JP2002096468A - Electrostatic actuator and ink jet head of electrostatic type - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet head which is equipped with a wiring substrate advantageous for wiring high density of a wiring for electric supply to a common electrode and an individual electrode. SOLUTION: A driving signal is supplied to an individual electrode terminal 42A and a common electrode terminal 37 of an ink jet head 1 of electrostatic type via a wiring substrate 6. The wiring substrate 6 is provided with a conductive main body 61 of the substrate and a wiring pattern 65 formed through an isolating film 61 on one surface of the substrate. Metal wirings 66b, 66c for the common electrode contained in the wiring pattern 65 are connected with the main body 61 of the substrate through an isolating film cutting off part 61b, and the main body 61 of the substrate functions as the wiring part for the common electrode. As a result, a resistance of a signal cable for the common electrode can be reduced and the characteristics of the signal transmitted through the cable can be stabilize. A wiring sturacture advantageous for high density wiring accompanied by high densification of an ink jet head which performs a high speed switching operation can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electrostatic actuator and an electrostatic ink jet head having an electrode wiring connection structure advantageous for high density.

[0002]

2. Description of the Related Art An electrostatic ink jet head having an electrostatic actuator includes a plurality of ink nozzles, ink pressure chambers communicating with the respective ink nozzles, and a diaphragm formed at the bottom of each ink pressure chamber. ing. Each diaphragm has
Individual electrodes formed on the surface of the electrode substrate are opposed to each other at regular intervals. The substrate (cavity substrate) on which the diaphragm is formed is a conductive substrate such as silicon and functions as a common electrode. Therefore, when a voltage is applied between the common electrode and each individual electrode to generate an electrostatic force between them, the diaphragm vibrates in an out-of-plane direction, and ink droplets are ejected from the ink nozzles. Is possible.

Here, it is necessary to connect a power supply wiring to the common electrode and the individual electrodes. As a wiring method for this purpose, for example, as disclosed in Japanese Patent Application Laid-Open No. Hei 6-47915, an electrode terminal of an ink jet head is connected to a flexible wiring board (FP) by wire bonding.
A connection to C) is known. In addition, Japanese Unexamined Patent Publication No.
Japanese Patent Application Publication No. 218918 discloses a method of connecting an electrode terminal of an ink jet head to an external electrode substrate using a conductive paste. Japanese Patent Application Laid-Open No. 9-164671 discloses a method of connecting an electrode terminal of an ink jet head to a rigid body. There is disclosed a method for connecting to an external electrode substrate having a configuration in which a wiring pattern is formed on a substrate surface using a conductive adhesive.

[0004]

However, such a conventional electrode wiring connection method has the following problems. As the density of the electrostatic inkjet head increases, it is necessary to increase the wiring density of each individual electrode. However, when each wiring pattern is miniaturized in order to increase the wiring density, there is a possibility that electrical specification such as noise resistance of the wiring pattern may be reduced. Further, there is a possibility that adverse effects such as instability of the high-speed switching operation of the elements such as the inkjet head driving IC may be caused. For this reason, conventionally, there has been a limit in increasing the density of the electrode wiring connection, which has been an obstacle to increasing the density and the number of nozzles of the ink jet head.

An object of the present invention is to propose an electrostatic actuator and an electrostatic ink jet head having a wiring connection structure capable of performing a high-speed switching operation stably even when the density is increased.

[0006]

In order to solve the above-mentioned problems, the present invention provides a first substrate on which a first electrode is formed, and a second substrate, which is disposed opposite to the first electrode. And a second substrate on which electrodes are formed, and the first and second substrates are relatively displaced by an electrostatic force generated by applying a voltage between these electrodes. In the electrostatic actuator: a first electrode terminal portion formed on the first electrode, a second electrode terminal portion formed on the second electrode, and at least one of these terminal portions overlapped with each other A wiring board that is more electrically connected; the wiring board includes a board body made of a conductive material, a wiring pattern formed on a surface of the board body via an insulating layer, and a wiring board. A connection portion; The joint includes a first joint connected to the first electrode terminal, and a second joint connected to the second electrode terminal, and one of these joints is It is characterized by being electrically connected to the substrate body.

In the electrostatic actuator of the present invention, the substrate body of the wiring board is used as a wiring portion for supplying power to the first or second electrode. The resistance of the substrate body is smaller than that of a fine wiring pattern, and the characteristics of a signal flowing through the substrate can be stabilized.

In this case, a wiring layer is formed via an insulating layer on the surface of the wiring substrate opposite to the surface on which the wiring pattern is formed on the substrate body, and is used as a ground wiring portion. be able to. If you do this,
Since the resistance of the ground wiring portion can be reduced, and the substrate body of the wiring substrate is set to the ground potential, the noise resistance of the wiring pattern formed on the surface is improved.

