JPH08323986A - Method for manufacturing ink jet recording head - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a manufacturing method in which a machining allowance by an excimer laser is small, and a discharge port with high processing accuracy can be easily obtained for various amorphous thermoplastic resins. A nozzle part in which an ink supply part 4, a flow path resistance adjusting part 6, and a pressurizing chamber part 7 are formed as concave grooves and vertically penetrates a terminal part of an ink flow path and an ejection port 9 is opened on the back side. The substrate 1 on which 8 is formed in a penetrating state is molded as a non-crystalline thermoplastic resin molded product by using the molding die 10 having the mold pins 12, and the ejection port of the obtained substrate is pressed from the pressure chamber side. Excimer laser light 20 is irradiated to remove burrs and the like slightly left at the opening of the ejection port.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a side chute type ink jet recording head used in a printing apparatus or the like, and more particularly to a method of manufacturing an ink jet recording head using a non-crystalline thermoplastic resin molding as a cavity plate. .

[0002]

2. Description of the Related Art A printing apparatus using an ink jet recording head mechanism is widely used in fields such as desktop printers and fax machines, which are required to be compact and lightweight because of its advantage of simple structure. Several methods have been proposed for the mechanism of the inkjet recording head, but a method of adhering a piezoelectric element to the diaphragm, applying an electric field to the piezoelectric element to expand and contract, and vibrating the diaphragm by the expansion and contraction movement is It has features such as a semi-permanent head life and low running costs, and is expected to be widely used in the future.

FIG. 5 shows an example of a conventional ink jet recording head, (a) is a plan view of a substrate portion of the ink jet recording head, and (b) is a sectional view of the ink jet recording head at a position AA in (a). is there. In the figure,
An ink supply section 4, a supply path 7A branched from the ink supply section 4 via a flow path resistance adjusting section 6, and a pressure chamber section 7 are formed as concave grooves on the surface of a substrate (also referred to as a cavity plate) 1. A plurality of ink flow paths 5 are formed by allowing the pressurizing chamber portion 7 to vertically penetrate the bottom portion thereof and communicate with a nozzle portion 8 having a discharge port 9 opened to the back side. Further, the diaphragm 2 is airtightly adhered to the surface of the substrate 1 to cover the ink supply section 4 and the ink flow path 5, and the surface of the diaphragm 2 facing the pressurizing chamber section 7 has the common electrode 3A interposed therebetween. The piezoelectric element 3 as an electromechanical conversion element is bonded to form an ink jet recording head.

In the ink jet recording head having such a structure, when a voltage is applied to the piezoelectric element 3 selected by the recording signal to cause the piezoelectric element 3 to vibrate, the volume of the pressurizing chamber 7 changes via the diaphragm 2. The ink in the pressure chamber 7 whose backflow is blocked by the flow path resistance adjusting unit 6 is ejected as an ink droplet from the back surface of the substrate 1 through the ejection port 9. In this way, when the surface to be bonded to the diaphragm 2 is the front surface of the substrate 1, a method in which ink droplets are ejected perpendicularly to the back surface is called a side shoot type inkjet recording head, and the ink droplets are generated by the diaphragm 2. The inkjet recording head is of a type that discharges in parallel to the vibrating surface of the.

By the way, as a method of reducing the manufacturing cost of this type of ink jet recording head, it is considered to use a plastic material such as an amorphous thermoplastic resin for the substrate 1 and the diaphragm 2. Specifically, a non-crystalline thermoplastic resin containing polyester, polyester carbonate, polyphenylene oxide, polyphenylene sulfide, polysulfone, polyether sulfone, polyarylate, polyether imide, and their modified products and copolymers are used. The substrate 1 is manufactured by a molding process such as injection molding, and the sheet material for the diaphragm is manufactured by a general sheet molding method such as extrusion molding or calendar molding.

Further, the nozzle portion is formed as a groove formed along the bonding surface between the substrate and the diaphragm, a method of using a metal plate by electroforming, a method of processing a plastic plate with an excimer laser, etc. Various methods have been proposed. Among them, the method of processing with an excimer laser is a method of processing by breaking a chemical bond of a polymer by photoexcitation of ultraviolet rays, and, for example, JP-A-1-29
No. 4040, JP-A-3-169559, JP-A-3-277554, JP-A-6-99581 and the like.

