JP2014069448A - Liquid jet device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid jet device in which a clearance between adjacent terminals can be larger while the plurality of connection terminals are arranged in high density.SOLUTION: An inkjet head includes: a piezoelectric body 40 including a plurality of piezoelectric elements; a plurality of connection terminals 48 that are arranged along an upper surface of the piezoelectric body 40 and connected to the plurality of piezoelectric elements, respectively; and a driver IC 46 that drives each of the piezoelectric elements. The driver IC 46 and the connection terminals 48 are connected through conductive wires 49. Height positions of the connection terminals 48 from the upper surface of the piezoelectric body 40 are different, between the adjacent connection terminals 48.

Description

  The present invention relates to a liquid ejecting apparatus that ejects liquid.

  Patent Document 1 discloses an ink jet head that ejects ink droplets. The inkjet head disclosed in Patent Document 1 includes a plurality of nozzles, a plurality of pressure generation chambers communicating with the plurality of nozzles, a plurality of piezoelectric elements that respectively apply pressure to ink in the plurality of pressure generation chambers, and a plurality of piezoelectric elements. And a driver IC for driving the element.

  The plurality of piezoelectric elements are disposed on the surface of an elastic film that covers the plurality of pressure generation chambers. A plurality of lead electrodes respectively drawn from the plurality of piezoelectric elements are also formed on the surface of the elastic film. The driver IC is disposed above the plurality of piezoelectric elements, and the driver IC and the plurality of lead electrodes are individually connected by wires (wire bonding). On the elastic film, a plurality of piezoelectric elements are arranged along the nozzle arrangement direction, whereas the tip portions (connection terminals) of the plurality of lead electrodes connected to the driver IC by wires are arranged in a nozzle arrangement. They are arranged in a so-called zigzag pattern in which the positions are alternately shifted in a direction orthogonal to the direction. Thereby, the space | interval of an adjacent connection terminal is large compared with the case where a some connection terminal is arranged linearly.

Japanese Patent Laying-Open No. 2006-240312 (FIG. 6)

  As the nozzles and piezoelectric elements are increased in density, a plurality of connection terminals connected to the plurality of piezoelectric elements are also required to have a high density arrangement. However, migration and short circuit are more likely to occur between adjacent connection terminals as the interval between the plurality of connection terminals becomes narrower. In this regard, in Patent Document 1, the intervals between adjacent connection terminals are somewhat widened by arranging the connection terminals of a plurality of lead electrodes in a staggered manner. However, there is a limit to increasing the interval by the above method, and it is difficult to realize a higher density arrangement.

  An object of the present invention is to provide a liquid ejecting apparatus capable of increasing a separation distance between adjacent connection terminals while arranging a plurality of connection terminals at high density.

A liquid ejecting apparatus according to a first aspect of the present invention is arranged along a predetermined plane, with a plurality of nozzles, a plurality of energy applying elements that respectively apply ejection energy to the liquid in the plurality of nozzles, and the plurality of energies. A plurality of connection terminals respectively connected to the applying elements; and driver ICs for driving the plurality of energy applying elements, respectively.
The driver IC and the plurality of connection terminals are connected by a plurality of conductive wires, and the height positions of the connection terminals from the predetermined plane are different between the adjacent connection terminals. It is a feature.

  In the present invention, a plurality of connection terminals arranged along a predetermined plane are connected to the driver IC and the conductive wires, respectively. Moreover, the height position from the said one plane differs between adjacent connection terminals. Thereby, since the positions of the adjacent connection terminals can be separated in the height direction, a short circuit between the adjacent connection terminals can be achieved while arranging the plurality of connection terminals along the predetermined plane with high density. Migration can be prevented.

  The liquid ejecting apparatus according to a second aspect of the present invention is the liquid ejecting apparatus according to the first aspect, wherein the terminal arrangement portion having a plurality of convex portions and a plurality of concave portions formed between the plurality of convex portions on the predetermined plane. The plurality of connection terminals are respectively disposed on top surfaces of the plurality of convex portions and bottom surfaces of the plurality of concave portions of the terminal arrangement portion.

  By arranging the connection terminals at the plurality of convex portions and the plurality of concave portions of the terminal arrangement portion, a configuration in which the height positions of the adjacent connection terminals from the predetermined plane are different is realized.

  In the liquid ejecting apparatus according to a third aspect, in the second aspect, the plurality of convex portions and the plurality of concave portions are alternately arranged along a direction parallel to the predetermined plane. It is a feature.

  A configuration in which a plurality of convex portions and a plurality of concave portions are alternately arranged along a predetermined direction, so that connection terminals adjacent along the direction have different height positions from the predetermined plane. Is realized.

  In the liquid ejecting apparatus according to a fourth aspect of the present invention, in the second or third aspect of the invention, the terminal arrangement portion includes a plurality of conductive portions connected to the plurality of connection terminals, and the convex portion and the concave portion. Between the conductive wire, the connection terminal, and the conductive portion of the connection terminal disposed on the convex portion and the concave portion so that the total sum of the electrical resistance of the conductive path including the conductive portion is equal. The conductive portions of the connection terminals arranged have different shapes.

