JP2002029060A - Ink jet head and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent costs of a head from increasing. SOLUTION: A diaphragm film 23 is formed via an interposing film 22 to an optical polishing substrate 21. The optical polishing substrate 21 is released after joining a second glass substrate 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head and a method for manufacturing the same, and more particularly, to an ink jet head having a diaphragm and a method for manufacturing the same.

[0002]

2. Description of the Related Art An ink jet head used in an ink jet recording apparatus used as an image recording apparatus (image forming apparatus) such as a printer, a facsimile, a copying machine, and a plotter includes a nozzle for discharging ink droplets and an ink flow communicating with the nozzle. A path (also referred to as a pressure chamber, a pressurized liquid chamber, a liquid chamber, a discharge chamber, etc.) and energy generating means for generating energy for pressurizing the ink in the ink flow path. When driven, the ink in the ink flow path is pressurized to eject ink droplets from the nozzles.

As a conventional ink jet head, a piezo type ink jet head which discharges ink droplets by deforming and displacing a diaphragm forming a wall surface of an ink flow path using an electromechanical transducer such as a piezoelectric element, A bubble type in which a bubble is generated by ink film boiling using a heating resistor disposed in a flow path to discharge ink droplets, and a diaphragm (or an electrode integrated therewith) which forms a wall surface of the ink flow path ) And an electrode that discharges ink droplets by deforming and displacing the diaphragm with electrostatic force.

Here, particularly in an electrostatic ink jet head that deforms a diaphragm by electrostatic force, the thickness of the diaphragm is controlled with high precision because the mechanical deformation characteristics of the diaphragm greatly affect the ink ejection characteristics. There is a need.

Therefore, as described in Japanese Patent Application Laid-Open Nos. 6-71882 and 53-63880, a silicon substrate is utilized by taking advantage of the low etching rate of a P-type high-concentration impurity layer. It is known that a diaphragm made of a P-type high-concentration impurity layer is formed by forming a P-type high-concentration impurity layer on the substrate and stopping the etching at the P-type high-concentration impurity layer. Also, Japanese Patent Application Laid-Open No. 6-14357
It is also known to form a diaphragm by an electroforming method as described in Japanese Patent Publication No. 3 (JP-A) No. 3 (1999).

[0006]

However, in the method of forming a vibration plate by etching a silicon substrate, the etching rate of the silicon substrate is low, and the etching takes a long time, so that the cost is high and the silicon substrate has a high concentration. It is difficult to control the time of etching stop by the P-type impurity layer, and it is difficult to form a diaphragm having a more accurate thickness. Further, in the method using the electroforming method, there are problems that a pinhole defect easily occurs, mass productivity is low, and it is difficult to reduce the cost.

The present invention has been made in view of the above points, and has as its object to reduce the cost and improve the reliability of an ink jet head.

[0008]

In order to solve the above-mentioned problems, a method of manufacturing an ink jet head according to the present invention comprises:
A film serving as a diaphragm is formed on an optical polishing substrate having an optical polishing surface via an intervening layer, a head component is joined to the film, and then the flat substrate is peeled off.

Here, the intervening layer may be a thermosetting resin, a phosphorus compound, a sulfur compound or a sulfuric acid compound, and the film serving as the diaphragm may be Mo, W, Ni—Cr or Ni. Further, the intervening layer can be made of a material whose adhesiveness changes with heating. further,
The intervening layer may be made of a material having a Curie effect.

[0010] The intervening layer may be made of a material having a different coefficient of thermal expansion from the film to be the diaphragm. Further, the intervening layer may be made of polysilicon or amorphous silicon.

A method of manufacturing an ink-jet head according to the present invention comprises a method of forming a film to be a vibration plate directly on an optical polishing substrate having an optical polishing surface, joining a head component to the film, and then peeling off a flat substrate. It is what it was.

