JPS60234853A - Preparation of nozzle of ink jet recording head - Google Patents

Abstract

PURPOSE:To align the emitting amount of ink, the emitting direction thereof and a recording characteristic, by a method wherein a half etching is applied to photosensitive glass, which was exposed to a predetermined pattern and developed, and, after the etched glass is masked by an etching solution resistant material, etching is again applied to the masked glass to pierce a part of the photosensitive glass. CONSTITUTION:Photosensitive glass 21, on which an exposure mask 22 was arranged, is exposed to ultraviolet rays and reaction of Ce<3+>+Ag<+>+ultraviolet rays Ce<4+>+Ag<0> is generated at the exposed parts 21b. Primary heat treatment is applied to the exposed glass to generate metal colloid of Ag and secondary heat treatment is further applied thereto to allow said glass to be easily resolvable around the metal colloid nuclei and Li2O-SiO2 is crystallized. Next, when half-etching is applied to both surfaces of the glass by an aqueous fluoric acid solution, parts 23, 24 are etched at a faster speed to form ring shaped protruded parts 25, 26. Subsequently, the entire single surface of the photosensitive glass 21 is masked by paraffin 28 and etching is performed until a hole is pierced from the protruded part 26 to the protruded part 25 in the opposite side.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a nozzle manufacturing method for an inkjet head that records characters, figures, images, etc. on a recording material by ejecting ink liquid from a minute opening.

2. Description of the Related Art Structures of Conventional Examples and Their Problems In recent years, inkjet recording apparatuses have come to be used as color printers and computer terminal equipment.

FIG. 1 shows a sectional view of an ink nozzle disclosed in Japanese Unexamined Patent Publication No. 57-131569. 1 is an ink nozzle plate, 2
3 is the nozzle end, and 3 is the ink discharge port. As shown in FIG. 1, if the nozzle end 2 is configured with a ring-shaped convex portion, the nozzle end 2 has a constant shape and has a sharp edge, so that ink droplets are ejected. After wetting the nozzle end 2, there is less remaining ink liquid due to wetting, and the lateral directing force of the attractive force due to surface tension becomes extremely small, and all the lateral directing forces are equal, so the ink liquid It is known that there is an effect that droplets are ejected in the axial direction of the ink ejection opening 3.

Although it is unclear how an ink nozzle with this configuration is manufactured as it is not disclosed in the above publication, it is possible to manufacture it using a photosensitive resin with a structure similar to that shown in Figure 1. A method shown in FIG. 2 is known.

In FIG. 2A, the exposure mask 17 is placed over the photosensitive resin 16 and exposed. There is a mask pattern 1B corresponding to the ink ejection opening 2o and a mesh mask pattern 19 around it, and since the pattern 18 does not transmit light, the photosensitive resin 16 in the area covered by the pattern 18 is not exposed. . Further, the area of the photosensitive resin 16 covered by the mesh pattern 19 is not completely masked and is therefore slightly exposed.

Further, the periphery of the pattern 18 is exposed in an annular manner.

The exposed portion of the photosensitive resin 16 undergoes a polymerization reaction, hardens, and becomes insoluble in solvents.

When the image is developed with a solvent after exposure in the state shown in FIG. 2a, the portion covered by the mask 18 is dissolved by the solvent, and the ink discharge ports 2o are perforated as shown in FIG. The solubility of the portion covered by the mesh mask pattern 19 in the solvent decreases, and as shown in FIG.
Melting is done up to the middle of the plate thickness. On the other hand, the ring-shaped portion around the mask 18 is sufficiently exposed, and since that portion is insoluble in the solvent, a convex portion is formed around the ink ejection port 2o as shown in FIG. Become. Finally, by cutting the shape of the ink discharge port 2o into a conical shape from the surface opposite to the surface on which the convex portion of the ink discharge port 20 is formed, the head nozzle having the configuration as shown in FIG. Obtained by using it. After the development process is completed, the photosensitive resin is cured by heating or ultraviolet irradiation.

However, in the above method, the diameter D2 of the ink discharge port 2o
Although the dimensional accuracy of the diameter D3 of the end face of the convex portion is good, the shape of the ink discharge port 20 is tapered and cannot be made into a shape with a counterbore.
It is difficult to reduce the resistance inside the pipe. Therefore, the injection energy became a problem. In addition, since the photosensitive resin 16 is an organic substance, it may swell with ink, especially oil-based ink, and has no rigidity, so ΔB shown in FIG.
There was a problem that if the shape was minute, such as having a size of 20 μm, it would be deformed.