Here, the substrate body of the wiring board is first
Alternatively, the substrate body may be used as a grounding wiring portion instead of being used as a power supply wiring portion to the second electrode. With this configuration, the resistance of the ground wiring portion can be reduced. Further, since the substrate body of the wiring substrate is set to the ground potential, the signal characteristics flowing through the fine wiring pattern formed on the surface thereof can be stabilized, and the noise resistance of the wiring pattern can be improved.

In this case, a wiring layer is formed via an insulating layer on a surface of the wiring substrate opposite to the surface on which the wiring pattern is formed on the substrate main body, and this is formed by a first or second wiring layer. May be a power supply wiring portion for the electrode.

Next, the present invention relates to a first substrate on which a first electrode is formed, and a second substrate on which a second electrode is formed so as to face the first electrode. Wherein the first and second substrates are relatively displaced by an electrostatic force generated by applying a voltage between these electrodes: formed on the first electrode The first electrode terminal portion,
A second electrode terminal portion formed on the first electrode and a wiring substrate electrically connected to at least one of the terminal portions by being overlapped with the second electrode terminal portion; A substrate main body made of a material, a wiring pattern formed on a first surface of the substrate main body via an insulating layer, a wiring layer formed on a second surface of the basic main body via an insulating layer, A first bonding portion connected to the first electrode terminal portion and a wiring bonding portion including a second bonding portion connected to the second electrode terminal portion; the first and second bonding portions One of the portions is electrically connected to the wiring layer.

Here, instead of using the wiring layer as a power supply wiring portion to the first or second electrode, the wiring layer can be used as a grounding wiring portion.

On the other hand, according to the present invention, a first substrate in which an ink pressure chamber communicating with an ink nozzle is formed and a vibrating plate portion which functions as a common electrode defining a bottom surface of the ink pressure chamber are disposed to face each other. The second individual electrode is formed
Substrate, and vibrates the vibrating plate portion by an electrostatic force generated by applying a voltage between the common electrode and the individual electrodes, thereby ejecting ink droplets from the ink nozzles. In the electrostatic ink jet head, the common electrode terminal formed on the common electrode and the individual electrode terminal formed on the individual electrode are electrically connected to each other by overlapping at least the individual electrode terminal. A wiring board, the wiring board comprising: a substrate body made of a conductive material;
A wiring pattern formed on the surface of the substrate body via an insulating layer; and a wiring joint including a common electrode joint connected to the common electrode terminal and an individual electrode joint connected to the individual electrode terminal. Wherein the common electrode junction is electrically connected to the substrate body.

In the electrostatic ink jet head according to the present invention, the resistance of the wiring portion of the common electrode can be reduced because the substrate body of the wiring substrate is used as the wiring portion for supplying power to the common electrode. Further, the signal characteristics of the wiring portion to the common electrode can be stabilized.

In this case, a wiring layer is formed via an insulating layer on a surface of the wiring board opposite to the surface on which the wiring pattern is formed on the substrate body, and this is used as a ground wiring portion. You can also.

Here, instead of using the substrate main body of the wiring board as a power supply wiring portion for a common electrode, the substrate main body may be used as a grounding wiring portion. With this configuration, the resistance of the ground wiring portion can be reduced. Further, since the substrate body of the wiring substrate is set to the ground potential, the signal characteristics flowing through the fine wiring pattern formed on the surface thereof can be stabilized, and the noise resistance of the wiring pattern can be improved.

In this case, a wiring layer is formed via an insulating layer on the surface of the wiring substrate opposite to the surface on which the wiring pattern is formed on the substrate main body, and the wiring layer is supplied to the common electrode. Wiring portion.

Next, according to the present invention, a first substrate in which an ink pressure chamber communicating with an ink nozzle is formed and a vibrating plate portion functioning as a common electrode defining a bottom surface of the ink pressure chamber are opposed to each other. Second electrode on which the formed individual electrode is formed
Substrate, and vibrates the vibrating plate portion by an electrostatic force generated by applying a voltage between the common electrode and the individual electrodes, thereby ejecting ink droplets from the ink nozzles. In the electrostatic ink jet head, the common electrode terminal formed on the common electrode and the individual electrode terminal formed on the individual electrode are electrically connected to each other by overlapping at least the individual electrode terminal. A wiring board, the wiring board comprising: a substrate body made of a conductive material;
A wiring pattern formed on the first surface of the substrate body via an insulating layer, a wiring layer formed on the second surface of the substrate body via the insulating layer, and the common electrode terminal. And a wiring joint including an individual electrode joining part connected to the individual electrode terminal part; wherein the common electrode joining part is electrically connected to the wiring layer. .

Instead of using the wiring layer as a power supply wiring portion for a common electrode, the wiring layer can be used as a grounding wiring portion.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an electrostatic ink jet head according to the present invention will be described below with reference to the drawings.

(Overall Configuration) FIG. 1 is a perspective view showing the overall configuration of the ink jet head of this embodiment, and FIG.
It is a schematic sectional drawing of the part cut | disconnected by the line. As shown in these figures, the ink jet head 1 of this embodiment has a head chip 1A which is an ink jet main body, and a wiring board for supplying a drive signal to the head chip 1A from the outside via a flexible wiring board 7. 6.

The head chip 1A is formed by bonding a nozzle substrate 2 made of a silicon single crystal substrate, a cavity substrate 3 also made of a silicon single crystal substrate, and an electrode glass substrate 4. Cavity substrate 3
Has a plurality of ink pressure chambers 31 and each ink pressure chamber 31
A common ink chamber 32 for supplying ink to the printer is formed. A vibrating plate 33 which is elastically displaceable in an out-of-plane direction is formed on the bottom surface of each ink pressure chamber 31.

On the side of the nozzle substrate 2, a back surface 21 joined to the cavity substrate 3 is provided with each of the ink pressure chambers 3.
A plurality of ink nozzles 22 communicating with each other and an ink supply port 23 communicating each ink pressure chamber 31 with a common ink chamber 32 are formed. Further, on the surface 24 of the nozzle substrate 2, a concave portion 25 is formed in a portion corresponding to the common ink chamber 32 so as to correspond to each ink pressure chamber 31. These recesses 25 have a truncated quadrangular pyramid shape having a predetermined depth spread toward the surface 24, and the bottom surface thereof is a diaphragm 26 that can be elastically displaced in the out-of-plane direction.

In the electrode glass substrate 4 bonded to the back surface 3a of the cavity substrate 3 by anodic bonding or adhesive bonding, a concave portion 41 is formed at a portion facing each diaphragm 33, and the bottom surface of each concave portion 41 is formed. Is formed with an individual electrode 42 made of ITO facing the vibration plate 33.

The concave portions 25A and 25B located at both ends of the cavity substrate 3 have an ink intake structure in which a large number of filter holes (not shown) having a smaller diameter than the ink nozzle 22 are formed at a constant density on the bottom surface. It is a mouth.

These ink inlets (recesses) 25
The connection portions 30 of the ink supply pipes 29 are connected to A and 25B, respectively (see FIG. 2). Ink supplied from an ink supply source (not shown) disposed outside is supplied to the common ink chamber 32 via the ink intake ports 25A and 25B.

The vibration plate 33 defining the bottom surface of the ink pressure chamber 31 formed in the cavity substrate 3 functions as a common electrode. When a driving voltage is applied between the cavity substrate 3 and each individual electrode 42 by the driving voltage applying means 50, the diaphragm 33 facing the individual electrode 42 to which the voltage is applied vibrates due to electrostatic force, Accordingly, the volume of the ink pressure chamber 31 changes, and the ink nozzle 22
, The ink droplets are ejected.

Here, power is supplied to the common electrode and the individual electrodes by using a wiring board 6 joined to the common electrode and an individual electrode via an anisotropic conductive adhesive 5 and a flexible board joined to the wiring board 6 as described later. This is performed via the wiring board 7.

(Electrode Wiring Connection Portion) Next, the wiring connection portion for the common electrode, the individual electrode, and the grounding wiring of the ink jet head 1 of this embodiment will be described in detail. FIG. 3 is a partial cross-sectional view taken along the line III-III in FIG. 1 to show a wiring connection state between the common electrode and the individual electrodes and the wiring board 6.

Referring to FIG. 3 as well, the electrode glass substrate 4 has a protruding portion 43 protruding laterally from the end face 35 of the cavity substrate 3, and the exposed surface 44 of the protruding portion 43 is formed with the individual electrode 42. And the exposed surface 44 is provided with each individual electrode 4.
A plurality of individual electrode terminal portions 42A having a constant width and made of ITO drawn out of the second electrode 2 are formed at regular intervals.

The cavity substrate 3 whose surface is covered with the insulating layer 30 has a protruding portion 34 protruding laterally from the end face 27 of the nozzle substrate 2, and a common electrode terminal portion 37 is provided on an exposed surface 36 of the protruding portion 34. Are formed. At the center position of the common electrode terminal portion 37, a through hole 38 formed in the cavity substrate projecting portion 34 is located. A common electrode connection electrode 40 made of ITO is formed on the front surface 44 of the electrode glass substrate facing the back surface 39 of the protruding portion 34 so as to face the through hole 38. Further, between the common electrode terminal portion 37 formed on the cavity substrate surface 36 and the common electrode connecting electrode 40 formed on the electrode glass substrate surface 44, a conductive paste 40A such as silver base filled in the through hole 38 electrically connects the common electrode terminal portion 37 and the electrode 40. It is connected to the.

As described above, in the common electrode terminal portion 37, the individual electrode terminal portion 42A extending from the individual electrode 42 is formed by the connection electrode lead portion composed of the conductive paste 40A and the common electrode connection electrode 40. Out to the surface 44 of the substrate. In other words, the common electrode connection electrode 40 and the individual electrode terminal portion 42A are located on the same plane. Therefore, these electrodes 40 and terminal portions 42A
By using the wiring substrate 6 in which the joints to the electrodes 40 and 42 are patterned on the same plane, the joints with the electrodes 40 and the terminal portions 42A can be easily formed.

