JP4070175B2 - Droplet ejection head, inkjet recording apparatus, image forming apparatus, and apparatus for ejecting droplets - Google Patents

Description

[0001]
[Industrial application fields]
  The present invention is a droplet discharge head,The present invention relates to an ink jet recording apparatus, an image forming apparatus, and an apparatus for discharging droplets.
[0002]
[Prior art]
In general, as an inkjet head which is a droplet ejection head in an inkjet recording apparatus used in an image recording apparatus (including an image forming apparatus) such as a printer, a facsimile machine, a copying apparatus, and a plotter, a nozzle for ejecting ink droplets and a nozzle are provided. A discharge chamber (also referred to as an ink flow path, an ink chamber, a liquid chamber, a pressure chamber, a pressurization chamber, a pressurization liquid chamber, etc.) that communicates, and a diaphragm that also serves as a first electrode that forms the wall surface of the discharge chamber An electrostatic ink jet head that includes an electrode (second electrode) facing the electrode and discharges ink droplets from a nozzle by deforming and displacing a diaphragm with an electrostatic force is known.
[0003]
As a conventional electrostatic ink jet head, for example, as disclosed in JP-A-6-71882 and JP-A-5-50601, a silicon substrate (this is referred to as “ A diaphragm substrate ”is used, and a borosilicate glass (pyrex glass) or a silicon substrate is used as a substrate on which an electrode is provided (referred to as“ electrode substrate ”).
[0004]
As a method for manufacturing such an ink jet head, (1) a method using water glass (sodium silicate solution) for bonding the electrode substrate and the diaphragm substrate as described in JP-A-9-286101, (2) As described in Japanese Patent Laid-Open No. 10-286554, an electrode substrate and a diaphragm substrate are joined via polysilazane. As shown in Japanese Patent Laid-Open No. 9-286101, an electrode is used. Known are those for anodically bonding a substrate and a diaphragm substrate, and (4) those for directly bonding an electrode substrate and a diaphragm substrate as described in JP-A-6-8449.
[0005]
[Problems to be solved by the invention]
However, in the case of using water glass (sodium silicate solution) for bonding the electrode substrate and the diaphragm substrate of the above (1), this material shows good bonding properties at a low temperature, but the water content is low. Due to the large amount, the influence of the outgas (such as water vapor) from the film is unavoidable, and the alkali metal is contained at a high concentration, so that there is a problem of contamination by alkali metal. Further, in the case of using the polysilazane for bonding the electrode substrate and the diaphragm substrate of the above (2), the reliability is excellent, but the problem of the outgas is still inherent.
[0006]
Further, in the case of using the anodic bonding described in (3) above, there is a problem of contamination by alkali metal depending on the conditions, or by applying a high voltage of 100 to 20000 V at a temperature of about 400 ° C. It has problems such as stress accumulation on the diaphragm. In addition, in the case of using the direct bonding described in the above (4), a bonding surface (mirror surface, Ra <0.2 nm or less) controlled at the atomic and molecular level is required. The manufacturing cost is high, such as the need for heating near 1 ° C (for example, 1100 ° C), and the range that can be used is limited. In addition, since direct bonding is a bonding technique that does not use a bonding material, there is a problem with liquid sealing properties. May appear.
[0007]
  The present invention has been made in view of the above problems, and is a low-cost and highly reliable droplet discharge head.Equipped with this droplet discharge headAn object of the present invention is to provide an ink jet recording apparatus, an image forming apparatus, and an apparatus for ejecting droplets.
[0008]
[Means for Solving the Problems]
  In order to solve the above problems, a droplet discharge head according to the present invention is provided on at least one of the bonding surfaces of a first substrate provided with a diaphragm and a second substrate provided with an electrode., Having a three-layer structure of a silicon oxide film not containing phosphorus and boron, a silicon oxide film containing phosphorus and boron, and a silicon oxide film not containing phosphorus and containing boron, and the bonding surface side does not contain phosphorus, It is a silicon oxide film containing boronA silicon oxide film layer is laminated, and the first and second substrates are directly bonded via the silicon oxide film layer.
[0009]
  The droplet discharge head according to the present invention is provided on at least one of the bonding surfaces of the first substrate provided with the vibration plate and the third substrate formed with the nozzle., Having a three-layer structure of a silicon oxide film not containing phosphorus and boron, a silicon oxide film containing phosphorus and boron, and a silicon oxide film not containing phosphorus and containing boron, and the bonding surface side does not contain phosphorus, It is a silicon oxide film containing boronA silicon oxide film layer is laminated, and the first and third substrates are directly bonded via the silicon oxide film layer.
[0010]
  The droplet discharge head according to the present invention is provided on at least one of the bonding surfaces of the first substrate provided with the vibration plate and the fourth substrate serving as the lid member., Having a three-layer structure of a silicon oxide film not containing phosphorus and boron, a silicon oxide film containing phosphorus and boron, and a silicon oxide film not containing phosphorus and containing boron, and the bonding surface side does not contain phosphorus, It is a silicon oxide film containing boronA silicon oxide film layer is laminated, and the first and fourth substrates are directly bonded via the silicon oxide film layer.
[0011]
  The droplet discharge head according to the present invention includes a silicon oxide film not containing phosphorus and boron, phosphorus and boron on at least one of the bonding surfaces of the first substrate provided with the vibration plate and the second substrate provided with the electrode. A silicon oxide film having a three-layer structure including a silicon oxide film including phosphorus and a silicon oxide film including no phosphorus and including phosphorus, and a bonding surface side does not include boron and is a silicon oxide film including phosphorusLaminating a silicon oxide film layer,In this configuration, the first and second substrates are directly bonded via the silicon oxide film layer.
[0012]
  The droplet discharge head according to the present invention includes a silicon oxide film not containing phosphorus and boron, phosphorus and boron on at least one of the bonding surfaces of the first substrate provided with the vibration plate and the third substrate formed with the nozzle. A silicon oxide film having a three-layer structure of a silicon oxide film containing phosphorus and a silicon oxide film containing no phosphorus and containing phosphorus, and a silicon oxide film layer that is a silicon oxide film containing phosphorus and containing no boron on the bonding surface side; The first and third substrates are directly bonded via the silicon oxide film layer.
[0013]
  The droplet discharge head according to the present invention is provided on at least one of the bonding surfaces of the first substrate provided with the vibration plate and the fourth substrate serving as a lid member,It has a three-layer structure of a silicon oxide film that does not contain phosphorus and boron, a silicon oxide film that contains phosphorus and boron, and a silicon oxide film that does not contain boron and contains phosphorus. It is a silicon oxide film containingA silicon oxide film layer is laminated, and the first and fourth substrates are directly bonded via the silicon oxide film layer.
[0017]
  The ink jet recording apparatus according to the present invention is configured such that the ink jet head is the liquid droplet ejection head according to the present invention.The image forming apparatus and the apparatus for ejecting droplets according to the present invention are equipped with the droplet ejection head according to the present invention.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an exploded perspective view of an ink jet head which is a droplet discharge head according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of the head in the longitudinal direction, and FIG. It is a principal part expanded sectional view of a hand direction.
[0019]
The inkjet head includes a flow path substrate 1 that is a first substrate using a single crystal silicon substrate, and an electrode substrate 2 that is a second substrate using a single crystal silicon substrate provided below the flow path substrate 1. A nozzle plate 3 that is a third substrate using a single crystal silicon substrate provided on the upper side of the flow path substrate 1, and is a plurality of nozzles 4 for discharging ink droplets, and an ink flow path in which each nozzle 4 communicates. A discharge chamber 6 and a common liquid chamber 8 that communicates with each discharge chamber 6 via a fluid resistance portion 7 that also serves as an ink supply path are formed.
