JPH05147360A - Forming method for fine pattern - Google Patents

Abstract

PURPOSE:To efficiently form fine patterns having fine line width and proper film thickness with high accuracy. CONSTITUTION:The recessed parts of a transparent substrate 1 are filled with ultraviolet curable ink 4 enhanced in anaerobic properties and the ink layers 4 in the recessed parts are cured by the irradiation with ultraviolet rays to bring the surface layer parts of the ink layers 4 to an imperfect cured state 4a and, thereafter, the ink layers 4 in the recessed parts are transferred to an object 6 to be processed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a fine pattern, and more particularly to a method for forming a fine pattern using an ink that emphasizes anaerobic property.

[0002]

2. Description of the Related Art Conventionally, in the process of processing a thin film transistor, a thin film diode, a solar cell, a thin film sensor, various semiconductor elements, etc., a fine pattern is formed on an object to be processed, and then the object is processed by etching. Was being done.

For example, a color liquid crystal display (LC
The thin film transistor (TFT) used in D) is usually manufactured by repeating the photolithography process consisting of resist coating, exposure, development and etching about 4 to 6 times.

Further, when forming a printed wiring, a circuit pattern, or a resist pattern for etching a metal plate, unlike the above-mentioned photolithography method, a resist pattern is formed on a workpiece by printing and an etching treatment is performed. Repeated printing methods are also widely adopted. For pattern formation by this printing method, a screen printing method, an offset printing method, or the like is used.

[0005]

However, when a large LCD such as 40 inches or 80 inches is manufactured by the photolithography method, a dedicated apparatus including a large exposure apparatus used in the photolithography process is required, which is required for the apparatus. The cost is enormous.

On the other hand, the above-mentioned printing method can relatively easily cope with the above-described large-sized LCD manufacturing by repeating the resist pattern formation by printing and the etching treatment. However, the printing method is liable to deform the printing pattern due to the fluidity of the ink, the influence of the pressure of the plate, and the fact that a part of the ink remains on the plate without being transferred to the work piece, Inferior in dimensional accuracy and reproducibility,
There is a problem that it is not suitable for forming a fine pattern having an image line of less than 100 μm.

Further, there is a problem that the pattern becomes thick due to the flow of the ink layer and the like, and a fine pattern of the order of several microns cannot be formed. The present invention has been made in view of the above circumstances, and a fine pattern forming method capable of efficiently forming a fine pattern having a fine line width and an appropriate film thickness with high accuracy. The purpose is to provide.

[0008]

In order to achieve such an object, the present invention forms a concave portion in a predetermined pattern on a transparent substrate, and fills the concave portion with an ultraviolet curable ink emphasizing anaerobic property for patterning. Then, a curing treatment with ultraviolet rays is performed so that at least the surface layer portion of the ink in the recess is in an incompletely cured state, and then the ink in the recess is transferred to a workpiece. did.

[0009]

[Function] The concave portion on the surface of the transparent substrate is filled with an ultraviolet curable ink which emphasizes anaerobic property, and the ink layer in the concave portion is cured by irradiation with ultraviolet rays. Is in an incompletely cured state, and if the ink is a color that does not easily transmit ultraviolet rays, or if the amount of irradiation that reaches the bottom of the ink layer in the recess is controlled to be suppressed, the surface layer of the ink is irradiated by irradiating from the surface. In addition, the bottom of the ink becomes incompletely cured and becomes tacky. That is, it is possible to suppress the ink flow in the completely cured part and to keep the pattern shape on the plate as it is. In the incompletely cured part, it has adhesiveness, so it is easily transferred to the work piece and processed. The fine pattern transferred to the object has a constant line width and high dimensional accuracy.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining a method of forming a fine pattern. In FIG. 1, first, a transparent substrate 1 is etched by a normal photoetching method to form a fine pattern concave portion 2 which becomes a predetermined printing image line, and is used as an intaglio plate (FIG. 1A). At this time, in order to increase the hardness of the surface of the intaglio portion, a hard metal layer 3 of nickel, chromium or the like may be formed on the surface other than the concave portion of the transparent substrate 1 (FIG. 1A). This makes it possible to provide durability when the ink is scraped off by a doctor or the like. Next, the ink layer 4 is formed by filling the concave portion 2 of the intaglio plate 1 with UV curable ink with an emphasized anaerobic property by a usual coating method such as a doctor mechanism (FIG. 1 (b)). The ultraviolet curable ink 4 emphasizing the anaerobic property is an ink that does not completely cure even if a portion in contact with air is subjected to a curing treatment by ultraviolet irradiation and does not lose adhesiveness and the like. Then, ultraviolet rays are irradiated from the back side of the transparent substrate 1. By this irradiation of ultraviolet rays, the ink layer 4 in the concave portion 2 is cured except for the surface portion 4a which is in contact with air, and the surface portion 4a of the ink layer 4 is not cured even by ultraviolet rays and has an adhesive property as it is. (Fig. 1 (c)). Then, the ink layer 4 in the recess 2 is once transferred to the blanket 10 (FIG. 1 (d)), and thereafter,
By pressing the blanket 10 onto the workpiece 6, the ink layer 4 is transferred to the workpiece 6 to form a fine pattern (FIG. 1E).

