JP5443528B2 - Ink jet head and method of manufacturing ink jet head - Google Patents

Description

  Embodiments described herein relate generally to an inkjet head and a method for manufacturing the inkjet head.

  The ink jet head includes a plurality of side walls formed by piezoelectric elements having different polarities attached to each other, electrodes provided on the side walls, and a nozzle plate having ink discharge holes at positions corresponding to pressure chambers formed by the side walls. . The side wall is elastically deformed by the voltage applied to the electrode, and this deformation changes the volume of the pressure chamber formed by the side wall. Due to the volume change of the pressure chamber, ink suction and discharge are performed from the ink discharge holes of the nozzle plate.

  The interval between the side walls and the ink ejection holes are minute, and it is difficult to accurately align the nozzle plate with the piezoelectric element.

  With respect to this point, conventionally, a plurality of pins are set up on the main body of the ink jet, an insertion hole for each pin is provided in the nozzle plate, and alignment is performed by passing the pins through the insertion holes at the time of manufacture.

  However, there is a case where a space for raising the pins cannot be provided due to a request for space saving.

Japanese Patent Laid-Open No. 11-10870

  Accordingly, there is a need for an inkjet head and an inkjet head manufacturing method capable of accurately and quickly aligning the nozzle plate.

  In order to solve the above-described problems, an embodiment of the present invention surrounds a piezoelectric element having a pressure chamber formed by a substrate, a side wall formed on a substrate and formed in a comb-teeth shape, and the substrate. And the first discharge hole provided at a position corresponding to the pressure chamber, the first alignment hole provided at a position corresponding to the upper surface of the first side wall, and the first side wall are different from each other. Provided is an inkjet head including a nozzle plate having a second alignment hole provided at a position corresponding to the upper surface of a second side wall and covering a piezoelectric element and a frame.

It is a perspective view of the inkjet head main-body part containing an inkjet head. It is a perspective view of an inkjet head. FIG. 3 is a cross-sectional view of the inkjet head taken along line AA in FIG. 2. FIG. 3 is a cross-sectional view of the inkjet head taken along line BB in FIG. 2. It is a top view of the inkjet head which removed the nozzle plate. It is a top view which shows a nozzle plate. It is a figure which shows the positional relationship of a side wall, a 1st alignment hole, and a 2nd alignment hole. It is a top view which shows the nozzle plate of this embodiment which concerns on an application example. It is a figure which shows the positional relationship of a 1st alignment hole and 2nd alignment hole which concern on a side wall and an application example. It is a figure which shows the adhesion method to the piezoelectric element of a nozzle plate. It is a figure which shows the case where an adhesive overflows. It is a figure which shows the mode of alignment. It is a figure which shows the position alignment by a position alignment mark. It is a figure which shows the positioning by a positioning scale.

  Hereinafter, an embodiment of an inkjet head and an inkjet head manufacturing method will be described in detail with reference to the drawings.

  The inkjet head of the present embodiment includes a substrate, a piezoelectric element that is provided on the substrate and has a pressure chamber formed by a side wall formed in a comb-like shape, and a frame body that is disposed so as to surround the piezoelectric element. Corresponding to the ink discharge hole provided at the position corresponding to the pressure chamber, the first alignment hole provided at the position corresponding to the upper surface of the first side wall, and the upper surface of the second side wall different from the first side wall A nozzle plate having a second alignment hole provided at a position and covering the piezoelectric element and the frame.

  FIG. 1 is a perspective view of an ink jet head main body 100 including the ink jet head of the present embodiment. As shown in FIG. 1, the ink jet head main body 100 includes an ink jet head 101 disposed at the tip, and a mask 201 that supports the ink jet head 101.

  FIG. 2 is a perspective view of the inkjet head 101. As shown in FIG. 2, the ink jet head 101 includes a substrate 11 made of alumina or the like, a piezoelectric element 12 installed on the substrate 11, a frame body 13 disposed so as to surround the piezoelectric element 12, and ink. A nozzle plate 14 having a discharge hole 15 and covering the piezoelectric element 12 and the frame body 13 is provided.

