JP3508861B2 - Ink jet recording head and method for manufacturing diaphragm thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head using a piezoelectric vibrator of a longitudinal vibration mode as a drive source, and more specifically to contraction of a pressure generating chamber in response to expansion and contraction of the piezoelectric vibrator.
The present invention relates to a structure of a diaphragm to be inflated and a manufacturing method thereof.

[0002]

2. Description of the Related Art In order to improve the recording density of a recording head, the pitch of nozzle opening rows tends to be small. Therefore, a silicon single crystal wafer is anisotropically etched,
A nozzle plate or diaphragm manufactured by another method is fixed to this with an adhesive to form a flow path unit, and the displacement of the piezoelectric vibrator is transmitted to this to generate pressure in the pressure generating chamber. Is configured to eject an ink droplet from the nozzle opening.

When the arrangement density of the pressure generating chambers is increased as described above, the width of the pressure generating chambers becomes extremely small. Therefore, it is necessary to efficiently deform the entire pressure generating chambers in the longitudinal direction.
A so-called island portion, which is a protrusion extending in the longitudinal direction of the pressure generating chamber, is formed on the elastically deformable plate material, and the displacement of the piezoelectric vibrator is transmitted to the diaphragm through the island portion.

As such a vibrating plate, a layer of a polymer material is formed on one surface of a metal thin plate by a dipping method, a roll coating method, a spray method or the like, and the metal thin plate is etched to form an island portion. It has been proposed that the polymeric material layer formed and exposed by etching is used as a diaphragm portion (WO93 / 25390).

However, due to the fact that the polymer material layer formed by the film forming method is used as the diaphragm portion, pinholes are easily generated in the diaphragm portion, and there is a risk of ink leaking out of the pressure generating chamber, and the strength is low. There is a risk of damage. In order to solve such a problem, it is conceivable to form the polymer material layer into a thick film, but the rigidity of the diaphragm portion becomes high, and a new problem occurs that the ejection efficiency decreases. There is also a problem that the thin metal plate constituting the diaphragm is damaged by electrolytic corrosion due to the current leaking from the vibration unit.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a vibrating plate having a metal as a constituent member, which has high durability and high reliability. An object is to provide an ink jet recording head.

[0007]

In order to solve such a problem, in the present invention, a nozzle plate having a nozzle opening, a pressure generating chamber, an ink supply port, and a common ink chamber are formed. A flow path unit formed by joining a spacer and a vibrating plate having an island portion facing the pressure generating chamber, and a longitudinal vibration mode piezoelectric vibrator that abuts the island portion and ejects ink droplets. And Dami
In an ink jet recording head including a piezoelectric vibrating unit including a vibrator, the vibrating plate is made of a bonding plate material of a metal thin plate and a polymer stretched film, and the metal thin plate is etched. The island part and the dummy
Is a vibrators abutting region is formed, and each of the areas before Symbol island unit and the dummy vibrators abut
The thin metal plate is removed by etching so as to surround the outer periphery of the.

[0008]

[Function] Since a polymer stretched film that has been rolled during processing into a film can be used as the diaphragm part,
Eliminating the pin hole of the diaphragm portion as much as possible, also to prevent the outflow piezoelectric vibrator and a dummy vibrator of current from electrically insulating the vibration unit and the abutting region and other regions electrolytic corrosion Prevents damage to the diaphragm.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the illustrated embodiments. 1 and 2 each show an embodiment of an ink jet recording head of the present invention. In the drawings, reference numeral 1 is a nozzle plate having nozzle openings 2, 2, 2, ... Are pressure generation chambers 4, 4, 4,
Spacers 7 for partitioning the ink supply ports 5, 5, 5, ... And the reservoir 6 are diaphragms characterized by the present invention. The nozzle plate 1 and diaphragm 7 are spacer members 3
Are bonded to each other with an adhesive so as to seal both sides of the channel unit.

The vibrating plate 7 is formed by etching a thin metal plate 20 laminated on the surface of the polymer stretched film 8 with an adhesive 21 in between, and generates pressure in the central region in the width direction of the pressure generating chamber 4. An island portion 9 extending in the longitudinal direction of the chamber 4 is provided, and a displacement is made by a piezoelectric vibrator 11 described later via the island portion 9.

Reference numeral 10 in the drawing denotes a vibrator unit constituted by fixing a plurality of piezoelectric vibrators 11 having a longitudinal vibration mode to a fixing plate 12, and a vibrator unit accommodating hole formed in a base 13. 14 and the fixing plate 12 is positioned so that the tip end thereof abuts the island portion 9 of the vibration plate 7.
It is fixed to the base 13 via.

