JP2009006539A - Liquid jet head unit and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jet head unit which can prevent poor bonding between a constituting member in which a through hole constituting a part of a liquid channel is formed and other constituting members, can prevent leakage of a liquid that flows in the liquid channel, and can prevent a part of an inner wall surface of the through hole of the constituting member from collapsing and mixing as a foreign substance with the ink, and to provide its manufacturing method. <P>SOLUTION: The through hole 231a constituting a part of the liquid channel has a channel forming member (head case constituting member 230a) formed of a metal blanked from one surface side towards the other surface side by press working. Corner parts 235 of opening edges of the through hole 231a formed to the one surface side and the other surface side of the channel forming member are defined by a shear surface formed to the inner wall surface of the through hole, and polishing surfaces 236 and 237 formed to the opening edge surfaces. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a liquid ejecting head unit that ejects liquid droplets, and more particularly to an ink jet recording head unit that ejects ink as a liquid and a method for manufacturing the same.

  Conventionally, there has been known a liquid ejecting head that ejects droplets from nozzle openings by applying pressure to the liquid by a pressure generating means such as a piezoelectric element, and a representative example thereof is an ink jet type that ejects ink droplets. A recording head. As such an ink jet recording head (unit), for example, a nozzle plate having a nozzle opening, a head case, and the like are joined to a flow path forming substrate in which a pressure generating chamber is formed to constitute a head main body. Some of these head members (head main bodies) are adhesively fixed to a fixing member (fixing plate) and covered with a head case (for example, see Patent Document 1). In such an ink jet recording head (unit), a liquid flow path connecting the nozzle opening and the ink cartridge is formed.

  Among the constituent members of such an ink jet recording head (unit), a through hole that is made of a metal material such as a head case and forms a part of the liquid flow path is formed by stamping. There is something that was done.

Japanese Patent Laying-Open No. 2005-096419

  However, by pressing a component member made of a metal material such as a head case, a through hole constituting a part of the liquid channel is formed by punching from one side of the channel forming member toward the other side. The inner wall surface of the through hole is not formed only by the shear surface. The opening on one side of the through hole has a sag that is plastically deformed toward the other side as it goes toward the center of the through hole, and the shear surface of the through hole. A fracture surface is formed on the inner wall surface on the other side.

  Then, an ink jet recording head (unit) having a liquid flow path as described above is configured by using a component having a through hole in which such a fracture surface is formed, and ink is supplied to the liquid flow path. When flowing, the ink flows while in contact with the fractured surface constituting a part of the inner wall surface of the through hole, so that part of the fractured surface may collapse and be mixed into the ink as a foreign substance. There was a problem.

  Similarly, the liquid flow path as described above is formed by adhering another component member via an adhesive or the like on one surface side of the component member having a through hole in which such sagging is formed. When an ink jet recording head (unit) is configured and ink is allowed to flow through the liquid flow path, a space is formed between the sagging of this constituent member and the other constituent members. There is a problem that leakage easily occurs from the road and a problem that adhesion failure between this component and other components tends to occur.

  Such a problem exists not only in an ink jet recording head that ejects ink, but of course in other liquid ejecting heads that eject ink other than ink.

  The present invention has been made in view of such circumstances, and can prevent adhesion failure between a component member in which a through-hole forming a part of a liquid channel is formed and another component member. Liquid ejecting head unit capable of preventing leakage of liquid flowing through liquid flow path, and preventing a part of inner wall surface of through hole of this component member from collapsing to be mixed into ink as foreign matter, and manufacturing method thereof The purpose is to provide.