[0020]
The flow path substrate 1 is formed with a plurality of discharge chambers 6 with which the nozzles 4 communicate with each other and concave portions that form a vibration plate 10 (also serving as an electrode) that forms the bottom of the wall of the discharge chamber 6. Forms a hole for forming the nozzle 4 and a groove for forming the fluid resistance portion 7, and a through-hole for forming the common liquid chamber 8 is formed in the flow path substrate 1 and the electrode substrate 2.
[0021]
Here, when a single crystal silicon substrate is used as the flow path substrate 1, boron is injected into the vibration plate thickness in advance to form a high-concentration boron layer serving as an etching stop layer, and after bonding to the electrode substrate 2, By anisotropically etching the concave portion that becomes the discharge chamber 6 using an etching solution such as an aqueous KOH solution, the high-concentration boron layer becomes an etching stop layer at this time, and the diaphragm 10 is formed with high accuracy. In addition, the active layer substrate can be used as the vibration plate 10 by using an SOI substrate in which the base substrate and the active layer substrate are bonded via an oxide film.
[0022]
Further, a single crystal silicon substrate is used as the electrode substrate 2, an oxide layer 2 a is formed by a thermal oxidation method or the like, a recess 14 is formed in this oxide layer 2 a, and the bottom surface of the recess 14 faces the diaphragm 10. The electrode 15 is provided, a gap 16 is formed between the diaphragm 10 and the electrode 15, and the diaphragm 10 and the electrode 15 constitute an actuator part (energy generating means). At this time, the depth of the recess 14 defines the length of the gap 16.
[0023]
Here, the concave portion 14 of the electrode substrate 2 has a shape in which the cross-sectional shape has an inclined surface in the lateral direction of the diaphragm as shown in FIG. 4, and the electrode 15 is formed on the bottom surface of the concave portion 14. And the electrode 15 are opposed to each other in a non-parallel state in the lateral direction of the diaphragm. The gap 16 formed by the non-parallel diaphragm 10 and the electrode 15 is referred to as a non-parallel gap. Of course, the diaphragm 10 and the electrode 15 can be opposed to each other in a parallel state, or a non-parallel gap can be formed in the longitudinal direction of the diaphragm.
[0024]
As the electrode 15 of the electrode substrate 2, gold, a metal material such as Al, Cr, or Ni generally used in a process for forming a semiconductor element, or a refractory metal such as Ti, TiN, or W is used. Can do.
[0025]
In the nozzle plate 3, a large number of nozzles 4 are formed, and a groove portion for forming a fluid resistance portion 7 for communicating the common liquid chamber 8 and the discharge chamber 6 is formed. Here, a water-repellent film is formed on the ink ejection surface (nozzle surface side). This nozzle plate 3 uses a stainless steel substrate, but in addition to this, a nickel plated film by electroforming (electroforming) method, excimer laser processing on a resin such as polyimide, and punching a metal plate by pressing. It can also be used.
[0026]
Here, the flow path substrate 1 and the electrode substrate 2 are bonded via a silicon oxide film layer 18 containing phosphorus and / or boron. By forming the silicon oxide film 18 on the entire surface of the electrode substrate 2, the surface of the electrode 15 also serves as the electrode protective film 17.
[0027]
The silicon oxide film layer 18 includes two layers of a silicon oxide film (NSG: Non-doped Silicate Glass) that does not contain phosphorus and boron and a silicon oxide film (BPSG: BoroPhospho-Silicate Glass) that contains phosphorus and boron. It can also be a structure.
[0028]
The silicon oxide film layer 18 includes a silicon oxide film (NSG) that does not contain phosphorus and boron, a silicon oxide film (BPSG) that contains phosphorus and boron, and a silicon oxide film (BSG) that does not contain phosphorus and contains boron. : Boro-Silicate Glass).
[0029]
Alternatively, a silicon oxide film (NSG) not containing phosphorus and boron, a silicon oxide film (BPSG) containing phosphorus and boron, and a silicon oxide film (PSG: Phospho-Silicate Glass) not containing boron and containing phosphorus A three-layer structure can also be used. Further, as the silicon oxide film layer 18, a coating type silicon oxide film (SOG: Spin On Glass) can be used.
[0030]
In this ink jet head, two rows of nozzles 4 are arranged, and two rows of discharge chambers 6, diaphragms 10 and electrodes 15 are arranged corresponding to each nozzle 4, and a common liquid chamber 8 is arranged in the center of each nozzle row. Thus, a configuration is adopted in which ink is supplied to the left and right ejection chambers 6. Thus, a multi-nozzle head having a large number of nozzles can be configured with a simple head configuration.
[0031]
The electrode 15 is extended to the outside to form a connection portion (electrode pad portion) 15a, and an FPC cable 21 on which a driver IC 20 as a head drive circuit is mounted by wire bonding is connected via an anisotropic conductive film or the like. is doing. At this time, the gap between the electrode substrate 2 and the nozzle plate 3 (gap 16 inlet) is hermetically sealed with a gap sealant 22 using an adhesive such as epoxy resin, and moisture enters the gap 16 and vibrates. The plate 10 is prevented from being displaced.
[0032]
Further, the entire inkjet head is bonded onto the frame member 25 with an adhesive. An ink supply hole 26 for supplying ink from the outside to the common liquid chamber 8 of the ink jet head is formed in the frame member 25, and the FPC cable 21 and the like are accommodated in a hole portion 27 formed in the frame member 25. The
[0033]
The frame member 25 and the nozzle plate 3 are sealed with a gap sealant 28 using an adhesive such as an epoxy resin, and the ink on the surface of the nozzle plate 3 having water repellency is transferred to the electrode substrate 2 or the FPC cable 21. To prevent it from going around. A joint member 30 with an ink cartridge is connected to the frame member 25 of the head, and ink is supplied from the ink cartridge to the common liquid chamber 8 through the ink supply hole 26 through a filter 31 thermally fused to the frame member 25. Supplied.
[0034]
In the ink jet head configured as described above, the diaphragm 10 is used as a common electrode, the electrode 15 is used as an individual electrode, and a drive waveform is applied between the diaphragm 10 and the electrode 15, whereby During this time, an electrostatic force (electrostatic attractive force) is generated, and the diaphragm 10 is deformed and displaced toward the electrode 15. As a result, the internal volume of the discharge chamber 6 is expanded and the internal pressure is lowered, so that the discharge chamber 6 is filled with ink from the common liquid chamber 8 via the fluid resistance portion 7.
[0035]
Next, when the voltage application to the electrode 15 is cut off, the electrostatic force stops working, and the diaphragm 10 is restored by its own elasticity. With this operation, the internal pressure of the discharge chamber 6 increases, and ink droplets are discharged from the nozzle 5. When a voltage is applied to the electrode again, the diaphragm is again pulled toward the electrode by electrostatic attraction.
[0036]
In this ink jet head, the first substrate (flow path substrate 1), the second substrate (electrode substrate 2) and the third substrate (nozzle plate 3) constituting the head are all made of a silicon substrate, so that thermal expansion between the substrates is achieved. There is no difference, and distortion due to thermal history in the head manufacturing process is eliminated. Further, even when a high-density line head (long head) is used, there is no influence on the printing characteristics and the reliability of the inkjet head because substrate distortion or the like due to temperature change during use does not occur.
[0037]
Since the first substrate (flow path substrate 1) and the second substrate (electrode substrate 2) are joined via the silicon oxide film layer 18 containing phosphorus and / or boron, the softening point of the silicon oxide film 18 The temperature required for the direct bonding of the silicon substrate can be lowered, and the surface of the silicon oxide film 18 is reflowed by heating, and the flatness of the bonding interface becomes Ra <0.2 nm or less. Therefore, the first substrate (flow path substrate 1) and the second substrate (electrode substrate 2) can be bonded at low cost.
[0038]
Here, since the silicon oxide film layer 18 is a two-layer structure film of an NSG film and a BPSG film (the bonding interface side is a BPSG film), the bonding interface can be covered with the BPSG film. Sealability is improved.
