JP2017121701A - Piezoelectric device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric device which can form a clearance of an adequate dimension not preventing displacement of a piezoelectric element between a piezoelectric element substrate and a counter substrate without applying a pressure to the piezoelectric element substrate or the counter substrate.SOLUTION: A piezoelectric device 50 includes: a piezoelectric element substrate 53 on which at least one piezoelectric element 51 displaced in response to application of a first drive signal and a second drive signal is arranged; a counter substrate 52 which is arranged opposite to the piezoelectric element substrate 53 and transmits respective drive signals to the piezoelectric element substrate 53; and a clearance forming member 54 which forms a clearance which can be displaced in response to the application of the respective drive signals of the piezoelectric element 51 between the piezoelectric element substrate 53 and the counter substrate 52. The clearance forming member 54 includes a first metal member 54a which melts at a first temperature, and a second metal member 54b which melts at a second temperature lower than the first temperature.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a piezoelectric device provided in a liquid ejecting head that ejects liquid.

  Some liquid ejecting apparatuses (for example, ink jet printers) are provided with a liquid ejecting head including a piezoelectric device having at least one piezoelectric element as an actuator. That is, the piezoelectric device has a plate-like member constituting a part of a pressure chamber provided in a liquid flow path communicating with the nozzle, and a piezoelectric element substrate having a piezoelectric element arranged in a laminated state on the plate-like member. Is provided. In the piezoelectric device, when a drive signal (voltage signal) is applied to the piezoelectric element, the piezoelectric element is displaced (contracted or expanded) by an electrostrictive effect, and the plate-like member is bent by a so-called bimetal principle. Pressure is applied to the liquid in the pressure chamber by the curvature of the plate member, and the liquid is ejected from the nozzle. Then, the ejected liquid adheres to the medium (for example, paper) to form (print) characters and images on the medium.

  In such a piezoelectric device, since the piezoelectric element is stably displaced, the electric field in the piezoelectric element generated by the applied drive signal needs to be an electric field that generates a predetermined electrostrictive effect on the piezoelectric element. There is. For this reason, conventionally, for example, there is a piezoelectric device provided with a sealing structure for sealing the piezoelectric element so as to be shielded from the atmosphere so that the electric field is not reduced due to generation of leakage current due to moisture in the piezoelectric element.

  For example, a driver IC (opposite substrate) in which a plurality of bumps are provided around the piezoelectric element in a state of covering the piezoelectric element disposed on the diaphragm (plate-like member) is disposed facing the diaphragm. To do. Then, the bumps of the driver IC arranged opposite to the connection terminals provided at the positions facing the bumps on the diaphragm (plate-like member) are connected and the resin sealing material is filled between the connected bumps. There is a piezoelectric device (piezoelectric actuator) having a sealing structure for sealing a piezoelectric element (for example, Patent Document 1).

JP 2014-51008 A

  However, in the conventional piezoelectric device, when connecting the bump of the driver IC and the connection terminal of the diaphragm, an anisotropic conductive material is interposed between the bump and the connection terminal, and the driver IC is pressed against the diaphragm. The diaphragm side is heated while crushing the anisotropic conductive material. For this reason, it is possible that a large pressure acts on the diaphragm locally from the bumps and deforms the diaphragm. In addition, there is a problem that it is difficult to form a gap having an appropriate dimension between the driver IC and the diaphragm due to variations in the degree of crushing of the anisotropic conductive material at this time.

  Note that such a problem is that a piezoelectric element substrate on which at least one piezoelectric element that is displaced in response to the application of a drive signal is mounted and the piezoelectric element substrate are disposed so as to transmit the drive signal to the piezoelectric element substrate. In general, the piezoelectric device including the counter substrate is common.

  The present invention has been made in view of such circumstances, and its purpose is to prevent displacement of the piezoelectric element between the piezoelectric element substrate and the counter substrate without applying pressure to the piezoelectric element substrate or the counter substrate. It is an object of the present invention to provide a piezoelectric device capable of forming a gap having no appropriate dimension.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
A piezoelectric device that solves the above problem is provided with a piezoelectric element substrate on which at least one piezoelectric element that is displaced in response to application of a drive signal is disposed, and opposed to the piezoelectric element substrate. A counter substrate that transmits to the piezoelectric element substrate, and a gap forming member that forms a gap between the piezoelectric element substrate and the counter substrate that can be displaced according to the application of the drive signal of the piezoelectric element, The gap forming member includes a first metal member that melts at a first temperature and a second metal member that melts at a second temperature lower than the first temperature.

  According to this configuration, when the gap forming member is arranged between the piezoelectric element substrate and the counter substrate, heating at the second temperature lower than the first temperature causes the gap between the piezoelectric element substrate and the counter substrate to be melted. While being joined by two metal members, the gap is formed by the first metal member that does not melt. Therefore, it is possible to form a gap having an appropriate dimension between the piezoelectric element substrate and the counter substrate without impeding displacement of the piezoelectric element without applying pressure to the piezoelectric element substrate or the counter substrate.

  In the piezoelectric device, a sealing space for sealing the piezoelectric element is formed between the piezoelectric element substrate and the counter substrate by the gap formed so as to surround the piezoelectric element by the gap forming member. It is preferable that

According to this configuration, since the piezoelectric element is displaced in the sealed space formed by the gap forming member, obstacles to the displacement of the piezoelectric element are suppressed, and deterioration due to the displacement of the piezoelectric element is suppressed.
In the piezoelectric device, it is preferable that the gap forming member is a signal transmission member that electrically transmits the driving signal from the counter substrate to the piezoelectric element substrate.

