JPS60206659A - Manufacturing of inkjet recording head - Google Patents

Abstract

PURPOSE:To stabilize discharge characteristics by adjusting light exposure to be given to photosensitive resin layer in response with the difference of reflectivity at the time of patterning with application of photosensitive resin layer on adhesive surfaces of different reflectivity. CONSTITUTION:A heater 2 which works as an energy generating body and an electrode 3 which supplies electricity to the heater 2 are formed on a substrate 1 by etching, screen printing, etc. In order to completely separate the electrode 3 and ink, an ink-resisting layer 6 is formed with an ink-resisting polyimide, etc. Then, a hardened resin layer 7 which forms walls for ink passage is formed, for instance, by lamination of a dry film. Further, for the formation of an ink passage wall by patterning, a photomask 20 which has a transparent portion which constitutes a nozzle wall is arranged over the hardened resin layer 7 after positioning is performed. Subsequently, light exposure is accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an inkjet recording head, specifically an inkjet recording head for ejecting and generating small droplets of recording ink in an inkjet recording system. The present invention relates to a method of manufacturing an F recording head.

[Prior Art] An inkjet recording head generally includes an orifice as a fine ink ejection opening, an ink passage that supplies ink to the first orifice, and a part of the ink passage that applies energy such as ejection pressure to the ink. It is equipped with an energy generator to generate the year.

As one of the methods for such inkjet recording,
A heater as an energy generator, an electrode to supply power to the heater, and an oxidation-resistant layer to prevent oxidation when the heater generates heat are provided on the substrate. In order to protect the oxidation-resistant layer, an anti-cavitation layer made of metal, for example, is provided, and an organic layer is provided as an ink-resistant layer in areas other than the top of the heater, and the cured resin film is patterned on the substrate and cured. An inkjet recording head in which an ink passage is formed by a resin film has been proposed.

In this case, two layers, an anti-cavitation layer and an ink-resistant layer, or three layers, including an oxidation-resistant layer, are formed at different levels on the surface of the substrate on which the cured resin film forming the ink passage is adhered. Because these various films have different reflectances, the exposure when patterning the cured resin film differs depending on these various films.

Therefore, the dimensions of the ink passages formed by patterning are not uniform, and there is a problem that it is difficult to form continuous ink passages according to the designed dimensions. In particular, since the cured resin film that serves as the ink passage requires high precision in its thickness, differences in thickness etc. will be noticeable due to differences in exposure amount.

Furthermore, the exposure amount that is the same as the proper exposure amount in the cured resin film that will become the ink passage on the cavitation-resistant layer on the heater, is applied to the part with the lowest reflectance, for example, on the ink-resistant layer. (organic material layer), the cured resin film will be exposed to insufficient light as a whole, and sufficient polymerization will not be obtained, and the ink passage wall will peel off from the substrate during development, resulting in a very low yield. There was a downside to it being bad.

[Objective] The present invention was made in view of the drawbacks of plate bodies, and its object is to provide a method for manufacturing a precise and highly reliable inkjet recording head.

Another object of the present invention is to provide a method for manufacturing an inkjet recording head that allows fine processing of ink passages with high precision and faithfulness to the design.

Still another object of the present invention is to provide a method for manufacturing an inkjet recording head that has excellent durability in use and does not cause peeling between the substrate and the channel wall.

Still another object of the present invention is to manufacture an inkjet recording head in which an ink passage wall made of a cured resin film is provided on a substrate provided with an ink energy generator.
Manufacture of an inkjet recording head that controls the amount of exposure given to a cured resin film according to the reflectance of each adhering surface when patterning ink passages across two or more adhering surfaces with different reflectances. The purpose is to provide a method.

Still another object of the present invention is that in controlling the above-mentioned exposure amount, after the entire portion that will become the ink passage wall is exposed in the first exposure, further An object of the present invention is to provide a method for manufacturing an inkjet recording head that performs second exposure.

[Example] The present invention will be described in detail below with reference to the drawings.

FIG. 1A shows sequential steps in an embodiment of the method for manufacturing an inkjet recording head according to the present invention.

This will be explained with reference to FIGS. 1B to 13.

First, a heater 2 serving as an energy generator and an electrode 3 for supplying power to the heater 2 are formed on a substrate 1 by machining, etching, screen printing, etc., as shown in FIGS. 1A and 1B.

In the process shown in FIG. 2, an oxidation-resistant layer 4 such as 5i02 is formed by sputtering or the like in order to prevent the heater 2 from being oxidized when it generates heat.

In the process shown in FIG. 3, the oxidation-resistant layer 4 is prevented from bursting due to the so-called cavitation phenomenon that occurs when the heater 2 generates heat and the ink in the ink passage formed as described below foams. For example, a metal film such as Ta is formed as the cavitation layer 5.

In the next step shown in FIG. 4A, an ink-resistant layer 6 is formed of an ink-resistant organic material, such as polyimide, in order to completely disconnect the electrode 3 from the ink. The substrate that has gone through the process of FIG. 6A is lifted upward (1) and it looks like FIG. 6B. Next, as shown in FIG. Then, as shown in FIG. 6A, in order to pattern the ink passage walls, a photomask 20 that is transparent only in the portion that will become the nozzle wall is placed on the cured resin film 7, as shown in FIG. 6B. Align and arrange using the method described above, and then perform exposure.

As shown in FIG. 4B, the part where the ink flow path wall is formed must be formed across two types of films: the anti-cavitation layer 5 made of metal or the like and the ink-resistant layer 6 made of organic material. However, since the reflectance of the ink-resistant layer 8 is significantly lower than that of the cavitation-resistant layer 5,
Cured resin 11 on anti-cavitation layer 5! When the same exposure amount as that given to I7 is given to the cured resin film 7 on the ink-resistant layer 6, that is, when exposure is performed only once using the photomask 20, the amount of exposure given to the ink-resistant layer 6 is The cured resin film 7 has an insufficient amount of exposure, and polymerization does not proceed sufficiently.
The width of the channel wall after development becomes small. On the other hand, since the cured resin jiff 7 on the anti-cavitation layer 5 is finished according to the designed dimensions, a convex portion is generated in the ink flow path at the boundary between the ink-resistant layer 6 and the anti-cavitation layer 5, preventing normal ink passage. This will have a major impact on the ejection characteristics.

Therefore, in the present invention, as shown in FIGS. 7A and 7B, using a photomask 30 whose portion corresponding to the anti-cavitation layer is opaque, the same process as in FIG. 6A is performed as shown in FIG. 7A. Then, apply the predetermined exposure amount again. Thereby, it is possible to form a continuous ink flow path according to the designed dimensions.

Figure ff18 is a sectional view taken along the line A-A in Figure 7A.

Furthermore, FIG. 8 shows the 7A after developing the cured resin film 7.
This is a sectional view taken along the line A-A in the figure, and an ink flow path 9 is formed. Next, as shown in FIG. 1θ, a cover 10 is provided over the ink passage 9.

FIG. 11 shows a schematic perspective view of the appearance of the inkjet recording head manufactured through the above two steps.

In FIG. 11, the ink passage 9 is connected to the ink supply chamber 9-1.
and an ink narrow channel 9-2. Reference numeral 11 indicates a through hole formed in the layer 1, 4.5 for connecting an ink supply pipe (not shown) to the ink supply chamber 8-1.

After the substrate on which the ink passages 9 are formed as described above and the cover 10 of the ink passages 8 are bonded together, the substrate is cut along the line CC shown in FIGS. 11 and 12. this is,
Ink energy generator 2 in ink narrow channel 9-2
This is done to optimize the distance between the ink discharge port 8-3 and the ink ejection port 8-3, and the area to be cut is appropriately determined accordingly.

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

Next, as shown in FIG. 13, the ink supply tube 12 is attached to the through hole 11, and the inkjet recording head is completed.

In the illustrated embodiment described above, two types of photomasks were used to expose the cured resin film twice as a method of controlling the amount of exposure applied to the cured resin film that forms the ink passage wall, but the present invention is not limited to this. do not have. Expose without using a photomask. For example, it is also effective to control the exposure amount according to the fouling rate of the adhered surface using a beam exposure method, a photoproa method, or the like. When this method is adopted, there is no deviation between the first photomask alignment and the second photomask alignment, so a highly accurate ink path can be obtained.

Alternatively, in the illustrated embodiment, the case where two types of reflectance of the adherend surface are used is described, but when using three or more types of reflectance, the adherend can be similarly exposed by partially exposing the surface multiple times. The amount of exposure can be given according to the reflectance of the surface.

[Effect 1] As explained in detail in Section 2, the present invention can exhibit the following various effects.

Even when patterning ink passages made of a cured resin film across adherend surfaces with different reflectances, uniform and continuous ink flow path dimensions can be obtained regardless of the adherend surface. A head with stable ejection characteristics can be obtained.

Furthermore, an inkjet recording head can be obtained in which the ink passages are finely machined with high accuracy and faithful to the design.

In addition, during development of the cured resin film, peeling between the substrate and the ink passage wall due to insufficient exposure does not occur, so the manufacturing yield is significantly improved.

[Brief explanation of drawings]

1A, 2, 3, 4A, 5, 6A, 7A, 8, 9, and 1θ are sequential steps for manufacturing the inkjet recording head of the present invention. 1B is a plan view corresponding to FIG. 1A, and FIG. 4B is a sectional view showing an example of the process.
A plan view corresponding to FIG. 6B and FIG. 7B are plan views showing two examples of photomasks used in the present invention, FIG. 11 is a perspective view showing an inkjet recording head manufactured according to the present invention, and FIG. 12 is a plan view corresponding to FIG. is a sectional view taken along line 2-2 in Fig. 11, and Fig. 13 is a sectional view taken along line 2-2 in Fig. 11.
FIG. 2 is a sectional view showing the next step of FIG. 2; l...Substrate, 2...Ink energy generator (heater), 3...
- Electrode, 4... Oxidation resistant layer, 5... Cavitation resistant layer, 6... Surface ink layer, 7... Cured resin film, 9... Ink passage 9-1... Ink supply chamber 9-2... Ink narrow channel. 8-3... Ink discharge port, 10... Ink passage cover 11... Through hole, 12... Ink and S joint tube, 20.30... Photomask. Fig. 1A Fig. 1H Fig. 2 Fig. 3 Fig. 4 A drawer 40 Fig. 5 Fig. 6B Fig. 7 A Fig. 4 Fig. 7 ■ Fig. 8

Claims (1)

[Claims] 1) A manufacturing method for an inkjet recording head comprising an orifice for forming flying droplets and an energy generator used to eject liquid as the droplets from the orifice. Inkjet recording characterized in that when patterning a photosensitive resin layer provided on an adhered surface having different reflectances, the amount of exposure given to the photosensitive resin layer is adjusted according to the difference in reflectance. Head manufacturing method.・h2) In controlling the amount of exposure given to the sensitive resin film, after the first exposure has exposed the entire portion that will become the ink flow path wall, only the portion of the adhered surface with low reflectance is exposed. 2. The method of manufacturing an ink jet recording head according to claim 1, further comprising performing a second exposure. (Hereafter, margin)