JP3062285B2 - Ink jet printer head and manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-demand type ink jet printer head and a manufacturing method.

[0002]

2. Description of the Related Art At present, as an ink jet printer head capable of quiet and high-density printing, an ink jet printer head which discharges ink droplets from an orifice and fixes it on a printing paper has been put to practical use. For example, in an on-demand type ink jet printer head, a vibrating film that can vibrate in a direction perpendicular to the surface is formed as a part of an inner wall surface of a pressure chamber that communicates with each of orifices connected in an array. It has a structure in which a piezoelectric element that operates according to drive power is provided on a film. In such an ink-jet printer head, the piezoelectric element vibrates together with the vibrating film by the supply of the driving power corresponding to the print image, and the ink in the pressure chamber is ejected from the orifice as ink droplets by the pressure due to the vibration. I have.

Here, in such an ink jet printer head, it is required to reduce the thickness of the vibrating film in order to realize power saving and improved responsiveness. 61-2025
And Japanese Patent Publication No. Sho 62-22790.

First, in an ink jet printer head 1 disclosed in Japanese Patent Publication No. 61-2025, as shown in FIG. 7, a first orifice 2 in which a plurality of orifices 2 and a pressure chamber 3 are connected to each other by a concave groove or the like. A second plate 5 made of a glass substrate or the like is integrally joined on the plate 4, and an arc-shaped concave groove 6 is formed on the surface of the second plate 5 by etching or cutting to face the pressure chamber 3. The vibrating film 7 has a thickness of 50 (μm) or the like, and a piezoelectric element 8 is mounted on the surface of each vibrating film 7.

In the ink jet printer head 9 disclosed in Japanese Patent Publication No. 62-22790, as shown in FIG. 8, the portion of the second plate 10 made of a substrate facing the pressure chamber 3 is made thinner to vibrate. The vibrating membrane 1 is a membrane 11
After forming an electrode 12 on PZT 1 (Lead Zirco
The piezoelectric element 13 is formed by printing a powder of Titanate) into a paste by adding a binder.

In the ink jet printer heads 1 and 9 described above, the thin vibrating films 7 and 11 formed on the portions of the second plates 5 and 10 facing the pressure chambers 3 vibrate satisfactorily. Responsibility can be improved, and the portions of the second plates 5 and 10 other than the vibrating films 7 and 11 are thick, so that the strength is secured.

[0007]

The ink jet printer heads 1, 9 as described above have thin vibrating films 7, 11 formed in portions opposed to the pressure chambers 3 so as to save power and improve responsiveness. With the realization of strength, the strength is secured.

Here, Japanese Patent Publication No. 61-2025 discloses that the vibration film 7 of the ink jet printer head 1 is formed by etching or cutting the second plate 5 made of a glass substrate or the like. However, in actuality, in controlling the etching time and mechanical precision machining, the layer thickness becomes uniform.
It is extremely difficult to form a vibration film 7 of 50 (μm).

Japanese Patent Publication No. Sho 62-22790 discloses that the thickness of the second plate 10 made of a glass or stainless steel substrate of the ink jet printer head 9 is partially 50 to 100 (μm), 11 is described, but a specific method of manufacturing the vibration film 11 is not disclosed.

That is, when the above-described ink jet printer heads 1 and 9 are implemented, the thickness of the vibrating films 7 and 11 becomes non-uniform or the thickness of the vibrating films 7 and 11 is incompletely reduced. It is feared that the printing quality is degraded due to the hindrance. Further, in such ink jet printer heads 1 and 9, as described above, the vibrating films 7, 1
Since it is difficult to reduce the thickness of the diaphragm 1, it is necessary to increase the area of the vibrating membranes 7 and 11 to secure the amplitude.

That is, in the above-described ink jet printer heads 1 and 9, it is difficult to arrange the pressure chambers 3 and the like with high density, which hinders reduction in size and weight of the apparatus.

