JPH0655736A - Ink jet recording head - Google Patents

Abstract

PURPOSE:To ensure that the part of a flow path wall which partitions ink flow passage grooves is at the same height as the part of a peripheral wall positioned at the periphery, when an ink flow passage groove is formed in a photosensitive resin layer laminated on the first substrate using photolithography technique. CONSTITUTION:The subject ink jet recording head consists of a photosensitive resin layer 12 laminated on the first substrate with energy activation parts 9, and an ink flow passage groove 15 and an ink supply chamber area 15 formed on the photosensitive resin layer 12 using photolithography technique. In addition, a film 11 of specified thickness is formed in an area where the ink flow passage groove 14 is formed between the first substrate and the photosensitive resin layer 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head for a liquid jet recording apparatus, and more particularly to a bubble jet type ink jet recording head.

[0002]

2. Description of the Related Art The non-impact recording method has recently attracted interest in that noise generation during recording is extremely small to a negligible level. Among them, the so-called inkjet recording method, which is capable of high-speed recording and is capable of recording without requiring a special fixing process on plain paper, is an extremely powerful recording method. Various methods have been proposed or already commercialized and put into practical use.

In such an ink jet recording method, a small droplet (droplet) of a recording liquid called a so-called ink is ejected,
Recording is performed by adhering it to a recording medium, and is roughly classified into several systems according to the method of generating the droplets and the control method for controlling the flight direction of the generated droplets.

The first method is, for example, US Pat. No. 3060.
No. 429 is disclosed. this is,
It is called the Teletype method, in which droplets are generated by electrostatic attraction, the generated droplets are subjected to electric field control according to a recording signal, and the droplets are selectively attached to a recording medium to perform recording. It is a thing.

More specifically, an electric field is applied between the nozzle and the accelerating electrode to discharge uniformly charged droplets from the nozzle.
Recording is performed by ejecting ejected liquid droplets between xy deflection electrodes configured to be electrically controllable according to a recording signal and selectively adhering the liquid droplets on a recording medium according to a change in electric field strength. Is.

The second method is, for example, US Pat. No. 3,596.
No. 275, U.S. Pat. No. 3,298,030, and the like. This is called the Sweet method, and a droplet whose charge amount is controlled is generated by the continuous vibration generation method, and this droplet whose charge amount is controlled is passed between the deflection electrodes to which a uniform electric field is applied. By flying, recording is performed on the recording medium.

Specifically, a charging electrode configured so that a recording signal is applied before an orifice (ejection port) of a nozzle, which is a part of a recording head provided with a piezoelectric vibrating element, has a predetermined distance. The piezoelectric vibrating elements are arranged apart from each other, and an electric signal having a constant frequency is applied to the piezoelectric vibrating elements to mechanically vibrate the piezoelectric vibrating elements, thereby ejecting liquid droplets from the orifices. At this time, electric charges are electrostatically induced in the droplets ejected by the charging electrodes, and the droplets are charged with an electric charge amount according to the recording signal. The droplets whose charge amount is controlled are deflected according to the added charge amount when flying between the deflection electrodes to which a constant electric field is uniformly applied, and only the droplets that carry the recording signal are recorded. It is designed to adhere to liquids.

The third method is, for example, US Pat. No. 3,416.
No. 153 is disclosed. this is,
It is called a Hertz method, and is a method of applying an electric field between a nozzle and a ring-shaped charging electrode to generate and atomize droplets by a continuous vibration generation method, and record the droplets. That is, the atomization state of liquid droplets is controlled by modulating the electric field strength applied between the nozzle and the charging electrode according to the recording signal, and the gradation of the recorded image is produced and recording is performed.

The fourth method is, for example, US Pat. No. 3747.
No. 120 specification. this is,
It is called the Stemme method and has a fundamentally different principle from the first to third methods. That is, in any of the first to third methods, the liquid droplets ejected from the nozzles are electrically controlled while the liquid droplets are flying, and the liquid droplets carrying the recording signal are selectively deposited on the recording medium. On the other hand, the Stem method is used for recording, while the droplets are ejected and ejected from an ejection port according to a recording signal to perform recording.

