Method for manufacturing inkjet head, inkjet head manufactured thereby and method for inspecting inkjet head

Abstract

The present application relates to a method of manufacturing an inkjet head, an inkjet head manufactured thereby, and a method of inspecting an inkjet head, the method of manufacturing an inkjet head comprising: forming a preliminary nozzle plate comprising an organic material; forming a nozzle plate including a plurality of nozzles formed by processing the preliminary nozzle plate using a laser; forming a piezoelectric plate on the nozzle plate; forming a first coating film on the lower surface of the nozzle plate; forming a second coating film covering the first coating film and including a material different from that of the first coating film; forming a third coating film under the second coating film and including a different material from the first coating film and the second coating film; and forming a fourth coating film under the third coating film and including a different material from the first coating film, the second coating film, and the third coating film.

Description

Technical Field

[0001] Embodiments generally provide a method of manufacturing an inkjet head, an inkjet head manufactured thereby, and a method of inspecting an inkjet head. More particularly, embodiments relate to a method of manufacturing an inkjet head used in a process of manufacturing a display device, an inkjet head manufactured thereby, and a method of inspecting an inkjet head. Background Art

[0002] With the development of information technology, the importance of display devices as a communication medium between users and information is becoming increasingly prominent. Therefore, the use of display devices such as liquid crystal display devices, organic light emitting display devices, plasma display devices, etc. is increasing.

[0003] Inkjet printing equipment can be used in the manufacturing process of display devices. For example, when manufacturing display devices such as organic light-emitting display devices, inkjet printing equipment can be used to form patterns such as color conversion layers and light-emitting layers.

[0004] An inkjet printing device may include a plurality of inkjet heads that eject ink. The inkjet heads may be coated with a plurality of coating films to improve ejection accuracy and protect nozzles of the inkjet heads. Summary of the Invention

[0005] Embodiments provide a method of manufacturing an inkjet head having improved wear resistance.

[0006] An embodiment provides an inkjet head manufactured by the method of manufacturing an inkjet head.

[0007] An embodiment provides a method of inspecting an inkjet head.

[0008] However, the embodiments are not limited to the embodiments described herein. The above and other embodiments will become more apparent to those skilled in the art to which the present disclosure pertains by referencing the detailed description of the present disclosure given below.

[0009] According to an embodiment, a method for manufacturing an inkjet head includes: forming a preliminary nozzle plate including an organic material; forming a nozzle plate including a plurality of nozzles, the plurality of nozzles being formed by processing the preliminary nozzle plate using a laser; forming a piezoelectric plate on the nozzle plate; forming a first coating film on a lower surface of the nozzle plate; forming a second coating film, the second coating film covering the first coating film and including a material different from the first coating film; forming a third coating film, the third coating film including a material different from the first coating film and the second coating film and being disposed under the second coating film; and forming a fourth coating film, the fourth coating film including a material different from the first coating film, the second coating film, and the third coating film and being disposed under the third coating film.

[0010] In an embodiment, when forming the first coating film, the first coating film may be formed to completely cover the inner surface of the nozzle plate exposed by each of the nozzles.

[0011] In an embodiment, when forming the second coating film, the second coating film may be formed to completely cover the side surface of the piezoelectric plate.

[0012] In an embodiment, the first coating film may include an organic material and an inorganic material, the second coating film may include at least one of a metal oxide and an organic-inorganic composite material containing a metal oxide, the third coating film may include an inorganic material, and the fourth coating film may include a polymer compound having hydrophobic properties and containing fluorine (F) and silicon (Si).

[0013] In an embodiment, the preliminary nozzle plate may include polyimide (PI).

[0014] In an embodiment, forming the piezoelectric plate may include: forming a first polymer layer on the nozzle plate; forming an organic layer on the first polymer layer; forming a piezoelectric member on the organic layer; forming a metal layer on the piezoelectric member; forming a glass layer on the metal layer; and forming a second polymer layer on the glass layer and the organic layer.

[0015] According to an embodiment, a method for manufacturing an inkjet head includes: forming a preliminary nozzle plate including an organic material; forming a preliminary first-first coating on the lower surface of the preliminary nozzle plate; forming a preliminary sacrificial coating on the lower surface of the preliminary first-first coating, the preliminary sacrificial coating including a material different from the preliminary first-first coating; forming a nozzle plate including a plurality of nozzles, a first-first coating forming a step with the nozzle plate, and a sacrificial coating forming a step with the nozzle plate by using laser processing the preliminary nozzle plate, the preliminary first-first coating, and the preliminary sacrificial coating; forming a piezoelectric plate on the nozzle plate; removing the sacrificial coating; forming a first-second coating on the lower surface of the first-first coating, the first-second coating covering the first-first coating; forming a second coating covering the first-second coating and including a material different from the first-first coating and the first-second coating; forming a third coating under the second coating, the third coating including a material different from the first-second coating and the second coating; and forming a fourth coating under the third coating, the fourth coating including a material different from the first-second coating, the second coating, and the third coating.

[0016] In an embodiment, when forming the first-second coating films, the first-second coating films may be formed to completely cover the inner surface of the nozzle plate exposed by each of the nozzles.

[0017] In an embodiment, when forming the second coating film, the second coating film may be formed to completely cover the side surface of the piezoelectric plate.

[0018] In an embodiment, the first-first coating film and the first-second coating film may include an organic material and an inorganic material, the second coating film may include at least one of a metal oxide and an organic-inorganic composite material containing a metal oxide, the third coating film may include an inorganic material, and the fourth coating film may include a polymer compound having hydrophobic properties and containing fluorine (F) and silicon (Si).

[0019] In an embodiment, the preliminary nozzle plate may include polyimide (PI).

[0020] In an embodiment, forming the piezoelectric plate may include: forming a first polymer layer on the nozzle plate; forming an organic layer on the first polymer layer; forming a piezoelectric member on the organic layer; forming a metal layer on the piezoelectric member; forming a glass layer on the metal layer; and forming a second polymer layer on the glass layer and the organic layer.

[0021] According to an embodiment, an inkjet head includes: a nozzle plate including an organic material and including a plurality of nozzles that discharge ink to the outside; a piezoelectric plate disposed on the nozzle plate; a first coating film disposed on a lower surface of the nozzle plate and on an inner surface of the nozzle plate exposed by each of the nozzles; a second coating film covering the first coating film and including a material different from the first coating film; a third coating film disposed under the second coating film, covering at least a portion of the second coating film, and including a material different from the first coating film and the second coating film; and a fourth coating film disposed under the third coating film and including a material different from the first coating film, the second coating film, and the third coating film.

[0022] In an embodiment, the first coating film may completely cover the inner surface of the nozzle plate.

[0023] In an embodiment, a first thickness of a portion of the first coating film in contact with the lower surface of the nozzle plate may be greater than a second thickness of a portion of the first coating film in contact with the inner surface of the nozzle plate.

[0024] In an embodiment, the second coating film may extend from under the first coating film to completely cover the side surface of the piezoelectric plate.

[0025] In an embodiment, the third coating film may extend from under the second coating film to at least a portion of the interior of the nozzle.

[0026] In an embodiment, the inner surface of the nozzle plate may include a first side surface perpendicular to the lower surface of the nozzle plate and a second side surface inclined in a direction away from each of the nozzles, and the third coating film may extend from under the second coating film to the interior of the nozzle to face the first side surface of the inner surface of the nozzle plate.

[0027] In an embodiment, the first coating film may include: a first-first coating film disposed on the lower surface of the nozzle plate and forming a step together with the nozzle plate; and a first-second coating film disposed on the lower surface of the first-first coating film and the inner surface of the nozzle plate to cover the first-first coating film.

[0028] In an embodiment, a first thickness of a portion of the first coating film in contact with the lower surface of the nozzle plate may be greater than a second thickness of a portion of the first coating film in contact with the inner surface of the nozzle plate.

[0029] In embodiments, the average thickness of the first coating film may be in a range of about 5 nm to about 25 nm, the average thickness of the second coating film may be in a range of about 5 nm to about 1000 nm, and the average thickness of the third coating film may be in a range of about 5 nm to about 1000 nm.

[0030] In an embodiment, the average thickness of the fourth coating film may be in the range of about 20 nm or less.

[0031] In an embodiment, the first coating film may include an organic material and an inorganic material, the second coating film may include at least one of a metal oxide and an organic-inorganic composite material containing a metal oxide, the third coating film may include an inorganic material, and the fourth coating film may include a polymer compound having hydrophobic properties and containing fluorine (F) and silicon (Si).

[0032] In an embodiment, the nozzle plate may include polyimide (PI).

[0033] In an embodiment, the piezoelectric plate may include a first polymer layer disposed on the nozzle plate, an organic layer disposed on the first polymer layer, a piezoelectric member disposed on the organic layer, a metal layer disposed on the piezoelectric member, a glass layer disposed on the metal layer, and a second polymer layer disposed on the glass layer and the organic layer.

[0034] In an embodiment, when ink is disposed inside the inkjet head, a brightness ratio of a first region of the inkjet head in which each of the nozzles is disposed to a second region of the inkjet head not including the nozzles may be about 1 or less.

