JP2000289213A - Production of ink-jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the mass productivity by facilitating formation of an ink supply opening without a level difference in the inside, in a method for producing an ink-jet head by bonding a silicon substrate having an ink channel formed therein and a glass substrate. SOLUTION: A silicon substrate 2 with an ink channel formed, and a glass substrate provided with a through hole 36 are bonded. The through hole side of the bonded substrates 2, 3 is covered with a protecting member 71 with a through hole 38 corresponding to the through hole 36 preliminarily formed. Then, a high pressure straight water stream is jetted thereto so as to break the silicon substrate at the through hole part for forming an ink supply opening 14 communicating the ink channel and the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing an ink jet head.

[0002]

2. Description of the Related Art As a method of manufacturing an ink jet head, there is a method of manufacturing an ink jet head by etching a silicon substrate and joining two glass substrates so as to sandwich a flow path substrate having an ink flow path formed therebetween. JP 5
No. -50601.

In order to supply ink from the outside to the ink jet head manufactured as described above, it is necessary to provide a hole serving as an ink supply port. Conventionally, as shown in FIG. 4, a hole 3 serving as a through hole is formed in one glass substrate (electrode substrate) 3.
6 is formed in advance, a hole 26 serving as a through hole is formed in the other silicon substrate 2 in advance, and a common ink supply port 14 is formed by joining the two substrates.

Conventionally, a method of providing a supply port for supplying ink from outside to an ink-jet head has been proposed.
There is one disclosed in JP-A-10-193611. As shown in FIG. 5, a hole 36 serving as a through-hole is formed in advance on one glass substrate (electrode substrate) 3 and the silicon substrate 2 on which the other ink flow path is formed is joined and then etched. An ink supply port connecting the ink flow path to the outside is formed.

[0005]

However, in a manufacturing method in which a through hole is formed in both substrates in advance and then joined, there is a problem that the position of each through hole is shifted by several μm. When such a shift occurs, a step is formed at the position of the through hole where the two substrates are joined, and the air bubble is caught by the step, and the air bubbles in the ink supply path inside the ink jet head or the ink supply path from the ink supply tank to the ink jet head can be discharged. There was a possibility that the problem of disappearing would occur.

In addition, there is a problem that the number of processing steps is increased because the through holes are formed in both substrates, and the unit cost of the head is increased.

On the other hand, the manufacturing method disclosed in Japanese Patent Application Laid-Open No. 10-193611 solves the above-mentioned problem of air bubble discharge, and requires only a glass substrate to form a through-hole before joining the two substrates. Become. However, when plasma etching is used to form an ink supply port common to both substrates as described above, it is desirable to cover the flow path side of the silicon substrate with the bare silicon substrate after bonding the two substrates. There was a problem that the cost per head increased.

Accordingly, the present invention is to solve the above-mentioned problems in manufacturing the ink-jet head, and it is possible to increase the number of ink supply ports penetrating both substrates at once and to easily process the ink supply heads, thereby improving mass productivity. An object of the present invention is to provide a method for manufacturing an excellent inkjet head.

[0009]

In order to solve the above-mentioned problems, a method of manufacturing an ink jet head according to the present invention comprises bonding a silicon substrate having an ink flow path formed thereon to a glass substrate having a through hole. The bonded substrate is subjected to break punching by high-pressure water injection from the through-hole side of the silicon substrate to form an ink supply port connecting the ink flow path to the outside.

The high-pressure water jet is a straight water flow.

Further, after the surface of the glass substrate is covered with a protective member on a portion other than the through-hole of the glass substrate, high-pressure water injection is performed.

According to the above configuration, after the glass substrate and the silicon substrate having the ink flow path formed thereon are joined together, the glass substrate is covered with a protective member having a through hole at the same position as a through hole provided in advance in the glass substrate. The silicon substrate is cut and punched by high-pressure water jet only at the through-hole portion to form an ink supply port that connects the ink flow path inside the head to the outside.Therefore, there is a step where air bubbles are trapped inside the ink supply port. And has the effect of improving the bubble discharging property.

Also, compared to the above-described method for forming an ink supply port by plasma etching, which can provide the same effect as the above-mentioned effect, the steps of bonding and peeling bare silicon can be reduced, so that the unit cost of the head is reduced. It has the effect of being able to.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing an ink jet head according to the present invention will be described below with reference to the drawings. In addition, the same thing is shown and demonstrated by the same number.

FIG. 1 is an exploded perspective view of an ink jet head showing one embodiment of the present invention, and FIG. 2 is a schematic sectional view of the entire ink flow path of an assembled ink jet head.

The ink jet head 10 of the present embodiment sucks and vibrates the vibration plate using electrostatic force,
In this type, ink droplets are ejected by changing the volume of an ink chamber communicating with a nozzle. Of course, it is also possible to adopt a type in which the volume of the ink chamber communicated with the nozzle is changed by using a piezoelectric element or the like to discharge ink droplets, or the ink in the ink chamber is formed by using a heating element. It is also possible to adopt a type in which the ink droplets are ejected by expanding. Further, in this example, a face eject type in which ink droplets are ejected from nozzle holes provided on a substrate is used, but an edge eject type in which ink droplets are ejected from nozzle holes provided at an end portion of the substrate may be used.

The structure of the ink jet head 10 will be described with reference to FIGS. The inkjet head 10 of the present example has a laminated structure in which three substrates 1, 2, and 3 are overlapped. The substrate 1 is a nozzle plate substrate,
The substrate 2 is a silicon substrate, and the substrate 3 is an electrode glass substrate. The silicon substrate 2 is made of, for example, single-crystal silicon, and has a recess 22 whose bottom wall forms a discharge chamber 6 (ink chamber) functioning as the diaphragm 5, and an orifice 7 provided at the rear of the recess 22. And a common ink cavity (reservoir) for supplying ink to each ejection chamber 6.
8 to form a concave portion 24. The narrow groove 23 constituting the orifice 7 may be formed in the nozzle plate 1 which is the substrate 1 described later. An insulating layer 25 made of SiO ₂ is formed on the lower surface of the silicon substrate 2 to prevent a short circuit between the vibration plate 5 and an individual electrode 31 described later when the inkjet head 10 is driven.

The nozzle plate 1 joined to the upper surface of the silicon substrate 2 is made of, for example, glass or plastic, a metal such as stainless steel, or a thin plate of silicon or the like.
Nozzles 4 are formed at positions corresponding to the number of ejection chambers 6. By joining the nozzle plate 1 and the silicon substrate 2, a discharge chamber 6, an orifice 7, and a reservoir 8 communicating with the nozzle 4 are formed.

The electrode glass substrate 3 bonded to the lower surface of the silicon substrate 2 is made of borosilicate glass having a thickness of 1 mm,
On its upper surface, a concave portion 35 constituting the vibration chamber 9 is provided.
Are provided on the bottom surface of the concave portion 35, and the lead portion 32
And an individual electrode 31 having a terminal portion 33. The bonding of the electrode glass substrate 3 and the silicon substrate 2 constitutes the vibration chamber 9 and the respective vibration plates 5
, The individual electrodes 31 are arranged at the respective positions.
Further, the electrode glass substrate 3 is provided with a through hole 36 which becomes a part of the ink supply port 14 from the outside of the ink jet head 10. When the silicon substrate 2 and the electrode glass substrate 3 are joined, the through holes 36
It is provided so that it may be arranged underneath. This through hole 3
Numerals 6 are provided at a plurality of locations according to the size of the reservoir 8 and the number of nozzles.

After bonding the electrode glass substrate 3 and the silicon substrate 2, the vibration chamber 9 is filled with a sealing material 41 such as epoxy resin.
Hermetically sealed from outside air. At this time, the interval between the individual electrode 31 of the vibration chamber 9 and the diaphragm 5 is maintained at about 0.2 μm.

Thereafter, as will be described later, only the portion of the electrode glass substrate 3 where the through-hole 36 is opened is perforated in the silicon substrate 2, and the hole penetrates the silicon substrate 2 and the electrode glass substrate 3. An ink supply port 14 is formed.

The common electrode 26 and the terminal 3 of each individual electrode 31
3, a lead wire is bonded, and the driver 2
20 is connected to the inkjet head 10 shown in FIG.
Can be driven and is completed.

Further, by connecting an ink supply pipe to the ink supply port 14 of the ink jet head 10, ink channels such as the reservoir 8 and the discharge chamber 6 are supplied from an ink tank (not shown) through the ink supply port 14. Filled with ink.

The ink to be used is prepared by dissolving or dispersing a surfactant such as ethylene glycol and a dye or pigment in a main solvent such as water, alcohol and toluene. Further, the ink jet head 10
If a heater or the like is additionally provided, hot melt ink can also be used.

For example, a driver 220 applies a positive voltage pulse to the individual electrodes 31 to
Is charged to a positive potential, the lower surface of diaphragm 5 corresponding to individual electrode 31 is charged to a negative potential. Accordingly, the diaphragm 5 is attracted by the electrostatic force and bends in a direction in which the distance between the diaphragm 5 and the individual electrode 31 is reduced. At this time, when the diaphragm 5 bends, ink is supplied from the reservoir 8 to the ejection chamber 6 via the orifice 7. Next, when the voltage pulse applied to the individual electrode 31 is turned off and the stored charge is discharged, the diaphragm 5 is restored to the original position. Due to this restoring operation, the internal pressure of the ejection chamber 6 rapidly rises, and ink droplets are ejected from the nozzles 4 onto a recording paper (not shown).
Discharge toward.

Although FIG. 1 shows a part of one ink jet head, actually, ink channels of a plurality of ink jet heads 10 are formed on a silicon substrate 2 in a wafer shape by etching. A nozzle plate 1 on which a plurality of inkjet head nozzles 4 are formed on the upper surface side, and a plurality of individual electrodes 31 on the lower surface side
Are bonded to each other, and then cut at predetermined positions to obtain individual inkjet heads 10. As described above, it is possible to manufacture a large number of ink jet heads 10 at the same time, and it is excellent in mass productivity.

FIG. 3 is a process chart showing a method for manufacturing an ink jet head according to the present invention.

The description will be given step by step.

FIG. 3A is a cross-sectional view of the vicinity of the through hole 36 and the concave portion 24 serving as the reservoir 8 after the silicon substrate 2 and the electrode glass substrate 3 are bonded together. As a method of bonding both substrates, anodic bonding may be used. The anodic bonding is performed by bonding the silicon substrate 2 side to a positive electrode and the electrode glass substrate side to a negative electrode, and is performed at 300 to 400 degrees for about 5 minutes, for 7 minutes.
A voltage of 00 to 900 V is applied. Thereby, both substrates can be completely adhered. In addition, as long as the two substrates can be brought into close contact with each other, a method of bonding with an adhesive may be selected.

FIG. 3B is a sectional view showing a state in which a hole serving as an ink supply port 14 is formed in the silicon substrate 2. The electrode glass substrate 3 side is fixed to the bonded silicon substrate 2 and electrode glass substrate 3 with a protective member 71 described later. In addition, the protective member 71 has a diameter of 0.1 mm only in a portion corresponding to the through hole 36 of the electrode glass substrate 3.
A through hole 38 that is 2 mm larger is provided, and the hole position accuracy of both through holes is ensured. The protection member 71 aims at protecting the electrode glass substrate 3 from the high-pressure straight water flow and efficiently flowing the high-pressure straight water flow into the through-hole 36. Although any member may be used, it is preferable that the member be as thin as possible and use a large amount of water. In this example, a SUS material having a thickness of 10 mm was selected.

In this embodiment, as a condition for drilling a hole in the silicon substrate 2, a nozzle 72 capable of injecting a high-pressure straight water flow having the same cross-sectional diameter as the diameter of the through hole 38 is protected at a position corresponding to the through hole 38. A device in which a plurality of nozzles are arranged at a height of 80 mm from the member 71.
When a straight water jet with a discharge pressure of 40 kgf / cm ² is performed from 2, the bottom surface of the reservoir 8 is broken and a hole can be formed in about 2 seconds per through hole. If a larger number of injection nozzles 72 can be attached to a plurality of through holes, drilling can be performed in a shorter time. As described above, the high-pressure straight water flow is restricted by the through hole 38 of the protection member 71 and the through hole 36 of the electrode glass substrate 3, and the silicon substrate 2
The ink supply port 14 penetrating the electrode glass substrate 3 and the silicon substrate 2 does not have a step inside.

Further, since the broken pieces 325 are removed by the high-pressure straight water stream at the same time as drilling, a post-processing step for removing the broken pieces 325 is not required.

According to the above-described method of processing the ink supply port 14, it is a simple processing method, the formation of holes is easy, the processing time is reduced, and an ink jet head excellent in mass productivity can be manufactured. .

[0034]

As described above, according to the method of manufacturing an ink jet head of the present invention, a silicon substrate having an ink flow path formed thereon and a glass substrate having a through hole formed therein are bonded together. The side was covered with a protective member, and a high-pressure straight water stream was injected only into the through-hole portion of the glass substrate to break the silicon substrate, forming an ink supply port that connects the ink flow path inside the head to the outside. Air bubbles are not trapped in the inside of the mouth, so that air bubbles can be discharged easily.

Further, since the processing of the ink supply port is easy and the processing time can be reduced, the mass productivity of the ink jet head is improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an ink jet head of the present invention.

FIG. 2 is a schematic sectional view showing the inkjet head of FIG.

FIG. 3 is a process chart showing a method for manufacturing an ink jet head of the present invention.

FIG. 4 is a process chart showing a conventional method for manufacturing an ink jet head.

FIG. 5 is a process chart showing a conventional method for manufacturing an ink jet head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle plate 2 Silicon substrate 3 Electrode glass substrate 4 Nozzle 5 Vibration plate 6 Discharge chamber (cavity) 8 Reservoir (Common ink chamber) 10 Inkjet head 14 Ink supply port 31 Individual electrode 36 Through hole 71 Protective member 72 Injection nozzle 325 Break fragment

Claims (3)

[Claims] A silicon substrate having an ink flow path formed therein;
An ink supply port for joining a glass substrate provided with a through hole, performing a break punching process on the silicon substrate from the side of the through hole by jetting high-pressure water to the silicon substrate, and connecting the ink flow path to the outside. Forming an ink jet head. 2. The method of manufacturing an ink jet head according to claim 1, wherein said high-pressure water jet is a straight water flow. 3. A process for manufacturing an ink jet head according to claim 1, wherein the surface of the glass substrate is covered with a protective member having a through hole at the same position as the through hole of the glass substrate, and then high-pressure water jetting is performed. A method for manufacturing an ink jet head, comprising: