JP2009160822A - Inkjet head and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet head whose manufacturing cost is kept low, and which is improved in diameter accuracy in terms of holes formed in a substrate. <P>SOLUTION: The inkjet head 11 includes: the substrate 12 having the holes as an ink supply port 31; a frame member 13 bonded to the substrate 12; a nozzle plate 14 bonded to the frame member 13; a pair of nozzle arrays 21 formed in the nozzle plate 14, and each including a plurality of nozzles 22; and a pair of piezoelectric members 15 having a plurality of driving elements corresponding to the plurality of nozzles 22, and bonded to the substrate 12 so that they separately corresponds to the pair of nozzle arrays 21. The pair of piezoelectric members 15 are bonded to the substrate 12 so as to partly close the hole while fixing a distance between them. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inkjet head capable of ejecting ink from a plurality of nozzles, and a method for manufacturing the inkjet head.

  For example, as an inkjet head, a type in which ink circulates in a flow path in the head is known. This inkjet head has several supply ports provided at one end of the head base, several recovery ports provided at the other end of the head base, and a number of nozzles provided between the supply port and the recovery port. And a piezoelectric element that is provided in the vicinity of the nozzle and ejects ink from the nozzle, a driver IC that drives the piezoelectric element, and a wiring that connects the driver IC and the piezoelectric element. The piezoelectric element is made of lead zirconate titanate. In such an ink jet head, ceramics having a low linear expansion coefficient are often used for the head base in order to align the thermal expansion coefficient with piezoelectric elements having a low linear expansion coefficient.

In this ink jet head, the ink flowing from the supply port is supplied to many nozzles, and is ejected as ink droplets from the nozzles by driving the piezoelectric elements. Ink that has not been used at the nozzles is collected at the collection port. In this way, the ink is circulated from the supply port to the recovery port to prevent the nozzles from being clogged with bubbles and ink lumps (see, for example, Patent Document 1).
JP 2002-113861 A

  By the way, it is not suitable for practical use to make holes such as a supply port and a recovery port by machining after firing a ceramic head base. On the other hand, ceramics have a large shrinkage rate during firing because of the volatilization of moisture during firing. For this reason, if a hole is formed in the head base by press molding or injection molding before firing the ceramic, there is a situation that the accuracy of the diameter of the hole does not come out.

  An object of the present invention is to provide an ink jet head capable of improving the accuracy of the diameter of a hole formed in a substrate while maintaining a low manufacturing cost.

  An inkjet head according to an aspect of the present invention is formed on a substrate having a hole serving as an ink supply port, a frame member bonded to the substrate, a nozzle plate bonded to the frame member, and the nozzle plate. And a pair of nozzle rows each including a plurality of nozzles and a plurality of drive elements corresponding to the plurality of nozzles, and a pair of substrates bonded to the substrate so as to correspond to the pair of nozzle rows, respectively. A piezoelectric member, and the pair of piezoelectric members are bonded to the substrate so as to block a part of the hole in a state in which a distance from each other is maintained constant.

  An inkjet head manufacturing method according to an aspect of the present invention includes a pair of piezoelectric members corresponding to a pair of nozzle rows, and a plurality of driving elements corresponding to a plurality of nozzles included in the nozzle rows. An ink-jet head manufacturing method, comprising: forming a hole serving as an ink supply port in an unfired ceramic substrate; firing the ceramic substrate formed with the hole; and firing the ceramic substrate. Then, the pair of piezoelectric members are bonded so as to block a part of the hole while maintaining a constant distance from each other.

  An inkjet head manufacturing method according to another aspect of the present invention includes a pair of piezoelectric members corresponding to a pair of nozzle rows, and a plurality of drive elements corresponding to a plurality of nozzles included in the nozzle rows are used as the piezoelectric members. A method for manufacturing an inkjet head, wherein a hole serving as an ink supply port is formed in an unfired ceramic substrate, the ceramic substrate formed with the hole is fired, and the fired ceramic substrate is Bonding a piezoelectric block to which a pair of piezoelectric members are connected so as to block a part of the hole, processing the piezoelectric block bonded to the ceramic substrate, and dividing the piezoelectric block as a pair of piezoelectric members .

  ADVANTAGE OF THE INVENTION According to this invention, the inkjet head which can improve the precision of the diameter of the hole formed in the board | substrate can be provided, maintaining manufacturing cost low.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
The ink jet head is a so-called ink circulation type ink jet head. As shown in FIGS. 1 and 2, the inkjet head 11 includes a substrate 12, a frame member 13 bonded to the substrate 12, a nozzle plate 14 bonded to the frame member 13, and a position inside the frame member 13. A piezoelectric member 15 bonded to the substrate 12 and a head driving IC 16 for driving the piezoelectric member 15 are provided.