  According to this configuration, the gap forming member that forms a gap between the piezoelectric element substrate and the counter substrate also serves as a signal transmission member that transmits a drive signal from the counter substrate to the piezoelectric element substrate. An increase in the number of members that are electrically connected to each other can be suppressed.

  In the piezoelectric device, a metal signal applying line for transmitting and applying the drive signal to the piezoelectric element is formed on the piezoelectric element substrate, and the gap forming member is formed by applying the signal to the first metal member. It is preferable that it is joined to the wire.

According to this structure, the 1st metal member which a clearance gap formation member has by joining metals can be easily joined with a piezoelectric element board | substrate.
The said piezoelectric device WHEREIN: It is preferable that the said signal application line is formed with the same metal as the said 1st metal member which the said clearance gap formation member has.

According to this configuration, the first metal member of the gap forming member joined to the piezoelectric element substrate can be formed when the signal application line is formed.
In the piezoelectric device, a metal signal transmission line through which the drive signal is transmitted is formed on the counter substrate, and the gap forming member has the first metal member joined to the signal transmission line. Is preferred.

According to this structure, the 1st metal member which a clearance gap formation member has by joining metals can be easily joined with a counter substrate.
In the piezoelectric device, it is preferable that the signal transmission line is formed of the same metal as the first metal member included in the gap forming member.

According to this configuration, the first metal member of the gap forming member joined to the counter substrate can be formed when the signal transmission line is formed.
In the piezoelectric device, in the gap forming member, it is preferable that the first metal member is copper and the second metal member is a metal containing at least tin.

  According to this configuration, the piezoelectric element substrate and the counter substrate are joined by a metal (solder) containing molten tin, and the gap is formed by copper that does not melt. A gap having an appropriate dimension that does not hinder the displacement of the piezoelectric element can be formed between the piezoelectric element substrate and the counter substrate without applying pressure to the substrate.

The perspective view which shows typically the structure of 1st Embodiment of a liquid ejecting apparatus. FIG. 3 is a plan view illustrating a liquid ejecting head attached to the liquid ejecting apparatus. FIG. 3 is a diagram illustrating a configuration of a liquid jet head provided with a piezoelectric device, and is a cross-sectional view taken along line 3-3 in FIG. 2. The top view which shows the piezoelectric element board | substrate which comprises a piezoelectric device. Sectional drawing which shows the piezoelectric device before the opposing board | substrate which comprises a piezoelectric device is joined with a piezoelectric element board | substrate. Sectional drawing which shows the piezoelectric device with which the piezoelectric element board | substrate and the opposing board | substrate were joined via the gap formation member. The top view which shows the piezoelectric element board | substrate provided with the joining area | region of the clearance gap formation member which forms the sealing space which seals a piezoelectric element about 2nd Embodiment of a liquid ejecting apparatus. Sectional drawing which shows the piezoelectric device before the opposing board | substrate provided with the clearance gap formation member which forms sealing space is joined with a piezoelectric element board | substrate. FIG. 3 is a cross-sectional view showing a piezoelectric device in which a piezoelectric element substrate and a counter substrate are joined via a gap forming member that forms a sealed space. Sectional drawing which shows the piezoelectric device before the piezoelectric element board | substrate provided with the clearance gap formation member which forms sealing space is joined with an opposing board | substrate about the liquid ejecting apparatus of a modification. Sectional drawing which shows the piezoelectric device with which the piezoelectric element board | substrate with which the gap formation member was provided, and the opposing board | substrate were joined via the gap formation member about the liquid ejecting apparatus of the modification.

(First embodiment)
Hereinafter, a first embodiment of a piezoelectric device will be described with reference to the drawings.
As illustrated in FIG. 1, the liquid ejecting apparatus 11 is an ink jet printer that performs printing (recording) by ejecting ink, which is an example of liquid, from a liquid ejecting head 23 onto paper P, which is an example of a medium. In the present embodiment, the paper P is conveyed in one direction at a position facing the liquid ejecting head 23 when printing on the paper P. A direction in which the sheet P is conveyed is defined as a conveyance direction Y, and a direction along the width direction of the sheet P that intersects (preferably orthogonally) the conveyance direction Y is defined as a scanning direction X. That is, the scanning direction X and the conveyance direction Y of the present embodiment are directions that intersect (preferably, orthogonal) to each other, and are directions that intersect (preferably, orthogonal) both of the gravity direction Z that is below.

  In the liquid ejecting apparatus 11, a medium support base 13 is extended at a lower part in a frame 12 having a substantially rectangular box shape with a scanning direction X as a longitudinal direction, and a paper feed motor 14 is provided at the lower part of the frame 12. ing. Then, the paper P is transported in the transport direction Y by the transport mechanism (not shown) through the drive of the paper feed motor 14 so as to pass over the medium support table 13.

  A carriage 21 that is movable in a direction crossing the transport direction Y is provided for the paper P transported on the medium support table 13. Further, above the medium support 13 in the frame 12, a guide shaft 15 having an axis along the scanning direction X, which is the longitudinal direction of the medium support 13, and a flat surface with a predetermined width along the scanning direction X. An elongated guide plate 16 is installed.

