JPH1120173A - Manufacture of nozzle plate of recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain stable printing result by eliminating deflection of an ink ejection direction and disturbed ejection and to readily manufacture a nozzle plate having excellent durability to wiping operation. SOLUTION: This head is so constituted that a masking tape 2 is stuck to a nozzle face at a side of ink ejection on a nozzle plate substrate 1 on which nozzle holes 12 are opened and the substrate 1 is dipped into a mixture liquid 3 for applying the water repellency thereto, then it is washed to be dried. In this manufacturing process, any treatment is not applied to the nozzle face at the side of ink ejection and the accuracy in the treatment which may be required for a repellency treatment on the face is not necessary, so that it is possible to readily manufacture the nozzle plate without deflection of the ink ejection direction. As a result, the quality is not deteriorated even when the wiping operation to the nozzle plate manufactured by the above processes is repeated, thereby preventing lowering of printing performance.

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 a nozzle plate of a recording head, and more particularly to a technique for preventing a defective ink jet by imparting hydrophilicity to the nozzle plate.

[0002]

2. Description of the Related Art Conventionally, a method of manufacturing a nozzle plate of a recording head by an ink-jet method, in particular, as a process performed on a nozzle plate in which nozzles for ejecting ink are formed, a nozzle hole of the nozzle plate is formed. There is known a device in which a water-repellent process is performed on at least the surface where the nozzle hole is provided to form a water-repellent film.
The steps of this manufacturing method are shown in FIGS. First, as shown in FIG. 5A, the nozzle plate substrate 1 'manufactured by molding a molten resin material is provided with a nozzle general shape (corresponding to the tapered surface of the nozzle hole) 12b at the time of molding. . The masking tape 2 is attached to the ink inlet surface (the surface to which the actuator is bonded) of the nozzle plate substrate 1 '.

[0005] Next, as shown in FIG. 5 (b), in performing a water-repellent treatment on the masked nozzle plate substrate 1 ′, in order to firmly bond the water-repellent layer to the nozzle plate substrate 1 ′. After being immersed in the base treatment liquid 7 at a constant speed and pulled up at a constant speed, it is immersed in the liquid repellent 8 at a constant speed and pulled up at a constant speed. . Alternatively, there is also a method of applying the liquid repellent agent 8 to a uniform thickness by spin coating after applying the base treatment liquid to the nozzle plate substrate 1 '. Thereafter, as shown in FIG. 5C, the masking tape 2 is removed from the nozzle plate substrate 1 ′ to which the liquid repellent agent 8 has been applied, and the nozzle plate substrate 1 ′ is placed in an oven 9 and subjected to a heat treatment, whereby the water repellent film 80 To form Then, as shown in FIG. 5 (d), the laser processing using an excimer laser or the like causes the ejection port 12a on the ink ejection surface (the surface facing the recording medium) of the nozzle plate substrate 1 'where the water-repellent film 80 is formed. Is formed to provide the nozzle holes 12, thereby completing the nozzle plate 10 '. By performing the water-repellent treatment in this manner, the ink and the periphery of the nozzle hole are cut well when the ink is ejected, so that the ink ejection direction does not bend or the ejection is disturbed,
Always stable printing results are obtained.

[0004]

