JP2020055284A - Liquid jet head and liquid jet device - Google Patents

Abstract

To secure electric connection between wirings respectively formed at two substrates sufficiently.SOLUTION: A liquid jet head includes: a first substrate formed with a drive element which causes a liquid to be jetted from nozzles and a first wiring electrically connected with the drive element; a second substrate which is bonded to the first substrate on a facing surface facing the first substrate by an adhesive and formed with a second wiring; and a bump electrode which is formed between the first substrate and the second substrate and electrically connects the first wiring with the second wiring and in which a conductive film is formed on a surface of an elastic body made of a resin. An expansion ratio of the elastic body to water is larger than an expansion ratio of the adhesive to water.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a liquid ejecting head and a liquid ejecting apparatus.

  2. Related Art A liquid ejecting head that ejects a liquid such as ink from a plurality of nozzles has been conventionally proposed. For example, Patent Document 1 discloses an ink jet recording head including a piezoelectric element that ejects liquid from a nozzle and a sealing plate that supplies a drive signal to the piezoelectric element. The substrate on which the piezoelectric element is formed and the sealing plate are bonded to each other with an adhesive, and the bump electrode formed on the sealing plate and the lower electrode of the piezoelectric element conduct.

JP 2016-168807 A

  Under the technique of Patent Document 1, when the adhesive and the bump electrode expand by absorbing moisture, the sealing plate and the substrate are separated from each other. Therefore, sufficient electrical connection between the bump electrode and the lower electrode cannot be ensured.

  In order to solve the above problem, a liquid ejecting head according to a preferred aspect of the present invention includes a liquid ejecting head having a driving element for ejecting liquid from a nozzle and a first wiring electrically connected to the driving element. A first substrate, a second substrate on which a second wiring is formed, which is bonded to the first substrate with an adhesive on a facing surface facing the first substrate, and between the first substrate and the second substrate; And a bump electrode formed by electrically connecting the first wiring and the second wiring and having a conductive film formed on a surface of an elastic body made of resin, wherein the elastic body has a swelling ratio to water. , The swelling ratio of the adhesive.

  A liquid ejecting head according to a preferred aspect of the present invention includes: a first substrate on which a driving element for ejecting liquid from a nozzle and a first wiring electrically connected to the driving element are formed; A second substrate on which a second wiring is formed, the second wiring being formed between the first substrate and the second substrate by bonding the first wiring to the first substrate on an opposing surface with an adhesive; Electrically connecting the second wiring, the first particles having a conductive film formed on the surface of an elastic body made of resin, the swelling ratio of the elastic body with respect to water, Greater than the swelling rate.

FIG. 1 is a block diagram illustrating a configuration of a liquid ejecting apparatus according to a first embodiment of the present invention. FIG. 3 is an exploded perspective view of the liquid jet head. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is sectional drawing which shows the structure of a piezoelectric element. FIG. 3 is a cross-sectional view of a diaphragm and a wiring board near a connection terminal. It is a top view of a connection terminal. It is sectional drawing of the diaphragm and wiring board which concern on 2nd Embodiment. It is sectional drawing of the diaphragm and wiring board which concern on 3rd Embodiment. It is sectional drawing of the conductive particle which concerns on 4th Embodiment. It is sectional drawing of the diaphragm and wiring board which concern on 5th Embodiment. It is sectional drawing of the diaphragm and wiring board which concern on a modification. FIG. 9 is a cross-sectional view of a liquid jet head according to a modification.

<First embodiment>
FIG. 1 is a configuration diagram illustrating a liquid ejecting apparatus 100 according to the first embodiment. The liquid ejecting apparatus 100 according to the first embodiment is an ink jet printing apparatus that ejects ink, which is an example of a liquid, onto a medium 12. The medium 12 is typically printing paper, but an object to be printed of any material such as a resin film or a cloth is used as the medium 12. As illustrated in FIG. 1, the liquid ejecting apparatus 100 is provided with a liquid container 14 for storing ink. For example, a cartridge detachable from the liquid ejecting apparatus 100, a bag-shaped ink pack formed of a flexible film, or an ink tank capable of replenishing ink is used as the liquid container 14. A plurality of types of inks having different colors are stored in the liquid container 14.

  As illustrated in FIG. 1, the liquid ejecting apparatus 100 includes a control unit 20, a transport mechanism 22, a moving mechanism 24, and a liquid ejecting head 26. The control unit 20 includes, for example, a processing circuit such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array) and a storage circuit such as a semiconductor memory, and integrally controls each element of the liquid ejecting apparatus 100. The transport mechanism 22 transports the medium 12 in the Y direction under the control of the control unit 20.

