JP2002225285A - Actuator inspection method, inkjet head manufacturing method, and inkjet recording apparatus - Google Patents

Abstract

(57) [Problem] To provide an inspection method for inspecting before joining an actuator block to a pressure chamber block, and a method for manufacturing an ink jet head using the inspection method. SOLUTION: A first electrode 15 and a piezoelectric element 3 are provided on a substrate 60.
0 and the second electrode 50 are sequentially laminated, and then the second electrode 50 and a part of the piezoelectric element 30 are etched to form the first electrode 15.
The exposed portion 15A is formed. Exposed portion 15 of first electrode 15
A and the inspection probe 69 are brought into contact with the second electrode 50,
The relative permittivity, dielectric loss, and piezoelectric constant of the piezoelectric element 30 are measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting an actuator, a method for manufacturing an ink jet head using the method, and an ink jet recording apparatus.

[0002]

2. Description of the Related Art Recently, for example, Japanese Patent Laid-Open No.
As disclosed in Japanese Unexamined Patent Publication (Kokai) No. H11-264, a high-density inkjet head manufactured using a so-called transfer method has been proposed. The transfer method is an excellent method for producing a high-density head. In the transfer method, first, individual electrodes are formed on a single-crystal MgO substrate, and then P electrodes are formed on the individual electrodes.
A thin-film actuator is manufactured by forming a piezoelectric body of a perovskite-type dielectric thin film made of ZT, and further forming a common electrode and a vibration plate on the piezoelectric body by a sputtering method or the like. Next, the actuator on the substrate is joined to a pressure chamber block in which a pressure chamber, a nozzle, and the like are formed. Thereafter, all or part of the substrate is removed.

[0003]

As the density of an ink jet head increases, the reliability of the ink jet head is required to be improved more than ever. Conventionally, inspection of an ink jet head including an actuator has been performed after transferring the actuator to a pressure chamber block.

However, according to the conventional method, when the actuator contains a defect, the pressure chamber block must be discarded together with the actuator even if there is no problem in the pressure chamber block. That is, it has not been possible to discard the actuator alone and use a good pressure chamber block as it is.

The inventor of the present application divides a conventional actuator into a plurality of actuators and applies a plurality of actuators to one pressure chamber block so that the transfer method can be effectively used even in a line type ink jet head. It is devised to provide an actuator (Japanese Patent Application 2000)
209408). In such an inkjet head using a plurality of actuators, even if one actuator has a defect, the other actuators may be non-defective. Therefore, if the inspection is performed after the actuator is transferred to the pressure chamber block as in the related art, the actuator cannot be discarded for each actuator. Therefore, a good actuator must be discarded together with some defective products. . But,
Then, it becomes a factor which causes increase in material cost and manufacturing cost. In addition, the yield also deteriorates. Therefore, it is preferable to perform a preliminary inspection of each actuator before joining it to the pressure chamber block, and discard defective products for each actuator.

The present invention has been made in view of the above points, and has as its object to provide an inspection method for inspecting an actuator before joining it to a pressure chamber block, and an ink jet head using the inspection method effectively. An object of the present invention is to provide a manufacturing method and an ink jet recording apparatus using the manufacturing method.

[0007]

According to a first aspect of the present invention, there is provided a method of inspecting an actuator having a piezoelectric element and first and second electrodes provided on both sides of the piezoelectric element. Forming a first member, a piezoelectric element, and a second electrode on a substrate in that order, and forming an actuator forming member in which a part of the first electrode is exposed; An inspection step of contacting the exposed portion of one electrode with the second electrode and inspecting characteristics of the piezoelectric element.

According to the first aspect, in a state where the first electrode, the piezoelectric element, and the second electrode are laminated on the substrate,
Since the exposed portion is formed on the first electrode, it is easy to bring the inspection probe into contact with the first electrode and the second electrode. Then, the inspection probe is connected to the exposed portion of the first electrode and the second electrode.
The first electrode and the second electrode are brought into contact with each other by pressing against the electrode.
By supplying a predetermined voltage or current between the electrodes, the characteristics of the actuator are inspected. for that reason,
Before joining the actuator to the pressure chamber block, its characteristics can be easily inspected.

According to a second aspect of the present invention, in the inspection method according to the first aspect, the step of manufacturing the actuator forming member includes the steps of: laminating a first electrode on a substrate; Having a step of sequentially stacking a piezoelectric element and a second electrode on another part while shielding a part of the first electrode using a mask so that a part of one electrode becomes an exposed part. It is.

According to a third aspect of the present invention, in the inspection method according to the first aspect, the step of manufacturing the actuator forming member includes the steps of: forming a first electrode, a piezoelectric element, a second electrode on a substrate; And a step of etching a part of the second electrode and the piezoelectric element so that a part of the first electrode becomes an exposed part.

According to a fourth aspect of the present invention, in the inspection method of the first aspect, the step of manufacturing the actuator forming member includes sequentially laminating a first electrode and a piezoelectric element on a substrate. A step of stacking a second electrode on another part while shielding a part of the piezoelectric element using a mask so that a part of the piezoelectric element becomes an exposed part; Etching the exposed portion of the piezoelectric element so that the portion becomes an exposed portion.

According to each of the second to fourth inventions, the member for forming the actuator can be easily manufactured.

According to a fifth aspect of the present invention, in the inspection method of the actuator according to any one of the first to fourth aspects, the inspection step comprises the steps of:
The method includes a step of fixing a conductive paste material to one or both of the electrodes, and bringing the inspection probe into contact with the first electrode or the second electrode via the paste material.

In the fifth aspect, the inspection probe is brought into contact with the exposed portion of the first electrode and the second electrode via the paste material. Then, a predetermined voltage or current is supplied between the first electrode and the second electrode, and the characteristics of the actuator are inspected. Since the test probe is firmly fixed to the electrode by the paste material, the electrical contact between the test probe and the electrode can be maintained without pressing the test probe with a strong force. Therefore, at the time of the characteristic inspection, an adverse effect due to the pressing force of the inspection probe is extremely reduced.

According to a sixth aspect of the invention, in the inspection method of the actuator according to any one of the first to fifth aspects, the inspection step may include one of a relative permittivity and a dielectric loss of the piezoelectric element. Or it includes the step of measuring both.

According to the sixth aspect, the relative permittivity or the dielectric loss of the piezoelectric element is measured, and the characteristics of the actuator are evaluated based on the measured value.

According to a seventh aspect of the invention, in the inspection method of the actuator according to any one of the first to sixth aspects, the inspection step includes a step of measuring a piezoelectric constant of the piezoelectric element. Things.

According to the seventh aspect, the piezoelectric constant of the piezoelectric element is measured, and the characteristics of the actuator are evaluated based on the measured value.

According to an eighth aspect of the present invention, there is provided a method of manufacturing an ink jet head, comprising: a common liquid chamber for storing ink, a plurality of pressure chambers communicating with the common liquid chamber, and a plurality of nozzles respectively communicating with the pressure chambers. , A plurality of actuator blocks having at least a piezoelectric element and first and second electrodes for applying a voltage to the piezoelectric element, and disposed on one surface of the pressure chamber block. A method for inspecting each actuator block by the inspection method according to any one of the first to seventh inventions before joining each of the actuator blocks to the pressure chamber block. Is what you do.

According to a ninth aspect of the present invention, there is provided a method of manufacturing an ink jet head, comprising: a first electrode, a piezoelectric element, and a second electrode sequentially laminated on a substrate having a smaller area than a pressure chamber plate; A step of producing a plurality of actuator forming members partially exposed; and connecting the inspection probe to the exposed portion of the first electrode of each actuator forming member and the second probe.
An inspection step of contacting the electrodes and inspecting the characteristics of each piezoelectric element; and a step of forming an actuator block on the substrate by laminating a diaphragm on the second electrode of each actuator forming member after inspection. Bonding the actuator blocks together with the substrate to one surface of the pressure chamber plate so as to cover the plurality of pressure chambers provided in the pressure chamber plate with the diaphragms of the actuator blocks; Removing the substrate, patterning the first electrode of each of the actuator blocks, and forming a flow path plate containing an ink flow path and a common liquid chamber for guiding the ink of each pressure chamber to each nozzle, A step of joining to the other surface of the chamber plate, and a step of joining a nozzle plate including the nozzle to the flow path plate. It is.

According to a tenth aspect of the present invention, there is provided a method of manufacturing an ink jet head, comprising: a first electrode, a piezoelectric element, and a second electrode sequentially laminated on a substrate having a smaller area than the pressure chamber plate; Manufacturing a plurality of actuator-forming members, each of which is partially exposed, and contacting an inspection probe with the exposed portion of the first electrode and the second electrode of each of the actuator-forming members to determine the characteristics of each piezoelectric element. An inspection step of inspecting, and each of the actuator forming members is disposed on one surface of the pressure chamber plate such that the plurality of pressure chambers provided in the pressure chamber plate are covered with the second electrodes of the actuator forming members after inspection. Bonding each other, removing each of the substrates, patterning the first electrode of each of the actuator forming members, and guiding ink in each of the pressure chambers to each of the nozzles. A step of joining a flow path plate containing the flow path and the common liquid chamber to the other surface of the pressure chamber plate, and a step of joining a nozzle plate containing the nozzle to the flow path plate. Is what it is.

According to the eighth to tenth aspects, each actuator block is inspected before the plurality of actuator blocks are joined to the pressure chamber block by using the transfer method, so that defective products are removed in advance. By doing
Only a good actuator block can be joined to the pressure chamber block. Therefore, it is not necessary to discard some defective products together with non-defective actuator blocks after joining, and waste of the actuator blocks is eliminated.

In particular, according to the tenth aspect, since the second electrode also serves as the diaphragm, the cost can be reduced by reducing the number of components.

According to an eleventh aspect of the present invention, there is provided an ink jet recording apparatus which moves the ink jet head manufactured by the manufacturing method according to any one of the eighth to tenth aspects of the invention and the ink jet head and the recording medium. Means.

According to the eleventh aspect, the effects of the eighth to tenth aspects can be obtained in an ink jet recording apparatus.