FIG. 5 is a partial cross-sectional view taken along the line IV-IV in FIG. 1. FIG. 4 is a perspective view of the wiring substrate 6 as viewed from the wiring pattern forming side.

As shown in these figures, the wiring board 6
It has a conductive substrate main body 61 made of rectangular silicon or the like, and an IC chip 63 for driving an inkjet head mounted on the surface of the substrate main body 61 covered with an insulating film 61a.

To describe the electrode glass substrate 2 side, a fine metal wiring pattern 65 is formed on the wiring substrate surface (IC chip mounting side surface) 62 so as to connect between the surface of one end 64 of the substrate main body 61 and the IC chip 63. The metal wiring 66b constituting the metal wiring pattern 65 is for connecting a common electrode, and an end of the metal wiring 66b serves as a common electrode joint 66a. The remaining wiring groups 67 are for connecting individual electrodes, and their ends are used as individual electrode joints 67a.

The common electrode metal wiring 66b is connected to the substrate main body 61 via the insulating film cutout 61b.

One end of the common electrode joint 66a is arranged so as to coincide with the common electrode connecting electrode 40 formed on the electrode glass substrate 2 side.
7a are also arranged at intervals corresponding to the distal end joining portions of the individual electrode terminal portions 42A. Here, between the common electrode junction 66a and the individual electrode junction 67a, and on both sides, grooves 68 for storing conductive particles having a fixed width and depth are provided.
Are formed.

A conductive adhesive 5 containing conductive particles is applied to the end 64 of this structure, and the common electrode connecting electrode 40 and the individual electrode terminal 4 on the ink jet head side are applied thereto.
When 2A are superposed and heated and pressed, these grooves 6
Since 8 serves as a reservoir for the excess adhesive 5, it is possible to prevent the excess adhesive from protruding from portions other than the joint portions, thereby preventing a short circuit or the like from occurring between adjacent electrodes.

Next, the wiring pattern on the side opposite to the electrode glass substrate 2 will be described.
A wiring pattern 70 for external connection and a metal wiring pattern 66c for connecting a common electrode are formed between the wiring pattern 70 and the IC chip 63 so as to connect them.
Is bonded to the wiring pattern of the flexible wiring board 7 by a known method, for example, a conductive paste.

Metal wiring pattern 66c for connecting common electrode
Has one end connected to a terminal of the IC chip 63 via an anisotropic conductive adhesive 5A, and is connected to the substrate main body 61 via an insulating film cutout 61e at an intermediate position. Thus, in the wiring board 6 of the present example, the conductive substrate body 61 is used as a common electrode wiring portion.

In the ink jet head 1 of the present embodiment thus configured, the wiring between the common electrode connecting electrode 40 and the individual electrode terminal portion 42A on the head chip 1A side and the flexible wiring board 7 for external wiring is provided. It is configured to relay via the board 6. Also, the wiring board 6
Are connected to the substrate main body 61, and the substrate main body 61 is used as a common electrode wiring portion. Therefore, the circuit resistance for the common electrode wiring between the IC chip 63 and the head chip 1A can be reduced, and
The characteristics of the signal flowing through the common electrode wiring portion of the configuration can be stabilized.

(Second Embodiment) Here, in the above example,
The substrate body 61 of the wiring substrate 6 is connected to a common electrode (diaphragm 33).
However, the substrate main body 61 can be used as a ground wiring portion of the IC chip 63.

FIG. 6 is a partial plan view and a partial plan view showing an embodiment of a wiring board using the board body as a ground wiring portion. The basic configuration of the wiring board 6A of this example is the same as that of the above-described wiring board 6, and the corresponding parts are denoted by the same reference numerals and description thereof will be omitted.

In the wiring board 6A of the present embodiment, one grounding metal wiring 701 included in the external connection wiring pattern 70 drawn from the IC chip 63 mounted on the wiring board 6A is located at the IC chip proximity position. Is connected to the substrate main body 61 via the insulating film cutout 61c formed in the above. Also,
Also at the position near the connection end 702 of the flexible wiring board 7 in the metal wiring 701, the insulating film cutout 61 is formed.
It is connected to the substrate main body 61 via d. The connection end 702 is connected to the ground terminal 703 of the flexible wiring board 7 by the anisotropic conductive adhesive 5C.

In the wiring board 6A of the present embodiment thus configured, the board main body 61 is used as a ground wiring. Therefore, the ground wiring resistance on the wiring substrate can be reduced. Also, the board body 61 of the wiring board
Are grounded as a whole, so that the electrical characteristics of the wiring pattern 65 formed on the surface can be stabilized,
Noise resistance can be improved.

(Third Embodiment) In each of the above embodiments, the substrate body 61 of the wiring boards 6 and 6A is connected to the common electrode (diaphragm 33).
, Or as a grounding wiring portion of the IC chip 63. Instead of using the substrate body 61, a wiring portion for a common electrode or a wiring portion for grounding can be formed by using the surface of the wiring substrate on the side where the wiring pattern 65 is not formed.