[0035] According to an embodiment, a method for inspecting an inkjet head includes manufacturing an inkjet head and imaging the inkjet head into a two-dimensional (2D) image with ink set inside the inkjet head, the inkjet head including: a nozzle plate including an organic material and including a plurality of nozzles that discharge ink to the outside; a piezoelectric plate formed on the nozzle plate; a first coating film formed on a lower surface of the nozzle plate; a second coating film covering the first coating film and including a material different from the first coating film; a third coating film formed under the second coating film, covering at least a portion of the second coating film, and including an inorganic material; and a fourth coating film formed under the third coating film and including a material different from the first coating film, the second coating film, and the third coating film.

[0036] In an embodiment, imaging the inkjet head as a 2D image with ink disposed inside the inkjet head may include measuring an amount of grayscale variation between a first region of the inkjet head where each of the nozzles is disposed and a second region of the inkjet head that does not include the nozzles.

[0037] In an embodiment, when ink is disposed inside the inkjet head, a luminance ratio of a first region of the inkjet head in which each of the nozzles is disposed to a second region of the inkjet head not including the nozzles is about 1 or less.

[0038] In an embodiment, imaging the inkjet head as a 2D image with ink disposed inside the inkjet head includes imaging the inkjet head in a reflection mode or a transmission mode using a microscope.

[0039] In an inkjet head according to an embodiment, the nozzle assembly of the inkjet head may include: a nozzle plate comprising an organic material; a first coating film disposed on the lower surface of the nozzle plate and on the inner surface of the nozzle plate exposed by each of the nozzles; a second coating film covering the first coating film; a third coating film disposed below the second coating film and covering at least a portion of the second coating film; and a fourth coating film disposed below the third coating film. The first coating film may include an inorganic material and an organic material, the second coating film may include a metal oxide, the third coating film may include an inorganic material, and the fourth coating film may have liquid repellency. Therefore, the occurrence of scratches, tears, etc. in the first coating film can be reduced. For example, degradation of the ink discharge characteristics of the inkjet head can be reduced, and the wear resistance of the inkjet head can be improved.

[0040] In the method for manufacturing an inkjet head according to an embodiment, before forming the first coating film, the second coating film, the third coating film, and the fourth coating film, a nozzle plate including a plurality of nozzles can be formed by processing a preliminary nozzle plate using a laser. In another example, after forming the nozzle plate, the first-first coating film on the lower surface of the nozzle plate, the sacrificial coating film having liquid repellency on the lower surface of the first-first coating film, and the piezoelectric plate on the nozzle plate, the sacrificial coating film can be removed. After removing the sacrificial coating film, the first-second coating film, the third coating film, and the fourth coating film can be formed in sequence. Thus, the first coating film can be formed on the inner surface of the nozzle plate, the first coating film is formed into the first-first coating film and the first-second coating film, and an inkjet head with improved wear resistance can be manufactured. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Exemplary, non-limiting embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings.

[0042] Figure 1 is a schematic perspective view showing an inkjet printing apparatus according to an embodiment.

[0043] Figure 2 It shows Figure 1 A schematic perspective view of a head module.

[0044] Figure 3 It is shown that the Figure 2 A schematic perspective view of an inkjet head in a head module.

[0045] Figure 4 It is shown that the Figure 3 Schematic plan view of a nozzle component in an inkjet head.

[0046] Figure 5 It is shown along Figure 3 A schematic cross-sectional view of an example of a cross section taken along line II'.

[0047] Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 and Figure 12 Is used to illustrate the manufacturing Figure 5 Schematic cross-sectional view of an inkjet head approach.

[0048] Figure 13 It is shown along Figure 3 A schematic cross-sectional view of another example of a cross section taken along line II'.

[0049] Figure 14 、 Figure 15 、 Figure 16 、 Figure 17 、 Figure 18 、 Figure 19 、 Figure 20 and Figure 21 Is used to illustrate the manufacturing Figure 13 Schematic cross-sectional view of an inkjet head approach.

[0050] Figure 22 It is shown along Figure 3 A schematic cross-sectional view of yet another example of a cross section taken along line II'.

[0051] Figure 23 is a flowchart illustrating a method of inspecting an inkjet head according to an embodiment. DETAILED DESCRIPTION

[0052] In the following description, for the purpose of illustration, many specific details are set forth in order to provide a thorough understanding of various embodiments or implementations of the present invention. As used herein, "embodiment" and "implementation" are interchangeable words that are non-limiting examples of the apparatus or method disclosed herein. However, it is apparent that various embodiments can be practiced without these specific details or with one or more equivalent arrangements. Here, various embodiments are not necessarily exclusive and do not limit the present disclosure. For example, the specific shape, configuration and characteristics of an embodiment can be used or implemented in another embodiment.

[0053] Unless otherwise indicated, the embodiments shown should be understood to provide features of the present invention. Therefore, unless otherwise indicated, the features, components, modules, layers, films, panels, regions and / or aspects of the various embodiments (hereinafter, individually or collectively referred to as "elements") may be combined, separated, interchanged and / or rearranged in other ways without departing from the scope of the present invention.

[0054] The use of cross hatching and / or shading in the drawings is generally provided to clarify the boundaries between adjacent elements. Therefore, unless specified, the presence or absence of cross hatching or shading does not convey or indicate any preference or requirement for a particular material, material properties, size, ratio, commonality between the elements shown and / or any other characteristics, attributes, properties, etc. of the elements. In addition, in the drawings, the size and relative size of the elements may be exaggerated for the purpose of clarity and / or description. When the embodiments can be implemented differently, the specific process sequence can be performed differently from the described sequence. For example, two processes described in succession can be performed substantially simultaneously, or in an order opposite to the described sequence. In addition, similar reference numerals represent similar elements.

[0055] When an element or layer is referred to as being "on," "connected to," or "coupled to" another element or layer, it may be directly on, directly connected to, or directly coupled to the other element or layer, or there may be intervening elements or layers. However, when an element or layer is referred to as being "directly on," "directly connected to," or "directly coupled to" another element or layer, there may be no intervening elements or layers. For this purpose, the term "connected" may refer to a physical connection, an electrical connection, and / or a fluid connection with or without intervening elements. In addition, the axis of the first direction DR1, the axis of the second direction DR2, and the axis of the third direction DR3 are not limited to three axes of a rectangular coordinate system, such as the X-axis, the Y-axis, and the Z-axis, and may be interpreted in a broader sense. For example, the axis of the first direction DR1, the axis of the second direction DR2, and the axis of the third direction DR3 may be perpendicular to each other, or may represent different directions that are not perpendicular to each other. For the purposes of this disclosure, "at least one of A and B" may be understood to mean only A, only B, or any combination of A and B. Furthermore, “at least one of X, Y, and Z” and “at least one selected from the group consisting of X, Y, and Z” may be interpreted as any combination of only X, only Y, only Z, or two or more of X, Y, and Z. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0056] Although the terms "first," "second," etc. may be used herein to describe various types of elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another. Thus, the first element discussed below may be referred to as a second element without departing from the teachings of the present disclosure.

[0057] For descriptive purposes, spatially relative terms such as "below," "beneath," "under," "down," "above," "up," "above," "higher," "side" (e.g., as in "sidewall"), etc. may be used herein and thereby describe the relationship of one element to another element(s) as shown in the accompanying drawings. Spatially relative terms are intended to encompass different orientations of the device in use, operation, and / or manufacture in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, elements described as "below" or "beneath" other elements or features will then be oriented "above" the other elements or features. Thus, the term "below" can encompass both above and below orientations. Furthermore, the device may be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and therefore, the spatially relative descriptors used herein should be interpreted accordingly.

[0058] The terms used herein are for the purpose of describing specific embodiments and are not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to also include plural forms, unless the context clearly indicates otherwise. In addition, when used in this specification, the terms "comprise", "comprises", "includes" and / or "includes" specify the existence of stated features, integral bodies, steps, operations, elements, components and / or their groups, but do not exclude the existence or addition of one or more other features, integral bodies, steps, operations, elements, components and / or their groups. It should also be noted that, as used herein, the terms "substantially", "about" and other similar terms are used as approximate terms and are not used as terms of degree, and are therefore used to explain the inherent deviations in measured values, calculated values ​​and / or provided values ​​that will be recognized by those of ordinary skill in the art.

[0059] Various embodiments are described herein with reference to cross-sectional views and / or exploded views that are schematic diagrams of embodiments and / or intermediate structures. Therefore, variations in the shapes of the figures, for example due to manufacturing techniques and / or tolerances, should be expected. Therefore, the embodiments disclosed herein should not necessarily be interpreted as limited to the specific illustrated shapes of the regions, but should include deviations in shapes, for example, due to manufacturing. In this way, the regions shown in the drawings may be schematic in nature, and the shapes of these regions may not reflect the actual shapes of the regions of the device, and therefore, are not necessarily intended to be limiting.