  The moving mechanism 24 reciprocates the liquid ejecting head 26 in the X direction under the control of the control unit 20. The X direction is a direction crossing the Y direction in which the medium 12 is transported. The moving mechanism 24 of the first embodiment includes a substantially box-shaped carrier 242 that accommodates the liquid ejecting head 26 and a conveyor belt 244 to which the carrier 242 is fixed. Note that a configuration in which the plurality of liquid ejecting heads 26 are mounted on the transport body 242 or a configuration in which the liquid container 14 is mounted on the transport body 242 together with the liquid ejecting heads 26 may be adopted.

  The liquid ejecting head 26 ejects ink supplied from the liquid container 14 to the medium 12 from a plurality of nozzles under the control of the control unit 20. The liquid ejecting head 26 ejects ink onto the medium 12 in parallel with the transport of the medium 12 by the transport mechanism 22 and the reciprocating reciprocation of the transport body 242, whereby a desired image is formed on the surface of the medium 12. Note that a direction perpendicular to the XY plane is hereinafter referred to as a Z direction. The direction of ink ejection by the liquid ejecting head 26 corresponds to the Z direction. The XY plane is, for example, a plane parallel to the surface of the medium 12.

  FIG. 2 is an exploded perspective view of the liquid ejecting head 26, and FIG. 3 is a sectional view taken along line III-III in FIG. As illustrated in FIG. 2, the liquid ejecting head 26 includes a plurality of nozzles N arranged in the Y direction. The plurality of nozzles N of the first embodiment are divided into a first row L1 and a second row L2, which are arranged side by side at intervals in the X direction. Each of the first row L1 and the second row L2 is a set of a plurality of nozzles N arranged linearly in the Y direction. Although the position of each nozzle N in the Y direction can be different between the first row L1 and the second row L2, the Y direction of each nozzle N is different between the first row L1 and the second row L2. In the following, a configuration in which the positions are matched will be exemplified for convenience. As can be understood from FIG. 3, the liquid ejecting head 26 according to the first embodiment is configured such that elements related to each nozzle N in the first row L1 and elements related to each nozzle N in the second row L2 are substantially line-symmetric. It is a arranged structure.

  As illustrated in FIGS. 2 and 3, the liquid ejecting head 26 includes a flow path substrate 32. As illustrated in FIG. 2, the pressure chamber substrate 34, the vibration plate 42, the wiring substrate 46, the housing 48, and the drive circuit 50 are provided on the negative side in the Z direction of the flow path substrate 32. The diaphragm 42 is an example of a first substrate. On the other hand, a nozzle plate 62 and a vibration absorber 64 are provided on the positive side in the Z direction of the flow path substrate 32. Each element of the liquid ejecting head 26 is a generally plate-like member elongated in the Y direction, and is joined to each other using, for example, an adhesive.

  The nozzle plate 62 is a plate-like member on which a plurality of nozzles N are formed, and is installed on the surface of the flow path substrate 32 on the positive side in the Z direction. Each of the plurality of nozzles N is a circular through-hole through which ink passes. In the nozzle plate 62 of the first embodiment, a plurality of nozzles N forming a first row L1 and a plurality of nozzles N forming a second row L2 are formed. For example, the nozzle plate 62 is manufactured by processing a single crystal substrate of silicon (Si) using a semiconductor manufacturing technique such as dry etching or wet etching. However, known materials and manufacturing methods can be arbitrarily used for manufacturing the nozzle plate 62.

  As illustrated in FIGS. 2 and 3, the flow path substrate 32 has a space Ra, a plurality of supply flow paths 322, a plurality of communication flow paths 324, and a supply liquid for each of the first row L1 and the second row L2. A chamber 326 is formed. The space Ra is an elongated opening formed along the Y direction in plan view from the Z direction, and the supply flow path 322 and the communication flow path 324 are through holes formed for each nozzle N. The supply liquid chamber 326 is an elongated space extending in the Y direction across the plurality of nozzles N, and allows the space Ra and the plurality of supply flow paths 322 to communicate with each other. Each of the plurality of communication channels 324 overlaps with one nozzle N corresponding to the communication channel 324 in plan view.

  As illustrated in FIGS. 2 and 3, the pressure chamber substrate 34 is a plate-like member in which a plurality of pressure chambers C are formed for each of the first row L1 and the second row L2. The plurality of pressure chambers C are arranged in the Y direction. Each pressure chamber C is a long space formed for each nozzle N and extending along the X direction in plan view. The channel substrate 32 and the pressure chamber substrate 34 are manufactured by processing a silicon single crystal substrate using, for example, a semiconductor manufacturing technique, similarly to the nozzle plate 62 described above. However, known materials and manufacturing methods can be arbitrarily adopted for manufacturing the flow path substrate 32 and the pressure chamber substrate 34.

