JP2007050598A - Electrostatic actuator, droplet discharging head, and droplet discharging device equipped with the droplet discharging head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic actuator which prevents short-circuiting by an anisotropy electric conduction adhesive from occurring while miniaturizing the electrostatic actuator by realizing the densification of an electrode mounting section, and to provide an IC package structure, a droplet discharging head, its manufacturing method, and a droplet discharging device equipped with the droplet discharging head. <P>SOLUTION: This electrostatic actuator is equipped with a cavity board having a plurality of vibration plates, individual electrodes which respectively face the vibration plates, and an electrode board on which an electrode mounting section for setting a driver IC which feeds driving signals to the individual electrodes, and lead wiring for connecting the individual electrodes and the electrode mounting section are formed. The electrostatic actuator makes the vibration plates driven by an electrostatic force generated by the application of a voltage to the individual electrodes. The electrode mounting section is constituted of a plurality of mounting sections to be connected with each output terminal of the driver IC which is set in the electrode mounting section. The mounting section is constituted of four rows having two rows on one side. The mounting sections of two rows on one side is made a set, and each set is arranged at symmetrical positions. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrostatic actuator, a droplet discharge head, and a droplet discharge apparatus provided with the droplet discharge head, and more particularly to a small electrostatic discharge having a high nozzle density and having a long and many nozzle rows. The present invention relates to an actuator, a droplet discharge head, and a droplet discharge apparatus including the droplet discharge head.

  Conventionally, “a substrate on which an electrothermal conversion element (actuator) and an ink flow path and an ink discharge port are formed and a protruding electrode (output side electrode) of an output of a control IC chip are mounted on one surface by fiss down. An inkjet head (droplet ejecting head) having a structure in which the input side of an IC chip is connected to an external extraction electrode of a flexible printed circuit board is disclosed (for example, see Patent Document 1).

  This ink-jet head is formed so that bumps (mounting portions) as output electrodes and bumps as input-side protruding electrodes (input electrodes) are formed on an IC chip so as to face the electrodes on the substrate. ing. The number of output side electrodes of the IC chip and the number of actuators are usually the same. Further, a resin layer (anisotropic conductive adhesive) is provided between the IC chip and the substrate, and each bump is connected to the substrate electrode.

Japanese Patent Laying-Open No. 2002-210969 (FIG. 7)

  In the above-described ink jet head configuration, since the number of output side electrodes of the IC chip and the number of actuators are the same, the mounting density of the output side electrodes of the element control IC is inevitably increased as the nozzle density increases. Must be converted. Further, each individual electrode is formed in a position parallel to the corresponding nozzle. Therefore, in order to correspond to the nozzle, the element control IC must be enlarged (lengthened). However, enlarging the element control IC has a problem of increasing the manufacturing cost.

  Further, the element control IC is electrically connected by an anisotropic conductive adhesive. In order to enable electrical connection, a predetermined electrode is applied to the output side electrode of the element control IC. Mounting area is required. However, if a mounting area is to be ensured, there is a problem that it is difficult to realize a high mounting density in the output side electrode of the element control IC. In other words, in the ink jet head as described above, it is difficult to ensure both mounting area and high mounting density. In particular, in the structure in which the mounting portions (bumps) of the output side electrodes of the element control IC are arranged in a row, it is more difficult to increase the density of the mounting portions.

  Further, in a long inkjet head having an increased number of nozzles per row, there is a problem that a plurality of element control ICs must be mounted. Although it is possible to form the actuator side with a single member or material, as described above, it is generally difficult to lengthen the element control IC, which also increases the cost. Because. When a plurality of element control ICs are mounted, a predetermined gap must be provided between the element control ICs in consideration of the protrusion of the anisotropic conductive adhesive. For this reason, the wiring lead existing between the actuator and the element control IC cannot be simply wired in a straight line. In general, the wiring lead must be laid out so as to reduce the wiring resistance while preventing a short circuit due to the anisotropic conductive adhesive.

  The present invention relates to an electrostatic actuator, a droplet discharge head, and a liquid equipped with the droplet discharge head, which prevents a short circuit due to an anisotropic conductive adhesive while achieving a high density of the electrode mounting portion and reducing the size. An object is to provide a droplet discharge device.

  An electrostatic actuator according to the present invention includes a cavity substrate having a plurality of diaphragms, an individual electrode facing each of the diaphragms, an electrode mounting portion for installing a driver IC that supplies a drive signal to the individual electrodes, and an individual electrode And an electrode substrate on which lead wiring for connecting the electrode mounting portion is formed, and an electrostatic actuator that applies a voltage to the individual electrode and drives the diaphragm by the electrostatic force generated thereby. Is characterized in that a plurality of rows of mounting portions are provided on each side with respect to a terminal group provided on both sides of a driver IC installed in the electrode mounting portion.

  The electrode mounting portion formed on the electrode substrate includes a plurality of mounting portions on each side so as to correspond to the terminal groups provided on both sides of the driver IC mounted on the electrode substrate. The range of IC size and type can be expanded. That is, the electrode mounting portion is configured by mounting portions corresponding to the number of output terminals and the number of columns of the driver ICs to be mounted, and thus the driver IC to be mounted is not limited to a fixed shape. In other words, since the driver IC to be mounted can be reduced in size, the electrostatic actuator can also be reduced in size.

  The electrostatic actuator according to the present invention is characterized in that a plurality of rows have a four-row configuration with two rows on one side, and each row is arranged in a symmetrical position with the two rows on one side as one set. According to this, the mounting density of the electrode mounting portion for mounting the driver IC can be halved. That is, the nozzle density can be increased. Therefore, it is possible to secure a sufficient mounting area for enabling electrical connection between the driver IC and the electrode mounting portion that are mounted by the anisotropic conductive adhesive.

