connects the plurality of electrode portions 133a, and includes a terminal portion 133c at the end of the wiring portion 133b. When the upper electrode 133 is connected to a constant voltage, a voltage control signal is applied to the lower electrode 131.

The lower electrode 131 is formed to have a thickness of 0.5 μm by laminating Ti (titanium) and Pt (platinum) by sputtering, for example. The film thickness of the lower electrode 131 is generally in the range of 0.01 to 1 μm. The lower electrode 131 is made of Ni (nickel), Cu (copper), Al (aluminum), Ti (titanium), W (tungsten), Mo (molybdenum), Au (gold), SrRuO ₃ (strontium ruthenium oxide), or the like. Other materials can be used. The lower electrode 131 can be used by laminating various metals.

The upper electrode 133 was formed of a Pt thin film. The thin film was formed using a sputtering method to a thickness of 0.5 μm. As another electrode material of the upper electrode 133, Ni, Cu, Al, Ti, W, Mo, Au, SrRuO ₃ or the like can be used. As another film forming method, vapor deposition or plating can be used. The upper electrode 133 can be used by laminating various metals. A desirable film thickness of the upper electrode 133 is 0.01 to 1 μm.

The nozzle plate 100 includes an insulating film 140 that insulates the lower electrode 131 from the upper electrode 133. For the insulating film 140, for example, SiO ₂ (silicon oxide) having a thickness of 0.5 μm is used. In the region of the driving element 130, the insulating film 140 covers the electrode portion 131a, the periphery of the piezoelectric film 132, and the electrode portion 133a. The insulating film 140 covers the wiring part 131 b of the lower electrode 131. The insulating film 140 covers the diaphragm 120 in the region of the wiring part 133 b of the upper electrode 133. The insulating film 140 includes a contact portion 140a that electrically connects the electrode portion 133a of the upper electrode 133 and the wiring portion 133b.

  The nozzle plate 100 includes a protective film 150 made of, for example, polyimide that protects the driving element 130. The protective film 150 includes a cylindrical solution passage portion 141 that communicates with the nozzle 110 of the diaphragm 120. The solution passage portion 141 has the same diameter of 20 μm as the diameter of the nozzle 110 of the vibration plate 120.

  The protective film 150 can also use other insulating materials such as other resins or ceramics. Other resins include ABS (acrylonitrile butadiene styrene), polyacetal, polyamide, polycarbonate, oil ether sulfone and the like. Examples of the ceramic include zirconia, silicon carbide, silicon nitride, and silicon oxide. The thickness of the protective film 150 is generally in the range of 1 to 50 μm.

  In selecting a material for the protective film 150, Young's modulus, heat resistance, insulation, thermal expansion coefficient, smoothness, and wettability with respect to a solution are also taken into consideration. The insulating property takes into consideration the influence of solution alteration caused by contact with the upper electrode 133 when the driving element 130 is driven in a state where a solution having high conductivity is used.

  The nozzle plate 100 includes a liquid repellent film 160 that covers the protective film 150. The liquid repellent film 160 is formed by spin-coating, for example, a silicone resin having a property of repelling a solution. The liquid repellent film 160 can also be formed of a material having a characteristic of repelling a solution such as a fluorine-containing resin. The thickness of the liquid repellent film 160 is, for example, 0.5 μm.

  The pressure chamber structure 200 is formed using, for example, a silicon wafer 201 having a thickness of 525 μm. The pressure chamber structure 200 includes a warp reduction film 220 that is a warp reduction layer on a surface opposite to the diaphragm 120. The pressure chamber structure 200 includes a pressure chamber 210 that penetrates the warp reduction film 220 to reach the position of the diaphragm 120 and communicates with the nozzle 110. For example, the pressure chamber 210 is formed in a circular shape having a diameter of 190 μm and positioned coaxially with the nozzle 110. The shape and size of the pressure chamber 210 are not limited.

