JPH07186379A - Ink jet piezoelectric element base member and piezoelectric displacing element using the member for ink jet head - Google Patents

Abstract

PURPOSE:To reduce a percentage of defect in mounting, reduce a variation in displacing amount between elements, and contrive a higher reliability and a lower cost by a method wherein first inner electrodes are provided in a first lap part, a second non-lap part, and a second lap part which are connected in order, and second inner electrodes are provided in a first non-lap part, the first lap part, and the second lap part which are connected in order. CONSTITUTION:An ink jet piezoelectric element base member 1 is formed by alternately laminating first inner electrodes 3 and second inner electrodes 4 with piezoelectric materials 2 between. A pattern 9 of the arrangement of a first non-lap part 5, a first lap part 6, a second non-lap part 7, and a second lap part 8 each of which is made of the electrodes 3 and/or the electrodes 4 is repeated in a longitudinal direction 10. As a bulk to be used for a piezoelectric displacing element for an ink jet head, the ink jet piezoelectric element base member 1 is cut at a cutting part 11 of the lap part 8 in the vicinity of the non-lap part 5. The electrodes 3 forming the lap part 8 are exposed on at least one of the cut surfaces of the bulk. By using the pattern in which the inner electrodes are lapped and unlapped, chips can be accumulated with high density except the cutting margins.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric displacement element which is an actuator suitable for an ink jet head of an ink jet recording apparatus, and a piezoelectric body mother member.

[0002]

2. Description of the Related Art A piezoelectric displacement element made of a piezoelectric material has a function as a conversion element for converting electric energy and mechanical energy, and is therefore applied to the field of actuators and the like. Furthermore, in recent years, the driving voltage has been significantly reduced by using a piezoelectric displacement element of a laminated type. A piezoelectric displacement element for an inkjet head is disclosed in Japanese Patent Application Laid-Open No. Sho 56
In Japanese Patent Laid-Open No. 120365, there is disclosed a method of significantly reducing a driving voltage by using a laminated type piezoelectric displacement element for an inkjet head as an actuator of the inkjet head. Further, as a structure of the piezoelectric displacement element for an inkjet head, by providing dummy internal electrodes even in a portion that does not actually generate piezoelectric strain, warpage and undulation due to stress strain generated during firing are alleviated, which is advantageous for mounting an inkjet head. Such a structure is disclosed in Japanese Patent Laid-Open No. 4-235041. Furthermore, a method of stacking patterns in which internal electrodes are connected, facilitating extraction of the internal electrodes after cutting, and taking a large number of piezoelectric displacement elements for inkjet heads from the inkjet piezoelectric mother material to improve the yield is a method. JP-A-62-104
No. 182 publication.

[0003]

However, although the prior art is advantageous as the structure of the piezoelectric displacement element for the inkjet head, each bulk or each chip is cut from the piezoelectric base member for inkjet to obtain a large number of them. The structure of the internal electrodes advantageous for the polarization treatment and further for mounting on the ink jet head is not shown, and as for the multi-cavity production, the method is merely to stack the internal electrodes in a multi-cavity pattern.

Further, since the internal electrodes are exposed in the bulk cut and divided from the conventional piezoelectric mother material for ink jet, short-circuiting between internal electrodes during the polarization treatment and a number of defective elements burning due to spark discharge occur. Was there.

Here, the names of the bulk and chip used in the present invention will be defined. Attaching an external electrode for applying a voltage to the internal electrode, and applying a voltage to the external electrode to polarize the piezoelectric material, a member cut from a piezoelectric base member for an inkjet head is a bulk, and an inkjet head is used from the bulk. The member cut to the size to be mounted on is used as a chip.

Inkjet printers that use piezoelectric displacement elements for inkjet heads as actuators for inkjet heads have already been commercialized, and the reliability and cost reduction of piezoelectric displacement elements for inkjet heads that are advantageous for ink ejection are promoted. This is important, and it is necessary to configure an internal electrode pattern that is advantageous for reducing the defective rate in separation cutting, polarization, and mounting from the inkjet piezoelectric base member to the inkjet head piezoelectric displacement element.

Further, when the piezoelectric material and the internal electrode are laminated and sintered, there is a large difference in characteristics between the central portion and the outer frame portion even within the piezoelectric base material for ink jet, so that the size of the chip itself is reduced. When the inkjet piezoelectric base member was formed and the elements were processed, the amount of displacement of each element varied greatly, and the print density of the inkjet head also varied greatly. For this reason, it is necessary to arrange a high-density internal electrode capable of obtaining a large number of piezoelectric displacement elements for an inkjet head on a large-sized inkjet piezoelectric base member to reduce the variation in the displacement amount within the inkjet head. is there.