[0039]
Further, as the silicon oxide film layer 18, a three-layer structure film of an NSG film, a BPSG film, and a BSG film (a bonding interface side is a BSG film) is used as a dopant for a silicon substrate that becomes the flow path substrate 1. When boron is used, it is possible to reduce changes in electrical characteristics due to boron absorption, and by making the bonding interface a BSG film, only the BSG film can be softened, resulting in a gap accuracy error. There is almost no and a high-precision gap can be secured.
[0040]
Further, the silicon oxide film 18 is a three-layer structure film of an NSG film, a BPSG film, and a PSG film (the bonding interface side is a PSG film), whereby phosphorus as a dopant for the silicon substrate that becomes the flow path substrate 1 is used. In this case, it is possible to reduce the change in electrical characteristics due to phosphorus absorption, and by using a PSG film as the bonding interface, it is possible to prevent deterioration of the electrode material due to the high protection characteristics of the PSG film. .
[0041]
Furthermore, by using an SOG film as the silicon oxide film layer 18, a thick silicon oxide film layer can be easily formed, and an unpolished substrate can be used as the silicon substrate. Further cost reduction can be achieved.
[0042]
Next, an inkjet head according to a second embodiment will be described with reference to FIGS. 5 is a cross-sectional explanatory diagram of the head in the longitudinal direction of the diaphragm, FIG. 6 is a cross-sectional explanatory diagram of the head in the lateral direction of the diaphragm, and FIG. 7 is a plan explanatory diagram of the head.
The inkjet head includes a flow path substrate 41 that is a first substrate, an electrode substrate 42 that is a second substrate provided below the flow path substrate 41, and a third substrate that is provided above the flow path substrate 1. A plurality of nozzles 44 that discharge ink droplets, discharge chambers 46 that are ink flow paths communicating with the nozzles 44, and fluid resistance units 47 that also serve as ink supply paths to the discharge chambers 46. A common liquid chamber 48 and the like communicating with each other are formed.
[0043]
The flow path substrate 41 is formed with a plurality of discharge chambers 46 with which the nozzles 44 communicate with each other, and a concave portion and a common liquid chamber 48 that form a diaphragm 50 (also serving as an electrode) that forms the bottom of the discharge chamber 46. A recess is formed, and a nozzle plate 43 is provided with a hole for forming the nozzle 44, a groove for forming the fluid resistance portion 47, and an ink supply hole 49 for supplying ink to the common liquid chamber 48 from the outside.
[0044]
A silicon oxide film 53 is formed on the electrode substrate 42, a recess 54 that is an electrode formation groove whose bottom surface is parallel to the diaphragm 50 is formed in the silicon oxide film 53, and an electrode 55 is formed on the bottom surface of the recess 54. Thus, the diaphragm 50 and the electrode 55 are arranged in parallel through the gap 56.
[0045]
The flow path substrate 41 and the electrode substrate 42 are bonded via a BPSG film 58 that is a silicon oxide film layer containing phosphorus and / or boron. The BPSG film 58 is also formed on the entire surface of the electrode substrate 42, so that it also serves as the electrode protective film 57 on the surface of the electrode 55. As the silicon oxide film layer containing phosphorus and / or boron, instead of the BPSG film 58, a BSG film, a PSG film, a two-layer structure film of an NSG film and a BPSG film, an NSG film, a BPSG film, and a BSG film are used. A three-layer structure film or a three-layer structure film of an NSG film, a BPSG film, and PSG can also be used.
[0046]
In addition, as shown in FIG. 7, the electrode 55 is extended outside to form an electrode pad portion 55a. Further, the nozzle plate 43 is formed with an electrode pad portion 50a for connecting the diaphragm 50 to the outside.
[0047]
Further, the flow path substrate 41 and the nozzle plate 43 are bonded together via a BPSG film 59 which is a silicon oxide film layer containing phosphorus and / or boron. In this case, as the silicon oxide film layer containing phosphorus and / or boron, the BSG film, the PSG film, the NSG film and the BPSG film, the NSG film, the BPSG film, and the BSG are used instead of the BPSG film 59. A three-layer structure film with a film, or a three-layer structure film with an NSG film, a BPSG film, and a PSG can also be used.
[0048]
Therefore, a method of manufacturing the ink jet head according to the second embodiment will be described with reference to FIGS. 8 to 10 are schematic explanatory diagrams in the diaphragm lateral direction showing the manufacturing process, and FIGS. 11 to 13 are schematic explanatory diagrams in the longitudinal direction of the diaphragm. Note that the terminology before the final process may be different, but the same reference numerals as those in FIGS. 5 to 7 are used for convenience.
[0049]
As shown in FIGS. 8A and 11A, p-type single crystal silicon (wafer is used) commercially available as a low-resistance product, and the crystal plane orientation is (110) or (100). A silicon oxide film 53 serving as a protective film is formed on the silicon substrate 42 serving as an electrode substrate to a thickness of about 2 μm by wet or dry thermal oxidation. Although a p-type single crystal silicon substrate is used here, an n-type substrate may be used.
[0050]
Subsequently, as shown in each figure (b), a recess 54 which is an electrode formation groove is dug in the silicon oxide film 53. Here, a photoresist is applied on the silicon oxide film 53 and patterning is performed to form electrodes. Using this photoresist pattern as a mask, a hydrogen fluoride solution containing a buffer component such as ammonium fluoride (for example, Daikin). The concave portion 54 is dug using an industrial product: BHF-63U or the like.
[0051]
The amount of digging at this time is digged by an amount corresponding to the thickness of the electrode material and a necessary space amount between the electrode 55 and the diaphragm 50. Since the digging amount at this time is as small as about 1 μm, even when digging by wet etching using a hydrogen fluoride solution, variation in the digging amount in the wafer surface can be extremely small.
[0052]
Then, a polycrystalline silicon film serving as an electrode material is deposited on the entire surface of the silicon oxide film 53 to a thickness of about 300 nm, and processed into a desired electrode shape using a photoetching technique, whereby each figure (c) is obtained. As shown, an electrode 55 is formed on the bottom surface of the recess 54. Here, polysilicon doped with impurities is used for the electrode 55. However, as described above, a refractory metal may be used or a conductive ceramic such as titanium nitride may be used as the electrode. It is.
[0053]
Next, as shown in each figure (d), a BPSG film 58, which is a silicon oxide film layer containing phosphorus and / or boron, is formed on the entire surface of the silicon oxide film 53 (the entire surface of the wafer) using a technique such as CVD. Deposit to thickness. The BPSG film 58 in this case also has the purpose of the protective film 57 that protects the electrode 55.
[0054]
Here, the BPSG film 58 was formed to have a phosphorus concentration of 4.5% and a boron concentration of 4.0%. The concentration of phosphorus and boron at this time is a concentration generally used in a semiconductor process, but is not limited to this concentration. Further, as described above, the silicon oxide film layer containing phosphorus and / or boron may be a PSG film containing no boron or a BSG film containing no phosphorus.
[0055]
That is, the emphasis of the present invention is to reduce the temperature required for direct bonding by lowering the softening point by containing phosphorus or boron in the silicon oxide film layer. If you only want to achieve the purpose of lowering the softening point, there is a technique to contain impurities other than phosphorus and boron, such as germanium, but when considering the compatibility with electrode materials and reliability as a device, The use of phosphorus / boron, which has a proven record in semiconductor processes, is more advantageous in achieving the present invention.
[0056]
Next, as shown in FIGS. 9A and 12A, the silicon wafer (electrode substrate 42) is heat-treated in a nitrogen gas atmosphere, so that the BPSG film 58 is softened and the side walls of the recesses 14 are formed. The gap between the electrodes 55 is filled.
