JP2011136462A - Liquid droplet ejecting head and liquid droplet ejecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid droplet ejecting head achieving high density of nozzles and miniaturization of the liquid droplet ejecting head. <P>SOLUTION: The liquid droplet ejecting head IJ1 includes: a flow passage forming substrate 10 in which a pressure generating chamber 12 communicating with a nozzle opening 21 is formed; a piezoelectric element 300 installed on one face side of the flow passage forming substrate 10 via an elastic film 50; a driving IC 150 which is flip-chip mounted on the terminal 90a of the piezoelectric element 300; and a sealing substrate 30 which is formed on the side opposite from the flow passage forming substrate 10 with the elastic film 50 interposed between the substrates and which has a piezoelectric element holding part 31 formed on the face opposite to the piezoelectric element 300 and the driving IC 150, the piezoelectric element holding part 31 securing a space having a dimension not to hinder the operation of the piezoelectric element 300 and hermetically sealing the piezoelectric element 300 and the driving IC 150 inside the space. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  Conventionally, as a droplet discharge head used in a droplet discharge device, a droplet discharge head that uses a piezoelectric element (piezo element) to displace an elastic film and discharges ink droplets from nozzles by the displacement of the elastic film is known. It has been. In this type of droplet discharge head, a second substrate for sealing the piezoelectric element is bonded onto the first substrate on which the elastic film and the piezoelectric element are formed, and the piezoelectric element is inserted into the opening formed in the second substrate. In general, a method is used in which a terminal is exposed and a driving IC is connected to the terminal by wire bonding. However, in this method, it is difficult to cope with the high density of the nozzles and the miniaturization of the droplet discharge head. Therefore, in Patent Document 1, the second substrate is omitted and the drive IC is flipped directly onto the terminals of the piezoelectric elements. A chip mounting method has been proposed.

Japanese Patent No. 3714073

  However, the method of Patent Document 1 has a problem that the piezoelectric element is deteriorated due to the presence of moisture or the like because the piezoelectric element is exposed to the outside. In the droplet discharge head disclosed in Patent Document 1, a driving IC is used as a sealing substrate, and a sealing resin is applied around the driving IC to protect the piezoelectric element. In this method, a large number are formed on the elastic film. Since it is necessary to cover the piezoelectric element with the driving IC, there is a problem that the size and shape of the driving IC are limited by the size and arrangement of the piezoelectric element. In addition, since the sealing resin is applied around the driving IC, the mounting area of the driving IC is increased by the sealing resin that has spread around the driving IC, and the effect of reducing the mounting area by performing flip chip mounting is sufficient. In addition, the sealing resin that wets and spreads in the gap between the driving IC and the first substrate may hinder the operation of the piezoelectric element and the elastic film disposed immediately below the driving IC.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a droplet discharge head and a droplet discharge device in which piezoelectric elements are unlikely to deteriorate due to the presence of moisture or the like.

  In order to solve the above-described problems, a droplet discharge head according to the present invention includes a first substrate having a pressure generation chamber communicating with a nozzle opening, a surface provided on the first substrate and facing the first substrate. A second substrate having a recess, a piezoelectric element provided in a space formed by the first substrate and the recess, and an electric terminal provided in the space via an output terminal made of a bump. The piezoelectric element and the driving IC are provided at positions not in contact with the second substrate.

  According to this configuration, the bumps of the driving IC are directly brought into contact with the terminals of the piezoelectric element to achieve electrical connection. Therefore, the interval between the terminals of the piezoelectric element can be shortened, and the nozzle density can be increased. Become. In addition, since the concave portion of the second substrate has a size that can accommodate the piezoelectric element and the driving IC, and the piezoelectric element and the driving IC are sealed in the space in the concave portion, the piezoelectric element and the driving IC deteriorate due to the presence of moisture or the like. It is suppressed. Furthermore, since the piezoelectric element is sealed by the second substrate, the degree of freedom in designing the size, shape, arrangement, number, etc. of the drive IC is high. For example, as shown in Patent Document 1, the size and shape of the drive IC are piezoelectric. The problem of being limited by the size and arrangement of elements is unlikely to occur.

  In the present invention, the second substrate has at least a part of a liquid chamber communicating with the pressure generating chamber, and the recess and the liquid chamber are adjacent to each other through a part of the second substrate. It is desirable that they are arranged. According to this configuration, the heat of the driving IC is easily transmitted to the ink in the liquid chamber, and can be effectively radiated.

  In the present invention, the first substrate is provided with one or a plurality of rows of the piezoelectric elements composed of the plurality of piezoelectric elements arranged in the first direction, and the output terminal of the drive IC extends along the first direction. A plurality of input terminals of the drive IC are provided along a second direction orthogonal to the first direction, and are connected to the input terminals at positions facing the input terminals of the drive IC on the first substrate. It is desirable that a conductive portion is provided, and the conductive portion is provided at a position spaced apart from the piezoelectric element array in the first direction.