  The present invention that solves the above-described problems is directed to applying pressure to the liquid in the pressure generating chamber provided in the middle of the liquid flow path that connects the nozzle opening and the storage means for storing the liquid by the pressure generating means. A liquid ejecting head unit that ejects droplets, wherein a metal flow path forming member in which a through-hole constituting a part of the liquid flow path is punched and formed from one side to the other side by pressing. A corner surface of the opening edge portion of the through hole formed on one side and the other surface side of the flow path forming member, a shear surface formed on the inner wall surface of the through hole, and the opening edge portion. The liquid ejecting head unit is defined by a polishing surface formed on a surface. In the present invention, since the inner wall surface of the through hole of the flow path forming member is constituted only by the shear surface, it is possible to prevent poor adhesion between the one surface of the flow path forming member and the other constituent member and The leakage of the liquid flowing through the flow path can be prevented, and a part of the inner wall surface of the through hole of the flow path forming member can be prevented from collapsing and entering the liquid as a foreign substance.

  Here, it is preferable that the inner wall surfaces of the through holes are all constituted by shear planes. According to this, a suitable liquid jet head having the above-described effects can be provided.

  The liquid ejecting head unit is fixed to the head main body for applying a pressure to the liquid in the pressure generating chamber communicating with the nozzle opening by pressure generating means to eject liquid droplets from the nozzle opening. A head case that is joined to a holding member to which the storage means is attached and in which a part of the liquid flow path for supplying the liquid stored in the storage means to the pressure generating chamber is formed. It is preferable that the path forming member is a constituent member constituting the head case. According to this, since the inner wall surface of the through hole of this component member is configured only by the shear surface, poor adhesion between this component member and other component members, the head body, or the holding member can be prevented. In addition, it is possible to prevent leakage of the liquid flowing through the liquid flow path, and to prevent a part of the inner wall surface of the through hole of this component member from collapsing and entering the liquid as a foreign substance. As a result, a suitable liquid jet head unit can be provided.

  In another aspect of the present invention, a pressure is applied to the liquid in the pressure generation chamber provided in the middle of the liquid flow path connecting the nozzle opening and the storage means for storing the liquid, and the liquid droplets are discharged from the nozzle opening. A method of manufacturing a liquid jet head unit for jetting a metal flow path forming member constituting the liquid jet head unit by pressing from one side to the other side thereof A primary step of punching and forming a machining hole penetrating the forming member; and a shear surface formed on an inner wall surface of the machining hole of the flow path forming member, and the opening of the machining hole is located on the one side The flow path forming member until there is no sagging formed by plastic deformation on the other surface side as it goes in the center direction of the processing hole and a fracture surface formed on the inner wall surface on the other surface side from the shear surface of the processing hole One of And in the method of manufacturing a liquid jet head unit, characterized by comprising a secondary processing step of polishing the other surface. In this aspect, since the inner wall surface of the through hole of the flow path forming member can be constituted only by the shear surface, it is possible to prevent poor adhesion between the one surface of the flow path forming member and the other constituent member and A liquid ejecting head unit capable of preventing leakage of the liquid flowing through the flow path and preventing a part of the inner wall surface of the through hole of the flow path forming member from collapsing and entering the ink as a foreign matter is manufactured. be able to.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
FIG. 1 is an exploded perspective view showing an ink jet recording head unit which is an example of a liquid ejecting head according to Embodiment 1 of the invention. As shown in the drawing, a cartridge case 210 which is a holding member constituting an ink jet recording head unit 1 (hereinafter also referred to as a head unit) which is an example of a liquid ejecting head unit of the present invention includes an ink supply unit (storage unit) (not shown). ) Are cartridge mounting portions 211 to which the respective ink cartridges are mounted. For example, in this embodiment, the ink cartridge is configured as a separate body filled with black and three color inks, and the ink cartridges of the respective colors are mounted in the cartridge case 210. Although not shown, the bottom surface of the cartridge case 210 is provided with a plurality of ink communication paths having one end opened to each cartridge mounting portion 211 and the other end opened to the head case side described later. In addition, an ink supply needle 213 that is inserted into the ink supply port of the ink cartridge is formed in the ink communication path in the ink communication path of the cartridge mounting portion 211 to remove bubbles and foreign matters in the ink. It is fixed via a filter (not shown).

  A plurality of ink jet recording heads 2 are fixed to the bottom surface side of such a cartridge case 210.

  A plurality of ink jet recording heads 2 are provided for each ink color of the ink cartridge. In this embodiment, one inkjet recording head unit 1 is provided with four inkjet recording heads 2.

