JP2006224311A - Droplet delivering head and droplet delivering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a droplet delivering head which facilitates setting of driving conditions thereof, is excellent in reliability, and compact and excellent in handling efficiency in a preferred embodiment. <P>SOLUTION: An inkjet head 10 as the droplet delivering head is a laminated body consisting of a circuit board 20 having a plurality of electrodes 36 arranged on the same plane, a channel forming substrate 111 having a plurality of grooves 12a (pressure generating chambers 12) corresponding to the respective electrodes, and a nozzle substrate 16 having nozzles 15 corresponding to the respective pressure generating cambers 12. The electrodes 36 arranged on the circuit board 20 have connection terminals 34 extended therefrom, and the channel forming substrate 111 is arranged on the same plane on which the electrodes 36 are placed. Then, the connection terminals 34 are extended to the outside of the channel forming substrate 111 and electrically connected to a driving circuit section 200A. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a droplet discharge head and a droplet discharge device.

2. Description of the Related Art Conventionally, an ink jet head (droplet discharge head) using an electrostatic actuator as pressure generating means for discharging a droplet is known. This type of inkjet head has a nozzle, an ink flow path communicating with the nozzle, a diaphragm formed in a part of the ink flow path, and an electrode provided to face the diaphragm, The diaphragm and the electrode form an electrostatic actuator as pressure generating means. If the ink flow paths, electrodes, wirings, and the like are formed on a silicon substrate using semiconductor technology, nozzles and electrostatic actuators can be arranged with high density.
However, when the electrostatic actuators are arranged with high density as described above, the terminals drawn from the electrostatic actuators need to be arranged with high density. An external connection terminal drawn from the actuator and an external drive circuit are electrically connected via a flexible printed circuit (FPC).
Japanese Patent Laid-Open No. 11-348283

However, in the configuration in which the electrostatic actuator and the external drive circuit are connected via the flexible substrate, it is necessary to gather terminals derived from a large number of electrostatic actuators at one end of the inkjet head to which the flexible substrate is connected. Therefore, as a result, the length of the wiring connecting the terminal and the external drive circuit differs between electrostatic actuators. As a result, the time constant differs for each electrostatic actuator, and there is a possibility that a nozzle that does not eject droplets even if a drive pulse set in advance with respect to the design value is input to the terminal may be generated.

The present invention has been made in view of the above-mentioned problems of the prior art, and is an electrical connection between pressure generating means for discharging droplets from a nozzle and a drive circuit for supplying an electric signal to the pressure generating means. An object of the present invention is to provide a droplet discharge head that can eliminate nonuniformity of time constants in connection, can easily set drive conditions, has excellent operation reliability, and is preferably space-saving and excellent in handling properties.
It is another object of the present invention to provide a droplet discharge apparatus that includes the droplet discharge head and can perform high-definition drawing processing.

In order to solve the above-described problems, the present invention provides a plurality of nozzles each including a nozzle that discharges droplets, a pressure generation chamber that communicates with the nozzle, and a pressure generation unit that is provided adjacent to the pressure generation chamber. A droplet discharge head in which droplet discharge units are arranged in a plane, and a drive circuit unit for supplying a drive signal to the pressure generating means is disposed along the arrangement direction of the droplet discharge units. A droplet discharge head is provided, wherein the droplet discharge head is electrically connected to a plurality of connection terminals extending in a direction intersecting with the arrangement direction of the droplet discharge portions from the pressure generating means.
According to this configuration, the droplet discharge units arranged in a predetermined direction and the drive circuit unit disposed along the droplet discharge unit are electrically connected by the connection terminals. The length can be made substantially the same length in each droplet discharge portion. Therefore, the lengths of the electrical paths related to the connection between the drive circuit section and each droplet discharge section can be made uniform, and the nonuniformity of the time constant can be eliminated. As a result, adjustment of the output timing of the electric signal in the drive circuit section becomes almost unnecessary, so that the drive conditions can be set very easily, and a liquid droplet discharge head with excellent reliability that is unlikely to cause a discharge failure or the like.

  In the droplet discharge head of the present invention, a plurality of electrode terminals arranged in a substantially straight line are formed in the drive circuit unit, and the arrangement direction of the plurality of electrode terminals and the droplet discharge unit constituting the droplet discharge unit It is preferable that the arrangement direction of the pressure generating means is substantially parallel. According to this configuration, since the electrode terminal connected to the connection terminal extending from each pressure generating means is disposed substantially in parallel with the pressure generating means, the electrical path through the connection terminal It becomes possible to align the length with higher accuracy. As a result, the time constant can be further uniformized, and the driving conditions can be set more easily.

  The droplet discharge head according to the present invention includes a plurality of droplet discharge unit groups in which the plurality of droplet discharge units are arranged substantially linearly, and the plurality of droplet discharge unit groups are the same drive circuit unit. Are preferably electrically connected to each other. According to this configuration, since a plurality of droplet discharge unit groups share one drive circuit unit, it is possible to reduce the number of components of the droplet discharge head, to reduce the manufacturing cost, and to make the head compact. Can do.

  In the droplet discharge head of the present invention, a pair of the droplet discharge unit groups are respectively arranged on both sides of the drive circuit unit, and the connection of the pressure generating means included in each droplet discharge unit group It is preferable that the terminal extends to the drive circuit unit side and is electrically connected to the drive circuit unit. That is, the droplet discharge unit groups extending along the extending direction of the driving circuit unit are arranged on both sides in the width direction of the driving circuit unit extending in one direction and electrically connected to the driving circuit unit. A configuration can also be adopted.