  According to this configuration, the conductive portions that input signals to the drive IC can be concentrated at a predetermined position. Therefore, a member connected to the conductive portion, for example, a flexible substrate can be reduced in size, and the droplet discharge head can be reduced in size. Preferably, the drive IC has a rectangular shape having the first direction as a long side and the second direction as a short side, and a plurality of the output terminals of the drive IC are provided along the long side, A plurality of the input terminals of the driving IC may be provided along the short side. As a result, the conductive portions for inputting signals to the drive IC can be concentrated on the short side of the drive IC, and the droplet discharge head can be further miniaturized.

  For example, the conductive portion may be provided only at one of the positions sandwiching both sides in the arrangement direction of the piezoelectric element rows. Or the said electroconductive part shall be provided in the position which pinches | interposes the arrangement direction both sides of the said piezoelectric element row | line | column.

  In the case where the conductive portion is provided only on one side in the arrangement direction of the piezoelectric element array, members (for example, flexible substrates) connected to the conductive portion can be concentrated in one place, so that the member cost can be reduced and the droplet discharge can be performed. The configuration is most suitable for downsizing the head. However, when the droplet discharge head has a large number of piezoelectric elements and not all of the piezoelectric elements can be driven by only one driving IC, the plurality of piezoelectric elements are divided into two in the arrangement direction, and one of them is the first It is also conceivable to drive with the driving IC and to drive the other with the second driving IC. In this case, such a problem is solved by providing the conductive portions on both sides in the arrangement direction of the piezoelectric element rows.

  In the present invention, the arrangement of the driving IC and the piezoelectric element can be arbitrarily designed according to the size of the driving IC. For example, when the driving IC is large, a plurality of rows of piezoelectric elements can be arranged on the first substrate, and the driving IC can be mounted across the plurality of rows. Specifically, two rows of the piezoelectric element rows are provided on the first substrate along the second direction, and the driving IC is disposed so as to cover the two rows of piezoelectric element rows. A configuration in which the output terminal of the drive IC and the terminal of the piezoelectric element are connected at positions on both sides of the piezoelectric element array of the array can be employed.

  When the drive IC is small and cannot be mounted across the piezoelectric elements arranged in a plurality of rows, the drive IC can be placed between the two rows of piezoelectric elements. Specifically, two rows of the piezoelectric element rows are provided on the first substrate along the second direction, and the driving IC is disposed between the two rows of piezoelectric element rows. It is possible to adopt a configuration in which the output terminal of the driving IC and the terminal of the piezoelectric element are connected in a region between the piezoelectric element arrays.

  As described above, in the droplet discharge head of the present invention, the drive IC and the piezoelectric element can be arranged relatively freely. Therefore, a small-sized droplet discharge head is provided by appropriately designing the arrangement thereof. Is possible.

  In the present invention, the driving IC is preferably flip-chip mounted on the piezoelectric element.

  Flip chip mounting is a mounting method in which bump electrodes called bumps are formed on the surface of the bare chip (circuit surface of the driving IC), and the bare chip is directly electrically connected to the first substrate with the surface facing down. In flip chip mounting, the circuit surface of the driving IC is arranged so as to face the first substrate, so that heat generated by the driving IC is easily transferred to the flow path formed on the first substrate, and the liquid flowing through the flow path There is an effect that thickening is suppressed.

  In the present invention, it is desirable that a flexible substrate is connected to the conductive portion.

  According to this configuration, since the droplet discharge head and the droplet discharge device main body can be connected by the flexible flexible substrate, the degree of freedom in arrangement of the droplet discharge head and the droplet discharge device main body. Will increase.

  The droplet discharge head of the present invention includes a nozzle, a first substrate having a pressure generation chamber communicating with the nozzle, and a recess provided on the first substrate and having an opening toward the first substrate. A second substrate having a piezoelectric element provided in a space formed by the first substrate and the recess, and electrically provided via an output terminal provided in the space and having a bump on a terminal of the piezoelectric element. The piezoelectric element and the drive IC are provided at positions separated from the second substrate.

  According to this configuration, the bumps of the driving IC are directly brought into contact with the terminals of the piezoelectric element to achieve electrical connection. Therefore, the interval between the terminals of the piezoelectric element can be shortened, and the nozzle density can be increased. Become. In addition, since the concave portion of the second substrate has a size that can accommodate the piezoelectric element and the driving IC, and the piezoelectric element and the driving IC are sealed in the space in the concave portion, the piezoelectric element and the driving IC deteriorate due to the presence of moisture or the like. It is suppressed. Furthermore, since the piezoelectric element is sealed by the second substrate, the degree of freedom in designing the size, shape, arrangement, number, etc. of the drive IC is high. For example, as shown in Patent Document 1, the size and shape of the drive IC are piezoelectric. The problem of being limited by the size and arrangement of elements is unlikely to occur.

  The droplet discharge device of the present invention has the above-described droplet discharge head of the present invention.

  According to this configuration, it is possible to form a fine image or a fine microdevice using a droplet discharge head having a small nozzle pitch, and the droplet discharge whose performance is not easily deteriorated due to the presence of moisture or the like. An apparatus can be provided.

