JP2006035453A - Manufacturing method for inkjet head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simply and inexpensively lead out a connection wiring line to a rear face of a head chip by penetration forming the connection wiring line which conducts to a driving electrode in each ink channel. <P>SOLUTION: In a manufacturing process of the head chip of an inkjet head which applies a voltage to each driving electrode via the connection wiring line, driving walls consisting of piezoelectric elements and the ink channels are alternately arranged in parallel, the driving electrodes are formed in the ink channels, a cover member is bonded to an upper part of the ink channels, and the connection wiring line which conducts to each driving electrode is formed penetrating to be led out from bottom parts in the ink channels to an outer face of the head chip. The manufacturing process includes a process of forming many through-holes to a photosensitive glass substrate through an exposure process and an etching process, a process of filling a conductive substance in the through-holes, a process of bonding a piezoelectric element substrate subjected to polarization processing to a surface of the photosensitive glass substrate and of forming the ink channels at positions corresponding to the through holes from the side of the piezoelectric element substrate up to a depth where the conductive substance in the through-holes is exposed to the bottom parts of the ink channels, a process of forming the driving electrodes which conduct to the conductive substance in the ink channels, and a process of bonding the cover member to cover the upper part of the ink channels. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an ink jet head, and more particularly, to a method for manufacturing an ink jet head in which an electrode can be easily taken out from a drive electrode in each ink channel portion.

  Ink channels in the ink channel are ejected from the nozzles by alternately arranging drive walls made of piezoelectric elements and ink channels and applying a voltage to the drive electrodes formed on the drive walls to shear the drive walls. In the share mode type ink jet head configured as described above, a connection wiring for electrically connecting the drive electrode and the drive circuit can be drawn from the ink channel to the outer surface of the head chip, and an FPC (flexible printed circuit board) or the like can be joined. Need to be formed.

  Conventionally, in Patent Document 1, a large number of ink channels straight to the piezoelectric element substrate are formed by grooving in parallel, and then a plating catalyst is adsorbed to form a thin plating as a whole by electroless plating. After removing the plating film attached to unnecessary portions between the ink channels over the entire surface of the head chip with a laser, the connection wiring that is electrically connected to each drive electrode is routed over the entire surface of the head chip by plating again. A technique for forming the above is disclosed. However, in this case, the connection wiring that is electrically connected to the drive electrode is formed so as to be three-dimensionally routed from the ink channel through the front surface and the rear surface of the head chip to the back surface of the head chip. When passing through the corner portion of the head chip, it is easy to cause disconnection at the corner portion, leaving a problem in the reliability of conduction.

  For this reason, Patent Document 2 proposes a technique of penetrating and forming a connection wiring that is electrically connected to the drive electrode from the bottom of each ink channel to the back surface of the head chip. This is because a tape-shaped photosensitive sheet is formed by exposing and developing through-holes in the form of spots, and a conductive paste containing fine metal particles serving as wiring is embedded in the through-holes by screen printing, and then a large number of sheets are formed. Each of the photosensitive sheets is aligned with each through-hole, laminated in multiple layers, and fired under pressure to form a base substrate, and a piezoelectric element substrate is bonded onto the substrate, and the inside of the through-hole After forming the ink channel by grooving to a depth that exposes the conductive paste, the drive electrode is formed in each ink channel, and the drive electrode and the conductive paste in each through hole are made conductive. Thus, the connection wiring that is electrically connected to each drive electrode is drawn to the back surface of the head chip. According to this, since the connection wiring can be drawn out almost linearly from the drive electrode in each ink channel to the back surface of the head chip, and there is no need to route it through the corner of the head chip. The problem seen in is solved.

