JP3298755B2 - Method of manufacturing inkjet head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention is, the ink-jet heads
It relates to a method of manufacturing a method of manufacturing an inkjet heads, in particular a laminated type piezoelectric element.

[0002]

2. Description of the Related Art The ink jet recording system has attracted attention because it can record without contacting a head on recording paper, and has a very simple recording process and is suitable for color recording. Conventionally, various methods have been proposed as the ink jet recording method, but at present, the so-called drop-on-demand (DOD) method in which ink is ejected only when a recording signal is input has become mainstream. Among the DOD methods, there are a so-called bubble jet method (Japanese Patent Publication No. 61-59913 and the like) utilizing bubbles generated in ink by thermal energy and a piezo actuator method using a piezoelectric element (Japanese Patent Publication No. 60-8953). Etc.).

As the latter piezo actuator system,
For example, as described in JP-A-3-10846, a wall constituting the pressurized liquid chamber has a deformable structure, a piezoelectric element is provided outside the deformable wall, and the piezoelectric element is used. There is a method in which the wall surface of the pressurized liquid chamber is deformed to change its internal volume, thereby applying pressure to the ink to form droplets and fly from the nozzles. In the piezo actuator method, a pulse-like pressure increase in the nozzle region or the pressurized liquid chamber on the front surface of the piezoelectric element is required,
The voltage waveform applied to the piezoelectric element is several μsec to several tens μsec.
And the ink is supplied by returning the displacement of the piezoelectric element to the original.

[0004] Such a piezo actuator type ink jet head has the advantage that there is no restriction on the type of ink used since the piezoelectric element does not directly contact the ink and the heat generated by the piezoelectric element can be neglected. On the other hand, multi-channel (here, "channel"
Each part is composed of one piezoelectric element, one pressurized liquid chamber and one nozzle. ), There is a disadvantage that the piezoelectric elements are arranged at a high integration density, and even when the piezoelectric elements are arranged at a high integration density, it is difficult to electrically connect the electrodes of the individual piezoelectric elements to the outside.

Therefore, conventionally, for example, Japanese Unexamined Patent Publication No. Hei.
As described in Japanese Patent Publication No. 7, after forming an electrode pattern on a substrate and bonding a piezoelectric element, slit processing is performed on the surface of the piezoelectric element and the substrate to form a plurality of piezoelectric elements, and There is an ink jet head which divides a pattern for use into a plurality of piezoelectric elements, thereby increasing the integration density and facilitating external electrical connection to each piezoelectric element. However, this ink jet head is of a type in which the piezoelectric element is directly exposed to the pressurized liquid chamber and the ink contacts the piezoelectric element.

[0006]

In the above-described conventional piezo-actuator type ink-jet head, although it is easy to integrate the piezoelectric elements at a high density and to take out the electrodes to the outside, in particular, the piezoelectric elements are preferably used. When a multilayer piezoelectric element is used and the displacement of the multilayer piezoelectric element in the d33 direction is used (see the above-mentioned JP-A-3-73347), the slit width and pitch of the piezoelectric element increase as the integration increases. It becomes difficult to electrically connect the internal electrodes provided on both sides of each layer to the outside, and when slit processing is performed, poor bonding between the substrate and the piezoelectric element occurs, Or be damaged.

The present invention has been made in view of the above points, and has as its object to improve the yield in the manufacturing process of an ink jet head and to reduce the cost.

[0008]

According to a first aspect of the present invention, there is provided a method of manufacturing an ink jet head, comprising the steps of: forming an individual lead electrode pattern and a common electrode pattern on an insulating substrate;
While forming the turn , the internal electrodes are alternately taken out in advance on both end faces, and the laminated piezoelectric element conductively connected to the end face electrodes formed on each end face is joined, and the individual extraction electrode pattern and one of the laminated piezoelectric elements are joined. An end electrode and the common electrode
Pattern and the other end face electrode of the multilayer piezoelectric element.
After conducting and connecting, respectively , the multilayer piezoelectric element and the surface portion of the substrate are simultaneously slit to form the plurality of multilayer piezoelectric elements and the individual drawing. The electrode pattern and the end face electrode are divided into individual extraction electrodes and individual end face electrodes respectively corresponding to the plurality of stacked piezoelectric elements. In addition, “ individual extraction electrode” means an electrode for extracting the electrode of the multilayer piezoelectric element to the outside,
The “end face electrode” is used to mean an external electrode connected to the internal electrode of the multilayer piezoelectric element.