FIG. 2 is an exploded perspective view of a droplet discharge head according to the first embodiment. It is the top view and sectional drawing of the droplet discharge head of 1st Embodiment. It is a disassembled perspective view of the droplet discharge head of 2nd Embodiment. It is the top view and sectional drawing of the droplet discharge head of 2nd Embodiment. It is a perspective view of a droplet discharge device provided with a droplet discharge head.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, an XYZ orthogonal coordinate system is set, and the positional relationship of each member will be described with reference to this XYZ orthogonal coordinate system. The predetermined direction in the horizontal plane is the X-axis direction, the direction orthogonal to the X-axis direction in the horizontal plane is the Y-axis direction, and the direction orthogonal to each of the X-axis direction and the Y-axis direction (that is, the vertical direction) is the Z-axis direction. To do.

[Droplet Discharge Head of First Embodiment]
FIG. 1 is an exploded perspective view of a droplet discharge head IJ1 according to a first embodiment of the present invention, and FIG. 2 is a plan view of FIG.

  The droplet discharge head IJ1 of this embodiment includes a first substrate including the flow path forming substrate 10, a drive IC 150 flip-chip mounted on the first, and a second substrate including the sealing substrate 30 that seals the drive IC 150. And a substrate. The first substrate includes a flow path forming substrate 10 in which a pressure generation chamber 12 communicating with a nozzle opening (nozzle) 21 of the nozzle plate 20 is formed, an elastic film 50 provided on the flow path forming substrate 10, and an elastic film. 50, and the piezoelectric element 300 provided on the insulating film 55. The second substrate has the piezoelectric element holding portion 31 formed on the surface facing the piezoelectric element 300 and the driving IC 150. And a compliance substrate 40 provided on the sealing substrate 30.

  In this embodiment, the flow path forming substrate 10 is composed of a silicon single crystal substrate having a plane orientation (110), and both surfaces thereof are composed of silicon dioxide previously formed by thermal oxidation, and an elastic film composed of a thin film having a thickness of 1 to 2 μm. 50 and a protective film 51 are formed.

  The flow path forming substrate 10 is formed with a pressure generating chamber 12 partitioned by a plurality of partition walls. The pressure generating chamber 12 has a longitudinal direction in the X direction. The flow path forming substrate 10 is provided with two rows of pressure generating chambers (pressure generating chamber rows) in the X direction corresponding to one row including a plurality of pressure generating chambers 12 arranged in the Y direction. On the outside in the longitudinal direction of the pressure generation chambers 12 in each row, communication is made with a reservoir section 35 provided on the sealing substrate 30 and constitutes a reservoir (liquid chamber) 100 serving as a common ink chamber for each pressure generation chamber 12. A portion 13 is formed. The communication portion 13 is in communication with one end portion in the longitudinal direction of each pressure generating chamber 12 via the ink supply path 14.

  The ink supply path 14 communicates with one end side in the longitudinal direction of the pressure generation chamber 12 and has a smaller cross-sectional area than the pressure generation chamber 12. For example, in the present embodiment, the ink supply path 14 has a width smaller than the width of the pressure generation chamber 12 by narrowing the flow path on the pressure generation chamber 12 side between the reservoir 100 and each pressure generation chamber 12 in the width direction. It is formed with. As described above, in this embodiment, the ink supply path 14 is formed by narrowing the width of the flow path from one side. However, the ink supply path may be formed by narrowing the width of the flow path from both sides.

  The pressure generating chamber 12, the communication portion 13, and the ink supply path 14 are formed by anisotropically etching the flow path forming substrate 10 made of a silicon single crystal substrate. For example, when a silicon single crystal substrate is immersed in an alkaline solution such as KOH, the first (111) plane perpendicular to the (110) plane is gradually eroded, and the first (111) plane is about 70 degrees. A second (111) plane appears that forms an angle and forms an angle of about 35 degrees with the (110) plane. Compared with the etching rate of the (110) plane, the etching rate of the (111) plane is about 1/180. Therefore, by anisotropic etching, precision processing is performed on the basis of parallelogram depth processing formed by two first (111) planes and two oblique second (111) planes. The pressure generating chambers 12 can be arranged with high density.

  In the present embodiment, the long side of each pressure generating chamber 12 is formed by the first (111) plane and the short side is formed by the second (111) plane. The pressure generation chamber 12 is formed by etching until it substantially passes through the flow path forming substrate 10 and reaches the elastic film 50. Here, the amount of the elastic film 50 that is affected by the alkaline solution for etching the silicon single crystal substrate is extremely small.

  The thickness of the flow path forming substrate 10 may be selected in accordance with the arrangement density of the pressure generation chambers 12, and the arrangement density of the pressure generation chambers 12 is, for example, about 180 pieces per inch (180 dpi). In this case, the thickness of the flow path forming substrate 10 may be about 220 μm. For example, when the flow path forming substrate 10 is arranged at a relatively high density of 200 dpi or more, the thickness of the flow path forming substrate 10 is 100 μm or less. It is preferable to make it relatively thin. This is because the arrangement density can be increased while maintaining the rigidity of the partition between adjacent pressure generation chambers 12.

