JPH09286101A - Ink jet head and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance yield in a method for producing an ink jet head using a silicon wafer. SOLUTION: A sodium silicate aq. soln. consisting of SiO2 , and water is diluted to be applied to the bonding surface of a silicone wafer 1 having nozzles formed thereto by using a spin coater to form a sodium silicate layer 7. Immediately after the sodium silicate layer 7 is formed, the silicon wafer 1 is laminated to a silicone wafer 2 having a vibration plate formed thereon and load is applied to both wafers on the side opposite to the bonding surface and both wafers are heated to 80-200 deg.C in the atmosphere to obtain a bonded wafer 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head used in an ink jet recording apparatus for ejecting ink droplets onto paper or the like for printing and a method for manufacturing the same.

[0002]

2. Description of the Related Art Inkjet printer heads have been rapidly reduced in price with the spread thereof in recent years. Among these, the demand for cost reduction of the head is increasing.

As a conventional diaphragm-forming substrate, there is a method of bonding two silicon substrates as shown in Example 3 of JP-A-6-8449.

[0004]

However, in the above-mentioned prior art, since the direct bonding process is used,
There is a problem that the joining cannot be performed stably and the manufacturing yield is low.

Therefore, the present invention solves such a problem, and an object of the present invention is to provide a method of manufacturing an ink jet head having a high yield by performing bonding using a sodium silicate layer. is there.

[0006]

An ink jet head according to the present invention comprises a plurality of nozzle holes, a plurality of independent discharge chambers communicating with each of the nozzle holes, and a part of at least one wall of the discharge chamber. A vibration plate that mechanically deforms, a driving unit that drives the vibration plate, and a common ink cavity that supplies ink to the plurality of ejection chambers,
An ink jet head that applies an electric pulse to the driving means to deform the vibrating plate corresponding to the driving means in a direction in which the pressure of the ejection chamber rises, and ejects ink droplets from the nozzle holes toward recording paper. In the above, the substrate on which the vibration plate is formed and the substrate on which the nozzle is formed are bonded to each other with the sodium silicate layer interposed therebetween.

Further, in the method for manufacturing an ink jet head of the present invention, a plurality of nozzle holes, a plurality of independent discharge chambers communicating with each of the nozzle holes, and at least a part of the wall of at least one of the discharge chambers are machined. A vibrating plate that is configured to deform dynamically, a driving unit that drives the vibrating plate, and a common ink cavity that supplies ink to the plurality of ejection chambers,
An ink jet head that applies an electric pulse to the driving means to deform the vibrating plate corresponding to the driving means in a direction in which the pressure of the ejection chamber rises, and ejects ink droplets from the nozzle holes toward recording paper. In the manufacturing method of 1., a substrate having a vibration plate or a substrate having a nozzle formed thereon is coated with a sodium silicate layer, the sodium silicate layer and the other substrate are bonded together, and heated to bond. And In addition, the substrate on which the diaphragm is formed is 2
It is formed by bonding two silicon substrates. The bonding method is to apply a sodium silicate layer to one of the silicon substrates, bond the sodium silicate layer and the other substrate, and heat to bond them. It is also characterized.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a sectional view of an ink jet head in one embodiment of the present invention. The inkjet head of the present embodiment has a structure in which a first substrate having nozzles, a second substrate having a diaphragm, and a third substrate having electrodes are laminated. The first substrate is a single crystal silicon wafer 1 having a thickness of 220 μm and a plane orientation of (110), and has a plurality of nozzles 5.
The second substrate is a single crystal silicon wafer 2 having a plane orientation of (110) and has a plurality of cavities 6 corresponding to the nozzles 5. The third substrate is the electrode glass substrate 3 having a thickness of 500 μm, and the ITO electrode thin film 4 is formed on the third substrate. Since this drawing is a sectional view, only one nozzle 5 and one cavity 6 are shown. In the present embodiment, double-sided polished wafers are used as the silicon wafer 1 and the silicon wafer 2, but a combination using either one-sided polished wafer or double-sided bright-etched wafer is also possible.

Next, a method of joining the silicon wafer 1 and the silicon wafer 2 will be described. FIG. 2 is a sectional view of the inkjet head showing the joining method. First, the silicon wafer 1 and the silicon wafer 2 are treated with a 98% nitric acid aqueous solution at 100 ° C.
For 10 minutes. Next, the silicon wafer 1 and the silicon wafer 2 are washed with ultrapure water to a purity of 15 megohm · cm and further dried with an explosion-proof spin dryer. Next, the sodium silicate layer 7 is applied to the bonding surface side of the silicon wafer 1. Sodium silicate layer 7 is composed of 35% to 38% SiO2 and 17%
To 19% Na2O and water to dilute an aqueous sodium silicate solution to a SiO2 concentration of 0.1 to 0.5%,
Rotation speed of 5000 rpm to 70 using spin coating
It is formed at 00 rpm. The thickness of the sodium silicate layer 7 is 13 nm to 50 nm. Immediately after forming the sodium silicate layer 7, the silicon wafer 1 and the silicon silicon wafer 2 are bonded together, and from the opposite side of the bonded surface,
A bonded wafer 8 is obtained by applying a load of 1 to 10 Kg / cm 2 and heating in an atmosphere of 80 ° C. to 200 ° C. for 30 minutes to 2 hours. Here, if the bonding temperature is 80 degrees Celsius or lower, sufficient bonding strength cannot be obtained, and if the bonding temperature is 200 degrees Celsius or higher, the sodium silicate layer 7 expands and bonding becomes difficult.