[0012]

According to the first aspect of the present invention,
Forming a plurality of O <br/> orifice for ejecting each ink droplet is continuously provided in an array, communicating with each of the orifice double
In an ink jet printer head, a vibrating film is formed as a part of the inner wall surface of the pressure chambers in a direction perpendicular to the surface thereof, and an electromechanical conversion film that operates according to driving power is provided on the vibrating film. the formation of the vibrating membrane on the respective pressure <br/> force chamber and the support on which a plurality of recesses formed facing one on one each through the membrane.

According to a second aspect of the present invention, there is provided an orifice which is connected in an array and discharges ink droplets, and forms a part of an inner wall surface of a pressure chamber communicating with each of the orifices in a direction orthogonal to the surface. In an ink jet printer head having a vibrating film that can freely vibrate and an electromechanical conversion film that operates on the vibrating film in accordance with the driving power, on the surface of a flat support made of a single crystal material, Forming a mask coating, forming an opening window to the surface of the support in the mask coating to form a mask, forming an etching channel covering both the mask and the support under the opening window; and, forming a lower portion layer covering the etching channels and the mask together the etching hole is formed to reach the etching channel outward from the opening window of the mask to the lower portion layer The etching channel is removed through the etching hole, an etching material is injected from the etching hole into a space where the etching channel is located, and a recess is formed by anisotropic etching on the support positioned under an opening window of the mask. forming a top to shield the etch hole to cover the lower portion layer after the formation of the recess
The lower portion of part film is formed, positioned on the recess of the support
And to form the vibrating membrane and the upper portion layer and film.

[0014]

According to the first aspect of the present invention, the vibrating film is formed on the support having the concave portion whose opening side opposed to the pressure chamber is widened through the vibrating film, so that the vibrating film located on the concave portion is formed. And pressure chambers are arranged at high density.

According to a second aspect of the present invention, a mask coating is formed on the surface of a flat support made of a single crystal material, and an opening window reaching the surface of the support is formed in the mask coating. forming a mask and the support of the underlying opening windows to form an etching channels covering together form a lower portion layer covering the etching channel and mask together, the lower portion
An etching hole is formed in the film to reach the etching channel outside of the opening window of the mask, the etching channel is removed through the etching hole, and an etching material is injected from the etching hole into the gap where the etching channel is located, thereby forming a mask. A recess is formed by anisotropic etching in the support located below the opening window of the opening, and after the formation of the recess, the recess is formed.
Suffered parts film forming the upper portion film for shielding the etching hole, by forming the vibrating membrane in the lower portion layer and the upper portion film located on the recess of the support, the vibrating film located on the concave Ya An ink jet printer head capable of high-density arrangement of pressure chambers is easily implemented.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. First, this inkjet printer head 1
In FIG. 4, as illustrated in FIG. 1, a flat pyramid-shaped support 16 in which a quadrangular pyramid-shaped recess 15 whose opening side is expanded is formed,
Mask 18 opening window 17 is formed on the concave portion 15 are stacked, the position on the recess 15 of the mask 18 are sequentially uniformly stacked formed lower-upper portion layer 19 and 20 on the vibration It is a film 21. Then, on the upper portion layer 20 is a lower electrode 22 and the electromechanical transducer layer 23 are sequentially uniformly stacked, that the upper electrode 24 is formed in a predetermined pattern on the electromechanical transducer layer 23 The piezoelectric element 25 is provided at a position on the vibrating film 21 with the members 12 to 2.
4.

As shown in FIG. 2, a flat orifice plate 27 mounted on a protective film 26 covering the electromechanical conversion film 23 and the upper electrode 24 has a structure as shown in FIG.
A pressure chamber 28 located on the piezoelectric element 25, an orifice 29 extending from the pressure chamber 28 to the front edge, an ink supply path 31 communicating the pressure chamber 28 with the ink tank 30, and the like are formed by a concave groove having a predetermined pattern. It is formed with.

FIG. 1 is a longitudinal sectional front view taken along the line AA of FIG.

