JP2009029069A - Liquid discharge head and manufacturing method of liquid discharge head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a liquid discharge head which is capable of easily and excellently performing the wiring of a base electrode, a piezoelectric element and an FPC. <P>SOLUTION: The liquid discharge head includes: a body plate 2 having a pressure chamber groove constituting a pressure chamber communicating with a nozzle hole for discharging liquid as a droplet; the piezoelectric element 3 allowing the pressure chamber to generate pressure; and a flexible board 42 supplying driving power to the piezoelectric element. In the piezoelectric element, one electrode of a pair of facing electrodes 3a possessed by the piezoelectric element is joined to a base electrode 40 provided in a surface opposite to a surface having the pressure chamber groove of the body plate and the base electrode and the other electrode of the piezoelectric element are joined to each other across the flexible board 42 having a common electrode 42-g to which the respective electrodes are connected and an individual electrode 42-d and an anisotropically conductive film 44. In the liquid discharge head, a conductive member 43 and the anisotropically conductive film exist in order from the base electrode, between the base electrode and the common electrode. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid discharge head and a method for manufacturing the liquid discharge head.

  An ink jet recording method using a liquid discharge head is one of non-impact recording methods, which enables high-speed recording and can be recorded on various recording media, and high-definition images can be recorded. can get. Because of these advantages, the ink jet recording method has rapidly become widespread while expanding its use in recent years as a recording means for copying machines, photographs, various printing, industrial high-definition patterning as well as printers as computer peripherals. is doing.

  Such a liquid discharge head includes a nozzle for causing a liquid such as ink to fly, and an energy generating means for applying energy for discharge to the liquid such as an ink in a pressure generating chamber communicating with the nozzle. . As this energy generating means, there is a liquid discharge head using a piezoelectric element (piezo element) which is an electromechanical conversion element. This piezoelectric element is attached to a diaphragm that forms part of the wall of the pressure generating chamber, and the pressure wave generated by the piezoelectric element propagates through the diaphragm to the liquid in the pressure generating chamber, thereby causing a meniscus at the tip of the nozzle. Is controlled to discharge droplets.

  By controlling the piezoelectric element to turn on / off a predetermined voltage, it is possible to control whether or not droplets are ejected and perform desired printing. For this reason, the piezoelectric element provided in the liquid discharge head is provided with wiring for applying a voltage.

As a method of wiring to the piezoelectric element included in the liquid discharge head, an FPC (Flexible Printed Circuits) is used as a wiring material, and an anisotropic conductive film is disposed between the FPC and the piezoelectric element and heat-pressed. There is a method (see Patent Document 1). A description will be given with reference to FIG. Between the piezoelectric element 201 and the FPC 203, an anisotropic conductive film 204 having an area of a portion to which the piezoelectric element 201 is to be bonded is disposed and pressed from above the FPC 203 by the preheated FPC pressing portion 206 of the thermocompression bonding apparatus. Wiring is done by applying pressure while heating moderately. Further, the anisotropic conductive film 204 is formed by disposing the anisotropic conductive film 205 between the common electrode plate 202 to which the piezoelectric element 201 is bonded and the FPC 203 in the same manner as the wiring of the piezoelectric element 201 and the FPC 203. And the common electrode plate 202 can be wired.
JP-A-3-345858

  However, as shown in FIG. 6, the distance between the common electrode plate 202 and the FPC 203 is wider than the distance between the piezoelectric element 201 and the FPC 203 by the thickness of the piezoelectric element 201. For this reason, if an attempt is made to wire the piezoelectric element 201 and the FPC 203 and the common electrode plate 202 and the FPC 203 at the same time with an anisotropic conductive film, the common electrode plate 202 and the FPC 203 may not be sufficiently pressurized, resulting in a wiring failure. . For this reason, wiring between the common electrode plate 202 and the FPC 203 and wiring between the piezoelectric element 201 and the FPC 203 need to be performed in two steps. In some cases, it is necessary to prepare anisotropic conductive films of two kinds of sizes, and there is a problem in that the manufacturing process is complicated and the manufacturing time becomes long. In order to make the liquid discharge head more compact, it is necessary to reduce the pitch between the piezoelectric elements 201 and to bring the position where the common electrode plate 202 and the FPC 203 are connected closer to the piezoelectric element 201 side. In this case, the degree of bending of the anisotropic conductive film becomes too large due to the difference in height of the wiring location depending on the thickness of the piezoelectric element 201, so that the connection cannot be made well.

