JP2019104236A - Inkjet head and inkjet printing device - Google Patents

Abstract

To provide an inkjet head that can form a pattern of an electronic device and an optical device at low cost, especially, form a pattern using ink having electric conductivity.SOLUTION: In an inkjet head, a nozzle plate having a plurality of nozzles, a flow channel formation substrate, a diaphragm and a piezoelectric element are laminated. The diaphragm has a laminated structure. An outermost layer nearest on a side of the flow channel formation substrate of the laminated structure is constituted of a resin. One of the layers other than the outermost layer is constituted of a metal.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an inkjet head and an inkjet printing apparatus.

  In the process of manufacturing electronic devices and optical devices, a process of forming a fine pattern on a substrate is frequently used. As a method of forming a fine pattern, there is a method of using photolithography such as etching or lift-off, for example, in the case of about 10 to several tens of microns although it depends on the desired pattern size. However, the method using photolithography has problems in that it requires an expensive photomask, material efficiency, chemical resistance of a substrate, and the like.

  Therefore, as a method of forming a fine pattern at low cost, a printing method in which a material of a desired pattern is inked and printing is performed on a substrate, in particular, an inkjet method which does not require a printing plate has attracted attention.

  Patent document 1 is mentioned as a prior art example of the inkjet head used for an inkjet method.

  In Patent Document 1, a diaphragm is formed using a material such as Ni or Si for the internal structure of the ink jet, and the diaphragm in contact with the piezoelectric element is displaced to print CMYK (cyan, magenta, yellow, black from the nozzle) Etc.) are ejected. These color material inks are mainly for forming an image on paper or film, and the color material ink is coated with a resin or a dispersing agent on the surface of fine particles of organic or inorganic pigment, water-based, organic solvent or UV curing In the case of a mold ink, it is prepared by dispersing it in a liquid monomer dispersion medium or the like. Since there are a wide choice of vehicle materials such as resins, dispersants, and dispersion media for dispersing pigments, it is possible to design an ink composition in consideration of the chemical resistance of the ink jet printing apparatus and the ejection characteristics of ink droplets. However, fine patterns formed on electronic devices and optical devices have strict requirements for their characteristics, and when inked, it is difficult to design the ink composition considering the chemical resistance of the ink jet printing apparatus and the ejection characteristics of ink droplets. There is.

JP-A-8-164607

  Examples of the material used for the ink jet head include metal materials such as stainless (for example, SUS303 and SUS304) nickel having a structure formed by machining a metal or photolithography, and silicon having a structure formed by photolithography.

 When the ink jet head is configured using a plurality of metal materials and conductive ink is introduced to the ink jet head to perform ink jet printing, when the metal materials are conductive, the ink and the metal material locally By forming a battery, galvanic corrosion occurs, and the metal having a lower ionization tendency is oxidized and corroded. In addition, even if a noble metal having a small ionization tendency and not easily corroded is used as the metal material, the local battery itself does not disappear, so that the deterioration due to oxidation or reduction occurs on the ink material side.

  In particular, when the pressure chamber portion is made of a stainless material (for example, SUS303, SUS304) and the diaphragm is made of a nickel material or a nickel-cobalt alloy material among the constituent materials of the ink jet head, nickel is compared with stainless steel. Galvanic corrosion occurs when the conductive ink is used because the nickel-cobalt material is easily ionized, and nickel and cobalt are eluted.

  In addition, when the ink is strongly acidic, corrosion of metal due to acid may occur instead of galvanic corrosion due to dissimilar metal bonding.

  Furthermore, because the diaphragm is a very thin member of several μm to several tens of μm due to functional needs, even slight corrosion generates pin holes that penetrate the diaphragm, and the ink leaks to reach the piezoelectric element portion. Since the ink is conductive, the electrodes of the piezoelectric element are shorted, and the function of the ink jet head is lost. Furthermore, the fine patterns formed on electronic devices and optical devices have strict requirements for their characteristics, and when the pattern forming material is made into ink, it is difficult to design the ink composition in consideration of the ejection characteristics, particularly, optimization of the ink viscosity is difficult There is.

  Therefore, an object of the present invention is to provide an inkjet head and an inkjet printing apparatus capable of expanding the viscosity range of a dischargeable ink without causing head corrosion or deterioration of the ink material even with a conductive ink. It is.

In order to solve the above problems,
In an inkjet head in which a nozzle plate having a plurality of nozzles, a flow path forming substrate, a diaphragm and a piezoelectric element are stacked,
The diaphragm is a laminated structure,
The outermost layer closest to the flow path forming substrate in the laminated structure is made of resin, and an ink jet head is used in which one of the layers other than the outermost layer is made of metal.