[0026]

As described above, according to the present invention, since the inspection is performed before the actuator is joined to the pressure chamber block, defective actuators can be removed in advance. Therefore, there is no need to discard the non-defective pressure chamber block together with the defective actuator, so that the pressure chamber block can be wasted. Further, when a plurality of actuators are used, it is sufficient to discard only some defective products, and it is not necessary to discard other good actuators together with some defective products. Therefore, waste of the actuator can be eliminated. Therefore, it is possible to reduce manufacturing costs and material costs.
Further, the yield can be improved.

In particular, according to each of the second to fourth inventions, the first invention
An actuator forming member with a part of the electrode exposed can be easily manufactured.

According to the fifth aspect, the adverse effect of the inspection probe can be reduced during the characteristic inspection, so that a highly accurate characteristic inspection can be performed.

According to the sixth aspect, the electrical characteristics of the actuator can be inspected.

According to the seventh aspect, the mechanical characteristics of the actuator can be inspected.

According to each of the eighth to tenth aspects of the present invention, prior inspection of the actuator is performed at the time of manufacturing the ink jet head, so that the cost can be reduced and the yield can be improved.

In particular, according to the tenth aspect, since the second electrode also serves as the diaphragm, there is no need to separately form the second electrode and the diaphragm. Therefore, cost reduction can be achieved by reducing the number of components.

According to the eleventh aspect, the above effects can be obtained in the ink jet recording apparatus.

[0034]

Embodiments of the present invention will be described below with reference to the drawings.

First, the configuration of an ink jet head and an ink jet recording apparatus to which the present invention is applied will be described, and then a method of inspecting an actuator of the ink jet head and a method of manufacturing the ink jet head will be described.

As shown in FIG. 1, the ink jet recording apparatus 90 is a line head type recording apparatus that discharges four color inks, and includes four independent line heads 1.
To 4 are provided. 1
Is a first line head for discharging black ink (Bk), 2 is a second line head for discharging cyan ink (C), 3 is a third line head for discharging magenta ink (M), and 4 is yellow ink (Y ) Is a fourth line head that discharges the ink. The inkjet head 5 is configured by combining the first to fourth line heads 1 to 4 so as to eject black, cyan, magenta, and yellow inks in this order. Each of the line heads 1 to 4 extends in the width direction of the recording medium 9, and the head longitudinal direction Y is orthogonal to the scanning direction X. Each of the line heads 1 to 4 is connected via an ink tube 10 to an ink tank 11 storing ink of each color.

The ink jet recording apparatus 90 has a pair of transport rollers 8, 8 and a pair of feed rollers 7, 7, and the recording medium 9 is sandwiched between the feed rollers 7, 7 and the transport rollers 8, 8. I have. The transport rollers 8 constitute moving means for relatively moving the inkjet head 5 and the recording medium 9, and the recording medium 9 is transported in the scanning direction X by the rotation of the transport rollers 8. A flat recording medium holding member 6 is provided below the inkjet head 5.
Is provided. Note that the recording medium holding member 6 is not limited to a flat plate, and may be, for example, a cylindrical member as long as the recording medium 9 and the inkjet head 5 are opposed to each other at a fixed interval.

The recording medium 9 passes between the ink jet head 5 and the recording medium holding member 6. The recording medium 9 is
Since the sheet is conveyed to the conveying rollers 8 while being sandwiched between the feed rollers 7, a tensile tension is applied by the rollers 7 and 8. As a result, the recording medium 9 forms a flat surface on the recording medium holding member 6 without bending.
Therefore, ink droplets ejected from the inkjet head 5 land on the recording medium 9 with high accuracy.

Although illustration is omitted, when the recording medium 9 is electrostatically attracted by applying static electricity to the recording medium holding member 6, a portion of the recording medium 9 on the recording medium holding member 6 becomes flatter. Therefore, means for applying static electricity to the recording medium holding member 6 may be provided.

The configuration of each line head will be described with reference to FIGS. However, since the first to fourth line heads 1 to 4 have the same shape, only the first line head 1 will be described below, and description of the other line heads 2 to 4 will be omitted.

As shown in FIG. 2, the line head 1 has one pressure chamber block 41 and a plurality of actuator blocks 40 joined to the pressure chamber block 41. Each actuator block 40 has one side in the longitudinal direction of the actuator block 40, that is, the head longitudinal direction Y.
And the other side is formed in a rectangular shape perpendicular to the head longitudinal direction Y. However, the shape of the actuator block 40 is not limited to a rectangular shape, and may be another shape such as a parallelogram. The actuator blocks 40, 40,... Are arranged in a staggered manner so that they do not come into contact with each other and partially overlap in the head longitudinal direction Y.

More specifically, a first block row 40A and a second block row 40B in which a plurality of actuator blocks 40, 40,... Are arranged at regular intervals in the head longitudinal direction Y are formed on the pressure chamber block 41. Have been.
The first block row 40A and the second block row 40B are arranged in the recording medium conveyance direction (that is, the scanning direction X).
The actuator blocks 40, 40 belonging to the same block row are separated from each other in the head longitudinal direction Y. The actuator blocks 40 belonging to the first block row 40A and the actuator blocks 40 belonging to the second block row 40B are separated from each other in the scanning direction X. Actuator block 4 of first block row 40A
0 and the actuator block 4 in the second block row 40B
0 is provided at a position shifted from each other in the head longitudinal direction Y. For example, the actuator blocks 40 of the first block row 40A are arranged in the head width direction Y.
The actuator blocks 40 of the second block row 40B,
It is located between 40.