Further, Patent Document 3 discloses that a through hole is provided in the bottom of the ink channel, and a conductive material is filled therein to lead out a connection wiring that is electrically connected to the drive electrode in the ink channel to the outside. Yes.
JP 2002-264342 A JP 2001-328268 A JP-A-10-76669

  In the case of the technique described in Patent Document 2, in order to produce a base substrate, a large number of photosensitive sheets must be laminated so that the substrate has a predetermined thickness. When laminating the sheets, it is necessary to align the through holes with high accuracy in order to ensure conduction to the back surface of the head chip. In addition, since the substrate is formed by baking after laminating a large number of photosensitive sheets, a dimensional shift or the like due to thermal shrinkage occurs during the baking, and a positional shift from the ink channel formed at a predetermined pitch is likely to occur. It is also difficult to correct this misalignment, leaving a practical problem.

  Also, in the technique described in Patent Document 3, since the through holes are formed in the state of the green sheet before firing the ceramics, even if accurate hole formation is performed, the holes expand and contract severely when fired at a high temperature. Therefore, it is difficult to form a through hole having a diameter of several tens of μm with an accuracy of several μm so as to match each ink channel.

  In addition, attempts have been made to process such through holes on a substrate such as ceramics using a drill or a laser. However, a large number of fine through holes must be processed at a fine pitch of each ink channel. Therefore, there is a problem that processing costs increase.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing an ink jet head that can easily and inexpensively penetrate and draw out a wiring that is electrically connected to a drive electrode in each ink channel to the back surface of the head chip.

  Other problems of the present invention will become apparent from the following description.

  The above problems are solved by the following inventions.

  According to the first aspect of the present invention, drive walls made of piezoelectric elements and ink channels are alternately arranged side by side, drive electrodes are formed in the ink channels, and a cover member is bonded so as to close the ink channels. A connection wire that is electrically connected to each drive electrode of the head chip is formed by being drawn out from the bottom of the ink channel to the outer surface of the head chip, and is connected to each other via the connection wire. A method of manufacturing an ink-jet head that shears and deforms the driving wall by applying a voltage to the driving electrode and discharges ink in the ink channel from a nozzle, wherein the head chip manufacturing step is performed on a photosensitive glass substrate. A step of forming a large number of through holes through an exposure step and an etching step, a step of filling a conductive material in the through holes, and a photosensitive step Bonding the polarized piezoelectric element substrate to the surface of the glass substrate, and connecting the ink channel to the position corresponding to the through hole from the piezoelectric element substrate side, the conductive substance in the through hole is at the bottom of the ink channel Forming an exposed depth, forming a drive electrode in conduction with the conductive material in the ink channel, and bonding a cover member so as to cover the ink channel. This is a method for manufacturing an inkjet head.

  According to a second aspect of the present invention, after the step of bonding the cover member, there is a step of cutting along a direction substantially orthogonal to the length direction of the ink channel so that each ink channel has a predetermined driving length. The method of manufacturing an ink jet head according to claim 1.

  According to a third aspect of the present invention, a connection electrode that is electrically connected to the conductive material filled in the through hole is bonded to the surface of the photosensitive glass substrate opposite to the surface to which the piezoelectric element substrate is bonded. 3. The method of manufacturing an ink jet head according to claim 1, further comprising a step of forming before or after.

  According to a fourth aspect of the present invention, in the method for manufacturing an ink jet head according to the first, second, or third aspect, the adhesive between the photosensitive glass substrate and the piezoelectric element substrate is performed by curing the adhesive at room temperature. is there.

  The invention according to claim 5 is characterized in that the piezoelectric element substrate is formed by bonding two piezoelectric element substrates having different polarization directions to each other. It is a manufacturing method.

  According to the first aspect of the present invention, the photosensitive glass substrate is subjected to the exposure process and the etching process to form a large number of through holes, and the connection wiring drawn out from each ink channel is formed by the through holes. The connection wiring that is electrically connected to the drive electrode in the channel can be easily and inexpensively drawn to the back surface of the head chip. In addition, since the photosensitive glass substrate can be made to have a desired thickness, it is not necessary to stack a large number of sheets as in the prior art, and there is no need for troublesome work steps such as aligning the through holes with high accuracy. It becomes.

