JP2000231201A - Pattern forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pattern forming method effective in pattern formation such as the formation of the partition walls of a plasma display panel and the formation of an electrode. SOLUTION: A photosensitive resin composition layer 3 is laminated on a substrate 1 (step 1), exposed through a patterned mask 4 (step 2) and developed (step 3) to form a resist image (step 4). A pattern forming material 7 such as a low melting glass paste is filled into the recesses of the formed resist image (step 5), the hardened resist of the photosensitive resin composition is removed by sandblasting (step 6) and the pattern forming material 7 is sintered by passing through a firing furnace to form the objective pattern on the substrate (step 7).

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 thick film pattern such as a partition wall and an electrode for a plasma display panel. More specifically, the present invention relates to a lift-off method for removing a cured resist of a photosensitive resin composition. The present invention relates to a pattern forming method capable of forming a good pattern because it can be easily removed.

[0002]

2. Description of the Related Art Conventionally, screen printing, sand blasting, lift-off, and the like have been used as a method for forming a pattern of a low-melting glass such as forming a partition or forming an electrode such as a wiring. In the case of forming a partition wall of a plasma display panel using a low melting point glass as a pattern forming material, in a screen printing method, a low melting point glass paste is repeatedly printed on a substrate by a screen printing method in the same pattern to a predetermined thickness many times. The partition wall pattern is formed, and thereafter, firing is performed to vitrify the low melting point glass.

In the sandblasting method, a low-melting glass paste is uniformly applied by a coater or screen printing, dried, laminated with a photoresist film for sandblasting, exposed and developed to form a resist image. Thereafter, a low-melting-point glass paste other than the low-melting-point glass paste protected by the resist film is ground and removed with a sandblasting device, and the resist is peeled off and fired to form partitions. In the lift-off method, a photoresist film is laminated on a substrate (if necessary to repeat to a predetermined thickness, lamination is repeated many times), and then a mask is put thereon to perform exposure and development to form a resist image. After embedding a low-melting glass paste in the concave portion of the resist image and drying, the resist is exfoliated by dipping in an alkaline stripping solution to swell the resist, and the remaining low-melting glass portion is baked to form a partition.

[0004]

However, in the above-described pattern forming method by the screen printing method, for example, one pattern is formed.
Since printing must be repeated 10 times or more in order to form a pattern of 80 μm, there is a limit to accurate overprinting at the same position, and it has been difficult to form a uniform pattern on a large substrate size. . For the same reason, there is a limit in making a pattern to be formed finer, and it is difficult to form the pattern to 80 μm or less in consideration of mass productivity. Therefore, pattern formation by the screen printing method is difficult in increasing the size, definition, and luminance of a plasma display panel.

Further, the pattern forming method by the sand blast method can be applied to a large-sized substrate with high definition. At present, this method is employed in forming a partition wall of a high-definition or large-sized plasma display panel. In addition, since a pattern forming material such as low-melting glass is applied to the entire surface of the substrate and is shaved off by sandblasting, the shaved material is discarded, thereby increasing the material cost. In forming the partition walls of the plasma display panel, 75% of the applied low-melting glass is discarded and 25% is used.
Further, there is a disadvantage that the shaved low-melting glass is mixed with the crushed abrasive and is difficult to regenerate, and since lead glass or the like is contained, the disposal is costly.

On the other hand, in the pattern forming method by the lift-off method, since the pattern forming material is buried in the concave portions of the resist image, only the necessary portion is used, so that it is not necessary to dispose of the low melting point glass, which is very efficient. In the method, when the cured resist of the photosensitive resin composition having a thick film is peeled off, the resist is swelled by being immersed in a peeling solution to be peeled off, and the pattern forming material embedded in the concave portion of the resist image is also removed. However, there was a disadvantage that the film was peeled off. In particular, in forming the partition walls of the plasma display panel, the ratio of the resist pattern to the embedded low-melting glass pattern is 3: 1, the low-melting glass pattern is narrower, and the low-melting glass pattern formed is also about 180 μm in height. Therefore, it is very difficult to remove the resist, and the embedded low-melting glass is also removed together with the resist. Therefore, it is not actually used for forming the partition walls of the plasma display panel.

