JP3528586B2 - A method for manufacturing an ink jet 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 of manufacturing an ink jet head for ejecting ink droplets onto paper or the like for printing.
About the law.

[0002]

2. Description of the Related Art In recent years, the number of nozzles in an ink jet recording apparatus has been increased to support high speed printing.
Due to the demand for higher resolution, minute actuators are required. For this reason, an inkjet head (for example, Japanese Patent Laid-Open No. 6-71882) using electrostatic force for the actuator has been proposed. This ink jet head has a feature that the actuator can be configured with high density because the actuator is composed of parallel plate electrodes and the size of the actuator can be easily reduced.

[0003]

However, if the actuator is constructed with a high density, the diaphragm also becomes thin,
There is a problem that the thin diaphragm is difficult to handle.

The present invention has been made to solve the above problems, and an object thereof is to provide a thin diaphragm.
It is an object of the present invention to provide a method for manufacturing an inkjet head , which does not require the use of a thin substrate for forming .

[0005]

[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 vibration plate formed on the lower surface of the discharge chambers. And a vibrating plate having electrodes facing each other with a gap, applying a voltage between the vibrating plate and the electrode to deform the vibrating plate, and ejecting ink droplets from a nozzle hole. The thickness of the first substrate is reduced to form the diaphragm and the partition walls of the discharge chamber, and the third substrate is bonded thereon to form the discharge chamber. Further, the method for manufacturing an inkjet head of the present invention has a plurality of nozzle holes, a plurality of independent discharge chambers communicating with each of the nozzle holes, a vibration plate formed on the lower surface of the discharge chamber, and a gap in the vibration plate. In the method of manufacturing an inkjet head, which includes electrodes facing each other, applies a voltage between the vibrating plate and the electrode to deform the vibrating plate, and ejects ink droplets from the nozzle holes. The number of the diaphragms is reduced to form the diaphragm, the partition walls and nozzle holes of the discharge chamber are formed in the third substrate, and the third substrate is bonded onto the first substrate to form the discharge chamber. Further, the method for manufacturing an inkjet head of the present invention includes a plurality of nozzle holes,
A plurality of independent discharge chambers that communicate with each of the nozzle holes, a vibration plate formed on the lower surface of the discharge chamber, and electrodes that face the vibration plate with a gap therebetween, and a voltage is applied between the vibration plate and the electrodes. In the method of manufacturing an inkjet head, in which the vibration plate is deformed to eject ink droplets from the nozzle holes,
A diaphragm is formed by reducing the thickness of the first substrate, and a dry film that is patterned in advance is laminated on the first substrate to form a discharge chamber and a nozzle hole. Further, in the method for manufacturing an inkjet head of the present invention, in the above manufacturing method, the first substrate is a silicon single crystal substrate,
Then, the thickness of the first substrate is reduced and thinned by wet etching. In addition, in the method for manufacturing an inkjet head of the present invention, the thickness of the first substrate is reduced and thinned by mechanical processing in the above manufacturing method.

[0007]

[0008]

[0009]

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1. 1 is a cross-sectional view of an inkjet head according to Embodiment 1 of the present invention, and FIG. 2 is a plan view of the inkjet head of FIG. In the first embodiment,
An example in which the present invention is applied to a face eject type in which ink droplets are ejected from nozzle holes provided on the surface of the substrate is dealt with.

The ink jet head according to the first embodiment has a laminated structure in which the electrode glass substrate 100, the vibration plate substrate 200 and the nozzle plate 300 are stacked and joined. An ink supply port 104 is opened in the electrode glass substrate 100, and the reservoir 2 is opened through the ink supply port 104.
The ink 400 supplied to 04 is evenly distributed to the plurality of cavities (ejection chambers) 203 via the orifice 302. The lower surface of the cavity 203 is a deformable diaphragm 2
01, and faces the individual electrode 101 with the insulating film 202 for short circuit prevention interposed therebetween. A voltage is applied between the diaphragm 201 and the individual electrode 101 to generate an electrostatic attractive force to deform the diaphragm 201 downward, and the spring force of the diaphragm 201 generated when the applied voltage is removed. The ink droplet 401 is ejected from the nozzle 301 by the pressure.