[0009]

[Action] A method for manufacturing an ink jet head according to claim 1, on an insulating substrate, pattern and a common collector for an individual lead electrode
The electrode pattern is formed, and the internal electrodes are alternately taken out in advance on both end faces, and the laminated piezoelectric element conductively connected to the end face electrodes formed on each end face is joined, and one of the individual extraction electrode pattern and one of the laminated piezoelectric elements is joined. For the common electrode
The pattern and the other end face electrode of the multilayer piezoelectric element
After conducting and connecting, respectively, the multi-layer piezoelectric element and the surface of the substrate are simultaneously slit to form a plurality of multi-layer piezoelectric elements, and a plurality of individual extraction electrode patterns and end face electrodes are laminated. Since the electrode is divided into individual extraction electrodes and individual end electrodes corresponding to the individual piezoelectric elements, each internal electrode and individual extraction electrode and
Connection with the through electrode can be easily performed.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an external perspective view of an inkjet head showing one embodiment of the present invention, FIG. 2 is an exploded perspective view of FIG.
FIG. 4 is a sectional view taken along the line AA of FIG. 1, FIG. 4 is a sectional view taken along the line BB of FIG. 1, and FIG. 5 is an enlarged sectional view of a main part of FIG.

The ink jet head includes an actuator unit 1 and a liquid chamber unit 2 joined on the actuator unit 1. The actuator unit 1 includes two rows of piezoelectric element rows 4 and 4 in which a plurality of stacked piezoelectric elements are arranged (arranged) in a row on a substrate 3 and the periphery of the two rows of piezoelectric element rows 4 and 4. The surrounding frame member 5 is joined by a joining agent 6. Piezoelectric element row 4
Is composed of a plurality of piezoelectric elements to which a driving pulse is applied to make ink droplets fly.
That. ), A plurality of piezoelectric elements which are located between the drive unit piezoelectric elements 7 and 7 and serve merely as a liquid chamber unit fixing member without being supplied with a drive pulse (this is referred to as a “fixed unit piezoelectric element”). 8, 8... Are alternately arranged.

The liquid chamber unit 2 has a liquid chamber flow path formed of a photosensitive resin film (dry film resist) for forming a pressurized liquid chamber, a common ink flow path, and the like on a diaphragm 12 having a diaphragm 11 formed thereon. The member 13 is bonded, and a nozzle plate 16 having a plurality of nozzles 15 formed thereon is bonded on the liquid chamber flow path forming member 13. The vibration plate 12, the liquid chamber flow path forming member 13, and the nozzle plate 16
A plurality of substantially independent pressurized liquid chambers 17 each having a diaphragm section 11 facing each driving piezoelectric element 7, 7,... Of the piezoelectric element row 4 are formed, and the nozzles 15, 15,. Are arranged so as to face the drive unit piezoelectric elements 7. The diaphragm 12 of the liquid chamber unit 2 is joined to the actuator unit 1 with high rigidity by an adhesive 18.

The substrate 3 of the actuator unit 1 has a thickness of about 0.5 to 5 mm and is made of a material similar to a piezoelectric element, and can be cut together with the piezoelectric element by, for example, a diamond grindstone. Is preferred.

At both ends of the substrate 3 in the direction perpendicular to the direction in which the piezoelectric elements are arranged, the end faces of the piezoelectric element rows 4 and 4 where the driving piezoelectric elements 7 and the fixed piezoelectric elements 8 are not opposed to each other. Individual extraction electrode 2 divided by connecting slit groove 21
Are formed, and each piezoelectric element row 4,
4, the common groove 2 deeper than the slit groove 21 in the direction orthogonal to the slit groove 21 (the direction in which the piezoelectric elements are arranged).
3 are formed, and each of the piezoelectric element rows 4 and 4 is formed in the common groove 23.
A common electrode 24 is formed to connect the opposing end faces of the individual drive unit piezoelectric elements 7 and fixed unit piezoelectric elements 8.
An ink supply pipe 25 is connected to an ink supply hole 3a formed at an end of the substrate 3.

Here, as shown in FIG. 5, there is a slight gap in the positional relationship between the driving portion piezoelectric element 7 and the individual extraction electrodes 22 and the common electrode 24. This is the driving piezoelectric element 7
When the electrode is placed on each of the electrodes 22 and 24, the thickness and error of the electrodes 22 and 24 affect the bonding quality of the piezoelectric elements 7 and 8, that is, the uniformity of bonding and the plane parallel accuracy after bonding. This is because it is not preferable. However, the drive unit piezoelectric element 7
There is little adverse effect if the individual extraction electrodes 22 and the common electrode 24 slightly overlap each other.

As the driving part piezoelectric element 7 and the fixed part piezoelectric element 8 constituting the piezoelectric element row 4, a laminated piezoelectric element having ten or more layers is used. This laminated piezoelectric element has a thickness of 20 to 50 μm / 1, for example, as shown in FIGS.
PZT (= Pb (Zr · Ti) O3) 26 of the layer and a thickness μ
An internal electrode 27 of m / 1 layer of silver / palladium (AgPd) is alternately laminated. Then, the uppermost layer 26 of the driving unit piezoelectric element 7 and the fixed unit piezoelectric element 8.
On the upper surface of “a”, an electrode corresponding to the internal electrode 27 is not formed and an inactive layer is formed. The material used for the piezoelectric element is not limited to the above, and BaTiO3, PbTiO3, (NaK) Nb which are generally used as the piezoelectric element material are used.
It is also possible to use a ferroelectric material such as O3.

A large number of internal electrodes 27 of the driving piezoelectric element 7 of each piezoelectric element row 4 are alternately taken out on both end faces alternately on both end faces, and individual end face electrodes 28 made of, for example, AgPd are formed on both end faces. , 29 and each piezoelectric element row 4,
4 are connected to the common electrode 24 on the substrate 3 by a Young's modulus of 2
Are connected via a conductive material 31 of not less than 00 kgf / mm 2, and the individual end surface electrodes 29, 29. , 22 are connected to each other via a conduction processing material 32. An FPC cable 33 is connected to each of the individual extraction electrodes 22, 22,... And the common electrode 24, and when a driving voltage is applied, an electric field is generated in the stacking direction.
A displacement in the lamination direction (a displacement in the d33 direction in the same direction as the electric field) is generated in the driving piezoelectric element 7. In the manufacturing process, each electrode of the fixed portion piezoelectric element 8 is provided similarly to the drive portion piezoelectric element 7, but a configuration in which no drive pulse is applied (a configuration in which only the drive portion piezoelectric element 7 is selectively driven). It has become.

As shown in FIG. 2, the frame member 5 has through holes 5a, 5b corresponding to the piezoelectric element rows 4, 4 in a plate-like member.
Are formed on one side in a direction orthogonal to the direction in which the driving piezoelectric elements 7, 7,... Of the piezoelectric element rows 4, 4 are arranged, and the two piezoelectric element rows are formed. A fixed portion 37 is also formed at the central portion, which is the other side of 4, 4,
The fixing portions 35 to 37 are provided with bridging portions 38 at both ends of the driving portion piezoelectric elements 7, 7.
38 is formed. Note that an ink supply hole 5c corresponding to the ink supply hole 3a of the substrate 3 is formed in one bridge portion 38 of the frame member 5.

Next, as shown in FIG. 3, the diaphragm 12 of the liquid chamber unit 2 has a flat surface on the lower liquid chamber flow path forming member 13 side and a diaphragm region 12a having a different thickness on the piezoelectric element row 4 side. , A joining area 12b and a relief area 12c, and a diaphragm section 11 corresponding to the driving piezoelectric elements 7, 7,... Of the piezoelectric element row 4. The diaphragm 12 is made of a Ni (nickel) metal plate.
It is manufactured by an electroforming method. Note that the diaphragm 12 also has an ink supply hole 12d.

The liquid chamber flow path forming member 13 is located between the upper surface of the vibration plate 12 and the nozzle plate 16 to form a flow path of the pressurized liquid chamber 17 and the like. It comprises a chamber flow path forming member 40 and an upper liquid chamber flow path forming member 41.

The lower liquid chamber flow path forming member 40 is
.. Made of a photosensitive resin film adhered to the upper surface, together with the upper liquid chamber flow path forming member 41, as shown in FIG. A number of inner partition walls 43 which form independent flow paths of the pressurized liquid chamber 17 and also form a fluid resistance portion 42 which also serves as an ink supply path to each pressurized liquid chamber 17; 17 and an outer peripheral partition wall 45 forming a common ink flow path 44. The upper liquid chamber flow path forming member 41 has substantially the same configuration as the lower liquid chamber flow path forming member 40, except that there is no portion corresponding to the fluid resistance portion 42 of the lower liquid chamber flow path forming member 40. different.

A large number of nozzles 15 are formed in the nozzle plate 16 as fine holes for causing ink droplets to fly.
The nozzle 15 is provided at a position corresponding to the vicinity of the center of the pressurized liquid chamber 17. The nozzle plate 16 is also made of a Ni (nickel) metal plate like the diaphragm 12, and is manufactured by an electroforming method.

Next, the manufacturing process of the ink jet head will be described. This ink jet head is manufactured by separately assembling the actuator unit 1 and the liquid chamber unit 2 in advance, and then bonding and bonding the units 1 and 2 to each other. By adopting such a manufacturing process,
A non-defective product of the two units 1 and 2 can be selected and assembled, thereby improving the yield, and also having an actuator unit 1 in which dust is likely to be generated in the processing and assembling process, and a liquid chamber unit 2 in which dust should be completely prevented from adhering. Can be assembled in separate steps, so that the quality itself of the completed inkjet head is improved. Hereinafter, a specific description will be given.

First, the steps of processing and assembling the actuator unit 1 are as follows. That is, FIG.
As shown in FIGS. 5 and 6, ink supply holes 3a are formed in advance on a substrate 3 made of an electrically insulating material such as ceramics and high-rigidity resin, and the piezoelectric elements are arranged in the direction in which the piezoelectric elements are arranged (the direction in which the nozzles are arranged). A common groove 23 is formed at the center along the line. The common groove 23 is formed deeper than the slit groove 21 which is a cut groove for cutting a piezoelectric element plate or the like described later.

Then, individual extraction electrode patterns 51 and 52 made of a conductive material for forming the individual extraction electrodes 22 are formed on both sides of the substrate 3 and the common groove 2 is formed.
3 and its vicinity and the pattern 51 for individual extraction electrodes,
A common electrode pattern 53 made of a conductive material is formed so as to face both ends of the substrate 3 bypassing the pattern 52, and between the individual extraction electrode pattern 51 and the common electrode pattern 53 and the individual extraction electrode pattern 52. And common electrode pattern 53
Are defined as the piezoelectric element bonding regions 54 and 55.

These electrode patterns 51 to 53 are formed by, for example, vapor deposition of metal such as Ni, Au, or Cu, electrolysis of the same metal, electroless plating, or printing of thick film conductor paste such as AgPd, AgPt, or Au paste. And adhered to the surface of the substrate 3. The common electrode is
After cutting the piezoelectric element plate and the individual extraction electrode patterns 51 and 52, which will be described later, they can be separately formed using a conductive paste or the like. Therefore, the minimum necessary electrode pattern is only the individual extraction electrode pattern.

Then, as shown in FIG. 7, the piezoelectric element plates 56, 56 each formed by forming a laminated piezoelectric element in a plate shape on the piezoelectric element bonding areas 54, 55 on the substrate 3, are bonded to the bonding agent 6 (see FIG. 3). ) To perform adhesive bonding. The bonding agent 6 used for bonding the piezoelectric element plate 56 to the substrate 3 is preferably a material having a Young's modulus of 200 kgf / mm 2 or more. In this case, a heat-curable epoxy-based adhesive is used. As the form of the adhesive, any of a one-liquid type, a two-liquid mixed type, a film type and the like can be used.

Then, these piezoelectric element plates 56,
End electrodes 57, 58 for forming the individual end electrodes (individual external electrodes) 28, 29 in advance on the long side end surfaces of 56.
Are formed, and after bonding on the substrate 3, these two
The end face electrodes 57, 57 on the opposite side of the two piezoelectric element plates 56, 56 are electrically connected to the common electrode pattern 53 on the substrate 3 by the conduction treatment material 32, and the two piezoelectric element plates 56, 56 are connected. 56 non-opposing end face electrodes 58,
Reference numeral 58 denotes each of the individual extraction electrode patterns 51, 51 on the substrate 3.
Are electrically connected to each other by a conduction treatment material 31. The conduction processing materials 31 and 32 have a Young's modulus of 200 kgf / mm.
Two or more are used. In addition, the conduction treatment material 31,
As the material 32, for example, a conductive adhesive, sputtering of Au or the like, vapor deposition of Au or the like, dipping of AgPd or the like can be used.

Next, the two piezoelectric element plates 56, 56 are set by a dicer or the like on which a diamond grindstone is set.
And a plurality of laminated piezoelectric elements which are to be cut into the surface portion of the substrate 3 at a predetermined pitch in a direction orthogonal to the end surface electrodes 57 and 58 so as to become the driving portion piezoelectric element 7 and the fixed portion piezoelectric element 8. At the same time, the end face electrode 5
7 and 58 are divided into individual end face electrodes 28 and 29 corresponding to the individual drive piezoelectric elements 7 (and the fixed piezoelectric elements 8).
At this time, as shown in FIG. 5, by cutting the substrate 3 to a predetermined depth and cutting it by inserting the slit groove 21, each of the drive unit piezoelectric elements 7 (and the fixed unit piezoelectric elements 8) is cut.
Is completely independent, and for individual extraction electrodes on the substrate 3
The individual extraction electrodes 2 corresponding to the patterns 58 individually correspond to the individual drive piezoelectric elements 7 (and the fixed piezoelectric elements 8).
Divided into 2,22 ... At this time, the individual lead-out electrodes 22, 22... Formed separately are separated from the individual end face electrodes 29, 29,... On the non-opposite end face sides of the individual drive unit piezoelectric elements 7 (and the fixed unit piezoelectric elements 8). Remain connected via The cutting pitch is a pitch at which the piezoelectric elements 7 and 8 having a width of, for example, about 100 μm per pitch are formed.

The common electrode pattern 53 on the substrate 3
Are partially divided corresponding to the individual driving piezoelectric elements 7 (and the fixed piezoelectric elements 8), but the common grooves 23 of the substrate 3
, The common electrode pattern 53 faces the drive unit piezoelectric elements 7 (and the fixed unit piezoelectric elements 8) of the two piezoelectric element rows 4 and 4 through the common groove 23 even after the cutting process. All the individual end face electrodes 28 on the end face side
And... Via the conductive material 31. Thereby, the common electrode 2 easily connected to the opposed individual end face electrodes 28 of the two piezoelectric element rows 4 and 4 can be formed.
4 can be secured.

As described above, in the manufacturing method of the ink jet head, the extraction electrode patterns 51 and 52 and the common electrode pattern 53 are formed on the insulating substrate 3 and the internal electrodes 27 are alternately taken out in advance on both end surfaces. The laminated piezoelectric element 56 electrically connected to the end surface electrodes 57 and 58 formed on each end surface is joined to form the extraction electrode patterns 51 and 52.
And the end face electrode 58 of the laminated piezoelectric element 56 are connected to a common electrode.
The pattern 53 and the end face electrode 57 of the multilayer piezoelectric element 56
After each of them is connected by conducting, the laminated piezoelectric element 56
And a slit process on the surface of the substrate 3 at the same time to form a plurality of laminated piezoelectric elements (the driving unit piezoelectric element 7 and the fixed unit piezoelectric element 8), and the extraction electrode patterns 51,
By dividing the electrode 52 and the end face electrodes 57 and 58 into individual extraction electrodes 22 and individual end face electrodes 28 and 29 individually corresponding to the plurality of stacked piezoelectric elements, high-density integration of the plurality of stacked piezoelectric elements can be achieved. It is easy to take out the electrodes from the internal electrodes, and the bonding strength between the laminated piezoelectric element and the substrate is increased, so the damage of the laminated piezoelectric element during slit processing is reduced, and the yield is reduced. Is improved,
Cost can be reduced.

