WO2012176874A1

WO2012176874A1 - Ink jet head and ink jet drawing device

Info

Publication number: WO2012176874A1
Application number: PCT/JP2012/065985
Authority: WO
Inventors: 坂井　繁一; 西　泰男; 康二郎吉田
Original assignee: コニカミノルタホールディングス株式会社
Priority date: 2011-06-22
Filing date: 2012-06-22
Publication date: 2012-12-27
Also published as: JPWO2012176874A1

Abstract

The purpose of the present invention is to provide: a highly-reliable ink jet head in which an adhesive force can be strengthened when a head substrate and a wiring board are joined via an adhesive resin layer; and an ink jet drawing device. The ink jet head is provided with: a plurality of pressure chambers that contain ink to be discharged from a nozzle; the head substrate, which has a plurality of actuators that apply pressure to the ink inside the pressure chambers; and the wiring board, which has wiring terminals that are electrically connected to individual electrodes provided to the plurality of actuators, and to a common electrode that is commonly provided to the plurality of actuators. By joining the wiring board from above the head substrate via the adhesive resin layer, the common electrode and the individual electrodes on the top surface of the head substrate are electrically connected to the wiring terminals of the wiring board. The common electrode is laminated on the top surface of the head substrate, but is not formed on at least an area where the adhesive resin layer is bonded, and the adhesive resin layer is bonded to the top surface of the head substrate without the common electrode therebetween.

Description

Ink jet head and ink jet drawing apparatus

The present invention relates to an ink jet head and an ink jet drawing apparatus, and more particularly, to an ink jet head with improved reliability of electrical connection of wiring for power supply to an actuator and an ink jet drawing apparatus equipped with the ink jet head.

In recent years, inkjet heads that form images on various recording media by ejecting ink from a plurality of fine nozzles have been required to have a higher density of nozzles in order to achieve more accurate and finer image formation. It has been.

The ink jet head is provided with a common ink flow path for each nozzle row, and also includes a pressure chamber for applying discharge pressure to the ink, and an individual flow path for supplying ink from the common flow path to each pressure chamber. These are provided individually for a plurality of nozzles. Therefore, if these common flow paths, pressure chambers, and individual flow paths are arranged side by side in the nozzle arrangement direction (horizontal direction), it becomes difficult to arrange a plurality of nozzles at high density.

Therefore, conventionally, by providing a pressure chamber above the nozzle and providing a common ink chamber in place of the common flow path further above the pressure chamber, it is possible to suppress the spread in the nozzle arrangement direction and enable high-density arrangement of the nozzles. An ink jet head has been proposed (Patent Document 1). This ink-jet head forms a head plate that forms the main body of the ink-jet head by laminating an actuator formed of piezoelectric elements on the upper surface of the vibration plate by forming the upper wall of the pressure chamber into a thin plate shape. is doing.

For this head substrate, it is necessary to form each wiring for supplying power to the actuator with high density, but on the upper surface of the head substrate, there is a flow for supplying ink to each pressure chamber in addition to the actuator itself. Since the road is open, there is not enough room for routing the wiring. Therefore, in Patent Document 1, a wiring board provided with wiring for supplying power to each actuator is separately formed, and this is bonded to the head board from above the actuator via an adhesive resin layer. The wiring is densified by having a structure in which each electrode on the side and each wiring on the wiring board side are electrically connected.

JP 2006-264322 A

The ink jet head configured in this way enables high-definition image formation with a high-density nozzle. However, according to experiments conducted by the present inventors, ink leakage and pressure chamber pressure leakage are caused by long-term use. I found that there was a problem that occurred. When the cause was examined, it was found that peeling was observed at the bonding portion between the head substrate and the adhesive resin layer, and ink leakage or pressure chamber pressure leakage occurred at the peeling portion.