  Here, the ink jet recording head 2 which is an example of the liquid jet head of the present embodiment will be described in detail. FIG. 2 is an exploded perspective view of the ink jet recording head, and FIG. 3 is a cross-sectional view of the ink jet recording head. As shown in FIGS. 2 and 3, the ink jet recording head 2 includes a head main body 220 and a head case 230 provided on the side opposite to the liquid ejecting surface A of the head main body 220.

  In this embodiment, the flow path forming substrate 10 constituting the head main body 220 is made of a silicon single crystal substrate, and an elastic film 50 made of silicon dioxide is formed on one surface thereof. The flow path forming substrate 10 is formed with two rows of pressure generating chambers 12 partitioned by a plurality of partition walls in a row along the width direction by anisotropic etching from the other side. Further, on the outer side in the longitudinal direction of the pressure generating chambers 12 in each row, there is communication with a reservoir unit 31 provided on a reservoir forming substrate 30 described later, and a communication composing a reservoir 100 serving as a common ink chamber for each pressure generating chamber 12. A portion 13 is formed. The communication portion 13 is in communication with one end portion in the longitudinal direction of each pressure generating chamber 12 via the ink supply path 14. That is, in the present embodiment, the pressure generation chamber 12, the communication portion 13, and the ink supply path 14 are provided as the flow paths formed on the flow path forming substrate 10. Therefore, in the ink jet recording head 2 of the present embodiment, the nozzle opening 21 and the ink cartridge are connected by the ink flow path including the pressure generating chamber 12, the communication portion 13, and the ink supply path 14 and the ink communication path described above. A liquid flow path is formed.

  Further, a nozzle plate 20 having a nozzle opening 21 communicating with the side opposite to the ink supply path 14 of each pressure generating chamber 12 on the opening surface side of the flow path forming substrate 10 is an adhesive, a heat-welded film, or the like. It is fixed through. In other words, in this embodiment, two nozzle rows 21 </ b> A in which the nozzle openings 21 are arranged in parallel are provided in one head main body 220. In the present embodiment, the surface of the nozzle plate 20 where the nozzle openings 21 are opened is the liquid ejection surface A.

  Examples of such a nozzle plate 20 include a metal substrate such as a silicon substrate and stainless steel (SUS).

  On the other hand, as shown in FIG. 3, on the side opposite to the opening surface of the flow path forming substrate 10, on the elastic film 50, a lower electrode film made of metal and a piezoelectric made of lead zirconate titanate (PZT) or the like. A piezoelectric element 300 formed by sequentially laminating a body layer and an upper electrode film made of metal is formed. On the flow path forming substrate 10 on which such a piezoelectric element 300 is formed, a reservoir forming substrate 30 having a reservoir portion 31 that constitutes at least a part of the reservoir 100 is joined. In this embodiment, the reservoir portion 31 is formed across the reservoir forming substrate 30 in the thickness direction and across the width direction of the pressure generating chamber 12, and as described above, the communication portion of the flow path forming substrate 10 is formed. The reservoir 100 is connected to the pressure generation chamber 12 and serves as a common ink chamber for the pressure generation chambers 12.

  A piezoelectric element holding portion 32 having a space that does not hinder the movement of the piezoelectric element 300 is provided in a region facing the piezoelectric element 300 of the reservoir forming substrate 30.

  Furthermore, a drive IC 110 for driving each piezoelectric element 300 is provided on the reservoir forming substrate 30. Each terminal of the drive IC 110 is connected to a lead wiring drawn from the individual electrode of each piezoelectric element 300 via a bonding wire or the like (not shown). Each terminal of the drive IC 110 is connected to the outside via an external wiring 111 such as a flexible printed circuit (FPC), and receives various signals such as a print signal from the outside via the external wiring 111. .

