JPH09267479A - Manufacture of ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably manufacture an ink jet head by the silicone direct bonding or the direct bonding in which a vibration plate for boron dispersion is used. SOLUTION: A silicone base on which nozzles are formed and another silicone base on which a vibration plate is formed are overlapped together to make a laminated base. The temperature of the laminated base is raised from the normal temperature up to 400 deg.C at the speed of 5 deg./minute, and also raised up to 1,100 deg.C at the speed of 8 deg./minute, and heated in the nitrogen atmosphere for one hour.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an ink-jet head, which is a main part of an ink-jet head recording apparatus for ejecting ink droplets only when recording is required and attaching the ink droplets to a recording sheet.

[0002]

2. Description of the Related Art In recent years, demands for miniaturization and high precision have increased in ink jet printer heads along with the demands for colorization and high definition.

Among them, there is an urgent need to reduce the thickness of the diaphragm, which is one of the driving elements, and make the thickness uniform. As a conventional diaphragm forming method, as shown in claim 2 of JP-A-6-23986, a second silicon substrate is bonded to a silicon substrate on which a nozzle and a pressure chamber are formed, and polishing is performed. Alternatively, a method of forming a diaphragm by thinning the second silicon substrate by etching, or a method of forming the diaphragm by high-concentration boron diffusion.

[0004]

However, in the above-mentioned prior art, there is no restriction on the temperature raising step in the direct joining process, and when the temperature raising rate from room temperature is higher than 5 degrees Celsius / minute, the joining is not performed. I found it unreliable. It is considered that this occurs because the air or moisture inside the cavities and the like existing on the bonding surface expands due to a rapid temperature rise, and the bonding surface peels off.

Therefore, the present invention is intended to solve such a problem, and an object thereof is to stably manufacture an ink jet head by silicon direct bonding or direct bonding using a diaphragm by boron diffusion. To provide the process.

[0006]

According to the method of 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 a part of at least one wall of the discharge chambers. Has a vibration plate that mechanically deforms, a driving unit that drives the vibration plate, and a common ink cavity that supplies ink to a plurality of ejection chambers, and applies an electric pulse to the driving unit. As a result, the vibration plate corresponding to the driving means is deformed in the direction in which the pressure in the discharge chamber rises, and in the method of manufacturing an inkjet head in which ink droplets are discharged from the nozzle holes toward the recording paper, the vibration formed by a silicon wafer is used. A feature of the present invention is that the plate-formed substrate and the nozzle-formed substrate are bonded together by direct bonding at a temperature rising rate from room temperature of 5 ° C./min or less.

Further, the high-concentration p-type silicon layer of the first silicon substrate having the high-concentration p-type silicon layer formed on one surface thereof is opposed to the second silicon substrate, and the temperature rising rate from room temperature is 5 degrees Celsius. It is characterized in that the vibrating plate is formed by bonding by direct bonding at a rate of not more than / minute.

[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 is a sectional view of an ink jet head according to an embodiment of the present invention. As shown in FIG. 1, the ink jet head of the present embodiment stacks a silicon substrate 1 having nozzles 5 formed thereon, a silicon substrate 2 having a diaphragm 6 formed thereon, and a glass substrate 3 having electrodes 4 formed thereon. -Has a structure formed by joining. FIG. 2 shows a cross-sectional view after the silicon substrate 1 and the silicon substrate 2 are joined. Further, FIG. 3 shows a temperature profile diagram of the direct bonding process of the ink jet head of one embodiment of the present invention.

First, the silicon substrate 1 and the silicon substrate 2
Was washed with a mixed solution of sulfuric acid and hydrogen peroxide (95 degrees Celsius), and washed with pure water to a purity of 15 MΩ. Next, it was dried. In this example, this drying was performed by explosion-proof spin drying. After drying, the silicon substrate 1 and the silicon substrate 2 were laminated at room temperature to obtain a bonded substrate 11. In this state, both substrates 1 and 2 are adsorbed by hydrogen bonds and can move without shifting. Next, the bonded substrate stack 11 is heat-treated at 1100 degrees Celsius in a nitrogen atmosphere for 1 hour. In this embodiment,
This heating was performed using a diffusion furnace which is a semiconductor manufacturing apparatus. The temperature of the bonded substrate 11 is raised from room temperature to 400 degrees Celsius at a rate of 1 degree / minute, and up to 1100 degrees Celsius is 8 degrees / degree.
The temperature was raised at a rate of minutes (Fig. 3).