  On the opening surface side of the flow path forming substrate 10, a nozzle plate 20 having a nozzle opening 21 communicating with the side opposite to the ink supply path 14 of each pressure generating chamber 12 is provided via an adhesive, a heat welding film, or the like. It is fixed. The nozzle plate 20 has a thickness of, for example, 0.05 to 1 mm, a linear expansion coefficient of 300 ° C. or less, and a glass ceramic or silicon single crystal of, for example, 2.5 to 4.5 [× 10 −6 / ° C.]. It consists of a substrate or non-rust steel. The nozzle plate 20 entirely covers one surface of the flow path forming substrate 10 on one surface, and also serves as a reinforcing plate that protects the silicon single crystal substrate that is the flow path forming substrate 10 from impact and external force. The nozzle plate 20 may be formed of a material having substantially the same thermal expansion coefficient as that of the flow path forming substrate 10. In this case, since the deformation by heat of the flow path forming substrate 10 and the nozzle plate 20 is substantially the same, it can be easily joined using a thermosetting adhesive or the like.

  Here, the size of the pressure generation chamber 12 that applies ink droplet discharge pressure to the ink and the size of the nozzle opening 21 that discharges the ink droplet are optimized according to the amount of ink droplet to be discharged, the discharge speed, and the discharge frequency. The For example, when recording 360 ink droplets per inch, the nozzle opening 21 needs to be accurately formed with a diameter of several tens of μm.

  An elastic film 50 having a thickness of, for example, about 1.0 μm is provided on the side opposite to the opening surface of the flow path forming substrate 10. A piezoelectric element 300 is provided on the elastic film 50 via an insulating film 55 having a thickness of about 0.4 μm, for example. The piezoelectric element 300 includes a lower electrode film 60 having a thickness of, for example, about 0.2 μm, a piezoelectric layer 70 having a thickness of, for example, about 1.0 μm, and an upper electrode film 80 having a thickness of, for example, about 0.1 μm. They are sequentially stacked.

  The piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. In general, one electrode of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12. In the present embodiment, the lower electrode film 60 is a common electrode of the piezoelectric element 300 and the upper electrode film 80 is an individual electrode of the piezoelectric element 300. However, this may be reversed for the convenience of a drive circuit and wiring.

  The lower electrode film 60, the elastic film 50, and the insulating film 55 of the piezoelectric element 300 function as a diaphragm. The piezoelectric element 300 is provided for each pressure generation chamber 12. The piezoelectric element 300 has a longitudinal direction in the X direction like the pressure generating chamber 12. On the elastic film 50, two rows of piezoelectric elements (piezoelectric element rows) for one row composed of a plurality of piezoelectric elements 300 arranged in the Y direction are provided in the X direction. The piezoelectric element 300 displaces the diaphragm (directly the elastic film 50 via the lower electrode film 60 and the insulating film 55), and ejects ink droplets from the nozzle openings 21 by the displacement of the diaphragm.

  A lead electrode 90 made of, for example, gold (Au) or the like is formed at one end of the piezoelectric element 300. The lead electrode 90 is formed at an end located on the outer peripheral side of the flow path forming substrate in the longitudinal direction (X direction) of the upper electrode film 80. The end of the lead electrode 90 opposite to the side connected to the upper electrode film 80 functions as a terminal 90 a of the piezoelectric element 300. The terminals 90a are arranged in the Y direction according to the arrangement of the piezoelectric elements 300. The elastic film 50 includes a total of two terminal rows each including one row of terminals 90a, one for each piezoelectric element row. It is disposed above (more specifically, on the insulating film 55).

  An output terminal 151 of a driving IC 150 that drives the piezoelectric element 300 is connected to the terminal 90 a of the piezoelectric element 300. An output terminal 151 made of a conductive bump is provided at a position facing each terminal 90a of the driving IC 150, and the driving IC 150 is face-down bonded with the output terminal 151 facing the terminal 90a of the piezoelectric element 300. Thus, the drive IC 150 is flip-chip mounted on the first substrate. In flip chip mounting, for example, a metal bump, preferably a gold bump, is formed as the output terminal 151 on the driving IC 150, a gold pad is formed as the terminal 90a of the piezoelectric element 300, and both are heated and pressed, ultrasonic bonding, brazing , Resin bonding or the like.

  In the case of this embodiment, the driving IC 150 has a sufficient size compared to the width in the longitudinal direction of the piezoelectric element 300, and the driving IC 150 straddles two piezoelectric element rows, that is, above the two piezoelectric element rows. It is possible to arrange so as to cover. For this reason, in this embodiment, two rows of piezoelectric element rows are arranged so that the terminals 90a do not face each other, and the output terminal 151 of the drive IC 150 and the piezoelectric device are positioned on both sides of the two rows of piezoelectric element rows. The terminal 90a of the element 300 is connected.

