KR20180003402U - Apparatus for thin filming resist layer - Google Patents

Abstract

[PROBLEMS] To provide a thin film forming apparatus for a resist layer capable of solving the problem of uneven treatment due to bubbles.
A thin film forming apparatus for thinning a resist layer provided with a thinning processing unit is provided with a dip tank 10 containing a thinning liquid 9 and a thinning treatment liquid 10 overflowed from the dip tank 10 9, a thin-film processing liquid storage tank 13, a thin-film processing liquid inlet port formed in the thin-film processing liquid storage tank 13, a thin-film processing liquid inlet port 11 formed in the dip tank 10, And a thinning process liquid supply pump 14 for supplying the thinning process liquid 9 sucked from the suction port to the dip tank 10. The thinning process liquid sucking port is provided with a filtration section 24, 24) is shielded on the upper surface side of the resist layer.

Description

[0001] APPARATUS FOR THIN FILMING RESIST LAYER [0002]

The present invention relates to an apparatus for thinning a resist layer.

Background Art [0002] With respect to miniaturization, weight reduction, and multifunctionalization of electric and electronic parts, photosensitive resin (photosensitive material) including dry film resist and solder resist for circuit formation has been required to have high resolution in order to cope with high density of printed wiring boards. Image formation by these photosensitive resins is carried out by exposing the photosensitive resin to light and then developing it.

There is a tendency that the photosensitive resin becomes thinner in order to cope with miniaturization and high functioning of the printed wiring board. As the photosensitive resin, there are a liquid resist of a type in which a liquid is applied and a dry film resist of a film type. In recent years, dry film resists having a thickness of 15 mu m or less have been developed, and their commercialization has also progressed. However, such a thin dry film resist has insufficient adhesiveness and trackability to irregularities as compared with a resist of conventional thickness, and there is a problem that peeling or voids are generated.

In order to improve the above-described points, various means for achieving high resolution while using a thick photosensitive resin have been proposed. For example, in a method for producing a conductive pattern by a subtractive method, a dry film resist is attached to a laminate substrate having a metal layer formed on one side or both sides of an insulating layer to form a resist layer, (Hereinafter, referred to as " patterning step "), and then performing an exposure step, a developing step, and an etching step of a circuit pattern (for example, refer to Patent Document 1). In the method of forming a solder resist pattern, a resist layer made of a solder resist is formed on a circuit board having a conductive pattern, a thinning process of the resist layer is performed, a pattern exposure process is then performed, And a thinning step of the resist layer is carried out (see, for example, Patent Documents 2 and 3).

Patent Document 4 discloses a thin film forming apparatus used in a step of thinning a resist layer. Specifically, the substrate on which the resist layer is formed is immersed (dipped) in a thinning treatment solution of a high concentration of an alkali aqueous solution to insolubilize the micelles of the components of the resist layer once, thereby making it difficult for the micelles to dissolve and diffuse into the thinning treatment liquid , And a micelle removal treatment unit for dissolving and removing micelles at a time by spraying a micelle removal liquid.

The thinning processing unit of the thinning apparatus disclosed in Patent Document 4 will be described with reference to the drawings. 6 and 7 are schematic sectional views of the thinning processing unit. Fig. 6 is a schematic sectional view seen from a direction CD perpendicular to the carrying direction MD of the substrate, and Fig. 7 is a schematic sectional view seen from the carrying direction MD of the substrate. In this thinning apparatus, the substrate 8 on which the resist layer is formed is transported by the transport roll pair 12 while being immersed in the thinning treatment liquid 9 in the dip tank 10, A thinning treatment is carried out. The thinning treatment liquid 9 is supplied from the thinning treatment liquid intake port 17 formed in the thinning treatment liquid storage tank 13 under the apparatus to the thinning treatment liquid supply port 14 through the thinning treatment liquid supply port 11, (10). The overflowed thinning treatment liquid 9 is recovered in the thinning treatment liquid recovery tank 30 and discharged from the recovery pipe outlet 22 through the recovery pipe 21 and stored in the thinning treatment liquid storage tank 13 do. By this repetition, the thinning treatment liquid 9 circulates between the dip tank 10 and the thinning treatment liquid storage tank 13.

6 and 7, when the thinning treatment liquid 9 is circulated, the thinning treatment liquid 9 is dropped from the degassing tank 10 to the thinning treatment liquid storage tank 13 by overflow . At this time, bubbles 15 are generated in the thinning treatment liquid 9 and the bubbles 15 adhere to the resist layer of the substrate 8 by circulation of the thinning treatment liquid 9, Unevenness in the film thickness (unevenness) may occur in some cases.