Therefore, in the present invention, in such a background, the pattern can be formed by efficiently using the pattern forming material to be embedded, and the resist can be satisfactorily removed after the pattern forming material is embedded. It is an object to provide a forming method.

[0008]

Means for Solving the Problems However, the present inventors have conducted intensive studies in view of such circumstances, and as a result, laminated a photosensitive resin composition layer on a substrate, and performed exposure and development through a pattern mask. After forming a resist image by embedding a pattern forming material in the concave portion of the formed resist image and removing the cured resist of the photosensitive resin composition by sandblasting, it is found that the pattern forming method meets the above object. Thus, the present invention has been completed.

That is, this is an effective method that allows only the cured resist to be removed without removing the embedded pattern forming material. The present invention is particularly useful for forming partition walls of a plasma display panel when the pattern forming material is a glass paste, and is useful for forming electrodes for a plasma display panel when the pattern forming material is an electrode forming material.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail (see FIG. 1). (Step 1) In the present invention, a photosensitive resin composition layer is first laminated on a substrate, but the photosensitive resin composition is not particularly limited as long as it is easily eroded by sandblasting. The photosensitive resin composition comprises a base polymer, an ethylenically unsaturated compound, and a photopolymerization initiator. For example, the following are preferably used.

It contains a base polymer having an acid value of 100 to 200 mg KOH / g and a weight average molecular weight of 30,000 to 120,000, an ethylenically unsaturated compound, P, P'-bis (dialkylamino) benzophenone, hexaarylbiimidazole and a leuco dye. And P, P'-bis (dialkylamino) benzophenone in an amount of 0.01 to 0.25 parts by weight and hexaarylbiimidazole in an amount of 1.0 to 0.2 parts by weight based on 100 parts by weight of the total of the base polymer and the ethylenically unsaturated compound. 10 parts by weight, 0.05 ~ leuco dye
9% by weight of an ethylenically unsaturated compound containing 2% by weight and having two polymerizable unsaturated groups.
A photosensitive resin composition containing 5% by weight or more
-248621),

A base polymer, an ethylenically unsaturated compound, N-phenylglycine, P, P'-bis (dialkylamino) benzophenone, an organic carboxylic acid having a pKa of 2 to 4, a benzotriazole derivative and a triazine derivative, 0.01 to 5 parts by weight of N-phenylglycine and 0.005 to 1.0 parts by weight of P, P'-bis (dialkylamino) benzophenone based on 100 parts by weight of the total of the base polymer and the ethylenically unsaturated compound. , P
Ka has 0.05 to 5 parts by weight of an organic carboxylic acid having 2 to 4,
0.03-1.0 parts by weight of the benzotriazole derivative,
A photosensitive resin composition containing 0.01 to 1.0 parts by weight of a triazine derivative (JP-A-6-148883);

It comprises a carboxyl group-containing polymer, an ethylenically unsaturated compound, a lophine dimer, a photopolymerization initiator (particularly benzyldimethyl ketal), and a leuco dye. The compound represented by the formula (1) is contained in an amount of 50 to 100% by weight based on the total amount of the ethylenically unsaturated compound. ~ 6.0 parts by weight,
0.1 to 10 parts by weight of the photopolymerization initiator and 0.1 to 10 parts by weight of the leuco dye.
A photosensitive resin composition containing 1 to 3.0 parts by weight (JP-A-10-115916);

[0014]

Embedded image Here, R ₁ and R ₂ are an alkyl group having 1 to 3 carbon atoms or hydrogen, which may be the same or different from each other. n is an integer of 4 to 20.