The base 13 is provided with an ink supply pipe 15 connected to an ink tank (not shown), and the ink supply pipe 15 is constituted by a spacer 3 at its tip via an ink supply port 32 of the vibration plate 7. And communicates with the common ink chamber 6. In the figure, reference numeral 16 is a frame body for fixing the flow path unit composed of the nozzle plate 1, the spacer 3, and the vibrating plate 7 and the base 13, and reference numeral 17 is for fixing the head to the carriage. Each of the substrates is shown.

FIGS. 3 and 4 show an embodiment of the above-mentioned diaphragm 7, and FIG. 3 shows a plurality of diaphragms 7, 7 ,.
7 shows a state in which 7 ... Are collectively built in one laminate material, and FIG. 4 shows one diaphragm separated from the laminate material.

Next, a method of manufacturing the above-mentioned diaphragm will be described with reference to FIG.
It will be described based on. An adhesive 21 is applied to one surface of a metal thin plate 20 having a thickness of 30 μm, which is durable against ink, for example, stainless steel, and the adhesive is pre-dried, and then a stretched polymer film 22 having a thickness of about 4 μm 22. For example, a stretched film of polyphenylene sulfide (PPS) resin is adhered to form a laminate material (FIG. 5 (I)).

This laminate material is cut into a desired size to cut out a large size, and holes 24 and 24 which serve as a reference at the time of exposure of an etching pattern and reference holes 25, 26, 27 and 28 for positioning when set in a press. And a reference hole 30 for positioning as a single diaphragm 7 cut from a large size,
31 and a through hole 33 such as a hole 32 serving as an ink supply port are preliminarily formed by press working (FIG. 5 (II)).

Then, the thin metal plate 20 of the laminated material is set on the glass substrate B so that the surface thereof is set, and the photosensitive resin film F is attached to the surface of the thin metal plate 20 so that the end portion extends to the surface of the glass substrate B. The entire laminate material is fixed to the glass substrate B with the film F.

By adopting such a step, it is possible to complete the step of adhering the photosensitive resin film F and the fixing of the work to the glass substrate B in one step. In addition, since a hole has been previously formed in the laminate material by pressing, it is necessary to protect the end surface of this hole from the etching liquid, but by using a resin film that has a higher protection ability against the etching liquid than liquid photoresist, It is possible to surely prevent the deformation of the holes during etching.

In this state, the mask having a pattern to be etched is positioned using the reference holes 24, 24 to expose the photosensitive resin film F. As a result, the etching windows W, W are made with a relative error as small as possible with respect to the reference holes 24, 24 accurately formed by press working.
Will be formed (FIG. 5 (III)).

Next, by etching the thin metal plate using the windows W, W, the thin metal plate is removed and the adhesive 21 is exposed, and the island portion 9 surrounded by the regions D, D to be the diaphragm portion. Will be formed (Fig. 5)
(IV)).

FIG. 3 shows a large-sized structure after the etching is completed. In this embodiment, each of the vibrating plates 7, 9 is formed in accordance with the formation of the island portions 9, 9 in the above-mentioned etching process. The groove 3 of the polymer stretched film 22 only is etched by penetrating the thin metal plate 20 around the periphery 7 and 7.
4 are formed, and the respective vibrating plates 7, 7, 7 ... Are connected via a stretched polymer film 22.

When the etching is completed, the laminate material is removed from the glass substrate B, and large-sized positioning reference holes 25, 26, 27 and 28 are inserted into the positioning pins of the press, and the respective vibrating plates 7 and 7 are inserted. , 7 ... Are cut in the grooves 34 and cut into individual diaphragms 7, 7, 7. Since the thin metal plate in the cutting region is removed by etching in this manner, the stretched polymer film 22 only needs to be cut, and the life of the press die is extended.

FIG. 4 shows the vibrating plate 7 that has been cut, and the region where the vibrating unit abuts, that is, the regions denoted by reference numerals 9, 9, 40 and 40 in the figure, is removed by etching the thin metal plate 20. Since the adhesive 21 is surrounded by the exposed region and is electrically insulated from the region where the vibration unit does not come into contact, the tip of the piezoelectric vibrator 11 and the electrode of the dummy piezoelectric vibrator are also formed. Current can be prevented from flowing out of the diaphragm, and damage to the diaphragm due to electrolytic corrosion can be prevented. In the figure, reference numeral 41 is a window for absorbing the vibration of the ink in the ink reservoir existing in the flow path 3, and only the thin metal plate 20 of the laminate material is etched and bonded to the polymer stretchable film 22. It is formed only as a layer with the agent.

FIG. 6 shows a cross-sectional structure of the above-mentioned diaphragm, in which the adhesive 2 is applied to the surface of the polymer stretchable film 8.
The island portion 9 is fixed via the first layer, and a diaphragm portion made of the polymer stretched film 8 with the adhesive 21 exposed on the surface is formed around the island portion 9.