  However, in the first embodiment, the pressure chamber 210 has an opening communicating with the opening 22 a of the solution holding container 22. It is preferable to make the size L in the depth direction larger than the size D in the width direction of the opening of the pressure chamber 210. By setting the size L in the depth direction to the size D in the width direction, the pressure applied to the solution in the pressure chamber 210 is delayed from escaping to the solution holding container 22 due to the vibration of the vibration plate 120 of the nozzle plate 100.

  In the pressure chamber structure 200, the side on which the diaphragm 120 is disposed is a first surface 200a, and the side on which the warp reduction film 220 is disposed is a second surface 200b. The solution holding container 22 is bonded to the warp reduction film 220 side of the pressure chamber structure 200 with, for example, an epoxy adhesive. The pressure chamber 210 of the pressure chamber structure 200 communicates with the opening 22 a of the solution holding container 22 through the opening on the warp reduction film 220 side. The opening area of the opening 22 a of the solution holding container 22 is larger than the opening area of the opening communicating with the opening 22 a of the solution holding container 22 of all the pressure chambers 210 formed in the droplet ejection array 27. Therefore, all the pressure chambers 210 formed in the droplet ejection array 27 communicate with the opening 22 a of the solution holding container 22.

The warp reduction film 220 is formed by, for example, heating a silicon wafer 201 for manufacturing the pressure chamber structure 200 in an oxygen atmosphere to form a 4 μm thick SiO ₂ (silicon oxide) film formed on the surface of the silicon wafer 201. Use. The warp reduction film 220 may be formed by forming a SiO ₂ (silicon oxide) film on the surface of the silicon wafer 201 by a CVD method (chemical vapor deposition method). The warp reduction film 220 reduces the warp generated in the droplet ejection array 27.

  The warp reduction film 220 is on the side of the silicon wafer 201 facing the diaphragm 120 side, and reduces the warp of the silicon wafer 201. The warp reduction film 220 reduces the warp of the silicon wafer 201 due to a difference in film stress between the pressure chamber structure 200 and the diaphragm 120 and a difference in film stress between various constituent films of the driving element 130. The warp reduction film 220 reduces the warp of the droplet ejection array 27 when forming the constituent members of the droplet ejection array 27 using a film forming process.

  The material and thickness of the warp reduction film 220 may be different from those of the diaphragm 120. However, if the warp reduction film 220 is made of the same material as the diaphragm 120 and has the same film thickness, the difference in film stress between the diaphragm 120 and the film stress between the warp reduction film 220 on both sides of the silicon wafer 201 is Be the same. Therefore, if the warp reduction film 220 is made of the same material as the diaphragm 120 and has the same film thickness, the warp generated in the droplet ejection array 27 is more effectively reduced.

  The diaphragm 120 is deformed in the thickness direction by the operation of the planar driving element 130. The droplet ejecting apparatus 2 ejects the solution supplied to the nozzle 110 due to a pressure change generated in the pressure chamber 210 of the pressure chamber structure 200 due to the deformation of the vibration plate 120.

An example of a manufacturing method of the droplet ejection array 27 will be described. In the droplet ejection array 27, first, SiO ₂ (silicon oxide) films are formed on the entire surface of both sides of the silicon wafer 201 for forming the pressure chamber structure 200. A SiO ₂ (silicon oxide) film formed on one surface of the silicon wafer 201 is used as the diaphragm 120. A SiO ₂ (silicon oxide) film formed on the other surface of the silicon wafer 201 is used as the warp reduction film 220.

For example, SiO ₂ (silicon oxide) films are formed on both surfaces of, for example, a disk-shaped silicon wafer 201 by a thermal oxidation method in which heat treatment is performed in an oxygen atmosphere using a batch-type reaction furnace. Next, a plurality of nozzle plates 100 and pressure chambers 210 are formed on the disk-shaped silicon wafer 201 by a film forming process. After forming the nozzle plate 100 and the pressure chamber 210, the disk-shaped silicon wafer 201 is cut and separated into a plurality of pressure chamber structures 200 integrated with the nozzle plate 100. Using the disk-shaped silicon wafer 201, a plurality of droplet ejection arrays 27 can be mass-produced at a time. The silicon wafer 201 does not have to be disk-shaped. The single nozzle plate 100 and the pressure chamber structure 200 may be individually formed using one rectangular silicon wafer 201.

