JP2008230052A - Plate laminate structure and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the leakage of liquid, and to prevent the adhesion of an adhesive agent squeezed from a clearance between plates to the inner wall surface of a penetration hole. <P>SOLUTION: A nozzle plate 130 with a nozzle hole 3 overlies a cover plate 129 with a descender hole 51. 8 thin and long grooves 71 in the thickness direction of the cover plate 129 are formed on the inner wall surface 70 of the descender hole 51. The groove 71 has a shape gradually narrowed toward the end as the tip is separated from the nozzle plate 130. The grooves 71 stores the adhesive agent by a capillary phenomenon squeezed from the clearance between the plates in the process for making the cover plate 129 overlie the nozzle plate 130. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a plate laminated structure in which a plurality of plates are laminated and a method for manufacturing the same.

  The inkjet head described in Patent Document 1 has a plate laminated structure in which a plurality of laminated plates are fixed with an adhesive.

  Each plate constituting the plate laminated structure according to Patent Document 1 is provided with a through-hole as a liquid flow path. A plurality of plates are stacked so that the through holes formed in each plate communicate with each other.

JP 2003-205610 A

  When manufacturing a plate laminated structure in which a plurality of plates each having a through-hole as a liquid flow path as described above are laminated, uncured adhesive protruding from between adjacent plates is contained in these through-holes. May spread on the wall. When the adhesive spreads on the inner wall surface of the through hole, problems such as clogging of the through hole, increase in flow path resistance, and decrease in flow rate occur. In particular, when one of the through holes is a nozzle hole for discharging a droplet, the presence of adhesive as a foreign substance and non-uniform wettability in the nozzle result in a drop flying directionality. The landing accuracy shown is deteriorated, and normal liquid discharge from the nozzle holes is not performed. If the amount of adhesive is reduced in order to avoid such a problem, sufficient bonding strength between adjacent plates cannot be obtained, and liquid leakage occurs from the plate interface.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a plate stacking structure in which liquid leakage is unlikely to occur, and the adhesive protruding from between the plates is difficult to adhere to the inner wall surface of a through hole formed in a predetermined plate, and a method for manufacturing the same. That is.

  The plate laminated structure of the present invention includes a first through hole, a first surface on which one opening of the first through hole is formed, and an opening on the other side of the first through hole and the first surface. Comprises a first plate having a second surface facing in the opposite direction and a second plate having a second through-hole penetrating in the thickness direction. Then, the first plate and the second plate are fixed so that the second plate is fixed to the second surface of the first plate in a state where the first through hole and the second through hole communicate with each other. Are laminated via an adhesive. A plurality of elongated grooves are formed on the inner wall surface of the second through hole in the thickness direction of the second plate. Furthermore, the groove has a tapered shape that becomes narrower as it gets away from the first plate.

  According to the present invention, when the first plate and the second plate are stacked, a part of the adhesive protruding from between the two plates is accommodated in the groove. At this time, since the groove is tapered, the capillary force increases as it approaches the tip of the groove, so that the adhesive is easily accommodated in the groove. Therefore, the amount of the adhesive entering the first through hole can be reduced, and the adhesive is difficult to adhere to the inner wall surface of the first through hole. Further, since it is not necessary to reduce the amount of the adhesive, there is almost no liquid leakage due to a decrease in the bonding strength between the plates, and a high manufacturing yield can be obtained.

  A boundary line between the portion of the inner wall surface of the second through-hole except the groove and the first plate, a boundary line between the inner surface of the groove defining the groove and the inner wall surface of the second through-hole However, they are preferably connected at an obtuse angle.

  It is preferable that the groove penetrates the second plate. As a result, the amount of the adhesive accommodated in the groove increases, so that the amount of the adhesive entering the first through hole can be further reduced.

  The plurality of grooves are preferably formed in the inner wall surface at an equal angle with respect to the central axis of the second through hole. As a result, the direction dependency on the amount of adhesive contained in the groove is reduced, and as a result, the amount of adhesive entering the first through hole can be further reduced.

