JP3721849B2 - Ink ejecting apparatus and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink ejecting apparatus and a manufacturing method thereof.
[0002]
[Prior art]
The ink ejecting apparatus applies ejecting energy to ink in the ink ejecting channel by deforming a piezoelectric material or the like or locally boiling the ink with a heater. These piezoelectric materials, heaters, and other actuators are arranged at high density in order to perform high-resolution printing, and it is necessary to devise a means for connecting a control circuit for supplying drive signals from the outside to these actuators.
[0003]
For example, in Japanese Patent Laid-Open No. 9-20006, a non-ejecting channel is provided on both sides of an ink ejecting channel, a side wall between the ejecting channel and the non-ejecting channel is made of a piezoelectric material, and side surfaces provided on both sides of the piezoelectric material. An ink ejecting apparatus of a type that ejects ink by deforming a piezoelectric material by applying a voltage to an electrode is disclosed. In such a configuration, the actuator substrate having a channel is composed of two members in the length direction of the channel, an electrode layer is formed on one of the joint surfaces of both members, and the side electrode in the non-injection channel Is electrically connected to one end of the electrode layer. Further, the other end of the electrode layer is exposed as an electrical contact on the back surface of the actuator substrate, and a wiring member is connected to the electrical contact, so that the side electrode in the non-injection channel is connected to the external control circuit via the electrode layer. Connected to.
[0004]
[Problems to be solved by the invention]
In this type of ink ejecting apparatus, electrical contacts corresponding to a plurality of side electrodes are arranged on a straight line on the back surface of the actuator substrate, and are adjacent to each other when the density of the ejecting channels is increased for high resolution printing. There is a problem that the distance between the electrical contacts is narrowed, and the wiring material is easily short-circuited and the reliability is lowered. The present invention has been made to solve the above-described problems. Even when the injection channels are arranged at a high density, the invention can be obtained at low cost and with high reliability in electrical connection between the actuator and an external control circuit. It is an object of the present invention to provide an ink ejecting apparatus and a manufacturing method thereof.
[0005]
[Means for Solving the Problems]
In order to achieve this object, the ink ejecting apparatus according to claim 1 is provided with a plurality of actuators arranged on the actuator substrate for imparting ejecting energy to the ink in a substantially planar manner, and the actuator is based on a signal from an external control circuit. In the ink ejecting apparatus that selectively drives the actuator substrate, the actuator substrate is configured by a plurality of members stacked in a direction orthogonal to the array direction of the plurality of actuators and in the array surface direction. On the end face parallel to the arrangement direction, a conductive inner electrode layer is formed with one end connected to the actuator and the other end exposed on the surface opposite to the ink ejection channel forming face of the actuator substrate. , Except for the inner electrode layer common to all actuators, corresponding to the adjacent actuators Layer electrode layer is formed on different said end face.
[0006]
As a result, the electrical contacts connected to the plurality of actuators are not arranged in a straight line in the arrangement direction of the actuators, but are positioned on the plurality of lines while being shifted from each other in the arrangement direction. Increase the distance to reduce the risk of short circuit when connecting the wiring material.
[0007]
In the above configuration, preferably, the common inner layer electrode layer is connected to all actuators and formed on the end face of one of the plurality of members, so that the common inner layer electrode layer is also the inner layer described above. Similar to the electrode layer, the actuator substrate is exposed on the surface opposite to the channel forming surface to facilitate connection with an external control circuit.
[0008]
In the above-described configuration, the actuator may be various materials such as a piezoelectric material or a heater. Preferably, the actuator includes at least a part of a polarized piezoelectric material, and a plurality of channels including the ink ejection channel. And side electrodes formed on both side surfaces of the side wall for supplying an electric field for deformation to the piezoelectric material. At that time, the inner layer electrode layer is exposed on the inner surface of the channel, the side electrode is formed to be connected to the inner surface electrode layer, and each side electrode formed on one side of the side wall and the inner layer electrode are interposed therebetween. Each connected electrical contact is exposed on the different end face. Thereby, in the side electrode of the piezoelectric material, it is possible to expose a plurality of electrical contacts on the surface opposite to the channel forming surface of the actuator substrate and to increase the distance between them.