  The vibration plate 120 formed on the silicon wafer 201 is patterned using an etching mask to form the nozzle 110. In the patterning, a photosensitive resist is used as an etching mask material. After applying a photosensitive resist on the surface of the vibration plate 120, exposure and development are performed to form an etching mask in which an opening corresponding to the nozzle 110 is patterned. The nozzle 120 is formed by dry-etching the diaphragm 120 from above the etching mask until it reaches the pressure chamber structure 200. After the nozzle 110 is formed on the diaphragm, the etching mask is removed using, for example, a stripping solution.

  Next, the driving element 130, the insulating film 140, the protective film 150, and the liquid repellent film 160 are formed on the surface of the diaphragm 120 where the nozzle 110 is formed. The formation of the driving element 130, the insulating film 140, the protective film 150, and the liquid repellent film 160 repeats the film forming process and the patterning process. The film forming process is performed by a sputtering method, a CVD method, a spin coating method, or the like. The patterning is performed, for example, by forming an etching mask on the film using a photosensitive resist, etching the film material, and then removing the etching mask.

  On the vibration plate 120, materials for the lower electrode 131, the piezoelectric film 132, and the upper electrode 133 are stacked. As a material for the lower electrode 131, a Ti (titanium) film and a Pt (platinum) film are sequentially formed by a sputtering method. Ti (titanium) and Pt (platinum) films may be formed by vapor deposition or plating.

On the lower electrode 131, PZT (Pb (Zr, Ti) O ₃ : lead zirconate titanate) is formed as a material of the piezoelectric film 132 by a RF magnetron sputtering method at a substrate temperature of 350 ° C. After the PZT film is formed, the PZT has good piezoelectric performance by heat treatment at 500 ° C. for 3 hours. The PZT film may be formed by a CVD (chemical vapor deposition method), a sol-gel method, an AD (aerosol deposition) method, or a hydrothermal synthesis method.

A Pt (platinum) film is formed on the piezoelectric film 132 as a material of the upper electrode 133 by a sputtering method. On the formed Pt (platinum) film, an etching mask is formed which leaves the material film of the lower electrode 131 and leaves the electrode portion 133a of the upper electrode 133 and the piezoelectric film 132. Etching is performed on the etching mask to remove the film of Pt (platinum) and PZT (Pb (Zr, Ti) O ₃ : lead zirconate titanate) to form the electrode portion 133a of the upper electrode and the piezoelectric film 132. To do.

  Next, an etching mask that leaves the electrode part 131a, the wiring part 131b, and the terminal part 131c of the lower electrode 131 is formed on the material of the lower electrode 131 on which the electrode part 133a of the upper electrode and the piezoelectric film 132 are formed. Etching is performed on the etching mask to remove the Ti (titanium) and Pt (platinum) films, thereby forming the lower electrode 131.

An SiO ₂ (silicon oxide) film is formed as a material for the insulating film 140 on the diaphragm 120 on which the lower electrode 131, the electrode portion 133 a of the upper electrode, and the piezoelectric film 132 are formed. The SiO ₂ (silicon oxide) film is formed at a low temperature by, for example, a CVD method to obtain good insulation. The insulating film 140 is formed by patterning the formed SiO ₂ (silicon oxide) film.

  On the diaphragm 120 on which the insulating film 140 is formed, Au (gold) is deposited by sputtering as a material for the wiring portion 133b and the terminal portion 133c of the upper electrode 133. The Au (gold) film may be formed by vapor deposition, CVD, or plating. An etching mask is formed to leave the electrode wiring portion 133b and the terminal portion 133c of the upper electrode 133 on the formed Au (gold) film. Etching is performed on the etching mask to remove the Au (gold) film, and the electrode wiring portion 133b and the terminal portion 133c of the upper electrode 133 are formed.

