JPH1110873A - Ink jet head and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the assembling efficiency and joining quality in a head by a method wherein a filmy adhesive is applied for the joining of a liquid chamber supporting member onto a board, on which slit grooves are formed. SOLUTION: A board 11 and a frame member 13 are joined together through an adhesive 14. As the adhesive 14, a filmy adhesive is used. As the filmy, adhesive, an epoxy-based filmy adhesive is preferable from the view points of water resistance, heat resistance joining strength and the like. Since the filmy adhesive is produced by bringing a liquid resin adhesive into a B stage (semi-hardened state), the lowering of the viscosity the adhesive due to the heat of hardening at its hardening is suppressed to a comparatively few. Further, as for the resinous material of the filmy adhesive, a material containing 1,000 or more oligomers is used in order to reduce the fluidity of the adhesive so as to allow to lower its viscosity more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink-jet head and a method of manufacturing the same, and more particularly, to an ink-jet head in which a liquid chamber supporting member is bonded to a substrate having a slit groove by an adhesive, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In general, an ink jet recording apparatus used for a printer, a facsimile, a copying machine, etc. has a nozzle for ejecting ink droplets, and an electromechanical transducer or an electrothermal transducer provided corresponding to the nozzle. An ink jet head having an actuator element and an ink flow path pressurized by the actuator element (hereinafter, referred to as a “pressurized liquid chamber”) is used as a recording head, and ink droplets are ejected from nozzles in accordance with a recording signal. High-speed, high-resolution, and high-quality printing is performed by discharging ink onto a printing medium (on which ink droplets adhere).

As a conventional ink jet head, as described in Japanese Patent Application Laid-Open No. 8-142324, for example, a plurality of piezoelectric elements are joined in a plurality of rows on a substrate in which a slit groove is formed. An actuator unit formed by joining a frame member serving as a liquid chamber support member positioned around the liquid crystal unit; a pressurized liquid chamber pressurized by a piezoelectric element via a diaphragm on a diaphragm having a diaphragm; In some cases, a liquid chamber partition member that forms a common liquid chamber for supplying ink to the chambers is stacked, and a liquid chamber unit in which a nozzle plate having nozzles formed thereon is stacked on the liquid chamber partition member.

A conventional adhesive bonding between a substrate and a liquid chamber supporting member (frame member) in such an ink jet head will be described with reference to FIG. 8. A slit groove 101 a is formed as shown in FIG. Piezoelectric element 102
When the substrate 101 to which is bonded is joined to a frame member 103 as shown in FIG. 3B, a room temperature curing type epoxy adhesive 106 is applied to the frame member 103 by a stamper 104 as shown in FIG. After the transfer, the frame member 103 is overlaid on the substrate 101 as shown in FIG.

In this case, when a liquid thermosetting adhesive is used in place of the normal temperature setting adhesive, the viscosity of the adhesive temporarily decreases at an ambient temperature for thermosetting, and as shown in FIG. The agent 106 may flow out into the slit groove 101a of the substrate 101 to form a resin film on the electrode surface 107 provided on the substrate 101. If the resin film is formed on the electrode surface on the substrate in this manner, a bonding failure occurs when the FPC cable or the like is bonded by thermocompression bonding. Therefore, a room temperature curing adhesive is used.

[0006]

When a room-temperature-curable adhesive is used as in the above-described ink jet head, the curing time is prolonged, and the assembling efficiency is deteriorated. In addition, when the stamping method is used as the coating method, it is difficult to control the thickness of the adhesive applied, which may cause variations in the coating quality and may cause poor bonding.

[0007] The present invention has been made in view of the above points, and has as its object to improve assembly efficiency and joining quality.

[0008]

According to a first aspect of the present invention, there is provided an ink jet head in which a liquid chamber supporting member is bonded to a substrate having a slit groove by using an adhesive. It was configured to be a film adhesive.

According to a second aspect of the present invention, in the inkjet head of the first aspect, the film adhesive is an epoxy resin adhesive.

A third aspect of the present invention is the ink jet head according to the first or second aspect, wherein the film adhesive contains a reinforcing material.

According to a fourth aspect of the present invention, in the ink jet head of the third aspect, the reinforcing material of the film adhesive is made of glass fiber.

According to a fifth aspect of the present invention, in the ink jet head of any one of the first to fourth aspects, the film adhesive has more than 1,000 oligomers.

According to a sixth aspect of the present invention, there is provided a method of manufacturing an ink jet head in which a liquid chamber supporting member is bonded to a substrate having a slit groove by an adhesive. Is applied and joined.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an exploded perspective view of an ink jet head to which the present invention is applied, FIG. 2 is an enlarged cross-sectional view of a main part of the head in a direction orthogonal to a channel direction (nozzle arrangement direction), and FIG. It is an expanded sectional view.

This ink jet head includes a drive unit 1, a liquid chamber unit 2, and a head cover 3. The drive unit 1 has a plurality of laminated piezoelectric elements 12 as energy generating elements arranged in two rows on a ceramic substrate, for example, an insulating substrate 11 such as barium titanate, alumina, or forsterite, and joined. A frame member (liquid chamber supporting member) 13 made of resin, ceramic, or the like surrounding the periphery of each of the two rows of piezoelectric elements 12 is joined by a film adhesive 14.

The plurality of piezoelectric elements 12 are provided between the driving elements 17, 17, to which driving pulses for driving the ink into droplets and for causing the ink to fly are provided. A piezoelectric element (hereinafter, referred to as a “non-driving unit”) that serves as a liquid chamber support member that simply fixes the liquid chamber unit 2 to the substrate 11 without being provided with a driving pulse.
... are alternately configured. Here, the plurality of piezoelectric elements 1
Reference numeral 2 denotes a single piezoelectric element which is divided into a plurality of pieces by subjecting a plurality of slits to a single piezoelectric element. A slit groove 11a is formed on the substrate 11 by cutting the substrate up to the substrate 11 during the slitting.

Here, as the piezoelectric element 12, a laminated piezoelectric element having ten or more layers is used. This laminated piezoelectric element has a thickness of 10 to 50 μm / 1, for example, as shown in FIG.
Layer of lead zirconate titanate (PZT) 20 and a thickness of several μ
An internal electrode 21 made of silver / paradium (AgPd) of m / 1 layer is alternately laminated, but the material used for the piezoelectric element is not limited to the above, and other electromechanical conversion elements may be used. Can also.

The internal electrodes 21 of each piezoelectric element 12 are left and right end face electrodes 22 and 23 made of AgPd every other layer (the opposing face sides of the two piezoelectric element rows are end face electrodes 22, and the non-opposing face sides are end face electrodes). 23). On the other hand, as shown in FIG.
Each pattern of the common electrode 24 and the individual electrode 25 is provided by Au plating, AgPt paste printing, AgPd paste printing, or the like.

The opposite end electrodes 22 of each row of the piezoelectric elements 12 are connected to the common electrode 24 via a conductive adhesive 26.
On the other hand, the non-opposing end surface electrodes 23 of the piezoelectric elements 12 in each row are connected to the individual electrodes 25 via the conductive adhesive 26 in the same manner. Thereby, the driving unit 17
When a drive voltage is applied to the drive unit 17, an electric field is generated in the stacking direction, and the driving unit 17 is displaced in the stacking direction (d 33).
Direction displacement) occurs. As shown in FIG. 2, the common electrode 24 has a hole 13a formed in the frame member 13.
By filling the inside with the conductive adhesive 26, the pattern connected to each piezoelectric element is conducted.

On the other hand, the liquid chamber unit 2 is a liquid chamber partition member having a multilayer structure formed of a laminate of metal thin films and a liquid chamber partition member formed of a photosensitive resin layer formed of a dry film resist (DFR). 32 and a nozzle plate 33 made of metal, resin, or the like, are sequentially laminated, and are formed by heat fusion. By each of these members, one piezoelectric element 12
(Driving unit 17), a diaphragm 34 corresponding to the one piezoelectric element 12, a pressurized liquid chamber 35 pressurized through each diaphragm 34, and both sides of the pressurized liquid chamber 35. Common liquid chambers 36, 36 for introducing ink to be supplied to the pressurized liquid chamber 35, and the pressurized liquid chamber 35 and the common liquid chambers 36, 36.
Ink supply paths 37, 37 communicating with the pressure liquid chamber 35.
One channel is formed by the nozzle 38 communicating with the nozzle, and a plurality of channels are provided in two rows.

The diaphragm 31 is made of a nickel plating film having a two-layer structure, and is formed integrally with the diaphragm portion 34 corresponding to the driving portion 17 and at the center of the diaphragm portion 34 for joining with the driving portion 17. Corresponding to the island-shaped convex portion 40, the partition wall portion 41 which becomes a beam to be joined to the non-driving portion 18 and makes each channel (nozzle) independent, the peripheral thick portion 42 to be joined to the frame member 13, and the common liquid chamber 36. Elastic part (hereinafter referred to as "damper part") that absorbs the pressure of
43 are formed.

