KR100358645B1 - Ink jet printer head and manufacturing method thereof - Google Patents

Abstract

This invention is an ink jet printer head and a method of manufacturing the same. First, the first glassy thin film is deposited on the first silicon substrate for forming the nozzle portion, and the second glassy thin film is deposited on the lower portion of the second silicon substrate for forming the diaphragm portion, and then the first glassy material of the first silicon substrate is deposited. A thin metal sheet on which a chamber portion, that is, a chamber is formed, is bonded to the upper portion of the thin film, and the second silicon substrate is bonded to the upper portion of the thin metal sheet using an anodic bonding. Next, the first and second silicon substrates are etched to a predetermined thickness, and then an etching process is performed to form nozzles on the first silicon substrate. At this time, the nozzle is formed at a position corresponding to the chamber formed on the thin metal plate. Next, a lower electrode is formed on the second silicon substrate, a piezoelectric film is formed on the lower electrode, and then an upper electrode is formed on the piezoelectric film to form a piezoelectric actuator. As such, as the semiconductor process is used to align the first and second silicon substrates with the metal thin plate and form nozzles and chambers, alignment errors may be greatly reduced, thereby achieving high resolution. In addition, it is possible to prevent the increase in price required to improve the alignment, thereby making it possible to manufacture a low cost ink jet printer head.

Description

Ink jet printer head and manufacturing method thereof {INK JET PRINTER HEAD AND MANUFACTURING METHOD THEREOF}

The present invention relates to an ink jet printer, and more particularly, to an ink jet printer head and a method of manufacturing the same.

In general, a printer is divided into a dot matrix method, an ink jet method, and a laser method. In particular, the ink ejection method is widely used because it can realize a high resolution at a low price.

A head of an ink jet printer using a conventional ink jetting method will be described with reference to the accompanying drawings.

1 is an exploded perspective view showing an exploded head of a conventional ink jet printer. The print head consists of a plurality of plates sequentially stacked on the paper surface to be printed.

More specifically, the first plate 1 having the nozzle 1a for ejecting ink onto paper (not shown), the second plate 3 having the ink supply passage 3a, and the ink supply And the third plate 5 on which the discharge channels 5a and 5b are formed, the fourth plate 7 on which the ink supply and discharge channels 7a and 7b are formed, and the ink chamber 9a on which the ink chamber 9a is formed. The fifth plate 9 and the sixth plate 11 closing the ink chamber 9a of the fifth plate 9 are sequentially stacked.

The first, second and third plates 1, 3 and 5 are typically made of a thin metal plate, and the fourth, fifth and sixth plates 7, 9 and 11 are made of a thin ceramic. The sixth plate 11 is made of a diaphragm, and is configured to vary the volume of the ink chamber 9a. The piezoelectric film 13 is attached to the upper end of the sixth plate 11 and the electrode 15 is connected to the flexible cable 17 at the upper end of the piezoelectric film 13 to conduct the piezoelectric film 13. It consists of structures that can be.

In the ink jet printer head having such a structure, ink flows into the ink supply path 3a of the second plate 3 and through the ink supply channels 5a and 7a of the third and fourth plates 5 and 7. It is stored in the ink chamber 9a of the fifth plate 9. At this time, when electricity is supplied through the flexible cable 17 and the electrode 15, the piezoelectric film 13 serves as an actuator to reduce the volume of the ink chamber 9a. The ink in the ink chamber 9a is then transferred to the nozzle 1a through the ink discharge channels 7b, 5b, and 3b, and the ink is ejected to the paper through the nozzle 1a. Therefore, ink is sprayed onto the paper to print.

In the case of manufacturing such a conventional ink jet printer head, the nozzles, the ink channels, the ink chambers, and the like are formed on the plurality of plates described above, respectively, and the plurality of plates are sequentially formed using a binder or the like. Bond.

However, in the case of joining a plurality of plates, since nozzles, ink channels, ink chambers, and the like are properly aligned at positions corresponding to each other, ink is normally ejected, and thus, very precise alignment is required at the time of plate alignment. .

Therefore, the alignment error should be very small at the time of plate alignment, since the resolution of the printer depends on the alignment error is required to improve the accuracy of the alignment technology has the disadvantage of increasing the price of the product.

In addition, as the alignment process is increased according to the number of plates used for manufacturing the print head, the yield may be reduced as the working time is increased, and the alignment technique and the plate manufacturing technique are obstacles in improving product performance.