  If the electrical resistance of the conductive path from the driver IC is different between the connection terminals at different height positions, the drive characteristics of the plurality of energy applying elements are different, and the ejection characteristics vary among the nozzles. Therefore, in the present invention, the electrical resistance of the conductive portion is adjusted by making the shape of the conductive portion different between the convex portion and the concave portion, and the sum of the electrical resistances of the conductive paths is made equal between the convex portion and the concave portion.

  The liquid ejecting apparatus according to a fifth aspect is the liquid ejecting apparatus according to the fourth aspect, wherein the conductive wire connected to the connection terminal of the convex portion and the length of the conductive wire connected to the connection terminal of the concave portion. And the conductive portion connected to the connection terminal of the convex portion and the conductive portion connected to the connection terminal of the concave portion have the same electrical resistance.

  Since the height of the arrangement surface of the connection terminal between the convex portion and the concave portion is different, the electrical resistances of the conductive portions formed in the convex portion and the concave portion tend to be different from each other. However, in the present invention, the length of the conductive wire to be connected, that is, the electrical resistance, is equal between the connection terminal arranged in the convex portion and the connection terminal arranged in the concave portion. Therefore, the electrical resistances of the conductive portion of the convex portion and the conductive portion of the concave portion are also equal to each other by adjusting their shapes.

  The liquid ejecting apparatus according to a sixth aspect of the present invention is the liquid ejecting apparatus according to the fourth aspect, wherein the conductive wire connected to the connection terminal of the convex portion and the length of the conductive wire connected to the connection terminal of the concave portion. And the electrical resistance of the conductive portion connected to the connection terminal of the convex portion and the concave portion of the concave portion so that the sum of the electrical resistance of the conductive path is equal between the convex portion and the concave portion. The electrical resistance of the conduction part connected to the connection terminal is different.

  In the present invention, the length of the conductive wire to be connected, that is, the electrical resistance, is different between the connection terminal arranged in the convex portion and the connection terminal arranged in the concave portion. Therefore, the electrical resistance of the conductive portion is made different between the convex portion and the concave portion by adjusting the shape of the conductive portion of the convex portion and the conductive portion of the concave portion. Thereby, the difference of the electrical resistance of the wire between a convex part and a recessed part can be offset, and the sum total of the electrical resistance of an electroconductive path | route can be made equal.

  According to a seventh aspect of the present invention, in any one of the second to sixth aspects, the plurality of convex portions and the plurality of concave portions are staggered and staggered along the predetermined plane. The connecting terminal arranged and arranged on the top surface of the convex part has a planar shape in which a corner close to another convex part is chamfered.

  When the plurality of convex portions and the plurality of concave portions are arranged in a staggered manner, the corner portions are close to each other between the two connection terminals respectively disposed on the top surfaces of two obliquely adjacent convex portions, and are short-circuited. Or migration may occur. In the present invention, the corners of the connection terminals arranged on the convex portions are chamfered, so that the distance between the two connection terminals provided on two obliquely adjacent convex portions is increased, and short circuit and migration are prevented. It becomes difficult to occur.

  According to an eighth aspect of the present invention, in any one of the second to seventh aspects, the area of the bottom surface of the concave portion is larger than the area of the top surface of the convex portion. . Thus, when the bottom area of the recess is large, it becomes easy to connect the conductive wire to the connection terminal disposed on the bottom surface of the recess.

  According to a ninth aspect of the present invention, in the liquid ejecting apparatus according to any one of the second to eighth aspects, the concave portion is formed in a tapered shape having a tapered cross-section that decreases toward the bottom surface. Is. When the concave portion is formed in a tapered shape like this, it becomes easy to connect the conductive wire to the connection terminal arranged on the bottom surface of the concave portion.

  According to a tenth aspect of the present invention, in any one of the second to ninth aspects, the plurality of connection terminals arranged in the terminal arrangement portion are along a direction parallel to the predetermined plane. The driver ICs are arranged side by side with the terminal arrangement portion in a direction orthogonal to the arrangement direction of the connection terminals, and have a plurality of output terminals arranged along the arrangement direction, and the terminals The arrangement unit is arranged beyond the arrangement range of the plurality of output terminals of the driver IC in the arrangement direction, and falls within the arrangement range of the plurality of output terminals in the arrangement direction of the terminal arrangement unit. In the portion, a plurality of first convex portions and a plurality of concave portions are alternately arranged in the arrangement direction, and a portion of the terminal arrangement portion that exceeds the arrangement range of the plurality of output terminals in the arrangement direction has a front part. A second convex portion that protrudes so that the position of the top surface is higher than the first convex portion is arranged, the plurality of first convex portions, the plurality of concave portions, and the second convex portion, A plurality of connection terminals are arranged, and the plurality of connection terminals are connected to the plurality of output terminals of the driver IC by the conductive wires.