  The electrostatic actuator according to the present invention is characterized in that two adjacent rows of mounting portions on one side are formed horizontally, and the horizontally formed mounting portions are arranged so as to be parallel to the column direction. Thereby, the surplus anisotropic conductive adhesive when the driver IC is mounted is efficiently pushed out of the driver IC from the electrode mounting portion. Therefore, there is no mounting floating of the driver IC, the driver IC can be securely fixed, and a highly reliable electrostatic actuator can be provided.

  The electrostatic actuator according to the present invention is characterized in that a part of the lead wiring is formed as an oblique wiring so as to be inclined in a plane. This facilitates pitch conversion between each pressure chamber (actuator) in which the electrode mounting portion and the individual electrodes are formed. Therefore, the electrostatic actuator can be miniaturized. That is, it is not necessary to form each mounting part constituting the electrode mounting part in a position parallel to each corresponding vibration chamber, and the size of the driver IC to be mounted can be easily changed. In addition, the electrode mounting part and the individual electrodes are formed on the same plane (on the electrode substrate), and it is easy to route the electrodes of the individual electrodes by the wiring leads. Further, the wiring of the electrodes is facilitated by the oblique wiring. Can be simplified.

  The electrostatic actuator according to the present invention is characterized in that oblique wiring is formed in a groove provided in an electrode substrate, and the electrode substrate and the cavity substrate are joined. As a result, the anisotropic conductive adhesive does not protrude from the diagonal wiring portion. That is, since the gap amount between the electrode substrate and the cavity substrate is about 0.2 μm and the diameter of the conductive particles is 4 to 6 μm, even if the driver IC is pressurized when the driver IC is mounted, The conductive particles do not protrude from the wiring. Therefore, even if the wiring interval between the diagonal wirings is narrowed, a short circuit can be prevented, and the head can be downsized.

  The electrostatic actuator according to the present invention is characterized in that a driver IC is mounted on an electrode mounting portion with an anisotropic conductive adhesive. That is, it is possible to easily connect the electrode mounting portion and the output terminal of the driver IC via the anisotropic conductive adhesive. Thereby, while electrically conducting by the conductive particles present in the anisotropic conductive adhesive, the conductive particles are not in contact with each other in the adjacent mounting portions, and insulation can be maintained.

  The electrostatic actuator according to the present invention is characterized in that the interval between the mounting portions of each set is three times or more the diameter of the conductive particles. In general, the diameter of the conductive particles is 4 to 6 μm, and if the interval between the mounting parts is set to three times or more the diameter of the conductive particles, it is possible to prevent a short circuit caused by the conductive particles. That is, if the interval between the mounting parts is set to be three times or more the diameter of the conductive particles, even if the anisotropic conductive adhesive protrudes when the driver IC is mounted, a short circuit can be sufficiently prevented.

  The electrostatic actuator according to the present invention is characterized in that the interval between each lead wiring from the electrode mounting portion to the diagonal wiring is three times or more the diameter of the conductive particles. As a result, if the interval between the lead wires is set to three times or more the diameter of the conductive particles, it is possible to prevent a short circuit caused by the conductive particles. That is, if the interval between the lead wires is set to be three times or more the diameter of the conductive particles, even if the anisotropic conductive adhesive protrudes when the driver IC is mounted, a short circuit can be sufficiently prevented.

  A droplet discharge head according to the present invention is characterized in that the electrostatic actuator according to any one of claims 1 to 8 is mounted for pressure fluctuation in a pressure chamber in which droplets for discharge are stored. By doing so, it becomes possible to apply the electrostatic actuator having the above characteristics to the droplet discharge head. Therefore, the driver IC to be mounted is not limited to a fixed one, which can contribute to the downsizing of the droplet discharge head.

  A droplet discharge head according to the present invention is mounted for pressure fluctuation of a pressure chamber in which discharge droplets are stored, and supplies the droplets to the pressure chamber. A reservoir substrate having a reservoir, a supply hole for transferring a droplet from the reservoir to the pressure chamber, and a nozzle communication hole for transferring the droplet from the pressure chamber to the nozzle hole; And a nozzle substrate having a plurality of nozzle holes. By doing so, it can be applied to a droplet discharge head having a four-layer structure.

  A droplet discharge head according to the present invention is mounted for pressure fluctuation of a pressure chamber in which discharge droplets are stored, and the electrostatic actuator according to claim 1 and a discharge stored in a pressure chamber. And a nozzle substrate on which a plurality of nozzle holes for discharging liquid droplets are formed. This makes it possible to apply to a three-layer structure droplet discharge head.

  A droplet discharge device according to the present invention is equipped with the droplet discharge head according to any one of claims 9 to 11. By doing so, it becomes possible to apply the droplet discharge head having the above-described effects to the droplet discharge apparatus. That is, since the pitch conversion between the electrode mounting portion and the individual electrodes can be facilitated, a miniaturized droplet discharge head can be mounted. In addition, the nozzle density is increased. Furthermore, since the electrode mounting portion and the individual electrode are formed on the same plane (on the electrode substrate), it is easy to route the individual electrode by the wiring lead. This simplifies the wiring layout and eliminates the labor involved in the manufacturing process.

  Hereinafter, a droplet discharge head 100 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view of a droplet discharge head 100 according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view showing an AA section in a state where the droplet discharge head 100 is assembled. The droplet discharge head 100 is a face eject type liquid that discharges droplets from nozzle holes provided on the surface side of a nozzle substrate as a representative of electrostatic actuators driven by electrostatic force. 2 represents a droplet discharge head. FIG. 1 also shows a part of an FPC (Flexible Printed Circuit) for supplying a drive signal.

  As shown in FIG. 1, the droplet discharge head 100 does not have a three-layer structure like a general electrostatic drive type droplet discharge head, but an electrode substrate 4, a cavity substrate 3, a reservoir substrate 2, and a nozzle substrate 1. A four-layer structure composed of four substrates is shown as an example. The nozzle substrate 1 is bonded to one surface of the reservoir substrate 2, and the cavity substrate 3 is bonded to the other surface of the reservoir substrate 2. An electrode substrate 4 is bonded to the opposite surface of the cavity substrate 3 to which the reservoir substrate 2 is bonded. That is, the electrode substrate 4, the cavity substrate 3, the reservoir substrate 2, and the nozzle substrate 1 are bonded in this order. Further, the droplet discharge head 100 is provided with a driver IC 15 that supplies a drive signal to the individual electrode 17.