The present invention is intended to solve the above-mentioned problems, and an object of the present invention is to reduce the separation and cutting into bulk, chips and devices, polarization, and the defective rate in mounting, and to reduce each defect in the ink jet head. To provide an inkjet head and an inkjet printer, which concretely show a configuration of an internal electrode pattern of a piezoelectric base member for inkjet, which is advantageous for reducing a variation in displacement amount of an element, and which realizes reliability improvement and cost reduction. It is in.

[0009]

A first ink jet piezoelectric base member according to the present invention comprises a first internal electrode and a second internal electrode which are alternately laminated with a piezoelectric material sandwiched between them. In a piezoelectric body member for inkjet in which a large number of piezoelectric displacement elements are arranged, the first and second electrodes are overlapped, and a first non-overlapped portion continuous in the length direction by non-overlapped, a first overlapped portion, Two non-overlapping parts, which is composed of repeating a series of patterns in the lengthwise direction of a second overlapping part, wherein the first internal electrode is a first overlapping part that is sequentially connected,
A second non-overlapping portion, a second non-overlapping portion, a second non-overlapping portion, a second non-overlapping portion, in which the second internal electrode is sequentially connected.
It is characterized in that it is arranged in the second overlapping portion.

The first piezoelectric displacement element for an inkjet head of the present invention is at least both cut surfaces which are cut in the vicinity of the first non-overlapping portion of the first inkjet piezoelectric base member and at the second overlapping portion. A first internal electrode that exposes the first internal electrode that constitutes the second overlapping portion on one side and that is formed on the cut surface and that connects the first internal electrode and the second internal electrode in parallel, respectively. A free end inactive part that has electrodes and takes out the displacement of the first non-overlapping part, an active part that displaces the first overlapping part, a second side non-overlapping part and a second overlapping part are fixed side inactive parts , And is characterized.

The second piezoelectric base material for ink jet of the present invention is a non-overlapping first and second electrode, a first non-overlapping portion which is continuous in the lengthwise direction due to the overlapping, a first overlapping portion, a second Of the non-overlapping portion, the second overlapping portion, the third non-overlapping portion, the third overlapping portion is repeated in the lengthwise direction of the pattern, and the first, the third overlapping portion length The first and second internal electrodes are configured to be substantially equal and the lengths of the second and third non-overlapping portions are approximately equal to each other, and the first internal electrodes are sequentially connected to each other. In the non-overlap portion, the third overlap portion, and the second internal electrode is arranged in the first non-overlap portion, the first overlap portion, the second overlap portion, and the third overlap portion. It is characterized by

A second piezoelectric displacement element for an ink jet head of the present invention is a cut divided near the center of the first non-overlap portion and near the center of the second overlap portion of the second ink jet piezoelectric base member. A surface and first and second external electrodes formed on the cut surface and connecting the first internal electrode and the second internal electrode in parallel, respectively, and the displacement of the first non-overlapping portion can be freely extracted. The end inactive part, the active part displacing the first or third overlapping part, and the second or third non-overlapping part and the second overlapping part are fixed side inactive parts.

Further, a third ink jet piezoelectric body mother member of the present invention is the same as the first and second ink jet piezoelectric substance mother members, wherein the first and second internal electrodes are on the outer side surfaces in the width direction. It is characterized in that the widthwise outside is covered with a piezoelectric material so as not to be exposed.

[0014]

【Example】

<Embodiment 1> FIG. 1 is a view showing a first constitution of a piezoelectric base member for an inkjet of the present invention. In the piezoelectric body member 1 for inkjet, the first internal electrodes 3 and the second internal electrodes 4 are alternately laminated with the piezoelectric material 2 interposed therebetween. Pattern 9 in which the first non-overlapping portion 5, the first non-overlapping portion 6, the second non-overlapping portion 7, and the second non-overlapping portion 8 formed by the first internal electrode 3 and the second internal electrode 4 are lined up Are repeated in the length direction 10. The bulk used for the piezoelectric displacement element for the inkjet head is in the vicinity of the first non-overlapping portion 5 of the piezoelectric base member 1 for inkjet and the cut portion 11 of the second overlapping portion 8.
Then, the first internal electrode 3 constituting the second overlapping portion 8 was exposed on at least one of both cut surfaces.