The droplet discharge head of the present invention corresponds to a circuit board having a plurality of electrodes arranged in a plane, a flow path forming substrate having a plurality of pressure generation chambers corresponding to the electrodes, and the pressure generation chambers. A plurality of connection terminals extending from each of the electrodes in a direction intersecting with an arrangement direction of the plurality of electrodes. The flow path forming substrate is arranged at a position overlapping the respective electrodes in a plan view, and the plurality of connection terminals are extended to the outside of the flow path forming substrate, and each electrode is extended at the extended position. It is electrically connected to a drive circuit portion for supplying a drive signal to the circuit.
According to this configuration, since the drive circuit unit is mounted at a position adjacent to the flow path forming substrate disposed on the circuit board, the length of the electrical path between the electrode and the drive circuit unit is set to It can be aligned between each electrode. As a result, it is possible to provide a liquid droplet ejection head that can equalize time constants, easily set drive conditions, hardly cause problems such as ejection failure, and has excellent reliability. In addition, since the drive circuit unit is mounted on the circuit board, it is only necessary to mount a wiring pattern on the wiring board for connecting to the external device, and the handling property when mounting to the external device is excellent. It becomes a droplet discharge head.

  In the liquid droplet ejection head according to the aspect of the invention, it is preferable that the nozzle substrate is disposed so as to cover a drive circuit unit disposed on the circuit substrate. According to this configuration, since the drive circuit unit can be built in between the nozzle substrate and the circuit substrate, the droplet discharge head can be made compact. In addition, since the drive circuit section is not exposed, the handling property of the droplet discharge head can be improved.

  In the liquid droplet ejection head according to the aspect of the invention, it is preferable that a thickness of the drive circuit unit is equal to or less than a thickness of the flow path forming substrate. According to this configuration, the drive circuit unit provided at a position adjacent to the flow path forming substrate on the circuit board is simply bonded to the nozzle substrate and the circuit board between the nozzle substrate and the circuit board. It is possible to provide a thin droplet discharge head that can be built in and easily manufactured.

  In the liquid droplet ejection head of the present invention, a plurality of vibration plates corresponding to the pressure generation chambers are provided on the circuit board side of the flow path forming substrate, and the vibration plates correspond to the circuit boards. It is preferable that the electrodes to be arranged are arranged to face each other with a predetermined interval. According to this configuration, it is possible to configure pressure generating means for applying pressure to the pressure generating chamber by the electrode on the circuit board and the diaphragm.

  In the liquid droplet ejection head of the present invention, the flow path forming substrate has a silicon substrate as a base, and a groove formed on one surface side of the silicon substrate forms the pressure generating chamber, and a bottom wall of the groove It is preferable that the part forms the diaphragm. According to this configuration, the pressure generating chamber and the diaphragm can be formed by the groove formed in the flow path forming substrate. By using a silicon substrate, it is possible to form high-precision grooves using semiconductor manufacturing technology, and even with a high-definition droplet discharge head that has a large number of pressure generation chambers formed at high density, It is possible to manufacture efficiently and with a high yield. In addition, since the diaphragm is integrally formed on the flow path forming substrate, the thickness and planar dimensions of the diaphragm can be controlled with high accuracy, and a droplet ejection head capable of uniform droplet ejection can be obtained.

  In the liquid droplet ejection head according to the aspect of the invention, it is preferable that a sealing member is provided at a peripheral portion of a region between the nozzle substrate and the circuit substrate. According to this configuration, since the drive circuit unit mounted on the circuit board can be sealed inside the droplet discharge head, the drive circuit unit is hardly affected by outside air and ink, and has excellent reliability. A droplet discharge head can be obtained.

  In the liquid droplet ejection head according to the aspect of the invention, it is preferable that the drive circuit unit is flip-chip mounted on the connection terminal on the circuit board. According to this configuration, since the mounting height of the drive circuit unit can be reduced, the interval between the nozzle substrate and the circuit substrate can be reduced, which is advantageous for reducing the thickness of the droplet discharge head.

  In the liquid droplet ejection head according to the aspect of the invention, it is preferable that a sealing member is provided in a conductive connection portion between the drive circuit portion and the connection terminal. According to this configuration, since the conductive connection portion between the circuit board and the drive circuit portion is sealed, the physical and electrical reliability around the drive circuit portion can be improved, and the reliability of the droplet discharge head can be improved. It becomes the structure which can contribute to property improvement.

  In the liquid droplet ejection head of the present invention, external connection terminals that are conductively connected to the drive circuit section directly or via a wiring pattern are formed on the side edges of the circuit board. It is preferable that a flexible wiring board is connected. According to this configuration, there is provided a droplet discharge head that can be easily mounted on an external device using a flexible wiring board connected to an external connection terminal. In the present invention, it is not necessary to provide a drive circuit portion on a flexible wiring board or an external circuit connected via the flexible wiring board, so that mounting on an external device becomes extremely easy.

The method for manufacturing a droplet discharge head according to the present invention includes a circuit board having a plurality of electrodes arranged in a plane, a flow path forming substrate having a plurality of pressure generation chambers corresponding to the electrodes, and the pressure generations. A method of manufacturing a droplet discharge head comprising a nozzle substrate having a nozzle corresponding to a chamber, wherein the pressure generating chamber of the flow path forming substrate is aligned with an electrode on the circuit substrate. A step of joining the circuit board and the flow path forming substrate, mounting a drive circuit unit on the circuit board outside the flow path forming substrate, and electrically connecting the drive circuit unit and the electrode And the nozzle substrate covering the flow path forming substrate and the drive circuit unit is disposed by aligning the pressure generating chamber of the flow path forming substrate and the nozzle, and the nozzle substrate and the flow path forming substrate And a step of bonding To.
According to this manufacturing method, it is possible to easily manufacture a compact and highly reliable droplet discharge head in which a drive circuit unit is built in between the circuit substrate and the nozzle substrate.

  A droplet discharge apparatus according to the present invention includes the droplet discharge head according to the present invention described above. According to this configuration, it is possible to provide a droplet discharge device that is easy to set operating conditions, has excellent operation reliability, has a droplet discharge head that is compact, and achieves improved reliability and size reduction. Can do.

