JP3114766B2 - Ink jet head and method of manufacturing the same - 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 head suitable for an ink jet recording apparatus for performing recording by discharging ink droplets, and a method of manufacturing the same.

[0002]

2. Description of the Related Art An ink jet head which pressurizes ink in a pressure chamber by displacement of one end of a vibrator and discharges ink droplets from a nozzle communicating with the pressure chamber has a structure as disclosed in JP-A-3-264360. is there. This type of head has the potential for low voltage drive, higher density, and higher power of the vibrator, and also has excellent ejection characteristics, but on the other hand, ejects ink droplets without falling down the elongated vibrator. There is a technical problem of arranging with high accuracy in the pressure chamber. That is, for example, the nozzle pitch is set to 180 DPI, that is, 1
When the pitch is 41 μm, the pressure chamber width is about 100 μm, and the vibrator width is a very fine size of 70 to 80 μm,
In addition, the displacement between the vibrator and each pressure chamber is 10 to 15 μm.
The vibrator cannot be directly opposed to the pressure chamber unless it is suppressed below.

[0003]

As shown in FIG. 14, such an ink-jet head has a toothed vibrator 2 as shown in FIG.
3 is arranged in the ink chamber block 24 using the support portion 22 as a guide. Therefore, in consideration of the position and pitch accuracy of the pressure chamber, the accuracy of the pressure chamber and the support 21 and the support portion 22, the clearance between the vibrator 23 and the support portion 22, and the pitch accuracy of each vibrator 23, the accuracy of each is within several μm. Desired. The present invention has been made in view of such circumstances, and an object of the present invention is to provide an inkjet apparatus that can easily position a high-density array of piezoelectric vibrators with high accuracy with respect to a pressure chamber. It also provides a head. Another object of the present invention is to propose a method for manufacturing the above-mentioned ink jet head.

[0004]

Means for Solving the Problems The present invention to achieve such a problem, a plurality of pressure chambers in a row, a nozzle communicating with the pressure chamber is formed by the volume change of the pressure chamber A chamber plate that ejects ink droplets, and selectively pressurizes the pressure chamber, is connected to each other at the other end , and
An oscillator group including a plurality of oscillators displaced in the longitudinal direction ;
In the ink jet head consisting of a fixed plate for positioning and fixing the transducer groups and the chamber plate, said chamber plate includes a reference hole for position determined location <br/> its Hiryuro formation region and said transducer group is supported with a positioning portion for positioning said pressure chamber to the distal end side
The other end of the vibrator on the holding substrate so that one end is a free end
Is configured to fix the side, the chamber plate the reference hole, and is fixed to one body to the fixed plate being positioned the transducer groups is by positioning <br/> Me portion of the support substrate I have.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the illustrated embodiments. FIGS. 1A, 1B and 1C show a chamber plate 30 of an ink jet head according to the present invention.
1 shows an embodiment of the manufacturing method of the present invention. FIG. 1 (a)
In the above, two layers of a dry film resist 41 having a thickness of 50 μm are laminated on the nozzle plate 4 in which the nozzles 6 are formed, and are exposed to ultraviolet rays through a mask 43a having a required pattern (I). Further, one layer of the same film is laminated and exposed through another mask 43b (II). By developing these dry films, pressure chambers, flow paths from the pressure chambers to the nozzles 6, and flow paths from each pressure chamber to a common ink chamber can be formed (III). The masks 43a and 43b are positioned by reference holes 40 and 41 formed in the nozzle plate 4 and exposed. Thereby, since each flow path is formed with reference to the reference holes 40 and 41, the relative position accuracy is improved.

On the other hand, as shown in FIG. 1B, a 50 μm-thick dry film resist 41 ′ is laminated on the pressure plate 5 side, and a mask having a required pattern is formed in the reference hole 44. It is positioned by 45 and exposed to ultraviolet light. Then, the dry film is developed to form a flow path that coincides with the nozzle plate 4 side. And FIG.
As shown in (c), when the above two bodies are fused under heating and pressurization with both reference holes aligned, the pressure chamber 7a, the flow path 7c communicating from the pressure chamber 7a to the nozzle 6, and the common pressure chamber The chamber plate 30 having the ink chamber 7b and the positioning reference holes 14, 14 is completed.

The thickness of the nozzle plate 4 is 30 to 120.
The nozzle 6 can be manufactured by any one of nickel electroforming, press working on a stainless steel plate, and laser working on a plastic film.