The liquid chamber partition member 32 is formed by applying a dry film resist in advance on the diaphragm 31 side, exposing it using a required mask, and developing it to form a first liquid chamber pattern.
The photosensitive resin layer 45 and the second photosensitive resin layer 46 on which a dry film resist is applied in advance on the nozzle plate 33 side, exposed using a required mask, and developed to form a predetermined liquid chamber pattern are heated. It is joined by crimping.

The nozzle plate 33 has a large number of nozzles 38, which are fine discharge ports for ejecting ink droplets. The internal shape (inner shape) of this nozzle 38 is
It can be formed in a substantially cylindrical shape, a substantially frustum shape, or a horn shape. The diameter of the nozzle 38 is about 25 to 35 μm on the ink droplet outlet side.

The ink ejection surface (nozzle surface side) of the nozzle plate 33 is a water-repellent surface 47 which has been subjected to a water-repellent surface treatment as shown in FIG. For example, PTF
Ink physical properties such as E-Ni eutectoid plating, electrodeposition coating of fluororesin, vapor-deposited evaporative fluororesin (for example, pitch fluoride), baking after solvent application of silicon resin or fluorine resin The water-repellent treatment film selected according to the above is provided to stabilize the ink droplet shape and the flying characteristics so that high-quality image quality can be obtained. The periphery of the nozzle plate 33 is a non-water-repellent surface 48 on which no water-repellent film is formed.

The drive unit 1 and the liquid chamber unit 2
After processing and assembling separately, the vibration plate 31 of the liquid chamber unit 2 and the piezoelectric element 12 and the frame member 13 of the drive unit 1 are joined with an adhesive 49.

Then, the substrate 11 is supported and held on a spacer member (head holder) 50 as a head support member, and the head driving I
C and the electrodes 24 and 25 connected to the piezoelectric elements 12 (drive unit 17) of the drive unit 1
They are connected via PC cables 51,51.

A nozzle cover (head cover) 3
Is formed in a box shape to cover the peripheral portion of the nozzle plate 33 and the side surface of the head. An opening is formed corresponding to the water-repellent surface 47 of the nozzle plate 33, and is left at the peripheral portion of the nozzle plate 33. The non-water-repellent surface 48 is adhesively bonded with an adhesive. Further, in order to supply ink from an ink cartridge (not shown) to the liquid chamber, the ink supply holes 52 are provided in the spacer member 50, the substrate 11, the frame member 13 and the vibration plate 31, respectively.
To 55 are provided.

In the ink jet head configured as described above, when a drive waveform (pulse voltage of 10 to 50 V) is applied to the drive unit 17 in accordance with a recording signal, a displacement in the stacking direction occurs in the drive unit 17, Diaphragm 31
The pressurized liquid chamber 35 is pressurized through the diaphragm section 34 of the above, and the pressure rises, and ink droplets are ejected from the nozzle 38. At this time, ink flows also in the direction of the ink supply passages 37, 37 leading from the pressurized liquid chamber 35 to the common liquid chamber 36. However, by reducing the cross-sectional area of the ink supply passages 37, 37, the fluid resistance portion is reduced. Function to reduce the flow of ink toward the common liquid chambers 36, 36, thereby preventing a drop in ink ejection efficiency.

Then, with the end of the ink droplet ejection, the ink pressure in the pressurized liquid chamber 35 decreases, and a negative pressure is generated in the pressurized liquid chamber 34 due to the inertia of the ink flow and the discharge process of the drive pulse. To the ink filling process. At this time, the ink supplied from the ink tank flows into the common liquid chambers 36, 36, and from the common liquid chambers 36, 36 to the ink supply paths 37, 3.
After that, it is filled into the pressurized liquid chamber 35. Then, the vibration of the ink meniscus surface near the outlet of the nozzle 38 is attenuated,
When the ink is returned to the vicinity of the outlet of the nozzle 38 due to surface tension (refill) and reaches a stable state, the operation shifts to the next ink droplet ejection operation.

Next, the joining of the substrate 11 and the frame member 13 during the assembly process of the drive unit will be described with reference to FIGS. In this inkjet head, as described above, the substrate 11 and the frame member 13 are joined using the adhesive 14. As the adhesive 14, a film adhesive is used. As the film adhesive, an epoxy-based film adhesive is preferable from the viewpoint of water resistance, heat resistance, bonding strength, and the like.

As the film adhesive, a liquid resin adhesive is used as B
It was confirmed by an experiment that the adhesive was formed by making it into a stage (semi-cured state), so that the decrease in the viscosity of the adhesive due to the heat of curing at the time of curing could be suppressed considerably. Further, by using a resin material of the film-like adhesive having 1000 or more oligomers for the purpose of reducing the fluidity, the viscosity can be further reduced. As a result, the joining between the substrate and the frame member can be thermoset, the assembling efficiency is improved, the flow of the adhesive is reduced, and the joining quality is improved.

