JPH08230184A - Ink jet record head and manufacture thereof - Google Patents

Abstract

PURPOSE: To rationalize a structure of pizoelectric element on a vibration plate so as to heighten rate of yield and reduce the cost. CONSTITUTION: On one face of a substrate 21, a pair of grooves are engraved in an opposed arrangement. In each groove, five groups of an ink nozzle 23, an ink pressure chamber 24, and an ink supply passage 25 communicate with one ink reservoir 26. A filter passage 27 is provided in between the ink supply passage 25 and the ink reservoir 26. A vibration plate is connected to the substrate 21 in a manner to cover the grooves. The outside surface of the vibration plate is covered with a common electrode in a manner to cover the whole of the ink pressure chamber 24. To the common electrode, a plate-like piezoelectric element having almost the same shape is connected by a thermosetting adhesive. The piezoelectric element is covered with an upper electrode 33 in common with its top face. On the upper electrode 33 and the surface layer of the piezoelectric element, division grooves 34 are cut into a matrix such that rectangular areas corresponding to each ink pressure chamber 24 are formed divisionally.

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 and a method for manufacturing the same, in which the piezoelectric element structure on a diaphragm is rationalized to improve the yield rate and reduce the cost.

[0002]

2. Description of the Related Art A conventional example will be described with reference to FIG. 5 which is a plan view of the substrate and FIG. 6 which is a sectional view thereof. The substrate (cavity plate) 14 is made of a plastic molded product by injection molding because it is easy to manufacture and can be mass-produced, and the ink nozzle 3 having the axis in the thickness direction is formed through the plastic molded product. On the upper surface, a plurality of sets of ejection passages 13 connected to the ink nozzles 3, ink pressurizing chambers 4, ink supply passages 5, and filter passages 7 (in FIG.
And a common ink reservoir 6 communicate with each other. The vibrating plate 8 is bonded to the substrate 14 so as to cover the concave portion, and the piezoelectric element 10 as an electromechanical conversion element corresponding to the position of the ink pressurizing chamber 4 is formed on the outer surface of the vibrating plate 8.
Are joined together via the common electrode 9. A thermosetting adhesive is used for this joining. A drive electrode 11 is formed on the outer surface of each piezoelectric element 10, and a drive voltage for ejecting ink is applied between the drive electrode 11 and the common electrode 9.
Based on the expansion and contraction movement of the piezoelectric element 10 due to the application of this drive voltage, the diaphragm 8 vibrates in the direction perpendicular to the plane by the bimorph effect. The vibration in the direction perpendicular to the surface of the vibrating plate 8 sharply reduces the volume of the ink pressurizing chamber 4, ejects ink droplets from the ink nozzles 3 through the ejecting flow path 13, and causes the recording paper not shown. To print and record.

[0003]

In the conventional example, the piezoelectric element is used.
10 was bonded to the diaphragm 8 via the common electrode 9 using a thermosetting adhesive. In this conventional example, when applying a small amount of adhesive to a relatively small area, it is difficult to adjust the amount,
When there is a large amount of adhesive, it rises and causes poor conduction in the upper electrode.On the other hand, when there is a small amount of adhesive, the efficiency of vibration transmission from the piezoelectric element to the diaphragm decreases due to imperfect adhesion, which lowers the yield rate. Brought. In addition, the piezoelectric element 10
Must be adhered to each ink pressurizing chamber 4, so that not only the number of steps is increased, but also the yield rate is decreased due to the adhesion failure.

The problem to be solved by the present invention is to solve the above problems of the prior art, rationalize the structure of the piezoelectric element on the diaphragm, and improve the yield rate and reduce the cost. And to provide a manufacturing method thereof.

[0005]

An ink jet recording head according to the present invention includes a substrate having a groove in which an ink nozzle, an ink pressurizing chamber, an ink supply path and an ink reservoir communicate with each other; With a diaphragm joined by
A common electrode is formed on the surface of the vibrating plate opposite to the substrate in a manner corresponding to all of the ink pressurizing chambers; bonded on the common electrode and on the surface opposite to the common electrode. A common piezoelectric element for forming a dividing groove in the surface layer portion including the upper electrode by depositing a common upper electrode and dividing a region corresponding to each ink pressurizing chamber; or an ink nozzle A substrate having a groove in which the ink pressurizing chamber, the ink supply path and the ink reservoir communicate with each other; a diaphragm bonded to the substrate so as to cover the groove; and a surface of the diaphragm opposite to the substrate. , A common electrode that is applied in a form corresponding to all of the ink pressurizing chambers; an upper electrode that is bonded to this common electrode and is on the surface opposite to this common electrode, corresponding to each ink pressurizing chamber And a common piezoelectric element for depositing each of them.