  At this time, the first through hole and the second through hole share a central axis, and an opening diameter of one opening of the second through hole facing the first plate is equal to that of the first through hole. It is preferably larger than the opening diameter of the other opening. As a result, the second surface of the first plate is exposed at the bottom of the second through hole, and the exposed portion of the second surface has an annular shape centering on the central axis of the two through holes. In other words, a distance is generated from the boundary line between the inner wall surface of the second through hole and the second surface to the other opening of the first through hole, the distance is almost constant, and there is a short distance where the adhesive easily flows. Disappear. Therefore, it becomes more difficult for the adhesive to flow into the first through hole. Moreover, even if it flows, there is a high possibility that a uniform amount of adhesive will flow from any direction.

  The first through hole is preferably a nozzle hole for discharging a liquid. As a result, the liquid can be discharged smoothly.

  In the method for manufacturing a plate laminated structure according to the present invention, the first through hole, the first surface on which one opening of the first through hole is formed, the other opening of the first through hole is formed, and the first through hole is formed. A first plate manufacturing step of manufacturing a first plate having a second surface facing in the direction opposite to the first surface; a second plate manufacturing step of manufacturing a second plate having a second through hole penetrating in the thickness direction; The first plate and the second plate are bonded so that the second plate is fixed to the second surface of the first plate in a state where the first through hole and the second through hole communicate with each other. A laminating step of laminating via an agent. The second plate manufacturing step is to form a plurality of grooves having a tapered shape that is elongated in the thickness direction of the second plate and narrows away from the first plate on the inner wall surface of the second through hole. And forming the second through hole penetrating the second plate in the thickness direction, covering the inner wall surface of the second through hole, and out of one or both surfaces of the second plate A coating step of forming a mask that covers a remaining region while exposing a plurality of regions that are continuous with an inner wall surface and arranged in the circumferential direction of the second through-hole, and the second plate that is coated with the mask And an etching process for performing an etching process. Thereby, the plate laminated structure according to the present invention can be easily manufactured.

  A preferred embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 is a plan view of an ink jet head including a plate laminated structure according to the present embodiment. FIG. 2 is an enlarged view of a region surrounded by a one-dot chain line in FIG. As shown in FIG. 1, the inkjet head 2 includes a flow path unit 9 and four actuator units 21 fixed to the upper surface 9 a of the flow path unit 9.

  As shown in FIG. 2, an ink flow path including a pressure chamber 110 is formed inside the flow path unit 9. The actuator unit 21 includes a plurality of actuators corresponding to the pressure chambers 110 and selectively applies ejection energy to the ink in the pressure chambers 110. In FIG. 2, the actuator unit 21 to be drawn by a solid line is indicated by a broken line, and the pressure chamber 110, the aperture 112 and the discharge port 108 which are to be drawn by the broken line below the actuator unit 21 are drawn by a solid line.

  Returning to FIG. 1, a total of ten ink supply ports 105 b to which ink is supplied are provided on the upper surface 9 a of the flow path unit 9. A manifold channel 105 communicating with the ink supply port 105 b and a sub-manifold channel 105 a branched from the manifold channel 105 are formed inside the channel unit 9. The lower surface of the flow path unit 9 is an ink ejection surface 31 (see FIG. 3) in which a large number of ejection ports 108 are arranged in a matrix. A large number of pressure chambers 110 are arranged in a matrix on the upper surface of the flow path unit 9, similarly to the discharge ports 108.

  In the present embodiment, 16 rows of pressure chambers 110 extending in the longitudinal direction of the flow path unit 9 including a plurality of pressure chambers 110 arranged at equal intervals are formed in one actuator unit 21. The number of pressure chambers 110 included in each pressure chamber row is larger as it is closer to the long side (lower bottom) of the actuator unit 21 and is smaller as it is closer to the short side (upper bottom). The same applies to the discharge port 108. In accordance with the outer shape of the actuator unit 21, each region where the pressure chamber 110 and the discharge port 108 are arranged has a trapezoidal outer shape.

