JP2006224310A - 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: The droplet delivering head is a laminated body of a circuit board 20 and a nozzle substrate having nozzles 15, and a driving circuit section is arranged between the circuit board 20 and the nozzle substrate 16, for driving electrodes. Then, flexible substrates 51 and 52 electrically connected at least to the driving circuit section are connected to one side edge of the circuit board 20, and a connection portion between the flexible substrates 51 and 52 and the circuit board 20 is sealed in a region sandwiched by the nozzle substrate 16 and the circuit board 20 by a sealing member 40. <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. In this case, since the time constant differs for each electrostatic actuator, there is a possibility that a nozzle that does not discharge droplets may be generated even if a drive pulse set in advance with respect to the design value is input to the terminal. There is a problem that the setting of the driving conditions becomes complicated.

The present invention has been made in view of the above-described problems of the prior art, and provides a droplet discharge head that is easy to set drive conditions, has excellent reliability, is space-saving, and has excellent handling properties. The purpose is to do.
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 problems, the present invention provides a circuit board having a plurality of electrodes arranged in a plane, a flow path forming board having a plurality of pressure generating chambers corresponding to each of the plurality of electrodes, A droplet discharge head formed by laminating a nozzle substrate having a nozzle corresponding to each of the pressure generation chambers, wherein a drive circuit unit for driving the electrode is provided between the circuit substrate and the nozzle substrate. An external connection part including at least a connection wiring electrically connected to the drive circuit part is provided on the electrode forming surface of the circuit board, and a wiring board having a wiring pattern is provided in the external connection part. Electrically connected, a sealing member is provided on the outer periphery of the region between the nozzle substrate and the circuit board, and the external connection portion is connected to the nozzle substrate and the circuit board by the sealing member. Sandwiched Providing a droplet discharge head, characterized by being sealed in the region.
According to this configuration, a drive circuit unit that supplies an electronic yellow signal to the electrode to perform a droplet discharge operation is provided between the circuit board and the nozzle substrate. Only the wiring pattern needs to be formed on the wiring board. Therefore, the droplet discharge head is excellent in space saving and excellent in handleability when mounted on an external device. In addition, the external connection portion forming the conductive connection structure between the wiring board and the circuit board is sealed in the region between the nozzle board and the wiring board by the sealing member. The physical and electrical reliability in the part can be greatly improved, and a liquid droplet ejection head with excellent reliability can be provided.

In the droplet discharge head of the present invention, a plurality of connection terminals extending from each of the electrodes are formed on the circuit board, and the plurality of connection terminals cover the electrodes and are on the circuit board. It is preferable that the circuit is extended to the outside of the flow path forming substrate disposed in the board and electrically connected to a drive circuit unit that supplies a drive signal to each electrode at the extended position.
According to this configuration, the drive circuit unit can be arranged at a position close to the flow path forming substrate arranged on the circuit board, and space saving of the droplet discharge head can be realized. In addition, since the distance between the nozzle substrate and the circuit substrate is equivalent to the thickness of the flow path forming substrate, it is possible to reduce the thickness of the droplet discharge head.

  In the droplet discharge head of the present invention, a plurality of the flow path forming substrates are disposed on the circuit board, and the drive circuit unit is mounted on the circuit board between the plurality of flow path forming substrates. It is preferable. According to this configuration, when the drive circuit unit is connected to the electrodes corresponding to the plurality of flow channel formation substrates, the flow channel formation substrate is disposed around the drive circuit unit. The lengths of the connection terminals can be easily set to the same length. In addition, since a configuration in which one drive circuit unit is provided corresponding to a plurality of flow path forming substrates can be adopted, it is possible to realize a reduction in manufacturing cost and a reduction in head size by reducing the number of components.

  In the liquid droplet ejection head according to the aspect of the invention, it is preferable that the sealing member is a resin member formed by filling a peripheral portion of a region between the nozzle substrate and the circuit substrate with a resin material. As a result, it is possible to easily and effectively seal the external connection portion, to realize a droplet discharge head that has excellent reliability and is easy to manufacture.

  In the liquid droplet ejection head of the present invention, another sealing member that seals at least the mounting portion of the drive circuit portion may be provided between the nozzle substrate and the circuit substrate. According to this configuration, since the mounting portion of the drive circuit portion is sealed, it greatly contributes to the improvement of reliability particularly in the mounting portion of the drive circuit portion.

