JP2005212294A - Electrostatic actuator manufacturing method, droplet discharge head manufacturing method, electrostatic actuator, droplet discharge head, and droplet discharge apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a droplet discharge head capable of preventing a variation in the discharge amount of liquid from the droplet discharge head and capable of high-precision printing quality, and a droplet discharge device including the droplet discharge head.
An electrostatic actuator 50 and a droplet discharge head 1 with high processing accuracy can be obtained by removing a work-affected layer X present on each substrate constituting the droplet discharge head 1 by etching. Therefore, the speed of ink ejected from the nozzles 21 of the droplet ejection head 1 and the amount of ink become substantially uniform.
[Selection] Figure 3

Description

  The present invention relates to an electrostatic actuator and a droplet discharge head. More particularly, the present invention relates to a structure of an electrostatic actuator and a droplet discharge head that reduces variations in the liquid discharge speed and amount between nozzles, and a droplet discharge device including the electrostatic actuator and the droplet discharge head.

  2. Description of the Related Art In recent years, various types of droplet discharge heads of a droplet discharge apparatus are known depending on a mechanism for generating (discharge) droplets. For example, there is a droplet discharge head of a type in which a heater is heated to boil a liquid and a droplet is discharged with a bubble pressure generated thereby. In addition, there is a droplet discharge head of a type that discharges droplets by expanding and contracting the volume of a pressure chamber by applying a voltage to a piezoelectric element attached to a pressure chamber that stores liquid. Further, there is a type in which droplets are discharged by changing the volume of a pressure chamber in which liquid is stored using electrostatic force. In any type of droplet ejection head, droplets are ejected only when necessary for recording using the pressure fluctuation in the pressure chamber.

  These types of droplet discharge heads are generally arranged corresponding to each of a plurality of nozzles, and supply pressure to each pressure chamber and a pressure chamber for discharging droplets from the corresponding nozzle by pressure fluctuation. Each of the pressure chambers has a reservoir and a liquid supply port communicating with the reservoir. The pressure chambers, reservoirs, and liquid supply ports are known for the configuration of the electrostatic actuator and the droplet discharge head that are partitioned and formed in a state in which they are arranged in a plane direction between these substrates by superimposing flat substrates. It has been.

  In addition, these types of electrostatic actuators and droplet discharge head manufacturing methods include a step of forming an electrode substrate by forming an electrode and an insulating film on the substrate, and an anisotropic etching of the silicon single crystal substrate. The step of forming the cavity plate by forming each part and the glass plate that is joined to the cavity plate to provide the pressure chamber that communicates with the nozzle hole at a position corresponding to the vibration plate portion therebetween. And a step of joining the electrode substrate, the cavity plate, and the glass plate by anodic bonding (see, for example, Patent Document 1).

JP 2002-127423 A

  However, in the electrostatic actuator and the droplet discharge head having the conventional structure, the electrode substrate (first substrate), the cavity plate (second substrate), and the glass plate (third substrate) are polished on the substrate surface. There was a work-affected layer (microcrack) due to. For this reason, when moisture enters the work-affected layer or when dirt such as organic matter and inorganic matter adheres, the step of forming the shape of each substrate and the respective substrates are joined by an anodic bonding method. In the process of manufacturing the electrostatic actuator and the droplet discharge head, various quality problems have occurred.

  Here, the electrode substrate is affected by the presence of a work-affected layer (microcrack) on the substrate, and when the electrode (ITO film) is formed on the electrode substrate, the thickness of the ITO film becomes rough (surface The film quality of the ITO film changed and the electrical characteristics changed. In addition, when moisture enters the gap portion formed by the vibration plate portion and the electrode portion, there is a problem in that the electrical characteristics change and the speed and amount at the time of ink ejection vary. There is also a problem that the bonding strength between the substrates becomes weak.

  Similarly, in the cavity plate, if a work-affected layer (microcrack) is present on this substrate, a difference occurs in the etching rate when the diaphragm portion is formed on the substrate by etching. In addition, due to the presence of metal impurities on the substrate, the metal impurities diffused into the silicon substrate in the thermal oxidation process, causing distortion in the crystal structure and a difference in etching rate. Due to the difference in the etching rate, there were a problem that the thickness and width dimensions of the vibration plate portion could not be formed with high accuracy and a problem of surface roughness (surface irregularities). The variation in the thickness of the diaphragm part leads to a variation in the ease of bending of the diaphragm part, and thus there is a problem that the amount of deflection when the same electrostatic force is applied varies.

  The surface roughness (surface irregularities) of the electrode and the diaphragm causes in-plane distribution in the gap, resulting in a variation in electrostatic force between head products.

  Also, in the process of anodic bonding of the electrode substrate and the cavity plate, and in the process of anodic bonding of the glass plate to the member in which the electrode substrate and the cavity plate are integrated, due to the influence of the work-affected layer (micro crack), There was a problem that the bonding strength between the substrates was lowered and it was difficult to ensure a predetermined bonding strength. As a result, the substrates may be separated from each other. In particular, there is a problem in that the ink flow path for discharging ink from the pressure chamber constituted by the glass plate and the cavity plate cannot be secured. It was.