Therefore, it is an object of this invention to manufacture an ink jet printer head having high resolution and high productivity by eliminating alignment errors such as nozzles, chambers and diaphragms.

1 is an exploded perspective view of a conventional ink jet printer head.

2 is a cross-sectional view of the ink jet printer head according to the embodiment of the present invention.

3A to 3J are diagrams sequentially showing the manufacturing process of the ink jet printer head according to the embodiment of the present invention.

4 is a cross-sectional view of an ink jet printer head according to another embodiment of the present invention.

In order to achieve this object, according to the present invention, in accordance with the semiconductor manufacturing process technology, the first silicon substrate and the metal thin plate on which the chamber is formed, and the second silicon substrate functioning as the diaphragm are sequentially joined, and then the first silicon substrate is bonded to the first silicon substrate. An ink jet printer head is manufactured by forming a nozzle and forming a piezoelectric actuator on a second silicon substrate.

According to an aspect of the present invention, there is provided a method of manufacturing an ink jet printer head, the method comprising: forming a chamber on a portion of the metal sheet by processing the metal sheet; Sequentially stacking and bonding a first silicon substrate, the metal thin plate, and a second silicon substrate functioning as a diaphragm; Forming a protective film on the lower portion of the first silicon substrate and the upper portion of the second silicon substrate; Etching the passivation layer under the first silicon substrate and a portion of the first silicon substrate to form a nozzle; Forming a lower electrode on the second silicon substrate; Forming a piezoelectric film on the lower electrode; And forming an upper electrode on the piezoelectric film.

In the step of laminating and bonding the first silicon substrate, the metal thin plate, and the second silicon substrate, a glassy thin film is deposited on the upper portion of the first silicon substrate, and a glassy thin film is deposited on the lower portion of the second silicon substrate. Controlling the residual stress of the glassy thin films deposited on the first and second silicon substrates, placing a metal thin plate on the glassy thin film of the first silicon substrate, and bonding the first silicon substrate and the metal thin plate using an anodic bonding. . In addition, the glass thin film of the second silicon substrate is positioned on the metal thin plate and the metal thin plate and the second silicon substrate are bonded by using an anodic bonding.

Preferably, the first and second silicon substrates and the glassy thin film have the same coefficient of thermal expansion and no residual stress in the thin film.

According to another aspect of the present invention, there is provided an inkjet printer head, comprising: a nozzle part formed of a silicon substrate, having a nozzle on which ink is sprayed, and having a first glassy thin film formed thereon; A chamber part disposed on the first glass-like thin film of the nozzle part and having a chamber for storing ink supplied to a position corresponding to the nozzle, the chamber part being made of metal; A diaphragm portion positioned above the chamber portion and having a second glassy thin film formed on a lower portion facing the chamber portion and formed of a silicon substrate; And a piezoelectric actuator positioned on the diaphragm portion and applying a constant pressure to the diaphragm portion to allow ink embedded in the chamber to be injected through the nozzle.

The nozzle portion and the chamber portion, and the chamber portion and the diaphragm portion are joined by anodic bonding, respectively.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

2 is a cross-sectional view of an ink jet printer head according to an embodiment of the present invention, and an ink jet printer head manufacturing process for explaining the embodiment of the present invention is sequentially shown in FIGS. 3A to 3J.

As shown in FIG. 2, an ink jet printer head according to an exemplary embodiment of the present invention may include a chamber in which a diaphragm portion 100 and a lower surface of the diaphragm portion 100 are attached to each other and are supplied and stored therein. A chamber portion 200 in which 210 is formed, a nozzle portion 300 in which a nozzle 330 is formed at a position corresponding to the chamber 210 and installed in contact with the lower surface of the chamber portion 200; It consists of a piezoelectric actuator 400 installed on the upper portion of the diaphragm portion (100).

The piezoelectric actuator 400 is provided with a lower electrode 410 bonded to an upper portion of the diaphragm portion 100, a piezoelectric film 420 provided on an upper portion of the lower electrode 410, and an upper portion of the piezoelectric film 420. The upper electrode 430 is formed.

The diaphragm part 100 and the nozzle part 300 are made of a silicon substrate, and the chamber part 200 is made of a thin metal plate. A glass-like thin film 310 is formed between the nozzle part 300 and the chamber part 200 so that the nozzle part 300, which is a silicon substrate, and the chamber part 200, which is a metal thin plate, are joined by an anodic bonding. Similarly, a glassy thin film 110 is formed between the chamber part 200 and the diaphragm part 100 so that the chamber part 200 and the diaphragm part 100 are joined by an anodic bonding.

