JP3239274B2 - Method of manufacturing inkjet head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an ink jet head used in an ink jet printer.

In a recording apparatus such as a printer or a facsimile, an ink jet head has been used as a printing means.

[0003]

2. Description of the Related Art FIG. 3 shows the structure of a conventional ink jet head. The ink jet head 1 includes a nozzle 2, a pressure chamber 4 that communicates with the nozzle 2 and receives supply of ink from an ink supply path 3, and a piezoelectric element 5 that generates pressure in a part of the pressure chamber 4. . The inkjet head 1 is mounted on a carrier (not shown) that reciprocates along a platen, and is movable with the carrier.

At the time of printing, the head is moved together with the carrier, and a voltage is applied to the piezoelectric element 5 at a predetermined time to drive it. As a result, pressure is generated in the pressure chamber 4 and the nozzle 2
, Ink particles 6 are ejected. The ejected ink particles 6 adhere to the recording paper 100 to perform printing.

[0005]

By the way, glass, metal, resin, stainless steel, etc. are used as a material for forming the above-mentioned head. Processing accuracy has been required. However, it is difficult to obtain high processing accuracy with the above materials.

As a solution to this problem, a method of producing an ink jet head with high processing accuracy by performing anisotropic etching on an Si (100) single crystal substrate or a Si (110) single crystal substrate using an alkaline aqueous solution such as a KOH aqueous solution. (Eg, JP-A-54-150127 and JP-A-54-146633).

However, when the above method is used, the following problem occurs. (1) When a Si single crystal substrate is used, it is difficult to form different etching shapes by anisotropic etching on each surface. (2) When a single crystal Si substrate is used, it is difficult to obtain different depths from each surface when performing double-sided etching by one anisotropic etching.

It is an object of the present invention to provide a method of manufacturing an ink jet head in which a desired etching shape can be obtained by simultaneously etching both surfaces of a bonding substrate by an anisotropic etching method.

[0009]

According to the present invention, there is provided a head substrate having a pressure chamber, an ink supply passage for supplying ink to the pressure chamber, and a nozzle communicating with the pressure chamber. In the method of manufacturing an ink jet head having the above, two bonded single crystal substrates having different thicknesses are bonded via a silicon oxide film to form a bonded substrate, and the ink supply path and the pressure chamber forming are formed on one surface of the bonded substrate. After forming the etching pattern for the nozzle and the etching pattern for forming the nozzle on the other surface, anisotropic etching is performed simultaneously on both surfaces using the silicon oxide film as an etching stop film. A part of the silicon oxide film is removed, and an etching part on both sides is connected to form a head substrate (first configuration). Adult) and to.

In the method of manufacturing an ink jet head according to the first configuration, the two single crystal substrates having different crystal orientations on their surfaces are used (second configuration). I do.

Further, in the method for manufacturing an ink jet head according to the first or second configuration, the bonding substrate is formed by direct bonding of both single crystal substrates by heating. Configuration).

[0012]

[Function] By performing anisotropic etching on both surfaces simultaneously using a bonded substrate obtained by bonding two single-crystal substrates having different thicknesses, it is possible to easily and accurately perform etching of a different shape on each surface. By using a silicon oxide film as an etching stop film, selective etching with a large etching depth can be performed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is an explanatory view of a method of manufacturing an ink jet head according to this embodiment, and FIGS. 1A to 1E show respective steps in order. Next, a method for manufacturing an ink jet head will be described with reference to FIG.

In manufacturing the head, a Si (100) single crystal substrate 11 and a Si (110) single crystal substrate 12 shown in FIG. An SiO ₂ film 13 is formed by a sputtering method or the like, and the two substrates 11 and 12 are directly joined by heating via the SiO ₂ film 13. After that, both substrates 11 and 12 are polished on both sides by a polishing machine to a set thickness to form a bonded substrate 14.
Is prepared. The polishing accuracy of the polishing machine is ± 1 ± 2 μm
In this example, the Si (100) single crystal substrate 11 is 80
Polishing was performed until the thickness of the μm, Si (110) single crystal substrate 12 became 200 μm.

Next, as shown in FIG. 1B, both sides and the peripheral surface of the bonding substrate 14 are formed with Si as an etching protection film.
After the O ₂ film 16 is formed by a thermal oxidation method or the like, a resist solution for exposure is applied, and the surface of the Si (100) single crystal substrate 11 side (the upper surface in FIG. Exposure and development of the etching pattern are performed, and exposure and development of the etching pattern of the nozzle are performed on the surface (the lower surface in FIG. 1B) on the side of the Si (100) single crystal substrate 12, respectively.

At this time, a double-sided exposure machine is used to align the etching pattern on each surface. In consideration of anisotropic etching, the shape of the etching pattern is a rectangle (square) 15a having one side in the <110> direction on the 100th side (upper side) as shown in FIG. As shown in FIG. 2B, the (lower surface side) becomes a parallelogram 15b having one side in the <112> direction and an acute angle of about 71 °. After the development, Si is exposed by removing the portion of the SiO ₂ film 16 from which the resist has been removed with an aqueous HF (fluoric acid) solution. 11a and 12a are exposed Si portions.