  The drive IC 150 has a rectangular shape with the Y direction as the long side direction and the X direction as the short side direction. The output terminals 151 of the drive IC 150 are provided in one row along the outer periphery of the drive IC 150 on the two long sides of the drive IC 150. On the short side of the drive IC 150, a plurality of input terminals 152 are provided along the outer periphery of the drive IC 150 for inputting signals relating to drawing information from an external device (not shown). On the elastic film 50 facing the input terminal 152 (more specifically, on the insulating film 55), the conductive portion 61 connected to the input terminal 152 is provided at a position separated from the piezoelectric element array in the Y direction. It has been. The end of the conductive part 61 opposite to the side connected to the input terminal 152 is an external terminal connected to the flexible substrate 160. The flexible substrate 160 is flexibly deformed and connected to an external device (not shown), and inputs a signal related to drawing information to the driving IC 150.

  The conductive portion 61 is provided for each input terminal 152 of the drive IC 150. The conductive portion 61 is provided at a position on at least one side of a position sandwiching both sides of the terminal row of the piezoelectric element 300 (that is, both sides in the arrangement direction of the piezoelectric element row composed of the plurality of piezoelectric elements 300 arranged in the Y direction). One end thereof is disposed on the piezoelectric element holding portion 31 and the other end extends to the outside of the piezoelectric element holding portion 31 and is exposed on the end of the flow path forming substrate 10.

  In the present embodiment, the conductive portion 61 is located only on one side in the longitudinal direction of the flow path forming substrate 10, that is, any of the positions sandwiching both sides in the arrangement direction of the piezoelectric element array composed of the plurality of piezoelectric elements 300 arranged in the Y direction. It is provided only at one of the positions. However, the conductive portions 61 may be provided at positions on both sides in the longitudinal direction of the flow path forming substrate 10, i.e., sandwiching both sides in the arrangement direction of the piezoelectric element array composed of the plurality of piezoelectric elements 300 arranged in the Y direction.

  In the case where the conductive portion 61 is provided only on one side in the arrangement direction of the piezoelectric element rows, the members (for example, the flexible substrate 160) connected to the conductive portion 61 can be concentrated in one place. The configuration is most suitable for downsizing the droplet discharge head IJ1. However, in the case where the droplet discharge head IJ1 has a large number of piezoelectric elements 300 and not all the piezoelectric elements 300 can be driven by only one driving IC 150, the plurality of piezoelectric elements 300 are arranged in the arrangement direction (Y direction). It is also possible to divide and drive one with a first driving IC and the other with a second driving IC. In this case, such a problem is solved by providing the conductive portions 61 on both sides in the arrangement direction of the piezoelectric element rows.

  A sealing substrate 30 that seals the piezoelectric element 300 and the driving IC 150 is joined to the flow path forming substrate 10 on the piezoelectric element 300 side (the side opposite to the flow path forming substrate 10 with the elastic film 50 interposed therebetween). A piezoelectric element holding portion 31 that can accommodate the piezoelectric element 300 and the drive IC 150 is provided on the surface of the sealing substrate 30 that faces the piezoelectric element 300 and the drive IC 150. The piezoelectric element holding portion 31 is a recess formed by digging the surface of the sealing substrate 30. The piezoelectric element holding unit 31 has a size that does not hinder the operation of the piezoelectric element 300. Even if the elastic film 50 vibrates by driving the piezoelectric element 300, the piezoelectric element 300 and the driving IC 150 are not It does not come into contact with the side or ceiling surface. That is, the piezoelectric element 300 and the drive IC 150 are provided at a position that does not contact the sealing substrate 30 or are provided at a position separated from the sealing substrate 30.

  The piezoelectric element holding portion 31 is formed so as to cover all the two rows of piezoelectric elements 300 and the driving IC 150 arranged in parallel, and simultaneously seals the two rows of piezoelectric elements 300 and the driving IC 150 arranged in parallel. The height of the piezoelectric element holding portion 31 (depth in the thickness direction of the flow path forming substrate) is, for example, 200 μm or more and 500 μm, specifically 300 μm. It can be adjusted by thinning.

  An opening 30H penetrating the sealing substrate 30 in the thickness direction is provided at a portion facing the conductive portion 61 of the sealing substrate 30, and the other end of the conductive portion 61 and the piezoelectric element are provided in the opening 30H. A portion 60a of the lower electrode film 60 of 300 is exposed. A flexible substrate 160 is electrically connected to the other end portion of the conductive portion 61 exposed to the opening 30H and a part 60a of the lower electrode film. For connection between the flexible substrate 160 and the other end of the conductive portion 61 and the lower electrode film portion 60a, resin bonding, anisotropic conductive film, bonding using brazing, or the like is used.

  As the sealing substrate 30, it is preferable to use a material substantially the same as the coefficient of thermal expansion of the flow path forming substrate 10, such as glass or ceramic material. In this embodiment, silicon having the same material as the flow path forming substrate 10 is used. It is formed using a single crystal substrate. The bonding between the sealing substrate 30 and the flow path forming substrate 10 is not particularly limited. For example, in the present embodiment, the thermosetting epoxy adhesive 110 is used. The sealing substrate 30 and the flow path forming substrate 10 are not limited to bonding via the adhesive 110. For example, a film made of gold (Au) is formed on each of the bonding surfaces, and both are gold-gold bonded. Alternatively, bonding may be performed by anodic bonding.