  In the present invention, the plurality of connection terminals and the plurality of output terminals of the driver IC are arranged in parallel, and the arrangement range of the plurality of connection terminals exceeds the arrangement range of the plurality of output terminals on the driver IC side. Assuming At this time, the connection terminal arranged in a portion beyond the output terminal arrangement range is considerably farther from the output terminal of the driver IC than the connection terminal within the output terminal arrangement range. Therefore, in the present invention, a second convex portion higher than the first convex portion in the output terminal arrangement range is provided in a portion of the terminal arrangement portion beyond the output terminal arrangement range. Since the height of the second convex portion is higher than that of the first convex portion, the distance from the driver IC can be shortened. This makes it easy to align the lengths of the wires connected to the plurality of connection terminals.

  According to the present invention, since the positions of adjacent connection terminals can be separated in the height direction, a plurality of connection terminals are arranged at a high density in a plane, and short circuit and migration between adjacent connection terminals are prevented. it can.

1 is a schematic plan view of an ink jet printer according to an embodiment. It is a top view of an inkjet head. (A) is the A section enlarged view of FIG. 2, (b) is the BB sectional drawing of (a). It is a perspective view of a terminal arrangement part and a driver IC. FIG. 5 is a cross-sectional view taken along line VV of the terminal arrangement portion of FIG. 4. It is sectional drawing of the terminal arrangement | positioning part which concerns on a modified form. It is a perspective view of a terminal arrangement part and driver IC concerning another modification. It is a partial expanded sectional view of the terminal arrangement | positioning part which concerns on another modification. It is sectional drawing of the inkjet head which concerns on another modification. It is a perspective view of the terminal arrangement | positioning part which concerns on another modification.

  Next, an embodiment of the present invention will be described. FIG. 1 is a schematic plan view of the ink jet printer of the present embodiment. First, a schematic configuration of the inkjet printer 1 will be described with reference to FIG. In the following, the front side in FIG. 1 is defined as the upper side, and the other side of the page is defined as the lower side, and the explanation will be made using direction words “up” and “down” as appropriate. As shown in FIG. 1, the inkjet printer 1 includes a platen 2, a carriage 3, an inkjet head 4, a transport mechanism 5, and the like.

  On the upper surface of the platen 2, a recording sheet 100 as a recording medium is placed. The carriage 3 is configured to reciprocate in the scanning direction along the two guide rails 10 and 11 in a region facing the platen 2. An endless belt 14 is connected to the carriage 3, and the endless belt 14 is driven by a carriage drive motor 15, whereby the carriage 3 moves in the scanning direction.

  The ink jet head 4 (liquid ejecting apparatus) is attached to the carriage 3 and moves in the scanning direction together with the carriage 3. The inkjet head 4 is connected to an ink cartridge (not shown) mounted on the printer 1 by a tube. A plurality of nozzles 16 are formed on the lower surface of the inkjet head 4 (the surface on the other side of the paper in FIG. 1). The inkjet head 4 ejects the ink supplied from the ink cartridge to the recording paper 100 placed on the platen 2 from the plurality of nozzles 16.

  The transport mechanism 5 includes two transport rollers 18 and 19 disposed so as to sandwich the platen 2 in the transport direction. The transport mechanism 5 transports the recording paper 100 placed on the platen 2 in the transport direction by two transport rollers 18 and 19.

  The ink jet printer 1 causes ink to be ejected from a recording paper 100 placed on the platen 2 from an ink jet head 4 that reciprocates in the scanning direction together with the carriage 3. At the same time, the recording paper 100 is transported in the transport direction by the two transport rollers 18 and 19. Through the above operation, images, characters, and the like are recorded on the recording paper 100.

  Next, the inkjet head 4 will be described. FIG. 2 is a plan view of the inkjet head. 3A is an enlarged view of a portion A in FIG. 2, and FIG. 3B is a cross-sectional view taken along line BB in FIG. In FIG. 3B, the ink filled in the ink flow path is indicated by “I”. As shown in FIGS. 2 and 3, the inkjet head 4 includes a flow path unit 20, a piezoelectric actuator 21, and the like.

  As shown in FIG. 4, the flow path unit 20 has a structure in which five plates 30 to 34 each having a flow path forming hole are laminated. When these five plates 30 to 34 are stacked, the respective flow path forming holes communicate with each other, whereby the flow path unit 20 is formed with an ink flow path as described below. In addition, although the material of the five plates 30-34 is not specifically limited, For example, metal plates, such as stainless steel and nickel alloy steel, are employable.

  As shown in FIG. 2, an ink supply hole 26 connected to an ink cartridge (not shown) is formed on the upper surface of the flow path unit 20. Two manifolds 25 each extending in the transport direction are formed inside the flow path unit 20. The two manifolds 25 are commonly connected to one ink supply hole 26, and the ink supplied from the ink cartridge is supplied to each of the two manifolds 25.