  The present invention has been made in view of the above problems, and an object of the present invention is to manufacture a liquid discharge head capable of easily and satisfactorily wiring the base electrode, the piezoelectric element, and the FPC. A method and a liquid ejection head are provided.

  Said subject is solved by the following structures.

1. A body plate having a pressure chamber groove that constitutes a pressure chamber communicating with a nozzle hole for discharging liquid as droplets;
A piezoelectric element for generating pressure in the pressure chamber;
A flexible substrate for supplying driving power to the piezoelectric element,
The piezoelectric element has one electrode of a pair of opposing electrodes of the piezoelectric element coupled to a base electrode provided on the opposite surface of the body plate where the pressure chamber groove is provided,
In the liquid discharge head, the base electrode and the other electrode of the piezoelectric element are coupled with the anisotropic conductive film sandwiched between the flexible substrate having the common electrode and the individual electrode to which the respective electrodes are connected,
A liquid discharge head, wherein a conductive member and the anisotropic conductive film are provided between the base electrode and the common electrode in order from the base electrode.

2. A body plate having a pressure chamber groove that constitutes a pressure chamber communicating with a nozzle hole for discharging liquid as droplets;
A piezoelectric element for generating pressure in the pressure chamber;
A flexible substrate for supplying driving power to the piezoelectric element,
The piezoelectric element has one electrode of a pair of opposing electrodes of the piezoelectric element coupled to a base electrode provided on the opposite surface of the body plate where the pressure chamber groove is provided,
Manufacturing of a liquid discharge head in which the base electrode and the other electrode of the piezoelectric element are coupled with a common electrode to which the respective electrodes are connected and the flexible substrate having the individual electrodes and an anisotropic conductive film interposed therebetween In the method
Providing the base electrode on the body plate;
Coupling one electrode of the piezoelectric element to the base electrode and coupling a conductive member to the base electrode;
Placing the body plate, wherein the piezoelectric element and the conductive member are coupled to the base electrode, on a fixed base;
Placing an anisotropic conductive film on the piezoelectric element and the conductive member of the body plate;
On the anisotropic conductive film, placing a flexible substrate so that the position of the common electrode and the individual electrode overlaps the position of the conductive member and the piezoelectric element;
Heating a pressing member that presses the flexible substrate;
Pressing the flexible substrate in a state where the pressing member is heated;
And a step of separating the pressing member from the flexible substrate.

  According to the present invention, the liquid discharge head includes a conductive member and an anisotropic conductive film in order from the base electrode between the base electrode provided on the body plate and the common electrode of the flexible substrate. Therefore, when the thickness of the conductive member is, for example, approximately the same as that of the piezoelectric element, the thickness of the anisotropic conductive film sandwiched between the conductive member and the piezoelectric element and the conductive member can be made uniform. For this reason, a base electrode and a piezoelectric element, and a flexible substrate can be couple | bonded easily and favorably.

  Accordingly, it is possible to provide a liquid discharge head manufacturing method and a liquid discharge head that can easily and satisfactorily perform wiring between the base electrode and the piezoelectric element and the flexible substrate.

Although the present invention will be described based on the illustrated embodiment, the present invention is not limited to the embodiment.
A liquid discharge head manufactured by the method of manufacturing a liquid discharge head according to the present invention will be described.