However, according to the conventional method of manufacturing a nozzle plate of a recording head as described above, the water-repellent film on the ink jetting surface of the nozzle plate substrate 1 'has the required performance. Therefore, fluorine compounds have been used, but due to the large binding energy of the fluorine compounds, if the processing thickness is not thin and uniform, laser processing can not produce clean holes and nozzle hole diameters vary. Causes deterioration. Therefore,
Water-repellent treatment requires control of strict conditions. In order to form a thin and uniform water-repellent film, application by dip coating or spin coating is most suitable, but any of these methods has great restrictions on the shape. That is, if the nozzle plate substrate 1 ′ is provided with irregularities or holes in advance,
There is an inconvenience that the liquid repellent agent 8 is excessively attached to the holes, the side surfaces of the convex portions, and the like. In addition, the applied water-repellent film cannot be firmly bonded to the nozzle plate substrate 1 ′ unless the heat treatment is performed. Therefore, the heat treatment is performed. Since heating is generally performed, the material of the nozzle plate substrate 1 'is restricted, and deformation due to heating also poses a problem. Further, since the heating step takes a long time, the productivity is reduced and the cost is increased. In addition, the manufactured nozzle plate has the following problems. In the ink jet recording head, in order to prevent the ink jet direction from being bent by the ink attached to the surface of the nozzle plate by repeating the ink jetting, a process of wiping the ink jetting surface of the nozzle plate after printing or the like, a so-called process. Although the wiping process is performed, if the wiping process is repeated, the water-repellent film may be peeled off, which may cause a printing failure.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a stable printing result can be obtained without causing the ink jetting direction to bend or disturbing the jetting. An object of the present invention is to provide a method for manufacturing a nozzle plate of a recording head, which can easily manufacture a nozzle plate having high durability.

[0006]

According to a first aspect of the present invention, there is provided a method of manufacturing a nozzle plate of a recording head, wherein the nozzle plate is joined to an actuator which forms an ink chamber. A method for manufacturing a nozzle plate of a recording head provided with a nozzle hole for ejecting the ink of the first aspect, comprising: a first step of opening the nozzle hole in a substrate serving as the nozzle plate; and a step of opening the nozzle hole in the first step. Masking the nozzle surface of the substrate on the ink ejection side, and immersing in a liquid for imparting hydrophilicity, and the nozzle imparted with hydrophilicity formed in the second step And a third step of drying the plate substrate.

In the above configuration, since a water-repellent film is not formed on the nozzle surface of the ink jetting side with a fluorine compound as in the prior art, high accuracy is required for processing for applying a thin and uniform film, or a laser is required. Simple processing with no holes in the water-repellent film, no variation in hole diameter, no restriction on the shape of the nozzle plate substrate, no reduction in productivity due to heating, no deformation due to heating, etc. The nozzle plate can be manufactured. In addition, since the manufactured nozzle plate does not peel off the water-repellent film as in the related art even when the wiping process is repeated, the quality of the nozzle plate does not deteriorate and the printing performance does not decrease. Since the inner surface of the nozzle hole is provided with hydrophilicity, the resistance of the ink ejection side nozzle surface to the ink liquid is smaller than that of the inside of the nozzle hole, and the ink is ejected from the nozzle hole when the ink is ejected from the nozzle hole. The cut between the droplet and the portion around the nozzle hole is improved. This allows
A stable printing result can be obtained without causing the bending of the ink ejection direction or the disturbance of the ejection.

According to a second aspect of the present invention, there is provided a method of manufacturing a nozzle plate of a recording head according to the first aspect.
The solution for imparting hydrophilicity in the process is a mixed solution of potassium dichromate and an acidic aqueous solution, a mixed solution of sodium dichromate and an acidic aqueous solution, a mixed solution of potassium permanganate and an acidic aqueous solution, or a permanganate solution. It consists of a mixture of sodium acid and an acidic aqueous solution.

In the above configuration, hydrophilicity can be more effectively imparted to portions other than the nozzle surface on the ink ejection side, and more stable printing results can be obtained by the manufactured nozzle plate. it can.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a nozzle plate of a recording head according to an embodiment of the present invention will be described below with reference to the drawings. FIGS. 1A to 1E are views showing each step of a method for manufacturing a nozzle plate. First, a nozzle plate substrate 1 in which a molten resin material is molded by a mold by injection molding is manufactured. As the resin material, for example, PPS
(Polyphenylene sulfite). In the nozzle plate substrate 1, similarly to the conventional one, a tapered surface 12b is formed at the time of injection molding, and laser processing is performed by an excimer laser device or the like to form an injection port 12a (FIG. 1).
(A)). This nozzle hole processing is performed simultaneously with the formation of the nozzle plate substrate by injection molding.
Alternatively, the injection port 12a may be formed.