  According to the second aspect of the present invention, a large number of head chips can be produced at one time from a single long substrate, which is excellent in mass productivity and improved production efficiency.

  According to the invention described in claim 3, it is possible to manufacture a head chip having good electrical connectivity with an FPC or the like.

  According to the fourth aspect of the present invention, since heating is not performed at the time of bonding, there is no warpage of the substrate due to the difference in thermal expansion coefficient between the photosensitive glass substrate and the piezoelectric element substrate, and there is little variation in ink ejection characteristics. An inkjet head can be obtained.

  According to the fifth aspect of the present invention, since the drive electrode in the ink channel is formed on the entire side surface of the drive wall, it is easy to ensure conduction with the conductive substance in the through hole at the bottom of the ink channel. Can do. In addition, since the entire drive wall is efficiently sheared and deformed with a large amount of deformation, a high pressure can be applied to the ink in the ink channel, and ink landing deviation can be suppressed and image quality can be improved.

  Embodiments of an ink jet head manufacturing method according to the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is an exploded perspective view showing an example of an inkjet head.

  In this ink jet head, reference numeral 1 denotes a head chip that functions as an actuator for ejecting ink droplets, an ink channel substrate 10 in which drive walls 11 made of piezoelectric elements and ink channels 12 are alternately arranged, and this ink. A cover substrate 14 is bonded to the upper portion of each drive wall 11 of the channel substrate 10 so as to close the upper side of the ink channel 12. In the illustrated example, six drive walls 11 and five ink channels 12 are formed, but the number is not limited. The shape of the illustrated ink channel 12 is such that both side walls are oriented vertically and are parallel to each other. Further, it is a straight type in which the size and shape are not substantially changed in the length direction from the inlet (back side in FIG. 1) to the outlet (front side in FIG. 1) of the ink channel 12. As a result, the head chip 1 becomes a so-called harmonica type, and an ink-jet head having good bubble removal, high power efficiency, little heat generation, and good high-speed response can be constituted by a straight ink channel structure.

  A drive electrode 13 is formed in each ink channel 12 of the head chip 1, and a connection wiring 15 conducting to the drive electrode 13 is drawn from the bottom to the lower surface, and a connection electrode 16 is formed on the lower surface.

  Reference numeral 2 denotes a nozzle plate attached to the front surface of the head chip 1, and nozzles 21 are formed at positions corresponding to the respective ink channels 12.

  Reference numeral 3 denotes an FPC attached to the lower surface of the head chip 1, and the same number of wirings 31 as the connection electrodes 16 formed on the lower surface of the head chip 1 are formed in parallel.

  Reference numeral 4 denotes a flow path regulating plate attached to the rear surface of the head chip 1, and an ink circulation port 41 is formed at a position corresponding to each ink channel 12.

  Reference numeral 5 denotes a manifold provided further on the rear surface of the flow path regulating plate 4. An ink supply chamber 51 in which ink is stored is formed, and the ink in the ink supply chamber 51 flows through the ink in the flow path regulating plate 4. The ink channel 12 flows through the mouth 41. Reference numeral 52 denotes an ink inlet for allowing ink to flow into the ink supply chamber 51.

  In this specification, the “front surface” refers to the surface on the side where ink droplets are ejected, and the “rear surface” refers to the surface on the opposite side. Further, “upper surface” and “lower surface” refer to upper and lower outer surfaces that are located with ink channels arranged in parallel.

  Next, the manufacturing process of the head chip 1 will be described.

  First, as shown in FIG. 2A, a photosensitive glass substrate 101 having a desired thickness is prepared as a base substrate.

Here, the photosensitive glass substrate 101 is a substrate made of a photosensitive glass containing a photosensitive metal component such as Ag, Au, or Cu and Ce (Ce oxide) as a sensitizer. When exposure is performed by irradiating the photosensitive glass substrate 101 with ultraviolet rays, the photosensitive metal component in the exposed portion changes to metal atoms. That is,
Ce ³⁺ → Ce ⁴⁺ + e ⁻
When a photoelectron reaction occurs and a part of the photoelectrons emitted from the Ce ³⁺ ions are captured by the photosensitive ions Me ⁺ ,
Me ⁺ + e ⁻ → Me
This happens.