[0060] As is customary in the art, some embodiments are described and illustrated in the accompanying drawings for functional blocks, units, and / or modules. Those skilled in the art will appreciate that these blocks, units, and / or modules are physically implemented by electrical circuits (or optical circuits) such as logic circuits, discrete components, microprocessors, hard-wired circuits, memory elements, wiring connectors, etc., which can be formed using semiconductor-based manufacturing techniques or other manufacturing techniques. Where blocks, units, and / or modules are implemented by microprocessors or other similar hardware, they can be programmed and controlled using software (e.g., microcode) to perform the various functions discussed herein, and can be selectively driven by firmware and / or software. It is also contemplated that each block, unit, and / or module can be implemented by dedicated hardware, or can be implemented as a combination of dedicated hardware for performing some functions and a processor for performing other functions (e.g., one or more programmed microprocessors and associated circuits). In addition, without departing from the scope of the present invention, each block, unit, and / or module of some embodiments can be physically separated into two or more interactive and discrete blocks, units, and / or modules. Furthermore, the blocks, units and / or modules of some embodiments may be physically combined into more complex blocks, units and / or modules without departing from the scope of the invention.

[0061] Hereinafter, a method of manufacturing an inkjet head, an inkjet head manufactured thereby, and a method of inspecting an inkjet head according to an embodiment will be described in detail with reference to the accompanying drawings. The same reference numerals are used for the same components in the drawings, and redundant descriptions of the same components will be omitted.

[0062] Figure 1 is a schematic perspective view showing an inkjet printing apparatus according to an embodiment.

[0063] In this specification, a plane may be defined as a plane defined by a first direction DR1 and a second direction DR2 intersecting the first direction DR1. For example, the second direction DR2 may be perpendicular to the first direction DR1. For example, the third direction DR3 may be perpendicular to the plane.

[0064] refer to Figure 1 , the inkjet printing apparatus IPA according to the embodiment may include a head module HM, a stage STA, a first rail RL1, a second rail RL2, a moving part TP, a control part CP, and a supporting part SP.

[0065] The head module HM may discharge the ink IK to the outside. For example, the head module HM may discharge the ink IK onto a substrate SUB disposed on the stage STA. For example, as the head module HM discharges the ink IK onto the substrate SUB, a color conversion layer or a light-emitting layer of a display device may be formed on the substrate SUB. However, embodiments are not limited thereto.

[0066] As described above, the substrate SUB can be placed on the stage STA. The stage STA can be moved in the second direction DR2 via a first guide rail RL1 connected to one side of the stage STA and a second guide rail RL2 connected to the other side of the stage STA. Therefore, the substrate SUB can also be moved in the second direction DR2 via the first and second guide rails RL1 and RL2. For example, ink IK discharged from the head module HM can be applied to a selected location on the substrate SUB. For example, each of the first and second guide rails RL1 and RL2 can extend in the second direction DR2.

[0067] The movable part TP can be combined with the head module HM (or connected to the head module HM). The movable part TP can move the head module HM in a specific direction. For example, the movable part TP can move the head module HM in a first direction DR1, in a direction opposite to the first direction DR1, in a third direction DR3, or in a direction opposite to the third direction DR3. When the movable part TP moves the head module HM in a specific direction, the position where the ink IK is discharged on the substrate SUB can be specified or controlled.

[0068] The control component CP can be connected to the head module HM. The control component CP may include an ink supply module and an ink control module. The ink supply module of the control component CP can supply ink IK to the head module HM via a connector CNL. The ink control module of the control component CP can control the head module HM by providing electrical signals to the head module HM. Thus, the ink control module of the control component CP can adjust the timing and position of the discharge of ink IK onto the substrate SUB.

[0069] The support member SP can fix the head module HM and the movable member TP so as to be positioned on the stage STA. The movable member TP can move along a portion of the support member SP in a first direction DR1 or in a direction opposite to the first direction DR1. Therefore, the head module HM coupled to the movable member TP can move along the portion of the support member SP in the first direction DR1 or in a direction opposite to the first direction DR1.

[0070] Figure 2 It shows Figure 1 A schematic perspective view of a head module. Figure 3 It is shown that the Figure 2 Schematic perspective view of an inkjet head (e.g., a single inkjet head) in a head module. Figure 4 It is shown that the Figure 3 Schematic plan view of a nozzle component in an inkjet head.

[0071] refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 4 , the head module HM may include an inkjet head frame IHF and inkjet heads IH.

[0072] The inkjet head frame IHF can support the inkjet head IH at the lower part of the inkjet head IH. For example, the inkjet head frame IHF can serve as (or be used as) a frame for the inkjet head IH. For example, the inkjet head IH can be inserted into the inkjet head frame IHF and fixed to the inkjet head frame IHF. For example, an opening can be defined (or formed) in the inkjet head frame IHF, and the inkjet head IH can be inserted into the opening and fixed to the opening respectively.

[0073] The inkjet head frame IHF may have various shapes. For example, the inkjet head frame IHF may have a square column shape. However, the embodiment is not limited thereto.

[0074] The head module HM can discharge ink IK to the outside through the inkjet heads IH. The inkjet heads IH can be set on the inkjet head frame IHF. The inkjet heads IH can be repeatedly arranged along the first direction DR1 and the second direction DR2 on the inkjet head frame IHF. The inkjet heads IH can constitute a head group. For example, a head group can be constituted by forming a set of five inkjet heads IH adjacent to each other in the second direction DR2. However, the embodiment is not limited to this, and the number of inkjet heads IH constituting a head group can vary.

[0075] Each of the inkjet heads IH may include a nozzle part NP, a driving part DP, an inlet IL, and an outlet OUL.

[0076] The nozzles NZ may be defined (or formed) in the nozzle part NP. The nozzles NZ may be repeatedly arranged along the first direction DR1 and the second direction DR2. The nozzles NZ may each be formed as a nozzle plate penetrating the nozzle part NP. The inkjet head IH may discharge the ink IK to the outside (e.g., Figure 1 substrate SUB).

[0077] The inlet IL and the outlet OUL may be provided on the nozzle part NP. The inlet IL and the outlet OUL may be arranged to be spaced apart from each other in the first direction DR1, with the driving part DP interposed between the inlet IL and the outlet OUL. For example, the inlet IL may be connected to one side of the nozzle part NP, and the outlet OUL may be connected to the other side of the nozzle part NP. The ink IK may flow in (or be injected) through the inlet IL. For example, the ink IK flowing in through the inlet IL may be discharged to the outside (for example, through the nozzle NZ of the nozzle part NP) through the nozzle NZ. Figure 1 Among the ink IK existing in (or provided in) the nozzle NZ of the nozzle part NP, the ink IK that is not discharged to the outside can be recovered through the outlet OUL.

[0078] The drive component DP may be disposed on the nozzle assembly NP. The drive component DP may be disposed between the inlet IL and the outlet OUL. For example, the drive component DP may be inserted into and fixed to the nozzle assembly NP. For example, the drive component DP may include various electronic components (e.g., a printed circuit board) for driving the nozzle assembly NP.

[0079] Figure 5 It is shown along Figure 3 A schematic cross-sectional view of an example of a cross section taken along line II'.

[0080] refer to Figure 3 and Figure 5The nozzle assembly NP of the inkjet head IH may include a nozzle plate NPT, a first coating film CF1, a second coating film CF2, a third coating film CF3, and a fourth coating film CF4, a piezoelectric plate PPT, a metal plate MPT, and a metal mesh MM. For example, the piezoelectric plate PPT may include a first polymer layer PL1, an organic layer OL, a piezoelectric member PM, a metal layer ML, a glass layer GL, and a second polymer layer PL2.

[0081] In an embodiment, the nozzle plate NPT may include an organic material. For example, the nozzle plate NPT may include polyimide (PI). However, the embodiment is not limited thereto.

[0082] Ink (e.g. Figure 1 The nozzles NZ through which the ink IK is discharged to the outside may be defined (or formed) in the nozzle plate NPT. The nozzles NZ may be formed to penetrate the nozzle plate NPT. For example, the nozzles NZ may be formed by penetrating the nozzle plate NPT in the third direction DR3.

[0083] The nozzle plate NPT may include an outer surface and an inner surface. The outer surface of the nozzle plate NPT may be the lower surface LS of the nozzle plate NPT facing the first coating film CF1, the second coating film CF2, the third coating film CF3, and the fourth coating film CF4. The inner surface of the nozzle plate NPT may be exposed by the nozzle NZ. The inner surface of the nozzle plate NPT may include a first side surface S1 and a second side surface S2. The first side surface S1 may connect the lower surface LS of the nozzle plate NPT and the second side surface S2. In an embodiment, the first side surface S1 may be perpendicular to the lower surface LS of the nozzle plate NPT, and the second side surface S2 may be inclined in a direction away from the nozzle NZ.

[0084] The diameter of the nozzle NZ may vary depending on the position (or location). In an embodiment, the diameter of the nozzle NZ contacting the first side surface S1 may be smaller than the diameter of the nozzle NZ contacting the second side surface S2. However, the embodiment is not limited thereto.

[0085] The piezoelectric plate PPT may be disposed on the nozzle plate NPT. For example, a first polymer layer PL1 may be disposed on the nozzle plate NPT. The first polymer layer PL1 may include an adhesive material. For example, the first polymer layer PL1 may include an adhesive material such as an epoxy-based resin or a silicone-based resin. These adhesive materials may be used alone or in combination.