  FIG. 3 shows an exploded perspective view of a configuration of an ink jet recording head (hereinafter referred to as a recording head) A as an example of a liquid discharge head. In FIG. 3, 1 is a nozzle plate for a liquid discharge head (hereinafter referred to as a nozzle plate), 5 is an intermediate plate, 2 is a body plate, 3 is a piezoelectric element, 30 is an ink supply path, and 42 is power to the piezoelectric element 3. 1 schematically shows a flexible substrate (hereinafter referred to as FPC (Flexible Printed Circuits)) that is a wiring material that supplies the substrate.

  The nozzle plate 1 has a plurality of nozzle holes 11 for discharging ink. A liquid repellent film 45 is provided on a surface (hereinafter referred to as a discharge surface) 13 having a discharge port for discharging droplets of the nozzle hole 11. The intermediate plate 5 is provided with a through hole 12 communicating with the nozzle hole 11. The diameter of the through hole 12 is larger than the diameter of the nozzle hole 11.

  Further, the nozzle plate 1 is bonded to the body plate 2 via the intermediate plate 5 so that the pressure chamber groove 24 serving as a pressure chamber, the ink supply path groove 23 serving as an ink supply path, and the common ink chamber serving as a common ink chamber. A groove 22 and an ink supply port 21 are formed.

  Then, the nozzle plate 1 and the body plate 2 are bonded to each other so that the nozzle hole 11 of the nozzle plate 1 and the pressure chamber groove 24 of the body plate 2 are in one-to-one correspondence. M is formed. Hereafter, the reference numerals of the pressure chamber groove, the supply path groove, and the common ink chamber groove used in the above description are also used for the pressure chamber, the supply path, and the common ink chamber, respectively. Further, an ink supply path 30 is coupled so as to communicate with the ink supply port 21. Ink can be supplied to the flow path unit M by connecting the ink supply path 30 and a separately prepared ink storage section (not shown) with a pipe (not shown).

  In the flow path unit M, as the actuator for changing the volume of the pressure chamber 24 to eject droplets from the nozzle hole 11, the piezoelectric element 3 is the bottom surface of each pressure chamber 24 opposite to the surface of the body plate 2 having the nozzle plate 1. It is bound to.

  FIG. 2 schematically shows the piezoelectric element 3, the FPC 42, and the periphery thereof of the recording head A as viewed from the back side of the paper surface in FIG. The body plate 2 is provided with a base electrode 40 connected to supply driving power to the piezoelectric element 3. The piezoelectric element 3 is provided with a pair of opposed electrodes 3 a for driving the piezoelectric element 3, and one of the electrodes 3 a is coupled to a position on the base electrode 40 corresponding to each pressure chamber 24. . Henceforth, when electrically connecting with the piezoelectric element 3, even when this electrode 3a is not shown, it means connecting with the electrode 3a.

  In addition, a conductive member 43 having substantially the same thickness as that of the piezoelectric element 3 is coupled to the base electrode 40 along with the piezoelectric element 3. The FPC 42 is connected to the individual electrode 42-d connected to the other electrode 3 a of each piezoelectric element 3 in order to supply power to each piezoelectric element 3 and the common member 43 connected to the base electrode 40. An electrode 42-g is provided on the base film 42-b. An anisotropic conductive film in which the common electrode 42-g and the individual electrode 42-d of the FPC 42 and the conductive member 43 and the electrode 3a of each piezoelectric element 3 are electrically and mechanically coupled to each other. (ACF: Anisotropic Conductive Film) 44. The connection by the anisotropic conductive film 44 will be described later.

  The other end of the FPC 42 is connected to a drive circuit (not shown) of the piezoelectric element 3 that is separately prepared, and a drive pulse voltage is applied between the base electrode 40 and the individual electrode 42-d. It can be driven independently. The vibration generated from the driven piezoelectric element 3 is transmitted to the pressure chamber 24, and the liquid in the pressure chamber 24 can be discharged as droplets from the nozzle hole 11 by changing the pressure in the pressure chamber 24 by this vibration.

