Liquid discharge head and liquid discharge apparatus

Abstract

A liquid discharge head includes: a nozzle plate including a nozzle; and a piezoelectric body in the nozzle plate to vibrate the nozzle plate; and a channel substrate on the nozzle plate, the channel substrate having a pressure chamber communicating with the nozzle, wherein the piezoelectric body has: a Curie point equal to or higher than 350°C; or no Curie point, and the piezoelectric body is driven to vibrate the nozzle plate to discharge molten resin or molten metal, heated to a temperature equal to or higher than 130°C in the channel substrate, from the nozzle in a discharge direction.

Description

[DESCRIPTION][Title of Invention]LIQUID DISCHARGE HEAD AND LIQUID DISCHARGE APPARATUS [Technical Field]

[0001] The present embodiment relates to a liquid discharge head and a liquid discharge apparatus. [Background Art]

[0002] Conventionally, there is known a liquid discharge head that includes a nozzle plate including a nozzle and a channel substrate having a pressure chamber communicating with the nozzle, and drives a piezoelectric body to cause liquid in the pressure chamber to be discharged from the nozzle.

[0003] As the liquid discharge head described above, Patent Literature (PTL) 1 describes a liquid discharge head that causes molten solder to be discharged from a nozzle to form solder bumps on a semiconductor chip or the like. A piezoelectric body is provided on a wall of the pressure chamber facing the nozzle plate, and the wall is vibrated to cause molten solder to be discharged from the nozzle. In addition, a heater is provided on a cover member covering the liquid discharge head, and solder in the liquid discharge head is heated to a temperature equal to or higher than a melting temperature.[Summary of Invention][Technical Problem]

[0004] However, there is a possibility that depending on the material of the piezoelectric body, molten resin or molten metal, such as solder, heated to a temperature of 130°C or higher may not be satisfactorily discharged from the nozzle.[Solution to Problem]

[0005] In an aspect of the present disclosure, a liquid discharge head is provided that includes: a nozzle plate including a nozzle; and a piezoelectric body in the nozzle plate to vibrate the nozzle plate; and a channel substrate on the nozzle plate, the channel substrate having a pressure chamber communicating with the nozzle, wherein the piezoelectric body has: a Curie point equal to or higher than 350°C; or no Curie point, and the piezoelectric body is driven to vibrate the nozzle plate to discharge molten resin or molten metal, heated to a temperature equal to or higher than 130°C in the channel substrate, from the nozzle in a discharge direction.[Advantageous Effects of Invention]

[0006] According to the present embodiment, molten resin or molten metal heated to 130°C or higher can be satisfactorily discharged from a nozzle.[Brief Description of Drawings]

[0007] A more complete appreciation of embodiments of the present disclosure and many of the attendant advantages and features thereof can be readily obtained and understood from the following detailed description with reference to the accompanying drawings.[FIG. 1]FIG. 1 is a schematic cross-sectional view of a nozzle vibration type liquid discharge head in the present embodiment.[FIG. 2]FIG. 2 is a schematic perspective view of the liquid discharge head.[FIG. 3]FIG. 3 is an enlarged cross-sectional view of a portion X in FIG. 1.[FIG. 4]FIG. 4 is a schematic configuration diagram of a printer as a liquid discharge apparatus.[FIG. 5]FIG. 5 is an explanatory diagram illustrating a plan view of a main part of a printer of another example.[FIG. 6]FIG. 6 is an explanatory diagram illustrating a side view of the main part of the printer of another example.[FIG. 7]FIG. 7 is an explanatory diagram illustrating a plan view of a main part of a liquid discharge device of another example.[FIG. 8]FIG. 8 is an explanatory diagram illustrating a front view of a liquid discharge device of still another example.The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. Also, identical or similar reference numerals designate identical or similar components throughout the several views. [Description of Embodiments]In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that have a similar function, operate in a similar manner, and achieve a similar result.Referring now to the drawings, embodiments of the present disclosure are described below. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0008] A best mode for carrying out the present embodiment will now be described herein with reference to the drawings. It is to be understood that those skilled in the art can easily change and modify the present embodiment within the scope of claims to form other embodiments, and these changes and modifications are included in the scope of claims. The following description is an example of the best mode of the present embodiment, and does not limit the scope of claims.

[0009] FIG. 1 is a schematic cross-sectional view of a nozzle vibration type liquid discharge head in the present embodiment. FIG. 2 is a schematic perspective view of the liquid discharge head.A liquid discharge head (head) 1 includes a nozzle plate 110, a channel substrate 100, and a frame member 120.