(Inkjet head)
FIG. 1 is a perspective configuration diagram of an ink jet head which is an embodiment of a droplet discharge head according to the present invention. FIG. 2 is a perspective configuration diagram of the inkjet head shown with the nozzle substrate shown in FIG. 1 removed. FIG. 3A is a sectional configuration diagram along line AA ′ in FIG. 2, and FIG. 3B is a view taken along the line BB ′ in FIG.
In each drawing referred to in this specification, the size, thickness, etc. of each part is appropriately changed and displayed in order to make the drawing easy to see, or arranged components (nozzles, pressure generation chambers, electrodes, etc.) The number is reduced.

  As shown in FIG. 1, the inkjet head 10 according to the present embodiment is a face-eject type inkjet head that ejects liquid droplets from a plurality of nozzles 15 arranged on one main surface of the head. The plurality of nozzles 15 penetrates the nozzle substrate 16 shown in FIG. 1, and the nozzle substrate 10 is fixed on a circuit substrate 20 having a glass substrate as a base, for example. At least the peripheral portion of the region between the nozzle substrate 10 and the circuit substrate 20 is sealed with a sealing member 40 made of a resin material or the like.

The nozzles 15 are arranged in four rows on the nozzle substrate 16 as shown in the figure, and a group of nozzles 15 constituting each row are arranged in order from the front side in the Y-axis direction in the drawing in a first nozzle group 151 and a second nozzle group. 152, the third nozzle group 153, and the fourth nozzle group 154. The nozzle groups 151 to 154 extend along the X-axis direction and are arranged substantially parallel to each other, and are arranged at positions facing each other in the Y-axis direction.
In FIG. 1, each nozzle group 151 to 154 is displayed as being composed of 21 nozzles 15. However, in an actual ink jet head, each nozzle group has a large number of about 720 nozzles 15. It is supposed to be arranged.

  The side edge of the front side (−X side) of the circuit board 20 protrudes from the edge of the nozzle substrate 16 placed on the board to the −X side, and the upper surface (− External connection portions 21a and 21b are formed on the Z side surface. A first flexible substrate (flexible wiring substrate, FPC (Flexible Print Circuit)) 51 and a second flexible substrate 52 are connected to each of the external connection portions 21a and 21b. A plurality of wiring patterns 511 and wiring patterns 521 that are electrically connected to external connection terminals (not shown) provided in the external connection portions 21a and 21b are formed on the flexible substrates 51 and 52, respectively.

  As shown in FIG. 2, the first flow path forming substrate 111, the second flow path forming substrate 112, and the third flow are formed on the circuit board 20 of the inkjet head 10 with the nozzle substrate 16 and the sealing member 40 removed. The path forming substrate 113 and the fourth flow path forming substrate 114 are arranged along the Y-axis direction. Each of the flow path forming substrates 111 to 114 has a groove having a predetermined shape that is engraved on the upper surface (−Z side surface) in the drawing.

  The flow path forming substrate 111 will be described. Among the groove portions formed on the upper surface thereof, the plurality of groove portions 12a arranged in a long rectangular shape along the Y-axis direction are formed by the previous nozzle substrate 16. At the same time, the pressure generating chamber 12 is formed as a space for temporarily storing the liquid material discharged as droplets. Of the grooves, the groove 24 a extending in a long rectangular shape along the X-axis direction is a space for temporarily storing the liquid material supplied to the pressure generating chambers 12 together with the nozzle substrate 16. A certain reservoir 24 is formed. A plurality of groove portions 22a that connect each of the groove portions 12a (pressure generation chambers 12) arranged in the X-axis direction and the groove portion 24a (reservoir 24) connect the reservoir 24 and each pressure generation chamber 12 together with the nozzle substrate 16. The ink flow path 22 is formed as a communication space.

  Of the flow path forming substrates 112 to 114, the third flow path forming substrate 113 has the same configuration as the first flow path forming substrate 111. On the other hand, the second flow path forming substrate 112 and the fourth flow path forming substrate 114 are, like the first flow path forming substrate 111, a plurality of pressure generating chambers 12, a reservoir 24, and a plurality of ink flow paths communicating these. 22, the groove portions 12 a..., The groove portions 22 a..., And the reservoir 24 are formed symmetrically with respect to the first flow path forming substrate 111 in the X-axis direction. . That is, in the first flow path forming substrate 111 and the second flow path forming substrate 112 arranged to face each other with respect to the Y-axis direction, the groove portions 12a (pressure generation chambers 12) are arranged on opposite side edges. The reservoir 24 extends outside the grooves 12a in the Y-axis direction. The third flow path forming substrate 113 and the fourth flow path forming substrate 114 are also arranged in the same manner as the first and second flow path forming substrates.

Each of the first flow path forming substrate 111 to the fourth flow path forming substrate 114 is based on a single crystal silicon substrate imparted with conductivity, and the groove portions 12a, 22a, and 24a are formed of each single crystal silicon. It is formed by subjecting the substrate to anisotropic etching.
Anisotropic etching is etching that takes advantage of the fact that the etching rate differs depending on the etching direction. When etching single crystal silicon, the etching rate of the Si (100) surface is compared with that of the Si (111) surface. This is an etching method utilizing the fact that it is about 40 times faster. The depth of each groove can be easily adjusted by the etching time.

  The pressure generating chamber 12, the reservoir 24, and the grooves 12 a, 24 a, and 22 a forming the ink flow path 22 that communicates with the pressure generation chamber 12, the amount and speed of the liquid droplets discharged in the ink supply path in the inkjet head 10, etc. It is a part sensitive to the characteristics of the material, and the highest machining accuracy is required. In the present embodiment, these portions requiring high processing accuracy are processed by anisotropic etching, so that grooves having different dimensions can be formed with high accuracy at a time. Therefore, by applying a single crystal substrate, particularly a single crystal silicon substrate, as the base of the flow path forming substrates 111 to 114, the flow path forming substrates 111 to 114 having high dimensional accuracy can be easily obtained.

  In addition to the above, there are various advantages in using silicon as a substrate material. First, silicon is a commonly used material for manufacturing integrated circuits, and the material is easily available. Silicon also withstands higher temperatures than devices using germanium. Furthermore, since the reverse current (saturation current) is extremely small in electrical rectification, it is advantageous for the present invention. Thus, the advantage of using silicon as the substrate material is great.