  According to the present invention, even if a conductive ink is used, it is possible to suppress the deterioration of the diaphragm due to the corrosion or the oxidation or reduction of the ink. In addition, by using a resin material as a constituent material of the diaphragm, it is possible to lower the longitudinal elastic modulus of the diaphragm compared to a metal material, and improve the response when driving the piezoelectric element in contact with the diaphragm. Thus, the viscosity range of the ink that can be discharged can be expanded.

Cross-sectional view of the ink jet head according to the first embodiment of the present invention Sectional view of an ink jet head according to a second embodiment of the present invention A plan view of the diaphragm of the second embodiment of the present invention Top view of the diaphragm of the third embodiment of the present invention The top view of the diaphragm of Embodiment 4 of this invention Top view of diaphragm of Embodiment 5 of the present invention The top view of the diaphragm of another example of Embodiment 5 of this invention BB 'cross section of FIG. 6A Top view of diaphragm of seventh embodiment of the present invention Sectional view of an ink jet head according to Embodiment 7 of the present invention The top view of the diaphragm of another example of Embodiment 7 of this invention Side view of the ink jet printing apparatus according to the tenth embodiment

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1
FIG. 1 shows a first embodiment of the present invention.
<Inkjet head 100>
FIG. 1 is a cross-sectional view (only a central portion and an end portion are shown) of the inkjet head 100 of the present invention. The ink jet head 100 according to the present invention communicates with at least a plurality of nozzles 2 on the nozzle plate 1 and the nozzles 2, and a flow path forming substrate 4 defining pressure chambers 3 by partition walls, and pressure chambers of the flow path forming substrate 4 The driving portion 6 of the piezoelectric element 5 provided in the area corresponding to 3, the pillar 7 of the piezoelectric element 5 provided in the area corresponding to the partition of the flow path forming substrate 4, the pressure chamber 3 and the piezoelectric element 5 And a housing (not shown) having a flow passage for supplying ink to the flow passage forming substrate, which holds the outer periphery of these members. The driving portion 6 of the piezoelectric element 5 is a portion that expands and contracts to pressurize the pressure chamber 3. On the other hand, the pillar portion 7 of the piezoelectric element 5 does not expand and contract but has a fixed portion, and supports the wall of the pressure chamber 3.

Furthermore, the diaphragm 8 is at least two layers or more, and includes at least a resin layer 80 and a metal layer 81. Although two layers are shown in FIG. 1, two or more layers are preferable. Further, an adhesive layer 9 is formed to adhere the diaphragm 8 to the drive portion 6 and the pillar portion 7 of the piezoelectric element 5, and a base 10 serving as a support is provided below the piezoelectric element 5.
<Nozzle plate 1 and nozzle 2>
The nozzle plate 1 is a flat plate on which a plurality of nozzles 2 are formed with a desired number and intervals.

  As a method of forming the plurality of nozzles 2 on the nozzle plate 1, there is a method of forming by laser processing, drilling, press processing, etching method, electroforming method or the like. However, in view of the degree of freedom in processing of the nozzle shape of the nozzle 2 and ease of shape control, it is preferable to form the nozzle 2 by laser processing. Further, a water repellent film may be formed on the surface of the nozzle plate 1. The water repellent film has an effect of returning the ink slightly exuded to the surface of the nozzle plate 1 in the vicinity of the nozzle when the ink is discharged, into the nozzle 2. If the ink that has leaked out in the vicinity of the nozzle 2 remains, the meniscus on the ink surface collapses to adversely affect the discharge of the next droplet, so the formation of the water repellent film is effective for maintaining stable discharge. It is. As a method of forming a water repellent film, there is a method of forming a solution by applying a solution of alkoxysilane having fluorine to a nozzle plate and performing baking, or a method of forming by vapor layer polymerization of a monomer having fluorine. Not limited to these.

  For example, a thin plate of metal or ceramic such as stainless steel can be used as the material of the nozzle plate 1, but since the nozzle plate 1 is a member closest to the printing work with the inkjet head 100, the nozzle plate 1 is If the head is in contact with the workpiece due to some trouble, the ceramic substrate may be broken. Therefore, it is more preferable to form with metals, such as stainless steel.

  Also, the number and spacing of the plurality of nozzles 2 to be formed are determined by the pattern shape of the electronic device or optical device to be created, but the pattern shape tends to be miniaturized in order to improve the performance of the electronic device or optical device. is there. As a result, the number of nozzles 2 required for the ink jet head 100 is increased, the distance is reduced, and the density of the nozzles 2 is increased. In particular, when the density of the nozzles 2 is increased, the distance between the nozzles 2 becomes very narrow, about 0.1 mm to 0.2 mm. In addition, the diameter of the nozzle 2 is also reduced in diameter, and a very small nozzle of 10 to 20 microns is required.