  A polyimide film that is a material of the protective film 150 is formed on the vibration plate 120 on which the upper electrode 133 is formed. The polyimide film is formed by applying a solution containing a polyimide precursor on the vibration plate 120 by spin coating, removing the thermal polymerization by baking, and the solvent. The formed polyimide film is patterned to form a protective film 150 that exposes the solution passage part 141, the terminal part 131 c of the lower electrode 131, and the terminal part 133 c of the upper electrode 133.

  A silicone-based resin film, which is a material of the liquid repellent film 160, is applied on the protective film 150 by a spin coating method, and the film is formed by removing the thermal polymerization by baking and the solvent. The formed silicone resin film is patterned to form a liquid repellent film 160 that exposes the nozzle 110, the solution passage portion 141, the terminal portion 131c of the lower electrode 131, and the terminal portion 133c of the upper electrode 133.

On the liquid repellent film 160, for example, a back protective tape for CMP (Chemical Mechanical Polishing) of the silicon wafer 201 is attached as a cover tape to protect the liquid repellent film 160, and the pressure chamber structure 200 is patterned. An etching mask exposing the diameter 190 μm of the pressure chamber 210 is formed on the warp reduction film 220 of the silicon wafer 201. First, the warp reduction film 220 is mixed with a mixed gas of CF ₄ (carbon tetrafluoride) and O ₂ (oxygen). To dry etch. Next, vertical deep dry etching dedicated to silicon wafers is performed using, for example, a mixed gas of SF ₆ (sulfur hexafluoride) and O ₂ . Dry etching is stopped at a position where it abuts on the diaphragm 120, and a pressure chamber 210 is formed in the pressure chamber structure 200.

  Etching for forming the pressure chamber 210 may be performed by a wet etching method using a chemical solution, a dry etching method using plasma, or the like. After the etching is completed, the etching mask is removed. By irradiating the cover tape affixed on the liquid repellent film 160 with ultraviolet rays to weaken the adhesiveness, the cover tape is peeled off from the liquid repellent film 160, and the disc-shaped silicon wafer 201 is cut. A droplet ejection array 27 is formed separately.

  Next, a method for manufacturing the droplet ejecting apparatus 2 will be described. The droplet ejection array 27 and the solution holding container 22 are bonded. At this time, the bottom surface (surface on the opening 22a side) of the solution holding container 22 is bonded to the warp reduction film 220 side (second surface 200b side) of the pressure chamber structure 200 in the droplet ejection array 27.

  Thereafter, the solution holding container 22 bonded to the droplet ejection array 27 is bonded to the recessed portion 21 a of the base member 21. Subsequently, the electrical board 23 is bonded to the inner bottom surface 21 b 1 of the recessed portion 21 b on the back surface side of the base member 21. At this time, the electrical board 23 is arranged in such a manner that the electrical board wiring 24 is arranged on the lower surface side (the surface opposite to the surface where the nozzle plate 100 contacts the pressure chamber 210) in FIGS. The electrical board 23 is bonded to the inner bottom surface 21b1 of the recessed portion 21b.

  Subsequently, the electrode terminal connection portion 26 of the electrical board wiring 24 and the terminal portion 131 c of the lower electrode 131 and the terminal portion 133 c of the upper electrode 133 of the droplet ejection array 27 are connected by the wire wiring 12. Other connection methods include a method using a flexible cable. This is a method of electrically connecting the electrode pad of the flexible cable and the electrode terminal connecting portion 26 or the terminal portion 131c and the terminal portion 133c by thermocompression bonding with an anisotropic conductive film.

  The other terminal of the electrical board wiring 24 is a control signal input terminal 25, which has a shape that can come into contact with, for example, a leaf spring connector that inputs a control signal output from a control circuit (not shown). Thereby, the droplet ejecting apparatus 2 is formed.