  The guide shaft 15 is a columnar or cylindrical shaft, and is inserted through a support hole formed so as to penetrate the carriage 21 in the scanning direction X on the side opposite to the carriage direction Y side of the carriage 21. The guide plate 16 is disposed so as to support a projecting portion 21a formed so as to project on the carriage 21 in the transport direction Y side from below. Accordingly, the carriage 21 is guided while being supported by the guide shaft 15 and the guide plate 16, and can reciprocate along the scanning direction X on the printing surface of the paper P.

  A drive pulley 17a and a driven pulley 17b are rotatably supported at positions near the both ends of the guide shaft 15 in the frame 12. An output shaft of the carriage motor 18 is connected to the drive pulley 17a, and an endless timing belt 17 partially connected to the carriage 21 is wound between the drive pulley 17a and the driven pulley 17b. . Accordingly, by driving the carriage motor 18, the carriage 21 reciprocates along the scanning direction X while being guided by the guide shaft 15 and the guide plate 16 via the timing belt 17.

  In the reciprocating carriage 21, a liquid ejecting head 23 that performs printing by ejecting ink onto the paper P is attached to the gravity direction Z side. An ink cartridge 22 that contains ink to be supplied to the liquid ejecting head 23 is mounted on the carriage 21. In this embodiment, four ink cartridges 22 each containing four types of ink (for example, four colors of ink of cyan, magenta, yellow, and black) are mounted on the carriage 21.

  In the liquid ejecting apparatus 11, the frame 12 includes a housing unit 19 that houses a signal generation circuit that generates a control signal for ejecting ink from the liquid ejecting head 23. A connection cable 25 that electrically connects the signal generation circuit housed in the housing portion 19 and the liquid jet head 23 is disposed. In the present embodiment, control signals corresponding to each of the four head units 24 are transmitted to the liquid jet head 23 via the connection cable 25.

  As shown in FIG. 2, in the liquid ejecting head 23, a plurality of nozzles N that eject ink are arranged in a row in the transport direction Y (here, there are two rows, and may be referred to as nozzle rows Na and Nb). ), Four head units 24 arranged side by side are arranged in the scanning direction X corresponding to each of the four ink cartridges 22. In the present embodiment, the four head units 24 that eject ink have the same configuration. Therefore, here, the one head unit 24 will be described with reference to FIGS.

  As shown in FIG. 3, the head unit 24 is attached to the head case 26 in a state where a flow path unit 30 that forms a flow path of ink and a piezoelectric device 50 that ejects ink from the head unit 24 are stacked on each other. It has been. Here, the stacking direction of the members is the vertical direction along the vertical direction (gravity direction Z).

  The flow path unit 30 includes, in order from the lower gravity direction Z side, a nozzle plate 31 in which a plurality of nozzles N are formed, a flow path substrate 32, a pressure chamber substrate 33, and a vibration plate 34. Structures fixed to each other in a stacked state. The flow path unit 30 which is such a structure includes a nozzle communication chamber 41 communicating with the nozzle N, a pressure chamber 42 communicating with the nozzle communication chamber 41, a liquid supply path 43 communicating with the pressure chamber 42, and a liquid A common liquid chamber 44 communicating with the supply path 43 is formed. Among these, the nozzle communication chamber 41, the pressure chamber 42 and the liquid supply path 43 are formed corresponding to each nozzle N, and the common liquid chamber 44 has the same type of ink for a plurality of nozzles N in one head unit 24. It is formed so as to be continuous (communication) over all the nozzles N so as to be supplied.

  A piezoelectric device 50 is stacked on the upper side of the flow path unit 30. The piezoelectric device 50 includes, in order from the lower gravitational direction Z side, a vibration plate 34 on which a plurality of piezoelectric elements 51 are disposed, and a counter substrate 52 disposed to face the vibration plate 34. . That is, in the present embodiment, the vibration plate 34 constitutes a part of the flow path unit 30 (pressure chamber 42) and the piezoelectric device 50 by providing the piezoelectric element 51. Therefore, here, the diaphragm 34 provided with the piezoelectric element 51 is referred to as a piezoelectric element substrate 53.

  The diaphragm 34 of the present embodiment is a flat plate member that can vibrate elastically. In the vibration plate 34, piezoelectric elements 51 are disposed on the plate surface opposite to the pressure chambers 42 corresponding to the pressure chambers 42. The piezoelectric element 51 is driven (expanded / contracted) when a voltage is applied, and the first electrode 56 and the second electrode serve as signal application lines on both sides in the vertical direction so as to sandwich the piezoelectric body 55. 57 is provided. The first electrode 56 is an individual electrode formed on the piezoelectric body 55 corresponding to each pressure chamber 42 (each nozzle N), and the second electrode 57 is an electrode formed on the plate surface of the diaphragm 34. The electrode is common to the plurality of piezoelectric elements 51 disposed corresponding to the plurality of pressure chambers 42 (the plurality of nozzles N). As shown in FIG. 4, the first electrode 56 includes a group of first electrodes 56 arranged in the transport direction Y so as to correspond to each nozzle N of the nozzle row Na on the left side of the piezoelectric element substrate 53, and the piezoelectric element substrate. And a group of first electrodes 56 arranged in the transport direction Y so as to correspond to the respective nozzles N of the nozzle row Nb on the right side of the paper. A protruding portion 56 a that protrudes toward the outer periphery of the piezoelectric element substrate 53 is formed at the left end portion of each first electrode 56 in the group of first electrodes 56 on the left side of the drawing. A protruding portion 56 a that protrudes toward the outer periphery of the piezoelectric element substrate 53 is formed at the right end portion of each first electrode 56 in the group of first electrodes 56 on the right side of the drawing.

  As shown in FIG. 3, in this embodiment, an output voltage corresponding to the amount of ink ejected from the nozzle N is applied to the first electrode 56 as a first drive signal for driving the piezoelectric element 51, and the second electrode A constant voltage that is a constant voltage is applied to 57 as a second drive signal that keeps the voltage constant. By applying these voltages as drive signals, a portion of the piezoelectric body 55 sandwiched mainly between the first electrode 56 and the second electrode 57 becomes a differential voltage between the applied output voltage and a constant voltage. Accordingly, the diaphragm 34 is bent by contracting (or extending) along the plate surface of the diaphragm 34. When the vibration plate 34 is displaced in the vertical direction by the bending of the vibration plate 34, the ink in the pressure chamber 42 is compressed and the ink is ejected from the nozzle N. Thus, the piezoelectric element 51 functions as an actuator.

  On the other hand, the head case 26 is a box-shaped member made of synthetic resin, and a liquid introduction path 27 for introducing ink into the common liquid chamber 44 in the flow path unit 30 is formed therein. The liquid introduction path 27 is a space for storing ink common to a plurality of pressure chambers 42 arranged in parallel with the flow path unit 30 together with the common liquid chamber 44. In this embodiment, two liquid introduction paths 27 are formed corresponding to the rows of pressure chambers 42 arranged in two rows. In addition, a recessed space 28 that is recessed in a rectangular parallelepiped shape is formed between the scanning direction X of the two liquid introduction paths 27 from the lower surface side of the head case 26 to the middle of the head case 26 in the vertical direction. A piezoelectric device 50 stacked on the flow path unit 30 is accommodated in the concave space 28. As shown in FIG. 3, the piezoelectric device 50 and the pressure chamber substrate 33 are accommodated in the concave space 28.

Next, a bonding structure between the piezoelectric element substrate 53 and the counter substrate 52 will be described with reference to FIGS.
As illustrated in FIG. 3, the piezoelectric device 50 includes a gap forming member that joins a piezoelectric element substrate 53 and a counter substrate 52 disposed to face the piezoelectric element substrate 53 with a gap of a predetermined size. 54. That is, a plurality of gap forming members 54 are provided, and a gap having a dimension that does not contact the counter substrate 52 is formed between the piezoelectric element substrate 53 and the counter substrate 52.

  Further, the gap forming member 54 is a signal transmission member that electrically transmits a first drive signal and a second drive signal for driving the piezoelectric element 51 from the counter substrate 52 to the piezoelectric element substrate 53. That is, the first drive signal and the second drive signal are output to the counter substrate 52 arranged to face the piezoelectric element substrate 53 on the upper side opposite to the piezoelectric element substrate 53 side based on the control signal. A drive IC 58 is disposed. Each drive signal output from the drive IC 58 is electrically transmitted to a plurality of signal transmission lines 52b arranged from the upper surface side to the lower surface side through connection wirings 52a formed through the counter substrate 52. The Each drive signal thus transmitted to the signal transmission line 52 b is electrically transmitted to the first electrode 56 and the second electrode 57 formed on each piezoelectric element 51 by the plurality of gap forming members 54. Note that the connection wiring 52a and the signal transmission line 52b of the present embodiment are made of copper.

  As shown in FIGS. 3 and 4, the plurality of gap forming members 54, which are signal transmission members that transmit the first drive signal, have a substantially cylindrical shape, and are formed on the piezoelectric element substrate 53. One electrode 56 is connected at one connection point (black circle in FIG. 4). As shown in FIG. 4, the gap forming member 54 that transmits the first drive signal is connected to the protruding portion 56 a of the first electrode 56. On the other hand, the plurality of gap forming members 54 that are signal transmission members that transmit the second drive signal have a substantially cylindrical shape, and the nozzle array Na and the second electrode 57 formed on the piezoelectric element substrate 53. A plurality of connection points (black circles in FIG. 4) are connected to the nozzle row Nb. By connecting the gap forming member 54, a gap is formed between the counter substrate 52 and the piezoelectric element substrate 53 so that the diaphragm 34 does not contact the counter substrate 52. In FIG. 4, the piezoelectric body 55 is omitted.

Next, the connection structure of the gap forming member 54 will be described.
As shown in FIG. 5, each gap forming member 54 protrudes from the counter substrate 52 toward the piezoelectric element substrate 53. In other words, in the present embodiment, each gap forming member 54 is substantially formed at the first metal member 54a formed in a substantially cylindrical shape with a predetermined protruding height on the signal transmission line 52b, and at the tip of the first metal member 54a. And a second metal member 54b formed in a hemispherical shape. The first metal member 54 a is electrically joined to the signal transmission line 52 b of the counter substrate 52. The first metal member 54a melts at the first temperature T1, and the second metal member 54b melts at the second temperature T2 that is lower than the first temperature T1. In the present embodiment, the first metal member 54a is formed of the same metal as the signal transmission line 52b. That is, the first metal member 54a of this embodiment is copper, and is formed integrally with the signal transmission line 52b when the signal transmission line 52b is formed, for example, by a known etching method or additive method. Further, the second metal member 54b of the present embodiment is a metal (for example, solder) containing at least tin. If the second temperature T2 at which the second metal member 54b melts can be maintained lower than the first temperature T1 at which the first metal member 54a melts, the first metal member 54a and the second metal member 54b are made of copper or Metal materials other than solder may be used. The material of the first metal member 54 a may be different from the material of the signal transmission line 52 b of the counter substrate 52.