Figure 3 shows the manufacturing process of forming an ink nozzle with a ring-shaped convex part using a nozzle plate with a two-layer structure in which a metal layer is formed on an insulating substrate. Indicates how the application was filed. FIG. 3a shows a nozzle plate having a two-layer structure in which a copper layer 13 is bonded to one side of an insulating substrate 12.

FIG. 3b shows the nozzle plate shown in FIG. 3a having been masked with a resist, and then 13 portions of the copper layer have been chemically etched to form convex portions. C in FIG. 3 shows that the ink ejection port 1 is formed by micro-drilling the convex portion of the copper layer 13.
4 has been drilled.

Although this method is good for forming one nozzle, there are various problems when forming a multi-nozzle in which two or more nozzles are lined up. That is, when processing by chemical etching, side etching is large, so that the diameter dimension D1 of the end face of the convex portion varies, and the shape of the end face does not become a perfect circle, resulting in variation. Furthermore, when the ink discharge port 14 is processed with a micro drill, an eccentricity ΔA occurs with respect to the end surface of the convex portion, and a burr 16 occurs.

Therefore, with the manufacturing method shown in Figure 3, it is difficult to improve the dimensional accuracy between each nozzle, and for this reason, in the case of multiple nozzles in which two or more are arranged, the recording characteristics of each nozzle may not be uniform. It was a problem.

OBJECT OF THE INVENTION The present invention solves the above-mentioned drawbacks, and aims to improve rigidity,
It is an object of the present invention to provide a method for manufacturing nozzles for an inkjet recording head that has excellent ink resistance, good dimensional accuracy, and can be easily processed.

Structure of the Invention In order to achieve the above object, the present invention exposes and develops photosensitive glass in a predetermined pattern, then performs half etching, and then masks the half etched photosensitive glass with an etching liquid-resistant material. Then, the photosensitive glass is etched again and a part of the photosensitive glass is penetrated to form a di-ink jet (the nozzle of the etching recording head).

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIG. 4 shows an example of a suitable ink jet recording apparatus using an ink nozzle plate manufactured according to the present invention. In FIG. 4, an insulating nozzle plate 4 has an air outlet 5 perforated therein, and a nozzle plate 6 is disposed parallel to this nozzle plate 4. The ink ejection lowers are perforated opposite to each other. The ink discharge lower is provided with a convex portion extending in the direction of the air discharge port 5. Air layer 8 formed by nozzle plate 4 and nozzle plate 6
An air flow is sent from the periphery and flows out from the air outlet 5, causing a sudden change in pressure gradient due to the bending of the air flow. The signal source 9 is located on the surface of the nozzle plate 4 and at the air outlet 5.
The ink supply tube 11 is electrically connected to a conductive ink supply pipe 11 that communicates with the electrode 10 and the ink discharge lower so that a potential difference is generated between the electrode 1o provided around the ink and the ink in the ink discharge lower. . Ink droplets are ejected by airflow and electrostatic forces. As shown in Fig. 4, if the ink discharge lower is provided with a convex portion extending in the direction of the air discharge ports 5, the air flow is bent more sharply due to the influence of the protruding ink discharge lower, and the ink discharge A dead area of the airflow occurs near the lower, and there is almost no pressure gradient in the airflow in this dead area, so even if the ink meniscus changes slightly at the ink ejection lower, no ink is ejected, and the ink The contact of the meniscus increases.

FIG. 5 shows a manufacturing process of an ink nozzle in which an ink discharge lower is formed on the nozzle plate 6 shown in FIG.

In FIG. 6a, 21 is photosensitive glass, for example Ce.
o2 Oyohi Aq2o containing 5iO2-A1203-Li
It is made of 2[deg.] type glass, and an exposure mask 22 is placed thereon, and exposure is performed by applying ultraviolet light with a wavelength of 280 to 350 .mu.m. In the exposure mask 22, a ring-shaped portion 22a
blocks light, and the portion 22b transmits light. Fig. 5 shows the state after irradiation with the light of Fig. 5a, and the portion 21b hit by the light is 3,000 Ce + Ag + ultraviolet light -) Ce' ++ Ag0
A reaction occurs, which is subjected to a first heat treatment to generate a metal colloid of Aq, and then a second heat treatment,
This metal colloid becomes the nucleus and L 120 S 102
Crystals form. Li2O-8iO2 crystals obtained by such heat treatment and development are extremely easy to dissolve in acids.