[0010] The nozzle plate 110 is formed as a thin film, and includes a plurality of nozzles 2 and piezoelectric elements 5. The plurality of nozzles 2 discharges liquid. The piezoelectric elements 5 are electromechanical transducer elements formed in an annular shape and disposed around the nozzles 2. The channel substrate 100 has a plurality of pressure chambers (also referred to as individual liquid chambers or pressurized liquid chambers) 4 respectively communicating with the plurality of nozzles 2. The frame member 120 has a common chamber 3 serving as a supply liquid chamber communicating with the plurality of pressure chambers 4. An electrical connection pad 6 for connecting to an electrical component such as an external power supply is provided at each end of the head 1.

[0011] A heater 130 is provided on an outer peripheral surface of the frame member 120. In the liquid discharge head according to the present embodiment, a metal material, such as solder, or a resin material that is solid at room temperature is used as a material to be discharged (discharge material). The discharge material in the common chamber 3 is heated to 130°C or higher and melted by the heater 130 provided on the frame member 120. Thus, the melted discharge material is discharged from the nozzles 2.

[0012] FIG. 3 is an enlarged cross-sectional view of a portion X in FIG. 1.The channel substrate 100 is a silicon-on-insulator (SOI) substrate, and includes a drive circuit 101 and a wiring layer 102 on a side on which a vibrating film 103 is formed. The drive circuit 101 is a circuit including a transistor, a resistor, and the like. The wiring layer102 includes a wiring portion for applying a drive waveform to a first electrode 51 and a wiring portion for applying a drive waveform to a second electrode 53.

[0013] By building the drive circuit into the channel substrate 100, it is possible to reduce steps for mounting the drive circuit using another substrate and to reduce the area of a connecting portion for external connection, leading to miniaturization of the head. In a case where the drive circuit is not built into the channel substrate 100, and an opening is provided in the nozzle plate 110 so as to perform drive control from the outside, the channel substrate 100 may be a silicon (Si) substrate. This also eliminates the need for the wiring layer 102.

[0014] The nozzle plate 110 has the plurality of nozzles 2 formed in the nozzle plate 110, and includes the vibrating film 103, the piezoelectric elements 5, and a surface layer 111 (surface film) covering the piezoelectric elements 5. The vibrating film 103 is preferably made of an inorganic substance such as silicon dioxide (SiCh), silicon nitride (SiN), or a metal oxide from the viewpoint of heat resistance, liquid resistance, and insulation properties. However, in order to increase displacement, it is desirable to use a material having a low Young’s modulus. In addition, considering a difference in a coefficient of linear expansion from the channel substrate 100, it is most desirable to use, as the material of the vibrating film 103, silicon dioxide (SiCF) having a relatively small difference in the coefficient of linear expansion.

[0015] As with the vibrating film 103, the surface layer 111 (surface film) is preferably made of an inorganic substance such as SiCh, SiN, or a metal oxide from the viewpoint of heat resistance, liquid resistance, and insulation properties. A liquid -repellent film may be formed on a nozzle surface of the surface layer 111. In a case where liquid is continuously discharged, mist generated at the same time as the liquid discharge adheres to the nozzle surface. When a large amount of mist adheres to the nozzle surface, there is a possibility that liquid discharged from the nozzle 2 may be affected by liquid adhering to the nozzle surface and may deviate from a desired position where liquid is to be applied. Formation of the liquidrepellent film on the nozzle surface makes it possible to prevent liquid from adhering to the nozzle surface. Thus, liquid discharged from the nozzle 2 can be prevented from being affected by liquid having adhered to the nozzle surface.

[0016] The piezoelectric element 5 of the nozzle plate 110 includes the first electrode 51 (also referred to as a lower electrode), a piezoelectric body 52, and the second electrode 53 (also referred to as an upper electrode). The piezoelectric element 5 is covered with a first insulating film 8a. As with the vibrating film 103, the first insulating film 8a desirably has insulation properties, a small Young’s modulus, and a coefficient of linear expansion close toa coefficient of linear expansion of constituent material. Therefore, it is desirable to use SiCh as with the vibrating film 103.

[0017] The first insulating film 8a has a third contact 7c and a fourth contact 7d. The third contact 7c is a hole- shaped contact for making electrical connection to the first electrode 51. The fourth contact 7d is a hole-shaped contact for making electrical connection to the second electrode 53.

[0018] A first lead wire 9a and a second lead wire 9b are formed on the first insulating film 8a. The first lead wire 9a electrically connects the first electrode 51 of the piezoelectric element 5 with the wiring layer 102 of the channel substrate 100. The second lead wire 9b electrically connects the second electrode 53 of the piezoelectric element 5 with the wiring layer 102 of the channel substrate 100.