  As illustrated in FIG. 2, a vibration plate 42 is formed on the surface of the pressure chamber substrate 34 opposite to the flow path substrate 32. The vibration plate 42 of the first embodiment is a plate-like member that can elastically vibrate. By selectively removing a part of the plate member having a predetermined thickness in a region corresponding to the pressure chamber C in the thickness direction, a part or all of the vibration plate 42 is integrated with the pressure chamber substrate 34. May be formed.

  As understood from FIG. 2, the pressure chamber C is a space located between the flow path substrate 32 and the vibration plate 42. A plurality of pressure chambers C are arranged in the Y direction for each of the first row L1 and the second row L2. As illustrated in FIGS. 2 and 3, the pressure chamber C communicates with the communication channel 324 and the supply channel 322. Therefore, the pressure chamber C communicates with the nozzle N via the communication flow path 324, and communicates with the space Ra via the supply flow path 322 and the supply liquid chamber 326.

  As illustrated in FIGS. 2 and 3, the liquid ejecting head 26 according to the first embodiment includes a plurality of piezoelectric elements 44 corresponding to different nozzles and a drive circuit 50 that drives each of the plurality of piezoelectric elements 44. Have. The drive circuit 50 outputs a drive signal for each piezoelectric element 44. The drive signal is a voltage signal for driving the piezoelectric element 44. On the surface of the vibration plate 42 opposite to the pressure chamber C, a plurality of piezoelectric elements 44 corresponding to different nozzles N are formed for each of the first row L1 and the second row L2. Each piezoelectric element 44 is a driving element that ejects ink from the nozzle N by changing the pressure in the pressure chamber C. Specifically, the piezoelectric element 44 is an actuator that is deformed by supplying a drive signal, and is formed in a long shape along the X direction in plan view. The plurality of piezoelectric elements 44 are arranged in the Y direction so as to correspond to the plurality of pressure chambers C. When the vibration plate 42 vibrates in conjunction with the deformation of the piezoelectric element 44, the pressure in the pressure chamber C fluctuates, so that the ink filled in the pressure chamber C passes through the communication channel 324 and the nozzle N and is ejected. Is done.

  FIG. 4 is a cross-sectional view illustrating the configuration of the piezoelectric element 44. As illustrated in FIG. 4, the piezoelectric element 44 is a laminate in which a piezoelectric layer 443 is interposed between a first electrode 441 and a second electrode 442 that face each other. The first electrode 441 is an individual electrode formed on the surface of the vibration plate 42 and formed for each piezoelectric element 44. On the other hand, the second electrode 442 is a common electrode continuous over the plurality of piezoelectric elements 44. A portion where the first electrode 441, the second electrode 442, and the piezoelectric layer 443 overlap in a plan view functions as the piezoelectric element 44. When the vibration plate 42 vibrates in conjunction with the deformation of the piezoelectric element 44, the pressure of the ink in the pressure chamber C fluctuates, and the ink filled in the pressure chamber C passes through the communication flow path 324 and the nozzle N, and becomes external. Injected to. Note that a configuration in which the first electrode 441 is a common electrode for each piezoelectric element 44 and the second electrode 442 is an individual electrode, or a configuration in which both the first electrode 441 and the second electrode 442 are individual electrodes can be adopted.

  The wiring board 46 in FIG. 2 is a plate-like member that faces the surface of the vibration plate 42 on which a plurality of piezoelectric elements 44 are formed at an interval. The wiring substrate 46 of the first embodiment also functions as a reinforcing plate for reinforcing the mechanical strength of the liquid jet head 26 and a sealing plate for protecting and sealing the piezoelectric element 44. As illustrated in FIG. 2, the wiring board 46 is electrically connected to the control unit 20 via the external wiring 52. The external wiring 52 is a flexible wiring board for supplying various voltages and drive signals from the control unit 20 to the wiring board 46. For example, a connection component such as FPC (Flexible Printed Circuits) or FFC (Flexible Flat Cable) is suitably adopted as the external wiring 52.

  The housing 48 is a case for storing ink supplied to the plurality of pressure chambers C. As illustrated in FIG. 3, a space Rb is formed in each of the first row L1 and the second row L2 in the housing section 48 of the first embodiment. The space Rb of the casing 48 and the space Ra of the flow path substrate 32 communicate with each other. The space formed by the space Ra and the space Rb functions as a liquid storage chamber R that stores the ink supplied to the plurality of pressure chambers C. Ink is supplied to the liquid storage chamber R via an inlet 482 formed in the housing 48. The ink in the liquid storage chamber R is supplied to the pressure chamber C via the supply liquid chamber 326 and each supply flow path 322. The vibration absorber 64 is a flexible film that forms a wall surface of the liquid storage chamber R, and absorbs pressure fluctuations of the ink in the liquid storage chamber R.