  In other words, due to the influence of the work-affected layer (micro cracks) on the electrode substrate, cavity plate, and glass plate, variations in electrostatic force occur due to variations in the diaphragm and gaps, and each nozzle There is a problem that variations occur in the speed and amount at the time of ink ejection. Therefore, when the electrostatic actuator built in the droplet discharge head is driven, the speed and amount of liquid discharged from each nozzle vary, and there is a problem that high-precision print quality cannot be obtained.

  The object of the present invention is to solve the above problems and suppress structural defects caused by a work-affected layer generated on a substrate by polishing when manufacturing an electrostatic actuator having a laminated structure in which a plurality of substrates are laminated. Accordingly, it is an object of the present invention to provide an electrostatic actuator manufacturing method, a droplet discharge head manufacturing method, an electrostatic actuator, a droplet discharge head, and a droplet discharge device that can further secure necessary drive characteristics.

  In the manufacturing method of the electrostatic actuator of the present invention, the first substrate on which the electrode for driving the vibration plate portion by electrostatic force is formed and the second substrate on which the vibration plate portion is formed are overlapped with each other. And a step of etching and removing the work-affected layer of the first substrate generated by polishing, and a step of forming the electrode on the first substrate. It is characterized by.

  According to the present invention, in the etching step, the work-affected layer of the first substrate is removed by etching, so that a surface having no work-affected layer is obtained on the substrate. In the electrode forming step, the ITO film as the electrode material is formed on this surface without being affected by the work-affected layer, so that the film quality is improved and the film thickness is formed with high accuracy. Therefore, the drive of the diaphragm part arrange | positioned at each pressure chamber is stabilized.

  In the manufacturing method of the electrostatic actuator of the present invention, the first substrate on which the electrode for driving the vibration plate portion by electrostatic force is formed and the second substrate on which the vibration plate portion is formed are overlapped with each other. In the manufacturing method of the electrostatic actuator comprising: the step of etching and removing the work-affected layer of the second substrate caused by polishing; and the groove processing by etching on the second substrate. And a step of forming a portion.

  According to this invention, in the etching step, the work-affected layer of the second substrate is removed by etching, so that a surface having no work-affected layer is obtained on the substrate. In the step of forming the diaphragm portion by performing groove processing by etching on this surface, the groove is formed with high accuracy without being affected by the work-affected layer. In addition, since the pattern dimensions that form the diaphragm portion are stably formed, the problem of dimensional defects can be eliminated, and variations in the thickness of the diaphragm portion can be prevented.

  The method for manufacturing an electrostatic actuator according to the present invention includes: a first substrate on which an electrode for driving the vibration plate portion by electrostatic force is formed; and the pressure chamber communicating with the nozzle at the vibration plate portion and a corresponding position. In the method for manufacturing an electrostatic actuator comprising superposing the formed second substrate and the second substrate and the substrate in this order, the work-affected layer of the third substrate generated by polishing is etched. The method includes a step of removing and a step of bonding the second substrate and the third substrate.

  According to the present invention, in the etching process, the work-affected layer of the third substrate is removed by etching, so that a surface having no work-affected layer is obtained on the third substrate. Since the step of bonding the third substrate to the second substrate is provided, a reliable bonding strength between the substrates can be obtained.

  The method for manufacturing an electrostatic actuator according to the present invention includes a step of bonding the first substrate and the second substrate.

  According to this invention, since the manufacturing method of the electrostatic actuator includes the step of joining the first substrate and the second substrate after removing the work-affected layer generated by polishing, A certain bonding strength can be obtained.

  The method for manufacturing a droplet discharge head according to the present invention includes a first substrate on which an electrode for driving a vibration plate portion by electrostatic force is formed, and the pressure chamber communicating with the nozzle at the vibration plate portion and a corresponding position. In the method of manufacturing a droplet discharge head, which comprises superimposing the second substrate on which the first substrate is formed, the step of removing the work-affected layer of the first substrate caused by polishing by etching; and Forming the electrode on one substrate.

  According to the present invention, in the etching step, the work-affected layer of the first substrate is removed by etching, so that a surface having no work-affected layer is obtained on the substrate. In the electrode formation process, the ITO film, which is the electrode material, is formed on this clean surface without being affected by the work-affected layer, so that the film quality is improved and the film thickness is accurately formed. The drive of the diaphragm portion arranged in each pressure chamber is stabilized.

  The method for manufacturing a droplet discharge head according to the present invention includes a first substrate on which an electrode for driving a vibration plate portion by electrostatic force is formed, and the pressure chamber communicating with the nozzle at the vibration plate portion and a corresponding position. In the method of manufacturing a droplet discharge head, which is formed by superimposing the second substrate on which the second substrate is formed, a step of etching and removing the work-affected layer of the second substrate caused by polishing; And a step of forming the diaphragm portion by performing groove processing by etching on the second substrate.

  According to this invention, in the etching step, the work-affected layer of the second substrate is removed by etching, so that a surface having no work-affected layer is obtained on the substrate. In the step of forming the diaphragm portion by performing groove processing by etching on this surface, the groove is formed with high accuracy without being affected by the work-affected layer. In addition, since the pattern dimensions that form the diaphragm portion are stably formed, the problem of dimensional defects can be eliminated, and variations in the thickness of the diaphragm portion can be prevented. Therefore, since the variation in the amount of bending of the diaphragm caused by the variation in the thickness of the diaphragm can be prevented, the driving of the diaphragm is stabilized.