  Next, the operation of the above configuration will be described. The droplet ejection device 2 of the present embodiment is used by being fixed to the droplet ejection device mounting module 5 of the solution dropping device 1. When using the droplet ejecting apparatus 2, first, a predetermined amount of solution is supplied from the upper surface opening 22 b of the solution holding container 22 to the solution holding container 22 by a pipetter (not shown). The solution is held on the inner surface of the solution holding container 22. The opening 22 a at the bottom of the solution holding container 22 communicates with the droplet ejection array 27. The solution held in the solution holding container 22 is filled into each pressure chamber 210 of the droplet ejection array 27 through the opening 22 a on the bottom surface of the solution holding container 22.

  In this state, the voltage control signal input to the control signal input terminal 25 of the electrical board wiring 24 is transferred from the electrode terminal connection portion 26 of the electrical board wiring 24 to the terminal portion 131c of the lower electrode 131 and the terminal portion 133c of the upper electrode 133. Sent. At this time, in response to the application of the voltage control signal to the drive element 130, the diaphragm 120 is deformed to change the volume of the pressure chamber 210, so that the solution becomes a solution droplet from the nozzle 110 of the droplet ejection array 27. Discharged. Then, a predetermined amount of liquid is dropped from the nozzle 110 to each well 4 b of the microplate 4.

  The amount of one droplet discharged from the nozzle 110 is 2 to 5 picoliters. Therefore, by controlling the number of times of dropping, it becomes possible to control dropping of a liquid of the order of pL to μL in each well 4b.

  Further, in the droplet ejecting apparatus 2 of the present embodiment, the first surface of the droplet ejecting array 27 (droplet ejecting unit) corresponds to the first surface 200 a of the pressure chamber structure 200. The actuator 170 is the diaphragm 120 and the driving element 130 disposed on the first surface 200 a of the pressure chamber structure 200. The nozzle 110 is formed on the diaphragm 120 and the driving element 130 on the first surface 200 a side of the pressure chamber structure 200. The wiring connected to the actuator 170 includes the wiring part 131b of the lower electrode 131, the terminal part 131c, the wiring part 133b of the upper electrode 133, the terminal part 133c, and the like connected to the driving element 130 of the droplet ejection array 27. They are the wire wiring 12 and the electrical board wiring 24 of the electrical board 23.

  Further, in the droplet ejecting apparatus 2 of the present embodiment, the base member 21 is configured to eject droplets for mounting the recessed portion 21b for mounting the electrical circuit board 23 and the droplet ejecting array 27 communicating with the recessed portion 21b. An array portion opening 21d is formed. The electrical board 23 is bonded and fixed to the inner bottom surface 21b1 of the recessed portion 21b. The droplet ejection array 27 adhered to the lower surface of the solution holding container 22 is disposed at a position corresponding to the droplet ejection array portion opening 21 d of the base member 21.

  As shown in FIG. 4, the distance from the first surface 200a of the pressure chamber structure 200, which is the first surface of the droplet ejection array 27, to the back surface 21c (surface on the solution discharge side) of the base member 21 is set to the second. Distance L2. Of the wirings connected to the drive element 130 of the droplet ejection array 27, the wire wiring 12 is located farthest in the solution discharge direction from the first surface 200a of the pressure chamber structure 200, and the pressure chamber structure A distance from the first surface 200a of the body 200 to the bottom surface (surface on the solution discharge side) of the wire wiring 12 is defined as a first distance L1.