  FIG. 4 shows a flowchart of the manufacturing process for manufacturing the recording head A described so far. The manufacture of the recording head A will be described with reference to FIGS. 1 to 3 and 5 along FIG.

(Preparation of nozzle plate, body plate, intermediate plate)
The nozzle plate 1, the intermediate plate 5, and the body plate 2 constituting the flow path unit M shown in FIG. 3 are manufactured. The material forming the nozzle plate 1 and the body plate 2 is Si, and the material forming the intermediate plate 5 is preferably borosilicate glass containing mobile ions. By using each plate for these materials, anodic bonding described later can be easily performed.

  A method of forming the nozzle holes 11 in the nozzle plate 1, a method of forming the through holes 12 in the intermediate plate 5, and a method of forming the pressure chamber grooves 24 and the like in the body plate 2 include known photolithography techniques (resist coating, exposure, Development) and etching techniques can be used. As an etching method, dry etching is preferable. The nozzle plate 1, the body plate 2, and the intermediate plate 5 are prepared by these methods.

(Joining)
Next, the prepared three plates of the nozzle plate 1, the intermediate plate 5, and the body plate 2 are superposed and joined by an anodic bonding apparatus shown in FIG. FIG. 5 schematically shows a state in which the three plates of the body plate 2, the nozzle plate 1 and the intermediate plate 5 are anodically bonded simultaneously. Hereinafter, the anodic bonding of the nozzle plate 1, the intermediate plate 5, and the body plate 2 will be described with reference to FIG.

  The nozzle plate 1, the intermediate plate 5, and the body plate 2 are sufficiently washed and dried so that there is no dust on the joint surfaces. Prior to this cleaning and drying, it is preferable that the surface roughness of each joint surface of the nozzle plate 1, the intermediate plate 5, and the body plate 2 is less than 10 nm by polishing or the like.

  Next, the nozzle plate 1, the intermediate plate 5, and the body plate 2 are superposed on a plate fixing base 20 including a heater (not shown) and an electrode 20 a for performing anodic bonding. At this time, the bonding surfaces are made to face each other in the order of the body plate 2, the intermediate plate 5, and the nozzle plate 1 from the electrode 20 a, and the positional relationship is adjusted and overlapped. The electrode 20a is made larger than the body plate 2 placed thereon.

  Next, a pressing member 110 serving as an electrode is provided on the nozzle plate 1, presses the nozzle plate 1, and heats three stacked plates by a heater (not shown) provided in the plate fixing base 20. . The three plates are heated to the anodic bonding temperature (approximately 350 ° C. to 550 ° C.), and a DC voltage (approximately 0.5 kV to 2 kV) is applied to the three plates while maintaining the anodic bonding temperature. . Specifically, the direct current voltage from the direct current power supply 90 with the electrode 20a in contact with the body plate 2 and the electrode probe 60 in contact with the pressing plate 110 serving as an electrode being positive and the electrode probe 61 in contact with the intermediate plate 5 being negative. Is applied to three plates.

  In order to bring the power probe 61 into contact with the intermediate plate 5, the nozzle plate 1 may be made smaller than the intermediate plate 5, or a notch may be provided in the nozzle plate 1 to expose a part of the intermediate plate 5.

  When the space between the three plates is narrowed by pressing with the pressing member 110, a thin air layer is pushed out to the surroundings, and the area where the air is pushed out has a surface roughness Ra of less than 10 nm by polishing or the like Has a very small interval, and the surfaces can be brought into contact with each other and brought into close contact by intermolecular force. The pressing member 110 that presses the nozzle plate 1 is not particularly limited as long as it is a material that becomes an electrode.

  The anodic bonding is a phenomenon in which mobile ions in the intermediate plate 5 are attracted to a high electric field and move and diffuse at the anodic bonding temperature, and glass in which this phenomenon is remarkable is preferable. Preferred glasses include Tempax (registered trademark) and Pyrex (registered trademark).