That is, the actuator has a shape in which a piezoelectric element is sandwiched between an individual electrode provided individually for each actuator and a common electrode provided in common to a plurality of actuators. It is laminated on the upper surface of the substrate. The adhesive resin layer functions to bond the two substrates between the head substrate and the wiring substrate. However, since the common electrode is exposed on the surface other than the actuator part, this common layer is used for the head substrate. Bonded to the upper surface of the electrode.

However, the adhesive resin layer cannot obtain adhesion due to hydrogen bonding to the metal film and has low adhesion. Moreover, the ink jet head is affected by heat due to heat generated during driving, and depending on the ink used, the ink may be intentionally heated using a heater or the like for the purpose of reducing the viscosity. When this heat is repeatedly applied to the inkjet head, the substrate repeatedly expands and contracts. This causes stress concentration between the adhesive resin layer with weak adhesive strength and the common electrode exposed on the top surface of the head substrate, causing delamination. It is thought that.

Patent Document 1 has a structure in which an insulating film made of a silicon oxide film and a resin layer are sequentially laminated on the upper surface of the common electrode on the head substrate side, and an adhesive resin layer is adhered on the resin layer. Further laminating the resin layer increases the man-hours and increases the cost. Therefore, there has been a demand for a structure of an ink jet head capable of strengthening the adhesive force between the head substrate and the wiring substrate with a simpler structure.

Therefore, the present invention can strengthen the adhesive force when bonding the head substrate and the wiring substrate through the adhesive resin layer without increasing the number of stacked layers, and a highly reliable inkjet head and the same. It is an object to provide a mounted inkjet drawing apparatus.

Other problems of the present invention will become apparent from the following description.

The above problems are solved by the following inventions.

1. A plurality of pressure chambers disposed corresponding to each of the plurality of nozzles that eject ink, and disposed corresponding to each of the pressure chambers, each accommodating a plurality of pressure chambers for ejecting ink from the nozzles. A head substrate having a plurality of actuators for applying pressure for discharging from the nozzle;
A wiring board having wiring terminals for electrically connecting to the individual electrodes respectively provided in the plurality of actuators and the common electrode provided in common to the plurality of actuators;
The wiring substrate is bonded from above the head substrate via an adhesive resin layer, whereby the individual electrode and the common electrode of the actuator and the wiring terminal of the wiring substrate disposed on the upper surface of the head substrate. Is an electrically connected inkjet head,
The common electrode is laminated on the upper surface of the head substrate and is not formed at least in a region to which the adhesive resin layer is bonded, and the adhesive resin layer does not pass through the common electrode. An ink jet head which is adhered to the upper surface of the ink jet head.

2. 2. The ink-jet head as described in 1 above, wherein an ink flow path for supplying ink to the pressure chamber of the head substrate is formed through the adhesive resin layer.

3. 3. The inkjet head according to 2 above, wherein the region where the common electrode is not formed is independent for each of the ink flow paths.

4). 4. The ink jet head according to the above 1, 2, or 3, wherein at least a region of the upper surface of the head substrate to which the adhesive resin layer is bonded is a non-metallic material.

5). 5. The inkjet head as described in 4 above, wherein the non-metallic material on the upper surface of the head substrate is synthetic resin or silicon oxide.

6). The ink jet head according to any one of 1 to 5, wherein the common electrode is made of a metal film of Au or Pt.

7). An ink jet drawing apparatus comprising the ink jet head according to any one of 1 to 6 above.

According to the present invention, it is possible to strengthen the adhesive force when bonding the head substrate and the wiring substrate through the adhesive resin layer without increasing the number of stacked layers, and to provide a highly reliable inkjet head and the same. A mounted inkjet drawing apparatus can be provided.