After this reaction, the metal atoms Me are gathered by applying heat treatment to produce a metal colloid. And this metal colloid becomes a crystal nucleus and precipitates a crystal phase partially. The crystallized portion and other glass portions have different dissolution rates in the etching solution, and the crystallized portion dissolves quickly. In addition, since the place where the first Ce ³⁺ ion photoelectron reaction occurs can be controlled, a highly accurate through hole can be formed by selectively exposing the upper surface of the photosensitive glass substrate 101 using the photomask 200. It is.

  The photomask 200 is provided with openings 201 for forming through holes at the same pitch as the ink channels 12 of the head chip 1 to be manufactured. The photomask 200 can be used without particular limitation as long as selective exposure is possible. For example, a light-shielding film such as a chromium film that does not substantially transmit ultraviolet light to a transparent glass thin plate and having a pattern formed with the openings 201 remaining can be used.

  After the photomask 200 is placed on the upper surface of the photosensitive glass substrate 101, ultraviolet rays are irradiated as shown in FIG. The ultraviolet light is irradiated to the photosensitive glass substrate 101 only through the opening 201 of the photomask 200. Therefore, the photosensitive glass substrate 101 is provided with the crystallized portion 101a along the thickness direction of the photosensitive glass substrate 101 only in the portion corresponding to the opening 201 as shown in FIG. It is formed.

  Next, the photosensitive glass substrate 101 that has been subjected to the exposure process is heat-treated. This heat treatment is a process for changing metal atoms generated by exposure in the photosensitive glass substrate 101 into a metal colloid, and is different from the conventional baking for forming a substrate. Therefore, it is sufficient and preferable that this heat treatment is performed at a temperature between the transition point and the yield point of the glass used for the photosensitive glass substrate 101. If the temperature is lower than the transition point, the effect of the heat treatment cannot be sufficiently obtained, and if the temperature is higher than the yield point, shrinkage due to heat may occur and the dimensional accuracy may be affected. In general, the temperature is preferably set to 450 ° C to 600 ° C. The heat treatment time is preferably about 30 minutes to 5 hours.

  Next, the photosensitive glass substrate 101 thus heat-treated is immersed in an etching solution, and only the exposed crystallized portion 101a is etched. As the etching solution, a hydrofluoric acid aqueous solution such as dilute hydrofluoric acid can be suitably used. By this etching process, as shown in FIG. 2D, only the crystallized portion 101a is selectively dissolved and removed from the photosensitive glass substrate 101 to form the through hole 101b. By using such a photosensitive glass substrate 101 as a base substrate and selectively forming through holes 101b by exposure, heat treatment and etching as described above, a large number of through holes 101b can be formed simultaneously. Thus, the processing time of the through hole 101b can be shortened, the processing can be facilitated, and the processing cost can be reduced.

  The size (hole diameter) of the through-hole 101b is preferably equal to or smaller than the width of the ink channel 12 formed in a later step. When the width of the ink channel 12 is 35 to 90 μm, the size is about 30 to 40 μm. It is preferable.

  Thus, after forming the through-hole 101b corresponding to each ink channel 12 in the photosensitive glass substrate 101, as shown in FIG.2 (e), each through-hole 101b is filled with the electroconductive substance 101c. As the conductive substance 101c, a conductive paste containing metal fine particles is filled by an appropriate means such as screen printing. As a result, the conductive substance 101 c is filled in the thickness direction of the photosensitive glass substrate 101 and exposed on the upper surface and the lower surface of the photosensitive glass substrate 101.

