JP2003127386A - Liquid drop ejection head and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that wiping resistance and nozzle port accuracy are not compatible. SOLUTION: A nozzle plate 43 is formed by laminating an organic resin member 71 and a high rigidity member 72, and laminating a fine particulate layer 74 containing fine particulate 82 of an organic material and a water repellent layer 75 on a surface of the organic resin member 71 sequentially.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a droplet discharge head and a method for manufacturing the same.

[0002]

2. Description of the Related Art As an ink jet head used in an ink jet recording apparatus used as an image recording apparatus such as a printer, a facsimile, a copying machine or an image forming apparatus, a nozzle for ejecting ink droplets, a pressure chamber communicating with the nozzle, (Also referred to as an ink flow path, a pressurized liquid chamber, a pressure chamber, a discharge chamber, a liquid chamber, etc.), an electromechanical conversion element such as a piezoelectric element that pressurizes ink in the pressure chamber, or an electric heat such as a heater. An ink is ejected from the nozzle by pressurizing the ink in the pressurizing chamber with the energy generated by the energy generating means, which includes a transducer that forms a wall surface of the ink flow path and a transducer and an energy generating means that faces the transducer. Eject drops.

As the droplet discharge head, for example, a droplet discharge head for discharging a liquid resist as droplets, DN
There is also a droplet discharge head that discharges the sample A as droplets, but in the following, an inkjet head will be mainly described.

Here, as the nozzle forming member in which the nozzle is formed, Japanese Patent Application Laid-Open No. 1-108056 and Japanese Patent Application Laid-Open No.
As disclosed in Japanese Patent No. 121842, etc., a plate made of an organic resin material is provided with holes (nozzle holes) to be nozzles by an excimer laser, or Japanese Patent Laid-Open Nos. 63-3963 and 1-hei. As described in Japanese Patent No. 42939, a resist pattern corresponding to the nozzle diameter is formed using a photosensitive resin material such as a dry film resist on an electroformed support substrate, and then nickel or the like is formed using this resist pattern. Is known to form a nozzle plate by depositing a highly rigid member by electroforming.

However, it is difficult to realize all the functions required for the nozzle, such as water repellency, high-precision nozzle, and high rigidity, in this kind of single-layer nozzle forming member.

Therefore, as described in Japanese Unexamined Patent Publication No. 8-34119, using a nozzle plate substrate in which a polymer layer is laminated with an epoxy adhesive on a metal layer in which nozzle holes are previously formed by an electroforming method. Also known is a polymer layer having a hole portion communicating with a nozzle hole formed by an excimer laser. Further, as described in Japanese Patent Application Laid-Open No. 6-314704, there is a stainless steel plate in which nozzle holes are formed by pressing, and nickel electroforming is performed on the back surface side of the stainless steel plate to form two metal layers.

In the ink jet head,
Since the ink (ink droplets) formed into droplets is ejected and ejected from the nozzles for recording, the nozzle shape, accuracy, etc. affect the ejection characteristics of the ink droplets (ink droplet ejection performance), and the nozzle holes are formed. The characteristics of the surface of the nozzle forming member that affects the ejection characteristics of the ink droplets. For example, when ink adheres to the peripheral portion of the nozzle hole on the surface of the nozzle forming member to cause uneven ink pool (so-called wetting unevenness), the ejection direction of the ink droplet is bent or the size of the ink droplet varies. It is known that inconveniences such as unstable flying speed of ink droplets occur.

Therefore, in the ink jet head, the surface of the nozzle forming member (the surface on the ejection surface side) where the polymer material such as the electrolytic nickel nozzle, the press perforated metal nozzle, and the polycarbonate is perforated by the excimer laser is coated with the fluoropolymer. A water-repellent film such as a film or eutectoid plating film is formed to impart ink repellency (water repellency), improve the uniformity of the surface of the nozzle forming member, and stabilize the flight characteristics of ink droplets. Is being done.

As such a head, Japanese Patent Laid-Open No. 10-
JP-A-6-87216, which has an organic resin layer containing a copolymer containing tetrafluoroethylene as one component as a water repellent layer on one surface of a supporting substrate, as described in JP-A-6-87216. As described, there is one in which a coating layer made of a fluoropolymer is provided on the surface of a nozzle forming member, and a nozzle hole is processed by irradiating an excimer laser from the back side of the coating layer.

As a method of manufacturing a nozzle plate of an ink jet head, as described in Japanese Patent No. 2914146, an adhesive member is attached to one surface of the nozzle plate and a laser beam is irradiated from the opposite side surface. Then, a method is known in which, after the plate is processed so that a part thereof remains, the adhesive member is peeled off and the part is left and removed.

[0011]

By the way, when a water repellent film of an organic material is formed on the surface of a resin material by using the nozzle forming member having at least the surface layer made of the resin material as described above, the resin material and the organic material are not used. The organic material water repellent cannot be directly applied because the adhesiveness to the water repellent material is poor and the material is easily peeled off.

Therefore, the surface of the resin material is chemically and mechanically roughened to form fine irregularities, and a water repellent agent of an organic material is applied on the surface to improve the adhesion, It is conceivable that a method of applying an undercoating agent as an intermediate layer between the material and the water-repellent film and then applying an organic material water-repellent agent thereon is used.

