JP2005088269A - Manufacturing method for liquid droplet ejection head, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the accuracy and droplet ejection characteristics of a head vary, for example, because center displacement of a nozzle hole and a communication port are caused when a nozzle forming member is joined to a member forming a liquid chamber and the nozzle hole is formed by laser processing, and because a remaining state of a by-product after processing and thermal expansion of a workpiece during the processing are caused by excimer laser processing. <P>SOLUTION: A nozzle/liquid chamber unit 51 is formed by joining the nozzle forming member 53 and a liquid-chamber component member 52 together, and a femtosecond laser beam 58 is applied to the unit 51, so that the communication port 5 and the nozzle hole 4 can be formed. This prevents the displacement of the communication port 5 and the nozzle hole 4, so as to enhance the accuracy and droplet ejection characteristics of the head. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a droplet discharge head and an image forming apparatus.

  For example, as an image forming apparatus such as a printer, a facsimile machine, a copying apparatus, or a plotter, a nozzle that discharges droplets and a liquid chamber (discharge chamber, pressure chamber, pressurizing chamber, ink flow path, etc.) communicating with the nozzle are also referred to. And a droplet discharge head equipped with actuator means for generating energy for pressurizing the liquid in the liquid chamber.

  In this droplet discharge head, since the droplet is discharged from the nozzle, the shape and accuracy of the nozzle have a great influence on the droplet discharge characteristics such as the droplet volume and the droplet velocity. It is also known that the surface characteristics of the nozzle forming member on which the nozzles are formed has a great influence on the droplet discharge characteristics. For example, if liquid (ink) adheres to the periphery of the nozzle holes on the surface of the nozzle forming member, Inconveniences such as the ejection direction being bent, variations in the size of the droplets, or the droplet ejection speed becoming unstable occur.

  Therefore, by forming a water repellent film (ink repellent film) on the discharge side surface of the nozzle, the uniformity of the discharge side surface of the nozzle is improved, thereby stabilizing the droplet discharge characteristics.

  Here, when a resin material is used as the nozzle forming member, since the adhesion between the resin material and the water repellent is not high, the water repellent is directly applied to the surface of the nozzle forming member made of the resin material. It is extremely difficult.

  For this reason, the surface of the nozzle forming member made of a resin material is roughened to form minute irregularities, and then a water repellent is applied, but this is still sufficient between the nozzle forming member and the water repellent layer. A good adhesion cannot be obtained.

  As described above, if the adhesion between the nozzle forming member and the water repellent layer is not sufficient, even if water repellency is obtained at the beginning of the formation of the water repellent layer by applying the water repellent agent, Since the wiping operation for removing foreign matters such as liquid and dust adhering to the surface of the forming member and the periphery of the nozzle is inevitable, the surface of the water-repellent layer is rubbed with time, and the water-repellent layer is gradually peeled off. As a result, water repellency is lowered.

  Therefore, in order to improve the adhesion between the water repellent for forming the water repellent layer and the resin material, a SiO2 film is formed on the surface of the resin material, and a fluorinated water repellent is coated thereon. A method of forming a water repellent film is known. In this case, if the SiO2 film is thick to some extent, for example, 200 mm or more, sufficient adhesion cannot be obtained.

On the other hand, as a method of processing the nozzle hole in the nozzle forming member, an excimer laser is used for the nozzle forming member after a resin member serving as the nozzle forming member is bonded in advance to a liquid chamber constituting member in which a liquid chamber communicating with the nozzle is formed. There are known methods for processing nozzle holes.
JP-A-2-121842 JP-A-1-108056

  Thus, when forming a nozzle hole by excimer laser processing, if the SiO2 film as described above is used for the water-repellent film, the SiO2 film is not good in excimer processability, so a highly accurate and clean nozzle hole is formed. It cannot be processed, and it becomes easy to generate irregular shaped nozzles.

  In this case, the coating method of the SiO2 film and the fluorine-based water repellent on the nozzle forming member is selected, that is, the SiO2 film is formed by a method of forming a SiO2 film by performing O2 ion treatment after sputtering of Si. It is also possible to form a water-repellent film by coating a fluorine-based water repellent with a vacuum vapor deposition method, but in general, such a SiO2 film has a problem that its liquid contact reliability with respect to an alkaline liquid is not sufficient. There is.

Further, in place of the excimer laser described above, a plurality of pulses of laser light emitted from a laser oscillator that oscillates with a pulse emission time of 1 picosecond or less (a laser that emits this laser light is referred to as a femtosecond laser) is irradiated. A method of processing the nozzle hole is also known.
JP 2001-198684 A JP 2001-219290 A JP 2001-287373 A

  By the way, when the water repellent film is formed on the nozzle forming member in which the nozzle hole is formed, the water repellent (water repellent layer) enters the already formed nozzle hole regardless of the water repellent film forming method. It is difficult to completely prevent this, and if a water-repellent layer is formed in the nozzle hole, it becomes difficult to control the meniscus position and the droplet discharge characteristics become unstable.

  For this reason, nozzle holes including the water repellent layer are processed by excimer laser processing on the nozzle forming member made of a resin material having a water repellent layer. However, there are problems such as residual by-products and thermal expansion of the workpiece during processing, and various countermeasures have been taken for this. Therefore, there is a problem that various restrictions occur in processing.