[0086] An organic layer OL may be disposed on the first polymer layer PL1. The organic layer OL and the nozzle plate NPT may be combined via the first polymer layer PL1. The organic layer OL may include a polymer compound. For example, the organic layer OL may include parylene. However, embodiments are not limited thereto. The organic layer OL may cover the lower surface and side surfaces of the piezoelectric member PM. For example, the organic layer OL may contact the lower surface and side surfaces of the piezoelectric member PM. Therefore, the organic layer OL may reduce damage to the piezoelectric member PM.

[0087] The piezoelectric member PM may be provided on the first polymer layer PL1 and the organic layer OL. The piezoelectric member PM may control the flow of ink supplied to the nozzle NZ during the ink discharge process. For example, from a control component (eg, Figure 1 The electrical signal generated by the control part CP can be transmitted to the piezoelectric plate PPT to generate vibration. Due to the vibration, pressure can be generated inside the nozzle part NP, thereby controlling the flow rate of ink.

[0088] For example, the piezoelectric member PM can adjust the pressure outside and inside the nozzle part NP. The piezoelectric member PM can adjust the external pressure and the pressure of the first ink chamber CB1 to be the same or different. For example, the piezoelectric member PM can adjust the pressure of the first ink chamber CB1 to be higher than the external pressure. Therefore, the ink inside the first ink chamber CB1 can be discharged to the outside through the nozzle NZ. In another example, the piezoelectric member PM can adjust the external pressure and the pressure of the first ink chamber CB1 to be substantially equal. Therefore, the ink inside the first ink chamber CB1 may not be discharged to the outside through the nozzle NZ.

[0089] The piezoelectric member PM may include a piezoelectric material. For example, the piezoelectric member PM may include a piezoelectric material such as lead zirconate titanate (PZT). However, the embodiment is not limited thereto.

[0090] The metal layer ML may be disposed on the piezoelectric member PM. The metal layer ML may contact the upper surface of the piezoelectric member PM and a portion of the organic layer OL. The metal layer ML may protect the piezoelectric member PM. For example, the metal layer ML may include aluminum (Al). However, the embodiment is not limited thereto.

[0091] The glass layer GL may be disposed on the metal layer ML. The glass layer GL may contact the upper surface of the metal layer ML and a portion of the organic layer OL. For example, the glass layer GL may include glass, quartz, etc. These may be used alone or in combination with each other.

[0092] The second polymer layer PL2 may be disposed on the glass layer GL and the organic layer OL. The lower surface of the second polymer layer PL2 may contact the upper surface of the glass layer GL and a portion of the organic layer OL. The second polymer layer PL2 may include an adhesive material. For example, the second polymer layer PL2 may include an adhesive material such as an epoxy-based resin or a silicon-based resin. These adhesive materials may be used alone or in combination.

[0093] Therefore, the piezoelectric plate PPT including the first polymer layer PL1 , the organic layer OL, the piezoelectric member PM, the metal layer ML, the glass layer GL, and the second polymer layer PL2 may be disposed on the nozzle plate NPT.

[0094] An ink supply channel (ISE) may be defined (or formed) in the piezoelectric plate PPT. The ink supply channel (ISE) may be formed by penetrating the piezoelectric plate PPT. The ink supply channel (ISE) may be connected to the nozzles NZ. For example, the ink supply channel (ISE) may expose the nozzles NZ. The ink supply channel (ISE) may be a passage through which ink passes. Thus, ink may be transferred to the nozzles NZ via the ink supply channel (ISE).

[0095] The metal plate MPT may be provided on the piezoelectric plate PPT. The metal plate MPT may include a metal material. For example, the metal plate MPT may include stainless steel (SUS). However, the embodiment is not limited thereto.

[0096] The first ink chamber CB1 may be defined (or formed) between the piezoelectric plate PPT and the metal plate MPT. The first ink chamber CB1 may be connected to the ink supply channel ISE. For example, the first ink chamber CB1 may expose the ink supply channel ISE. Ink may be stored within the first ink chamber CB1. The first ink chamber CB1 may transfer ink to the ink supply channel ISE. For example, when the pressure outside the inkjet head IH and the pressure of the first ink chamber CB1 are substantially the same, ink may be stored within the first ink chamber CB1. For example, ink may not be discharged from the first ink chamber CB1 through the ink supply channel ISE and the nozzle NZ to the outside.

[0097] The metal mesh MM may be provided on the metal plate MPT. The metal mesh MM may have a mesh shape in a plan view. The metal mesh MM may include a metal material. For example, the metal mesh MM may include stainless steel. However, the embodiment is not limited thereto.

[0098] The second ink chamber CB2 may be defined (or formed) between the metal plate MPT and the metal mesh MM. Ink may be stored inside the second ink chamber CB2. The second ink chamber CB2 may transfer ink to the first ink chamber CB1. The first ink chamber CB1 and the second ink chamber CB2 may be connected to each other through a connecting channel. Figure 5The nozzle part NP shown in FIG is connected to each other in different regions. For example, the second ink chamber CB2 may expose the first ink chamber CB1.

[0099] The third ink chamber CB3 may be defined (or formed) on the metal mesh MM. Ink may be stored within the third ink chamber CB3. The third ink chamber CB3 may transfer ink to the second ink chamber CB2. The third ink chamber CB3 and the second ink chamber CB2 may be connected to each other via a connecting channel. For example, the third ink chamber CB3 may expose the second ink chamber CB2. Thus, ink may pass from the third ink chamber CB3 through the second ink chamber CB2 and the first ink chamber CB1 in sequence and be transferred to the ink supply channel ISE.

[0100] As a result, the ink supply channel ISE, the first ink chamber CB1, the metal plate MPT, the second ink chamber CB2, the metal mesh MM, and the third ink chamber CB3 may form an ink passage that may control the flow rate of ink to discharge the ink to the outside.

[0101] The first coating film CF1 may be provided on the lower surface LS of the nozzle plate NPT. The first coating film CF1 may be used to bond the nozzle plate NPT and the second coating film CF2 (or function to bond the nozzle plate NPT and the second coating film CF2). For example, the wear resistance of the inkjet head IH may be improved due to the first coating film CF1.

[0102] The first coating film CF1 may extend from the lower surface LS of the nozzle plate NPT to at least a portion of the interior of the nozzle NZ. In an embodiment, the first coating film CF1 may extend from the lower surface LS of the nozzle plate NPT to cover the inner surface of the nozzle plate NPT. For example, the first coating film CF1 may cover (e.g., completely cover) the inner surface of the nozzle plate NPT. For example, the first coating film CF1 may contact the lower surface LS and the inner surface of the nozzle plate NPT. For example, no step may be formed between the first coating film CF1 and the nozzle plate NPT. Since the first coating film CF1 covers the inner surface of the nozzle plate NPT, the occurrence of scratches and tears in the first coating film CF1 can be reduced.

[0103] In an embodiment, the first coating film CF1 may include an organic material and an inorganic material. For example, the first coating film CF1 may include silicon oxycarbide (SiOC). However, the embodiment is not limited thereto.

[0104] For example, the average thickness of the first coating film CF1 may be in a range of approximately 5 nm to approximately 25 nm. However, embodiments are not limited thereto. For example, the first thickness TH1 of the portion of the first coating film CF1 in contact with the lower surface LS of the nozzle plate NPT may be different from the second thickness TH2 of the portion of the first coating film CF1 in contact with the inner surface of the nozzle plate NPT. In embodiments, the first thickness TH1 of the portion of the first coating film CF1 in contact with the lower surface LS of the nozzle plate NPT may be greater than the second thickness TH2 of the portion of the first coating film CF1 in contact with the inner surface of the nozzle plate NPT.

[0105] The second coating film CF2 may be disposed below the first coating film CF1. The second coating film CF2 may extend from below the first coating film CF1 to cover at least a portion of the side surface of the piezoelectric plate PPT. In an embodiment, the second coating film CF2 may cover (e.g., completely cover) the side surface of the piezoelectric plate PPT. For example, the second coating film CF2 may contact (e.g., completely contact) the side surface of the piezoelectric plate PPT.

[0106] The first coating film CF1 may contact the side surface of the piezoelectric plate PPT.

[0107] The second coating film CF2 may include a material different from that of the first coating film CF1. In an embodiment, the second coating film CF2 may include a metal oxide. In another embodiment, the second coating film CF2 may include a metal oxide and / or an organic-inorganic composite material including a metal oxide. Examples of metal oxides may include aluminum oxide (e.g., Al2O3), silicon tin oxide (SiSnO x ) etc. Examples of organic materials may include alkanes (C x H y ).

[0108] For example, the average thickness of the second coating film CF2 may be in the range of about 5 nm to about 1000 nm. However, the embodiment is not limited thereto. The second coating film CF2 may extend from under the first coating film CF1 to the side surface of the piezoelectric plate PPT with substantially the same (or similar) thickness.