As described above, according to the present invention, since the surface portion 4a of the ink layer 4 formed in the concave portion 2 is not cured and has an adhesive property as it is, transfer to a blanket is easy. Since the portion of the ink layer 4 excluding the surface portion 4a is hardened, it is possible to prevent the ink pattern from thickening due to the flow of ink and the like, and it is possible to form a fine pattern faithful to the plate.

Then, as shown in FIG. 2, the ink layer 4
The workpiece 6 (FIG. 2 (a)) on which the ink has been transferred is subjected to heat treatment to cure the surface portion 4a of the ink layer 4 as well, and is then subjected to etching treatment using the ink layer 4 as a resist (FIG. 2).
(B)) After that, the ink layer 4 is peeled from the workpiece 6 (FIG. 2 (c)).

Further, as shown in FIG.
A material having a photoresist 7 applied to the surface thereof can be used as. In this case, for example, in the positive type, a fine pattern including the ink layer 4 is formed on the photoresist 7 of the workpiece 6 as shown in FIG. 1 (FIG. 3A), and the photoresist 7 is used as the ink layer 4 as a plate. Is exposed and developed (FIG. 3 (b)). After that, the ink layer 4 is peeled off from the photoresist 7 (FIG. 3C), and the workpiece 6 is etched through the photoresist 7 (FIG. 3D),
After that, the photoresist 7 is peeled off from the workpiece 6 (FIG. 3E). Further, in the case of the negative type, the photoresist 7 is peeled off after exposure and development is performed.

FIG. 4 is a diagram for explaining another embodiment of the present invention. In FIG. 4, a UV curable ink having a color (for example, black) that hardly transmits ultraviolet rays in the concave portion 2 (FIG. 4A) of the intaglio plate 1 produced in the same manner as in FIG. And then filled to form the ink layer 5 (FIG. 4B). After that, ultraviolet rays are irradiated from the recess forming side of the intaglio 1. Due to the irradiation of ultraviolet rays, the surface portion 5a of the ink layer 5 in the recess 2 which is in contact with air is in an incompletely cured state even if it is irradiated with ultraviolet rays, and has an adhesive property. Further, since the irradiated ultraviolet ray does not reach the bottom portion 5c of the ink layer 5 in the recess 2 by being absorbed by the ink layer 5 having a color that hardly transmits the ultraviolet ray as described above, it does not reach the surface portion 5a. It is incompletely cured and has tackiness. Then, only the intermediate portion 5b of the ink layer 5 in the recess 2 is cured by the ultraviolet rays. Therefore, the ink layer 5 in the concave portion 2 is not cured and remains adhesive as it is, the surface portion 5a and the bottom portion 5c, and the cured middle portion 5
It has a three-layer structure of b. Further, when the ultraviolet curable ink is not colored with a color that does not easily transmit ultraviolet rays, the same effect can be obtained by reducing the irradiation amount of ultraviolet rays.

Next, the ink layer 5 in the recess 2 is covered with the surface portion 5.
It is once transferred to the blanket 10 due to the adhesiveness of a (FIG. 4D). Then, the blanket 10 is pressure-bonded to the workpiece 6, and the ink layer 5 on the blanket 10 is transferred to the workpiece 6 by the adhesiveness of the bottom portion 5c to form a fine pattern (FIG. 4 (e)).