  In addition, the compliance substrate 40 is bonded onto the reservoir forming substrate 30. An ink inlet 44 for supplying ink to the reservoir 100 is formed in a region facing the reservoir 100 of the compliance substrate 40 by penetrating in the thickness direction. In addition, the region of the compliance substrate 40 other than the ink introduction port 44 in the region facing the reservoir 100 is a flexible portion 43 formed thin in the thickness direction, and the reservoir 100 is sealed by the flexible portion 43. Has been. Compliance is given to the reservoir 100 by the flexible portion 43.

  A head case 230 is fixed on the surface of each head body 220 opposite to the liquid ejection surface A, that is, on the compliance substrate 40.

  The head case 230 is made of metal, and is formed by sequentially joining a first head case constituent member 230a, a second head case constituent member 230b, and a third head case constituent member 230c each having a thickness of about 1 mm. Yes. The liquid ejection surface A side surface (one surface) and the surface opposite to the liquid ejection surface A (other surface) of these head case constituent members 230a to 230c are both constituted by a polished surface. Further, through holes 231a to 231c penetrating in the thickness direction are formed in the head case constituent members 230a to 230c, respectively, and the ink supply communication passage 231 is formed when the head case constituent members 230a to 230c are joined. Configure. And the inner wall surface of these through-holes 231a-231c is comprised only by the shear surface formed when stamping and forming each through-hole 231a-231c by press work. Therefore, the corners of the opening edge portions of the through holes 231a to 231c on the one surface side and the other surface side of the head case constituent members 230a to 230c are sheared surfaces formed on the inner wall surfaces of the through holes 231a to 231c, respectively. These are defined by the polished surfaces formed on the surfaces of the opening edges.

  By configuring the head case 230 using the head case constituent members 230a to 230c configured as described above, poor adhesion between the head case constituent members 230a to 230c, the head case constituent member 230a and the head main body 220 can be prevented. Adhesion failure and adhesion failure between the head case constituent member 230c and the cartridge case 210 can be prevented, and leakage of ink flowing through the ink supply communication path 231 can be prevented, and one of the inner wall surfaces of the through holes 231a to 231c can be prevented. It is possible to prevent the portion from collapsing and mixing into the ink as foreign matter. As a result, the reliability of the ink jet recording head unit 1 can be improved.

  Further, in the head case 230, a concave portion 232 is formed in a region facing the flexible portion 43 of the compliance substrate 40, so that the flexible portion 43 is appropriately deformed. The head case 230 is provided with a drive IC holding part 233 penetrating in the thickness direction in a region facing the drive IC 110 provided on the reservoir forming substrate 30, and the external wiring 111 is connected to the drive IC holding part. The drive IC 110 is connected through the H.233.

  The ink jet recording head 2 according to this embodiment takes in ink from the ink cartridge from the ink introduction port 44 via the ink communication path and the ink supply communication path 231, and the inside from the reservoir 100 to the nozzle opening 21. After filling with ink, according to a recording signal from the drive IC 110, a voltage is applied to each piezoelectric element 300 corresponding to the pressure generating chamber 12 to bend and deform the elastic film 50 and the piezoelectric element 300, whereby each pressure generating chamber. The pressure inside the nozzle 12 increases and ink droplets are ejected from the nozzle openings 21.

  Next, a manufacturing method of the ink jet recording head unit 1 of this embodiment will be described. The head case constituent members 230a to 230c are the same as the conventional method for manufacturing the ink jet recording head unit, and the head case constituent members 230a to 230c can be manufactured in the same manner. Below, only the manufacturing method of the head case structural member 230a is demonstrated.

  First, as shown in FIG. 4A, a head case constituting member 230a is formed between a cylindrical punch 510 and a die plate 520 having a cylindrical through portion 521 having a diameter larger than the diameter of the punch 510. A plate-like member 400 is placed. Here, it is preferable that the difference between the diameter of the punch 510 and the diameter of the penetrating portion 521 is small. By reducing this difference, the surface area of the fractured surface portion described later can be reduced, and as a result, the secondary processing step described later can be shortened.