4 and 5 are explanatory views of the manufacturing process of the ink jet head in one embodiment of the present invention. First, the silicon substrate 21 having a thickness of 220 μm (110) plane orientation is subjected to wet oxidation at 1100 ° C. in a thermal oxidation furnace to form thermal oxide films 22 and 23 having a thickness of 1.2 μm (FIG. 4). (A)). Next, a resist film (not shown) is applied on the thermal oxide film 22 of the silicon substrate 21 and the silicon substrate 21 is etched in a hydrofluoric acid aqueous solution to remove the thermal oxide film 23 (FIG. 4B. )). Next, the p-type impurities are diffused from the etching surface side of the thermal oxide film 22 of the silicon substrate 21 to form the impurity diffusion layer 25 (FIG. 4).
(C)). In this embodiment, ion implantation is used as the diffusion method, and the diffusion concentration is 1 × 10 ^ 20 / cm ^.
3. Next, the silicon substrate 21 and the 220-micron (110) -thickness oriented silicon substrate 31 are washed with a mixed solution of sulfuric acid and hydrogen peroxide solution (95 degrees Celsius) for 10 minutes, and then with ultrapure water at 15 megohm · cm. Wash with water to a meter purity. Further, it is dried by an explosion-proof spin dryer. Next, the silicon substrate 21 and the silicon substrate 31 are opposed to each other with the impurity diffusion layer 25 interposed therebetween,
Bonding is performed at room temperature to obtain a bonded substrate 41 (FIG. 4).
(D)). At this time, the bonded substrate stack 41 is bonded by hydrogen bonding. Next, the bonded substrate 41 is set to 11 degrees Celsius.
Heat treatment is performed at 00 ° C. in a nitrogen atmosphere for 1 hour. In this example, heating was performed using a diffusion furnace which is a semiconductor manufacturing apparatus. The bonded substrate 41 is 400 degrees Celsius from room temperature.
The temperature was raised at a rate of 1 degree / minute to 1 degree, and at a rate of 8 degree / minute to 1100 degrees Celsius (FIG. 3). The heat treatment causes the bonded substrate 41 to have a peel strength of 10 at the bonding interface.
It had 0 Kg / cm ^ 2 or more.

Next, the bonded substrate 41 is polished from the silicon substrate 31 side until the thickness of the silicon substrate 31 becomes 5 μm (FIG. 5A). Then, the bonded substrate 41 is subjected to wet oxidation at 1100 degrees Celsius to obtain a thermal oxide film 42 (silicon substrate 31) having a thickness of 1.2 μm.
Side), and a thermal oxide film 43 (on the silicon substrate 21 side) is formed (FIG. 5B). Next, a resist is applied to both surfaces of the bonded substrate 41, patterning is performed on the thermal oxide film 43 side, and etching is performed with hydrofluoric acid.
An opening 44 is formed in the (FIG. 5 (c)). Next, the bonded substrate 41 is subjected to an anisotropic anisotropic etching to form the vibration plate 4.
5 is formed (FIG. 5D). In this embodiment, the alkali anisotropic etching liquid is 35% potassium hydroxide aqueous solution.
It uses 70 degrees Celsius.

[0013]

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 both formed of a silicon wafer, and the substrate on which the diaphragm is formed and the nozzle are formed. The substrates are bonded together by direct bonding, and the temperature increase rate in direct bonding is set to 5 ° C./min or less to stabilize the inkjet head by silicon direct bonding or direct bonding using a diaphragm by boron diffusion. It is possible to provide a process that can be manufactured by

[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 sectional view showing the joint structure of an inkjet head according to an embodiment of the present invention.

FIG. 3 is a temperature profile diagram of a direct bonding process of an inkjet head according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating an inkjet head manufacturing process according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating an inkjet head manufacturing process according to an embodiment of the present invention.

[Explanation of symbols]

 1, 2 Silicon substrate 3 Electrode glass substrate 4 Electrode 5 Nozzle 6 Vibrating plate 11 Laminated substrate 21 (110) Silicon substrate 22 Thermal oxide film 23 Thermal oxide film 25 Impurity diffusion layer 31 (110) Silicon substrate 41 Laminated substrate 42 Thermal Oxide film 43 Thermal oxide film 44 Opening 45 Vibration plate

Claims (2)

[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 a method of manufacturing an ink jet head in which the vibration plate is deformed in a direction in which the pressure in the discharge chamber rises and ink droplets are discharged from the nozzle holes toward a recording paper, a substrate formed with a vibration plate made of a silicon wafer is formed. A method for manufacturing an inkjet head, characterized in that the substrate on which the nozzle and the nozzle are formed is bonded by direct bonding at a rate of temperature increase from room temperature of 5 ° C./minute or less. 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 vibrating 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 high-concentration p-type silicon layer is formed on one side. The high-concentration p-type silicon layer of the second silicon substrate is faced to the second silicon substrate, and the temperature rising rate from room temperature is 5 degrees Celsius /
A method for manufacturing an inkjet head, characterized in that the vibration plate is formed by laminating the diaphragms by direct bonding for a period not more than a minute.