[0009]
In the method of manufacturing an ink ejecting apparatus according to claim 4, the step of preparing the plurality of members to form the actuator substrate by joining a plurality of members in a direction orthogonal to an arrangement direction of the plurality of actuators; A step of forming a conductive inner electrode layer on the bonding surfaces of the plurality of members by making the positions in the arrangement direction of the plurality of actuators different from each other, and the plurality of members facing each other with the bonding surfaces facing each other. Forming the plurality of actuators by being electrically connected to one end of the inner electrode layer on the actuator substrate, and forming a plurality of actuators on the actuator substrate. And a step of electrically connecting a wiring material connected to the control circuit to the other end of the inner electrode layer on the opposite side of the surface.
[0010]
Thereby, the arrangement of the above-described first aspect of the electrical contact can be easily realized by joining the plurality of members to the actuator substrate, and the electrical contact and the plurality of actuators can be reliably connected. To.
[0011]
In the above manufacturing method, it is preferable that at least one of the plurality of members constituting the actuator substrate is at least partly composed of a polarized piezoelectric material, and the step of forming the plurality of actuators includes an ink ejection channel. Forming a plurality of side walls constituting a plurality of channels including the plurality of members, exposing the inner electrode layer in the channels, and a side electrode for supplying an electric field for deformation to the piezoelectric material Are formed on both side surfaces of the side wall by connecting to the inner electrode layer. This makes it possible to form a plurality of electrical contacts exposed on the surface opposite to the channel forming surface of the actuator substrate by increasing the distance between them and securely connecting the side electrode to one end of the inner layer electrode. To do.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the ink ejecting apparatus includes an actuator substrate 10 having a plurality of ink ejecting channels 21 and a non-ejection channel 22, a cover plate 30 covering the upper surface, and a plurality of nozzle holes 33 communicating with the ejecting channels 21. And a manifold 31 for distributing ink from a supply source to the ejection channel 21.
[0013]
In the actuator substrate 10, a plurality (four in the figure) of members 15, 16, 17, and 18 are bonded via an adhesive layer 19 in the channel length direction (that is, the direction orthogonal to the channel arrangement direction). Each member is formed by laminating base materials 11 and 12 made of a piezoelectric material (for example, lead zirconate titanate (PZT) ceramic material) polarized in opposite directions (P in FIG. 4). Has been. Only one of the base materials 11 and 12 may be made of a piezoelectric material.
[0014]
In the actuator substrate 10, a large number of parallel channels serving as the ejection channels 21 and the non-injection channels 22 are formed with a depth extending over both the base materials 11 and 12 and a length extending over the four members 15 to 18. . As a result, the side wall 24 separating the ejection channel 21 and the non-ejection channel 22 has a configuration in which piezoelectric materials having opposite polarization directions are stacked in the height direction.
[0015]
As shown in FIG. 1, the ejection channel 21 is formed by opening the front and rear ends in the length direction (that is, the ink ejection direction) at the front and rear ends of the actuator substrate, and the non-ejection channel 22 is opened to the front end face 10a. The rising portion 23 is left so as to close the rear end surface 10b. As shown in FIG. 4, the first electrode 26 a is formed on the side surface of the side wall 24 in the injection channel 21 in the length direction and the depth direction, and the first electrode 26 a is similarly formed on both side surfaces of the side wall 24 in the non-injection channel 22. Two side electrodes 26b are respectively formed. The left and right second side electrodes 26b in the non-injection channel 22 are divided by the groove 25 along the bottom of the channel and are independent of each other.
[0016]
A cover plate 30 that covers an open surface along the length direction of the ejection channel 21 and the non-ejection channel 22 is bonded and fixed to the upper surface 10 c of the actuator substrate 10, and the front end surface 10 a of the actuator substrate 10 and the front end surface of the cover plate 30 are fixed. A nozzle plate 32 having a nozzle hole 33 corresponding to the ejection channel 21 is bonded and fixed to 30a, and a manifold 31 is bonded and fixed to the rear end face thereof.