FIG. 7 shows a wiring board in which a wiring portion for a common electrode is formed by using such a surface.
7A is a partial cross-sectional view and a partial plan view of a portion taken along line VV in FIG. 7B, which is a partial plan view.
The basic configuration of the wiring board 6B of this example is the same as that of each of the above examples. The surface 62 (first surface) on the side of the wiring board 6B of the present example, on which the IC chip 63 is mounted, is not shown, but is similar to the above-described embodiments, but has the wiring pattern 65 and the external lead-out wiring. A pattern 70 is formed. The wiring pattern 65 includes metal wirings 661 and 662 for the common electrode, and the common electrode joint 661 a formed at one end of the metal wiring 661 is connected to the electrode glass substrate 4 via the anisotropic conductive adhesive 5. Are connected to the common electrode connection electrode 40. Also, both metal wirings 66
Reference numerals 1 and 662 are connected to the common electrode terminals of the IC chip 63.

Here, the surface 610 on the opposite side of the wiring substrate
On the (second surface), a wiring layer 601 for a common electrode is entirely formed via an insulating film 61a. Through holes 663 and 664 are formed in a plurality of places in the substrate main body 61 of the wiring board, and the metal wirings 661 and 662 for the common electrode and the common electrode wiring layer 6 are formed through the conductive paste 665 filled therein.
01 is connected.

In the wiring board 6B of the present embodiment thus configured, the common electrode wiring layer 601 is formed on the surface 610 (second surface) via the insulating film 61a. Therefore, the wiring pattern 6 formed on the IC chip side surface
5, the head chip 1A and the IC chip 63 are different from the case where the fine metal wiring included in the semiconductor chip 5 is used as the common electrode wiring.
, And the characteristics of the common electrode power supply signal can be stabilized.

In this embodiment, the common electrode terminal 37 is
It is pulled out to a position on the same plane as the individual electrode terminal portion 42A on the electrode glass substrate, and is connected to the common electrode metal wiring 661 on the wiring substrate 6B side (see FIG. 3). However, in this example, the common electrode wiring layer 601 is provided on the surface 610 of the wiring substrate 6B opposite to the glass electrode substrate surface.
7A, the common electrode terminal portion 37 and the common electrode wiring layer 6 are formed as shown by imaginary lines in FIG.
01 can be directly connected using the conductive paste 666.

(Fourth Embodiment) FIG. 8 shows an example in which a ground wiring portion of an IC chip is formed by using the surface of the wiring substrate opposite to the surface on which the IC chip is mounted. The basic configuration of the wiring board 6C of the present example is the same as that of the wiring boards 6, 6A, and 6B of the above-described examples. A rectangular substrate body 61 made of a conductive material such as silicon and an insulating film covering the surface are provided. 61a, and wiring patterns 65, 7 formed on the IC chip mounting side surface 62 (first surface) of the wiring board.
0 (not shown).

In the wiring board 6C of this embodiment, a grounding wiring layer 620 is formed entirely on the surface 610 (second surface) opposite to the IC chip mounting side surface via the insulating film 61a. . The substrate body 61 has through holes 6 at a plurality of locations.
21 is formed, and the grounding wiring layer 620 is connected to the grounding metal wiring 711 included in the wiring pattern 70 formed on the surface on the opposite side of the substrate main body by the conductive paste 622 filled therein. ing. The ground metal wiring 711 is connected to the ground terminal 703 of the flexible wiring board 7 via the anisotropic conductive adhesive 5C.

In the ink jet recording apparatus provided with the wiring board 6C having this structure, the ground wiring resistance on the wiring board can be reduced as in the case of the wiring board according to the second embodiment shown in FIG. . Further, since the substrate main body 61 of the wiring substrate is set to the ground potential as a whole, the electrical characteristics of the individual electrode wiring pattern 67 formed on the surface can be stabilized, and the noise resistance can be improved.

(Fifth Embodiment) Wiring board 6D shown in FIG.
Uses the substrate body as a ground wiring portion, and uses the surface of the substrate body opposite to the IC chip mounting side as a common electrode wiring portion, as shown in the embodiment shown in FIG. 6 and FIG. The configuration is a combination of the embodiments.

The basic structure of the wiring board 6D of this embodiment is the same as that of the wiring boards 6, 6A, 6B and 6C of the above-described embodiments.
The surface of a rectangular substrate body made of a conductive material such as silicon is covered with an insulating film, and its IC chip mounting side surface 6
31 (first surface), a wiring pattern 633 for connecting the IC chip 632 and the head chip 1A is formed, and the IC chip 632 and the flexible wiring board 63 are formed.
4 are formed.

The wiring pattern 633 includes metal wirings 637 and 638 for the common electrode.
The common electrode joining portion 637a formed at one end of 37 is connected to the common electrode connecting electrode 40 via an anisotropic conductive adhesive. The wiring pattern 635 includes a grounding metal wiring 640 connected to the IC chip 632 and a grounding metal wiring 641 connected to the flexible wiring board 634.