  The method for manufacturing a droplet discharge head according to the present invention includes a first substrate on which an electrode for driving the diaphragm portion by electrostatic force is formed, a second substrate on which the diaphragm portion is formed, and the second substrate. A method for manufacturing a droplet discharge head comprising superimposing a substrate and a third substrate on each other, comprising a step of etching and removing the work-affected layer of the third substrate generated by polishing. Features.

  According to the present invention, in the etching step, the work-affected layer of the third substrate is removed by etching, so that a clean surface having no work-affected layer is obtained on the substrate. And the third substrate are improved in adhesion, and the substrates can be firmly bonded to each other.

  The method for manufacturing a droplet discharge head according to the present invention includes a step of bonding the first substrate and the second substrate.

  According to this invention, the manufacturing method of the droplet discharge head includes the step of bonding the first substrate and the second substrate after removing the work-affected layer generated by polishing. A reliable bonding strength between the two is obtained.

  The electrostatic actuator of the present invention is preferably an electrostatic actuator manufactured by the above-described manufacturing method.

  According to this invention, the electrostatic actuator can obtain a substrate with high processing accuracy in which the first substrate, the second substrate, and the third substrate are not affected by the processing-affected layer. Furthermore, an electrostatic actuator having a high bonding strength between the first substrate, the second substrate, and the third substrate can be obtained.

  The droplet discharge head of the present invention is desirably a droplet discharge head manufactured by the above-described manufacturing method.

  According to the present invention, the droplet discharge head can obtain a substrate with high processing accuracy in which the first substrate, the second substrate, and the third substrate are not affected by the processing-affected layer. Furthermore, a droplet discharge head having high bonding strength between the first substrate, the second substrate, and the third substrate can be obtained.

  The droplet discharge head of the present invention is preferably a droplet discharge head provided with an electrostatic actuator manufactured by the above-described manufacturing method.

  According to the present invention, since the droplet discharge head includes the high-precision electrostatic actuator, high-precision print quality is possible.

  The droplet discharge device of the present invention is desirably a droplet discharge device including the above-described droplet discharge head.

  According to this invention, since the droplet discharge device includes the above-described droplet discharge head, high-precision print quality can be obtained. Therefore, it is possible to provide a droplet discharge device that can obtain such an effect.

  Embodiments of an electrostatic actuator, a droplet discharge head, and a droplet discharge device including the droplet discharge head according to the present invention will be described below in detail with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is an exploded perspective view showing a part of an electrostatic actuator and a droplet discharge head as a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the electrostatic actuator and the droplet discharge head. FIG. 3 is a flowchart showing the manufacturing process of each substrate.

  As shown in FIGS. 1 and 2, the droplet discharge head 1 is a so-called edge ink jet type that discharges gas or ink droplets from a plurality of nozzles provided on the side surface end of the substrate, and is of an electrostatic drive type. Is. The droplet discharge head 1 has a laminated structure in which an electrode substrate 2 (first substrate), a cavity plate 3 (second substrate), and a glass plate 4 (third substrate) are bonded together in this order. ing.

  The cavity plate 3 which is the second substrate is, for example, a silicon substrate, and as shown in FIGS. 1 and 2, a pressure chamber 6 whose bottom wall functions as the diaphragm portion 5 is formed on the surface of the cavity plate 3. The concave portion 7 to be formed, the narrow groove 9 constituting the ink supply port 8 provided in the rear portion of the concave portion 7, and the ink reservoir 10 for supplying ink to each pressure chamber 6 are configured. The concave portion 11 to be formed is formed by etching. The lower surface of the cavity plate 3 is smoothed by mirror polishing and serves as a mounting portion for the electrode substrate 2. A common electrode 40 is formed as a common electrode to the electrode substrate 2.

  As shown in FIGS. 1 and 2, a plurality of nozzles 21 communicating with each pressure chamber 6 are formed on the side surface of the cavity plate 3. Moreover, as shown in FIG. 2, the nozzle 21 has a thin groove-shaped cross section.

  The glass plate 4 as the third substrate is, for example, a borosilicate glass substrate, and is overlapped with the cavity plate 3 as shown in FIG. 1 and FIG. In the meantime, the pressure chamber 6, the ink supply port 8, and the ink reservoir 10 are partitioned and formed so as to be arranged in the plane direction H.

  In the glass plate 4, an ink intake port (not shown) is formed in a wall portion on the side surface of the ink reservoir 10. This ink intake port communicates with the ink reservoir 10 and is connected to a connection pipe (not shown). This connection pipe (not shown) is connected to an ink supply source of the ink tank 101 (see FIG. 9) via a tube (not shown). Ink can be supplied from the ink tank 101 to the ink reservoir 10 via the ink intake port 31.

  The electrode substrate 2 which is the first substrate is, for example, a borosilicate glass substrate, and as shown in FIGS. 1 and 2, vibration chambers 12 are formed in portions facing the respective vibration plate portions 5. A recess 13 is formed. An individual electrode 14 that faces the diaphragm portion 5 is disposed on the bottom surface of the recess 13. The individual electrode 14 is connected to the terminal portion 16 via the lead portion 15. A lead wire 18 is bonded to the terminal portion 16. The lead wire 18 is connected to the driver 20 and is configured to be supplied with voltage from the outside (not shown).