  The inkjet head 101 has a common liquid chamber 16 in a space surrounded by the substrate 11, the piezoelectric element 12, the frame body 13, and the nozzle plate 14.

  3 is a cross-sectional view of the inkjet head 101 taken along line AA in FIG. As shown in FIG. 3, the piezoelectric element 12 includes a plurality of side walls 12S in which piezoelectric elements 12A1 and 12A2 having different polarities are bonded to each other with an adhesive 12B to form a comb-like shape. The side wall 12S forms a pressure chamber 12R in the gap.

  Pressure chamber electrodes 12C as electrodes are disposed on the bottom surfaces of the side walls 12S and the pressure chambers 12R. Further, a resin film 300 that covers the pressure chamber electrode 12C is provided.

  The pressure chamber 12 </ b> R communicates with the common liquid chamber 16. The pressure chamber electrode 12 </ b> C is connected to a driving element that applies a voltage to the piezoelectric element 12. The ink discharge hole 15 of the nozzle plate 14 is provided at a position corresponding to the pressure chamber 12R.

  For example, PZT (lead zirconate titanate) can be used for the piezoelectric element 12. For the resin film, for example, a paraxylylene-based polymer such as Parylene (registered trademark) can be used. When Parylene (registered trademark) is used, any grade may be used.

  When a voltage is applied, the side wall 12S is deformed, and the volume of the pressure chamber 12R changes due to this deformation. By this volume change, ink is sucked and discharged from the ink discharge hole 15.

  4 is a cross-sectional view of the inkjet head 101 taken along line BB in FIG. As shown in FIG. 4, the inkjet head 101 is attached to the mask 201 with the nozzle plate 14 side facing the recording medium side.

  The side wall 12S has a trapezoidal cross section. The nozzle plate 14 is fixed to the upper surface corresponding to the upper base of this trapezoid with an adhesive.

  FIG. 5 is a plan view of the inkjet head 101 with the nozzle plate 14 removed. As shown in FIG. 5, the inkjet head 101 includes a piezoelectric element 12 in a space surrounded by the substrate 11 and the frame body 13. The piezoelectric element 12 has side walls in the shape of comb teeth.

  FIG. 6 is a plan view showing the nozzle plate 14 of the present embodiment. As shown in FIG. 6, the nozzle plate 14 includes an ink discharge hole 15 provided at a position corresponding to the pressure chamber 12 </ b> R, and a first alignment hole provided at a position corresponding to a corner portion of the upper surface of the first side wall. 401A and a second alignment hole 401B provided at a position corresponding to a corner portion of the upper surface of the second side wall different from the first side wall.

  It is desirable that the first alignment hole 401A and the second alignment hole 401B be arranged away from each other in the diagonal direction from the center of gravity of the nozzle plate 14 in terms of improving the alignment accuracy.

  That is, the first alignment hole 401A and the second alignment hole 401B are provided at positions away from the center line in the long side direction and the center line in the short side direction of the nozzle plate 14.

  FIG. 7 is a diagram illustrating a positional relationship between the side wall 12S, the first alignment hole 401A, and the second alignment hole 401B.

  As shown in FIG. 7, the ink discharge holes 15 are arranged at positions corresponding to the pressure chambers 12 </ b> R of the piezoelectric elements 12. On the other hand, the first alignment hole 401A and the second alignment hole 401B are arranged at positions corresponding to the corners on the upper surface of the side wall 12S.

  The alignment is performed by visual confirmation so that the outer circumferences of the first alignment hole 401A and the second alignment hole 401B are in contact with the corners of the upper surface of the corresponding side wall.

  FIG. 8 is a plan view showing the nozzle plate 14 of the present embodiment according to an application example. As shown in FIG. 8, the nozzle plate 14 includes an ink discharge hole 15 provided at a position corresponding to the pressure chamber 12R, and a first alignment hole provided at a position corresponding to a corner of the upper surface of the first side wall. 401A and a second alignment hole 401B provided at a position corresponding to a corner portion of the upper surface of the second side wall different from the first side wall.