Next, as shown in FIGS. 1B and 1C, a masking tape (for example, aluminum tape) 2 is attached to the nozzle hole surface of the nozzle plate substrate 1 on the ink ejection side. Then, it is immersed in a mixed solution 3 of a saturated aqueous solution of potassium dichromate and concentrated sulfuric acid. The conditions of the immersion at this time are preferably set at a liquid temperature of 50 ° C. and an immersion time of 10 minutes, whereby the hydrophilicity can be most preferably imparted. After immersion in the mixed solution 3, the nozzle plate substrate 1 is washed with running water 4 as shown in FIG. Then, as shown in FIG. 1E, the nozzle plate substrate 1 after washing with water is put into a dryer 5 and dried. Alternatively, air is blown to blow off water droplets and dried.

Referring to FIGS. 2 and 3, the nozzle plate 10 which has been subjected to the water immersion treatment in the above steps will be described. FIG. 2 is a perspective view of the nozzle plate 10, and FIG. 3 is a sectional view of the nozzle hole 12. This nozzle plate 1
A value of 0 indicates that the nozzle hole surface 10a on the ink ejection side is not provided with hydrophilicity, and the ejection port 12a and the tapered surface 12b in the nozzle hole 12 are provided with hydrophilicity. Therefore, the resistance to the ink droplet is smaller at the nozzle hole surface 10a than at the ejection port 12a and the tapered surface 12b. Therefore, the ink droplet is ejected from the ejection port 12a and the tapered surface 12b.
When the ink passes through the nozzle hole 12 and is ejected from the nozzle hole 12, the difference between the resistance of the nozzle hole surface 10a and the ejection orifice 12a and the tapered surface 12b improves the disconnection of the ink droplet around the nozzle hole.

Next, a recording head using the nozzle plate 10 will be described with reference to FIG. FIG. 4 is an exploded perspective view of the recording head. The ink jet recording head 20 includes an actuator 22 having a plurality of channel walls 21 formed by polarized piezoelectric portions, and a cover plate 23 adhered and fixed to an upper portion of the actuator 22. Actuator 22, cover plate 23 and channel wall 21,
Due to 21, the ink chamber 25 to which the ink is supplied is formed in a large number of grooves.

Each of the ink chambers 25 is formed so that the vicinity of the rear end of the actuator 22 in FIG. 4 is shallow, and the cover plate 23 has an ink inlet 26 for introducing ink from an ink cartridge (not shown). A manifold 27 connected to the ink inlet 26 is formed. This cover plate 23 serves as each ink chamber 25.
The ink from the ink cartridge can reach each of the ink chambers 25 by the ink inlet 26 and the manifold 27. The nozzle plate 10 is adhered to one end surfaces of the actuator 22 and the cover plate 23, and the nozzle holes 12 are set to correspond to the positions of the respective ink chambers 25.

On the channel wall 21 of each ink chamber 25,
Electrodes 28 are provided on the piezoelectric portion of the channel wall 21 to generate a driving electric field substantially orthogonal to the polarization direction. A conductive pattern 31 corresponding to each of the ink chambers 25 is formed on the substrate 30, and the conductive pattern 31 and the electrodes 28 are connected to the conductive wires 32 by wire bonding.
Connected by A head driver (not shown) for driving and controlling the ink ejection is connected to the conductive pattern 31. The ink chamber 2 is formed by applying a voltage to the electrode 28 and causing a piezoelectric thickness slip of the channel walls 21 and 21.
The ink in 5 is ejected.

As described above, according to the method of manufacturing the nozzle plate of the recording head of the present embodiment, the process requiring high precision such as the water-repellent process is not performed on the nozzle surface of the ink ejection side. It is possible to easily manufacture the nozzle plate 10 which does not cause the ink ejection direction to bend. Also, since no processing is performed on the nozzle hole surface 10a of the nozzle plate 10, a nozzle plate having excellent durability against wiping processing can be obtained.