  Thereafter, press working is performed to punch out and form a processing hole 410 that becomes a through hole 231a from the upper side (one side) of the plate-like member 400 toward the lower side (the other side) (primary processing step). As a result, as shown in FIG. 4B, the plate-like member 400 has a shear surface portion 412 in which the inner wall surface of the processing hole 410 is formed of a shear surface, and is positioned on one side of the shear surface portion 412. In addition, a sagging portion 411 formed by plastic deformation as the opening portion of the processing hole 410 moves toward the center of the processing hole 410, and a fracture surface portion formed on the inner wall surface on the other side of the shearing surface portion 412 of the processing hole 410. 413 is formed.

  Next, the one-side surface 406 and the other-side surface 407 of the plate-like member 400 are uniformly polished (polished) until the sagging portion 411 and the fracture surface portion 413 disappear, thereby forming the head case constituent member 230a (2). Next processing step). In addition, when polishing the one surface side surface 406 and the other surface side surface 407 of the plate-like member 400, after polishing one of the surfaces, the remaining surface may be polished first, or both surfaces may be polished simultaneously. May be.

  As a result, as shown in FIG. 5, the corners 235 of the opening edge on one side and the other side of the through hole 231a of the head case constituent member 230a are sheared surfaces formed on the inner wall surface of the through hole 231a. , And the polishing surfaces 236 and 237 formed on the surface of the opening edge.

  Then, the head case 230 in which the ink supply communication path 231 is formed can be manufactured by bonding the head case constituent members 230a to 230c manufactured in this way through an adhesive or the like. In addition, the method of joining each head case structural member is not specifically limited, For example, you may join each head case structural member 230a-230c, respectively using anodic bonding.

  By producing the head case 230 using such head case constituent members 230a to 230c, the inner wall surface of the ink supply communication path 231 can be configured only by a shear surface, and thus each head case constituent member 230a to 230c. In addition, it is possible to prevent poor adhesion between the head case constituent member 230a and the head main body 220 and poor adhesion between the head case constituent member 230c and the cartridge case 210, and leakage of ink flowing through the ink supply communication path 231. And an ink jet recording head unit that can prevent a part of the inner wall surface of each of the through holes 231a to 231c from collapsing and being mixed into the ink as a foreign substance can be manufactured. As a result, the ink jet recording head unit 1 with improved reliability can be provided.

  On the other hand, as shown in FIG. 4B, a sag portion and a fracture surface portion are formed in the head case constituent member in which the processing hole is simply punched and formed by press working, as shown in FIG. Therefore, a head case is produced using a head case constituent member having such a fractured surface portion to form an ink jet recording head unit in which a liquid channel as described above is formed, and ink is supplied to the liquid channel. In such a case, the ink flows while coming into contact with the fracture surface that forms the inner wall surface of the primary hole, which may cause a problem that a part of the fracture surface collapses and enters the ink as foreign matter. There is sex. Similarly, on one side of the head case constituent member having such a sag portion, another constituent member is joined to form an ink jet recording head unit in which the liquid flow path as described above is formed, When ink is caused to flow through the liquid flow path, a space is formed between the sag portion of the head unit constituent member and other head case constituent members, so that the ink easily leaks from the liquid flow path. There is a possibility that such a problem that the adhesive failure between the head case constituent member and another head case constituent member is likely to occur. However, such a problem does not occur in the head case 230 according to the present embodiment.

(Other embodiments)
As mentioned above, although Embodiment 1 of this invention was demonstrated, the basic composition of this invention is not limited to what was mentioned above. For example, in the first embodiment described above, the flow path forming member has a through hole that constitutes a part of the liquid flow path, and the opening of the through hole formed on one side and the other side of the flow path forming member. The corner of the edge is defined by a shear surface formed on the inner wall surface of the through hole on one side and the other side of the flow path forming member, and a polished surface formed on the surface of the opening edge. As an example, the head case constituent members 230a to 230c are illustrated. However, the present invention is applied to a liquid channel substrate, a reservoir substrate, a compliance substrate, or the like in which a through hole constituting a part of the liquid channel is formed. Also good.

  In the first embodiment, the head case 230 is composed of the three head case constituent members 230a to 230c, but it goes without saying that the head case 230 may be composed of one head case constituent member.