The acid value is 95-250 mgKOH / g,
It comprises a base polymer having a weight-average molecular weight of 5,000 to 200,000, an ethylenically unsaturated compound, and a self-cleavable initiator, wherein 50% of ethylene oxide-modified trimethylolpropane triacrylate is contained in the ethylenically unsaturated compound.
Photosensitive resin composition containing at least
-161306),

A photosensitive resin composition comprising a base polymer, an ethylenically unsaturated compound, a photopolymerization initiator and a silane compound and comprising at least glycerin triacrylate as the ethylenically unsaturated compound 198031),

A photosensitive resin composition comprising a base polymer, an ethylenically unsaturated compound, a photopolymerization initiator and a silane compound, and using at least polyethylene glycol di (meth) acrylate as the ethylenically unsaturated compound ( JP-A-10-198032),

A base polymer, an ethylenically unsaturated compound and a photopolymerization initiator, and (meth) acrylic acid ester as a main component of the copolymer of the base polymer;
Photosensitive resin composition using (meth) acrylic acid and hydroxyl group-containing (meth) acrylic acid ester
198034) and the like. Specific examples of the photosensitive resin compositions (1) to (4) are as described in the respective publications.

The above-mentioned photosensitive resin composition is coated on a base film surface such as a polyester film, a polypropylene film or a polystyrene film, and then, if necessary, a polyethylene film, a polyvinyl alcohol-based film or the like is coated on the coated surface. And used as a photoresist film. As a use other than a photoresist film, the photosensitive resin composition can be directly applied to a substrate to be processed by a conventional method such as a dip coating method, a flow coating method, and a screen printing method. At the time of coating, a solvent such as methyl ethyl ketone, methyl cellosolve acetate, ethyl cellosolve acetate, cyclohexene, methyl cellosolve, methylene chloride, 1,1,1-trichloroethane can be added. The thickness of the photosensitive resin composition layer of the photoresist film is preferably 5 to 30 μm, and it is preferable to overprint the photoresist film to a thickness of 7 to 250 μm.

In laminating the photosensitive resin composition layer on the substrate, the adhesive strength between the base film of the photoresist film and the photosensitive resin composition layer and the adhesive strength between the protective film and the photosensitive resin composition layer Are compared, and the film having the lower adhesive strength is peeled off, and then the photosensitive resin composition layer side is attached to the substrate.

(Step 2) After laminating the photosensitive resin composition layer on the substrate, a pattern mask (polyester film, glass mask, etc.) is brought into close contact with the other film and exposed to light. Exposure is usually performed by UV irradiation,
At this time, high-pressure mercury lamp, ultra-high pressure mercury lamp, carbon arc lamp, xenon lamp, metal halide lamp,
A chemical lamp or the like is used. After the ultraviolet irradiation, if necessary, heating may be performed to complete the curing.

(Steps 3 and 4) After the exposure, the film on the resist is peeled off and developed, and then the unexposed portion is removed to form a resist image. For such development, since the photosensitive resin composition is of an alkali developing type, alkalis such as sodium carbonate and calcium carbonate are used.
This is performed using a dilute aqueous solution of about 3% by weight.

(Step 5) Next, in the present invention, a pattern forming material is embedded in the concave portion of the formed resist image,
Perform drying. (Steps 6 and 7) After drying, the cured resist of the photosensitive resin composition is removed by sandblasting to form a pattern such as a thick film. The pattern forming material is not particularly limited, and various materials are selected depending on the application.
Among them, in forming the partition walls of the plasma display panel, it is preferable to use a low-melting glass paste,
In forming electrodes of the plasma display panel, it is preferable to use an electrode-forming material.

The low melting point glass paste for forming the partition walls has a melting point of 400 to 650 ° C., preferably 40 ° C.
0 to 600 ° C., specifically, an organic paste material in which a low-melting glass powder, a skeleton, a heat-resistant pigment and the like are dispersed in an organic binder resin, and the like, examples of the skeleton include silica, alumina, Zirconia, SiC, BN, S
US, mica and the like are used, and examples of the heat-resistant pigment include chromium oxide, iron oxide, cobalt oxide, titanium oxide, copper oxide, and aluminum. Also, the paste material includes
Additives such as a curing agent, a stabilizer, and a dispersant may be added.

Further, as the organic binder resin, a thermosetting resin, an acrylic resin, an epoxy resin, an epoxy acrylate resin, a cellulosic resin, and those resins containing a plasticizer having a boiling point of 150 ° C. or higher,
Polybutadiene resin, polyisoprene resin and the like can be mentioned.