As described above, the Si exposed portions 11 are formed on the upper and lower surfaces.
The anisotropic etching is performed by immersing the bonding substrate 14 having the a and 12a formed therein in an alkaline aqueous solution such as a KOH aqueous solution. Thus, the Si exposed portions 11a and 12a are etched as shown in FIG. (11
1) Plane etching rate is (100) plane and (110) plane
Since the etching rate of the surface is 0.3 to 0.4%, which is much lower than that of the Si exposed portion 11a (100),
The (111) plane having an angle of ° is formed and etched.

The exposed Si portion 12a is etched by forming two surfaces having an angle of 90 ° with respect to the (110) plane and two surfaces having an inclination angle of about 35 °. In this example, S
i (100) single crystal substrate 11 having a thickness of 80 μm and Si
(110) Since the thickness of the single crystal substrate 12 is smaller than 200 μm, the etched surface from the exposed Si portion 11a reaches the SiO ₂ film 13 earlier than that from the Si exposed portion 12a.

If the anisotropic etching of the bonding substrate 14 is further continued, the SiO ₂ film 13 is not etched by the alkaline aqueous solution, and the etching rate of the (111) plane is much lower than the other planes. It can be considered that the exposed portion 11a is not etched. Therefore, only the Si exposed portion 12a is etched to reach the SiO ₂ film 13. After the above-described anisotropic etching is completed, the SiO ₂ film 13 exposed by the HF aqueous solution and both etching patterns 1 are formed.
Remove 5a and 15b. FIG. 1D shows this state.

According to the above process, a head substrate 17 having a pressure chamber and an ink supply path formed on the upper side and a nozzle formed on the lower side is obtained. As shown in FIG.
As shown in (E), another substrate 18 serving as a diaphragm is joined. As a material of the substrate 18, glass, resin, Si or the like can be considered, and as a joining method, joining by an adhesive or electrostatic joining (eg, Japanese Patent Application Laid-Open No. 54-14633) can be considered. An Si (100) single crystal plate was used as a material of the substrate 18, and this was directly bonded to the head substrate 17.

Thereafter, the substrate 18 is polished to a predetermined thickness.
Finally, a SiO ₂ film 19 is formed by a thermal oxidation method in order to improve the ink resistance and the wettability with the ink of the wall surface constituting the nozzle, the pressure chamber, and the ink supply path. 20 is a pressure chamber,
21 is a nozzle.

The ink jet head is obtained by joining a piezoelectric element to a position on the substrate 18 facing each pressure chamber 20.

[0024]

As described above, according to the present invention, the following various excellent effects can be obtained. (1) An anisotropic etching method facilitates formation of a different etching shape on each surface. (2) SiO at the bonding surface between two single crystal substrates having different thicknesses
By utilizing the fact that the etching rate of the _two films and the (111) plane is much slower than the other planes, high-precision etching can be performed in the depth direction and the direction along the substrate plane by one-sided etching. . (3) Due to the reason (2), the influence of the etching time on the etching accuracy can be reduced. (4) By using the SiO ₂ film on the bonding surface as an etching stop film, selective etching with a large etching depth can be performed.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a method of manufacturing an ink jet head according to an embodiment of the present invention, wherein FIG.
1B shows an etching pattern forming process diagram, FIG. 1C shows a first etching process diagram, FIG. 1D shows a second etching process diagram, and FIG. 1E shows a completed inkjet head. (No piezoelectric element attached).

2A and 2B are explanatory diagrams of an etching pattern in the step of FIG. 1B, wherein FIG. 2A shows an upper surface and FIG. 2B shows a lower surface.

FIG. 3 is a side view showing the structure of a conventional inkjet head.

[Explanation of symbols]

Reference Signs List 11 Si (100) single crystal substrate 11 a, 12 a Si exposed portion 12 Si (110) single crystal substrate 13, 16, 19 SiO ₂ film 14 Bonding substrate 17 Head substrate 18 Substrate (vibration plate)

Continuation of front page (56) References JP-A-55-49275 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/16 H01L 21/02 H01L 21/306

Claims (3)

(57) [Claims] 1. A method for manufacturing an ink jet head having a pressure chamber, an ink supply path for supplying ink to the pressure chamber, and a nozzle connected to the pressure chamber, the method comprising: Are bonded together via a silicon oxide film to form a bonded substrate, and one surface of the bonded substrate is provided with the etching pattern for forming the ink supply path and the pressure chamber, and the other surface is provided with the etching pattern for forming the nozzle. After each etching pattern is formed, anisotropic etching is performed on both surfaces simultaneously using the silicon oxide film as an etching stop film. Thereafter, the silicon oxide film on both the etching patterns and the etched portion is removed, and the etched portions on both surfaces are removed. A method for manufacturing an ink jet head, comprising forming a head substrate by contacting the head substrate. 2. The two single crystal substrates having different crystal orientations on their surfaces are used.
The manufacturing method of the inkjet head according to the above. 3. The method for manufacturing an ink jet head according to claim 1, wherein the bonding substrate is formed by direct bonding of both single crystal substrates by heating.