The surface 636 on the opposite side of the wiring board 6D (second
The wiring layer 642 for the common electrode is formed on the entire surface. A through hole is formed in the substrate main body of the wiring substrate 6D, and the common electrode metal wiring 637 on the IC chip mounting side is formed via the conductive paste 643 filled therein.
638 is connected to the common electrode wiring layer 642.
On the other hand, the ground metal wires 640 and 641 are connected to the substrate main body via the insulating film cutout 644 of the substrate main body.

In the wiring board 6D of the present embodiment thus configured, the substrate body of the wiring board is used as a ground wiring part, and the surface opposite to the IC chip mounting surface is used as a common electrode wiring part. You.

In this example, as in the case shown in FIG.
The common electrode terminal portion 37 is pulled out to a position on the same plane as the individual electrode terminal portion 42A on the electrode glass substrate, and is connected to the common electrode metal wiring 637 on the wiring substrate 6D side. However, in this example, since the common electrode wiring layer 642 is formed on the surface of the substrate body opposite to the surface of the glass electrode substrate in the wiring substrate 6D, the common electrode terminal portion 3 is formed.
7 and the common electrode wiring layer 642 can be directly connected using a conductive paste.

(Sixth Embodiment) Wiring board 6 shown in FIG.
E uses the substrate body as a common electrode wiring portion, and uses the surface of the substrate body opposite to the IC chip mounting side as I
It is used as the ground wiring part of the C chip.
It has a configuration in which the embodiment shown in FIG. 5 and the embodiment shown in FIG. 8 are combined.

The basic structure of the wiring board 6E of this embodiment is the same as that of the wiring boards 6, 6A, 6B, 6C and 6D of the above-described embodiments, and the surface of a rectangular substrate body made of a conductive material such as silicon is used. Is covered with an insulating film, and the IC chip mounting side surface 681 (first surface) has an IC chip 682,
A wiring pattern 683 for connecting to the inkjet head body side is formed, and a wiring pattern 68 for connecting the IC chip 682 and the flexible wiring board 684 is formed.
5 are formed.

The wiring pattern 683 includes metal wirings 687 to 690 for the common electrode.
7, 688a formed at one end of 688,
688a is connected to the common electrode connection electrode 40 via an anisotropic conductive adhesive. Also, the wiring pattern 68
5 includes ground metal wires 691 and 692 connected to the IC chip 632 and ground metal wires 693 and 694 connected to the flexible wiring board 684.

The surface 695 on the opposite side of the wiring board 6E (second
On the whole), a ground wiring layer 696 is formed. A through hole is formed in the substrate body of the wiring board 6E, and the grounding metal wirings 691 through 696 on the IC chip mounting side are provided through the conductive paste 697 filled therein.
94 is connected to the ground wiring layer 696. on the other hand,
The common electrode metal wirings 687 to 690 are connected to the substrate main body via the insulating film cutout 698 of the substrate main body.

In the wiring board 6E of the present embodiment thus configured, the board body of the wiring board is used as a common electrode wiring portion, and the surface of the wiring board opposite to the IC chip mounting surface is used as a ground wiring portion. Is done.

(Other Embodiments) The above description is an example in which the present invention is applied to an electrostatic ink jet head. However, the present invention can be similarly applied to an electrostatic actuator other than the ink jet head. .

[0066]

As described above, in the electrostatic actuator and the electrostatic ink jet head of the present invention, the wiring is provided through the wiring substrate having the substrate body made of a conductive material.
Power is supplied to the first and second electrodes, which are opposing electrodes, and a wiring formed in a solid state on the substrate body of the wiring substrate or the surface of the wiring substrate as a power supply wiring portion for one of the electrodes. They use layers. Further, in the present invention, the substrate body of the wiring board or the wiring layer formed in a solid state on the surface of the wiring board is used as the ground wiring portion.

Therefore, according to the present invention, the resistance of the power supply signal line to the electrode can be reduced, and its signal characteristics can be stabilized. Therefore, the wiring pattern formed on the wiring board can be made excellent in noise resistance, and the high-speed switching operation of an element such as a driving IC for performing a switching energization operation between the electrodes can be stabilized. As a result, according to the present invention, it is possible to increase the wiring pattern density on the wiring board, which is extremely effective for increasing the number of nozzles in the electrostatic ink jet head with high density.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an electrostatic inkjet head to which the present invention is applied.

FIG. 2 is a cross-sectional view of a portion taken along line II-II in FIG.

FIG. 3 is a partial cross-sectional view of a portion cut along a line III-III in FIG. 1;

FIG. 4 is a perspective view of the wiring board of FIG. 1 as viewed from a wiring pattern forming side.

FIG. 5 is a sectional configuration diagram of the wiring board of FIG. 4;

FIG. 6 is a partial cross-sectional view and a partial plan view showing a second embodiment of the wiring board.

FIG. 7 is a partial sectional view and a partial plan view showing a third embodiment of the wiring board.