  The nozzle plate 14 is formed of a square polyimide film. The nozzle plate 14 has a pair of nozzle rows 21. Each nozzle row 21 includes a plurality of nozzles 22.

  The piezoelectric member 15 is formed, for example, by bonding two piezoelectric plates 23 made of PZT (lead zirconate titanate) so that their polarization directions are opposed to each other. The piezoelectric member 15 has a trapezoidal cross section and is formed in a rod shape. The piezoelectric member 15 includes a plurality of pressure chambers 24 that are cut and formed in a groove shape on the surface, support columns 25 that are drive elements provided on both sides of each pressure chamber 24, side surfaces of each support column 25, and bottom portion of the pressure chamber 24. The electrode 26 is formed. The piezoelectric member is bonded to the substrate 12 so as to correspond to the nozzle row 21 on the nozzle plate 14. The pressure chamber 24 and the support column 25 are formed corresponding to the nozzle 22. A plurality of electrical wirings 27 are provided on the substrate 12. Each electrical wiring 27 is connected to the electrode 26 at one end and to the head driving IC 16 at the other end.

  The substrate 12 is formed in a square plate shape using ceramics such as alumina. The substrate 12 has a supply port 31 and a discharge port 32 each formed by a hole. As shown in FIG. 3, the hole which is the supply port 31 is circular. The substrate 12 has an edge 33 that defines the periphery of the hole of the supply port 31. The edge portion 33 includes a pair of arcs 33A facing each other with the center C of the hole therebetween. The pair of piezoelectric members 15 are arranged so as to overlap the arc 33A, and are bonded to the substrate 12 so as to block a part of the holes.

  As shown in FIG. 3, in the present embodiment, the area of the hole of the supply port 31 is, for example, about a × b = ab. At this time, the dimension of b is managed by a jig for holding the piezoelectric member 15 within an error range of ± 10 μm, for example. On the other hand, since the dimension of a varies in shrinkage when firing ceramics, when the hole diameter is 1 mm, for example, an error of ± 30 μm occurs.

On the other hand, if neither the diameter of the pores do not manage, the area of the holes is? Pa ^2/4. For this reason, it becomes the value squared about the dimension a which does not come out of accuracy, and management of the area of a hole becomes difficult. In this embodiment, although the value of a which is not accurate is related to the area of the hole, the accuracy of the area of the hole can be improved as compared with the case where the diameter of the hole is not managed. In addition, the cost does not increase excessively, and the manufacturing cost and the accuracy of the hole diameter can be balanced.

  In order to mount the inkjet head 11 having the above-described configuration on a printer and perform printing processing with the printer, it is necessary to supply ink to the inkjet head 11 from an ink tank of the printer. Ink is supplied through the supply port 31, and the ink flowing out of the ink tank is filled into the pressure chamber 24 through the supply port 31. Ink that has not been used in the pressure chamber 24 is collected in the ink tank by the discharge port 32.

  In this state, when the user instructs the printer to print, the control unit of the printer outputs a print signal to the inkjet head 11 to the head driving IC 16. Upon receiving the print signal, the head driving IC 16 applies a driving pulse voltage to the support column 25 via the electric wiring 27. As a result, the pair of left and right columns 25 are separated so as to bend by performing shear mode deformation. Then, by returning these to the initial position and increasing the pressure in the pressure chamber 24, the ink droplets are ejected from the nozzles 22 vigorously.

  Then, with reference to FIG. 4, the manufacturing process of the inkjet head 11 of this embodiment is demonstrated. First, the supply port 31 and the discharge port 32 are formed by press molding with respect to the board | substrate 12 comprised with the ceramic sheet (ceramics green sheet) before baking in step S1. Subsequently, in step S2, the substrate 12 is baked. Subsequently, in step S <b> 3, the pair of piezoelectric members 15 are bonded to the substrate 12. At this time, the distance between the pair of piezoelectric members 15 is kept constant by a jig (not shown). Further, the piezoelectric member 15 is positioned on the substrate 12 through the jig and is bonded to the substrate 12 to be in a state as shown in FIG.

  In step S <b> 4, so-called taper machining is performed on the corners of the piezoelectric member 15 bonded to the substrate 12. As a result, the piezoelectric member 15 is in a state as shown in FIG. In step S <b> 5, a groove that becomes the pressure chamber 24 is formed in the piezoelectric member 15. This groove processing uses, for example, a diamond wheel of a dicing saw used for cutting an IC wafer or the like. Subsequently, in step S <b> 6, the electrode 26 is formed on the inner surface of the groove, and the electric wiring 27 is formed on the substrate 12. The electrode 26 and the electric wiring 27 are made of, for example, a nickel thin film formed by electroless plating.