  In the present embodiment, the group of pressure generation chambers 12 formed by the group of groove portions 12 a arranged on the first flow path forming substrate 111 and the nozzle substrate 16 is referred to as a first pressure generation chamber group 121, and the second A group of pressure generation chambers 12 formed by the group of grooves 12a formed on the flow path forming substrate 112 and the nozzle substrate 16 is referred to as a second pressure generation chamber group 122 and is formed on the third flow path forming substrate 113. The group of pressure generation chambers 12 formed by the group of groove portions 12a and the nozzle substrate 16 is referred to as a third pressure generation chamber group 123, and the group of groove portions 12a and nozzles formed on the fourth flow path forming substrate 114. A group of pressure generation chambers 12 formed by the substrate 16 is referred to as a fourth pressure generation chamber group 124.

  The groove 12a (pressure generation chamber 12) formed in the first flow path forming substrate 111 to the fourth flow path forming substrate 114 is placed on the nozzle substrate 16 with the nozzle substrate 16 shown in FIG. The nozzles 15 communicated with the arrayed nozzles 15. That is, the first nozzle group 151 and the first pressure generation chamber group 121 of the nozzle substrate 16 are disposed so as to communicate with each nozzle 15 and the pressure generation chamber 12. The second nozzle group 152 and the second pressure generation chamber group 122, the third nozzle group 153 and the third pressure generation chamber group 123, and the fourth nozzle group 154 and the fourth pressure generation chamber group 124 have the same positional relationship. Are arranged.

Between the first flow path forming substrate 111 and the second flow path forming substrate 112, a drive circuit section 200A that is long in the Y-axis direction is disposed along the longitudinal direction of the flow path forming substrates 111 and 112. Between the three flow path forming substrate 113 and the fourth flow path forming substrate 114, a drive circuit section 200B that is long in the Y-axis direction is disposed along the longitudinal direction of the two flow path forming substrates 113 and 114. .
As will be described in detail later, the drive circuit unit 200A is provided in the first nozzle group 151 provided in the planar area of the first flow path forming substrate 111 and in the planar area of the second flow path forming substrate 112. An electric signal supplying operation for discharging droplets from the second nozzle group 152 is performed. The drive circuit unit 200B includes a third nozzle group 153 provided in the planar area of the third flow path forming substrate 113 and a fourth nozzle group 154 provided in the planar area of the fourth flow path forming substrate 114. The operation of supplying an electric signal for discharging a droplet from the liquid is performed.

  The drive circuit units 200A and 200B shown in FIG. 2 may be sealed with a gap between the circuit board 20 and the flow path forming boards 111 to 114 using a resin material or the like. With such a configuration, the drive circuit portions 200A and 200B can be protected even better in combination with the sealing member 40 provided on the peripheral portion of the nozzle substrate 16 and the circuit substrate 20, and the reliability of the inkjet head can be improved. .

  Next, referring to the AA ′ cross-sectional view shown in FIG. 3A and the BB ′ arrow view shown in FIG. 3B, the inkjet head 10 includes the circuit board 20 and the first flow path forming board. 111, the second flow path forming substrate 112, and the nozzle substrate 16 are stacked. A step is formed between the circuit substrate 20 and the nozzle substrate 16 and the first flow path forming substrate 111 at the side end of the inkjet head, and a sealing member 40 is provided to fill the step. Yes. The drive circuit unit 200A is thinner than the flow path forming substrates 111 and 112, and is accommodated in a space surrounded by the flow path forming substrates 111 and 112, the nozzle substrate 16, and the circuit board 20. .

  The circuit board 20 has, for example, a glass substrate as a base, and an electrode 36 and a connection terminal (wiring pattern) 34 extend from the electrode 36 toward the + Y side on the surface (−Z side surface). The first flow path forming substrate 111 is disposed on the circuit board 20 so as to cover the electrode 36, and the connection terminal 34 extending from the electrode 36 extends to the outside of the first flow path forming substrate 111. It extends. Then, with respect to the connection terminal 34 exposed to the outside of the first flow path forming substrate 111, the drive circuit portion 200A is flipped via a bump (electrode terminal) 200a provided on the lower surface (+ Z side surface). Chip mounted.

  A glass substrate or a silicon substrate can be used as the substrate for the circuit board 20. In this embodiment, the electrode 36, the connection terminal 34, and the like are formed by patterning a metal film such as Al on the surface of the glass substrate. Formed. The first flow path forming substrate 111 is based on a single crystal silicon substrate having conductivity doped with phosphorus (P) as an impurity. Grooves 12a, 22a, and 24a are formed on the upper surface side (-Z side) of the first flow path forming substrate 111, and a nozzle substrate 16 having a silicon substrate as a base is joined so as to cover them. The nozzle 15 of the nozzle substrate 16 is a through hole formed by fine processing using a micromachining technique.

  In FIGS. 2 and 3, the side walls of the grooves 12a, 22a, 24a, etc. are shown to be substantially perpendicular to the XY plane. However, in the grooves formed by anisotropic etching of single crystal silicon. Depending on the crystal orientation of the surface to be etched, the side wall is inclined with respect to the substrate surface. For example, when an anisotropic etching process using a KOH solution is performed on a Si (100) substrate, the side wall of the groove to be formed becomes an inclined surface that forms an angle of about 55 ° with respect to the substrate surface.

  A space formed between the nozzle substrate 16 and the first flow path forming substrate 111 forms a pressure generation chamber 12, a reservoir 24, and an ink flow path 22. The pressure generating chamber 12 communicates with the nozzle 15 formed on the nozzle substrate 16. A groove 26 a is formed on the lower surface side (+ Z side) of the first flow path forming substrate 111, and when the first flow path forming substrate 111 and the circuit board 20 are joined, the groove 26 a and the circuit board 20 are interposed. The electrode 36 is accommodated in the space to be formed. The groove part 26a is formed to a depth larger than the thickness of the electrode 36 accommodated therein, and the bottom wall part of the groove part 26a and the electrode 36 are separated from each other with a predetermined interval.