FIG. 3 shows a flowchart of manufacturing steps of the electrode substrate 2, the cavity plate 3, and the glass plate 4.
As shown in FIG. 3, after the electrode substrate 2 is polished, the work-affected layer X (see FIG. 4A) is etched in step S11, groove processing is performed in step S12, and electrode processing is performed in step S13. A thin film is formed, resist coating / exposure patterning is performed in step S14, and etching / pattern formation and resist stripping are performed in step S15 to obtain the electrode substrate 2. Here, the electrode substrate 2 is subjected to mechanical polishing such as lapping and polishing.
FIG. 4 shows a manufacturing process of the electrode substrate 2.
As shown in FIGS. 3 and 4, the electrode substrate 2 had a work-affected layer X of about 0.2 μm on the substrate surface by polishing. By immersing the substrate on which the work-affected layer X exists in, for example, an alkaline solution of KOH, the substrate surface is etched and the work-affected layer X is removed. As a method for confirming whether or not the work-affected layer X has been removed, for example, there is a method of evaluating with an optical measuring instrument such as an ellipsometer, and the presence or absence of the work-affected layer X can be confirmed. On the surface of the clean electrode substrate 2 obtained in this way, the recess 13 of the electrode forming portion is provided by etching. The individual electrodes 14 are formed in the recesses 13 by a method such as sputtering or vacuum deposition. Here, the individual electrodes 14 are formed by forming an ITO film with a thickness of about 150 nanometers by sputtering. Further, by applying a so-called photolithography process in which a resist is applied to the individual electrode 14, exposed, etched, and the resist is peeled off, the electrode 14 having a desired pattern is formed. The electrode substrate 2 (first substrate) provided with the individual electrode 14 (ITO film) thus obtained is completed.

As shown in FIG. 3, after the cavity plate 3 is polished, the work-affected layer X (see FIG. 5A) is etched in step S21, groove processing is performed in step S22, and oxide film is formed in step S23. Thus, the cavity plate 3 is obtained. Here, the cavity plate 3 has been subjected to mechanical polishing such as lapping and polishing.
FIG. 5 shows a manufacturing process of the cavity plate 3.
As shown in FIGS. 3 and 5, the cavity plate 3 also had a work-affected layer X produced on the substrate surface by polishing of about 0.2 μm. By immersing the substrate on which the work-affected layer X exists in, for example, an alkaline solution of KOH, the substrate surface is etched and the work-affected layer X is removed. The confirmation as to whether or not the work-affected layer X has been removed is the same as that described above. The cavity plate 3 is grooved by a photolithography etching process on the clean cavity plate 3 obtained in this way, thereby forming a groove portion between the concave portion 7 that becomes the pressure chamber 6 and the narrow groove 9 that forms the ink supply port 8. Is done. At the same time, the nozzle 21, the diaphragm 5, and the recess 11 of the ink reservoir 10 are formed. An oxide film is formed (not shown) on the cavity plate having the grooves of each part obtained in this way, and the cavity plate 3 (second substrate) is completed.

As shown in FIG. 3, after the glass plate 4 as the third substrate is polished, the work-affected layer X (see FIG. 6A) is etched in step S31, whereby the glass plate 4 is obtained. Here, the glass plate 4 has been subjected to mechanical polishing such as lapping and polishing.
FIG. 6 shows a manufacturing process of the glass plate 4.
As shown in FIGS. 3 and 6, the nozzle plate 4 also had a work-affected layer X generated on the substrate surface by the polishing of about 0.2 μm. By immersing the substrate on which the work-affected layer X exists in, for example, an alkaline solution of KOH, the substrate surface is etched and the work-affected layer X is removed. The confirmation as to whether or not the work-affected layer X has been removed is the same as that described above. The glass plate 4 thus obtained completes a glass plate 4 (third substrate) having a clean surface.

  Here, the substrate obtained in the step S15, the substrate obtained in the step S23, and the substrate obtained in the step S31 are joined to manufacture the droplet discharge head 1. At this time, the electrostatic actuator 50 is manufactured by bonding the substrate obtained in the step S15 and the substrate obtained in the step S23.

  FIG. 7A shows a state before the electrode substrate 2 and the cavity plate 3 are joined. Here, the bonding surface of the electrode substrate 2 and the bonding surface of the cavity plate 3 are polished flatly at the same time, and at the same time, as described above, the electrode substrate 2 and the cavity plate 3 are subjected to the work-affected layer X generated by the polishing. Has been removed from the substrate surface and has a clean surface. Next, FIG. 7B shows a state after bonding in which the electrode substrate 2 and the cavity plate 3 are anodically bonded. Here, the anodic bonding method is performed by stacking the substrates and heating at 300 to 500 ° C., applying a voltage of several hundred volts with the silicon substrate side as the anode and the glass substrate side as the cathode. Therefore, by joining the electrode substrate 2 and the cavity plate 3, the electrostatic actuator 50 having the electrode 14 and the diaphragm portion 5 is formed.