FIG. 8 is a partial cross-sectional view showing a fourth embodiment of the wiring board.

FIG. 9 is a view showing a fifth embodiment of the wiring board;
(A) is a partial plan view showing the surface on the side opposite to the IC chip mounting side, and (b) is a partial plan view showing the surface on the IC chip mounting side.

FIG. 10 is a view showing a sixth embodiment of the wiring board;
(A) is a partial plan view showing the surface on the side opposite to the IC chip mounting side, and (b) is a partial plan view showing the surface on the IC chip mounting side.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 electrostatic inkjet head 1A head chip 2 nozzle substrate 3 cavity substrate 4 electrode glass substrate 5 conductive adhesive 6, 6A, 6B, 6C, 6D, 6E wiring substrate 7 flexible wiring substrate 22 nozzle 34 projecting portion of cavity substrate 36 Exposed surface 37, 37A Common electrode terminal part 38 Through hole 40 Common electrode connection electrode 40A, 40B Conductive paste 42 Individual electrode 42A Individual electrode electrode terminal part 61 Substrate body 62 Surface of substrate body 63 IC chip 64 For electrode terminal Junction-side end 65 Wiring pattern 66 Metal wiring for common electrode bonding 66a Wiring bonding part 67 Metal wiring for individual electrode bonding 67a Wiring bonding part 61b, 61c, 61d Insulating film cutout part 701 Grounding metal wiring 610 IC chip mounting Surface opposite to side (second surface) 6 61, 662 Common electrode metal wiring 663, 664 Through hole 665, 666 Conductive paste 601 Common electrode wiring layer 620 Grounding wiring layer 621 Through hole 622 Conductive paste 711 Grounding metal wiring

Claims (12)