[0017]
Ink introduced into the manifold 31 from the ink supply source is supplied to the ejection channel 21, but is not supplied to the non-ejection channel 22 by the rising portion 23. One injection channel 21, side walls 24 and 24 on both sides thereof, and side electrodes 26a and 26b on the side walls constitute a set of actuators. When the first side electrode 26a in the ejection channel is connected to a common potential, for example, ground, and a voltage is applied to the second side electrodes 26b, 26b on the non-ejection channel 22 side of the side walls 24, 24, the first and second An electric field perpendicular to the polarization direction of the piezoelectric material is generated between the two side electrodes 26a and 26b, and as shown in FIG. 4, the piezoelectric materials on the upper and lower portions of the side walls 24 and 24 are sheared and deformed in opposite directions, respectively. The volume in the channel 21 is enlarged. When the application of voltage is stopped, when the side walls 24 and 24 return, pressure is applied to the ink in the ejection channel 21, and the ink can be ejected from the nozzle hole 33.
[0018]
Next, a configuration for connecting the side electrodes 26a and 26b to an external control circuit will be described. FIG. 2 is a view of the ink ejecting apparatus as viewed from below, and shows the positions of the AA line, the BB line, and the CC line, that is, the cross-sections at the joining boundary surfaces of the members 15 to 18. 5, FIG. 6, and FIG. 7, and what is viewed from the DD line direction corresponds to FIG. 8.
[0019]
Each member 15-18 is mutually joined in the end surface parallel to the arrangement direction of an actuator. Then, as shown in FIG. 5, the conductive inner layer electrode layer 27 connected to the second side surface electrodes 26 b and 26 b of the pair of actuators is formed on the front end surface of the member 16, that is, the joint surface on the member 15 side. A plurality of actuators are formed at intervals of a predetermined number (two in the figure) of actuators. The upper part of the inner electrode layer 27 is exposed on the surface on the non-injection channel 22 side of the side walls 24, 24 of the pair of actuators, and is electrically connected to the side electrodes 26b, 26b, and the lower end is the lower surface of the actuator substrate 10. 10d is exposed as an electrical contact 27a. The inner electrode layer 27 is divided into two parts at the upper part and is integrated at the lower part, as described in the above operation, the voltage is simultaneously applied to the two side electrodes 26b and 26b and is not connected to the side electrode 26a. It is for doing so.
[0020]
Also on the front end surface of the other member 17 (joint surface on the member 16 side) and the front end surface of the member 18 (joint surface on the member 17 side). As shown in FIGS. 6 and 7, an inner electrode layer 27 is formed in the same manner. However, the position where the inner electrode layer 27 is formed is shifted one by one with respect to the actuator. That is, the inner layer electrode layer 27 can be provided for all the actuators by disposing the inner layer electrode layer 27 on each joint surface with an interval corresponding to the number of the joint surfaces of the member minus one. .
[0021]
Further, as shown in FIG. 8, a common inner electrode layer 28 electrically connected to the first side electrodes 26a in all the ejection channels 21 is formed over the entire rear end surface of the member 18, The lower end of the inner electrode layer 28 is exposed as an electrical contact 28 a on the lower surface 10 d of the actuator substrate 10.
[0022]
As a result, as shown in FIG. 2, the plurality of electrical contacts 27 a individually connected to each actuator are positioned on a plurality of lines while being shifted from each other in a direction orthogonal to the direction in which the actuators are arranged. That is, the electrical contacts 27a of the adjacent actuators are located on the joint surface between different members, so that a predetermined number of actuators are spaced in the direction in which the actuators are arranged as described above, and in the direction perpendicular thereto. The distance between the members 16 and 17 by the length of the channel in the length direction can be set. In addition, the electrical contacts 28a of the inner electrode layer 28 on the common side are positioned behind the electrical contacts 27a with a distance corresponding to the length of the channel of the member 18 in the length direction. Therefore, the distance between each electrical contact becomes large, and the danger of a short circuit when connecting the wiring member 29 as described later can be reduced.
