JP2007216467A - Method for manufacturing liquid droplet delivering head and method for manufacturing liquid droplet delivering apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a liquid droplet delivering head capable of improving productivity and reliability and a method for manufacturing a liquid droplet delivering apparatus. <P>SOLUTION: The method includes a process in which on a silicon substrate 200 among joined substrates in which an electrode glass substrate and the silicon substrate 200 are joined, a recessed part becoming at least a delivering room is formed, and a part corresponding to a sealing part 30 and an electrode taking-out opening part 29 corresponding to a terminal part 31b are penetrated and formed, and a sealing process in which a gap between an individual electrode and a vibrating plate 22 is sealed to shut it from open air. The sealing process is constituted of a process in which a first mask substrate on which parts respectively corresponding to the sealing part 30 and the electrode taking-out opening part 29 are opened are tightly stuck to the silicon substrate 200, a process which tightly sticks a protective member 41 on the surface of the terminal part 31b to protect the terminal part 31b, and a process in which a sealing material is formed on the sealing part 30 to seal it through an opening of a part corresponding to the sealing part 30 of the first mask substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a droplet discharge head such as an inkjet head and a method for manufacturing a droplet discharge device.

  As a droplet discharge head for discharging droplets, for example, an inkjet head mounted on an inkjet recording apparatus is known. Ink jet heads generally include a nozzle plate in which a plurality of nozzle holes for discharging ink droplets are formed, and an ink in a discharge chamber, a reservoir, or the like that is joined to the nozzle plate and communicates with the nozzle holes. And a cavity plate in which a flow path is formed, and an ink droplet is ejected from a selected nozzle hole by applying pressure to the ejection chamber by a driving unit. As a driving means, there are a method using an electrostatic force, a piezoelectric method using a piezoelectric element, a bubble jet (registered trademark) method using a heating element, and the like.

  In the electrostatic drive type inkjet head, the bottom surface of the discharge chamber is formed as an elastically deformable diaphragm, and an individual electrode is disposed opposite to the diaphragm with a gap between the diaphragm and the individual electrode. An electrostatic force is generated by applying a drive voltage to the diaphragm, the diaphragm is deformed by the electrostatic force, and droplets are ejected from the nozzle.

  Here, in general, in an electrostatic drive type ink-jet head, a gap between the diaphragm and the individual electrode is sealed with a sealing material at an arbitrary position in a wiring path communicating with the atmosphere. This is to prevent water from adhering to the bottom surface of the diaphragm and the surface of the individual electrode, thereby reducing electrostatic attraction and electrostatic repulsion.

  As a sealing technique for blocking the gap between the diaphragm and the individual electrode from the atmosphere, an oxide film (sealing material) is deposited by CVD or the like at an arbitrary position on the wiring path communicating with the atmosphere. There is a method of sealing (see, for example, Patent Document 1).

JP 2002-1972

  However, due to the structure of the inkjet head, an electrode outlet port portion (hereinafter referred to as a terminal portion) of the individual electrode is disposed in the vicinity of the sealing portion. At the time of deposition, the sealing material was deposited on the terminal portion. For this reason, the removal process which removes the sealing material on a terminal part was needed. Thus, when only the sealing material is removed from the terminal portion, there is a possibility of damaging the sealing material of the terminal portion and the sealing portion, which is not a preferable method.

  The present invention has been made in view of the above points, and eliminates the need for a removal step of removing the sealing material from the terminal portion, and can improve productivity and reliability. And a method of manufacturing a droplet discharge device.

The method for manufacturing a droplet discharge head according to the present invention includes an electrode substrate in which individual electrodes and terminal portions of individual electrodes are formed in recesses, and silicon in which at least recesses serving as discharge chambers for storing and discharging liquid are formed. A bonding step of bonding the substrate with the individual electrode and the bottom portion of the discharge chamber facing each other via a gap, and forming at least a recess serving as a discharge chamber in the silicon substrate bonded to the electrode substrate; A step of penetrating and forming a portion corresponding to the sealing portion for sealing the electrode and an electrode outlet portion corresponding to the terminal portion, and a sealing step for sealing the gap. A first mask substrate having a portion corresponding to the stop portion and a portion corresponding to the electrode extraction port portion opened to be in close contact with the silicon substrate to cover the silicon substrate; and corresponding to the electrode extraction port portion of the first mask substrate. The first protective member is inserted into the electrode outlet port from the opening of the part, and the protective part protects the terminal part by closely contacting the surface of the terminal part, and the opening of the part corresponding to the sealing part of the first mask substrate And a sealing material depositing step of sealing the gap by depositing a sealing material on the sealing portion.
As a result, it is possible to prevent the sealing material from being formed on the terminal portion, and the conventional step of removing the sealing material on the terminal portion is not required, so that productivity is improved and the surface of the terminal portion is improved. Since it is not necessary to perform an etching process or the like, it is possible to manufacture a droplet discharge head with higher reliability than in the past.

Also, in the method for manufacturing a droplet discharge head according to the present invention, the second mask substrate having an opening corresponding to the sealing portion is provided on the first mask substrate between the protection step and the sealing material deposition step. In the sealing material deposition step, the sealing material is prevented from being deposited on the surface of the first mask substrate and the surface of the first protective member.
As a result, it is possible to prevent the sealing material from being deposited on the surface of the first mask substrate and the surface of the first protective member, and the warp occurs in the first mask substrate and the first protective member, and the surface of the silicon substrate and the surface of the terminal portion. It is possible to prevent the sealing material from being formed on the film.

Further, in the method for manufacturing a droplet discharge head according to the present invention, the first mask substrate and the second mask substrate are integrated instead of using the two mask substrates of the first mask substrate and the second mask substrate. A third mask substrate having the structure described above is used.
Thereby, the number of processes can be reduced.