  Since the groove portion 12a and the groove portion 26a are formed on both surfaces of the first flow path forming substrate 111, their bottom wall portions are thinned, and this thinned portion is the operation of the inkjet head 10. The diaphragm 14 is sometimes bent. As described above, the diaphragm 14 and the electrode 36 formed on the bottom wall portion of the groove portion 26a are spaced apart by a predetermined distance with the depth of the groove portion 26a. It becomes an operation space of the vibrating diaphragm 14. Under such a configuration, the diaphragm 14 and the electrode 36 form a pressure generating means 32 that causes a pressure change in the pressure generating chamber 12.

  In the planar structure shown in FIG. 3B, the electrode 36 accommodated in the groove 26a is a strip-like conductive film extending in the Y-axis direction, and the groove formed in the first flow path forming substrate 111. 12a (pressure generation chamber 12) is arranged so as to overlap with the plane. The nozzle 15 of the nozzle substrate 16 is also disposed in the plane area of the groove 12a.

  As described above, in the inkjet head 10 of the present embodiment, one nozzle 15 and one pressure generating means 32 (the diaphragm 14 and the electrode 36) are provided for one pressure generating chamber 12, and these The constituent elements constitute a droplet discharge unit 31 that performs a droplet discharge operation based on an electrical signal input from the drive circuit unit 200A when the inkjet head 10 is operated.

  FIG. 4 is a diagram conceptually illustrating a planar configuration of the inkjet head 10 when the droplet discharge unit 31 is viewed as one structural unit. As shown in the figure, when viewed from the inkjet head 10 as a whole, a plurality of droplet discharge portions 31 are provided along the X-axis direction in each planar region of the first flow path forming substrate 111 to the fourth flow path forming substrate 114. It is arranged. Reference numeral 311 indicates a first droplet discharge unit group composed of a group of droplet discharge units 31 arranged corresponding to the first flow path forming substrate 111. Reference numeral 312 indicates a second droplet discharge unit group composed of a group of droplet discharge units 31 arranged corresponding to the second flow path forming substrate 112. Reference numeral 313 indicates a third droplet discharge unit group including a group of droplet discharge units 31 arranged corresponding to the third flow path forming substrate 113. Reference numeral 314 indicates a fourth droplet discharge unit group including a group of droplet discharge units 31 arranged corresponding to the fourth flow path forming substrate 114. The droplet discharge units 31 constituting each of the droplet discharge unit groups 311 to 313 are the same as those described with reference to FIG.

  The first droplet discharge unit group 311 and the second droplet discharge unit group 312 are electrically connected to the drive circuit unit 200A disposed between them, and the electricity input from the drive circuit unit 200A. A droplet discharge operation is performed by a signal. In addition, the third droplet discharge unit group 313 and the fourth droplet discharge unit group 314 are also electrically connected to the drive circuit unit 200B disposed therebetween, and input from the drive circuit unit 200B. A droplet discharge operation is performed by an electrical signal.

  The flexible boards 51 and 52 connected to the side edges on the −X side of the circuit board 20 are connected to the drive circuit sections 200A and 200B via wiring patterns on the circuit board 20, respectively. Is connected to a control device 500 that controls the drive of the inkjet head 10. Further, the control device 500 is electrically connected to the first flow path forming substrate 111 to the fourth flow path forming substrate 114 via a wiring pattern on the flexible substrate and the circuit board 20.

  Next, the operation of the inkjet head 10 will be described with reference to FIG. In FIG. 3A, it is assumed that the reservoir 24, the ink flow path 22, and the pressure generation chamber 12 constituting the ink supply path are filled with a liquid material to be used for ejection. The control device 500 is electrically connected to the drive circuit unit 200A and the conductive flow path forming substrate 111.

When command information (electrical signal) is input from the control device 500 to the drive circuit 200A, the drive circuit unit 200A operates based on the command information and ejects droplets to be ejected to the selected electrode 36. A voltage (driving pulse) corresponding to the magnitude of is applied.
Then, since the first flow path forming substrate 111 is electrically connected to the control device 500 and held at a constant voltage, there is a potential difference between the electrode 36 and the diaphragm 14 (first flow path forming substrate 111). The flexible diaphragm 14 is attracted to the electrode 36 by the electrostatic force resulting from this potential difference. Thereby, the volume of the pressure generation chamber 12 is expanded, and the liquid material flows from the reservoir 24 into the pressure generation chamber 12. Thereafter, when the application of voltage by the drive circuit 200A is stopped at a timing when the liquid material is sufficiently supplied, the diaphragm 14 is released from the electrostatic force, and pressure is applied to the pressure generating chamber 12 by the restoring force. A droplet is discharged from the nozzle 15 by this pressure.
After that, when the vibration of the liquid material in the pressure generation chamber 12 and the ink flow path 22 is attenuated and converged by the flow path resistance, the liquid droplet discharge section 31 returns to the state before the discharge operation, so that the next liquid drop can be discharged. It becomes like this.

  In the inkjet head 10 of the present embodiment having the above-described configuration, the drive circuit unit 200A is arranged along the arrangement direction (X-axis direction) of the droplet discharge unit group 311 formed so as to be arranged substantially linearly. In addition, each droplet discharge unit 31 and the drive circuit unit 200 </ b> A are electrically connected via a connection terminal 34 extending from each droplet discharge unit 31. As a result, the length of the wiring path from the drive circuit unit 200A to each droplet discharge unit 31 (pressure generating means 32) is equal in each droplet discharge unit 31, and thus the electric power output from the drive circuit unit 200A. A delay in the signal can be prevented, and nonuniformity of the time constant in the electrical connection can be eliminated. As a result, the inkjet head 10 of the present embodiment is easy to set drive conditions and is excellent in operation reliability. This embodiment is a configuration suitable for use in a high-definition inkjet head in which an extremely large number of droplet discharge units 31 are arranged.