  As shown in FIGS. 2 and 3, the flow path unit 20 is communicated with the plurality of nozzles 16 formed on the lowermost nozzle plate 34 and opening on the lower surface of the flow path unit 20, respectively. The plurality of pressure chambers 24 are provided. As shown in FIG. 2, the plurality of nozzles 16 are arranged in two rows along the transport direction on the lower surface of the flow path unit 20 (the surface on the other side of the paper surface in FIG. 2). The arrangement of the plurality of nozzles 16 is a so-called staggered arrangement in which the positions of the nozzles 16 are shifted from each other in the conveyance direction between the two right and left nozzle rows.

  Each of the plurality of pressure chambers 24 has a substantially elliptical planar shape that is long in the scanning direction. The plurality of pressure chambers 24 are arranged in a plane, and the plurality of pressure chambers 24 are covered from above by a vibration plate 30 that is the uppermost plate. Further, the plurality of pressure chambers 24 are arranged in two rows in a staggered manner along the transport direction corresponding to the plurality of nozzles 16, respectively. Each pressure chamber 24 communicates with the corresponding nozzle 16 at one longitudinal end thereof.

  As shown in FIG. 2, the two pressure chamber rows are arranged at positions overlapping with the two manifolds 25, and each pressure chamber 24 communicates with the manifold 25 located immediately below. Thus, as shown in FIG. 3B, the flow path unit 20 is formed with a plurality of individual ink flow paths 27 that branch from the manifold 25 and reach the nozzles 16 through the pressure chambers 24.

  Next, the piezoelectric actuator 21 will be described. The piezoelectric actuator 21 is disposed on the upper surface of the vibration plate 30, which is a plate located in the uppermost layer of the flow path unit 20. As shown in FIGS. 2 and 3, the piezoelectric actuator 21 includes a piezoelectric body 40, a plurality of individual electrodes 42, and a common electrode 43.

  As shown in FIG. 3B, an insulating film 44 made of an insulating material such as a synthetic resin material is formed on almost the entire surface of the vibration plate 30. Two piezoelectric bodies 40 each having a rectangular planar shape are disposed on the upper surface of the diaphragm 30 covered with the insulating film 44. Each piezoelectric body 40 is made of a piezoelectric material mainly composed of ferroelectric lead zirconate titanate (PZT), which is a solid solution of lead titanate and lead zirconate. As shown in FIG. 2, the two piezoelectric bodies 40 are arranged so that their longitudinal directions are parallel to the nozzle arrangement direction so as to cover the two pressure chamber rows, respectively.

  The plurality of individual electrodes 42 are formed in regions on the upper surface of the piezoelectric body 40 that respectively face the plurality of pressure chambers 24. As a result, the plurality of individual electrodes 42 are arranged in two rows along the nozzle arrangement direction, like the plurality of pressure chambers 24. Each individual electrode 42 has a substantially oval planar shape that is slightly smaller than the pressure chamber 24, and is disposed so as to face the central portion of the corresponding pressure chamber 24. The common electrode 43 is formed over almost the entire upper surface of the diaphragm 30 covered with the insulating film 44.

  As shown in FIG. 4, a portion of the piezoelectric body 40 sandwiched between one individual electrode 42 and the common electrode 43 (hereinafter also referred to as “piezoelectric element 41”) is connected to the individual electrode 42 as described below. It is deformed when a driving voltage is applied, and becomes a portion that imparts ejection energy to the ink in one pressure chamber 24. That is, the piezoelectric element 41 corresponds to the energy applying element of the present invention. In the present embodiment, one piezoelectric body 40 is disposed across the plurality of pressure chambers 24 belonging to one row of pressure chambers, whereby a plurality of piezoelectric elements 41 corresponding to one row of pressure chambers are integrated. It has been configured. Each of the plurality of piezoelectric elements 41 is polarized in the thickness direction.

  As shown in FIG. 2, two driver ICs 46 are respectively arranged on one side (right side in the drawing) of the upper surface of the diaphragm 30 covered with the insulating film 44 in the scanning direction of the two piezoelectric bodies 40. . Each driver IC 46 has a rectangular planar shape, and is arranged such that the longitudinal direction of the rectangle is along the nozzle arrangement direction. As shown in FIG. 3, a plurality of output terminals 56 respectively corresponding to the plurality of individual electrodes 42 are provided on the upper surface of each driver IC 46 along the longitudinal direction thereof. Various circuits for driving the piezoelectric element 41 are incorporated in the driver IC 46. The two driver ICs 46 are connected to a control board (not shown), and various control signals are sent from the control board to the two driver ICs 46.

  Each driver IC 46 is connected to a common electrode 43 formed on the upper surface of the diaphragm 30, and the common electrode 43 is always held at the ground potential via the driver IC 46. As will be described in detail later, the plurality of output terminals 56 of each driver IC 46 are electrically connected to the plurality of individual electrodes 42 formed on the corresponding piezoelectric body 40. Then, the driver IC 46 outputs a drive signal generated based on the control signal input from the control board to the plurality of individual electrodes 42 to drive the plurality of piezoelectric elements 41 individually.