[0023]
The flexible wiring member 29 includes a plurality of conductive wires having a terminal 29a corresponding to the electrical contact 27a and a terminal 29b corresponding to the electrical contact 28a, and the terminals 29a and 29b are joined to the electrical contacts 27a and 28a by brazing or the like. As a result, each actuator is connected to an external control circuit (not shown).
[0024]
A method for manufacturing the above-described ink ejecting apparatus will be described.
[0025]
As shown in FIG. 9, first, each member 15-18 which comprises the actuator board | substrate 10 is comprised by what joined the base material 11.12 made from two piezoelectric materials already polarized, respectively. The inner electrode layer 27 is formed on each front end face of the members 16, 17, and 18 (joint surface with the member positioned in front of it) by a printing method, a vapor deposition method, an electroless plating method, or the like. At this time, the inner electrode layer 27 is formed so as to be shifted for each of the members 16, 17 and 18 as described above, corresponding to the position where each channel is to be formed.
[0026]
And each member 15-18 is joined by the adhesive bond layer 19, and the one actuator board | substrate 10 is produced. Thereafter, the plurality of ejection channels 21 and the non-ejection channels 22 are cut on the actuator substrate 10 with a diamond blade or the like. At this time, the upper bifurcated portion of the inner electrode layer 27 is positioned so as to partially overlap the non-injection channel 22, so that the portion of the inner electrode layer 27 is also scraped simultaneously with the processing of the non-injection channel 22. The upper part of the inner electrode layer 27 is exposed on the inner surface of the non-injection channel 22.
[0027]
Next, as shown in FIG. 10, a conductive material layer serving as an electrode is formed on the entire surface of the actuator substrate 10 including the inner surfaces of the ejection channel 21 and the non-ejection channel 22 by a method such as vapor deposition or electroless plating. To do. Then, as shown in FIG. 11, the conductive material layers on the upper surface 10c, the front end surface 10a, and the lower surface 10d of the actuator substrate 10 are removed by a method such as polishing.
[0028]
As a result, the conductive material layers on the inner surfaces of the injection channel 21 and the non-injection channel 22 are separated from each other and formed as first and second side electrodes 26a and 26b, respectively. By irradiating a laser beam along the bottom surface of the non-injection channel 22, the conductive material layer is removed in a groove shape (the groove is indicated by 25), whereby the second side electrodes 26 b on the inner surfaces on both sides of the non-injection channel 22. , 26b are separated from each other. By leaving the conductive material layer on the rear end face 10b without polishing, it is formed as a common inner electrode layer 28 and is electrically connected to the first side electrodes 26a in all the ejection channels 21. The second side electrode 26 b is formed in electrical connection with the upper part of the inner electrode layer 27 exposed on the inner surface of the non-injection channel 22. By removing the conductive material layer on the lower surface 10d of the actuator substrate 10, the lower ends of the inner electrode layers 27 and 28 are exposed as the electrical contacts 27a and 28a.
[0029]
By joining the cover plate 30, the manifold 31, the nozzle plate 32, and the wiring member 29 to the actuator substrate 10 as described above, the ink ejecting apparatus is completed.
[0030]
Next, a second embodiment will be described with reference to FIGS.
[0031]
In the present embodiment, the injection channels and the non-injection channels are not alternately arranged as in the above-described embodiment, and a plurality of injection channels 21a are arranged adjacent to each other with the side wall 24 interposed therebetween, and the injection channels 21a. Non-injection channels 22a are provided only at both ends of the row.
[0032]
Of the upper and lower base materials 11a and 12a forming the actuator substrate 10a, only the lower base material 11a is composed of a plurality of members 15a, 16a, 17a and 18a, and the upper base material 12a is as shown in FIG. It is composed of one material.
[0033]
The side electrode 26c is formed in a U-shaped cross section along the inner surface of each channel, and is connected to the inner electrode layer 27c formed on the front end surface of each of the members 16a, 17a, 18a. The inner electrode layer 27c is arranged with an interval in the channel arrangement direction and shifted in a direction orthogonal to the arrangement direction, as in the above embodiment. The lower end of the inner electrode layer 27c is exposed as an electrical contact on the lower surface of the actuator substrate 10a. The arrangement of the electrical contacts is substantially the same as that of the electrical contacts 27a in FIG.