Sectional drawing of the inkjet head which concerns on this invention Partial enlarged sectional view of the inkjet head shown in FIG. Top view of the head substrate Plan view showing aspects of head substrate Schematic perspective view showing an example of an ink jet drawing apparatus according to the present invention Diagram explaining the adhesive strength test

The ink jet head of the present invention has a laminate structure in which a head substrate and a wiring substrate are bonded via an adhesive resin layer. The head substrate is disposed corresponding to each of a plurality of nozzles that eject ink, and is disposed corresponding to each of a plurality of pressure chambers that store ink to be ejected from the nozzles, and the pressure chambers. And an actuator for applying a pressure for ejecting the ink from the nozzles.

Actuators are provided for each pressure chamber outside the upper wall of the pressure chamber located on the upper surface of the head substrate. The actuator body is composed of piezoelectric elements such as PZT. An electrode is provided, and a common electrode provided in common to all of the plurality of actuators is provided on the lower surface side in contact with the head substrate. The actuator deforms the actuator body when a predetermined drive signal is applied between these electrodes, and vibrates the diaphragm that forms the upper wall of the pressure chamber, thereby applying pressure for ejection to the ink in the pressure chamber. Give.

In the present invention, the vertical direction is based on the direction along the direction of ink ejection from the nozzles. Accordingly, the upper or upper surface in the present invention refers to a surface oriented in the direction opposite to or opposite to the ink ejection direction, and the lower or lower surface refers to a surface oriented in the ink ejection direction or ink ejection direction. .

The wiring board has wiring terminals for electrically connecting the individual electrodes exposed on the upper surface of the actuator and the common electrode exposed on the upper surface of the head substrate other than the actuator forming region. The head substrate and the wiring substrate are bonded to each other by being laminated on the head substrate from above the actuator via the adhesive resin layer and press-bonded at a predetermined heating temperature. Simultaneously with this joining, the individual electrodes and common electrodes on the head substrate side and the wiring terminals on the wiring substrate side are electrically connected to each other.

The adhesive resin layer is provided between the head substrate and the wiring substrate, and adheres between both substrates. In order not to interfere with the actuator provided on the head substrate, the adhesive resin layer is patterned so as to remove at least the actuator formation region and the periphery thereof, and an actuator accommodating space is secured between the two substrates. This adhesive resin layer has a predetermined elastic modulus (0.1 to 2.5 GPa) before bonding, and is cured by being heated to a predetermined curing temperature (for example, 200 ° C.) during bonding. It is a thermosetting adhesive resin layer that exhibits

A photosensitive adhesive resin sheet can be preferably used for such an adhesive resin layer. In the photosensitive adhesive resin sheet, an unnecessary portion that becomes an accommodation space for the actuator can be easily removed by exposure and development processing, and a layer having a desired pattern can be easily formed. As a specific adhesive resin layer, for example, Toray Co., Ltd. photosensitive polyimide adhesive sheet, DuPont PerMX series (trade name) or the like can be used.

The common electrode is laminated on the upper surface of the head substrate and is not formed at least in the region where the adhesive resin layer is bonded. For this reason, the adhesive resin layer is bonded to the upper surface of the head substrate without using a common electrode on the upper surface of the head substrate.

Thereby, since the adhesive resin layer does not adhere to the metal film constituting the common electrode having a weak adhesive force, the adhesive force can be strengthened and a highly reliable inkjet head can be obtained. In the present invention, it is not necessary to further laminate a separate layer on the common electrode of the head substrate for adhesion of the adhesive resin layer, so that the man-hour is not increased.

Ink is supplied to the pressure chambers of the head substrate from above the wiring substrate. Ink flow paths for supplying ink to the pressure chambers of the head substrate through the wiring substrate are preferably formed through the adhesive resin layer. In the present invention, since the adhesive resin layer and the head substrate are firmly bonded, there is no possibility that ink leakage will occur in the ink flow path even after long-term use.

The region where the common electrode is not formed on the upper surface of the head substrate is preferably independent for each ink flow path. Since the area of the common electrode can be made as wide as possible, the electrical resistance of the common electrode that is common to a plurality of actuators can be suppressed.

In order to be able to firmly bond the upper surface of the head substrate and the adhesive resin layer, it is preferable that at least the region of the upper surface of the head substrate to which the adhesive resin layer is bonded is a non-metallic material, More preferably, it is silicon oxide. Such a synthetic resin or silicon oxide can constitute a vibration plate serving as an upper wall of the pressure chamber. As the synthetic resin, for example, a polyimide resin or an epoxy resin can be used.

The common electrode can be formed of a metal film that can be generally used as an electrode, but is preferably made of a metal film of Au (gold) or Pt (platinum), particularly in terms of reducing electric resistance.

The ink jet drawing apparatus of the present invention is equipped with such an ink jet head. Thereby, it can be set as the inkjet drawing apparatus which can form a high quality image over a long period of time with the inkjet head with high reliability of adhesion | attachment between a head board | substrate and a wiring board.

Hereinafter, specific examples of the present invention will be further described with reference to the drawings.

FIG. 1 is a sectional view of an ink jet head according to the present invention, FIG. 2 is a partially enlarged sectional view thereof, and FIG. 3 is a plan view of a head substrate.

In the inkjet head 1, a head substrate 10 and a wiring substrate 20 are laminated and integrated by an adhesive resin layer 30. A box-shaped manifold 40 is provided on the upper surface of the wiring board 20, and a common ink chamber 41 in which ink is stored is formed between the wiring board 20 and the wiring board 20.

The head substrate 10 includes, from the lower side in the figure, a nozzle plate 11 formed of a Si (silicon) substrate, an intermediate plate 12 formed of a glass substrate, a pressure chamber plate 13 formed of a Si (silicon) substrate, and SiO _2. And a diaphragm 14 formed of a film (silicon oxide film). In the nozzle plate 11, a nozzle 11a is opened toward the lower surface.

In the pressure chamber plate 13, pressure chambers 13 a for storing ink for ejection are arranged in a two-dimensional manner, the upper wall is constituted by the vibration plate 14, and the lower wall is constituted by the intermediate plate 12. Yes. The intermediate plate 12 is formed with a communication passage 12a through which the inside of the pressure chamber 13a communicates with the nozzle 11a.

The actuator 15 is formed by sandwiching an actuator body 15a made of a thin film PZT between an individual electrode 15b having a uniform thickness on the upper surface and a common electrode 15c having a uniform thickness on the lower surface. The common electrode 15c is formed on the surface of the diaphragm 14 in common to all the actuators 15. On the common electrode 15c, the actuator main body 15a and the upper surface of the actuator main body 15a are individually provided so as to correspond to the pressure chamber 13a. The individual electrodes 15b are stacked.

On the individual electrodes 15b, gold stud bumps 16 as connection parts are formed so as to project toward the wiring board 20. Similarly, a gold stud bump 17 as a connection component is formed on the common electrode 15 c so as to protrude toward the wiring board 20.

The upper surface of the individual electrode 15b on which the gold stud bump 16 is formed is located higher than the upper surface of the common electrode 15c on which the gold stud bump 17 is formed because the actuator 15 is formed to protrude on the head substrate 10. . Therefore, unlike the gold stat bump 16, the height shape of the gold stud bump 17 is formed so as to be higher than the height shape of the gold stud bump 16 by the height of the actuator 15. In order to make the height shapes of the gold stud bumps 16 and 17 different in this way, the size of the gold ball when the bumps are formed from the thin gold wires may be changed according to the desired height shape.

Wiring board 20, the upper surface of the substrate body 21 made of Si substrate, via the wiring protective layer 22 made of SiO _2, and an upper wiring 23b of the common electrode 15c and the upper wiring 23a for the individual electrodes 15b are formed . An FPC (flexible printed circuit board) 28 on which the driving IC 27 is mounted is electrically connected to the upper wirings 23 a and 23 b at the end of the wiring board 20 by an ACF (anisotropic conductive film).

A part of the upper wiring 23 a for the individual electrode 15 b faces the lower surface of the substrate body 21 through a through hole 21 a formed in the substrate body 21, and a wiring protective layer 24 made of SiO ₂ is provided on the lower surface of the substrate body 21. The lower wiring 25a formed therethrough is electrically connected. A part of the lower wiring 25a is exposed on the wiring protection layer 24 facing the actuator 15, and the exposed lower wiring 25a has solder bumps 26a as wiring terminals for electrical connection with the individual electrodes 15b. A protrusion is formed toward the head substrate 10 at a position corresponding to the gold stat bump 16.

A part of the upper wiring 23b for the common electrode 15c faces the lower surface of the substrate body 21 through a through hole 21b formed in the substrate body 21, and a wiring protective layer made of SiO ₂ is formed on the lower surface of the substrate body 21. 24 is electrically connected to the lower wiring 25b formed through the wiring 24. A part of the lower wiring 25b is exposed on the wiring protective layer 24 facing the actuator 15, and a solder bump 26b as a wiring terminal for electrical connection with the common electrode 15c is exposed on the exposed lower wiring 25b. A protrusion corresponding to the gold stat bump 17 is formed toward the head substrate 10.

Each of the solder bumps 26a and 26b is formed by screen printing with Sn-Bi eutectic solder here, and is hemispherical at the same height from the surface of the

lower wiring

25a and 25b toward the head substrate 10, respectively. As a result, the front end surface (lower end surface) has a spherical shape.

The head substrate 10 and the wiring substrate 20 are separately manufactured, and then the upper surface of the head substrate 10 and the lower surface of the wiring substrate 20 face each other and are laminated and integrated through the adhesive resin layer 30. Further, after the upper surface of the pressure chamber plate 13 and the lower surface of the wiring substrate 20 face each other and are laminated and integrated through the adhesive resin layer 30, the intermediate plate 12 and the nozzle plate 11 may be laminated and integrated in this order. After the intermediate plate 12 is laminated and integrated with the pressure chamber plate 13, the upper surface of the pressure chamber plate 13 and the lower surface of the wiring substrate 20 face each other, and are laminated and integrated via the adhesive resin layer 30. Lamination and integration may be performed.

The adhesive resin layer 30 is a thermosetting photosensitive adhesive resin sheet, and a wiring protective layer of the wiring board 20 is provided between the head substrate 10 and the wiring board 20 so as to provide an interval corresponding to the thickness of the adhesive resin layer 30. It is affixed beforehand on the surface (lower surface) of 24. The surface of the wiring substrate 20 to which the adhesive resin layer 30 is attached is formed of a non-metallic material as with the head substrate 10. As a result, the adhesive resin layer 30 and the wiring board 20 are firmly bonded. Here, the surface of the wiring board 20 is the wiring protective layer 24 made of SiO ₂ , but it may be formed of a synthetic resin in the same manner as the head board 10.

The head substrate 10 and the wiring substrate 20 are arranged such that the wiring substrate 20 with the adhesive resin layer 30 is oriented with the bonding surface of the adhesive resin layer 30 facing the head substrate 10 and each of the solder bumps 26a and 26b. After aligning the corresponding gold stud bumps 16 and 17 so as to be electrically connected and laminating the adhesive resin layer 30 on the head substrate 10, it is heated to a predetermined curing temperature and pressed. Is bonded through the adhesive resin layer 30.

The adhesive resin layer 30 is removed by exposure and development so that it does not interfere with the actuator 15 after being attached to the wiring board 20 and before being laminated with the head substrate 10 so as not to interfere with the actuator 15. As a result, a housing space 31 for the actuator 15 (actuator body 15a and individual electrode 15b) is formed between the head substrate 10 and the wiring substrate 20. At the same time, the area around the gold stud bump 17 is also removed by exposure and development in the accommodation space 31 to accommodate the gold stud bump 17.