That is, in the Stemme system, an electric recording signal is applied to a piezo-vibration element attached to a recording head having an ejection port for ejecting a liquid droplet, and this electric recording signal is applied to the piezo-vibration element mechanical. The recording is performed by changing to the mechanical vibration, and ejecting droplets from the ejection port according to the mechanical vibration to cause the droplets to fly and adhere to the recording medium.

Each of these four methods has its own characteristics, but at the same time, it has problems to be solved.

First, in the first to third methods, direct energy for generating droplets is electrical energy, and deflection control of droplets is also electric field control. Therefore, the first method is simple in configuration, but requires a high voltage to generate droplets, and it is difficult to form the recording head with multiple nozzles, and is not suitable for high-speed recording.

The second method is suitable for high-speed recording because it is possible to use a recording head with multiple nozzles, but it is complicated in structure, and the electrical control of liquid droplets is high and difficult. Satellite dots are likely to occur on the top.

The third method enables recording with excellent gradation by atomizing droplets, but on the other hand, it is difficult to control the atomized state. Further, there are drawbacks such that fog occurs in a recorded image and it is not suitable for high-speed recording because it is difficult to form a recording head with multiple nozzles.

The fourth method has many advantages over the first to third methods. First, the structure is simple. In addition, since droplets are ejected on demand from the ejection ports of the nozzles for recording, among the droplets ejected and ejected as in the first to third methods, the droplets not required for image recording are collected. It becomes unnecessary to do. Further, unlike the first and second methods, there is no need to use a conductive recording liquid,
This has the advantage that the recording liquid has a large degree of freedom in terms of material. However, it is difficult to make the recording head multi-nozzle because there are problems in processing the recording head, and it is extremely difficult to downsize the piezoelectric vibrating element having a desired resonance frequency. Further, since the droplets are ejected and ejected by the mechanical energy of mechanical vibration of the piezo-vibration element, it is unsuitable for high-speed recording in combination with the difficulty of forming the multi-nozzle.

As described above, the conventional liquid jet recording method has advantages and disadvantages in terms of configuration, high-speed recording, multi-nozzle recording head, generation of satellite dots and fog of recorded image. However, there is a restriction that it can be applied only to the application in which its advantage is exerted.

However, such an inconvenience can be almost eliminated by adopting the ink jet recording system disclosed in Japanese Patent Publication No. 56-9429 proposed by the present applicant. In this method, the ink in the liquid chamber is heated to generate bubbles, thereby causing a pressure increase in the ink and ejecting the ink from a fine capillary nozzle to perform recording. Many inventions have been made by utilizing this principle.

One of them is, for example, Japanese Examined Patent Publication No. 62-59.
There is one disclosed in Japanese Patent No. 672. This is because a photosensitive resin layer is laminated on a heating element substrate provided with a large number of heating elements,
Ink passages are formed in the photosensitive resin layer by a photolithography method, and then a lid substrate is laminated on the photosensitive resin layer to cover the ink passages to form the ink passages. .

Here, FIG. 15 shows a Japanese Patent Publication No. 62-59672.
This shows a specific example of an ink jet recording head formed by the method described in Japanese Patent Laid-Open Publication No. 2003-242, in which a large number of heating elements 2 are provided on a heating element substrate 1 and a protective film 3 for covering these heating elements 2 is provided. And the photosensitive resin layer 4 on the protective film 3.
And the lid substrate 5 are laminated. A large number of ink flow channels 6 are formed in the photosensitive resin layer 4 at positions corresponding to the respective heating elements 2 by a photolithography method, and the ink flow channels 6 are covered with a lid substrate 5 to form ink flow channels. 7 are formed.

[0020]

In the photosensitive resin layer 4 after the ink channel grooves 6 are formed, each ink channel groove 6 is formed.
Comparing the flow path wall 4a partitioning each other with the outer peripheral walls 4b located at both ends in the arrangement direction of the ink flow path grooves 6, the flow path wall 4a
The film thickness at the portion a becomes low as indicated by "Δ", and a step is formed. Therefore, when the lid substrate 5 is laminated on the photosensitive resin layer 4, the channel wall 4a and the lid substrate 5 do not adhere to each other,
Separation of the ink flow paths 7 cannot be ensured, which adversely affects ink ejection performance.