  The operation of the piezoelectric element 41 when the drive signal is input will be described. When a drive signal is input from a driver IC 46 to a certain individual electrode 42, a potential difference is generated between the individual electrode 42 and the common electrode 43, and the portion of the piezoelectric body 40 between the two electrodes 42 and 43 (piezoelectric). An electric field in the thickness direction acts on the element 41). Since the direction of the electric field is parallel to the polarization direction of the piezoelectric element 41, the piezoelectric element 41 expands in the thickness direction and contracts in the plane direction. Due to the contraction of the piezoelectric element 41 in the surface direction, the diaphragm 30 covering the pressure chamber 24 is bent so as to protrude toward the pressure chamber 24, and the volume of the pressure chamber 24 is reduced. At that time, pressure (ejection energy) is applied to the ink in the pressure chamber 24, and ink droplets are ejected from the nozzles 16.

  Next, a connection structure between the driver IC 46 and the plurality of individual electrodes 42 will be described in detail. As shown in FIGS. 2 and 3, a plurality of wiring portions 47 respectively connected to the plurality of individual electrodes 42 are formed on the upper surface of each piezoelectric body 40. The plurality of wiring portions 47 are led out in parallel to each other along the longitudinal direction from one longitudinal end portion (right end portion in the figure) of the corresponding individual electrode 42.

  Further, a terminal arrangement portion 50 in which a plurality of connection terminals 48 arranged in the nozzle arrangement direction is arranged is joined to the upper surface of each piezoelectric body 40. FIG. 4 is a perspective view of the terminal arrangement portion and the driver IC. 5 is a cross-sectional view taken along line VV in FIG.

  As shown in FIGS. 4 and 5, the terminal arrangement portion 50 is formed of a semiconductor material such as silicon or an insulating material such as synthetic resin. The terminal arrangement part 50 has an elongated shape extending along the nozzle arrangement direction, and is arranged across the plurality of wiring parts 47. Further, the terminal arrangement unit 50 is arranged side by side with the driver IC 46 in the scanning direction. As can be understood from FIGS. 2, 4, and 5, the length of the terminal arrangement portion 50 in the nozzle arrangement direction is longer than that of the driver IC 46 arranged in parallel to the terminal arrangement portion 50. Further extending beyond both longitudinal ends of the.

  The upper surface of the terminal arrangement part 50 is formed in an uneven shape. First, a plurality of convex portions 51 (first convex portions) and a plurality of concave portions 52 are arranged in the central portion of the terminal arrangement portion 50, that is, in a portion that falls within the arrangement region of the plurality of output terminals 56 of the driver IC 46 in the nozzle arrangement direction. Are alternately arranged along the nozzle arrangement direction. Further, both end portions of the terminal arrangement portion 50, that is, portions beyond the arrangement region of the plurality of output terminals 56 of the driver IC 46 in the nozzle arrangement direction, are end-side protrusions that protrude higher than the top surface 51 a of the convex portion 51. The portions 53 and 54 (second convex portions) are arranged so as to sandwich the plurality of convex portions 51 and the plurality of concave portions 52. The end-side convex portion 54 located at the end is higher than the end-side convex portion 53 located on the inner side. Connection terminals 48 are disposed on the top surfaces 51a, 53a, and 54a of the convex portion 51 and the end-side convex portions 53 and 54 of the terminal arrangement portion 50 and the bottom surface 52a of the concave portion 52, respectively. As a result, the plurality of connection terminals 48 are arranged along the nozzle arrangement direction on the upper surface of the piezoelectric body 40, and the height position from the upper surface of the piezoelectric body 40 that is the reference surface is set between the adjacent connection terminals 48. They have different configurations.

  As shown in FIG. 5, the protruding portion 51, the end-side protruding portions 53 and 54, and the recessed portion 52 of the terminal arrangement portion 50 are connected to a conducting portion 55 that conducts to a connection terminal 48 arranged on the top surface or the bottom surface thereof. Is formed. In the drawing, the conductive portion 55 is formed inside the convex portions 51, 53, 54 and the concave portion 52, but the conductive portion 55 may be formed on the side surfaces of the convex portions 51, 53, 54 and concave portion 52. . The plurality of conducting portions 55 respectively conducting to the plurality of connecting terminals 48 are connected to the plurality of wiring portions 47 on the back surface of the terminal arrangement portion 50. Thereby, the connection terminal 48 is connected to the corresponding individual electrode 42 via the conduction portion 55 and the wiring portion 47.

  The plurality of connection terminals 48 arranged in the terminal arrangement unit 50 are respectively connected to a plurality of output terminals 56 provided on the upper surface of the driver IC 46 by a plurality of conductive wires 49 (wire bonding). The wire 49 is made of a metal material such as Au. Further, as shown in FIG. 3B, an insulating material 57 is injected across the driver IC 46 and the terminal arrangement portion 50 for the purpose of protecting the wire 49, the connection terminal 48, and the output terminal 56 and preventing short circuit. Has been. For simplification of the drawings, the insulating material 57 is not shown in FIGS. 2, 3 (a), 4, and 5.