  In addition, the through hole 101b can be filled with a conductive substance (plating metal) 101c by plating, in addition to filling with a conductive paste. As this plating treatment, an electroless plating treatment can be used. When plating metal is deposited in the through-hole 101b by performing electroless plating, the deposited plating metal eventually fills the through-hole 101b, and the through-hole 101b is filled with the plating metal as the conductive substance 101c. Can be made. A portion that does not require plating metal deposition during the electroless plating process may be appropriately masked or removed by polishing after the plating process.

  The length of the photosensitive glass substrate 101 can be the same as the length of the ink channel 12 (the length along the ink discharge direction) of the head chip 1 to be manufactured, as shown in FIG. It is preferable to make the substrate sufficiently longer than the length of the ink channel 12 of the head chip 1. In this case, the through holes 101b filled with the conductive material 101c are preferably formed so that a large number of rows corresponding to the number of the ink channels 12 arranged in parallel are arranged along the length direction. Although details will be described later, a large number of head chips 1 can be produced from one substrate. Here, the case where this elongate photosensitive glass substrate 101 is produced is demonstrated.

  After producing the photosensitive glass substrate 101 in which each through hole 101b is filled with the conductive substance 101c, as shown in FIG. 4, the wiring 31 of the FPC 3 is electrically connected to the lower surface of the photosensitive glass substrate 101. The connection electrode 16 for performing is formed. The connection electrode 16 is electrically connected to the conductive material 101c in each through hole 101b arranged in parallel at the same pitch as the ink channel 12 to be manufactured later on the photosensitive glass substrate 101, and the length of the photosensitive glass substrate 101 is increased. It is formed in parallel with the same pitch as the through holes 101b along the length direction (length direction along the ink discharge direction). Here, each connection electrode 16 is electrically connected to a conductive substance 101c in a plurality of through holes 101b having the same pitch as each ink channel 12 arranged along the length direction of the photosensitive glass substrate 101. ing.

  The connection electrode 16 can be formed by selectively forming a metal film using vapor deposition, sputtering, plating, or the like. In order to selectively form the metal film, a mask or a resist (not shown) having an opening serving as the connection electrode 16 is attached to the lower surface of the photosensitive glass substrate 101, and the metal film is formed only on the opening. You can do so. By forming the connection electrode 16 in this manner, the head chip 1 having good electrical connectivity with the FPC 3 can be manufactured.

  Subsequently, as shown in FIG. 5, a piezoelectric element substrate is bonded and laminated on the upper surface of the photosensitive glass substrate 101, that is, the surface opposite to the surface on which the connection electrodes 16 are formed. Here, two piezoelectric element substrates 102 and 103 are laminated. As a piezoelectric element material used for each of the piezoelectric element substrates 102 and 103, a known piezoelectric material that is deformed by applying a voltage can be used, but lead zirconate titanate (PZT) is particularly preferable.

  The two piezoelectric element substrates 102 and 103 are laminated with their polarization directions (indicated by arrows) opposite to each other, and are bonded to the photosensitive glass substrate 101 using an adhesive. As a result, the entire drive wall 11 formed by the piezoelectric element substrates 102 and 103 is efficiently deformed by shearing with a large amount of deformation, so that a high pressure can be applied to the ink in the ink channel 12, and ink landing The image quality can be improved while suppressing the deviation.

  When bonding the two piezoelectric element substrates 102 and 103 and the photosensitive glass substrate 101, it is possible to bond the three substrates simultaneously by applying an adhesive between the three substrates. In general, since the piezoelectric element substrates 102 and 103 are thin and have care in handling, first, one piezoelectric element substrate 103 is bonded and laminated on the photosensitive glass substrate 101, and then on the laminated body (on the piezoelectric element substrate 103). Preferably, the remaining piezoelectric element substrate 102 is bonded to the above.

  The substrates 101 to 103 are preferably bonded to each other by curing the applied adhesive at room temperature. This is because the adhesion between the piezoelectric element substrates 102 and 103 is the same substance, so there is no difference in characteristics between the substances. However, the piezoelectric element substrates 102 and 103 and the photosensitive glass substrate 101 are different substances. This is because when the materials are heated, warpage and distortion may occur in the laminated body after the adhesive is cured due to a difference in thermal expansion coefficient.

