JPS591267A - Manufacturing method of inkjet recording head - Google Patents

Abstract

PURPOSE:To obtain a highly reliable ink jet recording head, by a method wherein protective layers are provided on a base plate including ink jetting elements and after the surfaces thereof are treated with metal organic compound, photographic resins are deposited thereupon. CONSTITUTION:After a predetermined number of ink jetting pressure generating elements such as heat generating elements are provided on a base plate 1 made from ceramic, metal or the like, it is covered with inorganic oxide such as SiO2, glass BN or the like and/or inorganic nitride 3. Furthermore, the base plte 1 is cleaned at its surface and metal organic compound as metal alcoholate, metal acylate or the like are deposited on the layer 3 to form a layer 4. Thereafter, a dry film photoresist 5 is provided and a photomask 6 is deposited thereupon for exposure. After an ink passage 9 is defined by treating the unexposed part using dissolving agent, a plate 8 adapted to serve as a cover for the base 1 is secured thereto using adhesive agent 7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an inkjet recording head for generating recording ink droplets used in a so-called inkjet recording system.

An inkjet recording head applied to an inkjet recording method generally includes a fine ink ejection opening (orifice), an ink passage, and an ink ejection pressure generating section provided in a part of the ink passage.

Conventionally, the method for creating such an inkjet recording disk is, for example, by forming fine grooves on a glass or metal plate by cutting or etching, and then joining the plate with the grooves formed thereon to another suitable plate. Methods of forming ink channels are known.

However, in the head made by such conventional method,
If the inner wall surface of the ink passage to be cut is too rough, or the ink passage may be distorted due to the difference in etching rate, it is difficult to obtain a highly accurate ink passage, and the ink ejection characteristics of the inkjet recording head after manufacturing may be affected. Variations are likely to occur.

Another disadvantage is that the plate tends to chip or crack during cutting, resulting in a poor manufacturing yield. When etching is performed, there are many manufacturing steps, which is disadvantageous in that it increases manufacturing costs. Furthermore, the common drawbacks of the above-mentioned conventional methods are: 1. The grooved plate in which the ink passage grooves are formed, the piezoelectric element that generates the energy that acts on the ink,
When bonding to a substrate on which driving elements such as heating elements are provided, it is difficult to align each element with high precision, which results in a lack of mass productivity. As an inkjet recording head manufacturing method that can solve these drawbacks,
A method of forming an ink passage wall with a cured film of a photosensitive resin is known, for example, from JP-A-37-'13g76. According to this method, the ink passages are microfabricated with high precision, accuracy, and high yield.

Moreover, it can be said to be an excellent method because it is easy to mass-produce and can provide an inexpensive inkjet recording head.

However, in the inkjet recording head provided by the improved manufacturing method, although the above-mentioned drawbacks have been solved, the adhesion between the substrate 1 and the photosensitive resin cured film gradually decreases due to long-term immersion in ink. , slight peeling occurs, which affects the straightness of the ink droplet, that is, the accuracy of the landing point.

This has been considered a major stumbling block in recent years, as inkjet recording systems are required to produce high-resolution images using high-density nozzles.

The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a novel method for manufacturing an inkjet recording head that is precise, yet highly reliable.

Another object of the present invention is to provide a method for manufacturing an inkjet recording head having a structure in which the ink passages are microfabricated with high precision and faithful to the design, by a simple method and with high yield. Furthermore, it is another object of the present invention to provide a method for manufacturing an inkjet recording head that has excellent durability in use.

The present invention, which has achieved these objectives, provides an ink jet recording head in which an ink passage made of photosensitive resin is provided on the substrate surface and a cover is laminated on this passage. A protective layer made of an inorganic oxide and/or an inorganic nitride is provided on the installed substrate, and the surface of this protective layer is coated with metal alcoholade, metal acylate, and metal chelate (7 selected from the group consisting of E compounds). This method of manufacturing an inkjet recording head is characterized in that the inkjet recording head is treated with one or more metal organic compounds, and then the photosensitive resin is laminated thereon.

Hereinafter, the present invention will be described in detail based on the drawings.

1 to 4 are schematic diagrams illustrating the manufacturing process of an inkjet recording head according to the method of the present invention.

In the process shown in Figure 1, a desired number of ink ejection pressure generating elements such as heating elements and piezo elements are arranged on a substrate made of glass, ceramic, plastic, metal, etc. to impart ink resistance and electrical insulation properties. Purpose, S 402, Ta20
5. AL203. Glass, Si3N4. An inorganic oxide and/or inorganic nitride 3 such as BN is coated. These inorganic oxides and inorganic nitrides contain seven or more metal organic compounds selected from the group consisting of metal alcoholades, metal acylates, and metal chelate compounds, which are used to improve adhesion with the cured photosensitive resin film described later. It is a material that fully demonstrates the effects of compound treatment.

Although not shown, a signal input electrode is connected to the ink ejection pressure generating element 2.

Next, the surface of the substrate obtained in the step of FIG. 1 is cleaned,
After drying at 0 to 750℃ for 70 minutes,
Spinner coat at rpm to form a thin film by applying it uniformly onto the substrate, and heating and drying at 6° C. for 78 minutes to scatter the solvent.