As described above, in the present invention, the surface portion 5a of the ink layer 5 formed in the concave portion 2 is not cured and has an adhesive property as it is, so that it can be easily transferred to a blanket, and the ink can be easily transferred. Since the bottom portion 5c of the layer 5 is not cured and has adhesiveness as it is, transfer from the blanket to the workpiece 6 is easy. Since the intermediate portion 5b of the ink layer 5 is hardened, it is possible to prevent the ink pattern from thickening due to the flow of ink or the like, and it is possible to form a fine pattern faithful to the plate.

In this way, a fine pattern is formed on the workpiece 6 to which the ink layer 5 has been transferred by the procedure as shown in FIG. It is also possible to use a work coated with a photoresist as the work, transfer the ink layer 5 onto the photoresist of the work, and form a fine pattern by the procedure shown in FIG.

FIG. 5 is a diagram for explaining another embodiment of the present invention. In FIG. 5, a cylindrical substrate 8 is used as a transparent substrate, and concave portions 9 are formed in a predetermined pattern on the peripheral surface of the transparent cylindrical substrate 8 in the same manner as shown in FIG. 1 (FIG. 5 (a)). .. At this time, a sheet of transparent resin, rubber or the like having a recess may be wound. An ultraviolet lamp 11 is arranged inside the cylindrical substrate 8. Then, an ink layer 12 is formed by filling the concave portion 9 of the transparent cylindrical substrate 8 with an ultraviolet curable ink with an emphasized anaerobic property by a usual coating method such as a doctor mechanism (FIG. 5).
(B)). After that, the ultraviolet lamp 11 is turned on, and the ink layer 12 in the transparent cylinder is in contact with the air.
The surface portion 1 of the ink layer 12 is hardened except the portion a.
2a remains in an incompletely cured state even after being irradiated with ultraviolet rays and has an adhesive property (FIG. 5 (c)). Then, the transparent cylindrical substrate 8 is rotated on the workpiece 6 to move the ink layer 12
Can be transferred to the workpiece 6 to form a fine pattern (FIG. 5D).

As the transparent substrate, a glass plate, a resin substrate,
A transparent substrate such as ceramics can be used. The thickness of such a transparent substrate is preferably about 1.0 to 2.5 mm. Further, the surface of the transparent substrate on which the concave layer is formed may be subjected to some mirror surface treatment or release agent application in consideration of the releasability of the ink layers 4, 5, 12. When a cylindrical substrate is used as the transparent substrate, the size of the cylinder can be appropriately determined according to the purpose of use.

The recesses 2 and 9 can be formed by applying a photoresist on a transparent substrate, exposing and developing it through a mask having a predetermined shape, etching the photoresist, and stripping the photoresist.

A hard metal layer such as nickel or chrome or a ceramic layer may be formed on the surface of the intaglio other than the concave portion for the purpose of imparting durability when the ink is scraped off by a doctor. Such a durable intaglio plate is formed by various thin film forming methods such as an ion plating method, a vacuum deposition method, a sputtering method, a chemical vapor deposition method (CVD method), and a plating method. A thin film is formed on top of it, and then a photoresist is applied on this thin film, which is then exposed and developed through a mask of a predetermined shape. It may be formed by etching a transparent substrate (which may be an etching solution) to form a recess, and removing the photoresist. Examples of the photoresist used in this case include gelatin, casein, polyvinyl alcohol and the like to which a photosensitizer such as dichromate is added. Further, the depth of the recess formed in this way is from 1 to
It is preferably about 10 μm.

The ultraviolet curable ink which emphasizes anaerobic property is
In the polymerization process, the portion exposed to air has a property of inhibiting the polymerization reaction due to the effect of oxygen, and by utilizing this property, the ink surface layer portion in an incompletely cured state can be easily formed. It is an ink that uses anaerobic monomers and oligomers as its main components. Specifically, methacrylate compounds, allyl compounds, vinyl compounds,
A monofunctional acrylate compound, a compound having a double bond in the middle of the molecular chain, or the like is used. A photopolymerization initiator containing no aromatic tertiary amine is added to this. Thus, the reason why the photopolymerization initiator containing no aromatic tertiary amine is used is that the inclusion of acin accelerates the curing reaction and inhibits the anaerobic effect. Specifically, acrylated benzophenone, benzyl, benzoin ethyl ether, benzoin isobutyl ether, benzoin isopropyl ether, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-benzoyl 4'-methyldiphenyl sulfide, benzyldimethyl ketal, 2- Chlorothioxanthone, 2,4
-Diethylthioxanthone, 2,4-diisopropylthioxanthone, 3,3'-dimethyl-4-methoxybenzophenone, 2,4-dimethylthioxanthone, isopropylthioxanthone, methylbenzoylformate, 1-hydroxycyclohexyl Phenyl ketone, 2
-Methyl-1- [4- (methylthio) phenyl] -2-
Morpholino propanone-1 etc. are mentioned. And
It is composed by adding ink aids such as tack adjustment and, if necessary, coloring pigments and sensitizers.