A film serving as a diaphragm made of a conductive material is formed on an optical polishing substrate, and a DC voltage for anodic bonding the film and a head component and an AC voltage for heating the film are applied. It can be applied in a superimposed manner. Alternatively, a film serving as a vibration plate containing a magnetic material may be formed on an optical polishing substrate, and the film may be subjected to induction heating.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an explanatory cross-sectional view of an ink jet head manufactured by applying the manufacturing method according to the present invention in a longitudinal direction of a diaphragm, and FIG. 2 is an explanatory cross-sectional view of the same head in a lateral direction of the diaphragm.

This ink jet head has a first glass substrate 1 serving as a flow path substrate and a second glass substrate 3 serving as an electrode substrate provided on the lower surface of the first glass substrate 1 via a vibration plate 2.
Nozzles 4 for discharging a plurality of ink droplets (only one is shown for the sake of convenience); a discharge chamber 6 as an ink flow path in which each nozzle 4 communicates via a nozzle communication passage 5;
And a common liquid chamber 8 and the like that communicate with each other via a fluid resistance part 7 also serving as an ink supply path.

The first glass substrate 1 has a groove for forming the nozzle 4 and the nozzle communication path 5, a recess for forming the liquid chamber 6,
A groove forming the fluid resistance portion 7 and a concave portion forming the common liquid chamber 8 are formed. The channels of the first glass substrate 1 such as the nozzle 4 and the groove serving as the nozzle communication path 5, the liquid chamber 6, the fluid resistance portion 7, and the respective grooves serving as the common liquid chamber 8 are formed by a sandblasting method.

The vibration plate 2 is joined between the first glass substrate 1 and the second glass substrate 3 to form a wall surface (bottom surface) of the liquid chamber 6. The diaphragm 2 is made of, for example, Mo, W, Ni or N
It is formed of a material such as i-Cr.

A concave portion 14 for forming a gap is formed in the second glass substrate 3, and an electrode (second electrode) 15 facing the diaphragm 2 is provided on the bottom surface of the concave portion 14. A gap 16 is formed between the vibration plate 2 and the electrode 15, and the diaphragm 2 and the electrode 15 constitute a microactuator.

On the surface of the electrode 15, an insulating film 17 such as a SiO ₂ film is formed. Preferably, the thickness of the insulating film 17 is in the range of 50 to 5000 ° (0.05 to 0.5 μm). If the thickness is less than 0.05 μm, the electrode 15 will not function sufficiently as a protective film, and if it exceeds 0.5 μm, the gap 16 between the diaphragm 2 and the electrode 15 will be too large or will not be effective. The gap (here, the gap between the surfaces of the insulating films 17) is too small.

The electrode 15 can be made of a metal material such as Al, Al alloy, Cr, Ni, Ni-Cr, Pt, Au, Mo, or a high melting point metal such as Ti, TiN, W, or the like. . Then, as shown in FIG. 2, the bottom surface of the concave portion 14 of the second glass substrate 3 is formed as an inclined surface in the short direction of the diaphragm, and the electrode 15 is formed on this bottom surface.
The electrode 15 is arranged in a non-parallel state with respect to the diaphragm 2. The gap 16 formed by the non-parallel diaphragm 2 and the electrode 15 is referred to as a non-parallel gap.

Here, the vibration plate 2 is directly bonded or anodic bonded to the second glass substrate 3 which is a head component, and the first glass substrate 1 is directly bonded, anodic bonded or They are joined with adhesives.

In the ink jet head constructed as described above, a driving voltage is applied between the vibration plate 2 and the electrode 15 (one of which is a common electrode and the other is an individual electrode) to generate an electrostatic force. When the diaphragm 2 is deformed and displaced, and the internal volume / pressure of the ejection chamber 6 changes, ink droplets are ejected from the nozzles 4.

In this ink jet head, the diaphragm 2 is displaced toward the electrode 15 in a state where the diaphragm 2 is not brought into contact with the electrode 15 as a displacement driving method of the diaphragm, and the diaphragm 2 is returned by discharging from this state. Although a non-contact drive system in which ink droplets are ejected by the
The contact drive method in which the ink droplets are ejected by displacing the diaphragm until it comes into contact with the diaphragm 5 and discharging from this state to return the diaphragm 2 can perform more stable ink droplet ejection.