  3 is a cross-sectional view taken along the line III-III shown in FIG. As shown in FIG. 3, the flow path unit 9 includes a cavity plate 122, a base plate 123, an aperture plate 124, a supply plate 125, three manifold plates 126, 127, 128, a cover plate 129, and a nozzle in order from the top. The plate 130 is composed of nine metal plates such as stainless steel. These plates 122 to 130 have a rectangular planar shape that is long in the main scanning direction. In any of the plates 122 to 130, holes and recesses that are constituent elements of the ink flow path are formed corresponding to the pressure chambers 110. By laminating these plates 122 to 130 while aligning them with each other, an aperture 112 functioning as a throttle from the outlet of the manifold channel 105, the sub-manifold channel 105a, and the sub-manifold channel 105a in the channel unit 9. Furthermore, a large number of individual ink flow paths 132 are formed through the pressure chamber 110 to the discharge port 108.

  FIG. 4A is a partially enlarged plan view of the cover plate 129 laminated with the nozzle plate 130. FIG. 4B is a cross-sectional view taken along line IVB-IVB in FIG. As shown in these drawings, the nozzle hole 3 formed in the nozzle plate 130 is formed in the discharge port 108 formed in the discharge surface 31 of the nozzle plate 130 and the connection surface 32 opposite to the discharge surface 31. A through hole formed between the inlet 109 and the inflow port 109. The nozzle hole 3 is composed of a cylindrical portion 3 a having a discharge port 108 at one end and continuing to the discharge surface 31, and a truncated cone portion 3 b having an inflow port 109 at one end and continuing to the connection surface 32. The top part of the truncated cone part 3b has the same diameter as the cylindrical part 3a. The nozzle hole 3 is formed by a pressing process divided into two, a pressing process for providing the truncated cone part 3b and a pressing process for providing the cylindrical part 3a.

  In the cover plate 129 having a thickness of about 50 μm, a descender hole 51 having a diameter of about 180 μm, which is a through hole penetrating in the thickness direction, is formed. The descender hole 51 is formed between a lower opening 62 formed in the lower surface 52 of the cover plate 129 and an upper opening 63 formed in the upper surface 53, which is the opposite surface of the lower surface 52. The opening diameter of the lower opening 62 of the descender hole 51 is larger than the opening diameter of the inlet 109 of the nozzle hole 3. The descender hole 51 has a substantially cylindrical shape unless the groove 71 described later is taken into consideration, and the diameter of the lower opening 62 and the diameter of the upper opening 63 are the same. The nozzle hole 3 and descender hole 51 share the central axis X.

  FIG. 4C is a partially enlarged side view of the inner wall surface of the descender hole. As illustrated in FIG. 4A to FIG. 4C, eight elongated grooves 71 are formed in the inner wall surface 70 of the descender hole 51 in the thickness direction of the cover plate 129. As will be described later, the groove 71 functions as an adhesive escape groove that accommodates the adhesive protruding from between both plates in the stacking process of the cover plate 129 and the nozzle plate 130 by capillary action. The eight grooves 71 are formed in the inner wall surface 70 at an equal angle of 45 ° with respect to the central axis X. Each groove 71 is deepest at the lowermost portion thereof and becomes shallower as it is away from the nozzle plate 130. Each groove 71 penetrates the cover plate 129 in the thickness direction.

  As can be seen from FIG. 4C, the groove 71 has a tapered shape that becomes narrower as the distance from the nozzle plate 130 increases. The maximum width of the groove 71, that is, the width at the lowermost portion is set to be equal to or less than the thickness of the cover plate 129, and is about 30 to 40 μm here. A boundary line L1 between the nozzle plate 130 and a portion of the inner wall surface 70 of the descender hole 51 except for the groove 71, and a left and right boundary line L2 between the groove inner surface 74 defining the groove 71 and the inner wall surface 70 of the descender hole 51 Are connected at an obtuse angle θ. Therefore, the boundary line L <b> 2 is inclined in the direction of narrowing the width of the groove 71 as it is away from the nozzle plate 130, that is, toward the inside of the groove 71. Thereby, in the present embodiment, the tapered shape of the groove 71 is realized.

  Next, the actuator unit 21 will be described. As shown in FIG. 1, each actuator unit 21 has a trapezoidal planar shape. The four actuator units 21 are arranged in a staggered manner in the main scanning direction (longitudinal direction) so as to avoid the ink supply ports 105b. With respect to the sub-scanning direction, the actuator units 21 are alternately spaced at equal intervals in parallel and opposite directions. The parallel opposing sides of each actuator unit 21 are along the longitudinal direction of the flow path unit 9. The hypotenuses of adjacent actuator units 21 overlap each other in the sub-scanning direction.