FIG. 3 is an end view taken along the line AA of FIG. In the same 3, the thickness W of the partition wall 206 of the cavity 203 is 40
Although it is μm, the height L of the partition wall 206 is set as follows. The lower limit of the height L of the partition wall 206 is set to 100 μm or more, 120 μm or more, or 140 μm or more. This lower limit is determined from the viewpoint of the ink supply capacity (the lower the wall, the more difficult the ink to flow). The upper limit of the height L of the partition wall 206 is 160 μm or less, 150 μm or less.
m or less or 140 μm or less. This upper limit is
It is determined from the viewpoint of suppressing crosstalk and improving productivity (the higher the wall, the lower the rigidity of the partition wall, and the more difficult it is to effectively suppress crosstalk). By setting the height of the partition wall of the cavity 203 as described above, the lateral vibration of the partition wall of the cavity 203 is suppressed, and the occurrence of crosstalk caused by the vibration is prevented. The setting of the height of the partition wall of the discharge chamber is similarly applied to Embodiments 2 to 4 described later.

FIG. 4 is a process diagram showing a manufacturing process of the ink jet head of FIG. (A) A borosilicate glass substrate is used as the electrode glass substrate 100, and a step of 0.3 μm is formed on the borosilicate glass substrate.
It is formed by etching so as to surround a space for forming the individual electrode 101. Then, sputtering ITO, or after forming a 0.1μm membrane by vapor deposition and patterned at a pitch of 70μm individual electrode 101 by photolithography (Figure 4 (a)). (B) Next, B (boron) is diffused in a high concentration at a depth of 1 μm on the lower surface of the diaphragm substrate 200 made of a silicon single crystal having an initial thickness of 400 μm. The rate of Si etching by alkali depends on the B concentration and is high (about 5 × 10 ¹⁹ c
m ^-3 or more) is known to be extremely small.
By utilizing this characteristic, the diaphragm 201 having high uniformity can be formed by etching. B after spreading (boron) to form a thermal oxide film of 0.1μm made of an insulating film 202 (Figure 4 (b)).

(C) After heating the electrode glass substrate 100 and the vibration plate substrate 200 to 360 ° C., the electrode glass substrate 100
800V by connecting the negative electrode to the negative electrode and the positive electrode to the vibration plate substrate 200.
The voltage applied to anodic bonding (FIG. 4 (c)). (D) After anodic bonding, the entire substrate is immersed in a KOH aqueous solution to etch the diaphragm substrate 200 to a thickness of 100 μm (FIG. 4 (d)). Further, in this treatment, the grinding may be carried out by using a diamond wheel and then the grinding may be carried out by a lapping machine in the same manner as the usual grinding and polishing of a silicon substrate.

(E) After the above etching, a silicon dioxide film serving as an etching mask is formed on the entire surface of the diaphragm substrate 200 by CVD to a thickness of 1 μm, and a cavity pattern and a reservoir pattern are formed by photolithography. Form. Next, the whole substrate is immersed in a KOH aqueous solution of 10 w% and 80 ° C. to form the cavity 203 and the reservoir 20.
4, the electrode outlet 205 is formed. Further, the lower surface of the electrode substrate 100 and the reservoir 204 is perforated with a diamond drill to form the ink supply port 104. When the bottom surface of the cavity 203 reaches the boron-doped layer, the etching rate sharply decreases.
Diaphragm 202 can be easily formed (FIG. 4 (e)). (F) The nozzle plate 300 having the nozzle 301 and the orifice 302 is attached to the diaphragm substrate 2 with an epoxy adhesive.
No. 00 (FIG. 3 (f)). (G) After adhering the nozzle plate 300, in order to take out the individual electrode wiring 102, dry etching is performed to remove the silicon on the lower surface of the electrode taking-out port 205. After opening the electrode outlet 205, the edge of the electrode outlet 205 is sealed with a seal 103 made of epoxy resin for the purpose of preventing water or foreign matter from entering the actuator (FIG. 4 (g)). (H) Finally, each head is cut by dicing (FIG. 4 (h)).