Here, since the electrode 15 is inclined, when a driving voltage is applied, the diaphragm 2 starts generating displacement from a portion where the gap length between the diaphragm 15 and the electrode 15 is short, and the gap length gradually decreases. Therefore, the diaphragm 2 starts deforming and displacing at an extremely low voltage. That is, the electrostatic actuator operates by balancing the electrostatic force generated between the diaphragm 2 and the electrode 15 and the rigidity of the diaphragm 2, and this electrostatic force is inversely proportional to the square of the distance t between the two electrodes. Therefore, a desired electrostatic force can be obtained at a lower voltage V as the distance t between the electrodes is smaller.

Therefore, since the gap 16 between the diaphragm 2 and the electrode 15 is small on the end side of the diaphragm 2, the displacement of the diaphragm 2 is changed by the distance t according to the application of the driving voltage.
Starts from the smaller end. Then, as the displacement of the end of the diaphragm 2 starts, the distance between the diaphragm 2 and the electrode 15 gradually decreases, a large displacement can be obtained with a small increase in voltage, and low voltage driving can be achieved.

Next, a first embodiment of the method for manufacturing an ink jet head according to the present invention will be described with reference to FIGS. First, the manufacturing process of the second glass substrate 3 having the diaphragm 2 will be described with reference to FIG.
An optical polishing substrate 2 which is a flat substrate as shown in FIG.
1 and the optically polished substrate 21 as shown in FIG.
An intervening film (layer) 22 is formed on the optically polished surface. The thickness of the intervening layer 22 is preferably not more than 1 μm, and particularly preferably in the range of 0.05 to 0.2 μm.

Here, a film of an inorganic compound is formed as the intervening layer 22. As the inorganic compound, Ca ₃ (P
O ₄ ) ₃ and phosphorus compounds such as NaPO ₄ , liquid crystal films of WS ₂ and WS ₃ , or MoS ₃ or Mo ₃ S ₅ Mg ₂ SO ₄ , Ba
Examples thereof include a sulfur compound and a sulfuric acid compound such as a sputtered film such as SO ₄ and CaSO ₄ .

Thereafter, as shown in FIG. 1C, Mo, W, Ni or Ni-C
A film (diaphragm film) 23 of r, Ti, or the like is formed with an appropriate thickness, for example, 0.5 to 10 μm (here, 2 μm). Then, as shown in FIG. 2D, the second glass substrate 3 provided with the separately manufactured electrode 15 and the diaphragm film 2 are formed.
3 and 200 to 450 ° C. (preferably 300 to
° C), and as shown in FIG.
And the second glass substrate 3 are subjected to anodic bonding. FIG. 5 shows an example of the temperature dependence of the ion current.

At this time, a DC voltage (1000
V) is applied, but it depends on the bonding area.
A current of about 200 mA flows, and the inorganic compound forming the intervening layer 22 is partially thermally decomposed by local Joule heating by the current to generate a volatile gas including an occluded gas.

By this volatile gas, the optical polishing substrate 21 can be separated and separated from the diaphragm film 23 which has been ion-chemically bonded to the second glass substrate 3 by anodic bonding, as shown in FIG. That is, while the adhesion between the surface of the compound forming the intervening layer 22 and the diaphragm film 23 is weak due to the use of a sputtering device or a vapor deposition device, the vibration plate 2 and the second glass Since the substrate 3 is a strong bond by ionic bonding, when a pyrolysis volatile gas is generated, it can be easily separated and separated from the interface of the engineering polishing substrate 21. In this manner, the second diaphragm 2 joined with the diaphragm 2
A glass substrate 3 is obtained.

As described above, a film to be a vibration plate is formed on an optical polishing substrate having an optical polishing surface via an intervening layer, a head component is joined to the film, and the flat substrate is peeled off. Is formed, it is possible to form a highly accurate diaphragm with a small thickness variation, and the reliability of the head is improved. In addition, since the thin film diaphragm can be handled in a state of being bonded to the optical polishing substrate, the handling is easy, the process steps can be shortened, the process is simple, and the optical polishing substrate can be reused. Cost can be reduced.