  The wiring board 46 includes a base part 70 and a plurality of wirings 72. The base part 70 is an example of a second substrate. The base portion 70 is an insulating plate-like member elongated in the Y direction, and is located between the diaphragm 42 and the drive circuit 50. The base portion 70 is manufactured by processing a silicon single crystal substrate using, for example, a semiconductor manufacturing technique. However, a known material or manufacturing method can be arbitrarily adopted for manufacturing the base portion 70.

  The base portion 70 includes a first surface F1 and a second surface F2 located on mutually opposite sides, as illustrated in FIG. The second surface F2 faces the diaphragm 42. The second surface F2 is an example of the facing surface. Specifically, the base portion 70 is provided such that the second surface F2 faces the surface of the vibration plate 42 with an interval. 2, the drive circuit 50 and the external wiring 52 are mounted on the first surface F1 of the base portion 70. The drive circuit 50 is an IC chip that is long along the longitudinal direction of the base unit 70. The external wiring 52 is mounted on the negative end in the Y direction of the first surface F1 of the base portion 70. A plurality of wires 72 for transmitting a reference voltage and a drive signal supplied from the control unit 20 via the external wires 52 are formed on the first surface F1 and the second surface F2 of the base portion 70.

  As illustrated in FIG. 3, a connection terminal Tx and a connection terminal Te are formed between the diaphragm 42 and the base 70. In the first embodiment, the connection terminal Tx and the connection terminal Te are formed on the second surface F2 of the base portion 70. The wiring 72 formed on the second surface F2 is an example of the second wiring. Each wiring 72 is electrically connected to an output terminal of the drive circuit 50 via a through electrode formed on the wiring board 46. The connection terminal Tx is formed for each piezoelectric element 44. The wiring 72 for transmitting the drive signal is electrically connected to the first electrode 441 of the piezoelectric element 44 via the connection terminal Tx. Therefore, a drive signal is supplied to the first electrode 441 which is an individual electrode. On the other hand, the wiring 72 for transmitting the reference voltage is electrically connected to the second electrode 442 of the piezoelectric element 44 via the connection terminal Te. Therefore, the reference voltage is supplied to the second electrode 442 which is a common electrode. The number of connection terminals Te is arbitrary.

  Hereinafter, when there is no need to distinguish between the connection terminal Tx and the connection terminal Te, it is described as “connection terminal T”. FIG. 5 is a cross-sectional view of the diaphragm 42 and the wiring board 46 near the connection terminal T, and FIG. 6 is a plan view of the connection terminal T. As illustrated in FIG. 5, the connection terminal T is formed on the second surface F2 of the base portion 70 of the wiring board 46. The connection terminal T of the first embodiment includes an elastic body 90 and a conductive film 92. The elastic body 90 is formed of, for example, a resin material so as to protrude from the second surface F2. Specifically, the elastic body 90 is formed of a photosensitive resin. For example, the elastic body 90 is formed by irradiating the photosensitive resin with light and performing patterning, and then thermally curing the photosensitive resin. The thermosetting may not be performed on the photosensitive resin, but by performing the thermosetting, the liquid resistance can be improved or the swelling ratio can be adjusted. For example, a product name “AH-3000” provided by Hitachi Chemical Co., Ltd. is used as the photosensitive resin. By forming the elastic body 90 using a photosensitive resin, there is an advantage that the elastic body 90 can be formed in a desired region and shape. The elastic body 90 of the first embodiment is formed of an insulating material. The cross-sectional shape of the elastic body 90 is, for example, a semicircle. As illustrated in FIG. 6, the elastic body 90 is formed to extend in the Y direction over the plurality of wirings 72. As illustrated in FIG. 5, the conductive film 92 is formed of a conductive material so as to cover the elastic body 90. As illustrated in FIG. 6, a conductive film 92 continuous with each wiring 72 is formed on the surface of the elastic body 90. The wiring 72 and the conductive film 92 are formed in the same layer by a known film forming technique such as sputtering. One end of each wiring 72 is connected to the conductive film 92, and the other end is electrically connected to the drive circuit 50 via the through electrode of the wiring board 46. The connection terminal T functions as a protrusion that can be elastically deformed. As understood from the above description, the connection terminal T functions as a bump electrode in which the conductive film 92 is formed on the surface of the elastic body 90 made of resin. Note that the elastic bodies 90 may be individually formed for each wiring 72.