The cause of such a step difference is that the flow path wall 4
It is considered that a has a larger surface area per unit volume than the outer peripheral wall 4b, and the flow path wall 4a is easily dissolved by the developing solution in the developing step which is one of the steps of forming the ink flow path groove 6.

[0022]

The invention according to claim 1 is
A first substrate provided with a large number of energy acting portions, and the first substrate
A photosensitive resin layer formed on the substrate by a photolithography method to form a large number of ink flow channels corresponding to each of the energy acting portions and a common ink supply chamber region communicating with each ink flow channel, and the photosensitive resin layer. An ink jet recording head, comprising: a second substrate bonded on a layer to form an ink flow path and an ink supply chamber by covering the ink flow path groove and the ink supply chamber region; A coating film having a predetermined thickness was provided in a region where the ink flow channel groove was formed between the resin layer and the resin layer.

According to a second aspect of the present invention, in the invention according to the first aspect, a dummy which does not correspond to an energy acting portion is provided at both ends in the arrangement direction of a large number of ink flow channel grooves formed corresponding to each energy acting portion. In addition to forming the ink flow channel, the film was formed in the area where the dummy ink flow channel was formed.

According to a third aspect of the invention, in the second aspect of the invention, the dummy ink flow channel groove is formed without communicating with the ink supply chamber region.

[0025]

According to the invention of claim 1, the ink flow path groove and the ink supply chamber region are formed in the photosensitive resin layer laminated on the first substrate by the photolithography method. However, the first substrate and the photosensitive resin layer are formed. By providing a coating film of a predetermined thickness in the area for forming the ink flow channel between and, because the area for forming the ink flow channel in the photosensitive resin layer is preliminarily increased by the thickness dimension of the coating, In the developing step, which is one of the steps of forming the ink flow path groove, the flow path wall partitioning these ink flow path grooves is dissolved more than the outer peripheral wall part, so that the photosensitive resin layer becomes a flow path wall. And the outer peripheral wall portion have substantially the same height, and when the second substrate is joined to the photosensitive resin layer, the flow path wall portion and the outer peripheral wall portion are evenly joined to each other. The flow paths are reliably separated.

According to the second aspect of the present invention, by providing the coating film also in the region where the dummy ink flow path groove is formed, the region where the coating film is provided is widened, and the heating element is effectively protected by the coating film.

According to the third aspect of the present invention, since the dummy ink flow channel is not communicated with the ink supply chamber region, the dummy ink flow channel formed by covering the dummy ink flow channel with the second substrate. Therefore, air is not sucked into the ink supply chamber.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. First, FIG. 3 to FIG. 10 are schematic diagrams for explaining the manufacturing procedure of the ink jet recording head of this embodiment. In the process shown in FIG. 3, an energy action for generating an ink ejection pressure for ejecting ink such as a heating element or a piezo element on a heating element substrate 8 which is a first substrate made of a material such as silicon, glass or ceramics. A predetermined number of heating elements 9 as parts are arranged, and further,
A protective film 10 made of SiO ₂ , Ta ₂ O ₅ , glass or the like is coated, if necessary, for the purpose of imparting ink resistance and electric insulation. A signal input electrode (not shown) is connected to the heating element 9. Then, on this protective film 10,
A coating 11 of SiO ₂ , Si ₃ N ₄ or the like is coated to a predetermined thickness. The coating film 11 covers only the region where the heating element 9 is arranged, that is, the region where the ink flow channel groove is formed in the photoresist film described later.

In the step shown in FIG. 4, the surfaces of the protective film 10 and the film 11 obtained through the process of FIG. 3 are cleaned and dried, and then the protective film 10 and the film 1 are formed.
A dry film type photoresist film 12 (film thickness, about 25 to 100 μm), which is a photosensitive resin layer, on
It is heated to about 0 to 105 ° C. and laminated at a rate of 0.5 to 4 f / min and a pressure of 1 to ³ kg / cm ² . At this time, the photoresist film 4 is fused to the protective film 10 and the coating film 11. The portion of the photoresist film 12 that covers the coating film 11 has a greater thickness than the other portions.
It is in a state of being raised by the thickness of.

