JPS59194857A - Manufacture of ink jet recording head - Google Patents

Abstract

PURPOSE:To produce an ink jet recording head free from dispersion in response frequency on a mass-production basis by forming ink-flow paths of uniform lengths by a method in which a covering is set on side walls provided on a base plate to form ink-flow paths, the end portion on the downstream side is cut off, and the covering on the upstream side is cut off on the basis of the cut face. CONSTITUTION:After a base plate 1 on which side walls 11 of ink-flow paths are formed is joined with a covering 6, they are cut off along the line A-A' to form an ink discharge port 7 vertical to the direction of the ink-flow paths 10. On the basis of the cut face along the line A-A', the covering 6 is cut off along the line B-B' at a given position of the upstream side of the ink-flow paths. Ink-flow paths 10 consisting of the base plate 1 on which a given length of flow paths and an energy generator element 2 are provided, side walls 11, and the covering 6 can thus be formed. Lastly, a common liquid chamber 8 is connected to the base plate 1 to complete an ink jet recording head.

Description

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

An inkjet recording head applied to the inkjet recording method generally includes a fine ink ejection opening (orifice), an ink flow path, an energy generating section provided in a part of the ink flow path, and a common liquid chamber for storing ink. It is equipped with

The conventional method for creating such an inkjet recording head is to first form fine grooves on a glass or metal plate by cutting or etching, and then bond this plate to a substrate on which energy generating elements are arranged. A method is known in which an ink flow path is formed using a method.

However, with inkjet recording heads made by such conventional methods, the roughness of the inner wall surface of the ink flow path to be cut is too large, and distortion occurs in the ink flow path due to the difference in etching rate. It is difficult to obtain a flow path, and variations in ink ejection characteristics are likely to occur. In addition, with the conventional method, when the grooved plate with the ink channel grooves is attached to the substrate on which the energy generating element is arranged, alignment errors may occur, and the manufacturing process is complicated. However, there were also problems in the manufacturing process, such as low manufacturing yields. As a method of manufacturing an inkjet recording head that can solve these problems, a method of forming ink channels using a cured film of a photosensitive resin is known, for example, from Japanese Patent Laid-Open No. 57-43876. This method eliminates the problems of conventional etching or cutting methods, such as low finishing accuracy of the ink flow path, complexity of the manufacturing process, and low manufacturing yield, and eliminates the problems with the side walls of the ink flow path that constitute the ink flow path. In the adhesion process, the positioning of the cover and the substrate is done manually by visual inspection, which requires skill.Moreover, there is a problem in that the length of the flow path varies even if it is not done accurately. There were cases where variations in response frequency occurred between segments. This is a problem that needs to be improved as high-resolution image quality is required.

The present invention was made in view of the above-mentioned problems, and it is possible to manufacture an inexpensive, precise, and highly reliable inkjet recording head in which the ink flow path can be finely processed with high accuracy and high yield. The purpose is to propose a new method.

The above object is achieved by the present invention as described below.

That is, the present invention provides an ink flow path that is provided with an ink ejection port for forming flying droplets and an energy generating element that communicates with the ejection port and generates energy used to form the droplets. In a method of manufacturing an inkjet recording head having a common liquid chamber communicating with the ink flow path, a clay wall of the ink flow path is formed on a substrate provided with a side wall for forming the ink flow path. a step of arranging a covering member through the side wall for the ink flow, a step of cutting the downstream end of the ink flow path to form an ink ejection port surface, and a step of disposing a cover member on the upstream side of the ink flow path from the formed ejection port surface. The method of manufacturing an inkjet recording head is characterized in that it includes the step of cutting the cover member at a position.

Embodiments of the present invention will be described in detail below with reference to the drawings.

1 to 7B are schematic diagrams for explaining the structure and manufacturing procedure of the inkjet head of the present invention. First, as shown in FIG. 1, a suitable substrate 1 made of glass, ceramics, plastic, metal, etc. A desired number of energy generating elements 2 such as heating elements or piezoelectric elements are disposed thereon. (3 in the figure) Incidentally, when a heating element is used as the energy generating element 2, this element generates ink ejection pressure by heating ink in the vicinity. Further, when a piezoelectric element is used, ink ejection pressure is generated by mechanical vibration of this element. Note that signal input electrodes (not shown) are connected to these elements 2.

Next, after cleaning and drying the surface of the substrate 1 on which the energy generating element 2 is provided, a dry film photoresist 3 ( Film thickness, approximately 25μ to 100μ) to 0.5
Laminate under pressure conditions of 1-3 Kg at a speed of ~4 ftZ.

At this time, the dry film photoresist 3 is placed on the substrate surface 1.
It is crimped and fixed, and will not peel off from the substrate surface 1 even if some external pressure is applied thereafter.

Subsequently, as shown in FIG. 3, a photomask 4 having a predetermined pattern 5 is superimposed on the dry film photoresist 3 provided on the substrate surface IN.
Exposure is performed from the top. In addition, the above pattern 5 will be changed later.
This pattern 5 corresponds to a region constituting the ink flow path 10 and the ejection lower, and does not transmit light. Therefore, the dry film photoresist 3 in the area covered by the pattern 5 is not exposed. Further, at this time, it is necessary to align the installation position of the energy generating element 2 and the pattern 5 using a well-known method. That is, at least the element 2 is arranged so as to be located in the ink flow path 10 that will be formed later.

When exposed to light as described above, the photoresist 3 outside the area of the pattern 5 undergoes a polymerization reaction, hardens, and becomes insoluble in the solvent. On the other hand, the unexposed photoresist 3 is cured and remains solvent soluble.