Therefore, the portion 21b exposed to light can be easily etched with a hydrofluoric acid aqueous solution. The portion 21a that was not exposed to light is not crystallized and is not easily corroded by the hydrofluoric acid aqueous solution. Next, in FIG. 6C, both sides of the photosensitive glass 21 are half-etched to a predetermined depth using a hydrofluoric acid aqueous solution. For example, half-etching the crystallized portion 21b to a depth of 30 μm can be done in about 5 minutes by immersion etching in a hydrofluoric acid aqueous solution with a hydrofluoric acid concentration of 5% and a solution temperature of 20"C1.Crystals of the photosensitive glass 21 The etching rate ratio between the crystallized portion 21b and the non-crystallized portion 21a is about 3o:1, so the crystallized portion 21b is etched faster, so the etching rates 23 and 24 in the figure are different. The portions indicated by are etched quickly, and substantially the same ring-shaped convex portions 25 and 26 are formed on both sides.

Since the non-crystallized portion 21a is also slightly etched, the ring-shaped convex portions 25 and 26 become tapered. Next, as shown in FIG. 6d, one side of the photosensitive glass 1210 is entirely masked with a layer of an etching solution-resistant material, such as a paraffin-based electron wax (manufactured by Sodenshi Kogyo Co., Ltd.) 28 as a hydrofluoric acid-resistant material. electron wax 2
8 is a paraffin-based adhesive that becomes liquid at temperatures above about 48°C, so the photosensitive glass 21 is heated to 58°C, for example, and masked by applying electron wax 28 to the glass substrate for better handling. 29 to the electron wax 28. Then, the surface opposite to the surface masked with the electron wax 28 is masked with the electron wax 27 of the same material layer as described above.

The temperature of the photosensitive glass 21 is raised to, for example, 68° C., and the amount of electron wax 27 applied is adjusted to the appropriate amount depending on the area to be applied.
If held for a predetermined time, the electron wax 27 applied near the ring-shaped convex portion 26 will gradually wet and spread, masking the ring-shaped convex portion 26 without allowing the electron wax 27 to enter therein. be able to. Here, the film thickness of the electron wax 27 is set to 5 μm or more. Hydrofluoric acid aqueous solution with a hydrofluoric acid concentration of 5%, liquid temperature 20°C,
When etching was performed for about 6 minutes by immersion etching, the etched surface 24a of the crystallized portion 21b had a center line average roughness of 0.1 μm;
The end surface 26a and side surface 26b of the half-etched ring-shaped convex portion 26 of the non-crystallized portion 21a have center line average roughness of o, 01 μm and 0.06 μm, and the end surface 2
6a has a lower surface roughness than other surfaces, and thus has poor wettability with the electron wax 27. Therefore, since the end surface 26a has poor wettability, it is possible to hold the electron wax 27 at the peripheral edge 26a of the ring-shaped convex portion 26. Further, since the ring-shaped convex portion 26 is raised in a convex shape, the electron wax 27 can be stored therein, so that the electron wax 27 can be applied thickly.

For these reasons, the ring-shaped convex part 26 has the function of slowing down and stopping the speed of wetting of the electron wax 27, but if the dimensions are too small, the electron wax 27 will fall into the ring-shaped convex part 26. It will be difficult to prevent it from entering, so it is necessary to set it to an appropriate size. Here, in the figure, ΔC = 30 μm, Δ
D=20 μm. Next, in FIG. 6e, the photosensitive glass 21 is etched a second time from inside the ring-shaped convex part 26, starting from the side masked with the electron wax 27, and then into the ring-shaped convex part 26 on the opposite side. Continue until the hole goes through. Electron wax 27 is
Since it begins to soften at a temperature of about 34°C, it is better to etch it with a hydrofluoric acid aqueous solution at a temperature lower than 34°C, and since its mechanical strength is low, it is better to use a dipping method as the etching method. For example, the second etching depth is 170 μm.
When the diameter of one hole is about 50 μm, it can be made in 36 minutes using a hydrofluoric acid aqueous solution with a hydrofluoric acid concentration of 5%, a liquid temperature of 20° C., and a dipping method. The etched portion 30 is a penetrating portion where the crystallized portion 21b of the photosensitive glass 21 is largely etched, and the non-crystallized portion 21a is also slightly etched to form a tapered shape. The etched portion 31 is a side etched portion that is generated due to slight dissolution of the electron wax 27 by the hydrofluoric acid aqueous solution and etching of the non-crystallized portion 21a, and the crystallized portion 21b is also slightly side etched. ing. Next, as shown in FIG. 6f, after the above-mentioned etching, the electron wax 2
7 and 28, and also removed the glass substrate 29 at the same time.
A nozzle having a ring-shaped convex portion 25 as shown in the figure could be formed. If the opposite surface of the ring-shaped convex portion 26 is uneven and causes any inconvenience, it is advisable to polish it as shown in FIG. 5q to make it flat as shown. In addition, if the rigidity, acid resistance, heat resistance, etc. of the photosensitive glass 21 are to be further improved, it is preferable to generate L 120.2 S z02 crystals by irradiating the entire glass with ultraviolet rays again and performing a tertiary heat treatment. .