  FIG. 5A is a partially enlarged sectional view of the actuator unit 21, and FIG. 5B is a plan view showing individual electrodes arranged on the surface of the actuator unit 21 in FIG. 5A. As shown in FIG. 5A, the actuator unit 21 includes a piezoelectric body in which three piezoelectric layers 141 to 143 made of a lead zirconate titanate (PZT) ceramic material having ferroelectricity are laminated. It is out. An individual electrode 135 is formed in a region facing the pressure chamber 110 on the upper surface of the uppermost piezoelectric layer 141. A common electrode 134 formed on the entire surface of the sheet is interposed between the uppermost piezoelectric layer 141 and the lower piezoelectric layer 142. As shown in FIG. 5B, the individual electrode 135 has a substantially rhombic planar shape similar to the pressure chamber 110. In plan view, most of the individual electrodes 135 are in the region of the pressure chamber 110. One of the acute angle portions of the substantially rhomboid individual electrode 135 extends out of the pressure chamber 110, and a circular individual land 136 electrically connected to the individual electrode 135 is provided at the tip thereof. The individual land 136 is thicker than the individual electrode 135.

  The common electrode 134 and the individual electrode 135 are each connected to a driver IC (not shown) via wiring provided on a flat flexible substrate (not shown). A signal held at the ground potential is supplied from the driver IC to the common electrode 134. A drive signal for alternately taking the ground potential and the positive potential according to the image pattern to be printed is supplied to the individual electrode 135 from the driver IC.

  The piezoelectric layer 141 is polarized in the thickness direction. When an electric field is applied in the polarization direction to a portion (active portion) sandwiched between the individual electrode 135 and the common electrode 134 of the piezoelectric layer 141 by setting the individual electrode 135 to a potential different from that of the common electrode 134, the active portion causes the piezoelectric effect. Distorted at. For example, if the polarization direction is the same as the electric field application direction, the active portion contracts in a direction (plane direction) perpendicular to the polarization direction. On the other hand, the piezoelectric layers 142 and 143 are inactive layers that do not distort spontaneously. At this time, since the piezoelectric layers 141 to 143 are fixed to the upper surface of the cavity plate 122 that partitions the pressure chamber 110, a unimorph effect occurs. As a result, the region corresponding to the active portion of the piezoelectric layers 141 to 143 is deformed so as to protrude toward the pressure chamber 110. Due to such unimorph deformation, pressure, that is, ejection energy is applied to the ink in the pressure chamber 110, and ink droplets are ejected from the ejection port 108. As described above, in the actuator unit 21, the portion sandwiched between the individual electrode 135 and the pressure chamber 110 functions as an individual actuator. Therefore, the actuator unit 21 has the same number of actuators as the pressure chambers 110. Will be.

  Next, the manufacturing method of the inkjet head 2 described above will be described with reference to FIG. In the following description, for the sake of convenience, parts that are being manufactured will be described using the same reference numerals as those of the finished parts.

  In order to manufacture the inkjet head 2, the flow path unit 9 and the actuator unit 21 are separately manufactured, and then both are assembled. First, the manufacturing process of the flow path unit 9 will be described. In order to manufacture the flow path unit 9, in step S11, the plates 122 to 130 constituting the flow path unit 9 are subjected to etching processing or press processing using the patterned photoresist as a mask. Thereby, holes as shown in FIG. 3 are formed in each of the plates 122 to 130. For example, in order to form the descender hole 51 in the cover plate 129, as shown in FIG. 7A, a pressing process using a cylindrical punch 91 having the same diameter as the descender hole 51 to be formed is performed.

  Next, in step S <b> 12, eight grooves 71 are formed in the cover plate 129. In the present embodiment, the groove 71 is formed by an etching process using a photoresist. Specifically, first, a positive photoresist 93 is applied to the cover plate 129 so that the entire area of the inner wall surface 70 of the descender hole 51 and the lower surface 52 and the upper surface 53 of the cover plate 129 are covered.

