JP2002248767A - Ink-jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a plurality of leader electrodes to be connected to electrodes of a piezoelectric actuator, easily and integrally to the inside of a head body and protect the leader electrodes. SOLUTION: There are provided a laminate for constituting the piezoelectric actuator at least at a part thereof by laminating and sintering a plurality of piezoelectric material sheets, and a plurality of leader electrode formation films 15 which are formed penetrating the piezoelectric material sheets in a thickness direction of the sheets respectively and are mutually connected in a laminate direction of the sheets to form the leader electrodes 25. A part where the leader electrodes 25 penetrate the piezoelectric material sheets is positioned outside a deformation part of the piezoelectric actuator where the piezoelectric actuator deforms an ink channel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ink jet recording head.

[0002]

2. Description of the Related Art Conventionally, as an ink jet printer which ejects a small amount of ink droplets from an ink jet nozzle communicating with an ink passage to which ink is supplied from an ink supply source, an on-demand type which can be miniaturized and capable of high-speed recording. In particular, those employing a pressure control method or a bubble control method using heat have been widely used. In the pressure control system, an inkjet printer employing a piezoelectric system using a piezoelectric element such as a piezoelectric ceramic has been put to practical use, and various proposals have been made.

In an ink jet printer employing this piezoelectric system, a plurality of ink passages through which ink from an ink supply source is supplied via a manifold member, a plurality of partition walls comprising piezoelectric elements constituting these ink passages, A recording head having a plurality of electrodes provided on a pair of left and right side walls of these partitions is provided, and a drive signal from a drive IC is supplied to an electrode of the partition corresponding to an ink path for ejecting ink for a predetermined minute time. When the two adjacent partitions return to the original shape after being deformed by shear strain so as to increase the volume of the ink passage, the ink refilled into the ink passage is ejected from the ejection nozzle at the tip thereof. Has become.

[0004] For example, as shown in FIG. 14, in an ink jet printer, a recording plate in which a cover plate 140 is fixed to a head body 101 made of a piezoelectric material having a plurality of ink passages so as to cover the plurality of ink passages. The head 145 is fixed to the carriage 103. On the other hand, a printed circuit board 148 to which the drive IC 146 is attached is fixed to the carriage 103.
The wiring pattern 104 connected to the driving IC 146
Are formed.

Further, on a side surface of the head body 101, a plurality of extraction electrodes 105 for supplying power to actuators provided corresponding to a plurality of ink passages are formed, and the plurality of extraction electrodes 105 and the plurality of wiring patterns 104 are formed. Are electrically connected to each other by a flexible FPC (flexible print circuit) 147.

[0006]

In the ink jet type recording head 145 shown in FIG.
A plurality of extraction electrodes 105 for connecting the driving IC 146 and the plurality of actuators (electrodes) are exposed and formed on one side surface, and each extraction electrode 105 is several tens μm.
And a thickness of several μm, the extraction electrode 105 is connected to the head body 10 during the work of assembling the recording head 145 and the work of attaching the recording head 145 to the carriage 103.
There is a problem that it is easily peeled off from No. 1 and that it is easily broken.

SUMMARY OF THE INVENTION It is an object of the present invention to easily and integrally form a plurality of extraction electrodes connected to the electrodes of a piezoelectric actuator inside a head body to protect the extraction electrodes.

[0008]

According to a first aspect of the present invention, there is provided an ink jet recording head which deforms the piezoelectric actuator by applying a voltage to an electrode of the piezoelectric actuator via an extraction electrode, thereby causing ink in an ink passage to flow from a nozzle. In the ink jet recording head to be ejected, a plurality of piezoelectric material sheets are laminated and sintered, and at least a part of the laminated body constituting the piezoelectric actuator, and each piezoelectric material sheet penetrates in the thickness direction. A plurality of extraction electrode forming films formed and connected to each other in the stacking direction of the sheets to form the extraction electrodes, and a portion where the extraction electrodes penetrate the piezoelectric material sheet deforms the ink passage. It is located outside the deformed portion of the piezoelectric actuator. Here, the plurality of extraction electrode forming films may be formed so as to close the openings formed in the green sheet.

The piezoelectric actuator is deformed by a voltage applied through a plurality of extraction electrodes formed so as to extend in the thickness direction inside, and ejects ink in an ink passage from a nozzle. The extraction electrode is formed by connecting a plurality of extraction electrode forming films corresponding to each other when a plurality of piezoelectric material sheets are stacked in the stacking direction.

According to a second aspect of the present invention, in the ink jet recording head according to the first aspect, the direction in which the extraction electrode penetrates the piezoelectric material sheet at the portion where the extraction electrode penetrates the piezoelectric material sheet is the same as that of the ink passage. At right angles to the direction of deformation of the piezoelectric actuator that causes deformation.

According to a third aspect of the present invention, in the ink jet recording head according to the first or second aspect, a direction in which the pair of electrodes for deforming the piezoelectric actuator face each other is perpendicular to a depth direction of the ink passage.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, the present invention is applied to an ink jet recording head in which a plurality of sets of ink jet nozzles, ink passages, and piezoelectric actuators are incorporated. This is when the invention is applied.

The description will be made sequentially based on the manufacturing process of the ink jet recording head shown in FIG. However, the direction in which the inkjet nozzle is formed is defined as the front. First, in a first step K1, as shown in FIGS. 2 and 3,
A small amount of organic binder,
A slurry containing a plasticizer, a dispersant, and the like is formed into a thick film having a thickness of about several tens of μm by a film forming apparatus, and cut into a predetermined size corresponding to the size of the head body 1 to form a plurality of green sheets 10 to 10. 13 is created.

Next, in a second step K2, the rear ends of the plurality of green sheets 11 forming the ink passages are
In order to correspond to the plurality of electrodes 35 and 36 (see FIG. 8) provided on the side surface of the partition wall 31 corresponding to the ink passage 32, the width
A plurality of lead electrode openings 11a having a predetermined length of 10 μm are formed in a row at a predetermined pitch in the width direction (left-right direction), and the inner green sheet 1 close to the surface is formed.
2 includes a drive IC 46 for supplying drive signals to a plurality of electrodes in addition to the openings 12a similar to the openings 11a.
A plurality of second extraction electrode openings 12b each having a width of several 10 μm and having a predetermined length are formed in a row in the width direction at predetermined pitches.

Further, a plurality of green sheets 1 on the surface portion
3 has a width of 10 μm for connecting the output terminal of the drive IC 46.
m, a plurality of connection electrode openings 13a having a predetermined length
And the width of 10 μm connecting the input terminal of the drive IC 46
A plurality of connection electrode openings 13b having a predetermined length,
A plurality of connection electrode openings 13c having a predetermined length and a width of several 10 μm connected to the plurality of second extraction electrodes 26;
Each is formed in one row in the width direction at a predetermined pitch.

Next, in a third step K3, a fine powder of a metal such as platinum is applied to the plurality of green sheets 11 by using a mesh sheet (not shown) in which the portions other than the openings 11a are blinded. Are rubbed with a spatula or the like to form a plurality of extraction electrode forming films 15 penetrating through the plurality of extraction electrode openings 11a in the thickness direction. Similarly, a plurality of extraction electrode formation films 15 and a plurality of second extraction electrode formation films 16 penetrating through the plurality of second extraction electrode openings 12b in the thickness direction with respect to the plurality of green sheets 12 are formed. Then, a plurality of connection electrode forming films 17 to 19 are formed on the plurality of green sheets 13 so as to penetrate the plurality of connection electrode openings 13 a to 13 c in the thickness direction.

Next, in a fourth step K4, as shown in FIG. 4, when a plurality of green sheets 10 to 13 are stacked in this order, a corresponding plurality of electrode forming films 15 to 19 are formed.
Are laminated and thermocompression-bonded to produce a green laminate. Next, in a fifth step K5, the green laminate is first heated to 400 ° C.
After heating to about the temperature and performing a binder removal treatment for thermally decomposing all the organic components contained therein, reheating is performed at a temperature of about 1000 ° C. or more to sinter.