  As the adhesive used in this case, a room temperature curable adhesive can be used. Particularly for this purpose, epoxy-based room temperature curable adhesives such as Ablebond 342-3 and 342-13ACC manufactured by ABLESTIK are suitable. Further, the thermosetting adhesive can be cured at room temperature without heating the adhesive by setting the curing process for a relatively long time. Therefore, this may be used to cure the thermosetting adhesive at room temperature without heating. As the thermosetting adhesive, Epochec 353ND manufactured by Epoxy Technology is suitable.

  In this way, the adhesive is cured at room temperature when the two piezoelectric element substrates 102 and 103 and the photosensitive glass substrate 101 are bonded, thereby suppressing the occurrence of warpage and distortion due to the difference in thermal expansion coefficient. Ink jet heads with little variation in emission characteristics can be obtained.

  Further, as another method for bonding the two piezoelectric element substrates 102 and 103 and the photosensitive glass substrate 101, the two piezoelectric element substrates 102 and 103 are bonded together to form a laminate, The laminated body can be bonded to the photosensitive glass substrate 101. In this case, since the bonding between the piezoelectric element substrates 102 and 103 is the bonding between the same substances, there is no difference in characteristics between the substances, and an epoxy-based thermosetting adhesive is used to perform strong bonding. It becomes possible to heat-bond, but after that, when the laminate of the piezoelectric element substrates 102 and 103 and the photosensitive glass substrate 101 are bonded to each other, different materials are bonded to each other. It is preferable to cure the adhesive at room temperature from the viewpoint of preventing occurrence of distortion. As described above, this adhesive can be cured at room temperature without heating a room temperature curable adhesive or a thermosetting adhesive.

  After the photosensitive glass substrate 101 and the two piezoelectric element substrates 102 and 103 are bonded in this manner, a resist 300 is laminated on the upper surface of the piezoelectric element substrate 102. This resist 300 is for selectively forming a metal film to be the drive electrode 13 in each ink channel 12 in a later step.

  Next, as shown in FIG. 6, the groove-shaped ink channel 12 is ground from the front surface to the rear surface of the piezoelectric element substrates 102 and 103 from the side where the resist 300 is laminated using a dicing blade or the like. . The grinding of the ink channel 12 is performed along the length direction of the photosensitive glass substrate 101 so as to correspond to the through holes 101b arranged in parallel to the photosensitive glass substrate 101 so as to have the same pitch as the ink channel 12. They are arranged in parallel. Thereby, the ink channel 12 and the drive wall 11 left uncut are alternately formed. Each ink channel 12 includes a plurality of through-holes 101b along its length. Each side wall of each ink channel 12 faces in the vertical direction, and the size and shape (cross-sectional shape) in the length direction from the inlet (back side in FIG. 6) to the outlet (front side in FIG. 6) of the ink channel 12 It is formed in a straight shape that is almost unchanged.

  In addition, each ink channel 12 has a conductive surface filled in the through hole 101b of the photosensitive glass substrate 101 by slightly grinding the surface of the photosensitive glass substrate 101 from the piezoelectric element substrate 102 side through the piezoelectric element substrate 103. Grinding is performed to such a depth that the upper end 101 d of the substance 101 c is exposed at the bottom of each ink channel 12.

  After forming a large number of ink channels 12 in this way, drive electrodes 13 are formed in each ink channel 12. Examples of the method of forming the drive electrode 13 include a method using a vacuum apparatus such as a vapor deposition method, a sputtering method, a plating method, and a CVD (chemical vapor reaction method). Was performed by forming a metal film. Thereafter, when the resist 300 is removed, the drive electrode 13 is formed across both side walls and the bottom surface in the ink channel 12 as shown in FIG. At this time, since the upper end 101d of the conductive material 101c filled in the through hole 101b is exposed at the bottom of each ink channel 12, the drive electrode 13 and the conductive material 101c in the through hole 101b are , The upper end 101d conducts.