By using a thermosetting resin, a phosphorus compound, a sulfur compound or a sulfuric acid compound as an intervening layer formed on the optically polished substrate and using Mo, W, Ni—Cr or Ni for the film serving as a diaphragm, The polishing substrate can be easily peeled off, and a film serving as a diaphragm can be efficiently formed, thereby reducing costs.

Next, referring to FIG. 4, the first glass substrate 1
The manufacturing process will be described. A resist is applied or laminated on a glass substrate 31 serving as the first substrate 1 as shown in FIG. 3A, exposed and developed, and a nozzle is formed as shown in FIG. 4. A mask 32 is formed by a sand blast resist pattern having openings 33 corresponding to the flow path patterns of the nozzle communication path 5, the liquid chamber 6, the fluid resistance section 7, and the common ink chamber 8.

Next, as shown in FIG. 3C, a concave portion 34 is formed by sandblasting using an abrasive having a large abrasive particle size, and then, as shown in FIG. Sand blasting using small abrasive particles
A concave portion 35 having a finished wall surface is formed.

In the case of performing precision cutting by the sandblasting method, machining can be performed using abrasive grains having an abrasive grain size of less than 3 μm, but the cutting rate (cutting speed) at this time is extremely small (about 0.5 μm / min). ), Abrasive grain size is 15μm
When the abrasive grains exceeding the maximum grain size are used, the chipping becomes large, so that it is not suitable for high-speed precision cutting. On the other hand, the particle size of the abrasive grains used and the size of chipping during cutting have a substantially correlation. Therefore, first, a large particle size (for example, 15 μm)
About 80% of the target depth is cut by using the abrasive grain of the above, and then, cutting is performed to the target depth by using the abrasive grain of a small particle size (for example, 3 μm) to reduce the size of chipping on the cut surface. In addition, the cutting speed (tact time) can be increased.

Thereafter, as shown in FIG. 3 (e), chipping by sandblasting and hair cracks are spin-coated with polysilazane, and this is thermally decomposed and oxidized at 150 to 450 ° C. to form the surface coat layer 37 of SiO _2. Then, the concave portion 36 and the like which become the liquid chamber 6 whose wall surface is smoothed are formed. Here, the thickness of the surface coat layer 37 of SiO ₂ is 500-5000 °, preferably 1000-20.
00 °. The polysilazane becomes a pure amorphous SiO ₂ film by thermal decomposition oxidation, and the ink reliability (liquid contact resistance) is improved.

When the liquid chamber 6 and the like are formed on the first glass substrate 1 by a sandblasting method, polysilazane is used as a surface coat layer such as a liquid chamber wall surface to form the second glass substrate 3 (here, the vibration plate 2). Anodic bonding with
Direct solid joining becomes possible at low cost. That is, when a polysilazane film is formed on the entire surface of the first glass substrate 1, the polysilazane-treated film has good surface smoothness and, when a voltage is applied at the time of anodic bonding, has a low resistance due to a small amount of impurities and has a high electric charge. Will be concentrated. Thereby, the mobile ions contained in the first glass substrate 1 move together with the charge concentration to the bonding interface, and are bonded (bonded) by an ion reaction. At this time, the film thickness is set within a range where the ion current is not reduced by high resistance, preferably 1000 to 2000 °. This facilitates anodic bonding.

The sand blast surface can be smoothed by chemical etching using, for example, a simple substance of sulfuric acid, phosphoric acid, nitric acid, or acetic acid containing 5 to 30 wt% of hydrofluoric acid, or a mixed acid of two or more acids. As a result, chipping becomes 1 μm or less, hair cracks due to sandblasting are also removed, and a glass-like surface can be secured. Also, for example, heating a glass substrate at 300 ° C.
Even by performing scan annealing with a carbon dioxide gas laser, the cloudiness of the cut portion is annealed and melted, and the chipping and hair cracks are melted and turned into a translucent glass.