The present invention is not limited to the configuration of the above-described embodiment, but can be variously modified. For example, in the above embodiment, a mixed solution of a saturated aqueous solution of potassium dichromate and concentrated sulfuric acid is used as the mixed solution 3 for imparting hydrophilicity to the nozzle plate substrate 1. However, the present invention is not limited to this, and other liquids may be used as long as they are suitable for imparting hydrophilicity. For example, a mixed solution of another acidic aqueous solution and potassium dichromate, or a mixed solution of sodium dichromate and an acidic aqueous solution, or a mixed solution of potassium permanganate and an acidic aqueous solution, or a mixed solution of sodium permanganate and an acidic aqueous solution And the like.

[0018]

As described above, according to the method for manufacturing a nozzle plate of a recording head according to the first aspect of the present invention, a water-repellent film is formed on a nozzle surface of an ink ejecting side with a fluorine compound as in the prior art. Because it is not formed, there is no need for precision in the process of coating the film thinly and uniformly, no clear holes are formed in the water-repellent film by laser processing, the hole diameter does not vary, and the shape of the nozzle plate substrate is limited In addition, the nozzle plate can be easily manufactured without lowering of productivity due to heating, deformation due to heating, and the like. Also, the manufactured nozzle plate is
Even if the wiping process is repeated, the water-repellent film is not peeled off unlike the conventional case, so that the quality of the nozzle plate does not deteriorate. Since the inner surface of the nozzle hole is provided with hydrophilicity, the resistance of the ink ejection side nozzle surface to the ink liquid is smaller than that of the inside of the nozzle hole, and the ink is ejected from the nozzle hole when the ink is ejected from the nozzle hole. The cut between the droplet and the portion around the nozzle hole is improved. Accordingly, a stable printing result can be obtained without causing the bending of the ejection direction of the ink and the disturbance of the ejection.

According to the method for manufacturing a nozzle plate of a recording head according to the second aspect of the present invention, it is possible to more effectively impart hydrophilicity to portions other than the nozzle surface on the ink ejection side. Therefore, according to the manufactured nozzle plate, a more stable printing result can be obtained.

[Brief description of the drawings]

FIGS. 1A to 1E are views showing each step of a method for manufacturing a nozzle plate.

FIG. 2 is a perspective view of a nozzle plate on which a water immersion process has been performed according to the above process.

FIG. 3 is a sectional view of a nozzle hole portion of the nozzle plate.

FIG. 4 is an exploded perspective view of a recording head using the nozzle plate.

5 (a) to 5 (d) are views showing each step of a conventional method for manufacturing a nozzle plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate for nozzle plate 2 Masking tape 3 Mixed liquid 5 Dryer 10 Nozzle plate 12 Nozzle hole

Claims (2)

[Claims] 1. A method of manufacturing a nozzle plate of a recording head which is joined to an actuator forming an ink chamber and provided with a nozzle hole for ejecting ink in the ink chamber by the actuator. A first step of opening a nozzle hole, and after masking the nozzle surface on the ink ejection side of the substrate having the nozzle hole opened in the first step, immersion in a liquid for imparting hydrophilicity A method of manufacturing a nozzle plate for a recording head, comprising: a second step; and a third step of drying the nozzle plate substrate provided with the hydrophilic property formed in the second step. 2. The solution for imparting hydrophilicity in the second step is a mixed solution of potassium dichromate and an acidic aqueous solution, a mixed solution of sodium dichromate and an acidic aqueous solution, or a mixed solution of potassium permanganate and an acidic aqueous solution. 2. The method for manufacturing a nozzle plate of a recording head according to claim 1, comprising a mixed solution of an aqueous solution or a mixed solution of sodium permanganate and an acidic aqueous solution.