In the ink jet printer head according to the embodiment of the present invention having such a structure, the supplied ink is stored in the chamber 210, and an electric field is applied between the lower electrode 410 and the upper electrode 430 of the piezoelectric actuator 400. Even poles are formed in the vertical direction of the ground piezoelectric film 420. At this time, the piezoelectric film 420 increases in volume in the direction in which the diaphragm portion 100 is pressed, so that the diaphragm portion 100 pressurizes the chamber 210.

Therefore, by applying a constant pressure to the chamber 210, the ink contained in the chamber 210 is sprayed to the paper located outside through the nozzle 330 to print.

Next, a method of manufacturing an ink jet print head according to an embodiment of the present invention having such a structure will be described.

In the embodiment of the present invention, the silicon substrate for forming the nozzle portion, the metal thin plate for forming the chamber portion, and the silicon substrate for forming the diaphragm portion are sequentially laminated and bonded, and then the silicon substrate for forming the nozzle portion is formed. An inkjet printer head is formed by etching a portion corresponding to a chamber formed on a thin metal plate to form a nozzle, and forming a piezoelectric actuator, that is, a lower electrode, a piezoelectric film, and an upper electrode, on a silicon substrate for forming a diaphragm portion. To prepare.

Hereinafter, for convenience of description, the same reference numerals as those of the nozzle part 300 are given to the silicon substrate for forming the nozzle part 300, and the chamber part 200 is formed on a thin metal plate for forming the chamber part 200. The same reference numerals have been given, and the same numbers as those of the diaphragm portion 100 are given to the silicon substrate for forming the diaphragm portion 100.

First, as shown in FIG. 3A, a glassy thin film 110 is deposited on the lower portion of the substrate for forming the diaphragm, that is, the silicon substrate 100 that will function as the diaphragm. The glassy thin film 110 is formed of a material having substantially the same thermal expansion coefficient as that of the silicon substrate 100, and is deposited on the silicon substrate 100 by a known vacuum deposition method or a sputtering method.

At the same time, the chamber portion is formed. That is, as shown in FIG. 3B, the metal thin plate 200 is machined to form a chamber 210 in which ink supplied to a portion of the metal thin plate 200 is stored.

As shown in FIG. 3C, the glass thin film 310 is deposited on the silicon substrate 300 to form a nozzle by about several micrometers, and in this case, the glass thin film 310 is formed of the silicon substrate 300. Have substantially the same coefficient of thermal expansion.

The reason why the glassy thin films 110 and 310 have the same thermal expansion coefficient as that of the silicon substrates 100 and 300 is to ensure that the glassy thin films 110 and 310 and the silicon substrates 100 and 300 are equally expanded by high temperature heating during the anodic bonding described later. At this time, it is essential to control the residual stress in the glass thin film (110,310) in order to increase the reliability and mass production yield of the product by performing a successful anodic bonding. To this end, it is required to minimize residual stress in the glassy thin film using a process such as heat treatment. The heat treatment temperature at this time is suitably carried out at 200 to 400 ° C.

Next, the silicon substrate 300, the metal thin plate 200, and the silicon substrate 100 are sequentially laminated and bonded.

As shown in FIG. 3D, the thin metal plate 200 is positioned and bonded to the glassy thin film 310 of the silicon substrate 300, and the glassy thin film 110 of the silicon substrate 100 is bonded to the thin metal plate 200. ) And place them in contact.

In the exemplary embodiment of the present invention, an anodic bonding method is used to bond the silicon substrate 300 and the metal thin plate 200 or to bond the metal thin plate 200 and the silicon substrate 100.

Anodic bonding is a method of bonding a conductor or a semiconductor with a glass material that contains movable ions. First, the glassy thin film 310 and the metal thin plate 200 of the silicon substrate 300 to be bonded are heated to about 400 ° C. so that the ions in the glassy thin film 310 are easily moved, and at the same time, a strong electric field is applied. Accordingly, the ions in the glass thin film 310 and the ions of the metal thin film 200, that is, the ions having opposite polarities to the ions of the glass thin film 310, move toward the bonding surface of the glass thin film 310 and the metal thin film 200. As a result, the silicon substrate 300 and the metal thin plate 200 are bonded.

In the same manner, the metal thin plate 200 and the silicon substrate 100 are heated and the electric field is applied to bond the metal thin plate 200 and the silicon substrate 100.

Alternatively, the metal thin plate 200 and the silicon substrate 100 may be bonded first, and then the silicon substrate 300 and the metal thin plate 200 may be bonded.