That is, in the method disclosed in Japanese Patent Laid-Open No. 1-294040, an ink flow path, a jetting hole, and a suction hole are formed in a substrate by an excimer laser. In addition, JP-A-3-16955
In the method disclosed in Japanese Patent Publication No. 9, a plastic plate (also referred to as a nozzle plate) that closes the outlet of the nozzle portion is adhered to the substrate, and the plastic plate is irradiated with an excimer laser so as to communicate with the outlet of the nozzle portion (nozzle hole). Also called).

Further, in the method disclosed in Japanese Patent Laid-Open No. 3-277554, a blind blind blind hole is formed in the bottom of the pressurizing chamber by injection molding, and an excimer laser is irradiated from the blind blind side to penetrate the nozzle hole. And shape the discharge port. Further, according to the method disclosed in Japanese Patent Laid-Open No. 6-99581, a shaping process is performed in which the ejection port is formed in the nozzle plate in advance, and the ejection port is irradiated with an excimer laser from the opening end face side to remove burrs protruding from the ejection port during shaping. I do.

[0009]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The method disclosed in Japanese Patent No. 0 has a problem in that the machining cost due to the excimer laser is large and the processing time is enormous, resulting in an economic disadvantage. It is possible to increase the laser power density to shorten the processing time. However, if the power density is increased too much, the heat effect of the excimer laser causes the machined surface and its surroundings to carbonize, resulting in a smooth machined surface. Hard to get. According to our experience, a plate thickness of about 0.3 mm is considered to be a practical limit thickness.

In the method disclosed in Japanese Patent Laid-Open No. 3-169559, the machining allowance is determined by the thickness of the nozzle plate.
Although the processing time is shorter than that of the method disclosed in Japanese Patent Laid-Open No. 1-294040, the processing time is still long, and it is difficult to control the shape of a nozzle taper or the like due to the limitation of laser processing, and the ink droplet ejection characteristics are excellent. There is a problem that it is difficult to obtain a discharge port.

Further, in the method disclosed in Japanese Patent Laid-Open No. 3-277554, similarly to the method described above, it is difficult to control the shape of the nozzle taper due to the limitation of laser processing, and it is difficult to obtain an ejection port having excellent ink droplet ejection characteristics. There is a problem. Furthermore, in the method disclosed in Japanese Patent Laid-Open No. 6-99581, by irradiating the edge of the discharge port with a laser from the nozzle end surface side, the peripheral nozzle end surface is affected by heat and the flatness is obstructed. There is a risk that it will interfere with the process of applying the water-repellent film. Further, as a characteristic of the excimer laser processing, the processed hole is smaller on the emitting side than on the incident side. Therefore, the nozzle hole formed by irradiating the edge of the discharge port with laser from the nozzle end face side has a large inner diameter on the opening side, which makes it difficult to form a discharge port having a tapered nozzle taper. . Further, the use of the nozzle plate makes it difficult to align the nozzle plate with the nozzle part already formed on the substrate side when bonding the nozzle plate to the substrate, and it is difficult to obtain an ejection port having excellent ejection characteristics of ink droplets. There is also a problem that the manufacturing cost is increased.

An object of the present invention is to provide a manufacturing method in which a machining allowance by an excimer laser is small and a discharge port with high processing accuracy can be easily obtained for various amorphous thermoplastic resins.

[0013]

In order to achieve the above-mentioned object, the invention according to claim 1 provides an ink supply section formed as a concave groove on the surface, and a flow path resistance adjusting section from this ink supply section. And a substrate having an ink flow path structure having an ink flow path having a branched pressure chamber portion, and a nozzle portion that vertically penetrates a terminal portion of the ink flow path and has a discharge port opened on the back side, and the substrate. Method for manufacturing an ink jet recording head including a vibrating plate that is airtightly adhered to the surface of the vibrating plate to cover the ink supply unit and the ink flow path, and a piezoelectric element that is adhered to the surface of the vibrating plate facing the pressure chamber section In, a molding step of integrally molding a substrate having an ink flow path structure as a non-crystalline thermoplastic resin molded product, and deburring by irradiating the discharge port of the obtained substrate with laser light from the pressure chamber side. Finishing process Including the.