Since the island portion 9 is fixed to the polymer stretched film 8 via the layer of the adhesive 21 as described above, the stress at the tip of the island portion 9 is diffused by the adhesive 21 to the polymer stretched film. In addition to alleviating the stress concentration of the ink, the adhesive 21 on the surface serves as a kind of sealing material and prevents the leakage of the ink even if the polymer stretchable film 8 has a scratch or a defect. be able to.

In general, the stretchable film cannot be finished into a product because it breaks in the manufacturing process if defects such as pinholes exist in the manufacturing process. For this reason,
For stretched films of well-vetted materials,
It is a highly reliable material with almost no defects such as pinholes even when the thickness is extremely thin, about several μm. Therefore, it is possible to provide a highly reliable product as compared with the conventional method of forming a layer of a polymer film on a metal thin plate by a solvent casting method or the like.

Although stainless steel is used as the thin metal plate in the above-mentioned embodiments, other metals that can be etched and have high adhesiveness, such as copper, nickel, iron, stainless steel, and silicon, are used. Thin plates can be used.

Further, although polyphenylene sulfide (PPS) resin is used as the stretched polymer film, other stretchable polymer materials such as polyimide (PI) are used.
Resin, polyetherimide (PEI) resin, polyamidoimide (PAI) resin, polyparabanic acid (PPA) resin, polysulfone (PSF) resin, polyethersulfone (PES) resin resin, polyetherketone (PEK)
Resin, polyetheretherketone (PEEK) resin,
Polyolefin (APO) resin, polyethylene naphthalate (PEN) resin, aramid resin, polypropylene resin, vinylidene chloride resin, polycarbonate resin and the like can also be used.

[0028]

As described above, according to the invention of claim 1, a polymer stretchable film having no defects and high durability can be used as a diaphragm, and a piezoelectric vibrator can be used. Since the thin metal plate at the boundary between the non-contact area and the area where the piezoelectric vibrator contacts is removed and electrically insulated, it prevents the current from flowing out from the electrode of the piezoelectric vibrator and prevents the electric corrosion. It is possible to realize a highly reliable recording head by preventing the vibration plate from being damaged. From claim 2
According to Ming, the process of adhering the photosensitive resin film to the work
And fixing the work to the glass substrate in one step
It is also possible to press the laminator beforehand.
If the hole is formed in the sheet material, the end face of the hole is
While protecting from the etching liquid, the diaphragm is not damaged by electrolytic corrosion.
It is easy to manufacture a complicated and reliable recording head.
it can.

[Brief description of drawings]

FIG. 1 is an assembled perspective view showing an embodiment of an ink jet recording head of the present invention.

FIG. 2 is a sectional view showing an embodiment of the ink jet recording head of the present invention.

FIG. 3 is a diagram showing a state in which a plurality of diaphragms used in the ink jet recording head of the present invention are formed on the same laminate material.

FIG. 4 is an enlarged view showing the same diaphragm.

FIG. 5 (I) to (IV) are views showing a manufacturing process of the diaphragm, respectively.

FIG. 6 is a cross-sectional view showing the cross-sectional structure of the above diaphragm in an enlarged manner in the vicinity of an island portion.

[Explanation of symbols]

1 nozzle plate 3 spacers 4 Pressure generation chamber 5 Ink supply port 6 common ink chamber 7 diaphragm 8 Polymer stretched film 9 Island section 10 Piezoelectric vibration unit 11 Piezoelectric vibrator 21 Adhesive 22 Polymer stretched film 24 Positioning reference hole for exposure mask set 25-28 Positioning reference hole for press setting 30, 31 When assembling 34 Press cutting groove

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-6-91871 (JP, A) JP-A-5-261920 (JP, A) JP-A-5-177837 (JP, A) JP-A-6- 166178 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B41J 2/045 B41J 2/055 B41J 2/16

Claims (2)

(57) [Claims] 1. A vibrating plate having a nozzle plate having a nozzle opening, a spacer forming a pressure generating chamber, an ink supply port, and a common ink chamber, and an island portion facing the pressure generating chamber. An ink jet recording head including a flow path unit formed by joining and a piezoelectric vibration unit including a piezoelectric vibrator in a vertical vibration mode that abuts the island portion to eject ink droplets and a dummy vibrator. In the above, the vibrating plate is made of a bonding plate material of a thin metal plate and a polymer stretched film, and the thin metal plate is etched to form a region where the island portion and the dummy vibrator contact each other. And an ink jet type in which the thin metal plate is removed by etching so as to surround the outer peripheries of the regions in contact with the dummy vibrators. Recording head. 2. A laminate material composed of a thin metal plate and a stretched polymer film is fixed to a base with a photosensitive resin film to form a required etching pattern such as an island portion and a region where a dummy vibrator contacts. And a step of etching until the metal thin plate is penetrated, and a method of manufacturing a vibration plate of an ink jet recording head.