  Thereafter, the photoresist 93 is selectively exposed using a photomask (not shown). Specifically, only the photoresist 93 on the eight rectangular regions 52 a that are continuous with the inner wall surface 70 of the lower surface 52 and are arranged at equal intervals in the circumferential direction of the descender hole 51 is exposed. Then, the eight exposed rectangular areas are dissolved with a developer. As a result, as shown in FIGS. 7B and 8, eight holes 93 a are formed in the photoresist 93. From the eight holes 93a, the rectangular regions 52a of the lower surface 52 are respectively exposed.

  Further, by etching the cover plate 129 using the photoresist 93 in which the eight holes 93a are formed as a mask, as shown in FIG. 7C, the eight grooves 71 reaching the upper surface 53 are covered. Form on plate 129. Since the etching process performed at this time is isotropic, the shape of the groove 71 is narrower and shallower as the distance from the nozzle plate 130 increases, as illustrated in FIGS. 4B and 4C. Tapered shape. Thereafter, the photoresist 93 is removed.

  Next, in step S13, the nine plates 122 to 130 are stacked such that the manifold channel 105, the sub-manifold channel 105a, and the individual ink channel 132 are formed, and fixed with an adhesive. Specifically, an epoxy-based thermosetting adhesive is applied to the lower surfaces (surfaces facing the nozzle plate 130) of the eight plates 122 to 129 excluding the nozzle plate 130, and then the eight plates 122 to 129 are applied. 129 is laminated in the aligned state. Then, the obtained laminate is pressed while being heated to a temperature equal to or higher than the curing temperature of the thermosetting adhesive. Thereby, the flow path unit 9 in which the nine plates 122 to 130 are laminated and fixed is formed.

  In order to manufacture the actuator unit 21, first, three green sheets of piezoelectric ceramics are prepared in step S21. The green sheet is shaped in advance in anticipation of the amount of shrinkage caused by firing. On one of the green sheets, a conductive paste is screen-printed on the common electrode 134 pattern.

  Next, in step S22, the conductive paste is printed with the pattern of the common electrode 134 under the green sheet on which the conductive paste is not printed while aligning the three green sheets using a jig. Then, one green sheet is overlaid, and further, one green sheet on which no conductive paste is printed is overlaid thereon. Thereby, a laminate of three green sheets is obtained. Then, the obtained laminate is degreased in the same manner as known ceramics, and further fired at a predetermined temperature. As a result, the three green sheets become the piezoelectric layers 141 to 143, and the conductive paste becomes the common electrode 134.

  Thereafter, in step S23, a conductive paste is screen-printed on the pattern of the individual electrodes 135 on the uppermost piezoelectric layer 141. Further, the conductive paste is baked to form the individual electrodes 135 on the piezoelectric layer 141. Thereafter, gold containing glass frit is printed on the surface of the extended portion of the individual electrode 135 to form the individual land 136. In this way, the production of the actuator unit 21 as illustrated in FIGS. 5A and 5B is completed. In addition, since both the flow path unit 9 and the actuator unit 21 are independent members, any production may be performed first or in parallel.

  Next, in step S31, an epoxy-based thermosetting adhesive is applied to the upper surface of the flow path unit 9 obtained in step S14 using a bar coater.

  Thereafter, in step S <b> 32, the four actuator units 21 are placed on the thermosetting adhesive layer applied to the flow path unit 9. At this time, each actuator unit 21 is positioned with respect to the flow path unit 9 so that the individual electrode 135 and the pressure chamber 110 face each other. This positioning is performed based on positioning marks (not shown) previously formed on the flow path unit 9 and the actuator unit 21.

  Next, in step S33, the laminated body of the flow path unit 9 and the actuator unit 21 obtained in step S32 is pressurized while being heated to a temperature equal to or higher than the curing temperature of the thermosetting adhesive. As a result, the four actuator units 21 are fixed to the flow path unit 9.

  In step S34, the laminate is naturally cooled. The inkjet head 2 shown in FIGS. 1 to 5 is manufactured through the steps so far. According to the ink jet head manufacturing method described here, the ink jet head 2 having the above-described plate laminated structure can be easily manufactured.