<Pressure Chamber 3 and Channel Forming Substrate 4>
The flow path forming substrate 4 is a member in which partition walls corresponding to the arrangement of the nozzles 2 are provided at equal intervals on a flat plate. The space between the partition walls is the pressure chamber 3, and the ink is supplied from a common flow path disposed in the front of the paper surface of FIG. 1. The flow path forming substrate 4 can also be formed by laser processing, etching or the like. Further, depending on the structure of the flow path forming substrate 4, a plurality of separately processed substrates may be stacked to form one flow path forming substrate 4. The nozzle plate 1 and the flow path forming substrate 4 can be bonded by metal bonding, an adhesive, or the like. When using an adhesive, the type is not particularly limited, but a thermosetting adhesive, a two-component adhesive, a UV curable adhesive, an anaerobic adhesive, or an adhesive that cures due to the combined use of these is used. be able to. The material of the flow path forming substrate 4 may be metal such as stainless steel or ceramic, but in the case of using a thermosetting adhesive, the nozzle plate 1 and the flow path forming substrate are used to prevent deviation or warping due to a difference in thermal expansion coefficient. It is preferable that 4 is the same material, and it is preferable to use a stainless steel material.

<Piezoelectric element 5>
The piezoelectric element 5 is formed by laminating a piezoelectric thin plate (sheet) such as lead zirconate titanate having two comb-like internal electrodes interengaging with each other, and then two internal electrodes among the side surfaces of the laminated piezoelectric layers. The front surface electrode and the back surface electrode are formed on both sides (front and back surface side of the paper surface in FIG. 1) which are exposed facing each other. The internal electrodes are formed so as to be alternately overlapped partially for each layer of the laminated piezoelectric material, and each layer is arranged to be alternately connected to the surface electrode and the back electrode.

  Since the internal electrodes connected to the front surface electrode and the internal electrodes connected to the back surface electrode are alternately arranged, when a potential difference is generated between the front surface electrode and the back surface electrode, the piezoelectric element 5 is shown in FIG. Stretches in the vertical direction of the paper.

  Further, in the piezoelectric element 5, a plurality of channels corresponding to the arrangement of the nozzles 2 are provided in a row, and a groove is present between the respective channels. The grooves are formed when dicing is performed to divide the plurality of channels after the piezoelectric element 5 is integrally formed, and the channels are separated and insulated by the grooves. Further, this channel is connected to a flexible cable, and a driving unit 6 that vibrates according to an input signal, and pillars 7 that are disposed under the partition wall and support the flow path forming substrate 4 are alternately disposed. . The piezoelectric element 5 is supported by a base 10 which is a base made of ceramic or metal.

<Diaphragm 8>
The diaphragm 8 vibrates due to the displacement generated by the piezoelectric element 5 to change the volume inside the pressure chamber 3. By this, pressure is generated in the ink, and the ink is ejected from the nozzle 2. The diaphragm 8 has a laminated structure of at least two or more layers, and the resin layer 80 (the outermost layer, which is the diaphragm) on the flow path forming substrate 4 side most of them is made of resin. Among the other layers, at least one metal layer 81 is made of metal. There may be other layers.

  In the case of the conventional structure, the diaphragm 8 does not have the resin layer 80, and has used what formed nickel or nickel cobalt alloy by electroforming. In this case, if a conductive ink is used, a local battery is formed by the diaphragm 8, the flow path forming substrate 4 and the conductive ink, galvanic corrosion occurs, and nickel and cobalt materials are eluted.

  In the diaphragm 8 of the present embodiment, since the resin layer 80 is formed of a resin, galvanic corrosion does not occur.

  When the entire diaphragm 8 is formed of resin, the resin material absorbs moisture or thermally deforms in the manufacturing process due to member cleaning and heat drying, and dimensional accuracy decreases or warpage occurs. I will. However, since the metal layer 81 of the diaphragm 8 of the present embodiment is formed of metal and the dimensions thereof are corrected by the metal layer 81, the reduction in dimensional accuracy and warpage due to the load in the manufacturing process are small.

A thin film may be further formed on the resin layer 80 which is the layer closest to the flow path forming substrate 4 of the diaphragm 8 in the present embodiment. This film is a thin film for improving adhesion strength when bonding the diaphragm 8 and the flow path forming substrate 4 and is a sputtered film such as a metal or an oxide film or a nitride film. However, the film thickness of the sputtered layer is as thin as several tens of nanometers, and there are pinholes with a diameter of several microns or less than 1 micron due to the influence of particles at the time of film formation, thereby protecting the resin layer 80 from corrosion. Do not play a role. Therefore, in the present embodiment, the thin film of the sputtered layer is not regarded as a layer constituting the diaphragm 8.
In the diaphragm 8 of the first embodiment, the metal layer 81 is not formed in the portion corresponding to the pressure chamber 3. It is preferable that only the resin layer 80 be in this portion.