[0057]
The heat treatment conditions at this time were 850 ° C. and 2 hours. Here, the temperature of 850 ° C. is higher by 50 ° C. than the temperature of 800 ° C. of the next direct bonding to be performed next. Of course, if the temperature of direct bonding is lower than this, heat treatment at a lower temperature may be used. However, the temperature is higher than the temperature at which the BPSG film 58 exhibits reflow properties.
[0058]
By this heat treatment, moisture, hydrogen gas, and the like present in the BPSG film 58 are released, and generation of voids due to outgas during direct bonding can be prevented. In addition, the surface of the BPSG film 58 is reflowed by this heat treatment. Immediately after the film formation, the surface evaluation using the AFM shows that the surface roughness of the Ra value of about 1 to 3 nm is 0.1 to 0.2 nm. It can be made to have good direct bondability.
[0059]
Then, as shown in each figure (b), a silicon substrate 41 which is a flow path substrate provided with a vibration plate is a double-side polished silicon substrate having p-type polarity and having a (110) plane orientation. The purpose of using such a silicon substrate is to obtain an accurate processed shape by utilizing the surface anisotropy of the etching rate during wet etching of silicon. High-concentration boron is implanted into the bonding surface of the silicon substrate 41 (5 × 10 5¹⁹Atom / cm^ThreeAfter that, this is activated and diffused to a predetermined depth (thickness of the diaphragm) to form a diffusion layer 50 to be a diaphragm.
[0060]
Here, a silicon substrate into which impurities are implanted at a high concentration is used. However, as described above, for example, an active layer of an SOI (Silicon On Insulator) substrate can be used as a vibration plate. Alternatively, an epitaxial layer of a substrate obtained by epitaxially growing silicon on a high concentration impurity substrate can be used as a vibration plate.
[0061]
Then, as shown in each figure (c), the silicon substrate 41 used as a flow path board | substrate and the silicon substrate 42 used as an electrode substrate are joined.
[0062]
Here, after each substrate 41, 42 is cleaned using a substrate cleaning method known as RCA cleaning, it is immersed in a hot mixed solution of sulfuric acid and hydrogen peroxide water to directly bond the bonding surfaces by making them hydrophilic. Easy surface condition. Thereafter, the substrates 41 and 42 are gently aligned, and the substrates 41 and 42 are joined.
[0063]
Next, the substrates 41 and 42 that have been aligned are introduced into a vacuum chamber, and 1 × 10^-3Depressurize until the degree of vacuum is below mbar. Subsequently, pre-bonding was completed by pressing the wafers in a state where the alignment of the substrates 41 and 42 did not shift. At this time, it is important to hold the pressure so as not to be displaced, and to strongly press the pressing force as long as the substrates 41 and 42 are not distorted or displaced. Thereafter, the bonded wafers were baked at 800 ° C. for 2 hours in a nitrogen gas atmosphere to obtain a strong bond.
[0064]
Thereafter, the silicon substrate 41 is made thinner than the initial thickness of the wafer by mechanical, physical, or chemical methods such as polishing, grinding, and CMP. In this case, the interface joined by direct joining is not peeled off or destroyed. Here, a commercially available 400 μm thick silicon wafer was bonded as the silicon substrate 41 and then polished until the liquid chamber height (discharge chamber height) became 95 ± 5 μm. Note that polishing is not required when the initial thickness of the silicon wafer is used as it is.
[0065]
Subsequently, as shown in FIGS. 10A and 13A, the silicon substrate 41 is etched to form a recess for forming the discharge chamber 46 and the vibration plate 50 and a recess for forming the common liquid chamber 48.
[0066]
Here, the substrate is heat-treated to form a buffer oxide film with a thickness of about 50 nm, and a silicon nitride film as an etching barrier layer in a later process is formed to a thickness of about 100 nm by a method such as CVD. Then, patterning for forming a liquid chamber or the like is performed using a photo-etching method, and the silicon nitride film and the silicon oxide film are sequentially etched using the photoresist film as a mask to correspond to the liquid chamber pattern on the substrate. A pattern having openings is formed.
[0067]
Then, the substrate is immersed in a high concentration potassium hydroxide solution (for example, a 30% concentration KOH solution heated to 80 ° C.) and anisotropic etching of the silicon substrate 41 is performed. A recess to be the liquid chamber 48 is formed. Here, when the etching solution reaches the high-concentration boron diffusion layer 50, the etching rate is remarkably lowered, so that the etching is almost automatically stopped, and the diaphragm 50 composed of the high-concentration boron diffusion layer is formed. Is done.
[0068]
In addition to the etching using a high concentration aqueous solution of alkali metal, wet etching using TMAH (tetramethylammonium hydroxide) may be used. Then, after rinsing with ultrapure water (about 10 minutes), it is dried by spin drying or the like.
[0069]
Further, as shown in each figure (b), a BPSG film 49, which is a silicon oxide film, is also deposited on the nozzle plate 43 made of a silicon substrate by a method such as CVD. The film forming conditions at this time are the same as those of the BPSG film 48 formed on the electrode substrate 42, but it goes without saying that the composition and the like can be freely changed depending on the structure of the device and the manufacturing method.
[0070]
Then, the nozzle plate 43 on which the BPSG film 59 is formed is subjected to heat treatment (850 ° C., 2 hours) in a nitrogen gas atmosphere in the same manner as in the above process. Of course, if the temperature of direct bonding is lower than this, heat treatment at a temperature lower than this may be used, but the temperature is higher than the temperature at which the BPSG film 59 exhibits reflow properties. By this heat treatment, moisture, hydrogen gas, and the like present in the BPSG film 59 are released, and generation of voids due to outgas at the time of bonding can be prevented. In addition, the surface of the BPSG film 59 is reflowed by this treatment, and immediately after the film formation, the surface evaluation using the AFM shows that the roughness of the surface, which has a Ra value of about 1 to 3 nm, becomes 0.1 to 0.2 nm. It can be made to have good direct bondability.
[0071]
Then, after aligning the nozzle plate 43 and the flow path substrate 41, the two substrates are bonded together, fired and bonded under the same conditions as described above, and then the surface (ink ejection surface) of the nozzle plate 43 is water repellent. The ink jet head shown in FIGS. 5 and 6 is completed by performing a layer forming process. At this time, it is preferable to bake at a temperature lower than that of the previously bonded wafer (substrates 41 and 42). However, if baking is performed at least at the same temperature as the previously bonded substrate, there is no problem of outgassing. Can be joined.
[0072]
In addition, since minute surface scratches generated during the process at this time are filled when the BPSG films 58 and 59 are reflowed, it is possible to prevent the occurrence of leakage or the like when a liquid such as ink is passed. Of course, since deep scratches and wide scratches cannot be filled, it is necessary to design a process that does not cause such scratches. The bonding strength is sufficient as described above.
[0073]
In the head of this embodiment, the nozzle plate 43 is joined to the flow path substrate 41. However, the nozzle plate 43 has a multilayer structure of a flow path plate that forms a nozzle communication path and a nozzle formation member that forms a nozzle. You can also. Further, in the above process, the substrates are sequentially joined from the substrate to be an electrode, but after processing each substrate into a desired shape, a BPSG film or the like is formed on the joining surface, and an aligner for wafer bonding (for example, , EV 400 series: trade name, etc.).
[0074]
In the ink jet head manufactured in this way, since the main member constituting the head is silicon, the expansion of the head is uniform even when the temperature rises during actual use, and therefore no warping or distortion of the head occurs. If the head design is devised, it is possible to produce a long head (for example, an A4 size head) called a line head.
[0075]
Next, an inkjet head according to a third embodiment of the present invention will be described with reference to FIGS. 14 is a cross-sectional explanatory view of the head in the longitudinal direction of the diaphragm, and FIG. 15 is a cross-sectional explanatory view of the head in the lateral direction of the diaphragm.