[0109] The third coating film CF3 may be disposed below the second coating film CF2. The third coating film CF3 may cover at least a portion of the second coating film CF2. The third coating film CF3 may be used to join the second coating film CF2 and the fourth coating film CF4 (or serve to join the second coating film CF2 and the fourth coating film CF4).

[0110] The third coating film CF3 may extend from under the second coating film CF2 to at least a portion of the interior of the nozzle NZ. In an embodiment, the third coating film CF3 may extend from under the second coating film CF2 to the interior of the nozzle NZ so as to face the first side surface S1 of the inner surface of the nozzle plate NPT. For example, the third coating film CF3 may contact a portion of the second coating film CF2. However, embodiments are not limited thereto. In another embodiment, the third coating film CF3 may extend to cover (e.g., completely cover) the second coating film CF2. For example, the third coating film CF3 may contact (e.g., completely contact) the second coating film CF2.

[0111] The third coating film CF3 may include a material different from that of the first coating film CF1 and the second coating film CF2. In an embodiment, the third coating film CF3 may include an inorganic material. For example, the third coating film CF3 may include silicon oxide (e.g., SiO2). In another example, the third coating film CF3 may include silicon nitride (SiN x ), silicon oxynitride (SiN x O y ), metal oxides, etc. These may be used alone or in combination with each other.

[0112] For example, the average thickness of the third coating film CF3 may be in the range of about 5 nm to about 1000 nm. However, embodiments are not limited thereto. If the average thickness of the third coating film CF3 exceeds about 1000 nm, the ink discharge characteristics of the nozzle NZ may deteriorate. The third coating film CF3 may extend from below the second coating film CF2 to at least a portion of the interior of the nozzle NZ with substantially the same (or similar) thickness.

[0113] The fourth coating film CF4 may be disposed below the third coating film CF3. The fourth coating film CF4 may contact at least a portion of the third coating film CF3. For example, the fourth coating film CF4 may contact a surface of the third coating film CF3 that faces the lower surface LS of the nozzle plate NPT. For example, the fourth coating film CF4 may not extend into the interior of the nozzle NZ.

[0114] The fourth coating film CF4 may have liquid repellency. The fourth coating film CF4 may include a compound having hydrophobic properties. For example, the fourth coating film CF4 may have a water contact angle of about 100 degrees to about 200 degrees based on DI water.

[0115] The fourth coating film CF4 may include a material different from that of the first coating film CF1, the second coating film CF2, and the third coating film CF3. In an embodiment, the fourth coating film CF4 may include a polymer compound including fluorine (F) and silicon (Si), such as perfluoroalkoxyalkane (PFA).

[0116] For example, the average thickness of the fourth coating film CF4 may be in the range of about 20 nm or less. However, the embodiment is not limited thereto.

[0117] In an embodiment, when ink is present (or disposed) inside the inkjet head IH (e.g., inside the nozzle part NP), the brightness ratio of a first region in which each of the nozzles NZ of the inkjet head IH (e.g., the nozzle part NP) is located to a second region of the inkjet head IH (e.g., the nozzle part NP) that does not include the nozzles NZ is about 1 or less. For example, the average thickness of the second coating film CF2 may be in the range of about 30 nm or more.

[0118] Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 and Figure 12 Is used to illustrate the manufacturing Figure 5 A schematic cross-sectional view of an inkjet head method. For example, Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 and Figure 12 is shown in the manufacture included in Figure 5 A schematic cross-sectional view of a nozzle part NP in an inkjet head IH.

[0119] refer to Figure 6 and Figure 7 , the preliminary nozzle plate NPT_P including an organic material may be formed. For example, the preliminary nozzle plate NPT_P may include an organic material such as polyimide (PI).

[0120] Laser L may be irradiated to the preliminary nozzle plate NPT_P. For example, the nozzles NZ may be formed by processing the preliminary nozzle plate NPT_P with laser L. Thus, a nozzle plate NPT including a plurality of nozzles NZ may be formed. Figure 5 Before forming the first coating film CF1 , the second coating film CF2 , the third coating film CF3 , and the fourth coating film CF4 , the nozzle NZ may be formed by processing the preliminary nozzle plate NPT_P with the laser L. Therefore, no step may be formed between the nozzle plate NPT and the first coating film CF1 .

[0121] refer to Figure 8A piezoelectric plate PPT may be formed on the nozzle plate NPT. For example, a first polymer layer PL1, an organic layer OL, a piezoelectric member PM, a metal layer ML, a glass layer GL, and a second polymer layer PL2 may be sequentially formed on the nozzle plate NPT. An ink supply channel ISE may be formed in the piezoelectric plate PPT, penetrating the piezoelectric plate PPT and connected to the nozzle NZ.

[0122] refer to Figure 9 , a metal plate MPT and a metal mesh MM may be sequentially formed on the piezoelectric plate PPT. For example, the metal plate MPT and the metal mesh MM may include stainless steel.

[0123] When the metal plate MPT and the metal mesh MM are sequentially formed on the piezoelectric plate PPT, a first ink chamber CB1 may be defined (or formed) between the piezoelectric plate PPT and the metal plate MPT, a second ink chamber CB2 may be defined (or formed) between the metal plate MPT and the metal mesh MM, and a third ink chamber CB3 may be defined (or formed) on the metal mesh MM. The first ink chamber CB1, the second ink chamber CB2, and the third ink chamber CB3 may be connected to each other via a connecting channel, and the first ink chamber CB1 may be connected to the ink supply channel ISE.

[0124] refer to Figure 10 , a first coating film CF1 may be formed on the lower surface LS of the nozzle plate NPT. The first coating film CF1 may be formed to extend to at least a portion of the interior of the nozzle NZ. In an embodiment, the first coating film CF1 may be formed to cover (e.g., completely cover) the inner surface of the nozzle plate NPT exposed by the nozzle NZ. In an embodiment, the first coating film CF1 may include an inorganic material and an organic material. For example, the first coating film CF1 may be formed by a chemical vapor deposition (CVD) process, an atomic layer deposition (ALD) process, or a physical vapor deposition (PVD) process.

[0125] refer to Figure 11 , a second coating film CF2 may be formed under the first coating film CF1. The second coating film CF2 may be formed to cover the first coating film CF1. In an embodiment, the second coating film CF2 may be formed to cover (e.g., completely cover) the side surface of the piezoelectric plate PPT. In an embodiment, the second coating film CF2 may include a metal oxide and / or an organic-inorganic composite material including a metal oxide. For example, the second coating film CF2 may be formed by a chemical vapor deposition process, an atomic layer deposition process, or a physical vapor deposition process.

[0126] refer to Figure 12, a third coating film CF3 may be formed below the second coating film CF2. In an embodiment, the third coating film CF3 may be formed to extend to at least a portion of the interior of the nozzle NZ. In an embodiment, the third coating film CF3 may include an inorganic material. For example, the third coating film CF3 may be formed by a chemical vapor deposition process, an atomic layer deposition process, or a physical vapor deposition process.

[0127] Reference again Figure 5 , a fourth coating film CF4 may be formed below the third coating film CF3. The fourth coating film CF4 may not be formed to extend into the interior of the nozzle NZ. The fourth coating film CF4 may have liquid repellency. In an embodiment, the fourth coating film CF4 may include a polymer compound having hydrophobic properties and containing fluorine (F) and silicon (Si). For example, the fourth coating film CF4 may be formed by a physical vapor deposition process.

[0128] Reference again Figure 3 , forming the inlet IL and outlet OUL connected to the nozzle part NP, and the driving part DP can be inserted into the nozzle part NP. Figure 3 inkjet head IH.

[0129] Figure 13 It is shown along Figure 3 A schematic cross-sectional view of another example of a cross section taken along line II'.

[0130] In addition to the first coating film CF1', reference Figure 13 The nozzle part NP' of the inkjet head described can be compared with the reference Figure 5 The nozzle parts NP of the inkjet head 1H described are substantially the same or similar. Hereinafter, for convenience of description, overlapping descriptions are omitted or simplified.

[0131] refer to Figure 13 The nozzle assembly NP' of the inkjet head may include a nozzle plate NPT, a first coating film CF1', a second coating film CF2, a third coating film CF3, a fourth coating film CF4, a piezoelectric plate PPT, a metal plate MPT, and a metal mesh MM. For example, the piezoelectric plate PPT may include a first polymer layer PL1, an organic layer OL, a piezoelectric member PM, a metal layer ML, a glass layer GL, and a second polymer layer PL2.

[0132] The first-first coating film CF11 may be disposed on the lower surface LS of the nozzle plate NPT. A step may be defined (or formed) between the nozzle plate NPT and the first-first coating film CF11. For example, the first-first coating film CF11 may expose a portion of the lower surface LS of the nozzle plate NPT adjacent to the nozzle NZ. In an embodiment, the first-first coating film CF11 may include an inorganic material and an organic material. For example, the first-first coating film CF11 may include silicon oxycarbide (SiOC). However, embodiments are not limited thereto.