  According to the embodiment described above, a part of the adhesive protruding from between the nozzle plate 130 and the cover plate 129 is accommodated in the groove 71 by capillary action when the nine plates 122 to 130 are stacked in step S13. Is done. At this time, since the groove 71 is tapered, the capillary force increases as it approaches the tip of the groove 71, so that the adhesive is easily accommodated in the groove 71. Therefore, the amount of the adhesive that enters the nozzle hole 3 from the inlet 109 can be reduced, and the adhesive hardly adheres to the inner wall surface of the nozzle hole 3. Therefore, the ink ejection characteristics including the flying directionality of the ink droplets ejected from the nozzle holes 3 are improved. In addition, since it is not necessary to reduce the amount of the adhesive, ink leakage does not occur due to a decrease in the bonding strength between the nozzle plate 130 and the cover plate 129, and a high manufacturing yield can be obtained.

  Moreover, since the groove | channel 71 has penetrated the cover plate 129, the quantity of the adhesive agent accommodated in the groove | channel 71 is large compared with the case where it does not penetrate. Therefore, the amount of the adhesive that enters the nozzle hole 3 is further reduced when the nine plates 122 to 130 are stacked in step S13.

  In addition, since the eight grooves 71 are formed on the inner wall surface 70 at an equal angle with respect to the central axis X of the descender hole 51, the direction dependency regarding the amount of adhesive accommodated in the grooves 71 is reduced. As a result, the amount of adhesive entering the nozzle hole 3 is further reduced when the nine plates 122 to 130 are stacked in step S13.

  Further, the descender hole 51 and the nozzle hole 3 share the central axis X, and the opening diameter of the lower opening 62 of the descender hole 51 is larger than the opening diameter of the inlet 109 of the nozzle hole 3. Therefore, the connection surface 32 of the nozzle plate 130 is exposed at the bottom of the descender hole 51, and the exposed portion of the connection surface 32 has an annular shape with the central axis X as the center. That is, a distance corresponding to the width of the exposed annular region is generated from the boundary line between the inner wall surface 70 of the descender hole 51 and the connection surface 32 to the inlet 109, and the adhesive hardly reaches the inlet 109. Further, this distance is almost constant, and there is no short distance where the adhesive can easily flow. Therefore, the adhesive is less likely to flow into the nozzle hole 3 when the nine plates 122 to 130 are stacked in step S13. Further, even if it flows, there is a high possibility that a uniform amount of adhesive will flow from any direction, and the adverse effect on the ink ejection characteristics is minimized.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various design changes can be made to the above-described embodiments as long as they are described in the claims. It is possible to apply. For example, in the above-described embodiment, the groove 71 passes through the cover plate 129, but the groove 71 may not pass through the cover plate 129. One or more grooves 71 need only be provided in the descender hole 51, and even if a plurality of grooves 71 are provided, they need not be equiangular with respect to the central axis X.

  Further, the descender hole 51 and the nozzle hole 3 may not share the central axis X, and these central axes may be shifted from each other. Further, the opening diameter of the lower opening 62 of the descender hole 51 may be the same as or smaller than the opening diameter of the inlet 109 of the nozzle hole 3.

  Furthermore, although the positive type photoresist is used in the above-described embodiment, a negative type photoresist may be used. In this case, a photomask having a reverse pattern to that described above is used.

  The present invention is not limited to the laminated structure of the nozzle plate 130 in which the ejection port 108 for ejecting ink is formed and the cover plate laminated on the nozzle plate 130, for example, a laminated structure of other plates constituting the flow path unit 9. Is also applicable. Further, the present invention is applicable not only to an ink jet head but also to any member as long as it has a plate laminated structure in which through holes constituting flow paths are respectively formed.

  In the above-described embodiment, the hole 93a of the photoresist 93 is provided only on one side of the cover plate 129. However, the hole 93a of the photoresist 93 may be provided on both sides of the cover plate 129. Further, the descender hole 51 provided with the groove 71 as shown in FIGS. 4A to 4C may be formed by a method other than etching using a photoresist. For example, in the above-described embodiment, the descender hole 51 having the groove 71 is formed by combining pressing and etching. However, the descender hole 51 having the groove 71 may be formed only by pressing. At this time, the surface of the punch for press only needs to have irregularities corresponding to the grooves 71, and there may be irregularities that generate a plurality of streaks that act on the adhesive against the capillary force. Alternatively, the descender hole 51 having the groove 71 may be formed only by etching.