[Electrode substrate 4]
The electrode substrate 4 may be formed of glass such as borosilicate glass. Here, a case where the electrode substrate 4 is formed of borosilicate glass is shown as an example, but the present invention is not limited to this. For example, the electrode substrate 4 may be formed of single crystal silicon. A concave portion (glass groove) 12 is formed in the electrode substrate 4. The recess 12 may be formed with a depth of 0.3 μm, for example. In addition, the individual electrodes 17 are formed inside the recess 12 so as to face a diaphragm 8 described later at a constant interval. The individual electrode 17 is preferably made by sputtering ITO (Indium Tin Oxide) with a thickness of 0.1 μm, for example.

  The recess 12 is patterned in a slightly larger shape similar to these shapes so that a part of the recess 12 can be fitted with the individual electrode 17. The other part (center part) is patterned so that the driver IC 15 can be mounted. In this embodiment, the case where the driver IC 15 is installed at the center is shown as an example. Although the number of driver ICs 15 is not particularly limited, a case where two driver ICs 15 are installed is shown here as an example.

  One end (IC output mounting portion 18) of the individual electrode 17 is connected to the driver IC 15 so that a drive signal is supplied from the driver IC 15. Here, as shown in the figure, a case where a connection terminal formed at the lower part of the driver IC 15 and the individual electrode 17 are connected is shown as an example. A portion where a connection terminal for connecting the individual electrode 17 below the driver IC 15 is formed is referred to as a connection portion. Note that the connecting portion is not limited to the lower portion of the driver IC 15. For example, the connection terminal may be formed in a portion other than the lower portion of the driver IC 15. In such a case, a portion where the individual electrode 17 and the driver IC 15 are connected is referred to as a connection portion.

  In the droplet discharge head 100, a plurality of individual electrodes 17 are formed in a rectangular shape having long sides and short sides, and the individual electrodes 17 are arranged so that their long sides are parallel to each other. Two electrode rows extending in the short side direction of 17 are formed. In addition, when the short side of the individual electrode 17 is formed obliquely with respect to the long side and the individual electrode 17 has an elongated parallelogram shape, an electrode array extending in a direction perpendicular to the long side direction is formed. What should I do?

  In the droplet discharge head 100, the driver IC 15 is installed between the two electrode rows and is connected to both electrode rows. Therefore, it becomes possible to supply drive signals from the driver IC 15 to the two electrode rows, and it is easy to increase the number of electrode rows. Furthermore, since the number of driver ICs 15 can be reduced, the cost required for manufacturing can be reduced, and the droplet discharge head 100 can be downsized. The A region shown in the figure will be described in detail with reference to FIG.

  An ink supply hole 11 is formed in the electrode substrate 4. The ink supply hole 11 is formed so as to penetrate the electrode substrate 4. Further, the FPC mounting portion 21 is formed on the electrode substrate 4. In addition, after the electrode substrate 4 and the cavity substrate 3 are joined, the sealing member 14 for sealing the IC output mounting portion 18 and the vibration chamber 13 (gap) is formed. Is described in detail in FIG.

[Cavity substrate 3]
The cavity substrate 3 is made of, for example, single crystal silicon, and a plurality of pressure chambers 7 (or discharge chambers) whose bottom wall is the diaphragm 8 are formed. The pressure chambers 7 are formed in two rows corresponding to the electrode rows of the individual electrodes 17. In addition, a first hole 22 is formed in the cavity substrate 3 so as to penetrate the cavity substrate 3 between the electrode arrays. Further, the cavity substrate 3 has a common electrode 16 for applying a voltage to the diaphragm 8. The common electrode 16 is connected to the FPC 30.

  The cavity substrate 3 is made of single crystal silicon, and an insulating film (not shown) made of TEOS (Tetra Ethyl Ortho Silicate) is formed on the entire surface by plasma CVD (Chemical Vapor Deposition). This is for preventing dielectric breakdown and short-circuit when the diaphragm 8 is driven, and for preventing etching of the cavity substrate 3 by droplets of ink or the like.

The diaphragm 8 may be formed of a high concentration boron doped layer. The etching rate in etching single crystal silicon with an alkaline solution such as an aqueous potassium hydroxide solution is very small in a high concentration region of about 5 × 10 ¹⁹ atoms / cm ³ or more when the dopant is boron. For this reason, when the diaphragm 8 is made of a high-concentration boron-doped layer and the pressure chamber 7 is formed by anisotropic etching with an alkaline solution, the boron-doped layer is exposed and the etching rate becomes extremely small, so-called etching stop. By using the technique, the diaphragm 8 can be formed in a desired thickness.

  When the electrode substrate 4 and the cavity substrate 3 are joined, a vibration chamber 13 (gap) that is a gap is formed between the individual electrode 17 and the diaphragm 8. The vibration chamber 13 is formed to have a depth of 0.2 μm, for example. In addition, ink supply holes 11 are formed in the cavity substrate 3 so as to penetrate the cavity substrate 3.

[Reservoir substrate 2]
The reservoir substrate 2 is made of, for example, single crystal silicon, and two reservoirs 10 for supplying droplets to the pressure chamber 7 are formed. A supply hole 9 for transferring droplets from the reservoir 10 to the pressure chamber 7 is formed on the bottom surface of the reservoir 10. An ink supply hole 11 is formed on the bottom surface of the reservoir 10 so as to penetrate the bottom surface of the reservoir 10.

  The ink supply hole 11 formed in the reservoir substrate 2, the ink supply hole 11 formed in the cavity substrate 3, and the ink supply hole 11 formed in the electrode substrate 4 are the reservoir substrate 2, the cavity substrate 3, and the electrode substrate. 4 are connected to each other in a joined state, and droplets are supplied to the reservoir 10 from the outside (see FIG. 2). Further, a second hole 23 that penetrates the reservoir substrate 2 and corresponds to the first hole 22 is formed between the two reservoirs 10.

  As shown in FIG. 2, the first hole portion 22 provided in the cavity substrate 3 and the second hole portion 23 provided in the reservoir substrate 2 communicate with each other to form an accommodating portion 24. The driver IC 15 is accommodated inside the accommodating portion 24. Further, nozzle communication holes 6 are formed in portions of the reservoir substrate 2 other than the reservoir 10 so as to communicate with the respective pressure chambers 7 and to transfer droplets from the pressure chambers 7 to the nozzle holes 5 described later. The nozzle communication hole 6 penetrates the reservoir substrate 2 and communicates with one end of the pressure chamber 7 opposite to one end with which the supply hole 9 communicates.

[Nozzle substrate 1]
The nozzle substrate 1 is made of, for example, a silicon substrate having a thickness of 100 μm, and a plurality of nozzle holes 5 communicating with the respective nozzle communication holes 6 are formed. The nozzle holes 5 are formed in two stages to improve the straightness when discharging droplets (see FIG. 2). Further, when the electrode substrate 4, the cavity substrate 3, the reservoir substrate 2 and the nozzle substrate 1 are bonded, when the silicon substrate and the borosilicate glass substrate are bonded, the silicon substrates are bonded to each other by anodic bonding. If so, it can be joined by direct joining. Further, the substrates made of silicon can be bonded using an adhesive.

  As shown in FIG. 2, in the droplet discharge head 100, the driver IC 15 is accommodated in the accommodating portion 24, and the accommodating portion 24 is closed by the nozzle substrate 1, the reservoir substrate 2, the cavity substrate 3, and the electrode substrate 4. ing. That is, the nozzle substrate 1 forms the upper surface of the housing portion 24, the electrode substrate 4 forms the lower surface of the housing portion 24, and the cavity substrate 3 and the reservoir substrate 2 form the side surfaces of the housing portion 24, thereby closing the housing portion 24. It is like that. In addition, it is desirable that the accommodating portion 24 be sealed in order to protect the driver IC 15 from liquid droplets and outside air.

The sealing member 14 seals the gap 13 between the diaphragm 8 and the individual electrode 17. The sealing member 14 is formed of, for example, silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), silicon oxynitride (SiON), silicon nitride (SiN), polyparaxylylene, or the like having low moisture permeability. Good. In addition, polyparaxylylene is a crystalline polymer resin and has properties that are excellent in moisture permeation prevention and chemical resistance. If these materials are formed by sputtering, CVD, or the like, the sealing member 14 having low moisture permeability can be formed small, and the droplet discharge head 100 can be further downsized.

  Next, the operation of the droplet discharge head 100 will be described. A droplet of ink or the like is supplied to the reservoir 10 from the outside through the ink supply hole 10. In addition, droplets are supplied from the reservoir 10 to the pressure chamber 7 through the supply hole 9. A drive signal (pulse voltage) is supplied to the driver IC 15 from a control unit (not shown) of the droplet discharge device via the FPC internal wiring (IC input) 32 of the FPC 30 and the IC input mounting unit 20 provided on the electrode substrate 4. Has been.

  Then, a pulse voltage of about 0 V to 40 V is applied from the driver IC 15 to the individual electrode 17, the individual electrode 17 is positively charged, and the corresponding diaphragm 8 is connected to the droplet discharge device via the FPC internal wiring (COM) 31. A drive signal (pulse voltage) is supplied from a control unit (not shown) to be negatively charged. If it does so, the diaphragm 8 will be attracted | sucked by the individual electrode 17 side by an electrostatic force, and will be bent. When this pulse voltage is turned off, the electrostatic force applied to the diaphragm 8 disappears and the diaphragm 8 is restored. At this time, the pressure inside the pressure chamber 7 rises rapidly, and the droplets in the pressure chamber 7 pass through the nozzle communication hole 6 and are discharged from the nozzle hole 5. Thereafter, the droplet is replenished from the reservoir 10 through the supply hole 9 into the pressure chamber 7 and returns to the initial state.

  The supply of droplets to the reservoir 10 of the droplet discharge head 100 is performed by, for example, a droplet supply tube (not shown) connected to the ink supply hole 11. The FPC 30 is connected to the driver IC 15 so that the longitudinal direction of the FPC 30 is parallel to the short side direction of the individual electrodes 17 forming the electrode array. For example, when the short side of the individual electrode 17 is inclined with respect to the long side and the individual electrode 17 has an elongated parallelogram shape, the FPC 30 is connected in a direction perpendicular to the long side of the individual electrode 17. That's fine. Thereby, the droplet discharge head 100 having a plurality of electrode rows and the FPC 30 can be connected in a compact manner.

  FIG. 3 is a detailed plan view showing a region A of the electrode substrate 4. Here, a case where two driver ICs 15 are installed on the electrode substrate 4 is shown as an example (an IC outline represented by a wavy line). As shown in the figure, the electrode mounting portion 40 is formed on the same plane as the individual electrode 17. Therefore, the electrode lead portion 41 and the oblique electrode lead portion 42 (oblique wiring) that connect the electrode mounting portion 40 and the individual electrode 17 facilitate the electrode routing of the individual electrode 17. That is, the wiring layout of the electrode substrate 4 is easy.

  Further, the case where the electrode mounting portion 40 has a parallel two-row configuration is shown as an example. This makes it possible to halve the packaging density. The electrode mounting portion 40 is not limited to being configured in two parallel rows. For example, the first row and the second row may be shifted to form a two-row configuration. Further, the number of columns is not limited to two, and may be three or more. In this case, it may be determined in consideration of the pitch interval of the electrode mounting portion 40.