<Effect>
As described above, in order to print the pattern shape to be miniaturized to improve the performance of the electronic device and the optical device, the diameter of the nozzle 2 and the distance between the nozzles 2 become smaller, and the dimensional accuracy required for the members of the inkjet head 100 is more It gets tougher. Even if the resin layer 80 is formed of a resin, the diaphragm 8 of the present embodiment stably forms a high-definition inkjet head 100 because the dimensional accuracy is reduced and warpage is small due to the load in the manufacturing process. can do.

  Furthermore, fine patterns formed on electronic devices and optical devices have strict requirements for their characteristics, and it becomes difficult to design the ink composition considering the flight characteristics, particularly the optimization of the ink viscosity, when the pattern forming material is made into ink . However, when the resin layer 80 is formed of a resin as in the present embodiment, the resin material has a longitudinal elastic coefficient smaller than that of the metal material, and thus, the resin layer 80 faces the pressure chamber 3. The flexibility of the portion (hereinafter referred to as the free end 82) in the portion without the adhesive layer 9 for bonding to the piezoelectric element 5 on the back surface is improved, and the responsiveness of the diaphragm is improved. Therefore, even if the viscosity of the ink is increased, the ejection characteristics of the ink are not easily deteriorated, and the ink of high viscosity can be ejected. Therefore, the material selectivity of the ink is broadened, and the above-mentioned problem is met that the ink composition can be designed in consideration of the chemical resistance of the ink jet printing apparatus and the ejection characteristics of the ink droplet. The thickness of the resin layer 80 formed of a resin is preferably 1 to 30 μm, and more preferably 1 to 20 μm in order to obtain flexibility.

Second Embodiment
FIG. 2 is a cross-sectional view (only the central portion is shown) for explaining the second embodiment of the ink jet head 100 of the present invention. 3 is a view of only the diaphragm 8 of FIG. 2 as viewed from the lower side of the sheet of FIG.

  The diaphragm 8 shown in FIGS. 2 and 3 includes a resin layer 80 and a metal layer 81. The resin layer 80 is bonded to the piezoelectric element 5 via the bonding layer 9. Furthermore, in the metal layer 81, a drive gain portion 81a disposed at a position corresponding to the drive portion 6 and a column gutter portion 81b disposed at a position corresponding to the column portion 7 are alternately disposed. These points are different from the first embodiment. The other components are the same as in the first embodiment.

  The drive gutter portion 81a and the pillar gutter portion 81b are formed at positions corresponding to the position of the nozzle 2, respectively, so the bonding area and bonding position between the diaphragm 8 and the drive portion 6 of the piezoelectric element 5 and the pillar portion 7 are accurately determined. It can be defined.

  Therefore, the shape and the area of the free end 82 can be kept constant. As mentioned above, the free end 82 of the diaphragm 8 greatly influences the discharge characteristics of the corresponding nozzle 2. For this reason, if the shape or area of the free end 82 varies, particularly in the case of a high viscosity ink, specifically, an ink having a viscosity higher than 10 mPa · s, the discharge speed of the ink and the droplet volume of the ink vary. Print quality is not stable. According to the configuration of the second embodiment of the present invention, the material selectivity of the ink is broadened, and the ink composition can be designed in consideration of the chemical resistance of the ink jet printing apparatus and the ejection characteristics of the ink droplet. The shape may be different between the drive gain portion 81a and the column gain portion 81b.

  In addition, as a method of forming the drive gutter portion 81a and the column gutter portion 81b, a film to be the resin layer 80 and a metal foil to be the metal layer 81 are bonded in advance, and then photolithography with high pattern formation accuracy There is a method of forming a resist pattern on metal foil and patterning the metal layer 81 by etching. Moreover, the reverse resist pattern is formed in the resin layer 80 by photolithography, and the method of forming the metal layer 81 by electroless-plating etc. can be mentioned after a plating catalyst process.

  When the etching process is used, an adhesive layer may be sandwiched between the resin layer 80 and the metal layer 81, or after the metal layer 81 is etched, a metal layer is further formed on the metal layer 81 by electroless plating or electrolytic plating. 81 may be stacked.

  In the case of forming a metal pattern by plating, a layer of electrolytic plating may be laminated on the electroless plating layer. However, in this case, it is necessary to connect the pattern of the drive gutter portion 81 a and the pillar gutter portion 81 b with the surrounding metal layer 81 at any position.