According to the second aspect of the present invention, in the molding step, a mold pin having a tapered portion corresponding to a discharge port at a tip portion of a round bar having a diameter corresponding to a diameter of a nozzle portion is penetrated through the molding die. Then, the nozzle is inserted into the cavity at the position where the nozzle is formed, the distance between the tip and the inner wall surface of the cavity is maintained at 20 μm or less, and the molding step is performed in this state. Also,
According to a third aspect of the present invention, the molding work is performed in a state where the distance between the tip of the mold pin and the inner wall surface of the cavity is maintained at 20 μm or more, and before the crystalline thermoplastic resin is cured, the mold is molded. The pin is pushed into the cavity until it comes into contact with the inner wall surface of the cavity, and a process of forming an open discharge nozzle hole is included.

Further, in the invention of claim 4, after forming a water-repellent film around the discharge port of the substrate after the molding step, laser light is irradiated from the pressure chamber side to discharge the water-repellent film. It is necessary to move to a finishing process for removing burrs including the protruding portion to the outlet.

[0016]

According to the first aspect of the present invention, the nozzle portion perpendicular to the substrate, which connects the discharge port opened on the back surface of the substrate and the ink flow path formed as the concave groove on the surface, is formed as the through hole in the molding process. At the end of the molding process, the nozzle taper and the like have already been formed and are almost completed. Therefore, excimer laser processing does not require nozzle shape control,
In the molding process, the finishing process of cutting out the burr protruding to the nozzle opening is enough, the machining cost is small, and the nozzle part with high dimensional accuracy is easy without damaging the nozzle shape obtained by molding due to heat influence. Can be formed into Also,
By irradiating the discharge port of the substrate with the laser light from the pressure chamber side, it is possible to avoid the thermal influence on the nozzle end face and maintain the flatness of the nozzle end face. Further, since the nozzle portion in the through state in the molding step can be easily molded without being influenced by the fluidity of the amorphous thermoplastic resin, it is possible to expand the types of the amorphous thermoplastic resin to be used. Become.

Here, as in the invention described in claim 2,
Mold a mold pin having a taper part corresponding to the discharge port at the tip of a round bar with a diameter corresponding to the diameter of the nozzle part, while maintaining the distance between the tip and the inner wall surface of the cavity to 20 μm or less. By doing so, the molding resin does not enter into the gap of 20 μm or less, so that the substrate having the nozzle portion with the discharge port opened can be easily obtained as a non-crystalline thermoplastic resin molded product, and the excimer to be performed thereafter. The machining allowance for laser finishing is reduced.

According to the third aspect of the invention, the distance between the tip of the die pin and the inner wall surface of the cavity is 20.
By performing the molding work while keeping the thickness above μm,
The amorphous thermoplastic resin that has entered the gap of 20 μm or more is pushed out into the cavity until the tip of the mold pin comes into contact with the inner wall surface of the cavity before the crystalline thermoplastic resin is hardened, and is expelled. A substrate provided with a nozzle portion in a state of opening is easily obtained as a non-crystalline thermoplastic resin molded product.

Further, according to the invention of claim 4, a water-repellent film is formed around the discharge port of the substrate after the molding step,
After that, if the molding process such as deburring including the protruding part of the water-repellent film to the ejection port by irradiating the laser beam from the nozzle side, it penetrated and solidified in the process of forming the water-repellent film. It becomes possible to remove the excess portion together with the burr and shape the discharge port.

[0020]

EXAMPLES The present invention will be described below based on examples.
Since the members having the same reference numerals as those of the conventional example have the same functions as those of the conventional example, the description thereof will be omitted. 1A and 1B are views showing an embodiment of a method for manufacturing an inkjet recording head according to the present invention. FIG. 1A is a sectional view of a molding die showing a substrate forming step, and FIG. 1B is a substrate showing an excimer laser finishing step. FIG. In the figure, in the molding process of the substrate 1, a molding die 10 including an upper die 10A having a cavity 11 having a shape corresponding to the substrate 1 and a flat plate-shaped lower die 10B is used, and a diameter corresponding to the diameter of the nozzle portion 8 is used. Nozzle taper part 12A corresponding to the discharge port 9 at the tip of the round bar
The mold pin 12 having the above is penetrated through the upper mold 10A and inserted at the nozzle portion forming position in the cavity 11, and the gap length g between the tip and the inner wall surface of the lower mold 10B is maintained at 20 μm or less. In this state, a polyetherimide resin as a non-crystalline thermoplastic resin was injection molded. In the obtained substrate 1, the nozzle taper portion 12A holds a smooth molding surface, and a slight burr is observed at the edge of the discharge port 9 in the state of being opened on the back surface of the substrate 1, and molding is performed in a gap of 20 μm or less. Nozzle part 8 in which resin does not enter and therefore the discharge port is open to the back
It was proved that the substrate 1 provided with was obtained as a non-crystalline thermoplastic resin molded product.