In this embodiment, in the ink jet head of the second embodiment, the BPSG film 60 which is a silicon oxide film layer containing phosphorus and / or boron is also formed on the flow path side of the flow path substrate 41 to manufacture the head of the second embodiment. A film is formed under the same conditions as described in the process, and the nozzle plate 43 and the flow path substrate 41 are joined to each other between the silicon oxide films 59 and 60.
[0076]
In this case, as the silicon oxide film layer containing phosphorus and / or boron, the BSG film, the PSG film, the NSG film and the BPSG film, the NSG film, the BPSG film, and the BSG are used instead of the BPSG film 60. A three-layer structure film with a film, or a three-layer structure film with an NSG film, a BPSG film, and a PSG can also be used.
[0077]
In this way, the flow path surface of the flow path substrate 41 obtained through each manufacturing process can be covered with the silicon oxide film 60 such as a BPSG film, and the surface damage on the flow path surface can be reduced. Ink fluidity is stabilized.
[0078]
Next, an inkjet head according to a fourth embodiment of the present invention will be described with reference to FIGS. 16 is a sectional explanatory view of the head in the longitudinal direction of the diaphragm, and FIG. 17 is a sectional explanatory view of the head in the lateral direction of the diaphragm.
[0079]
This embodiment is different from the ink jet head of the second embodiment only in the configuration on the electrode substrate 42 side. To explain this point, a silicon oxide film 53 is formed on the electrode substrate 42, and this silicon oxide film An electrode 55 facing the vibration plate 50 is formed on the surface of the film 53, and a BPSG film 58, which is a silicon oxide film layer containing phosphorus and / or boron, is deposited on the silicon oxide film 53 and the electrode 55, and this BPSG film A concave portion 54 for forming a gap 56 between the diaphragm 50 and the electrode 55 is formed in 58. The bottom surface of the recess 54 is formed non-parallel to the diaphragm 50 in a cross-section in the diaphragm lateral direction, thereby making the gap 56 a non-parallel gap.
[0080]
A manufacturing process of the ink jet head according to the fourth embodiment will be described with reference to FIGS. 18 and 19 are schematic explanatory diagrams in the diaphragm lateral direction showing the manufacturing process, and FIGS. 20 and 21 are schematic explanatory diagrams in the longitudinal direction of the diaphragm. Note that the terminology before the final process may be different, but the same reference numerals as those in FIGS. 16 and 17 are used for convenience.
[0081]
First, as shown in FIGS. 18 (a) and 20 (a), an electrode substrate of p-type single crystal silicon sold as a low resistance product and having a plane orientation of (110) or (100) is obtained. A silicon oxide film 53 serving as a gap layer and an insulating film is formed on the silicon substrate 41 to a thickness of 2.5 μm by wet or dry thermal oxidation. Although a p-type single crystal silicon substrate is used here, an n-type substrate may be used.
[0082]
Subsequently, an electrode 55 is formed on the silicon oxide film 53 as shown in each drawing (b). Here, titanium nitride serving as an electrode material is deposited on the entire surface of the silicon oxide film 53 by sputtering, and further a silicon oxide film serving as a mask is deposited using a CVD method or the like, and then a photo-etching technique is used to form the electrode. The silicon oxide film as a mask is etched with hydrogen fluoride water using the photoresist film as a mask, and then ammonia water + An electrode 55 having a desired electrode shape was formed by etching titanium nitride using a mixed solution of hydrogen peroxide water + pure water.
[0083]
Further, a BPSG film 58 which is a silicon oxide film containing phosphorus and / or boron is deposited on the entire surface of the silicon oxide film 53 on which the electrode 55 is formed to a thickness of about 400 nm using a technique such as CVD. The BPSG film 58 in this case also has the purpose of protecting the electrodes. At this time, the BPSG film 58 was formed to have a phosphorus concentration of 4.5% and a boron concentration of 4.0%. The concentrations of phosphorus and boron are those generally used in semiconductor processes, but are not limited to these concentrations. Further, it may be a PSG film that does not contain boron or a BSG film that does not contain phosphorus.
[0084]
Next, as shown in FIG. 3C, a process for flattening the surface of the BPSG film 58 is performed. In the first example of this flattening process, the surface of the BPSG film 58 of the electrode substrate 42 is polished by using a CMP method to flatten the irregularities on the surface of the BPSG film 58 to obtain a surface shape that can be bonded. With the current CMP technology, a polishing variation of about 0.008 μm can be achieved with a polishing amount of about 0.01 μm, and very good flatness can be obtained. Moreover, the surface roughness is Ra value, and a very smooth surface of 0.1 to 0.2 nm is obtained, which increases the direct bondability.
[0085]
Thereafter, the silicon wafer (electrode substrate 42) is heat-treated at 850 ° C. for 2 hours in a nitrogen gas atmosphere. Of course, if the temperature of the direct bonding is lower than this, the heat treatment may be performed at a temperature lower than this. However, as described above, the temperature should not be lower than the temperature at which the BPSG film 58 exhibits reflow properties. By this heat treatment, moisture, hydrogen gas, and the like present in the BPSG film 58 are released, and generation of voids due to outgas at the time of bonding can be prevented.
[0086]
As a second example of the planarization process, the silicon wafer (electrode substrate 42) is heat-treated at 1000 ° C. for 2 hours in a nitrogen gas atmosphere. By this heat treatment, moisture, hydrogen gas, and the like present in the BPSG film 58 are released, and generation of voids due to outgassing during bonding can be prevented, the fluidity of the BPSG film 58 is increased, and the height of the electrode 55 is increased. The projections of the BPSG film 58 generated by the above are flattened globally and become a plane that can be directly joined. At the same time, the roughness of the surface having a Ra value of about 1 to 3 nm becomes 0.1 to 0.2 nm, and it is possible to have a very good direct bonding property.
[0087]
After performing such planarization, as shown in each figure (d), a resist is applied on the planarized BPSG film 58, patterning is performed to form a gap, and this photoresist pattern is masked. As described above, a recess 54 serving as an electrode formation groove is dug into the BPSG film 58 using a hydrogen fluoride solution containing a buffer component such as ammonium fluoride (for example, BHF-63U (trade name) manufactured by Daikin Industries, Ltd.).
[0088]
The amount of digging at this time becomes the gap depth. Since the digging amount at this time is as small as about 1 μm, even in the digging by wet etching using a hydrogen fluoride solution, the variation in the digging amount in the wafer surface becomes extremely small. In this case, the gap shape is formed in a non-parallel state by inclining the thickness of the resist pattern and performing dry etching over the resist.
[0089]
Thereafter, as shown in FIGS. 19A and 21A, the silicon substrate 41 to be the flow path substrate is placed on the electrode substrate 42 through the BPSG film 58, as in the manufacturing process of the second embodiment described above. After the direct bonding, anisotropic etching is performed to form the discharge chamber 46, the vibration plate 50, the common liquid chamber 48, etc. on the flow path substrate 41 as shown in FIG. Bonding directly on the flow path substrate 41 via the BPSG film 49. The details of this process are the same as the manufacturing process of the second embodiment described above.
[0090]
Next, an inkjet head according to a fifth embodiment of the invention will be described with reference to FIGS. 22 is a cross-sectional explanatory view of the head in the longitudinal direction of the diaphragm, and FIG. 23 is a cross-sectional explanatory view of the head in the short side of the diaphragm.
In this embodiment, in the ink jet head of the fourth embodiment, a BPSG film 60 which is a silicon oxide film layer containing phosphorus and / or boron is also formed on the flow path side of the flow path substrate 41 to manufacture the head of the fourth embodiment. A film is formed under the same conditions as described in the process, and the nozzle plate 43 and the flow path substrate 41 are joined to each other between the BPSG films 59 and 60.