  In the present embodiment, as shown in FIGS. 4 and 5, the height position from the upper surface of the piezoelectric body 40 is different between adjacent connection terminals 48. Therefore, by arranging the plurality of connection terminals 48 on the upper surface of the piezoelectric body 40 in a high density in a plane and shifting the positions of the adjacent connection terminals 48 in the height direction, a short circuit between the adjacent connection terminals 48 can be achieved. Migration can be reliably prevented.

  As can be understood from FIGS. 3B, 4, and 5, wire bonding is originally a suitable connection method when connecting two points having different height positions. Therefore, even if the height positions of the adjacent connection terminals 48 are greatly deviated, the wires 49 having different lengths are used, or the bending of the wires 49 is changed to change the bending of the wires 49. The difference in height can be easily absorbed. In other words, the height positions between the adjacent connection terminals 48 can be greatly varied, which can reliably prevent a short circuit and migration.

  If the electrical resistances of the conductive paths from the driver IC 46 to the individual electrodes 42 are different between the connection terminals 48 at different height positions, the drive characteristics of the plurality of piezoelectric elements 41 are different, and the ejection characteristics between the nozzles 16. Variation occurs. Specifically, when a drive signal is supplied from the driver IC 46 to each of the plurality of individual electrodes 42, if the electrical resistance of the conductive path to the individual electrode 42 is different, the difference in RC time constant For example, the waveform of the drive signal output to the individual electrode 42 changes. Therefore, it is preferable that the total sum of the electrical resistances of the plurality of conductive paths from the driver IC 46 to the individual electrode 32 through the wire 49, the connection terminal 48, and the conduction portion 55 is equal to each other.

  For example, the plurality of wires 49 connected to the plurality of connection terminals 48 having different height positions are the same in length, thickness, and material. Thereby, the electrical resistances of the plurality of wires 49 are equal to each other. Note that the fact that the height positions of the plurality of connection terminals 48 are different means that the heights of the connection positions of one end portions of the plurality of wires 49 are different. However, even if the heights of the connection positions are different, as shown in FIG. 5, the wire 49 having the same length can be connected to the driver IC 46 by devising the bending method of the wire 49 and changing the height of the bending portion. It is not particularly difficult to connect to the different height positions of the terminal arrangement portion 50 from each other.

  However, as shown in FIGS. 4 and 5, among the plurality of connection terminals 48, some of the connection terminals 48 on both ends in the nozzle arrangement direction are arranged in the nozzle arrangement direction of the plurality of output terminals 56 of the driver IC 46. It is out of range. In these connection terminals 48, the distance from the output terminal 56 of the driver IC 46 is considerably longer than the connection terminal 48 on the center side within the arrangement range of the output terminal 56. Therefore, in the present embodiment, end convex portions 53 and 54 higher than the convex portion 51 within the arrangement range of the output terminal 56 are provided in a portion of the terminal arrangement portion 50 beyond the arrangement range of the output terminal 56. It is done. The distance from the driver IC 46 can be shortened by the height of the end-side convex portions 53 and 54 higher than the convex portion 51. This makes it easy to align the lengths of the wires 49 connected to the plurality of connection terminals 48.

  Further, the electrical resistances of the conductive parts 55 are adjusted to be equal by changing the shapes of the conductive parts 55 from each other. For example, as shown in FIG. 5, when the conducting portion 55 is formed in a vertically penetrating shape, the length of the conducting portion 55 increases as the distance from the upper surface of the piezoelectric body 40 to the connection terminal 48 increases. Therefore, in the concave portion 52 with the shortest distance, the thickness of the conductive portion 55 is the thinnest, and the conductive portion 55 is in order of increasing the distance, that is, in the order of the convex portion 51, the end side convex portion 53, and the end side convex portion 54. If the thickness of each of the conductive portions 55 is increased, the electrical resistances of all the conductive portions 55 can be made equal.

  As described above, by making the electrical resistances of the plurality of wires 49 equal to each other and also making the electrical resistances of the plurality of conductive portions 55 equal to each other, the electrical resistance of the plurality of conductive paths from the driver IC 46 to the individual electrodes is reduced. It is possible to make all sums equal.

  Next, modified embodiments in which various modifications are made to the embodiment will be described. However, components having substantially the same configuration as those of the above embodiment are denoted by the same reference numerals and description thereof is omitted as appropriate.

1] In the above embodiment, the lengths of the wires 49 connected to the plurality of connection terminals 48 are all equal. However, as shown in FIG. The length of the wire 49 connected to 48 may be different. For example, when it is desired to align the height positions of the bending vertices of the plurality of wires 49, the configuration of FIG. If the length of the wire 49 can be varied, a long wire 49 may be used for the connection terminal 48 located on the end side, and the height position of the connection terminal 48 on the end side is set to the center side. There is no need to make it higher than the connection terminal 48. Therefore, as shown in FIG. 6, the end-side convex portions 53 and 54 of the above embodiment can be omitted, and the terminal arrangement portion 50 has a configuration having only a plurality of convex portions 51 and a plurality of concave portions 52 arranged alternately. There may be.