Therefore, a finishing step is carried out in which the discharge port 9 of the obtained substrate 1 is irradiated with excimer laser light 20 from the pressure chamber 7 side to remove burrs slightly protruding from the edge of the opening of the discharge port 9. Carried out. As a result, the substrate 1 in which the circular ejection port 9 was opened to the back side was obtained in a short processing time without thermally affecting the nozzle taper portion 12A. In addition, a plurality of ink flow paths 5 branched from the ink supply unit 4 were formed by heat-sealing a polyetherimide sheet having a thickness of 300 μm as the vibration plate 2 on the surface of the obtained substrate 1 to cover the groove. .

As described above, according to the method for manufacturing the ink jet recording head of the embodiment, the nozzle including the ejection port 9 opened on the back surface of the substrate and the flow path perpendicular to the substrate connecting the ejection port and the pressure chamber portion. The portion 8 is formed as a through hole in the molding process, and the nozzle taper or the like is already formed at the end of the molding process. Therefore, it is not necessary to control the shape of the nozzle in the excimer laser processing, and the finishing process of cutting out the burr protruding into the nozzle opening in the molding process is sufficient. Therefore, there is an advantage that the nozzle portion having high dimensional accuracy can be easily formed in a short processing time without being damaged.

Further, by irradiating the discharge port 9 of the substrate with the laser beam from the pressurizing chamber 7 side, it is possible to avoid the thermal influence on the nozzle end face and maintain the flatness of the nozzle end face.
The advantage that the water-repellent treatment of the nozzle end surface performed thereafter can be facilitated is obtained. Further, since the nozzle portion in the through state in the molding step can be easily molded without being affected by the fluidity of the amorphous thermoplastic resin, the optimum amorphous thermoplastic resin for the inkjet recording head is selected, The advantage that a substrate having excellent ink droplet ejection performance can be economically advantageously provided is obtained.

Further, since it is not necessary to use the nozzle plate, the processing time required for the nozzle plate alignment and the bonding work is eliminated, and the advantage that the manufacturing cost of the substrate can be reduced can be obtained. 2A and 2B are views showing a different embodiment of the method for manufacturing an ink jet recording head according to the present invention. FIG. 2A is a view showing a state of die pins in an initial stage of a substrate molding process, and FIG. 2B is a latter stage of the substrate molding process. It is a figure which shows the state of the die pin in. In the figure, the difference between this embodiment and the embodiment shown in FIG. 1 is that the gap length g between the tip of the mold pin 12 and the inner wall surface of the lower mold 10B is maintained at 20 μm or more as shown in (a). After injecting the crystalline thermoplastic resin 15 into the cavity 11 in the state, before the resin is hardened, the tip of the die pin 12 contacts the inner wall surface of the lower die 10B (g≈0) until the die is placed in the cavity. It is configured so as to include the process of pushing the pin 12 and forming the discharge port 9 opened on the back surface of the substrate 1. This has an advantage that the finishing machining allowance by the excimer laser can be further reduced and the processing time can be shortened.