  In a region corresponding to the communication portion 13 of the flow path forming substrate 10 of the sealing substrate 30, a reservoir portion 35 constituting at least a part of the reservoir 100 which is a common ink chamber of the plurality of pressure generating chambers 12 is formed. Yes. In this embodiment, the reservoir portion 35 is formed across the width direction of the pressure generating chamber 12 through the sealing substrate 30 in the thickness direction. The reservoir unit 35 communicates with the communication unit 13 of the flow path forming substrate 10 to configure the reservoir 100.

  The reservoir part 35 and the piezoelectric element holding part 31 are arranged so as to be adjacent to each other via a partition wall 39 which is a part of the sealing substrate 30. As a result, the heat of the drive IC 150 is easily transferred to the ink in the reservoir section 35, and can be effectively dissipated. The thickness (width in the X direction) of the partition wall 39 is preferably 100 μm or more and 200 μm or less from the viewpoint of improvement in mechanical strength and heat dissipation from the piezoelectric element holding portion 31.

  A compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the sealing substrate 30. The sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm), and one surface of the reservoir portion 35 is sealed by the sealing film 41. . The fixing plate 42 is formed of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm). A region of the fixing plate 42 facing the reservoir 100 is an opening 43 that is completely removed in the thickness direction, and one surface of the reservoir 100 is sealed only by a flexible sealing film 41. Yes.

  An ink introduction port 44 for supplying ink to the reservoir 100 is formed on the compliance substrate 40 on the outer side of the central portion of the reservoir 100 in the longitudinal direction. The sealing substrate 30 is provided with an ink introduction path 37 that communicates the ink introduction port 44 with the sidewall of the reservoir 100. In the droplet discharge head IJ1 of the present embodiment, ink is taken in from an ink introduction port 44 connected to an external ink supply means (not shown), and the interior from the reservoir 100 to the nozzle opening 21 is filled with ink, and then from the drive IC. In accordance with the drive signal, a voltage is applied between each of the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generation chamber 12 to bend the elastic film 50, the insulating film 55, the lower electrode film 60, and the piezoelectric layer 70. By deforming, the pressure in each pressure generating chamber 12 is increased, and ink droplets are ejected from the nozzle openings 21.

  According to the droplet discharge head IJ1 of the present embodiment, since the driving IC 150 is flip-chip mounted on the terminal 90a of the piezoelectric element 300, the interval between the terminals 90a of the piezoelectric element 300 can be shortened, and the nozzle density can be reduced. Improvement is achieved. In addition, since the piezoelectric element holding portion 31 of the sealing substrate 30 has a size that can accommodate the piezoelectric element 300 and the driving IC 150, and the piezoelectric element 300 and the driving IC 150 are sealed in the piezoelectric element holding portion 31, there is presence of moisture or the like. As a result, the deterioration of the piezoelectric element 300 and the driving IC 150 is suppressed, and the mechanical strength is also improved. Furthermore, since the sealing of the piezoelectric element 300 is performed by the sealing substrate 30, the degree of freedom in design of the size, shape, arrangement, number, etc. of the drive IC 150 is high. However, the problem of being limited by the size and arrangement of the piezoelectric element 300 hardly occurs.

  In the droplet discharge head IJ1 of the present embodiment, the output terminal 151 of the drive IC 150 is provided on the long side of the drive IC 150, and the input terminal 152 of the drive IC 150 is provided on the short side of the drive IC 150. The conductive portion 61 connected to the 152 can be concentrated on the short side of the drive IC 150. Therefore, the member connected to the conductive portion 61, for example, the flexible substrate 160 can be reduced in size, and the droplet discharge head IJ1 can be reduced in size.

  In the present embodiment, two piezoelectric element arrays each including a plurality of piezoelectric elements 300 arranged in the Y direction are provided. However, the number of piezoelectric element arrays is not limited to this, and is one or three or more. You can also In this case, the output terminals 151 of the drive IC 150 may be one or more rows, or a plurality of drive ICs having one or two rows of output terminals may be combined and mounted on the terminals of the piezoelectric elements.

[Droplet Discharge Head of Second Embodiment]
FIG. 3 is an exploded perspective view of a droplet discharge head IJ2 according to the second embodiment of the present invention, and FIG. 4 is a plan view of FIG. 3 and a sectional view taken along line BB ′. The droplet discharge head IJ2 of the present embodiment differs from the droplet discharge head IJ1 of the first embodiment in that the arrangement of the terminals of the piezoelectric element, the size and arrangement of the driving IC, and the accompanying lower electrode film The shape and the arrangement and shape of the conductive part. The configuration of the nozzle plate, the flow path forming substrate, the elastic film, and the insulating film is the same as that of the droplet discharge head IJ1 of the first embodiment. Accordingly, in the droplet discharge head IJ2 of the present embodiment, the same reference numerals are given to components common to the droplet discharge head IJ1 of the first embodiment, and detailed description thereof is omitted.

