JPH04216946A - Manufacture of ink jet recording head - Google Patents

Abstract

PURPOSE:To efficiently prepare an ink jet recording head capable of obtaining high printing quality. CONSTITUTION:A head substrate 1 is formed by injection molding and the connection part of an ink chamber 2 and a pressure chamber 4 is irradiated with laser beam to form a supply passage 3. A polymer resin film 7 is bonded to the head substrate 1 having the supply passage 3 formed thereto and nozzle orifices 6 are formed to the polymer resin film 7 bonded to the head substrate 1 by the irradiation with laser beam.

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 inkjet recording head used in an inkjet recording apparatus.

0002

2. Description of the Related Art In order to meet the high print quality required of on-demand ink jet recording devices, it is necessary to further increase the nozzle density. For this purpose, for example, as seen in Japanese Patent Application Laid-Open No. 56-172, a high-density inkjet is created by alternately arranging a plurality of ink chambers on both sides of a nozzle row formed on a common head substrate. A recording head has been proposed. In order to form this type of recording head at low cost, methods have been adopted in which the head substrate is formed by injection molding of a polymeric resin material.

In other words, the conventional method of manufacturing an inkjet recording head uses injection molding of a polymer resin material to form a pressure chamber on one surface and a through hole located at one end of the pressure chamber and oriented perpendicular to the surface. The first step is to form a head substrate that has an ink chamber on the other side and a supply path that connects the pressure chamber and the ink chamber, and a nozzle hole that has uniform nozzle holes processed by electroforming, etching, etc. The second step consisted of bonding the formed metal nozzle plate to the head substrate using an adhesive such as epoxy resin.

[0004] In order to form fine dimensions with high precision,
As seen in Japanese Patent Application Laid-Open No. 1-294047, there is a method of processing all the ink chambers, pressure chambers, supply channels, and nozzle holes with a laser beam, but this requires a lot of man-hours and is impractical.

[0005]

[Problems to be Solved by the Invention] In order to obtain high print quality using a high-density inkjet recording head, the ink enters the pressure chamber from the ink chamber via a supply path, is pressurized within the pressure chamber, and the It is required that a series of ink behaviors ejected from a nozzle hole communicating with one end, that is, ink flight speed, flight direction, ink amount per dot, etc., be uniform. Factors that greatly influence variations in ink behavior are variations in the cross-sectional area of the supply path, which corresponds to the inlet of the pressure chamber, and the cross-sectional area of the nozzle hole, which corresponds to the outlet. It has been experimentally confirmed that if the variation in cross-sectional area of the supply path and nozzle hole is ±15% or less, printing quality is ensured even if other parts vary.

Translating this into the dimensional accuracy of each part, the supply channel and nozzle hole with a circular cross section have ±40 μm in diameter.
It becomes 2.5 μm. However, in reality, it is difficult to mold such minute dimensions with high precision by injection molding of polymer resin materials.

[0007] Conventionally, due to shape and cost constraints, there was no suitable method for forming the supply channel other than injection molding at the same time when the ink chamber and pressure chamber were formed, and variations in the cross-sectional area of the nozzle hole is as much as ±50% or more, resulting in a problem that high print quality cannot be obtained.

[0008] Regarding the nozzle holes, a method has been taken in which a nozzle plate with uniform nozzle holes formed by electroforming or etching is adhered to the head substrate. Problems have arisen in terms of reliability due to clogging and misaligned ink flight.

The present invention has been made in view of these problems, and its purpose is to propose a new manufacturing method that can efficiently manufacture an inkjet recording head that provides high print quality. It's about doing.

0010

[Means for Solving the Problems] The present invention is a method of manufacturing an inkjet recording head to solve the above problems. First, a pressure chamber is formed on one side, and one end of the pressure chamber is formed by injection molding of a polymer resin material. a head substrate having a through hole located at and perpendicular to the surface and an ink chamber on the other surface, and then irradiated with a laser beam to connect the pressure chamber and the ink chamber. Further, the ink chamber is closed and a polymer resin film is attached so as to make the through hole a blind hole, and a laser beam is irradiated from the pressure chamber side to the innermost surface of the blind hole. A nozzle hole is formed extending from the inner surface to the other surface.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 4 show the first to fourth steps of a method for manufacturing an ink jet recording head according to an embodiment of the present invention.