  In addition, as shown in FIG. 6, when the length of the wire 49 is different between the convex portion 51 and the concave portion 52, the shape of the conductive portion 55 of the convex portion 51 and the conductive portion 55 of the concave portion 52 is adjusted, It is preferable that the electrical resistances of the conductive portion 55 of the convex portion 51 and the conductive portion 55 of the concave portion 52 are different. Thereby, the difference of the electrical resistance of the wire 49 between the convex part 51 and the recessed part 52 can be offset, and the sum total of the electrical resistance of a conductive path can be made equal. For example, the conductive portion 55 of the connection terminal 48 to which the long wire 49 is connected has a different shape such that the thickness of the conductive portion 55 is thicker than the conductive portion 55 of the connection terminal 48 to which the short wire 49 is connected. Reduce electrical resistance.

2] The adjustment of the electrical resistance of the conducting portion 55 is not limited to the form in which the thickness of the conducting portion 55 is varied. For example, the conductive portion 55 is formed in a zigzag bent shape, so that the conductive portion 55 can be lengthened and the electrical resistance can be increased as compared to the linearly formed conductive portion 55. In addition, the electrical resistance may be varied by forming the conductive portion 55 using metal materials having different resistivity.

3] As shown in FIG. 7, two or more rows of connecting terminals 48 may be arranged adjacent to each other. In this case, in order to make the height positions of the adjacent connection terminals 48 different between the connection terminals 48 in one row and the connection terminals 48 in the other row, as shown in FIG. The plurality of recesses 52 are preferably in a so-called checkered arrangement in which the recesses 52 are staggered and arranged alternately. 7 discloses a configuration in which two rows of connection terminals 48 are connected to two driver ICs 46, respectively, but all the connection terminals 48 arranged in two rows have one driver IC 46. It may be connected to.

Further, in the form of FIG. 7, the corners of the two connection terminals 48 arranged on the top surfaces 51 a of the two convex portions 51 that are obliquely adjacent to each other are close to each other, which may cause a short circuit or migration. There is. Therefore, as shown in FIG. 7, it is preferable that the connection terminal 48 disposed on the top surface of the convex portion 51 has a planar shape in which a corner portion close to another convex portion 51 is chamfered. As a result, the distance between the two connection terminals 48 provided on the two convex portions 51 that are obliquely adjacent to each other is increased, and short-circuiting and migration are less likely to occur.
Unlike the convex portion 51, the concave portion 52 is separated from another concave portion 52 that is obliquely adjacent by a wall, so that the convex portion is between the two connection terminals 48 disposed in the two concave portions 52. Compared with 51, it can be said that short circuit and migration are less likely to occur. However, as with the convex portion 51, the corner portion close to another concave portion 52 may be chamfered with respect to the connection terminal 48 disposed on the bottom surface 52 a of the concave portion 52.

4] It is somewhat difficult to connect the wire 49 to the connection terminal 48 disposed on the bottom surface of the concave portion 52 as compared to the connection terminal 48 disposed on the top surface of the convex portion 51. Therefore, as shown in FIG. 8A, the area of the bottom surface 52 a of the concave portion 52 may be larger than the area of the top surface 51 a of the convex portion 51. Or the recessed part 52 may be formed in the taper taper shape to which a cross-sectional area becomes small, so that it goes to the bottom face 52a. As described above, when the bottom area of the recess 52 is large or the recess 52 is formed in a tapered shape, the wire 49 can be easily connected to the connection terminal 48 arranged on the bottom surface of the recess 52.

5] The base material on which the plurality of connection terminals 48 (terminal arrangement portions 50) connected to the plurality of individual electrodes 42 is provided is not limited to the piezoelectric body 40. For example, as shown in FIG. 9, a plurality of connection terminals 48 may be arranged on the diaphragm 30. In FIG. 9, the common electrode 43 is disposed on the upper surface of the piezoelectric body 40, the individual electrode 42 is disposed on the lower surface of the piezoelectric body 40, and the wiring portion led out from the individual electrode 42 is disposed on the upper surface of the diaphragm 30 covered with the insulating film 44. 47 is formed. In addition, the terminal arrangement part 50 is arranged on the upper surface of the diaphragm 30 so as to cover the wiring part 47. The member on which the terminal arrangement part 50 is arranged is not particularly limited, but the surface on which the individual electrode 42 is formed (the upper surface of the piezoelectric body 40 in FIG. 3B) as shown in FIGS. When the terminal arrangement portion 50 is arranged on the upper surface of the diaphragm 30 in FIG. 9, the connection between the individual electrode 42 and the terminal arrangement portion 50 is performed by the wiring portion 47 drawn along the arrangement surface from the individual electrode 42. Terminal 48 can be easily connected.