  A lead electrode 90 made of, for example, gold (Au) or the like is formed at one end of the piezoelectric element 300. The lead electrode 90 is formed at an end located on the center side of the flow path forming substrate in the longitudinal direction (X direction) of the upper electrode film 80. The end of the lead electrode 90 opposite to the side connected to the upper electrode film 80 functions as a terminal 90 b of the piezoelectric element 300. The terminals 90b of the piezoelectric element 300 are arranged in the Y direction according to the arrangement of the piezoelectric elements 300, and a terminal row composed of such a row of terminals 90b is provided for two rows, one for each piezoelectric element row. The elastic film 50 is disposed on the elastic film 50 (more specifically, on the insulating film 55).

  A driving IC 170 for driving the piezoelectric element 300 is flip-chip mounted on the terminal 90 b of the piezoelectric element 300. An output terminal 171 made of a conductive bump is provided at a position facing the terminal 90b of each piezoelectric element 300 of the drive IC 170, and the output IC 171 faces the terminal 90b of the piezoelectric element 300 with the output terminal 171 facing the face. The two are connected by down bonding.

  In the case of the present embodiment, the drive IC 170 is smaller than the width in the longitudinal direction of the piezoelectric element 300 and cannot be mounted across the piezoelectric elements 300 arranged in a plurality of rows. Therefore, in this embodiment, two rows of piezoelectric element rows are arranged so that the terminals 90b face each other, and in the region between the two rows of piezoelectric element rows, the output terminals 171 of the drive IC 170 and the piezoelectric elements 300 are arranged. The terminal 90b is connected.

  The drive IC 170 has a rectangular shape with the Y direction as the long side direction and the X direction as the short side direction. The output terminals 171 of the drive IC 170 are provided in one row along two outer sides of the drive IC 170 along the outer periphery of the drive IC 170. On the short side of the drive IC 170, a plurality of input terminals 172 are provided along the outer periphery of the drive IC 170 for inputting signals relating to drawing information from an external device (not shown). A conductive portion 62 connected to the input terminal 172 is provided on the elastic film 50 (more specifically, on the insulating film 55) facing the input terminal 172. The end of the conductive part 62 opposite to the side connected to the input terminal 172 is an external terminal connected to the flexible substrate 180. The flexible substrate 180 is flexibly deformed and connected to an external device (not shown), and inputs a signal related to drawing information to the driving IC 150.

  The conductive portion 62 is provided for each input terminal 172 of the drive IC 170. The conductive portion 62 is provided at a position on one side of positions sandwiching both sides of the terminal row of the piezoelectric element 300 (that is, both sides in the arrangement direction of the piezoelectric element row composed of the plurality of piezoelectric elements 300 arranged in the Y direction), One end portion thereof is disposed on the piezoelectric element holding portion 31, and the other end portion extends outside the piezoelectric element holding portion 31 and is exposed on the end portion of the flow path forming substrate 10.

  A sealing substrate 30 for sealing the piezoelectric element 300 and the drive IC 170 is bonded to the piezoelectric element 300 side of the flow path forming substrate 10 (the side opposite to the flow path forming substrate 10 with the elastic film 50 interposed therebetween). In the sealing substrate 30, a piezoelectric element holding portion 31 capable of sealing the space in a state where a space having a size that does not hinder the movement of the piezoelectric element 300 is secured on a surface facing the piezoelectric element 300 and the driving IC 170. Yes. The piezoelectric element holding unit 31 is formed so as to cover all of the two rows of piezoelectric elements 300 and the driving IC 170 arranged in parallel, and simultaneously seals the two rows of piezoelectric elements 300 and the driving IC 170 arranged in parallel.

  An opening 30H penetrating the sealing substrate 30 in the thickness direction is provided in a portion facing the conductive portion 62 of the sealing substrate 30. The other end of the conductive portion 62 and the piezoelectric element are provided in the opening 30H. A portion 60b of the lower electrode film 60 of 300 is exposed. A flexible substrate 180 is electrically connected to the other end portion of the conductive portion 62 exposed to the opening 30H and a part 60b of the lower electrode film 60.

  The droplet discharge head IJ2 of the present embodiment also has the same effects as the droplet discharge head IJ1 of the first embodiment described above. The droplet discharge head IJ2 of this embodiment is arranged so that the terminals 90b of the piezoelectric elements 300 provided in two rows face each other, and is a suitable configuration when a small drive IC is used. In the present invention, since the driving IC and the piezoelectric element can be relatively freely arranged, it is possible to provide a small droplet discharge head by appropriately designing the arrangement.