  In this case, many of the processing problems associated with excimer laser processing can be solved by performing nozzle hole processing using a femtosecond laser as disclosed in Patent Documents 3 to 5.

  However, as disclosed in Patent Documents 3 to 5, when a head is manufactured by joining a nozzle forming member in which a nozzle hole is formed and a liquid chamber constituting member in which a liquid chamber is formed, a positional deviation occurs. As described above, the nozzle hole is formed by excimer laser processing after joining the liquid chamber forming member forming the liquid chamber and the resin member serving as the nozzle forming member. It is difficult to align the liquid chamber and the communication port central axis that communicates with the nozzles with high accuracy, and the misalignment of both causes problems such as bending of the flying direction of the droplets and degradation of image quality.

  The present invention has been made in view of the above problems, and provides a method for manufacturing a droplet discharge head excellent in droplet discharge characteristics and an image forming apparatus equipped with a droplet discharge head manufactured using this manufacturing method. For the purpose.

  In the method of manufacturing a droplet discharge head according to the present invention, a nozzle / liquid chamber unit is formed by joining a nozzle forming member and a liquid chamber constituent member to form an integrated unit. The nozzle and the communication port are formed by a plurality of pulses of laser light emitted from a laser oscillator that oscillates with a pulse emission time of picoseconds or less.

  Here, it is preferable to perform the process of sequentially forming the communication port and the nozzle without moving the nozzle / liquid chamber unit. Moreover, it is preferable to perform the process which forms a nozzle using a 2nd mask, after performing the process which forms a communicating port from the liquid chamber structural member side using a 1st mask.

  Furthermore, the liquid chamber constituent member is preferably formed of Si, ceramics, polyimide, or PPS. The water repellent layer formed on the discharge side surface of the nozzle forming member is preferably an FEP coat layer. Further, the thickness of the FEP coat layer is preferably in the range of 0.5 to 5 μm.

  Moreover, it is preferable to perform the process which forms a nozzle in the state which stuck the peelable film member on the surface of the water repellent layer. In this case, it is preferable to perform the process of forming the nozzle in a state in which a film member that can be peeled off via a liquid is adhered to the surface of the water repellent layer. Moreover, it is preferable to use a surfactant solution or a monohydric alcohol as the liquid for closely contacting the film member.

  Furthermore, after processing the nozzle and the communication port for the unit in which the nozzle forming member and the liquid chamber constituent member assembly in which the plurality of liquid chamber constituent members are integrally arranged are joined, the nozzle is formed and cut into a predetermined size and separated. After forming the chip-like nozzle / liquid chamber unit, it is preferable to join the actuator substrate for pressurizing the liquid in the liquid chamber.

  An image forming apparatus according to the present invention includes the droplet discharge head according to the present invention.

  According to the method for manufacturing a droplet discharge head according to the present invention, after the nozzle forming member and the liquid chamber constituting member are joined to form an integrated nozzle / liquid chamber unit, the nozzle / liquid chamber unit is formed. Since the nozzle and the communication port are formed by a plurality of pulses of laser light emitted from a laser oscillator that oscillates with a pulse emission time of 1 picosecond or less, it is possible to form a highly accurate and beautiful nozzle. In addition, the droplet discharge amount and the droplet discharge characteristics can be stabilized, and high-quality recording can be performed.

  The image forming apparatus according to the present invention includes the droplet discharge head manufactured by the method for manufacturing a droplet discharge head according to the present invention, so that high-quality recording can be performed.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
First, an example of an ink jet head manufactured by the method of manufacturing a droplet discharge head according to the present invention will be described with reference to FIGS. 1 is a plan sectional view of the head, FIG. 2 is a plan view of the head in an exploded state, FIG. 3 is a sectional view taken along line AA in FIG. 2, and FIG. It is sectional explanatory drawing which follows the -B line.

  This inkjet head is configured by joining an actuator substrate (actuator unit) 1 and a nozzle / liquid chamber unit 10 in which a flow path substrate 2 that is a liquid chamber constituting member and a nozzle substrate 3 that is a nozzle forming member are joined, By bonding these three substrates 1, 2, and 3, liquid (ink) is supplied to the liquid chamber 6 and the liquid chamber 6 that communicate with each other via the nozzle communication path 5 that is a communication port of the nozzle 4 that discharges droplets. A fluid resistance portion 7 and an ink supply hole 8 for supply are formed. Each liquid chamber 6 is partitioned by a liquid chamber interval wall 9.

  Actuator elements 11 are formed on the actuator substrate 1 corresponding to the respective liquid chambers 6. The actuator element 11 includes a diaphragm 12 and electrodes (individual electrodes) 14 facing the diaphragm 12 via a gap (air gap) 13 formed by sacrificial layer etching.

  In addition, the ink supply hole 8 of the flow path substrate 2 faces the actuator substrate 1 to form an ink supply path 18 through which ink is supplied from the outside.

  On the other hand, the flow path substrate 2 constituting the nozzle / liquid chamber unit 10 is obtained by, for example, anisotropically etching a single crystal silicon (Si) substrate having a crystal plane orientation (110) with a strong alkaline etching solution such as a KOH aqueous solution. A recess that becomes the liquid chamber 6 is formed. In addition, as the flow path substrate 2 serving as the liquid chamber constituent member, ceramics, polyimide, PPS, or the like can be used.