The actuator block 40 is provided with a piezoelectric element 30 of a perovskite type dielectric thin film made of PZT having a thickness of 0.5 μm to 8 μm (see FIG. 3). Each surface of the piezoelectric element 30 has a first electrode 15 made of a conductive material (for example, Pt or the like) having a thickness of about 0.1 μm for individually applying a potential, and a thickness for supplying a voltage to the first electrode 15. A lead portion 16 made of a conductive material of about 0.1 μm and an input terminal 17 connected to an FPC 13 as a control plate are arranged.

As shown in FIGS. 4 and 5, the pressure chamber block 41 is configured by laminating a pressure chamber plate 21, a flow path plate 38, and a nozzle plate 36. As shown in FIG. 2, the pressure chamber plate 21 is provided with an ink inlet 12 for introducing ink in the ink tube 10, and the ink tube 10 is fitted into the ink inlet 12.

As shown in FIG. 3, in the actuator block 40, Pt, Ct is placed on the diaphragm 14 made of nickel, chromium, silicon oxide, ceramics or the like.
A second electrode 50 made of a conductive material such as u or Ti is laminated. The second electrode 50 is a common electrode for applying a common potential to each of the piezoelectric elements 30 in the actuator block 40. The piezoelectric element 30 is provided on the second electrode 50.
Are stacked, and the first electrode 15 and the lead portion 16 are stacked on the piezoelectric element 30. As shown in FIG. 2, each actuator block 40 covers a plurality of pressure chambers 22, 22,... Of a pressure chamber block 41. The upper portion of each pressure chamber 22 in the actuator block 40 is an actuator section that performs flexural deformation to increase or decrease the volume of each pressure chamber 22. Accordingly, each actuator block 40 includes a number of actuators corresponding to the pressure chambers 22, 22,. In order to enable high-density arrangement, the thickness of the actuator block 40 is preferably 8 μm or less.

FIG. 4 is a sectional view taken along line CC of FIG. FIG.
As shown in (1), the first line head 1 is configured such that one pressure chamber plate 21, a flow path plate 38, and a nozzle plate 36 are joined. These pressure chamber plates 2
1, the flow path plate 38 and the nozzle plate 36 are positioned with high accuracy by the positioning means 25. In the present embodiment, the positioning means 25 is constituted by through holes 23, 24 through which the positioning pins 23a, 24a pass. That is, the nozzle plate 36, the flow path plate 38, and the pressure chamber plate 21 are positioned with high accuracy by overlapping each other so that the positioning pins 23a, 24a pass through the through holes 23, 24 of each plate. ing. The through hole 24 is a circular hole, and the through hole 23 is an elliptical hole.

However, the positioning means 25 is not limited to physical means, and other means may be used. For example, a marker for alignment may be provided on each plate, and the alignment of each plate may be performed by optical means.

FIG. 5 is a perspective view of a main part including a section taken along line AA of FIG. As shown in FIG. 5, a pressure chamber 22 is provided in the pressure chamber plate 21. The channel plate 38 is
A first plate 33 provided with an ink flow path inlet 20 and an ink supply port 19; a second plate 34 provided with an ink flow path 32 and a common liquid chamber 18;
A third hole provided with a hole for introducing ink from the nozzle 37 to the nozzle 37
And a plate 35. Channel plate 38
Is made of a metal material such as SUS, a photosensitive glass or a resin material. Nozzle plate 36
Is made of a metal material such as SUS having a thickness of 20 μm to 150 μm or a resin material such as PI (polyimide). The nozzle 37 is formed in the nozzle plate 36. The ink flows through the head in the order of the common liquid chamber 18 → the ink supply port 19 → the pressure chamber 22 → the ink flow path inlet 20 → the ink flow path 32 → the nozzle 37, flies from the nozzle 37, and lands on the recording medium 9. I do.

As shown in FIG. 6, the pressure chamber 22 is formed to have an elliptical planar shape,
They are arranged at an interval of dpi (42.3 μm). However,
The pressure chambers 22 are not arranged in a line along the head longitudinal direction Y, but are arranged in the scanning direction X while being appropriately shifted in order to increase the head density.

More specifically, the pressure chamber plate 21 has four pressure chambers 22A, 22B, and 2 in which four pressure chambers 22 are arranged so as to be inclined with respect to the head longitudinal direction Y.
2C and 22D are formed. In other words, each of the pressure chamber rows 22 </ b> A to 22 </ b> D is formed by four pressure chambers 22 arranged diagonally downward and rightward in FIG. 6. The pressure chamber row 22A and the pressure chamber row 22B, and the pressure chamber row 22C and the pressure chamber row 22D are adjacent to each other in the head longitudinal direction Y. On the other hand, the pressure chamber row 22B and the pressure chamber row 22C are shifted in the scanning direction X. Next to the four pressure chamber rows 22A to 22D in the head longitudinal direction Y, pressure chamber rows 22A to 22 formed in a similar pattern.
D is arranged. Although only two sets of pressure chamber rows 22A to 22D are shown in FIGS. 2 and 6 for the sake of simplicity, a large number of pressure chamber rows 22A to 22D are actually formed in the head longitudinal direction Y. Have been.