  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, it is easy to reduce the thickness of the droplet discharge head.

In the liquid droplet ejection head according to the aspect of the invention, the plurality of electrodes are arranged in a substantially linear shape on the circuit board, and the connection terminals extend from the plurality of electrodes in a direction crossing the arrangement direction. In addition, the drive circuit unit may be arranged along the arrangement direction and mounted on the plurality of connection terminals.
According to this configuration, since the electrodes arranged in a predetermined direction and the drive circuit unit arranged along these electrodes are electrically connected by the connection terminals, the lengths of the connection terminals are substantially the same. They can be the same length. Therefore, the lengths of the electrical paths related to the connection between the drive circuit section and each electrode 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, the other plurality of the electrodes are arranged substantially linearly on the opposite side across the drive circuit unit, and the connection terminal extends from the other plurality of electrodes. However, it may be configured to be electrically connected to the drive circuit portion. According to this configuration, since one drive circuit unit can be electrically connected to a plurality of groups of electrodes corresponding to a plurality of flow path forming substrates, the number of components can be reduced, and the drive circuit unit Since the drive circuit unit can be connected to the electrodes arranged on both sides of the electrode via connection terminals of substantially the same length, the nonuniformity of the time constant in the electrical path is eliminated, and the drive conditions can be easily set Become.

  Next, 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 are penetrated through a nozzle substrate 16 shown in FIG. 1, and the nozzle substrate 16 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 16 and the circuit substrate 20 is sealed with a sealing member 40 made of a resin material or the like. Two flexible boards (wiring boards) 51 and 52 are disposed so as to be partially inserted between the sealing member 40 and the circuit board 20.

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.

  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.

  The flexible boards 51 and 52 shown in FIG. 1 are connected to the side edge of the circuit board 20 on the near side (−X side). The flexible substrate 51 has a plurality of wiring patterns 511 formed on one surface side (+ Z side), and these wiring patterns 511 are external connection portions 21 a formed on the side edge portions of the circuit board 20. Is electrically connected. The flexible substrate 52 has a plurality of wiring patterns 521 formed on one surface side (+ Z side), and these wiring patterns 521 are formed adjacent to the external connection portion 21a. Is electrically connected.

  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 of the flow path forming substrate 111, the plurality of groove portions 12a arranged in the X-axis direction in the shape of a rectangle elongated in the Y-axis direction are the previous nozzle substrate. 16 and the pressure generating chamber 12 which is a space for temporarily storing a liquid material to be discharged as droplets. Of the groove portions, the groove portion 24a extending in a long rectangular shape in the X-axis direction is a reservoir that is a space for temporarily storing the liquid material supplied to the pressure generating chambers 12 together with the nozzle substrate 16. 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 reservoirs 24 are formed in X-axis symmetry with respect to the first flow path forming substrate 111. 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. Also for the third flow path forming substrate 113 and the fourth flow path forming substrate 114, the positional relationship between the grooves 12a,..., 22a, and 24a is the same as that of the first and second flow path forming substrates.

The first flow path forming substrate 111 to the fourth flow path forming substrate 114 are all based on a single crystal silicon substrate provided with conductivity, and the grooves 12a, 22a, and 24a are The single crystal silicon substrate is formed by performing an anisotropic etching process.
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 groove portions 12a, 24a, and 22a that form the pressure generation chamber 12, the reservoir 24, and the ink flow path 22 that communicates with the pressure generation chamber 12, the amount of ink discharged in the ink jet head 10, and the speed of the droplets It is a part sensitive to characteristics, 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, that is, the 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 arranged so that the nozzles 15 and the pressure generation chamber 12 communicate with each other. 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. Yes.

  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. The diaphragm 14 and the electrode 36 are spaced apart from each other by a predetermined distance, and the groove 26 a becomes an operation space of the diaphragm 14 that bends when the inkjet head 10 is operated. 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 liquid droplet ejection unit group 311 and the second liquid droplet ejection unit group 312 are connected to each other via a connection terminal 34 extending from the pressure generating means 32 constituting the driving circuit unit 200A. Are electrically connected to each other, and a droplet discharge operation is performed by an electric signal input from the drive circuit unit 200A. In addition, the third liquid droplet ejection unit group 313 and the fourth liquid droplet ejection unit group 314 also have a drive circuit unit arranged between them via a connection terminal 34 extending from the pressure generating means 32 constituting them. It is electrically connected to 200B, and a droplet discharge operation is performed by an electric signal input from the drive circuit unit 200B.

