JPH06143588A - Manufacture of ink jet recording head - Google Patents

Abstract

PURPOSE:To obtain an ink jet recording head having reliability by easy steps by so forming a conductive film as to cover many grooves of a board, removing the film on the board, then forming an insulating film made of paraxylene on the board, and irradiating the surface with a UV ray to integrally adhere the upper board to the board. CONSTITUTION:A conductive film 3 is so formed on a board 1 as to cover grooves 2 on the board 1 provided with many grooves 2 for forming ink channels. Then, after the film 3 on the board 1 is removed, independent electrodes 4 are formed on inner walls of the grooves 2. Thereafter, an insulating film 5 made of paraxylene for protecting the electrodes 4 is so vapor- deposited from above the board 1 as to cover the electrodes 4, and then irradiated with a UV ray. After the film 4 is converted from hydrophobic to hydrophilic by the irradiation, an upper board 6 is integrally adhered to the board 1, thereby completing an ink jet recording head having a plurality of ink channels 7 therein.

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 ink jet recording head having a large number of ink channels having electrodes on the inner surface.

[0002]

2. Description of the Related Art An electrode is provided on a wall portion that divides an ink flow path, and a pulse voltage corresponding to a recording / writing signal is applied to the electrode to deform the wall portion to pressurize ink in the flow path, An ink jet printer in which the ink is ejected from a nozzle as an ink drop onto a recording medium is disclosed in Japanese Patent Application Laid-Open No. 63-252750.

In this type of ink jet recording head, an electrode is provided on the inner wall of the ink flow path. Therefore, when conductive ink is used, it is necessary to apply an insulating film to the electrode surface.

On the other hand, when applying an insulating film to this kind of small-sized component, a material such as ceramic Si3 n4 or Parylene (trade name) is generally used. When based on such a viewpoint, parylene is preferable. However, on the other hand, since this type of material has poor adhesiveness, when this material is used as a coating material, not only a step of removing the coating on the adhesive surface is required, but also in the process of removing the coating. There is a problem in that a reliable product cannot be manufactured due to the inconvenience that a part of it peels off and the electrode is exposed.

That is, in order to form the above-mentioned ink jet recording head using this type of coating material, as shown in FIG. 2, a conductive film c is applied to a substrate a made of a piezoelectric material having ink grooves b. In addition (II), the conductive film c is formed on the substrate a.
After removing from the upper surface (III), the ink groove b is replaced with each ink groove b.
Independently of each other, then the above-mentioned insulating film e is applied so as to cover the electrode d on the substrate a (IV), and this film e with poor adhesion is removed from the upper surface of the substrate a (V). Finally, the upper substrate f is bonded onto the substrate a.

As described above, in the molding method using this type of coating material, the insulating coating c on the substrate a must be removed by polishing, so that the work is not only troublesome, but also this polishing treatment is required. As a result, the corner portions of the insulating film c are peeled off, or the piezoelectric material is chipped to form a portion having poor insulation properties, resulting in a problem of impairing the reliability of the product.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to:
It is an object of the present invention to provide a new method for manufacturing an ink jet recording head, which enables easy and reliable molding of a product.

[0008]

That is, according to the present invention, as a method of manufacturing an ink jet recording head for achieving such a problem, a substrate provided with a large number of grooves forming ink flow paths is covered with the grooves. After forming a conductive film on the upper surface of the substrate, and then removing the conductive film on the upper surface of the substrate,
An insulating film made of paraxylene is formed on the upper surface of the substrate so as to cover the conductive film in the groove, and finally, the surface of the insulating film is irradiated with ultraviolet rays to integrate the upper substrate with the upper surface of this substrate. It is designed to adhere to each other.

[0009]

Embodiments Now, the embodiments shown in the drawings will be described. FIG. 1 shows a forming process of an ink jet recording head which constitutes an embodiment of the present invention.