Then, a photomask 13 having a predetermined pattern is overlaid on the photoresist film 12, and exposure is performed from above the photomask 13. At this time, the installation position of the heating element 9 and the pattern of the photomask 13 are aligned by a known method. As shown in FIGS. 1 and 2, the photomask 13 is provided with a pattern for forming a large number of ink flow channel grooves 14 and ink supply chamber regions 15.

FIG. 5 shows the exposed photoresist film 12
2 shows a step of dissolving and removing the unexposed portion of the sample in a developing solution containing a predetermined organic solvent such as trichloroethane. By this step, only the exposed portions 12a and 12b of the photoresist film 12 remain, and the unexposed portions are dissolved and removed, so that the photoresist film 12 has a large number of ink flow channel grooves 14 and ink supply chambers. Area 15 is formed. In the developing process, the remaining portion which is not dissolved is the flow path wall 12a partitioning the ink flow path grooves 14 from each other, both ends in the arrangement direction of the ink flow path grooves 14 and the outer periphery of the ink supply chamber region 15. It is the outer peripheral wall 12b located in the section.

Here, the flow path wall 12a has a larger surface area per unit volume than the outer peripheral wall 12b and is easily dissolved by the developing solution, but the coating film 11 is provided in the region where the flow path wall 12a is formed. , Is in a state of being raised as compared with the region where the outer peripheral wall 12b is formed. Therefore, the portion of the flow passage wall 12a is dissolved more than the portion of the outer peripheral wall 12b, and as a result, the portion of the flow passage wall 12a and the portion of the outer peripheral wall 12b are melted as shown in FIG. The heights are almost equal.

Then, in order to improve the ink resistance of the flow path wall 12a and the outer peripheral wall 12b, a heat curing treatment (for example, 150 to
Heating at 250 ° C. for 30 minutes to 6 hours) or irradiation with ultraviolet rays (for example, ultraviolet intensity of 50 to 200 mW / cm ² or higher) is carried out to sufficiently advance the polymerization and curing reaction. In addition,
It is also effective to perform both the heat curing treatment and the ultraviolet ray curing treatment.

Although the example in which the ink flow path groove 14 and the ink supply chamber region 15 are formed in the dry film type photoresist film 12 has been described above, the ink flow path is formed by, for example, a photolithography method for a liquid photoresist. A groove or an ink supply chamber area may be formed. At this time, the composition of the liquid photoresist is the photoresist film 12
The same as or similar to is desirable for performing post-treatment joining. When a liquid photoresist is used, its coating method may be spin coating, roll coating, dip coating, screen spraying, printing or the like.

Next, referring to FIG. 6, a dry film type photosensitive resin such as ultraviolet rays is provided on one surface of a lid substrate 16 which is a second substrate which covers the ink flow channel 14 and the ink supply chamber region 15. It shows a process of laminating a dry film 17 which is a cured resin. The dry film 17 may be laminated by the same method as that for the photoresist film 12. The lid substrate 16 is made of a material that transmits electromagnetic waves (for example, an ultraviolet light transmissive material) and is not easily deformed by the contraction stress of the photosensitive resin such as the dry film 17, but is manufactured. Considering the above convenience and economy, glass, epoxy resin, acrylic resin, vinyl resin and the like are suitable.

FIG. 7 shows a step of laminating the heating element substrate 8 and the lid substrate 16 and bonding (pressing and adhering) the photoresist film 12 and the dry film 17 which face each other. At the time of this bonding, the laminated heating element substrate 8 and lid substrate 16 are placed on a hot plate in a range of 100 to 1
It is carried out by heating to 20 ° C. and applying a pressure of 0.03 kg / cm ² for 2 seconds. After the joining is completed, the dry film 17 laminated on the lid substrate 16 made of a transparent ultraviolet light material is irradiated with ultraviolet rays (for example, 50%) in a non-oxygen atmosphere.
-200 mW / cm ² or higher (ultraviolet ray intensity) to sufficiently cure the dry film 9. Furthermore, heat curing treatment (for example, at 130 to 250 ° C. for 30 minutes to
6 hours) is also effective.

