JP5485208B2 - Inkjet head - Google Patents

Description

  Embodiments described herein relate generally to an inkjet head.

  A share mode shear wall type inkjet head used in an inkjet printer is an insulating substrate formed of a ceramic material, a nozzle plate disposed opposite to the insulating substrate, and a drive disposed in a stacked manner between the insulating substrate and the nozzle plate. An element and a frame member made of a ceramic material forming a common liquid chamber and a pressure chamber by surrounding the drive element are provided.

  The drive element has a pair of piezoelectric elements made of a PZT (lead zirconate titanate) piezoelectric ceramic material. The drive element is driven by a drive circuit, and an electrode pattern that allows the drive element and the drive circuit to communicate with each other is formed on an insulating substrate. Further, both end faces of the drive element are tapered.

  In conventional inkjet heads, the frame material is stepped and adhesive is not applied to the frame material and mask fitting part, but rather, the adhesive is applied around the frame material to form the frame material and mask fitting part. Was bonded so as to flow using the capillary phenomenon when bonded.

  For this reason, it is necessary to provide a step in the frame material, and parts are made by diffusion bonding or the like in order to provide a shape, so that expensive parts are required.

  In addition, since the portion where the mask plate is in contact with the surface is bonded with only a part of the outer peripheral portion of the frame material, the bonding strength is weak and weak against impact.

JP 2007-190892 A

  The problem to be solved by the present invention is to provide a highly reliable ink jet head that is inexpensive and adheres to a mask plate and also reliably protects exposed electrode portions.

  An ink jet head according to an embodiment is provided with a nozzle plate having a plurality of nozzles, a plurality of pressure chambers corresponding to the nozzles, and adjacent to the pressure chambers, and pressurizes the pressure chambers to discharge liquid from the nozzles. A piezoelectric element to be bonded, a substrate to which the piezoelectric element is bonded, a frame placed on the substrate so as to surround the piezoelectric element, an electrode for driving the piezoelectric element, and the nozzle plate A mask plate; a tab member on which an electrical component that is connected to the electrode and drives the piezoelectric element is placed; and a spacer that covers one end surface of the tab member and a part of the wiring pattern of the electrode. The region formed by the frame and the spacer was filled with an adhesive, and the mask plate was adhered to the tab member.

It is a figure showing the structure of an inkjet head. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1 of the ink jet head according to the first embodiment. It is a top view which shows the state which removed the mask plate of the inkjet head which concerns on 1st Embodiment. FIG. 3 is a cross-sectional view taken along the line AA in FIG. 1 of an inkjet head according to a second embodiment. It is a top view which shows the state which removed the mask plate of the inkjet head which concerns on 2nd Embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same portions are denoted by the same reference numerals, and redundant description is omitted.

  The share mode share wall type ink jet print head is configured by providing a plurality of ink chambers (grooves) and side walls, and a nozzle plate is bonded to the upper portion of the ink jet print head.

(First embodiment)
1 and 2 are diagrams illustrating a configuration of an inkjet head 100 according to the embodiment. The ink jet head 100 includes an insulating substrate 11 formed of a dielectric, a piezoelectric element 12 placed on the substrate 11 and engraved with a pressure chamber having a space and a conductor layer therein, and the piezoelectric element. 12 is provided with a frame 13 placed on the substrate 11 so as to surround 12, and a nozzle plate 14 having a plurality of nozzle holes 15 bonded to the upper end of the side wall of the piezoelectric element 12.

  The substrate 11 is made of alumina, for example. As the material of the other substrate 11, an insulating material such as glass epoxy resin can be used.

  The ink jet head 100 has two rows of piezoelectric elements 12 on a substrate 11. The piezoelectric element 12 is formed of PZT (lead zirconate titanate). Other piezoelectric element 12 materials include PTO (PbTiO3: lead titanate), PMNT (Pb (Mg1 / 3Nb2 / 3) O3-PbTiO3: lead magnesium niobate), PZNT (Pb (Zn1 / 3Nb2 / 3) O3- PbTiO3), ZnO or the like can also be used.