  In the present embodiment, the process of bonding the body plate 2, the intermediate plate 5, and the nozzle plate 1 simultaneously by the anodic bonding method has been described as an example. By simultaneously joining three plates, the manufacturing process can be simplified and the time can be shortened. Of course, the body plate 2 and the intermediate plate 5 may be joined, and then the intermediate plate 5 and the nozzle plate 1 may be joined together in order to perform anodic bonding.

(Washing)
Next, the flow path unit M in which the body plate 2, the intermediate plate 5, and the nozzle plate 1 are anodically bonded is cleaned. In particular, it is preferable that the discharge surface 13 of the nozzle plate 1 provided with the liquid repellent film 45 be sufficiently cleaned. By forming the liquid repellent film 45 on the cleaned discharge surface 13, the adhesion of the liquid repellent film 45 to the discharge surface 13 can be sufficiently ensured, and the durability can be improved. The liquid-repellent film 45 is not easily peeled off even when the recording surface is operated by rubbing and wiping with a head cleaner to clean the ejection surface 13, and good droplet ejection performance can be maintained over a long period of time.

  As a cleaning method, for example, there is ultrasonic cleaning, and the cleaning liquid is not particularly limited as long as it does not cause chemical change such as erosion in the material forming the flow path unit M, and is appropriately selected according to the contaminant. Just choose. For example, there can be mentioned an alkaline detergent excellent in removability and degreasing power of particle stains such as glass and Si, and a neutral detergent which is easy to handle, and it is appropriately selected and used depending on the contaminant. Further, an RCA cleaning method may be applied.

  The flow path unit M that has been subjected to ultrasonic cleaning using the cleaning liquid as described above is rinsed with pure water and dried. Thereafter, an ashing process using oxygen plasma (also referred to as oxygen plasma process) may be performed.

  The improvement in adhesion by the cleaning is not limited to the liquid repellent film 45 provided on the ejection surface 13. Needless to say, the adhesion also improves with respect to a metal film used as a base electrode 40 of the piezoelectric element 3 to be described later.

(Liquid repellent film formation)
Next, the liquid repellent film 45 provided on the ejection surface 13 will be described. A liquid repellent film 45 is provided on the ejection surface 13 of the nozzle plate 1. By providing the liquid repellent film 45, it is possible to suppress the seepage and spread due to the liquid getting into the ejection surface 13 from the nozzle hole 11. Specifically, for the liquid repellent film 45, for example, a material having water repellency is used if the liquid is aqueous, and a material having oil repellency is used if the liquid is oil. In general, fluororesins such as FEP (ethylene tetrafluoride, propylene hexafluoride), PTFE (polytetrafluoroethylene), fluorinated siloxane, fluoroalkylsilane, and amorphous perfluororesin are often used. A film is formed on the discharge surface 12 by a vacuum deposition method or an immersion method. The thickness of the liquid repellent film 45 may be appropriately determined depending on the material and the forming method of the liquid repellent film 45.

  The liquid repellent film 45 can be formed directly on the ejection surface 13 of the nozzle plate 1, but in order to improve the adhesion of the liquid repellent film 45, an underlayer such as a TEOS (tetraethoxysilane) film is interposed. It is preferable to form a film. The TEOS film can be formed using a TEOS gas by a plasma CVD method.

  Incidentally, it is preferable to mask the discharge port when forming the liquid repellent film 45. By masking, the liquid repellent film 45 does not block the discharge port, and a good discharge port can be obtained without removing the liquid repellent film at the discharge port portion after the liquid repellent film 45 is formed.

(Base electrode formation)
Next, the base electrode 40 is provided on a portion corresponding to the position of the pressure chamber 24 on the back surface (the surface opposite to the side where the nozzle plate 1 is located) of the flow path unit M (a portion functioning as a so-called diaphragm) (FIG. 1). 2). The base electrode 40 functions as a common electrode for driving by applying a voltage to all the piezoelectric elements 3 provided thereon. The material forming the base electrode 40 is not particularly limited as long as it is a material to be an electrode, and examples thereof include Al, Au, Cu, and Ag. Moreover, you may provide base layers, such as Cr for improving adhesiveness. A method for forming the base electrode 40 is not particularly limited, and examples thereof include known sputtering and vacuum deposition.