  In this embodiment, since the drive wall 11 is formed by the piezoelectric element substrates 102 and 103 having different polarization directions, the drive electrode 13 is formed on the entire side surface in order to shear the entire drive wall 11. Therefore, by forming a metal film on the bottom of the ink channel 12, it is possible to easily ensure conduction with the conductive material 101c in the through hole 101b.

  Thus, the conductive substance 101 c in each through hole 101 b functions as a connection wiring 15 for drawing out the drive electrode 13 in each ink channel 12 to the lower surface of the ink channel substrate 10. The connection wiring 15 made of the conductive material 101c partially exposes the photosensitive glass substrate 101 to form a through hole 101b, and is drawn out from each ink channel 12 by the through hole 101b. The connection wiring 15 that is electrically connected to the drive electrode 13 can be drawn out to the back surface of the head chip 1 easily and inexpensively. In addition, since the photosensitive glass substrate 101 can have a desired thickness, there is no need to stack a large number of sheets as in the conventional case, and the laborious work process for aligning the through holes 101b with high accuracy. Is also unnecessary.

  In the case where the drive electrode 13 is formed by electroless plating, the lower surface of the photosensitive glass substrate 101 on which the connection electrode 16 is formed is appropriately masked with a resist or the like, and then immersed in a plating solution so as to be in each ink channel 12. After the plating film is deposited, the resist 300 on each drive wall 11 may be removed together.

  After the drive electrode 13 is formed in each ink channel 12 to produce the ink channel substrate 10, a cover member 14 is bonded so as to cover the upper part of the ink channel 12 as shown in FIG. The cover member 14 is formed in the same size as the ink channel substrate 10 using a substrate such as a ceramic substrate, preferably the same substrate as the piezoelectric element substrates 102 and 103, without polarization.

  After the cover member 14 is bonded, as shown in the plan view of FIG. 9, the cover member 14 is cut along the cut lines C <b> 1, C <b> 2. 1 are produced. As a result, a large number of head chips 1, 1,... Can be produced at a time from a single long substrate, which is excellent in mass productivity and improved in production efficiency. In the state before cutting, a metal film may be formed on the front or rear surface of the substrate. In this case, it may be cut and removed as an unnecessary portion in advance.

  The cut lines C1, C2,... Determine the drive length of the ink channel 12 of the head chip 1 produced thereby, and are appropriately determined according to the drive length. FIG. 9 shows a state in which each ink channel 12 is cut along the cut lines C1 and C2 so that one connection wiring 15 (through hole 101b and conductive material 101c) is included, but the cut line C1 is shown. , C2..., Each of the head chips 1, 1... Cut by each of the head chips 1, 1..., And at least one connection wiring 15 may be included. May be included.

  After producing the head chip 1 in this way, as shown in FIG. 1, the nozzle plate 2 is adhered to the front surface, the flow path regulating plate 4 and the manifold 5 are adhered to the rear surface, The connection electrode 16 formed on the lower surface is connected to the wiring 31 of the FPC 3 for electrical connection with a drive circuit (not shown), and is connected by an anisotropic conductive film, a conductive adhesive, or the like. By the connection of the FPC 3, a voltage based on the drive signal is applied to each drive electrode 13 through the wiring 31 of the FPC 3, the connection electrode 16 of the head chip 1, and the connection wiring 15.

  Here, the connection electrode 16 on the lower surface of the head chip 1 is previously formed on the photosensitive glass substrate 101 before bonding the piezoelectric element substrates 102 and 103. However, when the connection electrode 16 is formed, the connection electrode 16 is piezoelectric. Alternatively, the element substrates 102 and 103 may be formed after bonding. In this case, the ink channel 12 may be formed before or after grinding, or may be formed after the cover member 14 is bonded.

  In addition, the inkjet head described above is manufactured with one head chip 1 having one nozzle row. However, by bonding the cover members 14 of the two head chips 1, two nozzle rows can be formed. You may make it produce the inkjet head which has.