  The drive circuit 200A is electrically connected to both the first droplet discharge unit group 311 and the second droplet discharge unit group 312 arranged on both sides in the width direction (Y-axis direction). The droplet discharge unit 31 constituting the droplet discharge unit group can be driven. With this configuration, it is possible to realize a space saving of the drive circuit unit in the inkjet head 10 and the wiring path to the drive circuit unit, thereby realizing a compact inkjet head.

  The drive circuit units 200A and 200B are built in between the nozzle substrate 16 and the circuit substrate 20 that face each other with the flow path forming substrates 111 to 114 interposed therebetween. As a result, compared to the case where the drive circuit units 200A and 200B are provided on a flexible substrate or an external circuit via the flexible substrate, it is possible to realize a space saving and an inkjet head having excellent handling properties. .

  In addition, since the drive circuit units 200A and 200B are built in, the wiring with the control device 500 connected via the flexible boards 51 and 52 is limited to the wiring for the control signal and the power source, and the external connection unit 21a. , 21b (connecting portions with the flexible substrates 51 and 52), the number of wires to be drawn out can be reduced, and the electrical connection with the flexible substrates 51 and 52 can be easily and accurately obtained.

  Furthermore, the drive circuit portions 200A and 200B mounted on the circuit board 20 are arranged inside the ink jet head 10 by a sealing member provided at the peripheral portion thereof or a sealing member 40 provided at the peripheral portion of the nozzle substrate 16. Therefore, the semiconductor element and the like are hardly affected by oxygen and moisture contained in the outside air, and thus have excellent reliability.

(Inkjet head manufacturing method)
Next, a method for manufacturing the inkjet head 10 according to the above embodiment will be described with reference to FIGS. 5 to 10 show only the portion around the connection end with the flexible substrate 51 in the inkjet head 10 shown in FIGS. 1 to 4, but the same applies to the periphery of the connection end with the flexible substrate 52. It is the composition.

In order to manufacture the ink jet head 10, first, as shown in FIG. 5, a circuit board 20, a first flow path forming substrate 111, and a second flow path forming substrate 112 are prepared.
The circuit board 20 can be manufactured by forming various wiring patterns using a wiring material such as Al on a glass substrate made of borosilicate glass or the like using a photolithography technique. On the surface (upper surface in the drawing) of the circuit board 20 according to the present embodiment, a plurality of electrodes 36 having a substantially rectangular shape in plan view, connection terminals 34 extending from the electrodes 36, and electrodes 371 having a substantially rectangular shape in plan view. , 372 and a flexible substrate 51 are formed with a plurality of connection wirings 27a to 27c constituting an external connection portion 21a. Among the connection wirings 27a to 27c, connection wirings 27a and 27b formed at both ends (Y-axis direction both ends) in the drawing are common electrode wirings connected to the electrodes 371 and 372, respectively. The connection wiring 27 c including a plurality of (in the drawing, five) wiring patterns is a drive circuit wiring extending toward the center of the circuit board 20.

  The drive circuit wiring 27c is formed so that the line width increases from the center side to the side edge of the circuit board 20, and the wiring pitch increases accordingly. It is configured so that the conductive connection can be easily performed.

As described in the previous embodiment, the first flow path forming substrates 111 and 112 are based on a single crystal silicon substrate provided with conductivity, and a plurality of groove portions on the upper surface side of the single crystal silicon substrate. 12a, a groove portion 22a extending from each groove portion 12a, and a groove portion 24a extending across the plurality of groove portions 22a. Although not shown in the figure, the electrode 36 on the circuit board 20 is provided on the lower surface side of the drawing. Is provided with a groove 26a.
At one corner of the first flow path forming substrates 111 and 112, notches 111 a and 112 a are formed by notching the corners, and when the circuit board 20 is joined, The connection wiring is not in contact with the flow path forming substrates 111 and 112.

  Next, the first flow path forming substrate 111 and the second flow path forming substrate 112 are aligned and bonded to predetermined positions on the circuit board 20 (see FIG. 6). Specifically, the substrates are aligned so that the grooves 12a (pressure generation chambers 12) of the flow path forming substrates 111 and 112 overlap each other with respect to the electrodes 36 on the circuit board 20. And join. By this joining, the electrode 36 is accommodated in the groove portion 26a of the flow path forming substrates 111 and 112, and the diaphragm 14 and the electrode 36 formed on the bottom wall portion of the groove portion 26a are arranged to face each other to form pressure generating means. .

  In the case of the present embodiment, since the base of the circuit board 20 is a glass substrate and the base of the flow path forming substrates 111 and 112 is a silicon substrate, anodic bonding can be used for the bonding between them. “Anodic bonding” is a method in which a large electrostatic attraction is generated between glass and silicon by heating to 300 to 400 ° C. in a state where both are brought into contact and applying a voltage of about 500 V to 1 kV. This is a technology for bonding substrates by chemical bonding.

  As shown in FIG. 6, the electrodes 371 and 372 on the circuit board 20 come into contact with the flow path forming substrates 111 and 112, respectively, by the bonding step, and the first flow path forming substrate 111 and the common electrode wiring 27a Are electrically connected, and the second flow path forming substrate 112 and the common electrode wiring 27b are electrically connected. Thereby, the connection terminal to the 1st flow path formation board | substrate 111 and the 2nd flow path formation board | substrate 112 will be pulled out by the external connection part 21a.

Next, with respect to the connection terminal 34 exposed on the circuit board 20 between the first flow path forming substrate 111 and the second flow path forming substrate 112, and the drive circuit wiring 27c extending from the external connection portion 21a, The drive circuit unit 200A is flip-chip mounted. In the drawing, only a part on the −X side of the drive circuit section 200A that is long in the X-axis direction is shown.
As flip chip mounting, Au-Au bonding, bonding with an anisotropic conductive material such as ACP (anisotropic conductive paste), ACF (anisotropic conductive film), NCP (conductive paste), NCF Various forms such as adhesion using a nonconductive material such as (conductive film) can be employed. By employing each of the mounting methods exemplified above, it is possible to obtain electrical bonding with excellent reliability while suppressing the mounting thickness, and it is possible to realize a compact ink jet head and improved reliability.