  The nozzle substrate 3 is formed of a resin member such as a polyimide film. In addition, a water repellent film 30 is formed on the discharge direction surface of the nozzle substrate 3 by a known method such as a plating film or a water repellent coating in order to ensure water repellency with ink.

  Here, the flow path substrate 2 in which the concave portion to be the liquid chamber 6 is formed and the nozzle substrate 3 in which the water repellent film 30 is formed are bonded in advance to form the nozzle / liquid chamber unit 10, as will be described later. The nozzle communication path (communication port) 5 of the flow path substrate 2 and the nozzle 4 of the nozzle substrate 3 are processed and formed by the second laser.

  Further, a specific configuration of the actuator substrate 1 will be described with reference to FIGS. 3 and 4. An insulating film such as a thermal oxide film 22 is formed on the silicon substrate 21, and an individual film is formed on the thermal oxide film 22. The electrode 14 is formed by patterning into a required electrode shape, and an insulating film 23, a sacrificial layer 24 such as polysilicon, and an insulating film 25 are sequentially laminated on the individual electrode 14, and a diaphragm electrode 26 is formed on the insulating film 25. After patterning into a required shape and further forming an insulating film 27, an etching hole (sacrificial layer removal hole) 28 is formed in the insulating films 25 and 27, and between the individual electrode 14 and the diaphragm electrode 26. The sacrificial layer is removed by etching to form the gap 13, the communication path 17, and the diaphragm 12, and then the sacrificial layer removal hole 28 is sealed and the liquid resistance of the actuator element 11 is improved. The sealing Se'ekimaku 29 made of a resin material for forming on the vibrating plate 12.

  A polysilicon film is used as the individual electrode 14 and the diaphragm electrode 26. As the material of the electrode, a material having high temperature resistance, excellent workability, and less unevenness on the film formation surface is preferable. Other than polysilicon, a high melting point metal material such as TiN is also preferable. The individual electrode 16 is connected to an external electrode pad 32 via a pad wiring 31.

  Further, the individual electrode side insulating film 23 and the diaphragm side insulating film 25 formed on the opposing surface side of the individual electrode 14 and the diaphragm electrode 26 prevent damage due to short circuit and discharge at the time of contact, and the sacrificial layer 24. Combined with the remaining portion, it also serves as a spacer for the gap 13. Furthermore, as the sealing wetted film 29 formed on the vibration plate 12 and sealing the etching hole 28, a PBO film (polybenzoxazole film) is preferable.

  In the head configured as described above, the diaphragm 12 is used as a common electrode, and a driving pulse voltage is applied between the individual electrode 14, whereby the diaphragm is generated by the electrostatic force generated between the diaphragm 12 and the individual electrode 14. 12 is deformed and displaced toward the individual electrode 14. Thereafter, by discharging the drive pulse voltage, the diaphragm 12 is restored and deformed, and ink droplets are ejected from the nozzles 4 due to the change in the internal volume of the liquid chamber 6 and the action of pressure.

  Here, as an example of using an electrostatic actuator as an actuator unit as a droplet discharge head manufactured by applying the method for manufacturing a droplet discharge head according to the present invention, the present invention is not limited to this. Piezoelectric actuators such as electromechanical transducers, thermal actuators utilizing film boiling for electrothermal transducers, and the like can also be used. However, the electrostatic actuator has advantages over other methods in terms of downsizing, high speed, high density, and power saving.

  Next, a first embodiment of a method for manufacturing a droplet discharge head according to the present invention will be described with reference to FIGS. 5 is a schematic optical path diagram of the mask pattern projection optical system of the femtosecond laser processing apparatus used for carrying out the present invention, FIG. 6 is a cross-sectional explanatory diagram of the nozzle / liquid chamber unit before laser processing, and FIG. 7 is a laser of the unit. It is sectional explanatory drawing after a process.

  First, an outline of a femtosecond laser processing apparatus will be described with reference to FIG. 5. A light beam 41 oscillated from a short pulse oscillation laser body is decomposed into a plurality of light beams by a fly-eye lens 42, and the decomposed light beam is A photomask 44 having a mask pattern is superimposed through the lens 43, and the photomask 44 is uniformly irradiated. The mask pattern formed on the photomask 44 is projected and imaged on the workpiece 47 via the aperture 45 and the projection lens 46, and the workpiece 47 is processed by laser oscillation. The workpiece 47 is used as a nozzle / liquid chamber unit 51 as described later, and the communication port 5 and the nozzle 4 are processed and formed.

  Therefore, in the present invention, as shown in FIG. 6, first, the nozzle / liquid chamber unit 51 to be the nozzle / liquid chamber unit 10 described above is manufactured after processing. The nozzle / liquid chamber unit 51 is obtained by joining the nozzle forming member 53 to be the nozzle substrate 3 and the liquid chamber constituting member 52 to be the flow path substrate 2 with an epoxy adhesive 54. A fluorine-based water repellent film 30 is formed by coating the surface of the substrate with a fluorine-based water repellent.

  A protective film 57 with an adhesive 56 is attached to the nozzle side surface of the nozzle / liquid chamber unit 51, that is, the surface of the fluorine-based water repellent film 30.