  As shown in FIG. 5, the gap forming member 54 that transmits the first drive signal contacts the overhanging portion 56 a of the first electrode 56, and the plurality of gap forming members 54 that transmit the second drive signal are the second electrode 57. The counter substrate 52 is disposed to face the piezoelectric element substrate 53 so as to be in contact with the piezoelectric element substrate 53. In this state, since the temperature of the piezoelectric element substrate 53 and the counter substrate 52 is lower than the second temperature T2, the second metal member 54b is not melted.

  Next, as shown in FIG. 6, the piezoelectric element substrate 53 and the counter substrate 52 are at or above the second temperature T2 while the gap forming member 54 is in contact with the protruding portion 56a of the first electrode 56 and the second electrode 57. Heating is performed at a temperature lower than the first temperature T1. Accordingly, as shown in FIG. 6, in each gap forming member 54, the second metal member 54b is melted, while the first metal member 54a is not melted. When the heating of the piezoelectric element substrate 53 and the counter substrate 52 is stopped, the second metal member 54 b is cooled and solidified in each gap forming member 54. Thereby, the piezoelectric element substrate 53 and the counter substrate 52 are joined.

  As indicated by a two-dot chain line in FIG. 4, after the piezoelectric element substrate 53 and the counter substrate 52 are joined, a plurality of gap forming members 54 that transmit the first drive signal are sealed by a resin sealing material 59. May be filled. Thereby, the space surrounded by the piezoelectric element substrate 53, the counter substrate 52, the plurality of gap forming members 54 that transmit the first drive signal, and the sealing material 59 (the space surrounded by the two-dot chain line on the inside in FIG. 4). Forms a sealing space SC for sealing the piezoelectric element 51.

The operation of this embodiment will be described with reference to FIG.
When the plurality of gap forming members 54 are disposed between the piezoelectric element substrate 53 and the counter substrate 52, the piezoelectric element substrate 53 and the counter substrate 52 are heated at a temperature equal to or higher than the second temperature T2 and lower than the first temperature T1. The second metal member 54b of the gap forming member 54 is melted, while the first metal member 54a is not melted. At this time, the melted second metal member 54 b is crushed by its own weight such as the counter substrate 52 and the drive IC 58 without applying pressure, and is removed from between the first metal member 54 a and the first electrode 56 or the second electrode 57. Extruded. As a result, the thickness of the second metal member 54b remaining between the first metal member 54a and the first electrode 56 or the second electrode 57 is relatively small with respect to the protruding height of the first metal member 54a. It becomes. Therefore, the gap between the piezoelectric element substrate 53 and the counter substrate 52 is approximately the vertical dimension that is the protruding height of the first metal member 54a. In other words, by setting the vertical dimension of the first metal member 54 a to a size that does not hinder the displacement of the piezoelectric element 51, the gap between the piezoelectric element substrate 53 and the counter substrate 52 is displaced by the displacement of the piezoelectric element 51. Appropriate dimensions that do not hinder.

  In addition, for example, the second metal member 54b melted and pushed out around the cylindrical side surface of the first metal member 54a in the overhanging portion 56a of the first electrode 56 is in principle the first metal due to its surface tension. An action of positioning the member 54a at the center of the projecting portion 56a, that is, a so-called self-alignment action is generated.

According to this embodiment, the following effects can be obtained.
(1) The piezoelectric device 50 includes a gap forming member 54 that forms a gap between the piezoelectric element substrate 53 and the counter substrate 52 that can be displaced according to the application of the first drive signal and the second drive signal of the piezoelectric element 51. Is provided. As a result, the piezoelectric element substrate 53 and the counter substrate 52 are bonded to each other without applying pressure to the piezoelectric element substrate 53 or the counter substrate 52, so that the gap between the piezoelectric element substrate 53 and the counter substrate 52 is reduced. It is possible to make the dimensions appropriate so as not to disturb the displacement. In addition, since the second metal member 54b is solder, it is possible to suppress the positional deviation between the piezoelectric element substrate 53 and the counter substrate 52 in the transport direction Y and the scanning direction X by self-alignment due to surface tension when the solder is melted. .

  By the way, as a method of bonding the piezoelectric element substrate 53 and the counter substrate 52 without applying pressure, a method of bonding the piezoelectric element substrate 53 and the counter substrate 52 with solder balls (not shown) instead of the gap forming member 54. Can be considered.

  However, since all of the solder balls are melted, the gap between the piezoelectric element substrate 53 and the counter substrate 52 may not have an appropriate dimension that does not hinder the displacement of the piezoelectric element 51. With respect to this problem, by increasing the size of the solder ball, the gap between the piezoelectric element substrate 53 and the counter substrate 52 can be set to an appropriate dimension that does not hinder the displacement of the piezoelectric element 51, but the solder ball has melted. Sometimes the range extending in the transport direction Y and the scanning direction X becomes large, and the first electrodes 56 cannot be arranged in the transport direction Y at a narrow pitch.