When a coloring pigment is used, the addition amount should be such that the ultraviolet rays do not reach the bottom of the ink layer in consideration of the thickness of the ink layer, the irradiation amount of the ultraviolet rays, etc., and the anaerobic property is emphasized. UV curable ink 10-15
About wt% is preferable.

The thickness of the ink layer made of the ultraviolet curable ink which emphasizes the anaerobic property as described above is the same as or slightly larger than the depth of the recess, and is preferably about 1 to 10 μm.

The viscosity of the above-mentioned anaerobic UV-curable ink is preferably 400 ps or less and a relatively low viscosity. As an ultraviolet irradiation source, an ultraviolet irradiation device such as a low pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a pulse xenon lamp, an electrodeless discharge lamp can be used, and an ozoneless type irradiation source is particularly preferable. It is effective. And the irradiation dose is 0.2-
About 1.5J is preferable. In addition, a cold mirror may be used to remove infrared light to prevent the temperature of the object to be irradiated from rising. Next, the present invention will be described in more detail with reference to experimental examples. (Experimental Example 1) On a surface of a glass substrate (thickness: 2.3 mm),
A metal chrome thin film having a film thickness of 1000 Å was formed by the sputtering method. Next, a photoresist (OFPR800 20 cps manufactured by Tokyo Ohka Co., Ltd.) was formed on the metal chromium thin film.
Was applied, and exposure treatment, development treatment, etching treatment, and resist peeling were performed using a mask having a predetermined shape to form an intaglio plate having a recess having a line width of 10 μm and a depth of 5 μm (see FIG. 1A).

After that, the monomer (KAYAMER P
(M: 21, Nippon Kayaku) 100 parts by weight of a photopolymerization initiator (Irgacure 184, manufactured by Ciba Geigy)
Of 3 parts by weight, and further containing other components such as an ink auxiliary agent and a coloring pigment, UV-curable ink which emphasizes anaerobic property is supplied to the concave portion, and excess ink is removed by a doctor to form an ink layer. Formed (see FIG. 1 (b)).

Next, a curing treatment was carried out by irradiating from the back side of the glass substrate with an intensity of 45 mW / cm ² for about 30 seconds with an ultra-high pressure mercury lamp. As a result, the portion of the ink layer that was not in contact with air was cured, and the surface portion that was in contact with air was in an incompletely cured state and remained tacky.

Thereafter, the blanket is pressure-bonded to the substrate to temporarily transfer the ink in the recess to the blanket (see FIG. 1).
(D)) The ink layer was transferred onto the glass plate by press-bonding this blanket onto the glass plate as the workpiece to form a fine pattern (FIG. 1 (e)). The fine pattern formed by transferring in this way has a resolution of about 10 μm.
It was m. (Experimental Example 2) An intaglio was prepared in the same manner as in Experimental Example 1 (see FIG.
(A)), UV curable ink emphasizing anaerobic property was supplied to the concave portion, and excess ink was removed by a doctor to form an ink layer (see FIG. 4 (b)). This ink is obtained by dispersing 15% by weight of carbon black in the ink used in Experimental Example 1.

Then, the glass substrate was irradiated with a high-pressure mercury lamp at an intensity of 45 mW / cm ² for about 20 seconds to perform a curing treatment (see FIG. 4 (c)). By this treatment, the surface portion of the ink layer which is in contact with air and the bottom portion where ultraviolet rays are hard to reach become incompletely cured, while the intermediate portion is cured. After that, the ink in the concave portion is once transferred to the blanket by pressing the blanket onto the glass substrate (FIG. 4 (d)), and the blanket is rotated and pressed onto the glass plate as the workpiece. The ink layer was transferred onto a glass plate to form a fine pattern (FIG. 4 (e)). The resolution of the fine pattern formed by transferring in this way was about 10 μm. (Comparative Example 1) A fine pattern was formed in the same manner as in Experimental Example 1 except that an acrylate-based UV-curable ink which was normally used was used instead of the anaerobic UV-curable ink.