FIG. 8 shows the appearance of the ink jet recording head after the process shown in FIG. 7 is completed. By covering the ink channel groove 14 with the lid substrate 16, the ink channel 18 is formed.
Is formed, and the ink supply chamber 19 is formed by covering the ink supply chamber region 15 with the flat plate-shaped member 16.

By covering the protective film 10 in the region where the ink flow channel 14 is formed with the coating film 11, the flow channel wall 12a and the outer peripheral wall 12b have substantially the same height. Therefore, the upper end surfaces of the flow path wall 12a and the outer peripheral wall 12b are in close contact with the dry film 17 of the lid substrate 16, and the respective ink flow paths 18 can be reliably separated.

After the lamination of the heating element substrate 8 and the lid substrate 16 and the joining of the photoresist film 12 and the dry film 17 are completed as described above, the ink flow as shown in FIGS. 8 and 9 is performed. Cutting is performed along the line aa orthogonal to the path 18, and the ink ejection port 20 is formed at the tip of the ink flow path 18 on the cut surface. The reason for performing such cutting is to optimize the distance between the heating element 9 and the ink ejection port 20 in the ink flow path 18, and the area to be cut is appropriately determined. Further, this cutting may be performed by a dicing method usually adopted in the semiconductor industry.

FIG. 10 is a sectional view taken along the line bb in FIG. 8, in which the cut surface along the line aa is polished and smoothed, and the ink inlet 21 formed in the lid member 16.
The ink jet recording head shown in FIG. 10 is completed by attaching the ink supply pipe 22 to.

The above-mentioned photosensitive resin is not limited to the ultraviolet curable resin, but may be any composition which is sensitive to electromagnetic waves such as visible light, X-rays, electron beams and laser light.

Here, the principle of ejection of the liquid droplets 23 by the ink jet recording head manufactured through the above steps is shown in FIG.
It will be described based on 1. The figure (a) is a steady state,
At the ink ejection port 20 formed at the tip of the ink flow path 18, the surface tension of the ink 24 filling the ink flow path 18 and the external pressure are kept in equilibrium.

FIG. 6B shows a state in which the heating element 9 is heated by energizing the signal input electrodes 25 and 26 connected to the heating element 9, and the surface temperature of the heating element 9 rises sharply and the adjacent ink A boiling phenomenon occurs in the layer, and minute bubbles 27 are generated.

In FIG. 6C, the adjacent ink layer which is rapidly heated on the entire surface of the heating element 9 is instantly vaporized to form a boiling film,
The bubble 27 has grown. At this time, the ink flow path 1
The pressure in 8 rises as much as the bubble 27 grows, the balance with the external pressure at the ink ejection port 20 is lost, and the ink column starts to grow from the ink ejection port 20.

FIG. 6D shows a state in which the bubble 27 has grown to the maximum, and the ink 24 corresponding to the volume of the bubble 27 is pushed out from the ink ejection port 20 as an ink column.
At this time, the power supply to the signal input electrodes 25 and 26 has already been cut off, and the surface temperature of the heating element 9 is decreasing. That is, the timing at which the volume of the bubble 27 becomes maximum is slightly behind the timing at which the signal input electrodes 25 and 26 are energized.

FIG. 6E shows a state in which the bubble 27 is cooled by the ink 24 or the like and starts to contract. The front end of the ink column moves forward while maintaining the pushing speed, and at the rear end of the ink column, the ink flow path 1 accompanying the contraction of the bubbles 27 is generated.
The ink 24 flows back into the ink flow path 18 due to the pressure drop in the ink channel 8, and the ink column is constricted.

In FIG. 6F, the bubble 27 is further contracted, and the ink 24 comes into contact with the upper surface of the heating element 9, so that the heating element 9
The upper surface of the is rapidly cooled. Ink ejection port 2
At 0, the external pressure is higher than the pressure in the ink flow path 18, so that the meniscus is large and enters the ink flow path 18. On the other hand, the tip of the ink column becomes a droplet 23,
The ink is ejected at a speed of 5 to 10 m / s toward a recording paper (not shown) provided at a position facing the ink ejection port 20.