In each step shown by (I) to (III) in the figure, a plurality of grooves 2 forming an ink flow path are first formed in a substrate 1 made of a piezoelectric material as in the conventional forming step (I). ,
Then, a film 3 made of a conductive material such as a metal is applied to the entire surface of the substrate 1 so as to cover these grooves 2 by means such as vapor deposition (II), and finally, the conductivity of the upper surface of the substrate 1 is provided by an appropriate means. The film 3 is removed to form independent electrodes 4 ... on the inner wall of each groove 2 (III).

(IV) shows a process of forming the insulating film 5 for protecting the electrode 4. The insulating film material used here is a chemical formula called Parylene C (trademark).

[0012]

[Chemical 1]

Chemical formulas called poly-monochloro-para-xylene and parylene N (trade name)

[0014]

[Chemical 2]

Polyparaxylene and a chemical formula called Parylene D (trademark)

[0016]

[Chemical 3]

Mention may be made of polydichloroparaxylene.

These parylenes are slightly different from each other in terms of hardness and heat resistance of the coating film, but are excellent in chemical resistance and insulating property and are excellent in forming a fine film, This material is used to deposit an insulating film 5 on the substrate 1 so as to cover the electrodes 4, and then, as shown in (V), the insulating film 5 is irradiated with ultraviolet rays in the next step.

By the irradiation of the ultraviolet rays, the surface of the insulating film 5 made of parylene changes its property from hydrophobic to hydrophilic. Finally, as shown in (VI), the surface of the insulating film 5 or An adhesive is applied to the back surface of the upper substrate 6, and the upper substrate 6 is pressed onto the substrate 1 to bond them together to complete an ink jet recording head having a plurality of ink flow paths 7 inside.

(Example) On one surface of a substrate having a width of 3 mm and a length of 10 mm, a groove having a width of 0.15 mm divided by a partition wall having a width of 0.05 mm was formed.
Formed 0 pieces, applied an insulating film of Parylene C on it, and further removed this insulating film from the substrate surface, and made it as Specimen 1, and leaving this insulating film on the substrate surface. Sample ² was prepared by irradiating the insulating film on the surface of the substrate with ultraviolet rays for 60 seconds at an intensity of 3.5 mw / cm ² , and prepared as Sample 3 on each of which an epoxy adhesive was applied. (Able Stick Co., Ltd. #
93-1) was applied to a thickness of 5 μm, an upper plate was placed thereon, and the adhesive was cured by heating at 100 ° C. for 10 hours while applying a pressure of ² kgf / cm ² .

Then, a force (adhesive force) when peeling from the substrate was measured by applying a force to each of these upper plates, and the results shown in Table 1 were obtained.

[0022]

[Table 1]

From this, it was found that when the surface of the insulating film made of paraxylene was irradiated with ultraviolet rays, the adhesive strength on the surface was increased to the same level as that of a normal one having no insulating film.

[0024]

As described above, according to the present invention, the insulating film made of paraxylene is applied to the upper surface of the substrate so as to cover the conductive film in the groove, and then the insulating film having the hydrophobic property is formed. Since the surface of the film is irradiated with ultraviolet rays to impart hydrophilicity to it, the step of removing the insulating film from the upper surface of the substrate can be omitted, and at the same time, the film can be removed without peeling. Since the substrates can be bonded to each other, molding of this type of ink jet recording head can be further simplified, and highly reliable product formation can be achieved.

[Brief description of drawings]

FIG. 1 (I) to (VI) are views showing a forming process of an ink jet recording head which constitutes an embodiment of the present invention.

FIG. 2 is a diagram showing a forming process of a conventional inkjet recording head.

[Explanation of symbols]

 1 substrate 2 groove 3 conductive film 4 electrode 5 insulating film 6 upper substrate

Claims (1)

[Claims] 1. A substrate having a large number of grooves forming ink flow paths, a conductive film is formed on the upper surface of the substrate so as to cover the grooves, and then the conductive film is formed on the upper surface of the substrate. After the removal, an insulating film made of paraxylene is formed on the upper surface of the substrate so as to cover the conductive film in the groove, and finally, the surface of the insulating film is irradiated with ultraviolet rays so that the substrate A method for manufacturing an ink jet recording head, wherein an upper substrate is integrally bonded to the upper surface of the substrate.