In addition, the method for manufacturing a droplet discharge head according to the present invention includes a step of forming a recess, a sealing portion, and an electrode extraction port portion serving as a discharge chamber in a silicon substrate, and a sealing step between the step of forming the recess. A droplet protective film forming step for forming a droplet protective film, and in the droplet protective film forming step, a second protective member is inserted into the electrode outlet port portion of the silicon substrate and is brought into close contact with the surface of the terminal portion. The droplet protective film is formed in a state where the portion is protected.
Thereby, it is possible to prevent the droplet protective film from being formed on the terminal portion.

In the method for manufacturing a droplet discharge head according to the present invention, an insertion guide serving as a guide for inserting the second protective member into the electrode outlet port of the silicon substrate is formed on the silicon substrate in the droplet protective film forming step. In this state, the second protective member is inserted.
Thereby, the workability at the time of insertion of the second protective member can be improved, the displacement of the second protective member can be eliminated, and the droplet protective film can be reliably prevented from being formed on the terminal portion.

In the method for manufacturing a droplet discharge head according to the present invention, a TEOS film, an Al2O3 film, and a TEOS film are laminated in this order in the sealing material deposition step.
In this way, the Al ₂ O ₃ film having a high moisture permeation prevention property is sandwiched between TEOS films that can be easily formed in a short time, so that the water permeation prevention property can be reduced while shortening the formation time. It is possible to configure an excellent sealing part.

Further, the manufacturing method of the droplet discharge head according to the present invention deposits the sealing material by the CVD method.
Further, the manufacturing method of the droplet discharge head according to the present invention deposits the sealing material by the sputtering method.
Thus, by sealing and depositing a sealing material by CVD or sputtering, a plurality of wafers can be reliably sealed at a time, and manufacturing efficiency is high and reliability is high. Airtight sealing can be performed.

In the method for manufacturing a droplet discharge head according to the present invention, each protective member is formed of a protective plate or a protective tape.
In the method for manufacturing a droplet discharge head according to the present invention, the protective plate is made of a silicon plate.
In the method for manufacturing a droplet discharge head according to the present invention, the protective tape is made of a heat-resistant tape.
As described above, a protective plate or a protective tape is used as the protective member. In the case of the protective plate, a silicon plate can be adopted, and in the case of the protective tape, a heat-resistant tape can be adopted. Thereby, reliable film formation without harmful effects can be performed in the CVD method or the sputtering method.

In the method for manufacturing a droplet discharge head according to the present invention, each mask substrate is made of a silicon plate.
Thus, by using a silicon plate as each mask substrate, the mask shape can be easily formed by etching.

In addition, a method for manufacturing a droplet discharge device according to the present invention is a method for manufacturing a droplet discharge device by applying any one of the above-described methods for manufacturing a droplet discharge head.
Thereby, a highly reliable droplet discharge device can be obtained.

Embodiment 1. FIG.
Hereinafter, embodiments of a droplet discharge head manufactured by the manufacturing method of the present invention will be described with reference to the drawings. Here, as an example of the droplet discharge head, a face discharge type electrostatic drive type inkjet head will be described with reference to FIGS. Note that the present invention is not limited to the structure and shape shown in the following drawings, and can be similarly applied to an edge discharge type droplet discharge head.

  FIG. 1 is an exploded perspective view showing an exploded schematic configuration of the ink jet head according to the first embodiment, and a part thereof is shown in cross section. FIG. 2 is a cross-sectional view of the inkjet head showing a schematic configuration of the right half of FIG. FIG. 3 is a top view of the inkjet head of FIG. 1 and 2 are shown upside down from a state in which they are normally used.

  As shown in FIGS. 1 and 2, the inkjet head 10 (an example of a droplet discharge head) 10 according to the first embodiment includes a nozzle plate 1 in which a plurality of nozzle holes 11 are provided at a predetermined pitch, and each nozzle hole 11. On the other hand, the cavity plate 2 provided with the ink supply path independently and the electrode substrate 3 provided with the individual electrodes 31 facing the diaphragm 22 of the cavity plate 2 are bonded together. The manufacturing method will be described in detail later.

  The nozzle plate 1 is made of, for example, a silicon single crystal substrate (hereinafter also simply referred to as a silicon substrate) having a thickness of 180 μm. In the nozzle plate 1, a recess 12 is formed in a region where a plurality of nozzle holes 11 are provided, and a nozzle hole 11 for ejecting ink droplets is opened on the bottom surface of the recess 12. That is, the flow path resistance of each nozzle hole 11 is adjusted by thinning the length of the nozzle portion (substrate thickness) by the recess 12. This ensures uniform ejection performance and prevents other objects such as recording paper from coming into direct contact with the ejection surface (bottom surface of the recess 12), so that the recording paper is soiled or the tip of the nozzle hole 11 is damaged. Can be prevented.

  The nozzle holes 11 for ejecting ink droplets are composed of, for example, two-stage cylindrical nozzle holes having different diameters, that is, an ejection port portion 11a having a smaller diameter and an introduction port portion 11b having a larger diameter. It is configured. The injection port portion 11a and the introduction port portion 11b are provided perpendicular to and coaxially with respect to the substrate surface. The injection port portion 11a has a tip opening on the surface of the nozzle plate 1, and the introduction port portion 11b is the nozzle plate 1. Are opened on the back surface (the surface on the bonding side to be bonded to the cavity plate 2).

  As described above, the nozzle hole 11 is configured in two stages from the ejection port portion 11a and the inlet port portion 11b having a larger diameter, thereby aligning the ink droplet ejection direction with the central axis direction of the nozzle hole 11. And stable ink ejection characteristics can be exhibited. That is, there is no variation in the flying direction of ink droplets, there is no scattering of ink droplets, and variations in the ejection amount of ink droplets can be suppressed. In addition, the nozzle density can be increased.

  Further, in FIG. 2 of the nozzle plate 1, an orifice (narrow groove) 13 that forms a part of the ink flow path is provided on the lower surface (the surface on the joint side with the cavity plate 2). Further, a diaphragm portion 14 that is thinned by a concave portion is provided at a position corresponding to a reservoir 23 of the cavity plate 2 described later. The diaphragm portion 14 is provided to suppress pressure fluctuation in the reservoir 23.