  FIG. 8A shows a state in which the electrode substrate 2 and the cavity plate 3 are joined, and a state before the glass plate 4 is joined to the laminated substrate (a joined body of the electrode substrate 2 and the cavity plate 3). Show. Here, the bonding surfaces of the cavity plate 3 and the glass plate 4 are polished to be flat with each other, and at the same time, as described above, the work-affected layer X generated by the polishing of the cavity plate 3 and the glass plate 4 is the substrate surface. And has a clean surface. Next, FIG.8 (b) shows the state after joining in which the glass plate 4 is further joined to this laminated substrate (joined body of the electrode substrate 2 and the cavity plate 3), and the joining method at this time is as follows. Bonding is performed by the anodic bonding method described above.

  FIG. 9 is a schematic perspective view showing a configuration example of a droplet discharge apparatus (inkjet printer) equipped with the droplet discharge head 1 of the present embodiment. The droplet discharge device 100 includes an ink tank 101, a carriage 102, a platen 103, a recording paper 104, and the like, and the droplet discharge head 1 is mounted on the carriage 102.

  The configuration of the droplet discharge head 1 and the electrostatic actuator 50 incorporated therein is as described above, and the operation will be described with reference to FIGS.

  The droplet discharge device 100 supplies ink from the ink tank 101 while moving the carriage 102 while transporting the recording sheet 104 by the platen 103 and controlling the relative position between the recording sheet 104 and the droplet discharge head 1. Then, by ejecting ink droplets 23 from the droplet ejection head 1, arbitrary characters and images are printed on the recording paper 104.

  As shown in FIGS. 1 and 2, the diaphragm portion 5 that defines the bottom surface of each pressure chamber 6 formed in the cavity plate 3 functions as a portion where the pressure chamber 6 vibrates. A driver 20 is connected via a lead wire 18 between the terminal portion 16 and the common electrode 40 of each individual electrode 14 provided to face each other. When a voltage is applied to the individual electrode 14 by the driver 20, the diaphragm portion 5 facing the individual electrode 14 to which the voltage is applied vibrates due to electrostatic force, and the pressure in the pressure chamber 6 fluctuates accordingly. Ink droplets 23 are ejected from the nozzles 21.

  For example, when a positive voltage pulse is applied to charge the surface of the individual electrode 14 to a positive potential, the corresponding lower surface of the diaphragm portion 5 is charged to a negative potential. Therefore, the diaphragm portion 5 is attracted by the electrostatic force and bent downward. Next, when the voltage pulse applied to the individual electrode 14 is turned off, the diaphragm portion 5 returns to the original position. By this returning operation, the internal pressure of the pressure chamber 6 is rapidly increased, and the ink droplet 23 is ejected from the nozzle 21. Then, when the vibration plate portion 5 is bent downward, ink is supplied from the ink reservoir 10 to the pressure chamber 6 via the ink supply port 8.

As described above, the electrode substrate 2, the cavity plate 3, and the glass plate 4 have the processed alteration layer X after polishing removed by etching. Therefore, the electrode substrate 2, the cavity plate 3, and the glass plate 4 are processed alteration layers. It has a clean surface without any. By this etching for removing the work-affected layer, moisture on the substrate surface, and dirt such as organic substances and inorganic substances are also removed.
Here, since the electrode substrate 2 has a clean surface without a work-affected layer, the film quality of the individual electrode 14 formed on the electrode substrate 2 is stabilized and the film thickness of the individual electrode 14 is substantially constant. become. This stabilizes the electrical characteristics of the individual electrode 14. In addition, since the cavity plate 3 has a clean surface without a work-affected layer, the etching rate becomes uniform, so that various groove portions (concave portion 7, groove portion 9, and concave portion 11) provided in the cavity plate 3 are provided. The shape is formed with high accuracy. Further, since the nozzle plate 4 has a clean surface without a work-affected layer, the adhesion of the bonding surfaces between the substrates is improved, so that a plurality of nozzles can be formed when the glass plate 4 and the cavity plate 3 are bonded. Since the shape of the nozzle 21 can be expected to be formed uniformly, the dimensional accuracy of the nozzle 21 is improved. Therefore, a plurality of stable quality nozzles 21 with little variation can be formed.
That is, the electrical characteristics of the electrode substrate 2 are stabilized, and the shape of the diaphragm portion of the cavity plate 3 is formed with high accuracy, so that a stable operation as an electrostatic actuator can be ensured, and at the same time, the droplet discharge head 1 The discharge speed and discharge amount of the droplets 23 discharged from the nozzle 21 are stabilized.

  Further, the processed alteration layer X after polishing of each of the electrode substrate 2, the cavity plate 3, and the glass plate 4 is removed by etching, and the electrode substrate 2, the cavity plate 3, and the nozzle plate 4 are made of moisture, organic matter, and inorganic matter. Since there is no clean surface, the influence of these contaminants is eliminated when bonding the substrates. Accordingly, when the substrates are bonded by the anodic bonding method, the substrates are firmly bonded and fixed. That is, the electrode substrate 2, the cavity plate 3, and the glass plate 4 are firmly fixed to each other, so that the ink in the pressure chamber 6 constituted by the cavity plate 3 and the glass plate 4 does not leak.