  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 unit 200A, the drive circuit unit 200A operates based on the command information and discharges liquid to the selected electrode 36. A voltage (drive pulse) corresponding to the size of the droplet 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 unit 200A is stopped at the 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 particularly suitable for a high-definition inkjet head in which an extremely large number of droplet discharge units 31 are arranged.

  The drive circuit unit 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, space can be saved and the inkjet head is excellent in handling performance compared to the case where the drive circuit units 200A and 200B are provided on a flexible substrate or an external circuit via a flexible substrate. .

  In the inkjet head 10 according to the present embodiment, the external connection portions 21a and 21b forming the conductive connection portions between the circuit board 20 and the flexible substrates 51 and 52 are covered with the nozzle substrate 16 in a planar manner, and the sealing member 40 is used. Therefore, the conductive connection structure in the external connection portions 21a and 21b can be well protected. For example, the flexible substrates 51 and 52 are bent when the inkjet head 10 is connected to an external device such as a printer. It is possible to effectively prevent the flexible substrates 51 and 52 from being peeled off from the external connection portions 21a and 21b or the electrical connection from being damaged due to the bending. In addition, since the conductive connection portion is hermetically sealed, the portion is not easily affected by outside air, and excellent electrical reliability can be obtained.

  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.

  Further, the drive circuit portions 200A and 200B mounted on the circuit board 20 are sealed around the sealing member 40 provided at the peripheral edge of the nozzle substrate 16 and around the drive circuit portions 200A and 200B provided as necessary. Since the inside of the inkjet head 10 is sealed by the member, the semiconductor element or the like is hardly affected by oxygen or moisture contained in the outside air, and thus has 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 9 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 produced by forming various wiring patterns made of 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 12a on the upper surface side of the single crystal silicon substrate. And a groove portion 22a extending from each groove portion 12a and a groove portion 24a extending across the plurality of groove portions 22a. It is provided with a groove 26a for accommodating.
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 27 c 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 26a formed on the lower surface side (+ Z side) of the flow path forming substrates 111 and 112, and the diaphragm 14 formed on the bottom wall portion of the groove 26a (and the groove 12a). And the electrode 36 are arranged opposite to each other to form a 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 are brought into contact with the flow path forming substrates 111 and 112, respectively, through the bonding process, and the first flow path forming substrate 111 is interposed via these electrodes. 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, the flexible substrate 51 is connected to the external connection portion 21 a at the edge of the circuit board 20. As shown in FIG. 7, a plurality of connection terminals 512 are arranged on the lower end side (+ Z side) of the flexible substrate 51 on the + X side, and these connection terminals 512 are circuit boards. The widths and pitches correspond to the connection wirings 27a to 27c formed in the 20 external connection portions 21a. Then, the connection terminal 512 and the connection wirings 27a to 27c of the external connection portion 21a are aligned and arranged, and an anisotropic conductive material such as ACP or ACF, or a nonconductive material using NCF or NCP. The flexible substrate 51 and the circuit board 20 can be connected to each other by bonding using.

  A plurality of connection terminals 513 are arrayed on the side edge of the flexible substrate 51 on the front side (−X side) in the figure, and each connection terminal 512 is connected to a corresponding connection terminal 513 via a wiring pattern 511. Electrically connected. 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.

  Next, as shown in FIG. 8, 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.

As shown in FIG. 9, when the nozzle substrate 16, the flow path forming substrates 111 and 112, and the circuit board 20 are stacked and connected, a resin material or the like is formed in the groove portion 550 formed in the side end portion of these stacked bodies. The sealing member 40 made of is filled. The sealing member 40 is also provided in a portion of the flexible substrate 51 that overlaps the circuit substrate 20 in a planar manner, and thereby the connection portion between the flexible substrate 51 and the external connection portion 21a is sealed.
In the groove portion 550, the nozzle substrate 16 and the circuit substrate 20 have substantially the same shape in plan view, and the edges of the flow path forming substrates 111 and 112 sandwiched between them are formed on the nozzle substrate 16 and the circuit substrate 20. It is formed to be disposed at a position slightly retracted from the edge toward the center of the substrate.