The first glass substrate 1 having the flow path formed as described above is replaced with the second glass substrate 3 having the above-described diaphragm 2.
The head is completed by being superposed on and joined by a joining method such as anodic joining. In this case, since the surface of the metal film serving as the diaphragm 2 partially reacts with the compound to form an oxide film, anodic bonding with high strength to the first glass substrate 1 can be performed.

Next, another embodiment of the method for manufacturing an ink jet head according to the present invention will be described. Note that the basic steps are the same as those in FIG.
First, a second embodiment will be described. In this embodiment, as an intervening film (layer) 22 formed on an optically polished surface of an optically polished substrate 21, a material whose crystal structure is changed by heating to change adhesion is used. For example, a suboxide is formed. Examples of the suboxide include low oxides such as cuprous oxide, aluminum suboxide, and SnO. Then, the diaphragm film 23 is formed on the intervening layer 22.

In this case, when the diaphragm film 23 and the second glass substrate 3 are heated and anodically bonded, the suboxide of the intervening film 22 changes to a higher oxide due to the effects of heating and local module heating. For example, 2Cu ₂ O + 1 / 2O ₂ = 2CuO,
At this time, SnO + 1 / 2O ₂ = SnO ₂ . Also, S
Similarly, an iO film or a NiO film becomes a high-order oxide at about 300 ° C. when heated. When this suboxide changes to a higher-order oxide, the adhesion deteriorates, and a peeling interface is formed.

As described above, by forming the intervening film whose adhesiveness changes by heating on the optically polished substrate, the first
Evaporation conditions that take into account the change in the composition of the inorganic compound as in the embodiment are not required, film formation can be performed by a single-target sputtering apparatus, and a target intervening film of a sputtering gas can be easily obtained. The optical polishing substrate can be reused by performing swab cleaning and acid cleaning.

Next, a third embodiment will be described.
In this embodiment, as the intervening film (layer) 22 formed on the optically polished surface of the optically polished substrate 21, a material having a Curie effect, for example, amorphous (amorphous) or low-temperature crystalline transformation (100 to 450 ° C.) Use materials that occur in For example, when γ-AL203 is used as a deposition film, γ-AL20
No. 3 retains 1.9 to 5.5% of water, so that dehydration occurs due to heating for anodic bonding, and some β-A
Transforms into L203, deteriorating the adhesion at the interface, and can be separated.

[0043] Further, by trace containing Li and Al in the SiO ₂ film, a SiO ₂ alpha-beta transition temperature 300
The temperature can be set to about ° C., and degradation accompanying transformation occurs at the time of anodic bonding, so that peeling can be performed.

As described above, by forming the intervening layer made of a material having a Curie effect on the optically polished substrate, the intervening film only undergoes crystal transformation and partial degassing (moisture).
The peeling interface can reproduce the flatness of the optically polished substrate, and can secure the flatness of the alignment surface when joining a flow path substrate formed of a silicon substrate or a glass substrate on the vibration plate.

Next, a fourth embodiment will be described.
In this embodiment, as the intervening film (layer) 22 formed on the optically polished surface of the optically polished substrate 21, a material having a different coefficient of thermal expansion from the film 23 to be the diaphragm, for example, Al, Ag, Sn,
A film of Co, Cu, Zn, brass or the like is formed. The coefficient of thermal expansion of the optically polished substrate is about 4 × 10E-6, and Mo, W,
A diaphragm material such as a Ni alloy having a high corrosion resistance is almost the same. On the other hand, Al, Ag, Sn, Co,
Cu, Zn, brass and the like have a thermal expansion coefficient of 4 to 7 times.

More specifically, for example, aluminum (Al) is formed to a thickness of about 0.3 μm on the optical polishing substrate 21, and then Mo is formed to a thickness of 2 μm as the film 23 to be a diaphragm.
When this film formation substrate and the electrode substrate made of a glass substrate are anodically bonded, the Al film (intervening film 22) and the Mo film
3 generates an internal stress. Here, in the anodic bonding, the bonding portion between Mo and the glass substrate due to the ionic reaction is firmly bonded, so that the Al film contracts during cooling and peels off from the interface where the internal stress is large.