  The first alignment hole 401A and the second alignment hole 401B can be disposed at a position closest to the center line in the long side direction from the center of gravity of the nozzle plate 14 and farthest from the center line in the short side direction. .

  This arrangement has the advantage that it is less susceptible to errors due to thermal expansion of the nozzle plate 14.

  FIG. 9 is a diagram illustrating a positional relationship between the sidewall 12S and the first alignment hole 401A and the second alignment hole 401B according to the application example.

  As shown in FIG. 9, the ink ejection holes 15 are arranged at positions corresponding to the pressure chambers 12 </ b> R of the piezoelectric element 12. On the other hand, the first alignment hole 401A and the second alignment hole 401B are arranged at positions corresponding to the corners on the upper surface of the side wall 12S.

  The alignment is performed by visual confirmation so that the outer circumferences of the first alignment hole 401A and the second alignment hole 401B are in contact with the corners of the upper surface of the corresponding side wall.

  FIG. 10 is a diagram illustrating a method for bonding the nozzle plate 14 to the piezoelectric element 12. As shown in FIG. 10, the nozzle plate 14 has a protective film 14 </ b> A on the surface facing the bonding surface.

  First, as shown in FIG. 10A, an adhesive 801 is applied to the upper surface of the side wall 12S of the piezoelectric element 12.

  Next, as shown in FIG. 10B, after alignment, the nozzle plate 14 is bonded to the piezoelectric element 12. At this time, excess adhesive 801 on the upper surface of the side wall 12S enters the first alignment hole 401A and the second alignment hole 401B, and the first alignment hole 401A and the second alignment hole 401B are blocked. It is.

  Therefore, ink does not leak from the first alignment hole 401A and the second alignment hole 401B.

  Next, the protective film 14A is removed.

  FIG. 11 is a diagram illustrating a case where the adhesive 801 overflows. As shown in FIG. 11, the nozzle plate 14 has a protective film 14 </ b> A on the surface facing the bonding surface.

  First, as shown in FIG. 11A, an adhesive 801 is applied to the upper surface of the side wall 12S of the piezoelectric element 12.

  Next, as shown in FIG. 11B, after alignment, the nozzle plate 14 is bonded to the piezoelectric element 12. At this time, excess adhesive 801 on the upper surface of the side wall 12S enters the first alignment hole 401A and the second alignment hole 401B, and the first alignment hole 401A and the second alignment hole 401B are blocked. It is.

  Therefore, ink does not leak from the first alignment hole 401A and the second alignment hole 401B.

  Next, as shown in FIG. 11C, the protective film 14A is removed. At this time, the overflowing adhesive 801 is removed together with the protective film 14A.

  FIG. 12 is a diagram showing a state of alignment. As shown in FIG. 12, the alignment is performed by visual confirmation so that the outer periphery of the first alignment hole 401A and the second alignment hole 401B is in contact with the corner 12P on the upper surface of the corresponding side wall.

  FIG. 13 is a diagram showing alignment by the alignment mark 1101. As shown in FIG. 13, an alignment mark 1101 can be provided as an alignment mark on the upper surface of the first side wall and the upper surface of the second side wall. The shape of the alignment mark 1101 does not matter.

  In this case, the alignment mark 1101 is visually aligned so that both are positioned at the center of the first alignment hole 401A and the second alignment hole 401B.

  FIG. 14 is a diagram showing alignment by the alignment scale 1201. As shown in FIG. 14, an alignment scale 1201 can be provided as an alignment mark on the upper surface of the first side wall and the upper surface of the second side wall. The shape of the alignment scale 1201 does not matter.

  In this case, the alignment is performed by visual observation so that the centers of the alignment scales 1201 come to the centers of the first alignment hole 401A and the second alignment hole 401B.