In the adhesive resin layer 30, an ink channel 32 penetrating in the vertical direction is similarly formed by exposure and development, and one end (upper end) thereof communicates with an ink supply channel 29 formed on the wiring substrate 20. The other end (lower end) communicates with the inside of the pressure chamber 13 a through an opening 14 a formed in the vibration plate 14 of the head substrate 10. The ink supply path 29 is opened on the upper surface of the wiring board 20, and the ink in the common ink chamber 41 can be introduced from the opening 29 a and supplied into the pressure chamber 13 a through the ink flow path 32.

The ink supplied into the pressure chamber 13a is deformed by the drive signal supplied from the drive IC 27, and the vibration plate 14 vibrates, so that pressure for ejection is applied, and the nozzle passes through the communication path 12a. The liquid droplets are ejected from 11a.

A common electrode 15c serving as a lower electrode common to the actuators 15 is laminated on the upper surface of the head substrate 10 (the upper surface of the vibration plate 14), and is exposed on the upper surface of the head substrate 10. FIG. As shown in FIG. 4, the common electrode 15c is not formed in the surrounding area including the opening 14a of the vibration plate 14 corresponding to the ink flow path 32 formed through the adhesive resin layer 30. Is provided with a non-metal film region 10a where the common electrode 15c is not formed.

This non-metal film region 10a is formed by laminating and forming a metal film to be the common electrode 15c on the entire surface of the vibration plate 14 of the head substrate 10, and then masking the parts other than the part to be the non-metal film region 10a. When the metal film existing in the film region 10a is removed by etching, or when the metal film to be the common electrode 15c is formed, the part of the non-metal film region 10a is masked and the electrode forming metal is sputtered. Patterning can be performed by applying by vapor deposition or plating.

As a result, the diaphragm 14 is exposed in the non-metal film region 10a. Therefore, the adhesive resin layer 30 is directly bonded to the upper surface of the diaphragm 14. Since the vibration plate 14 is made of a non-metallic material SiO ₂ film, the vibration plate 14 is superior in adhesive strength to the adhesive resin layer 30 compared to the common electrode 15c, and firmly bonds the head substrate 10 and the wiring substrate 20 together. In particular, since the ink flow path 32 is formed in the adhesive resin layer 30 bonded to the non-metal film region 10a so as to communicate with the opening 14a, the adhesive resin layer 30 and the head substrate 10 are firmly bonded. As a result, there is no possibility that ink leakage from the ink flow path 32 will occur even after long-term use or repeated heating.

As shown in FIG. 3, a non-metal film region 10b where the common electrode 15c is not formed is formed so as to surround the periphery of the upper surface of the head substrate 10. The adhesive resin layer 30 is directly bonded to the upper surface of the head substrate 10 also in the non-metal film region 10b.

FIG. 3 shows a mode in which the non-metal film region 10a where the common electrode 15c is not formed is formed to have a size including a plurality of openings 14a of the diaphragm 14 communicating with the ink flow path 32 of the adhesive resin layer 30. 4 shows an aspect in which the non-metal film region 10a in which the common electrode 15c is not formed is formed independently for each ink flow path 32 formed in the adhesive resin layer 30, that is, for each opening 14a of the vibration plate 14.

In this embodiment, the non-metal film region 10 a on the upper surface of the head substrate 10 is individually formed so as to surround each opening 14 a of the vibration plate 14 communicating with the ink flow path 32 of the adhesive resin layer 30. The adhesive resin layer 30 is directly bonded to the vibration plate 14 on the upper surface of the head substrate 10 only in the non-metal film region 10 a and the non-metal film region 10 b around the head substrate 10. For this reason, compared with the aspect shown in FIG. 3, the area of the common electrode 15c can be increased, and the electrical resistance of the common electrode 15c can be reduced accordingly.

FIG. 5 is a schematic perspective view showing an example of an ink jet drawing apparatus equipped with the ink jet head 1.