  The cavity plate 2 is made of, for example, a (110) plane-oriented silicon single crystal substrate having a thickness of about 50 μm (this substrate is also simply referred to as a silicon substrate hereinafter). This silicon substrate has a boron-doped layer, and by performing anisotropic wet etching on the silicon substrate, recesses 24 and 25 for constituting the discharge chamber 21 and the reservoir 23 of the ink flow path are formed with high accuracy. A plurality of recesses 24 are independently formed at positions corresponding to the nozzle holes 11. Therefore, as shown in FIG. 2, when the nozzle plate 1 and the cavity plate 2 are joined, each recess 24 constitutes a discharge chamber 21 and communicates with each nozzle hole 11 and the orifice 13 serving as an ink supply port. Both communicate with each other. And the diaphragm 22 with high thickness precision is comprised by the thickness of the boron dope layer which comprises the bottom wall of the discharge chamber 21 (recessed part 24).

  The other recess 25 is for storing liquid material ink, and constitutes a common reservoir (common ink chamber) 23 for each discharge chamber 21. The reservoirs 23 (recesses 25) communicate with all the discharge chambers 21 through the orifices 13, respectively. Further, a hole penetrating the electrode substrate 3 described later is provided in the bottom of the reservoir 23, and ink is supplied from an ink cartridge (not shown) through an ink supply port 35 of the hole.

An insulating film 26 made of a TEOS (Tetraethylorthosilicate Tetraethoxysilane) film is formed on the lower surface of the cavity plate 2, that is, the surface facing the electrode substrate 3 by plasma CVD (Chemical Vapor Deposition) to a thickness of about 0.1 μm. Is formed. This insulating film 26 is provided for the purpose of preventing dielectric breakdown and short circuit when the ink jet head is driven.
On the upper surface of the cavity plate 2, that is, the surface facing the nozzle plate 1 (including the inner surfaces of the discharge chamber 21 and the reservoir 23), a TEOS film serving as the ink protection film 27 is formed by plasma CVD. This ink protective film 27 is provided in order to prevent corrosion of the flow path by ink.

  The electrode substrate 3 is made from a glass substrate having a thickness of about 1 mm, for example. Among them, it is suitable to use a borosilicate heat-resistant hard glass having a thermal expansion coefficient close to that of the silicon substrate of the cavity plate 2. This is because when the electrode substrate 3 and the cavity plate 2 are anodically bonded, the thermal expansion coefficients of the two substrates are close to each other, so that the stress generated between the electrode substrate 3 and the cavity plate 2 can be reduced, and as a result, peeling, etc. This is because the electrode substrate 3 and the cavity plate 2 can be firmly bonded without causing the above problem.

The electrode substrate 3 is provided with a recess 32 at a position on the surface of the cavity plate 2 facing each diaphragm 22. The recess 32 is formed to a depth of about 0.2 μm by etching. In general, individual electrodes 31 made of ITO (Indium Tin Oxide) are formed on the bottom surface of each recess 32 by sputtering, for example, with a thickness of about 0.1 μm. At this time, an ITO pattern to be the equipotential contact 33 is also formed at the same time.
Therefore, the gap (gap) formed between the diaphragm 22 and the individual electrode 31 is determined by the depth of the recess 32 and the thickness of the insulating film 26 covering the individual electrode 31 and the diaphragm 22. This gap (interelectrode gap) greatly affects the ejection characteristics of the inkjet head. Here, the material of the individual electrode 31 and the equipotential contact 33 is not limited to ITO, and a metal such as chrome may be used. However, as described later, the equipotential contact 33 can be formed simultaneously, and the ITO is transparent. Therefore, ITO is generally used because it is easy to inspect the gap between the electrodes.

  The individual electrode 31 has a lead part 31a and a terminal part 31b connected to a flexible wiring board (not shown). As shown in FIGS. 1 to 3, these terminal portions 31 b are exposed in an electrode extraction port portion 29 in which the end portion of the cavity plate 2 is opened for wiring.

As described above, the nozzle plate 1, the cavity plate 2, and the electrode substrate 3 are bonded together as shown in FIG. Further, the open end portion (sealing portion) 30 of the inter-electrode gap formed between the diaphragm 22 and the individual electrode 31 is sealed by depositing a sealing material 37 by plasma CVD or the like. In this example, a TEOS film and an Al ₂ O ₃ film are used as the sealing material 37, and a sealing film is formed by laminating a TEOS film, an Al ₂ O ₃ film, and a TEOS film in this order. By sealing the gap between the electrodes in this way, moisture, dust, etc. can be prevented from entering the gap between the electrodes, and the reliability of the inkjet head 10 can be kept high.

Finally, as shown in a simplified manner in FIGS. 2 and 3, a drive control circuit 4 such as an IC driver is connected to the terminal portion 31 b of each individual electrode 31 and the common electrode 28 provided on the cavity plate 2. They are connected via a wiring board (not shown).
Thus, the ink jet head 10 is completed.

Next, the operation of the inkjet head 10 configured as described above will be described.
The drive control circuit 4 is an oscillation circuit that controls the supply and stop of charges to the individual electrodes 31. This oscillation circuit oscillates at, for example, 24 kHz, and supplies electric charges by applying pulse potentials of, for example, 0 V and 30 V to the individual electrodes 31. When the oscillation circuit is driven and charges are supplied to the individual electrode 31 to be positively charged, the diaphragm 22 is negatively charged and an electrostatic force (Coulomb force) is generated between the individual electrode 31 and the diaphragm 22. Therefore, the diaphragm 22 is attracted to the individual electrode 31 by this electrostatic force and bends (displaces). As a result, the volume of the discharge chamber 21 increases. When the supply of electric charges to the individual electrode 31 is stopped, the diaphragm 22 returns to its original state due to its elastic force, and at this time, the volume of the discharge chamber 21 decreases rapidly. Part of the ink is ejected from the nozzle hole 11 as an ink droplet. Next, when the vibration plate 22 is similarly displaced, ink is supplied from the reservoir 23 to the discharge chamber 21 through the orifice 13.