The content of the organic binder is preferably 3 to 40 parts by weight, more preferably 5 to 30 parts by weight, particularly preferably 10 to 30 parts by weight, based on 100 parts by weight of the glass powder and the organic binder. It is. If the content of the organic binder is less than 3 parts by weight, the ceramic pattern will be damaged when the cured resist is removed by blasting. If the content exceeds 40 parts by weight, the amount of residual carbon may increase in firing after forming the ceramic pattern. It is not preferable because the property increases.

The glass component usually has an average particle size of 10 μm.
It is used as the following fine powder, and it is preferable to use, as a component of this glass powder, one having a softening point of 540 to 650 ° C., preferably 540 to 600 ° C., in part or in whole. If the softening point is lower than 540 ° C., the glass melts too quickly to cause inclusion of gas, and if it exceeds 650 ° C., the glass does not melt and the partition wall strength cannot be obtained, which is not preferable. In forming the partition walls, the thickness of the pattern forming material is preferably from 75 to 250 μm, and particularly preferably from 100 to 200 μm.

Examples of an electrode-forming material for forming an electrode include a silver-containing paste, a solder-containing paste, a zinc-containing paste, and a copper-containing paste. In the above electrode formation, the thickness of the pattern forming material is preferably from 5 to 70 μm, particularly preferably from 7 to 50 μm.

In the method of embedding the pattern forming material, the pattern forming material is poured into the opening of the concave portion, and a squeegee or a scraper made of rubber or metal is moved in parallel with the substrate while being in contact with the upper part of the resist pattern. At the same time as removing the excess pattern forming material that has protruded, the openings are filled without excess or shortage, and then dried at about 80 to 120 ° C. This embedding step may be repeated a plurality of times as necessary, or depending on the filling property, finally applying a pattern forming material over the entire upper surface via a screen plate, and then removing excess by cutting or polishing. Is also good. Here, when embedding the glass paste, the glass paste is butyl carbitol acetate,
It is preferable to dilute with a solvent such as cellosolve acetate and methylnaphthalene to about 60 to 90% by weight.

For the sandblasting, for example,
SiC, CaC having a particle diameter of about 0.1 to 100 μm
Using an inorganic powder such as O ₃ or H ₃ BO ₃ or an organic powder such as glucose, the hardened resist is removed by spraying at a blast pressure of 0.5 to 10 kg. After removing the cured resist,
The formed pattern forming material such as glass is fired.

Thus, according to the present invention, in patterning a pattern forming material such as a low-melting glass paste or an electrode forming material, a resist image of a photosensitive resin composition is formed on a substrate, particularly on a substrate for forming a plasma display panel. In order to embed the pattern forming material in the concave portion of the resist image and remove the cured resist of the photosensitive resin composition by sandblasting, the embedded pattern forming material does not peel off together with the cured resist,
Good pattern formation can be obtained.

[0032]

The present invention will be specifically described below with reference to examples. In the examples, “%” and “parts” mean on a weight basis unless otherwise specified.

Example 1 (Adjustment of dope) The following monomer (B), the following photopolymerization initiator (C) and other additives (D) were mixed with the following base polymer (A) to form a photosensitive resin. Adjust the composition,
Further, as a solvent, 100 parts of methyl ethyl ketone and 10 parts of methyl cellosolve were mixed to obtain a dope.

Base Polymer (A) Copolymer having a copolymerization ratio of methyl methacrylate / n-butyl methacrylate / 2-ethylhexyl acrylate / methacrylic acid of 50/10/15/25 by weight (acid value 163.1 mg KOH) / G, glass transition point 66 ° C, weight average molecular weight 80,000) 60 parts

Monomer (B) 30 parts of ethylene oxide-modified trimethylolpropane triacrylate (“Biscoat # 360” manufactured by Osaka Organic Co., Ltd.) 10 phenoxyhexaethylene glycol acrylate (“AMP-60G” manufactured by Shin-Nakamura Chemical Co., Ltd.) 10 Department

Photopolymerization initiator (C) -p, p'-bis (diethylamino) benzophenone 0.02 parts-hexaarylbiimidazole 3.0 parts

Other Additives (D) 0.3 parts of Leuco Crystal Violet 0.05 parts of Malachite Green