Next, as illustrated in FIG. 3E, the silicon substrates 100 and 300 are etched using a physical, chemical or mechanical method or a mixture thereof. That is, the silicon substrates 100 and 300 are etched to the required thickness of the diaphragm and nozzles by using machining such as lapping and polishing or by chemical etching or simultaneously.

At this time, the silicon substrate 100 functioning as a diaphragm is etched to a thickness of several tens to several tens of micrometers, and the silicon substrate 300 on which the nozzle is formed is etched to a thickness of tens to hundreds of micrometers.

Next, as shown in FIG. 3F, in order to protect the silicon substrates 100 and 300 from the chemical solution to be performed thereafter, a silicon oxide film (SiO ₂ ) is disposed on the upper portion of the silicon substrate 100 and the lower portion of the silicon substrate 300. ) Or a silicon nitride film (SiNx) or a silicon carbide film (SiC) is deposited to a thickness of 1 to 2 μm to form protective films 120 and 320, respectively.

Next, a portion of the protective film 320 formed under the silicon substrate 300 is removed to form a protective film pattern 321 having an opening for forming a nozzle. That is, as shown in FIG. 3G, the protective film formed at the position corresponding to the chamber 210 of the metal thin plate 200 is removed from the protective film 320 formed under the silicon substrate 300 to form the nozzle. The protective film pattern 321 is formed. The process of removing the protective film 320 uses a general photolithography method.

The upper surface of the exposed silicon substrate 300 is etched using the protective film pattern 321 formed as described above as an etching mask. In this case, a dry etching method or a wet etching method may be used. As the exposed top surface of the silicon substrate 300 is etched, a nozzle 330 is formed on the silicon substrate 300 as shown in FIG. 3H.

Next, the protective films 120 and 320 formed on the upper and lower portions of the silicon substrates 100 and 300 are removed, and a lower electrode 410 is formed on the silicon substrate 100, as shown in FIG. 3I. The lower electrode 410 is preferably made of platinum (Pt) having excellent conductivity.

Next, as shown in FIG. 3J, a piezoelectric film 420 serving as an actuator is formed on the lower electrode 410. The piezoelectric film 420 is formed by a thick film or a thin film process and forms an upper electrode 430 on the top thereof. The upper and lower electrodes 420 and 400 are for driving the piezoelectric film 420 by applying electricity. After the piezoelectric film 420 is formed, a piezoelectric actuator 400 is formed by applying a polarization step by applying an electric field of 4 to 5 KV / mm at 20 ° to 140 ° for 20 to 40 minutes.

The piezoelectric film 420 preferably uses BBC (xBO1.5-yBiO1.5-zCdO) or BC (3BaO-7CuO) as a low-temperature baking flux. This may lower the firing temperature of 300 ° C. or higher than the firing temperature of a typical piezoelectric system, thereby enabling a silicon process. The physical properties of these materials are 52% or more of electromechanical coefficient (Kp), 1300 or more of dielectric constant, and 95% or more of theoretical density.

In particular, the piezoelectric film 420 has a mole ratio of 51/49 to 53/47 of PbZrO ₃ / PbTiO ₃ , and 0 to 0.5 wt% (wt%) of manganese oxide (MnO ₂ ) is added thereto. 3-7 wt% (wt%) of BBC (xBO1.5-yBiO1.5-zCdO, x + y + z = 1, 0.25≤x≤0.35, 0.40≤y≤0.50) was added to manganese oxide. The piezoelectric film 420 is manufactured by baking at 900 degreeC / 4hr-950 degreeC / 4hr. In addition, the piezoelectric film 420 may be formed of a mole ratio of 51/49 to 53/47 of PbZrO ₃ / PbTiO ₃ , and 0 to 0.5 weight percent (wt%) of manganese oxide (MnO ₂ ) is added thereto. The piezoelectric film 420 may be prepared by adding 2-6 wt% (wt%) of BC (3BaO-7CuO) described above to manganese oxide and baking it at 900 ° C / 4hr to 950 ° C / 4hr.

If the firing conditions of the piezoelectric film are at a temperature above the above-mentioned range, there is a great possibility of damage to the silicon substrate when the piezoelectric film is formed on the silicon substrate.

In the ink jet printer head manufactured as described above, when pressure is applied from the piezoelectric actuator 400 to the silicon substrate 100, the ink contained in the chamber 210 is injected through the nozzle 330, thereby printing. .