An ink jet drawing apparatus 100 rotates on an apparatus base 101 an ink jet head 1 for performing ink jet drawing, a stage 102 for placing and supporting a substrate W on an upper surface, and a stage 102 to rotate in the θ direction. The θ rotation mechanism 103, the stage 102, and the θ rotation mechanism 103 are both linearly moved along the Y direction, and the Y movement mechanism 104, and both the stage 102 and the θ rotation mechanism 103 are linearly moved along the X direction. Each has.

Note that the X direction and the Y direction are directions orthogonal to each other on a horizontal plane.

The ink jet head 1 is attached to a gantry 106 laid in parallel along the X direction in the vicinity of the end portion on the apparatus base 101 through a slider 107 and a θ rotation mechanism 108 so that the nozzle surface is a lower surface. It is arranged so as to face the surface of the recording material W on the stage 102 arranged below it in parallel. The inkjet head 1 reciprocates along the X direction as the slider 107 slides along the gantry 106, and is moved in the Z direction, which is a normal direction perpendicular to the X and Y directions, by the θ rotation mechanism 108. The direction of rotation is rotationally moved in the θ direction, and the Z moving mechanism 109 can be moved up and down in the Z direction together with the θ rotating mechanism 108.

The stage 102 is a surface plate having a rectangular shape in plan view provided on the X moving mechanism 105 extending along the X direction via the θ rotation mechanism 103, and the upper surface thereof is for placing the recording material W thereon. It is set as a horizontal mounting surface, and this mounting surface is arrange | positioned so that it may become a predetermined height position with respect to the nozzle surface of the inkjet head 1. FIG. The stage 102 moves linearly along the X direction by sliding along the X moving mechanism 105 together with the θ rotation mechanism 103, and the X moving mechanism 105 is moved to the Y moving mechanism 104 extending along the Y direction. By moving along the Y direction together with the θ rotation mechanism 103 by sliding along the Y direction, the direction along the Z direction while maintaining parallel to the nozzle surface of the inkjet head 1 by the θ rotation mechanism 103 is further achieved. The axis can be rotated in the θ direction.

The ink jet drawing apparatus 100 moves the ink jet head 1 and the stage 102 relatively, and controls the ejection of liquid droplets from the ink jet head 1 based on predetermined ejection pattern data according to each position information at that time. The desired drawing is performed by landing on the surface of the recording material W on the stage 102.

(Comparative example)
A pressure chamber plate prepared from a Si substrate having a thickness of 150 μm on which a diaphragm made of a SiO ₂ film (silicon oxide film) having a thickness of 2 μm is stacked is prepared. An Au metal film having a thickness of 200 nm was deposited as a common electrode on the diaphragm by vapor deposition, and then PZT was further patterned by sputtering at a predetermined location as an actuator with a thickness of 2 μm. An intermediate plate formed of a glass substrate and a nozzle plate formed of a Si (silicon) substrate are bonded in this order to the pressure chamber plate to produce a head substrate, and the vibration side of the head substrate and the wiring substrate are heated. After bonding so that the adhesive resin layer was bonded to the Au metal film, which is a common electrode, by pressure bonding, a head was manufactured by attaching a manifold to the wiring board. This is a comparative example.

Example 1
Similarly, a pressure chamber plate made of a 150 μm thick Si substrate on which a diaphragm made of a SiO ₂ film (silicon oxide film) having a thickness of 2 μm is laminated is prepared. After applying resist on the vibration plate, mask exposure, and development, an Au metal film of 200 nm is deposited and deposited as a common electrode by vapor deposition, and after the resist is peeled off, patterning is performed in substantially the same shape as the patterning shape of the adhesive resin layer. A common electrode in which the non-metal film region formed was formed was formed. Thereafter, PZT was patterned as an actuator with a thickness of 2 μm at a predetermined location by sputtering. An intermediate plate formed of a glass substrate and a nozzle plate formed of a Si (silicon) substrate are bonded in this order to the pressure chamber plate to produce a head substrate, and the vibration side of the head substrate and the wiring substrate are heated. Bonding was performed by pressure bonding so that the adhesive resin layer was bonded to the non-metal region, and then a manifold (common ink chamber) was attached to the wiring board to produce a head. This head is referred to as Example 1.