  In FIG. 6, for simplification, the liquid chamber constituent member 52 does not show a flow path (liquid chamber) pattern such as a recess serving as a liquid chamber, but the liquid chamber 6 of the flow path substrate 2 described above. A flow path such as a concave portion is formed by a well-known patterning technique. Here, silicon is used as the material for the liquid chamber constituting member 52, and polyimide film is used as the material for the nozzle forming member 53.

  As shown in FIG. 7, the femtosecond laser beam 58 is irradiated from the liquid chamber constituting member 52 side to the nozzle / liquid chamber unit 51 configured as described above, and the communication port (nozzle communication path) 5 and the nozzle hole are irradiated. 4 are sequentially processed and formed. That is, by irradiating the femtosecond laser beam 58 from the liquid chamber constituting member 52 side, the silicon liquid chamber constituting member 52, the epoxy adhesive 54, the polyimide film nozzle forming member 53, and the fluorine-based water repellent 55 are obtained. Etching is sequentially performed with a laser to form a hole (hereinafter referred to as “nozzle hole 4”) to be the communication port 5 and the nozzle 4.

  At this time, processing is performed up to the middle of the layer of the protective film 57 with the adhesive 56. In this way, by performing laser processing to the middle of the protective film 57 layer, the outlet of the nozzle hole 4 is processed beautifully, the nozzle diameter accuracy is improved, and processing is stopped in the middle of the protective film 57 layer. Thus, since the surface of the nozzle forming member 53 other than the processed part is kept covered with the protective film 57, contamination by by-products can be prevented.

  Since the laser processing depth is determined by the laser energy density and the number of shots, an appropriate processing depth can be obtained by selecting the number of shots. In FIG. 7, the taper angles of the processed communication port 5 and the nozzle hole 4 are exaggerated and greatly illustrated, but the taper angle can be adjusted by changing the laser output, and the thickness of the constituent members It can be appropriately selected according to the above.

  Thereafter, the protective film 57 is peeled off from the nozzle / liquid chamber unit 51 together with the adhesive 56 to obtain the nozzle / liquid chamber unit 10 described above.

  After forming the nozzle / liquid chamber unit by joining the nozzle forming member and the liquid chamber constituent member in this way, the communication port and the nozzle are connected to the nozzle / liquid chamber unit using a femtosecond laser. By forming the nozzle, the communication port and the nozzle can be formed sequentially without moving the nozzle / liquid chamber unit, and the positional deviation between the communication port and the nozzle can be eliminated. Bending in the droplet flight direction does not occur, and excellent droplet ejection characteristics can be obtained, and image quality can be improved.

  In addition, by processing the communication port provided in the liquid chamber constituent member using the femtosecond laser and the nozzle hole provided in the nozzle forming member, there are almost no restrictions on the selection of materials that can be used for both members, rigidity, liquid contact resistance, It becomes possible to select the most suitable material for other processing and assembly.

  Furthermore, by performing the process of forming the nozzle with the peelable film member in close contact with the surface of the water-repellent layer, even a femtosecond laser with little by-product generation, a slight amount of by-product is generated. Although generated, this by-product can be prevented from adhering to the nozzle hole outlet surface, and it can be more reliably prevented that the injection direction is disturbed.

Next, a second embodiment of the method for manufacturing a droplet discharge head according to the present invention will be described with reference to FIG.
The nozzle / liquid chamber unit 51 manufactured by the manufacturing method of the present embodiment has an opening diameter on the nozzle forming member 53 side of the communication port 5 formed in the liquid chamber constituting member 52 and the opening diameter of the nozzle hole 4 on the liquid chamber constituting member 52 side. A stepped portion 60 is formed between the communication port 5 and the nozzle hole 4.

  That is, in the first embodiment described above, the communication port 5 and the nozzle hole 4 are linear without any step including the portion bonded by the epoxy adhesive 54 by processing the communication port 5 and the nozzle hole 4 continuously. Formed. In this case, when the depth of the hole including the thickness of the communication port 5 and the nozzle hole 4 becomes deep, for example, when the depth becomes 30 μm or more, the ink (liquid) passes through the communication port 5 and the nozzle hole 4. When ejected, the fluid resistance of the wall surface increases, resulting in inconveniences such as variations in droplet sizes or unstable droplet ejection speed.

  Therefore, in the second embodiment, the diameter of the communication port 5 formed in the liquid chamber constituting member 52 is made larger than the diameter of the nozzle hole 4 to suppress an increase in fluid resistance against ink, and the droplet ejection characteristics. Stabilization is planned.

  However, if the size of the stepped portion 60 becomes too large (the difference between the opening diameter of the communication port 5 and the opening diameter of the nozzle hole 4 becomes too large), the flow of ink at the time of ink filling is obstructed, and bubbles are formed due to stagnation. 8 is trapped. As shown by the dotted line in FIG. 8, the taper angle of the communication port 5 and the nozzle hole 4 is varied to increase the level of the communication port 5 and make a step between the nozzle hole 4 and the nozzle hole 4. It can also be processed into a shape that does not occur.

  Here, the step portion between the communication port 5 and the nozzle hole 4 is formed at the boundary portion between the liquid chamber constituting member 52 and the nozzle forming member 53, but the step portion 60 is not necessarily formed at the boundary portion. Or you may form the level | step-difference part 60 in the position shifted from the boundary part as shown in FIG.