In the first embodiment, the ink jet head is manufactured as described above, and after the diaphragm substrate 200 is bonded to the electrode glass substrate 100, the thickness is reduced to form the diaphragm 201. , This diaphragm substrate 200 is relatively thick (with respect to the thickness of the diaphragm)
Large substrates can be used. For example, a wafer having a diameter of 4 inches and a thickness of 100 μm does not have rigidity, is difficult to handle, and cannot take out an inkjet head at a high density. However, the diameter is 4 inches and the thickness is 4
Since a wafer of 00 μm has a certain degree of rigidity, it is easy to handle, and the inkjet head can be taken out with high density (for example, 50 wafers from one wafer). Therefore, productivity can be improved.

Embodiment 2. 5 is a sectional view of an inkjet head according to a second embodiment of the present invention, and FIG.
FIG. 3 is a plan view of the inkjet head of FIG. Second embodiment
In FIG. 3, the cavity 203 and the reservoir 204 are provided in the nozzle plate 300, and the orifice 302 is provided so as to narrow the cross section of the cavity 203 in the horizontal direction.

FIG. 7 is a sectional process drawing showing a manufacturing process of the ink jet head of FIG. The second embodiment is performed up to the anodic bonding process of the first embodiment (FIG. 4A to FIG.
Since the steps up to (d) are the same, the description of the processing up to that point will be omitted and the subsequent processing will be described. (A) Anodically bonded in the process of FIG.
(D)) After that, the entire diaphragm substrate 200 is etched to a thickness of 1 μm to form the diaphragm 201, and the electrode glass substrate 100 and the diaphragm substrate 20 are diamond-drilled.
0 is punched and used as the ink supply port 104. (Fig. 7
(A)). (B) Next, a nozzle plate 300 made of a silicon single crystal having a thickness of 180 μm is thermally oxidized, a nozzle pattern is formed by photolithography, and a nozzle straight portion 301a having a diameter of 20 μm and a depth of 20 μm is formed by anisotropic dry etching. Form. After forming the nozzle straight portion 301a, the whole is again thermally oxidized to form an etching mask (FIG. 7B).

(C) Nozzle taper portion pattern 311b,
The reservoir pattern 214, the cavity pattern 213,
The orifice pattern 312 and the electrode lead-out port pattern 215 are patterned to form the reservoir pattern 2
14 and the cavity pattern 213 and the orifice pattern 312 leave a thin thermal oxide film by half etching (FIG. 7C). (D) The nozzle taper portion 301b is etched with a KOH aqueous solution of 10 w% and 80 ° C., leaving the depth of the cavity 203 (FIG. 7D). (E) Then, using the hydrofluoric acid buffer, the reservoir pattern 21
4, the thermal oxide film on the cavity pattern 213 and the orifice pattern 312 is etched (FIG. 7E).

(F) The cavity 203, the reservoir 204, and the nozzle 30 are etched again with an aqueous KOH solution.
1, the orifice 302 and the electrode outlet 205 are formed (FIG. 7F). (G) Next, nozzle plate 300 with epoxy adhesive
Is bonded to the diaphragm substrate 200 (FIG. 7G). (H) After that, FIG. 4 (f) and (g) of the above-described first embodiment.
The head is completed through the same process as in (7 (h)).

Embodiment 3. 8 is a sectional view of an inkjet head according to Embodiment 3 of the present invention, and FIG. 9 is a plan view of the inkjet head of FIG.

In the third embodiment, the steps up to the whole surface etching step (FIG. 7A) of the above-described second embodiment are the same, and therefore, FIGS. 4A to 4D and FIG. Go through the processing steps. However, after that, the cavity 203 and the reservoir 204, the orifice 302, the nozzle taper portion 301b, and the nozzle straight portion 301a are patterned and laminated on the three dry films, respectively, to manufacture an inkjet head. In this case, since the dry film is sequentially laminated on the electrode glass substrate 100 via the vibration plate 200, even a thin dry film can be easily handled. As a result, the depth of the cavity 203 can be made sufficiently low, and the partition wall 20
Since the rigidity of 6 is high, sufficient rigidity can be obtained even with a dry film.