FIG. 2 shows the bulk 12 taken by the cutting section 11. In the bulk 12 taken from the piezoelectric base member 1 for inkjet, the free end inactive part 13 for taking out the displacement, the active part 14 displaced when a voltage is applied, the fixed side inactive part 15 and the internal electrode are overlapped. A dummy electrode 16 which is not driven by voltage application is formed. The first internal electrode 3 is exposed only on the end face 17 and is not exposed on the end face 18. Here, the first non-overlapping portion 5 corresponds to the free end inactive portion 15, and the first overlapping portion 6 is hereinafter referred to as the active portion 14.
In addition, the second non-overlapping portion 8 and the second overlapping portion 9 correspond to the fixed-side inactive portion 15. The dummy electrode 16 is composed of the second overlapping portion 9.

FIG. 8 is a view in which the external electrodes 31 and 32 are formed on the bulk 12 cut from the piezoelectric base material 1 for ink jet. The bulk 12 is subjected to polarization treatment by applying a voltage to the external electrodes 31 and 32, and then cut into a width 33 of a member (chip) of an appropriate size when used in an inkjet head. As the external electrodes 31 and 32, thin-film electrodes are formed by sputtering or vapor deposition, or thick-film electrodes are formed with a conductive adhesive. In the polarization process, the optimum temperature for the piezoelectric material,
The voltage and voltage application time are appropriately selected and used. here,
By designing a bulk size that allows multiple chips to be taken, it is possible to suppress variations that occur in the polarization process step.

As described above, by using the overlapping and non-overlapping patterns of the internal electrodes in the piezoelectric body member for inkjet used in the piezoelectric displacement element for the inkjet head of the present invention, cutting is made in the piezoelectric body member for inkjet. It can be seen that the chips are integrated at a high density except for the cutting margin.

FIG. 21 shows a second structure of the bulk taken by the cutting section 11. Free end inactive portion 13 for extracting displacement in bulk 19, active portion 1 that is displaced when a voltage is applied
4, the fixed side inactive portion 15 and the internal electrode overlap, but a dummy electrode 16 which is not driven by voltage application is formed. The first internal electrode 3 is exposed on both sides of the end face 17 and the end face 18. External electrode 31 similar to bulk 12
And 32 are formed, a voltage is applied to the external electrodes 31 and 32, polarization processing is performed, and then the chip width 33 is cut.
Here, the first internal electrode 3 exposed on the end face 18 and the end face 17
Since the first internal electrode 3 exposed at 1 has the first non-overlapping portion 5, no short circuit occurs due to the voltage application. Therefore,
The mother electrode 12 and the mother member 19 have different internal electrode configurations,
It is possible to construct an external electrode of the same form and perform polarization treatment.

Here, the bulk 12 in FIG. 2 and the bulk 19 in FIG. 21 are obtained by shifting the position of the cutting portion 11 in FIG. Although the bulk 12 and the bulk 19 have different internal electrodes in appearance, they have the same characteristics. Therefore,
Variation is allowed in the cutting portion 11, which will be described with reference to FIG. 22 is a partially enlarged view of the mother member 1 of FIG.
When the cutting part 11 is cut at the boundary 121 between the first non-overlapping part 5 and the second overlapping part 8, the bulk 12 is obtained. on the other hand,
The cutting part 11 has a boundary 121 within the range 122 of the second overlapping part 8.
Bulk 19 is obtained when cut at a point 123 which is more inside.

A positional deviation is allowed in the range 122 of the cutting portion 11 when the mother member 1 in which the patterns 9 of the internal electrodes are repeatedly arranged is cut in bulk. Therefore, the base member 1 can not only take a large number of conventional piezoelectric displacement elements for inkjet heads, but also has a similar characteristic in piezoelectric displacement elements for inkjet heads, which are misaligned during cutting and have different internal electrode patterns. It was found that it can be used for an inkjet head.

An outline of using the piezoelectric displacement element for an ink jet head manufactured in the constitution of this embodiment in an ink jet head is shown below.