  The type of adhesive used for the adhesive layer 9 is not particularly limited, but a thermosetting adhesive, a two-component adhesive, an ultraviolet curable adhesive, an anaerobic adhesive, or an adhesive that cures due to the combined use of these. A material etc. can be used. The adhesive may be applied to either the metal layer 81 surface side or the piezoelectric element 5 side. As a method of application, a method such as a dispenser, screen printing, transfer from a flat surface such as a blanket on which an adhesive material is applied solidly, and copying can be adopted, but it is not limited thereto. Also, spacer beads may be mixed with the adhesive to stabilize the adhesive film thickness.

Third Embodiment
FIG. 4A is a cross-sectional view (only the central portion is shown) for explaining the third embodiment of the inkjet head 100 of the present invention. Compared with FIG. 3 showing Embodiment 2 of the inkjet head 100 of the present invention, one end of the drive gutter portion 81a of the drive gutter portion 81a and the column gutter portion 81b formed on the metal layer 81 is a termination portion The difference is in 81c, and the other components are the same as in the second embodiment.
Here, the end portion 81c means a closed portion. The end 81 c closes the metal layer 81.

  By setting one end of the drive gutter portion 81a as a termination portion, the free ends 82 on both sides of the drive gutter portion 81a are connected, and the distance between the column gutter portions 81b in this portion is increased. The second moment can be reduced.

As a result, the responsiveness of the drive gear portion 81a is improved, so that even if the ink viscosity is high, the ejection characteristics of the ink are unlikely to be deteriorated, and the ink of high viscosity can be ejected.
Embodiment 4
FIG. 4B is a cross-sectional view (only the central portion is shown) for explaining the fourth embodiment of the inkjet head 100 of the present invention. Compared with FIG. 3 showing the second embodiment of the inkjet head 100 according to the present invention, of the drive gutter portion 81a and the column gutter portion 81b formed on the metal layer 81, the drive gutter portion 81a has an isolated pattern. The other components are the same as those of the second embodiment.

  The free ends 82 on both sides of the drive gain portion 81a are connected at two places by setting the drive gain portion 81a in an isolated pattern, and the distance between the column gain portions 81b in this portion is increased. The second moment of the cross section can be reduced. As a result, the responsiveness of the drive gear portion 81a is further improved, so that even if the ink viscosity is high, the ejection characteristics of the ink are less likely to be deteriorated, and high viscosity ink can be ejected.

However, in the case where drive gutter portion 81a is an isolated pattern, it is impossible to use the method of laminating the layer of electrolytic plating on drive gutter portion 81a in the method of forming metal layers shown in the second embodiment.
Fifth Embodiment
FIG. 5 is a plan view of the diaphragm 8 of the ink jet head 100 according to the fifth embodiment of the present invention, as viewed from the lower side of the sheet of FIG. The resin layer 80 is disposed in the back direction of the drawing, and the metal layer 81 is disposed in the front direction.

  In the fifth embodiment, unlike the above embodiment, the diaphragm 8 has a laminated structure of at least two or more layers, and the layer closest to the flow path forming substrate 4 is composed of the resin layer 80, and the other layers are different. Of these, at least one layer is formed of a metal layer 81, and the metal layer 81 has at least a solid portion 83 covering substantially the entire area except a part or all of the outer peripheral part of the diaphragm 8.

  In FIG. 2, the outside of the diaphragm 8 separating the pressure chamber 3 through which the ink flows and the piezoelectric element 5 is the resin layer 80, and the metal layer 81 is on the surface where the drive portion 6 of the piezoelectric element 5 and the column 7 contact the diaphragm 8. It only needs to exist. In the fifth embodiment of the present invention, as shown in FIG. 5, the metal layer 81 has a solid portion 83 (an area surrounded by a broken line) extending substantially the entire area of the diaphragm 8. Therefore, it can play a role of a support layer for maintaining the strength of the resin layer 80 having high flexibility, and the handling property is improved as compared with the case of using only the diaphragm layer, and the handling of members at the time of forming the ink jet head 100 Mistakes are less likely to occur.

  Further, the resin layer portion 84 of FIG. 2 is provided on a part or the entire periphery of the solid portion 83 within a range in which the metal layer 81 can maintain its role as a support layer. When the metal layer 81 is formed to the edge of the end face of the diaphragm 8, the cross section of the metal layer 81 is exposed on the outer surface of the ink jet head 100, but printing ink may adhere to the outer surface of the ink jet head 100. When the ink adheres to the outer surface, if the metal layer 81 is exposed, there is a risk that the ink may cause corrosion from that portion, but the problem does not occur in the configuration of the fifth embodiment of the present invention. .

  The solid portion 83 may have an alignment mark or the like.

  FIG. 6A is a plan view schematically showing the case where a slit 85 is provided in the diaphragm 8 of the ink jet head 100, which is another example of the fifth embodiment of the present invention. As shown in FIG. 6, there is a slit 85 for ink to pass through as shown in FIG. 6 in the portion corresponding to the outside of the pressure chamber 3 in the ink flow path in the diaphragm 8 of FIG. It is done. By providing the slits 85, a part of the solid portion 83 disappears, but the slits 85 are provided in such a range that the function as a support layer for maintaining the strength of the resin layer 80 is not lost.