[Claims] A first substrate on which a first electrode is formed; and a second substrate on which a second electrode is formed to face the first electrode. The electrostatic force generated by applying a voltage between the electrodes of
An electrostatic actuator adapted to relatively displace the first and second substrates, wherein a first electrode terminal formed on the first electrode and a second electrode formed on the second electrode A terminal portion, and a wiring substrate electrically connected to at least one of the terminal portions by being overlapped with the terminal portion. The wiring substrate includes a substrate main body made of a conductive material; A wiring pattern formed on the surface of the main body via an insulating layer, and a wiring joint; wherein the wiring joint is a first joint connected to the first electrode terminal; A second joint connected to a second electrode terminal, wherein one of the joints is electrically connected to the substrate body. 2. The wiring board according to claim 1, wherein the substrate main body of the wiring substrate includes first and second surfaces, wherein the wiring pattern is formed on the first surface via an insulating layer, A wiring layer is formed on the surface of the device via an insulating layer, and the wiring layer is a grounding wiring portion. 3. A semiconductor device comprising: a first substrate on which a first electrode is formed; and a second substrate on which a second electrode is formed so as to face the first electrode. The electrostatic force generated by applying a voltage between the electrodes of
In an electrostatic actuator adapted to relatively displace the first and second substrates, a first electrode terminal portion formed on the first electrode and a second electrode formed on the second electrode A terminal portion, and a wiring substrate electrically connected to at least one of the terminal portions by being overlapped with the terminal portion. The wiring substrate includes a substrate main body made of a conductive material; A wiring pattern formed on the surface of the main body via an insulating layer, a first joint connected to the first electrode terminal, and a second joint connected to the second electrode terminal. Wherein the substrate body of the wiring substrate is a ground wiring portion. 4. The wiring board according to claim 3, wherein the substrate main body of the wiring substrate has first and second surfaces, wherein the first surface is provided with the wiring pattern via an insulating layer, A wiring layer is formed on the surface of the device via an insulating layer, and one of the first and second joints is electrically connected to the wiring layer. 5. A semiconductor device comprising: a first substrate on which a first electrode is formed; and a second substrate on which a second electrode is formed so as to face the first electrode. The electrostatic force generated by applying a voltage between the electrodes of
In an electrostatic actuator adapted to relatively displace the first and second substrates, a first electrode terminal portion formed on the first electrode and a second electrode formed on the second electrode A terminal portion, and a wiring substrate electrically connected to at least one of the terminal portions by being overlapped with the terminal portion. The wiring substrate includes a substrate main body made of a conductive material; A wiring pattern formed on the first surface of the main body via an insulating layer, a wiring layer formed on the second surface of the basic body via an insulating layer, and the first electrode terminal portion; A wiring joint including a first joint and a second joint connected to the second electrode terminal, wherein one of the first and second joints is electrically connected to the wiring layer. Electrostatic actuator characterized by being electrically connected Yueta. 6. A semiconductor device comprising: a first substrate on which a first electrode is formed; and a second substrate on which a second electrode is formed to face the first electrode. The electrostatic force generated by applying a voltage between the electrodes of
An electrostatic actuator adapted to relatively displace the first and second substrates, wherein a first electrode terminal formed on the first electrode and a second electrode formed on the second electrode A terminal portion, and a wiring substrate electrically connected to at least one of the terminal portions by being overlapped with the terminal portion. The wiring substrate includes a substrate main body made of a conductive material; A wiring pattern formed on the first surface of the main body via the insulating layer, a wiring layer formed on the second surface of the main body via the insulating layer, and the first electrode terminal portion; A wiring connection part including a first connection part and a second connection part connected to the second electrode terminal part, wherein the wiring layer is a ground wiring part. Actuator. 7. A first substrate in which an ink pressure chamber communicated with an ink nozzle is formed, and an individual electrode which is opposed to a diaphragm portion which defines a bottom surface of the ink pressure chamber and also functions as a common electrode. Having a second substrate formed,
In an electrostatic ink jet head configured to vibrate the vibrating plate portion by electrostatic force generated by applying a voltage between these common electrodes and individual electrodes to eject ink droplets from the ink nozzles, A common electrode terminal portion formed on the common electrode, an individual electrode terminal portion formed on the individual electrode, and a wiring board electrically connected to at least the individual electrode terminal portion by being overlapped with the individual electrode terminal portion; The wiring board, a substrate body made of a conductive material, a wiring pattern formed on the surface of the substrate body via an insulating layer, a common electrode joint portion connected to the common electrode terminal portion, and A wiring joint including an individual electrode joint connected to the individual electrode terminal, wherein the common electrode joint is electrically connected to the substrate body. Electrostatic inkjet head according to claim Rukoto. 8. The wiring board according to claim 7, wherein the substrate main body of the wiring substrate includes first and second surfaces, wherein the first surface is provided with the wiring pattern via an insulating layer, A wiring layer is formed on the surface of the substrate via an insulating layer, and the wiring layer is a ground wiring portion. 9. A first substrate in which an ink pressure chamber communicated with an ink nozzle is formed, and an individual electrode which is opposed to a diaphragm portion which defines a bottom surface of the ink pressure chamber and also functions as a common electrode. Having a second substrate formed,
In an electrostatic ink jet head configured to vibrate the vibrating plate portion by electrostatic force generated by applying a voltage between these common electrodes and individual electrodes to eject ink droplets from the ink nozzles, A common electrode terminal portion formed on the common electrode, an individual electrode terminal portion formed on the individual electrode, and a wiring board electrically connected to at least the individual electrode terminal portion by being overlapped with the individual electrode terminal portion; The wiring board, a substrate body made of a conductive material, a wiring pattern formed on the surface of the substrate body via an insulating layer, a common electrode joint portion connected to the common electrode terminal portion, and A wiring connection part including an individual electrode connection part connected to the individual electrode terminal part, wherein the substrate body is a ground wiring part. Type inkjet head. 10. The wiring board according to claim 9, wherein the substrate main body of the wiring substrate has first and second surfaces, wherein the wiring pattern is formed on the first surface with an insulating layer interposed therebetween. A wiring layer is formed on the surface of the substrate via an insulating layer, and the common electrode junction is electrically connected to the wiring layer. 11. A first substrate in which an ink pressure chamber communicated with an ink nozzle is formed, and an individual electrode which is opposed to a diaphragm portion which defines a bottom surface of the ink pressure chamber and also functions as a common electrode. A second substrate formed thereon, and ejecting ink droplets from the ink nozzles by vibrating the diaphragm portion by electrostatic force generated by applying a voltage between the common electrode and the individual electrodes. In the electrostatic inkjet head, the common electrode terminal formed on the common electrode, the individual electrode terminal formed on the individual electrode, and at least the individual electrode terminal are overlapped with each other. A wiring board electrically connected to the wiring board, wherein the wiring board has a substrate body made of a conductive material, and an insulating layer A wiring pattern formed through the insulating layer, a wiring layer formed on the second surface of the substrate main body via an insulating layer, a common electrode joint connected to the common electrode terminal, and the individual electrode terminal. A wiring joint including an individual electrode joint to be connected, wherein the common electrode joint is electrically connected to the wiring layer. 12. A first substrate in which an ink pressure chamber communicated with an ink nozzle is formed, and an individual electrode which is disposed to face a diaphragm portion which defines a bottom surface of the ink pressure chamber and also functions as a common electrode. A second substrate formed thereon, and ejecting ink droplets from the ink nozzles by vibrating the diaphragm portion by electrostatic force generated by applying a voltage between the common electrode and the individual electrodes. In the electrostatic inkjet head, the common electrode terminal formed on the common electrode, the individual electrode terminal formed on the individual electrode, and at least the individual electrode terminal are overlapped with each other. A wiring board electrically connected to the wiring board, wherein the wiring board has a substrate body made of a conductive material, and an insulating layer A wiring pattern formed through the insulating layer, a wiring layer formed on the second surface of the substrate main body via an insulating layer, a common electrode joint connected to the common electrode terminal, and the individual electrode terminal. A wiring connection part including an individual electrode connection part to be connected, wherein the wiring layer is a ground wiring part.