JPH04107150A - Manufacturing of ink-jet head - Google Patents

Abstract

PURPOSE:To prevent a buckling from occurring which may be produced in a plate-like piezoelectric transducer, prevent cracks from occurring and to ensure stability for position of a vibrating part to a nozzle-forming substrate by a method wherein a plate-like piezoelectric element for the plate-like piezoelectric transducer is divided and the divided elements are struck to a base part. CONSTITUTION:A plate-like piezoelectric element 13 and a plate-like elastic body 15 are bonded together. After the bonding, a part 13a is made by cutting on the plate-like piezoelectric element 13, and the plate-like piezoelectric element 13 is divided into two bodies. Thus, plate-like piezoelectric transducers 17 are made up. The plate-like piezoelectric transducer 17 are fixed to electrodes 2 that re placed on a base part 1. Then piezoelectric transducers 7 are made by dividing the plate-like piezoelectric transducers 17 by dicing. A nozzle-forming substrate 8 is struck to the surface of a fixing part 12 of the piezoelectric transducers 7 with polyimide 16 in which finely granulated resin made up in sizes necessary for distancing a vibrating part 11 from the nozzle-forming substrate 8 with Ni plating applied thereon are scattered and mixed, and thereby an ink-jet part for jetting of the ink is formed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to inkjet print recording,
In particular, the present invention relates to an inkjet recording apparatus that drives a piezoelectric transducer in ink to eject ink from a nozzle opening to form an ink image on a medium such as recording paper.

More specifically, the present invention relates to a method of manufacturing an inkjet head.

[Prior Art] A nozzle forming substrate having a plurality of nozzle openings and a piezoelectric transducer placed at a certain interval on the back of the nozzle forming substrate and directly contacting ink to apply pressure are laminated. An inkjet head is disclosed in Japanese Patent Publication No. 60-8953.In this inkjet head, a piezoelectric transducer having a cantilevered or double-sided beam structure is displaced in a direction substantially perpendicular to a nozzle forming substrate. This generates pressure to eject ink between the piezoelectric transducer and the nozzle forming substrate.

An inkjet head using such a piezoelectric transducer has a plate-shaped piezoelectric transducer made by laminating a piezoelectric element and an elastic body in a cantilever structure on a base part during manufacturing, and if it is fixed at room temperature or above, the plate will break. The plate-shaped piezoelectric transducer is fixed in a tilted state inside the hollow base, and the tip position of the vibrating part of the piezoelectric transducer after being divided is stably secured. The problem is that it is not possible. Therefore, in order to improve the accuracy of the position of the tip of the vibrating part in the piezoelectric transducer that forms the gap with the nozzle forming substrate, conventionally, as shown in FIG. The piezoelectric transducer 30 is fixed and the plate-shaped piezoelectric transducer 30 is divided to manufacture piezoelectric transducers.

[The invention tries to solve ill! ] The conventional manufacturing method described above has the problem that cracks occur in the piezoelectric elements 31 in the plate-shaped piezoelectric transducer 30 when the plate-shaped piezoelectric transducer 30 is bonded onto the base portion 1. That is, when the coefficient of thermal expansion of the base part 1 is larger than that of the piezoelectric element 31, after the plate-shaped piezoelectric transducer 30 is heated and fixed on the base part 1, the large thermal contraction of the base part 1 during cooling causes the piezoelectricity in the base hollow part 1a to increase. There was a problem in that buckling B occurred in the element 31 as shown in FIG. 5, and cracks occurred. In addition, if the relationship between the magnitude of the thermal expansion coefficient is different,
During heating, compressive stress was generated due to thermal expansion of the piezoelectric element 31, so that cracks were generated in the pentaelectric element 31.

The present invention is intended to solve these problems, and its purpose is to prevent the piezoelectric element from being destroyed and to ensure stability at the tip position of the vibrating part in the piezoelectric transducer.

[Means for Solving the Problems] A method for manufacturing an inkjet head according to the present invention includes: a nozzle forming substrate having a plurality of nozzle openings; a piezoelectric transducer disposed one-to-one with the nozzle opening; A method of manufacturing an inkjet head in which a base part to which a transducer is fixed is laminated, and the plate-shaped piezoelectric element and the plate-shaped elastic body are first laminated to form a plate-shaped piezoelectric element. Making a transducer, then dividing the plate-shaped piezoelectric element of this plate-shaped piezoelectric transducer into at least two pieces and stacking them on a base part, and then dividing the plate-shaped piezoelectric transducer to form the piezoelectric transducer. It is characterized by

[Example] An example of the present invention will be described based on the drawings using an example of an inkjet head in which the piezoelectric transducer has a cantilever structure and this structure is arranged in two rows parallel to each other.

FIGS. 1 and 2 are a partial perspective view and a sectional view showing a row of cantilever structures in an inkjet section of an inkjet head that ejects ink. The base portion 1 is made of a highly rigid material such as metal or ceramics in order to prevent deformation of the inkjet portion that ejects ink. On the base part 1, a rod-shaped electric wire 1i is arranged in one-to-one correspondence with the piezoelectric transducer 7 and for transmitting electric signals.
2 is provided. A plurality of piezoelectric transducers 7 arranged parallel to each other on this electrode 2 are each composed of a piezoelectric element 3 and a highly rigid elastic body 5 made of metal and arranged on the nozzle opening 6 side. There is. This piezoelectric element 3 has an electrode 4a on the elastic body 5 side and an electrode 4a on the base part 1 side.
b is formed. The piezoelectric transducer 7 has a cantilever structure fixed to the base part 1 and consists of a freely displaceable vibrating part 11 and a fixing part 12 to the base part 1. Electrical conduction between the electrode 4b of the piezoelectric transducer 7 and the electrode 2 on the ceramic portion 1 can be achieved by using a thermosetting adhesive containing metal particles or fine resin particles whose surface has been metallized, or by brazing. The spacer 9 is for forming electrical continuity between the electrode 4a of the five elastic members of the piezoelectric transducer 7 and the nozzle forming substrate 8, and for keeping the gap between the piezoelectric transducer 7 and the nozzle shaped substrate 8 constant. . As the spacer 9, it is possible to use a thermosetting adhesive containing a metal thin plate, metal particles similar to those described above, or metal-treated fine resin particles with a limited particle size. This creates the necessary gap size and also provides continuity. The nozzle forming substrate 8 has a plurality of nozzle openings 6 that face the plurality of piezoelectric transducers 7 one-on-one. Furthermore, due to the electrical conduction provided by the spacer 9, it serves as a common electrode for the IE poles 4a on the elastic body 5 side of the piezoelectric element 3. An inkjet section for ejecting ink is constructed by laminating the above-mentioned members as shown in FIG. 2. Then, an FPC (Flexible Pr.
1nte, dC1rcuits) 10 is connected to the electrode 2 to form a head.

Here, the principle of ejecting ink from the nozzle will be briefly explained.

When a voltage is applied and discharged between the voltages 14a and 4b on both sides of the piezoelectric element 3 of the piezoelectric transducer 7, the piezoelectric element 3 contracts and expands due to the piezoelectric effect, and this longitudinal vibration is caused by the elastic body 5 to vibrate the free end 11a of the vibrating part 11. is displaced in a direction substantially perpendicular to the nozzle opening 6.

This displacement increases the pressure of the ink near the nozzle opening 6, and ink droplets are ejected from the nozzle 6.

Therefore, by selectively applying and discharging a voltage, the free end of the vibrating portion 11 is deformed and displaced, and ink in the vicinity can be ejected from the nozzle 6 to perform printing.

The elastic body 5 is designed to prevent the piezoelectric element 3 from being damaged even if the vibrating part 11 contacts the nozzle forming substrate 8 during vibration.
In the present embodiment, it is arranged on the nozzle forming substrate 8 side, but the same displacement can be obtained even if it is arranged on the opposite side.