By using a material having a Young's modulus of 200 kgf / mm 2 or more as the conductive material 31 or 32 for electrically connecting the end face electrode of the laminated piezoelectric element and the lead electrode on the substrate, the laminated piezoelectric element and the substrate can be electrically connected to each other. Vibration can be reduced, and damage to the laminated piezoelectric element during slit processing is further reduced. Further, the substrate 3 and the driving unit piezoelectric element 7
By using a bonding agent 6 having a Young's modulus of 200 kgf / mm 2 or more, vibration between the laminated piezoelectric element and the substrate can be reduced, and breakage of the piezoelectric element during slit processing can be reduced. In addition, it is possible to prevent a decrease in displacement efficiency when the driving unit piezoelectric element 7 is driven, thereby improving the characteristics of the head.

Thus, the piezoelectric element plate 56,
The frame member 5 is bonded and bonded to the substrate 3 on which the slit processing such as 56 has been completed by using a bonding agent 6. Here, the upper surfaces of the frame members 5 and the upper surfaces of the piezoelectric element rows 4 and 4 after the frame members 5 are joined need to be accurately and coplanar. This is because the diaphragm 12 of the liquid chamber unit 2 is joined to this portion as described later, and if the surface accuracy is poor, the diaphragm portion 11 that is not bonded is generated. Therefore, it is possible to perform surface processing as an inactive layer without forming an electrode on the upper surface of the uppermost layer 26a of the driving unit piezoelectric element 7 (the same applies to the fixed unit piezoelectric element 7). After bonding the frame member 5 which is slightly higher,
Grinding the surface and grinding until the upper surface of each of the piezoelectric elements 7 and 8 of the piezoelectric element rows 4 and 4 are slightly shaved to be on the same plane, reduce the dimensional accuracy of both parts and the difficulty of the bonding method. Has been resolved.

Thereafter, the individual extraction electrodes 22, 22 of the substrate 3
Then, the FPC cable 33 is joined to the common electrode 24 by applying heat and pressure to complete the actuator unit 1. In addition,
The FPC cable 33 has a pattern that can selectively drive the driving piezoelectric elements 7, 7,... Of the piezoelectric element rows 4, 4.
The joint is pre-plated with solder.

Then, on the actuator unit 1 completed in this way, the liquid chamber unit 2 which has been separately processed and assembled is placed with its diaphragm 12 side (joining surface) downward.
Adhesively bond while aligning. Finally, the ink supply pipe 25 is inserted into the ink supply hole 3a of the substrate 3, and an adhesive is applied and hardened and fixed.

Next, the operation of the ink jet head constructed as described above will be described. A driving pulse of 20 to 50 V is selectively applied to the driving piezoelectric elements 7, 7... Of the piezoelectric element rows 4, 4 in accordance with a recording signal. When the voltage is applied, the driving piezoelectric element 7 to which the pulse voltage is applied is displaced, and the corresponding diaphragm 11 of the diaphragm 12 is moved to the nozzle 1.
The ink is deformed in five directions, and the ink in the pressurized liquid chamber 17 is pressurized by a change in the volume (volume) of the pressurized liquid chamber 17, and the ink is ejected as droplets from the nozzles 15 of the nozzle plate 16 to perform recording. be able to.

Then, the ink pressure in the pressurized liquid chamber 17 decreases as the ink droplets are ejected, and a slight negative pressure is generated in the pressurized liquid chamber 17 due to the inertia of the ink flow at this time. In this state, by turning off the application of the voltage to the drive unit piezoelectric element 7, the diaphragm portion 11 of the diaphragm 12 returns to the original position, and the pressurized liquid chamber 17 becomes the original shape. , Further negative pressure is generated.

At this time, the ink that has entered from the ink supply pipe 25 that leads to the ink tank (not shown) is filled into the pressurized liquid chamber 17 from the fluid resistance section 42 through the common ink flow path 44. Then, after the vibration of the ink meniscus surface of the nozzle 15 is attenuated and stabilized, a pulse voltage is applied to the driving unit piezoelectric element 7 for discharging the next ink droplet.

In the above embodiment, the individual end face electrodes 28 and 29 on both end faces of the driving piezoelectric element 7 and the common electrode 2
4, a conduction treatment material 3 for conducting treatment with the individual extraction electrode 22
The electrodes 1 and 32 are attached to part of the outer surfaces of the individual end electrodes 28 and 29, but as shown in FIG.
2 is adhered to the entire surface of the individual end face electrodes 28 and 29 to perform the conduction process, whereby the bonding strength between the piezoelectric element plate 56 before slitting and the piezoelectric element plate 56 before slitting and the substrate 3 before forming the driving section piezoelectric element 7 is obtained. Can be dramatically improved, and breakage of the laminated piezoelectric element during slit processing can be further reduced.