In such a configuration, when the piezoelectric element 25 vibrates together with the vibration film 21 by the supply of the driving power corresponding to the print image, the ink jet printer head 14 is provided in the pressure chamber 28 located on the vibration film 21. ink
(Not shown) is ejected from the orifice 29 as ink droplets (not shown), and the ink droplets adhere to printing paper (not shown) to form an image.

Here, in the ink jet printer head 14, the vibrating film 21 is formed on the support 16 except for the portion facing the pressure chamber 28, so that the vibrating film 21 has good strength. Since the concave portion 15 released from the support 16 has a quadrangular pyramid shape whose opening side is expanded, the vibration film 21 and the pressure chamber 2 located on the concave portion 15 are formed.
8 can be arranged at high density.

Here, a method of manufacturing the ink jet printer head 14 will be described in detail with reference to FIGS. Here, the vertical cross-sectional view illustrated in FIG. 3 is a cross-sectional view of a state in which the structure illustrated in FIG. 4 is cut along a plane located on a diagonal line of the opening window 17. First, as illustrated in FIGS. 3A and 4A, the surface of a flat support 16 made of single-crystal silicon, which is a flat single-crystal material,
As illustrated in FIG. 3B, silicon nitride (Si ₃ N ₄ ) or silicon thermal oxide (Si
O ₂₎ the mask film 32 is formed consisting of the like, as illustrated in FIG. 3 (c) and FIG. 4 (b), forming the opening window 17 of the square to the mask film 32 by lithography or the like Thus, the mask 18 is formed. Then, as illustrated in FIG. 3D, LPCVD (Low Pressure-Chemi) is placed on the mask 18 and the support 16 below the opening window 17.
cal. Vapor Deposition) method with a thickness of 1500 to 2000 (Å)
As shown in FIG. 3E, an etching channel 34 is formed by patterning the polysilicon film 33 into a predetermined shape.
At this time, as illustrated in FIG. 4C, the etching channel 34 is formed in a shape such as adding a circle to four corners of a square covering the square opening window 17. Then, as illustrated in FIG. 3 (f), to form the lower part membrane 19 made of a film thickness of 2000 (Å) of about silicon nitride by LPCVD or the like onto this etching channel 34 and the mask 18, Figure 3 (g) and as illustrated in FIG. 4 (d), to form a four etching holes 35, each leading to a circular portion of the etch channel 34 corners in the lower part membrane 19. Next, the etching channel 34 is removed by, for example, injecting a KOH solution into the etching hole 35, and as shown in FIGS. 3 (h) and 4 (e), the gap where the etching channel 34 is located is formed. By injecting an etching material from the etching hole 35, the support 16 located below the opening window 17 of the mask 18
The quadrangular pyramid-shaped concave portion 15 whose opening side is expanded is formed by crystal plane anisotropic etching. And FIG.
As illustrated in FIG.
Thickness by LPCVD or the like on the part layer 19 1.0 to form the upper portion layer 20 made of ([mu] m) approximately silicon nitride or silicon oxide by blocking the etch holes 35, the recess of the support member 16 lower-upper portion layer 19 located on 15,
At 20, the vibrating film 21 is formed. In addition,
On the upper film 20 of the vibration film 21 thus formed, for example, a coating solution for forming a SiO ₂ film is applied and baked by a spinner method, a dipping method, a spraying method, a brush coating method or the like. Thus, it is also possible to adjust the thickness and strength of the vibration film 21.