In order to bond the substrate 11 and the frame member 13 using such a film-like adhesive, the film-like adhesive 14 is formed into a bonding surface shape of the frame member 13 with the substrate 11 as shown in FIG. The application of the adhesive is completed by patterning and placing the patterned film adhesive 14 on the bonding surface of the frame member 13 in a fixed positional relationship as shown in FIG. Therefore, this frame member 1
The frame member 13 and the substrate 11 are joined by superposing the adhesive surface of the substrate 11 on the film-like adhesive 14 on 3 and thermally curing the same.

Here, when the pattern processing of the film-like adhesive 14 is performed, a mold corresponding to the processing pattern is generally prepared and extracted, but if the rigidity of the film itself is low, a fine pattern is formed. Processing becomes more difficult. Therefore, as shown in FIG. 6 and FIG. 7, the rigidity of the film-like adhesive is increased by using a film-like adhesive 14a with a reinforcing material 14b sandwiched between the film-like adhesives 14a, 14a. A simple pattern processing can be facilitated, and handleability can be improved. Glass fiber or the like can be used as the reinforcing member 14b.

[0034]

As described above, according to the ink jet head of the first aspect, since the substrate having the slit groove and the liquid chamber supporting member are joined by the film adhesive, the assembling efficiency and joining quality are improved. I do.

According to the ink jet head of the second aspect, since the epoxy resin adhesive is used as the film adhesive in the ink jet head of the first aspect, it is possible to secure the water resistance, the heat resistance, and the bonding strength, and to perform the bonding. Reliability is improved.

According to the ink jet head of the third aspect, in the ink jet head of the first or second aspect, the film adhesive has a structure including a reinforcing material.
Pattern processing is facilitated, and assemblability is improved.

According to the ink jet head of the fourth aspect, in the ink jet head of the third aspect, since the reinforcing material of the film adhesive is made of glass fiber, pattern processing is facilitated and assemblability is improved. I do.

According to a fifth aspect of the present invention, in the ink jet head of any one of the first to fourth aspects, the film adhesive has 100 oligomers.
Since the number of components exceeds zero, the decrease in viscosity can be further reduced.

According to the method of manufacturing an ink jet head according to the sixth aspect, since a film-like adhesive is applied to the substrate or the liquid chamber supporting member and joined, the assembly efficiency and the joining quality are improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an inkjet head to which the present invention has been applied.

FIG. 2 is an enlarged sectional view of a main part in a direction orthogonal to the nozzle arrangement direction in FIG.

FIG. 3 is an enlarged sectional view of a main part in a nozzle arrangement direction of FIG. 1;

FIG. 4 is an explanatory perspective view of a film adhesive before bonding.

FIG. 5 is an explanatory perspective view showing a state where a film adhesive is applied to a frame member.

FIG. 6 is a schematic cross-sectional view illustrating a film-like adhesive containing a reinforcing material.

FIG. 7 is a schematic perspective view illustrating the reinforcing material-containing film adhesive.

FIG. 8 is an explanatory view illustrating a conventional method of joining a substrate and a liquid chamber support member.

FIG. 9 is a perspective explanatory view for explaining an adhesive for bonding a substrate and a liquid chamber supporting member;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Drive unit, 2 ... Liquid chamber unit, 11 ... Substrate, 1
1a: slit groove, 12: piezoelectric element, 13: frame member, 14: film adhesive, 23: diaphragm, 24, 2
5, 26: photosensitive resin layer, 28: nozzle plate.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Seiji Nagaba 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Masayuki Iwase 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Noboru Nakane 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Hideyuki Makita 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd.

Claims (6)

[Claims] 1. An ink jet head for bonding a liquid chamber support member with an adhesive on a substrate having a slit groove formed therein,
The inkjet head, wherein the adhesive is a film adhesive. 2. The ink jet head according to claim 1, wherein the film adhesive is an epoxy resin adhesive. 3. The ink jet head according to claim 1, wherein the film adhesive contains a reinforcing material. 4. The ink jet head according to claim 3, wherein the reinforcing material for the film adhesive is made of glass fiber. 5. The ink jet head according to claim 1, wherein the film adhesive has more than 1,000 oligomers. 6. A method for manufacturing an ink jet head in which a liquid chamber supporting member is bonded to a substrate having a slit groove by an adhesive, wherein a film adhesive is applied to the substrate or the liquid chamber supporting member and bonded. Manufacturing method of an inkjet head.