[0133] The first-second coating film CF12 may be disposed below the first-first coating film CF11. The first-second coating film CF12 may cover the first-first coating film CF11 and may also be disposed on the inner surface of the nozzle plate NPT. In an embodiment, the first-second coating film CF12 may extend from the lower surface LS of the nozzle plate NPT to cover the inner surface of the nozzle plate NPT. For example, the first-second coating film CF12 may cover (e.g., completely cover) the inner surface of the nozzle plate NPT. For example, the first-second coating film CF12 may contact the lower surface of the first-first coating film CF11 and the inner surface of the nozzle plate NPT. Since the first-second coating film CF12 covers the inner surface of the nozzle plate NPT, the step between the first-first coating film CF11 and the nozzle plate NPT may be compensated. Therefore, the occurrence of scratches, tears, etc. in the first-first coating film CF11 and the first-second coating film CF12 may be reduced.

[0134] In an embodiment, the first-second coating film CF12 may include an inorganic material and an organic material. For example, the first-second coating film CF12 may include silicon oxycarbide (SiOC). However, the embodiment is not limited thereto.

[0135] For example, the first-first coating film CF11 and the first-second coating film CF12 may include the same material. However, the embodiment is not limited thereto.

[0136] The first-first coating film CF11 and the first-second coating film CF12 may be combined to define (or form) a first coating film CF1'. As a result, the portion of the first coating film CF1' facing the lower surface LS of the nozzle plate NPT may be composed of a double film (or formed as a double film), and the first coating film CF1' facing the inner surface of the nozzle plate NPT may be composed of a single film (or formed as a single film).

[0137] For example, the average thickness of the first coating film CF1' may be in a range of approximately 5 nm to approximately 25 nm. However, embodiments are not limited thereto. For example, the first thickness TH1' of the portion of the first coating film CF1' that contacts the lower surface LS of the nozzle plate NPT may be different from the second thickness TH2' of the portion of the first coating film CF1' that contacts the inner surface of the nozzle plate NPT. In embodiments, the first thickness TH1' of the portion of the first coating film CF1' that contacts the lower surface LS of the nozzle plate NPT may be greater than the second thickness TH2' of the portion of the first coating film CF1' that contacts the inner surface of the nozzle plate NPT.

[0138] The second coating film CF2 may be disposed under the first coating film CF1'. The second coating film CF2 may extend from under the first coating film CF1' to cover at least a portion of the side surface of the piezoelectric plate PPT. In an embodiment, the second coating film CF2 may cover (e.g., completely cover) the side surface of the piezoelectric plate PPT. For example, the second coating film CF2 may contact (e.g., completely contact) the first coating film CF1' and may contact the side surface of the piezoelectric plate PPT. The second coating film CF2 may include a material different from that of the first coating film CF1'. In an embodiment, the second coating film CF2 may include a metal oxide and / or an organic-inorganic composite material including a metal oxide.

[0139] For example, the average thickness of the second coating film CF2 may be in the range of about 5 nm to about 1000 nm.

[0140] The third coating film CF3 may be provided below the second coating film CF2. The third coating film CF3 may cover at least a portion of the second coating film CF2.

[0141] The third coating film CF3 may extend from under the second coating film CF2 to at least a portion of the interior of the nozzle NZ. In an embodiment, the third coating film CF3 may extend from under the second coating film CF2 to the interior of the nozzle NZ so as to face the first side surface S1 of the inner surface of the nozzle plate NPT. For example, the third coating film CF3 may contact a portion of the second coating film CF2. However, embodiments are not limited thereto. In another embodiment, the third coating film CF3 may extend to cover (e.g., completely cover) the second coating film CF2. For example, the third coating film CF3 may contact (e.g., completely contact) the second coating film CF2. The third coating film CF3 may include a material different from the first coating film CF1 and the second coating film CF2. In an embodiment, the third coating film CF3 may include an inorganic material.

[0142] For example, the average thickness of the third coating film CF3 may be in the range of about 5 nm to about 1000 nm. However, the embodiment is not limited thereto.

[0143] The fourth coating film CF4 may be disposed below the third coating film CF3. The fourth coating film CF4 may contact at least a portion of the third coating film CF3. For example, the fourth coating film CF4 may contact the side surface of the third coating film CF3 that faces the lower surface LS of the nozzle plate NPT. For example, the fourth coating film CF4 may not extend into the interior of the nozzle NZ. The fourth coating film CF4 may have liquid repellency. In an embodiment, the fourth coating film CF4 may include a polymer compound having hydrophobic properties and containing fluorine (F) and silicon (Si).

[0144] For example, the average thickness of the fourth coating film CF4 may be in the range of about 20 nm or less. However, the embodiment is not limited thereto.

[0145] In an embodiment, when ink is present (or disposed) inside the inkjet head (e.g., inside the nozzle block NP'), a luminance ratio of a first region in which each of the nozzles NZ of the inkjet head (e.g., the nozzle block NP') is located to a second region of the inkjet head (e.g., the nozzle block NP') not including the nozzles NZ is about 1 or less. For example, the average thickness of the second coating film CF2 may be in the range of about 30 nm or more.

[0146] Figure 14 、 Figure 15 、 Figure 16 、 Figure 17 、 Figure 18 、 Figure 19 、 Figure 20 and Figure 21 Is used to illustrate the manufacturing Figure 13 A schematic cross-sectional view of an inkjet head method. For example, Figure 14 、 Figure 15 、 Figure 16 、 Figure 17 、 Figure 18 、 Figure 19 、 Figure 20 and Figure 21 is shown in the manufacture included in Figure 13 Schematic cross-sectional view of a method of manufacturing a nozzle part NP' in an inkjet head.

[0147] In the following, for the convenience of description, the Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 and Figure 12 The contents of the method for manufacturing the inkjet head IH are described overlapping with the description.

[0148] refer to Figure 14 and Figure 15, the preliminary nozzle plate NPT_P including an organic material may be formed. For example, the preliminary nozzle plate NPT_P may include an organic material such as polyimide (PI).

[0149] A preliminary first-first coating film CF11_P may be formed (e.g., completely formed) on the lower surface of the preliminary nozzle plate NPT_P. In an embodiment, the preliminary first-first coating film CF11_P may include an inorganic material and an organic material. For example, the preliminary first-first coating film CF11_P may be formed by a chemical vapor deposition process, an atomic layer deposition process, or a physical vapor deposition process.

[0150] A preliminary sacrificial coating film CF_P may be formed (e.g., completely formed) on the lower surface of the preliminary first-first coating film CF11_P. The preliminary sacrificial coating film CF_P may have liquid repellency. The preliminary sacrificial coating film CF_P may include a material different from that of the preliminary first-first coating film CF11_P. In an embodiment, the preliminary sacrificial coating film CF_P may include a polymer compound having hydrophobic properties and containing fluorine (F) and silicon (Si). For example, the preliminary sacrificial coating film CF_P may be formed by a physical vapor deposition process.

[0151] Laser light L may be irradiated onto the preliminary nozzle plate NPT_P, the preliminary first-first coating film CF11_P, and the preliminary sacrificial coating film CF_P. For example, the preliminary nozzle plate NPT_P, the preliminary first-first coating film CF11_P, and the preliminary sacrificial coating film CF_P may be processed with laser light L to form a nozzle plate NPT, a first-first coating film CF11, and a sacrificial coating film CF in which a plurality of nozzles NZ are defined (or formed). At this time, a step may be formed between the nozzle plate NPT and the first-first coating film CF11, and a step may be formed between the nozzle plate NPT and the sacrificial coating film CF. For example, the first-first coating film CF11 and the sacrificial coating film CF may expose portions of the lower surface LS of the nozzle plate NPT adjacent to the nozzles NZ.

[0152] refer to Figure 16 A piezoelectric plate PPT may be formed on the nozzle plate NPT. For example, a first polymer layer PL1, an organic layer OL, a piezoelectric member PM, a metal layer ML, a glass layer GL, and a second polymer layer PL2 may be sequentially formed on the nozzle plate NPT. An ink supply channel ISE may be formed in the piezoelectric plate PPT, penetrating the piezoelectric plate PPT and connected to the nozzle NZ.

[0153] refer to Figure 17 , a metal plate MPT and a metal mesh MM can be formed in sequence on the piezoelectric plate PPT.

[0154] When the metal plate MPT and the metal mesh MM are sequentially formed on the piezoelectric plate PPT, a first ink chamber CB1 may be defined (or formed) between the piezoelectric plate PPT and the metal plate MPT, a second ink chamber CB2 may be defined (or formed) between the metal plate MPT and the metal mesh MM, and a third ink chamber CB3 may be defined (or formed) on the metal mesh MM. The first ink chamber CB1, the second ink chamber CB2, and the third ink chamber CB3 may be connected to each other via a connecting channel, and the first ink chamber CB1 may be connected to the ink supply channel ISE.

[0155] refer to Figure 18 In an embodiment, the sacrificial coating film CF may be removed. For example, the sacrificial coating film CF may be removed by an etching process.

[0156] refer to Figure 19 , a first-second coating film CF12 may be formed under the first-first coating film CF11. The first-second coating film CF12 may be formed to cover the first-first coating film CF11. In an embodiment, the first-second coating film CF12 may be formed to cover (e.g., completely cover) the inner surface (e.g., the first side surface S1 and the second side surface S2) of the nozzle plate NPT exposed by the nozzle NZ. In an embodiment, the first-second coating film CF12 may include an inorganic material and an organic material. For example, the first-second coating film CF12 may be formed by a chemical vapor deposition process, an atomic layer deposition process, or a physical vapor deposition process.