  That is, in the example shown in FIG. 9, the communication port 5 is formed with a relatively large diameter hole portion 5 a on the liquid chamber side and the hole portion 5 a so that the step portion 60 is formed in the liquid chamber constituting member 52. It is formed with a hole 5b on the nozzle side having a small diameter. In this case, as shown by a broken line in FIG. 9, the hole 5a can be narrowed so that the stepped portion 60 between the hole 5a and the hole 5b constituting the communication port 5 is eliminated.

  Further, in the example shown in FIG. 10, a hole portion 4 a having a diameter larger than that of the nozzle hole 4 is formed continuously to the communication port 5 of the liquid chamber constituting member 52 so that the step portion 60 is formed in the nozzle forming member 53. The nozzle forming member 53 is formed. Also in this case, as shown by a broken line in FIG. 10, the stepped portion 60 between the nozzle 4 and the wall surface from the communication port 5 to the hole 4a can be eliminated by using a continuous tapered surface.

  With this configuration, the rigidity of the nozzle forming member 53 and the fluid resistance of the wall surface of the nozzle hole 4 can be set independently, and the degree of freedom in structural design can be increased.

Therefore, the manufacturing process of the present embodiment will be described with reference to FIGS. 11 and 12 in the configuration example of FIG.
First, as shown in FIG. 11A, a nozzle forming member 53 constituting the nozzle / liquid chamber unit 51 is prepared. Here, a polyimide film that is a resin film is used as the nozzle forming member 53. For example, Upilex (trade name) which is a polyimide film made by Ube Industries, or Kapton (trade name) made by DuPont is suitable.

  Then, as shown in FIG. 11B, a fluorine-based water repellent layer 30 is formed by coating the surface of the nozzle forming member 53 made of a resin film with a fluorine-based water repellent. Here, liquid FEP (FEP dispersion) is used as a fluorine-based water repellent, and this is coated. By using FEP as the water repellent, it is possible to obtain a water repellent film having high wiping durability and excellent ink contact resistance.

  As coating methods, methods such as dipping coat, spin coater, roll coater, screen printing, spray coater, etc. are known, but here, after dipping, the solvent is removed by heating and the water repellent film is adhered to the polyimide film. The dipping coating method is used.

  If the FEP coat layer is too thin, unevenness of the formation of the film can occur, and a portion with poor water repellency efficiency is produced. If it is too thick, it is difficult to keep the surface uniform. According to experiments, it is preferable to form the water repellent film 30 so that the thickness falls within the range of 0.5 μm to 5 μm.

  In the conventional excimer laser processing, the FEP film has a problem that the processability is poor and a beautiful round nozzle hole 4 cannot be obtained. In the present invention, however, the femtosecond laser is used to process the nozzle hole. Many of the problems associated with excimer laser processing can be solved.

  Thereafter, as shown in FIG. 11 (c), an epoxy adhesive 54 is applied to the joint surface side of the liquid chamber constituent member 52 in which a predetermined liquid chamber pattern (not shown) is formed by etching, and then water-repellent processed. The nozzle / liquid chamber unit 51 is formed by bonding with the nozzle forming member (polyimide film) 53.

  At this time, if bubbles are generated on the joint surface between the liquid chamber constituting member 52 and the nozzle forming member 53, ink leakage may occur in the completed droplet discharge head, so care must be taken not to mix bubbles. There is. Further, although a one-component epoxy adhesive is used as the adhesive 54, it takes time to cure at room temperature, so that the curing time can be shortened by heating.

  In addition, as a material used for the liquid chamber constituent member 52, when processing the communication port 5 with a femtosecond laser, there is no restriction from the processing surface of the communication port, but Si or ceramic is suitable from the viewpoint of the rigidity of the liquid chamber. In view of other workability, resins such as polyimide and PPS are suitable. By using these materials, the head manufacturing process is simplified, and a high-quality head can be obtained at low cost.

  Next, as shown in FIG. 11 (d), a protective film 57 is attached to the surface of the water repellent film 30. Here, a protective film 57 coated with an adhesive 56 is used and attached to the surface of the fluorine-based water repellent film 30. Also in this case, it is necessary to pay attention so that bubbles do not occur on the joint surface. When bubbles are mixed, the nozzle holes 4 opened at the positions where the bubbles are present may cause by-products or the like to adhere to the nozzle during laser processing, resulting in a loss of quality.

  Here, although the thing with the adhesive 56 is used as the protective film 57, depending on processing conditions, when peeling the protective film 57 after laser processing, the adhesive 56 remains in the nozzle hole 4 periphery. As a result, the water repellency is impaired and the droplet discharge direction may be bent.

  Therefore, it is possible to use a liquid instead of the adhesive 56 as a medium to which the protective film 57 is attached. By sticking the protective film with a liquid interposed, the adhesive material does not remain around the nozzle holes, and a normal nozzle surface can be obtained after the film is peeled off.

  In this case, the liquid may be water, but excellent bondability can be obtained by using a surfactant solution or alcohol that has a low surface tension and can form a liquid film thinly and uniformly. Moreover, monohydric alcohol (C = 1-3) is more suitable in alcohol. By using alcohol, the protective film can be more uniformly adhered, and it can be evaporated immediately after peeling and without residue, so that the cleanliness of the nozzle outlet surface can be maintained.