As described above, by forming an intervening film made of a material having a different thermal expansion coefficient from that of the film to be the diaphragm on the optically polished substrate, the peeling interface between the optically polished substrate and the diaphragm becomes thermally expanded with the metal diaphragm. Because the separation surface holds the reproducibility of the optically polished substrate, it can be reused while holding the metal separation film (intervening film) of the optically polished substrate. Become. In addition, since the cleaning of the optically polished substrate is only to the extent that dust adheres, the cleaning and reuse are easy.

Next, a fifth embodiment of the present invention will be described. In this embodiment, polysilicon or amorphous silicon is used as the intervening film 25 formed on the optical polishing substrate 21. The thickness of the polysilicon or amorphous silicon is preferably 0.05 to 1 μm.

At this time, the optical polishing substrate 21 is made of a material mainly composed of SiO ₂ , and the interface with the film 25 is partially S
Bonding of i-O-Si occurs, and the adhesion is 20 kg / cm ^2.
The above shear strength is obtained. Further, a stable metal, which is a diaphragm material, has no reactivity with Si, is based on physical adhesion, and has a strength of about 5 kg / cm ² . Further, the thermal expansion coefficient of Si is the same as that of the optical glass substrate, but the metal film material has a coefficient 1.5 to 2 times.

When the film-forming substrate and the electrode substrate formed of a glass substrate are anodically bonded, separation occurs from the interface of polysilicon or amorphous silicon due to a synergistic effect.

As described above, by forming a polysilicon film or an amorphous silicon film as an intervening film on the optically polished substrate, the optically polished substrate and the intervening film are made of the same material, ie, a Si-based material. Oxidation of the surface can be neglected, the management and operation of the optically polished substrate can be facilitated, and the surface properties of the vibration plate are good, there is no oxidation, and there is no need for partial heating or voltage application.

Next, a sixth embodiment of the method for manufacturing an ink jet head according to the present invention will be described with reference to FIG. In this embodiment, the diaphragm film 23 made of a conductive material is formed directly on the optical polishing substrate 21 without the interposition of the intervening film 22. And this optical polishing substrate 2
1 and the second glass substrate 3 are superimposed, and the optically polished substrate 21
The electrode 41 made of Fe or the like is disposed on the side of the second glass substrate 3 and the electrode 42 made of Fe or the like is disposed on the side of the second glass substrate 3. OV is applied from the DC power supply 43 to the electrode 25, and DC voltage (−0.
5 to 2 KV) and a DC voltage (−0.5 to 2 KV) between the diaphragm film 23 and the electrode substrate side electrode 26.
And the electrode 25 and the diaphragm 2
AC voltage (3 to 20 V) is superimposed and applied between them.

Thus, the anodic bonding between the diaphragm film 23 and the second glass substrate 3 is performed by the DC voltage applied between the electrode 41 and the electrode 42, and the diaphragm film 23 is When the voltage is applied, the temperature rapidly rises to 350 ° C. to 400 ° C., and peeling occurs from the optical polishing substrate 21 having weak adhesion (no ionic bonding occurs).

As described above, the diaphragm is formed by forming a film serving as a diaphragm made of a conductive material on the optical polishing substrate, bonding the film to a head component, and then peeling the optical polishing substrate. A highly accurate diaphragm having a small thickness variation can be formed, and the reliability of the head can be improved. In addition, since the thin film diaphragm can be handled in a state of being bonded to the optical polishing substrate, the handling is easy, the process steps can be shortened, the process is simple, and the optical polishing substrate can be reused. Cost can be reduced. further,
Since there is no intervening film, the peeled surface reproduces the surface of the optically polished substrate, no cleaning is required, and the utilization efficiency is increased.

Then, a film serving as a diaphragm made of a conductive material is formed on the optically polished substrate, and a DC voltage for anodic bonding the film and a head component and an AC voltage for heating the film are applied. By superimposing the application, ionic bonding and peeling by local heating can be performed at the same time, so that the process can be simplified and the cost can be reduced.