  The driver IC 15 is attached to the electrode substrate 4 with an anisotropic conductive adhesive. An anisotropic conductive adhesive is applied to the connection terminals of the driver IC 15 or the electrode mounting portion 40, and the driver IC 15 is pressurized and fixed to the housing portion 24. In a connection method using an anisotropic conductive adhesive, a predetermined mounting area is required to enable electrical connection. In other words, if the electrode mounting portions are configured in a single row, it is difficult to increase the density, and the demand for increasing the nozzle density cannot be met. Therefore, it is possible to increase the nozzle density, which is difficult in the electrode mounting portion having a single row configuration.

  The anisotropic conductive adhesive includes a film-like one and a paste-like one. The anisotropic conductive adhesive on the film is referred to as ACF (Anisotropic Conductive Film), and the paste-like anisotropic conductive adhesive is referred to as ACP (Anisotropic Conductive Paste). Here, a case where ACF is used for the anisotropic conductive adhesive will be described as an example, but ACP may be used.

  The driver IC 15 is attached to the electrode substrate 4 via an anisotropic conductive adhesive (ACF). This anisotropic conductive adhesive is obtained by dispersing conductive particles in a thermosetting resin. The conductive particles enter between the output terminal of the driver IC 15 and the electrode mounting portion 40 formed on the electrode substrate 4 so that the driver IC 15 and the electrode substrate 4 are electrically connected. Further, the driver IC 15 and the electrode substrate 4 are mechanically connected by a thermosetting resin cured by heating, and this electrical connection portion is protected.

  That is, the driver IC 15 and the electrode substrate 4 are electrically connected by the conductive particles present in the anisotropic conductive adhesive, but the conductive particles are not in contact with each other on the left and right electrode mounting portions, Insulation can be maintained. In general, the diameter of the conductive particles is 4 to 6 μm. If each electrode interval of the electrode mounting portion 40 and each lead interval of the electrode lead portion 41 is set to three times or more the diameter of the conductive particles, short-circuiting by the conductive particles is caused. Disappear. That is, each electrode interval is set to 16 μm and each lead interval is set to 20 μm to prevent a short circuit due to conductive particles (see FIG. 7).

  Further, since the electrode mounting portion 40 has a parallel two-row configuration, excess anisotropic conductive adhesive under the driver IC 15 is efficiently pushed out of the driver IC 15 from between the electrodes. Yes. Therefore, it is possible to make the droplet discharge head 100 with high reliability without causing the driver IC 15 to be mounted and lifted. As described above, the electrode mounting portion 40 is not limited to the parallel two-row configuration. However, in order to most effectively extrude the excess anisotropic conductive adhesive to the outside of the driver IC 15 and secure the mounting area. As shown in the figure, it is desirable that the electrode mounting portions 40 are configured in two parallel rows.

  FIG. 4 is a detailed plan view showing a glass groove (a part of the recess 12) provided in the electrode substrate 4 in the region A shown in FIG. In the figure, the wavy line represents the glass groove. The electrode mounting portion 40 has a two-row configuration in which mounting portions (bumps) are parallel at a predetermined interval. That is, it has a parallel two-row configuration so as to correspond to the output terminal of the driver IC 15. Here, a case where the electrode mounting portion 40 has a parallel two-row configuration will be described as an example. However, the configuration is not limited to this, and any configuration corresponding to the arrangement of the output terminals of the driver IC 15 may be used. However, it is desirable to set in consideration of the characteristics of the anisotropic conductive adhesive and the pitch of the electrode mounting portion 40.

  As shown in the drawing, a part of the lead wiring between the electrode mounting portion 40 and the individual electrode portion 43 is an oblique wiring in a plane (oblique electrode lead portion 42). By doing so, the pitch conversion of the electrode mounting part 40 and the individual electrode part 43 is facilitated. In addition, since the pitch conversion can be easily changed or set, the droplet discharge head 100 can be made compact. Here, as an example, the glass grooves of the oblique electrode lead portions 42 are not formed in the same number as the number of each lead (see FIG. 5), and two adjacent individual electrodes 17 are formed as a set. ing.

  The oblique electrode lead portion 42 is laid out so as to be bonded to the cavity substrate 3. By doing so, the anisotropic conductive adhesive applied to the electrode mounting portion 40 is prevented from protruding into the oblique electrode lead portion 42. Since the gap amount between the electrode substrate 4 and the cavity substrate 3 is about 0.2 μm and the diameter of the conductive particles is 4 to 6 μm, the conductive particles do not protrude into the oblique electrode lead portion 42. Therefore, a short circuit due to conductive particles does not occur between the wirings of the oblique electrode lead part 42. Further, since a short circuit does not occur, the width of the wiring interval (space) of the oblique electrode lead portion 42 can be reduced. Furthermore, it is possible to reduce the wiring resistance by forming each wiring of the oblique electrode lead part 42 thickly.

  As described above, since the oblique electrode lead portion 42 does not cause a short circuit due to the anisotropic conductive adhesive, it is not necessary to form a glass groove at the location of each lead of the oblique electrode lead portion 42. Become. That is, as shown in the figure, the glass groove of the oblique electrode lead portion 42 is formed by two adjacent electrodes of the electrode mounting portion 40 as a parallel two-row configuration. By doing so, the wiring layout can be simplified and the labor can be omitted. The layout of the oblique electrode lead part 42 is not limited as shown in the figure.

  FIG. 5 is a detailed plan view showing the ITO wiring of the electrode substrate 4 in the region A shown in FIG. This ITO wiring is formed in the glass groove (a part of the recess 12) shown in FIG. That is, the glass groove is patterned in a slightly larger shape similar to these shapes so that the ITO wiring can be mounted. In addition, the case where the space | interval of each lead | read | reed of the diagonal electrode lead part 42 is set to 7 micrometers is shown as an example (refer FIG. 8).