6] In the above-described embodiment, the terminal arrangement part 50 having the concavo-convex shape is manufactured separately from the piezoelectric body 40 and then joined to the upper surface of the piezoelectric body 40. It may be formed integrally with the substrate. Further, as shown in FIG. 10, the recess 52 is formed to be recessed on the upper surface of the piezoelectric body 40, and the connection terminal 48 disposed on the bottom surface of the recess 52 is connected to the connection terminal 48 disposed on the upper surface of the piezoelectric body 40. It may be arranged at a lower position.

7] It is not necessary that the plurality of connection terminals 48 be provided on the same member. That is, a plurality of connection terminals 48 are respectively provided on a plurality of base materials arranged so that the height positions are different with respect to a certain reference surface, so that the height with respect to the reference surface between adjacent connection terminals 48 is increased. The structure in which the position differs may be sufficient.

4 Inkjet head 16 Nozzle 40 Piezoelectric body 41 Piezoelectric element 46 Driver IC
48 connection terminal 49 wire 50 terminal arrangement part 51 convex part (first convex part)
51a Top surface 52 Recessed portion 52a Bottom surface 53, 54 End side convex portion (second convex portion)
55 Conducting part 56 Output terminal

Claims (10)

Multiple nozzles,
A plurality of energy applying elements that respectively apply ejection energy to the liquid in the plurality of nozzles;
A plurality of connection terminals arranged along a predetermined plane and connected to the plurality of energy applying elements, and
A driver IC for driving each of the plurality of energy applying elements,
The driver IC and the plurality of connection terminals are connected by a plurality of conductive wires,
The liquid ejecting apparatus according to claim 1, wherein a height position of the connection terminal from the predetermined plane is different between the adjacent connection terminals. A terminal arrangement portion having a plurality of convex portions and a plurality of concave portions formed between the plurality of convex portions is provided on the predetermined plane,
The liquid ejecting apparatus according to claim 1, wherein the plurality of connection terminals are respectively disposed on top surfaces of the plurality of convex portions and bottom surfaces of the plurality of concave portions of the terminal arrangement portion.   The liquid ejecting apparatus according to claim 2, wherein the plurality of convex portions and the plurality of concave portions are alternately arranged along a direction parallel to the predetermined one plane. The terminal arrangement portion has a plurality of conduction portions respectively connected to the plurality of connection terminals,
Between the convex portion and the concave portion, the conductive wire, the connection terminal, and the connection terminal of the connection terminal arranged on the convex portion so that the total sum of electric resistances of the conductive path including the conductive portion is equal. 4. The liquid ejecting apparatus according to claim 2, wherein a shape of the conductive portion of the connection terminal disposed in the concave portion is different from that of the conductive portion. The length of the conductive wire connected to the connection terminal of the convex portion and the length of the conductive wire connected to the connection terminal of the concave portion,
5. The liquid ejecting apparatus according to claim 4, wherein the conductive portion connected to the connection terminal of the convex portion and the conductive portion connected to the connection terminal of the concave portion have the same electrical resistance. . The conductive wire connected to the connection terminal of the convex portion is different from the length of the conductive wire connected to the connection terminal of the concave portion,
The electrical resistance of the conductive portion connected to the connection terminal of the convex portion and the connection terminal of the concave portion are connected so that the sum of the electrical resistance of the conductive path is equal between the convex portion and the concave portion. The liquid ejecting apparatus according to claim 4, wherein the electrical resistance of the conductive portion is different. The plurality of convex portions and the plurality of concave portions are staggered and alternately arranged along the predetermined plane.
The liquid according to claim 2, wherein the connection terminal disposed on the top surface of the convex portion has a planar shape in which a corner portion adjacent to another convex portion is chamfered. Injection device.   The liquid ejecting apparatus according to claim 2, wherein an area of a bottom surface of the concave portion is larger than an area of a top surface of the convex portion.   The liquid ejecting apparatus according to claim 2, wherein the concave portion is formed in a tapered shape having a tapered cross-section that decreases toward the bottom surface. The plurality of connection terminals arranged in the terminal arrangement part are arranged along a direction parallel to the predetermined plane,
The driver IC is arranged side by side with the terminal arrangement portion in a direction orthogonal to the arrangement direction of the connection terminals, and has a plurality of output terminals arranged along the arrangement direction,
The terminal arrangement portion is arranged beyond the arrangement range of the plurality of output terminals of the driver IC in the arrangement direction,
In the portion of the terminal arrangement portion that falls within the arrangement range of the plurality of output terminals in the arrangement direction, a plurality of first protrusions and a plurality of depressions are alternately arranged in the arrangement direction,
A portion of the terminal arrangement portion that exceeds the arrangement range of the plurality of output terminals in the arrangement direction has a second convex portion that protrudes so that the position of the top surface is higher than the first convex portion. And
The plurality of connection terminals are respectively disposed on the plurality of first protrusions, the plurality of recesses, and the second protrusion, and the plurality of connection terminals are connected to the plurality of output terminals of the driver IC and the plurality of output terminals. The liquid ejecting apparatus according to claim 2, wherein the liquid ejecting apparatus is connected by a conductive wire.

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