FIG. 6 is a sectional view of a nozzle formed by the above manufacturing method. The ink discharge port consists of an etched portion 23a and an etched portion 30a.

In the first etching, the ring-shaped convex portion 25a and the etched portion 23a of the ink ejection port are formed to a depth of ΔF, and in the second etching, the etched portion 30a of the ink ejection port is formed to a depth of ΔF. There is.

In the second etching, electron wax is put into the etching part 23a for masking, and then etching is performed, and from the point where the etching has penetrated, the etching is slightly overetched to enlarge the hole diameter of the etching part 30a, as shown in the figure. Since it is possible to form an ink ejection port with a counterbore, according to this embodiment, it is possible to form an ink ejection port with low internal resistance. According to this embodiment, the nozzle is formed by etching twice, but once
The second etching time is short and there is little side etching, making it easier to achieve dimensional accuracy.Also, masking is performed after the first etching to protect the first etching surface before the second etching. The dimensional accuracy of the variations in the diameters D4 and D6 of the ink ejection ports and the diameter D6 of the ring-shaped convex portion 25a, which are particularly important dimensions, can be suppressed to ±2 μm. This also applies to a multi-nozzle structure in which a plurality of nozzles are lined up.

The specific dimensions of this example are D4-45μm, D5=
50 μm, D6=90 prn, ΔF=30
μm, ΔF-17·0 μm. According to this example, by using the ring-shaped convex portion, the hydrofluoric acid concentration is 6.
Electron wax, a hydrofluoric acid-resistant material, can be masked to a thickness of 5 μm or more so that it can withstand etching for 30 minutes or more using a hydrofluoric acid aqueous solution with a liquid temperature of 25°C and a dipping method. Since it is possible to mask even high-density patterns such as those arranged in rows, it is possible to form high-density nozzles with high precision.

Although the dimension of ΔG is as small as 20 μm, since the photosensitive glass has rigidity, a nozzle that does not deform can be created.

FIG. 7 is a sectional view for explaining a method of manufacturing a nozzle in another embodiment of the present invention. In Figure 7a,
Approximately the same ring-shaped convex portion 3 on both sides of the photosensitive glass 320
4 and 37 are formed by the same steps as steps a-C of the embodiment of FIG.

32a is a non-crystallized portion, and 32b is a crystallized portion. One side of the photosensitive glass 320 is masked with a layer of an etching liquid-resistant material, such as Epicoat (an epoxy resin adhesive manufactured by Chenope Chemical Co., Ltd.) 33 made of a hydrofluoric acid-resistant material. Here, the main ingredient, which is liquid at room temperature, is Epicoat 828. Ebicure Z is used as a hardening agent. Raise the temperature of the photosensitive glass 32 to 40"C, for example, and apply Epicoat 3.
If the amount of coating No. 3 is set appropriately according to the area to be coated and the coating is maintained for a predetermined time, the Epicoat 33 will be masked without entering into the ring-shaped convex portion 34 for the same reason as the embodiment shown in FIG. be able to. Here, the thickness of the epicoat 33 is set to 5 μm or more.

Next, Epicoat 33 is temporarily cured at room temperature for 50 hours, and then permanently cured at a temperature of 70° C. for 60 minutes. If this temporary hardening is removed, when the temperature is raised, inside the ring-shaped convex part 34,
Care must be taken because Epicoat 33 enters with a low viscosity. Then, the temperature of the photosensitive glass 32 is raised to 68° C., and the entire surface opposite to that masked with Epicoat 33 is masked with electron wax 35 as an etching liquid-resistant material layer. A glass substrate 36 is pasted on. Next, in FIG. 7, the photosensitive glass 32 is etched a second time from the side masked with Epicoat 33, from inside the ring-shaped convex part 34 to the ring-shaped convex part 37 on the opposite side. Continue until the hole goes through. The etched portion 38 is a penetrating portion. Etching part 3
Reference numeral 9 denotes a side etching portion produced by etching the non-crystallized portion 32a, and the crystallized portion 32b is also slightly etched. Next, in FIG. 7C, after etching with the hydrofluoric acid aqueous solution, the electron wax 35 is peeled off by washing with water and ultrasonic cleaning with trichlorethylene, and at the same time the glass substrate 35 is removed.
Also removes. After that, the shear epicoat 33 is peeled off by oxygen plasma ashing, and a ring-shaped convex portion 37 as shown in the figure is formed.
We were able to form a nozzle with FIG. 7d shows the state in which the other surface of the photosensitive glass 32 has been polished and made flat. Further, the photosensitive glass 32 is subjected to a tertiary heat treatment by being exposed to ultraviolet rays.