In the present invention, on the layer of inorganic oxide and/or inorganic nitride, in addition to the above-mentioned Improvil triisostearoyl titanium, seven compounds selected from the group consisting of metal alcoholades, metal acylates, and metal chelate compounds are added. The above metal organic compounds can be used. The metals constituting these metal-organic compounds are preferably L'lj, fluminiram, zirconium, cobalt, titanium, etc. Other metals are also effective, but have problems in terms of cost and toxicity. Metal alcoholates include ethylate, propylade, butylade, etc., and industrially available metal alcoholates include aluminum isopropylade, titanium impropylade, and zirconium tert-butylade. In addition, as the chelate compound, these metal alcoholades are commonly known as acetylacetone, 3
- It is obtained by reacting with a chelating agent such as ethylacetylacetone, 3-phenylacetylacetone, 3-methoxyacetylacetone, dibenzoylacetone, and methoxycarbonium acetone.

Depending on the composition of the photosensitive resin used, the metal organic compound
It is preferable to select and use a metal organic compound having a functional group that reacts with the photosensitive resin.

Typical of these metal-organic compounds are summarized in Tables 1 to 3 on the metal side.

Table/Titanium Table 2 Aluminum Table 3 Zirconium Table G Cobalt The substrate whose surface has been treated with a metal-organic compound in this way is then heated to about θ°C to /θj°C with a dry film photoresist S (film thickness). , about 2Sμ~/θθμ
) are laminated at a speed of θj-0&f/min and under pressure of /~3 kg/am2. At this time, the dry film photoresist j exhibits self-adhesive properties and is fused and fixed to the surface of the substrate, so that it will not peel off from the substrate even if a considerable external force is applied thereafter.

Subsequently, as shown in FIG. 3, a photomask 6 having a predetermined pattern is superimposed on the dry film photoresist S provided on the substrate surface, and then exposure is performed from above the photomask B. At this time, the ink ejection pressure generating element 2
It is necessary to align the installation position of the pattern with the pattern using a well-known method.

FIG. 9 is an explanatory diagram showing a process in which the unexposed portions of the exposed dry film photoresist S are dissolved and removed using a developer made of a predetermined organic solvent such as trichloroethane, and ink passages are formed. .

Next, in order to improve the ink resistance of the exposed portion jP of the dry film photoresist left on the substrate, and to further increase the adhesion between the dry film photoresist and the substrate via the isopropyltriinstearoyl titanate layer, heat curing is performed. treatment (e.g. heating at /jθ~2Sθ°C for 3θ minutes to 6 hours) or ultraviolet irradiation (e.g. jθ~2θθmW/
cIn2 or higher). It is also effective to use both the above-mentioned heat curing and ultraviolet curing.

By the way, if the isopropyl triinstearoyl titanate layer used remains in the groove 2, it may dissolve into the ink and deteriorate the quality of the ink, or impair the function of the ink ejection pressure generating cord. The isopropyl triinstearoyl titanate layer exposed in the laminate 2 is preferably removed by ashing with oxygen plasma or the like (FIG. S).

Figure 4 shows a dry film photoresist SP that has been sufficiently polymerized and cured as described above, and is fixed by adhering it to a flat plate that will serve as a cover on a substrate/with grooves 2 that will serve as ink passages, using an adhesive layer 7. Although this is a diagram illustrating this, it may be fixed by pressure bonding without using an adhesive.

In the process shown in Figure 4, the specific method for attaching the cover is as follows: /) After spinner-coating a flat plate g of glass, ceramic, metal, plastic, etc. with an epoxy adhesive to a thickness of 3 to 3 μg. The adhesive 7'f:tfimB is staged by preheating, and this is bonded onto the cured photoresist film jP to fully cure the adhesive. Or 1. 2) Photoresist film 5P cured with a flat plate of thermoplastic resin such as acrylic resin, ABS resin, polyethylene, etc.
There is a method of directly heat-sealing it.

Here, the external appearance of the inkjet recording head after completing the process shown in FIG. 6 is shown in a schematic perspective view in FIG. In Figure 7,
So/ is the ink supply chamber, 9-2 is the ink narrow channel, /θ is the ink supply chamber? - / shows a through hole for connecting an ink supply pipe (not shown).

After completing the above process and joining the grooved substrate and the flat plate, the substrate is cut along line cc' in FIG. 7. This is done to optimize the distance between the ink ejection pressure generating element and the ink ejection port 9-3 in the ink narrow flow path 9-2, and the area to be cut here is determined as appropriate. Ru.

For this cutting, a dicing method commonly used in the semiconductor industry is used.

The third figure is a sectional view taken along the line zz' in FIG. 7. and,
The cut surface is polished and smoothed, and the ink supply tube // is attached to the through hole /θ to complete the inkjet recording head (FIG. 2).