FIG. 3 is a view showing a further different embodiment of the method for manufacturing an ink jet recording head of the present invention,
(A) is a diagram showing the state of the ejection port of the substrate obtained in the step of molding the substrate, (b) is a diagram showing the state of the ejection port after the water-repellent film forming process, (c) is a finish by excimer laser It is a figure which shows the state of the discharge port of the board | substrate obtained by processing. In the figure, the difference between this embodiment and the embodiment shown in FIG. 1 is that after a water-repellent film 33 is formed on the nozzle end face 32 around the discharge port 9 of the substrate 1 after the molding process, the nozzle portion 8 is used. The excimer laser light 20 is radiated as a finishing process to collectively remove the burr 31 and the water-repellent film 33, which are generated in the molding process, and the protruding portion 34 to the ejection port 9. According to the method of this embodiment, since the excess portion that has penetrated into the discharge port and solidified in the process of forming the water-repellent film can be removed together with the burr by irradiation of excimer laser light, the burr 31 and the protrusion 34 of the water-repellent layer 34. Compared with the case where the above steps are performed separately, the finishing process by the excimer laser can be simplified, and an advantage that the processing cost can be reduced can be obtained. Further, since the excimer laser light 20 is radiated through the nozzle portion 8 to perform the finishing process, the water-repellent layer 33 is not affected by heat, so that the ink ejected from the ejection port is attached to the nozzle end surface. It becomes possible to fly as ink droplets without doing so, and an inkjet recording head excellent in image forming performance can be obtained.

FIG. 4 is a plan view of a substrate obtained by another embodiment of the method for manufacturing an ink jet recording head of the present invention. In the figure, a polysulfone resin is used as the non-crystalline thermoplastic resin, and a gap length g between the tip of the die pin supported by the upper die so as to be movable in the axial direction and the inner wall surface of the lower die is 500.
The resin was injected into the cavity while maintaining the thickness at μm, and the mold pin was immediately pressed into contact with the lower mold, and the polysulfone resin was cured in this state. The obtained substrate 1 is
A water-repellent agent (trade name, Cytop: made by Asahi Glass) is applied to the end surface of the nozzle to form a water-repellent film, and then the discharge port 9 is irradiated with an excimer laser through the nozzle portion 8 to discharge the discharge port. Finishing processing was performed to collectively remove burrs including the water-repellent film protruding from the opening of No. 9. The obtained substrate 1
Needless to say, a plurality of ink flow paths 5 branched from the ink supply unit 4 are formed by solvent-bonding a polysulfone sheet having a thickness of 200 μm as a vibration plate on the surface to cover the concave groove.

In the substrate 1 shown in FIG. 4, the position of the widest pressurizing chamber 7 in the ink flow path 5 is alternately shifted in the flow path direction, and 26 ink flow paths 5 are limited in the substrate 1. It is configured to be accumulated in the space and to shorten the ejection time width of ink droplets. For this reason, the length and shape of the supply flow path 7A branched from the ink supply section 4 in the flow path resistance adjusting section 6 and the nozzle flow path 8A extending from the pressurizing chamber 7 to the nozzle section 8 are complicated. With the manufacturing method according to this embodiment, the ink flow path portion 5 having a complicated structure as shown in the drawing, as well as the nozzle portion penetrating the substrate vertically from the end portion of the ink flow path and having the ejection port 9 on the back side is opened. 8 can also be formed without causing a defective portion, and as a result, the finishing process by the excimer laser is labor-saving and time-saving, so that the inkjet recording head provided with a substrate having a low manufacturing cost is economical. It has been proved that it can be advantageously provided to

[0028]

As described above, the method of manufacturing the ink jet recording head according to the present invention includes the ink supply section, the ink flow path,
And the ink flow path structure consisting of the nozzle part with the discharge port opened on the back side is manufactured in a molding process up to near the completed state, and then finishing processing such as deburring is performed by irradiating the excimer laser light from the surface side of the substrate. Configured to do. As a result, the machining allowance is significantly reduced compared to the conventional technology that irradiates an unpenetrated nozzle section with excimer laser light to machine the nozzle taper, and since it is not necessary to use a nozzle plate, the machining time is greatly reduced. And the effect of reducing the manufacturing cost can be obtained. In addition, there are many types of amorphous thermoplastic resins that can be molded, and the advantage that the degree of freedom in material selection is widened is obtained.

Further, since it is not necessary to form a hole by excimer laser light and only relatively weak excimer laser light is applied from the flow path side to deburr, there is also a heat effect on the nozzle taper and the nozzle end face portion. Therefore, there is an advantage that an inkjet recording head provided with a base material excellent in ink ejection performance by maintaining a smooth nozzle taper surface obtained by molding can be economically and advantageously provided.