In the method of manufacturing an ink jet recording head according to the present invention, a step of forming a groove on the surface of the substrate, which is formed by communicating an ink nozzle, an ink pressurizing chamber, an ink supply path and an ink reservoir; Joining the diaphragm in a covering manner; depositing a common electrode on the surface of the diaphragm opposite to the substrate in a form corresponding to all of the ink pressurizing chambers; And a step of joining a common piezoelectric element in which a common upper electrode is attached to the surface opposite to the surface; and a region corresponding to each ink pressurizing chamber is divided into a surface layer portion including the upper electrode of the piezoelectric element. Forming a dividing groove; or forming a groove on the surface of the substrate in which an ink nozzle, an ink pressurizing chamber, an ink supply path, and an ink reservoir communicate with each other; And the step of joining the diaphragm with; A step of depositing a common electrode on the surface of the moving plate opposite to the substrate in a manner corresponding to all the ink pressurizing chambers; a step of bonding a common piezoelectric element on the common electrode; And a step of depositing an upper electrode corresponding to each ink pressurizing chamber on the surface opposite to the common electrode.

[0007]

According to the present invention, the diaphragm is joined to the substrate so as to cover the groove, and the common electrode is attached to the surface of the diaphragm opposite to the substrate so as to correspond to all the ink pressurizing chambers. A common piezoelectric element having a common upper electrode deposited on the surface opposite to the common electrode is joined to the common electrode. Further, since the dividing groove is formed in the surface layer portion including the upper electrode of the common piezoelectric element in a manner of dividing the region corresponding to each ink pressurizing chamber, the piezoelectric element corresponds to all the ink pressurizing chambers. In order to correspond to each ink pressurizing chamber, functional separation is performed by dividing grooves. Alternatively, a vibration plate is bonded to the substrate so as to cover the groove, and a common electrode is formed on the surface of the vibration plate opposite to the substrate so as to correspond to all the ink pressurizing chambers. A common piezoelectric element is bonded to. Then, since the upper electrode corresponding to each ink pressurizing chamber is attached to the outer surface of the common piezoelectric element, the corresponding ink pressurizing chamber is driven by the upper electrode via the common piezoelectric element. It will be.

[0008]

Embodiments of the ink jet recording head according to the present invention will be described below with reference to the drawings. First, the first embodiment will be described with reference to the plan view of FIG. 1 (a) excluding the diaphragm, the plan view of FIG. 1 (b), and the sectional view of FIG. 1A and 2, the substrate 21 has an ink nozzle 23 on one surface thereof and an ink pressurizing chamber.
A pair of grooves in which five sets of 24 and the ink supply path 25 communicate with one ink reservoir 26 are engraved so as to face each other. That is, two rows of five rows of the ink nozzles 23 are provided. Further, a filter flow path 27 is provided between the ink supply path 25 and the ink reservoir 26. The substrate 21 is basically the same as the substrate 14 in the conventional example.

In FIG. 2, a diaphragm 30 is joined to the substrate 21 so as to cover the groove. A common electrode 31 is attached to the outer surface of the vibrating plate 30 so as to correspond to all of the ink pressurizing chambers 24, and a flat plate-shaped piezoelectric element 32 having substantially the same shape is thermosetting bonded to the common electrode 31. Glued by the agent. This bonding requires sufficient degassing so that no bubbles remain at the bonded location. A common upper electrode 33 is attached to the upper surface of the piezoelectric element 32 (the lower electrode is attached to the lower surface, but not shown). The upper electrode 33 and the piezoelectric element 32
In the surface layer portion of, the dividing grooves 34 in a matrix form so as to divide and form a rectangular area corresponding to each ink pressurizing chamber 24,
It is diced with a diamond cutter or an ultrasonic cutter. Here, the dividing groove 34 has, for example, a width of 0.2 mm and a depth of 50 μm.
m.

FIG. 4 is a plan view of the second embodiment, and FIG.
This will be described with reference to the sectional view of FIG. In FIG. 3 and FIG. 4, the substrate 41 has five sets of the ink nozzle 42, the ejection passage 43, the ink pressurizing chamber 44, the ink supply passage 45, and the filter passage 47 as one ink reservoir 46. It is carved as a groove communicating with. This substrate 41 is basically the same as the substrate 14 in the conventional example. The diaphragm 50 is bonded so as to cover the groove of the substrate 41. On the outer surface of the vibrating plate 51, a common electrode 51 is attached in a form corresponding to all of the ink pressurizing chambers 44, and similarly, a rectangular plate-like shape is formed corresponding to all of the ink pressurizing chambers 44. The common piezoelectric element 52 is bonded under sufficient deaeration using a thermosetting adhesive. Next, five upper electrodes 53 are attached to the outer surface of the common piezoelectric element 52 so as to correspond to each ink pressurizing chamber 44. Here, this deposition is performed using a screen mask and silver paste. Alternatively, a metal such as gold is deposited using a metal mask.