  Next, as shown in FIG. 7, a separately prepared nozzle substrate 16 is prepared, and is positioned and bonded to the first flow path forming substrate 111 and the second flow path forming substrate 112 arranged on the circuit board 20. . At this time, the nozzle substrate 16 and the flow path forming substrates 111 and 112 are arranged so that the nozzles 15 of the nozzle substrate 16 are arranged in the planar region of the groove portion 12a of the corresponding flow path forming substrates 111 and 112. Aligned. By this bonding step, the pressure generating chamber 12 is formed in the space surrounded by the groove 12a and the nozzle substrate 16 formed in the flow path forming substrates 111 and 112, and the space surrounded by the groove 22a and the nozzle substrate 16 is formed. The ink flow path 22 is formed, and the reservoir 24 is formed in a space surrounded by the groove 24 a and the nozzle substrate 16.

  Since the nozzle substrate 16 and the flow path forming substrates 111 and 112 are both based on a silicon substrate, in addition to the method using eutectic bonding, the insulating films formed on the surface of the silicon substrate are used for the bonding. It is possible to employ a method of joining the layers and a method of joining with an adhesive. In eutectic bonding, strong bonding can be obtained at a low temperature of about 400 ° C. by bonding gold or another binder at the bonding interface between the flow path forming substrates 111 and 112 and the nozzle substrate 16.

  Through the above steps, the main body portion of the inkjet head 10 can be manufactured as shown in FIG. In FIG. 8, in order to show the laminated state of each part, the end part 16a on the external connection part 21a side of the nozzle substrate 16 is slightly retreated to the + X side, and the flow path forming substrates 111 and 112 are displayed. The same applies to FIGS. 9 and 10 referred to later.

  Next, as shown in FIG. 9, a flexible substrate 51 is connected to the main body portion of the inkjet head 10. As shown in FIG. 9, a plurality of connection terminals 512 are arrayed and formed on the side end portion on the + X side on the lower surface side (+ Z side) of the flexible substrate 51, and a plurality of connection terminals are provided on the side end portion on the −X side. 513 are arranged, and each of the connection terminals 512 is electrically connected to the corresponding connection terminal 513 through a wiring pattern 511. The connection terminals 512 formed on the side edges on the + X side are formed with a width and a pitch corresponding to the connection wiring formed on the external connection portion 21 a of the circuit board 20, and are connected to these connection terminals 512. The connection terminals 513 are formed with a larger line width and pitch than the connection terminals 512. By using the flexible substrate 51 having such a configuration, it is possible to improve handling when the inkjet head 10 is connected to an external device, and to improve connection reliability.

  The flexible substrate 51 is bonded to each connection wiring (27a to 27c) of the external connection portion 21a exposed on the circuit board 20 in a state where the connection terminals 512 are aligned. In this bonding, a bonding method using ACF or ACP can be suitably used, but a bonding method using metal bonding or NCF or NCP may be used.

  If the flexible board 51 is connected to the circuit board 20 as shown in FIG. 10, the head periphery between the nozzle board 16 and the circuit board 20 is sealed with a resin material or the like as shown in FIG. By disposing the member 40, the inkjet head 10 is obtained. In FIG. 1, the connecting portion between the flexible substrate 51 and the circuit board 20 is not sealed by the sealing member 40, but the connecting portion may be sealed by the sealing member 40 or another sealing member. Of course, by performing such sealing, the physical and electrical reliability at the connection portion between the flexible substrate 51 and the circuit substrate 20 can be enhanced.

  In the above embodiment, the case where one inkjet head 10 is manufactured has been described. However, a plurality of inkjet heads 10 can be manufactured collectively using a large substrate. That is, a large circuit board on which a plurality of circuit boards 20 are formed, a large flow path forming board on which a plurality of flow path forming substrates 111 to 114 are formed, and a plurality of nozzle boards 16 are provided. A large-sized nozzle substrate built in is prepared, subjected to the above-described steps, joined, and then diced and separated at a position corresponding to the outer peripheral end of the ink-jet head 10, whereby the ink-jet head shown in FIG. A body portion can be made. And if the flexible substrates 51 and 52 are connected to the main body portion thus manufactured, a plurality of inkjet heads 10 can be efficiently manufactured.

  As described above in detail, according to the method of manufacturing the ink jet head 10 of the present embodiment, after the circuit board 20 is bonded to the first flow path forming substrate 111 and the second flow path forming substrate 112, the first A drive circuit unit 200A is mounted in a region on the circuit board 20 between the flow path forming substrate 111 and the second flow path forming substrate 112, and the nozzle substrate 16 is covered with the flow path forming substrate so as to cover the mounted drive circuit unit 200A. Since it joins to 111,112, thickness reduction and the compactization in the inkjet head 10 whole are realizable. In addition, since the drive circuit unit 200A is sealed inside the inkjet head 10, the inkjet circuit head 200A itself and the mounting unit of the drive circuit unit 200A are not easily affected by outside air or ink, and an inkjet head excellent in reliability is provided. realizable.

(Droplet discharge device)
Next, an example of a droplet discharge device including the inkjet head 10 described above will be described with reference to FIG. In this example, an ink jet recording apparatus including the above-described ink jet head will be described as an example.

  The ink jet head constitutes a part of a recording head unit having an ink flow path communicating with an ink cartridge or the like, and is mounted on an ink jet recording apparatus. As shown in FIG. 11, the recording head units 1A and 1B having an ink jet head are detachably provided with cartridges 2A and 2B constituting ink supply means, and a carriage on which the recording head units 1A and 1B are mounted. 3 is attached to a carriage shaft 5 attached to the apparatus main body 4 so as to be movable in the axial direction.

  The recording head units 1A and 1B, for example, are configured to eject a black ink composition and a color ink composition, respectively. Then, the driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and a timing belt 7 (not shown), so that the carriage 3 on which the recording head units 1A and 1B are mounted moves along the carriage shaft 5. It is like that. On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S which is a recording medium such as paper fed by a paper feed roller (not shown) is conveyed onto the platen 8. It is like that. Since the ink jet recording apparatus having the above configuration includes the above-described droplet discharge head, the ink jet recording apparatus is small, highly reliable, and low in cost.

  FIG. 11 shows an ink jet recording apparatus as a single printer as an example of the liquid droplet ejection apparatus of the present invention. However, the present invention is not limited to this, and a printer realized by incorporating such a liquid droplet ejection head. It can also be applied to units. Such a printer unit is attached to a display device such as a television or an input device such as a whiteboard, and is used to print an image displayed or input by the display device or the input device.

  The droplet discharge head can also be applied to a droplet discharge apparatus for forming various devices by a liquid phase method. In this embodiment, as the functional liquid discharged from the droplet discharge head, a liquid crystal display device forming material for forming a liquid crystal display device, an organic EL forming material for forming an organic EL display device, an electronic circuit A material including a wiring pattern forming material for forming a wiring pattern is used. According to the manufacturing process in which these functional liquids are selectively arranged on a substrate by a droplet discharge device, the pattern arrangement of the functional material is possible without going through a photolithography process, so a liquid crystal display device, an organic EL device, a circuit board Etc. can be manufactured at low cost.

1 is a perspective configuration diagram of an ink jet head according to an embodiment. FIG. The perspective view block diagram which shows the state which removed the nozzle board | substrate same as the above. The principal part of the head is expanded, a partial cross-sectional configuration diagram, and a plan configuration diagram. FIG. 3 is a plan configuration diagram conceptually showing the arrangement of droplet discharge units. The manufacturing process figure of the ink jet head concerning an embodiment. The manufacturing process figure of the ink jet head concerning an embodiment. The manufacturing process figure of the ink jet head concerning an embodiment. The manufacturing process figure of the ink jet head concerning an embodiment. The manufacturing process figure of the ink jet head concerning an embodiment. The manufacturing process figure of the ink jet head concerning an embodiment. The perspective block diagram which shows an example of a droplet discharge device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Inkjet head (droplet discharge head), 12 Pressure generation chamber, 14 Vibration plate, 15 nozzle, 16 Nozzle substrate, 20 Circuit board, 22 Ink flow path, 24 Reservoir, 31 Droplet discharge part, 32 Pressure generation means, 34 Connection terminal, 36 electrodes, 51, 52 Flexible substrate (wiring substrate), 111-114 flow path forming substrate, 151-154 nozzle group, 200A, 200B drive circuit section, 200a Bump (electrode terminal), 311-314 Droplet ejection Group, 371, 372 electrodes

Claims (14)

A plurality of droplet discharge portions each having a nozzle for discharging droplets, a pressure generation chamber communicating with the nozzle, and pressure generation means provided adjacent to the pressure generation chamber are arranged in a plane. A droplet discharge head,
A drive circuit unit that supplies a drive signal to the pressure generating unit is disposed along the arrangement direction of the droplet discharge units, and extends from the pressure generation unit in a direction that intersects the arrangement direction of the droplet discharge units. A droplet discharge head, wherein the droplet discharge head is electrically connected to a plurality of connection terminals. A plurality of electrode terminals arranged in a substantially straight line are formed in the drive circuit unit,
2. The droplet discharge head according to claim 1, wherein an arrangement direction of the plurality of electrode terminals and an arrangement direction of the pressure generating means constituting the droplet discharge unit are substantially parallel. A plurality of droplet discharge unit groups in which the plurality of droplet discharge units are arranged substantially linearly,
The droplet discharge head according to claim 1, wherein a plurality of the droplet discharge unit groups are electrically connected to the same drive circuit unit. A pair of the droplet discharge unit groups are respectively disposed on both sides of the drive circuit unit,
4. The connection terminal of the pressure generating means included in each droplet discharge unit group extends to the drive circuit unit side and is electrically connected to the drive circuit unit. The droplet discharge head described. A circuit board having a plurality of electrodes arranged in a plane, a flow path forming substrate having a plurality of pressure generation chambers corresponding to the electrodes, and a nozzle substrate having nozzles corresponding to the pressure generation chambers are stacked. A droplet discharge head comprising:
On the circuit board, a plurality of connection terminals extending from each electrode in a direction crossing the arrangement direction of the plurality of electrodes is formed, and the flow path forming board is disposed at a position overlapping the electrodes in a plane. And
The plurality of connection terminals extend to the outside of the flow path forming substrate, and are electrically connected to a drive circuit unit that supplies a drive signal to each electrode at the extended position. Droplet discharge head.   The liquid droplet ejection head according to claim 5, wherein the nozzle substrate is disposed so as to cover a drive circuit unit disposed on the circuit substrate.   The droplet discharge head according to claim 6, wherein a thickness of the drive circuit unit is equal to or less than a thickness of the flow path forming substrate. A plurality of diaphragms corresponding to the respective pressure generation chambers are provided on the circuit board side of the flow path forming substrate,
8. The droplet discharge according to claim 5, wherein each of the diaphragms and the corresponding electrode of the circuit board are arranged to face each other with a predetermined interval. head. The flow path forming substrate has a silicon substrate as a base,
9. The liquid according to claim 8, wherein a groove formed on one side of the silicon substrate forms the pressure generating chamber, and a bottom wall of the groove forms the diaphragm. Drop ejection head.   10. The droplet discharge head according to claim 5, wherein a sealing member is provided at a peripheral portion of a region between the nozzle substrate and the circuit substrate.   11. The droplet discharge head according to claim 5, wherein the drive circuit unit is flip-chip mounted on the connection terminal on the circuit board.   The liquid droplet ejection head according to claim 5, wherein a sealing member is provided in a conductive connection portion between the drive circuit portion and the connection terminal. External connection terminals that are conductively connected to the drive circuit unit directly or via a wiring pattern are formed on the side edges of the circuit board,
The liquid droplet ejection head according to claim 5, wherein a flexible wiring board is connected to the external connection terminal.   A droplet discharge apparatus comprising the droplet discharge head according to claim 1.

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