[0091]
In this way, the flow path surface of the flow path substrate 41 obtained through each manufacturing process can be covered with the BPSG film 60, surface damage on the flow path surface can be reduced, and the fluidity of the ink can be reduced. Stabilize. In this case, as the silicon oxide film layer containing phosphorus and / or boron, the BSG film, the PSG film, the NSG film and the BPSG film, the NSG film, the BPSG film, and the BSG are used instead of the BPSG film 60. A three-layer structure film with a film, or a three-layer structure film with an NSG film, a BPSG film, and a PSG can also be used.
[0092]
Next, an inkjet head according to a sixth embodiment of the present invention will be described with reference to FIGS. 24 is a cross-sectional explanatory view of the head in the longitudinal direction of the diaphragm, and FIG. 25 is a cross-sectional explanatory view of the head in the lateral direction of the diaphragm.
This embodiment is different from the inkjet head of the fourth embodiment only in the configuration on the electrode substrate 42 side, and this point will be described.
[0093]
An NSG film 61, which is a silicon oxide film, is formed on the electrode substrate 42, an electrode 55 facing the diaphragm 50 is formed on the NSG film 61, and an NSG film 62 is formed on the NSG film 61 and the electrode 55. Further, a BPSG film 58, which is a silicon oxide film containing phosphorus and / or boron, is deposited on the NSG film 62, and a recess for forming a gap 56 between the diaphragm 50 and the electrode 55 is formed on the BPSG film 58. 54 is formed. The bottom surface of the recess 54 is formed non-parallel to the diaphragm 50 in a cross-section in the diaphragm lateral direction, thereby making the gap 56 a non-parallel gap.
[0094]
A manufacturing process for the ink jet head according to the sixth embodiment will be described with reference to FIGS. FIG. 26 is a schematic explanatory view in the lateral direction of the diaphragm showing the same manufacturing process, and FIG. 27 is a schematic explanatory view in the longitudinal direction of the diaphragm. Note that the terminology before the final process may be different, but the same reference numerals as those in FIGS. 24 and 25 are used for convenience.
[0095]
First, as shown in each figure (a), NSG is formed by a method such as CVD on a p-type single crystal silicon sold as a low-resistance product and having a plane orientation of (110) or (100). A film 61 is formed. Although a p-type single crystal silicon substrate is used here, an n-type substrate may be used. Alternatively, SOG may be spin-coated using a spin coater or the like to form an oxide film layer, and then heat-treated.
[0096]
Subsequently, as shown in each figure (b), titanium nitride serving as an electrode material is deposited on the entire surface of the substrate by sputtering, and a silicon oxide film serving as a mask is deposited using CVD or the like, followed by photoetching. Using the technique, patterning to form electrodes is performed, using the photoresist film as a mask, etching the silicon oxide film with hydrogen fluoride water, and then using the photoresist film and the silicon oxide film as a mask, Using a mixed solution of ammonia water + hydrogen peroxide water + pure water, titanium nitride is etched to form an electrode 55 having a desired shape.
[0097]
Then, an NSG film 62 is formed on the NSG film 61 and the electrode 55 by a method such as CVD. The NSG film 62 at this time only needs to be thick enough to cover the electrode 55. Subsequently, a BPSG film 58 is continuously deposited to a thickness of about 150 nm. At this time, the BPSG film 58 was formed to have a phosphorus concentration of 4.5% and a boron concentration of 4.0%. The phosphorus and boron concentrations are those generally used in semiconductor processes, but are not limited to these concentrations. Further, it may be a PSG film that does not contain boron or a BSG film that does not contain phosphorus. It is also easy to switch the gas type at the final stage of film formation to form a BSG film on the surface side of the BPSG film 58 or to form a PSG film.
[0098]
Next, as shown in each figure (c), after performing the process which planarizes the surface of the BPSG film | membrane 58 (similar to the 1st example of the planarization process mentioned above, the 2nd example), each figure ( As shown in d), a recess 54 to be a gap forming groove is dug in the BPSG film 58. After that, since it is the same as the manufacturing process of each embodiment mentioned above, description is abbreviate | omitted.
[0099]
Next, an inkjet head according to a seventh embodiment of the present invention will be described with reference to FIGS. 28 is a cross-sectional explanatory view of the head in the longitudinal direction of the diaphragm, and FIG. 29 is a cross-sectional explanatory view of the head in the lateral direction of the diaphragm.
This embodiment is different from the inkjet head of the fourth embodiment only in the configuration on the electrode substrate 42 side, and this point will be described.
[0100]
An SOG film 64, which is a silicon oxide film, is formed on the electrode substrate 42, an electrode 55 facing the vibration plate 50 is formed on the SOG film 64, and an SOG film 65 is formed on the SOG film 64 and the electrode 55. In addition, a recess 54 is formed in the SOG film 65 to form a gap 56 between the diaphragm 50 and the electrode 55. The bottom surface of the recess 54 is formed non-parallel to the diaphragm 50 in a cross-section in the diaphragm lateral direction, thereby making the gap 56 a non-parallel gap.
[0101]
Therefore, a manufacturing process of the ink jet head according to the seventh embodiment will be described. First, similarly to the manufacturing process of each of the above-described embodiments, a p-type single crystal silicon sold as a low-resistance product and having a (110) or (100) plane orientation is used. Then, the SOG film 64 is formed by a method such as spin coating. Thereafter, heat treatment was performed to obtain a stable oxide film.
[0102]
Subsequently, titanium nitride serving as an electrode material is deposited on the entire surface of the SOG film 64 by sputtering, and a silicon oxide film serving as a mask is deposited using a CVD method or the like, and the electrode is formed using a photoetching technique. The silicon oxide film is etched with hydrogen fluoride water using the photoresist film as a mask, followed by ammonia water + hydrogen peroxide water using the photoresist film and silicon oxide film as a mask. The titanium nitride is etched using a mixed solution of + pure water to obtain an electrode 55 having a desired shape.
[0103]
Next, the SOG film 65 is formed on the SOG film 64 and the electrode 55 by a method such as spin coating, and heat treatment is performed to stabilize the SOG film 65. Thereafter, a planarization process by the above-described CMP method or a planarization process to increase the reflow property by increasing the heat treatment temperature is performed to form the recess 54 for forming the gap in the SOG film 65, and then the flow path substrate 41, The nozzle plate 45 is joined to complete the ink jet head.
[0104]
Next, an inkjet head according to an eighth embodiment of the invention will be described with reference to FIGS. 30 is an explanatory sectional view of the head in the longitudinal direction of the diaphragm, and FIG. 31 is an explanatory sectional view of the head in the lateral direction of the diaphragm.
[0105]
Since this embodiment is different only in the configuration of the ink jet head of the second embodiment and the flow path substrate 41 side, this point will be described. A lid member 73 that is a fourth substrate is joined to the flow path substrate 71 to form a nozzle 74, a discharge chamber 76 that communicates with the nozzle 74 via a nozzle communication path 75, a fluid resistance portion 77, and a common liquid chamber 78. ing.
[0106]
And here, the groove | channel which forms the nozzle 74 and the nozzle communication path 75 in the flow-path board | substrate 71, the recessed part which forms the discharge chamber 76 and the diaphragm 80, the groove | channel which forms the fluid resistance part 77, and the common liquid chamber 78 are formed. The lid member 73 is a simple plate material. The lid member 73 and the flow path substrate 71 are bonded via the BPSG film 59 in the same manner as the nozzle plate 43 described above. An ink supply hole 79 is formed in the lid member 73.
[0107]
This ink jet head is of an edge shooter type, but it may have a structure in which a groove for forming the nozzle 74, the nozzle communication path 75 and a groove for forming the fluid resistance portion 77 are provided on the lid member 73 side. 73 is a nozzle plate.
[0108]
  Next, an ink jet head which is a droplet discharge head according to the present invention is mounted.As an image forming apparatus according to the present invention, including an apparatus for discharging droplets according to the present inventionAn outline of the mechanism of the ink jet recording apparatus will be briefly described with reference to FIGS. 32 and 33. FIG.