  FIG. 6 is a detailed plan view showing a region A when the electrode substrate 4 and the cavity substrate 3 are combined. The wavy line represents the glass groove formed in the electrode substrate 4, and the solid line represents the shape of the cavity substrate 3. Since the driver IC 15 is attached to the electrode mounting portion 40, the first hole portion 22 that is a through hole is formed in the cavity substrate. Further, the oblique electrode lead part 42 is joined without the cavity substrate 3 being etched. In addition, the individual electrode portion 43 is formed with a recess for forming the pressure chamber 7 (actuator). Although not shown, it is assumed that ITO wiring is mounted inside the glass groove.

  FIG. 7 is an enlarged detail view showing the electrode mounting portion 40. Here, the electrode mounting portion 40 is shown as the first row and the second row for convenience. It is assumed that the first column represents the mounting portion (bump) on the center side of the driver IC 15 and the second column represents the mounting portion on the individual electrode 17 side. As shown in the drawing, each mounting portion in the first row and the electrode lead portion 41 corresponding to the mounting portion are connected by leads formed between the mounting portions in the second row. An example is shown in which the distance between the mounting portion in the second row and the leads formed therebetween is 16 μm. Further, the case where the lead interval of the electrode lead portion 41 is 20 μm is shown as an example.

  As described above, the diameter of the conductive particles is generally 4 to 6 μm, and if there is an interval (distance) of three times or more the diameter of the conductive particles, a short circuit due to the conductive particles is eliminated. Therefore, by setting the distance between the mounting portion in the second row and the leads formed between them to 16 μm and the distance between the leads of the electrode lead portion 41 to 20 μm, it is possible to ensure a conductivity of 3 times or more the diameter of the conductive particles. Short circuit by particles is prevented. When the conductive particles are 6 μm, the distance between the mounting portion in the second row and the leads formed therebetween may be set to 18 μm or more.

  FIG. 8 is an enlarged detail view showing the oblique electrode lead portion 42 and the individual electrode portion 43. In the example, the interval between the leads of the oblique electrode lead portion 42 is 7 μm, and the interval between the individual electrodes 17 is 5 μm. That is, since the anisotropic conductive adhesive is not applied to the oblique electrode lead portion 42 and the individual electrode portion 43, the interval can be set short without considering the diameter of the conductive particles. .

  FIG. 9 is a schematic block diagram showing a control system of a droplet discharge device on which the droplet discharge head 100 is mounted. Here, a case where the droplet discharge device is a general ink jet printer will be described as an example. A control system of a droplet discharge device on which the droplet discharge head 100 is mounted will be described with reference to the drawings. However, the control system of the droplet discharge device on which the droplet discharge head 100 is mounted is not limited to the case shown here.

  The ink jet printer includes a control device 50 for driving and controlling the droplet discharge head 100. The control device 50 is configured around a CPU (central processing unit) 51. The CPU 51 receives print information from an external device 60 such as a personal computer or a remote control device (remote control). This print information is input via the bus 52 or input by a wireless signal such as an infrared signal. The CPU 51 is connected to the ROM 54, the RAM 55, and the character generator 56 via the internal bus 53.

  The control device 50 uses the storage area in the RAM 55 as a work area, executes a control program stored in the ROM 54, and drives the droplet discharge head 100 based on character information generated from the character generator 56. Control signal is generated. The control signal becomes a drive control signal corresponding to the print information via the logic gate array 57 and the drive pulse generation circuit 58, and is supplied to the driver IC 15 built in the droplet discharge head 100 via the connector 65. In addition, it is supplied to the COM generation circuit 59. The driver IC 15 is also supplied with a drive pulse signal V3 for printing, a control signal LP, a polarity inversion control signal REV, and the like (see FIG. 4). Note that the COM generation circuit 59 may be constituted by a common electrode IC (not shown) for generating a drive pulse, for example.

  The COM generation circuit 59 outputs a drive signal to be applied to the common electrode 16 of the droplet discharge head 100, that is, each diaphragm 8, from a common output terminal COM (not shown) based on the supplied signals. ing. In the driver IC 15, a drive signal to be applied to each individual electrode 17 is applied to each individual electrode 17 based on each supplied signal and the drive voltage Vp supplied from the power supply circuit 70. To output. A potential difference between the output of the common output terminal COM and the output of the individual output terminal SEG is applied between each diaphragm 8 and the individual electrode 17 facing it. When the diaphragm 8 is driven (when droplets are ejected), a drive potential difference waveform in the designated direction is given, and when the diaphragm 8 is not driven, no drive potential difference is given.

  FIG. 10 is a schematic block diagram showing an example of the internal configuration of the driver IC 15 and the COM generation circuit 59. The driver IC 15 and the COM generation circuit 59 supply driving signals to the 64 individual electrodes 17 and the diaphragm 8 in one set. Further, an example is shown in which the driver IC 15 is a CMOS 64-bit output high voltage driver that operates by being supplied with the high voltage drive voltage Vp and the logic circuit drive voltage Vcc from the power supply circuit 70.

  The driver IC 15 applies one of the drive voltage pulse and the GND potential to the individual electrode 17 in accordance with the supplied drive control signal. The driver IC 15 has a 64-bit shift register 81. The shift register 81 is an XSCL pulse that is a basic clock pulse that synchronizes the DI signal input of 64-bit length transmitted from the logic gate array 57 as serial data with the DI signal. It is a static shift register that shifts up data by a signal input and stores it in a register in the shift register 81. The DI signal is a control signal indicating selection information for selecting each of the 64 individual electrodes 17 by ON / OFF, and this signal is transmitted as serial data.

  The driver IC 15 has a 64-bit latch circuit 82. The latch circuit 82 latches the 64-bit data stored in the shift register 81 with a control signal (latch pulse) LP to store the data. This is a static clutch that outputs the data to the 64-bit inversion circuit 83 as a signal. In the latch circuit 82, the DI signal of the serial data is converted into a 64-bit parallel signal for outputting 64 segments for driving each diaphragm 8.