[0011]

According to the present invention, the common piezoelectric element and the common upper electrode are bonded to each other so as to correspond to all the ink pressurizing chambers, and the dividing groove is cut in the surface layer portion of the upper electrode and the piezoelectric element to divide each divided region. Depending on whether they correspond to the ink pressurizing chambers, or the common piezoelectric elements are joined in a form corresponding to all the ink pressurizing chambers, and the respective upper electrodes are joined in a form corresponding to the ink pressurizing chambers. In any case, the piezoelectric element is common to all the ink pressurizing chambers. Therefore, the following excellent effects can be expected. That is, (1) there is no need for complicated alignment adjustment for bonding (bonding) the piezoelectric element, and the bonding is easy to complete, which reduces or eliminates poor conduction of the upper electrode, and vibration from the piezoelectric element to the diaphragm. The transfer efficiency can be improved, and as a result, the yield rate can be improved, a thinner piezoelectric element having a thickness of about 50 μm can be easily handled, and reliable ink ejection can be performed by a relatively low driving voltage. (2) The number of man-hours required for bonding (adhesion) is reduced, and the cost can be reduced together with the improvement of the yield rate.

[Brief description of drawings]

FIG. 1 is a plan view of the first embodiment according to the present invention without the diaphragm, and (b) is a plan view thereof.

FIG. 2 is a sectional view of the first embodiment.

FIG. 3 is a plan view of a second embodiment according to the present invention.

FIG. 4 is a sectional view of the same second embodiment.

FIG. 5 is a plan view of a conventional substrate.

FIG. 6 is a sectional view of a conventional example.

[Explanation of symbols]

 21 Substrate 23 Ink Nozzle 24 Ink Pressurizing Chamber 25 Ink Supply Channel 26 Ink Reservoir 27 Filter Channel 30 Vibrating Plate 31 Common Electrode 32 Piezoelectric Element 33 Upper Electrode 34 Dividing Groove 41 Substrate 42 Ink Nozzle 43 Ejecting Channel 44 Ink Pressurizing Chamber 45 Ink Supply Channel 46 Ink Reservoir 47 Filter Channel 50 Vibrating Plate 51 Common Electrode 52 Piezoelectric Element 53 Upper Electrode

Claims (4)

[Claims] 1. A substrate having a groove in which an ink nozzle, an ink pressurizing chamber, an ink supply path and an ink reservoir communicate with each other;
A vibrating plate joined to the substrate so as to cover the groove; a common electrode attached to the surface of the vibrating plate opposite to the substrate in a form corresponding to all the ink pressurizing chambers; The upper electrode, which is bonded to the upper surface and is opposite to the common electrode, is covered with a common upper electrode, and a region corresponding to each ink pressurizing chamber is divided into a divided groove in the surface layer portion including the upper electrode. And a common piezoelectric element to be formed. 2. A method for manufacturing an ink jet recording head according to claim 1, wherein a groove is formed on the surface of the substrate, the groove connecting the ink nozzle, the ink pressurizing chamber, the ink supply path and the ink reservoir. A step of bonding a diaphragm to the substrate so as to cover the groove; a step of depositing a common electrode on the surface of the diaphragm opposite to the substrate in a form corresponding to all the ink pressurizing chambers; A step of joining a common piezoelectric element on which a common upper electrode is coated on the surface opposite to this common electrode; and a surface layer portion including the upper electrode of the piezoelectric element corresponding to each ink pressurizing chamber A step of forming a dividing groove in a form of dividing the area to be formed. 3. A substrate having a groove in which an ink nozzle, an ink pressurizing chamber, an ink supply path and an ink reservoir communicate with each other;
A vibrating plate joined to the substrate so as to cover the groove; a common electrode attached to the surface of the vibrating plate opposite to the substrate in a form corresponding to all the ink pressurizing chambers; An ink jet recording head, comprising: a common piezoelectric element, which is bonded to the upper side and has an upper electrode corresponding to each ink pressurizing chamber, on a surface opposite to the common electrode; 4. The method of manufacturing an ink jet recording head according to claim 3, wherein a groove is formed on the surface of the substrate, the groove being in communication with the ink nozzle, the ink pressurizing chamber, the ink supply passage, and the ink reservoir. A step of bonding a diaphragm to the substrate so as to cover the groove; a step of depositing a common electrode on the surface of the diaphragm opposite to the substrate in a form corresponding to all the ink pressurizing chambers; A step of joining a common piezoelectric element on the common electrode; and a step of depositing an upper electrode corresponding to each ink pressurizing chamber on the surface of the piezoelectric element opposite to the common electrode. A method of manufacturing an inkjet recording head, comprising: