JPH10275946A - Method for manufacturing piezoelectric actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a piezoelectric actuator that is used for an ink jet recording head efficiently and inexpensively. SOLUTION: First and second piezoelectric plates 41 and 42 that are in rectangular shape, have different lengths L1' and L2', and have identical widths W1' and W2' are positioned while both side parts 41a, 41b, 42a, and 42b being extended in the longer direction are on the same straight line and are adhered on a substrate 5 with a given spacing 45. Then, a dicing saw 44 is scanned for a plurality of times in the longitudinal direction of the first and second piezoelectric plates 41 and 42, and grooves 48 and 49 that run through the first and second piezoelectric plates 41 and 42 in the longitudinal direction are provided with the given spacing in a width direction. The first and second piezoelectric plates 41 and 42 are divided into each plurality of piezoelectric actuators by the grooves 48 and 49.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drop-on-demand (DOD) type ink jet recording head for recording an image by ejecting ink droplets in accordance with an image signal and attaching the ink droplet to a recording medium such as recording paper. The present invention relates to a method for manufacturing a piezoelectric actuator to be used.

[0002]

2. Description of the Related Art To perform high-speed printing with high image quality using an ink-jet recording head, it is effective to express gradation by adjusting a printing dot diameter. It is necessary to change the amount of ink ejected from the nozzle in accordance with the gradation stage. On the other hand, conventionally, there has been proposed an ink jet recording head having a plurality of head portions and having a nozzle diameter of each head portion different from that of another head portion.

However, if the nozzle diameter of each head is changed to another nozzle, the width of the gradation is not so widened, and it is difficult to realize a smooth intermediate gradation expression like a photograph.
For this reason, the present applicant has previously proposed an ink jet recording head in which the size of a piezoelectric actuator for pressurizing ink contained in an ink cavity and discharging the ink from a nozzle is different for each head unit (Japanese Patent Application No. Hei. 8-118
840).

[0004]

According to the present invention, a piezoelectric actuator having a different size for each head portion is efficiently provided.
In addition, the first and second piezoelectric elements have a rectangular shape, are rectangular in shape, have different lengths, and have the same width and thickness. After the plates are adhered on the substrate at predetermined intervals with both sides extending in the longitudinal direction thereof being located on the same straight line, the first and second piezoelectric plates are longitudinally cut in the longitudinal direction. A plurality of grooves are formed at predetermined intervals in the width direction, and the first and second piezoelectric plates are divided into a plurality of piezoelectric actuators, respectively. .

[0005]

According to the manufacturing method of the present invention, the first and second rectangular piezoelectric plates are bonded to the substrate such that both sides extending in the longitudinal direction are respectively located on the same straight line. . For this reason, the first and second piezoelectric plates are each provided with a plurality of piezoelectric plates by a single process of providing grooves that vertically traverse the first and second piezoelectric plates in the length direction at intervals in the width direction. It can be divided into actuators.
Therefore, in the manufacturing method of the present invention, there is no need to perform a process of providing a groove in the width direction of the piezoelectric plate, and efficiently, and
Two types of piezoelectric actuators having different lengths can be manufactured at low cost.

[0006]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 4
Indicates an inkjet recording head 1. The ink jet recording head 1 has a small-diameter ink droplet discharge head unit (hereinafter, referred to as “small-diameter head unit 10”) and a large-diameter ink droplet discharge head unit 20 (hereinafter, “small-diameter head unit 20”).
Consists of These small diameter head section 10 and large diameter head section 20
As shown in FIGS. 2 and 4, the top plate 2, the partition 3, the frame 4,
The piezoelectric actuators 15 and 25 and the substrate 5 are combined.

The top plate 2 is made of a material such as a metal, a synthetic resin, or a ceramic, and the ink 6 is applied to a portion corresponding to the small-diameter head portion 10 and the large-diameter head portion 20 at a portion (facing surface) facing the partition wall 3. A plurality of ink cavities 11 and 21 to be accommodated;
The nozzles 14 and 24 for discharging the ink 6 in the ink cavities 11 and 21, the ink supply chambers 13 and 23 for storing the replenishment ink, and the ink cavities 11 and 21.
Are connected to the ink storage chambers 13 and 23, respectively.

The partition 3 is made of a thin film such as a metal or a synthetic resin, and is fixed between the top plate 2 and the frame 4 in a state where tension is applied.

The frame 4 is formed of metal, synthetic resin, ceramic, or the like, and is fixed between the partition 3 and the substrate 5. The frame 4 includes a frame portion 4 a along the outer edge of the substrate 5.
And a frame portion 4b along the center line 7 of the substrate 5.
One of the two spaces surrounded by the frame portions 4a and 4b corresponds to the small-diameter head portion 10, and the other corresponds to the large-diameter head portion 20.