Next, the manufacturing process of this embodiment will be explained using FIGS. 3 and 4. Figures 3(a) and 7-(d) show piezoelectric transducers 7 having a two-row structure with the tips of the vibrating parts of the cantilever structure facing each other.
FIG. 2 is a perspective view for explaining the manufacturing method. Figure 4 shows
FIG. 3 is an exploded perspective view of a laminated member of an inkjet section that ejects ink. The manufacturing method up to the formation of the piezoelectric transducer 7 will be explained with reference to FIG. First, as shown in FIG. 3(a), the plate-shaped piezoelectric element 13 and the plate-shaped elastic body 15 are joined. Here, since the plate-like elastic body 15 is made of metal and has ductility,
After joining with the plate-shaped piezoelectric element 13, it becomes difficult to divide the piezoelectric transducer 7 by dicing, so most of the portions 15a that will be divided later by dicing are removed by etching or cutting in advance. After bonding, as shown in FIG. 3(b), parts 1 and 3a of the plate-shaped piezoelectric element 13 corresponding to the tip position of the vibrating part 11 shown in FIG. 2 are cut, and the plate-shaped piezoelectric element 13 is Split into two. In this way, the plate-shaped piezoelectric transducer 17 is manufactured. Next, this plate-shaped piezoelectric transducer 17 is fixed onto the electrode 2 placed on the base portion 1 as shown in FIG. 3(C). Then, as shown in FIG. 3(d), the piezoelectric transducer 7 is manufactured by dividing the plate-shaped piezoelectric transducer 17 by dicing. After forming the piezoelectric transducer 7 through the above steps, the nozzle forming substrate 8 is placed on the fixing part 12 of the piezoelectric transducer 7. It is fixed by polyimide 16 into which fine resin particles are dispersed. An inkjet section that discharges ink can be manufactured through the above steps.

According to this embodiment, as shown in FIG. 3(b), the piezoelectric element 13 of the plate-shaped piezoelectric transducer 17 is cut at a portion 13a corresponding to the tip position of the vibrating part 11, and is divided into two pieces. Buckling as previously occurring does not occur, and therefore cracks can be prevented from occurring.

By the way, the elastic body 15 of the plate-shaped piezoelectric transducer 17 is not divided;
In order to easily divide the opposing rows at once, and by dividing the tip positions of the vibrating parts of the two opposing rows at an angle, it is possible to easily shift the nozzle position between the rows. It is.

[Effects of the Invention] According to the present invention, by dividing the plate-shaped piezoelectric element of the plate-shaped piezoelectric transducer and then fixing it to the base part, buckling that occurs in the plate-shaped piezoelectric transducer can be eliminated and cracks can be prevented. Therefore, the position of the vibrating part relative to the nozzle forming substrate can be stably secured.

[Brief explanation of the drawing]

FIG. 1 is a partial perspective view of an inkjet section for ejecting ink in an embodiment of an inkjet head manufactured according to the present invention. FIG. 2 is a sectional view of the same as above. FIGS. 3(a) to 3(d) are perspective views showing a method of manufacturing an inkjet head according to the present invention. FIG. 4 is an exploded perspective view of an inkjet unit that discharges ink. FIG. 5 is a cross-sectional view of an inkjet section for explaining the problems of the conventional manufacturing method. 1 ・ 2 ・ 3 ・ 5 ・ 6 ・ 7 ・ 8 ・ 9 ・ ・Base part・Base part upper electrode・Piezoelectric element・Elastic body・Nozzle・Piezoelectric transducer・Nozzle forming substrate・Spacer・FPC ・Vibrating part・Fixing part・Plate-shaped piezoelectric element, insulating layer, plate-shaped elastic plate, plate-shaped piezoelectric transducer, etc. Applicant: Seiko Epson Co., Ltd. Representative Patent attorney: Sanbu Takumi 1 person 1/E2 diagram!・-Ys: p Figure 1 Figure 4 Figure 5

Claims (1)

[Claims] A nozzle forming substrate having a plurality of nozzle openings, a piezoelectric transducer arranged one-to-one with the nozzle openings, and a base portion to which the piezoelectric transducer is fixed are laminated. In this method of manufacturing an inkjet head, first, a plate-shaped piezoelectric transducer is manufactured by laminating a plate-shaped piezoelectric element and a plate-shaped elastic body, and then, at least two plate-shaped piezoelectric elements of this plate-shaped piezoelectric transducer are laminated. 1. A method of manufacturing an inkjet head, comprising dividing the plate-shaped piezoelectric transducer into two pieces, stacking the plate-shaped piezoelectric transducer on a base part, and then dividing the plate-shaped piezoelectric transducer to form the piezoelectric transducer.