As a result, as shown in FIG. 5, the head main body 1 made of a piezoelectric ceramic as a sintered body can be manufactured, and at the same time, a plurality of laminated extraction electrode formation films 15 and a plurality of connection electrode formation films 17 are formed. The plurality of extraction electrodes 25 and the first connection terminals 27 connected to the electrodes of the piezoelectric actuator, the plurality of second extraction electrode formation films 16 and the plurality of connection electrode formation films 18 and 19 are respectively integrated. , The second extraction electrode 26, the second connection terminal 28, and the third connection terminal 2
9 are formed inside the head body 1 respectively. That is, each of the first to third connection terminals 27 to 29 is exposed on the surface of the head main body 1. Next, in a sixth step K6, a high DC voltage is applied to the two opposing end faces of the head body 1 so that the polarization is formed in the predetermined direction 38 indicated by the dashed line arrow. Perform processing. As a result, the polarization direction 38 of the head main body 1 can be formed in a predetermined direction, for example, a direction going upward in FIG.

Next, in a seventh step K7, FIGS.
As shown in FIG. 5, a plurality of narrow grooves 30 extending in the front-rear direction are formed at the lower end of the head body 1 by using a groove processing cutter.
It is formed at predetermined pitches in the left-right direction. At this time, the rear ends of the plurality of narrow grooves 30 correspond to the adjacent extraction electrodes 25, and the extraction electrodes 25 are exposed in the narrow grooves 30 by processing the narrow grooves 30. At this time, a plurality of partition walls 31 that partition the plurality of narrow grooves 30 are formed,
An ink passage 32 is formed by every other narrow groove 30. Next, in an eighth step K8, as shown in FIG. 8, the lower half of the side surface of each narrow groove 30 is masked with a masking seal (shown by a two-dot chain line), and a metal such as platinum is deposited. Thus, the electrodes 35 and 36 are formed. Electrode 3
Reference numerals 5 and 36 denote extraction electrodes 25 exposed in the narrow groove 30.
To the end of the. Thereafter, the unnecessary masking seal is removed.

That is, a grounded electrode 35 is formed in the upper half of the side surface of each partition 31 facing the ink passage 32, and the upper half of the side surface of the partition 31 facing the narrow groove 30 which is not the ink passage 32. An electrode 36 to which a drive voltage V from a drive IC 46 to be described later is supplied is formed in the portion. here,
Each of the electrodes 35 and 36 is connected to the corresponding extraction electrode 25. The partition walls 31 on both sides of the ink passage 32
And electrodes 35 and 36 formed on the side surfaces of the partition walls 31.
Thus, a piezoelectric actuator is formed.

As a result, as shown in FIG. 9, when a drive voltage V output from a drive IC 46 described later is supplied to the electrodes 36 of the two partition walls 31 adjacent to the ink passage 32, the right side of the ink passage 32 The upper half portion of the partition wall 31 undergoes shear deformation (thickness-shear deformation) to the right side perpendicular to the polarization direction 38, so that the partition wall 31 is deformed in a substantially rectangular shape. The upper half portion of the partition wall 31 is sheared and deformed to the left, and the partition wall 31 is deformed into a substantially rectangular shape. At this time, ink from an ink supply source (not shown) is replenished into the ink passage 32, and then the electrode 36
When the supply of the drive voltage V to the partition wall 31 is stopped, the ink in the ink passage 32 is ejected from the ink jet nozzle 42 as the shear deformation of the partition wall 31 is released.

Next, in a ninth step K9, as shown in FIG.
And a nozzle forming plate 41 having a plurality of inkjet nozzles 42 formed thereon is bonded and fixed to the front end surface of the head main body 1. Thus, a recording head 45 having a structure in which a plurality of sets of the ink jet nozzle 42, the ink passage 32, and the piezoelectric actuator are incorporated can be manufactured. Here, as shown in FIG. 11, an ink supply notch 40a extending in the width direction is formed in the rear end side portion of the cover plate 40. The ink supply notch 40a has An ink supply member connected to an ink cartridge (not shown) is attached.