In the embodiments described above based on the drawings, a dry film type, that is, a solid one, was used as the photosensitive composition (photoresist) for creating grooves, but the present invention is limited to this. Of course, a liquid photosensitive composition can also be used. In the case of a liquid, the method for forming the photosensitive composition coating film on the substrate is a method using a squeegee, which is used when producing a relief image. A method can be applied in which the composition is placed around the substrate and excess composition is removed using a squeegee. In this case, the viscosity of the photosensitive composition is preferably in the range of /θθcp to 3θθcp, and the height of the wall needs to be determined in consideration of the evaporation loss of the solvent in the photosensitive composition.

On the other hand, in the case of a solid, the photosensitive composition sheet is attached to the substrate by heat-pressing. In the present invention, it is advantageous to use a solid film type material in terms of its handling and the fact that the thickness can be easily and accurately controlled.

Examples of such solid materials include permanent photopolymer coating RISTON manufactured by DuPont.
(Full goo mask) 73θS1 7g θS1 73θ
There are photosensitive resins commercially available under trade names such as FR1 7g θFR and FR1 SM/. In addition, photosensitive compositions that can be used in the present invention include many photosensitive compositions used in the field of normal photophosphorography, such as photosensitive resins and photoresists, such as: Diazoresins, P-diazoquinones, photopolymerizable photopolymers using vinyl monomers and polymerization initiators, dimerized photopolymers using polyvinyl cinnamate, etc. and sensitizers, orthonaphthoquinonediazide and novolak-type phenolic resins. A mixture of polyvinyl alcohol todiaso resin, a polyether type photopolymer made by copolymerizing goo glycidyl ethylene oxide with benzophenone or glycidyl chalcone,
Copolymers of N,N-dimethylmethacrylamide and acrylamide benzophenone, unsaturated polyester photosensitive resins (e.g. APR (Asahi Kasei), Tepista (Ondai), Sonne (Kansai Paint), etc.), unsaturated urethane oligomers Photosensitive resin, photosensitive composition prepared by mixing a trifunctional acrylic monomer with a photopolymerization initiator and a polymer, dichromate photoresist, non-chromium water-soluble photoresist, polyvinyl cinnamate photoresist, cyclized rubber −
Examples include azide-based photoresists.

The effects of the present invention described in detail above include the following.

/ Due to the increased adhesion between the substrate and the photosensitive resin, the photosensitive resin no longer peels off from the substrate even when the ink ejection port formation is cut, which is particularly impactful.

! The solvent resistance of the bonded portion has been improved, and the passage walls of the substrate and photosensitive resin cured film no longer separate from each other even when ink containing a solvent such as ethylene glycol is used.

3. Since the shape stability of the ink ejection port is high, the accuracy of the ink landing point over time is high.

These effects of the present invention will be explained more specifically by the examples shown below.

The steps of the example shown above (Fig. 1 to A large number of inkjet recording heads having /θ ink ejection orifices were experimentally manufactured according to the method shown in Fig. 6). Among these prototype heads, water 2θ and ethylene glycol gO
A 7,000 hour immersion test was conducted in a solution with a composition of % gθ°C.

These results are shown in Table S.

In addition, when the inkjet recording head obtained in Example/and Comparative Example/ was subjected to a durability printing test of /θ8 pulse, the impact point accuracy of the head of Example was 73μ/,
:1 mm flight distance, whereas the head of the comparative example had a flight distance of ±6θμ/, :1 mm.

The photosensitive resin used was RISTON7JθS dry film photoresist (manufactured by DuPont, trade name).

Table 5

[Brief explanation of the drawing]

1 to 6 are schematic diagrams showing the manufacturing process of the inkjet recording head of the present invention. FIG. 7 is a perspective view of an inkjet recording head obtained by the method of the present invention, and FIG. 7 and FIG. 2 are cross-sectional views. /: Substrate, 2: Ink ejection pressure generating element 3: Protective layer 11: Metal-organic compound layer S: Photosensitive resin SP: Ink passage wall B: Photomask 7: Adhesive g: Cover 9: Groove 2-/: Ink supply room? -2=Ink narrow flow path 702 through hole //: Ink supply pipe l 1st f! 1 Figure 2 9 Figure 3 Figure 4 Figure 5 Figure 6 wJ Procedural amendment (voluntary) September 20, 1980 Commissioner of the Patent Office Sir 1, Indication of the case 1988 Patent application No. 110613
No. 8 No. 2, Title of the invention: Method of manufacturing an inkjet recording head 3, Relationship to the amended case Applicant (100) Canon Co., Ltd. 4, Agent address: 1-9-20-5 Akasaka, Minato-ku, Tokyo. "Detailed Description of the Invention" column of the specification to be amended. 8. The description of r T 1205J in the column of material of the surface of the protective layer corresponding to Example 3 in Table 5 on page 21 of the specification of amendments was changed to r
The description of Ta205 J has been corrected.

Claims (1)

[Claims] / When manufacturing an inkjet recording head in which an ink passage made of a photosensitive resin is provided on the substrate surface and a cover is laminated on this passage, an inorganic oxide and / Alternatively, a protective layer made of an inorganic nitride is provided, and the surface of this protective layer is treated with a metal-organic compound in the group consisting of metal alcoholades, metal acylates, and metal chelate compounds. A method for manufacturing an inkjet recording head characterized by laminating photosensitive resin.