FIG. 1 shows the first step, that is, the injection molding step of the head substrate. The head substrate 1 is integrally molded from a polymeric resin material such as polysulfone, polyethersulfone, or polycarbonate, which is injected between the movable template 10 and the stationary template 20.

The movable mold plate 10 used for this molding has molding convex portions 14 in its cavity portion corresponding to the pressure chambers 4 on the head substrate 1 to be molded. A pin 15 for forming a through hole 5 for communicating with the nozzle hole 6 is provided at one end of the chamber forming convex portion 14 .

On the other hand, the fixed side template 20 has the following features:
In the cavity part, molding convex parts 12 corresponding to the ink chambers 2 on the head substrate 1 to be molded are formed, and in the part facing the pins 15 for forming the above-mentioned through holes 5, A support hole 21 is formed at the tip of the pin 15. In addition, the code|symbol 22 in a figure has shown the runner part, 23 has shown the gate part, and 24 has shown the ejector pin.

When the above-mentioned polymeric resin material is injected between the mold plates 10 and 20 constructed in this way through the runner part 22 and the gate part 23, a pressure chamber 4 is formed on one side, and the pressure is A head substrate 1 having a through hole 5 for communicating with a nozzle hole 6 provided in a polymer resin film 7 shown in FIG. 8 at one end of the chamber and an ink chamber 2 at the other side is molded. FIG. 2 shows the second step, that is, the step of forming the supply path 3 to the head substrate 1 formed as described above. Head substrate 1 molded by the above-described first step
is fixed with the surface forming the pressure chamber 4 facing up, and the ink chamber 2
A required supply path 3 is formed by irradiating the connecting portion of the pressure chamber 4 with a laser beam. FIG. 5 is a perspective view of the formed supply path 3. FIG. 6 is a cross-sectional view of the formed supply path 3.

Laser beam generator 40 used for this purpose
As a laser catalyst, ArF, KrF, XeCl,
The oscillation wavelength is 193 to 351 nm using XeF etc.
An excimer laser device that can oscillate high-intensity high-energy photons in the ultraviolet region necessary to directly cleave chemical bonds is preferable. A laser beam outputted from the device 40 is focused on a connecting portion between the ink chamber 2 and the pressure chamber 4 on the head substrate 1 using an image mask 41 and a condensing lens 42, thereby forming a required supply path 3.

The head substrate 1 is actually made of polycarbonate by injection molding, and a condensing lens 42 with a reduction ratio of 8 is used at the connecting portion of the ink chamber 2 and the pressure chamber 4, so that the energy density is 6.0 J. When irradiated with a laser beam of /cm2, a repetition rate of about 60
Hole diameter 40μm, depth 120μm depending on the number of shots
3 per supply path with a taper angle θ of approximately 2 degrees.
It could be formed in seconds.

A required number of supply channels 3 are formed on the head substrate 1 by sequentially moving either the head substrate 1 or the laser beam device 40 relative to each other according to the arrangement of the supply channels 3 as necessary. do.

FIG. 3 shows the third step, that is, the step of bonding the polymer resin film 7 to the head substrate 1 on which the supply path 3 is formed.

The polymer resin film 7 is pasted by a solvent adhesive method so as to close the ink chamber 2 and make the through hole 5 on the ink chamber 2 side a blind hole.

In the solvent bonding method, first, a solvent is uniformly applied to the polymer resin film 7 or the head substrate 1, and then the polymer resin film 7 and the head substrate 1 are pasted together and left under a constant load for several hours. The adhesive is completely adhered by removing the load and leaving it at a constant temperature for several hours.

In order to uniformly apply the solvent, it is preferable to spin-coat the solvent onto the polymer resin film 7 or to apply the solvent onto the head substrate 1 using a roller adsorbed with the solvent.

FIG. 4 shows the fourth step, that is, the head substrate 1
This figure shows the process of forming a nozzle hole in the polymer resin film 7 pasted on. The head substrate 1 formed in the third step described above is fixed with the surface on which the pressure chamber 4 is formed facing up, and from the pressure chamber side to the inner inner surface of the blind hole,
A desired nozzle hole 6 is formed by irradiating a laser beam so as to form a nozzle hole 6 extending from the innermost surface to the other surface. FIG. 7 is a cross-sectional view of the formed nozzle hole 6.

Laser beam generator 40 used for this purpose
is the same as in the second step shown in FIG. Device 4
Using an image mask 41 and a condensing lens 42, the laser beam outputted from 0 is focused from the pressure chamber side on the head substrate 1 to the innermost surface of the blind hole to form the desired nozzle hole 6. Form.

Actually, using polycarbonate as a material, a polymer resin film 7 with a thickness of 80 μm and a head substrate 1 are bonded together using a solvent bonding method, and a condensing lens 42 with a reduction ratio of 8 is used on the inner surface of the blind hole. energy density is 6.0J
/cm2 Laser beam irradiation revealed that the hole diameter was 4 after approximately 400 shots at a repetition frequency of 200Hz.
Nozzle holes 6 with a diameter of 0 μm, a depth of 80 μm, and a taper angle θ of about 2 degrees could be formed in 2 seconds per nozzle hole.

If necessary, one of the head substrate 1 and the laser beam device 40 is sequentially and relatively moved according to the arrangement of the nozzle holes 6, and a required number of nozzle holes 6 are formed.
form.

As shown in FIG. 8, a wall member 8 is attached to the head substrate 1 that has completed the first to fourth steps described above so as to cover the pressure chamber 4, and then a wall member 8 is attached thereon to cover the pressure chamber 4. , a piezo vibrator 8a is attached thereto, and an ink supply member 9 communicating with an ink tank is attached thereon to form an inkjet recording head.

By this method, when 100 head substrates with 48 supply channels and 48 nozzle holes were processed, the total dimensions of the circular cross-section supply channels and nozzle holes were 40 μm in average diameter.
, were distributed with a standard deviation value of 0.5 μm, and the taper angle θ maintained uniformity. This is ±7.5 in cross-sectional area variation.
%, and it was possible to ensure high print quality even in actual printing.

In addition to the embodiments described above, it is possible to manufacture an inkjet recording head that achieves similar effects by modifying the shapes and positions of the head substrate 1, ink chambers 2, and pressure chambers 4.

[0030]

According to the present invention, parts such as pressure chambers, through holes, and ink chambers of the substrate where dimensional accuracy does not directly affect printing quality can be efficiently formed by injection molding, and dimensional accuracy has a large effect on printing quality. By irradiating a laser beam to the connecting portion between the pressure chamber and the ink chamber formed by injection molding to form the supply path that is affected, it has become possible to minimize variations in processing dimensions. Similarly, for the nozzle hole, whose dimensional accuracy greatly affects printing quality, a polymer resin film of a certain thickness is pasted using a solvent adhesive method so that the through hole of the board is a blind hole, and then a laser is applied to the inner surface of the blind hole. By forming by beam irradiation, there is no clogging of the nozzle hole or positional shift due to adhesive, and it is possible to minimize variations in processing dimensions. As a result of the above, it was possible to efficiently manufacture an inkjet recording head that provides high print quality.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a manufacturing process of an inkjet head according to the present invention.

FIG. 2 is a diagram showing a manufacturing process of an inkjet head according to the present invention.

FIG. 3 is a diagram showing a manufacturing process of an inkjet head according to the present invention.

FIG. 4 is a diagram showing a manufacturing process of an inkjet head according to the present invention.

FIG. 5 is a perspective view of the formed supply channel 3.

FIG. 6 is a cross-sectional view of the formed supply path 3.

FIG. 7 is a cross-sectional view of the formed nozzle hole 6.

FIG. 8 is a sectional view showing an inkjet head assembled based on a head substrate.

[Explanation of symbols]

1 Head board 2 Ink chamber 3 Supply route 4 Pressure chamber 5 Through hole 6 Nozzle hole 7 Polymer resin film 40 Laser beam generator

Claims (1)

[Claims] Claim 1: Made by injection molding of a polymeric resin material, it has a pressure chamber on one side, a through hole located at one end of the pressure chamber and perpendicular to the plane, and an ink chamber on the other side. a second step of forming a supply path connecting the pressure chamber and the ink chamber by irradiating the head substrate with a laser beam, and closing the ink chamber and forming the through hole. A third step is to paste a polymer resin film using a solvent adhesive method so as to form a blind hole, and a laser beam is irradiated from the pressure chamber side to the innermost surface of the blind hole to form a blind hole. A fourth forming a nozzle hole that reaches the surface.
A method of manufacturing an inkjet recording head comprising the steps of.