The bottom of each pressure chamber 22 has an ink supply port 1
9 and an ink flow path inlet 20 are provided. The ink supply port 19 allows the common liquid chamber 18 and the pressure chamber 22 to communicate with each other. The inside of the common liquid chamber 18 is filled with ink. The central part of the common liquid chamber 18 is branched into two rows of liquid chambers extending in the head longitudinal direction Y, and these two rows of liquid chambers are united at both ends. At both ends, ink inlets 12 are provided, respectively, and ink is supplied to the common liquid chamber 18 through the ink inlets 12.

-Inspection Method of Actuator Block-Next, a characteristic inspection of the actuator block 40 will be described. This characteristic inspection is performed during the manufacturing process of the inkjet head 5.

First, a 20 mm × 25 mm MgO, S
A substrate 60 made of i, SUS, or the like is prepared. In the present embodiment, an MgO substrate is used.

Next, as shown in FIG. 7A, a first platinum electrode 15 is formed on the entire surface of the substrate 60 by RF sputtering (high frequency sputtering).

Next, as shown in FIG. 7B, a mask 65 made of a metal mask is arranged above the first electrode 15, and the PZT thin film piezoelectric element 30 is formed on the first electrode 15 by RF sputtering. To form Here, the mask 65 is formed in a pattern that shields a portion to be the exposed portion 15A of the first electrode 15. Therefore, the piezoelectric element 3
0 is laminated only on a part of the first electrode 15. The other portion of the first electrode 15 becomes the exposed portion 15A without the piezoelectric element 30 being laminated. Here, in particular, M
Since a single crystal substrate of gO is used, when the piezoelectric element 30 is manufactured after the first electrode 15 made of platinum is formed on the (100) plane of the MgO substrate 60, the piezoelectric element 30 has a stable high piezoelectric property. It has characteristics.

Next, as shown in FIG. 7C, the platinum second electrode 50 is formed on the piezoelectric element 30 by RF sputtering while the mask 65 is placed above the piezoelectric element 30 in the same manner as described above. To form As a result, an actuator forming member 66 in which the first electrode 15, the piezoelectric element 30, and the second electrode 50 are sequentially laminated on the substrate 60 and a part of the first electrode 15 is the exposed portion 15A is obtained. Can be

The shape of the exposed portion 15A of the first electrode 15 is not particularly limited. The exposed portion 15A may be formed on the entire edge of the substrate 60 in the width direction, for example, as shown in FIG.
As shown in FIG. 8B, it may be provided at a corner of the substrate 60.

In the characteristic inspection according to the present embodiment, as shown in FIG.
Is formed (Step ST1), and the electrical characteristics are evaluated (Step ST2). Thereafter, a part of the actuator forming member 66 is cut out (step ST3), and mechanical characteristics evaluation is performed using the cut out part of the actuator forming member 66 as a sample (step ST4).

The evaluation of the electrical characteristics is performed as shown in the flowchart of FIG. That is, first, as schematically shown in FIG. 11, the inspection probe 69 is pressed against the exposed portion 15A of the first electrode 15 of the actuator forming member 66 and the second electrode 50, and under a predetermined condition (for example, At a measuring frequency of 1 kHz and a voltage of several volts applied), the dielectric loss tan δ of the piezoelectric element 30 and the capacitance Cp
[F] is measured (step ST11).

Next, to calculate the relative dielectric constant epsilon _r using the measured value of the capacitance Cp (step ST12). The relative permittivity ε _r is calculated using the following equation.

[0061]

(Equation 1) Then, it is determined whether or not the relative permittivity ε _r and the dielectric loss tan δ each reach a predetermined acceptable level (step ST13). Specifically, the relative permittivity ε _r ≧ 250,
It is determined whether the condition of dielectric loss tan δ ≦ 5 [%] is satisfied. As a result, when the above condition is satisfied, it is determined to be a non-defective product (step ST14). Conversely, when the above condition is not satisfied, it is determined to be a defective product (step ST14).
15).

When the evaluation of the electrical characteristics is completed, the mechanical characteristics are evaluated next. However, the evaluation of the mechanical properties is performed using a sample 67 (see FIG. 13) obtained by cutting out a part of the actuator forming member 66. Therefore, prior to the mechanical characteristic evaluation, a part of the actuator forming member 66, specifically, a part including the exposed portion 15A of the first electrode 15 is cut (step ST3). For example, a part including the exposed portion 15A of the actuator forming member 66 is 20 mm ×
The sample is cut into a 2 mm strip to obtain a sample 67.

The evaluation of the mechanical characteristics is performed as shown in FIG. First, as shown in FIG. 13, a silver paste 68 is fixed to the second electrode 50 as a paste material (step ST21). This silver paste 68 is used for the inspection probe 6.
This is provided to stabilize the electrical contact between the second electrode 9 and the second electrode 50. Thereby, the inspection probe 6
Even without pressing the sample 9 against the second electrode 50 of the sample 67 with a strong force, the inspection probe 69 can be reliably brought into contact with the second electrode 50. That is, the load of pushing the inspection probe 69 into the second electrode 50 is reduced. Therefore, an extra load at the time of measurement can be removed, and characteristic evaluation can be performed more accurately.