  In that respect, the gap forming member 54 of the present embodiment has a gap between the piezoelectric element substrate 53 and the counter substrate 52 because the second metal member 54b is melted as described above and the first metal member 54a is not melted. Therefore, the amount of the second metal member 54b (the amount of solder) can be reduced as compared with the solder ball. Accordingly, the first electrodes 56 can be arranged at a narrow pitch in the transport direction Y.

  (2) Since the sealing space SC is formed between the piezoelectric element substrate 53 and the counter substrate 52 by the gap forming member 54 and the sealing material 59, and the piezoelectric element 51 is displaced in the sealing space SC, the piezoelectric element 51 Obstacles to the displacement of the piezoelectric element 51 are suppressed, and deterioration due to the displacement of the piezoelectric element 51 is suppressed.

  (3) Since the gap forming member 54 that forms a gap between the piezoelectric element substrate 53 and the counter substrate 52 also serves to transmit each drive signal from the counter substrate 52 to the piezoelectric element substrate 53, the counter substrate 52 and the piezoelectric substrate 53 are piezoelectric. An increase in the number of members that are electrically connected to the element substrate 53 can be suppressed.

  (4) The first metal member 54 a of the gap forming member 54 is joined to the signal transmission line 52 b of the counter substrate 52. For this reason, the 1st metal member 54a which the gap formation member 54 has by joining metals can be easily joined with the counter substrate 52.

  (5) Since the signal transmission line 52b of the counter substrate 52 and the first metal member 54a of the gap forming member 54 are formed of the same metal, the first member joined to the counter substrate 52 is formed when the signal transmission line 52b is formed. One metal member 54a can be formed.

  (6) Since the first metal member 54a of the gap forming member 54 is copper and the second metal member 54b is a metal (solder) containing at least tin, there is no gap between the piezoelectric element substrate 53 and the counter substrate 52. In addition to joining with a metal (solder) containing tin that melts, the gap is formed of copper that does not melt. Therefore, a gap having an appropriate dimension that does not hinder the displacement of the piezoelectric element 51 can be formed between the piezoelectric element substrate 53 and the counter substrate 52 without applying pressure to the piezoelectric element substrate 53 or the counter substrate 52.

(Second Embodiment)
A piezoelectric device 50 according to the second embodiment will be described with reference to FIGS. The piezoelectric device 50 according to the present embodiment is different from the piezoelectric device 50 according to the first embodiment in the position of the first electrode 56 and the position and shape of the second electrode 57. Accordingly, the piezoelectric device 50 of the present embodiment includes the position of the gap forming member 54 that transmits the first drive signal on the counter substrate 52, the position of the gap forming member 54 that transmits the second drive signal on the counter substrate 52, and The shape is different.

  As shown in FIG. 7, the protruding portion 56 a of each first electrode 56 in the group of the first electrodes 56 on the left side of the drawing is straddling the center line L along the transport direction Y in the piezoelectric element substrate 53. It protrudes to the right side of the paper, which is the inside of 53. Further, the projecting portion 56 a of each first electrode 56 in the group of the first electrodes 56 on the right side of the paper surface is projected to the left side of the paper surface inside the piezoelectric element substrate 53 so as to straddle the center line L of the piezoelectric element substrate 53.

  The second electrode 57 includes an electrode portion 57a that is electrically connected to the group of the first electrodes 56 on the left side of the paper, an electrode portion 57b that is electrically connected to the group of the first electrodes 56 on the right side of the paper, and the first electrode 56. And an annular outer peripheral electrode portion 57c that surrounds all from the outside. At both ends of the electrode portion 57a and the electrode portion 57b in the transport direction Y, the electrode portion 57a, the electrode portion 57b, and the outer peripheral electrode portion 57c are continuous with each other. The overhanging portions 56a of the first electrodes 56 in the group of the first electrodes 56 on the left side of the drawing and the overhanging portions 56a of the first electrodes 56 in the group of the first electrodes 56 on the right side of the drawing are the electrode portion 57a and the electrode portion 57b. Are arranged in the scanning direction X.

  As shown in FIG. 8, the gap forming member 54 protrudes from the counter substrate 52 toward the piezoelectric element substrate 53. That is, the plurality of gap forming members 54 that transmit the first drive signal are provided in the center of the counter substrate 52 in the scanning direction X, and have a predetermined protruding height, similar to the gap forming member 54 of the first embodiment. It includes a substantially cylindrical first metal member 54a and a hemispherical second metal member 54b. On the other hand, the gap forming member 54 that transmits the second drive signal is formed on the entire circumference of the annular first metal member 54c along the outer peripheral electrode portion 57c and the front end surface of the first metal member 54c. A metal member 54d. The first metal member 54c of the gap forming member 54 that transmits the second drive signal is indicated by a two-dot chain line in FIG. As shown in FIG. 7, the plurality of gap forming members 54 that transmit the first drive signal have intersections between the projecting portions 56 a of the first electrodes 56 and the center line L as connection points (black circles in FIG. 7). Connected to the first electrode 56. The gap forming member 54 that transmits the second drive signal is connected to the outer peripheral electrode portion 57c.

Next, the connection structure of the gap forming member 54 will be described.
As shown in FIG. 8, the plurality of gap forming members 54 that transmit the first drive signal come into contact with each of the protruding portions 56a of the first electrode 56, and the gap forming member 54 that transmits the second drive signal is the second. The counter substrate 52 is disposed to face the piezoelectric element substrate 53 so as to contact the outer peripheral electrode portion 57 c of the electrode 57.