FIG. 9 is a diagram showing a driving unit for an ink jet head using the piezoelectric displacement element for an ink jet head of the present invention. Chips 41 individually taken from the bulk 12 with a width 33 are attached to a base material 42 such as ceramics with an adhesive 43.
Be glued through. An electrode 47 is formed on the surface of the base material 42. The electrode 47 of the base material 42 is electrically connected to the external electrode 32. Chip 41 bonded on base material 42
Was cut into a comb-tooth shape 46 having an element width 44 and an element interval 45 by using a dicing saw, a wire saw, a laser, or the like. At the time of cutting, in order to completely separate the chip 41 into individual elements, the base material 42 is also cut into the electrodes 47 and the electrodes 51 corresponding to the comb-tooth shape 46 are divided for each element. ing. Therefore, the electrode 51 corresponds to each element individually and electrical continuity is secured. Comb shape 4
Dummy elements 48 that are not involved in ink ejection are provided at both ends of 6.
Is provided. Next, in order to apply a voltage to each element, processing for taking out the external electrodes 31 and 32 was performed. First, the external electrode 31 and the electrode 47 were connected by the conductive member 49, and the electrode 47 was connected to the electrode (common electrode) 53 commonly connected to each element. Secondly, the individual electrodes 52 corresponding to the intervals between the electrodes 51 were connected so as to overlap the electrodes 51. A lead frame or a flexible printed circuit was used for the conductive member 49, the common electrode 53, and the individual electrode 52. For the connection using the conductive members 49, 53 and the individual electrode 52, a conductive adhesive such as solder was used. The individual electrode 52 corresponding to each element was used as a segment electrode, and the common electrode 53 connected to each element was used as a common electrode, which was used as a drive unit 54 for ejecting ink of the inkjet head.

FIG. 10 is a diagram in which a drive unit using the piezoelectric displacement element for an inkjet head of the present invention is used in an inkjet head. A pressure plate 60 for transmitting the piezoelectric strain generated when a voltage is applied to the individual electrode 52 and the common electrode 53 of the drive unit 54 as a pressure of ink ejection, and a flow path formation in which an ink chamber corresponding to each element is provided. A substrate 61 and a nozzle plate 62 having a nozzle hole 63 for ejecting ink are laminated and adhered, and the pressure plate 60 is a device end surface 6 of the drive unit 54.
4 is glued on. The flow path forming substrate 61 has an ink flow path 65, an ink chamber 66 corresponding to each element, and an ink chamber 66.
A flow path 67 is formed for the ink to flow into. Further, the ink flows into the ink flow path 65 of the flow path forming substrate 61 through the ink pipe 68 and the ink hole 69 formed in the pressure plate 60.

When a chip cut from the ink jet piezoelectric base member of the present invention was processed into a piezoelectric displacement element for an ink jet head and used as an actuator of the ink jet head for printing, the ink ejection amount and ink ejection speed varied. I was able to obtain a small, very clear and beautiful printed material.

Next, the manufacturing method of the first constitution of the piezoelectric base member for inkjet of the present invention will be briefly described.
FIG. 3, FIG. 4, FIG. 5, FIG. 6, and FIG. 7 are diagrams showing a procedure for alternately stacking piezoelectric materials and internal electrodes.

As shown in FIG. 3, first, the piezoelectric material 2 of FIG.
The raw sheet 21 of the piezoelectric body is formed. Next, as shown in FIG. 4, the electrode paste 22 of the first internal electrode is printed on the piezoelectric green sheet 21. Next, as shown in FIG. 5, the piezoelectric green sheet 21 is laminated on the electrode paste 22, and the electrode paste 23 which is the second internal electrode is further laminated on the piezoelectric green sheet as shown in FIG. Print. By repeating the stacking of the piezoelectric green sheet and the printing of the electrode paste as described above, a stacked body 24 of the piezoelectric green sheet and the electrode paste as shown in FIG. 7 is manufactured. At this time, a piezoelectric green sheet on which an electrode paste is printed may be manufactured for each piezoelectric green sheet unit of each piezoelectric material, and finally each piezoelectric green sheet may be laminated. Then, the laminated body 24 of the piezoelectric green sheet and the electrode paste is subjected to thermocompression bonding and then sintered at a high temperature of about 1000 ° C. to manufacture the piezoelectric body member for inkjet of the present invention. In the above manufacturing process, printing of the internal electrodes, thermocompression bonding of the laminate, or sintering is a process in which manufacturing variations easily occur. As a result, it is possible to inevitably reduce the variation between bulks or chips and improve the manufacturing yield.