[0019] The first lead wire 9a is electrically connected to the first electrode 51 via the third contact 7c, and is electrically connected to the wiring layer 102 via a first contact 7a. The second lead wire 9b is electrically connected to the second electrode 53 via the fourth contact 7d, and is electrically connected to the wiring layer 102 via a second contact 7b.

[0020] The first lead wire 9a and the second lead wire 9b are covered with a second insulating film 8b. For the second insulating film 8b, it is desirable to use SiN that is widely used as a semiconductor protective film, so as to improve the reliability of humidity resistance. Since the second insulating film 8b has two functions of insulation properties and moisture barrier properties, the nozzle plate 110 can be made thinner than in a case where a moisture-proof protective film is formed on the second insulating film 8b. As a result, the vibrating film 103 is easily deformed, so that vibration efficiency can be enhanced.

[0021] A lead-out wiring portion may be provided in each of the first electrode 51 and the second electrode 53, and may be electrically connected directly to the wiring layer 102 via a contact opened in the vibrating film. An adhesion improving film for securing adhesion to the surface layer 111 may be formed on the second insulating film 8b. In addition, the wiring layer 102 is electrically connected to the electrical connection pad 6 via the third contact 7c opened in the vibrating film 103.

[0022] In the present embodiment, a protective film 11 for preventing contamination by molten metal or molten resin is formed on an inner peripheral surface of the pressure chamber 4. The protective film 11 is made of an inorganic substance such as metal oxide, metal nitride, ceramic oxide, ceramic nitride, or carbide ceramics. More specifically, aluminum oxide(AI2O3), silicon dioxide (SiCh), silicon nitride (SiN), zirconium oxide (ZrO), silicon carbide (SiC), or the like can be used as the protective film 11.

[0023] Piezoelectric zirconate titanate (PZT) is widely used as an electro strictive material of a piezoelectric body of an inkjet head because of its high piezoelectric properties. PZT is a ferroelectric substance, and has an electric dipole where a substance is locally separated into a positively charged portion and a negatively charged portion even when no electric field is applied from the outside. However, PZT generally has a Curie point of 150 to 350°C at which the crystal structure of PZT changes to lose piezoelectric properties. Thus, a temperature environment in which PZT can be used is limited. As a result, a metal or the like having a high melting temperature cannot be used as the discharge material.

[0024] Therefore, in the present embodiment, aluminum nitride (AIN) is used as the electro strictive material of the piezoelectric body 52. AIN has a melting point of 2000°C or higher, and has no Curie point. Thus, AIN can be satisfactorily driven even in a high-temperature environment.

[0025] Furthermore, in the present embodiment, a nozzle vibration system is adopted in which the piezoelectric element 5 is disposed on the nozzle plate 110, and pressure in the pressure chamber 4 is changed by the piezoelectric element 5 of the nozzle plate 110 to discharge liquid in the pressure chamber from the nozzle. The nozzle vibration system is characterized in that droplets can be splashed with a smaller force than in a general unimorph piezo head (a head that discharges liquid by vibrating a surface of the pressure chamber facing a wall portion (nozzle communication wall) having a communication port communicating with a nozzle of the pressure chamber). Therefore, even when AIN having a displacement amount lower than the displacement amount of PZT is used as the electro strictive material of the piezoelectric body 52, liquid can be discharged satisfactorily.As a result, even a discharge material having a high melting temperature can be melted and discharged.

[0026] In addition, by adopting the nozzle vibration system described above, it is possible to provide an opening through which molten material is supplied from the common chamber, at a portion of the pressure chamber facing the nozzle plate. As a result, compared to a case where an opening through which molten material is supplied is provided on a side surface of the pressure chamber, the nozzles can be arranged with high density, so that the liquid discharge head can be downsized. Thus, the heat capacity of the liquid discharge head can be reduced, and the discharge material can be efficiently heated to a temperature equal to or higher than a melting temperature. Thus, power consumption can be reduced.

[0027] Furthermore, it is also possible to obtain the following advantages by using AIN as the electro strictive material. In other words, it is possible to improve piezoelectric properties by aligning the crystal orientation of the piezoelectric body 52, but it is necessary to provide an orientation control layer between the vibrating film 103 and the first electrode 51 so as to control the orientation. When AIN is used as the material of the piezoelectric body 52, it is possible to make the lattice constant of the first electrode 51 made of Mo close to AIN by using AIN also as the orientation control layer. As a result, the crystal orientation of the piezoelectric body 52 becomes uniform, and the piezoelectric properties can be improved.