It is a top view of the inkjet head manufactured by the manufacturing method concerning one embodiment of the present invention. It is an enlarged view of the area | region enclosed with the dashed-dotted line of FIG. It is sectional drawing along the III-III line | wire shown in FIG. (A) is a partial enlarged plan view of a cover plate laminated with a nozzle plate, (b) is a cross-sectional view taken along line IVB-IVB in (a), and (c) is an inside of a descender hole. It is a partial expanded side view of a wall surface. (A) is the elements on larger scale of the actuator unit drawn by FIG. 1, (b) is a top view of the separate electrode arrange | positioned on the surface of an actuator unit. FIG. 2 is a manufacturing process diagram of the inkjet head depicted in FIG. 1. It is sectional drawing which shows the detail of step S12 of FIG. 6 in order of a process. It is a top view of the cover plate corresponding to FIG.7 (b).

Explanation of symbols

2 Inkjet head 3 Nozzle hole 3a Column portion 3b Frustum portion 9 Flow path unit 21 Actuator unit 31 Discharge surface 32 Connection surface 51 Decender hole 52 Lower surface 52a Rectangular region 53 Upper surface 62 Lower opening 63 Upper opening 70 Inner wall surface 71 Groove 93 Photoresist 93a hole 108 discharge port 109 inflow port 110 pressure chamber 122 cavity plate 123 base plate 124 aperture plate 125 supply plate 126, 127, 128 manifold plate 129 cover plate 130 nozzle plate 132 individual ink flow path 134 common electrode 135 individual electrode 141 to 143 piezoelectric layer

Claims (7)

A first surface on which one opening of the first through-hole is formed, and a second surface on which the other opening of the first through-hole is formed and facing away from the first surface A first plate having a surface;
A second plate having a second through hole penetrating in the thickness direction;
The first plate and the second plate are bonded so that the second plate is fixed to the second surface of the first plate in a state where the first through hole and the second through hole communicate with each other. Is laminated through the agent,
A plurality of elongated grooves are formed in the thickness direction of the second plate on the inner wall surface of the second through hole,
The plate laminated structure, wherein the groove has a tapered shape that is narrower as it is farther from the first plate.   A boundary line between the portion of the inner wall surface of the second through-hole except the groove and the first plate, a boundary line between the inner surface of the groove defining the groove and the inner wall surface of the second through-hole Are connected at an obtuse angle. 2. The plate laminated structure according to claim 1, wherein:   The plate laminated structure according to claim 1, wherein the groove penetrates the second plate.   4. The plate laminated structure according to claim 1, wherein the plurality of grooves are formed in the inner wall surface at an equal angle with respect to a central axis of the second through hole.   The first through hole and the second through hole share a central axis, and an opening diameter of one opening of the second through hole facing the first plate is the other of the first through holes. The plate laminated structure according to claim 4, wherein the plate laminated structure is larger than an opening diameter of the opening.   The plate laminated structure according to claim 1, wherein the first through hole is a nozzle hole for discharging a liquid. A first surface on which one opening of the first through-hole is formed, and a second surface on which the other opening of the first through-hole is formed and facing away from the first surface A first plate manufacturing step of manufacturing a first plate having a surface;
A second plate manufacturing step of manufacturing a second plate through which the second through hole penetrates in the thickness direction;
The first plate and the second plate are bonded so that the second plate is fixed to the second surface of the first plate in a state where the first through hole and the second through hole communicate with each other. And a lamination process of laminating via an agent,
The second plate manufacturing step is to form a plurality of grooves having a tapered shape that is elongated in the thickness direction of the second plate and narrows away from the first plate on the inner wall surface of the second through hole. And
Forming the second through-hole penetrating the second plate in the thickness direction;
The inner wall surface of the second through-hole is covered, and a plurality of regions that are continuous with the inner wall surface and arranged in the circumferential direction of the second through-hole among one or both surfaces of the second plate are exposed. A coating process for forming a mask covering the remaining area,
And an etching step of performing an etching process on the second plate covered with the mask.

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