Further, as the piezoelectric material, a piezoelectric material is appropriately selected from PZT system such as lead titanate-lead zirconate. Piezoelectric green sheets are prepared by first sintering the piezoelectric material into powder, mixing it with an organic binder, plasticizer, dispersant, and solvent to make a slurry, and then attaching the slurry to a roller and making it thick with a blade. The material was transferred evenly in size, punched into a certain size, and dried to obtain a piezoelectric green sheet. The electrode paste was appropriately selected or mixed from silver, palladium, platinum, etc., and mixed with a solvent and a binder before use.

Comparative Example 1 In this comparative example, the amount of displacement between a chip individually taken from the inkjet piezoelectric base member of the present invention and a chip individually taken from the inkjet piezoelectric base member having a single chip size. Were compared.

FIG. 11 is a diagram showing a piezoelectric base member for an ink jet of a single chip size. The ink jet piezoelectric body mother member 71 having a single chip size is formed, and the width 72,
It cut | disconnected to the length 73, and took the chip | tip 74 used for the piezoelectric element for ink jets. FIG. 12 is a diagram in which the external electrodes 31 and 32 are formed on the chip 74.

In FIG. 13, a large number of chips 76 having a width 72 and a length 73 are taken from a piezoelectric mother material 75 for an ink jet having a width 77 in which internal electrode patterns capable of making a large number of the present invention are arranged at a high density. It is a figure which shows what was done. still,
As the internal electrode material and the piezoelectric material, the same material was used for the inkjet piezoelectric base member 71 and the inkjet piezoelectric base member 75. In FIG. 14, the chip 76 has an external electrode 31,
It is the figure which formed 32. Here, the chip 74 and the chip 76 are completely the same in appearance.

After the chips 74 and 76 were polarized under the same conditions, the amount of displacement of each element was measured when it was processed into a piezoelectric displacement element for ink jet with a width of about 150 m ^-6 . FIG. 15 is a diagram showing the distribution of the displacement amounts of the tip 74 and the tip 76. The amount of displacement of the tip 74 is shown by the curve 79. On the other hand, the chip 76 has a non-uniform distribution of displacement amount depending on the cutting position from the piezoelectric body member for inkjet 75, but the piezoelectric body member for inkjet 7
When the values were plotted corresponding to the positions of the respective chips within the width 77 of 5, it was found that they were distributed on the curve 80. From the above results, the piezoelectric piezoelectric mother members 71 and 75 made of the same material have the same variation range 78 of the displacement amount. However, when comparing chips of the same size with a width of 72, it was found that the variation range of the chip 76 obtained by a large number was 81 or 82, which was smaller than the variation range 78 of the chip 74.

Therefore, the piezoelectric displacement element for an ink jet head according to the present invention not only realizes an improvement in yield and cost reduction by taking a large number of piezoelectric ink jet mother materials but also reduces the variation range of the displacement amount and improves reliability. Is improving.

<Comparative Example 2> Chip 74 in Comparative Example 1
Ink was discharged by using the chip 76 and the chip 76 as an inkjet head. FIG. 16 is a diagram in which the weight of the ink droplets ejected from the nozzle holes of the inkjet head and the number of nozzles are plotted. The inkjet head using the chip 74 has a curve 83, and the inkjet head using the chip 76 has a curve 84. Therefore, it has been found that the piezoelectric displacement element for an inkjet head according to the present invention in which the displacement range of the displacement amount in the chip size is reduced also reduces the variation range of the weight of the ink ejected from the inkjet head and improves the printing quality. . Further, when printing was carried out by an inkjet printer using the piezoelectric displacement element for an inkjet head of the present invention, it was possible to realize a very clear print quality with less variation in shading as compared with a conventional inkjet printer.

<Embodiment 2> In the pattern 9 of the internal electrodes of the piezoelectric base member 1 for inkjet shown in FIG. 1 of Embodiment 1, the lengths of the first non-overlapping portion 5 and the second non-overlapping portion 7 are almost the same. The same piezoelectric base member 1 for inkjet was formed. Further, the cutting portion 11 of the piezoelectric displacement element for an inkjet head from the piezoelectric body member 1 for inkjet is cut in the vicinity of the first non-overlap portion 5 and at the second overlap portion 8,
The first internal electrode 3 forming the second overlapping portion 8 was exposed on at least one of both cut surfaces. The cutting pitch was the same as that of the printed pattern 9. By the above process,
Since only the size of the bulk and the chip used for the piezoelectric displacement element for the inkjet head and the cut margin at the time of cutting are arranged in the piezoelectric base material for inkjet, the bulk and the chip can be arranged in a very high density pattern. done.