[0034]
When ink is ejected from the ejection channel 21a-1 in FIG. 13, a voltage is applied to the side electrode 26c-1 of the channel, and the side electrodes 26c-2 and 26c-3 of the channels on both sides thereof are grounded. In the present embodiment, since the base materials 11a and 12a are polarized in the direction P facing each other, the ejection channel 21a-1 is generated by the electric field generated in the direction from the side electrodes 26c-1 to 26c-2 and 26c-3. The side walls 24, 24 on both sides are deformed in the direction of increasing the volume of the channel. When the application of voltage is stopped and the side wall returns, pressure acts on the ink and the ink is ejected from the nozzle hole 33. When ink is ejected from the adjacent ejection channel, similarly, a voltage is applied to the side electrode 26c-2 of the channel, and the side electrodes 26c-1 and 26c-4 of the channels on both sides are grounded. Therefore, in the present embodiment, there is no distinction between the inner layer electrode layer to which a voltage is applied and the inner layer electrode layer on the common side as in the previous embodiment.
[0035]
In the method of manufacturing the ink ejecting apparatus described above, first, the lower substrate 11a is integrally sintered with a plurality of members 15a, 16a, 17a, and 18a interposed between the inner electrode layers 27c. Thereafter, the lower base material 11a is subjected to polarization treatment, and the upper base material 12a subjected to polarization treatment is bonded thereon. Thereafter, the process of processing the channel and the like is substantially the same as in the above embodiment.
[0036]
In both the above embodiments, since all the electrical contacts are formed on one surface of the actuator substrate, the wiring material connected to the external control circuit can be electrically connected quickly and easily in one step. In addition, since the electrode contacts corresponding to the adjacent ejection channels are formed at different joining interfaces, they are arranged in a straight line at a pitch that is an integral multiple of the pitch of the ejection channels. Therefore, even when the arrangement density of the injection channels is increased, short circuit between adjacent electrical contacts due to brazing or the like is unlikely to occur, and high electrical reliability is obtained.
[0037]
The inner electrode layer may be formed not on the front end face of the members 16, 17, 18, 16a, 17a, 18a but on the rear end face of the member facing the inner electrode layer. The common-side internal electrode layer 28 of the first embodiment may be formed on the joint surface between the members, and the inner-layer electrode layer 27a of one row of the second embodiment is provided after the actuator substrate. You may form in an end surface. The member 18 according to the first embodiment does not need to be formed using a piezoelectric material because there are few portions to be deformed due to the rising portion 23.
[0038]
In the first embodiment, as in the second embodiment, only the lower substrate 11 is formed by sintering a plurality of members, and the upper substrate 12 is formed of one material. You can also. In the second embodiment, the upper base 12 can be composed of a plurality of members.
[0039]
The present invention can be applied to an ink ejecting apparatus using various actuators in addition to the actuator of the type in which the piezoelectric material is shear-deformed as described above.
[0040]
【The invention's effect】
As described above, according to the present invention, each electrical contact connected to a plurality of actuators is positioned on a plurality of lines while being shifted from each other in the arrangement direction without being arranged on a straight line in the arrangement direction of the actuators. Therefore, the distance between the electrical contacts is increased, the risk of short circuit is reduced, and the electrical reliability is improved.
[0041]
In addition, the arrangement of the electrical contacts can be easily realized by joining a plurality of members to the actuator substrate, and at that time, the electrical contacts and the plurality of actuators are securely connected. can do.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view illustrating an ink ejecting apparatus according to an embodiment of the invention.
FIG. 2 is a perspective view of the ink ejecting apparatus as viewed from below.
FIG. 3 is a horizontal sectional view of the ink ejecting apparatus.
FIG. 4 is an enlarged vertical sectional view of the ink ejecting apparatus.
FIG. 5 is a cross-sectional view taken along line AA in FIG.
6 is a cross-sectional view taken along line BB in FIG.
7 is a cross-sectional view taken along line CC in FIG.
FIG. 8 is an end view of FIG. 2 viewed from the direction of the line DD.
FIG. 9 is an exploded perspective view showing a manufacturing process of the actuator substrate.
FIG. 10 is a perspective view showing a manufacturing process of the actuator substrate.
FIG. 11 is a perspective view showing a manufacturing process of the actuator substrate.
FIG. 12 is a cross-sectional view corresponding to FIG. 5 of the ink ejecting apparatus according to the second embodiment.
FIG. 13 is a cross-sectional view corresponding to FIG. 6 of the ink ejecting apparatus according to the second embodiment.
FIG. 14 is a cross-sectional view corresponding to FIG. 7 of the ink ejecting apparatus according to the second embodiment.
FIG. 15 is an exploded perspective view illustrating a manufacturing process of the actuator substrate of the ink ejecting apparatus according to the second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Actuator board | substrate 15, 16, 17, 18 Member 21 and 22 which comprise an actuator board | substrate Channel 24 Side wall 26a, 26b Side electrode 27, 28 Inner layer electrode layer 27a, 28a Electrical contact

Claims (5)

In an ink ejecting apparatus that provides a plurality of actuators arranged on a substantially planar surface to give ink ejection energy to an actuator substrate, and selectively drives the actuators based on a signal from an external control circuit.
The actuator substrate is composed of a plurality of members stacked in a direction perpendicular to the arrangement direction of the plurality of actuators and in the arrangement surface direction, and the end surface parallel to the arrangement direction of the plurality of members at one end Forming a conductive inner electrode layer that is connected to the actuator and has the other end exposed on the surface opposite to the ink ejection channel forming surface of the actuator substrate;
2. An ink ejecting apparatus according to claim 1, wherein the inner layer electrode layers corresponding to adjacent actuators are formed on different end faces except for an inner layer electrode layer common to all actuators. 2. The ink ejecting apparatus according to claim 1, wherein the common inner electrode layer is connected to all actuators and formed on the end face of one of the plurality of members. Each of the actuators is at least partly composed of a polarized piezoelectric material, and includes a side wall formed with a plurality of channels including the ink ejection channel, and formed on both side surfaces of the side wall for deformation of the piezoelectric material. A side electrode that supplies the electric field of
The inner electrode layer is exposed on the inner surface of the channel, and the side electrode is formed connected to the inner electrode layer,
The ink ejecting apparatus according to claim 1, wherein each electrical contact connected to each side electrode formed on one surface of the side wall via the inner layer electrode is exposed to the different end surface. In a method for manufacturing an ink ejecting apparatus, in which a plurality of actuators that impart ink ejection energy to an actuator substrate are arranged, and the actuators are selectively driven based on a signal from an external control circuit.
Preparing the plurality of members to form the actuator substrate by joining a plurality of members in a direction orthogonal to the direction of arrangement of the plurality of actuators;
Forming a conductive inner electrode layer on the joint surfaces of the plurality of members by making the positions of the plurality of actuators in the arrangement direction different from each other;
Forming the actuator substrate by bonding the plurality of members to each other with the bonding surfaces facing each other;
Forming the plurality of actuators in electrical connection with one end of the inner electrode layer on the actuator substrate;
And a step of electrically connecting a wiring material connected to the control circuit to the other end of the inner electrode layer on the side opposite to the surface on which the plurality of actuators are formed of the actuator substrate. A method of manufacturing an ink ejecting apparatus. At least one of the plurality of members constituting the actuator substrate constitutes at least a part of a polarized piezoelectric material,
The step of forming the plurality of actuators includes forming a plurality of side walls constituting a plurality of channels including an ink ejection channel across the plurality of members, exposing the inner electrode layer in the channels, The method of manufacturing an ink ejecting apparatus according to claim 4, further comprising a step of forming side electrodes for supplying an electric field for deformation to the piezoelectric material on the both side surfaces of the side wall by connecting to the inner electrode layer. Method.

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