(Preparation of Photoresist Film and Lamination on Substrate)
Using a mill applicator, apply on a 20 μm thick polyester film, leave at room temperature for 1 minute 30 seconds,
Each was dried in an oven at 60 ° C., 90 ° C., and 110 ° C. for 3 minutes to obtain a photoresist film having a resist thickness of 50 μm (no protective film was provided). After laminating this on a glass substrate, the cover film (polyester film) of the photoresist film was peeled off, and a second photoresist film was further laminated.
This operation was repeated again to provide a laminate of a photoresist film having a thickness of 150 μm. In the above laminating step, the glass substrate was preheated to 60 ° C. in an oven,
Laminate roll temperature 100 ° C, roll pressure 3kg / c
The lamination was performed at m ² and a lamination speed of 1.5 m / min.

(Exposure and development) Line / space = 300 μm / 1 on the surface of the laminate of the above photoresist film
Applying a pattern mask of 00 μm, and using an exposure machine HMW-532D manufactured by Oak Manufacturing Co., Ltd. with a 2 kW ultrahigh pressure mercury lamp
Exposure at mj. After a hold time of 15 minutes after the exposure, development was performed at 1% Na ₂ CO ₃ aqueous solution at 30 ° C. for 1.5 times the minimum development time, and an opening width of 97 μm was formed on the substrate.
m, concave part of resist image with opening height of 150 μm (female type)
Was formed.

(Embedding of Pattern Forming Material) A glass paste (melting point: 550 ° C.) having the following formulation is poured into the opening obtained by the above-mentioned concave portion (female mold), and the opening is completely and properly filled with a rubber squeegee. After filling, 12
Drying was performed at 0 ° C. for 60 minutes. This operation was repeated three times to perform filling.

Glass paste / glass powder (PbO / B ₂ O ₅ / SiO ₂ / Al ₂ O ₃ / TiO ₂ = 31.1 parts / 15.1 parts / 9.2 parts / 34.2 parts / 10.4 Of a binder (methyl methacrylate / n-butyl methacrylate / methacrylic acid = 45 parts / 54.5 parts / 0.5 parts) (acid value 3.3 mg KOH / g, weight average molecular weight 1) 50000) 8 parts ・ Ethylene oxide-modified bisphenol A type diacrylate 18 parts

(Sand blasting) After embedding the glass paste, SCM-1ADE-40 manufactured by Fuji Seisakusho
1 and spraying pressure of the abrasive CaCO ₃ at 3 kg / cm ₂
And sprayed from a nozzle distance of 50 mm to remove the cured resist of the photosensitive resin composition by sandblasting.

When the shape of the glass pattern formed above was observed with a scanning electron microscope, a relatively good pattern was obtained with a slightly rounded upper end but close to a rectangular shape. As a result of having a demineralization step at 380 ° C. and sintering through a mesh belt type sintering furnace set at Max 580 ° C., it was good.

Example 2 The procedure of Example 1 was repeated, except that the following electrode-forming material was used as the pattern-forming material. (40 μm in thickness of electrode forming material ) 80 parts of electrode forming material (silver-containing paste)・ Binder (methyl methacrylate / n-butyl methacrylate / methacrylic acid = 45 / 54.5 / 0.5 (weight ratio)) 5 parts of copolymer (acid value 3.3 mg KOH / g, weight average molecular weight 150,000) 15 parts of ethylene oxide-modified bisphenol A type diacrylate 15 parts of n-butyl carbitol acetate

When the shape of the electrode pattern formed above was observed with a scanning electron microscope, a relatively good pattern was obtained with a slightly rounded upper end and a relatively good rectangular shape. Decalcification step at ℃
As a result of sintering through a mesh belt type sintering furnace set to ax 580 ° C., the results were good.

Example 3 The procedure of Example 1 was repeated, except that the following photosensitive resin composition dope was used. (Preparation of dope) The following base polymer (A) was mixed with the following monomer (B), the following photopolymerization initiator (C) and other additives (D) to prepare a photosensitive resin composition,
Further, as a solvent, 100 parts of methyl ethyl ketone and 10 parts of methyl cellosolve were mixed to obtain a dope.