Therefore, hereinafter, the piezoelectric element 25 is formed by the existing thin film process and the orifice plate 27 is formed.
Are joined. For example, each electrode 2 of the piezoelectric element 25
2 and 24 are metals such as Al and Ti or ITO (Indium-Tin).
Oxide) layer or the like, and the electromechanical conversion film 23 is formed by a melt epitaxy method, a sol-gel method,
It is deposited from the liquid phase by a precipitation reaction method, an anodic reaction method, chemical plating or the like. Here, the liquid-phase electromechanical conversion film 2
By precipitating 3, since the controllability of the particle morphology is good and the controllability of the addition amount and distribution uniformity of different elements is also good, the characteristics are uniform and the performance is stable, and Also, the growth rate is higher than that of the sputtering method. For example, in a sol-gel method or the like which is one of the methods for forming the electromechanical conversion film 23 from a liquid phase, hydrolysis is performed by adding water, an acid, or an alkali into a homogeneous solution having a predetermined chemical composition. A sol is generated by inducing the sol, and a gel is generated by dispersing the sol with fine particles of a desired composition by evaporating or cooling the solvent.

Here, an example of a specific manufacturing method when the electromechanical conversion film 23 made of a PZT film is formed by a sol-gel method or the like will be described in detail below. First, Pb (CH ₃ COO) ₂ .3H ₂ O is dissolved in CH ₃ COOH at a ratio of 1.0 (ml) to 2.0 (g), dried at 105 ° C., and then cooled to 80 ° C. And here, Zr (C ₃ H ₇ O) ₄ and Ti [(CH ₃ ) ₂ CH
O] ₄ were sequentially added and mixed by ultrasonication.
A substrate obtained by adding CH ₂ CH ₂ OH and H ₂ O is coated on a substrate by a spinner method or the like, and this is annealed at 300 to 500 ° C. to form a PZT film. In addition, as another production method from such a liquid phase, Pb (OAc) ₂ -Ti (OBu) ₄
By dipping of complex oxyalkoxide solution
For example, it is possible to form the electromechanical conversion film 23 made of bTiO ₃ .

As a method for manufacturing the electromechanical conversion film 23 as described above from a solid phase, a method in which a raw material attached to a substrate by coating or the like is formed into a film by thermal decomposition or a solid reaction, There is a method of forming a film by a solid phase reaction between a raw material and a substrate. As a method of manufacturing from a gas phase, a sputtering method or MOCVD (Metal Organic Chemistry) is used.
ical Vapor Deposition) method.

The protective film 26, which is the uppermost layer of the piezoelectric element 25, is formed of silicon nitride, silicon oxide, or the like.

Further, in the ink jet printer head 14, the orifice plate 27 is formed of a photosensitive glass or a photosensitive resin, and the pressure chamber 28 and the orifice 29 are formed as a concave groove having a predetermined depth. . In addition, as illustrated in FIG.
An ink jet printer head 39 having an orifice plate 38 with a two-part structure of 6, 37 can also be implemented. In this case, the orifice plate 38 is formed, for example, by coating a photosensitive resin on a substrate by a spinner method, and providing a member 36 for forming the pressure chamber 28 or the orifice 29 formed of a through groove by this optical patterning. It is implemented as a structure in which flat plates 37 made of stainless steel or the like are joined. Further, as illustrated in FIG. 6, an ink jet printer head 43 in which a concave portion 41 and a piezoelectric element 42 are continuously provided below the elongated pressure chamber 40 to improve the ink ejection characteristics can be implemented.

The BB vertical front view of the ink jet printer head 43 illustrated in FIG. 6 has the same structure as the ink jet printer head 39 illustrated in FIG. 5, for example.

[0028]

According to the first aspect of the present invention, a plurality of orifices which are arranged in an array and discharge ink droplets are formed, and a part of the inner wall surface of the plurality of pressure chambers which communicate with each of the orifices. the freely vibrating membrane vibration is formed in the direction perpendicular to the surface as an inkjet printer head provided with electromechanical transducer layer which operates in accordance with the drive power on the vibrating membrane, respectively the respective pressure chambers via the vibrating membrane
By forming the vibrating film on a support having a plurality of recesses opposed to each other on a one-to-one basis, since the vibrating film is formed on the support except for a portion facing the pressure chamber, the strength is good. Since the opening for opening the vibrating membrane from the support in this manner is open, the vibrating membrane and the pressure chambers located on the concave can be arranged at a high density. It is.