As described above, the inkjet head 10 according to the first embodiment includes the cylindrical ejection port portion 11a in which the nozzle holes 11 are perpendicular to the surface (ejection surface) of the nozzle plate 1 and the same axis as the ejection port portion 11a. And the inlet port portion 11b having a diameter larger than that of the jet port portion 11a, the ink droplets can be discharged straight in the direction of the central axis of the nozzle hole 11 and have extremely stable discharge characteristics. .
Furthermore, since the cross-sectional shape of the inlet port portion 11b can be formed in a circular shape, a quadrangular shape, or the like, the density of the inkjet head 10 can be increased.

  In addition, the cross-sectional shape of the injection port portion 11a and the introduction port portion 11b of the nozzle hole 11 is not particularly limited, and is formed in a square shape or a circular shape. However, a circular shape is preferable because it is advantageous in terms of discharge characteristics and workability.

Next, a method for manufacturing the inkjet head 10 will be described with reference to FIGS. The physical quantities such as specific numerical values shown below are merely examples, and are not limited thereto.
FIG. 4 is a top view of a part of the electrode glass substrate 301 as viewed from above, and represents the electrode glass substrate of a certain head chip (inkjet head). FIG. 5 is an enlarged cross-sectional view of the equipotential contact 33 portion of the electrode glass substrate 301. 6 to 9 are cross-sectional views of the manufacturing process showing the method for manufacturing the ink jet head 10. 6A to 6D show a cross section at the equipotential contact 33 portion of the electrode glass substrate 301, and FIG. 6E and subsequent drawings show a cross section at the individual electrode 31 portion of the electrode glass substrate 301.

  First, as shown in FIG. 4 and FIG. 6A, an electrode glass substrate 301 that is the basis of the electrode substrate 3 having the individual electrodes 31 and the equipotential contacts 33 is manufactured. In this step, for example, a borosilicate heat-resistant hard glass substrate having a thickness of about 1 mm is used as the glass substrate 300, and the glass substrate 300 is etched with hydrofluoric acid using, for example, a gold / chromium etching mask. Thus, a recess 32 having a depth of about 0.2 μm is formed in accordance with the shape pattern of the electrode part (referred to as an electrode part including the individual electrode 31, the lead part 31a, and the terminal part 31b). As shown in FIG. 4, the portion that becomes the equipotential contact 33 is left without being etched so as to form a contact portion on the surface of the glass substrate 300. Here, the shape of the equipotential contact 33 is not limited as long as the electrode portion and the silicon substrate can be brought into contact with each other to be equipotential.

Then, after forming the recesses 32 and 34, an ITO film serving as an electrode portion with a thickness of about 0.1 μm is formed on the surface of the glass substrate 300 by, for example, sputtering, and individually formed on the bottom surface of the recess 32 by photolithography. The electrode 31 is formed. At that time, an ITO film is similarly formed on the portion to be the equipotential contact 33 and patterned.
Finally, the ink supply port 35 and the air opening hole 38 are formed from the surface side of the glass substrate 300 by cutting using, for example, a sandblast method or a drill.
Thus, the electrode glass substrate 301 is manufactured.

Next, as shown in FIG. 6B, one side of a single crystal silicon substrate having a low oxygen concentration with a plane orientation of (110) is mirror-polished to produce a silicon substrate 200 having a thickness of about 220 μm.
Thereafter, the surface on which the boron doped layer 201 to be the vibration plate 22 is formed on the silicon substrate 200 is set on a quartz boat so as to face a solid diffusion source mainly composed of B ₂ O ₃ . Then, the quartz boat is set in a vertical furnace, the inside of the furnace is put into a nitrogen atmosphere, the temperature is raised to 1050 ° C., and the temperature is kept as it is for 7 hours to diffuse boron into the silicon substrate 200, and the boron doped layer 201. Form. In the boron doping process, it is preferable that the silicon substrate 200 is charged at 800 ° C. and the silicon substrate is taken out at 800 ° C. Accordingly, it is possible to quickly pass through a region (600 ° C. to 800 ° C.) where the growth rate of oxygen defects is high, so that the generation of oxygen defects can be suppressed. Further, although a boron compound is formed on the surface of the boron doped layer 201 (not shown), it can be etched with a hydrofluoric acid aqueous solution by oxidizing for 1 hour 30 minutes in an oxygen and water vapor atmosphere at 600 ° C. It can be chemically changed to B ₂ O ₃ + SiO ₂ . B ₂ O ₃ + SiO ₂ is removed by etching with a hydrofluoric acid aqueous solution in a state where it is chemically changed to B ₂ O ₃ + SiO ₂ .

Then, a TEOS insulating film 26 is formed with a thickness of about 0.1 μm on the surface on which the boron doped layer 201 is formed by plasma CVD (Chemical Vapor Deposition). The TEOS insulating film 26 is formed, for example, at a temperature of 360 ° C., a high frequency output of 250 W, a pressure of 66.7 Pa (0.5 Torr), a gas flow rate of TEOS flow rate of 100 cm ³ / min (100 sccm), and an oxygen flow rate of 1000 cm ³ / min (1000 sccm). )
Next, a resist is applied to the surface of the formed TEOS insulating film 26, resist patterning is performed to open the window portion 26a to which the equipotential contact 33 contacts at the time of anodic bonding, and etching is performed with a hydrofluoric acid aqueous solution to etch the TEOS insulating film 26. Is patterned. Then, the resist is peeled off.