The manufacturing method can be carried out by the same procedure as in FIG. 3, FIG. 4, FIG. 5, FIG. 6 and FIG.
6 and the printing pattern of the internal electrodes in FIG. 6 are common, the first internal electrode 22 and the second internal electrode 23 are set to the sum of the dimensions of the first overlapping portion 6 and the second non-overlapping portion 7 in FIG. It can also be realized by printing by shifting to a corresponding dimension. Moreover, in the method using the common print pattern described above, the first internal electrode 22 and the second internal electrode 23
It is possible to arbitrarily set the length of the first overlapping portion 6 in FIG. 1, that is, the length of the active portion to be displaced, by arbitrarily setting the dimension to be shifted at the time of printing, and It has become possible to flexibly comply with the standards.

<Embodiment 3> FIG. 17 is a view showing a third constitution of the piezoelectric base member for inkjet of the present invention. In the piezoelectric body member 91 for inkjet, the first internal electrode 92 and the second internal electrode 93 are alternately laminated with the piezoelectric material 2 interposed therebetween. A first non-overlapping portion 94 formed by the first internal electrode 92 and the second internal electrode 93, a first overlapping portion 95, a second non-overlapping portion 96, a second overlapping portion 97,
The pattern 100 in which the third non-overlapping portion 98 and the third overlapping portion 99 are arranged is repeated in the length direction 101. The second non-overlapping part 96 and the third non-overlapping part 98, and the second non-overlapping part 95 and the third non-overlapping part 99 have the same dimensions. The bulk is a cut portion 102 near the center of the first non-overlap portion 94 and a cut portion 103 near the center of the second overlap portion 97 in the inkjet piezoelectric base member 91.
Is cut by. FIG. 18 shows a bulk 104 that is cut by the cutting units 102 and 103. The bulk 104 corresponds to the first embodiment.
It has the same structure as the bulk 12 individually taken from the inkjet piezoelectric base member 1. In the bulk 104, the free end inactive portion 105 for extracting displacement, the active portion 106 displaced by voltage application, and the fixed-side inactive portion 10
7 and the internal electrode overlap, but a dummy electrode 108 which is not driven by voltage application is formed. The bulk 104 was cut into a chip width 109 and used as a piezoelectric displacement element for an inkjet head.

As described above, by using the overlapping and non-overlapping patterns of the internal electrodes in the piezoelectric body member for inkjet of the present invention, bulk and It can be seen that the chips are densely integrated.

FIG. 23 is a partially enlarged view of the mother member 91 of FIG. The cutting portion 102 is the range 13 of the first non-overlapping portion 94.
With 1, the positional deviation during cutting is allowed. On the other hand, the cutting unit 10
3 is a range 132 of the second overlapping portion 97, and positional deviation at the time of cutting is allowed. If the cutting portion 102 and the cutting portion 103 are displaced in the range 131 and the range 132, respectively, the bulk 1
It is possible to obtain the bulk of the internal electrode pattern similar to 04. Therefore, the base member 91 can not only take a large number of conventional piezoelectric displacement elements for inkjet heads, but also has a permissible range of misalignment upon cutting, and even if misalignment occurs, the same internal electrode as in the related art can be used. It was found that a piezoelectric displacement element for an inkjet head having the above structure can be obtained.

Piezoelectric base member 9 for ink jet of the present invention
When chips obtained from 1 were processed into a piezoelectric displacement element for an inkjet head and used for the inkjet head, very clear printing with small variation in shading was possible.

<Embodiment 4> FIG. 19 is a view showing a fourth embodiment of the present invention. Piezoelectric piezoelectric base member 11
In FIG. 1, the inkjet piezoelectric mother member 1 of the first embodiment or the inkjet piezoelectric mother member 91 of the third embodiment is configured in the portion 112, and the outer side surface portions 114 and 115 in the width direction 113 are the first, The second internal electrode is covered with a piezoelectric material so as not to be exposed. Outer side surface part 11
The piezoelectric material forming 4 and 115 may be the same or different than the piezoelectric material used in portion 112.

The mother member is used for an ink jet head through the steps of bulk cutting, forming external electrodes on the bulk, polarization treatment, and chip cutting. Since the mother member 111 of the present invention has the effect of reducing the occurrence of defects in the polarization process of the above steps and improving the manufacturing yield of chips, the steps from bulk cutting to polarization will be shown below to explain the effects.