Base Polymer (A) A copolymer having a copolymerization ratio of methyl methacrylate / n-butyl methacrylate / 2-ethylhexyl acrylate / methacrylic acid of 20/40/20/20 (acid value: 150 mgKOH / g) , Glass transition point 67.1 ° C, weight average molecular weight 90,000) 60 parts

20 parts of monomer (B) / epichlorohydrin-modified glycerin triacrylate (manufactured by Nagase & Co., Ltd., "Denacol DA-314") ・ Propylene glycol # 400 diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., "NK Ester APG-400") 10 parts ・ Phenoxytetraethylene glycol acrylate (Toagosei Co., Ltd., “Aronix M-102” 10 parts

Photopolymerization initiator (C) 0.3 part of 4- (4-methoxynaphthyl) -2,6-bis (trichloromethyl) -triazine

Other additives (D) • Malachite green 0.02 parts • Leuco crystal violet 0.5 parts

When the shape of the electrode pattern formed above was observed with a scanning electron microscope, a relatively good pattern was obtained with a slightly rounded upper end and a shape close to a rectangular shape. Decalcification step at ℃
As a result of sintering through a mesh belt type sintering furnace set to ax 580 ° C., the results were good.

Example 4 The procedure of Example 1 was repeated, except that the abrasive for sandblasting was changed to glucose. When the shape of the electrode pattern formed above was observed with a scanning electron microscope, the upper end was slightly rounded but close to a rectangular shape,
A relatively good pattern is obtained, which is 350-380
As a result of sintering through a mesh belt type sintering furnace having a decalcification step at 580 ° C. and a Max of 580 ° C., the results were good.

Comparative Example 1 In Example 1, after embedding the pattern forming material,
Instead of performing sandblasting, perform showering with a 3% aqueous sodium hydroxide solution heated to 50 ° C.
The cured resist was stripped.

When the shape of the glass pattern formed above was observed with a scanning electron microscope, the glass paste pattern was also affected when the resist was peeled off. And satisfactory partition walls could not be obtained.

[0055]

According to the pattern forming method of the present invention, in the patterning of a pattern forming material such as a low-melting glass paste or an electrode forming material, a photosensitive resin composition is formed on a substrate, particularly on a substrate for forming a plasma display panel. A resist image is formed, the pattern forming material is embedded in the concave portion of the resist image, and the cured resist of the photosensitive resin composition is removed by sandblasting, so that the embedded pattern forming material does not peel off together with the cured resist. It exhibits an excellent effect on pattern formation, and is particularly useful for forming partition walls and forming electrodes of a plasma display panel.

[Brief description of the drawings]

FIG. 1 is a process chart relating to a pattern forming method of the present invention. Step 1 is a step of laminating a photoresist film on a substrate, Step 2 is an exposure step with ultraviolet light, Step 3 is a step of developing an unexposed portion of the photosensitive resin composition, Step 4 is a resist image forming step, and Step 5 is a pattern formation. Step 6 is a sand blasting step, and step 7 is a pattern forming step.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Laminator roll of photoresist film 3 ... Photoresist film 4 ... Pattern mask 5 ... Ultraviolet 6 ... Developer 7 ... Pattern forming material 8 ... Sandblast nozzle 9: abrasive

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/66 101 H04N 5/66 101A F term (Reference) 2H096 AA27 BA05 BA20 EA02 GA08 HA01 JA04 LA06 5C027 AA01 AA09 5C040 GC19 GF19 JA02 JA09 JA15 JA17 JA20 JA22 KA01 KA09 KA16 MA23 MA24 MA25 5C058 AA11 AB01 BA35

Claims (5)

[Claims] Claims: 1. A photosensitive resin composition layer is laminated on a substrate,
After performing exposure and development through a pattern mask to form a resist image, a pattern forming material is embedded in a concave portion of the formed resist image, and a cured resist of the photosensitive resin composition is removed by sandblasting. Pattern forming method. 2. The pattern forming method according to claim 1, wherein the pattern forming material is a glass paste. 3. The pattern forming method according to claim 1, wherein the pattern forming method is an electrode forming material. 4. The pattern forming method according to claim 1, wherein the photosensitive resin composition layer is a photoresist film obtained by laminating the photosensitive resin composition on a base film. 5. The pattern forming method according to claim 1, wherein the substrate is a substrate for forming a plasma display panel.