Next, as shown in FIG. 6C, after heating the silicon substrate 200 and the electrode glass substrate 301 to 360 ° C., the negative electrode is connected to the electrode glass substrate 301 and the positive electrode is connected to the silicon substrate 200, and a voltage of 800 V is applied. Application and anodic bonding (bonding process). At this time, if the voltage boosting rate is too high, a large current flows through the equipotential contact and damages to the ITO wiring. Therefore, it is preferable to join the electrodes while confirming that the current does not exceed 10 mA.
In addition, during anodic bonding, there are cases where glass is electrochemically decomposed at the interface between the silicon substrate 200 and the electrode glass substrate 301 to generate oxygen. In some cases, gas adsorbed on the substrate surface is generated by heating. Since these gases are discharged to the outside from the atmosphere opening hole 38, the inside of the gap between the electrodes does not become a positive pressure. Accordingly, it is possible to prevent a situation in which the diaphragm is cracked when a recess serving as a discharge chamber is formed by etching as will be described later.

Next, as shown in FIG. 6D, after anodic bonding, the surface of the silicon substrate 200 is ground until the thickness of the silicon substrate 200 becomes about 60 μm. Thereafter, in order to remove the work-affected layer, the silicon substrate 200 is etched by about 10 μm with a potassium hydroxide solution having a concentration of 32 wt%. As a result, the thickness of the silicon substrate 200 is about 50 μm.
In this grinding step and work-affected layer removal step, the air opening hole 38 is closed using, for example, a single-sided protective jig or tape so that the etching solution does not enter the gap between the electrodes from the air opening hole 38. The inside of the gap between electrodes is protected. Since the ink supply port 35 is closed at the joint surface between the silicon substrate 200 and the glass substrate 300 at this stage, the etching liquid does not enter the interelectrode gap through the ink supply port 35.

Next, as shown in FIG. 6E, a TEOS etching mask 204 with a thickness of about 1.5 μm is formed on the entire etching surface of the silicon substrate 200 using plasma CVD. The TEOS etching mask 204 is formed, for example, at a temperature of 360 ° C., a high frequency output of 700 W, a pressure of 33.3 Pa (0.25 Torr), a gas flow rate of TEOS flow rate 100 cm ³ / min (100 sccm), and an oxygen flow rate of 1000 cm ³ / min ( 1000 sccm).

Next, as shown in FIG. 6 (f), for example, an epoxy adhesive is poured into the atmosphere opening hole 38 to seal the atmosphere opening hole 38. As a result, the gap between the electrodes is hermetically sealed, and liquid and gas do not enter from the air opening hole 38 in the subsequent processes.
Next, in order to etch the TEOS etching mask 204 in the portion 21a corresponding to the discharge chamber, resist patterning (not shown) is performed, and etching is performed using a hydrofluoric acid solution until the TEOS etching mask disappears. Pattern. After etching, the resist is peeled off.

  Next, as shown in FIG. 6G, resist patterning (not shown) is performed to etch the TEOS etching mask 204 of the portions 23a, 29a, and 30a corresponding to the reservoir, the sealing portion, and the electrode outlet port portion. The TEOS etching mask 204 is patterned by etching about 1.2 μm with a hydrofluoric acid aqueous solution. As a result, the thickness of the TEOS etching mask 204 remaining in the reservoir, the sealing portion, and the electrode outlet is about 0.3 μm. This remaining thickness must be varied depending on the desired reservoir depth. After etching, the resist is peeled off.

Next, as shown in FIG. 7 (i), in order to remove the TEOS etching mask 204 in the reservoir, the sealing portion, and the electrode outlet port portion, the substrate already bonded to the hydrofluoric acid aqueous solution (the silicon substrate 200 and the electrode glass substrate 301). (Refer to the substrate after bonding).
Next, as shown in FIG. 7 (j), the bonded substrate is immersed in an aqueous solution of potassium hydroxide having a concentration of 35 wt% and 3 wt%, and wet etching is performed until the etching stop due to the decrease in the etching rate in the boron doped layer 201 is sufficiently effective. to continue. By performing etching using the two types of potassium hydroxide aqueous solutions having different concentrations, the surface roughness of the diaphragm 22 is suppressed, and the thickness accuracy of the diaphragm 22 is set to 0.80 ± 0.05 μm or less. And the ejection performance of the inkjet head can be stabilized. Further, the etching time is controlled so that the thickness of the reservoir 23, the sealing portion 30, and the electrode outlet port portion 29 is about 20 μm.

  This is because the reservoir 23, the sealing portion 30 and the electrode outlet port portion 29 have a larger area than the diaphragm 22 portion, and therefore, when the bottom is thinned by silicon etching, it is the same as the diaphragm 22 as before. This is because if the structure is such that a thin film with a certain thickness remains, the rigidity is very weak, and it may break due to mechanical vibrations or a force that pushes up foreign matter sandwiched in the gap between electrodes. Therefore, if the structure having a thickness of about 20 μm is used as in the first embodiment, it will not break in the thinning process, and the chemical solution can be prevented from entering the gap between the electrodes.

Next, as shown in FIG. 7K, after the silicon etching is completed, the bonded substrate is immersed in a hydrofluoric acid aqueous solution, and the TEOS etching mask 204 on the silicon substrate surface is peeled off.
Next, as shown in FIG. 7L, a silicon mask (not shown) is attached to the surface of the silicon substrate in order to remove the silicon thin film remaining in the electrode outlet port 29 and the sealing portion 30, and RF Under the conditions of power 200 W, pressure 40 Pa (0.3 Torr), CF ₄ flow rate 30 cm ³ / min (30 sccm), RIE dry etching is performed for about 1 hour, and plasma is applied only to the electrode extraction port 29 and the sealing unit 30, Open. At this time, the gap between the electrodes is opened to the atmosphere.
The silicon mask is mounted by pin alignment in which pins are passed through the bonded substrate and the silicon mask.