(Adhesive strength test example)
As shown in FIG. 6, air with a pressure of 100 kPa is supplied from the outside to the manifold (common ink chamber) of the head manufactured here, and the head is immersed in a solvent (isopropyl alcohol), and there is no air leakage. I confirmed. As a result, in Example 1 in which the adhesive resin layer was bonded to the non-metal region, there was no air leakage except for the air discharged from the nozzle provided on the nozzle plate, whereas the resin adhesive layer was made of the Au metal film. In the bonded comparative example, it was confirmed that air leakage occurred between the head substrate and the wiring substrate.

That is, in the head obtained by the present invention, it was confirmed that the wiring substrate and the head substrate were firmly bonded by the adhesive resin layer.

1: Inkjet head 10:

Head substrate

10a, 10b: Non-metal film region 11: Nozzle plate 11a: Nozzle 12: Intermediate plate 12a: Communication path 13: Pressure chamber plate 13a: Pressure chamber 14: Vibration plate 14a: Opening 15: Actuator 15a: Actuator body 15b: Individual electrode 15c: Common electrode 16, 17: Gold stud bump 20: Wiring board 21:

Board body

21a, 21b: Through hole 22: Wiring protection layer 23a, 23b: Upper wiring 24:

Wiring protection layer

25a, 25b:

Lower wiring

26a, 26b: Solder bump 27: Drive IC
28: FPC
DESCRIPTION OF SYMBOLS 29: Ink supply path 29a: Opening part 30: Adhesive resin layer 31: Accommodating space 32: Ink flow path 40: Manifold 41: Common ink chamber 100: Inkjet drawing apparatus 101: Apparatus base 102: Stage 103: θ rotation mechanism 104 : Y moving mechanism 105: X moving mechanism 106: Gantry 107: Slider 108: θ rotating mechanism 109: Z moving mechanism W: Recording material

Claims

A plurality of pressure chambers disposed corresponding to each of the plurality of nozzles that eject ink, and disposed corresponding to each of the pressure chambers, each accommodating a plurality of pressure chambers for ejecting ink from the nozzles. A head substrate having a plurality of actuators for applying pressure for discharging from the nozzle;
A wiring board having wiring terminals for electrically connecting to the individual electrodes respectively provided in the plurality of actuators and the common electrode provided in common to the plurality of actuators;
The wiring substrate is bonded from above the head substrate via an adhesive resin layer, whereby the individual electrode and the common electrode of the actuator and the wiring terminal of the wiring substrate disposed on the upper surface of the head substrate. Is an electrically connected inkjet head,
The common electrode is laminated on the upper surface of the head substrate and is not formed at least in a region to which the adhesive resin layer is bonded, and the adhesive resin layer does not pass through the common electrode. An ink jet head which is adhered to the upper surface of the ink jet head.
2. An ink jet head according to claim 1, wherein an ink flow path for supplying ink to each of the pressure chambers of the head substrate is formed through the adhesive resin layer.
3. The ink jet head according to claim 2, wherein the region where the common electrode is not formed is independent for each ink flow path.
The inkjet head according to claim 1, 2 or 3, wherein at least a region of the upper surface of the head substrate to which the adhesive resin layer is bonded is a non-metallic material.
The inkjet head according to claim 4, wherein the non-metallic material on the upper surface of the head substrate is a synthetic resin or silicon oxide.
The ink jet head according to any one of claims 1 to 5, wherein the common electrode is made of a metal film of Au or Pt.
An ink-jet drawing apparatus comprising the ink-jet head according to any one of claims 1 to 6.