  The inverting circuit 83 outputs an exclusive OR of the signal input from the latch circuit 82 and the REV signal to the level shifter 84. The level shifter 84 is a level interface circuit that converts the voltage level of the signal from the inverting circuit 83 from the logic system voltage level (5 V level or 3.3 V level) to the head drive system voltage level (0 to 45 V level). The SEG driver 85 is a 64 channel transmission gate output, and outputs either a drive voltage pulse input or a GND input to the segment outputs SEG1 to SEG64 by the input of the level shifter 84. A COM driver 86 built in the COM generation circuit 59 outputs either a drive voltage pulse or a GND input to the COM in response to the REV input.

  The XSCL, DI, LP, and REV signals are logic system voltage level signals that are transmitted from the logic gate array 57 to the driver IC 15. In this way, by configuring the driver IC 15 and the COM generation circuit 59, even when the number of segments to be driven (the number of diaphragms 8) increases, the driving voltage for driving the diaphragm 8 of the droplet discharge head 100 can be easily achieved. It is possible to switch between pulse and GND.

  11 and 12 are longitudinal sectional views showing an example of the manufacturing process of the droplet discharge head 100. FIG. An example of a method for manufacturing the droplet discharge head 100 is shown here, but the present invention is not limited to this. First, the cavity substrate 3 having a thickness of, for example, 525 μm is anodically bonded to the electrode substrate 4 on which the individual electrodes 17 and the ink supply holes 11 are formed (a). In the droplet discharge head 100, the electrode substrate 4 is made of borosilicate glass, and the electrode substrate 4 is manufactured by forming two pairs of electrode rows in parallel two rows.

  Here, an example of the manufacturing method of the electrode substrate 4 will be briefly described. First, a resist is applied to the entire surface of the glass substrate and patterned into a predetermined shape, and then etched with a hydrofluoric acid aqueous solution or the like to form a recess 12 to peel off the resist. Then, ITO is formed on the entire surface where the recess 12 is formed by sputtering or the like, a resist is applied to the surface of the ITO and patterned, and after the individual electrodes 17 are formed by etching, the resist is peeled off. The ink supply hole 11 can be formed by a drill or the like.

  Next, the cavity substrate 3 is thinned by mechanical grinding so that the thickness of the cavity substrate 3 is 140 μm (b). In addition, it is desirable to remove the work-affected layer generated on the surface of the cavity substrate 3 with a potassium hydroxide aqueous solution or the like after mechanical grinding. After forming an oxide film with a TEOS film or the like by plasma CVD on the surface of the cavity substrate 3 (c), a resist is applied to the surface of the oxide film to form the pressure chamber 7, the first hole 22, and the shape of the ink supply hole 11. Is patterned (d).

  Then, for example, the cavity substrate 3 is etched with an aqueous potassium hydroxide solution to form the pressure chamber 7, the first hole 22, and the ink supply hole 11, and the oxide film is peeled off (e). If the boron doped layer is formed on the cavity substrate 3 as described above, the boron doped layer remains as a thin film such as the diaphragm 8. Thereafter, the silicon thin film remaining in the first hole 22 and the ink supply hole 11 is removed by RIE (Reactive Ion Etching) or the like to form the first hole 22 and the ink supply hole 11 (f).

  Then, the driver IC 15 is prepared, and the driver IC 15 is mounted on the electrode substrate 4 so as to be connected to the individual electrode 17 through the connection portion in the first hole portion 22 (g). The driver IC 15 is mounted by attaching ACF or ACP, which is an anisotropic conductive adhesive, to a connection terminal formed below the driver IC 15. This anisotropic conductive adhesive may be applied to the connection terminal of the driver IC 15 or may be applied to the IC output mounting portion 18.

  A sealing member 14 is formed in the first hole 22 to seal the gap 13 between the individual electrodes 17 (h). At this time, it is desirable to cover the portion of the individual electrode 17 that is not sealed by the sealing member 14 with the sealing member 14. In the case where a resin such as polyparaxylene is used as a material, the sealing member 14 can be formed by applying a sealing material at a predetermined position with a needle. Further, when a metal material such as silicon oxide, aluminum oxide, silicon oxynitride, or silicon nitride is used as the material of the sealing member 14, it can be formed by CVD using a mask made of silicon or the like.

  Next, the reservoir substrate 2 is bonded to the surface of the cavity substrate 3 where the pressure chambers 7 are formed (i). At this time, the first hole portion 22 and the second hole portion 23 communicate with each other to form the accommodating portion 24. In the reservoir substrate 2, a reservoir 10 for supplying droplets to the pressure chamber 7 in advance, a supply hole 9 for transferring droplets from the reservoir 10 to the pressure chamber 7, and droplets from the pressure chamber 7 to the nozzle hole 5 are provided. The nozzle communicating hole 6 to be transferred and the second hole portion 23 are formed. The reservoir substrate 2 is formed by forming a silicon oxide film on the silicon substrate, patterning a resist on the surface of the silicon oxide film to etch a predetermined portion of the silicon oxide film, and then etching the silicon substrate with a potassium hydroxide aqueous solution or the like. Can be formed.

  Then, the nozzle substrate 1 in which the nozzle holes 5 are formed by ICP (Inductively Coupled Plasma) discharge or etching or the like is bonded to the reservoir substrate 2 using an adhesive or the like (j). Finally, the bonded substrate to which the electrode substrate 4, the cavity substrate 3, the reservoir substrate 2, and the nozzle substrate 1 are bonded is diced (cut) to complete each droplet discharge head 100.

  As described above, the first hole portion 22 is provided in the cavity substrate 3, the second hole portion 23 is provided in the reservoir substrate 2, and the accommodating portion 24 is formed by the first hole portion 21 and the second hole portion 23. Since the driver IC 15 is accommodated in the accommodating portion 24, the size of the droplet discharge head 100 can be reduced. Therefore, the distance between the printing paper and the nozzle hole 5 can be reduced, and high-definition printing is possible. Further, since the surface on which the nozzle holes 5 are formed can be flattened, wiping (a step of removing unnecessary droplets) can be easily performed. Since the accommodating portion 24 is closed by the nozzle substrate 1, the cavity substrate 3, the reservoir substrate 2, and the electrode substrate 4, it is not necessary to provide a separate layer for protecting the driver IC 15 from droplets, and the driver IC 15 is protected from the outside air. It becomes possible to do.