  Next, as shown in FIG. 9, the second metal members 54b and 54d are melted in a state in which the gap forming member 54 is in contact with the overhanging portion 56a of the first electrode 56 and the second electrode 57 (outer peripheral electrode portion 57c). The piezoelectric element substrate 53 and the counter substrate 52 are heated at a temperature equal to or higher than the second temperature T2 and lower than the first temperature T1 at which the first metal members 54a and 54c melt. Thereby, as shown in FIG. 9, the second metal members 54b and 54d are melted, while the first metal members 54a and 54c are not melted. When the heating of the piezoelectric element substrate 53 and the counter substrate 52 is stopped, the second metal members 54b and 54d are cooled and solidified. Thereby, the piezoelectric element substrate 53 and the counter substrate 52 are joined. As described above, the gap forming member 54 that transmits the second drive signal surrounds the first electrode 56 from the outside, so that the space surrounded by the gap forming member 54 becomes the sealed space SC.

  At this time, the melted second metal members 54b and 54d are crushed by their own weights such as the counter substrate 52 and the drive IC 58 without applying pressure, and the first metal member 54a and the first electrode 56 or the first metal member 54c and the first metal member 54c It is pushed out from between the two electrodes 57 (outer peripheral electrode 57c). As a result, the thickness of the second metal member 54b or the second metal member 54d remaining between the first metal member 54a and the first electrode 56 or the first metal member 54c and the second electrode 57 is equal to the first metal member 54a. , 54c relative to the protruding height. For this reason, the gap between the piezoelectric element substrate 53 and the counter substrate 52 is approximately the vertical dimension that is the protruding height of the first metal members 54a and 54c. In other words, by setting the vertical dimension of the first metal members 54 a and 54 c to a size that does not hinder the displacement of the piezoelectric element 51, the gap between the piezoelectric element substrate 53 and the counter substrate 52 is reduced. Appropriate dimensions do not hinder the displacement of the.

According to this embodiment, in addition to the effects of the first embodiment, the following effects can be obtained.
(7) Since the gap forming member 54 forms the sealing space SC, the sealing material 59 of the first embodiment can be omitted. For this reason, the sealing space SC between the piezoelectric element substrate 53 and the counter substrate 52 can be easily formed.

(Modification)
In addition, you may change each said embodiment like the modification shown below. Moreover, each said embodiment and each modification can be combined arbitrarily.

  In each of the above embodiments, the gap forming member 54 (first metal member 54a) is not necessarily formed integrally with the signal transmission line 52b when the signal transmission line 52b is formed. For example, a well-known copper pillar may be adopted as the gap forming member 54, and the copper pillar may be formed on the signal transmission line 52b after the signal transmission line 52b is formed.

In the first embodiment, the sealing material 59 may be omitted.
In the second embodiment, a plurality of the second metal members 54d of the gap forming member 54 that transmits the second drive signal may be formed at intervals in the circumferential direction of the first metal member 54c.

  In the first embodiment, as shown in FIG. 10, the gap forming member 54 is not on the counter substrate 52 side, but on the piezoelectric element substrate 53 side, that is, the first electrode 56 and the second electrode 57 that are signal application lines. May be formed respectively. In this case, the first metal member 54a of the gap forming member 54 is joined to the first electrode 56 and the second electrode 57, and protrudes from the first electrode 56 and the second electrode 57 toward the counter substrate 52. Yes. The first metal member 54 a is preferably formed of the same metal as the material of each first electrode 56 and the material of the second electrode 57. The second metal member 54b is provided at the tip (on the counter substrate 52 side) of the first metal member 54a. As shown in FIG. 11, the counter substrate 52 is disposed with respect to the piezoelectric element substrate 53 in a state where each of the second metal members 54 b is in contact with each of the signal transmission lines 52 b of the counter substrate 52. Then, the piezoelectric element substrate 53 and the counter substrate 52 are heated at a temperature equal to or higher than the second temperature T2 at which the second metal member 54b melts and lower than the first temperature T1 at which the first metal member 54a melts. As shown, the second metal member 54b melts while the first metal member 54a does not melt. Therefore, as in the first embodiment, the first metal member 54a secures a gap having an appropriate dimension that does not hinder the displacement of the piezoelectric element 51 between the piezoelectric element substrate 53 and the counter substrate 52, and the piezoelectric element. The substrate 53 and the counter substrate 52 are joined via the gap forming member 54.

  According to this configuration, since the first metal member 54a of the gap forming member 54 is bonded to the first electrode 56 and the second electrode 57, the first metal member 54a included in the gap forming member 54 is piezoelectrically bonded by metal bonding. It can be easily joined to the element substrate 53. Further, the first electrode 56 and the second electrode 57 and the first metal member 54a are formed of the same metal, so that the first electrode 56 and the second electrode 57 are bonded to the piezoelectric element substrate 53 when the first electrode 56 and the second electrode 57 are formed. The first metal member 54a of the gap forming member 54 can be formed. In the second embodiment, similarly, the gap forming member 54 may be formed on each of the first electrode 56 and the second electrode 57 instead of the gap forming member 54 formed on the counter substrate 52. .