  Thereafter, as shown in FIG. 12A, primary femtosecond laser processing is performed from the liquid chamber constituting member 52 side. In the primary femtosecond laser processing, the liquid chamber constituting member 52 is processed using the first photomask pattern having a slightly larger diameter provided on the photomask 44 shown in FIG. Here, laser etching is performed to a depth substantially equal to the thickness of the liquid chamber constituting member 52, and laser oscillation is temporarily stopped. The communication port 5 is formed by this primary femtosecond laser processing.

  Thereafter, as shown in FIG. 12B, secondary femtosecond laser processing is performed. Here, as described above, the first photomask used in the primary femtosecond laser processing is performed by moving the photomask 44 shown in FIG. 5 with the laser oscillation after the primary processing temporarily stopped as described above. A second photomask pattern having a slightly smaller diameter provided adjacent to the pattern is changed.

  Then, the processing is stopped when the etching progresses to the middle of the layer of the protective film 57 with the adhesive 56. The nozzle hole 4 is formed by this secondary femtosecond laser processing.

  Thus, after performing the process which forms a communicating port from the liquid chamber structural member side using the 1st mask, and performing the process which forms a nozzle using the 2nd mask, the mask from which a diameter differs Thus, the communication port diameter can be set independently of the nozzle hole diameter, and as described above, an appropriate diameter that suppresses an increase in fluid resistance can be selected.

  Although only one nozzle hole is shown in FIGS. 11 and 12, actually, a plurality of nozzle holes and communication ports are processed, and further, the steps of FIGS. 12 (a) and 12 (b) are performed. This process is repeated for the required number of nozzles.

  Then, after all the nozzle hole processing is completed, as shown in FIG. 12C, the protective film 57 with the adhesive 56 is peeled off to obtain the nozzle / liquid chamber unit in which the communication port 5 and the nozzle hole 4 are formed. . In addition, when performing the process from FIG. 11A to FIG. 12B in a state where a plurality of nozzle / liquid chamber units are integrated, the process of dividing (cutting) into individual nozzle / liquid chamber units is performed. After performing, it is preferable to peel off the protective film 57.

  Therefore, an example in which processing is performed in a state where the plurality of nozzle / liquid chamber units 51 are integrated, and then the member is cut and divided into individual nozzle / liquid chamber units 51 (chips) is shown in FIGS. 13 and 14. The description will be given with reference.

  First, as shown in FIG. 13, for example, a film for forming a plurality of nozzle forming members 53 having a size of about 150 × 120 mm, for example, after forming the water-repellent film 30 with a sheet 71 of about 500 × 1000 mm as a unit. Cut into sheets 73.

  On the other hand, as shown in FIG. 14, for example, an area to be the liquid chamber constituting member 52 is allocated to a 6-inch Si wafer 72, and each liquid is used by using a generally known photolithographic process of semiconductor manufacturing. A predetermined liquid chamber pattern is formed in a portion that becomes the chamber constituting member 52. FIG. 14 shows an arrangement example in which 42 liquid chamber constituting members 52 (chips) are allocated to a 6-inch wafer.

  Thereafter, a film formed by applying an epoxy adhesive 54 with a thickness of 1 to 2 μm to the surface of the silicon wafer 72 to be bonded to the nozzle forming member 53 with an adhesive thin film transfer device or the like, and cutting the resin sheet 71 as described above. A sheet 73 is pasted. The film sheet 73 need not be aligned with high accuracy, and may be aligned so that the film sheet 73 does not come off from the chip area (the region that becomes the liquid chamber constituting member 52).

  As the adhesive used here, an epoxy adhesive (for example, an epoxy one-component adhesive “Ablebond GA-4” (trade name) manufactured by Nippon Able Stick Co., Ltd.) is suitable. In addition, since the heating temperature required for curing these adhesives is usually not so high as about 50 to 70 ° C., the difference in thermal expansion coefficient between the nozzle forming member 53 and the liquid chamber constituting member 52 is a problem here. Don't be.

  In this way, after the protective film 57 is attached to the nozzle / liquid chamber unit assembly 75 in which the silicon wafer 72 and the film sheet 73 are joined and integrated, the communication port 5 and the nozzle hole are formed by a femtosecond laser processing apparatus. Process 4 is performed.

  As described above, after femtosecond laser processing is performed on a wafer basis, for example, a dicing process used in a general IC manufacturing process is applied to cut into individual chips.

  First, the wafer after the femtosecond laser processing is set in a dicing machine with the UV curable adhesive tape side as the processing table side, and dicing is performed along the chip outline indicated by a virtual line in FIG. Here, it is preferable to set the depth of dicing to about the middle of the UV curable adhesive tape layer. By doing so, the nozzle / liquid chamber unit 51 is completely cut, and the UV curable adhesive tape expands in the next step.

  In addition, when using a dicing machine, there is a washing station, and using a machine that can continuously wash chips after dicing can improve the cleaning effect. To preferred.

  The chip-sized nozzle / liquid chamber unit 51 formed in this way is aligned with and bonded to the actuator substrate 1 manufactured in a separate process, thereby constituting a droplet discharge head.