  FIG. 13 is a perspective view showing an example of a droplet discharge device 150 on which the droplet discharge head 100 is mounted. The droplet discharge device 150 is a general ink jet printer. As described above, the droplet discharge head 100 according to the embodiment is small in size and excellent in discharge stability and durability. Further, the droplet discharge device 150 equipped with the droplet discharge head 100 is also small and has high printing performance and high durability.

  In addition to the ink jet printer shown in FIG. 13, the droplet discharge head 100 can be used to produce liquid crystal color filters, to form light emitting portions of organic EL display devices, It can also be applied to discharge or the like. Further, the droplet discharge head 100, the manufacturing method thereof, and the droplet discharge device 150 are not limited to the embodiments of the present invention, and can be modified within the scope of the present invention. For example, the sealing member position may be sealed at two places.

It is a disassembled perspective view of the droplet discharge head concerning an embodiment of the invention. It is a longitudinal cross-sectional view which shows the AA cross section of the state by which the droplet discharge head was assembled. It is a detailed top view which shows A area | region of an electrode substrate. It is a detailed top view which shows the glass groove | channel provided in the electrode substrate of A area | region. It is a detailed top view which shows the ITO wiring of the electrode substrate of A area | region. It is a detailed top view which shows A area | region at the time of combining an electrode substrate and a cavity board | substrate. It is an enlarged detail drawing which shows an electrode mounting part. It is an enlarged detail drawing which shows an oblique electrode lead part and an individual electrode part. It is a schematic block diagram which shows the control system of the droplet discharge apparatus by which a droplet discharge head is mounted. It is a schematic block diagram which shows an example of an internal structure of a driver IC and a COM generation circuit. It is a longitudinal cross-sectional view which shows an example of the manufacturing process of a droplet discharge head. It is a longitudinal cross-sectional view which shows an example of the manufacturing process of a droplet discharge head. It is the perspective view which showed an example of the droplet discharge apparatus carrying a droplet discharge head.

Explanation of symbols

1 nozzle substrate, 2 reservoir substrate, 3 cavity substrate, 4 electrode substrate, 5 nozzle hole, 6 nozzle communication hole, 7 pressure chamber, 8 diaphragm, 9 supply hole, 10 reservoir, 11 ink supply hole, 12 recess (glass groove) ), 13 Vibration chamber (gap), 14 Sealing member, 15 Driver IC, 16 Common electrode, 17 Counter electrode (Individual electrode ITO), 18 IC output (SEG) mounting part, 20 IC input mounting part, 21 FPC mounting part , 22 1st hole part, 23 2nd hole part, 30 FPC, 31 FPC internal wiring (COM), 32 FPC internal wiring (IC input), 40 electrode mounting part, 41 electrode lead part, 42 oblique electrode lead part , 43 Individual electrode section, 50 control device, 51 CPU, 52 bus, 53 internal bus, 54 ROM, 55 RAM, 56 character generator, 57 theoretical gate array, 5 8 drive pulse generation circuit, 59 COM generation circuit, 60 external device, 65 connector, 70 power supply circuit, 100 droplet ejection head, 150 droplet ejection device.

Claims (12)

A cavity substrate having a plurality of diaphragms;
An electrode on which an individual electrode facing each of the diaphragms, an electrode mounting portion for installing a driver IC for supplying a driving signal to the individual electrode, and a lead wiring for connecting the individual electrode and the electrode mounting portion are formed A substrate,
An electrostatic actuator that applies a voltage to the individual electrodes and drives the diaphragm by electrostatic force generated thereby,
The electrode mounting portion includes a plurality of rows of mounting portions on each side with respect to a terminal group provided on both sides of a driver IC installed in the electrode mounting portion. . The plurality of rows has a four-row configuration with two rows on one side,
2. The electrostatic actuator according to claim 1, wherein the two rows on one side are set as a set and each set is arranged in a symmetrical position. Form two adjacent rows of mounting parts horizontally on one side,
The electrostatic actuator according to claim 2, wherein the horizontally formed mounting portions are arranged so as to be parallel to the column direction. The electrostatic actuator according to claim 1, wherein a part of the lead wiring is an oblique wiring so as to be oblique in a plan view. The electrostatic actuator according to claim 4, wherein the diagonal wiring is formed in a groove provided in the electrode substrate, and the electrode substrate and the cavity substrate are joined. The electrostatic actuator according to claim 1, wherein a driver IC is mounted on the electrode mounting portion with an anisotropic conductive adhesive. The electrostatic actuator according to claim 6, wherein an interval between the mounting portions of each set is set to be not less than three times the diameter of the conductive particles. The electrostatic actuator according to claim 6, wherein an interval between each lead wiring from the electrode mounting portion to the diagonal wiring is set to be not less than three times a diameter of the conductive particles. A droplet discharge head comprising the electrostatic actuator according to any one of claims 1 to 8 mounted for pressure fluctuation in a pressure chamber in which droplets for discharge are stored. The electrostatic actuator according to any one of claims 1 to 8, which is mounted for pressure fluctuation of a pressure chamber in which discharge droplets are stored,
A reservoir substrate having a reservoir for supplying droplets to the pressure chamber, a supply hole for transferring droplets from the reservoir to the pressure chamber, and a nozzle communication hole for transferring droplets from the pressure chamber to the nozzle holes;
The droplet discharge head according to claim 9, further comprising: a nozzle substrate fixed to the reservoir substrate and having a plurality of nozzle holes for discharging droplets. The electrostatic actuator according to any one of claims 1 to 8, which is mounted for pressure fluctuation of a pressure chamber in which discharge droplets are stored,
The droplet discharge head according to claim 9, further comprising: a nozzle substrate having a plurality of nozzle holes for discharging droplets for discharge stored in the pressure chamber. A liquid droplet ejection apparatus, comprising the liquid droplet ejection head according to claim 9.

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