After the silver paste 68 is fixed, one of the inspection probes 69 is brought into contact with the second electrode 50 through the silver paste 68 and the other is brought into contact with the exposed portion 15A of the first electrode 15, under predetermined conditions (for example, the measurement frequency 500 Hz, the maximum applied voltage is applied to the following sine wave 30 V) for detecting a piezoelectric constant d ₃₁ of the piezoelectric element 30 in (step ST22). The piezoelectric constant d ₃₁ is calculated using the following equation.

[0065]

(Equation 2) Then, to assess whether the piezoelectric constant d ₃₁ has reached a predetermined acceptable level (step ST23). Specifically, it is determined whether or not the condition of piezoelectric constant d ₃₁ ≧ 70 [C / N] is satisfied. As a result, when the above condition is satisfied, it is determined to be non-defective (step ST24). Conversely, when the above condition is not satisfied, it is determined to be defective (step ST25).

After the above inspection, the actuator forming member 66 determined to be defective in the above-described electrical characteristic evaluation or mechanical characteristic evaluation is removed, and is determined to be good in both the electrical characteristic evaluation and the mechanical characteristic evaluation. Only the obtained actuator forming member 66 is used in the following inkjet head manufacturing process.

Next, a method of manufacturing an ink jet head will be described. This manufacturing method uses a so-called transfer method. As described above, in the method of manufacturing an ink jet head, first, the above-described actuator forming member 66 is inspected, and only the non-defective actuator forming member 66 is used.

After the inspection, as shown in FIG. 14A, the diaphragm 14 made of chromium is formed on the second electrode 50 by RF sputtering. Thus, the substrate block 61 is completed. The substrate block 61 is for transferring the actuator block 40 from the substrate 60 to the pressure chamber plate 21 and includes the substrate 60 and the actuator block 40.

Next, as shown in FIG. 14B, a uniform electrodeposition resin layer (not shown) is formed on the pressure chamber plate 21 by using an electrodeposition method, and thereafter, the electrodeposition resin layer is formed. The plurality of substrate blocks 61 are joined to the pressure chamber plate 21 such that the vibration plate 14 and the pressure chamber plate 21 are in contact with each other. When joining the substrate block 61, the diaphragm 1
In order to uniformly and reliably join the substrate block 4 to the pressure chamber plate 21, the substrate blocks 61 are prevented from contacting each other. In other words, the board blocks 61 are separated from each other so as to provide a gap between the adjacent board blocks 61 (see FIG. 2).

After the bonding of the substrate block 61 as described above, the substrate 60 is etched away using an acidic solution as shown in FIG.

Next, after the mask (not shown) manufactured with high accuracy by the exposure machine is positioned by the positioning means 25 provided on the pressure chamber plate 21, as shown in FIG. The first electrode 15 is patterned to form the first electrode 15 and the lead 16 in a predetermined shape. As described above, the first electrode 15 and the lead portion 16 can be formed with high accuracy by aligning the pressure chamber plate 21 with the mask using the alignment unit 25.

Next, as shown in FIG. 14E, the pressure chamber plate 21 and the flow path plate 38 are positioned with respect to each other using the positioning means 25 provided on the pressure chamber plate 21, and then joined. .

Next, as shown in FIG. 14F, the flow path plate 38 and the nozzle plate 36 are positioned by using the positioning means 25 provided on the pressure chamber plate 21 or the flow path plate 38. Join from. As a result, a line head in which each plate is aligned with high precision is completed.

Thereafter, by combining the four line heads manufactured as described above, an ink jet head 5 for discharging ink of four colors is obtained.

-Effects of Embodiment- As described above, according to the present embodiment, before transferring the actuator block 40 to the pressure chamber block 41, the electrical and mechanical characteristics thereof are inspected. In addition, defective products having inferior characteristics can be extracted in advance. Therefore, the inkjet head can be manufactured after removing defective products in advance, so that the reliability of the inkjet head can be improved. Further, the yield of the inkjet head can be improved.

In particular, in the present embodiment, by providing a plurality of actuator blocks 40 for one pressure chamber block 41, each actuator block 40 is reduced in size, whereby the line heads 1 to 4 are transferred using the transfer method. Making it possible to manufacture. Therefore, many actuator blocks 40 are used.
However, since the above-described inspection is performed when the inkjet head 5 is manufactured, a defective actuator forming member 6
While removing 6, the other good actuator forming member 66 can be used as it is. In the conventional line head, one actuator block is provided for one pressure chamber block 41. Therefore, if a part of the actuator block is defective, the entire actuator block including a normal part is defective. Had to be discarded. However, according to the present embodiment, it is sufficient to discard only defective products, so that waste of materials can be eliminated.

At the time of evaluating the mechanical characteristics, the silver paste 68 was fixed to the second electrode 50 and the inspection probe 69 was brought into contact with the second electrode 50 via the silver paste 68. The electrical contact between the inspection probe 69 and the second electrode 50 can be ensured only by making the probe 69 lightly contact the second electrode 50. Therefore, since the pressing force of the inspection probe 69 is reduced, the influence of the pressing force of the inspection probe 69 can be extremely reduced in evaluating the mechanical characteristics, and the characteristic evaluation can be performed accurately.