According to this embodiment, the size of the etched portion 39 can be made smaller because the Epicoat 33 has better adhesion to the photosensitive glass 32 and greater mechanical strength than the electron wax of the embodiment shown in FIG. Furthermore, the etching method using the hydrofluoric acid aqueous solution can be performed not only by dipping but also by spraying. In this example, Epicoat 33 and Electron Wax 36 were used as masking materials. However, if Epicoat 33 and Electron Wax 36 are used instead of Electron Wax 36, the temperature of the hydrofluoric acid aqueous solution during etching can be increased and the etching speed can be increased. be able to.

In the above description, the masking material is electron wax and Epicoat. However, the masking material may be other paraffin, other adhesive, resist, or the like. Further, the shape of the convex portion is not limited to a circle, and may be formed in any other shape such as a square or a triangle. Furthermore, both sides of the photosensitive glass may be half-etched separately so that the ring-shaped convex portions have different sizes.

Effects of the Invention As described above, the present invention exposes and develops photosensitive glass in a predetermined pattern, and then performs no-fetching.
Then, by masking the etched photosensitive glass with an etching liquid-resistant material and etching it again to penetrate a part of the photosensitive glass,
This is an inkjet recording head formed with a nozzle having a ring-shaped convex part, and has the following effects.0(1) Good dimensional accuracy of the nozzle, ink ejection amount, and ink ejection direction and recording characteristics can be matched.

(2) Since the ink ejection port has a counterbore shape and the resistance inside the tube is reduced, the driving voltage in the inkjet head can be lowered.

(3) Etching with a hydrofluoric acid aqueous solution with a hydrofluoric acid concentration of 5%,
So that it can withstand being heated for more than 3 o's at 25°C.
Hydrofluoric acid-resistant material can be masked to a thickness of 5 μm or more, and nozzle holes can be etched with high precision.

(4) High-density, high-precision multi-nozzles can be formed.

(5) Photosensitive glass that is rigid and has excellent ink resistance can be easily processed.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a nozzle part of a conventional inkjet recording head, FIG. 2 is a process diagram illustrating a conventional ink nozzle manufacturing method, and FIG. 3 is a diagram related to an earlier application filed by the present applicant. FIG. 4 is a sectional view showing an example of an inkjet recording apparatus to which the present invention is applied; FIG. 6 is a process diagram showing an embodiment of the nozzle manufacturing method according to the present invention. 6 is an enlarged sectional view of an inkjet recording head nozzle obtained according to the present invention, and FIG. 7 is a process diagram showing another embodiment of the nozzle manufacturing method according to the present invention. 21.32...Photosensitive glass, 22...
Exposure mask, 23a, 30a... etching part,
25°25a, 26.34.37---Convex portion, 27.28°33.35...Etching liquid resistant material layer, 29°36---Glass substrate . Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4 Figure 5 Figure 9/'b

Claims (1)

[Claims] (1) A first step of exposing and developing photosensitive glass in a predetermined pattern, a second step of half etching the exposed and developed photosensitive glass, and a second step of half etching the exposed and developed photosensitive glass. An inkjet method comprising: a third step of masking the photosensitive glass with an etching-resistant material; and a fourth step of etching the photosensitive glass again to penetrate at least a portion of the photosensitive glass. Recording head nozzle manufacturing method. (2) The first step includes a step of applying a ring-shaped pattern that is not exposed and developed on the photosensitive glass, and a ring-shaped protrusion is formed on the photosensitive glass corresponding to the notch turn. A method for manufacturing nozzles for an inkjet recording head according to claim 1. (3) In the third step, areas other than the curved portion of the half-etched photosensitive glass are masked with an etching liquid-resistant material.
A method for manufacturing a nozzle for an inkjet recording head as described in 1. (4) The method for manufacturing nozzles for an inkjet recording head according to claim 1, wherein in the third step, the etching liquid-resistant material is paraffin. (6) The method for manufacturing nozzles for an inkjet recording head according to claim 1, wherein in the third step, the etching liquid-resistant material is an adhesive.