Next, a seventh embodiment of the method for manufacturing an ink jet head according to the present invention will be described with reference to FIG. In this embodiment, the diaphragm film 45 made of a magnetic metal material, for example, Fe, Ni—Fe, or the like is formed directly on the optical polishing substrate 21 without the interposition of the intervening film 22. Then, the optical polishing substrate 21 and the second glass substrate 3 are overlapped, and an electrode 46 made of copper or the like is provided on the optical polishing substrate 21 side, and an electrode 47 made of copper or the like is provided on the second glass substrate 3 side.
And an OV from the DC power supply 43 to the electrode 46 and the electrode 47
A DC voltage (for example, 1 kV) is applied to the diaphragm and the diaphragm film 45 and the electrode 46 are connected.

Thus, anodic bonding by ionic bonding is performed between the diaphragm film 45 and the second glass substrate 3 by the DC voltage applied between the electrodes 46 and 47. Then, by operating a dielectric heating device (not shown), the diaphragm film 45 is made of a magnetic material, so that the diaphragm film 45 is dielectrically heated and its temperature rises to 350 ° C. to 400 ° C. Separation occurs due to a difference in thermal expansion between the optical polishing substrate 21 and a weakly polished (no ionic bond) substrate 21.

As described above, the film to be the diaphragm containing the magnetic material is formed on the optically polished substrate, and the film is induction-heated to peel off the optically polished substrate. However, since there is no intervening film, the peeled surface is a reproduction of the optically polished substrate surface, and cleaning is not necessary,
Usage efficiency is increased. When a jig (electrode) used for anodic bonding is made of a magnetic metal material, dielectric heating can be performed, and separation and division can be performed based on a difference in expansion due to a difference in heat transfer.

In each of the above embodiments, the present invention has been described as an example in which the present invention is applied to a method of manufacturing an electrostatic ink jet head. However, the same applies to a method of manufacturing an ink jet head using an electromechanical transducer such as a piezoelectric element. Can be applied to

[0060]

As described above, according to the method of manufacturing an ink jet head according to the present invention, a film serving as a diaphragm is formed on an optical polishing substrate having an optical polishing surface via an intervening layer. Since the flat substrate is peeled off after joining the head components, a thin film diaphragm having high surface accuracy can be formed by a simple process, and the cost and reliability of the ink jet head can be reduced.

Here, when the intervening layer is made of a thermosetting resin, a phosphorus compound, a sulfur compound or a sulfuric acid compound, and the film serving as the diaphragm is made of Mo, W, Ni—Cr or Ni, The optically polished substrate can be easily separated from the film to be the diaphragm, and the optically polished substrate can be easily reused. In addition, since the intervening layer is made of a material whose adhesiveness changes when heated, the formation of the film serving as the vibration plate is simplified, and the reuse of the optically polished substrate is also simplified. Furthermore, when the intervening layer is made of a material having a Curie effect, the planarity of the optical polishing substrate can be reproduced at the peeling interface, and the uniformity of the bonding surface with the head component can be ensured.

Further, since the intervening layer is made of a material having a different coefficient of thermal expansion from the film to be the diaphragm, the planarity of the optically polished substrate can be reproduced at the peeling interface, and the bonding with the head component can be performed. While ensuring the uniformity of the surface,
The optically polished substrate can also be reused while holding the intervening film. Further, since the intervening layer is made of polysilicon or amorphous silicon, the flatness is good, and the management and operation of the optically polished substrate can be performed ignoring surface oxidation, and the surface property of the diaphragm is also improved. .

According to the method of manufacturing an ink jet head according to the present invention, a film to be a vibration plate is directly formed on an optical polishing substrate having an optical polishing surface, and a head component is joined to the film. With this configuration, the planarity of the optically polished substrate can be reproduced on the diaphragm, the reuse efficiency of the optically polished substrate can be improved, and the cost and reliability of the inkjet head can be reduced.