  Next, as shown in FIG. 7 (m), the insertion guide 40 for setting the protection member (protection plate or protection tape) 41 of the next process is placed on the cavity plate 2. In this example, the insertion guide 40 is formed of a silicon plate. As shown in a plan view of FIG. 10, an opening 40 a corresponding to the electrode outlet portion 29 and an opening 40 b corresponding to the sealing portion 30. An opening 40c corresponding to a portion where the ink protective film needs to be formed is formed. By placing the insertion guide 40 having such a configuration on the cavity plate 2, an insertion guide wall is formed around the electrode extraction port portion 29 and the sealing portion 30. The insertion guide 40 may be used if the bonded substrate has a certain thickness or more, and there is no particular problem in workability when the protective member 41 is inserted in the next process.

  Then, as shown in FIG. 7 (n), a protection member 41 for protecting the surface of the terminal portion 31b is inserted into the electrode outlet 29 using the insertion guide 40, and is in close contact with the surface of the terminal portion 31b. The surface of the terminal portion 31b is protected. The protective member 41 is formed of a protective plate or a protective tape. When the protective member 41 is formed of a protective plate, the protective member 41 has a thickness that does not warp the protective plate itself in order to improve the adhesion with the terminal portion 31b. To do. Specifically, the protective plate is made of, for example, a silicon plate, and the protective tape is made of, for example, a heat resistant tape.

Next, as shown in FIG. 7 (o), a TEOS ink protective film 27 is formed to a thickness of about 0.1 μm on the upper surface of the silicon substrate 200 by plasma CVD (droplet protective film forming step). The TEOS ink protective film 27 is formed, for example, at a temperature of 360 ° C., a high frequency output of 250 W, a pressure of 66.7 Pa (0.5 Torr), a gas flow rate of TEOS flow rate of 100 cm ³ / min (100 sccm), and an oxygen flow rate of 1000 cm ³ / min ( 1000 sccm). The TEOS ink protective film 17 may be a SiO ₂ film formed by a sputtering method other than the plasma CVD method.
In addition to the effect of preventing the ink flow path from being corroded by the ink protective film 27, the stress of the insulating film 26 and the stress of the TEOS ink protective film 27 are offset, so that the warpage of the diaphragm 22 is reduced. .
Here, since the protective member 41 is in close contact with the surface of the terminal portion 31b, the TEOS ink protective film 27 is prevented from being formed on the surface of the terminal portion 31b when the TEOS ink protective film 27 is formed. can do.
After the ink protective film 27 is formed, the insertion guide 40 and the protective member 41 are removed.

  In this example, the ink protective film 27 is formed after the electrode outlet 29 is opened. However, this may occur when the ink protective film 27 is formed before the electrode outlet 29 is opened. This is to avoid cracking of the electrode outlet 29. That is, when the ink protective film 27 is formed before the opening of the electrode outlet port 29, the gap is hermetically sealed, so that the gas in the gap expands due to the processing temperature during film formation to form a thin film portion. The electrode outlet port 29 may be broken. This is because the electrode outlet 29 has a smaller area than the bottom surface of each discharge chamber that becomes the diaphragm 22, so that the rigidity is weak. Therefore, as in this example, it is necessary to open the electrode outlet 29 first to open the gap to the atmosphere.

Next, a sealing step for sealing is performed to block communication between the gap between the electrodes and the atmosphere. The sealing step includes the steps of FIGS. 8P to 8S including the pretreatment step performed prior to the step of depositing the sealing material 37 on the sealing portion 30. Hereinafter, it demonstrates in order.
First, as shown in FIG. 8 (p), the first mask substrate 42 in which portions corresponding to the sealing portion 30 and the terminal portion 31b are opened is brought into close contact with the upper surface of the cavity plate 2, and the sealing portion 30 and the terminal portion. Covers parts other than 31b. The mounting of the first mask substrate 42 is performed by pin alignment in which pins are passed through the bonded substrate and the first mask substrate 42. For the first mask substrate 42, for example, a silicon plate, carbon plate, or aluminum plate having a thickness of 200 to 500 μm is used.
Subsequently, as shown in FIG. 8 (q), the protective member 43 is inserted using the opening formed in the first mask substrate 42 as an insertion guide, and is brought into close contact with the surface of the terminal portion 31b to protect the terminal portion 31b (see FIG. 8Q). Protection process).
Then, as shown in FIG. 8 (r), a second mask substrate 44 having only an opening corresponding to the sealing portion 30 is further adhered onto the first mask substrate 42, and the first mask substrate 42 is further provided thereon. And the surface of the protection member 43 are covered. The mounting of the second mask substrate 44 is performed by pin alignment in which pins are passed through the bonded substrate and the second mask substrate 42. For the second mask substrate 44, for example, a silicon plate, carbon plate, or aluminum plate having a thickness of 200 to 500 μm is used.

Then, as shown in FIG. 8S, a sealing material 37 is deposited on the sealing portion 30 by plasma CVD to seal the sealing portion 30 (sealing material deposition step). As the sealing material 37, a TEOS film and an Al ₂ O ₃ film are used in this example, and a TEOS film, an Al ₂ O ₃ film, and a TEOS film are laminated in this order, and the electrode is formed to a thickness of about 3 μm as a whole. Seal the gap between. In addition to the plasma CVD method, a SiO ₂ film formed by sputtering or a laminated film of SiO ₂ + Al ₂ O ₃ + SiO ₂ may be used.

  Here, the second mask substrate 44 is further placed on the first mask substrate 42 for the following reason. When the sealing material 37 is formed to a thickness of about 3 μm without placing the second mask substrate 44, the surface of the protective member 43 and the first surface of the protective member 43 are formed simultaneously with the formation of the sealing material 37 on the sealing portion 30. A sealing material 37 is also formed on the surface of the mask substrate 42. Thus, when the sealing material 37 is formed in a thick film on the surface of the protective member 43, the protective member 43 is warped by the film stress. As a result, a gap is formed between the terminal portion 31b and the protective member 43, and the film forming gas flows into the gap and the sealing material 37 is formed on the terminal portion 31b. Similarly, when the sealing material 37 is formed on the surface of the first mask substrate 42, the first mask substrate 42 is warped, and the sealing material 37 is formed on the surface of the silicon substrate 200. there is a possibility. In order to prevent these disadvantages, the second mask substrate 44 is further placed on the first mask substrate 42 so that the sealing material 37 is not formed on the surface of the protective member 43 and the surface of the first mask substrate 42. I have to.