  The nozzle plate 14 is formed of a resin film such as polyimide. A water repellent film (not shown) is formed on the surface of the nozzle plate 14 on the ink droplet discharge side, for example, with a fluororesin. As another nozzle plate 14 material, a nickel plate or a silicon plate can also be used.

  The nozzle holes 15 function as ink droplet ejection holes and are formed at equal intervals.

  2 is a cross-sectional view of the inkjet head 100 according to the first embodiment taken along line AA in FIG. As shown in FIG. 2, the inkjet head 100 has an ink inlet 17 and an ink outlet 16 in the substrate 11. Ink circulates through the ink inlet 17, the pressure chamber 30, and the ink outlet 16. The pressure chamber 30 has a space and a conductor layer inside. An ink chamber 8 surrounded by the substrate 11, the frame body 13, and the nozzle plate 14 is formed.

  A piezoelectric element 12 is bonded to the surface of the substrate 11. In this case, the configuration of the substrate 11 / piezoelectric element 12 is alumina / PZT. Note that the surface layer 11 </ b> A may be formed on the surface of the substrate 11. PZT can be used as the material of the surface layer 11A, but alumina, PTO, PMNT, PZNT, ZnO, or the like can also be used as a material for manufacturing the other surface layer 11A.

  Further, the side wall of the pressure chamber 30 of the piezoelectric element 12 has a trapezoidal cross section. The nozzle plate 14 has a nozzle hole 15 above the pressure chamber 30.

  The inkjet head 100 includes a driver IC 18 that drives the piezoelectric element 12 outside the frame body 13, and an electrode 19 that connects the driver IC 18 and the piezoelectric element 12. The driver IC 18 is attached to the tab member 20. In FIG. 1, reference numeral 25 denotes a substrate.

  The electrode 19 has a pattern wired on the surface layer 11 </ b> A of the substrate 11. The wiring pattern is connected to an electronic component that performs ink ejection control, such as the driver IC 18.

  The ink jet head 100 ejects ink by the deformation of the pressure element 12 driven by the driver IC 18. That is, ink is introduced into the pressure chamber 30 with the increased volume, and the pressure chamber 30 with the reduced volume discharges the pressurized ink from the nozzle hole 15.

  The nozzle hole 15 for discharging ink and the electrode 19 to which the driver IC 18 and the printed board are connected are close to each other. Therefore, if the pattern is exposed in the wiring pattern part after connecting the driver IC 18 or the printed circuit board, mist-like ink adheres to the wiring pattern part when the ink jet head is used, or surplus ink by the wiper at the time of maintenance may be There is a possibility of adhering to the part. Due to the adhesion of the ink, the electrode is short-circuited due to the deposition of carbon contained in the ink or the adhesion of a metal substance, which causes non-ejection. Therefore, it is necessary to cover the exposed part of the electrode 19 of the wiring pattern.

  As shown in FIG. 2, the tab member 20 is formed in an L shape, and is attached to the substrate 11 on one end side thereof, for example, via an anisotropic conductive film. A spacer 21 is mounted on the tab member 20 so as to partially cover the tab member 20 and the substrate 11. The spacer 21 is an insulator and is made of, for example, a film made of PET resin.

  As shown in FIG. 2, the upper surface of the frame body 13 is flat, and a space is formed between the end of the spacer 21 and the frame body 13. This space (space) is filled with an adhesive 23, and a mask plate 22 is bonded to protect the nozzle plate 14 from contact with a medium and a wiper during maintenance. In other words, the space is a receiving tank for the adhesive 23, and in this embodiment, the mask plate 22 is bonded, and at the same time, the wiring pattern portion of the electrode 19 is covered with the adhesive 23 so as not to be exposed. Yes.

  FIG. 3 is a top view showing a state where the mask plate 22 and the nozzle plate 14 of the inkjet head 100 according to the first embodiment are removed.