  In the liquid droplet ejecting apparatus 2 of the first embodiment, the second distance L2 from the first surface 200a of the pressure chamber structure 200 to the back surface 21c of the base member 21 (surface on the solution discharge side) is the pressure chamber. It is longer than the first distance L1 from the first surface 200a of the structure 200 to the bottom surface (surface on the solution discharge side) of the wire wiring 12. Therefore, each wiring connected to the actuator 170 (the wiring part 131b of the lower electrode 131, the terminal part 131c, the wiring part 133b of the upper electrode 133, the terminal part 133c, the wire wiring 12, and the electrical board of the electrical board 23) The wirings 24) are all housed in the recesses 21b of the base member 21 and the droplet ejection array opening 21d. Therefore, the drive element 130 or each of the above wirings is the back surface 21c of the base member 21 (surface on the solution discharge side) in the operation of storing the droplet ejection device 2 in the storage case, the removal, or the mounting operation to the dropping device 1. It does not protrude from the outside to the outside. Therefore, it is possible to prevent the driving element 130 or each of the wirings 131b, 131c, 133b, 133c, 12, 24 from contacting a part of the storage case, so that the driving element 130 or each of the wirings 131b, 131c, 133b, 133c can be prevented. , 12 and 24 do not come into contact with a part of the storage case and are not damaged, or are placed on the table with the solution discharge surface side down and are not damaged. As a result, the actuator 170 and each of the wirings 131b, 131c, 133b, 133c, 12, 24 connected to the actuator 170 are damaged in the storage and removal operations in the storage case, the attachment to the dropping device, and the removal operation. The liquid droplet ejecting apparatus 2 that does not occur can be provided.

(Second Embodiment)
FIG. 8 is a longitudinal sectional view showing the main structure of the droplet ejecting apparatus 2 according to the second embodiment. In the present embodiment, an integrated member 230 is provided in which the base member 21 and the solution holding container 22 of the droplet ejecting apparatus 2 according to the first embodiment are integrated with, for example, a resin component. Other parts are the same as those of the droplet ejecting apparatus 2 according to the first embodiment.

  Therefore, in the present embodiment as well, the second distance L2 from the first surface 200a of the pressure chamber structure 200 to the back surface 21c (surface on the solution discharge side) of the base member 21 is equal to the pressure, as in the first embodiment. It is longer than the first distance L1 from the first surface of the chamber 210 to the surface on the bottom surface side of the wire wiring 12 (surface on the solution discharge side). Therefore, each wiring connected to the actuator 170 (the wiring part 131b of the lower electrode 131, the terminal part 131c, the wiring part 133b of the upper electrode 133, the terminal part 133c, the wire wiring 12, and the electrical board of the electrical board 23) The wirings 24) are all housed in the recesses 21b of the base member 21 and the droplet ejection array opening 21d. Therefore, the drive element 130 or each of the wirings 131b, 131c, 133b, 133c, 12, 24 is used as the base member in the operation of storing the droplet ejection device 2 in the storage case, the removal, or the installation operation to the dropping device 1. No protruding from the back surface 21c (surface on the solution discharge side) 21 to the outside. Therefore, it is possible to prevent the driving element 130 or each of the wirings 131b, 131c, 133b, 133c, 12, 24 from contacting a part of the storage case, so that the driving element 130 or each of the wirings 131b, 131c, 133b, 133c can be prevented. , 12 and 24 do not come into contact with a part of the storage case and are not damaged, or are placed on the table with the solution discharge surface side down and are not damaged. As a result, the actuator 170 and each of the wirings 131b, 131c, 133b, 133c, 12, 24 connected to the actuator 170 are damaged in the storage and removal operations in the storage case, the attachment to the dropping device, and the removal operation. The liquid droplet ejecting apparatus 2 that does not occur can be provided.

  In the embodiment described above, the drive element 130 which is a drive unit is circular, but the shape of the drive unit is not limited. The shape of the drive unit may be, for example, a rhombus or an ellipse. The shape of the pressure chamber 210 is not limited to a circle, and may be a rhombus, an ellipse, or a rectangle.

  In the embodiment, the nozzle 110 is arranged at the center of the driving element 130, but the position of the nozzle 110 is not limited as long as the solution in the pressure chamber 210 can be discharged. For example, the nozzle 110 may be formed outside the drive element 130 instead of in the area of the drive element 130. When the nozzle 110 is disposed outside the driving element 130, it is not necessary to pattern the nozzle 110 through the plurality of film materials of the driving element 130. The plurality of film materials of the drive element 130 do not require opening patterning at positions corresponding to the nozzles 110, and the nozzles 110 can be formed only by patterning the diaphragm 120 and the protective film 150, and patterning becomes easy.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