  As illustrated in FIG. 5, a wiring 82 that is electrically connected to the piezoelectric element 44 is formed on the vibration plate 42. Specifically, a plurality of wirings 82 electrically connected to the respective wirings 72 via the connection terminals T are formed on the diaphragm 42. The wiring 82 is an example of a first wiring. The wiring 82 connected to the connection terminal Tx is connected to the first electrode 441 of the piezoelectric element 44. The first electrode 441 and the wiring 82 connected to the first electrode 441 are formed, for example, in the same layer. On the other hand, the wiring 82 connected to the connection terminal Te is connected to the second electrode 442 of the piezoelectric element 44. The second electrode 442 and the wiring 82 connected to the second electrode 442 are formed, for example, in the same layer. As illustrated in FIG. 5, a portion near the top of the connection terminal T contacts the surface of the wiring 82. That is, the wiring 82 is formed so as to overlap the connection terminal T in plan view. The connection terminal T contacts the wiring 82 in an elastically deformed state. That is, one of the vibration plate 42 and the connection terminal T is pressed against the other. As understood from the above description, the wiring 72 and the wiring 82 are electrically connected via the connection terminal T.

  As illustrated in FIG. 3, the diaphragm 42 and the wiring board 46 are fixed to each other using the adhesive B. More specifically, the second surface F2 of the base portion 70 of the wiring board 46 and the vibration plate 42 are bonded with the adhesive B. Specifically, a photosensitive adhesive is suitable as the adhesive B. For example, the adhesive B is thermally cured after being irradiated with light and patterned. The adhesive B does not have to be thermally cured, but by performing the thermal curing, the liquid resistance can be improved or the swelling ratio can be adjusted. For example, the product name “TMMR (registered trademark)” provided by Tokyo Ohka Kogyo Co., Ltd. is used as the adhesive B. By using the photosensitive adhesive as the adhesive B, there is an advantage that the adhesive B can be applied to a desired area and shape. The adhesive B is applied between the wiring board 46 and the vibration plate 42 so as not to contact the piezoelectric element 44. Specifically, the adhesive B is applied around the connection terminals T. As illustrated in FIG. 5, in the first embodiment, the connection terminal T contacts the adhesive B. For example, in a state where the adhesive B is applied so as to be in contact with the surface of the connection terminal T in the base portion 70, the base portion 70 and the vibration plate 42 are joined so that the connection terminal T is pressed against the surface of the wiring 82. You. However, the adhesive B is not interposed between the connection terminal T and the wiring 82. In the first embodiment, since the adhesive B is applied around the connection terminal T, the connection terminal T can be firmly fixed between the base portion 70 and the vibration plate 42.

  Hereinafter, the swelling ratio of the connection terminal T and the swelling ratio of the adhesive B will be described. Swelling is a phenomenon in which a substance absorbs moisture and expands, and the swelling ratio is the ratio of the volume after swelling to the volume before swelling. That is, the larger the swelling ratio, the larger the volume increase due to swelling. The moisture absorbed by the connection terminal T and the adhesive B is, for example, moisture existing in the atmosphere of the use environment or moisture caused by the ink. Since the conductive film 92 has a sufficiently small thickness as compared with the elastic member and hardly swells due to the absorption of moisture, the swelling ratio of the connection terminal T is substantially equal to the swelling ratio of the elastic body 90 in the first embodiment. Equivalent to the rate. Here, for example, in a configuration in which the swelling ratio of the connection terminal T is smaller than the swelling ratio of the adhesive B (hereinafter referred to as “comparative example”), when the connection terminal T and the adhesive B absorb moisture, the adhesive B Swells more than the connection terminals T, so that the vibration plate 42 and the base portion 70 of the wiring board 46 are separated from each other, so that the pressure from one of the vibration plate 42 and the connection terminals T to the other is reduced. Therefore, in the comparative example, there is a problem that the electrical connection between the wiring 72 and the wiring 82 is insufficient. Therefore, in the first embodiment, the swelling ratio of the connection terminal T is made larger than the swelling ratio of the adhesive B. Specifically, the swelling rate of the elastic body 90 in water is larger than the swelling rate of the adhesive B in water. Further, the swelling ratio of the elastic body 90 with respect to the ink is larger than the swelling ratio of the adhesive B with respect to the ink. That is, the amount of increase in volume due to the absorption of moisture is larger in the connection terminal T than in the adhesive B. The magnitude of the swelling ratio is compared after immersing the adhesive B and the connection terminal T in water at the same temperature for the same time. According to the above configuration, when the connection terminal T and the adhesive B absorb moisture or ink in the air, the pressure from one of the vibration plate 42 and the connection terminal T to the other increases. Therefore, in the first embodiment, the electrical connection between the wiring 72 and the wiring 82 can be sufficiently ensured as compared with the comparative example.

<Second embodiment>
A second embodiment will be described. In the following examples, the same reference numerals are used for elements having the same functions as in the first embodiment, and detailed descriptions thereof will be omitted as appropriate.