  The adhesive 23 is preferably an epoxy adhesive because it has corrosion resistance to the ink and insulation is required for the ink containing carbon. It should be noted that the adhesive 23 is not excessively filled so that the gap between the end face of the nozzle plate 14 and the upper end face of the frame 13 and the end face of the mask plate 22 is filled. If the adhesive 23 protrudes from the surface of the nozzle plate 14 or the surface of the mask plate 22, the nozzle hole 15 is blocked or the flatness of the nozzle plate 14 or the mask plate 22 is not maintained. This is because the ink cannot be wiped off with the wiper.

  The height of the mask plate 22 after bonding is made convex with respect to the nozzle plate 14 by, for example, about several tens of microns. It goes without saying that the height of the mask plate 22 may be flush with the nozzle plate 14 depending on the specifications of the ink jet print head.

  According to the present embodiment, it is possible to provide an escape area for the surplus adhesive and further cover the wiring pattern while ensuring a bonding area at the time of bonding the mask plate without requiring complicated processing on the frame member.

(Second Embodiment)
Next, a second embodiment will be described. The basic configuration of the inkjet head 100 according to the second embodiment is largely the same as that of the first embodiment except for the spacer.

  4 is a cross-sectional view of the inkjet head 100 according to the second embodiment taken along line AA in FIG. FIG. 5 is a top view showing a state in which the mask plate of the ink jet head according to the second embodiment is removed.

  As shown in FIGS. 4 and 5, the spacer 24 is formed with a plurality of long grooves 24 a. Compared to the space (space) in the first embodiment, the groove 24a can receive more adhesive as the adhesive receiving portion, so that the adhesive can be reliably prevented from protruding to the mask plate 22 surface. Can be suppressed. The number of the groove portions 24a is two, for example, and the shape of the groove 24a is preferably a long hole, for example.

  According to the present embodiment, the frame material is not provided with a step structure, and a spacer member is provided so as to provide a groove on the outer periphery of the frame, thereby securing a bonding area when the mask plate is bonded, and a place for escape of excess adhesive. In addition, the wiring pattern can be covered, and an inexpensive inkjet head can be manufactured.

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

100: inkjet head,
9 ... Nozzle array 11 ... Substrate,
12 ... Piezoelectric element,
13 ... Frame,
14 ... Nozzle plate,
15 ... Nozzle hole,
16: Ink discharge port,
17: Ink inlet,
18 ... Driver IC,
19 ... Electrodes,
20 ... Tab member,
21 ... spacer,
22 ... Mask plate,
23: Adhesive,
24 ... spacer,
24a ... groove,
25 .. substrate
30: Pressure chamber.

Claims (9)

A nozzle plate having a plurality of nozzles;
A plurality of pressure chambers corresponding to the nozzle, a piezoelectric element provided adjacent to the pressure chamber and pressurizing the pressure chamber to discharge liquid from the nozzle;
A substrate to which the piezoelectric element is bonded;
A frame mounted on the substrate so as to surround the piezoelectric element;
An electrode for driving the piezoelectric element;
A mask plate for protecting the nozzle plate;
A tab member for mounting an electrical component connected to the electrode and driving the piezoelectric element;
A spacer that covers one end side surface of the tab member and a part of the wiring pattern of the electrode;
Comprising
An inkjet head in which an area formed by the frame body and the spacer is filled with an adhesive and the mask plate is bonded to the tab member.   The inkjet head according to claim 1, wherein the tab member is formed in an L shape and is attached on the surface layer of the substrate at the one end side.   The ink jet head according to claim 2, wherein the tab member is attached via an anisotropic conductive film. The inkjet head according to any one of claims 1 to 3 , wherein the spacer is attached so as to partially cover the tab member and the surface layer of the substrate. The inkjet head according to any one of claims 1 to 4 , wherein the spacer is made of a film made of PET resin. The adhesive, ink jet head according to any one of claims 1 to 5 is an epoxy resin adhesive. Wherein the spacer, the ink-jet head according to any one of claims 1 to 6 grooves are formed. The inkjet head according to claim 7 , wherein the groove is plural. The ink jet head according to claim 7 or 8 , wherein the shape of the groove is a long hole.

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