  Furthermore, in the first embodiment described above, the ink jet recording head 2 having the flexural vibration type piezoelectric element 300 is exemplified, but the present invention is not limited to this. For example, the piezoelectric material and the electrode forming material are alternately stacked to form the shaft. Application to head units having ink jet recording heads of various structures, such as longitudinal vibration type ink jet recording heads that expand and contract in the direction and ink jet recording heads that eject ink droplets by bubbles generated by heat generation from heating elements, etc. Needless to say, you can.

  Note that the head unit having an ink jet recording head that discharges ink as a liquid ejecting head has been described as an example, but the present invention is intended for a method of manufacturing a liquid ejecting head unit having a liquid ejecting head widely. Examples of the liquid ejecting head include a recording head used for an image recording apparatus such as a printer, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an organic EL display, and an electrode formation such as an FED (field emission display). Electrode material ejecting heads used in manufacturing, bioorganic matter ejecting heads used in biochip production, and the like.

FIG. 3 is an exploded perspective view of the head unit according to the first embodiment. FIG. 3 is an exploded perspective view of the recording head according to the first embodiment. FIG. 3 is a cross-sectional view of the recording head according to the first embodiment. FIG. 5 is a cross-sectional view illustrating the method for manufacturing the head case constituent member according to the first embodiment. FIG. 3 is a cross-sectional view of a head unit constituent member according to the first embodiment.

Explanation of symbols

  A liquid ejecting surface, 1 ink jet recording head unit (liquid ejecting head unit), 2 ink jet recording head (liquid ejecting head), 10 flow path forming substrate, 12 pressure generating chamber, 13 communicating portion, 21 nozzle opening, 30 reservoir Forming substrate, 40 compliance substrate, 210 cartridge case, 220 head body, 230 head case, 235 corner, 236, 237 polished surface, 240 cover head, 250 fixing plate, 400 plate member, 406 one side of plate member Surface, 407 plate-side member, surface on the other side, 410 processing hole, 411 sag portion, 412 shear surface portion, 413 fracture surface portion

Claims (4)

  A liquid ejecting head unit that applies pressure to the liquid in the pressure generating chamber provided in the middle of the liquid flow path that connects the nozzle opening and the storage unit that stores the liquid, and ejects liquid droplets from the nozzle opening. A through-hole constituting a part of the liquid flow path has a metal flow path forming member formed by stamping from one side to the other side by pressing, and the flow path forming member The corners of the opening edge of the through hole formed on the one surface side and the other surface side are a shear surface formed on the inner wall surface of the through hole and a polished surface formed on the surface of the opening edge. A liquid jet head unit characterized by being defined. The liquid ejecting head unit according to claim 1, wherein an inner wall surface of the through-hole is configured by a shear surface.   The liquid ejecting head unit is configured to apply a pressure to the liquid in a pressure generating chamber communicating with the nozzle opening by pressure generating means to eject liquid droplets from the nozzle opening, and is fixed to the head main body and the reservoir A head case in which a part of the liquid flow path for supplying the liquid stored in the storage means to the pressure generating chamber is joined to a holding member to which the means is attached, The liquid ejecting head unit according to claim 1, wherein the member is a constituent member constituting the head case.   The liquid ejecting head unit ejects liquid droplets from the nozzle opening by applying pressure to the liquid in the pressure generating chamber provided in the middle of the liquid flow path connecting the nozzle opening and the storing means for storing the liquid. In the manufacturing method, a metal flow path forming member constituting the liquid jet head unit is pressed from one surface side to the other surface side, thereby forming a processing hole penetrating the flow path forming member. The primary process of punching and the shearing surface formed on the inner wall surface of the processing hole of the flow path forming member is positioned on one side, and the opening of the processing hole is directed toward the center of the processing hole. Polish one surface and the other surface of the flow path forming member until the sagging formed by plastic deformation on the other surface side and the fracture surface formed on the inner wall surface on the other surface side from the shear surface of the processed hole disappear. You The method of manufacturing a liquid jet head unit, characterized by comprising a secondary processing step.

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