After that, the glass substrate 3 having the electrodes formed thereon and the bonded wafer 8 are bonded together. In this embodiment, the third substrate is made of borosilicate glass, and the bonded wafer 8 and the electrode glass substrate 3 are bonded by anodic bonding. In the present embodiment, the bonded wafer 8 and the electrode glass substrate 3 are bonded after the silicon wafer 1 and the silicon wafer 2 are bonded. However, after the silicon wafer 2 and the electrode glass substrate 3 are anodically bonded, It is also possible to join via the sodium silicate layer 7. The numerical values used in the present embodiment are the most preferable examples, and other conditions are possible.

FIG. 3 is an explanatory view of the silicon manufacturing process in the second embodiment of the present invention. First, a silicon wafer 21 and a silicon wafer 31 having a thickness of 220 μm and a (110) plane orientation are subjected to wet oxidation at 1100 ° C. in a thermal oxidation furnace to form thermal oxide films 22 and 32 having a thickness of 1.2 μm. (FIGS. 3A and 3B). Next, the silicon wafers 21 and 31 are washed with sulfuric acid at 95 ° C. for 10 minutes, and with ultrapure water to a purity of 15 megohm · cm. Further, it is dried by an explosion-proof spin dryer. Next, the sodium silicate layer 33 is applied to one surface of the silicon wafer 31 (FIG. 3C). The sodium silicate layer 33 comprises 35% to 38% SiO2 and 17% to 19%.
% Sodium silicate and water,
Dilute to a SiO2 concentration of 0.1 to 0.5% and spin coat to rotate at 5000 rpm to 7000 rp.
It is formed by m. The thickness of the sodium silicate layer 33 is 13 nm to 50 nm. Immediately after forming the sodium silicate layer 33, the silicon wafer 21 and the silicon wafer 3
1 is sandwiched with a sodium silicate layer 33, and a load of 1 to 10 kg / cm2 is applied from the opposite side of the bonded surface, in an atmosphere of 80 ° C to 200 ° C for 30 minutes or more and 2 hours. Then, heating is performed to obtain the bonded wafer 23 (FIG. 3D).

Next, FIG. 4 shows a process diagram after joining in the silicon manufacturing process of FIG. A resist is applied to the silicon wafer 31 side of the bonded wafer 23, patterning is performed,
Etching is performed with hydrofluoric acid to form an opening 34 in the thermal oxide film 32 (FIG. 4A). Next, the bonded wafer 2
3 is polished from the silicon wafer 21 side to have a thickness of 5 μm from the bonding interface (FIG. 4B). Next, the bonded wafer 23 is anisotropically etched by alkali to form the vibration plate 35 (FIG. 4C). In the present embodiment, the etching solution used is 35% aqueous potassium hydroxide solution and 70 degrees Celsius.
The degree is used.

[0014]

As described above, according to the present invention, the substrate on which the diaphragm is formed and the substrate on which the nozzle is formed are bonded together by using sodium silicate, so that the bonding is performed by using the sodium silicate layer. Thus, there is an effect that it is possible to provide a method for manufacturing an inkjet head with high yield.

[Brief description of drawings]

FIG. 1 is a sectional view of an inkjet head according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating the manufacturing process of the embodiment of the present invention.

FIG. 3 is a sectional view of an inkjet head manufacturing process of the second embodiment of the present invention.

FIG. 4 is a sectional view of an inkjet head manufacturing process of the second embodiment of the present invention.

[Explanation of symbols]

 1 Silicon Wafer 2 Silicon Wafer 3 Electrode Glass Substrate 4 ITO Electrode Thin Film 5 Nozzle 6 Cavity 7 Sodium Silicate Layer 8 Bonded Wafer 21 (110) Silicon Wafer 22 Thermal Oxide Film 23 Bonded Wafer 31 (110) Silicon Wafer 32 Thermal Oxide Film 33 Silicic Acid Sodium layer 34 Opening 35 Vibration plate

Claims (3)

[Claims] 1. A plurality of nozzle holes, a plurality of independent discharge chambers communicating with each of the nozzle holes, and a part of at least one wall of the discharge chambers are mechanically deformed. A vibrating plate, a driving unit that drives the vibrating plate, and a common ink cavity that supplies ink to the plurality of ejection chambers are provided. By applying an electric pulse to the driving unit, the driving unit corresponds to the driving unit. In an inkjet head that deforms the vibration plate in a direction in which the pressure of the discharge chamber rises and discharges ink droplets toward the recording paper from the nozzle hole, the substrate on which the vibration plate is formed and the substrate on which the nozzle is formed are An ink jet head characterized by being bonded via a sodium silicate layer. 2. A plurality of nozzle holes, a plurality of independent discharge chambers communicating with each of the nozzle holes, and a part of at least one wall of the discharge chambers are mechanically deformed. A vibrating plate, a driving unit that drives the vibrating plate, and a common ink cavity that supplies ink to the plurality of ejection chambers are provided. By applying an electric pulse to the driving unit, the driving unit corresponds to the driving unit. In a method of manufacturing an ink jet head in which the vibration plate is deformed in a direction in which the pressure of the discharge chamber rises and ink droplets are discharged from the nozzle holes toward a recording paper, a substrate on which the vibration plate is formed or a nozzle is formed. A method for manufacturing an inkjet head, characterized in that a sodium silicate layer is applied to another substrate, and the sodium silicate layer and the other substrate are bonded together and heated to bond them. 3. The substrate on which the vibration plate is formed is formed by bonding two silicon substrates, and the bonding method is such that one of the silicon substrates is coated with a sodium silicate layer and the other is a sodium silicate layer. 3. The substrate and the other substrate are bonded together and heated to bond them together.
The manufacturing method of the inkjet head according to the above.