Further, a film serving as a diaphragm made of a conductive material is formed on the optically polished substrate, and a DC voltage for anodic bonding the film and a head component and an AC voltage for heating the film are applied. By superimposing and applying, with a simple process,
The planarity of the optically polished substrate can be reproduced on the vibration plate, the reuse efficiency of the optically polished substrate can be improved, and the cost of the inkjet head can be reduced. Also, by forming a film serving as a diaphragm containing a magnetic material on an optical polishing substrate and inducing this film by induction heating, the planarity of the optical polishing substrate can be reproduced on the diaphragm by a simple process. As well as improving the efficiency of reusing optically polished substrates,
The cost of the inkjet head can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view in the longitudinal direction of a diaphragm of an inkjet head manufactured by applying a manufacturing method according to the present invention.

FIG. 2 is an explanatory cross-sectional view of the head in a lateral direction of a diaphragm.

FIG. 3 is an explanatory diagram for explaining a first embodiment of a method for manufacturing an ink jet head according to the present invention;

FIG. 4 is an explanatory diagram illustrating an example of a manufacturing process of the flow channel substrate in the embodiment.

FIG. 5 is an explanatory diagram for explaining the relationship between ion current and temperature in anodic bonding;

FIG. 6 is an explanatory view for explaining a sixth embodiment of the method for manufacturing an ink jet head according to the present invention;

FIG. 7 is an explanatory view for explaining a sixth embodiment of the method for manufacturing an ink jet head according to the present invention;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st glass substrate, 2 ... diaphragm, 3 ... 2nd glass substrate, 3 ... 3rd glass substrate, 4 ... nozzle, 6 ... discharge chamber, 7
... Fluid resistance part, 8 ... Common liquid chamber, 14 ... Concave part, 15 ... Electrode, 16 ... Gap, 21 ... Optical polishing substrate, 22 ... Intervening film, 23 ... Vibrating plate film.

Claims (10)

[Claims] 1. A method of manufacturing an ink jet head, comprising: an ink flow path to which a nozzle for discharging ink droplets communicates; a vibration plate forming a wall surface of the ink flow path; and means for deforming and displacing the vibration plate. An inkjet head, comprising: forming a film serving as the vibration plate on an optical polishing substrate having an optical polishing surface via an intervening layer; bonding a head component to the film; and peeling the flat substrate. Production method. 2. The method for manufacturing an ink jet head according to claim 1, wherein the intervening layer is made of a thermosetting resin, a phosphorus compound, a sulfur compound or a sulfate compound, and the film serving as the diaphragm is made of Mo, W, Ni—. A method for manufacturing an inkjet head, wherein the method is Cr or Ni. 3. The method for manufacturing an ink jet head according to claim 1, wherein said intervening layer is made of a material whose adhesiveness changes with heating. 4. The method for manufacturing an ink jet head according to claim 1, wherein said intervening layer is made of a material having a Curie effect. 5. The method for manufacturing an ink jet head according to claim 1, wherein the intervening layer is made of a material having a different coefficient of thermal expansion from the film to be the vibration plate. 6. The method according to claim 1, wherein the intervening layer is made of polysilicon or amorphous silicon. 7. A method of manufacturing an ink jet head comprising: an ink flow path to which a nozzle for discharging ink droplets communicates; a vibration plate forming a wall surface of the ink flow path; and means for deforming and displacing the vibration plate. A method of forming a film to be the vibration plate directly on an optical polishing substrate having an optical polishing surface, bonding a head component to the film, and then peeling the flat substrate. 8. The method for manufacturing an ink jet head according to claim 7, wherein a film serving as a diaphragm made of a conductive material is formed on the optical polishing substrate, and the film and the head component are anodic-bonded. A method for manufacturing an ink jet head, wherein a DC voltage and a AC voltage for heating the film are superimposed and applied. 9. The method for manufacturing an ink jet head according to claim 7, wherein a film serving as a vibration plate containing a magnetic material is formed on the optical polishing substrate, and the film is induction-heated. Manufacturing method. 10. An ink jet head comprising: an ink flow path through which a nozzle for discharging ink droplets communicates; a vibration plate forming a wall surface of the ink flow path; and means for deforming and displacing the vibration plate. An ink jet head, wherein a plate is formed on an optical polishing substrate having an optical polishing surface and bonded to a head component, and then the flat substrate is peeled off and bonded to another head component.