  In the modification shown in FIGS. 10 and 11, the gap forming member 54 (first metal member 54 a) does not necessarily have to be formed integrally with the first electrode 56 and the second electrode 57. For example, a known copper pillar may be employed as the gap forming member 54, and the copper pillar may be formed on the first electrode 56 and the second electrode 57 after the first electrode 56 and the second electrode 57 are formed.

  In each of the above embodiments, the gap forming member 54 may not electrically connect the piezoelectric element substrate 53 and the counter substrate 52. That is, a bump for electrically connecting the first electrode 56 and the second electrode 57 of the piezoelectric element substrate 53 and the signal transmission line 52 b of the counter substrate 52 may be formed separately from the gap forming member 54.

In each of the above embodiments, the ink may be supplied from an ink tank (not shown) provided outside the frame 12 instead of from the ink cartridge 22.
The liquid ejecting apparatus 11 of each of the above embodiments may be, for example, a large format printer that performs printing (recording) on a sheet P that is an example of a long medium. In this case, the liquid ejecting apparatus 11 may be configured such that the paper P is unwound from the state of being wound in a roll shape and conveyed onto the medium support base 13.

  In each of the above embodiments, the liquid ejecting apparatus 11 is a so-called full-line type in which the liquid ejecting head 23 is not provided in the carriage 21 and includes a long and fixed head unit 24 corresponding to the entire width of the paper P. It may be a printer. The plurality of nozzles N provided in the head unit 24 in this case are arranged so as to cover the entire width of the paper P in the scanning direction X.

  In each of the above embodiments, the liquid used for printing is a fluid other than ink (a liquid, a liquid obtained by dispersing or mixing particles of functional material, a fluid such as a gel, or a fluid. It may include a solid that can be discharged). For example, printing (recording) is performed by discharging a liquid material that contains dispersed or dissolved materials such as electrode materials and color materials (pixel materials) used in the manufacture of liquid crystal displays, EL (electroluminescence) displays, and surface-emitting displays. ).

  In each of the above-described embodiments, the liquid ejecting apparatus 11 ejects a solid such as a fluid ejecting apparatus that ejects a fluid such as a gel (for example, a physical gel) or a powder (a granular material) such as a toner. It may be a granular material discharge device (for example, a toner jet recording device). In the present specification, the term “fluid” is a concept that does not include a fluid consisting of only gas, and examples of the fluid include liquid (inorganic solvent, organic solvent, solution, liquid resin, liquid metal (metal melt), etc. ), Liquids, fluids, powders (including granules and powders), and the like.

  In each of the above embodiments, the liquid ejecting apparatus 11 is not limited to a printer that performs printing (recording) by discharging a fluid such as ink. As long as the piezoelectric device 50 is included, a non-impact printer such as a laser printer, an LED printer, or a thermal transfer printer (including a sublimation printer) may be used, or an impact printer such as a dot impact printer may be used.

  In each of the above embodiments, the medium is not limited to the paper P, and may be a plastic film or a thin plate material, or a fabric used in a textile printing apparatus or the like.

  DESCRIPTION OF SYMBOLS 30 ... Channel unit, 31 ... Nozzle plate, 32 ... Channel substrate, 33 ... Pressure chamber substrate, 34 ... Vibration plate, 50 ... Piezoelectric device, 51 ... Piezoelectric element, 52 ... Opposite substrate, 52b ... Signal transmission line, 53 ... Piezoelectric element substrate, 54 ... Gap forming member (signal transmission member), 54a ... First metal member, 54b ... Second metal member, 54c ... First metal member, 54d ... Second metal member, 55 ... Piezoelectric body, 56 ... first electrode as an example of signal application line, 56a ... overhang, 57 ... second electrode as an example of signal application line, SC ... sealed space, T1 ... first temperature, T2 ... second temperature, N ... Nozzle, Na, Nb ... Nozzle row.

Claims (8)

A piezoelectric element substrate on which at least one piezoelectric element that is displaced in response to application of a drive signal is disposed;
A counter substrate disposed opposite to the piezoelectric element substrate and transmitting the drive signal to the piezoelectric element substrate;
A gap forming member that forms a gap between the piezoelectric element substrate and the counter substrate that can be displaced according to the application of the drive signal of the piezoelectric element, and
The gap forming member is
A piezoelectric device comprising: a first metal member that melts at a first temperature; and a second metal member that melts at a second temperature lower than the first temperature.   A sealing space for sealing the piezoelectric element is formed between the piezoelectric element substrate and the counter substrate by the gap formed so as to surround the piezoelectric element by the gap forming member. The piezoelectric device according to claim 1.   The piezoelectric device according to claim 1, wherein the gap forming member is a signal transmission member that electrically transmits the driving signal from the counter substrate to the piezoelectric element substrate. The piezoelectric element substrate is formed with a metal signal application line for transmitting and applying the drive signal to the piezoelectric element,
4. The piezoelectric device according to claim 1, wherein the gap forming member has the first metal member joined to the signal applying line. 5.   5. The piezoelectric device according to claim 4, wherein the signal applying line is made of the same metal as the first metal member of the gap forming member. A metal signal transmission line through which the drive signal is transmitted is formed on the counter substrate,
4. The piezoelectric device according to claim 1, wherein the gap forming member has the first metal member joined to the signal transmission line. 5.   The piezoelectric device according to claim 6, wherein the signal transmission line is formed of the same metal as the first metal member included in the gap forming member.   8. The piezoelectric device according to claim 1, wherein in the gap forming member, the first metal member is copper, and the second metal member is a metal containing at least tin.

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