As described above, the silicon substrate, the metal thin plate, and the silicon substrate are sequentially stacked and bonded, and then a nozzle, a diaphragm, a piezoelectric actuator, or the like is formed, thereby eliminating alignment errors between the chamber, the nozzle, the diaphragm, and the like.

On the other hand, in the ink jet printer head manufactured as described above, it is also possible to form the shape of the nozzle 330 differently. 4 is a cross-sectional view of an ink jet printer head according to another embodiment of this invention.

In the above-described embodiment, the nozzle 330 formed on the silicon substrate 300 is vertically formed with respect to the lower portion of the silicon substrate 300. However, ink in the chamber 210 is more easily formed by the piezoelectric action of the diaphragm. As illustrated in the accompanying FIG. 4 so as to be sprayed, it may be formed to be inclined at an angle with respect to the lower portion of the silicon substrate 300. That is, the nozzle 330 may be formed so that the discharge port b is wider than the opening a at the chamber 210 side, so that the ink may be more easily discharged from the chamber 210 to the outside.

In addition, the present invention can be applied not only to the head of an ink jet printer, but also to a high precision micro pump and a micro ejection system used for biochemical or military use, and various modifications can be made without departing from the claims described below. .

As described above, according to the exemplary embodiment of the present invention, the silicon substrate, the metal thin plate, and the silicon substrate are sequentially stacked and bonded, and then, as the nozzle, the diaphragm, the piezoelectric actuator, and the like are formed using a semiconductor process, an alignment error is obtained. Can be significantly reduced to achieve high resolution.

In addition, the technical constraints for achieving high resolution can be reduced, and the alignment error can be eliminated to prevent the cost increase in precision, and the productivity of the alignment process is eliminated. This is improved.

Claims (8)

(Correcting) processing the thin metal plate to form a chamber in a portion of the thin metal plate; Sequentially stacking and bonding a first silicon substrate, the metal thin plate, and a second silicon substrate functioning as a diaphragm; After the bonding of the first silicon, the metal thin plate and the second silicon substrate is performed, forming a protective film on the lower portion of the first silicon substrate and the upper portion of the second silicon substrate; Etching the passivation layer under the first silicon substrate and a portion of the first silicon substrate to form a nozzle; Forming a lower electrode on the second silicon substrate; Forming a piezoelectric film on the lower electrode; And Forming an upper electrode on the piezoelectric film Ink jet printer head manufacturing method comprising a. (Correction) The method according to claim 1, Joining the first silicon substrate, the metal thin plate and the second silicon substrate, Depositing a glassy thin film on top of the first silicon substrate; Depositing a glassy thin film on the lower portion of the second silicon substrate; Controlling the residual stress of the glassy thin films deposited on the first and second silicon substrates; Placing a thin metal plate on the vitreous thin film of the first silicon substrate, and then bonding the first silicon substrate and the metal thin plate using an anodic bonding; And Placing the glassy thin film of the second silicon substrate on the metal thin plate and then bonding the metal thin plate and the second silicon substrate using an anodic bonding. Ink jet printer head manufacturing method comprising a. (Correction) According to claim 1 or 2, And the first and second silicon substrates and the vitreous thin film have the same coefficient of thermal expansion and no residual stress in the thin film. The method according to claim 1 or 2, Forming the nozzle, Forming an opening for forming a nozzle by etching a portion of the passivation layer under the first silicon substrate; And Forming a nozzle by etching the first silicon substrate through the opening using an unetched passivation layer among the passivation layers as an etching mask; Ink jet printer head manufacturing method comprising a. A nozzle part formed of a silicon substrate, and having a nozzle for injecting ink thereon and having a first glassy thin film formed thereon; A chamber part disposed on the first glass-like thin film of the nozzle part and having a chamber for storing ink supplied to a position corresponding to the nozzle, the chamber part being made of metal; A diaphragm portion positioned above the chamber portion and having a second glassy thin film formed on a lower portion facing the chamber portion and formed of a silicon substrate; And A piezoelectric actuator positioned on the diaphragm portion and applying a constant pressure to the diaphragm portion so that the ink embedded in the chamber is injected through the nozzle; Including; And the nozzle portion and the chamber portion, and the chamber portion and the diaphragm portion are joined to each other by anodic bonding . The method of claim 5, And the nozzle portion, the diaphragm portion, and the glassy thin film have the same thermal expansion coefficient. (delete) The method according to claim 5 or 6, The nozzle has an ink jet printer head having a wider discharge portion for discharging ink than an opening in contact with the chamber portion.