However, even if such a method is used, the water-repellent agent made of an organic material is excellent in water-repellent performance in the initial stage after application, but ink drops or ink droplets adhering to the nozzle plate surface or the nozzle opening surface are The water repellency deteriorates with time, such that the wiping operation performed to remove dust and the like gradually wears it off and eventually disappears. Further, even if the film of the water repellent layer is thickened in order to extend the life of the wiping, there is a problem that the water repellent agent made of an organic material is weak in abrasion resistance and can be used only several hundred times.

The present invention has been made in view of the above problems, and provides a droplet discharge head having excellent wiping resistance, a highly accurate nozzle shape, and stable droplet discharge characteristics for a long time, and a manufacturing method thereof. The purpose is to

[0015]

In order to solve the above-mentioned problems, in a droplet discharge head according to the present invention, a water repellent layer is provided on the surface of a nozzle forming member via a fine particle layer containing fine particles of an organic material. It is a thing.

Here, the fine particles contained in the fine particle layer are preferably made of a polyimide material. Further, the amount of the fine particles contained in the fine particle layer is in the range of 0.05 to 1.0% by weight based on the amount of the fine particle layer material at the time of coating, and particularly, the amount of the fine particles contained in the fine particles is at the time of coating. It is preferable that the amount is in the range of 0.3 to 0.6% by weight based on the amount of the fine particle layer material.

A method of manufacturing a droplet discharge head according to the present invention is a method of manufacturing a droplet discharge head according to the present invention, in which a nozzle hole is formed by excimer laser processing after forming a fine particle layer and a water repellent layer. To do.

Here, it is preferable that after the resin member is joined to the high-rigidity member to form the nozzle forming member, the fine particle layer and the water repellent layer are formed on the nozzle forming member.

Further, it is preferable that after attaching an adhesive tape made of an acrylic material to the side surface of the water repellent layer, excimer laser processing is performed from the side opposite to the water repellent layer to form the nozzle hole. In this case, the adhesive strength of the adhesive tape is 0.
It is preferably in the range of 5 to 3 N / cm.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic perspective view of a mechanical section of an inkjet recording apparatus according to the present invention, and FIG. 2 is a side view of the mechanical section.

The ink jet recording apparatus is composed of a carriage movable in the main scanning direction inside the recording apparatus main body 1, a recording head including an ink jet head mounted on the carriage, an ink cartridge for supplying ink to the recording head, and the like. The printing mechanism unit 2 and the like for storing the paper 3 fed from the paper feed cassette 4 or the manual feed tray 5 and recording a desired image by the printing mechanism unit 2 and then the discharge tray mounted on the rear surface side. Paper is discharged to 6.

The printing mechanism unit 2 slides the carriage 13 in the main scanning direction (the direction perpendicular to the paper surface in FIG. 2) by the main guide rod 11 and the sub guide rod 12 which are guide members which are laterally mounted on the left and right side plates (not shown). Hold it at will, this carriage 1
3, a head 14 including an inkjet head that ejects ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk) is mounted with the ink droplet ejection direction facing downward, Each ink tank (ink cartridge) 15 for supplying ink of each color to the head 14 is replaceably mounted on the upper side of 13.

The ink cartridge 15 has an atmosphere port communicating with the atmosphere in the upper part, a supply port supplying the ink to the ink jet head 14 in the lower part, and a porous body filled with the ink inside, which is porous. The ink supplied to the inkjet head 14 is maintained at a slight negative pressure by the capillary force of the body. Ink is supplied from the ink cartridge 15 into the head 14.

Here, the carriage 13 is slidably fitted to the main guide rod 11 on the rear side (downstream side in the sheet conveying direction), and the front side (upstream side on the sheet conveying direction) in the sub guide rod 1.
2 is slidably mounted. Then, since the carriage 13 is moved and scanned in the main scanning direction, the main scanning motor 1
A timing belt 20 is stretched between a drive pulley 18 and a driven pulley 19 which are rotationally driven by 7, and the timing belt 20 is fixed to the carriage 13. It is driven back and forth.

Further, although the heads 14 of the respective colors are used as the recording heads in the present embodiment, a single head having nozzles for ejecting ink droplets of the respective colors may be used. Furthermore, head 1
As described below, 4 is an electrostatic type that includes a vibration plate that forms at least a part of the wall surface of the ink flow path and an electrode that faces the vibration plate, and deforms and displaces the vibration plate by electrostatic force to press the ink. An inkjet head is used.

On the other hand, the paper 3 set in the paper feed cassette 4
For feeding the paper 3 to the lower side of the head 14, a paper feed roller 21 and a friction pad 22 for separating and feeding the paper 3 from the paper feed cassette 4, and a guide member 23 for guiding the paper 3.
A transport roller 24 that reverses and transports the fed paper 3, a transport roller 25 that is pressed against the peripheral surface of the transport roller 24, and a tip roller 26 that defines the feed angle of the paper 3 from the transport roller 24. Is provided. The transport roller 24 is rotationally driven by the sub-scanning motor 27 via a gear train.