After the exposure operation, the dry film photoresist 3 is immersed in a volatile organic solvent such as trichloroethane to dissolve and remove the unpolymerized (uncured) photoresist, resulting in a cured photoresist film 3P (hardened photosensitive resin). The four parts shown in FIG. 4(g) are formed on the film (film) according to pattern 5. Thereafter, the cured photoresist film 3P left on the substrate 1 is further cured in order to improve its solvent resistance.

The method is thermal polymerization (100°C at 130°C to 160°C).
It is preferable to heat the mixture for about 60 minutes, irradiate it with ultraviolet rays, or use a combination of both.

The four portions of the cured photoresist film 3Pi thus formed correspond to the ink channels 10 as shown in FIG.

Through the diagonal ascent process, the cover member 6 constituting the ceiling is adhered and laminated on the upper surface of the substrate 1 on which the side walls 11 of the ink flow path 10 and the like are formed, as shown in FIG. This specific method is glass and ceramics.

After coating a flat plate of metal, plastic, etc. with an epoxy adhesive to a thickness of 3 to 4 μm using a spinner, the adhesive is preheated to a so-called B stage, and the adhesive is bonded onto the cured photoresist film 3P. This is a method of permanently curing the adhesive.

As described above, this is done in order to optimize the distance from the ink discharge lower after the substrate on which the side walls 11 of the ink flow path etc. are formed and the cover member 6 are bonded, and the area to be cut here is To be determined accordingly.

By cutting along the line A-A', the ink discharge lower side of the inkjet recording head is
As shown by the line ', a cut surface is obtained in which the ink discharge lowers are uniformly perpendicular to the direction of the ink flow path 10.

Next, the cover 6 is cut along a predetermined line based on the cut surface along the line AA'. In this cutting, a cutting grindstone is lifted from the substrate 1 by the thickness of the hardened photoresist film 3P provided on the substrate 1, and only the cover 6 is cut.

When cutting each of the above, the semiconductor industry and the cover 6
An ink flow path 1o consisting of the following can be formed.

A substrate 1 on which a flow path 10 and an ink discharge lower are formed.
The inkjet recording head is completed.

According to the method of the present invention described in detail above, two cutting steps are performed, that is, cutting for forming the ejection port, and the flow path length is determined based on the cut surface, and the end of the ink flow path on the common liquid chamber side is By cutting the cover at the end, it is possible to create a predetermined, almost uniform length for each ink flow path, which makes it possible to mass-produce high-precision inkjet recording heads with almost no variation in response frequency. can.

Further, when attaching the ink flow path cover to the ink flow path wall soil, there is no need to perform accurate positioning of each, and no skill is required, which is advantageous in terms of the manufacturing process.

In one preferred embodiment of the present invention, a dry film photoresist is used for the side walls constituting the ink flow path, but any photosensitive resin may be used instead. Further, instead of laminating two layers of photosensitive resin on the substrate, a liquid photosensitive resin may be applied onto the substrate, exposed to light in a desired pattern, and developed to form the side walls constituting the ink flow path.

In addition, the energy generating element is arranged on a substrate and side wall that are integrated using photosensitive glass or photosensitive ceramics, and a covering member that becomes the ceiling is laminated, and then the diagonal upper It goes without saying that the recording head may be manufactured using the manufacturing method.

These effects of the present invention will be specifically explained by the following examples and comparative examples.

EXAMPLE Inkjet recording was carried out using seven inkjet recording heads (number of orifices: 20, orifice installation density: 28 pieces/thigh) manufactured by the method of the present invention described above. In carrying out the experiment, the length of each flow path was measured, and the ejection response frequency of each orinois segment during recording was also measured. From the measurement results, the length of each flow path is within the range of 22 to 2.6 mm, and as shown in Table 1, the discharge response frequency of each segment has almost no variation between segments. Ta.

Comparative Example The process of attaching a covering member constituting the ceiling of an ink channel to a substrate on which groove walls such as ink channels are formed was carried out visually and manually using the conventional method. Inkjet recording was made. Using this recording head, the flow path length was measured according to the method of the example (2), inkjet recording was performed, and the ejection response frequency of each orifice segment was measured.Similar to the example, the distribution range of the flow path length and The discharge response frequency distribution of each segment was determined.In this comparative example, the flow path length was distributed in the range of 1.4 to 3.0++1I11, and as shown in Table 1, the discharge response frequency of each segment was are widely distributed and vary widely.

Table 1

[Brief explanation of drawings]

1 to 7B are schematic diagrams for explaining the manufacturing process of the Infusiera recording head of the present invention. 1...Substrate 2...Energy generating element 3...Photosensitive resin (photoresist) 4...Photosensitive resin cured film (cured photoresist film) 5...Pattern 6...Covering member 7...・・Ink discharge port
8... Common liquid chamber 9... Ink supply pipe 10
... Ink flow path 11 ... Side wall of ink flow path Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 A Fig. 5 B Fig. 6 B Part 71Σ! A Figure 7 8

Claims (1)

[Claims] An ink flow path provided with an ink ejection port for forming flying droplets, an energy generating element that communicates with the ejection port and generates energy used to form the droplets, and the ink. In a method of manufacturing an inkjet recording head having a common liquid chamber communicating with a flow path, a cover for forming a clay wall of an ink flow path is provided on a substrate provided with a side wall for forming an ink flow path. a step of arranging the member via the side wall, a step of cutting the downstream end of the ink flow path to form an ink ejection port surface, and a step of disposing the member at a predetermined position upstream of the ink flow path from the formed ejection port surface. A method for manufacturing an inkjet recording head, comprising the step of cutting a cover member.