Through the above process, as shown in FIG. 1, the inkjet head 10 in which the gap between the nozzle substrate 16 and the circuit board 20 at the periphery of the head is filled with the sealing member 40 made of a resin material or the like is obtained.
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. After preparing a large nozzle substrate built in, and using them for each of the above steps to produce a plurality of inkjet heads 10 at once, dicing and separating at a position corresponding to the outer peripheral edge of the inkjet head 10, A plurality of inkjet heads 10 can be obtained.

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.
Further, after connecting the flexible boards 51 and 52 for connecting the inkjet head 10 to an external device to the external connection portions 21a and 21b of the circuit board 20, the nozzle substrate 16 is bonded so as to cover the external connection portions 21a and 21b. In addition, since the connecting portions between the flexible boards 51 and 52 and the circuit board 20 are sealed by the sealing member 40 provided between the nozzle board 16 and the circuit board 20, the flexible boards 51 and 52 An ink jet head which is extremely excellent physically and electrically can be manufactured at the connection portion.
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 apparatus provided with the above-described inkjet head 10 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. 10, cartridges 2A and 2B constituting ink supply means are detachably provided in recording head units 1A and 1B having an inkjet head, 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.

  In FIG. 10, an ink jet recording apparatus as a single printer is shown 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 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 generating chamber, 14 Vibration plate, 15 Nozzle, 16 Nozzle substrate, 20 Circuit board, 21a, 21b External connection part, 22 Ink flow path, 24 Reservoir, 31 Droplet discharge part , 32 Pressure generating means, 34 connection terminal, 36 electrode, 51, 52 flexible substrate (wiring substrate), 111-114 flow path forming substrate, 151-154 nozzle group, 200A, 200B drive circuit unit, 200a bump (electrode terminal) , 311 to 314 Droplet discharge unit group, 371, 372 Electrode

Claims (9)

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 each of the plurality of electrodes, and a nozzle having a nozzle corresponding to each of the pressure generation chambers A droplet discharge head formed by laminating a substrate,
A drive circuit unit for driving the electrode is provided between the circuit board and the nozzle substrate,
An external connection portion including at least a connection wiring electrically connected to the drive circuit portion is provided on the electrode formation surface of the circuit board, and a wiring substrate having a wiring pattern is electrically connected to the external connection portion. Has been
A sealing member is provided on the outer periphery of the region between the nozzle substrate and the circuit board,
The liquid droplet ejection head, wherein the external connection portion is sealed in a region sandwiched between the nozzle substrate and a circuit substrate by the sealing member.   A plurality of connection terminals extending from each of the electrodes are formed on the circuit board, and the plurality of connection terminals cover the electrodes and are disposed on the circuit board. The droplet discharge head according to claim 1, wherein the droplet discharge head is electrically connected to a drive circuit unit that extends to the outside and supplies a drive signal to each electrode at the extended position.   The plurality of flow path forming substrates are arranged on the circuit board, and the drive circuit unit is mounted on the circuit board between the plurality of flow path forming substrates. 3. A droplet discharge head according to 2.   4. The resin member according to claim 1, wherein the sealing member is a resin member formed by filling a resin material in a peripheral portion of a region between the nozzle substrate and the circuit board. 5. Droplet discharge head.   The other sealing member which seals the mounting part of the said drive circuit part at least between the said nozzle substrate and the said circuit board is provided. The droplet discharge head described.   6. The droplet discharge head according to claim 1, wherein the drive circuit unit is flip-chip mounted on a connection terminal on the circuit board. A plurality of the electrodes are arranged in a substantially straight line on the circuit board, and the connection terminals extend from the plurality of electrodes in a direction intersecting the arrangement direction,
7. The liquid droplet ejection head according to claim 1, wherein the drive circuit unit is disposed along the arrangement direction and is mounted on the plurality of connection terminals. 8. A plurality of other electrodes are arranged in a substantially linear shape on the opposite side across the drive circuit section,
The liquid droplet ejection head according to claim 7, wherein the connection terminals extending from the other plurality of electrodes are electrically connected to the drive circuit unit.   A droplet discharge apparatus comprising the droplet discharge head according to claim 1.

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