Next, in a tenth step K10, FIG.
As shown in FIG. 7, a drive IC 46 for supplying a drive signal to a plurality of electrodes 36 is connected to a plurality of first connection terminals 2 by an output terminal portion.
7 and its input terminals are connected to the plurality of second connection terminals 28 by brazing, and at the same time, are attached to the head main body 1 with an adhesive or the like. In addition, as shown in FIG. 12, a plurality of third connection terminals 29 are connected to one end of an FPC (flexible print circuit) 47 by brazing. Further, the rear end of the recording head 45 is
By attaching the other end of the FPC 47 to a wiring pattern (not shown) formed on the printed circuit board 48, the recording head 45 can be mounted as a unit on a carriage (not shown). FPC4
7 includes a clock signal line, a data signal line, a voltage line, and a ground line, and the driving IC 46 is configured to output a clock signal line based on a continuous clock pulse supplied from the clock signal line.
From the data appearing on the data signal line, it is determined from which nozzle 42 ink should be ejected, and the voltage of the voltage line is applied to the corresponding extraction electrode 25.

As shown in FIG. 13, the cover plate 40A is manufactured by laminating a plurality of green sheets and sintering, while forming a plurality of narrow grooves 50 corresponding to the narrow grooves 30A of the head body 1A. Then, polarization processing is performed so that the polarization direction 51 is opposite to the polarization direction 38 of the head main body 1A,
An electrode 52 corresponding to the electrode 35 on the ground side and an electrode 53 corresponding to the electrode 36 on the drive side may be integrally formed over these two narrow grooves 30A and 50.

As described above, in order to form the head body 1 by laminating a plurality of green sheets 10 to 13 made of a piezoelectric material, some of the green sheets 11 to 12 are penetrated in the thickness direction. A plurality of extraction electrode forming films 15
When forming the green sheets 10 to 13,
Since a plurality of corresponding extraction electrode forming films 15 are laminated to form a plurality of extraction electrodes 25 connected to the electrodes 35 and 36 of the piezoelectric actuator, the plurality of extraction electrodes 25 are integrally formed inside the head main body 1. The plurality of extraction electrodes 25 can be reliably protected from damage and disconnection.

A plurality of second extraction electrode forming films 16 are formed on the green sheet 12 near the surface of the head main body 1, and the plurality of extraction electrodes 25 and the second extraction electrode 26 are provided with piezoelectric actuators. Drive IC for driving
When the drive IC 46 is attached to the head main body 1, the drive IC 46 and the plurality of extraction electrodes 2 are connected.
5 and the second extraction electrode 26 at the same time. Furthermore, since the drive IC 46 is provided on the surface of the head main body 1, the heat generated by the drive IC 46 by the ink ejection operation is efficiently transmitted to the head main body 1, so that the heat of the drive IC 46 can be effectively radiated, and Ink passage 32 by heat
The temperature of the ink increases, the viscosity of the ink decreases, and the ink ejection performance improves.

Further, a plurality of second extraction electrodes 26 for connecting the drive IC 46 to a wiring pattern of a printed board 48 outside the recording head are formed on the head main body 1, and the second extraction electrodes 26 connected to the second extraction electrodes 26 are formed. Since the three connection terminals 29 are exposed on the surface of the head main body 1, the number of signal lines connected to the input terminals of the drive IC 46 via the second extraction electrodes 26 is several, such as data signals and control signals. The electrical connection structure between the third connection terminals 29 and the wiring patterns on the printed circuit board 48 can be simplified.

Here, as a modification of the above embodiment,
The plurality of third connection terminals 29 are formed at the rear end of the head body 1, and when the rear end of the recording head 45 is attached to the printed board 48, these third connection terminals 29 are connected to the wiring of the printed board 48. The FPC 47 may be omitted by simultaneously connecting to the pattern by brazing or wire bonding. Further, it is possible to apply the present invention to various methods of manufacturing an ink jet recording head, such as a recording head that ejects ink by generating bubbles by heat, and the recording head.