Each of the piezoelectric actuators 15 and 25 is an elongated rectangular body made of a piezoelectric material.
As shown in FIG. 7, metal electrode layers 30 and 31 are formed respectively. These piezoelectric actuators 14 and 25 are provided in the ink cavities 11 and 21 in the space between the small-diameter head portion 10 and the large-diameter head portion 20 surrounded by the frame body 4, respectively.
Are arranged in parallel along. In addition, one metal electrode layer 30 is connected to ground via a conductive adhesive layer 32 and a partition 3, and the other metal electrode layer 31 is formed on the substrate 5 by a conductive adhesive layer 33. To the individual lead-out wiring 34.

The sizes of the piezoelectric actuators 15 and 25 are different between the small diameter head 10 and the large diameter head 20.
That is, as shown in FIGS. 1 and 2, the widths W1 and W2 and the thicknesses T1 and T2 of the piezoelectric actuators 15 and 25 are the same, but the lengths L1 and L2 are smaller than those of the piezoelectric actuator 15 of the small diameter head unit 10. The piezoelectric actuator 25 of the large diameter head section 20 is longer.

The substrate 5 is made of a hard material such as ceramic, metal or synthetic resin.

In the ink jet recording head 1 having the above structure, ink supply chambers 13 and 2 are provided from an ink tank (not shown).
3. The ink 6 is supplied to the ink cavities 11 and 21 via the inklets 12 and 22. Then, an image signal control circuit (not shown) supplies a piezoelectric actuator 15,
When a voltage (image signal) is applied to 25, the piezoelectric actuators 15 and 25 are deformed toward the ink cavities 11 and 21. This deformation is transmitted to the partition 3, whereby the ink 6 in the ink cavities 11 and 21 is pressurized, and the ink droplets fly through the nozzles 14 and 24.

A method of manufacturing the piezoelectric actuators 15, 25 will be described with reference to FIGS. First,
As shown in FIG. 5, a conductive adhesive 36 is applied by means such as screen printing on the substrate 5 on which the individual lead-out wirings 34 (only shown in FIG. 2) are provided in advance. As shown in FIG. 5, the adhesive 36 has two rectangular areas 37 and 38 to which piezoelectric plates 41 and 42 to be described later are bonded, respectively.
Applied to The adhesive 36 applied to these rectangular regions 37 and 38 constitutes the adhesive layer 33 of FIG. On the other hand, an adhesive non-applied region 39 is formed on a portion of the substrate 5 corresponding to the attachment position to the frame 4, that is, in the vicinity of the outer edge and the center of the substrate 5.

Next, as shown in FIG.
The piezoelectric plates 41 and 42 are fixed to the two regions 37 and 38, respectively, on which is applied. These piezoelectric plates 41,
Reference numeral 42 denotes a rectangular plate made of a piezoelectric material such as PZT (lead zirconate + lead titanate) on which the metal electrode layers 30, 31 are formed on the upper and lower surfaces by sputtering or plating. Further, the piezoelectric plates 41 and 42 have a width W1′W
2 ′, thickness T1′T2 ′ is the same, and length L
1'L2 'is different. That is, one piezoelectric plate 4
Numeral 1 is for forming the piezoelectric actuator 15 of the small-diameter head unit 10, and its length L1 'is the same as the length L1 of the piezoelectric actuator 15 of the small-diameter head unit 10. The other piezoelectric plate 42 is for forming the piezoelectric actuator 25 of the large-diameter head section 20, and its length L2 'is the same as the length L2 of the piezoelectric actuator 25 of the large-diameter head section 20 described above. And

The piezoelectric plates 41 and 42 are arranged on the substrate 5 so as to be arranged in the length direction of the substrate 5. That is, both side portions 41a and 41b extending in the length L1 'direction of the piezoelectric plate 41 and both side portions 42a and 42a extending in the length L2' direction of the piezoelectric plate 42 are provided on the substrate 5 respectively.
Are located on the same straight line 42a, 42 extending in the length direction. Further, the piezoelectric plate 4 adhered on the substrate 5
An interval 45 exists between 1 and 42.

Next, as shown in FIG. 7, the rotating dicing saw 43 is
The scanning is performed in the direction of the lengths L1 'and L2' of the piezoelectric plates 1 and 42, that is, in the direction in which the two piezoelectric plates 41 and 42 are arranged on the substrate 5 as described above. Each time the dicing saw 43 has finished moving from one end 5a to the other end 5b in the longitudinal direction of the substrate 5, the base 5 is moved to the piezoelectric plates 41 and 42 indicated by the arrow 46.
In the width W1 ′ and W2 ′ directions, ie, the piezoelectric plate 4
The feeders 1 and 42 are fed and moved at a constant pitch in a direction orthogonal to the direction in which they are arranged. On the contrary, the dicing saw 43
May be fed and moved with respect to the base 5.

The dicing saw 43 holds the substrate 5 at one end 5 thereof.
Each time one pass from a to the other end 5b is made, the first and second piezoelectric plates 41, 42 are substantially straight, vertically extending from one end 41a, 42a in the length L1 ', L2' direction to the other end 41b, 42b. Grooves 48, 49 are formed, and these grooves 48, 49 are formed on one straight line. Further, as described above, the base 5 is relatively moved to the width W by the dicing saw 43.
The grooves 48, 49 formed in the piezoelectric plates 41, 42 are parallel and at equal intervals because they are sent at the same pitch in the direction of 1 ', W2' (the direction of arrow 46). As shown in FIG. 4, the grooves 48 and 49 are formed so that the substrate 5 is slightly cut away, and the adhesive layer 33 between the piezoelectric actuators 15 and 25 adjacent in the width direction is cut off to form the adjacent piezoelectric elements. The actuators 15 and 25 are electrically separated from each other.

As shown in FIG. 8, each piezoelectric plate 4 is formed by grooves 48 and 49 formed by the dicing process.
Each of the piezoelectric actuators 1 and 42 is divided into a portion that becomes the piezoelectric actuators 15 and 25 and a portion that becomes the side walls 51 and 52 provided between the adjacent piezoelectric actuators 15 and 25. In this state, high voltage is applied to the metal electrode layers 30 and 31 by the individual lead wirings 34 and the conductive partition walls 3 to perform polarization processing on the portions to be the piezoelectric actuators 15 and 25. Then, while the frame 4 is bonded to the substrate 5 and the partition 3 is bonded to the top plate 2, the piezoelectric actuators 15 and 25 and the frame 4 attached to the substrate 5 are bonded to the partition 3 by a conductive adhesive 36. I do.

In the manufacturing method of the present embodiment, the lengths L1 'and L2' of the two piezoelectric plates 41 and 42 are set to be the same as the lengths L1 and L2 of the piezoelectric actuators 15 and 25, respectively. Plates 41 and 42 have length L1 '
The two side portions 41a and 42b extending in the L2 'direction are adhered to the substrate 5 so as to be arranged on the same straight lines 42a and 42, respectively. Therefore, the piezoelectric actuators 15, 25
In order to adjust the length of the piezoelectric plates 41, 42, the width W1 ', W
There is no need to provide a groove in the 2 'direction. Therefore, the piezoelectric actuators 15 and 25 of the small-diameter head unit 10 and the large-diameter head unit 20 can be simultaneously formed by the single dicing process, and the piezoelectric actuators can be manufactured efficiently and at low cost.

The piezoelectric plate for forming the piezoelectric actuator may be composed of a laminated piezoelectric member in which a plurality of metal electrode layers and piezoelectric materials are alternately stacked.
Further, the formation of the groove in the piezoelectric plate is not limited to dicing, and may be performed by another processing method. Furthermore, the lead-out structure and the like of the metal electrode layers 30 and 31 are not limited to the above embodiment, and various modifications are possible. The rectangular areas 37 and 38 to which the adhesive has been applied do not need to be separately applied at the time of application. That is, an adhesive is applied to the entire surface of the substrate 5 and the piezoelectric plate 4 made of PZT is applied.
After bonding and drying, two rectangular regions 37,
38 may be separated. 9 and 10
As shown in FIG. 7, the width of the piezoelectric actuator 71 of the small-diameter head unit 10 and the width of the piezoelectric actuator 70 of the large-diameter head unit 20 can be changed by changing the interval between grooves formed by dicing on the piezoelectric plates 41 and 42. Good. Also in this case, the wall portions 61 and 70 of the small diameter head portion 10 and the large diameter head portion 20 have the same width.

[Brief description of the drawings]

FIG. 1 is a front view of an ink jet recording head.

FIG. 2 is a sectional view taken along line II-II of the inkjet recording head of FIG.

FIG. 3 is a perspective view of the inkjet recording head of FIG.
It is a line sectional view.

FIG. 4 is a cross-sectional view of the inkjet recording head of FIG. 2, taken along line IV-IV.

FIG. 5 is a perspective view showing a substrate and an adhesive application area on the substrate.

FIG. 6 is a perspective view showing a substrate and a piezoelectric plate adhered on the substrate.

FIG. 7 is a perspective view showing a groove forming step by dicing.

FIG. 8 is a perspective view of a piezoelectric plate in which grooves are formed by dicing.

FIG. 9 is a perspective view showing another example of a groove forming step by dicing.

FIG. 10 is a perspective view showing another example of a piezoelectric plate in which grooves are formed by dicing.

[Explanation of symbols]

1 ... inkjet recording head, 5 ... substrate, 10 ...
Small-diameter head, 15, 25 ... piezoelectric actuator,
20: large diameter head, 41, 42: piezoelectric plate,
43 ... dicing saw, 48, 49 ... groove 51, 7
0,61 ... side wall

Claims (1)

[Claims] 1. A first and a second piezoelectric plate, each having a rectangular shape, different lengths, and the same width and thickness, are arranged on both sides extending in the length direction on the same straight line. After being positioned and adhered on the substrate at a predetermined interval, a plurality of grooves are formed at predetermined intervals in the width direction to form a plurality of grooves for vertically traversing the first and second piezoelectric plates in the length direction. And dividing the second piezoelectric plate into a plurality of piezoelectric actuators.