[0109]
In this recording apparatus, a main support guide rod 101 and a sub support guide rod 102 are horizontally mounted between side plates on both sides in a substantially horizontal positional relationship, and the carriage 103 is controlled by the main support guide rod 101 and the sub support guide rod 102. It is slidably supported in the scanning direction. On the lower surface side of the carriage 103, a head 104 composed of an inkjet head according to the present invention that discharges yellow (Y) ink, magenta (M) ink, cyan (C) ink, and black (Bk) ink, respectively, is discharged. A surface (nozzle surface) is mounted facing downward, and an ink cartridge 105 for each color for supplying ink of each color to the head 104 is mounted on the upper surface side of the carriage 103 in a replaceable manner.
[0110]
As the head 104, a plurality of heads that eject ink droplets of each color may be used, or a single head having a nozzle that ejects ink droplets of each color may be used.
[0111]
The carriage 103 is connected to a timing belt 110 that is stretched between a driving pulley (drive timing pulley) 108 and a driven pulley (idler pulley) 109 that are rotated by the main scanning motor 107 to drive the main scanning motor 107. By controlling, the carriage 103 is moved and scanned in the main scanning direction.
[0112]
As shown in FIG. 33, a conveyance roller 112 for feeding the paper 111 in a sub-scanning direction orthogonal to the main scanning direction is rotatably held between side plates (not shown). The conveyance roller 112 transmits the rotation of the sub-scanning motor 113 shown in FIG. 32 through a gear train (not shown). The transport roller 112 is set in the paper feed cassette 114 and transports the paper 111 fed by the paper feed roller 115 while being reversed.
[0113]
A pressure roller 116 for turning (reversing) the paper 111 along the surface of the transport roller 112 and a tip roller 117 as a pressing roller are rotatably disposed on the peripheral surface of the transport roller 112. Then, on the downstream side of the conveyance roller 112 in the sheet conveyance direction, the sheet 111 facing the head 104 and fed from the conveyance roller 112 corresponding to the movement range of the carriage 103 in the main scanning direction is guided below the head 104. A printing receiving member 118 is disposed.
[0114]
The printing receiving member 118 has a length corresponding to the moving range of the carriage 103 in the main scanning direction printing area, and a large number of ribs 119 and a plurality of ribs 120 are formed at a required interval in the main scanning direction. Yes. The sheet 111 is guided while being in contact with the uppermost surfaces of the ribs 119 and 120, whereby the distance between the head 104 and the surface of the sheet 111 (printing surface) is defined.
[0115]
Then, on the upstream side of the printing receiving member 118 in the paper conveyance direction, a paper pressing member 121 made of a torsion coil spring as an elastic member is attached to the rib 120 side at a position corresponding to the rib 120 of the printing receiving member 118. It is attached to the support shaft of the tip roller 117 which is a pressing roller so as to be rotatable.
[0116]
Further, on the downstream side of the printing receiving member 118 in the paper transport direction, a first paper discharge roller 125 that is rotationally driven to send the paper 111 in the paper discharge direction, a spur roller 126 that contacts the first paper discharge roller 125, and a transport path forming member 127. A second paper discharge roller 128 and a spur roller 129 in contact with the second paper discharge roller 128 are arranged, and a paper discharge tray 130 mounted in an inclined state for stocking the paper 111 to be discharged is provided.
[0117]
In this ink jet recording apparatus, the paper 111 is fed from the cassette 114 by the paper feed roller 115, thereby being reversed by the intermediate roller 116 along the peripheral surface of the transport roller 112 and being pressed by the leading roller 117. The paper 111 is guided by the printing receiving member 118, and the paper 111 is conveyed with a predetermined distance from the head 104. Therefore, ink droplets are ejected from the head 104, and an image is printed on the paper 111 by, for example, an interlaced printing method and discharged onto the paper discharge tray 130.
[0118]
  In the above embodiment, the present invention is mainly applied to a side shooter type inkjet head in which the vibration plate displacement direction and the ink droplet ejection direction are the same. However, as described above, the vibration plate displacement direction and the ink droplet ejection direction are the same. The present invention can be similarly applied to an orthogonal edge shooter type inkjet head. Furthermore, the present invention can be applied not only to an ink jet head but also to a droplet discharge head that discharges a liquid resist or the like. Further, although the diaphragm and the liquid chamber substrate are formed from the same substrate, the diaphragm and the liquid chamber substrate can be joined separately.Further, as described above, the liquid droplet ejection head according to the present invention can be mounted on an image forming apparatus such as a printer, a facsimile machine, or a plotter, and an apparatus for ejecting liquid droplets.
[0119]
【The invention's effect】
  As described above, according to the droplet discharge head according to the present invention, the first substrate provided with the diaphragm and the second substrate provided with the electrode.A first substrate provided with a vibration plate, a third substrate formed with a nozzle, a first substrate provided with a vibration plate, and a fourth substrate serving as a lid member,On at least one of the joint surfaces, Having a three-layer structure of a silicon oxide film not containing phosphorus and boron, a silicon oxide film containing phosphorus and boron, and a silicon oxide film not containing phosphorus and containing boron, and the bonding surface side does not contain phosphorus, It is a silicon oxide film containing boronSince the silicon oxide film layer is stacked and bonded directly via the silicon oxide film layerIn addition, it is possible to reduce the change in electrical characteristics when boron is used as the dopant of the substrate on which the diaphragm is provided, and to improve the gap accuracy.
[0120]
  According to the droplet discharge head according to the present invention, the first substrate provided with the vibration plate, andA second substrate provided with an electrode, a first substrate provided with a diaphragm, a third substrate formed with a nozzle, a first substrate provided with a diaphragm, and a fourth substrate serving as a lid member,On at least one of the joint surfaces, Having a three-layer structure of a silicon oxide film that does not contain phosphorus and boron, a silicon oxide film that contains phosphorus and boron, and a silicon oxide film that does not contain boron and contains phosphorus, the bonding surface side does not contain boron, A silicon oxide film layer which is a silicon oxide film containing phosphorusBecause they are stacked and bonded directly via a silicon oxide film layerIn addition, it is possible to reduce the change in electrical characteristics when phosphorus is used as the dopant of the substrate on which the diaphragm is provided, and to improve the electrode protection characteristics.
[0126]
  According to the ink jet recording apparatus according to the present invention, since the ink jet head is the droplet discharge head according to the present invention, a recording apparatus with low cost and high reliability can be obtained.According to the image forming apparatus and the apparatus for ejecting liquid droplets according to the present invention, since the liquid droplet ejection head according to the present invention is provided, a low-cost and highly reliable apparatus can be obtained.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of an ink jet head which is a liquid droplet ejection head according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional explanatory view of the head in the longitudinal direction of the diaphragm.
3 is an enlarged explanatory view of the main part of FIG.
FIG. 4 is an enlarged cross-sectional view of the main part of the head in the short direction of the diaphragm.
FIG. 5 is a cross-sectional explanatory view in the longitudinal direction of a diaphragm of an ink jet head which is a liquid droplet ejection head according to a second embodiment of the present invention.
FIG. 6 is a cross-sectional explanatory view of the head in the lateral direction of the diaphragm.
FIG. 7 is an explanatory plan view of the head.
FIG. 8 is an explanatory diagram of the diaphragm in the lateral direction explaining the manufacturing process of the head
FIG. 9 is an explanatory view of the diaphragm in the lateral direction explaining the manufacturing process of the head
FIG. 10 is an explanatory diagram of the diaphragm short side direction explaining the manufacturing process of the head
FIG. 11 is an explanatory view in the longitudinal direction of the diaphragm for explaining the manufacturing process of the head
FIG. 12 is an explanatory view in the longitudinal direction of the diaphragm for explaining the manufacturing process of the head
FIG. 13 is an explanatory view in the longitudinal direction of the diaphragm for explaining the manufacturing process of the head
FIG. 14 is a cross-sectional explanatory view in the longitudinal direction of a diaphragm of an ink jet head which is a liquid droplet ejection head according to a third embodiment of the present invention.