[0029]

According to the ink jet recording head of the present invention, a plurality of piezoelectric material sheets are laminated and sintered, and at least a part of the laminated body constituting the piezoelectric actuator and the piezoelectric material sheets are provided. A plurality of extraction electrode forming films formed so as to penetrate in the thickness direction thereof and connected to each other in the stacking direction of the sheets to form the extraction electrodes, wherein the extraction electrodes penetrate the piezoelectric material sheet. Is located outside the deformed portion of the piezoelectric actuator that deforms the ink passage, so that a voltage is applied to the piezoelectric actuator through a plurality of extraction electrodes formed to extend in the thickness direction inside the piezoelectric actuator. The piezoelectric actuator is deformed, and the ink in the ink passage can be ejected from the nozzle.

Furthermore, the extraction electrode can be easily formed by connecting a plurality of extraction electrode forming films corresponding to each other when the plurality of piezoelectric material sheets are laminated in the laminating direction, and can be protected from it.

In the above structure, the direction in which the extraction electrode penetrates the piezoelectric material sheet at the portion where the extraction electrode penetrates the piezoelectric material sheet is defined as the deformation direction of the piezoelectric actuator that deforms the ink passage. With the right angle, the extraction electrode is easily and integrally provided inside the laminate without damage or disconnection.

Further, in the above configuration, the facing direction of the pair of electrodes for deforming the piezoelectric actuator is
By making it perpendicular to the depth direction of the ink passage,
The extraction electrode is easily and integrally provided inside the laminate without being damaged or disconnected.

[Brief description of the drawings]

FIG. 1 is a process chart showing a manufacturing process of an ink jet recording head according to an embodiment of the present invention.

FIG. 2 is a perspective view of a green sheet in which a plurality of openings and an electrode forming film are formed and stacked.

FIG. 3 is a vertical side view of a green sheet on which a plurality of openings and an electrode forming film are formed and stacked.

FIG. 4 is a vertical sectional side view of a main part of a plurality of stacked green sheets.

FIG. 5 is a vertical sectional side view of a main part of a head main body formed by sintering.

FIG. 6 is a diagram corresponding to FIG. 5 in which a narrow groove is formed.

7 is a sectional view taken along the line VII-VII in FIG. 6;

FIG. 8 is an enlarged longitudinal sectional view of a main part of the head body.

FIG. 9 is a diagram corresponding to FIG. 8 when a partition wall is deformed by shearing.

FIG. 10 is an exploded perspective view of a recording head.

FIG. 11 is a perspective view of a recording head.

FIG. 12 is a perspective view of a recording head attached to a printed circuit board.

FIG. 13 is a diagram corresponding to FIG. 8 according to a modified embodiment.

FIG. 14 is a perspective view of a recording head and a printed circuit board according to a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Head main body 10-13 Green sheet 25 Leader electrode 42 Ink jet nozzle 32 Ink passage 35, 36 Electrode 15 Leader electrode forming film

Claims (3)

[Claims] 1. An ink jet recording head which deforms a piezoelectric actuator by applying a voltage to an electrode of the piezoelectric actuator through an extraction electrode to eject ink in an ink passage from a nozzle, wherein a plurality of piezoelectric material sheets are formed. A laminated body which is laminated and sintered, and constitutes at least a part of the piezoelectric actuator, and which is formed in each of the piezoelectric material sheets so as to penetrate in the thickness direction thereof and is connected to each other in the lamination direction of the sheets. A plurality of extraction electrode forming films forming extraction electrodes, wherein a portion where the extraction electrode penetrates the piezoelectric material sheet is located outside a deformed portion of the piezoelectric actuator that deforms the ink passage. Inkjet recording head. 2. A direction in which the extraction electrode penetrates the piezoelectric material sheet at a portion where the extraction electrode penetrates the piezoelectric material sheet is perpendicular to a deformation direction of the piezoelectric actuator that deforms the ink passage. The ink jet recording head according to claim 1, wherein 3. The ink jet recording head according to claim 1, wherein a direction in which the pair of electrodes deform the piezoelectric actuator is perpendicular to a depth direction of the ink passage.