A print receiving member 29, which is a paper guide member for guiding the paper 3 delivered from the transport roller 24 below the recording head 14 in correspondence with the range of movement of the carriage 13 in the main scanning direction, is provided. There is. A conveying roller 31 and a spur 32, which are rotationally driven to send out the sheet 3 in the sheet discharging direction, are provided on the downstream side of the printing receiving member 29 in the sheet conveying direction.
Further, a paper discharge roller 33 and a spur 34 for sending the paper 3 to the paper discharge tray 6 and guide members 35 and 36 forming a paper discharge path are provided.

At the time of recording, by driving the recording head 14 in accordance with the image signal while moving the carriage 13, ink is ejected onto the stopped paper 3 to record one line, and the paper 3 is moved by a predetermined amount. After transportation, the next line is recorded. Upon receiving a recording end signal or a signal that the trailing edge of the sheet 3 has reached the recording area, the recording operation is terminated and the sheet 3 is ejected.

A recovery device 37 for recovering the ejection failure of the head 14 is disposed at a position outside the recording area on the right end side of the carriage 13 in the moving direction. Recovery device 3
7 has a cap means, a suction means, and a cleaning means. While waiting for printing, the carriage 13 is moved to the recovery device 37 side and the head 14 is capped by the capping means, and the ejection port portion (nozzle hole) is kept in a wet state to prevent ejection failure due to ink drying.
Further, by ejecting (purging) ink that is not related to recording during recording or the like, the ink viscosity of all the ejection ports is made constant, and stable ejection performance is maintained.

When an ejection failure occurs, the ejection port (nozzle) of the head 14 is sealed by the capping means, and the ink is adhered to the ejection port surface by sucking the ink together with the ink from the ejection port through the tube. The dust and the like are removed by the cleaning means and the ejection failure is recovered. Further, the sucked ink is discharged to a waste ink reservoir (not shown) installed in the lower portion of the main body, and is absorbed and held by an ink absorber inside the waste ink reservoir.

Next, the ink jet head constituting the head 14 of this ink jet recording apparatus will be described with reference to FIGS. 3 is an exploded perspective view of the inkjet head, FIG. 4 is a cross-sectional explanatory view of the same head taken along the longitudinal direction of the diaphragm, and FIG. 5 is an enlarged cross-sectional explanatory view of main parts of the same head taken along the longitudinal direction of the diaphragm. FIG. 4 is an enlarged cross-sectional view of a main part of the same head taken along the lateral direction of the diaphragm.

The ink jet head 40 is provided on the lower side of the flow channel substrate 41, which is a first substrate using a silicon substrate such as a single crystal silicon substrate, a polycrystalline silicon substrate, or an SOI substrate. A plurality of electrodes are provided, including an electrode substrate 42 that is a second substrate using a silicon substrate, a Pyrex (registered trademark) glass substrate, a ceramics substrate, and the like, and a nozzle plate 43 that is a third substrate provided on the upper side of the flow path substrate 41. A nozzle 44 that ejects ink droplets, a pressure chamber 46 that is an ink flow path that communicates with each nozzle 44, and a common liquid chamber flow path that communicates with each pressurization chamber 46 via a fluid resistance portion 47 that also serves as an ink supply path. 48 and the like are formed.

The flow path substrate 41 is provided with a pressure chamber 46 and a recess for forming the diaphragm 50 which also serves as the first electrode forming the bottom of the pressure chamber 46. The nozzle plate 43 has a fluid resistance. A groove that forms the portion 47 is formed, and a penetrating portion that forms the common liquid chamber channel 48 is formed in the channel substrate 41 and the electrode substrate 42.

Here, when the flow path substrate 41 is, for example, a single crystal silicon substrate, boron is previously injected to the thickness of the vibrating plate to form a high-concentration boron layer to serve as an etching stop layer. After the bonding, the concave portion to be the pressurizing chamber 46 is anisotropically etched using an etching solution such as a KOH aqueous solution so that the high-concentration boron layer serves as an etching stop layer and the diaphragm 50 is formed with high accuracy. To be done. When the diaphragm 50 is formed of a polycrystalline silicon substrate, a method of forming a polycrystalline silicon thin film to serve as the diaphragm on the liquid chamber substrate, or by flattening the electrode substrate 42 with a sacrificial material in advance It can be formed by removing the sacrificial material after forming the polycrystalline silicon thin film.

Although an electrode film may be separately formed on the diaphragm 50, the diaphragm also serves as an electrode due to diffusion of impurities as described above. Also, the diaphragm 50
An insulating film may be formed on the surface of the electrode substrate 42 side. As the insulating film, an oxide film type insulating film such as SiO ₂ or S
A nitride insulating film such as i ₃ N ₄ can be used.
The insulating film can be formed by thermally oxidizing the surface of the diaphragm to form an oxide film, or by using a film forming method. Further, the flow path substrate 1 is provided with a common electrode. This common electrode is attached by sputtering a metal such as Al and sintering (thermally diffusing) it to ensure continuity with the flow path substrate 1 and ohmic contact with the flow path substrate 1 made of a semiconductor substrate. Is taking

Further, an oxide film layer 42a is formed on the electrode substrate 42, a recess 54 is formed in the oxide film layer 42a, and an electrode which is a second electrode facing the diaphragm 50 is formed on the bottom of the recess 54. 15, a predetermined gap 56 (having a gap of 0.2 μm) is formed between the diaphragm 50 and the electrode 55, and the diaphragm 50 and the electrode 55 form an actuator section. The electrode 55
An electrode protective film 57 made of an oxide insulating film such as a SiO ₂ film and a nitride insulating film such as a Si ₃ N ₄ film is formed on the surface, but the electrode protective film 57 is formed on the electrode surface 55. Alternatively, an insulating film may be formed on the diaphragm 50 side.