  In step S <b> 7, patterning is performed by irradiating a laser to remove the nickel thin film from portions other than the electrode 26 and the electrical wiring 27. In step S <b> 8, the frame member 13 is bonded to the substrate 12. In step S <b> 9, the nozzle plate 14 is bonded to the frame member 13. In step S10, the nozzle 22 is formed by irradiating the nozzle plate 14 with a laser. Further, in step S 11, a driving circuit (head driving IC 16) is fixed to the substrate 12 so as to be connected to the electric wiring 27 on the substrate 12. In step S12, an ink case (not shown) is bonded to the substrate 12, and the manufacturing process of the inkjet head 11 is completed.

  In this embodiment, the supply port 31 and the discharge port 32 are formed by press molding. However, the substrate 12 is prepared by injection molding, and the supply port 31 and the discharge port 32 are formed in the substrate 12 in advance. It may be. In addition, the piezoelectric member 15 is partially overlapped with the supply port 31 to manage the diameter of the supply port 31, but the piezoelectric member 15 is partially overlapped with the discharge port 32 to discharge the discharge port 31. You may make it manage the diameter of 32.

  According to the first embodiment, the inkjet head 11 includes a substrate 12 having a hole serving as an ink supply port 31, a frame member 13 bonded to the substrate 12, and a nozzle plate 14 bonded to the frame member 13. The nozzle plate 14 includes a pair of nozzle rows 21 each including a plurality of nozzles 22 and a plurality of drive elements corresponding to the plurality of nozzles 22 so as to correspond to the pair of nozzle rows 21 respectively. A pair of piezoelectric members 15 bonded to the substrate 12, and the pair of piezoelectric members 15 are bonded to the substrate 12 so as to block a part of the holes while maintaining a constant distance from each other. .

  In addition, the inkjet head manufacturing method includes a pair of piezoelectric members 15 corresponding to the pair of nozzle rows 21, and a plurality of driving elements corresponding to the plurality of nozzles 22 included in the nozzle row 21 are formed in the piezoelectric members 15. With respect to the recessed ink jet head, a hole serving as an ink supply port 31 is formed in an unfired ceramic substrate 12, the ceramic substrate 12 having the hole is fired, and a pair of piezoelectric members is formed on the fired ceramic substrate 12. 15 are bonded so as to block a part of the hole while maintaining a constant distance from each other.

  According to these configurations, the accuracy of the diameter of the hole can be improved by blocking a part of the hole with the piezoelectric member 15. As a result, the amount of ink flowing can be prevented from varying between the holes. As a result, the amount of ink discharged from the nozzles 22 can be made uniform. Further, the accuracy of the diameter of the hole can be improved while maintaining the manufacturing cost at a low cost as compared with the case of making the hole by machining. Thereby, it is possible to balance the manufacturing cost with the accuracy of the hole diameter.

  In this case, the hole has a circular shape, and the substrate 12 has an edge portion 33 that defines the periphery of the hole, and the edge portion 33 includes a pair of arcs 33A that face each other with the center of the hole interposed therebetween. The piezoelectric members 15 are arranged so as to overlap the arc 33A. According to this configuration, either one of the diameters in the vertical direction and the horizontal direction of the hole can be defined by the dimension between the piezoelectric members 15. Thus, one of the vertical and horizontal diameters of the hole can be set to a dimension with a small error, and the area of the hole can be managed with high accuracy.

  Next, a second embodiment of the inkjet head will be described with reference to FIG. The inkjet head 11 according to the second embodiment is different from that of the first embodiment in the bonding method of the piezoelectric member 15, but the other parts are common to the first embodiment. For this reason, different parts are mainly described, and common parts are denoted by common reference numerals and description thereof is omitted.

  The configuration of the inkjet head 11 of the second embodiment is the same as that of the first embodiment. However, the inkjet head 11 of the second embodiment is different in manufacturing process from the manufacturing process of the first embodiment.

  In the second embodiment, the supply port 31 and the discharge port 32 are formed by press molding in step S1 on the substrate 12 composed of a ceramic sheet (ceramic green sheet) before firing. Subsequently, in step S2, the substrate 12 is baked. Subsequently, in step S <b> 3, the piezoelectric block 41 is bonded to the substrate 12. The piezoelectric block 41 has a shape in which two piezoelectric members 15 shown in the first embodiment are connected. In other words, the piezoelectric block 41 has a thick plate shape having a groove 42 at the center.

  In step S4, the piezoelectric block 41 bonded to the substrate 12 is divided into two piezoelectric members 15 by applying grinding or cutting. This grinding process is performed along the two-dot chain line shown in FIG. 7, and the piezoelectric member 15 having the same shape as that of the first embodiment is formed. At this time, the corner portion of each piezoelectric member 15 is tapered. As a result, the piezoelectric member 15 is in a state as shown in FIG. The subsequent steps are the same as those in the first embodiment.