The inkjet piezoelectric base member 111 is cut at the cutting portion 11 corresponding to the inkjet piezoelectric base member 1 of the first embodiment or at the cutting portions 102 and 103 corresponding to the inkjet piezoelectric base member 91 of the third embodiment. It was cut to obtain bulk 117. FIG. 20 is a diagram in which the external electrodes 31 and 32 are formed on the bulk 117. In the bulk 117, since the internal electrodes are not exposed at the outer side surface portions 114 and 115 in the width direction 113, when a voltage is applied to the outer electrodes 31 and 32 by the polarization treatment, a short circuit that has conventionally occurred between the outer side surface internal electrodes. It was possible to prevent the failure of the element burning due to the spark discharge. When the configuration of the present example is added to the piezoelectric body members for inkjet of Examples 1, 2, and 3 in which the piezoelectric displacement elements for inkjet head are arranged at high density, the occurrence of defects in the polarization process is prevented and the yield is improved. As a result, we were able to significantly reduce costs.

[0043]

As described above, according to the present invention, a high density internal electrode pattern capable of forming a large number of piezoelectric displacement elements for inkjet heads is formed on the piezoelectric base material for inkjets. The manufacturing process such as separation and cutting from the piezoelectric mother member to the piezoelectric displacement element for the inkjet head, polarization, and mounting was made advantageous (*! *), And the manufacturing yield could be greatly improved. Also,
Since the internal electrodes are not exposed on the outer side surface in the width direction of the piezoelectric body member for inkjet, it is possible to prevent the occurrence of defects in the polarization treatment process, so that the manufacturing yield can be improved more effectively. It is possible to realize improvement and cost reduction.

Further, the piezoelectric displacement element for an ink jet head of the present invention has a smaller variation in displacement amount within a chip of the same size as compared with the conventional piezoelectric displacement element for an ink jet head, and thus the reliability is greatly improved. As a result, it was also found that the inkjet head using the piezoelectric displacement element for an inkjet head of the present invention has a small variation in the amount of ejected ink and the reliability is significantly improved.

Further, by using the pattern of the internal electrodes of the piezoelectric base member for inkjet of the present invention, it is possible to give a tolerance for the cutting position deviation during bulk cutting, and cutting within the tolerance is possible. It has been revealed that an element having an internal electrode pattern similar to that of the conventional piezoelectric displacement element for an inkjet head, or an element having similar characteristics even if the internal electrode pattern is different.

Therefore, by using the piezoelectric displacement element for an ink jet head of the present invention, it becomes possible to supply an ink jet head and an ink jet printer which realize a drastic cost reduction and improvement in reliability as compared with the prior art.

[Brief description of drawings]

FIG. 1 is a diagram showing a piezoelectric base member for inkjet according to a first embodiment of the present invention.

FIG. 2 is a view showing a bulk individually taken from the piezoelectric body member for inkjet according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a manufacturing process of the inkjet piezoelectric base member of the present invention.

FIG. 4 is a view showing a manufacturing process of the inkjet piezoelectric base member of the present invention.

FIG. 5 is a diagram showing a manufacturing process of the piezoelectric base member for inkjet of the present invention.

FIG. 6 is a diagram showing a manufacturing process of the piezoelectric base member for inkjet of the present invention.

FIG. 7 is a diagram showing a manufacturing process of the inkjet piezoelectric base member of the present invention.

FIG. 8 is a view in which an external electrode is formed on a bulk individually taken from the piezoelectric base material for inkjet of the present invention.

FIG. 9 is a diagram showing a drive unit of an inkjet head using the piezoelectric displacement element for inkjet head of the present invention.

FIG. 10 is a diagram showing an inkjet head using the piezoelectric displacement element for an inkjet head of the present invention.

FIG. 11 is a diagram showing a piezoelectric base member for an inkjet of a single chip size.

FIG. 12 is a diagram in which external electrodes are formed on a chip.

FIG. 13 is a diagram showing an inkjet piezoelectric base member of the present invention.

FIG. 14 is a view in which external electrodes are formed on a chip individually taken from the piezoelectric base material for inkjet of the present invention.

FIG. 15 is a diagram comparing the displacement distributions of the piezoelectric displacement element for an inkjet head of the present invention and the conventional piezoelectric displacement element for an inkjet head.

FIG. 16 is a diagram comparing variations in ink ejection amount between an inkjet head using the piezoelectric displacement element for an inkjet head of the present invention and an inkjet head using a conventional piezoelectric displacement element for an inkjet head.