The flow path substrate 41 and the electrode substrate 42 can be joined by an adhesive, but a more reliable physical connection, for example, when the electrode substrate 42 is made of silicon, A direct bonding method via an oxide film can be used. This direct bonding is performed at a high temperature of about 1000 ° C. Further, when the electrode substrate 42 is glass, anodic bonding can be performed. When the electrode substrate 42 is made of silicon and anodic bonding is performed, Pyrex glass may be formed between the electrode substrate 42 and the flow path substrate 41, and anodic bonding may be performed through this film. Further, it is also possible to use a silicon substrate for the flow path substrate 41 and the electrode substrate 42 and join them by eutectic joining with a binder such as gold interposed on the joining surface.

As the electrode 55 of the electrode substrate 42,
A commonly used in the process of forming semiconductor devices
A metal material such as l, Cr, or Ni, a high melting point metal such as Ti, TiN, or W, or a polycrystalline silicon material whose resistance is reduced by impurities can be used. When the electrode substrate 42 is formed of a silicon wafer, it is necessary to form an insulating layer (the above-mentioned oxide film layer 42a) between the electrode substrate 42 and the electrode 55. When using an insulating material such as glass for the electrode substrate 42, it is not necessary to form an insulating layer between the electrode substrate 42 and the electrode 55.

When a silicon substrate is used as the electrode substrate 42, an impurity diffusion region can be used as the electrode 55. In this case, the impurity used for diffusion is an impurity having a conductivity type opposite to the conductivity type of the substrate silicon, a pn junction is formed around the diffusion region, and the electrode 55 and the electrode substrate 42 are formed.
To electrically insulate.

The nozzle plate 43 is formed by arranging a large number of nozzles 44 in two rows, and the ejection surface is subjected to water repellent treatment. Here, the nozzle plate 43 is composed of a multilayer member of a resin member and a metal member, as will be described later. The nozzle plate 43 is bonded to the flow path substrate 41 with an adhesive.

In this ink jet head 40, the nozzles 44 are arranged in two rows, and the pressurizing chamber 46, the vibration plate 50, the electrodes 55, etc. are also arranged in two rows corresponding to each nozzle 44, and are common to the central portion of each nozzle row. The liquid chamber channel 48 is arranged to supply ink to the left and right pressurizing chambers 46. This makes it possible to configure a multi-nozzle head having a large number of nozzles with a simple head configuration.

The electrode 55 of the ink jet head 40 is extended to the outside to form a connection portion (electrode pad portion) 55a, and an FPC cable 61 having a driver IC 60 as a head drive circuit mounted thereon is connected to an anisotropic conductive film or the like. Connected through. At this time, the electrode substrate 42 and the nozzle plate 43
As shown in FIG. 4, a gap sealant 62 using an adhesive such as an epoxy resin is used to hermetically seal the gap between and.

Further, the entire ink jet head 40 is bonded onto the frame member 65 with an adhesive. An ink supply hole 66 for supplying ink from the outside to the common liquid chamber flow path 48 of the inkjet head 40 is formed in the frame member 65, and the FPC cable 61 and the like have a hole 67 formed in the frame member 65. Is stored in.

The gap between the frame member 65 and the nozzle plate 43 is sealed with a gap sealant 68 using an adhesive such as an epoxy resin as shown in FIG. The ink is the electrode substrate 42 and the FPC cable 6
It prevents it from going around to the 1st grade.

Then, the frame member 6 of the head 14
5 is a joint member 70 with the ink cartridge 15.
Are connected to each other, and the common liquid chamber flow path 48 from the ink cartridge 15 through the ink supply hole 66 through the filter 71.
Ink is supplied to.

In this ink jet head 40, the diaphragm 50 is used as a common electrode, the electrode 55 is used as an individual electrode, and a driving voltage is applied between the diaphragm 50 and the electrode 55, whereby the diaphragm 50 and the electrode 55 are separated from each other. The vibrating plate 50 is deformed and displaced toward the electrode 55 by the electrostatic force generated between the vibrating plate 50 and the electrode 55, and the vibrating plate 50 is restored and deformed by discharging the electric charge between the vibrating plate 50 and the electrode 55. By changing the internal volume (volume) / pressure of
Ink droplets are ejected from the nozzle 44.

That is, when a pulse voltage is applied to the electrode 55 serving as an individual electrode, a potential difference is generated between the electrode 50 and the diaphragm 50 serving as a common electrode, and an electrostatic force is generated between the individual electrode 55 and the diaphragm 50. As a result, the diaphragm 50 is displaced according to the magnitude of the applied voltage. After that, the applied pulse voltage is lowered to restore the displacement of the vibration plate 50, and the restoring force increases the pressure in the pressurizing chamber 46, and the ink droplets are ejected from the nozzle 44.

Therefore, the details of the nozzle plate 43 which is the nozzle forming member in the ink jet head 40 will be described with reference to FIG. In this nozzle plate 43, an organic resin member 71 and a high-rigidity member 72 are joined with a thermoplastic adhesive (for example, a thermoplastic polyimide adhesive) 73, and a fine particle layer 74 and a fine particle layer 74 are formed on the surface (the ejection side surface) of the organic resin member 71. A water-repellent film (water-repellent layer) 75 is sequentially laminated and formed, and a nozzle hole 44 having a required accuracy is formed in an organic resin member 71, and a nozzle communication port 76 communicating with the nozzle hole 44 is formed in a high-rigidity member 72. is doing. The nozzle plate 43 has the high-rigidity member 72 side bonded to the flow path substrate 41 with an adhesive.

Here, as the organic resin member 71, it is preferable to select an organic resin material having thermosetting, solvent resistance, chemical resistance, and heat resistance, such as thermosetting polyimide, polyether sulfone, and polyphenylene sulfide. . A thickness of 10 to 50 μm is sufficient for the organic resin member 71.

As the high-rigidity member 72, Ni / Co / Fe is used.
Is used as a Kovar material which is a low expansion coefficient alloy having a coefficient of thermal expansion of 3 to 4 × 10E ⁻⁶ / ° C. The Kovar material is a silicon substrate (coefficient of thermal expansion 2 to 3 × 1) that forms the flow path substrate 41.
0E- ⁶ / ° C) and the coefficient of linear thermal expansion are almost the same,
It is possible to reduce the occurrence of strain due to joining. The high-rigidity member 72 has a thickness of about 20 to 50 μm.

Further, as the high-rigidity member 72, Fernico material, stainless steel material (SUS304, 430), ceramic material that can be used as a normal green sheet, BaTi
O ₃ , Mg / Al 2 O ₃ , zeolite, Ni, glass, resin or the like can be used.

These organic resin member 71 and high rigidity member 7
The rigidity of the entire nozzle plate 43 can be increased by joining the nozzle plate 2 and the nozzle plate 43 together. That is, the Young's modulus of the organic resin member 71 is about 100 to 300 kg / mm ² ,
0 ~ 15000Kg / mm ² , 10000 of ceramics
Since it is much smaller than 20,000 Kg / mm ² , the organic resin member 71 alone may be deformed following the driving pressure of the ink jet, causing a pressure loss and lowering the ink drop velocity Vj. A high-rigidity member 72 such as metal or ceramics is attached under the resin member 71 with a thin film adhesive (adhesive layer) 73 to improve the overall rigidity.

As the adhesive layer 73, thermoplastic polyimide is used. Depending on the material, the heat and pressure joining using thermoplastic polyimide is 150-300 ° C / 0.1-8Kg /
cm ² can complete the bonding in 1 to 30 seconds,
Process tact can be shortened. Thermoplastic polyimide is a polyimide with thermosetting polyimide as a main skeleton and side-chained thermoplastic material, or wholly aromatic polyimide, which is a highly alkali-resistant polyimide material, so that good ink durability can be obtained. .

The fine particle layer 74 is formed by mixing and dispersing fine particles 82 of an organic material in the undercoat agent 81. As the undercoat agent 81, a silane coupling agent, a plastic polyimide, polyester, a polyurethane-based emulsion type or an organic solvent-based one can be used. The fine particles 82 of the organic resin material may be organic fine particles that can be processed by an excimer laser, and for example, a polyimide material can be used.

Here, fine particles 82 made of a polyimide material, for example, fine particles of Upilex powder "UIP-S" (trade name) manufactured by Ube Industries, are mixed with an emulsion type polyurethane liquid as the undercoat agent 81.
It was dispersed and used.

The water-repellent film 75 preferably contains a fluorine-containing amorphous compound such as a silicon-containing organic fluorine-containing polymer or a tehrocyclic amorphous fluorine-containing compound. Water repellent film 75
The water repellency is improved by containing a fluorine amorphous compound.

As described above, by forming the water repellent layer 75 on the surface of the organic resin member 71 forming the nozzle forming member through the fine particle layer 74 containing fine particles, the wiping resistance is improved.

That is, as shown in the partially enlarged schematic view of FIG. 8, the fine particle layer 74 applied to the resin member 71 has the fine particles 82 such that the heads of the fine particles 82 slightly protrude from the thickness of the undercoating agent 81. The diameter, the addition amount, and the layer thickness of the undercoat agent 81 are selected. At this time, the thin undercoat agent 81 is also attached to the heads of the protruding fine particles 82. Since the water-repellent film 75 is formed on it in a thin layer, the surface of the nozzle plate 43 has an uneven water-repellent film surface.

Here, since the tip of the wiper for wiping performed when the head is mounted on a recording device such as a printer as a head has a shape that does not reach the concave portion of the uneven surface, only the head portion of the convex portion is rubbed. become. Water-repellent film 7 in recess
No. 5 does not rub or hits very softly, so that good water repellency can be maintained for a long period of time without abrasion or peeling.

By forming the fine particles 82 with an organic material, the excimer laser processability is improved, and irregular holes (irregular nozzle holes 44) do not occur during nozzle hole processing.

That is, in order to increase the wiping resistance
Has high wear resistance as fine particles contained in the fine particle layer.
Machine material system such as CaF₂, SiO₂, SiON, BN, T
iO _TwoIt is preferable to use fine particles of Ti, TiN, SiC, etc.
Good When such fine particles of inorganic materials are used
The particle size of the fine particles added to the undercoating agent is within an appropriate range.
You need to be in the fence.

That is, when the particle size is too large, when the nozzle hole is processed by the excimer laser processing in the next step, if the fine particles are just present in the outer shape of the nozzle, the outer peripheral part of the nozzle cannot be processed by the excimer laser and the convex particle is formed. Will remain as. If the convex particles remain, the outer peripheral portion of the nozzle is naturally deformed and the ejection characteristics are affected. On the other hand, when the particle size of the fine particles is too small, the wiping resistance of the water repellent layer is reduced, and the water repellent performance does not last until the required life. Further, if the material of the fine particles has poor workability with respect to the excimer laser, even if the particle size is small, there is a possibility that the fine particles may remain in the portion that will be the outer circumference of the nozzle, which may affect the ejection characteristics. Become.

As described above, in the case of using the inorganic material type fine particles having high abrasion resistance, when the nozzle holes are processed by the excimer laser, if the fine particles are present on the outer peripheral portion of the holes processed by the laser, Since the fine particles are not cleanly processed by the excimer laser, the nozzle hole may not be a clean circle and may be a deformed hole.

On the other hand, by using the fine particles 82 made of an organic material, the processability of the excimer laser on the fine particles is improved. For example, polyimide, which is used for the resin member 71, has high ablation property against excimer laser and high heat resistance, and therefore has excellent workability by excimer laser. Therefore, even if there are fine particles on the outer peripheral portion of the hole processed by the laser, the fine particles are processed by the excimer laser cleanly, and the nozzle hole becomes a clean circle. As a result, it is possible to obtain a head having a nozzle hole having excellent droplet ejection characteristics with good yield.

By using a material having excellent workability for excimer laser as the fine particles contained in the fine particle layer, in this case, an organic material, water repellency durability can be ensured, and nozzle hole processing that does not cause irregular shape can be performed. It will be possible.

Therefore, by using such a nozzle plate, a head capable of obtaining stable droplet discharge characteristics for a long period of time can be obtained, and by mounting this head on a recording device, stable high-quality recording can be performed for a long period of time. be able to.

Here, the fine particles 8 included in the fine particle layer 74.
Explaining the amount of 2, if the amount of the fine particles 82 is too small, the effect of protecting the wiper blade from hitting (or strongly hitting) the recessed surface of the water-repellent layer 75 during wiping is lost. However, when the amount of the fine particles 82 is too large, although the excimer processability is exhibited, the exit end of the nozzle hole is affected to a considerable extent. That is, when there are too many fine particles, for example, when they are gathered at the exit end of the nozzle hole that is subjected to excimer processing, they may not be processed completely and may remain slightly. It will happen.

Therefore, as a result of repeating the experiments by the inventors, the amount of fine particles satisfying both characteristics (wiping resistance and ensuring the circularity of the nozzle) is determined to be the fine particle layer 74 when applied to the resin material member 71. It was confirmed that it is appropriate that the amount of the fine particles 82 be within the range of 0.05 to 1.0 VOL% (wt%) with respect to the amount of the material. It was further confirmed that, more preferably, a better effect is exhibited when the ratio is within the range of 0.3 to 0.6 VOL% (% by weight).

Next, an example of the manufacturing process of the nozzle plate in which the nozzle forming member is the resin member will be described with reference to FIG. As shown in FIG. 3A, an organic resin material (here, a polyimide film which is a resin film) 71 that serves as a base material of the nozzle forming member is prepared. It is necessary to change the thickness of the resin film according to the application, and if you want to increase the strength of the base material, increase the thickness of the resin film of this base material or other resin films (PS, PPS, PES,
Polyolefin type) may be used. In addition to the film, a molded resin or a resin sheet that is generally commercially available can be used.

Then, as shown in FIG. 6B, an undercoat agent 81 containing fine particles 82 is applied to the surface of the resin film 71 as a base material to form a fine particle layer 74. Here, as described above, an emulsion type polyurethane is used as the undercoat agent 81, and an organic material, for example, fine particles 82 such as polyimide are mixed and dispersed. As the undercoat coating method, a spin coater, roll coater, screen printing, spray coating or the like can be used.

The undercoating agent 81 applied on the resin film 71 as the base material is thermally dried to form the fine particle layer 74. This is performed in order to evaporate the solvent and water contained in the undercoating agent 81 by heat and fix the fine particles 82 to the undercoating agent 81 to form an uneven surface.

Next, as shown in FIG. 6C, a water repellent 93 containing a fluorine compound such as a silicon-containing organic fluorine-containing polymer, a tehrocyclic amorphous fluorine compound, and a fluorine-containing amorphous compound-containing water repellent agent. Use liquid medication. The water repellent agent is applied onto the undercoat layer by a spin coater, roll coater, screen printing, spray coating, or the like, as in the case of applying the undercoat agent.

Then, as shown in FIG. 9D, the water repellent layer 75 is formed by thermal drying after coating the water repellent film. By this heat drying, the solvent contained in the water repellent layer 75 is evaporated by heat, and the water repellent film 75 is cured and stabilized. The drying condition at this time was 160 ° C. for 30 minutes.

Next, as shown in FIG. 7E, the member having the fine particle layer 74 and the water repellent layer 75 formed on the resin film 71 is bonded to the high rigidity member 71 with an adhesive.

Thereafter, as shown in FIG. 6F, the adhesive tape 92 is attached to the surface of the water repellent layer 75. When sticking this adhesive tape 92, it is necessary to stick it so that no bubbles are generated. If there are bubbles, the quality of the nozzle holes opened at the positions where the bubbles are present may be poor due to deposits during processing.

This adhesive tape 92 is mainly for removing a processing residue at the end of processing, which occurs when the excimer processing is performed because the entire surface of the nozzle hole does not necessarily progress microscopically and uniformly. . However, it was confirmed by experiments that the finish of the shape of the nozzle hole outlet end is affected depending on the type of the adhesive of the adhesive tape. That is, according to the experiment, when the material of the pressure-sensitive adhesive was silicone-based or rubber-based, a good result was not obtained, but when the material of acrylic-based was used, the finish was good. Therefore, it is preferable to use the adhesive tape 92 made of an acrylic material.

Further, since the adhesive tape 92 is peeled off from the nozzle plate after the excimer laser processing, if the adhesiveness is too high, the handleability at the time of peeling at the time of sticking becomes very bad, and in the worst case, the processed product is damaged. It may happen. Therefore, as a result of repeating the experiments, the present inventors found that the adhesive force of the adhesive tape 92 was within the range of 0.5 to 3 N / cm (the adherend was a mirror wafer), and the nozzle hole outlet end. It was confirmed that the finished shape of the part and the handleability at the time of sticking and peeling were both satisfactory.

After that, as shown in FIG. 9G, excimer laser is irradiated from the polyimide film (resin film) 71 side to form the nozzle holes 44 to obtain the nozzle plate 43. In the excimer laser processing, holes are formed from the resin film 71 side with the water repellent layer 75 side facing down. Nozzle hole 44
After processing, the adhesive tape 92 is peeled off and used.

The laser beam machine uses an excimer laser beam 102 emitted from a laser oscillator 101 for mirrors 103, 105, 1 as shown in FIG.
It is reflected by 08 and is guided to the processing table 110. A beam expander 104, a mask 106, a field lens 107, and an imaging optical system 109 are provided in a predetermined manner so that an optimum beam for the workpiece W can reach an optical path of the laser beam 101 to reach the processing table 110. It is located in a position.

Then, the workpiece W (member to be the nozzle plate)
Is placed on the processing table 110, and the laser beam 1
02 will be received. The processing table 110 is composed of a well-known XYZ table or the like, and is capable of moving the workpiece W as necessary to irradiate the laser beam 102 at a desired position.

Next, another manufacturing process of the nozzle plate using the resin member as the nozzle forming member will be described with reference to FIG. In this manufacturing process, as shown in FIG. 2B, after the high-rigidity member 72 is adhesively bonded to the resin film 71,
As shown in FIGS. 7C and 7D, the fine powder layer 74 and the water repellent layer 75 are formed.

That is, the resin film 71 and the high-rigidity member 72 are joined by heating and pressurizing using the adhesive 73. In this case, 250 for heat and pressure joining.
Since heating is performed up to about 300 ° C., when the high-rigidity member 72 is joined after the fine particle layer 74 is formed on the resin film 71 as in the above-described manufacturing process example, the fine particle layer 74 is formed.
Must withstand the heat of this bond.

When the emulsion type polyurethane used in this example is used for the undercoat agent 81, this heat resistance is not sufficient, and the water repellent performance of the water repellent layer 75 may be slightly deteriorated after the heat and pressure joining. Was observed.

Therefore, a material having insufficient heat resistance against heat and pressure bonding is formed of the undercoat agent 8 of the fine particle layer 74.
When used as No. 1, it is preferable to change the order of steps and form the fine particle layer and the water-repellent layer after joining the high-rigidity member to the resin member as in the manufacturing process of this example.

In the above embodiment, the present invention is applied to the nozzle forming member of the electrostatic ink jet head. However, the present invention can be applied to the nozzle forming member other than the ink jet head. It can be applied to a nozzle forming member such as an inkjet head or a bubble type (thermal type) inkjet head, and further can be applied not only to a serial type inkjet recording device but also to a line type inkjet recording device. In addition to the inkjet head, a head for ejecting liquid resist, DN
It can also be used as a head for ejecting the A sample.

[0086]

As described above, according to the droplet discharge head of the present invention, since the water repellent layer is provided on the surface of the nozzle forming member through the fine particle layer containing the fine particles of the organic material, the wiping is performed. It is possible to obtain a head having excellent durability, a highly accurate nozzle shape, and long-term stable droplet ejection characteristics.

Since the fine particles contained in the fine particle layer are made of a polyimide material, the wiping durability can be sufficiently satisfied and good excimer laser processability can be obtained. The amount of fine particles contained in the fine particle layer is 0.05 to 1.0% by weight based on the amount of the fine particle layer material at the time of coating.
Within the range, the accuracy of nozzle hole processing by excimer laser processing is improved, and particularly the amount of fine particles contained in the fine particles is 0.3 to 0.
Within the range of 6% by weight, the nozzle hole processing accuracy is further improved.

According to the method of manufacturing the droplet discharge head of the present invention, the method of manufacturing the droplet discharge head of the present invention comprises forming a fine particle layer and a water repellent layer and then performing excimer laser processing to form nozzle holes. Therefore, it is possible to form a higher quality nozzle.

Here, after the resin member is joined to the high-rigidity member to form the nozzle forming member, the fine particle layer and the water repellent layer are formed on the nozzle forming member, whereby the high-rigidity member and the resin member are formed. It is possible to avoid the influence of heat associated with bonding on the fine particle layer and the like, and prevent deterioration of water repellency.

Further, after sticking an adhesive tape made of an acrylic material on the side surface of the water-repellent layer, excimer laser processing is performed from the side opposite to the water-repellent layer to form a nozzle hole. The shape of the end portion becomes sharp and the nozzle quality can be improved. In this case, the adhesive strength of the adhesive tape is within the range of 0.5 to 3 N / cm,
It is possible to prevent the nozzle forming member from being damaged due to sticking and peeling.

[Brief description of drawings]

FIG. 1 is a schematic perspective explanatory view of a mechanism portion of an inkjet recording apparatus according to the present invention.

FIG. 2 is an explanatory side view of the mechanism section.

FIG. 3 is an exploded perspective view illustrating an inkjet head of the recording apparatus.

FIG. 4 is a schematic cross-sectional explanatory view of the same head taken along the longitudinal direction of the diaphragm.

FIG. 5 is an enlarged explanatory view of a main part of the same head along a longitudinal direction of a diaphragm.

FIG. 6 is a schematic cross-sectional explanatory view of the same head taken along the lateral direction of the diaphragm.

FIG. 7 is an enlarged cross-sectional explanatory view of the nozzle plate of the same head.

FIG. 8 is a partially enlarged schematic explanatory view of the nozzle plate.

FIG. 9 is an explanatory diagram illustrating an example of a manufacturing method according to the present invention.

FIG. 10 is a schematic configuration diagram illustrating an example of an excimer laser beam machine.

FIG. 11 is an explanatory diagram illustrating an example of a manufacturing method according to the present invention.

[Explanation of symbols]

13 ... Carriage, 14 ... Head, 24 ... Conveying roller,
33 ... Paper discharge roller, 41 ... Flow path substrate, 42 ... Electrode substrate,
43 ... Nozzle plate, 44 ... Nozzle, 46 ... Pressurizing chamber, 47 ...
Fluid resistance part, 48 ... Common liquid chamber, 50 ... Vibration plate, 55 ... Electrode, 56 ... Gap, 71 ... Organic resin member, 72 ... High rigidity member, 73 ... Adhesive layer, 74 ... Fine particle layer, 75 ... Water repellent layer , 81 ... Undercoat agent, 82 ... Fine particles.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2C057 AF65 AF93 AG55 AP02 AP13                       AP23 AP25 AP34 AP57 AP60                       AQ01 AQ02 AQ03 AQ06                 4F033 AA01 BA03 DA01 EA05 MA00

Claims (8)

[Claims] 1. A nozzle forming member having a plurality of nozzles for ejecting liquid droplets, and a plurality of ink liquid chambers in which the nozzles communicate with each other, and an energy generating means corresponding to each nozzle is driven to drive the liquid chamber. In a droplet discharge head that discharges droplets from the nozzle by changing the volume, a water repellent layer is provided on the surface of the nozzle forming member via a fine particle layer containing fine particles of an organic material. Droplet ejection head. 2. The droplet discharge head according to claim 1, wherein the fine particles contained in the fine particle layer are made of a polyimide-based material. 3. The droplet discharge head according to claim 1, wherein the amount of the fine particles contained in the fine particle layer is 0.05 to 1.0% by weight with respect to the amount of the fine particle layer material at the time of coating. A droplet discharge head characterized by being within a range. 4. The droplet discharge head according to claim 3, wherein the amount of fine particles contained in the fine particles is within a range of 0.3 to 0.6% by weight based on the amount of fine particle layer material at the time of coating. A droplet discharge head characterized by being present. 5. The method of manufacturing a droplet discharge head according to claim 1, wherein the nozzle hole is formed by excimer laser processing after forming the fine particle layer and the water repellent layer. Method for manufacturing droplet discharge head. 6. The method of manufacturing a droplet discharge head according to claim 5, wherein a resin member is joined to a high-rigidity member to form the nozzle forming member, and then the fine particle layer and the nozzle forming member are formed. A method of manufacturing a droplet discharge head, which comprises forming a water repellent layer. 7. The droplet discharge head according to claim 5, wherein after sticking an adhesive tape made of an acrylic material on the side surface of the water repellent layer, the excimer is applied from the side opposite to the water repellent layer. A method of manufacturing a droplet discharge head, characterized by forming a nozzle hole by laser processing. 8. The method of manufacturing a droplet discharge head according to claim 7, wherein the adhesive force of the adhesive tape is 0.5 to 3
A method of manufacturing a droplet discharge head, characterized in that it is within a range of N / cm.