  Next, an example of a mechanism part of an ink jet recording apparatus as an image forming apparatus equipped with a droplet discharge head manufactured by the method for manufacturing a droplet discharge head according to the present invention will be described with reference to FIGS. . 15 is a perspective explanatory view of the apparatus, and FIG. 16 is a side explanatory view of a mechanism portion of the apparatus.

  This ink jet recording apparatus includes a carriage movable in the main scanning direction inside the recording apparatus main body 111, a recording head comprising the ink jet head according to the present invention mounted on the carriage, an ink cartridge for supplying ink to the recording head, and the like. A sheet feeding cassette 114 capable of stacking a large number of sheets 113 from the front side can be removably attached to the lower part of the apparatus main body 111, and the sheets 113 can be manually inserted. The manual feed tray 115 for feeding the paper can be opened up, the paper 113 fed from the paper feed cassette 114 or the manual feed tray 115 is taken in, a required image is recorded by the printing mechanism unit 112, and then the rear side The paper is discharged to a paper discharge tray 116 attached to the printer.

  The printing mechanism 112 holds a carriage 123 slidably in the main scanning direction by a main guide rod 121 and a sub guide rod 122 which are guide members horizontally mounted on left and right side plates (not shown). (Y), cyan (C), magenta (M), black (Bk) each head is composed of an ink jet head that is a liquid droplet ejection head according to the present invention for ejecting ink droplets of each color, and a plurality of ink ejection openings are mainly used. They are arranged in a direction crossing the scanning direction and mounted with the ink droplet ejection direction facing downward. Also, each ink cartridge 125 for supplying each color ink to the head 124 is replaceably mounted on the carriage 123. The ink cartridge according to the present invention can be mounted.

  The ink cartridge 125 has an air port that communicates with the atmosphere upward, a supply port that supplies ink to the inkjet head below, and a porous body filled with ink inside, and the capillary force of the porous body Thus, the ink supplied to the inkjet head is maintained at a slight negative pressure.

  Further, although the heads 124 of the respective colors are used here as the recording heads, a single head having nozzles for ejecting ink droplets of the respective colors may be used.

  Here, the carriage 123 is slidably fitted to the main guide rod 121 on the rear side (downstream side in the paper conveyance direction), and is slidably mounted on the sub guide rod 122 on the front side (upstream side in the paper conveyance direction). doing. In order to move and scan the carriage 123 in the main scanning direction, a timing belt 130 is stretched between a driving pulley 128 and a driven pulley 129 that are rotationally driven by a main scanning motor 127. The carriage 123 is reciprocally driven by forward and reverse rotations of the main scanning motor 127.

  On the other hand, in order to convey the sheet 113 set in the sheet cassette 114 to the lower side of the head 124, the sheet 113 is guided from the sheet feeding cassette 114 to the sheet feeding roller 131 and the friction pad 132. A guide member 133, a transport roller 134 that reverses and transports the fed paper 113, a transport roller 135 that is pressed against the peripheral surface of the transport roller 134, and a tip that defines the feed angle of the paper 113 from the transport roller 134 A roller 136 is provided. The transport roller 134 is rotationally driven by a sub-scanning motor 137 through a gear train.

  A printing receiving member 139 is provided as a paper guide member that guides the paper 113 fed from the transport roller 134 on the lower side of the recording head 124 corresponding to the movement range of the carriage 123 in the main scanning direction. On the downstream side of the printing receiving member 139 in the paper conveyance direction, a conveyance roller 141 and a spur 142 that are rotationally driven to send the paper 113 in the paper discharge direction are provided, and paper discharge that further feeds the paper 113 to the paper discharge tray 116. A roller 143 and a spur 144, and guide members 145 and 146 forming a paper discharge path are disposed.

  At the time of recording, the recording head 124 is driven according to the image signal while moving the carriage 123, thereby ejecting ink onto the stopped sheet 113 to record one line. Record the line. Upon receiving a recording end signal or a signal that the trailing edge of the sheet 113 reaches the recording area, the recording operation is terminated and the sheet 113 is discharged.

  A recovery device 147 for recovering defective ejection of the head 124 is disposed at a position outside the recording area on the right end side in the movement direction of the carriage 123. The recovery device 147 includes a cap unit, a suction unit, and a cleaning unit. The carriage 123 is moved to the recovery device 147 side during printing standby, and the head 124 is capped by the capping unit, and the ejection port portion is kept in a wet state to prevent ejection failure due to ink drying. Further, by ejecting ink that is not related to recording during recording or the like, the ink viscosity of all the ejection ports is made constant and stable ejection performance is maintained.

  When a discharge failure occurs, the discharge port (nozzle) of the head 124 is sealed by the capping unit, and bubbles and the like are sucked out from the discharge port by the suction unit through the tube. Is removed by the cleaning means to recover the ejection failure. Further, the sucked ink is discharged to a waste ink reservoir (not shown) installed at the lower part of the main body and absorbed and held by an ink absorber inside the waste ink reservoir.

  As described above, since the ink jet recording apparatus is equipped with the ink jet head according to the method of manufacturing a liquid droplet ejecting head according to the present invention, there is little variation in ink droplet ejection characteristics, and an image capable of recording an image with high image quality. A forming device is obtained.