  FIG. 7 is a cross-sectional view of the diaphragm 42 and the wiring board 46 according to the second embodiment. As illustrated in FIG. 7, also in the second embodiment, the vibration plate 42 and the base portion 70 of the wiring board 46 are bonded with the adhesive B as in the first embodiment. However, in the first embodiment, the connection terminal T comes into contact with the adhesive B, whereas in the second embodiment, a space E is formed between the connection terminal T and the adhesive B. That is, the adhesive B does not contact the connection terminal T.

  In the second embodiment, the same effect as in the first embodiment is realized. In the second embodiment, since the space E is formed between the connection terminal T and the adhesive B, when the connection terminal T swells, the contact surface between the connection terminal T and the wiring 72 increases. Specifically, the contact surface is enlarged in the XY plane as shown by the broken line in FIG. Therefore, the electrical connection between the wiring 72 and the wiring 82 is sufficiently ensured. On the other hand, according to the configuration of the first embodiment in which the connection terminal T is in contact with the adhesive B, there is an advantage that the diaphragm 42 and the base 70 can be firmly bonded.

<Third embodiment>
FIG. 8 is a cross-sectional view of the diaphragm 42 and the wiring board 46 according to the third embodiment. In the third embodiment, the connection terminal T is omitted. As illustrated in FIG. 8, the wiring 72 of the third embodiment is formed so as to overlap the wiring 82 in a plan view. In the third embodiment, the anisotropic conductive film 93 including the conductive particles 94 is used for bonding the base portion 70 and the diaphragm 42. That is, the anisotropic conductive film 93 is interposed between the base portion 70 and the diaphragm 42. The anisotropic conductive film 93 is a film in which conductive particles 94 formed of, for example, a metal are dispersed in an adhesive B. The adhesive B is, for example, an insulating resin material. The conductive particles 94 are elastically deformable. The swelling ratio of the conductive particles 94 is larger than the swelling ratio of the adhesive B.

  With the anisotropic conductive film 93 interposed between the wiring 72 and the wiring 82, the diaphragm 42 and the base portion 70 are bonded by the anisotropic conductive film 93. During bonding, the diaphragm 42 and the base 70 are pressed from one side to the other. With the conductive particles 94 interposed between the wiring 72 and the wiring 82, the diaphragm 42 and the base 70 are bonded. Therefore, the wiring 72 and the wiring 82 are electrically connected via the conductive particles 94. The conductive particles 94 of the third embodiment are formed between the vibration plate 42 and the base part 70, electrically connect the wiring 72 and the wiring 82, and function as elastically deformable protrusions.

  In the third embodiment, the same effect as in the first embodiment is realized. In the third embodiment, since the conductive particles 94 included in the anisotropic conductive film 93 function as projections, there is an advantage that the step of forming the projections becomes unnecessary.

<Fourth embodiment>
FIG. 9 is a sectional view of the conductive particles 94 according to the fourth embodiment. The type of the conductive particles 94 of the fourth embodiment is different from the type of the conductive particles 94 of the third embodiment. The conductive particles 94 of the fourth embodiment are particles in which an elastic body 941 formed of a resin material is covered with a conductive film 942 formed of a metal or the like. That is, particles having a conductive film formed on the surface of an elastic body made of resin are used as the conductive particles 94. The conductive particles 94 are examples of “first particles”. Note that the adhesive B of the fourth embodiment is a photosensitive adhesive as in the first embodiment.

  The swelling ratio of the elastic body 941 in water is larger than the swelling ratio of the adhesive B in water. The swelling ratio of the elastic body 941 with respect to the liquid is larger than the swelling ratio of the adhesive B with respect to the ink. As illustrated in FIG. 9, the conductive particles 94 come into contact with the adhesive B. According to the configuration illustrated in FIG. 9, similarly to the first embodiment, a sufficient electrical connection between the wiring 72 and the wiring 82 can be ensured.

<Fifth embodiment>
FIG. 10 is a cross-sectional view of the diaphragm 42 and the wiring board 46 according to the fifth embodiment. The adhesive B of the fifth embodiment includes the adhesive particles 96. Note that the configuration is the same as that of the fourth embodiment except that the adhesive B includes the adhesive particles 96. The adhesive particles 96 are examples of “second particles”. The adhesive particles 96 function as spacers for maintaining a space between the base portion 70 and the diaphragm 42. For example, particles obtained by covering an elastic body 961 formed of a resin material with a conductive film 962 formed of metal or the like are used as the adhesive particles 96. That is, conductive particles whose surface is formed by the conductive film 962 are exemplified as the adhesive particles 96. Note that, for example, particles formed entirely of metal or the like may be used as the adhesive particles 96. The volume average diameter of the adhesive particles 96 is smaller than the volume average diameter of the conductive particles 94. The volume average diameter is a weighted average of the particle diameters with the volume of each of the plurality of adhesive particles 96 as a weight value.