  In the second embodiment, the area of the hole is, for example, about a × b = ab. At this time, since the pair of piezoelectric members 15 is manufactured by machining, the dimension of b, which is the diameter in the horizontal direction of the hole, is managed within an error range of, for example, ± 5 μm.

  According to the second embodiment, the inkjet head manufacturing method includes a pair of piezoelectric members 15 corresponding to the pair of nozzle rows 21, and includes a plurality of drive elements corresponding to the plurality of nozzles 22 included in the nozzle row 21. A method of manufacturing an ink-jet head built in a piezoelectric member 15, wherein a hole serving as an ink supply port 31 is formed in an unfired ceramic substrate 12, the ceramic substrate 12 having the hole is fired, and the fired ceramics A piezoelectric block 41 to which a pair of piezoelectric members 15 are connected is bonded to the substrate 12 so as to block a part of the holes, and the piezoelectric members 15 bonded to the ceramic substrate 12 are processed to form a pair of piezoelectric blocks 41. The piezoelectric member 15 is divided.

  According to this configuration, since the piezoelectric block 41 is processed to form the piezoelectric member 15, the size of the gap between the pair of piezoelectric members 15 can be managed with higher accuracy.

  In this case, the piezoelectric member 15 is bonded to a pair on both sides of the hole center. According to this configuration, it is possible to manage the dimension with high accuracy for one of the diameters in the vertical and horizontal directions of the hole.

  The present invention is not limited to the embodiment described above. Of course, various modifications can be made without departing from the scope of the invention.

1 is a perspective view showing a partially broken ink jet head according to an embodiment. Sectional drawing cut | disconnected in the position of F2-F2 line shown in FIG. The top view which expands and shows the circumference | surroundings of the hole which is a supply port shown in FIG. 5 is a flowchart showing a manufacturing process of the inkjet head according to the first embodiment. Sectional drawing which shows the state which completed the process of step S3 shown in FIG. Sectional drawing which shows the state which completed the process of step S4 shown in FIG. Sectional drawing which shows the state after adhere | attaching a piezoelectric block on a board | substrate in the manufacturing process of the inkjet head which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Inkjet head, 12 ... Board | substrate, 13 ... Frame member, 14 ... Nozzle plate, 15 ... Piezoelectric member, 21 ... Nozzle row, 22 ... Nozzle, 31 ... Supply port, 32 ... Discharge port, 33 ... Edge, 33A ... Arc, 41 ... piezoelectric block

Claims (6)

A substrate having holes serving as ink supply ports;
A frame member bonded to the substrate;
A nozzle plate bonded to the frame member;
A pair of nozzle rows each formed on the nozzle plate and including a plurality of nozzles;
A pair of piezoelectric members having a plurality of drive elements corresponding to the plurality of nozzles and bonded to the substrate so as to correspond to the pair of nozzle rows,
Comprising
The pair of piezoelectric members is bonded to the substrate so as to close a part of the hole in a state where the distance between the pair of piezoelectric members is kept constant. The hole has a circular shape,
The substrate has an edge that defines the periphery of the supply port;
The edge includes a pair of arcs facing each other with the center of the hole in between,
The inkjet head according to claim 1, wherein the piezoelectric members are respectively disposed so as to overlap the arc. A method of manufacturing an ink jet head having a pair of piezoelectric members respectively corresponding to a pair of nozzle rows, wherein a plurality of drive elements corresponding to a plurality of nozzles included in the nozzle row are formed in the piezoelectric members,
Form a hole to serve as an ink supply port in an unfired ceramic substrate,
Firing the ceramic substrate having the holes formed therein;
A method for manufacturing an ink jet head, comprising: bonding the pair of piezoelectric members to the fired ceramic substrate so as to close a part of the holes while maintaining a constant distance from each other.   The method of manufacturing an ink jet head according to claim 3, wherein the piezoelectric member is bonded to a pair on both sides of the center of the hole. An inkjet head manufacturing method comprising a pair of piezoelectric members corresponding to a pair of nozzle rows, and a plurality of drive elements corresponding to a plurality of nozzles included in the nozzle rows formed in the piezoelectric members,
Form a hole to serve as an ink supply port in an unfired ceramic substrate,
Firing the ceramic substrate having the holes formed therein;
Adhering a piezoelectric block having a pair of piezoelectric members connected to the fired ceramic substrate so as to close a part of the hole;
A method of manufacturing an ink jet head, comprising: processing the piezoelectric block bonded to the ceramic substrate to divide the piezoelectric block as the pair of piezoelectric members.   The method of manufacturing an ink jet head according to claim 5, wherein the piezoelectric member is bonded to a pair on both sides of the center of the hole.

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