[0157] The first-first coating film CF11 and the first-second coating film CF12 may be combined to form a first coating film CF1 ′.

[0158] refer to Figure 20 , a second coating film CF2 may be formed under the first coating film CF1' to cover the first coating film CF1'. In an embodiment, the second coating film CF2 may be formed to cover (e.g., completely cover) the side surface of the piezoelectric plate PPT. In an embodiment, the second coating film CF2 may include a metal oxide and / or an organic-inorganic composite material including a metal oxide.

[0159] refer to Figure 21 , a third coating film CF3 may be formed under the second coating film CF2. In an embodiment, the third coating film CF3 may be formed to extend to at least a portion of the inside of the nozzle NZ. In an embodiment, the third coating film CF3 may include an inorganic material.

[0160] Reference again Figure 13, a fourth coating film CF4 may be formed below the third coating film CF3. The fourth coating film CF4 may not be formed to extend into the interior of the nozzle NZ. The fourth coating film CF4 may have liquid repellency. In an embodiment, the fourth coating film CF4 may include a polymer compound having hydrophobic properties and containing fluorine (F) and silicon (Si).

[0161] An inlet and an outlet connected to the nozzle part NP' may be formed, and a driving part may be inserted into the nozzle part NP'. The inlet, the outlet, and the driving part may correspond to Figure 3 The inlet IL, outlet OUL and driving part DP are formed. Thus, the inkjet head can be manufactured.

[0162] In the inkjet head according to the comparative example, a step is formed between the nozzle plate composed of an organic material and the first coating film composed of both organic and inorganic materials. Consequently, friction may concentrate on the step due to repeated ink discharge and ink absorption. For example, the first coating film may be damaged, and the ink discharge characteristics of the inkjet head may deteriorate.

[0163] Reference again Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 and Figure 5 as well as Figure 13 In the inkjet head IH according to the embodiment, the nozzle parts NP and NP' of the inkjet head IH may include a nozzle plate NPT containing an organic material, first coating films CF1 and CF1' provided on the lower surface LS of the nozzle plate NPT and the inner surface of the nozzle plate NPT exposed by each of the nozzles NZ (e.g., the first side surface S1 and the second side surface S2), a second coating film CF2 covering the first coating film CF1, a third coating film CF3 provided under the second coating film CF2 and covering at least a portion of the second coating film CF2, and a fourth coating film CF4 provided under the third coating film CF3. The first coating films CF1 and CF1' may include an inorganic material and an organic material, the second coating film CF2 may include a metal oxide, the third coating film CF3 may include an inorganic material, and the fourth coating film CF4 may have liquid repellency.

[0164] Therefore, the occurrence of scratches, tears, etc. in the first coating films CF1 and CF1' can be reduced. For example, the degradation of the ink discharge characteristics of the inkjet head 1H can be reduced, and the wear resistance of the inkjet head 1H can be improved.

[0165] Figure 22 It is shown along Figure 3 A schematic cross-sectional view of yet another example of a cross section taken along line II'.

[0166] In addition to the first coating film CF1 "and the fifth coating film CF5, reference Figure 22 The nozzle part NP" of the inkjet head described can be compared with the reference Figure 5 The nozzle parts NP of the inkjet head 1H described are substantially the same or similar. Hereinafter, for convenience of description, overlapping descriptions are omitted or simplified.

[0167] refer to Figure 22 The nozzle part NP" of the inkjet head may include a nozzle plate NPT, a first coating film CF1", a second coating film CF2, a third coating film CF3, a fourth coating film CF4 and a fifth coating film CF5, a piezoelectric plate PPT, a metal plate MPT and a metal mesh MM. For example, the piezoelectric plate PPT may include a first polymer layer PL1, an organic layer OL, a piezoelectric member PM, a metal layer ML, a glass layer GL and a second polymer layer PL2.

[0168] The first coating film CF1″ may be disposed on the lower surface LS of the nozzle plate NPT. A step may be defined (or formed) between the nozzle plate NPT and the first coating film CF1″. For example, the first coating film CF1″ may expose a portion of the lower surface LS of the nozzle plate NPT adjacent to the nozzle NZ. In an embodiment, the first coating film CF1″ may include an inorganic material and an organic material. For example, the first coating film CF1″ may include silicon oxycarbide (SiOC). However, embodiments are not limited thereto.

[0169] The fifth coating film CF5 may be disposed on the lower surface of the first coating film CF1". For example, the fifth coating film CF5 may contact the lower surface of the first coating film CF1". A step may be defined (or formed) between the fifth coating film CF5 and the nozzle plate NPT. For example, the fifth coating film CF5 may expose a portion of the lower surface LS of the nozzle plate NPT adjacent to the nozzle NZ. The fifth coating film CF5 may be liquid-repellent. In an embodiment, the fifth coating film CF5 may include a polymer compound having hydrophobic properties and containing fluorine (F) and silicon (Si).

[0170] The second coating film CF2 covering the first coating film CF1" and the fifth coating film CF5 can be set under the fifth coating film CF5. The second coating film CF2 can extend from under the fifth coating film CF5 to cover at least a portion of the side surface of the piezoelectric plate PPT. In an embodiment, the second coating film CF2 can cover (for example, completely cover) the side surface of the piezoelectric plate PPT. For example, the second coating film CF2 can contact the lower surface of the fifth coating film CF5 and the side surface of the piezoelectric plate PPT. Since the second coating film CF2 covers the first coating film CF1" and the fifth coating film CF5, the steps between the first coating film CF1" and the nozzle plate NPT and the steps between the fifth coating film CF5 and the nozzle plate NPT can be compensated. Therefore, the occurrence of scratches, tears, etc. in the first coating film CF1" and the second coating film CF2 can be reduced.

[0171] In an embodiment, the second coating film CF2 may include a metal oxide and / or an organic-inorganic composite material including the metal oxide.

[0172] The third coating film CF3 may be disposed below the second coating film CF2. The third coating film CF3 may cover at least a portion of the second coating film CF2. For example, the third coating film CF3 may extend from below the second coating film CF2 to at least a portion of the interior of the nozzle NZ. In an embodiment, the third coating film CF3 may include an inorganic material.

[0173] The fourth coating film CF4 may be disposed below the third coating film CF3. The fourth coating film CF4 may contact at least a portion of the third coating film CF3. For example, the fourth coating film CF4 may contact the side surface of the third coating film CF3 that faces the lower surface LS of the nozzle plate NPT. For example, the fourth coating film CF4 may not extend into the interior of the nozzle NZ. The fourth coating film CF4 may have liquid repellency. In an embodiment, the fourth coating film CF4 may include a polymer compound having hydrophobic properties and containing fluorine (F) and silicon (Si).

[0174] In an embodiment, when ink is present (or provided) inside the inkjet head (e.g., inside the nozzle part NP″), a brightness ratio of a first region in which each of the nozzles NZ of the inkjet head (e.g., the nozzle part NP″) is located to a second region of the inkjet head (e.g., the nozzle part NP″) that does not include the nozzles NZ is about 1 or less. For example, the average thickness of the second coating film CF2 may be in the range of about 30 nm or more.

[0175] Figure 23 is a flowchart illustrating a method of inspecting an inkjet head according to an embodiment.

[0176] refer to Figure 23 , the method of inspecting an inkjet head may include manufacturing the inkjet head S100 and imaging a nozzle part of the inkjet head S200.

[0177] For example, an inkjet head S100 may be manufactured. The inkjet head may include a nozzle part, an inlet connected to the nozzle part, an outlet connected to the nozzle part, and a driving part inserted into and fixed to the nozzle part. For example, the nozzle part may correspond to Figure 5 Nozzle components NP, Figure 13 Nozzle component NP' or Figure 22 The nozzle part NP", the inlet can correspond to Figure 3 The inlet IL, the outlet can correspond to Figure 3 The output of the drive unit can correspond to Figure 3 The driving component DP.

[0178] In an embodiment, in an ink (e.g., Figure 1When the ink (IK) is present (or disposed) inside the inkjet head (e.g., inside the nozzle assembly), the nozzle assembly of the inkjet head may be imaged as a 2D image (S200). For example, the nozzle assembly of the inkjet head may be imaged using a microscope in a reflection mode or a transmission mode. However, embodiments are not limited thereto.

[0179] Through 2D images, it is possible to measure the nozzles of inkjet heads (e.g. Figure 4 The amount of grayscale change between a first region in which each of the nozzles (e.g., the nozzle assembly) is located and a second region of the inkjet head that does not include the nozzles. For example, when ink is present (or disposed) inside the inkjet head (e.g., inside the nozzle assembly), the brightness ratio of the first region to the second region may be approximately 1 or less.

[0180] By the method of inspecting the inkjet head, it is possible to confirm that the second coating film (for example, Figure 5 、 Figure 13 or Figure 22 For example, the average thickness of the second coating film CF2 may be in the range of about 30 nm or more.