It is a plane sectional view of a droplet discharge head manufactured by a method for manufacturing a droplet discharge head according to the present invention. It is a plane explanatory view in the state where the same head was disassembled. FIG. 3 is a cross-sectional explanatory view taken along line AA in FIG. 2. FIG. 3 is a cross-sectional explanatory view taken along line BB in FIG. 2. It is a schematic optical path diagram of the mask pattern projection optical system of the femtosecond laser processing apparatus used for carrying out the present invention. FIG. 4 is a cross-sectional explanatory diagram of the nozzle / liquid chamber unit before laser processing for the first embodiment of the method for manufacturing a droplet discharge head according to the present invention. It is a cross-sectional explanatory view of the nozzle / liquid chamber unit after laser processing of the same embodiment. Similarly, it is sectional explanatory drawing of the nozzle and the liquid chamber unit after the laser processing of 2nd Embodiment. It is sectional explanatory drawing which shows the example from which the embodiment differs. It is sectional explanatory drawing which shows the other different example of the embodiment. It is explanatory drawing with which it uses for description of the manufacturing process of the nozzle and the liquid chamber unit which concerns on the same embodiment. It is explanatory drawing with which it uses for description of the process following FIG. It is plane explanatory drawing with which it uses for description of the manufacturing process by the batch process of a nozzle and a liquid chamber unit. It is a plane explanatory drawing of a wafer unit similarly. 1 is a perspective explanatory view illustrating an example of an image forming apparatus according to the present invention. It is side surface explanatory drawing of the mechanism part of the apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Actuator board | substrate 2 ... Channel board 3 ... Nozzle board 4 ... Nozzle 5 ... Nozzle communication path 6 ... Liquid chamber 7 ... Fluid resistance part 8 ... Ink supply hole 9 ... Liquid chamber space | interval wall 10 ... Nozzle and liquid chamber unit 11 ... Actuator element 12 ... Diaphragm 13 ... Gap (gap)
14 ... Electrode (individual electrode)
DESCRIPTION OF SYMBOLS 41 ... Laser beam 42 ... Fly eye lens 43 ... Field lens 44 ... Photomask 45 ... Averter 46 ... Projection lens 47 ... Nozzle plate 51 ... Nozzle and liquid chamber unit 52 ... Liquid chamber component 53 ... Nozzle formation member 53 ... Epoxy adhesion Agent 55 ... Fluorine-based water repellent layer 56 ... Adhesive 57 ... Protective film

Claims (11)

  A nozzle forming member having a plurality of nozzles for discharging droplets and having a water repellent layer formed on the surface thereof, and a liquid chamber constituting member having a plurality of liquid chambers in which the nozzles communicate with each other through communication ports. In the method of manufacturing a droplet discharge head, after the nozzle forming member and the liquid chamber constituting member are joined and integrated to form an integrated nozzle / liquid chamber unit, the nozzle / liquid chamber unit is 1 picosecond or less. A method of manufacturing a droplet discharge head, wherein the nozzle and the communication port are formed by a plurality of pulses of laser light emitted from a laser oscillator that oscillates at a pulse emission time of.   2. The method of manufacturing a droplet discharge head according to claim 1, wherein the communication port and the nozzle are sequentially formed without moving the nozzle / liquid chamber unit. Method.   3. The method of manufacturing a droplet discharge head according to claim 1, wherein the first mask is used to form the communication port from the liquid chamber constituent member side, and then the second mask is used. A method of manufacturing a droplet discharge head, wherein a process for forming the nozzle is performed.   4. The method of manufacturing a droplet discharge head according to claim 1, wherein the liquid chamber constituting member is made of Si, ceramics, polyimide, or PPS. Method.   5. The method of manufacturing a droplet discharge head according to claim 1, wherein the water repellent layer formed on the discharge side surface of the nozzle forming member is a FEP coating layer. Manufacturing method of the discharge head.   6. The method of manufacturing a droplet discharge head according to claim 5, wherein a thickness of the FEP coat layer is in a range of 0.5 to 5 [mu] m.   7. The method of manufacturing a droplet discharge head according to claim 1, wherein the nozzle is formed while a peelable film member is in close contact with the surface of the water repellent layer. A method for manufacturing a droplet discharge head.   7. The method of manufacturing a liquid droplet ejection head according to claim 1, wherein the nozzle is formed in a state where a film member that can be peeled off via a liquid is in close contact with the surface of the water repellent layer. A method for manufacturing a droplet discharge head.   9. The method for manufacturing a droplet discharge head according to claim 8, wherein a surfactant solution or a monohydric alcohol is used as the liquid for closely contacting the film member.   10. The method for manufacturing a droplet discharge head according to claim 1, wherein the nozzle forming member and a unit in which a liquid chamber constituent member assembly in which a plurality of liquid chamber constituent members are integrally arranged is joined. After processing the nozzle and the communication port, the chip-shaped nozzle / liquid chamber unit is formed by cutting and separating into a predetermined size, and then joined to an actuator substrate for pressurizing the liquid in the liquid chamber A method for manufacturing a droplet discharge head. An image forming apparatus that includes a droplet discharge head that discharges droplets from a nozzle and forms an image on a recording medium. The droplet discharge head is manufactured by the manufacturing method according to claim 1. An image forming apparatus, which is a droplet discharge head.

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