JP2002052718A - Method for manufacturing ink jet recording head, ink jet recording head manufactured by that method and laser material processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an ink jet recording head by irradiating a laser beam from the side opposite to ink supply side, i.e., the outer surface side of an orifice plate, using a femtosecond laser. SOLUTION: At the time of laser processing an ink jet recording head having ink supply ports, and the like, formed by bonding a plate material, the ink jet recording head is processed by irradiating a laser beam from the side opposite to ink supply side, i.e., the outer surface side of an orifice plate, using a laser beam comprising a plurality of pulses having high spatial and temporal energy densities radiated from a laser oscillator oscillating at a pulse radiation time not longer than 1 picosec.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an ink jet recording head for causing ink droplets to fly on a recording medium by flying ink droplets, an ink jet recording head manufactured by the method, and a laser processing method.

[0002]

2. Description of the Related Art In an ink jet printer, print quality largely depends on characteristics of a nozzle portion, which is a portion where ink is ejected, and the characteristics of the nozzle portion are substantially determined by variations in the nozzle diameter and the shape of the nozzle. . There are roughly two methods for forming the nozzle, an electric discharge machining method using an electroforming method using a metal plate, and an ultraviolet laser for sublimating an organic polymer resin material using a high energy laser such as an excimer laser. A processing method has been proposed, but at present, it is more common to perform fine processing using the latter ultraviolet laser processing method.

Conventionally, when an organic polymer resin material is subjected to sublimation processing with such an ultraviolet laser, by irradiating the laser with a suitable energy density, the processing area gradually decreases from the laser incident side to the laser emission side.
A so-called tapered processing characteristic is obtained. by the way,
In the ink jet recording head, a nozzle plate having a nozzle having a tapered taper shape on an ink ejection side is required as a nozzle plate having an ejection port to improve print quality. The laser processing method described above has been used, and in this case, a step has been adopted in which the nozzle plate is irradiated with laser from the ink supply side to process the nozzles, and then the nozzle plate is connected to the ink supply member.

However, the length of the ink discharge nozzle is required to be about several tens of μm to about 100 μm in terms of print quality, and the plate forming this nozzle naturally has the same thickness. . For this reason, the nozzle plate becomes a very easily deformable member, and as described above, the ejection port forming plate must be laser-processed from the ink supply side. Since there is a restriction that the ink must be connected to the supply member, the nozzle plate undergoes stress deformation after the connection. Then, due to the stress deformation, a plurality of ink ejection nozzles aligned in the same direction cannot be formed, and the ejection direction of the ink varies, which causes a problem of deteriorating print quality.

In order to solve such a problem, the following method has been proposed as a method of processing and forming an ink discharge nozzle after assembling an ink jet recording head. One of them is a method proposed in Japanese Patent Publication No. Hei 6-510958, in which a light beam restricted by a mask pattern is obliquely incident on an ejection port forming plate from two directions. Due to the oblique incidence, the plate is processed in the traveling direction of the light beam, and as a result, a tapered shape having a wider processing width on the inner side than on the outer side is formed as a nozzle plate on which the discharge ports are formed. The other is a method proposed in Japanese Patent Publication No. Hei 6-24874. In this method, a light beam is irradiated in such a manner that a mask plate on which a nozzle pattern is formed is in close contact with an ink discharge port forming plate. The processing proceeds in the direction of incidence of the light beam by swinging or rotating the pivot so that the light beam is obliquely incident on the mask plate and the ink ejection port forming plate that are brought into close contact with each other. An outwardly tapered nozzle is formed.

[0006]

However, in the case of the method proposed in Japanese Patent Application Laid-Open No. 6-510958, the light beam is processed in only two directions. A tapered taper is formed on the outside of the nozzle plate, but in a direction perpendicular to this, a tapered shape with a wide mouth is formed on the outside, and a symmetric cone-shaped taper is not formed with respect to the ink ejection direction,
In the direction of the outwardly tapered shape, the ink discharge fluid resistance causes a problem that the period of the ink discharge becomes slow and high-speed printing cannot be performed. There is a disadvantage that mist sometimes occurs.

Also, in the method proposed in Japanese Patent Publication No. Hei 6-24874, the mask plate and the ink discharge port forming plate are tilted with respect to the light beam with time, so that the processing starts and ends. Depending on the state, that is, due to the aging process of the processing, it becomes difficult to process the tapered shape symmetrical with respect to the axis of the ink discharge direction, and as a result, the ink discharge becomes stable in each ink jet recording head. Is difficult to fly in a uniform direction. Conventionally,
2. Description of the Related Art A laser processing method using an ultraviolet laser is used as a laser processing method for finely processing a structure requiring a fine structure and precision. Examples of such fine processing include processing of an ink flow path and an ink discharge port of an inkjet head. JP-A-2-2-1218
No. 42 or JP-A-2-121845 describes that high-precision processing can be performed by processing ink flow paths and ink discharge ports using an excimer laser, which is a typical ultraviolet laser. Have been. That is, this excimer laser excites a mixed gas of a rare gas and a halogen gas by discharge excitation to produce a short pulse (15 to 35 ns).
These lasers can oscillate ultraviolet light having an oscillation energy of several 100 mJ / pulse and a pulse repetition frequency of 10 to 500 Hz. When high-brightness short-pulse ultraviolet light such as excimer laser light is applied to the surface of the polymer resin, the irradiated part is instantaneously decomposed and scattered with plasma emission and impact sound, and Ablative Photodecompositio
An n (APD) process occurs, which allows the so-called laser ablation of the polymer resin.

As a laser processing, a YAG laser generally used before that has a drawback that a hole is formed but an edge surface is roughened, and a CO ₂ laser which is infrared rays has a crater around the hole. Was. These laser processings are so-called laser thermal processings, and processing is performed by converting light energy into heat energy. In the laser ablation processing using an excimer laser, sublimation etching is performed by a photochemical reaction that breaks a covalent bond of a carbon atom, so that the processing shape is not easily broken and extremely high-precision processing can be performed.

Here, the laser ablation processing method means a method of performing a sublimation processing by a laser without passing through a liquid state. Particularly in the field of inkjet technology, the laser ablation processing technology using these excimer lasers has made dramatic progress with the practical use, and it is new to the present day that it has reached today.

As the laser processing technology using the excimer laser is put into practical use, the following has been found. That is, the oscillation pulse time of the irradiation laser is about several tens nanoseconds for the excimer laser, which is the above-described ultraviolet laser, and about 100 picoseconds to several nanoseconds for the harmonic oscillation ultraviolet light of the YAG laser. The irradiated laser beam does not use all its light energy to break the covalent bonds of atoms. Then, due to the light energy that is not used for breaking the covalent bonds of atoms, the laser-processed portion of the workpiece is scattered before being completely decomposed, thereby producing by-products around the processed portion. In addition, a part of light energy that is not used for breaking a covalent bond of an atom is converted into heat energy. Since the energy density of excimer laser light is only 100 megawatts at the maximum in the oscillation pulse, it is difficult to process metals, ceramics, minerals (such as silicon) with high thermal conductivity, and quartz and glass with low light absorption. Therefore, it can only be used for sublimation ablation processing of organic fat materials. Etc. are known.

[0011]

All of these are inevitable phenomena caused by the use of excimer lasers, and various re-use techniques have been proposed so that these phenomena do not affect the actual head. I have. For example, assembling an inkjet recording head with the above-mentioned by-products remaining causes clogging of the discharge port, so a step of removing the by-products is newly provided. In addition, since a part of light energy is converted into heat energy, a workpiece may thermally expand during processing or may partially melt, so a material having a high glass transition point is used. Or lowering the processing pitch. As described above, since none of the techniques can be fundamentally solved, it is a reality that various restrictions are brought about in laser processing. On the other hand, in the above-described inkjet recording head, in recent years, high definition of image quality has been demanded, and therefore, the arrangement density of the ejection ports and the ink flow paths has conventionally been sufficient even at 300 to 400 dpi. Recently, array densities up to 600 dpi and 1200 dpi have been required.

Accordingly, there is a need for a forming method for forming minute intervals or minute shapes such as arrangement intervals of a discharge port and a recording liquid flow path of 50 μm or less and a processing diameter of 20 μm or less with higher precision. However, the phenomenon seen in the above-mentioned excimer laser becomes more conspicuous as the processing interval and the processing diameter become finer, and thus, the production of the above-mentioned high-definition type head has begun to be limited. From these facts, the present inventors have recognized that all of the above-mentioned phenomena are caused by laser ablation processing using an ultraviolet laser represented by an excimer laser. Intensive research from a simple point of view shows that these phenomena can be solved fundamentally, and that laser ablation can respond to the microfabrication technology that will further advance in the future, and further improve versatility. It is a discovery of processing technology.

Further, in the conventional ink jet recording head, the shapes of the ink supply path and the ink discharge port cannot be smoothly connected, and the velocity vector of the ink operation is directed only in the flying direction. Therefore, there is a problem that the print quality is lowered. That is, the ink ejection port of the ink jet recording head adapted to the ink jet recording method forms a plate having a predetermined thickness and a truncated cone or a truncated polygonal hole having a taper angle tapered in the ink ejection direction in the plate ejection portion. The inside of the outlet hole is made hydrophilic with respect to the liquid ink, and from the edge of the hole on the ink ejection side to the periphery, it is made water-repellent to the liquid ink. The ink droplets are made to fly by applying a pressure to the liquid ink using a mechanical displacement element or a thermal foaming element, and extruding the liquid ink stored in the inkjet. Further, there has been proposed a method in which an ink liquid interface is formed by a liquid surface tension in a boundary area of hydrophilic water repellency by making water repellent up to a predetermined inside of an ink discharge port, and an ink droplet is caused to fly in the same manner as described above.

However, conventionally, in the laser processing method, it is not possible to perform three-dimensional processing of a frustum shape in which a processing cross section continuously changes from a second shape to a first shape, so that the above-described ink jet recording head is used. At
The ink supply path and the ink ejection port cannot be connected smoothly, and turbulence occurs due to the corner of the ink ejection port on the ink supply side, and as a result, there is an error in the landing accuracy of the ink liquid bullet. In addition, the mist is generated in the ink liquid bullet, so that the printing dot does not have a perfect round shape, so that the printing quality is degraded.

In the conventional ink jet recording head, since the velocity vector of the operation of the liquid ink is directed only in the flight direction, the portion of the wall surface of the discharge port nozzle which receives the fluid resistance varies in the flight direction. As a result, the error of the landing accuracy of the ink liquid bullet becomes large, and the mist is generated in the ink liquid bullet. Had the problem that In order to improve this, if the discharge port nozzle shape can be processed into a spiral shape, the liquid bullet of the liquid ink can have a rotation component around the flight direction axis with respect to the flight direction,
The liquid bullet of the liquid ink can fly stably due to the rotational inertia force and solve the above-mentioned problem. However, conventionally, in a laser processing method, for example, a laser beam is irradiated by an excimer laser or the like. By simply irradiating the workpiece, it is impossible to process a circular or elliptical cross-sectional shape or a spiral frustum shape having a bottom shape that is approximately polygonal by connecting to a polygonal shape. there were.

Further, in the conventional ink jet recording head, there is a problem that the adhesion of the ink mist accumulates at the ink discharge port, which adversely affects the ink flying. That is, in the above-described conventional ink jet recording head, when the ink droplets fly as described above, the flight direction of the main droplet of the ink droplet and the sub-droplet that flies in a manner to follow the main droplet called a satellite is: When both fly along the axis of symmetry of the ink ejection port, high-precision printing quality can be obtained, but as the number of ink ejections increases, ink mist adheres to the ink ejection port, and This will adversely affect ink flight. In order to prevent this, a wiping and cleaning means such as a wiper capable of removing ink mist attached to the ink discharge port is required. When the ink liquid interface formed on the surface on the ink discharge side is wiped using such a wiper, the ink discharge surface of the ink discharge port plays an important role in determining the direction of ink flight. There is a problem that the edge is damaged, the water-repellent film is peeled off, and the performance of the ink jet recording head is deteriorated.

Also, the ink usually flies in the form of being dissolved in an aqueous solution. However, if the ink jet recording head is left unused, water evaporates from the ink and the ink discharge port becomes blocked due to solidification of the ink. If the inkjet recording head is left for a certain period of time or longer,
An ink suction operation is performed from the ink discharge side. This operation not only involves wasteful consumption of ink, but also causes a problem that printing is not instantaneously started. This problem can be solved by placing a cap on the ink ejection port so that it does not come into contact with the atmosphere.However, when the cap is brought into close contact, bubbles tend to be mixed into the ink nozzles, In order to achieve this, it is necessary to adhere the elastic material to the ink ejection surface. For this purpose, rubber, urethane and other materials are conceivable as cap materials.However, these materials are highly degraded with respect to the alkalinity of the ink. There is a problem that the flight direction of the ink droplet changes, and it has not been realized yet.

In a method of forming an ink liquid interface by liquid surface tension in a boundary area of hydrophilic water repellency by making water repellent up to a predetermined inside of the ink discharge port and causing ink droplets to fly in the same manner as described above, the ink discharge method It is technically possible to prevent the ink discharge port from being clogged by drying and solidifying the ink by capping the outlet so as not to come into contact with the ink. However, with respect to the flight direction of the ink droplet, the flight direction of the ink droplet flies along the axis of symmetry of the ink discharge port. The ink is pulled to the position where the van der Waals force is exerted the most in accordance with the flying state in the portion of the discharge port where the water repellent film is attached, and the flying direction of the satellite droplet is changed by pulling the ink. There is a problem that the droplet and the satellite sub-droplet do not land at the same position. In addition, since this problem is affected by a very delicate balance of the ink adhesive force on the water-repellent surface inside the ink ejection port, it is difficult to control and the flying direction of the satellite droplet every time the ink is ejected. Will randomly change, and as the print quality, the print density will be unstable, and it will also generate noise such as image roughness,
It is not yet at a practical level.

Therefore, if the conical portion spreading on the irradiation side of the laser beam and the conical portion expanding on the opposite side can be processed into a shape in which the axes of symmetry are connected in common, the ink ejection can be performed. By forming an ink liquid interface by the liquid surface tension of the ink inside the outlet, the ink discharge port is capped so as not to come into contact with the ink to prevent clogging of the ink discharge port due to drying and solidification of the ink. In addition, it is possible to form a discontinuous surface boundary at a boundary between a region extending toward the ink supply side, which is an ink hydrophilic region, and a region extending toward the ink ejection side, which is an ink water repellent region. Drops droplets at the discontinuous surface boundary position, and always makes the flying directions of the main ink droplets and satellite droplets fly along the axis of symmetry of the ink ejection port, thereby achieving high-precision marking. It is possible to solve the above-mentioned problems, but conventionally, in a laser processing method, for example, depending on an excimer laser or the like, only irradiating a laser beam to a workpiece, the above-described shape can be obtained. It was impossible at all.

In view of the above, the present invention solves the above-mentioned problems in the prior art, and has a shape symmetrical with respect to the ink discharge direction axis by laser processing from the outside of the ink discharge port forming plate (from the ink discharge side). Therefore, the entire outer side can form a tapered shape that is tapered, and it is possible to cope with high definition, there is no generation of by-products, and the heat energy converted during laser processing is reduced to resin or the like. An object of the present invention is to provide a method of manufacturing an ink jet recording head that can fundamentally prevent accumulation on a workpiece, an ink jet recording head manufactured by the manufacturing method, and a laser processing method. Further, according to the present invention, it is possible to perform a three-dimensional processing of a frustum shape in which a processing cross section continuously changes from a second shape to a first shape, or to connect a predetermined cross-sectional shape to substantially multiple shapes. Manufacture of an ink jet recording head capable of processing a spiral frustum shape having a square bottom shape, or capable of processing a spiral frustum shape having a predetermined shape by being connected to a substantially polygonal cross-sectional shape It is an object of the present invention to provide a method, an inkjet recording head manufactured by the manufacturing method, and a laser processing method. Further, according to the present invention, it is possible to process the cone-shaped portion expanding on the irradiation side of the laser beam and the cone-shaped portion expanding on the opposite side into a shape in which the symmetry axes are connected to each other, thereby drying the ink. It can be configured so as to prevent clogging of the ink ejection port due to solidification, and also to always fly the flying direction of the main droplet of the ink droplet and the satellite droplet along the symmetry axis of the ink ejection port, An object of the present invention is to provide a method of manufacturing an ink jet recording head that can be configured to perform high-precision printing, an ink jet recording head manufactured by the manufacturing method, and a laser processing method.

[0021]

In order to achieve the above object, the present invention provides a method of manufacturing an ink jet recording head constituted as described in the following (1) to (66), and an ink jet recording head manufactured by the method. A head and a laser processing method are provided. (1) an ink discharge port for discharging ink droplets to be attached to a recording medium, a liquid chamber for storing ink to be supplied to the discharge port, an ink flow path communicating the discharge port with the liquid chamber, An ink-jet device in which an energy generating element provided in a part of an ink flow path for generating energy for discharging ink, an ink supply port for supplying ink from outside to the liquid chamber, and the like are formed by joining or bonding plate materials. In the method of manufacturing a recording head, when laser processing an orifice plate in which the ink discharge port is formed, a spatial and temporal radiation emitted from a laser oscillator oscillating at a pulse emission time of 1 picosecond or less as the laser light is used. An orifice sprayer using a plurality of pulses of a laser beam having a very high energy density and being opposite to the side on which the ink is supplied; Of the laser beam is irradiated from the outer surface side, a manufacturing method of an ink jet recording head, characterized in that machining by the machining pattern of the ink discharge port on the outer surface of the orifice plate to focus projection. (2) The plurality of ink discharge ports are simultaneously formed at a predetermined interval by irradiating a laser beam through a mask having a plurality of opening patterns formed at a predetermined pitch. 3. The method for manufacturing an ink jet recording head according to item 1. (3) Inkjet that forms an ink jet recording head by a laser processing method, in which a pressure generation source is brought into contact with ink and energy is applied to transmit pressure to an ink ejection port to eject ink droplets and attach the ink droplets to a recording medium. In the method of manufacturing a recording head, when laser processing an orifice plate in which the ink discharge port is formed, a spatial and temporal radiation emitted from a laser oscillator oscillating at a pulse emission time of 1 picosecond or less as the laser light is used. Very large energy density, using a plurality of pulses of laser light, a laser beam emitted from the laser oscillator, a predetermined energy density, under a predetermined numerical aperture, the beam cross-sectional shape at a non-focus point of the laser beam A first shape, and a mask pattern having a second shape different from the first shape. Then, by irradiating the orifice plate at the projection focus point of the mask pattern, performing a three-dimensional processing of a frustum shape in which a processing cross section continuously changes from the second shape to the first shape. A method for manufacturing an ink jet recording head, comprising: (4) The first shape of the beam cross-sectional shape at the non-focus point of the laser beam is a substantially polygonal shape, and the second shape different from the first shape in the mask pattern is a circular or elliptical shape. The ink jet recording head according to (3), wherein the cross-sectional shape on the ink ejection surface side is processed into a circular or elliptical shape, and the cross-sectional shape on the ink supply side is processed into a frustum shape that is a substantially polygonal shape. Production method. (5) The method according to (4), wherein the substantially polygonal shape of the first shape is formed by forming a pupil image pattern of the projection lens into a polygonal shape. . (6) The method for manufacturing an ink jet recording head according to (4), wherein the substantially polygonal shape of the first shape is formed by forming a diaphragm pattern of the projection lens into a polygonal shape. (7) The ink jet recording according to any one of (3) to (6), wherein the cross-sectional shape of the ink supply side is formed in a substantially polygonal shape that is substantially smoothly connected to an ink supply path. Head manufacturing method. (8) The beam sectional shape is a polygonal shape, and the second
By irradiating the beam cross-sectional shape to the orifice plate while rotating the beam cross-sectional shape around the optical axis at a projection focus point of the mask pattern, the nozzle cross-sectional shape is changed from the second shape to the second shape. The method of manufacturing an ink jet recording head according to the above (3), wherein a three-dimensional processing of a spiral frustum shape that continuously changes in a spiral shape is performed while increasing a cross-sectional area to a polygonal shape. (9) The method of manufacturing an ink jet recording head according to (8), wherein the spiral frustum shape is gradually twisted smoothly and the continuous bottom shape is processed into a substantially polygonal spiral frustum shape. Method. (10) The spiral frustum shape forms a polygonal shape of a beam cross-sectional shape at a non-focus point of the laser beam by making a pupil image pattern of the projection lens a polygonal shape, and covers the pupil image pattern. The method for manufacturing an ink jet recording head according to the above (8) or (9), wherein the workpiece is rotated around the optical axis in association with the processing progress of the workpiece to be processed. (11) The spiral frustum shape is formed by forming a polygonal shape of a beam cross-sectional shape at a non-focus point of the laser beam by making a diaphragm pattern of a projection lens a polygonal shape, and forming the diaphragm pattern on a workpiece. The method for manufacturing an ink jet recording head according to the above (9) or (10), wherein the rotation is performed around the optical axis in association with the progress of the processing. (12) The focus point is set on a surface side of the orifice plate facing the irradiation side of the laser beam, or at a position away from a surface side of the orifice plate facing the irradiation side of the laser beam, (3) to (1), wherein the three-dimensional processing of the frustum shape is performed.
The method of manufacturing an ink jet recording head according to any one of 1). (13) In any one of the above (3) to (12), a water-repellent film is formed in an ink ejection port of the ink jet recording head in a region near the ink ejection port and near the ink ejection port. 3. The method for manufacturing an ink jet recording head according to item 1. (14) Ink jet forming a laser processing method to form an ink jet recording head for ejecting ink droplets and attaching the ink droplets to a recording medium by transmitting a pressure to an ink ejection port by contacting a pressure generation source with the ink to apply energy. In the method of manufacturing a recording head, when laser processing an orifice plate in which the ink discharge port is formed, a spatial and temporal radiation emitted from a laser oscillator oscillating at a pulse emission time of 1 picosecond or less as the laser light is used. Very large energy density, using a plurality of pulses of laser light, a laser beam emitted from the laser oscillator, a predetermined energy density, under a predetermined numerical aperture, a predetermined pattern image, at a predetermined focus point, By irradiating the orifice plate, a cone-shaped portion that spreads to the ink ejection side When manufacturing method for an ink jet recording head, characterized in that processing the cone-shaped portion extending to the ink supply side, the shape of connecting the symmetry axis in common. (15) The conical portion spreading on the ink discharge side is processed by setting the focus point at a position deeper than the ink discharge side surface of the orifice plate, and the conical portion expanding on the ink supply side is (14) The method according to the above (14), wherein after the processing of the conical portion spreading to the ink discharge side, the focus point is set at a portion connecting the symmetry axis in common.
3. The method for manufacturing an ink jet recording head according to item 1. (16) The above-mentioned (1), wherein the expansion of the conical portion spreading to the ink discharge side is processed into a conical portion larger than the expansion of the conical portion spreading to the ink supply side.
4) or the method for manufacturing an ink jet recording head according to the above (15). (17) The method for manufacturing an ink jet recording head according to any one of the above (14) to (16), wherein the ink discharge ports are formed of a hydrophilic material. (18) A water-repellent film is formed on the surface of the conical portion spreading on the ink ejection side and on the ink ejection port side and in the vicinity of the ink ejection port.
(17) The method for manufacturing an inkjet recording head according to any one of (17) and (22). (19) The water-repellent film is formed on the ink discharge side after processing and forming the conical portion spreading on the ink discharge side, and thereafter the conical portion spreading on the ink supply side is formed and processed. (18) The method for manufacturing an ink jet recording head according to (18). (20) The method of manufacturing an ink jet recording head according to any one of (14) to (19), wherein the conical portion of the ink discharge port is processed into a conical portion. (21) The above (14) to (19), wherein the cone-shaped portion of the ink discharge port is processed into a polygonal cone-shaped portion.
The method for manufacturing an ink jet recording head according to any one of the above. (22) The method of manufacturing an ink jet recording head according to (21), wherein the polygonal pyramid-shaped portion is processed by setting a beam cross-sectional shape of a laser beam to a polygonal shape. (23) The method of manufacturing an ink jet recording head according to (22), wherein the polygonal shape of the beam cross-sectional shape of the laser beam is formed by making the pupil image pattern of the projection lens into a polygonal shape. Method. (24) The method for manufacturing an ink jet recording head according to (22), wherein the polygonal shape of the beam cross-sectional shape of the laser beam is formed by making the aperture pattern of the projection lens a polygonal shape. . (25) The above (14) to (14) to (14), wherein the conical portion of the ink discharge port is processed into a spiral conical portion.
(19) The method for manufacturing an ink jet recording head according to any one of (19) and (22). (26) The inkjet according to (25), wherein the spiral cone portion is processed by irradiating a workpiece while rotating a beam cross-sectional shape of the laser beam around an optical axis. Manufacturing method of recording head. (27) The conical portion of the ink ejection port has a conical portion,
Alternatively, the method of manufacturing an ink jet recording head according to any one of the above (16) to (19), wherein the processing is performed in combination with any one of a polygonal pyramid-shaped part and a spiral pyramid-shaped part. (28) The method for manufacturing an ink jet recording head according to any one of the above (1) to (27), wherein the member forming the discharge port is a resin. (29) The member forming the discharge port is Si or Si
(1) to (2), comprising a compound material.
7) The method for manufacturing an ink jet recording head according to any one of the above items. (30) The method for manufacturing an ink jet recording head according to any one of (1) to (27), wherein the wavelength of the laser light is in a range of 350 to 1000 nm. (31) The pulse emission time of the laser light is 500 femtoseconds or less.
The method for manufacturing an ink jet recording head according to any one of the above. (32) As for the energy density of the laser beam, a represents the absorptivity of the material to be processed with respect to the irradiation laser wavelength, n represents the numerical aperture on the workpiece side of the optical system for projecting a processing pattern on the workpiece, and n represents the workpiece. The energy per unit area of a laser beam applied to a material and the unit energy per unit oscillation pulse time are E (unit [J / cm ² / pulse]), and the oscillation pulse time width of the laser is t (unit [sec]). , (A × nxE) / t> 13 × 10 ⁶ [W / cm ² ].
The method of manufacturing an ink jet recording head according to any one of 1). (33) The method for manufacturing an ink jet recording head according to any one of (1) to (32), wherein the laser oscillator is a laser oscillator having a spatial compression device for light propagation. (34) The ink jet recording head according to the above (33), wherein the spatial compression device for light propagation is constituted by a chirping pulse generating means and a longitudinal mode synchronizing means utilizing light wavelength dispersion characteristics. Manufacturing method. (35) an ink discharge port for discharging ink droplets to be attached to a recording medium, a liquid chamber for storing ink to be supplied to the discharge port, an ink flow path communicating between the discharge port and the liquid chamber, An energy generating element that is provided in a part of the ink flow path and generates energy for discharging ink;
In an ink jet recording head in which an ink supply port or the like for supplying ink from outside to the liquid chamber is formed by joining or bonding plate materials, the ink ejection port of the ink jet recording head has a pulse emission time of 1 picosecond or less. The laser light radiated from the outer surface of the orifice plate, which is opposite to the side on which the ink is supplied, is irradiated with a plurality of pulses of laser light having a very large spatial and temporal energy density emitted from a laser oscillator that oscillates. An ink jet recording head, wherein a cross-sectional shape processed by focusing and projecting a processing pattern of an ink discharge port on an outer surface of the orifice plate has a tapered cross-sectional shape in a direction toward the outer surface of the orifice plate. (36) The ink jet recording head according to (35), wherein a plurality of the ink ejection ports are formed at a predetermined interval. (37) In an ink jet recording head for causing a pressure generation source to come into contact with ink and applying energy to transmit pressure to an ink ejection port to eject ink droplets and attach the ink droplets to a recording medium, A laser beam emitted from a laser oscillator by a plurality of pulses of laser light having a very large spatial and temporal energy density emitted from a laser oscillator whose emission port oscillates with a pulse emission time of 1 picosecond or less. At a predetermined energy density and a predetermined numerical aperture.
From the second shape, processed by irradiating an orifice plate at a projection focus point of the mask pattern through a mask pattern of a second shape different from the first shape. An ink jet recording head having a frustum-shaped cross-sectional shape that continuously changes to a first shape. (38) The ink ejection port of the ink jet recording head has a circular or elliptical cross section on the ink ejection surface side, and a substantially polygonal cross section on the ink supply side. 3. The ink jet recording head according to item 1. (39) The ink jet recording head according to the above (38), wherein the cross-sectional shape on the ink supply side is formed in a substantially polygonal shape that is connected substantially smoothly to an ink supply path. (40) The ink discharge port of the ink jet recording head has a circular or elliptical or polygonal cross section on the ink discharge surface side, and a substantially polygonal cross section on the ink supply side. (37) characterized by having a spiral frustum shape that is smoothly twisted and continuous.
3. The ink jet recording head according to item 1. (41) The ink jet recording head according to (40), wherein the spiral frustum shape is gradually and smoothly twisted and a continuous bottom shape is a substantially polygonal spiral frustum shape. (42) The method according to any of (37) to (41), wherein a water-repellent film is formed in a region near the ink discharge port on the ink discharge side of the ink discharge port of the inkjet recording head. The inkjet recording head according to any one of the above. (43) In an ink jet recording head, a pressure generating source is brought into contact with ink to apply pressure energy, whereby pressure is transmitted to an ink ejection port to eject ink droplets and adhere to a recording medium. An ink jet recording head, wherein an ink discharge port has a cross-sectional shape in which a symmetrical axis is commonly connected to a conical portion expanding on an ink discharge side and a conical portion expanding on an ink supply side. (44) The ink jet recording head according to the above (43), wherein the cone-shaped portion expanding toward the ink ejection side is larger than the cone-shaped portion expanding toward the ink supply side. (45) The ink jet recording head according to the above (43) or (44), wherein the ink ejection port is made of a hydrophilic material. (46) A water-repellent film is provided on the surface of the conical portion spreading on the ink discharge side and on the ink discharge port side and in the vicinity of the ink discharge port.
3) The ink jet recording head according to any one of (45) to (45). (47) The water-repellent film is formed by processing and forming a conical portion spreading on the ink discharge side, coating the ink discharge side, and thereafter processing and forming a conical portion spreading on the ink supply side. An ink jet recording head according to the above (46). (48) The inkjet recording head according to any one of (43) to (47), wherein the conical portion of the ink ejection port is a conical portion. (49) The ink jet recording head according to any one of (43) to (47), wherein the cone-shaped portion of the ink ejection port is a polygonal cone-shaped portion. (50) The above (43) to (47), wherein the conical portion of the ink discharge port is a spiral conical portion.
The inkjet recording head according to any one of the above. (51) The conical portion of the ink ejection port has a conical portion,
Alternatively, the inkjet recording head according to any one of the above (43) to (47), comprising a combination with any one of a polygonal pyramid-shaped part and a spiral pyramid-shaped part. (52) In a laser processing method for performing laser ablation processing on a workpiece by irradiating the workpiece with laser light, a laser oscillator is used as the laser light when forming a through hole or the like in the workpiece by ablation processing. Using a laser light of a plurality of pulses, which has a very large spatial and temporal energy density emitted from a laser oscillator oscillating at a pulse emission time of 1 picosecond or less,
A laser beam is irradiated from the outer surface side of the workpiece on which the laser ablation processing such as the through hole is performed, and a processing pattern such as a through hole is focused and projected on the outer surface of the workpiece to perform processing. Laser processing method. (53) The plurality of through holes and the like are simultaneously formed at a predetermined interval by irradiating a laser beam through a mask having a plurality of opening patterns formed at a predetermined pitch. 2. The laser processing method according to 1. above. (54) Laser processing for performing optical ablation processing by irradiating a workpiece with a laser beam from a laser oscillator that continuously emits a light pulse having a large spatial and temporal energy density at a pulse emission time of 1 picosecond or less. A method, comprising: forming a laser beam emitted from the laser oscillator under a predetermined energy density and a predetermined numerical aperture into a first beam shape at a non-focus point of the laser beam; By irradiating the workpiece at the projection focus point of the predetermined mask pattern through the mask pattern of the second shape different from the shape, the processed cross section is continuously changed from the second shape to the first shape. A three-dimensional machining of a frustum shape that changes gradually. (55) The first shape of the beam cross-sectional shape at the non-focus point of the laser beam is formed by making a pupil image pattern of a projection lens into a polygonal shape. Laser processing method. (56) The laser according to the above (54), wherein the first shape of the beam cross-sectional shape of the laser beam at the non-focus point is formed by making the aperture pattern of the projection lens a polygonal shape. Processing method. (57) The beam cross-sectional shape is made to be a polygonal shape, and the beam cross-sectional shape is rotated around the optical axis at the projection focus point of the mask pattern via the mask pattern having the second shape. By irradiating, the cross-sectional shape of the workpiece increases the cross-sectional area from the predetermined shape to the polygonal shape, and performs three-dimensional processing of a spiral frustum that continuously changes in a spiral shape. The laser processing method according to the above (54). (58) The laser processing method according to the above (57), wherein the spiral frustum shape is gradually and smoothly twisted and a continuous bottom shape is machined as a substantially polygonal spiral frustum shape. (59) The spiral frustum shape forms a polygonal shape of a beam cross-sectional shape at a non-focus point of the laser beam by making a pupil image pattern of the projection lens a polygonal shape, and covers the pupil image pattern. The laser processing method according to the above (57) or (58), wherein the workpiece is rotated around the optical axis in association with the processing progress of the workpiece to be processed. (60) The spiral frustum shape is formed by forming a polygonal shape of a beam cross section at a non-focus point of the laser beam by making a diaphragm pattern of a projection lens into a polygonal shape, and forming the diaphragm pattern on a workpiece. The laser processing method according to the above (57) or (58), wherein the laser processing is performed by rotating about the optical axis in association with the processing progress of (1). (61) The focus point is set to a surface side of the workpiece directed to the irradiation side of the laser beam or a position away from a surface side of the workpiece directed to the irradiation side of the laser beam. The laser processing method according to any one of the above (52) to (60), wherein three-dimensional processing of the frustum shape is performed. (62) The above (54) to (61), wherein the wavelength of the laser light is within a range of 350 to 1000 nm.
The laser processing method according to any one of the above. (63) The pulse emission time of the laser light is 500 femtoseconds or less.
The laser processing method according to any one of 2). (64) The above-mentioned (52) to (6), wherein the workpiece is a resin, Si or a Si compound material.
The laser processing method according to any one of 3). (65) The laser processing method according to any one of (52) to (64), wherein the laser oscillator is a laser oscillator having a spatial compression device for light propagation. (66) The laser processing method according to the above (65), wherein the spatial compression device for light propagation is constituted by a chirping pulse generation unit and a longitudinal mode synchronization unit using optical wavelength dispersion characteristics. .

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the above configuration of the present invention, a plurality of pulses having a very large spatial and temporal energy density emitted from a laser oscillator which oscillates with a pulse emission time of 1 picosecond or less as a laser beam. Laser light is used, and this laser is called “Next Generation Optical Technology Integration”
(Issued by Optronics Co., Ltd. in 1992, Part 1 Elemental Technology; Generation and Compression of Ultrashort Optical Pulses, pp. 24 to 31) and so-called femtosecond lasers. Some commercially available femtosecond lasers have a pulse emission time of 150 femtoseconds or less and a light energy of 500 microjoules per pulse. According to this, the energy density of the emitted laser light reaches a level of about 3 GW in the oscillation pulse.

According to the present invention, by using such a femtosecond laser as described above, the light wavelength of the laser emitted at a pulse oscillation time of 1 picosecond or less is not necessarily ultraviolet. If it is a wavelength that the workpiece absorbs light, visible light and infrared light may be used, and since the temporal light energy density is very large, if this is used, the material is sublimated in a short time, so that it does not pass through the liquid phase. Ablation processing can be performed. The numerical aperture (N
A) The bright projection lens of A) can be used, and the material used for the orifice plate, which is the workpiece, is not limited to the resin material, and is irradiated with light even if the material has a high heat conduction efficiency such as a ceramic material or a metal material. Since the working process ends before the thermal diffusion proceeds from the point in time, it is possible to perform ablation working without going through the liquid phase state. Furthermore, even if the material has high light transmission efficiency (transmittance) such as quartz, optical crystal, or glass material, the ablation process can be performed even if the light absorptance is slight due to the high temporal concentration of energy. Can be awakened. That is, the processing material is not limited to resin materials such as polyimide and polysulfone, which have been generally used for the structure of the ink discharge ports or ink flow paths or ink liquid chambers or ink supply ports of the inkjet, and inorganic materials. Since the laser ablation process can be performed on a glass material, a metal material, and even a semiconductor material, the structure of the ink ejection port member can have a high degree of freedom in material selection. Thus, a high heat treatment or the like can be performed for the water-repellent treatment of the surface of the ink discharge port.

Further, if a material having a small thermal expansion is used, it is possible to prevent a displacement of the joining surface of each member due to a shearing force, and it is also possible to form an ink jet made of such a material having a small thermal expansion. Since the recording head and the like can be prevented from being deformed due to heat even when transported by sea mail passing immediately below the equator, it is possible to reduce distribution costs. In addition, if a ceramic material or a glass material is used, an ink jet recording head having excellent durability and storability that does not corrode even against strongly alkaline ink can be manufactured.

In one embodiment of the present invention, by applying the above configuration using such a femtosecond laser, a laser beam is irradiated from the surface side of the orifice plate to form a tapered tapered shape. Can be formed. This makes it possible to form the ink ejection ports in the final step after assembling the ink jet recording head, and eliminates the problem regarding the non-uniformity of the direction of the ink ejection nozzle due to the deformation due to the conventional orifice plate assembly and coupling. In addition, by irradiating a laser beam from the surface side of the orifice plate to form a taper shape that is partially or entirely tapered, the ejection direction of ink droplets is stabilized in a certain direction, and the ink flow is Since the fluid resistance is reduced and the flow velocity is improved, the ink ejection frequency is increased at the same driving source, and the flying speed of the ejected ink can be improved.
The print quality can be remarkably improved, and at the same time, high-speed printing can be performed.

Further, in another embodiment of the present invention, by applying the above configuration using such a femtosecond laser, for example, the ink discharge port can be made to have a circular or circular cross section on the ink discharge surface side. It can be processed into a truncated frustum shape which is an elliptical shape and a substantially polygonal shape whose cross-sectional shape on the ink supply side is substantially smoothly connected to the ink supply path. This improves the shape continuity between the ink supply path and the ink discharge port, thereby enabling the liquid ink to fly in a substantially flowing state, and to allow the liquid bullet to fly in a stable manner. This makes it possible to reduce the variation in the landing position on the printing target body and perform the landing with high accuracy. Further, this makes it possible to reduce the generation of mist. Further, for example, a spiral frustum shape having a bottom shape whose nozzle cross-section is substantially polygonal can be laser-processed, and the liquid bullet of the liquid ink has a rotational component around the flight direction axis with respect to the flight direction. This makes it possible to stably advance and fly the liquid bullets of the liquid ink by the rotational inertia force, thereby making it possible to reduce the dispersion of the landing positions on the printing target body and to carry out the landing accurately. Furthermore, this can also reduce the generation of mist.

Further, in still another embodiment of the present invention, by applying the above-described configuration using such a femtosecond laser, for example, the ink discharge port of the ink jet recording head can be placed on the irradiation side of the laser beam. It is possible to process the conical portion that spreads out and the conical portion that spreads out on the opposite side into a shape in which the rotationally symmetric axes are commonly connected.
As a result, by forming an ink liquid interface inside the ink ejection port by the liquid surface tension of the ink, the ink ejection port is capped so as not to come into contact with the ink, thereby preventing clogging of the ink ejection port due to drying and solidification of the ink. On the other hand, by forming a discontinuous surface boundary at a boundary between a region extending toward the ink supply side, which is an ink hydrophilic region, and a region extending toward the ink ejection side, which is an ink water-repellent region, ink flying droplets can be formed. Can be separated at the boundary of the discontinuous surface, so that the flying directions of the main droplet and the satellite droplet of the ink droplet both fly along the axis of symmetry of the ink ejection port. Accurate print quality can be obtained. Further, according to the above configuration, the area that spreads toward the ink discharge side has a shape that spreads at a predetermined angle to the ink discharge side surface side of the member that forms the ink discharge port. Because it has no corners, even if the ink mist adheres to the area spreading on the ink ejection side, it accumulates and grows in the corners and contacts the ink liquid interface, hindering ink droplet flight. Nothing. Further, the ink mist adhering to the area spreading on the ink ejection side differs depending on the installation direction of the ink jet recording head. However, if the ink ejection side is oriented in the direction of the gravitational vector, the ink ejection side surface of the member forming the ink ejection port is damaged. Flow and disappear. If the ink ejection side faces in the direction opposite to the direction of the gravitational vector, the ink flows toward the ink liquid interface side in a fine mist state and is absorbed.
In this case, with respect to the flight of the ink droplets, since the attached ink is a very small amount of mist, the harmful effect is very small. Therefore, in a region extending to the ink ejection side, since there is no corner portion that is not continuous with the ink liquid interface, a state in which ink contamination does not always occur is maintained. This makes it possible to improve the reliability and durability of the inkjet recording head without deteriorating the print quality of the inkjet recording head. In addition, by making the area that spreads toward the ink supply side into a spiral shape, the liquid bullet of the liquid ink can have a rotation component around the axis in the flight direction with respect to the flight direction.
The liquid bullet of the liquid ink flies stably due to the rotational inertia force, and the position where it lands on the printing object is less scattered.
It is possible to fly with high accuracy.

[0028]

Embodiments of the present invention will be described below. Embodiment 1 FIG. 1 is a schematic optical path diagram of a mask pattern projection optical system of a laser processing apparatus using a femtosecond laser according to Embodiment 1 of the present invention. In FIG. 1, a light beam 101 oscillated from a short-pulse oscillation laser main body (not shown) is guided to an optical integrator 110 such as a fly eye to divide an incident laser light beam into a plurality of light beams. Illuminates the mask by correcting the illumination intensity of the superposed laser substantially uniformly. The field lens 111 is a fly-eye lens 110
Thus, a point image focused on a plurality of points is projected on the position of the stop 112 of the mask pattern projection lens 113 to form a Koehler illumination system. The laser beam is illuminated on the mask 1 by such an optical system, and the mask pattern formed on the mask 1 is projected by the projection imaging lens 113 onto the orifice plate 2 of the inkjet recording head 3 which is the workpiece.
Is focused and projected on the surface of the substrate, and the ink ejection port is processed by laser oscillation.

That is, as shown in FIG. 2, a polysulfone is used for the orifice plate, and the light absorption at a laser oscillation wavelength of 775 nm is as low as about 2%. Because the mask image is focused and projected on the surface position, the NA of the projection lens is bright and the mask image is projected at NA = 0.3, and the energy density of the irradiation laser is very high and the laser oscillation pulse The time is 150 femtoseconds, the laser oscillation energy per pulse is 800 μJ, and the laser irradiation of the orifice plate is performed by projecting and irradiating the mask with 1 mJ / cm ² / pulse per unit area per unit area irradiated on the orifice plate. The absorptivity for the wavelength is a, the optics that projects the processing pattern on the orifice plate Of a workpiece-side NA (numerical aperture) n,
The energy per unit area and unit oscillation pulse of the laser beam irradiating the orifice plate as the workpiece
(Unit [J / cm ² / pulse]), and assuming that the oscillation pulse time width of the laser is t (unit [sec / pulse]), (a × nxE) / t> 13 × 10 ⁶ [W / cm ^2] ] On the left side is (0.02 × 0.3 × 0.00
1) / (150 × 10 ^{( −15)} = 40 × 10 ⁶ [W / cm
² ], the orifice plate, which is a workpiece, is processed substantially in the traveling direction of the laser, and as shown in FIG. 2, the tapered ink ejection port is tapered outside the orifice plate. Can be formed.

[Embodiment 2] FIG. 3 is a schematic view of an ink discharge port according to Embodiment 2 of the present invention. In FIG.
The ink discharge port 200 formed within the thickness of the orifice plate 201 has a circular shape on the ink discharge side surface of the orifice plate 201 and a rectangular shape on the ink supply path 203 side to which ink is supplied. In the ink jet recording head of the surface discharge type according to the present embodiment, the ink discharge port 200 located above the ink discharge pressure generating element is connected to the ink supply path forming member 20.
7, the ink supply path 203 is formed so as to be connected to the wall of the ink supply passage 203 so that the wall through which the ink flows smoothly is connected.

Next, the outline of the ink discharge operation of the ink jet recording head of this embodiment will be described with reference to FIGS. First, as shown in FIG. 4 (a), the above-described ink ejection side 200 of the orifice plate 201 is formed in a circular shape on the ink ejection side surface and a square shape on the opposite surface. The orifice plate 201 is filled with ink into an ink jet recording head (not shown) so that the orifice plate 2
01 and the ink 204 is disposed. This ink 20
The orifice plate 4 is filled with a water-repellent film (not shown) by being filled with a hydrophilic ink supply path forming member 207 and a side surface of the ink discharge port 200 of the orifice plate 201 because of being present as an aqueous solution. 20
No. 1 is in a state where it is not adsorbed by the water repellent action on the ink ejection side surface.

Next, as shown in FIG. 4B, the ink 204 is released into the atmosphere by the pressure (the pressure indicated by the arrow in the figure) generated from the ink discharge pressure generating element disposed in the ink jet recording head (not shown). Pushed out to the side. At this time,
In the configuration of the present embodiment, since the wall surface of the ink supply path forming member 207 and the side surface of the ink discharge port 200 are gently connected, turbulence does not easily occur when the ink flows, Extruded. Next, FIG.
As shown in (c), the extruded ink 204 undergoes extrusion growth, and starts to deform into a sphere due to the surface energy of the ink 204 because the energy is minimized.

Next, as shown in FIG. 5D, the pressure generated from the ink ejection pressure generating element arranged in the ink jet recording head (not shown) is stopped, and the ink 204 flies due to its inertia. While the spherical deformation progresses. Next, as shown in FIG. 5E, the ink 204 is separated into the main droplet 250 and the satellite droplet 251 by the balance between the length of the ink and the surface tension at the time of the spherical deformation.
At the same time, the ink is cut symmetrically at the ink ejection side edge of the orifice plate 201, which is the boundary between hydrophilicity and water repellency, and the ink jet recording head is separated from the ink droplets. Next, FIG.
The main droplet 250 and the satellite droplet 251 of the separated ink droplets fly in the same direction (the direction of the arrow in the drawing) which is the axial direction of the ink discharge port as shown in FIG.

Next, a method for forming an ink ejection port having a circular cross section on the ink ejection side surface of the orifice plate having the configuration of the present embodiment and a quadrangular frustum on the opposite surface is described. Will be described with reference to the drawings. FIG. 6 is an optical schematic diagram of a laser processing apparatus for processing and forming the ink discharge ports of the present embodiment. A laser beam 202 emitted from a short-pulse oscillation laser body (not shown) in the direction indicated by the bold line in FIG. 6 is guided to a zoom beam compressor 210, converted into a predetermined light beam diameter, guided to a mask illumination lens 211, and subjected to a predetermined convergence angle. Is formed, and a part of the mask pattern portion 215 of the mask 214 in FIG. 7 is illuminated. At this time, the effective NA (numerical aperture) for finally processing the workpiece is determined by the compression ratio of the zoom beam compressor 210 and the focal length of the mask illumination lens 211. The taper angle of the workpiece is determined by the NA. Conversely, the compression ratio of the zoom beam compressor 210 and the focal length of the mask illumination lens 211 are determined or adjusted according to the processing shape of the workpiece. .

Next, the laser beam that has passed through the mask pattern 215 of the mask 214 shown in FIG. 7 passes through the square pattern of the opening 216 of the light beam stop 212 shown in FIG. The laser beam is converted into a beam, and the pattern image is irradiated by focus projection onto the surface of the orifice plate 201 of the inkjet recording head 3 which is the workpiece by the projection lens 213, and the ink ejection port is processed by laser oscillation. By setting the beam cross-sectional shape of this laser beam to a square and the mask pattern to a circular shape, the shape can be processed into a circular shape at the focus point and a substantially square shape at the non-focus point. That is, this focus point is
Processing a frustum shape having a cross-sectional shape extending from the ink discharge side, which is a substantially square shape, connected to a circular cross-sectional shape to the ink supply side by setting the surface side of the workpiece to be irradiated with the laser beam. Can be. Also, in the case of processing the orifice plate alone and processing from the ink supply side, if this focus point is set to the surface position of the ink discharge side on the back surface of the orifice plate, the ink supply side which is a substantially square shape It becomes possible to process a frustum shape having a narrowed cross-sectional shape.

Further, even if the stop 212 is not disposed near the projection lens 213 as described above, the Koehler illumination optical system can be used to distribute the light beam stop or the light image at different positions in the laser light path. Then, the same processing can be performed by projecting a pupil image onto the projection lens and forming the pupil image of the projection lens 213 into a square or an arbitrary shape. Simultaneously with the irradiation of the laser beam, the mask 214
The inkjet recording head main body 3 including the orifice plate 201 as a workpiece and the workpiece is simultaneously synchronized by a mechanical stage (not shown) in a direction perpendicular to a predetermined optical axis at a predetermined speed and in a direction indicated by a thin arrow in FIG. Or the reciprocating movement in the directions of the thin arrow and the dotted arrow, the entire mask pattern 215 is processed.

[Embodiment 3] FIG. 9 is a schematic view of an ink discharge port according to Embodiment 3 of the present invention. In the figure,
The ink ejection port 300 formed within the thickness of the orifice plate 301 has a circular shape on the ink ejection side surface of the orifice plate 301 and has a square shape on the ink supply path 303 side where ink is supplied, In addition, the shape is a spiral frustum shape that is twisted gradually and smoothly. In the surface-ejection type ink jet recording head according to the present embodiment, the ink ejection port 300 located above the ink ejection pressure generating element is gentle with respect to the wall surface in the ink supply path 303 formed in the ink supply path forming member 307. It is arranged so that the wall through which ink flows is connected.

Next, the outline of the ink discharging operation of the ink jet recording head of the present invention will be described with reference to FIGS. First, as shown in FIG. 10 (a), the above-described ink discharge side 300 of the orifice plate 301 is formed in a circular shape on the ink discharge side surface and a square shape on the opposite surface. The ink 304 is arranged in contact with the orifice plate 301 by filling the orifice plate 301 with ink in an ink jet recording head (not shown). Since the ink 304 exists as an aqueous solution, the side of the ink ejection port 300 of the hydrophilic orifice plate 301 is filled with capillary force by the capillary force, and the ink ejection side of the orifice plate 301 provided with a water-repellent film (not shown). The surface does not adsorb due to water repellency.

Next, as shown in FIG. 10B, the ink 304 is moved to the atmosphere side by the pressure (the pressure indicated by the arrow in the drawing) generated from the ink discharge pressure generating element arranged in the ink jet recording head (not shown). Extruded. At this time, since the ink ejection port 300 has a spiral shape, the ink receives fluid resistance along the helix pattern, so that when the ink flows, a rotational force with the ink ejection direction as a rotation axis is applied. As a result, the ink liquid bullet travels while causing a rotational motion in the ejection direction and is pushed to the atmosphere side.
Next, as shown in FIG.
04 undergoes extrusion growth and begins to deform into a sphere due to the surface tension of the ink 304 in order to minimize energy.

Next, as shown in FIG. 11D, the pressure generated from the ink ejection pressure generating element arranged in the ink jet recording head (not shown) is stopped, and the ink 304 flies due to its inertia. While the spherical deformation progresses. Next, as shown in FIG. 11E, the ink 304 is separated into the main droplet 350 and the satellite droplet 351 by the balance between the length of the ink and the surface tension at the time of the spherical deformation. At the same time, the ink is cut symmetrically at the ink ejection side edge of the orifice plate 301 at the boundary between hydrophilicity and water repellency, and the ink jet recording head and the ink droplets are separated. Next, FIG.
The main droplet 350 of the ink droplet separated as shown in FIG.
And the satellite droplet 351 fly in the same direction (the direction of the arrow in the drawing), which is the axial direction of the ink ejection port, and both the ink droplet droplet 350 and the satellite droplet 351 rotate with the flying direction as the rotation axis. To fly while raising,
Similar to the principle of the pistol bullet, the liquid bullet of the ink makes the flying direction vector difficult to change its shape due to the rotational inertia force and keeps storing the vector. It can be made to fly with less precision.

Next, the orifice plate 301 having the structure of the above-described embodiment has a circular shape on the ink ejection side surface and a square shape on the ink supply path 303 side where the ink is supplied, and A method for processing and forming a spiral frustum-shaped ink discharge port that is gradually and smoothly twisted will be described with reference to the drawings. Figure 1
FIG. 2 is an optical schematic diagram of a laser processing apparatus for processing and forming the ink discharge ports. A laser beam 302 emitted from a short-pulse oscillation laser body (not shown) in a direction indicated by a thick arrow in FIG. 12 is guided to a zoom beam compressor 310.
The laser beam is converted into a predetermined light beam diameter, guided to a mask illumination lens 311 to form a laser beam having a predetermined convergence angle, and illuminates a part of the mask pattern portion 315 of the mask 314 in FIG. At this time, the effective NA (numerical aperture) for finally processing the workpiece is determined by the compression ratio of the zoom beam compressor 310 and the focal length of the mask illumination lens 311.
Is determined. The taper angle of the workpiece is determined by the NA. Conversely, the compression ratio of the zoom beam compressor 310 and the focal length of the mask illumination lens 311 are determined or adjusted according to the processing shape of the workpiece. .

Next, the laser beam that has passed through the mask pattern 315 of the mask 314 shown in FIG. 7 passes through the square pattern of the opening 316 of the light beam stop 312 shown in FIG. The converted and projected pattern image is projected by the projection lens 313 onto the surface of the orifice plate 301 of the ink jet recording head body 3 which is a workpiece, and the beam stop 312 is synchronized with the processing of the ink ejection port by laser oscillation.
Is linked to the progress of the processing of the workpiece, and is rotated by using the optical axis as a rotation axis.

By making the beam cross-sectional shape of this laser beam square and the pattern of the mask circular, it is possible to process the shape into a circle at the focus point and a substantially square shape at the non-focus point, Since the beam cross-sectional shape of the laser beam is rotated around the optical axis, a spiral frustum shape can be formed. That is, the focus point is set on the surface side of the workpiece, which is the irradiation side of the laser beam, and the workpiece is irradiated while rotating the beam cross-sectional shape around the optical axis at a predetermined rotation angle. By
A spiral frustum shape extending from the ink ejection side having a circular cross section to the ink supply side having a square cross section can be processed. In the case of processing the orifice plate alone and processing from the ink supply side, by setting this focus point to the surface position of the ink ejection side on the back surface of the orifice plate, processing is performed in a substantially square shape. It becomes possible to process a spiral frustum shape having a cross-sectional shape narrowing from a certain ink supply side to the ink discharge side.

An aperture 312 is located near the projection lens 313.
Without using the configuration of disposing the Koehler illumination optical system, the pupil image is projected on the projection lens by arranging a light beam stop or an optical image at a different position on the laser beam path, and using the projection lens 313. The same processing can be performed by making the pupil image of a square or an arbitrary shape. Simultaneously with the irradiation of the laser beam, the ink jet recording head body 3 including the mask 314 and the orifice plate 301 as a workpiece is simultaneously synchronized by a mechanical stage (not shown) in a direction perpendicular to a predetermined optical axis and at a predetermined speed. FIG.
The entire mask pattern 315 is processed by reciprocating in the direction of the thin arrow in the middle or in the directions of the thin arrow and the dotted arrow.

Fourth Embodiment FIGS. 13 and 14 are schematic views of an ink discharge port according to a fourth embodiment of the present invention. 13 and 14, an ink of an ink jet recording head having a shape in which a conical portion expanding on the ink ejection side and a conical portion expanding on the ink supply side according to the present embodiment are connected to a rotationally symmetric axis in common. An outline of the ejection operation will be described. First, as shown in FIG. 13A, an ink jet recording (not shown) is performed on an orifice plate 401 having an ink ejection port including an area 402 expanding on the ink ejection side and an area 403 expanding on the ink supply side. When the head is filled with the ink, the ink 404 is arranged in contact with the orifice plate 401.
Since the ink 404 is present as an aqueous solution, the region 403 extending toward the hydrophilic ink supply side is filled with the capillary force and the region 402 extending toward the ink ejection side provided with a water-repellent film (not shown). , And is not adsorbed by the water repellent action. Next, FIG.
As shown in (2), the ink 404 is pushed to the atmosphere side by the pressure (the pressure indicated by the arrow in the drawing) generated from the ink discharge pressure generating element arranged in the ink jet recording head (not shown). Next, as shown in FIG. 13C, the extruded ink 404 is extruded and grows.
With a surface tension of 04, it begins to deform into a sphere to minimize energy.

Next, as shown in FIG. 14D, the pressure generated from the ink discharge pressure generating element arranged in the ink jet recording head (not shown) is stopped, and the ink 404 flies due to its inertia. While the spherical deformation progresses. Next, as shown in FIG. 14E, the ink 404 is separated into the main droplet 410 and the satellite droplet 411 by the balance between the length of the ink and the surface tension at the time of the spherical deformation. At the same time, the ink is cut symmetrically at the boundary between the region 402 extending toward the ink ejection side and the region 403 extending toward the ink supply side, which is the boundary between hydrophilicity and water repellency, and the ink jet recording head and the ink droplets are cut off. Are separated. Next, as shown in FIG. 14F, the separated main droplet 410 and the satellite droplet 411 of the ink droplet fly in the same direction which is the axial direction of the ink ejection port.

Next, with reference to FIG. 15, an example in which a cap for preventing ink from drying from the ink discharge ports of the ink jet recording head in this embodiment will be described. When the ink jet recording head is not operated, the water content of the aqueous ink solution evaporates rapidly into the atmosphere, and the concentration of the non-evaporable substance in the aqueous ink solution increases, which causes clogging of the ink discharge ports. To prevent this, when the inkjet recording head is not operating,
A cap 405 as shown in FIG. 15 is brought into close contact with the ink ejection port to prevent contact with the atmosphere. At this time, the ink 40
4 and the cap 405 do not come into contact with each other.

Next, with reference to FIG. 16, a description will be given of the prevention of ink mist contamination of the ink ejection port portion of the ink jet recording head of this embodiment. As shown in FIG. 16A, when gravity acts in the direction of the thick arrow in the drawing, the ink mist 420 in the ink ejection port portion is formed in the region 402 spreading on the ink ejection side provided with a water-repellent film (not shown). The slope is rolled down in the direction of the thin arrow in the drawing due to the water-repellent effect, and is absorbed by the ink 404 inside the ink discharge port. This makes it difficult for the ink mist 420 to unite with each other and to form a large ink ball, thereby reducing the adverse effect on ink ejection. On the other hand, as shown in FIG. 16B, when gravity acts in the direction of the bold line arrow in the figure, the ink mist 420 in the ink ejection port portion is spread over the ink ejection side provided with the water-repellent film (not shown). Due to the water repellent effect, the slope of 402 is rolled down in the direction of the thin line arrow in the drawing and is discharged from the ink discharge port, thereby eliminating the adverse effect on the ink discharge.

Next, with reference to FIGS. 17 and 18, an outline of an ink ejection operation of a conventional ink jet recording head in which a water-repellent film is provided to the inside of an ink ejection port will be described. First, as shown in FIG. 17A, an orifice plate 401 having a water-repellent ink ejection port 400 formed to a predetermined depth is filled with an ink in an ink jet recording head (not shown) to form an orifice. The ink 404 is provided in contact with the plate 401. Since the ink 404 exists as an aqueous solution, the hydrophilic region is filled with the capillary force, and the region provided with the water-repellent film (not shown) is not adsorbed by the water-repellent action. Next, as shown in FIG. 17B, the ink 404 is pushed to the atmosphere side by the pressure (the pressure indicated by the arrow in the drawing) generated from the ink discharge pressure generating element arranged in the ink jet recording head (not shown). . Next, FIG.
As shown in FIG. 7C, the extruded ink 404 undergoes extrusion growth, and starts to be deformed into a spherical shape due to the surface tension of the ink 404 because the energy is minimized.

Next, as shown in FIG. 18D, the pressure generated from the ink ejection pressure generating element disposed in the ink jet recording head (not shown) is stopped, and the ink 404 flies due to its inertia. While the spherical deformation progresses, the ink 404 absorbs a part of the water-repellent portion of the ink discharge port 400 due to the van der Waals force, thereby causing a non-axisymmetric liquid flow. Next, FIG.
As shown in (e), the ink 404 is formed by the main droplet 4 due to the balance between the length of the ink and the surface tension during the spherical deformation.
10 and satellite drops 411. At the same time, the satellite droplet portion 411 of the flying ink that caused a non-axisymmetric liquid flow due to the Van der Waals force advances while being pulled by the resistance of the wall surface of the ink discharge port 400, and the ink is cut. The ink jet recording head and the ink droplet are separated. Next, as shown in FIG. 18F, the main droplet 410 and the satellite droplet 41 of the separated ink droplets
1 fly in the direction of the arrow in the figure, and the main droplet 410 flies in the axial direction of the ink discharge port, but the satellite droplet flies in a different direction.

Next, with reference to FIG. 19, a description will be given of a conventional example in which a cap for preventing drying of ink from an ink discharge port is provided on an ink jet recording head having an ink liquid interface on the surface of the ink discharge port. . In this case, since the ink 404 and the cap 405 come into contact with each other,
The ink 404 permeates the interface between the surface of the orifice plate 401 and the cap 405. In this case, in order to bring the cap into close contact, it is necessary to adhere an elastic material following the ink ejection surface.
There is a problem that the property of the ink is highly degraded with respect to the alkalinity, the durability of the cap material is changed, and the cap material is deteriorated and adheres to the ink discharge port, thereby changing the flying direction of the ink droplet.

Next, with reference to FIG. 20, a description will be given of ink mist stains on the ink ejection port portion of a conventional ink jet recording head having a counterbore step formed around the surface portion of the ink ejection port. As shown in FIGS. 20A and 20B, the ink mist 420 at the ink ejection port moves and accumulates at the corner of the counterbore step portion provided with a water-repellent film (not shown). When the amount increases to a predetermined amount, the ink eventually comes into contact with the ink liquid interface, and due to the surface tension, as shown in FIG.
Move in the direction of the arrow in FIG.
Absorbed in 4. At this time, since a large amount of ink flows, an effect such as an ink ejection failure or a change in the ink ejection direction is exerted, which has an adverse effect on ink ejection.

Next, an outline of a method of manufacturing the ink discharge port portion of the ink jet recording head of this embodiment will be described with reference to FIGS. First, as shown in FIG. 21A, laser light 151 emitted from a laser oscillator that outputs laser light with a pulse emission time of 1 picosecond or less is applied to an orifice plate 401 through a projection lens 450. The mask pattern shown is irradiated with a predetermined pattern image with a predetermined energy density and a predetermined NA (numerical aperture) at a predetermined focus point inside the orifice plate 401. Next, as shown in FIG. 21B, a region that spreads toward the ink ejection side is formed by laser irradiation processing. Next, as shown in FIG. 21C, the water-repellent film 406 is coated to a predetermined thickness by a coating device such as a microspray.

Next, as shown in FIG.
The laser light 4 emitted from the laser oscillator that outputs the laser light with a pulse emission time of 1 picosecond or less is provided on the orifice plate 401 marked with 06 in the same manner as in the step (a).
51, a mask pattern (not shown) meeting the projection lens 450, a predetermined pattern image at a predetermined energy density,
At a predetermined NA (numerical aperture), a predetermined position of the water-repellent area inside the orifice plate 401 is focused and irradiated. Next, as shown in FIG. 22E, a region 403 extending to the ink supply side is formed by laser irradiation processing.

Here, when processing the region 402 expanding on the ink discharge side or the region 403 expanding on the ink supply side into a polygonal pyramid shape, the beam cross section of the laser beam is made polygonal. Can be processed. At this time, the polygonal shape of the beam cross-sectional shape of the laser beam is formed, for example, by making the pupil image pattern of the projection lens a polygonal shape, or by making the aperture pattern of the projection lens a polygonal shape. Can be. Further, in order to process the cone-shaped portion of the ink discharge port into a spiral cone-shaped portion, the laser beam can be processed by irradiating the workpiece while rotating the beam cross-sectional shape around the optical axis. .

Next, based on FIG.
An ink jet recording head to which the ejection port processing method in the fourth embodiment is applied will be described. In FIG. 23, reference numeral 33 denotes a substrate on which an ink discharge pressure generating element 34 such as an electrothermal conversion element or an electromechanical conversion element for discharging ink is provided. The ink discharge pressure generating element 34 is connected to the ink flow path 31 communicating with the discharge port 21.
And the individual ink flow paths 31 are provided in the common liquid chamber 3.
It communicates with 2. An ink supply pipe (not shown) is connected to the common liquid chamber 32, and ink is supplied from an ink tank via the ink supply pipe. Reference numeral 35 denotes a top plate having a concave portion for forming the ink flow path 31 and the common liquid chamber 32.
1. A common liquid chamber 32 is formed. Further, the ejection port 21 is provided on the ink flow path end side of the joined body of the substrate 33 and the top plate 35.
Is provided with a discharge port plate 2 (hereinafter, referred to as an orifice plate).

Such an ink jet recording head is
It can be created as follows. That is, first,
A substrate 33 is formed by patterning a heater 34, which is a heating resistance element for generating an ink ejection pressure, an integrated circuit such as a shift register (not shown), and electric wiring, on a silicon substrate to form a substrate 33, an ink flow path 31, and an ink liquid chamber. A concave portion 32 and an ink supply port (not shown) are formed on the silicon plate by chemical etching to form the top plate 35. Thereafter, the substrate 33 and the top plate 35 are arranged such that the ink discharge side end face and the arrangement of the ink flow path 31 and the heater 34 match.
And alignment bonding. After this bonding, the orifice plate 2 in a state where the nozzle is not formed is adhered to the ink discharge side end surface of the joined top plate and base plate, and in this state, the nozzle is formed by using the above-described ink discharge nozzle processing method. I do. Thereafter, an electric substrate on which a heater driving terminal (not shown) is patterned is connected, an aluminum base plate is connected to the substrate 33, and then a holder for holding each member and an ink tank for ink supply are connected. To assemble the inkjet recording head.

By manufacturing the ink jet recording head in this manner, it is possible to prevent the ink ejection direction from fluctuating due to processing of the ejection port in a non-uniform direction. When an ink jet recording head was prepared according to these examples and the shape of the ejection ports was observed, the edges of all the ejection ports were clearly formed, and the ink ejection ports aligned in high density in parallel were formed. Also, the variation in the opening diameter of the ink ejection side end of each ejection port has been significantly reduced as compared with the related art.
In addition, when printing was actually performed with the ink jet recording head created in this manner, printing dots arranged evenly were recorded, and the dot shape was a beautiful circle, and an image of excellent print quality was obtained. Was.

In the above description of the first to fourth embodiments, an example of a method of forming an ink ejection port has been described.
The present invention is not limited to this, and the effects described above can be obtained even when processing the ink flow path, the ink liquid chamber, and the ink supply port. Further, in the above description, the inkjet recording head has been described. However, the present invention is not limited to this. For example, the present invention can be suitably used in laser machining in micromachining of a semiconductor substrate or the like. Is included.

[0060]

As described above, according to the present invention, the laser processing from the outside of the ink ejection port forming plate (from the ink ejection side) has a shape symmetric with respect to the axis of the ink ejection direction. It is possible to realize a method of manufacturing an ink jet recording head capable of forming a tapered shape that is entirely tapered outside, an ink jet recording head manufactured by the manufacturing method, and a laser processing method. According to the present invention, the absorptance of the orifice plate with respect to the irradiation laser wavelength is a, and the numerical aperture N of the optical system for projecting the processing pattern on the orifice plate is on the workpiece side.
A is n, the energy per unit oscillation pulse per unit area of the laser beam irradiating the orifice plate as a workpiece is E [J / cm ² / pulse], and the oscillation pulse time width of the laser is t [sec / pulse]. ], A pulse emission time of 1 picosecond or less is provided by configuring such a relationship that the following conditional expression is satisfied: (a × nxE) / t> 13 × 10 ⁶ [W / cm ² ]. The temporal energy density is dramatically increased by the laser that oscillates, so that a workpiece such as a resin can be ablated despite very little light energy, and a visible or near-infrared laser is used. As a result, since abundant optical materials can be used, a projection lens having a high NA (numerical aperture) can be easily used. By laser irradiation, it is easy to form a tapered ink ejection port outside the orifice plate. For this reason, high quality processing becomes possible, and the performance of the ink jet recording head can be remarkably improved. Further, according to the present invention, the processing material is not limited to the resin material, and even if the material has a high heat conduction efficiency such as a ceramic material or a metal material, the processing process is performed before the thermal diffusion proceeds from the time of light irradiation. Because of the termination, it is possible to perform ablation processing that does not pass through the liquid phase state. Further, even if the material has high light transmission efficiency (transmittance) such as quartz, optical crystal, or glass material, the energy can be reduced. Since the temporal concentration is high, ablation processing can be performed even with a small light absorption rate. Further, according to the present invention, if a ceramic material or a glass material is used, it is possible to produce an ink jet recording head having excellent durability and storability that does not corrode even with strongly alkaline ink. Also, according to the present invention,
The ability to form a tapered ink outlet on the outside of the orifice plate allows the ink outlet to be formed in the final step after assembling the inkjet recording head, thereby forming the ink outlet. The non-uniformity of the direction of the ink discharge nozzle due to the deformation due to the assembly and connection of the plate is eliminated, and a tapered shape that is partially or entirely tapered outside the ink discharge port forming plate (on the ink discharge side) is formed. By doing so, the ejection direction of the ink droplets is stabilized in a certain direction, the fluid resistance of the ink flow is reduced, and the flow velocity is improved, so that the ink ejection frequency is increased by the same driving source, and the ink to be ejected flies. It is possible to improve the printing speed and improve the printing quality. It is possible to realize a de. Also,
According to the present invention, a laser processing means for performing three-dimensional processing of a frustum shape in which a processing cross section continuously changes from a second shape to a first shape is applied to a method of manufacturing an inkjet recording head or an inkjet recording head. By doing so, the ink discharge port is processed into a frustum shape in which the cross-sectional shape on the ink discharge surface side is a circular or elliptical shape and the cross-sectional shape on the ink supply side is a substantially polygonal shape that connects to the ink supply path almost smoothly. Therefore, the shape continuity between the ink supply path and the ink discharge port can be improved. Therefore,
This makes it possible for the liquid ink to fly in a substantially swirling state, to allow the liquid bullet to fly in a stable manner, and to reduce variations in the landing position on the printing target,
It is possible to fly with high accuracy. Furthermore, this makes it possible to reduce the generation of mist. Further, according to the present invention, a laser processing means for processing a spiral frustum shape having a substantially polygonal bottom surface shape is applied to, for example, a method for manufacturing an ink jet recording head or an ink jet recording head by the manufacturing method. Therefore, the liquid bullet of the liquid ink can have a rotation component around the axis of the flight direction with respect to the flying direction, and the liquid bullet of the liquid ink can be stably advanced and fly by the rotational inertia force. Variations in the landing position on the printing object can be reduced, and the landing can be performed with high accuracy. Furthermore, this can also reduce the generation of mist. Further, according to the present invention, it is possible to process the conical portion expanding on the irradiation side of the laser beam and the conical portion expanding on the opposite side into a shape in which the symmetry axes are commonly connected. Then, by applying such a laser processing means to, for example, a method for manufacturing an ink jet recording head or an ink jet recording head according to the manufacturing method, an ink discharge port of the ink jet recording head, a conical portion spreading to the ink discharge side, The conical portion spreading to the ink supply side can be formed into a shape in which the rotational symmetry axes are commonly connected. Accordingly, in the present invention, by forming an ink liquid interface by the liquid surface tension of the ink inside the ink discharge port, the ink discharge port is capped so as not to contact the ink, and the ink is dried and solidified. Discharge port clogging can be prevented. In addition, by forming a discontinuous surface boundary at a boundary between a region extending toward the ink supply side, which is an ink hydrophilic region, and a region extending toward the ink ejection side, which is an ink water repellent region, the ink flying droplets are positioned at the discontinuous surface boundary position. It is possible to always fly both the main droplet of the ink droplet and the satellite droplet in the flight direction along the axis of symmetry of the ink ejection port. Quality can be obtained. As a result, since the ink mist does not have a corner portion that is not continuous with the ink liquid interface, even if the ink mist adheres to a region spreading to the ink ejection side, the ink mist accumulates in the corner portion, grows, and comes into contact with the ink liquid interface. And does not hinder the flight of the ink droplets. In addition, such an ink mist flows and disappears on the surface on the ink discharge side of the member forming the ink discharge port if the ink discharge side faces the gravity vector direction, or the ink discharge side faces in the direction opposite to the gravity vector direction. If it is oriented, it will flow to the ink liquid interface side and be absorbed in a fine mist state, and the harmful effect of ink mist flying of ink droplets will be significantly improved, and the reliability and durability of the ink jet recording head can be improved Becomes

[Brief description of the drawings]

FIG. 1 is a schematic optical path diagram of a mask pattern projection optical system of a laser processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining formation of an inverted tapered shape according to the first embodiment of the present invention.

FIG. 3 is a schematic view of an ink ejection port according to a second embodiment of the present invention.

FIG. 4 is a view for explaining flying of ink droplets from an ink discharge port of an ink jet recording head according to a second embodiment of the present invention.

FIG. 5 is a view for explaining the flight of ink droplets from the ink discharge ports of the ink jet recording head according to the second embodiment of the present invention following FIG. 4;

FIG. 6 is an optical schematic diagram of an inkjet recording head processing apparatus according to a second embodiment of the present invention.

FIG. 7 is a pattern diagram of a photomask used in Examples 2 and 3 of the present invention.

FIG. 8 is a pattern diagram of a beam stop used in Embodiments 2 and 3 of the present invention.

FIG. 9 is a schematic view of an ink ejection port according to a third embodiment of the invention.

FIG. 10 is a view for explaining flying of ink droplets from an ink discharge port of an ink jet recording head according to a third embodiment of the present invention.

FIG. 11 is a diagram illustrating the flight of ink droplets from the ink discharge ports of the ink jet recording head according to the third embodiment of the present invention, following FIG.

FIG. 12 is an optical schematic diagram of an inkjet recording head processing apparatus according to a third embodiment of the present invention.

FIGS. 13A to 13C are diagrams for explaining flying of ink droplets from an ink discharge port of an inkjet recording head according to Embodiment 4 of the present invention.

FIGS. 14 (d) to (f) are diagrams for explaining the flight of ink droplets from the ink discharge ports of the ink jet recording head, following FIGS. 1 (a) to (c) of FIG. 1 according to Embodiment 4 of the present invention. .

FIG. 15 is a diagram showing an arrangement of caps for preventing ink from drying from ink discharge ports of an ink jet recording head according to Embodiment 4 of the present invention.

FIG. 16 is a diagram illustrating prevention of ink mist contamination of an ink ejection port portion of an inkjet recording head according to a fourth embodiment of the present invention.

FIGS. 17A to 17C are diagrams illustrating the flight of ink droplets from ink discharge ports of an ink jet recording head in a conventional example.

FIGS. 18 (d) to (f) are diagrams illustrating the flight of ink droplets from the ink ejection ports of the ink jet recording head following the above-described conventional example from FIGS. 5 (a) to (c).

FIG. 19 is a diagram showing a cap arrangement for preventing ink drying from an ink ejection port of an ink jet recording head in a conventional example.

FIG. 20 is a diagram illustrating ink mist contamination of an ink ejection port portion of an ink jet recording head in a conventional example.

FIGS. 21A to 21C are diagrams illustrating a process of manufacturing an ink ejection port portion of an inkjet recording head according to a fourth embodiment of the present invention.

FIGS. 22 (d) and (e) are views for explaining a manufacturing process of an ink discharge port portion of the ink jet recording head following the above-mentioned FIGS. 9 (a) to 9 (c) according to the fourth embodiment of the present invention.

FIG. 23 is a schematic view showing an inkjet head manufactured by a method for manufacturing an inkjet head to which a processing method according to an embodiment of the present invention is applied.

[Explanation of symbols]

 1: Mask 2: Orifice plate 3: Ink jet recording head main body 21: Ink ejection nozzle 31: Ink flow path 32: Ink chamber 33: Substrate 34: Ink ejection pressure generating element 35: Top plate 101: Laser beam 110: Fly Eye lens 111: Field lens 112: Aperture 113: Projection lens 200: Ink ejection port 201: Orifice plate 202: Laser beam 203: Ink supply path 204: Ink 207: Ink supply path forming member 208: Ink ejection pressure generating element 210: Zoom beam compressor 211: Mask illumination lens 212, 312: Beam stop 213: Projection lens 214, 314: Mask 215, 315: Mask pattern 216, 316: Beam stop pattern 250: Main droplet of ink liquid bullet 251: Ink droplet Light droplet 300: Ink ejection port 301: Orifice plate 302: Laser beam 303: Ink supply path 304: Ink 307: Ink supply path forming member 308: Ink ejection pressure generating element 310: Zoom beam compressor 311: Mask illumination lens 312: Light flux Aperture 313: Projection lens 314: Mask 350: Main droplet of ink droplet 351: Ink droplet satellite droplet 400: Ink ejection port 401: Ink ejection port forming base material 402: Water repellent area of ink ejection port 403: Ink ejection port Hydrophilic area 404: Ink 405: Cap 406: Water repellent film 410: Main droplet of ink flying droplet 411: Satellite droplet (sub-droplet) of ink flying droplet 420: Ink mist 421: Ink pool 450: Lens 451: Laser light 500: I repelled to a certain depth Click discharge port 501: hydrophilic ink discharge port 502: ink discharge port

 ──────────────────────────────────────────────────続 き Continued on the front page (31) Priority claim number Japanese Patent Application No. 2000-165454 (P2000-165454) (32) Priority date June 2, 2000 (2000.6.2) (33) Priority claim country Japan (JP) F-term (Reference) 2C057 AF43 AF93 AG02 AG05 AG07 AP02 AP13 AP23 AP59 AP60 AQ02 AQ03 BA03 4E068 CA01 CA04 CD05 CD10 DA09

Claims (66)

[Claims] An ink discharge port for discharging ink droplets to be attached to a recording medium; a liquid chamber for storing ink to be supplied to the discharge port; and an ink flow path communicating the discharge port with the liquid chamber. Forming an energy generating element provided in a part of the ink flow path to generate energy for discharging ink, an ink supply port for supplying ink from outside to the liquid chamber, and the like by joining or bonding plate materials. In the method for manufacturing an ink jet recording head, when laser processing an orifice plate in which the ink discharge port is formed, a spatial time radiated from a laser oscillator oscillating with a pulse radiation time of 1 picosecond or less as the laser light. Energy density is very large,
Using a plurality of pulses of laser light, irradiating the laser light from the outer surface side of the orifice plate opposite to the side where the ink is supplied, focus-projecting and processing the processing pattern of the ink discharge port on the outer surface of the orifice plate A method for manufacturing an ink jet recording head. 2. A method according to claim 1, wherein a plurality of said ink discharge ports are simultaneously formed at a predetermined interval by irradiating a laser beam through a mask having a plurality of opening patterns formed at a predetermined pitch. 2. The method for manufacturing an ink jet recording head according to item 1. 3. An ink jet recording head is formed by a laser processing method in which a pressure generating source is brought into contact with the ink to apply energy to transmit the pressure to an ink discharge port to eject ink droplets and attach the ink droplets to a recording medium. In the method of manufacturing an ink jet recording head, a spatial time radiated from a laser oscillator oscillating at a pulse emission time of 1 picosecond or less as the laser light when laser processing an orifice plate in which the ink ejection port is formed. Energy density is very large,
Using a plurality of pulses of laser light, the laser beam emitted from the laser oscillator is given a predetermined energy density and a predetermined numerical aperture, and the beam cross-sectional shape of the laser beam at a non-focus point is set to a first shape. By irradiating the orifice plate at a projection focus point of the mask pattern through a mask pattern of a second shape different from the first shape, the processed cross section changes from the second shape to the first shape. A three-dimensional processing of a frustum shape that continuously changes. 4. A first shape of a beam cross section at a non-focus point of the laser beam is substantially polygonal, and a second shape different from the first shape in the mask pattern is a circle or an ellipse. 4. An ink jet recording head according to claim 3, wherein the cross-sectional shape on the ink ejection surface side is circular or elliptical, and the cross-sectional shape on the ink supply side is a substantially polygonal frustum shape. Manufacturing method. 5. The method according to claim 4, wherein the substantially polygonal shape of the first shape is formed by forming a pupil image pattern of the projection lens into a polygonal shape. Method. 6. The method according to claim 4, wherein the substantially polygonal shape of the first shape is formed by forming a diaphragm pattern of the projection lens into a polygonal shape. . 7. The ink-jet apparatus according to claim 3, wherein a cross-sectional shape of the ink supply side is formed in a substantially polygonal shape that is connected to the ink supply path substantially smoothly. Manufacturing method of recording head. 8. The orifice, wherein the beam cross-sectional shape is polygonal, and the beam cross-sectional shape is rotated about an optical axis at a projection focus point of the mask pattern via a mask pattern having the second shape. By irradiating the plate, the nozzle cross-sectional shape increases the cross-sectional area from the second shape to the polygonal shape,
The method for manufacturing an ink jet recording head according to claim 3, wherein three-dimensional processing of a spiral frustum shape that continuously changes in a spiral shape is performed. 9. The ink jet recording head according to claim 8, wherein the spiral frustum shape is gradually and smoothly twisted and a continuous bottom shape is processed into a substantially polygonal spiral frustum shape. Production method. 10. A pupil image pattern of a projection lens, wherein the spiral frustum shape forms a polygonal shape of a beam cross-sectional shape at a non-focus point of the laser beam. The method of manufacturing an ink jet recording head according to claim 8, wherein the substrate is rotated around an optical axis in association with the progress of processing of the workpiece. 11. The spiral frustum shape is obtained by forming a polygonal shape of a beam cross section at a non-focus point of the laser beam by making a diaphragm pattern of a projection lens a polygonal shape, and covering the diaphragm pattern. The method for manufacturing an ink jet recording head according to claim 9, wherein the processing is performed by rotating the workpiece about an optical axis in association with the progress of the workpiece. 12. The focus point is set to a surface side of an orifice plate facing the irradiation side of the laser beam or a position away from a surface side of the orifice plate facing the irradiation side of the laser beam. The three-dimensional processing of the frustum shape is performed.
12. The method for manufacturing an ink jet recording head according to any one of items 11 to 11. 13. The ink-jet recording head according to claim 3, wherein a water-repellent film is formed in a region near the ink discharge port on the ink discharge side of the ink discharge port. Item 13. The method for producing an ink jet recording head according to item 9. 14. A pressure generating source is brought into contact with the ink to apply energy, thereby transmitting the pressure to the ink ejection port.
In a method of manufacturing an ink jet recording head, which forms an ink jet recording head for ejecting ink droplets and attaching the ink droplets to a recording medium by a laser processing method. A very large spatiotemporal energy density emitted from a laser oscillator oscillating with a pulse emission time of 1 picosecond or less,
Using a plurality of pulses of laser light, irradiating a laser beam emitted from the laser oscillator with a predetermined energy density and a predetermined numerical aperture under a predetermined pattern image onto the orifice plate at a predetermined focus point. And processing the conical portion extending toward the ink ejection side and the conical portion extending toward the ink supply side into a shape in which the symmetry axes are commonly connected. 15. The conical portion spreading on the ink discharge side is processed by setting the focus point at a position deeper than the ink discharge side surface of the orifice plate, and the conical portion spreading on the ink supply side is formed. 15. The ink jet recording head according to claim 14, wherein after processing the conical portion spreading to the ink ejection side, the focus point is set to a portion connecting the symmetry axis in common. Production method. 16. The method according to claim 14, wherein the conical portion expanding on the ink discharge side is processed into a conical portion larger than the conical portion expanding on the ink supply side. 3. The method for manufacturing an ink jet recording head according to item 1. 17. The method according to claim 14, wherein the ink discharge ports are formed of a hydrophilic material. 18. A water-repellent film is formed on the surface of the conical portion spreading on the ink ejection side and on the area near the ink ejection port on the ink ejection port side.
18. The method for manufacturing an ink jet recording head according to any one of items 17. 19. The method according to claim 19, wherein the water-repellent film is formed on the ink discharge side after processing and forming the conical part spreading on the ink discharge side, and then processing the conical part expanding on the ink supply side. The method for manufacturing an ink jet recording head according to claim 18. 20. The method according to claim 14, wherein the conical portion of the ink discharge port is processed into a conical portion. 21. The conical portion of the ink discharge port is processed into a polygonal pyramid-shaped portion.
The method for manufacturing an ink jet recording head according to any one of the above items. 22. The method according to claim 21, wherein the polygonal pyramid-shaped portion is processed by making the beam cross section of the laser beam into a polygonal shape. 23. The polygonal beam cross-sectional shape of the laser beam is formed by forming a pupil image pattern of a projection lens into a polygonal shape.
3. The method for manufacturing an ink jet recording head according to item 1. 24. The polygonal shape of the beam cross section of the laser beam is formed by making the aperture pattern of the projection lens a polygonal shape.
3. The method for manufacturing an ink jet recording head according to item 1. 25. A method according to claim 14, wherein the conical portion of the ink discharge port is processed into a spiral conical portion.
20. The method for manufacturing an ink jet recording head according to any one of items 19 to 19. 26. The method according to claim 25, wherein the spiral cone portion is processed by irradiating a workpiece while rotating a beam cross-sectional shape of the laser beam around an optical axis. A method for manufacturing an ink jet recording head. 27. The method according to claim 27, wherein the conical portion of the ink discharge port is processed in combination with any one of a conical portion, a polygonal pyramid portion, and a spiral conical portion. 20. The method of manufacturing an ink jet recording head according to any one of 16 to 19. 28. The method for manufacturing an ink jet recording head according to claim 1, wherein the member forming the discharge port is made of a resin. 29. The member forming the discharge port is made of Si or a Si compound material.
28. The method for manufacturing an ink jet recording head according to any one of items 27 to 27. 30. The laser beam has a wavelength of 350 to 1000.
The method for manufacturing an ink jet recording head according to any one of claims 1 to 27, wherein the distance is within the range of nm. 31. A pulse emission time of said laser beam is 500
31. The sub-femtosecond sub-second.
The method for manufacturing an ink jet recording head according to any one of the above items. 32. The energy density of the laser beam is represented by a as the absorptivity of the material to be processed with respect to the irradiation laser wavelength, n as the numerical aperture on the workpiece side of the optical system for projecting the processing pattern on the workpiece, and n as the energy density. The energy per unit area and unit oscillation pulse time of the laser beam irradiating the material to be processed is E
(Unit [J / cm ² / pulse]), and assuming that the oscillation pulse time width of the laser is t (unit [sec]), (a × n × E) / t> 13 × 10 ⁶ [W / cm ² ] The method for manufacturing an ink jet recording head according to any one of claims 1 to 31, wherein a conditional expression is satisfied. 33. The method according to claim 1, wherein the laser oscillator is a laser oscillator having a light propagating spatial compression device. 34. An ink jet recording apparatus according to claim 33, wherein said spatial compression device for light propagation comprises chirping pulse generation means and longitudinal mode synchronization means utilizing light wavelength dispersion characteristics. Head manufacturing method. 35. An ink discharge port for discharging ink droplets to be attached to a recording medium, a liquid chamber for storing ink to be supplied to the discharge port, and an ink flow path communicating between the discharge port and the liquid chamber. Forming an energy generating element provided in a part of the ink flow path to generate energy for discharging ink, an ink supply port for supplying ink from outside to the liquid chamber, and the like by joining or bonding plate materials. A multi-pulse laser, wherein the ink ejection port of the inkjet recording head has a very large spatial and temporal energy density emitted from a laser oscillator oscillating with a pulse emission time of 1 picosecond or less. By irradiating laser light from the outer surface side of the orifice plate opposite to the side to which the ink is supplied, An ink jet recording head, wherein a cross-sectional shape processed by focusing and projecting a processing pattern of an ink discharge port on an outer surface of a plate has a tapered cross-sectional shape in a direction toward the outer surface of the orifice plate. 36. An ink jet recording head according to claim 35, wherein a plurality of said ink discharge ports are formed at a predetermined interval. 37. A method in which a pressure source is brought into contact with ink and energy is applied thereto to transmit pressure to an ink ejection port.
An ink jet recording head for ejecting ink droplets and attaching the ink droplets to a recording medium, wherein an ink ejection port of the ink jet recording head is spatially and temporally radiated from a laser oscillator oscillating with a pulse emission time of 1 picosecond or less. Very large energy density, by a plurality of pulses of laser light, a laser beam emitted from the laser oscillator, a predetermined energy density,
Under a predetermined numerical aperture, the beam cross-sectional shape of the laser beam at a non-focus point is set to a first shape, and
Via a mask pattern of a second shape different from the shape of
At a projection focus point of the mask pattern, the mask pattern has a frustum-shaped cross-section processed by irradiating an orifice plate and continuously changing from the second shape to the first shape. Inkjet recording head. 38. An ink discharge port of the ink jet recording head, wherein a cross-sectional shape on the ink discharge surface side is circular or elliptical, and a cross-sectional shape on the ink supply side is substantially polygonal. 38. The ink jet recording head according to 37. 39. The ink jet recording head according to claim 38, wherein the cross-sectional shape on the ink supply side is formed in a substantially polygonal shape which is connected substantially smoothly to the ink supply path. 40. An ink discharge port of the ink jet recording head, wherein a cross-sectional shape on the ink discharge surface side is circular or elliptical or polygonal, and a cross-sectional shape on the ink supply side is substantially polygonal. The ink jet recording head according to claim 37, wherein the ink jet recording head has a spiral frustum shape that is twisted gradually and smoothly. 41. The ink jet recording head according to claim 40, wherein the spiral frustum shape is a spiral frustum shape in which a continuous bottom surface is twisted gradually and smoothly and has a substantially polygonal bottom shape. 42. The ink jet recording head according to claim 37, wherein a water-repellent film is formed in a region near the ink discharge port on the ink discharge side of the ink discharge port. 2. The ink jet recording head according to claim 1. 43. An ink jet recording head, wherein a pressure generating source is brought into contact with ink to apply pressure energy to transmit pressure to an ink ejection port to eject ink droplets and attach the ink droplets to a recording medium. An ink jet recording head, wherein an ink ejection port of the head has a cross-sectional shape in which a symmetric axis is commonly connected to a conical portion extending toward the ink ejection side and a conical portion extending toward the ink supply side. 44. The ink jet recording head according to claim 43, wherein the conical portion expanding toward the ink ejection side is wider than the conical portion expanding toward the ink supply side. 45. The ink jet recording head according to claim 43, wherein the ink discharge port is made of a hydrophilic material. 46. A water-repellent film is provided on the surface of the conical portion spreading on the ink ejection side and on the area near the ink ejection port on the ink ejection port side.
The inkjet recording head according to any one of Items 3 to 45. 47. The method according to claim 47, wherein the water-repellent film is formed on the ink discharge side after processing and forming the conical part spreading on the ink discharge side, and thereafter the conical part expanding on the ink supply side is processed and formed. An ink jet recording head according to claim 46. 48. The ink jet recording head according to claim 43, wherein the conical portion of the ink discharge port is a conical portion. 49. The ink jet recording head according to claim 43, wherein the conical portion of the ink discharge port is a polygonal pyramid portion. 50. A cone-shaped portion of said ink discharge port is a spiral cone-shaped portion.
The inkjet recording head according to any one of the above. 51. The conical portion of the ink discharge port is formed of a combination with any one of a conical portion, a polygonal pyramid portion, and a spiral conical portion. 48. The ink jet recording head according to any one of items 47. 52. A laser processing method for performing laser ablation processing on a workpiece by irradiating the workpiece with laser light, wherein when forming a through hole or the like in the workpiece by ablation processing, the laser light is used as the laser light. Laser ablation processing of the through-holes and the like is performed by using a plurality of pulses of laser light having a very large spatial and temporal energy density emitted from a laser oscillator that oscillates with a pulse emission time of 1 picosecond or less from the laser oscillator. A laser processing method comprising: irradiating a laser beam from an outer surface side of a workpiece to be applied; and performing focus projection on a processing pattern such as a through-hole on the outer surface of the workpiece to perform processing. 53. A plurality of through holes and the like are simultaneously formed at predetermined intervals by irradiating a laser beam through a mask having a plurality of opening patterns formed at a predetermined pitch. 52. The laser processing method according to 52. 54. Optical ablation processing by irradiating a workpiece with a laser beam from a laser oscillator that continuously emits a light pulse having a large spatial and temporal energy density with a pulse emission time of 1 picosecond or less. A laser processing method, comprising: forming a laser beam emitted from the laser oscillator under a predetermined energy density and a predetermined numerical aperture into a first beam shape at a non-focus point of the laser beam; By irradiating an object to be processed at a projection focus point of a predetermined mask pattern through a mask pattern of a second shape different from the shape of 1, the processed cross section changes from the second shape to the first shape. And a three-dimensional machining of a frustum shape that continuously changes. 55. The method according to claim 54, wherein the first shape of the beam cross section at the non-focus point of the laser beam is formed by forming a pupil image pattern of the projection lens into a polygonal shape. Laser processing method. 56. The method according to claim 54, wherein the first shape of the beam cross section at the non-focus point of the laser beam is formed by making the aperture pattern of the projection lens a polygonal shape. Laser processing method. 57. A beam cross section having a polygonal shape,
Through the mask pattern having the second shape, by irradiating the orifice plate while rotating the beam cross-sectional shape around the optical axis at the projection focus point of the mask pattern, the cross-sectional shape of the workpiece is reduced. 55. The laser processing method according to claim 54, wherein a three-dimensional processing of a spiral frustum that continuously changes in a spiral shape is performed while increasing a cross-sectional area from a predetermined shape to the polygonal shape. 58. The spiral frustum shape according to claim 57, wherein the spiral frustum shape is gradually and smoothly twisted and the continuous bottom shape is processed as a substantially polygonal spiral frustum shape.
2. The laser processing method according to 1. above. 59. The spiral frustum shape, wherein the polygonal shape of the beam cross section at the non-focus point of the laser beam is formed by making the pupil image pattern of the projection lens a polygonal shape. 59. The laser processing method according to claim 57, wherein the laser beam is rotated around the optical axis in association with the processing progress of the workpiece to be processed. 60. The spiral frustum shape is formed by forming a polygonal shape of a beam cross-sectional shape at a non-focus point of the laser beam by making a diaphragm pattern of a projection lens a polygonal shape, and covering the diaphragm pattern. 59. The laser processing method according to claim 57, wherein the laser beam is rotated around the optical axis in association with the processing progress of the workpiece to be processed. 61. A method according to claim 61, further comprising: setting the focus point on a surface side of the workpiece which is directed to the irradiation side of the laser beam, or
61. The three-dimensional processing of the frustum shape is performed by setting a position away from the surface side of the workpiece directed to the irradiation side of the laser beam, and performing the three-dimensional processing of the frustum shape. The laser processing method as described. 62. The laser beam has a wavelength of 350 to 1000.
62. The method according to claim 52, wherein the distance is within the range of nm.
The laser processing method according to any one of the above. 63. A pulse emission time of said laser beam is 500
7. The method according to claim 5, wherein the time is less than a femtosecond.
3. The laser processing method according to any one of 2. 64. The workpiece according to claim 52, wherein the workpiece is resin, Si or a Si compound material.
4. The laser processing method according to any one of 3. 65. The laser processing method according to claim 52, wherein said laser oscillator is a laser oscillator having a light-propagating spatial compression device. 66. The laser processing apparatus according to claim 65, wherein said spatial compression device for light propagation comprises chirping pulse generation means and longitudinal mode synchronization means utilizing optical wavelength dispersion characteristics. Method.