[0181] The embodiments can be applied to processes for manufacturing various display devices. For example, the embodiments can be applied to processes for manufacturing various display devices such as display devices for vehicles, ships, and aircraft, portable communication devices, display devices for display or information transmission, medical display devices, etc.

[0182] At the end of the detailed description, it will be appreciated by those skilled in the art that many changes and modifications may be made to the embodiments without departing substantially from the principles, spirit and scope of the present disclosure. Therefore, the disclosed embodiments are used in a general and descriptive sense only and not for the purpose of limitation.

Claims

1. A method for manufacturing an inkjet head, the method comprising: forming a preliminary nozzle plate comprising an organic material; forming a nozzle plate including a plurality of nozzles, the plurality of nozzles being formed by machining the preliminary nozzle plate using a laser; forming a piezoelectric plate on the nozzle plate; forming a first coating film on the lower surface of the nozzle plate; forming a second coating film that covers the first coating film and includes a material different from that of the first coating film; forming a third coating film comprising a material different from that of the first coating film and the second coating film and disposed below the second coating film; as well as A fourth coating film is formed that includes a material different from that of the first coating film, the second coating film, and the third coating film and is provided under the third coating film.

2. The method according to claim 1, wherein When forming the first coating film, the first coating film is formed so as to completely cover the inner surface of the nozzle plate exposed by each of the nozzles.

3. The method according to claim 1, wherein When forming the second coating film, the second coating film is formed so as to completely cover the side surface of the piezoelectric plate.

4. The method according to claim 1, wherein The first coating film includes organic material and inorganic material, The second coating film includes at least one of a metal oxide and an organic-inorganic composite material including the metal oxide, The third coating film includes an inorganic material, and The fourth coating film includes a polymer compound having hydrophobic properties and containing fluorine and silicon.

5. The method according to claim 1, wherein The preliminary nozzle plate includes polyimide.

6. The method according to claim 1, wherein Forming the piezoelectric plate includes: forming a first polymer layer on the nozzle plate; forming an organic layer on the first polymer layer; forming a piezoelectric member on the organic layer; forming a metal layer on the piezoelectric member; forming a glass layer on the metal layer; and A second polymer layer is formed on the glass layer and the organic layer.

7. A method for manufacturing an inkjet head, the method comprising: forming a preliminary nozzle plate comprising an organic material; forming a preliminary first-first coating film on the lower surface of the preliminary nozzle plate; forming a preliminary sacrificial coating film on a lower surface of the preliminary first-first coating film, the preliminary sacrificial coating film comprising a material different from that of the preliminary first-first coating film; Forming a nozzle plate including a plurality of nozzles, a first-first coating film forming a step with the nozzle plate, and a sacrificial coating film forming a step with the nozzle plate by processing the preliminary nozzle plate, the preliminary first-first coating film, and the preliminary sacrificial coating film using a laser; forming a piezoelectric plate on the nozzle plate; removing the sacrificial coating; forming a first-second coating film on a lower surface of the first-first coating film, the first-second coating film covering the first-first coating film; forming a second coating film that covers the first-second coating film and includes a material different from that of the first-first coating film and the first-second coating film; forming a third coating film below the second coating film, the third coating film comprising a material different from that of the first-second coating films and the second coating film; as well as A fourth coating film is formed under the third coating film, the fourth coating film including a material different from the first-second coating films, the second coating film, and the third coating film.

8. The method according to claim 7, wherein: When forming the first-second coating films, the first-second coating films are formed to completely cover the inner surface of the nozzle plate exposed by each of the nozzles.

9. The method according to claim 7, wherein: When forming the second coating film, the second coating film is formed so as to completely cover the side surface of the piezoelectric plate.

10. The method according to claim 7, wherein: The first-first coating film and the first-second coating film include organic materials and inorganic materials, The second coating film includes at least one of a metal oxide and an organic-inorganic composite material including the metal oxide, The third coating film includes an inorganic material, and The fourth coating film includes a polymer compound having hydrophobic properties and containing fluorine and silicon.

11. The method according to claim 7, wherein: The preliminary nozzle plate includes polyimide.

12. The method according to claim 7, wherein: Forming the piezoelectric plate includes: forming a first polymer layer on the nozzle plate; forming an organic layer on the first polymer layer; forming a piezoelectric member on the organic layer; forming a metal layer on the piezoelectric member; forming a glass layer on the metal layer; and A second polymer layer is formed on the glass layer and the organic layer.

13. An inkjet head, comprising: a nozzle plate including an organic material and including a plurality of nozzles for discharging ink to the outside; a piezoelectric plate disposed on the nozzle plate; a first coating film provided on a lower surface of the nozzle plate and an inner surface of the nozzle plate exposed by each of the nozzles; a second coating film covering the first coating film and comprising a material different from that of the first coating film; a third coating film disposed below the second coating film, covering at least a portion of the second coating film, and comprising a material different from that of the first coating film and the second coating film; as well as A fourth coating film is provided below the third coating film and includes a material different from that of the first coating film, the second coating film, and the third coating film.

14. The inkjet head according to claim 13, wherein The first coating film completely covers the inner surface of the nozzle plate.

15. The inkjet head according to claim 13, wherein A first thickness of a portion of the first coating film in contact with the lower surface of the nozzle plate is greater than a second thickness of a portion of the first coating film in contact with the inner surface of the nozzle plate.

16. The inkjet head according to claim 13, wherein The second coating film extends from below the first coating film to completely cover the side surface of the piezoelectric plate.

17. The inkjet head according to claim 13, wherein The third coating film extends from below the second coating film to at least a portion of the interior of the nozzle.

18. The inkjet head according to claim 13, wherein the inner surface of the nozzle plate includes a first side surface perpendicular to the lower surface of the nozzle plate and a second side surface inclined in a direction away from each of the nozzles, and The third coating film extends from under the second coating film to the interior of the nozzle to face the first side surface of the inner surface of the nozzle plate.

19. The inkjet head according to claim 13, wherein The first coating film comprises: a first coating film provided on the lower surface of the nozzle plate and forming a step together with the nozzle plate; and A first-second coating film is provided on a lower surface of the first-first coating film and the inner surface of the nozzle plate to cover the first-first coating film.

20. The inkjet head according to claim 19, wherein A first thickness of a portion of the first coating film in contact with the lower surface of the nozzle plate is greater than a second thickness of a portion of the first coating film in contact with the inner surface of the nozzle plate.

21. The inkjet head according to claim 13, wherein The average thickness of the first coating film is in the range of 5 nm to 25 nm, The average thickness of the second coating film is in the range of 5 nm to 1000 nm, and The average thickness of the third coating film is in the range of 5 nm to 1000 nm.

22. The inkjet head according to claim 13, wherein The average thickness of the fourth coating film is in the range of 20 nm or less.

23. The inkjet head according to claim 13, wherein The first coating film includes organic material and inorganic material, The second coating film includes at least one of a metal oxide and an organic-inorganic composite material including the metal oxide, The third coating film includes an inorganic material, and The fourth coating film includes a polymer compound having hydrophobic properties and containing fluorine and silicon.

24. The inkjet head according to claim 13, wherein The nozzle plate includes polyimide.

25. The inkjet head according to claim 13, wherein The piezoelectric plate comprises: a first polymer layer disposed on the nozzle plate; an organic layer disposed on the first polymer layer; a piezoelectric member disposed on the organic layer; a metal layer, disposed on the piezoelectric component; a glass layer disposed on the metal layer; and A second polymer layer is disposed on the glass layer and the organic layer.

26. The inkjet head according to claim 13, wherein In a case where the ink is provided inside the inkjet head, a luminance ratio of a first region of the inkjet head in which each of the nozzles is provided to a second region of the inkjet head not including the nozzles is 1 or less.

27. A method for inspecting an inkjet head, the method comprising: Manufacturing the inkjet head, the inkjet head comprising: a nozzle plate including an organic material and including a plurality of nozzles for discharging ink to the outside; a piezoelectric plate formed on the nozzle plate; a first coating film formed on the lower surface of the nozzle plate; a second coating film covering the first coating film and comprising a material different from that of the first coating film; a third coating film formed under the second coating film, covering at least a portion of the second coating film, and comprising an inorganic material; and a fourth coating film formed under the third coating film and including a material different from that of the first coating film, the second coating film, and the third coating film; and With the ink disposed within the inkjet head, the inkjet head is imaged as a two-dimensional image.

28. The method according to claim 27, wherein Imaging the inkjet head into the two-dimensional image with the ink disposed within the inkjet head includes: An amount of grayscale variation between a first region of the inkjet head in which each of the nozzles is disposed and a second region of the inkjet head that does not include the nozzles is measured.

29. The method according to claim 27, wherein In a case where the ink is provided inside the inkjet head, a luminance ratio of a first region of the inkjet head in which each of the nozzles is provided to a second region of the inkjet head not including the nozzles is 1 or less.

30. The method of claim 27, wherein: Imaging the inkjet head into the two-dimensional image with the ink disposed within the inkjet head includes: The inkjet head was imaged using a microscope in either reflection mode or transmission mode.

Images