Embodiment 4. FIG. 10 shows a fourth embodiment of the present invention.
3 is an exploded perspective view of the inkjet head according to FIG. The inkjet heads of Embodiments 1 to 3 described above are of an electrostatic drive type, but the inkjet head of Embodiment 4 adopts a piezo drive method.
As shown in FIG.
It has a laminated structure in which the layers are stacked and joined. Upper substrate 5
01 is provided with a large number of nozzle holes 504 (in the example of the drawing, an example in which they are arranged in two rows is shown), and constitutes a nozzle plate. The intermediate substrate 502 is bonded to the upper substrate 501 and the thin film 502a,
The cavity 506, the orifice (not shown) and the reservoir 508 are formed, and the upper substrate 501 and the thin film 5 are formed.
A flow path unit is configured with 02a. The bottom surface of the cavity 506 forms a vibration plate. The lower substrate 503 has a recess 536 for accommodating the vibrator unit 513 and an ink supply pipe 514 connected to an ink tank (not shown). The vibrator unit 513 is housed / fixed in the recess 536. To be done. Further, the flow path unit (the substrates 501 and 502, the thin film 502a) is fixed to the lower substrate 503 by a frame 540 to construct an inkjet head, and the inkjet head is mounted on the carriage via the substrate 541. It is fixed to.

The above intermediate substrate (made of silicon) 502
Forms a recess corresponding to the cavity 506, the orifice and the reservoir 508 by patterning single crystal silicon having a plane orientation (100) by photolithography and performing wet anisotropic etching. The thickness of a silicon substrate that is generally commercially available is 400 to 500 μm.
However, in order to give sufficient rigidity to the partition wall of the discharge chamber 506, in the case of 180 dpi, the partition wall thickness is 40 to 50 μm.
Since it is m, it is necessary to reduce the thickness of the intermediate substrate 502. Therefore, the following process is performed to manufacture an inkjet head. The silicon substrate is roughly ground with a diamond grindstone to a required thickness, and the work-affected layer caused by grinding is removed by lapping with fine-grained abrasive grains and an alkaline grinding liquid. Then, by photolithography and wet anisotropic etching, recesses corresponding to the cavity 506, the orifice and the reservoir 508 are formed in the substrate. On the silicon substrate, a polyimide film provided with an island portion at a portion where the vibrator unit 513 hits is attached to form a diaphragm. Next, the above silicon substrate is cut corresponding to each inkjet head. Cut silicon substrate (intermediate substrate 50 in FIG. 10)
The nozzle plate 501 and the thin film 502a are bonded to 2) and the lower substrate 503 in which the vibrator unit 513 is housed and fixed is bonded.

Embodiment 5. By the way, Embodiment 1 described above
The inkjet heads 600 according to 4 to 4 are attached to the carriage 601 as shown in FIG. 11, and the carriage 601 is movably attached to the guide rail 602, and the width of the sheet 604 sent by the roller 603. Its position is controlled in the direction. The mechanism shown in FIG. 11 is mounted on the inkjet recording apparatus 610 shown in FIG.

(Evaluation Test) It was confirmed that crosstalk did not occur in the ink jet heads of Embodiments 1 to 4 above, and it was confirmed that crosstalk did not occur. The evaluation method is as follows. (1) Crosstalk test method A plurality of nozzles in the inkjet head are driven in various combinations, and it is confirmed that ink droplets are not ejected from the non-driven nozzles at this time. The crosstalk is most likely to occur when all the nozzles except one nozzle are in the driving state, and this driving state is also performed. In addition, the ejection of ink is observed by a CCD camera with a magnifying lens. At that time, a stationary ink droplet is observed by blinking a strobe in synchronization with an ink ejection signal. (2) Crosstalk determination method The presence or absence of crosstalk is determined by the above-described test method. When the ink droplets due to the crosstalk are extremely small, a printing test is finally performed, and it is determined whether the stain of the characters due to the crosstalk is within the allowable range in consideration of the specifications of the printer.

[0026]

As described above, according to the present invention, the thickness of the first substrate is obtained after the first substrate, which constitutes the vibrating plate, and the second substrate having the individual electrodes are joined. Since it is possible to use a relatively thick substrate because it is possible to use a thin substrate as the first substrate because the diaphragm is formed by reducing the Can be used, and a large number of inkjet heads can be taken out at high density.
Therefore, productivity can be improved.

[Brief description of drawings]

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

FIG. 2 is a plan view of the inkjet head shown in FIG.

FIG. 3 is an end view taken along the line AA of FIG.

FIG. 4 is a process diagram showing a manufacturing process of the inkjet head of FIG. 1.

FIG. 5 is a sectional view of an inkjet head according to a second embodiment of the present invention.

FIG. 6 is a plan view of the inkjet head of FIG.

7A to 7C are cross-sectional process diagrams showing a manufacturing process of the inkjet head of FIG.

FIG. 8 is a sectional view of an inkjet head according to a third embodiment of the present invention.

9 is a plan view of the inkjet head of FIG. 8. FIG.

FIG. 10 is an exploded perspective view of an inkjet head according to a fourth embodiment of the present invention.

FIG. 11 is an explanatory diagram showing a mechanism around the inkjet head according to the first to fourth embodiments of the present invention.

12 is an external view of an ink jet recording apparatus incorporating the mechanism of FIG.

[Explanation of symbols]

100 electrode glass substrate 101 individual electrode 102 Individual electrode wiring 103 seal 104 ink supply port 200 diaphragm substrate 201 diaphragm 202 insulating film 203 Discharge chamber 204 reservoir 205 Electrode outlet 206 partition 213 Cavity (discharge chamber) pattern 214 reservoir pattern 215 Electrode outlet pattern 300 nozzle plate 301 nozzle 301a Nozzle straight part 301b Nozzle taper part 302 Orifice 311b Nozzle taper pattern 312 Orifice pattern 400 ink 401 ink drops

Claims (5)

(57) [Claims] 1. A plurality of nozzle holes, a plurality of independent discharge chambers communicating with each of the nozzle holes, a vibration plate formed on the lower surface of the discharge chamber, and an electrode facing the vibration plate with a gap. A method of manufacturing an inkjet head, comprising: applying a voltage between the vibrating plate and the electrode to deform the vibrating plate to eject ink droplets from the nozzle holes, the vibrating plate being configured. After joining the first substrate and the second substrate having the electrode, the first substrate
By reducing the thickness of the plate, the diaphragm and the partition wall of the discharge chamber
Is formed, and a third substrate is bonded thereon to form the discharge chamber.
A method for manufacturing an inkjet head, which comprises forming the same. 2. A plurality of nozzle holes, and each of the nozzle holes
A plurality of independent discharge chambers communicating with each other and a shape formed on the lower surface of the discharge chambers.
The vibrating plate formed and the electric
A pole is provided, and a voltage is applied between the diaphragm and the electrode.
Then, the vibrating plate is deformed and ink drops are ejected from the nozzle holes.
In a method of manufacturing an inkjet head for discharging, a first substrate that constitutes the vibrating plate, and the electrode.
After bonding the second substrate having a pole, the thickness of the first substrate is reduced to form the diaphragm, and the partition wall of the ejection chamber and the nozzle hole are formed on the third substrate. A method for manufacturing an inkjet head, wherein the discharge chamber is formed by bonding the third substrate onto the first substrate. 3. A plurality of nozzle holes, and each of the nozzle holes
A plurality of independent discharge chambers communicating with each other and a shape formed on the lower surface of the discharge chambers.
The vibrating plate formed and the electric
A pole is provided, and a voltage is applied between the diaphragm and the electrode.
Then, the vibrating plate is deformed and ink drops are ejected from the nozzle holes.
In a method of manufacturing an inkjet head for discharging, a first substrate that constitutes the vibrating plate, and the electrode.
After bonding with a second substrate having a pole, the thickness of the first substrate is reduced to form the diaphragm, and a pre-patterned dry film is laminated on the first substrate. Forming the ejection chamber and the nozzle hole. Wherein said first substrate is a silicon single crystal substrate, and, according to the thickness of the first substrate to one of claims 1 to 3, characterized in that reduced by wet etching Inkjet head manufacturing method. 5. The method of manufacturing an inkjet head according to claim 1, wherein the thickness of the first substrate is reduced by mechanical processing.