In FIG. 2, the nozzle plate 4 is provided with two rows of nozzles 6 for discharging ink droplets arranged at equal pitches, and the flow path is formed by rectangular pressure chambers 7a arranged at the same pitch as the nozzles 6. And a common ink chamber 7b for supplying ink to each pressure chamber 7a. The pitch of the nozzle 6 and the pitch of the pressure chamber 7a are the same as the pitch of the vibrator 1 described later. The nozzle plate 4, the flow path portion 7, and the pressure plate 5 are respectively positioned at both ends of a region where a flow path is not formed by inserting pins 33, 33 described later, and positioning holes 40, which are positioned. 41, 4
2, 43, 44 and 45 are perforated. In addition, the nozzle 6a located away from the nozzle row of the nozzle plate 4
Is for discharging bubbles in the common ink chamber 7b through the flow path 7d.

FIGS. 3A, 3B, and 3C show an embodiment of a method of manufacturing a vibrator group 31 composed of the vibrator 1 and the support substrate 2, with four vibrators 1 for simplicity. The support substrate 2 has a U-shaped cutout 2b, and a thin film electrode 2v is attached to one surface thereof. The plate-shaped vibrator plate 1b is joined to the thin film electrode surface of the support substrate 2 by brazing such as an adhesive or solder. At this time, the distance between the notch 2b and the one end 1c of the vibrator plate 1b, that is, the free end length L of the vibrator 1 must be accurately adjusted to the reference value using a jig. It is. Also,
In order to join the vibrator tip 1a to the chamber plate 30, the one end 1c of the vibrator plate 1b is formed to have a straightness of several μm. Further, in the case of the assembling method described later with reference to FIG. 6, the distance between the side surface 2d of the support substrate 2 and the side surface 1d of the vibrator plate 1b is also accurately adjusted.

Next, the vibrator plate 1b and the thin-film electrode 2v on the supporting substrate 2 are simultaneously cut by a cutting machine such as a rotary blade or a wire saw, with the side surface 1d as a reference. 1f is made into a strip shape, and the thin film electrode 2v is divided so that the extraction electrode 2v
make. At this time, the support substrate 2 is cut to such an extent that the electrode 2v can be cut. The pitch accuracy of each vibrator 1 is determined by the feed accuracy of a rotating blade or wire saw, etc.
It can be kept around or below.

To give a specific example, the vibrator 1 is 1/18
Twenty-four vibrators 1 are arranged at a pitch of 0 inches (141 μm), and the dimensions of the vibrator 1 are 70 μm in width, 500 μm in thickness, and the free end length L is 5 mm. The degree determining part 1f has a width of 500 μm.
As m, the strength to withstand the assembling is secured. The vibrator is configured as a laminated piezoelectric vibrator in which a large amount of displacement and a displacement speed are obtained at a low voltage, and a piezoelectric material having a thickness of 25 μm is laminated in multiple layers via electrodes in order to increase its rigidity.

The support substrate 2 is provided with regions serving as positioning portions 2a on both sides in preparation for assembling a group of vibrators, which will be described later. In this region, the plate thickness and the flatness are assured with specified accuracy. If necessary, the straightness of the side surface 2d of the support substrate 2 also has a specified accuracy.

In addition to these functions, the supporting substrate 2 firmly fixes the vibrator 1, prevents warping and bending of the vibrator 1, and causes crosstalk between the vibrators 1. Various functions are required, such as not to be performed and electrical connection at the joint. Therefore, the supporting substrate 2
A material having a high flatness and a high Young's modulus and a thermal expansion coefficient as close as possible to the vibrator, for example, a plastic, a metal, and more preferably a ceramic material is used.

FIG. 4 is an exploded perspective view of a head using the above-described chamber plate 30 and vibrator group 31, and FIG. 5 is a view showing a cross-sectional structure of one flow path. In this embodiment, two vibrator groups 31 are arranged on one chamber plate 30. Thin film electrode 2 of support substrate 2
When a driving signal is applied to the vibrator 1 by the lead 3 and the lead 3 is connected to v, the vibrator 1 moves in the longitudinal direction.
That is, it contracts in the direction of the arrow z in the figure, expands when discharged, and pressurizes the ink in the pressure chamber 7a of the chamber plate. The fixing plate 10 has a function of firmly fixing the supporting substrate 2 to which the vibrator 1 is fixed, and preventing the vibrator 1 from retreating from the chamber plate 30 due to a reaction force at the time of ejecting ink droplets. In the drawing, reference numeral 13 denotes a circuit board on which a driving integrated circuit connected to the lead 3 is mounted, and reference numeral 8 denotes a pipe for supplying ink from an ink cartridge (not shown) to a common ink chamber 7b. Is shown.

The pressure plate 5 covers the pressure chamber 7a to prevent ink leakage, and is connected to the tip 1a of the vibrator. The pressure plate 5 is composed of a rectangular island-shaped thick portion 5a with increased rigidity, a thin portion 5b that bends when the vibrator 1 is displaced, and a thick portion 5c around the pressure chamber. The pressure plate 5 is made of, for example, nickel electroforming. The thickness of the thin portion 5b is selected from the range of 0.5 μm to 3 μm, and the thickness of the thick portions 5a and 5b is selected from the range of 10 to 100 μm. In addition, the pressure plate 5 can be formed separately into a thin portion and a thick portion. For example, a thick portion can be formed by plating or a resin layer on a thin metal film. FIG.
2, a flow path 7c connecting the pressure chamber 7a and the nozzle 6 in FIG. 1 is omitted.

FIG. 6 is a perspective view of the pressure plate 5 as viewed from the transducer coupling surface, and FIG.
FIG. 3 is an enlarged view showing a contact area between the pressure determining plate 1f and the pressure plate 5;

As a specific example, the pressure chamber 7a is 1 m
m, a length of 2 mm, and a depth of 0.1 mm. The thick island portion 5a is located at the center of the pressure chamber and has a width of 0.03 mm and a length of 1.7 mm. Since the width of the vibrator 1 is 70 μm and the width of the thick portion 5 a is 30 μm, the relative position accuracy is maintained at 20 μm or less so that the tip 1 a of the vibrator 1 does not deviate from the thick portion 5 a. There is a need to.

FIGS. 8A and 8B show the vibrator group 3 respectively.
FIGS. 8A and 8B show an embodiment of an assembling method for joining the chamber plate 1 and the chamber plate 30. FIG. 8A is a cross-sectional view taken along the X direction in FIG. 4, and FIG. It is sectional drawing cut | disconnected along.

As shown in FIG. 8A, the pins 33 are aligned with the two positioning holes 14 of the chamber plate 30, and the chamber plate 30 is set on the jig 32. After applying a thin adhesive to the joint surface of the fixing plate 10 or the chamber plate 30, the positioning holes 1 of the fixing plate 10
6 is aligned with the pin 33 and inserted, and the fixed plate 10 and the chamber plate 30 are joined. In addition, fixed plate 1
0 is provided with a shallow hole 10e around the positioning hole 16,
It is desirable to prevent the adhesive from flowing into the pins 33.

Next, the tip 1a of the vibrator 1 of the vibrator group 31
Then, an adhesive is applied by a transfer method to the tip of the determining portion 1f provided on both sides thereof. As shown in FIG. 8B, the positioning portion 2a of the transducer group 31 is
2a, the side end of the support substrate 2 is pressed against the guide wall 32c of the jig 32 by the pin 36 and the spring 35, and the position in the X and Y directions shown in FIG. 4 is changed to the guide 32a as shown in FIG. , 32c and the positioning section 2a.
Further, when the tip of the stabilizing portion 1 c of the vibrator group 31 abuts against the chamber plate 30, the vibrator group 31 is defined with respect to the fixed plate 10 and the chamber plate 30 already set in accordance with the positioning holes 14. Aligned to the position. Since no channel is formed in the chamber plate 30 in the region where the tip of the degree determining portion 1f contacts, the rigidity is high, and the vibrator group 31 is accurately positioned in the Z direction.

The tip of the determining portion 1c is the chamber plate 3
At the stage where the vibrator group abuts on the vibrator group, the vibrator group is prevented from being lifted by the elastic force of the leaf spring 34, and in this state, the vibrator group 31 is temporarily fixed to the fixing plate 10 with a temporary fixing adhesive, for example, an ultraviolet curable adhesive. I do. The temporary fixing is fixed plate 1
Any gap with 0 is possible. After the temporary fixing, the temporarily fixed fixing plate 10 and the chamber plate 30 are fixed to the jig 3.
Then, the thermosetting adhesive 11 (FIG. 9) is injected into a portion that does not hinder the movement of the vibrator 1, for example, into the gap 15 in FIG. In this way, by temporarily fixing the jig 32 while being loaded into the jig 32, the fixing plate 1
0, the chamber plate 30, and the vibrator group 31
2. The jig can be taken out of the jig in a more accurately positioned state, the actual bonding operation can be easily performed without restricting the working space of the jig, and the jig can be opened in a short time. Equipment costs can be reduced by minimizing the number of jigs required in the manufacturing process.

FIG. 10 shows another embodiment of the method of joining the vibrator group 31 and the chamber plate 30 together. In this embodiment, the vibrator group 31 is formed by accurately processing the outer end surfaces of the staging portion 1f, in particular, the position of the distal end thereof, and the vibrator is processed into a strip shape based on the position. When the vibrator group 31 is assembled using the guide 32a of the jig 32, the tip of the stitch determining portion 1f is formed on two slopes 1 of the fixed plate 10.
In this case, the tip of the determining portion 1f comes into contact with the chamber plate 30. As a result, the tip 1a of the vibrator moves in the left-right direction (Y
Direction) by two short straight portions 10c, and the depth direction (X direction 9 by the guide 32a and the positioning portion 2a).
Further, the vertical direction (Z direction) is positioned at the tip of the degree determination unit 1f. In this state, the oscillator group 31 is fixed to the fixed plate 1.
0 is fixed with an adhesive. According to this embodiment, the position in the Y direction can be positioned near the tip of the vibrator 1.

Another embodiment will be described with reference to FIG.
In this embodiment, as shown in FIG. 12, the vibrator plate 1b is joined to the thin-film electrode surface of the support substrate 2 so that the free end length L of the vibrator is accurately adjusted. A slit is formed in the vibrator plate 1b, and the determining portion 1f, the vibrator 1,
Another positioning slit 1h 'is formed. This allows
Each vibrator 10 is positioned with respect to the slit 1h with a processing accuracy of a cutting machine, for example, an accuracy of several μm.

On the other hand, the chamber plate 30 is provided with a reference hole 11 corresponding to the slit, and the pressure chamber and the pressure plate are positioned with reference to the reference hole 11. The four reference holes 11 are provided on both sides of the pressure chamber row.

For such a member, the chamber plate 30 is set on the jig 32 and then the fixing plate 10 is connected, similarly to the embodiment described with reference to FIG.
The reference hole 11 of the chamber plate 30 is
8, the vibrator group 31, which has been coated with an adhesive beforehand, is incorporated while determining the position in the X direction with the jig 32 or the fixing plate 10 as a guide. The slit 1h engages with the pin 38. Thus, the relative position in the Y direction between the tip 1a of the vibrator 1 and the chamber plate 30 is determined. Then, the tip of the degree determining portion 1f abuts on the chamber plate 30 to determine the position in the Z direction.

In the above-described embodiment, the positioning slit 15 is formed in the piezoelectric vibrating plate, but the same effect can be obtained by forming the slit 15 in the supporting substrate 2 for fixing the vibrator. According to this embodiment, as compared with the vibrator, the support substrate 2 has a high degree of freedom in its material, shape, and processing method, is excellent in strength, and does not break or bend even when pressed, so that the assembling accuracy is increased. Further, since the size of the vibrator plate can be reduced, the cost can be reduced. FIG.
As shown in FIG. 3, the vibrator plate is processed into a comb shape to form a vibrator group 31, and the vibrator group 31 is formed.
Positioning portions 1e may be formed on both sides.

[0027]

In the present invention, as more than above Description, according to the present invention,
A plurality of positioning reference holes are formed in the non-flow path forming area of the chamber plate, and the vibrator group is positioned on the front end side of the vibrator in order to position each vibrator in the pressure chamber. /> because portions have been formed, the reference hole chamber plates, and since the transducer group is positioned on the fixed plate by the positioning unit, the tip of the transducer to be displaced axially in three-dimensional directions with respect to the pressure chamber Positioning can be easily performed with high accuracy.

[Brief description of the drawings]

FIGS. 1A to 1C are views showing one embodiment of a method of manufacturing a chamber plate of an ink jet head according to the present invention.

FIG. 2 is an exploded perspective view showing one embodiment of a chamber plate of the inkjet head.

FIGS. 3A to 3C are diagrams illustrating a process of manufacturing a vibrator group used in the inkjet head according to the first embodiment.

FIG. 4 is an exploded perspective view showing the overall structure of the inkjet head.

FIG. 5 is a diagram showing a cross-sectional structure in a pressure chamber of the inkjet head.

FIG. 6 is a view showing a structure and a structure on a pressure plate side of the chamber plate.

FIG. 7 is an enlarged view showing a joined state of the vibrator and the pressure plate.

FIGS. 8 (a) and (b) are views showing steps of assembling the same ink jet head.

FIG. 9 is a top view showing a state where a group of transducers, a chamber plate, and a fixing plate of the inkjet head are set in a jig.

FIG. 10 is a view showing another embodiment of the method of manufacturing an ink jet head according to the present invention.

FIG. 11 is a view showing another embodiment of the method for manufacturing an ink jet head of the present invention.

FIG. 12 is a view showing one embodiment of a vibrator group suitable for the manufacturing method.

FIG. 13 is a diagram showing another example of a vibrator group suitable for the ink jet head of the present invention.

FIG. 14 is a diagram illustrating an example of a conventional inkjet head.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 vibrator 1 f degree determining part 2 support substrate 2 a vibrator group positioning part 4 nozzle plate 5 pressure plate 6 nozzle 7 flow path plate 7 a pressure chamber 7 b common ink chamber 10 fixing plate 11 fixing member 14 chamber plate positioning hole 16 Fixing plate positioning hole 30 Chamber plate 31 Vibrator group 32 Jig

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 2/045 B41J 2/055 B41J 2/16

Claims (5)

(57) [Claims] A plurality of pressure chambers and a nozzle communicating with the pressure chambers are formed in a row, and a chamber plate for discharging ink droplets by a change in the volume of the pressure chambers; An ink jet head comprising: a vibrator group comprising a plurality of vibrators that are pressed and connected to each other at the other end side and are displaced in the longitudinal direction; and a chamber plate and a fixed plate that positions and fixes the vibrator group. The plate is provided with a reference hole for positioning in the non-flow path forming region, and the vibrator group has a free end at one end side of the vibrator on a support substrate having a positioning portion for positioning in the pressure chamber at a distal end side. The other end is fixed such that the chamber plate is positioned by the reference hole, and the vibrator group is positioned by the positioning portion of the support substrate. An inkjet head that is integrally fixed to the fixing plate Te. 2. A plurality of pressure chambers and a nozzle communicating with the pressure chambers are formed in a row, and a chamber plate that discharges ink droplets according to a change in the volume of the pressure chambers, and the pressure chambers are selectively added. An ink jet head comprising: a vibrator group comprising a plurality of vibrators that are pressed and connected to each other at the other end side and are displaced in the longitudinal direction; and a chamber plate and a fixed plate that positions and fixes the vibrator group. A plurality of positioning reference holes are formed in the non-flow path forming region of the plate, and a shape that protrudes from both sides of the vibrator in the row direction and extends toward the distal end of the vibrator, and fixes one end of the vibrator. The vibrator is fixed to a support substrate having a positioning portion for positioning the vibrator in the pressure chamber at a distal end side of a region protruding from the both sides, An inkjet head that is fixed in position integral with the fixing plate by plate said reference hole, and said transducer groups the positioning portion. 3. The chamber plate is defined by a pin in a position of the vibrator group in the plane direction and by a positioning portion formed in the vibrator group in a displacement direction of the group of piezoelectric vibrators. The inkjet head according to claim 1 or claim 2. 4. A plurality of pressure chambers and a nozzle communicating with the pressure chambers are formed in a row, and a chamber plate that discharges ink droplets due to a change in the volume of the pressure chambers, and a vibrator from both sides in the row direction. A positioning part for positioning the vibrator in the pressure chamber at a distal end side of a region protruding from the both sides and having a shape that protrudes and extends to the distal end side of the vibrator and fixes one end of the vibrator. A step of positioning a vibrator unit in which the plurality of vibrators are fixed to a supporting substrate having a jig on a fixing plate, and a step of temporarily fixing the chamber plate and the vibrator group to the fixing plate with an adhesive, Removing the jig and fixing the chamber plate and the vibrator group to the fixing plate. 5. A plurality of pressure chambers and a nozzle communicating with the pressure chambers are formed in a row, and a chamber plate for discharging ink droplets due to a change in the volume of the pressure chambers, and a vibrator from both sides in the row direction. A positioning part for positioning the vibrator in the pressure chamber at a distal end side of a region protruding from the both sides and having a shape that protrudes and extends to the distal end side of the vibrator and fixes one end of the vibrator. Positioning a vibrator unit, in which a plurality of vibrators are fixed to a supporting substrate, on a fixing plate via a jig by a positioning reference hole for positioning the chamber plate and a positioning portion of the vibrator unit; Temporarily fixing the plate and the vibrator group to the fixing plate with an adhesive; and removing the jig to fix the chamber plate and the vibrator group to the fixing plate. And method of manufacturing an ink jet head made of.