  Further, in the head chip 1 described above, the shape of the ink channel 12 is such that both side walls face the vertical direction and are parallel to each other, and the size and shape in the length direction from the inlet to the outlet of the ink channel 12 are almost the same. A so-called harmonica type that is a straight type that does not change is illustrated. In such a head chip 1, it is difficult to pull out the connection wiring from the drive electrode 13. Therefore, by applying the present invention, the connection wiring can be easily and inexpensively drawn to the outer surface of the head chip 1. Although the present invention is effective, the present invention is not limited to the manufacture of an inkjet head having such a head chip, but has a head chip of a type in which the ink channel structure gradually becomes a shallow groove shape toward the rear end. It can also be applied to the manufacture of an inkjet head.

Exploded perspective view of inkjet head (A)-(e) is explanatory drawing explaining the process of forming a through-hole in the photosensitive glass substrate. The perspective view which shows the photosensitive glass substrate which filled the inside with the electroconductive substance in the through-hole The perspective view which shows the state which formed the connection electrode in the lower surface of the photosensitive glass substrate in a partial cross section Front view showing a state in which a piezoelectric element substrate is laminated on a photosensitive glass substrate The perspective view which shows the state which formed the ink channel in a partial cross section Sectional drawing which shows the state which formed the drive electrode in the ink channel The perspective view which shows the state which adhered the cover member to the ink channel board | substrate. Plan view showing how to cut along the cut line

Explanation of symbols

1: Head chip 10: Ink channel substrate 11: Drive wall 12: Ink channel 13: Drive electrode 14: Cover member 15: Connection wiring 16: Connection electrode 2: Nozzle plate 21: Nozzle 3: FPC
31: Wiring 4: Flow path restricting plate 41: Ink flow port 5: Manifold 51: Ink supply chamber 52: Ink flow port 101: Photosensitive glass substrate 101a: Crystallization part 101b: Through hole 101c: Conductive substance

Claims (5)

Drive heads made of piezoelectric elements and ink channels are alternately arranged side by side, drive electrodes are formed in the ink channels, and a head chip is formed by adhering a cover member so as to close the ink channels. A connection wiring that is electrically connected to each drive electrode of the head chip is drawn out from the bottom of the ink channel through the outer surface of the head chip, and a voltage is applied to each drive electrode via the connection wiring. A method of manufacturing an ink jet head, wherein the driving wall is shear-deformed by the ink and the ink in the ink channel is ejected from a nozzle.
The manufacturing process of the head chip includes:
Forming a large number of through holes in the photosensitive glass substrate through an exposure step and an etching step; and
Filling the through hole with a conductive material;
A polarized piezoelectric element substrate is bonded to the surface of the photosensitive glass substrate, and from the piezoelectric element substrate side, the ink channel is placed at a position corresponding to the through hole, and the conductive substance in the through hole is the ink channel. Forming to a depth exposed at the bottom,
Forming a drive electrode in conduction with the conductive material in the ink channel;
Adhering a cover member so as to cover the ink channel;
A method of manufacturing an ink jet head, comprising:   2. The method according to claim 1, further comprising a step of cutting along a direction substantially orthogonal to a length direction of each ink channel so that each ink channel has a predetermined driving length after the step of bonding the cover member. The manufacturing method of the inkjet head of description.   Forming a connection electrode, which is electrically connected to the conductive material filled in the through-hole, on the opposite surface of the photosensitive glass substrate to the surface to which the piezoelectric element substrate is bonded, before or after bonding to the piezoelectric element substrate; The method of manufacturing an ink-jet head according to claim 1 or 2.   4. The method of manufacturing an ink jet head according to claim 1, wherein the photosensitive glass substrate and the piezoelectric element substrate are bonded by curing an adhesive at room temperature.   The method of manufacturing an ink jet head according to claim 1, wherein the piezoelectric element substrate is formed by bonding two piezoelectric element substrates having different polarization directions to each other.

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