  The ink used in the droplet discharge head 1 is prepared by dissolving or dispersing a main solvent such as water and alcohol, or a surfactant such as main dispersion medium ethylene glycol, and a dye or pigment. Further, if a heater is provided in the droplet discharge head 1, hot melt ink can be used. Further, since gas can be used as the electrostatic actuator, it can be used for discharging gas such as oxygen, nitrogen, hydrogen and the like.

In the first embodiment as described above, the following effects are obtained.
(1) The work-affected layer X existing on each substrate constituting the droplet discharge head 1 is removed by etching, and these substrates have a clean surface free of the work-affected layer, and as described above. The influence of the work-affected layer is eliminated. Therefore, the electrostatic actuator 50 and the droplet discharge head 1 with high processing accuracy can be obtained, and the speed and the amount of ink discharged from the nozzles 21 of the droplet discharge head 1 are almost uniform. For this reason, when the droplet discharge head 1 provided in the droplet discharge apparatus 100 prints an arbitrary character or image on the recording paper 104, high-precision print quality can be obtained.

[Second Embodiment]
Next, 2nd Embodiment of this invention is described based on drawing.
In addition, the same code | symbol is attached | subjected to the component same as the above-mentioned 1st Embodiment, and the component which has the same function, and description is abbreviate | omitted.
FIG. 10 is an exploded perspective view showing a part of a droplet discharge head according to the second embodiment. FIG. 11 is a cross-sectional view of the droplet discharge head. FIG. 12 is a flowchart showing the manufacturing process of each substrate.

  Here, as shown in FIGS. 10 and 11, the liquid droplet ejection head 1 is a face ink jet type that ejects ink droplets 23 from nozzles 21 provided on the upper surface of the substrate, which is greatly different from the first embodiment. It is. However, the electrostatic drive method is the same as in the first embodiment.

  As shown in FIG. 10, the droplet discharge head 1 includes three substrates: an electrode substrate 2 (first substrate), a cavity plate 3 (second substrate), and a nozzle plate 4a (third substrate). It has a laminated structure joined in a superposed state.

  The cavity plate 3 is, for example, a silicon substrate, and provided on the surface of the cavity plate 3 at the rear portion of the concave portion 7 that forms the pressure chamber 6 whose bottom wall functions as the vibration plate portion 5 and the concave portion 7. A narrow groove 9 that constitutes the ink supply port 8 and a recess 11 that constitutes an ink reservoir 10 for supplying ink to each pressure chamber 6 are formed by etching. The lower surface of the cavity plate 3 is smoothed by mirror polishing and serves as a mounting portion for the electrode substrate 2.

  In the nozzle plate 4 a bonded to the upper surface of the cavity plate 3 (the substrate surface on the groove forming side), a plurality of nozzles 21 communicating with each pressure chamber 6 are formed on the wall portion defining the upper surface of the pressure chamber 6. Yes. As shown in FIG. 11, the nozzle 21 has a stepped cross section, a circular small cross-section nozzle portion 21a is formed on the front side in the ejection direction of the ink droplet 23, and a circular large cross-section nozzle portion is formed on the rear side. 21b is formed.

  By superposing the nozzle plate 4a and the cavity plate 3 on each other, the pressure chamber 6, the ink supply port 8, and the ink reservoir 10 are arranged in the plane direction H between the nozzle plate 4a and the cavity plate 3. Partitioned into a state.

  In the nozzle plate 4a, an ink intake port 31 is formed in a wall portion corresponding to the bottom surface (upper surface in FIG. 11) of the ink reservoir 10. The ink intake port 31 communicates with the ink reservoir 10 and is connected to a connection pipe 32. The connection pipe 32 is connected to an ink supply source of the ink tank 101 (see FIG. 9) via a tube 33. Ink can be supplied from the ink tank 101 to the ink reservoir 10 via the ink intake port 31.

  As shown in FIGS. 10 and 11, in the electrode substrate 2, a concave portion 13 that forms the vibration chamber 12 is formed in a portion facing each diaphragm portion 5. An individual electrode 14 that faces the diaphragm portion 5 is disposed on the bottom surface of the recess 13. The individual electrode 14 is connected to the terminal portion 16 via the lead portion 15. The individual electrodes 14 and the lead portions 15 except for the terminal portions 16 are covered with an insulating film 17 (not shown in FIG. 11). A lead wire 18 is bonded to each terminal portion 16. The lead wire 18 is connected to the driver 20 and is configured to be supplied with voltage from the outside (not shown).

Here, FIG. 12 shows a flowchart of manufacturing steps of the electrode substrate 2 (first substrate), the cavity plate 3 (second substrate), and the nozzle plate 4a (third substrate).
As shown in FIG. 12, the electrode substrate 2 is, for example, a glass substrate, and after polishing, the work-affected layer X is etched in step S51, grooved in step S52, and used for electrodes in step S53. A thin film is formed, resist coating / exposure patterning is performed in step S54, and etching / pattern formation resist peeling is performed in step S55 to obtain the electrode substrate 2. Here, the electrode substrate 2 having a clean surface without the work-affected layer X is obtained.

  As shown in FIG. 12, the cavity plate 3 is, for example, a silicon substrate, and after polishing, etching processing is performed in step S61, and groove processing is performed in step S62, whereby the cavity plate 3 is obtained. Here, the cavity plate 3 having a clean surface without the work-affected layer X is obtained.

  As shown in FIG. 12, the nozzle plate 4a is, for example, a silicon substrate. After polishing, the nozzle plate 4a is etched in the step S71, the nozzle hole is processed in the step S72, and the oxide film is formed in the step S73. Nozzle plate 4a is obtained. Here, the nozzle plate 4a having a clean surface without the work-affected layer X is obtained.

  Next, the electrode substrate 2 obtained in the step S55 and the cavity plate 3 obtained in the step S63 are anodically bonded, and a bonded laminated substrate is obtained in the step S56. An electrostatic actuator is manufactured.

  Furthermore, the droplet discharge head 1 is changed to S57 by bonding the nozzle plate 4a obtained in S73 to the laminated substrate obtained by joining the electrode substrate 2 and cavity plate 3 obtained in S56 with an adhesive. Obtained in the process.

  The configuration of the droplet discharge head 1 in the second embodiment of the present invention is as described above, and its operation will be described with reference to FIGS.

  Here, the droplet discharge apparatus 100 shown in FIG. 9 provided with the droplet discharge head 1 on the carriage 102 moves the carriage 102 while conveying the recording paper 104 by the platen 103, and discharges the recording paper 104 and the droplet. An arbitrary character or image is printed on the recording paper 104 by supplying ink from the ink tank 101 and ejecting the ink droplet 23 from the droplet ejection head 1 while controlling the relative position with the head 1.

  As shown in FIGS. 10 and 11, the diaphragm portion 5 defining the bottom surface of each pressure chamber 6 formed in the cavity plate 3 functions as a common electrode, and the terminal portion of the common electrode and each individual electrode 14. A driver 20 is connected to 16. When a voltage is applied to the individual electrode 14 by the driver 20, the diaphragm portion 5 facing the individual electrode 14 to which the voltage is applied vibrates due to electrostatic force, and the pressure in the pressure chamber 6 fluctuates accordingly. Ink droplets 23 are ejected from the nozzles 21.

  For example, when a positive voltage pulse is applied to charge the surface of the individual electrode 14 to a positive potential, the corresponding lower surface of the diaphragm portion 5 is charged to a negative potential. Therefore, the diaphragm portion 5 is attracted by the electrostatic force and bent downward. Next, when the voltage pulse applied to the individual electrode 14 is turned off, the diaphragm portion 5 returns to the original position. By this returning operation, the internal pressure of the pressure chamber 6 is rapidly increased, and the ink droplet 23 is ejected from the nozzle 21. Then, when the vibration plate portion 5 is bent downward, ink is supplied from the ink reservoir 10 to the pressure chamber 6 via the ink supply port 8.

  When a voltage is applied to the individual electrode 14 by the driver 20, the diaphragm portion 5 facing the individual electrode 14 to which the voltage is applied vibrates due to electrostatic force, and the pressure in the pressure chamber 6 fluctuates with this vibration. Ink droplets 23 are ejected from the nozzles 21.

  Since the processing damaged layer X of each substrate of the electrode substrate 2, the cavity plate 3, and the nozzle plate 4a is removed, each substrate has a clean surface without the processing damaged layer, as in the first embodiment. . Moreover, dirt such as moisture, organic matter, and inorganic matter is also removed. Therefore, the electrode substrate 2, the cavity plate 3, and the nozzle plate 4a constituting the droplet discharge head 1 can be accurately formed as described above. At the same time, the substrates are firmly bonded to each other, so that the ink droplets 23 are ejected from the nozzles 21 without leaking ink. Therefore, the electrostatic actuator 50 and the droplet discharge head 1 of the type in which the nozzle 21 is provided on the upper surface and ink is discharged can be obtained.

In the second embodiment as described above, the following effects can be obtained in addition to the effects obtained in the first embodiment.
(2) Since the nozzle 21 of the droplet discharge head 1 is a type provided on the upper surface, it can be used for a face inkjet type droplet discharge device, and expansion of applications can be expected.

  It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention. A modification is shown below.

(Modification 1)
The droplet discharge head to which the manufacturing method of the present invention is applied is not limited to an inkjet head that discharges ink. For example, the present invention can be applied to a method for manufacturing a droplet discharge head that discharges a liquid such as water, an organic solvent, an adhesive, a dye functional liquid, or a coating agent. Examples of the dye functional liquid include a dye functional liquid material that is discharged to a sub-pixel region on a filter substrate when a color filter used in a liquid crystal display device is manufactured by applying an inkjet technique.

(Modification 2)
The electrostatic actuator to which the manufacturing method of the present invention is applied is not limited to a droplet discharge head (inkjet head). For example, the electrostatic actuator may be used as a discharge drive source in a gas discharge device that discharges gas from a nozzle or the like. Furthermore, the electrostatic actuator may be used as a vibration generation drive source in a vibration generator that applies vibration to a medium such as a liquid or a solid.

(Modification 3)
Although the etching steps S11, S21, S31, S51, S61, and S71 for removing the work-affected layer X are adopted for all of the first, second, and third substrates, it is not always necessary to perform the etching step on all the substrates. . For example, if an etching process for removing the work-affected layer X is performed only on the electrode substrate 2 that is the first substrate, the bonding strength of the first and second substrates is improved, the pattern shape of the electrode 14 is optimized, and the surface roughness is suppressed. realizable. Further, if the etching process for removing the work-affected layer X is performed only on the cavity plate 3 that is the second substrate, it is possible to realize thickness variation and surface roughness suppression of the diaphragm portion 5. Furthermore, if only the nozzle plate 4a, which is the third substrate, is subjected to an etching process for removing the work-affected layer X, it is possible to improve the bonding strength of the second and third substrates. Of course, it is also possible to employ a manufacturing method in which an etching process for removing the work-affected layer X is performed only on two selected substrates among the first to third substrates.

  The technical idea including the above-described embodiments and modifications includes a step of bonding the substrates after removing the work-affected layer X for all of the first, second, and third substrates. A method of manufacturing a droplet discharge head characterized by the above.

  According to this technical idea, it is possible to accurately manufacture a large number of droplet discharge heads incorporating an electrostatic actuator.

FIG. 3 is an exploded perspective view illustrating a part of the droplet discharge head according to the first embodiment. Sectional drawing of a droplet discharge head. The flowchart which shows the manufacturing process of each board | substrate. The figure which shows the manufacturing process of a 1st board | substrate. The figure which shows the manufacturing process of a 2nd board | substrate. The figure which shows the manufacturing process of a 3rd board | substrate. The figure which shows the manufacturing process of a droplet discharge head. The figure which shows the manufacturing process of a droplet discharge head. The perspective view which shows the structural example of a droplet discharge apparatus. The disassembled perspective view which shows a part of droplet discharge head of 2nd Embodiment. Sectional drawing of a droplet discharge head. The flowchart which shows the manufacturing process of each board | substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Droplet discharge head, 2 ... Electrode substrate, 3 ... Cavity plate, 4 ... Glass plate, 5 ... Vibration plate part, 6 ... Pressure chamber, 21 ... Nozzle, 50 ... Electrostatic actuator, 100 ... Droplet discharge apparatus, X: Processed layer.

Claims (12)

In a method for manufacturing an electrostatic actuator comprising: a first substrate on which an electrode for driving a diaphragm portion by electrostatic force is formed; and a second substrate on which the diaphragm portion is formed.
Etching and removing the work-affected layer of the first substrate caused by polishing;
And a step of forming the electrode on the first substrate. A first substrate on which an electrode for driving the diaphragm part by electrostatic force is formed and a second substrate on which the pressure chamber communicating with the nozzle is formed at a position corresponding to the diaphragm part. In a method of manufacturing an electrostatic actuator comprising:
Etching and removing the work-affected layer of the second substrate caused by polishing;
And a step of forming grooves on the second substrate by etching to form the diaphragm portion. A first substrate on which an electrode for driving the diaphragm portion by electrostatic force is formed; a second substrate on which the pressure chamber communicating with the nozzle is formed at the position corresponding to the diaphragm portion; In the method of manufacturing an electrostatic actuator comprising superposing two substrates and a third substrate in this order,
Etching and removing the work-affected layer of the third substrate generated by polishing;
A method for manufacturing an electrostatic actuator, comprising the step of bonding the second substrate and the third substrate.   3. The method of manufacturing an electrostatic actuator according to claim 1, further comprising a step of bonding the first substrate and the second substrate. A first substrate on which an electrode for driving the diaphragm portion by electrostatic force is formed; a second substrate on which the pressure chamber communicating with the nozzle is formed at the position corresponding to the diaphragm portion; In a method for manufacturing a droplet discharge head, which comprises superposing two substrates and a third substrate in this order,
Etching and removing the work-affected layer of the first substrate caused by polishing;
And a step of forming the electrode on the first substrate. A first substrate on which an electrode for driving the diaphragm portion by electrostatic force is formed; a second substrate on which the pressure chamber communicating with the nozzle is formed at the position corresponding to the diaphragm portion; In a method for manufacturing a droplet discharge head, which comprises superposing two substrates and a third substrate in this order,
Etching and removing the work-affected layer of the second substrate caused by polishing;
A droplet discharge head comprising: a step of etching a groove on the second substrate to form the pressure chamber that communicates with the nozzle at the position corresponding to the diaphragm portion. Manufacturing method. A first substrate on which an electrode for driving the diaphragm portion by electrostatic force is formed; a second substrate on which the pressure chamber communicating with the nozzle is formed at the position corresponding to the diaphragm portion; In a method for manufacturing a droplet discharge head, which comprises superposing two substrates and a third substrate in this order,
Etching and removing the work-affected layer of the third substrate generated by polishing;
A method of manufacturing a droplet discharge head, comprising a step of bonding the second substrate and the third substrate.   8. The method of manufacturing a droplet discharge head according to claim 6, further comprising a step of bonding the first substrate and the second substrate. Method.   An electrostatic actuator manufactured by the manufacturing method according to claim 1.   A liquid droplet ejection head manufactured by the manufacturing method according to claim 5.   A droplet discharge head comprising the electrostatic actuator according to claim 9. A droplet discharge apparatus comprising the droplet discharge head according to claim 10.

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