In the formation of the fine pattern, the ink layer in the intaglio plate was completely cured, the ink layer was not transferred to the blanket, and the fine pattern was found to be chipped. (Comparative Example 2) An intaglio was prepared in the same manner as in Experimental Example 1, and a fine pattern was formed by a usual printing method using a usual acrylate-based UV curable ink.

In this case, the pattern was thickened and the resolution was about 20 μm.

[0032]

As described above in detail, according to the present invention, the concave portion on the surface of the transparent substrate is filled with the ultraviolet curable ink which emphasizes the anaerobic property, and the ink layer in the concave portion is cured by the irradiation of ultraviolet rays. Since at least the surface of the ink layer is in contact with air, it is incompletely cured even when irradiated with ultraviolet rays and has adhesive properties. The ink layer is easily transferred to the work piece due to the adhesiveness of the surface without causing thickening or chipping, and the fine pattern transferred to the work piece is a dimension that is faithful to the concave part of the transparent substrate and has a constant line width. It will be highly accurate.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a method of forming a fine pattern according to the present invention.

FIG. 2 is a diagram for explaining an etching process of a workpiece on which a fine pattern is formed.

FIG. 3 is a diagram for explaining an etching process of a workpiece on which a fine pattern is formed.

FIG. 4 is a diagram for explaining another example of the fine pattern forming method of the present invention.

FIG. 5 is a diagram for explaining another example of the fine pattern forming method of the present invention.

[Explanation of symbols]

1, 8 ... Transparent substrate 2, 9 ... Recessed portion 4, 5, 12 ... Ink layer 4a, 5a, 5c, 12a ... Incompletely cured state portion of ink layer 6 ... Workpiece 10 ... Blanket

Claims (9)

[Claims] 1. An ink in a concave portion is formed by forming a concave portion in a predetermined pattern on a transparent substrate, filling the concave portion with an ultraviolet curable ink emphasizing anaerobic property, and patterning it, and then performing a curing treatment by ultraviolet rays. The method of forming a fine pattern, characterized in that at least the surface layer portion is set to an incompletely cured state, and then the ink in the concave portion is transferred to a workpiece. 2. An ink containing a methacrylate compound, an allyl compound, a vinyl compound, a monofunctional acrylate compound, and a compound having a double bond in the middle of a molecular chain as a main material, as an ultraviolet curable ink emphasizing anaerobic property. The method for forming a fine pattern according to claim 1, wherein 3. The ultraviolet curable ink emphasizing anaerobic property contains a photopolymerization initiator, and the photopolymerization initiator does not contain an aromatic tertiary amine. Forming method of fine pattern. 4. A curing treatment is performed by irradiating ultraviolet rays from the back surface side of the transparent substrate so that the surface layer portion of the ultraviolet curable ink in the concave portion, which is in contact with the atmosphere, is in an incompletely cured state. The method for forming a fine pattern according to claim 1, wherein the fine pattern is formed. 5. A curing treatment is performed by irradiating ultraviolet rays from the surface side of the transparent substrate, and the surface layer portion and the bottom portion of the ultraviolet curable ink in the recesses, which are in contact with the atmosphere, are incompletely cured. The method for forming a fine pattern according to claim 1, wherein the method is performed. 6. The method for forming a fine pattern according to claim 1, wherein an ozoneless type light source lamp is used in the curing treatment with ultraviolet rays. 7. A roller-shaped blanket is brought into close contact with the transparent substrate to transfer the ink layer in the recess onto the blanket, and then the blanket is pressed against a workpiece to remove the ink layer on the blanket. The method for forming a fine pattern according to claim 1, wherein the fine pattern is transferred onto the workpiece. 8. The method for forming a fine pattern according to claim 1, wherein the transparent substrate is a roller-shaped blanket. 9. An ultraviolet non-transmissive film is formed on one surface of the transparent substrate, and concave portions are formed in a predetermined pattern on the transparent substrate from the ultraviolet non-transmissive film side.
9. A method of forming a fine pattern according to any one of 8 to 8.