JPH10193612A - Ink jet type recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent discharge of adhesive used to fix a piezoelectric vibrator by providing a polymer film fixed to an end of an island to overhang in a channel unit having an elastic plate including the island opposed to a pressure generating chamber. SOLUTION: To manufacture the ink jet type recording head, a plate obtained by laminating, for example, a metal thin plate on a surface of a polymer oriented film 8 via an adhesive layer 10 is used as an elastic plate (vibration plate), and etching the thin plate by utilizing a photosensitive resin film 24 to form an island 12 having a diaphragm part 11 and the film 24 remaining in an overhanging state. A nozzle plate 1 and the elastic plate are connected with adhesive to seal both the surfaces of spacer material 3 to constitute a channel unit. Thereafter, an end of a piezoelectric vibrator 20 of the unit is coated with adhesive P, the vibrator 20 is adhered to the island 12 to constitute the head.

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 in a longitudinal vibration mode as a driving source, and more particularly, to an elasticity for contracting and expanding a pressure generating chamber by expansion and contraction of the piezoelectric vibrator. The present invention relates to a structure of a plate 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 a row of nozzle openings tends to be small. Therefore, a silicon single crystal wafer is anisotropically etched.
A nozzle plate or an elastic plate manufactured by another method is fixed with an adhesive to form a flow path unit, and the displacement of the piezoelectric vibrator is transmitted thereto to generate pressure in the pressure generation chamber. Is configured to eject ink droplets from the nozzle openings.

[0003] When the arrangement density of the pressure generating chambers increases as described above, the width of the pressure generating chambers becomes extremely small, so that it is necessary to efficiently deform the entire longitudinal direction of the pressure generating chambers.
A projecting portion extending in the longitudinal direction of the pressure generating chamber, a so-called island portion, is formed on the elastically deformable plate member, and the displacement of the piezoelectric vibrator is transmitted to the elastic plate via the island portion.

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

A tip of a piezoelectric vibrator of a longitudinal vibration mode extending in the axial direction is brought into contact with the island portion of the elastic plate thus configured, and is fixed by an adhesive to constitute an ink jet recording head. .

[0006]

At this time, there is a problem that the adhesive flows into the diaphragm portion, and the rigidity of the diaphragm portion is changed, thereby changing the ejection performance of ink droplets. In order to solve such a problem, the height of the island portion is made as high as possible so that the adhesive is absorbed on the side wall of the island portion.
There is a problem that the bottom portion in contact with the diaphragm becomes unnecessarily wide, and the high-density arrangement becomes difficult, the etching time becomes long, and the etching accuracy decreases. The present invention has been made in view of such a problem, and an object of the present invention is to prevent an adhesive used for fixing to a piezoelectric vibrator from flowing out, and to increase the height of an island portion as much as possible. An object of the present invention is to provide an ink jet recording head which can be lowered.

[0007]

According to the present invention, there is provided a nozzle plate having a nozzle opening formed therein, a pressure generating chamber, an ink supply port, and a spacer forming a reservoir. An ink jet comprising a flow path unit formed by joining an elastic plate having an island portion opposed to the pressure generating chamber, and a longitudinal vibration mode piezoelectric vibrator for ejecting ink droplets in contact with the island portion. The type recording head has a polymer film fixed to the tip of the island portion so as to overhang.

[0008]

When the adhesive for fixing the piezoelectric vibrator and the island portion tries to overflow to the outside, the adhesive is received by the film having a larger area than the island portion provided so as to overhang from the island portion and moves to the bottom portion. Is blocked.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the illustrated embodiments. 1 and 2 show one embodiment of an ink jet recording head according to the present invention. In the drawings, reference numeral 1 denotes a nozzle plate having nozzle openings 2, 2, 2. Is a member that partitions the pressure generating chamber 4, the ink supply port 5, and the reservoir 6.

Reference numeral 7 denotes an elastic plate characterized by the present invention.
As shown in the figure, a rigid and etchable material such as a metal, for example, a metal thin plate 9 is laminated on the surface of a stretched polymer film 8 via an adhesive layer 10 on the surface of the stretched polymer film 8. The nozzle plate 1 is formed by etching to form a diaphragm portion 11 and an island portion 12.
The elastic plate 7 is joined to the spacer member 3 with an adhesive so as to seal both surfaces of the spacer member 3, thereby forming a flow path unit 13.

Reference numeral 14 in the figure denotes a vibrator unit.
As shown in FIG. 2, the electrode 15 serving as one pole and the electrode 16 serving as the other pole are laminated in a sandwich shape via a piezoelectric material 17, and one electrode 15 is provided on the tip side and the other electrode 17 is provided. Are exposed to the rear end side, and the piezoelectric vibrator 20 connected to the segment electrode pole 18 and the common electrode 19 at each end face is exposed.
Are fixed to the fixed substrate 21 at a constant pitch, and the front ends of the piezoelectric vibrators 20 are fixed to the head frame 23 via the fixing plate 22 with the tips of the piezoelectric vibrators 20 abutting on the island portions 12.

In this embodiment, the diaphragm 7
As described above, the adhesive 10 is applied to one surface of a thin metal plate having a durability of 20 μm with respect to ink, for example, a stainless steel plate 9, and after the adhesive 10 is pre-dried, the thickness is 4 μm. A stretched polymer film 9 of a certain degree, for example, a laminated material obtained by bonding a stretched film of polyphenylene sulfide (PPS) resin, is etched because the thin metal plate stainless steel plate 9 is etched into the island portion 12. Thickness used during etching 1
It is configured such that the photosensitive resin film 24 of 0 to 40 μm is left as one member constituting the island portion 12 without being removed.

That is, an adhesive 10 is applied to one surface of a thin metal plate, for example, a stainless steel plate 9 having a thickness of 20 μm, which is durable with respect to ink, and after the adhesive is pre-dried, the thickness is about 4 μm. A laminated material 25 is formed by bonding a stretched polymer film 8 of, for example, a stretched film of polyphenylene sulfide (PPS) resin (FIG. 6).
(I)).

The laminated material 25 is cut into a required size to cut out a large size, a hole serving as a reference for etching pattern exposure, a positioning hole for positioning when setting in a press, and a single elastic cut from the large size. A reference hole for positioning as the plate 7 and a through-hole such as a hole serving as an ink supply port are formed in advance by press working.

Next, the stainless steel plate 9 of the laminated material 20 is set on a glass substrate so that the surface thereof is exposed, and a photosensitive resin film 24 is attached to the surface of the stainless steel plate 9.
Desirably, the entire laminate material 25 is fixed to the substrate with the photosensitive resin film 24 (FIG. 6 (II)).

In this state, the photosensitive resin film 24 is exposed using a mask on which a pattern to be etched is formed, leaving the photosensitive resin film 24 in a region to be the island portion 12 and penetrating the diaphragm portion 11. An etching protection film to be a hole is formed (FIG. 6 (III)).

Next, when the laminate 25 is etched using the etching protection film, the stainless steel plate 9 is etched.
From the surface and become thinner (Fig. 6 (I
V)). When the etching proceeds in this manner, the etching proceeds not only in the thickness direction of the stainless steel plate 9 but also in the horizontal direction. Therefore, the stainless steel plate 9 on the back surface 24a of the photosensitive resin film 24 functioning as an etching protection film is also formed. Etching, photosensitive resin film 24
Are exposed like eaves (FIG. 6 (V)).

As the etching proceeds further, the adhesive 8 is exposed and the etching in the thickness direction of the stainless steel plate 9 is stopped. As a result, a thin portion composed of the adhesive layer 10 and the stretched polymer film 8, that is, an island portion 12 surrounded by the diaphragm portion 11 is formed. At the end of the etching,
The back surface 24a of the photosensitive resin film 24 is also considerably etched, so that the island portion 12 is formed in a trapezoidal cross section (FIG. 6 (VI)).

The flow path unit 13 having the elastic plate 7 thus configured is fixed to the fixing portion 25 of the head frame 23, and the head frame 23 is set again so that the flow path unit 13 is at a lower position. An adhesive P is applied to the tip of the piezoelectric vibrator 20 of the vibrator unit 14 to which a flexible cable (not shown) is connected, so that the head frame 2
When the piezoelectric vibrator unit 14 is dropped from the opening 26 of the third plate 3, the tip of the piezoelectric vibrator 20 is bonded to the island portion 12 of the elastic plate 7 constituting the flow path unit 13 as shown in FIG. The contact is made via the agent P.

At this time, the adhesive P applied to the piezoelectric vibrator 20 tends to overflow due to the pressure of the island portion 12 and the piezoelectric vibrator 20, but most of the adhesive P1 is , The island portion 1 as shown in FIG.
2 functions as a protective film for etching,
The surface area of the photosensitive resin film 24 which has a size larger than that of the surface of the photosensitive resin film 2 is received by the photosensitive resin film 24 and is prevented from moving to the island portion 12.

Further, for example, the adhesive P2 that cannot be absorbed on the surface of the photosensitive resin film 24 flows into the gap between the photosensitive resin film 24 and the island portion 12, and is held by the capillary force and solidified. As a result, it is prevented from flowing out to the diaphragm 11.

As described above, since the flow of the adhesive for fixing the piezoelectric vibrator 20 and the island portion 12 can be completely prevented from flowing out to the diaphragm portion 11 by the photosensitive resin film 24, the height H of the island portion 12 can be prevented. (FIG. 5
It is necessary to allow (b)) a value as small as possible so that the displacement of the piezoelectric vibrator 20 can be transmitted to the pressure generating chamber 4, that is, allowance for preventing the flow of the adhesive P to the diaphragm portion 11. Since there is no such material, a material having a thickness of 20 μm or less can be used, and the difference between the width W1 at the tip of the island portion and the width W2 at the bottom can be made as small as possible.
The island portion is formed with an ideal shape or with high precision, thereby making it possible to increase the density of the recording head.

When the fixing of the vibrator unit 14 is completed in this manner, the metal frame 27 also serving as a shield plate is put on the flow path unit 13 side and fixed to the head frame 23 to complete the ink jet recording head. I do.

In the above embodiment, stainless steel is used as the metal thin plate. However, another metal which can be etched and has high adhesiveness, for example, a thin plate of copper, nickel, iron or silicon is used. Can be used.

Although a polyphenylene sulfide (PPS) resin is used as the polymer stretched film, other polymer materials that can be stretched, for example, polyimide (PI)
Resin, polyether imide (PEI) resin, polyamide imide (PAI) resin, polybalavanic acid (PPA) resin, polysulfone (PSF) resin, polyether sulfone (PES) resin resin, polyether ketone (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.

[0026]

As described above, according to the present invention, in the present invention, the nozzle plate having the nozzle openings formed therein, the pressure generating chamber, the ink supply port, the spacer forming the reservoir, and the pressure generating chamber are opposed to each other. In an ink jet recording head including a flow path unit formed by joining an elastic plate having an island portion and a piezoelectric vibrator in a longitudinal vibration mode in which an ink droplet is ejected by contacting the island portion, Since the polymer film is fixed to the tip so as to overhang, even if the adhesive for fixing the piezoelectric vibrator and the island part overflows to the outside, it is provided so as to overhang from the island part. It can be received and blocked by a large area of the film, and the island is formed in the ideal shape using a metal plate that is as thin as possible. Or formed with high accuracy density of recording head is possible.

[Brief description of the drawings]

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

FIG. 2 is a view showing one embodiment of an ink jet recording head of the present invention in a longitudinal section of a pressure generating chamber.

FIG. 3 is a top view showing one embodiment of the elastic plate.

FIGS. 4A and 4B are a perspective view and a cross-sectional view, respectively, showing an example of a vibrator unit.

FIGS. 5A and 5B are enlarged views of one embodiment of the ink jet recording head of the present invention, showing a cross section in the direction in which the pressure generating chambers are arranged and one island portion. .

FIGS. 6 (I) to (VI) are diagrams showing steps of manufacturing the elastic plate, respectively.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle plate 3 Spacer 4 Pressure generating chamber 5 Ink supply port 6 Reservoir 7 Elastic plate 8 Polymer stretched film 9 Metal plate 10 Adhesive layer 11 Diaphragm part 12 Island part 13 Channel unit 14 Piezoelectric vibration unit 20 Piezoelectric vibrator P, P1, P2 Adhesive 24 Photosensitive resin film

Claims (8)

[Claims] 1. A nozzle plate having a nozzle opening formed therein, a spacer forming a pressure generating chamber, an ink supply port, and a reservoir, and an elastic plate having an island facing the pressure generating chamber. An ink jet recording head comprising: a flow path unit formed in the above-described manner; and a piezoelectric vibrator in a longitudinal vibration mode in which an ink droplet is ejected in contact with the island portion. The ink jet recording head is fixed so as to overhang at the tip of the island portion. Ink jet recording head having a polymer film. 2. The ink jet recording head according to claim 1, wherein the island portion is formed by etching a thin metal plate. 3. The ink jet recording head according to claim 1, wherein the polymer film is a photosensitive resin film. 4. The metal thin plate has a thickness of 10 to 20 μm.
The inkjet recording head according to claim 1, wherein m is m. 5. The ink jet recording head according to claim 1, wherein the elastic plate is made of a laminate material in which a thin metal plate and a stretched polymer film are bonded via an adhesive. 6. The polymer film having a thickness of 10 to 4
The ink jet recording head according to claim 1, which has a thickness of 0 µm. 7. The ink jet recording head according to claim 1, wherein the piezoelectric vibrator and the polymer film are fixed via an adhesive layer. 8. The ink jet recording head according to claim 1, wherein the photosensitive film also serves as an etching protection film for the thin metal plate.