FIG. 9G shows a state in which the ink 24 is supplied again into the ink flow path 18 by the capillarity after the discharge of the droplet 23 is completed, and the same state as that in FIG. The bubble 27 has completely disappeared.

Next, specific product names that can be used as the dry film type photoresist film 12 in the present invention will be illustrated. For example, permanent photopolymer coating RISTOM manufactured by DuPont, solder mask 700S, 740S, 700FR, 7
40FR, SX1 and PhotecS manufactured by Hitachi Chemical Co., Ltd.
R-1000, SR-2000, SR-3000
And Audil SE-250, S made by Tokyo Ohka Kogyo Co., Ltd.
E-238, SE-225, SP-750, SP
-740, SP-725, SX-350, SY-
There are 325 mag. In addition, as the photosensitive resin that can be used, many of the photosensitive resin compositions used in the field of ordinary photolithography can be mentioned. For example, diazoresin, p-diazoquinone, and further, a photopolymerization type photopolymer using a vinyl monomer and a polymerization initiator, a dimerization type photopolymer using polyvinyl cinnamate, etc. and a sensitizer, orisonaphthoquinodiazide And a novolac-type phenol resin, a mixture of polyvinyl alcohol and a diazo resin, a polyether type photopolymer obtained by copolymerizing 4-glycidyl ethylene oxide with benzophenone or glycidyl chalcone, di-N, N-dimethylmethacrylamide For example, a copolymer with acrylamide benzophenone, an unsaturated polyester photosensitive resin (for example, APR
(Manufactured by Asahi Kasei Corp.), Tevista (manufactured by Teijin Ltd.), Sonne (manufactured by Kansai Paint Co., Ltd.), an unsaturated urethane oligomer-based photosensitive resin, a photosensitive resin composition in which a photopolymerization initiator is mixed with a bifunctional acrylic monomer, Dichromate photoresist,
Examples include non-chromium-based water-soluble photoresists, polyvinyl cinnamate-based photoresists, oxidized rubber-azide-based photoresists, and the like.

When the photosensitive resin layer on the heating element substrate 8 is formed of a liquid photoresist, the dry film photoresist used in the present invention may be dissolved in a solvent. As liquid photoresist products, BMRS100 manufactured by Tokyo Ohka Kogyo Co., Ltd.
0 is known.

Further, the dry film 17 is attached to the lid substrate 16
The method of laminating on top is not limited to the pressure sticking method, and any method capable of uniformly laminating the photosensitive resin such as the dry film 17 may be used. For example, the usual spin coating, roll coating, dip coating, screen spraying, printing method and the like as described above can be used.

Next, FIG. 12 shows the structure of the bubble generating portion using the heating resistor 9a as the energy acting portion. The heating resistor 9a has signal input electrodes 25a and 26a.
The power supply device 28 is connected via a. The heating resistor 9a and the signal input electrodes 25a and 26a are covered with a protective film 10a.

Examples of useful materials for the heating resistor 9a include tantalum-SiO ₂ mixture, tantalum nitride, nichrome, silver-palladium alloy, silicon semiconductor, or hafnium, lanthanum, zirconium, titanium, tantalum. Examples thereof include borides of metals such as tungsten, molybdenum, niobium, chromium and vanadium. Among these materials forming the heating resistor 9a, the metal boride can be mentioned as an especially excellent one. Among them, hafnium boride has the most excellent characteristic, and then zirconium boride. The order is lanthanum boride, tantalum boride, vanadium boride, and niobium boride. Moreover, the heating resistor 9a can be formed by using a method such as electron beam vapor deposition or sputtering, using the above materials. The film thickness of the heating resistor 9a is determined according to the area, the material, the shape and size of the heat-acting portion, and the actual power consumption so that the amount of heat generated per unit time is as desired. However, it is usually 0.001 to 5 μm, and preferably 0.01 to 1 μm.

As the material forming the signal input electrodes 25a, 26a, many of the commonly used electrode materials are effectively used. Specifically, for example, Al, Ag, A
n, Pt, Cu and the like are used, and these are provided at a predetermined position with a predetermined size, shape and thickness by a method such as vapor deposition.