-Modification- In the present embodiment, the joining is performed in the order of the pressure chamber plate 21, the passage plate 38, and the nozzle plate 36.
The pressure chamber plate 21 and the flow path plate 38 may be bonded after the flow path plate 38 and the nozzle plate 36 are bonded.

In this embodiment, the diaphragm 14 and the second
Although the electrode 50 and the electrode 50 are formed as separate elements,
15A is made of a conductive material such as chromium, the diaphragm 14 can also serve as the second electrode 50.
As shown in (1), the diaphragm 14 and the second electrode 50 may not be separately provided, and only the diaphragm 14 serving as the second electrode may be provided.

Further, between the piezoelectric element 30 and the vibration plate 14, Cu is added to improve the withstand voltage and strengthen the bonding force.
A conductive material such as Ti or Ti may be interposed as an intermediate layer.

As shown in FIG. 15B, the piezoelectric element 30 may be patterned and divided together with the first electrode 15. In this case, the diaphragm 14 is easily bent, and a larger displacement can be obtained even when the same voltage is applied.

Further, immediately after the first electrode 15 is formed on the substrate 60, the first electrode 15 is patterned, as shown in FIG.
Can be arranged around the piezoelectric element 30. Thereby, the withstand voltage between the first electrode 15 and the lead portion 16 and the diaphragm 14 can be improved.

In the present embodiment, in order to manufacture the actuator forming member 66, the piezoelectric element 30 and the second electrode 50 are formed using a mask so that a part of the first electrode 15 becomes the exposed portion 15A. Although a mask film forming method to be formed is adopted, a method for manufacturing the actuator forming member 66 is not limited to the above method.

For example, as shown in FIGS. 16A to 16E, the first electrode 15, the piezoelectric element 30, and the second electrode 50 are sequentially laminated on the substrate 60 on one surface, and then the second electrode is etched. The exposed portion 15A of the first electrode 15 may be formed by removing a part of the electrode 50 and a part of the piezoelectric element 30.

Also, as shown in FIGS. 17A to 17D, the first electrode 15 and the piezoelectric element 30 are sequentially laminated on the substrate 60 on one surface, respectively. The second electrode 50 is partially laminated, and then the piezoelectric element 3
The exposed portion 15A of the first electrode 15 may be formed by removing the exposed portion of 0 by etching.

In the above embodiment, the first electrode and the second electrode are the individual electrode and the common electrode, respectively. That is, the first electrode may be a common electrode and the second electrode may be an individual electrode. As shown in FIG. 18, after patterning the second electrode to form the individual electrode 50, the inspection probe 69 is pressed against the individual electrode 50 and the first electrode (common electrode) 15 to perform the inspection. Is also good.

In the evaluation of the electrical characteristics, a part of the actuator forming member 66 was cut out as a sample.
The relative dielectric constant and dielectric loss of the sample may be evaluated to evaluate the actuator forming member 66 itself. Also, in the electrical characteristic evaluation, the inspection probe 69 may not be brought into direct contact with the electrode, but may be brought into indirect contact with the electrode via a conductive paste material.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of an ink jet recording apparatus.

FIG. 2 is a plan view of the line head.

FIG. 3 is a sectional view taken along line BB of FIG. 2;

FIG. 4 is a sectional view taken along line CC of FIG. 2;

FIG. 5 is a perspective view of a main part of the head including a cross section taken along line AA of FIG. 2;

FIG. 6 is a plan view of a pressure chamber block.

FIGS. 7A to 7C are process diagrams showing a method of manufacturing an actuator forming member.

FIGS. 8A and 8B are perspective views of an actuator forming member.

FIG. 9 is a flowchart illustrating an inspection method.

FIG. 10 is a flowchart of an electrical characteristic evaluation.

FIG. 11 is a perspective view of a member for forming an actuator when an electrical characteristic is evaluated.

FIG. 12 is a flowchart of mechanical characteristic evaluation.

FIG. 13 is a perspective view of an actuator forming member when evaluating mechanical characteristics.

14A to 14F are process diagrams showing a method for manufacturing a line head.

FIGS. 15 (a) to (c) are diagrams corresponding to FIG. 3 of modified examples.

FIGS. 16A to 16E are process diagrams showing another method for manufacturing an actuator forming member.

FIGS. 17A to 17D are process diagrams showing another method of manufacturing the member for forming an actuator.

FIG. 18 is a diagram corresponding to FIG. 11 of a modified example.