[0028] Aluminum nitride (AIN) containing at least one material of scandium, yttrium, titanium, magnesium, hafnium, zirconium, tin, chromium, and boron may be used as the electrostrictive material of the piezoelectric body. Specifically, a part of aluminum of aluminum nitride is replaced with at least one of the above materials. Thus, the aluminum nitride can contain at least one of the above materials. It is possible to enhance piezoelectric performance by using, as the piezoelectric material, aluminum nitride containing aluminum a part of which has been replaced with at least one of the above materials.

[0029] The electrostrictive material of the piezoelectric body 52 is not limited to aluminum nitride, and may be an electrostrictive material having a Curie point of 350°C or higher or an electrostrictive material having high heat resistance and no Curie point. By using an electrostrictive material having a Curie point of 350°C or higher, it is possible to use a discharge material having a high melting temperature as compared with PZT. It is thus possible to increase the number of materials that can be discharged.

[0030] The channel substrate 100 and the frame member 120 are bonded to each other by use of a bonding agent 140. A metal having a melting temperature higher than the melting temperature of discharge material is used as the bonding agent 140. This makes it possible to prevent the bonding agent 140 from being melted by the heating of discharge material.

[0031] Next, an example of the liquid discharge apparatus according to the present embodiment will be described.FIG. 4 is a schematic configuration diagram of a printer 300 as the liquid discharge apparatus. As illustrated in FIG. 4, the printer 300 includes a liquid discharge device 301 and a table 320. The liquid discharge device 301 includes the head 1 and a supply device 302. A substrate 310 is placed on the table 320.

[0032] The supply device 302 includes a pellet loading portion 302a into which solder pellets are loaded. The solder pellets are supplied from the pellet loading portion 302a to the common chamber 3. The solder pellets supplied to the common chamber 3 are heated by the heater130 to enter a molten state. A heater may be provided in the supply device so as to supply molten solder to the common chamber 3.

[0033] The liquid discharge device 301 is movable in a left-right direction in the drawing (hereinafter, referred to as a sub scanning direction) and a direction orthogonal to the paper surface (hereinafter, referred to as a main scanning direction). Then, while moving in the main scanning direction and the sub scanning direction, the liquid discharge device 301 discharges molten solder from the nozzle 2 to form solder bumps at desired positions on the substrate 310 on the table 320.

[0034] The liquid discharge device 301 may be configured such that liquid can be discharged from one end to the other end in the main scanning direction. Then, the liquid discharge device 301 may be fixed, and the substrate 310 may be conveyed in the sub scanning direction by a conveyor to form solder bumps at desired positions on the substrate 310.

[0035] Next, another example of the printer serving as the liquid discharge apparatus according to the present embodiment will be described with reference to FIGS. 5 and 6.FIG. 5 is an explanatory diagram illustrating a plan view of a main part of a printer of the present example.FIG. 6 is an explanatory diagram illustrating a side view of the main part of the printer of the present example.

[0036] A printer 500 is a serial type inkjet recording apparatus, and a carriage 403 is reciprocally moved in the main scanning direction indicated by arrow “MSD” in FIG. 5 by a main scan moving unit 493. The main scan moving unit 493 includes a guide 401, a main scan motor 405, a timing belt 408, and the like. The guide 401 is bridged between a left-side plate 491A and a right-side plate 49 IB to movably hold the carriage 403. The main scan motor 405 reciprocally moves the carriage 403 in the main scanning direction MSD via the timing belt 408 bridged between a drive pulley 406 and a driven pulley 407.

[0037] The carriage 403 is equipped with a liquid discharge device 440. The head 1 according to the present embodiment and a head tank 441 form the liquid discharge device 440 as a single unit. The head 1 of the liquid discharge device 440 discharges liquid of each color, for example, yellow (Y), cyan (C), magenta (M), and black (K). The head 1 includes a nozzle array including multiple nozzles arrayed in the sub scanning direction as indicated by arrow “SSD”. The sub scanning direction is orthogonal to the main scanning direction MSD. The head 1 is attached to the carriage 403 such that ink droplets are discharged downward.

[0038] The printer 500 includes a conveyor 495 to convey a sheet 410. The conveyor 495 includes a conveyance belt 412 as a conveyor and a sub scan motor 416 to drive the conveyance belt 412. The conveyance belt 412 attracts the sheet 410, and conveys the sheet 410 to a position facing the head 1. The conveyance belt 412 is an endless belt stretched between a conveyance roller 413 and a tension roller 414. Attraction of the sheet 410 to the conveyance belt 412 may be applied by electrostatic adsorption, air suction, or the like. The conveyance belt 412 rotates in the sub scanning direction SSD as the conveyance roller 413 is rotationally driven by the sub scan motor 416 via a timing belt 417 and a timing pulley 418.

[0039] At one side in the main scanning direction MSD of the carriage 403, a maintenance unit 420 to maintain the head 1 in good condition is disposed on a lateral side of the conveyance belt 412. The maintenance unit 420 includes, for example, a cap 421 to cap the nozzle surface of the head 1 and a wiper 422 to wipe the nozzle surface of the head 1. The main scan moving unit 493, the maintenance unit 420, and the conveyor 495 are mounted onto a housing including the left-side plate 491A, the right-side plate 491B, and a back plate 491C.

[0040] In the printer 500 thus configured, the sheet 410 is conveyed on and attracted to the conveyance belt 412, and is conveyed in the sub scanning direction SSD by a cyclic rotation of the conveyance belt 412. The head 1 is driven in response to image signals while the carriage 403 moves in the main scanning direction MSD, to discharge a liquid to the sheet 410 stopped, thus forming an image on the sheet 410.

[0041] Next, another example of the liquid discharge device 440 according to the present embodiment is described with reference to FIG. 7.FIG. 7 is an explanatory diagram illustrating a plan view of a main part of a liquid discharge device of the present example.

[0042] The liquid discharge device 440 includes a housing, the main scan moving unit 493, the carriage 403, and the head 1 among components of the liquid discharge apparatus. The leftside plate 491 A, the right-side plate 49 IB, and the back plate 491C form the housing.

[0043] Note that, in the liquid discharge device 440, the maintenance unit 420 described above may be mounted on the right-side plate 49 IB, for example.

[0044] Next, still another example of the liquid discharge device 440 according to the present embodiment is described with reference to FIG. 8.FIG. 8 is an explanatory diagram illustrating a front view of a liquid discharge device of the present example.

[0045] The liquid discharge device 440 includes the head 1 to which a channel part 444 is attached, and a tube 456 connected to the channel part 444.

[0046] The channel part 444 is disposed inside a cover 442. Instead of the channel part 444, the liquid discharge device 440 may include the head tank 441. A connector 443 electrically connected with the head 1 is provided on an upper part of the channel part 444.

[0047] In the printer 500 configured as described above, it is possible to use, as the discharge material, resin ink such as solid ink to be used after being heated and melted, by using the liquid discharge head of the present embodiment.

[0048] The above-described embodiment is illustrative and does not limit the present disclosure. Thus, numerous additional modifications and variations are possible in light of the above teachings.

[0049] In the present application, liquid to be discharged is not limited to a particular liquid as long as the liquid has a viscosity or surface tension that allows the liquid to be discharged from a head. Meanwhile, the liquid preferably has a viscosity not greater than 30 mPa- s at least when heated. Examples of the liquid include a solution, a suspension, an emulsion, and molten metal, such as solder, that contain, for example, a solvent, such as water or an organic solvent, a colorant, such as dye or pigment, a functional material, such as a polymerizable compound, a resin, or a surfactant, a biocompatible material, such as DNA, amino acid, protein, or calcium, or an edible material, such as a natural colorant. Such a solution, a suspension, an emulsion, and molten metal can be used for, e.g., inkjet ink, surface treatment solution, a liquid for forming components of an electronic element or light-emitting element or a resist pattern of an electronic circuit, a liquid for forming solder bumps, or a material solution for three-dimensional fabrication.

[0050] The “liquid discharge device” is an assembly of parts relating to liquid discharge. The term “liquid discharge device” represents a structure including the head and a functional part(s) or unit(s) combined with the head to form a single unit. For example, the “liquid discharge device” includes a combination of the head with at least one of a head tank, a carriage, a supply unit, a maintenance unit, a main scan moving unit, and a liquid circulation apparatus.

[0051] Examples of the “single unit” include a combination in which the head and one or more functional parts and units are secured to each other through, e.g., fastening, bonding, or engaging, and a combination in which one of the head and the functional parts and units is movably held by another. The head may be detachably attached to the functional part(s) or unit(s) each other.

[0052] For example, the head and the head tank may form the liquid discharge device as a single unit. Alternatively, the head and the head tank coupled (connected) with a tube or the like may form the liquid discharge device as a single unit. A unit including a filter may be added at a position between the head tank and the head of the liquid discharge device.

[0053] In another example, the head and the carriage may form the liquid discharge device as a single unit.

[0054] In still another example, the liquid discharge device includes the head movably held by a guide that forms part of a main scan moving unit, so that the head and the main scan moving unit form a single unit. The liquid discharge device may include the head, the carriage, and the main scan moving unit that form a single unit.

[0055] In still another example, a cap that forms a part of the maintenance unit may be secured to the carriage on which the head has been mounted so that the head, the carriage, and the maintenance unit form a single unit to form the liquid discharge device.

[0056] Furthermore, in still another example, the liquid discharge device includes tubes connected to the head tank or the head with a channel part attached thereto so that the head and the supply unit form a single unit. A liquid in a liquid reservoir source such as an ink cartridge is supplied to the head through this tube.

[0057] The main scan moving unit may be a guide only. The supply unit may be a tube(s) only or a loading unit only.

[0058] The “liquid discharge device” includes a head module including the above-described head, and a head device in which the above-described functional components and mechanisms are combined to form a single unit.

[0059] The term “liquid discharge apparatus” used herein also represents an apparatus including the head, the liquid discharge device, the head module, the head device, and the liquid discharge device to discharge liquid by driving the head. The liquid discharge apparatus may be, for example, an apparatus that can discharge a liquid to a material to which liquid can adhere or an apparatus to discharge liquid toward gas or into liquid.

[0060] The liquid discharge apparatus may include devices to feed, convey, and eject the material to which liquid can adhere. The liquid discharge apparatus may further include a pretreatmentapparatus to coat the material with a treatment liquid, and a post-treatment apparatus to coat the material with a treatment liquid, onto which the liquid has been discharged.

[0061] The “liquid discharge apparatus” may be, for example, an image forming apparatus to form an image on a sheet by discharging ink, or a three-dimensional fabrication apparatus to discharge a fabrication liquid to a powder layer in which powder material is formed in layers to form a three-dimensional fabrication object.

[0062] The liquid discharge apparatus is not limited to an apparatus to discharge liquid to visualize meaningful images, such as letters or figures. For example, the liquid discharge apparatus may be an apparatus to form meaningless images, such as meaningless patterns, or fabricate three-dimensional images.

[0063] The above-described term “material to which liquid can adhere” represents a material to which liquid can at least temporarily adhere, a material to which liquid adheres and is fixed, or a material to which liquid adheres to permeate. Examples of the “material to which liquid can adhere” include recording media, such as a paper sheet, recording paper, a recording sheet of paper, a film, and cloth, electronic components, such as an electronic substrate and a piezoelectric element, and media, such as a powder layer, an organ model, and a testing cell. The “material to which liquid can adhere” includes any material to which liquid can adhere, unless particularly limited.

[0064] Examples of the above-described term “material to which liquid can adhere” include any materials to which liquid can adhere even temporarily, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, and ceramics.

[0065] The “liquid discharge apparatus” may be an apparatus to relatively move the head and a material to which liquid can adhere. However, the liquid discharge apparatus is not limited to such an apparatus. For example, the liquid discharge apparatus may be a serial head apparatus that moves the head or a line head apparatus that does not move the head.

[0066] Examples of the “liquid discharge apparatus” further include a treatment liquid coating apparatus to discharge treatment liquid to a sheet to coat a sheet surface with the treatment liquid so as to reform the sheet surface and an injection granulation apparatus in which a composition liquid including raw materials dispersed in a solution is discharged through nozzles to granulate fine particles of the raw materials. Furthermore, there is an injection granulation apparatus for spraying a composition liquid in which raw materials are dispersed in a solution through a nozzle to granulate fine particles of the raw material.

[0067] The terms “image formation”, “recording”, “printing”, “image printing”, and “fabricating” used herein may be used synonymously with each other.

[0068] The above-described embodiment is illustrative and does not limit the present disclosure. Thus, numerous additional modifications and variations are possible in light of the above teachings.