Furthermore, in order to prevent the ink passing through the slit 85 from touching the metal layer 81 formed of metal, it may have a region 86 of only the resin layer 80, which is disposed around the slit 85.
The nozzle plate 1, the flow path forming substrate 4, and the housing 4a are attached to the diaphragm 8 of FIG. 6A, and the BB cross section is taken as FIG. 6B. In FIG. 6B, the common flow path 4c of the flow path forming substrate 4 communicating with the pressure chamber 3 and the common flow path 4b formed in the housing 4a communicate with each other by the slits 85 of the diaphragm 8; It is possible to form a supply flow path of the ink supplied to the flow path 4b.
Further, the adhesive 86a for bonding the diaphragm 8 and the housing 4a adheres to the region 86 so that the adhesive 86a covers the side surface of the metal layer 81 facing the slit 85, and the metal layer 81 It is possible not to touch the ink.

Sixth Embodiment
In the inkjet head 100 according to the sixth embodiment of the present invention, the diaphragm 8 has a laminated structure of at least two or more layers, and the layer closest to the flow path forming substrate 4 is composed of the resin layer 80 among them. Of these, at least one layer is composed of a metal layer 81 having a thickness of 2 microns or more.

  In the present embodiment, the metal layer 81 of the diaphragm 8 is a layer for forming the drive gutter portion 81a and the column gutter portion 81b, together with the function of maintaining the strength of the resin layer 80 which is a resin that is very flexible and difficult to handle. is there. An adhesive layer 9 is formed by an adhesive and the drive gutter portion 81a and the column gutter portion 81b are joined to the piezoelectric element. However, if the thickness of the metal layer 81 is too small in the step of applying the adhesive, the adhesive will stick to the resin layer 80 beyond the metal layer 81 if the adhesive overflows due to process variations. When the adhesive adheres to the resin layer 80, the state of vibration of that portion becomes different from the other, causing variation in the ejection characteristics of the ink jet head 100. However, according to the configuration of the sixth embodiment of the present invention, since the metal layer 81 has a sufficient thickness, the metal layer 81 can be prevented from reaching the resin layer 80 even if the adhesive overflows, and the stability of the ejection characteristics can be enhanced. At the same time, the handleability at the time of member handling can be sufficiently secured. In the case of the metal layer 81 thinner than 2 microns in thickness, the diaphragm 8 is difficult to handle.

Seventh Embodiment
FIG. 8 is a plan view of the diaphragm 8 of the ink jet head 100 according to the seventh embodiment of the present invention, as viewed from the lower side of the paper surface of FIG. In the diaphragm 8, the resin layer 80 is disposed in the back direction in the drawing, and the metal layer 81 is disposed in the front direction. 8 is a schematic cross-sectional view of the vicinity of the end of the row of the plurality of nozzles 2 viewed from the same direction as FIG. 2, and the diaphragm 8 shown in FIG. It becomes the cross section of.

  The inkjet head 100 according to the seventh embodiment of the present invention is the inkjet head 100 having the piezoelectric element 5, the flow path forming substrate 4, the diaphragm 8, and the nozzle plate 1 having the plurality of nozzles 2. The flow path forming substrate 4 and the nozzle plate 1 have through holes 21 and 31 for aligning with the piezoelectric element 5 respectively. Furthermore, the resin layer 80 of the diaphragm 8 has light transparency, and the resin layer 80 further blocks the through holes 21 and 31. Furthermore, the metal layer 81 does not block the through holes 21 and 31. Matters not described are the same as those in the above embodiment.

  In the seventh embodiment of the present invention, the nozzle plate 1 is provided with the through holes 21 of the nozzle plate 1 for aligning with the piezoelectric element 5, and the flow path forming substrate 4 is a flow for aligning with the piezoelectric element 5. The through holes 31 of the passage forming substrate 4 are provided, and the through holes 11 (FIG. 7 and FIG. 8) of the metal layer 81 for aligning with the piezoelectric element 5 are provided in the metal layer 81. The through hole 11 is not opened in the resin layer 80 at the position corresponding to.

  In the ink jet head 100 according to the present invention, in order to form the nozzle plate 1, the flow path forming substrate 4, the diaphragm 8 and the piezoelectric element 5 in precise alignment and bonding, alignment is performed on each member except the resin layer 80. Through holes 11, 21 and 31 are open. Further, the base 10 is processed into a shape that causes the outer side portion of the piezoelectric element 5 to project upward. That is, the base 10 is concave as a whole. The base 10 has holes 51 for alignment. Since the shape of the base 10 is not a thin plate, the hole 51 is not a through hole. Alternatively, without using the base 10, the piezoelectric element 5 may be extended to the alignment portion to form the alignment hole 51 on the piezoelectric element 5.