FIG. 17 is a diagram showing an inkjet piezoelectric body mother member according to a third embodiment of the present invention.

FIG. 18 is a view showing a bulk obtained from an inkjet piezoelectric base member according to a third embodiment of the present invention.

FIG. 19 is a diagram showing a fourth configuration of the piezoelectric body member for inkjet according to the fourth embodiment of the present invention.

FIG. 20 is a diagram in which external electrodes are formed on a bulk obtained from a piezoelectric mother material for inkjet according to a fourth embodiment of the present invention.

FIG. 21 is a diagram showing a second structure of a bulk individually taken from the piezoelectric body member for inkjet according to the first embodiment of the present invention.

FIG. 22 is a partially enlarged view of FIG. 1 showing a first embodiment of the present invention.

FIG. 23 is a partially enlarged view of FIG. 17 showing a second embodiment of the present invention.

[Explanation of symbols]

 1 Inkjet Piezoelectric Base Member 2 Piezoelectric Material 3 First Internal Electrode 4 Second Internal Electrode 5 First Non-Overlapping Section 6 First Overlapping Section 7 Second Non-Overlapping Section 8 Second Overlapping Section 9 Pattern 10 Length direction 11 Cutting part

Claims (6)

[Claims] 1. A piezoelectric body member for inkjet, wherein first internal electrodes and second internal electrodes are alternately laminated with a piezoelectric material sandwiched therebetween, and a large number of piezoelectric displacement elements for inkjet head are arranged. 1, the length of a series of patterns of the first non-overlapping portion, the first non-overlapping portion, the second non-overlapping portion, and the second overlapping portion that are continuous in the length direction due to the duplication of the second internal electrode and the non-overlapping The first internal electrode is sequentially connected to the first overlapping portion, the second non-overlapping portion, the second overlapping portion, and the second internal electrode is sequentially connected to the first overlapping portion. A piezoelectric body member for inkjet, which is disposed in one non-overlapping portion, a first overlapping portion, and a second overlapping portion. 2. The piezoelectric body member for inkjet according to claim 1, wherein the first and second non-overlapping portions have substantially the same length. 3. A piezoelectric body member for inkjet, wherein first internal electrodes and second internal electrodes are alternately laminated with a piezoelectric material sandwiched between them, and a plurality of piezoelectric displacement elements for inkjet head are arranged. The mother member is a non-overlap of the first and second electrodes, a first non-overlap portion that is continuous in the length direction due to the overlap, a first overlap portion, a second non-overlap portion, a second overlap portion, a third Of the non-overlapping portion and the third overlapping portion, which are repeated in the length direction, and the lengths of the first and third overlapping portions are substantially equal and the lengths of the second and third non-overlapping portions are the same. Are substantially equal to each other, the first internal electrodes are sequentially connected to a first overlapping portion, a second non-overlapping portion, a second overlapping portion, a third non-overlapping portion, a third overlapping portion, Further, the second internal electrode is a first non-overlap portion, a first overlap portion, a second overlap portion, a third overlap portion. Inkjet piezoelectric base member, characterized in that it is set. 4. The inkjet according to claim 1, wherein the widthwise outside is covered with a piezoelectric material so that the first and second internal electrodes are not exposed at the widthwise outside side surface. Piezoelectric mother material. 5. The second overlap on at least one of the two cut surfaces separated by the second overlap portion in the vicinity of the first non-overlap portion of the inkjet piezoelectric base member according to claim 1 or 2. A first internal electrode forming a part, and having first and second external electrodes formed on the cut surface and connecting the first internal electrode and the second internal electrode in parallel, respectively. It is characterized in that one non-overlapping portion is a free end inactive portion for taking out displacement, an active portion displacing the first overlapping portion, and a second non-overlapping portion and a second overlapping portion are fixed side inactive portions. A piezoelectric displacement element for an inkjet head. 6. A cut surface, which is cut in the vicinity of the center of the first non-overlapping portion and in the vicinity of the center of the second overlapping portion, of the piezoelectric body member for inkjet according to claim 3, and formed on the cut surface. A first inner electrode and a second inner electrode that respectively connect the second inner electrode in parallel, and have first and second outer electrodes, and a free end inactive portion from which the displacement of the first non-overlap portion is taken out, the first or third A piezoelectric displacement element for an inkjet head, wherein the overlapping portion is an active portion that is displaced, and the second or third non-overlapping portion and the second overlapping portion are fixed side inactive portions.