  When forming the TEOS ink protective film 27 shown in FIG. 7 (o), the TEOS ink protective film 27 is formed directly on the surface of the protective member 41. 27 is much thinner than the film thickness of the sealing material 37 and has a small film stress. Therefore, by adopting the protective member 41 that does not warp, there is no problem even if a mask substrate is not used. .

  In this example, the two mask substrates 42 and 44 are used, but instead of using the two mask substrates 42 and 44, the mask substrates 42 and 44 are integrated as shown in FIG. The third mask substrate 45 having the structure described above may be used. In this case, the number of steps can be reduced.

  Then, the second mask substrate 44, the first mask substrate 42, and the protective member 43 are removed, and laser processing or the like is performed from the hole that becomes the ink supply port 35 of the electrode glass substrate 301 as shown in FIG. Then, the ink supply port 35 is formed through the bottom of the reservoir of the silicon substrate 200.

  Then, as shown in FIG. 9 (u), the nozzle plate 1 prepared in advance is bonded to the upper surface of the cavity plate 2 with an epoxy adhesive.

  Finally, as shown in FIG. 9 (v) and FIG. 4, the main body of the inkjet head 10 shown in FIG. 2 is obtained by dicing along the dicing line 50 and cutting into individual heads. At this time, the individual electrode 31 and the equipotential contact 33 that are short-circuited at the time of anodic bonding are individually divided. Further, the sealed atmosphere opening hole 38 and the groove on the glass substrate communicating therewith are also cut and separated from the completed inkjet head 10.

  As described above, according to the manufacturing method of the ink jet head of the first embodiment, the sealing material 37 is formed in a state where the protective member 43 is brought into close contact with the terminal portion 31b to protect the surface of the terminal portion 31b. Since it performed, it can prevent that the sealing material 37 forms into a film on the terminal part 31b. Therefore, the step of removing the sealing material 37 on the terminal portion 31b is not required as in the prior art, the productivity is improved, and it is not necessary to perform any etching process or the like on the surface of the terminal portion 31b. A highly efficient inkjet head 10 can be obtained.

  In addition, the second mask substrate 44 having an opening corresponding to the sealing portion 30 is brought into close contact with the first mask substrate 42 and sealed in a state where the surface of the first mask substrate 42 and the surface of the protection member 43 are covered. Since the material deposition step is performed, it is possible to prevent the sealing material 37 from being deposited on the surface of the first mask substrate 42 and the surface of the protection member 43, and warping occurs in the first mask substrate 42 and the protection member 43. Thus, the sealing material 37 can be prevented from being formed on the surface of the silicon substrate 200 or the surface of the terminal portion 31b.

  Similarly, when the ink protective film 27 is formed, the ink protective film 27 is formed on the terminal portion 31b because the surface of the terminal portion 31b is protected by the protective member 41. Can be prevented.

  In addition, since the insertion guide 40 serving as a guide for inserting the protection member 41 into the electrode extraction port portion 29 of the silicon substrate 200 is placed on the silicon substrate 200, the protection member 41 is inserted. The workability at the time of insertion is good, and the terminal portion 31b can be reliably protected.

As the sealing material 37, using the TEOS film and the Al ₂ O ₃ film, a TEOS film, an Al ₂ O ₃ film, since to perform the sealing film formation laminated in an order of the TEOS film, TEOS film and Al ₂ The sealing portion 30 can be formed taking advantage of the characteristics when using each of the O ₃ films. In other words, the formation of Al ₂ O ₃ film having a high moisture permeation prevention property sandwiched between TEOS films that can be easily formed in a short time, although there is one aspect that the film formation takes a long time. The sealing part 30 excellent in moisture permeation preventing property can be configured while shortening the time.

  In addition, since the sealing material 37 is deposited and sealed by the CVD method, the sputtering method, or the like, the sealing process can be reliably performed on a plurality of wafers at once, and the manufacturing efficiency is good.

  Moreover, when using a protection plate as each protection member 41 and 43, a silicon plate can be employ | adopted, and when using a protection tape, heat resistant tapes, such as a polyimide tape, can be employ | adopted.

  Further, since a silicon plate is used for each mask substrate 40, 42, 44, the mask shape can be easily formed by etching.

  Further, in this example, since a method of forming each part such as a discharge chamber after bonding the silicon substrate and the electrode glass substrate is used, handling is facilitated, and cracking of the substrate can be reduced. Can be made larger. If the diameter can be increased, a large number of inkjet heads can be taken out from a single substrate, so that productivity can be improved.

  In this example, separate protective members are used in the process of FIG. 7 (n) and the process of FIG. 8 (q). However, the same protective member is used, and ink is replaced only by replacing each mask substrate. The protective film 7 and the sealing material 37 may be formed. In this case, the process can be further simplified.

Embodiment 2. FIG.
FIG. 12 is a perspective view showing an example of a droplet discharge device equipped with a droplet discharge head manufactured by the method of manufacturing an inkjet head (droplet discharge head) described in the first embodiment. A droplet discharge apparatus 100 shown in FIG. 12 is a general inkjet printer, and the droplet discharge head obtained by the method for manufacturing a droplet discharge head shown in Embodiment 1 is a highly reliable droplet. Since it is an ejection head, the droplet ejection apparatus 100 according to Embodiment 2 is also highly reliable. In addition, the droplet discharge apparatus 100 as shown in FIG. 12 can be manufactured using a known manufacturing method.

  In addition to the inkjet printer shown in FIG. 12, the droplet discharge head obtained by the method for manufacturing a droplet discharge head shown in Embodiment 1 can be used for various colors of liquid crystal displays to change the color of a liquid crystal display. Application to filter manufacture, formation of light emitting part of organic EL display device, formation of wiring part of wiring board manufactured by printed wiring board manufacturing apparatus, discharge of biological liquid (production of protein chip or DNA chip), etc. Can do.

  In addition, the manufacturing method of the droplet discharge head and the manufacturing method of the droplet discharge device of the present invention are not limited to the above-described embodiments, and can be modified within the scope of the idea of the present invention.

FIG. 2 is an exploded perspective view illustrating a schematic configuration of the inkjet head according to the first embodiment. FIG. 2 is a cross-sectional view of the inkjet head showing a schematic configuration of the right half of FIG. 1. FIG. 3 is a top view of the inkjet head of FIG. 2. The top view which shows a part of electrode glass substrate. The expanded sectional view of the equipotential contact part of an electrode glass substrate. Sectional drawing of the manufacturing process which shows the manufacturing method of an inkjet head. Sectional drawing which shows the manufacturing process following FIG. Sectional drawing which shows the manufacturing process following FIG. Sectional drawing which shows the manufacturing process following FIG. The top view of an insertion guide. The figure which shows the example of the mask substrate of the structure which integrated the two mask substrates of FIG. FIG. 3 is a perspective view of a droplet discharge device on which the droplet discharge head according to Embodiment 1 is mounted.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nozzle plate, 2 Cavity plate, 3 Electrode board | substrate, 4 Drive control circuit, 10 Inkjet head, 11 Nozzle hole, 11a Ejection port part, 11b Introduction port part, 12 Recessed part, 13 Orifice, 14 Diaphragm part, 17 Ink protective film, 21 Discharge chamber, 22 Diaphragm, 23 Reservoir, 24 Recessed part, 25 Recessed part, 26 Insulating film, 27 Ink protective film, 28 Common electrode, 29 Electrode outlet part, 30 Sealing part, 31 Individual electrode, 31a Lead part, 31b Terminal portion, 32 concave portion, 33 equipotential contact, 35 ink supply port, 37 sealing material, 38 air release hole, 40 insertion guide, 41 protective member (second protective means), 42 first mask substrate, 43 protective member ( (First protection means), 44 second mask substrate, 45 third mask substrate, 100 inkjet printer.

Claims (13)

An electrode substrate in which an individual electrode and a terminal portion of the individual electrode are formed in a recess, and a silicon substrate in which at least a recess serving as a discharge chamber for storing and discharging liquid is formed, and the individual electrode and the discharge chamber A joining step of joining the bottom portion to face each other through a gap;
A portion corresponding to a sealing portion for sealing the gap and an electrode outlet portion corresponding to the terminal portion are formed at least in the recess serving as a discharge chamber in the silicon substrate bonded to the electrode substrate. A step of forming a through-hole,
Sealing step for sealing the gap,
The sealing step includes a step of covering the silicon substrate by closely contacting the silicon substrate with a first mask substrate in which a portion corresponding to the sealing portion and a portion corresponding to the electrode extraction port portion are opened; A protection step of protecting the terminal portion by inserting a first protective member into the electrode extraction port portion from an opening corresponding to the electrode extraction port portion of the first mask substrate and bringing the first protection member into close contact with the surface of the terminal portion; A sealing material deposition step of sealing the gap by depositing a sealing material on the sealing portion through an opening of a portion corresponding to the sealing portion of the first mask substrate. A method for manufacturing a droplet discharge head.   Between the protection step and the sealing material deposition step, a step of closely attaching a second mask substrate having an opening corresponding to the sealing portion on the first mask substrate is performed, and the sealing material deposition is performed. 2. The method of manufacturing a droplet discharge head according to claim 1, wherein in the step, the sealing material is prevented from being deposited on the surface of the first mask substrate and the surface of the first protective member.   Instead of using the two mask substrates of the first mask substrate and the second mask substrate, a third mask substrate having a structure in which the first mask substrate and the second mask substrate are integrated is used. The method of manufacturing a droplet discharge head according to claim 2.   A droplet that forms a droplet protective film on the surface of the silicon substrate between the step of forming the recess serving as the discharge chamber, the sealing portion, and the electrode outlet port on the silicon substrate and the sealing step A protective film forming step, and in the droplet protective film forming step, a second protective member is inserted into the electrode outlet port portion of the silicon substrate, and is in close contact with the surface of the terminal portion to protect the terminal portion. 4. The method of manufacturing a droplet discharge head according to claim 1, wherein a droplet protective film is formed in a state.   In the droplet protective film forming step, an insertion guide serving as a guide for inserting a second protective member into the electrode outlet port of the silicon substrate is placed on the silicon substrate, and in this state, the second protective member The method of manufacturing a droplet discharge head according to claim 4, wherein: 6. The method for manufacturing a droplet discharge head according to claim 1, wherein in the sealing material deposition step, a TEOS film, an Al ₂ O ₃ film, and a TEOS film are laminated in this order.   The method for manufacturing a droplet discharge head according to claim 1, wherein the sealing material is deposited by a CVD method.   The method for manufacturing a droplet discharge head according to claim 1, wherein the sealing material is deposited by a sputtering method.   The method for manufacturing a droplet discharge head according to claim 1, wherein each of the protection members comprises a protection plate or a protection tape.   The method for manufacturing a droplet discharge head according to claim 9, wherein the protective plate is made of a silicon plate.   The method for manufacturing a droplet discharge head according to claim 9, wherein the protective tape is made of a heat-resistant tape.   The method for manufacturing a droplet discharge head according to claim 1, wherein each of the mask substrates is made of a silicon plate. A method for manufacturing a droplet discharge device, wherein the method for manufacturing a droplet discharge head according to any one of claims 1 to 12 is applied to manufacture a droplet discharge device.

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