(Piezoelectric element, conductive member combination)
Next, a separately prepared piezoelectric element 3 is coupled onto the base electrode 40. A pair of opposing electrodes 3a such as Au is provided in advance on the two surfaces to which a voltage is applied to the piezoelectric element 3, and one surface of this electrode 3a is formed on a base using a conductive adhesive such as silver paste. Coupled to electrode 40. Further, when the piezoelectric element 3 is provided on the base electrode 40, the conductive member 43 is coupled onto the base electrode 40 in the same manner as the piezoelectric element 3. The position at which the conductive member 43 is provided on the base electrode 40 is not particularly limited. However, in consideration of the combination with the FPC described later, it is shown in FIG. 3 because of the ease of work, the shape of the FPC and the anisotropic conductive film, and the like. Thus, it is preferable to provide on the extension in which the piezoelectric elements 3 are arranged.

  The material of the conductive member 43 is not particularly limited as long as it is a material that serves as an electrode, and examples thereof include foil-like metals such as Al and Cu, and a conductive adhesive on one surface that can be easily bonded to the base electrode 40. You may use the metal foil tape etc. in which the agent was provided. The thickness of the conductive member 43 is preferably substantially the same as the thickness of the piezoelectric element 3. The thickness of the piezoelectric element 3 is, for example, about 30 μm to 100 μm although it depends on the specifications.

(FPC wiring)
Next, the FPC 42 for supplying driving power to each piezoelectric element 3 coupled to the flow path unit M is coupled. As shown in FIG. 2, the conductive member 43 and each piezoelectric element 3 are coupled to the FPC 42 on the opposite surface of the nozzle plate 1 of the flow path unit M using an anisotropic conductive film (ACF: Anisotropic Conductive Film).

  An anisotropic conductive film is formed by dispersing fine particles of a conductive substance such as a conductive metal in a binder component such as an epoxy resin or polyimide excellent in insulation and adhesion. This anisotropic conductive film is disposed between the bonding surface and the surface to be bonded, and by applying appropriate heating and pressurizing simultaneously, the bonding surface and the surface to be bonded are bonded together, and insulation in the surface direction is also performed. It is the connection material which can make the joining surface and to-be-joined surface of a thickness direction electrical conduction, maintaining property.

  An example of a method for bonding the base electrode 40 and the piezoelectric element 3 to the FPC 42 with the anisotropic conductive film 44 interposed therebetween is shown in FIG. On the fixed base 51, the flow path unit M is placed with the side on which the piezoelectric element 3 is provided facing up. As described above, the conductive member 43 and the piezoelectric element 3 are coupled to the flow path unit M on the base electrode 40. On top of this, an anisotropic conductive film 44 having a size capable of covering the conductive member 43 and the piezoelectric element 3 is placed. Since the anisotropic conductive film 44 is a thin film and can be easily cut into an arbitrary shape, it is possible to easily prepare an anisotropic conductive film according to the required bonding area and shape, and the bonding quality is good. Can be maintained. In the anisotropic conductive film 44, 44a schematically shows a binder, and 44b schematically shows fine particles.

  Next, the FPC 42 is placed on the anisotropic conductive film 44. The FPC 42 is provided with a common electrode 42-g connected to the conductive member 43 and an individual electrode 42-d connected to the piezoelectric element 3 on the base film 42-b constituting the FPC 42. When the film 44 is placed on the film 44, the position of the conductive member 43 and the piezoelectric element 3 positioned below the film 44 is adjusted.

  Next, the pressing portion 53 of the thermocompression bonding apparatus heated in advance from above the FPC 42 is pressed from above the FPC 42 and pressed while being appropriately heated. The applied pressure, heating temperature, and heating time at this time may be appropriately determined depending on the anisotropic conductive film to be used.

  By providing a conductive member 43 having a thickness substantially the same as the thickness of the piezoelectric element 3 on the base electrode 40, a surface electrically connected to the FPC 42, that is, the conductive member 43 facing the FPC 42, the piezoelectric element 3. These connection surfaces are substantially in the same plane and can be flat without unevenness. For this reason, when the FPC 42 is pressed from above by the pressing portion 53, the anisotropic conductivity is held between the conductive member 43 and the piezoelectric element 3, and the common electrode 42-g and the individual electrode 42-d facing each other. The film 44 can be pressed and compressed almost uniformly without depending on the connection point. Accordingly, the common electrode 42-g and the individual electrode 42-d of the FPC 42 can be simultaneously and uniformly electrically connected to the conductive member 43 and the piezoelectric element 3 (specifically, the electrode 3a), and mechanically the flow path unit. M can be fixed.

(Ink supply path connection)
An ink supply path 30 for supplying ink to the ink supply port 21 opened in the flow path unit M is coupled with an adhesive or the like. By providing the ink supply path 30 in the flow path unit M, the ink supply path 30 and a separately provided ink storage section (not shown) can be connected by a pipe, and ink can be supplied to the flow path unit M. . Thus, the recording head A can be completed.

Example 1
20 recording heads A were manufactured according to FIG. Each of the nozzle plate 1, the intermediate plate 5, and the body plate 2 was manufactured from a Si substrate, a Pyrex (registered trademark) substrate, and a Si substrate by using a photolithography technique (resist coating, exposure, development) and an etching technique. Thereafter, the flow path unit M provided with the lyophobic film 45 and the base electrode 40 was prepared by anodic bonding. The piezoelectric element 3 is provided with a pair of opposing electrodes 3a in advance, and one electrode 3a is attached on the base electrode 40 with silver paste. The number of piezoelectric elements 3 per channel unit M was 16 pieces.

  Thereafter, a conductive tape was fixed on the base electrode 40 as the conductive member 43. The thickness of the piezoelectric element 3 was 50 μm including the electrode 3a, and CU-35C manufactured by Sumitomo 3M Limited was used as the conductive tape. From the catalog, the conductive tape CU-35C has a copper foil thickness of 35 μm and a thickness including the conductive adhesive of 70 μm.

  Next, as shown in FIG. 1, the flow path unit M in which the piezoelectric element 3 and the conductive member 43 are provided on the base electrode 40 prepared as described above was placed on the fixed base 51. Further, a portion provided with the common electrode 42-g and the individual electrode 42-d at one end of the FPC 42 and the anisotropic conductive film 44 having a size matching the bonding surface was placed thereon. When mounting the FPC 42, the position adjustment was performed so that the common electrode 42-g, the individual electrode 42-d, the conductive member 43, and the piezoelectric element 3 face each other. Moreover, the anisotropic conductive film 44 used Hitachi Chemical Co., Ltd. ANISOLM AC-2102Y-45.

  Next, the temperature of the pressing portion 53 of the thermocompression bonding apparatus was set to 80 ° C. and the applied pressure of 1 MPa, and the FPC 42 was heated and pressurized for 3 seconds. Subsequently, the temperature was set to 180 ° C. and the applied pressure of 3 MPa for 15 seconds. Thereafter, the ink supply path 30 is coupled to the flow path unit M. Thus, 20 recording heads A were manufactured.

  When the other end of the FPC 42 was connected to the drive circuit and energized, it was confirmed that all the piezoelectric elements 3 of the 20 recording heads A operated without problems.

(Comparative Example 1)
Twenty recording heads A were manufactured in the same manner as in Example 1 except that the conductive tape serving as the conductive member 43 was not provided.