The characteristics required for the protective film 10a are such that the heat generated in the heating resistor 9a is not effectively transferred to the ink 24, and the heating resistor 9a and the signal input electrodes 25a and 26a are discharged from the ink 24. Is to protect.
Examples of useful materials for forming the protective film 10a include silicon oxide, silicon nitride, magnesium oxide, zirconium oxide, and the like, which can be formed by a method such as electron beam evaporation or sputtering. it can. The thickness of the protective film 10a is usually 0.01 μm.
m to 10 μm, preferably 0.1 to 5 μm, optimally 0.
It is 1 to 3 μm.

Next, an embodiment of the invention described in claim 2 will be described with reference to FIG. The same parts as those described with reference to FIGS. 1 to 12 are designated by the same reference numerals, and the description thereof will be omitted (same below). In this embodiment, dummy ink flow channel grooves 1 that do not correspond to the heating elements 9 are provided at both ends in the arrangement direction of the multiple ink flow channel grooves 14 that are formed corresponding to each heating element 9.
4a is formed. The coating film 11 covers the area where the ink flow channel 14 and the dummy ink flow channel 14a are formed.

In such a structure, the droplets 23 are not ejected from the dummy ink flow channel (not shown) formed by covering the dummy ink flow channel 14a with the cover substrate 16. This dummy ink channel groove 14a
Since the coating film 11 is also coated on the region where the heating element 9 is formed, the heating element 9 can be effectively protected by the coating film 11. Therefore, the durability of the heating element 9 against corrosion is higher than in the case where the dummy ink flow channel 14a is not formed.

Next, an embodiment of the invention described in claim 3 will be described with reference to FIG. In this embodiment, dummy ink flow channel grooves 14b that do not correspond to the heating elements 9 are formed at both ends in the arrangement direction of the large number of ink flow channel grooves 14 that are formed corresponding to each heating element 9. The dummy ink flow path groove 14b is formed without communicating with the ink supply chamber region 15. The coating film 11 covers the area where the ink flow channel 14 and the dummy ink flow channel 14b are formed.

In such a structure, the droplets 23 are not ejected from the dummy ink flow channel (not shown) formed by covering the dummy ink flow channel 14b with the cover substrate 16. This dummy ink channel groove 14b
Since the film 11 is also applied to the region where the heat-generating element 9 is formed, the heating element 9 can be effectively protected by the film 11. Therefore,
The durability of the heating element 9 against corrosion is higher than that in the case where the dummy ink flow channel 14b is not formed.

Since the dummy ink flow channel 14b is not connected to the ink supply chamber region 15, the dummy ink flow channel 14b is formed by covering the dummy ink flow channel 14b with the cover substrate 16. It is not necessary to suck air into the ink supply chamber 19 (not shown). Therefore, it is prevented that air bubbles are generated in the ink supply chamber 19 due to sucking air into the ink supply chamber 19, and the ejection performance of the droplet 23 is deteriorated by the bubbles.

[0061]

As described above, according to the first aspect of the invention, the first substrate provided with a large number of energy acting portions, and the large number of ink flow channel grooves corresponding to each of the energy acting portions on the first substrate. And a photosensitive resin layer forming a common ink supply chamber region communicating with each ink flow channel groove by a photolithography method, and the ink flow channel groove and the ink supply chamber region being bonded on the photosensitive resin layer. In an ink jet recording head in which a second substrate that covers an ink flow path and an ink supply chamber is laminated, a predetermined area is formed between the first substrate and the photosensitive resin layer in which the ink flow path groove is formed. Since the film having the thickness is provided, the area where the ink flow channel is formed in the photosensitive resin layer is increased in advance by the thickness dimension of the film, which is one of the steps of forming the ink flow channel. In some cases, the portion of the flow path wall partitioning these ink flow passage grooves is dissolved more than the portion of the outer peripheral wall, so that the photosensitive resin layer has substantially the same height as the flow passage wall and the outer peripheral wall. Therefore, when the second substrate is joined to the photosensitive resin layer, the flow path wall portion and the outer peripheral wall portion can be evenly bonded, and therefore each ink flow path can be reliably separated and each This has the effect of improving the performance of ejecting liquid droplets from the ink flow path.