  In the inkjet head 100 according to the seventh embodiment of the present invention, the through holes 11 for alignment are provided, but since the resin layer 80 blocks the through holes 11, printing is performed with this inkjet head 100. Even when the conductive ink enters the through hole 11 at this time, it is blocked by the resin layer 80 and neither corrodes the metal layer 81 nor penetrates into the piezoelectric element 5 to cause a short circuit.

  Further, in the process of manufacturing the ink jet head 100, in the process of bonding the piezoelectric element 5 after bonding the nozzle plate 1, the flow path forming substrate 4 and the diaphragm 8, alignment is performed using the camera 12 of FIG. At this time, since the resin layer 80 of the diaphragm 8 is light transmissive, it is possible to perform alignment by recognizing the alignment holes 51 on the side of the piezoelectric element 5 in the resin layer 80 with the camera 12. Therefore, according to the configuration of the seventh embodiment of the present invention, even when the alignment holes 51 are formed on the piezoelectric element 5, the metal layer is not corroded or a short circuit is caused, so the problem is solved. .

<Modification>
A modification of the seventh embodiment is shown in FIG. In the diaphragm 8 of FIG. 9, the resin layer 80 does not have the through holes 11 at the positions of the holes for aligning the nozzle plate 1, the flow path forming substrate 4 and the piezoelectric element 5, and the metal layer 81 is The through hole 11 is open, and there is a play mark portion 13 which is a part where the metal layer 81 blocks the through hole 11 at this position.

  Since the play mark portion 13 is formed by photolithography simultaneously with the drive gain portion 81a and the column gain portion 81b, the relative position with respect to the drive gain portion 81a and the column gain portion 81b is accurate.

  In the step of bonding the piezoelectric element 5 after bonding the nozzle plate 1, the flow path forming substrate 4 and the diaphragm 8 by using the diaphragm 8, alignment is performed using the camera 12 of FIG. Since the resin layer 80 constituting the resin layer 80 of the diaphragm 8 is light transmissive, the resin layer 80 recognizes the positioning hole 51 on the piezoelectric element 5 side of the resin layer 80 at the back and aligns the position It can be performed. Further, since the position alignment can be performed by confirming the position of the getter mark portion 13 at the back of the resin layer 80 across the resin layer 80, the alignment accuracy can be further improved.

  The shape of the play mark portion 13 is not particularly limited as long as it can be used for alignment, and can be any shape. Also, the play mark portion 13 may be continuous with the metal layer 81 or may be isolated. Also, the number may be one or more.

  As described above, the nozzle diameter and the nozzle interval become smaller to print the pattern shape which is miniaturized as the electronic device and the optical device become more sophisticated, and the dimensional accuracy required for the member of the inkjet head 100 becomes stricter. By using the diaphragm of Embodiment 8, the required accuracy of alignment can be satisfied.

Eighth Embodiment
In the inkjet head 100 according to the eighth embodiment of the present invention, the diaphragm 8 has a laminated structure of at least two or more layers, and the layer closest to the flow path forming substrate 4 is composed of the resin layer 80 among them. Among them, at least one layer is composed of the metal layer 81, and the resin layer 80 is polyimide.

  By forming the resin layer 80 with polyimide having high chemical resistance, the application range of the ink material can be broadened, and various electronic devices and optical devices can be produced.

(Embodiment 9)
The ink jet head according to the ninth embodiment of the present invention has a piezoelectric element, a flow path forming substrate, a diaphragm, and a nozzle plate having a plurality of nozzles, and the diaphragm has a laminated structure having at least two or more layers. Of the layers, the layer closest to the flow path forming substrate is made of resin, and at least one of the other layers is made of metal, and the resin layer of the metal layers is the most. The layer on the side is copper.

  By forming the metal layer with copper excellent in etching characteristics, it is possible to further increase the processing dimensional accuracy in forming the pattern shapes of the drive gutter portion and the column gutter portion by etching.

  As described above, although the dimensional accuracy required for the members of the inkjet head 100 becomes stricter, the use of the diaphragm having the high dimensional accuracy of the ninth embodiment can further stabilize the ejection characteristics for each nozzle.

(Embodiment 10) Inkjet printing apparatus 200
An ink jet printing apparatus 200 according to a tenth embodiment of the present invention is shown in FIG. In the inkjet printing apparatus 200, the inkjet head 100 is disposed in the frame 105. The transport tool 102 holding the object 101 moves in the lower part of the ink jet head 100. The transfer tool 102 moves on the rail 103. The rails 103 are fixed on the base 104.
The ink jet printing apparatus 200 mounts the ink jet head 100 according to any one of the first to tenth embodiments.