  The swelling ratio of the adhesive particles 96 is smaller than the swelling ratio of the conductive particles 94. Specifically, the swelling rate of the elastic body 961 in water is smaller than the swelling rate of the elastic body 941 in water. The swelling ratio of the elastic body 961 with respect to the ink is smaller than the swelling ratio of the elastic body 941 with respect to the ink.

  In the fifth embodiment, since the swelling ratio of the adhesive particles 96 is smaller than the swelling ratio of the conductive particles 94, it is possible to prevent the gap between the base portion 70 and the diaphragm 42 from becoming excessively large. Therefore, sufficient electrical connection between the wiring 72 and the wiring 82 can be ensured. According to the configuration of the fifth embodiment in which the volume average diameter of the adhesive particles 96 is smaller than the volume average diameter of the conductive particles 94, the conductive particles 94 sufficiently contact the wiring 72 and the wiring 82. Sufficient electrical connection with the device. In the fifth embodiment, since the surface of the adhesive particles 96 is formed of the conductive film 962, the adhesive particles 96 can be used for connecting the wiring 72 and the wiring 82.

<Modification>
Each form exemplified above can be variously modified. Specific modifications that can be applied to the above-described embodiments will be exemplified below. Two or more aspects arbitrarily selected from the following examples can be appropriately combined within a range not inconsistent with each other.

(1) In the first and second embodiments, the connection terminal T is configured by the elastic body 90 and the conductive film 92, but the configuration of the connection terminal T is not limited to the above example. For example, the connection terminal T may be formed of a conductive elastic material. In the above configuration, the connection terminal T is formed on the surface of the wiring 72 as illustrated in FIG. The connection terminal T is individually formed for each wiring 72.

(2) In the first embodiment and the second embodiment, the connection terminals T are formed on the base portion 70. However, the connection terminals T may be formed on the diaphragm 42. In the above configuration, the conductive film 92 of the connection terminal T is connected to the wiring 82, and a portion near the top of the connection terminal T contacts the surface of the wiring 72. As understood from the above description, the connection terminal T may be formed on the base portion 70 or on the diaphragm 42 as long as the connection terminal T is formed between the diaphragm 42 and the base portion 70.

(3) In the conductive particles 94 of the third to fifth embodiments, a configuration in which a space is formed inside is also adopted. That is, the conductive particles 94 may be hollow. According to the above configuration, since the conductive particles 94 are easily elastically deformed, the electrical connection between the wiring 72 and the wiring 82 can be sufficiently ensured.

(4) In the first embodiment and the second embodiment, as illustrated in FIG. 12, in a region of the vibration plate 42 different from the active portion P that vibrates by driving the piezoelectric element 44, the vibration plate 42 and the base portion Also, a configuration in which 70 is bonded by an adhesive B is adopted. That is, the connection terminal T and the adhesive B are located in a region other than the active portion P of the diaphragm 42 when viewed from the Z direction perpendicular to the diaphragm 42. The active portion P is a region of the diaphragm 42 that overlaps the pressure chamber C in a plan view from the Z direction. It can be said that a region of the vibration plate 42 that is not fixed to the pressure chamber substrate 43 is the active portion P. That is, the connection terminal T and the adhesive B are located in a region of the diaphragm 42 where the connection terminal T and the adhesive B do not vibrate. With the configuration described above, it is possible to reduce the possibility that the connection terminal T and the adhesive B inhibit the vibration of the diaphragm 42 and the separation of the diaphragm 42 from the pressure chamber substrate 43 or the adhesive B. Similarly, in the third to fifth embodiments, a configuration in which the conductive particles 94 and the adhesive B are located in a region other than the active portion P of the vibration plate 42 is also employed.

(5) The driving element for ejecting the liquid in the pressure chamber C from the nozzle N is not limited to the piezoelectric element 44 illustrated in each of the above embodiments. For example, a heating element that generates bubbles in the pressure chamber C by heating to change the pressure can be used as the driving element. As understood from the above examples, the driving element is comprehensively expressed as an element for ejecting the liquid in the pressure chamber C from the nozzle N, and it does not matter what the operation method or the specific configuration is.

(6) In each of the above-described embodiments, the serial type liquid ejecting apparatus 100 that reciprocates the carrier 242 on which the liquid ejecting head 26 is mounted has been exemplified. The present invention can be applied to an injection device.