Next, a method for manufacturing the ink jet head 101 of this embodiment will be described.
(1) A pair of piezoelectric elements 12 are bonded to the substrate 11. The distance between the pair of piezoelectric elements 12 is determined by a jig.
(2) The piezoelectric element 12 is cut to form a groove that becomes the pressure chamber 12R. For this cutting, a diamond wheel can be used.
(3) The pressure chamber electrode 12C is formed inside the groove. The pressure chamber electrode 12C is formed, for example, by generating a nickel thin film by electroless plating.
(4) The frame 13 is bonded to the substrate 11.
(5) The resin film 300 is formed on the piezoelectric element 12. The resin film 300 is formed by CVD (Chemical Vapor Deposition).
When Parylene (registered trademark) is used for the resin, a film of Parylene C is formed with a thickness of 1 μm to 10 μm. Parylene (registered trademark) may be any grade.
A portion where the resin film 300 is not necessary is masked with a masking tape such as a polyimide tape. Alternatively, after forming the resin film 300, only necessary portions may be covered with a jig, and unnecessary resin film 300 may be removed by etching by plasma treatment.
(6) The nozzle plate 14 is positioned by the first alignment hole 401A and the second alignment hole 401B and bonded to the side wall 12S and the frame body 13.
(7) The ink discharge holes 15 are formed in the nozzle plate 14 by irradiating laser.
(8) The mask 201 is bonded to the frame 13 with an ink-resistant adhesive.
(9) The ink supply pipe and the ink discharge pipe are bonded to the substrate 11.

  As described above, the inkjet head 101 of the present embodiment includes the substrate 11, the piezoelectric element 12 having the pressure chamber 12 </ b> R formed on the substrate 11 and formed by the side wall 12 </ b> S formed in a comb-teeth shape, A frame 13 arranged so as to surround the element 12, an ink discharge hole 15 provided at a position corresponding to the pressure chamber 12R, and a first alignment hole 401A provided at a position corresponding to the upper surface of the first side wall. And a second alignment hole 401B provided at a position corresponding to the upper surface of the second side wall different from the first side wall, and the nozzle plate 14 covering the piezoelectric element 12 and the frame body 13; .

  Therefore, there is an effect that the alignment of the nozzle plate 14 can be performed accurately and rapidly by performing the alignment while visually recognizing from the first alignment hole 401A and the second alignment hole 401B.

  Although several embodiments have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

11: Substrate 13: Frame 13A: Mounting portion 14: Nozzle plate 401A: First alignment hole 401B: Second alignment hole

Claims (6)

A substrate,
Piezoelectric elements having pressure chambers formed on the substrate and formed by comb-shaped sidewalls;
A frame disposed so as to surround the piezoelectric element;
An ink ejection hole provided at a position corresponding to the pressure chamber, a first alignment hole provided at a position corresponding to the upper surface of the first side wall, and an upper surface of a second side wall different from the first side wall. A nozzle plate having a second alignment hole provided at a corresponding position and covering the piezoelectric element and the frame;
An inkjet head comprising: The first alignment hole is blocked by an adhesive on the upper surface of the first sidewall;
The inkjet head according to claim 1, wherein the second alignment hole is blocked by an adhesive on the upper surface of the second side wall. The first side wall has an alignment mark at a position corresponding to the first alignment hole,
The inkjet head according to claim 2, wherein the second side wall has an alignment mark at a position corresponding to the second alignment hole. The first alignment hole provided at a position corresponding to the upper surface of the first side wall and the second alignment hole provided at a position corresponding to the upper surface of the second side wall different from the first side wall Aligning the plate with the piezoelectric element;
Coating the piezoelectric element with the nozzle plate;
A method for manufacturing an ink-jet head comprising: The first alignment hole is blocked by an adhesive on the upper surface of the first sidewall;
The inkjet head manufacturing method according to claim 4, wherein the second alignment hole is closed by an adhesive on an upper surface of the second side wall. The first side wall has an alignment mark at a position corresponding to the first alignment hole,
The inkjet head manufacturing method according to claim 5, wherein the second side wall has an alignment mark at a position corresponding to the second alignment hole.

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