  When a drive circuit was connected to the other end of the FPC 42 and energized, 17 of the 20 recording heads A did not operate. In any recording head A, it was assumed that the base electrode 40 serving as a common electrode and the common electrode 42-g could not be connected because all the piezoelectric elements 3 of each recording head A did not operate. In order to confirm this, a continuity test between the electrode on the drive circuit side leading to the common electrode 42-g of the FPC 42 and the base electrode 40 was performed with a tester, and it was found that the continuity was not established.

  From the results of Example 1 and Comparative Example 1 described above, by providing a conductive tape as the conductive member 43 between the base electrode 40 and the anisotropic conductive film, the common electrode 42-g and the individual electrodes of the FPC 42 are provided. It was confirmed that 42-d can be easily and reliably connected to the conductive member 43 and the piezoelectric element 3 simultaneously. Therefore, wiring between the base electrode and the piezoelectric element and the FPC can be easily and satisfactorily performed.

It is a figure explaining the method of couple | bonding a base electrode and a piezoelectric element, and FPC on both sides of an anisotropic conductive film. It is a figure which shows a mode that the electroconductive member and each piezoelectric element, and FPC are couple | bonded using an anisotropic conductive film. FIG. 2 is an exploded perspective view illustrating a configuration of an ink jet recording head as an example of a liquid discharge head. It is a figure which shows the flow of the manufacturing process which manufactures an inkjet recording head. It is a figure which shows the example of an anodic bonding apparatus. It is a figure explaining the prior art example which couple | bonds a base electrode and a piezoelectric element, and FPC on both sides of an anisotropic conductive film.

Explanation of symbols

1 Nozzle plate 2 Body plate 3 Piezoelectric element 3a Electrode 5 Intermediate plate 40 Base electrode 42 Flexible substrate (FPC)
42-b Base film 42-d Individual electrode 42-g Common electrode 43 Conductive member 44 Anisotropic conductive film 44a 44a
44b Fine particles 45 Liquid repellent film 51 Fixing base 53 Pressing part M Channel unit

Claims (2)

A body plate having a pressure chamber groove that constitutes a pressure chamber communicating with a nozzle hole for discharging liquid as droplets;
A piezoelectric element for generating pressure in the pressure chamber;
A flexible substrate for supplying driving power to the piezoelectric element,
The piezoelectric element has one electrode of a pair of opposing electrodes of the piezoelectric element coupled to a base electrode provided on the opposite surface of the body plate where the pressure chamber groove is provided,
In the liquid discharge head, the base electrode and the other electrode of the piezoelectric element are coupled with the anisotropic conductive film sandwiched between the flexible substrate having the common electrode and the individual electrode to which the respective electrodes are connected,
A liquid discharge head, wherein a conductive member and the anisotropic conductive film are provided between the base electrode and the common electrode in order from the base electrode. A body plate having a pressure chamber groove that constitutes a pressure chamber communicating with a nozzle hole for discharging liquid as droplets;
A piezoelectric element for generating pressure in the pressure chamber;
A flexible substrate for supplying driving power to the piezoelectric element,
The piezoelectric element has one electrode of a pair of opposing electrodes of the piezoelectric element coupled to a base electrode provided on the opposite surface of the body plate where the pressure chamber groove is provided,
Manufacturing of a liquid discharge head in which the base electrode and the other electrode of the piezoelectric element are coupled with a common electrode to which the respective electrodes are connected and the flexible substrate having the individual electrodes and an anisotropic conductive film interposed therebetween In the method
Providing the base electrode on the body plate;
Coupling one electrode of the piezoelectric element to the base electrode and coupling a conductive member to the base electrode;
Placing the body plate, wherein the piezoelectric element and the conductive member are coupled to the base electrode, on a fixed base;
Placing an anisotropic conductive film on the piezoelectric element and the conductive member of the body plate;
On the anisotropic conductive film, placing a flexible substrate so that the position of the common electrode and the individual electrode overlaps the position of the conductive member and the piezoelectric element;
Heating a pressing member that presses the flexible substrate;
Pressing the flexible substrate in a state where the pressing member is heated;
And a step of separating the pressing member from the flexible substrate.

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