[Droplet discharge device]
The droplet discharge head of each embodiment described above constitutes a part of a head unit including an ink flow path communicating with an ink cartridge or the like, and is mounted on the droplet discharge device. FIG. 5 is a schematic diagram showing an example of the droplet discharge device IJP. As shown in FIG. 5, the head units 1A and 1B having the droplet discharge heads are detachably provided with cartridges 2A and 2B constituting the ink supply means, and the carriage 3 on which the head units 1A and 1B are mounted is A carriage shaft 5 attached to the apparatus body 4 is provided so as to be movable in the axial direction. The head units 1A and 1B, for example, discharge a black ink composition and a color ink composition, respectively.

  The driving force of the driving motor 6 is transmitted to the carriage 3 through a plurality of gears and timing belt 7 (not shown), so that the carriage 3 on which the head units 1A and 1B are mounted is moved along the carriage shaft 5. . On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller (not shown), is conveyed on the platen 8. It is like that.

  Note that the droplet discharge head and the droplet discharge device that discharge ink as the droplet discharge head have been described as an example. However, the droplet discharge head is not limited to a recording head used in an image recording apparatus such as a printer. Color material ejection head used for manufacturing color filters such as displays, organic EL display, electrode material ejection head used for electrode formation such as FED (surface emitting display), bio-organic matter ejection head used for biochip production, etc. Can be applied to In either case, a fine image or a fine microdevice can be formed using a droplet discharge head having a small nozzle pitch.

DESCRIPTION OF SYMBOLS 10 ... Flow-flow formation board | substrate, 12 ... Pressure generating chamber, 21 ... Nozzle opening, 30 ... Sealing board | substrate, 31 ... Piezoelectric element holding | maintenance part (recessed part), 50 ... Elastic film, 90a, 90b ... Terminal of a piezoelectric element, 61, 62 ... conductive portion, 150, 170 ... drive IC, 151,171 ... output terminal of drive IC, 152,172 ... input terminal of drive IC, 160,180 ... flexible substrate, 300 ... piezoelectric element,
IJ1, IJ2 ... droplet ejection head, IJP ... droplet ejection device

Claims (12)

A first substrate having a pressure generating chamber communicating with the nozzle opening;
A second substrate provided on the first substrate and having a recess on a surface facing the first substrate;
A piezoelectric element provided in a space formed by the first substrate and the recess;
A drive IC provided in the space and electrically connected to the terminals of the piezoelectric element via output terminals made of bumps,
The liquid droplet ejection head, wherein the piezoelectric element and the driving IC are provided at a position not in contact with the second substrate. The second substrate has at least a part of a liquid chamber communicating with the pressure generating chamber,
2. The liquid droplet ejection head according to claim 1, wherein the concave portion and the liquid chamber are arranged so as to be adjacent to each other through a part of the second substrate. The first substrate is provided with one or a plurality of rows of piezoelectric elements composed of a plurality of the piezoelectric elements arranged in the first direction,
A plurality of output terminals of the driving IC are provided along the first direction, and a plurality of input terminals of the driving IC are provided along a second direction orthogonal to the first direction;
A conductive portion connected to the input terminal is provided at a position facing the input terminal of the driving IC on the first substrate,
3. The droplet discharge head according to claim 2, wherein the conductive portion is provided at a position spaced in the first direction with respect to the piezoelectric element array.   4. The droplet discharge head according to claim 3, wherein the conductive portion is provided only at any one of the positions sandwiching both sides in the arrangement direction of the piezoelectric element rows. 5.   4. The liquid droplet ejection head according to claim 3, wherein the conductive portion is provided at a position sandwiching both sides in the arrangement direction of the piezoelectric element rows. The drive IC has a rectangular shape in which the first direction is a long side and the second direction is a short side;
A plurality of the output terminals of the drive IC are provided along the long side;
6. The droplet discharge head according to claim 3, wherein a plurality of the input terminals of the driving IC are provided along the short side. Two rows of the piezoelectric element rows are provided along the second direction on the first substrate,
The driving IC is disposed so as to cover the two rows of piezoelectric element rows,
The output terminal of the drive IC and the terminal of the piezoelectric element are connected at positions on both sides of the two rows of piezoelectric element rows. Droplet discharge head. Two rows of the piezoelectric element rows are provided along the second direction on the first substrate,
The drive IC is arranged between the two rows of piezoelectric elements, and an output terminal of the drive IC and a terminal of the piezoelectric elements are connected in a region between the two rows of piezoelectric elements. The liquid droplet ejection head according to claim 3, wherein the liquid droplet ejection head is a liquid crystal ejection head.   The liquid droplet ejection head according to claim 1, wherein the driving IC is flip-chip mounted on the piezoelectric element.   The droplet discharge head according to claim 3, wherein a flexible substrate is connected to the conductive portion. A nozzle,
A first substrate having a pressure generating chamber communicating with the nozzle;
A second substrate having a recess provided on the first substrate and having an opening formed toward the first substrate;
A piezoelectric element provided in a space formed by the first substrate and the recess;
A drive IC provided in the space and electrically connected via an output terminal having a bump to the terminal of the piezoelectric element;
The liquid droplet ejection head, wherein the piezoelectric element and the driving IC are provided at positions separated from the second substrate.   A liquid droplet ejection apparatus comprising the liquid droplet ejection head according to claim 1.

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