As described above, the second aspect of the present invention provides the energy acting portions at both ends in the arrangement direction of the multiple ink flow channel grooves formed corresponding to the respective energy acting portions in the first aspect of the invention. Since a dummy ink flow channel that does not correspond to the dummy ink flow channel is formed and a film is also provided in the area where the dummy ink flow channel is formed, the area where the film is provided is wide and the heating element is effectively protected by the film. As a result, it is possible to improve the durability of the heat generating element against corrosion as compared with the case where the dummy ink flow channel is not formed.

According to the third aspect of the invention, as described above, the dummy ink flow channel groove is formed in the invention according to the second aspect without being communicated with the ink supply chamber region. Therefore, the dummy ink flow channel groove is formed. It is possible to prevent air from being sucked into the ink supply chamber from the dummy ink flow path formed by being covered with the second substrate, and the sucked air becomes bubbles in the ink supply chamber to improve ink discharge performance. This has the effect of preventing the occurrence of a situation of lowering.

[Brief description of drawings]

FIG. 1 is a plan view showing a region to be coated with a coating film according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a front view showing a state in which a heating element, a protective film, and a coating are formed on a heating element substrate.

FIG. 4 is a front view showing a state in which an ink flow path groove and an ink supply chamber region are formed by a photolithography method on a photoresist film laminated on a heating element substrate.

FIG. 5 is a front view showing a state in which an ink flow path groove is formed by a photolithography method.

FIG. 6 is a front view showing a state in which a dry film is laminated on the lid substrate.

FIG. 7 is a front view showing a state in which a heating element substrate and a lid substrate are laminated.

FIG. 8 is a perspective view showing a state in which a heating element substrate and a lid substrate are laminated.

9 is a sectional view taken along line bb in FIG.

FIG. 10 is a vertical cross-sectional side view of the recording head showing a state in which an ink supply pipe is attached and completed.

FIG. 11 is an explanatory diagram illustrating the principle of ink ejection.

FIG. 12 is a vertical cross-sectional side view showing an enlarged structure of a bubble generating portion in the inkjet recording head.

FIG. 13 is a plan view showing a position where a dummy ink flow channel groove is formed and a region where a film is covered in an embodiment of the invention described in claim 2;

FIG. 14 is a plan view showing a position where a dummy ink flow path groove is formed and an area where a film is covered in an embodiment of the invention described in claim 3;

FIG. 15 is a vertical cross-sectional front view illustrating an inconvenience in the case where an ink flow path groove is formed by a photolithography method in a conventional example.

[Explanation of symbols]

 8 First Substrate 9 Energy Applying Part 11 Coating 12 Photosensitive Resin Layer 14 Ink Flow Channel Grooves 14a, 14b Dummy Ink Flow Channel Groove 15 Ink Supply Chamber Region 16 Second Substrate 18 Ink Flow Channel 19 Ink Supply Chamber

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Claims (3)

[Claims] 1. A first substrate provided with a large number of energy acting portions, a large number of ink flow passage grooves corresponding to each energy acting portion on the first substrate, and a common ink communicating with the respective ink flow passage grooves. A photosensitive resin layer for forming a supply chamber region by a photolithography method, and an ink flow channel and an ink supply chamber are formed by being bonded on the photosensitive resin layer and covering the ink flow channel groove and the ink supply chamber region. In the ink jet recording head in which the second substrate is laminated, a coating film having a predetermined thickness is provided in a region where the ink flow channel groove is formed between the first substrate and the photosensitive resin layer. Inkjet recording head. 2. A dummy ink flow channel that does not correspond to an energy acting part is formed at both ends in the arrangement direction of a large number of ink flow channels formed corresponding to each energy acting part and the dummy ink flow is formed. The ink jet recording head according to claim 1, wherein a film is also provided in a region where the road groove is formed. 3. The ink jet recording head according to claim 2, wherein the dummy ink flow path groove is formed without communicating with the ink supply chamber region.