On the other hand, if the nozzle end surface of the base material obtained by molding is subjected to water repellency treatment and then deburred by irradiating excimer laser light from the channel side, smoothness without heat influence is obtained. A thin water-repellent film can be easily formed on the end face of the nozzle, and burrs and excess water-repellent film that has run off can be removed collectively by excimer laser light, which simplifies the finishing process and reduces ink drops. There is an advantage that an inkjet recording head provided with a side chute type substrate that is well cut and has excellent ink ejection performance can be provided economically and advantageously.

[Brief description of drawings]

1A and 1B are views showing an embodiment of a method for manufacturing an ink jet recording head of the present invention, in which FIG. 1A is a sectional view of a molding die showing a substrate molding step, and FIG. 1B shows a finishing step by an excimer laser. Board cross section

2A and 2B are views showing a different embodiment of the method for manufacturing the ink jet recording head of the present invention, FIG. 2A is a view showing the state of the mold pins in the initial stage of the substrate forming step, and FIG. 2B is the substrate forming step. Diagram showing the state of mold pins in the latter half

FIG. 3 is a view showing a further different embodiment of the method for manufacturing an ink jet recording head of the present invention, FIG. 3 (a) is a view showing a state of a discharge port of a substrate obtained in a substrate forming step,
(B) is a view showing a state of the discharge port after the water-repellent film forming process,
FIG. 3C is a diagram showing the state of the discharge port of the substrate obtained by the finishing process with the excimer laser.

FIG. 4 is a plan view of a substrate obtained in another embodiment of the method for manufacturing an ink jet recording head of the present invention.

5A and 5B show an example of a conventional inkjet recording head, FIG. 5A is a plan view of a substrate portion of the inkjet recording head, and FIG. 5B is a cross-sectional view of the inkjet recording head at a position AA in FIG.

[Explanation of symbols]

 1 Substrate (cavity plate) 2 Vibration plate 3 Piezoelectric element 4 Ink supply section 5 Ink flow path 6 Flow path resistance adjusting section 7 Pressurizing chamber section 7A Supply flow path 8 Nozzle section 8A Nozzle flow path 9 Discharge port 10 Mold 10A Upper Mold 10B Lower mold 11 Cavity 12 Mold pin 12A Nozzle taper part 15 Amorphous thermoplastic resin 20 Excimer laser light 31 Burr 32 Nozzle end face 33 Water repellant film 34 Water repellant film protruding part g Gap length

Claims (4)

[Claims] 1. An ink supply part formed as a groove on the surface, an ink flow path having a pressurizing chamber part branched from the ink supply part via a flow path resistance adjusting part, and a terminal part of the ink flow path. A substrate having an ink flow path structure consisting of a nozzle part that penetrates vertically and has a discharge port opened on the back side, and a diaphragm that is airtightly adhered to the surface of the substrate and covers the ink supply part and the ink flow path. In a method of manufacturing an ink jet recording head including a piezoelectric element adhered to a surface of a vibration plate facing the pressure chamber, a substrate having an ink flow path structure is integrally formed as a non-crystalline thermoplastic resin molded product. And a finishing step of irradiating the discharge port of the obtained substrate with a laser beam from the pressure chamber side to remove burrs and the like. 2. The method for manufacturing an ink jet recording head according to claim 1, wherein the forming step includes forming a die pin having a taper portion corresponding to a discharge port at the tip of a round bar having a diameter corresponding to the diameter of the nozzle portion. An ink jet characterized by being inserted into a position for forming the nozzle portion in a cavity through a molding die, maintaining a distance between a tip of the die and an inner wall surface of the cavity to 20 μm or less, and performing a molding step in this state. Recording head manufacturing method. 3. The method for manufacturing an ink jet recording head according to claim 1 or 2, wherein the molding operation is performed in a state in which the distance between the tip of the mold pin and the inner wall surface of the cavity is maintained at 20 μm or more. An inkjet recording head characterized by including a process of pushing the mold pin into the cavity until the tip of the mold pin contacts the inner wall surface of the cavity before the crystalline thermoplastic resin is hardened to form an open discharge nozzle hole. Manufacturing method. 4. The method for manufacturing an ink jet recording head according to claim 1, wherein after forming a water-repellent film around the ejection port of the substrate, the laser beam is irradiated from the pressure chamber side. A method for manufacturing an ink jet recording head, characterized by shifting to a finishing process for removing burrs including a protruding portion of a water-repellent film to an ejection port.