    DESCRIPTION OF SYMBOLS 1 ... Dropping device, 2 ... Droplet ejecting device, 3 ... Base, 4 ... Microplate, 4b ... Well, 5 ... Droplet ejecting device mounting module, 6a ... X direction guide rail, 6b ... X direction guide rail, 7a DESCRIPTION OF SYMBOLS ... Fixed base, 7b ... Fixed base, 8 ... Y direction guide rail, 9 ... X direction moving base, 10 ... Y direction moving base, 12 ... Wire wiring, 21 ... Base member, 21a ... Recessed part, 21b ... Recessed part, 21b1 ... inner bottom surface, 21c ... back surface, 21d ... droplet ejection array portion opening, 22 ... solution holding container, 22a ... opening portion, 22b ... upper surface opening portion, 23 ... electrical substrate, 24 ... electrical substrate wiring, 24a ... wiring pattern , 24b ... wiring pattern, 25 ... control signal input terminal, 26 ... electrode terminal connection part, 27 ... droplet ejection array (droplet ejection part), 100 ... nozzle plate, 110 ... nozzle, 120 ... diaphragm, 130 ... drive Element 131 ... Lower electrode 131a ... Electrode part 131b ... Wiring part 131c ... Lower electrode terminal part 132 ... Piezoelectric film 133 ... Upper electrode 133a ... Electrode part 133b ... Wiring part 133c ... Upper electrode terminal Part 140, insulating film 140a contact part 141 solution passing part 150 protective film 160 liquid repellent film 170 actuator 200 pressure chamber structure 200a first surface 200b first 2 surface, 201 ... silicon wafer, 210 ... pressure chamber, 220 ... warpage reduction film, L1 ... first distance, L2 ... second distance.

Claims (5)

A pressure chamber communicating with the nozzle for discharging the solution and filled with the solution is formed, and a first surface on the side for discharging the solution from the nozzle and a second on the side for supplying the solution to the pressure chamber A droplet ejecting portion having a surface;
A solution holding port attached to the second surface and receiving a solution; a solution holding container having a solution outlet communicating with the pressure chamber;
An actuator for changing the pressure in the pressure chamber and discharging the solution in the pressure chamber from the nozzle;
An electrical board having wiring connected to the actuator;
A base member for holding the liquid droplet ejecting portion,
The base member is formed with an electrical substrate recess for mounting the electrical substrate, and an opening for mounting the droplet ejecting portion communicating with the electrical substrate recess,
The liquid droplet ejecting apparatus, wherein a first distance in the solution discharge direction from the first surface to the wiring is shorter than a second distance from the first surface to an end surface of the base member in the solution discharge direction. The actuator includes a driving element having an electrode portion of a lower electrode and an electrode portion of an upper electrode across a piezoelectric body,
The wiring has a wiring part connected to the driving element, an electrical board wiring of the electrical board, and a wiring connection part that connects between the wiring part and the electrical board wiring,
The first distance includes a distance between the first surface and the wiring portion, a distance between the first surface and the electrical board wiring, and the first surface and the wiring connection portion. The droplet ejecting apparatus according to claim 1, which is the longest distance between the two.   The base member has a concave portion for a solution holding container for mounting the solution holding vessel for fixing the solution holding vessel on the upper surface side, and the concave portion for the electric board and the concave portion for the electric board on the lower surface side. The liquid droplet ejecting apparatus according to claim 1, wherein the opening communicating with the liquid droplets is formed. The electrical substrate has a surface opposite to the surface on which the wiring is disposed, and is bonded and fixed to the inner bottom surface of the recessed portion for the electrical substrate of the base member,
The droplet ejecting unit is disposed in the opening of the base member in a state where the second surface is bonded and fixed to an end surface of the solution holding container on the solution outlet side.
4. The droplet ejecting apparatus according to claim 1, wherein the wiring is housed inside the recessed portion for the electrical board and the opening. 5.   The droplet ejecting apparatus according to claim 1, wherein the base member is formed integrally with the solution holding container.