According to a second aspect of the present invention, there is provided an orifice for continuously ejecting ink droplets formed in an array and forming a part of an inner wall surface of a pressure chamber communicating with each of the orifices in a direction perpendicular to the surface. In an ink jet printer head having a vibrating film that can freely vibrate and an electromechanical conversion film that operates on the vibrating film in accordance with the driving power, on the surface of a flat support made of a single crystal material, Forming a mask coating, forming an opening window to the surface of the support in the mask coating to form a mask, forming an etching channel covering both the mask and the support under the opening window; forming a lower portion layer covering the etching channel and the mask together form an etching hole reaching the etch channel outward from the opening window of the mask to the lower portion layer, the etching hole Then, an etching material is injected from an etching hole into a space where the etching channel is located, and a recess is formed by anisotropic etching on a support located under an opening window of the mask. after suffering from lower portions film to form a <br/> upper portion film for shielding the etching hole, the lower portion layer and the upper located on the recess of the support
The vibrating film is formed with the partial film, so that the vibrating film can be made thinner by utilizing the selectivity of the etching. In addition, the vibrating film is a support member except for the portion facing the pressure chamber. Since it is formed on the upper surface, the strength is good, and the concave portion for releasing the vibration film from the support has a shape in which the opening side is expanded, so that the vibration film and the pressure chambers located on the concave portion are densely arranged. And the like.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view taken along the line AA of FIG. 2 showing an embodiment of the present invention.

FIG. 2 is a plan view.

FIG. 3 is a process chart showing a manufacturing method.

FIG. 4 is a process chart showing a manufacturing method.

FIG. 5 is a longitudinal sectional front view showing a modification corresponding to the BB section of the structure of FIG. 6;

FIG. 6 is a longitudinal sectional front view showing another modification.

FIG. 7 is a structural view showing a first conventional example.

FIG. 8 is an exploded perspective view showing a second conventional example.

[Explanation of symbols]

14,39,43 inkjet printer head 15, 41 recess 16 support 17 opening window 18 mask 19 lower portion layer 20 upper part film 21 vibrating membrane 25,42 electromechanical transducer layer 28, 40 pressure chambers 29 orifice 32 film mask 34 Etching channel 35 Etching hole

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 2/045 B41J 2/055 B41J 2/16

Claims (2)

(57) [Claims] 1. A plurality of orifices which are connected in an array and eject ink droplets are formed, and vibrate in a direction perpendicular to the surface as a part of inner wall surfaces of a plurality of pressure chambers which communicate with each of the orifices. forming a freely vibrating membrane, in the ink jet printer head provided with electromechanical transducer layer which operates in accordance with the drive power on the vibration membrane, a plurality of facing respectively one-to-one with each of the pressure chambers via the vibrating membrane < An ink jet printer head comprising the vibrating film formed on a support having a concave portion. 2. An orifice for continuously ejecting ink droplets formed in an array and forming a part of an inner wall surface of a pressure chamber communicating with each of the orifices, the vibrating membrane being capable of vibrating in a direction orthogonal to the surface. In an ink-jet printer head provided with an electromechanical conversion film that operates according to drive power on the vibrating film, a mask film is formed on the surface of a flat support made of a single crystal material, and the mask film is formed. An opening window reaching the surface of the support is formed in the coating to form a mask, an etching channel covering both the mask and the support below the opening window is formed, and the etching channel and the mask are formed. forming a lower portion layer covering both
Wherein an etching hole reaching the etch channel outward from the opening window of the mask to the lower portion layer, the etch channel is removed through the etching hole, from the etching hole in the clearance this etching channel is located upper part film by injecting an etching material to form a recess by anisotropic etching to the support located below the opening windows of the mask to shield the etch hole to cover the lower portion layer after the formation of the recess forming a said support manufacturing method for an ink jet printer head is characterized in that so as to form the vibrating membrane and the lower portion layer and the upper portion film located on the concave portion of the.