[0069] The above-described embodiment is a limited example, and the present disclosure includes, for example, the following aspects having advantageous effects.Aspect 1According to Aspect 1, a liquid discharge head 1 that drives a piezoelectric body 52 to cause liquid in a pressure chamber 4 to be discharged from a nozzle 2 includes: a nozzle plate 110 having the nozzle 2; and a channel substrate 100 having the pressure chamber 4, the pressure chamber 4 communicating with the nozzle 2, wherein the nozzle plate 110 includes the piezoelectric body 52 having a Curie point equal to or higher than 350°C or no Curie point, the nozzle plate 110 vibrates as the piezoelectric body 52 is driven, and molten resin or molten metal heated to a temperature equal to or higher than 130°C is discharged from the nozzle 2.In a liquid discharge head that discharges a material (hereinafter, referred to as a discharge material) that is solid at room temperature, such as solder, from a nozzle, it is necessary to heat the discharge material to a temperature equal to or higher than a melting temperature by a heater. Therefore, the temperature of the piezoelectric body rises due to the discharge material heated to the temperature equal to or higher than the melting temperature. Piezoelectric zirconate titanate (PZT) has high piezoelectric properties. However, PZT generally has a Curie point of 150 to 350°C at which the crystal structure of PZT changes to lose piezoelectric properties. Thus, a temperature environment in which PZT can be used as the material of the piezoelectric body is limited. Therefore, when the molten resin or molten metal heated to a temperature of 130°C or higher is discharged from the nozzle, the piezoelectric properties may be lost.As the material of the piezoelectric body, there is a piezoelectric material having a higher Curie point than PZT, such as aluminum nitride (AIN), or a piezoelectric material having no Curie point, but such a piezoelectric material has lower piezoelectric properties than PZT. Therefore, in the configuration of PTL 1 in which the piezoelectric body is provided on the wall of the pressure chamber facing the nozzle plate, sufficient pressure cannot be generated, so that there is a possibility that molten resin or molten metal heated to a temperature of 130°C or higher cannot be discharged from the nozzle.Meanwhile, in Aspect 1, the piezoelectric body is provided on the nozzle plate, and the nozzle plate is vibrated to discharge liquid. As a result, it is possible to satisfactorily discharge liquid from the nozzle with a small pressure as compared with the case of discharging liquidby vibrating a wall of the pressure chamber facing the nozzle plate. Therefore, liquid can be satisfactorily discharged from the nozzle even when either of the following is used as the material of the piezoelectric body: a piezoelectric material that has a lower piezoelectric properties than PZT, leading to generated pressure lower than PZT, but has a higher Curie point than PZT; or a material having high heat resistance, such as aluminum nitride (AIN), which has no Curie point and does not change the amount of displacement even at a high temperature. As a result, it is possible to satisfactorily discharge the molten resin or molten metal having a melting temperature of 130°C or higher.

[0070] Aspect 2According to Aspect 2, in the liquid discharge head of Aspect 1, the nozzle plate 110 includes a surface layer 111 including an inorganic substance.According to this aspect, heat resistance can be enhanced as compared with an organic substance such as resin. As a result, even when a discharge material having a high melting temperature is used, the nozzle plate is not softened, and liquid can be discharged satisfactorily.

[0071] Aspect 3According to Aspect 3, in the liquid discharge head of Aspect 1 or 2, the pressure chamber 4 has an opening on a side facing the nozzle plate 110, liquid being supplied through the opening.According to this aspect, as described in the embodiment, it is possible to achieve densification of the nozzles and downsizing of the liquid discharge head as compared with the case where a side wall of the pressure chamber 4 has an opening through which liquid is supplied. Since the liquid discharge head can be downsized, the heat capacity of the liquid discharge head can be reduced, and the discharge material can be efficiently heated to a temperature equal to or higher than a melting temperature. Thus, power consumption can be reduced.

[0072] Aspect 4According to Aspect 4, in the liquid discharge head of any one of Aspects 1 to 3, a protective layer such as a protective film 11 made of an inorganic substance is provided on an inner peripheral surface of the pressure chamber 4.According to this aspect, as described in the embodiment, a side wall of the channel substrate 100 forming the pressure chamber 4 can be protected from contamination by discharge material such as elution of molten discharge material.

[0073] Aspect 5According to Aspect 5, in the liquid discharge head of Aspect 4, the protective layer such as the protective film 11 includes metal oxide, metal nitride, ceramic oxide, ceramic nitride, or carbide ceramics.According to this aspect, corrosion and erosion by molten discharge material can be favorably prevented, so that the channel substrate 100 forming the pressure chamber 4 can be satisfactorily protected.

[0074] Aspect 6According to Aspect 6, in the liquid discharge head of any one of Aspects 1 to 5, the piezoelectric body 52 includes aluminum nitride or aluminum nitride including at least one of scandium, yttrium, titanium, magnesium, hafnium, zirconium, tin, chromium, and boron. According to this aspect, as described in the embodiment, the heat resistance of the piezoelectric body 52 can be enhanced. As a result, even when the temperature of the piezoelectric body is increased by heated liquid in the pressure chamber or the heater, the liquid is satisfactorily displaced. Thus, the liquid can be satisfactorily discharged from the nozzle.

[0075] Aspect 7According to Aspect 7, in the liquid discharge head of any one of Aspects 1 to 6, the channel substrate 100 and a substrate such as a frame member 120 are joined by metal having a melting temperature equal to or higher than a melting temperature of the molten resin or the molten metal, the substrate having a supply liquid chamber such as a common chamber 3 for supplying liquid to the pressure chamber 4.According to this aspect, it is possible to prevent the metal that joins the channel substrate 100 and the substrate, such as the frame member 120, from being melted by the heating of the discharge material.

[0076] Aspect 8According to Aspect 8, in the liquid discharge head of any one of Aspects 1 to 7, the nozzle 2 and the pressure chamber 4 include a plurality of nozzles 2 and a plurality of pressure chambers 4, respectively.According to this aspect, molten metal or molten resin can be discharged from the plurality of nozzles.

[0077] Aspect 9According to Aspect 9, in the liquid discharge head of any one of Aspects 1 to 8, the liquid to be discharged from the nozzle is molten metal, and the molten metal is solder.According to this aspect, as described in the embodiment, solder bumps can be formed on the substrate.

[0078] Aspect 10According to Aspect 10, a liquid discharge apparatus includes a liquid discharge head, wherein the liquid discharge head of any one of Aspects 1 to 9 is used as the liquid discharge head.According to this aspect, a solid discharge material such as resin or metal can be melted and discharged in a room-temperature environment.The above-described embodiments are illustrative and do not limit the present invention. Thus, numerous additional modifications and variations are possible in light of the above teachings. For example, elements and / or features of different illustrative embodiments may be combined with each other and / or substituted for each other within the scope of the present invention.This patent application is based on and claims priority to Japanese Patent Application No. 2024-032263, filed on March 4, 2024, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.[Reference Signs List]

[0079] 1 : Liquid discharge head2: Nozzle3: Common chamber4: Pressure chamber5: Piezoelectric element6: Electrical connection pad7a: First contact7b: Second contact7c: Third contact7d: Fourth contact8a: First insulating film8b: Second insulating film9a: First lead wire9b: Second lead wire11 : Protective film14: Nozzle51 : First electrode52: Piezoelectric body53: Second electrode100: Channel substrate101: Drive circuit102: Wiring layer103: Vibrating film110: Nozzle plate111: Surface layer120: Frame member130: Heater140: Bonding agent300: Printer301: Liquid discharge device302: Supply device302a: Pellet loading portion310: Substrate320: Table440: Liquid discharge device500: Printer[Citation List][Patent Literature]

[0080] [PTL 1]Japanese Patent No. 4142800

Claims

[CLAIMS]

1. A liquid discharge head comprising: a nozzle plate including: a nozzle; and a piezoelectric body in the nozzle plate to vibrate the nozzle plate; and a channel substrate on the nozzle plate, the channel substrate having a pressure chamber communicating with the nozzle, wherein the piezoelectric body has: a Curie point equal to or higher than 350°C; or no Curie point, and the piezoelectric body is driven to vibrate the nozzle plate to discharge molten resin or molten metal, heated to a temperature equal to or higher than 130°C in the channel substrate, from the nozzle in a discharge direction.

2. The liquid discharge head according to claim 1, wherein the nozzle plate includes a surface layer including an inorganic substance.

3. The liquid discharge head according to claim 1, further comprising: a frame member on the channel substrate, the frame member having a common chamber communicating with the pressure chamber, wherein the pressure chamber is between the common chamber and the nozzle in the discharge direction, and the common chamber faces the nozzle via the pressure chamber.

4. The liquid discharge head according to claim 1, wherein the pressure chamber includes a protective layer including an inorganic substance on an inner peripheral surface of the pressure chamber.

5. The liquid discharge head according to claim 4, wherein the protective layer includes metal oxide, metal nitride, ceramic oxide, ceramic nitride, or carbide ceramics.

6. The liquid discharge head according to claim 5, wherein the protective layer includes aluminum oxide (A12O3), silicon dioxide (SiO2), silicon nitride (SiN), zirconium oxide (ZrO), or silicon carbide (SiC).

7. The liquid discharge head according to claim 1,wherein the piezoelectric body includes aluminum nitride including at least one of scandium, yttrium, titanium, magnesium, hafnium, zirconium, tin, chromium, or boron.

8. The liquid discharge head according to claim 1, further comprising: a frame member having a common chamber communicating with the pressure chamber; and metal bonding the channel substrate and the frame member, wherein the metal has a melting temperature equal to or higher than a melting temperature of the molten resin or the molten metal.

9. The liquid discharge head according to claim 1, further comprising: a plurality of nozzles having the nozzle; and a plurality of pressure chambers having the pressure chamber.

10. The liquid discharge head according to claim 1, wherein the liquid discharge head discharges the molten metal including solder from the nozzle.

11. A liquid discharge apparatus comprising: the liquid discharge head according to claim 1 ; and a carriage mounting the liquid discharge head to move the liquid discharge head.

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