  This printing apparatus has high chemical resistance and is compatible with conductive ink, and can discharge high viscosity ink accurately, and is an ink for forming patterns of electronic devices and optical devices at low cost. Printing machine suitable for

As a function of the pattern formed with this printing apparatus, a conductor layer, a resistor layer, a dielectric layer, an insulator layer, a light shielding layer, a colored layer, a reflective layer, a reflection preventing layer, a light receiving layer of a solar cell, a dye layer, The light emitting layer of the organic EL element, the hole transport / injection layer of the organic EL element or solar cell, the electron transport / injection layer, the recognition marks used in the production process, and the like can be exemplified, but are limited thereto is not.
(effect)
According to the present invention, it is possible to provide an ink jet head 100 capable of stably discharging even a conductive and highly viscous ink without causing head corrosion or deterioration of ink material. Furthermore, the inkjet printing apparatus for forming the pattern of an electronic device or an optical device at low cost can be provided.
(as a whole)
The embodiments can be combined.

  The present invention is useful for an inkjet head for forming a pattern of an electronic device or an optical device at low cost.

DESCRIPTION OF SYMBOLS 1 nozzle plate 2 nozzle 3 pressure chamber 4 flow path formation substrate 4a housing 4b common flow path 4 c common flow path 5 piezoelectric element 6 drive portion 7 column portion 8 diaphragm 9 adhesive layer 10 base 11 through hole 12 camera 13 getter mark 21 Through hole 31 through hole 51 hole 80 resin layer 81 metal layer 81 a drive portion 81 b column end portion 81 c end portion 82 free end portion 83 solid portion 84 portion only of resin layer 85 slit 86 area 86 a adhesive EL organic 100 inkjet head 101 Object 102 Transport tool 103 Rail 104 Base 105 Frame 200 Ink jet printing apparatus

Claims (13)

In an inkjet head in which a nozzle plate having a plurality of nozzles, a flow path forming substrate, a diaphragm and a piezoelectric element are stacked,
The diaphragm is a laminated structure,
The outermost layer by the side of a flow-path formation board among the above-mentioned lamination structure is constituted by a resin layer, and an ink jet head by which one layer is constituted by a metal layer among layers other than the outermost layer. The inkjet head according to claim 1, wherein the metal layer forms a pattern corresponding to the arrangement of the plurality of nozzles. The ink jet head according to claim 1 or 2, wherein the resin layer has a free end where the metal layer and the flow path forming substrate do not exist. The metal layer forms a pattern corresponding to the arrangement of the plurality of nozzles, and further, among the patterns, a plurality of drive gutter portions in contact with at least a portion to be driven of the piezoelectric element are the plurality of nozzles The ink jet head according to any one of claims 1 to 3, wherein the ink jet head is connected at both ends in the direction of the row of and the direction orthogonal to the laminating direction of the diaphragm. The metal layer forms a pattern corresponding to the arrangement of the plurality of nozzles, and in the pattern, at least a drive gain portion in contact with a portion to be driven of the piezoelectric element is formed by the plurality of nozzles. The ink jet head according to any one of claims 1 to 3, further comprising an end portion intercepted by the diaphragm in one direction out of the direction of the row and the direction orthogonal to the stacking direction of the diaphragm. The metal layer forms a pattern corresponding to the arrangement of a plurality of nozzles, and further, of the pattern, at least a drive gain portion in contact with a portion to be driven of the piezoelectric element is an isolated pattern. The inkjet head of any one of -3. The ink jet head according to any one of claims 1 to 6, wherein the metal layer has a solid portion covering at least a region excluding a part or all of the outer peripheral portion of the diaphragm. Of the two or more layers of the diaphragm, the outermost layer closest to the flow path forming substrate is made of a resin layer, and one of the layers other than the outermost layer is a metal layer having a thickness of 2 microns or more The ink jet head according to any one of claims 1 to 7, which is configured. The flow path forming substrate and the nozzle plate have through holes for aligning with the piezoelectric element, and the resin layer in the diaphragm is light transmissive and blocks the through holes. The ink jet head according to any one of claims 1 to 8, wherein the metal layer does not close the through hole. The flow path forming substrate and the nozzle plate have through holes for aligning with the piezoelectric element, and the resin layer of the diaphragm has light transparency and closes the through holes.
The ink jet head according to any one of claims 1 to 9, wherein at least a part of the metal layer is configured not to close the through hole. The ink jet head according to any one of claims 1 to 10, wherein the layer of the resin is a polyimide.   The ink jet head according to any one of claims 1 to 11, wherein the layer closest to the resin layer among the metal layers is a copper layer. An inkjet printing apparatus equipped with the inkjet head according to any one of claims 1 to 12.

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