FIG. 15 is a cross-sectional explanatory view of the head in the lateral direction of the diaphragm.
FIG. 16 is a cross-sectional explanatory view in the longitudinal direction of a diaphragm of an ink jet head which is a liquid droplet ejection head according to a fourth embodiment of the present invention.
FIG. 17 is a cross-sectional explanatory diagram of the head in the lateral direction of the diaphragm.
FIG. 18 is an explanatory diagram of the diaphragm in the lateral direction explaining the manufacturing process of the head
FIG. 19 is an explanatory diagram of the diaphragm short direction explaining the manufacturing process of the head
FIG. 20 is an explanatory diagram in the longitudinal direction of the diaphragm for explaining the manufacturing process of the head
FIG. 21 is an explanatory view in the longitudinal direction of the diaphragm for explaining the manufacturing process of the head
FIG. 22 is a cross-sectional explanatory view in the longitudinal direction of a diaphragm of an ink jet head which is a droplet discharge head according to a fifth embodiment of the present invention.
FIG. 23 is a cross-sectional explanatory view of the head in the short direction of the diaphragm.
FIG. 24 is a cross-sectional explanatory view in the longitudinal direction of a diaphragm of an ink jet head which is a liquid droplet ejection head according to a sixth embodiment of the present invention.
FIG. 25 is a cross-sectional explanatory diagram of the head in the lateral direction of the diaphragm.
FIG. 26 is an explanatory diagram of the diaphragm short side direction explaining the manufacturing process of the head
FIG. 27 is an explanatory view in the longitudinal direction of the diaphragm for explaining the manufacturing process of the head
FIG. 28 is a cross-sectional explanatory view in the longitudinal direction of a diaphragm of an ink jet head which is a droplet discharge head according to a seventh embodiment of the present invention.
FIG. 29 is a cross-sectional explanatory view of the head in the lateral direction of the diaphragm.
FIG. 30 is a cross-sectional explanatory view in the longitudinal direction of a diaphragm of an ink jet head which is a liquid droplet ejection head according to an eighth embodiment of the present invention.
FIG. 31 is a cross sectional explanatory view of the head in the short direction of the diaphragm.
FIG. 32 is an explanatory perspective view illustrating an example of an ink jet recording apparatus according to the present invention.
FIG. 33 is an explanatory diagram of a mechanism unit of the recording apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 41 ... Flow path substrate, 2, 42 ... Electrode substrate, 3, 43 ... Nozzle plate, 4, 44 ... Nozzle, 6, 46 ... Discharge chamber, 7, 47 ... Fluid resistance part, 8, 48 ... Common liquid chamber DESCRIPTION OF SYMBOLS 10, 50 ... Diaphragm, 14, 54 ... Recess, 15, 55 ... Electrode, 16, 56 ... Gap, 18 ... Silicon oxide film containing phosphorus and / or boron, 58 ... BSPG film.

Claims (9)

A nozzle for discharging droplets; a discharge chamber in communication with the nozzle; a diaphragm that forms a wall surface of the discharge chamber; and an electrode that faces the diaphragm; In a droplet discharge head for discharging droplets,
At least one of the bonding surfaces of the first substrate provided with the diaphragm and the second substrate provided with the electrode is provided with a silicon oxide film not containing phosphorus and boron, a silicon oxide film containing phosphorus and boron, and phosphorus. It does not contain, it has a three-layer structure with a silicon oxide film containing boron, the silicon oxide film layer which is a silicon oxide film containing boron and does not contain phosphorus on the bonding surface side is laminated,
A liquid droplet ejection head, wherein the first and second substrates are directly bonded via the silicon oxide film layer. A nozzle for discharging droplets; a discharge chamber in communication with the nozzle; a diaphragm that forms a wall surface of the discharge chamber; and an electrode that faces the diaphragm; In a droplet discharge head for discharging droplets,
A silicon oxide film not containing phosphorus and boron, a silicon oxide film containing phosphorus and boron, and a phosphorus oxide on at least one of the bonding surfaces of the first substrate provided with the vibration plate and the third substrate formed with the nozzle It does not contain, it has a three-layer structure with a silicon oxide film containing boron, the silicon oxide film layer which is a silicon oxide film containing boron and does not contain phosphorus on the bonding surface side is laminated,
A droplet discharge head, wherein the first and third substrates are directly bonded via the silicon oxide film layer. A nozzle for discharging droplets; a discharge chamber in communication with the nozzle; a diaphragm that forms a wall surface of the discharge chamber; and an electrode that faces the diaphragm; In a droplet discharge head for discharging droplets,
At least one of the bonding surfaces of the first substrate provided with the diaphragm and the fourth substrate serving as a lid member includes a silicon oxide film that does not contain phosphorus and boron, a silicon oxide film that contains phosphorus and boron, and phosphorus. First, a silicon oxide film having a three-layer structure with a silicon oxide film containing boron, a silicon oxide film layer that is a silicon oxide film containing boron and does not contain phosphorus on the bonding surface side, is laminated,
A liquid droplet ejection head, wherein the first and fourth substrates are directly bonded via the silicon oxide film layer. A nozzle for discharging droplets; a discharge chamber in communication with the nozzle; a diaphragm that forms a wall surface of the discharge chamber; and an electrode that faces the diaphragm; In a droplet discharge head for discharging droplets,
A silicon oxide film containing no phosphorus and boron, a silicon oxide film containing phosphorus and boron, and boron on at least one of the bonding surfaces of the first substrate provided with the diaphragm and the second substrate provided with the electrode It does not contain, has a three-layer structure with a silicon oxide film containing phosphorus, the silicon oxide film layer which is a silicon oxide film containing phosphorus and does not contain boron on the bonding surface side is laminated,
The first and second substrates are directly bonded via the silicon oxide film layer.
A droplet discharge head characterized by that. A nozzle for discharging droplets; a discharge chamber in communication with the nozzle; a diaphragm that forms a wall surface of the discharge chamber; and an electrode that faces the diaphragm; In a droplet discharge head for discharging droplets,
A silicon oxide film not containing phosphorus and boron, a silicon oxide film containing phosphorus and boron, It does not contain, has a three-layer structure with a silicon oxide film containing phosphorus, the silicon oxide film layer which is a silicon oxide film containing phosphorus and does not contain boron on the bonding side,
The first and third substrates are directly bonded via the silicon oxide film layer.
A droplet discharge head characterized by that. A nozzle for discharging droplets; a discharge chamber in communication with the nozzle; a diaphragm that forms a wall surface of the discharge chamber; and an electrode that faces the diaphragm; In a droplet discharge head for discharging droplets,
A silicon oxide film not containing phosphorus and boron, a silicon oxide film containing phosphorus and boron, and boron are included in at least one of the bonding surfaces of the first substrate provided with the diaphragm and the fourth substrate serving as a lid member A silicon oxide film layer having a three-layer structure with a silicon oxide film containing phosphorus, a bonding surface side not containing boron, and a silicon oxide film that is a silicon oxide film containing phosphorus ;
The first and fourth substrates are directly bonded via the silicon oxide film layer.
A droplet discharge head characterized by that. 7. An ink jet recording apparatus equipped with an ink jet head, wherein the ink jet head is the droplet discharge head according to any one of claims 1 to 6 . 7. An image forming apparatus equipped with a droplet discharge head, wherein the droplet discharge head is the droplet discharge head according to any one of claims 1 to 6 . An apparatus for ejecting droplets by a droplet ejection head, wherein the droplet ejection head is the droplet ejection head according to any one of claims 1 to 6 .

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