[Explanation of symbols]

1-4 line head 5 inkjet head 6 recording medium holding member 7 feed roller 8 transport roller 9 recording medium 10 ink tube 11 ink tank 14 diaphragm 15 first electrode 15A first electrode exposed portion 18 common liquid chamber 21 pressure chamber plate 22 Pressure chamber 30 Piezoelectric element 36 Nozzle plate 37 Nozzle 38 Flow path plate 40 Actuator block (actuator) 41 Pressure chamber block 50 Second electrode 60 Substrate 65 Mask 66 Actuator forming member 67 Sample 68 Silver paste 69 Inspection probe 90 Ink jet type Recording device

 ──────────────────────────────────────────────────の Continued on the front page (72) Koji Ikeda 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Jun Sogami 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Masaichiro Tachikawa 1006 Kazuma Kadoma, Kazuma, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. (reference) 2C057 AF93 AF99 AG15 AG44 AN05 AP02 AP24 AP52 AP77 AP82 BA04 BA14

Claims (11)

[Claims] An inspection method for an actuator having a piezoelectric element and first and second electrodes provided on both sides of the piezoelectric element, wherein the first electrode, the piezoelectric element, and the second electrode are formed on a substrate. Producing an actuator forming member that is laminated in order and exposes a part of the first electrode; and bringing an inspection probe into contact with the exposed portion of the first electrode and the second electrode, An inspection step of inspecting characteristics of the piezoelectric element. 2. The method for inspecting an actuator according to claim 1, wherein the step of producing the actuator forming member includes the steps of: laminating a first electrode on a substrate; Stacking a piezoelectric element and a second electrode sequentially on another part while shielding a part of the first electrode using a mask so as to form an exposed part. Inspection methods. 3. The method for inspecting an actuator according to claim 1, wherein the step of manufacturing the actuator forming member includes the steps of sequentially laminating a first electrode, a piezoelectric element, and a second electrode on a substrate. Etching the second electrode and a part of the piezoelectric element so that a part of the first electrode becomes an exposed part. 4. The method for inspecting an actuator according to claim 1, wherein the step of manufacturing the actuator forming member includes: sequentially stacking a first electrode and a piezoelectric element on a substrate; A step of laminating a second electrode on another part while shielding a part of the piezoelectric element using a mask so that a part of the first electrode becomes an exposed part; and a part of the first electrode becomes an exposed part. Etching the exposed portion of the piezoelectric element as described above. 5. The method for inspecting an actuator according to claim 1, wherein in the inspecting step, one or both of the exposed portion of the first electrode and the second electrode are electrically conductive. Stick the paste material of
A method for inspecting an actuator, comprising a step of bringing an inspection probe into contact with a first electrode or a second electrode via the paste material. 6. The method for inspecting an actuator according to claim 1, wherein the inspecting step measures one or both of a relative permittivity and a dielectric loss of the piezoelectric element. A method for inspecting an actuator, comprising: 7. The actuator inspection method according to claim 1, wherein the inspection step includes a step of measuring a piezoelectric constant of the piezoelectric element. Inspection method. 8. A pressure chamber block provided with a common liquid chamber for storing ink, a plurality of pressure chambers communicating with the common liquid chamber, and a plurality of nozzles respectively communicating with each of the pressure chambers. A method for manufacturing an ink jet head, comprising: an element and first and second electrodes for applying a voltage to the piezoelectric element; and a plurality of actuator blocks disposed on one surface of the pressure chamber block. A method for manufacturing an ink jet head, comprising: inspecting each of the actuator blocks by the inspection method according to any one of claims 1 to 7 before joining each of the actuator blocks to the pressure chamber block. . 9. A plurality of actuators in which a first electrode, a piezoelectric element, and a second electrode are sequentially laminated on a substrate having a smaller area than the pressure chamber plate, and a part of the first electrode is exposed. A step of fabricating a member for inspection, a step of contacting an inspection probe with an exposed portion of a first electrode and a second electrode of each member for forming an actuator, and inspecting characteristics of each piezoelectric element, and each actuator after inspection. Forming an actuator block on the substrate by laminating a diaphragm on the second electrode of the forming member; and covering the plurality of pressure chambers provided in the pressure chamber plate with the diaphragm of each of the actuator blocks. Joining the actuator blocks together with the substrate to one surface of the pressure chamber plate, removing the substrates, A step of patterning the first electrode of the reservoir, and a flow path plate including an ink flow path for guiding the ink of each pressure chamber to each nozzle and a common liquid chamber on the other surface of the pressure chamber plate. And a step of joining a nozzle plate including the nozzle to the flow path plate. 10. A plurality of actuators in which a first electrode, a piezoelectric element, and a second electrode are sequentially laminated on a substrate having an area smaller than a pressure chamber plate, and a part of the first electrode is exposed. A step of fabricating a member for testing, a step of contacting an inspection probe with an exposed portion of a first electrode and a second electrode of each member for forming an actuator, and testing characteristics of each piezoelectric element; Bonding the actuator forming members to one surface of the pressure chamber plate so as to cover the plurality of pressure chambers covered by the second electrodes of the actuator forming members after inspection; and removing the substrates. And a step of patterning the first electrode of each of the actuator forming members. A flow path plate containing an ink flow path and a common liquid chamber that guides the ink of each of the pressure chambers to each nozzle, Process and method of manufacturing the ink jet head is characterized in that it a nozzle plate which encloses the nozzle and a step of bonding to the flow path plate to be bonded to the other surface of the pressure chamber plate. 11. An ink jet head manufactured by the method for manufacturing an ink jet head according to claim 8, and moving means for relatively moving the ink jet head and a recording medium. An ink jet recording apparatus characterized by the above-mentioned.