(7) The liquid ejecting apparatus 100 exemplified in each of the above-described embodiments can be employed in various apparatuses such as a facsimile apparatus and a copying machine in addition to apparatuses dedicated to printing. However, the application of the liquid ejecting apparatus of the present invention is not limited to printing. For example, a liquid ejecting apparatus that ejects a color material solution is used as a manufacturing apparatus that forms a color filter of a display device such as a liquid crystal display panel. In addition, a liquid ejecting apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus that forms wiring and electrodes of a wiring board. In addition, a liquid ejecting apparatus that ejects a solution of an organic substance related to a living body is used, for example, as a manufacturing apparatus for manufacturing a biochip.

REFERENCE SIGNS LIST 100 liquid ejecting device, 12 medium, 14 liquid container, 20 control unit, 22 transport mechanism, 24 moving mechanism, 242 transport body, 244 transport belt, 26 liquid ejecting head, 30 flow path Forming part, 32: channel substrate, 322: supply channel, 324: communication channel, 326: supply liquid chamber, 34: pressure chamber substrate, 42: diaphragm, 44: piezoelectric element, 441: first electrode, 442 ... second electrode, 443 ... piezoelectric layer, 46 ... wiring board, 48 ... housing, 482 ... inlet, 50 ... drive circuit, 52 ... external wiring, 62 ... nozzle plate, 64 ... vibration absorber, 70 ... substrate Part, 72 ... wiring, 82 ... wiring, 90 ... elastic body, 92 ... conductive film, 93 ... anisotropic conductive film, 94 ... conductive particles, 941 ... elastic body, 942 ... conductive film, 96 ... connecting particles, 961 ... Elastic body, 962 ... conductive film.

Claims (19)

A first substrate on which a driving element for ejecting liquid from a nozzle and a first wiring electrically connected to the driving element are formed;
A second substrate on which a second wiring is formed by bonding the first substrate to the first substrate on an opposing surface facing the first substrate with an adhesive;
A bump electrode formed between the first substrate and the second substrate for electrically connecting the first wiring and the second wiring, and having a conductive film formed on a surface of an elastic body made of resin; With
A liquid jet head, wherein the swelling rate of the elastic body in water is larger than the swelling rate of the adhesive in water. The liquid ejecting head according to claim 1, wherein a swelling ratio of the elastic body to the liquid is larger than a swelling ratio of the adhesive to the liquid. The liquid ejecting head according to claim 1, wherein the bump electrode contacts the adhesive. The liquid ejecting head according to claim 1, wherein a space is formed between the bump electrode and the adhesive. The first substrate is a diaphragm having an active portion that vibrates by driving the driving element,
The liquid ejecting head according to any one of claims 1 to 4, wherein the bump electrode and the adhesive are located in a region other than the active portion of the diaphragm when viewed from a direction perpendicular to the diaphragm. The liquid ejecting head according to claim 1, wherein the adhesive is formed around the bump electrode. The liquid ejecting head according to claim 1, wherein the adhesive is a photosensitive adhesive. The liquid ejecting head according to claim 1, wherein the elastic body is formed of a photosensitive resin. A first substrate on which a driving element for ejecting liquid from a nozzle and a first wiring electrically connected to the driving element are formed;
A second substrate on which a second wiring is formed by bonding the first substrate to the first substrate on an opposing surface facing the first substrate with an adhesive;
A first conductive layer formed between the first substrate and the second substrate, electrically connecting the first wiring and the second wiring, and having a conductive film formed on a surface of an elastic body made of resin. And particles,
A liquid jet head, wherein the swelling rate of the elastic body in water is larger than the swelling rate of the adhesive in water. The liquid ejecting head according to claim 9, wherein a swelling ratio of the elastic body to the liquid is larger than a swelling ratio of the adhesive to the liquid. The liquid ejecting head according to claim 9, wherein the first particles come into contact with the adhesive. The liquid ejecting head according to any one of claims 9 to 11, wherein the adhesive includes second particles having a lower swelling ratio of water in the first particles than in the elastic body. The liquid ejecting head according to claim 12, wherein the second particles have a smaller swelling ratio of the first particles with respect to the liquid than the elastic body. The liquid ejecting head according to claim 9, wherein the adhesive includes second particles having a smaller volume average diameter than the first particles. The liquid ejecting head according to claim 12, wherein the second particles are conductive particles having a surface formed of a conductive film. The liquid ejecting head according to any one of claims 9 to 15, wherein a space is formed inside the first particle. The first substrate is a diaphragm having an active portion that vibrates by driving the driving element,
The liquid ejecting head according to any one of claims 9 to 16, wherein the first particles and the adhesive are located in a region of the diaphragm other than the active portion when viewed from a direction perpendicular to the diaphragm. The liquid ejecting head according to any one of claims 9 to 17, wherein the adhesive is a photosensitive adhesive. A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1.

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