Further, in the above embodiment, the individual end face electrodes 28 and 29 in which the internal electrodes 27 are alternately connected are formed on both end faces of the driving portion piezoelectric element 7, but the continuity processing material is provided on substantially the entire end face. 31 and 32 can be attached to directly connect the internal electrode 27 drawn out to both end surfaces to the common electrode 24 and the individual lead-out electrode 22, thereby reducing man-hours and cost.

Further, in the above embodiment, an example was described in which the present invention was applied to a side shooter type ink jet head in which the opening direction of the nozzle was coaxial with the displacement direction of the piezoelectric element. The present invention can also be applied to an edge shooter type ink jet head in a direction orthogonal to the above. Furthermore, in the above-described embodiment, the drive unit piezoelectric elements and the fixed unit piezoelectric elements are alternately arranged in a bi-pitch structure. However, a normal pitch structure in which all the piezoelectric elements are the drive units may be used. The fixed portion piezoelectric element 8 also becomes the drive portion piezoelectric element 7.

[0042]

As described above, according to the ink jet head manufacturing method of the first aspect, the connection between the internal electrode of the multilayer piezoelectric element and the individual extraction electrode and the common electrode can be easily performed. The yield in the process can be improved, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an inkjet head showing one embodiment of the present invention.

FIG. 2 is an exploded perspective view of FIG. 1;

FIG. 3 is a sectional view taken along the line AA in FIG. 1;

FIG. 4 is a sectional view taken along the line BB of FIG. 1;

FIG. 5 is an enlarged sectional view of a main part of FIG. 3;

FIG. 6 is a perspective view of a substrate for explaining a process of assembling and assembling the actuator unit.

FIG. 7 is a perspective view showing a state in which a piezoelectric element plate is joined to a substrate used for explaining the same process.

FIG. 8 is an enlarged cross-sectional view of a main part similar to FIG. 5 for explaining another embodiment.

[Explanation of symbols]

1. Actuator unit, 2. Liquid chamber unit, 3.
Substrate, 4 ... piezoelectric element row, 5 ... frame member, 6 ... adhesive, 7 ... driving section piezoelectric element, 8 ... fixed section piezoelectric element, 11 ...
Diaphragm part, 12: diaphragm, 13: liquid chamber channel forming member, 15: nozzle, 16: nozzle plate, 17: pressurized liquid chamber, 21: slit groove, 22: individual extraction electrode, 23 ...
Common groove, 24 common electrode, 27 internal electrode, 28, 29
... individual end face electrodes, 51, 52 ... patterns for individual extraction electrodes, 53 ... patterns for common electrodes, 56 ... piezoelectric element plates, 57, 58 ... external electrodes.

Continuation of the front page (72) Inventor Michio Umezawa 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-4-125158 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41J 2/16 B41J 2/045 B41J 2/055

Claims (1)

(57) [Claims] 1. An ink jet head in which a plurality of laminated piezoelectric elements are arranged in a row on a substrate, and a pressurized liquid chamber is pressurized by displacement of each laminated piezoelectric element in a direction d33 to eject ink from a nozzle. In the method, an individual extraction electrode pattern and a common electrode pattern were formed on an insulating substrate, and the internal electrodes were alternately taken out in advance on both end faces and electrically connected to end face electrodes formed on each end face. The stacked piezoelectric element is joined, and the individual extraction electrode pattern and one end face electrode of the stacked piezoelectric element are connected to the common electrode pattern and the stacked electrode.
After connecting the other end face electrode of the piezoelectric element and conducting processing respectively , the slit processing is simultaneously performed on the surface of the laminated piezoelectric element and the substrate to form the plurality of laminated piezoelectric elements, a method of manufacturing an ink jet head, characterized by dividing the individual extraction electrode pattern and the end surface electrodes respectively to the individual extraction electrode and the individual end surface electrodes corresponding individually to said plurality of laminated piezoelectric elements.