In order to solve the problem of treatment unevenness due to bubbles, a thinning apparatus equipped with various bubble suppression devices is disclosed (for example, refer to Patent Document 5). The bubble suppression apparatus includes a bubble induction plate 16 (FIG. 8) provided between the thinning treatment liquid supply port 11 for supplying the thinning treatment liquid 9 to the dip tank 10 and the transport roll pair 12, The bubble induction plates 18 and 19 (FIG. 8) provided in the thinning treatment liquid storage tank 13 and the recovery pipe 9 provided below the liquid level of the thinning treatment liquid 9 in the thinning treatment liquid storage tank 13 An ultrasonic wave generating device provided in the degassing tank 10 or the thinning process liquid storage tank 13 and an ultrasonic wave generating device provided in a position lower than the surface of the thinning process liquid 9 in the dip tank 10 (For example, refer to Patent Document 5). Patent Document 5 discloses a method of supplying a thinning treatment liquid 9 to a degassing tank 10 through a thinning treatment liquid supply port 11 by a thinning treatment liquid supply pump 14 from a thinning treatment liquid storage tank 13 Thus, means for suppressing bubbles in the thinning treatment liquid 9 is not described, and there is room for further improvement.

The present invention also provides a substrate processing apparatus for immersing a substrate in a processing solution to perform a substrate processing, the substrate processing apparatus comprising: an immersion tank for immersing the substrate in the stored processing solution by immersing the substrate in the processing solution; a recovery tank for temporarily collecting the processing solution overflowed from the immersion tank; And a circulating flow path for sucking the treatment liquid stored in the recovery tank from the treatment liquid discharge port of the recovery tank and supplying the treatment liquid to the immersion tank, wherein the treatment liquid discharge port is formed at the bottom of the recovery tank, There is disclosed a substrate processing apparatus in which a suction inhibiting member, which changes a flow to a bending phase and forms a filling region of a treatment liquid at a treatment liquid discharge port and its peripheral portion, is attached to a collection tank, Even if the treatment liquid swirls at the discharge port and the vicinity thereof, there is no fear of drawing air in the central portion thereof, and air bubbles flow into the circulation flow path (See, for example, Patent Document 6). Examples of the suction restraining member are a suction restraining plate, a suction restraining ball, and a suction restraining mat.

The recovery tank and the treatment liquid discharge port described in Patent Document 6 correspond to the thinning treatment liquid storage tank and the thinning treatment liquid intake port. In the apparatus of Patent Document 6, a treatment liquid discharge port through which the treatment liquid falls downward is formed on the bottom of the recovery tank. Patent Document 6 does not disclose means for suppressing air bubbles in an apparatus in which a treatment liquid discharged from a treatment liquid discharge port flows in a lateral direction.

In addition to the above, there is provided a substrate processing apparatus for immersing a substrate in a processing liquid in a processing tank to perform predetermined processing, the substrate processing apparatus comprising: an outer tank disposed outside the processing tank and recovering the processing liquid spilled from the processing tank; A circulation path communicating with the outer tank and the treatment tank and supplying the treatment liquid discharged from the treatment tank to the treatment tank again, and an opening formed in an end portion of the circulation path on the outer tank side A substrate processing apparatus having a suction pipe is disclosed (for example, see Patent Document 7). The suction pipe of the outer tank and the end described in Patent Document 7 corresponds to the thinning treatment liquid storage tank and the thinning process liquid intake port. In Patent Document 7, as shown in Fig. 9, the flow rate of the treatment liquid in the vicinity of the liquid surface can be reduced by making the thinning treatment liquid intake port 17, which is the end of the thinning process liquid supply pipe 20, downward, And prevents the bubbles in the treatment liquid from being entrained by the vortex.

However, in the case where the suction pipe (thinning processing liquid inlet port 17) is downward, a lot of thinning processing liquid near the bottom of the processing tank is sucked, and a uniform liquid in the outer tank (thinning processing liquid storage tank 13) Occasionally interfering with circulation. Further, in order to suck a sufficient amount of the thinning treatment liquid, it is necessary to adjust and fix the height so that the thinning treatment liquid intake port 17 does not come into contact with the bottom of the thinning treatment liquid storage tank 13. Patent Document 7 discloses a structure in which the suction pipe is formed so that the opening face of the thin film processing liquid inlet 17 is formed to have an angle with respect to the bottom of the outer tank (thin film processing liquid storage tank 13) However, in this case, since the processing liquid existing in the upper part to the lower part of the suction pipe is sucked, the effect of suppressing the occurrence of the vortex is weakened and the processing unevenness due to the bubbles sometimes occurs.

International Publication No. 2009/096438 pamphlet Japanese Laid-Open Patent Publication No. 2011-192692 International Publication No. 2012/043201 pamphlet Japanese Laid-Open Patent Publication No. 2012-27299 Japanese Utility Model Registration No. 3182371 Japanese Patent Application Laid-Open No. 2000-91293 Japanese Laid-Open Patent Publication No. 11-176783

The object of the present invention is to provide a thin film forming apparatus for a resist layer capable of solving the problem of uneven treatment due to bubbles in an apparatus for thinning a resist layer.

The above problems can be solved by the following means.

(1) In a thin film forming apparatus for a resist layer having a thinning processing unit,

Wherein the thinning treatment unit comprises a thinning treatment liquid storage tank for storing a thinning treatment liquid containing a thinning treatment liquid and an overflowed thinning treatment liquid overflowed from the dip tank, a thinning treatment liquid intake port formed in the thinning treatment liquid storage tank, And a thinning treatment liquid supply pump for supplying the thinning treatment liquid sucked from the thinning treatment liquid intake port to the dip tank,

Wherein the filtration section is provided in the thin-film processing liquid inlet port, and the upper surface side of the filtration section is shielded.

(2) The thinning device for a resist layer according to (1) above, wherein the ratio of the area of the shielded area to the area of the filtration part seen from above is not less than 0.25 and not more than 1.

It is possible to provide a thin film forming apparatus for a resist layer capable of solving the problem of uneven treatment due to bubbles in an apparatus for thinning a resist layer.

1 is a schematic cross-sectional view showing an example of a thinning treatment unit in the thinning apparatus of the present invention.
Fig. 2 is an enlarged perspective view showing an example of a thin-film processing solution inlet in the thinning apparatus of the present invention.
Fig. 3 is an enlarged perspective view showing an example of a thin-film processing solution inlet in the thinning apparatus of the present invention.
Fig. 4 is an enlarged perspective view showing an example of a thin-film processing liquid inlet in the thinning apparatus of the present invention.
Fig. 5 is a schematic plan view of an example of the thinning process liquid inlet port from above, in the thinner of the present invention. Fig.
6 is a schematic cross-sectional view showing the thinning treatment unit in the thinning apparatus of the prior art.
7 is a schematic cross-sectional view showing the thinning treatment unit in the thinning apparatus of the prior art.
8 is a schematic cross-sectional view showing a thinning treatment unit in the thinning apparatus of the prior art.
9 is a schematic cross-sectional view showing a thinning treatment unit in the thinning apparatus of the prior art.
10 is a cross-sectional process diagram showing an example of a method of forming a resist pattern to be performed using the apparatus for thinning a resist layer of the present invention.
11 is a cross-sectional process drawing showing an example of a method of forming a resist pattern to be carried out using the apparatus for thinning a resist layer of the present invention.
12 is a cross-sectional process diagram showing an example of a method of forming a resist pattern to be performed using the apparatus for thinning a resist layer according to the present invention.
13 is a cross-sectional process drawing showing an example of a method of forming a resist pattern to be carried out by using the apparatus for thinning a resist layer of the present invention.

Hereinafter, a thin film forming apparatus for a resist layer of the present invention will be described in detail.

A method of forming a resist pattern to be performed using the apparatus for thinning a resist layer of the present invention will be described with reference to FIGS. 10 to 13. FIG.

A method (1) of forming a resist pattern in the case of forming a conductive pattern by the subtractive method will be described with reference to FIG.

10a] A laminate substrate on which a metal layer 7 is formed on an insulating layer 1 is prepared.

10b] An alkali developing type resist layer 3 is formed on a laminated substrate.

10C] The resist layer 3 is thinned (thinning step) by the thinning treatment liquid while suppressing the adhesion of air bubbles to the resist layer 3.

10d] Pattern exposure is performed on the thinned resist layer 3 by an actinic ray 5 (exposure step).

(Fig. 10E) The resist layer 3 of the unexposed portion is removed by development (developing step).

This makes it possible to form a resist pattern having no treatment unevenness in thinning by bubbles as shown in Fig. 10E. 10E and thereafter, in the etching step, the metal layer 7 not covered with the resist pattern is etched to obtain a conductive pattern.

A method (2) of forming a resist pattern using a solder resist will be described with reference to Fig.

11A) A circuit board on which a conductor wiring 2 and a connection pad 6 are formed on an insulating layer 1 is prepared.

[Fig. 11 (b)] An alkali development type resist layer 3 is formed on a circuit board.

(FIG. 11C) The resist layer 3 in a portion other than the region to be thinned is exposed by the actinic ray 5 (exposure step).

11D is a plan view of the resist layer 3 of the unexposed portion by the thinning treatment liquid until the thickness of the resist layer 3 becomes thinner than the thickness of the connection pad 6 while suppressing the adhesion of bubbles to the resist layer 3 3) is thinned (thinning step).

11D, the conductor wiring 2, which is free from the unevenness of thinning due to bubbles, is coated with the resist layer 3, and the connection pad 6 is exposed from the resist layer 3, Can be formed.

A method (3) of forming a resist pattern in the case of forming a conductive pattern by the subtractive method will be described with reference to FIG.

12A) A laminate substrate on which a metal layer 7 is formed on an insulating layer 1 is prepared.

12B] An alkali development type resist layer 3 is formed on a laminated substrate.

12C] The resist layer 3 in a portion other than the area to be thinned is exposed by an actinic ray 5 (first exposure step).

12D] The resist layer 3 of the unexposed portion is made thin (thinning step) by the thinning treatment liquid while suppressing the adhesion of air bubbles to the resist layer 3.

(Fig. 12E) The resist layer 3 in a portion other than the developed region is exposed by the actinic ray 5 (second exposure step).

12F] The resist layer 3 of the unexposed portion is removed by development (developing step).

Thereby, it is possible to form a resist pattern of a multistage structure having a partially thinned resist layer 3, as shown in Fig. 12F, without unevenness in processing of thinning by bubbles. Next, in the etching step, the metal layer 7 not covered with the resist pattern is etched to obtain a conductive pattern.

A method (4) of forming a resist pattern using a solder resist will be described with reference to FIG.

13A) A circuit board on which a conductor wiring 2 and a connection pad 6 are formed on an insulating layer 1 is prepared.

[Fig. 13 (b)] An alkali development type resist layer 3 is formed on a circuit board.

13C] The resist layer 3 in a portion other than the region to be thinned at the first time is exposed by the actinic ray 5 (first exposure step).

13D] While the resist layer 3 is prevented from adhering air bubbles, the resist layer 3 of the unexposed portion is removed by the thinning treatment solution until the thickness of the resist layer 3 becomes equal to or greater than the thickness of the connection pad 6 ) Is thinned (first thinning step).

(Fig. 13 (e)) The resist layer 3 in a portion other than the region to be thinned for the second time is exposed by the actinic ray 5 (second exposure step).

13F] While the thickness of the resist layer 3 is thinner than the thickness of the connection pad 6 while suppressing the adhesion of air bubbles to the resist layer 3, the resist layer 3 Is thinned (second thinning step).

13F, the conductive wiring 2 is covered with the resist layer 3, and the connection pad 6 is exposed from the resist layer 3 in a multi-step structure (not shown) Can be formed.

As the substrate, a substrate for a printed wiring board; A substrate for a lead frame; And a circuit board obtained by processing a substrate for a printed wiring board or a substrate for a lead frame.

Examples of the substrate for a printed wiring board include a flexible substrate and a rigid substrate. The insulating layer of the flexible substrate has a thickness of 5 to 125 占 퐉 and a metal layer of 1 to 35 占 퐉 is formed on both sides or on one side thereof to form a laminated substrate and has high flexibility. As the material of the insulating layer, polyimide, polyamide, polyphenylene sulfide, polyethylene terephthalate, liquid crystal polymer and the like are usually used. The material having the metal layer on the insulating layer can be formed by a bonding method in which bonding is performed with an adhesive, a casting method in which a resin liquid is coated on a metal foil, a thin conductive layer having a thickness of several nm formed on a resin film by sputtering, A sputter / plating method in which a metal layer is formed by electrolytic plating on a seed layer (seed layer), a lamination method in which hot paste is applied, or the like may be used. As the metal of the metal layer, any metal such as copper, aluminum, silver, nickel, chromium, or an alloy thereof can be used, but copper is common.

Examples of the rigid substrate include a laminated substrate having a metal layer formed thereon. This laminated substrate is obtained by laminating an insulating substrate on which a paper base material or a glass base material is immersed with an epoxy resin or a phenol resin or the like as an insulating layer and placing a metal foil on one or both sides thereof by heating and pressing . Also, a multilayer shield plate for multilayer lamination of prepregs, metal foils and the like after the processing of the inner layer wiring pattern, and a multilayer board having through holes or non-through holes can be used. The thickness is 60 mu m to 3.2 mm, and its material and thickness are selected by the final use form as a printed wiring board. As the material of the metal layer, copper, aluminum, silver, gold and the like can be mentioned, but copper is the most common. Examples of these boards for printed wiring boards are described in "Printed Circuit Technology Handbook - Second Edition" (Published by the Society of Printed Circuits, published in 1987, published by Nikkan Kogyo Shimbun) or "Multilayer Printed Circuit Handbook" (JA Scarlet, 1992 Published by Kagaku Kagaku Sha, Inc.).

Examples of the substrate for the lead frame include substrates made of iron nickel alloy, copper-based alloy, and the like.

The circuit board is a substrate on which a connection pad for connecting electronic components such as a semiconductor chip is formed on an insulating substrate. The connection pad is made of metal such as copper. Conductor wirings may be formed. Examples of the method for producing the circuit board include a subtractive method, a semi-additive method, and an additive method. In the subtractive method, for example, an etching resist pattern is formed on the substrate for a printed wiring board, and an exposure step, a development step, an etching step, and a resist stripping step are performed to produce a circuit board.

As the resist, an alkali development type resist can be used. The resist may be a liquid resist, a dry film resist, a thin film forming solution which is an alkaline aqueous solution, or a resist which can be developed by a developing solution which is a lower alkaline aqueous solution than the thinning treatment liquid. It can also be used. The alkali developing type resist includes a photocurable resin component. The photo-crosslinkable resin component contains, for example, an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, and the like. The resist may contain an epoxy resin, a thermosetting agent, an inorganic filler, or the like.

Examples of the alkali-soluble resin include organic polymers such as an acrylic resin, a methacrylic resin, a styrene resin, an epoxy resin, an amide resin, an amide epoxy resin, an alkyd resin and a phenol resin . Of these, those obtained by polymerization (radical polymerization or the like) of a monomer having an ethylenically unsaturated double bond (polymerizable monomer) are preferred. These alkali-soluble resins may be used alone or in combination of two or more. Examples of the monomer having an ethylenically unsaturated double bond include styrene, vinyltoluene,? -Methylstyrene, p-methylstyrene, p-ethylstyrene, p-methoxystyrene, p- Styrene derivatives such as styrene and p-bromostyrene; Acrylamide such as diacetone acrylamide; Acrylonitrile; Esters of vinyl alcohols such as vinyl-n-butyl ether; (Meth) acrylic acid alkyl ester, (meth) acrylate tetrahydrofurfuryl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) acrylate diethylaminoethyl ester, (meth) acrylic acid glycidyl ester, 2,2,2 (Meth) acrylic acid,? -Bromo (meth) acrylic acid,? -Chlor (meth) acrylate, (meth) acrylic acid monomers such as? -furyl (meth) acrylic acid and? -styryl (meth) acrylic acid; Maleic acid monomers such as maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, and monoisopropyl maleate; Fumaric acid, cinnamic acid,? -Cyano cinnamic acid, itaconic acid, crotonic acid, and propiolic acid.

Examples of the photopolymerizable compound include a compound obtained by reacting an?,? - unsaturated carboxylic acid with a polyhydric alcohol; Bisphenol A (meth) acrylate compounds; A compound obtained by reacting an?,? - unsaturated carboxylic acid with a glycidyl group-containing compound; Urethane monomers such as (meth) acrylate compounds having a urethane bond in the molecule; Nonylphenoxypolyethylene oxyacrylate; phthalic acid such as? -chloro? -hydroxypropyl-? '- (meth) acryloyloxyethyl-o-phthalate,? -hydroxyalkyl-?' - (meth) acryloyloxy- Based compound; (Meth) acrylic acid alkyl ester, EO, PO-modified nonylphenyl (meth) acrylate, and the like. Here, EO and PO represent ethylene oxide and propylene oxide, the EO-modified compound has a block structure of ethylene oxide group, and the PO-modified compound has a block structure of propylene oxide group. These photopolymerizable compounds may be used alone or in combination of two or more.

Examples of the photopolymerization initiator include benzophenone, N, N'-tetramethyl-4,4'-diaminobenzophenone (Michler's ketone), N, N'-tetraethyl-4,4'-diaminobenzophenone, (4-morpholinophenyl) -butanone-1, and 2-methyl-1- [4- (methylthio) ) Phenyl] -2-morpholino-propanone-1; Diethylanthraquinone, 2,3-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-di 2-methyl anthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethyl anthraquinone Quinones such as quinone; Benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether; Benzoin compounds such as benzoin, methylbenzoin and ethylbenzoin; Benzyl derivatives such as benzyl dimethyl ketal; 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (o- (O-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- , 2,4,5-triarylimidazole dimer such as 5-diphenylimidazole dimer; Acridine derivatives such as 9-phenylacridine and 1,7-bis (9,9'-acridinyl) heptane; N-phenylglycine, N-phenylglycine derivatives, coumarin-based compounds and the like. The substituents of the aryl groups of the two 2,4,5-triarylimidazoles in the 2,4,5-triarylimidazole dimer are the same and may be symmetrical, and may be asymmetric Phosphorus compound may be added. In addition, a thioxanthone compound and a tertiary amine compound may be combined, such as a combination of diethylthioxanthone and dimethylaminobenzoic acid. These may be used alone or in combination of two or more.

The epoxy resin is sometimes used as a curing agent. The resist is crosslinked by reacting a carboxylic acid of an alkali-soluble resin with an epoxy to improve heat resistance and chemical resistance. However, since the reaction of the carboxylic acid with the epoxy proceeds at room temperature, the storage stability of the resist is poor. For this reason, the alkali developing type solder resists generally take a form of a two-part liquid which is mixed before use in many cases. The resist may contain an inorganic filler. Examples of the inorganic filler include talc, barium sulfate, and silica.

The method of forming the resist layer on the surface of the substrate may be any method such as a screen printing method, a roll coating method, a spraying method, a dipping method, a curtain coating method, a bar coating method, an air knife method, A coating method, a brush coating method, and an offset printing method. In the case of a dry film resist, a lamination method is preferably used.

In the exposure step, an actinic ray is irradiated onto the resist layer. It is possible to use a reflective image exposure using a xenon lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, an ultra-high-pressure mercury lamp, or a UV fluorescent light as a light source, a single-sided surface using a photomask, a double-side contact exposure method, When a scanning exposure is performed, a laser light source such as UV laser, He-Ne laser, He-Cd laser, argon laser, krypton ion laser, ruby laser, YAG laser, nitrogen laser, dye laser, excimer laser, Exposure can be performed by scanning exposure using SHG wavelength conversion, or scanning exposure using a liquid crystal shutter or a micro mirror array shutter.

In the development step, the resist layer of the unexposed portion is developed with a developer. Unlike the thinning process, the resist layer of the unexposed portion is completely removed. As a developing method, a method of spraying a spray toward the surface of a substrate is generally used by using a developing solution suitable for the resist layer to be used. As the developing solution, an alkali aqueous solution having a lower concentration than the thinning treatment solution used in the thinning treatment is used. As the developing solution (low-concentration alkaline aqueous solution), 0.3 to 3 mass% of an aqueous solution of sodium carbonate is generally used.

In the etching process, a method described in "Printed Circuit Technology Manual" (published by Japan Printed Circuit Industry Association, published in 1987, published by Nikkan Kogyo Shimbun, Inc.) can be used. The etching solution is one capable of dissolving and removing the metal layer, and at least the resist layer has resistance. In general, when copper is used for the metal layer, a ferric chloride aqueous solution, a cupric chloride aqueous solution, or the like can be used.

The thinning process of the resist layer includes a micellization treatment (thinning treatment) in which the photocurable resin component in the resist layer is micellized by a thinning treatment liquid, a micelle removal process in which micelles are removed by water or an alkali aqueous solution of pH 5 to 9 . In addition, it may also include a resist layer surface which can not be removed completely, a water treatment treatment which rinses the remaining thinning treatment liquid by washing with water, and a drying treatment which removes wash water.

Examples of the alkaline compound used in the thinning treatment liquid include alkali metal silicates of alkali metals such as lithium, sodium or potassium, alkali metal hydroxides, alkali metal phosphates, alkali metal carbonates, ammonium phosphates and ammonium carbonates Alkaline compounds; Monoethanolamine, diethanolamine, triethanolamine, methylamine, dimethylamine, ethylamine, diethylamine, triethylamine, cyclohexylamine, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, trimethyl- And organic alkaline compounds such as hydroxyethyl ammonium hydroxide (choline). The alkaline compound may be used alone or as a mixture.

The content of the alkaline compound in the thinning treatment liquid is 0.1% by mass or more and 50% by mass or less. In order to make the surface of the resist layer more uniformly thin, sulfate and sulfite may be added to the thinning treatment liquid. Examples of the sulfate or sulfite include sulfates of alkali metals such as lithium, sodium or potassium or sulfates or sulfites of alkaline earth metals such as sulfite, magnesium and calcium.

As the thinning treatment liquid, among them, an inorganic alkaline compound selected from the group of alkali metal carbonate, alkali metal phosphate, alkali metal hydroxide and alkali metal silicate, and at least one organic alkaline compound selected from the group of TMAH and choline And an alkaline aqueous solution having an alkaline compound content of 5 to 25% by mass can be preferably used because the surface can be more uniformly thinned. When the content of the alkaline compound is less than 5% by mass, unevenness may easily occur in the thinning process. When the content of the alkaline compound exceeds 25% by mass, the stability of the liquid over time and the workability may be inferior. The content of the alkaline compound is more preferably 7 to 17 mass%, and still more preferably 8 to 13 mass%. The pH of the thinning treatment liquid is preferably 10 or more. Further, a surfactant, defoaming agent, solvent, etc. may be appropriately added to the thinning treatment liquid 1.

The thinning treatment by the thinning treatment liquid is carried out by dipping (dip) a substrate on which a resist layer is formed in the thinning treatment liquid in the dip tank. The treatment methods other than the dip treatment tend to cause air bubbles to be generated in the thinning treatment liquid, and the resulting bubbles may adhere to the surface of the resist layer during the thinning treatment, resulting in non-uniform film thickness.

In the resist pattern forming method using the resist bath thinning apparatus of the present invention, the thickness of the resist layer is determined by the thickness after formation of the resist layer and the amount of thinning of the resist layer. In addition, the amount of thinning can be adjusted freely in the range of 0.01 to 500 탆.

1 to 5, an apparatus for thinning a resist layer of the present invention will be described.

The apparatus for thinning a resist layer of the present invention comprises a thinning processing unit. The thinning treatment unit is provided with a dip tank 10 containing a thinning treatment liquid 9, a thinning treatment liquid storage tank 13 storing a thinning treatment liquid 9 overflowed from the dip tank 10, A thinning processing liquid inlet port formed in the storage tank 13 and a thinning processing liquid inlet port 11 formed in the dip tank 10 and a thinning processing liquid 9 sucked from the thinning processing liquid inlet port are supplied to the dip tank 10 And a thinning process liquid supply pump 14 for supplying the thinned process liquid.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing an example of a thinning treatment unit in the thinning apparatus of the present invention, and is a schematic sectional view seen from the carrying direction of the substrate. Fig. In this thinning apparatus, the substrate 8 on which the resist layer is formed is transported by the transport roll pair 12 while being immersed in the thinning treatment liquid 9 in the dip tank 10, A thinning treatment is carried out. The thinning treatment liquid 9 is supplied from the thinning treatment liquid inlet port formed in the thinning treatment liquid storage tank 13 under the apparatus to the dip tank 10 through the thinning treatment liquid supply port 11 by the thinning treatment liquid supply pump 14, . The overflowed thinning treatment liquid 9 is recovered in the thinning treatment liquid recovery tank 30 and discharged from the recovery pipe outlet 22 through the recovery pipe 21 and stored in the thinning treatment liquid storage tank 13 do. By this repetition, the thinning treatment liquid 9 circulates between the dip tank 10 and the thinning treatment liquid storage tank 13.

In the present invention, in order to suppress adhesion of bubbles to the resist layer of the substrate 8, the filtration section 24 is provided in the thin-film processing liquid inlet port, and the upper surface side of the filtration section 24 is shielded . Fig. 2 is an enlarged perspective view showing an example of a thinning treatment liquid inlet in the thinning apparatus of the present invention. Fig. At the end of the thinning process liquid supply pipe 20 in the thinning process liquid storage tank 13, a filtration unit 24 which is a rectangular parallelepiped is provided. The upper surface of the filtration part 24 is a shielded area (shielded area) 25, and the thinned solution 9 can not be sucked from the shielded area 25. The surface other than the upper surface of the filtration part 24 is composed of a porous plate or a mesh plate, and the thinning treatment liquid 9 can be passed through. By using a porous plate or a mesh plate other than the shielding region 25, it is possible to remove foreign matters in the thinning treatment liquid 9. [ In the thinning treatment liquid storage tank 13, the bubbles 15 are gradually floated to the liquid surface, so that a large amount of bubbles 15 are contained in the upper portion of the thinning liquid 9. Therefore, if the upper surface side of the filtration part 24 is shielded, the amount of the bubbles 15 that are sucked into the thinning processing solution suction port and transferred to the dip tank can be reduced. Even if the filtration portion 24 is in contact with the bottom of the thinning treatment liquid storage tank 13, a sufficient amount of the thinning treatment liquid 9 can be supplied to the surface of the filtration portion 24, (Fig. 1 (A)). Alternatively, the filtration section 24 may be separated from the bottom of the thinning treatment liquid storage tank 13 (Fig. 1 (B)). The position of the filtration part 24 in the thinning treatment liquid storage tank 13 may be the end or the vicinity of the center, but in order to uniformly circulate the thinning treatment liquid 9 in the thinning treatment liquid storage tank 13 , And the center is preferable.

Figs. 3 and 4 are enlarged perspective views showing another example of the thin-film processing solution inlet in the thinning apparatus of the present invention. Fig. The filtration unit 24 in Fig. 3 is a hexagonal column, and the filtration unit 24 in Fig. 4 is a cylinder. The shape of the filtration portion 24 is not limited to a rectangular parallelepiped, a hexagonal column, and a cylindrical column, and may be a polygonal column other than a hexagonal column, an elliptic column, a spherical shape, a semi-spherical shape, or a main shape.

Fig. 5 is a schematic plan view of the thinning treatment liquid inlet of Fig. 3 viewed from above. Fig. The ratio of the area of the shielding region 25 to the area of the filter portion 24 viewed from above is preferably 0.25 or more and 1 or less, more preferably 0.35 or more and 1 or less, still more preferably 0.45 or more and 1 or less. When the ratio of the area of the shielding region 25 to the area of the filtration portion 24 is less than 0.25, the bubble suppression effect may be excessively low.

As the material of the filtration part 24, various materials resistant to the thinning treatment liquid 9 can be used. Specific examples thereof include synthetic resins such as polyethylene, polypropylene, rigid polyvinyl chloride, acrylonitrile-butadiene-styrene (ABS) resin and polystyrene resin, fiber reinforced plastics such as glass fiber reinforced polypropylene and glass fiber- Titanium, Hastelloy (registered trademark), and the like can be used. The thinning treatment liquid inlet may be one or more than one.

In the present invention, the bubble suppression device described in Japanese Utility Model Registration No. 3182371 can be used in combination. 8) provided between the transfer roll pair 12 and the thin-film processing solution supply port 11 for supplying the thinning process liquid 9 to the dip tank 10, The bubble induction plates 18 and 19 (FIG. 8) provided in the thinning treatment liquid storage tank 13 and the number of times provided below the liquid level of the thinning treatment liquid 9 in the thinning treatment liquid storage tank 13 The ultrasonic wave generating apparatus provided in the tube outlet 22 (Fig. 8), the dip tank 10 or the thinning processing liquid storage tank 13, the ultrasonic wave generating apparatus disposed in a position lower than the surface of the thinning liquid 9 in the dip tank 10 And a thinning treatment liquid jetted out through the nozzle.

The temperature of the thinning treatment liquid 9 can be controlled by a heating heater provided in the thinning treatment liquid storage tank 13, a cooling tube circulating the cooling water, and the like. The temperature control thermometer is preferably provided not only in the thinning treatment liquid storage tank 13 but also in the dip tank 10 so that the temperature of the thinning treatment liquid 9 in the circulation path is kept constant. The size of the dip tank 10 is not particularly limited as long as the substrate 8 having the resist layer formed thereon by the transport roll pairs 12 is transported to be thinned so that the resist layer can contact the thinning treatment liquid. . The shape and size of the thinning treatment liquid recovery tank 30 need only be capable of recovering the overflow of the thinning treatment liquid 9 from the dip tank 10 and can be freely determined.

The shape and material of the pair of transport rolls 12 are not particularly limited as long as the substrate on which the resist layer is formed can be transported. For example, polyolefin (polypropylene, olefinic thermoplastic elastomer (THERMORUN, registered trademark) Etc.), polyvinyl chloride, fluorine resin (Teflon (registered trademark), etc.) can be used. The mounting position and the number of pairs of transport rolls 12 can be set so that the substrate 8 on which the resist layer is formed can be transported The present invention is not limited thereto.

The material used for the thinning device of the resist layer is not particularly limited. In the parts contacting with the thinning treatment liquid 9, various materials resistant to the thinning treatment liquid 9 can be used.

The photocurable resin component in the resist layer is micellized by the thinning treatment liquid 9 in the micellization treatment (thinning treatment) of the thinning process of the resist layer, The micelle is removed by an aqueous solution or water containing a pH of from 5 to 9 containing an alkaline compound that is leaner, and the resist layer is thinned. If the pH of the aqueous solution is less than 5, the resist layer components dissolved in the aqueous solution aggregate and become insoluble sludge, which may adhere to the surface of the resist layer after thinning. On the other hand, if the pH of the aqueous solution exceeds 9, the dissolution diffusion of the resist layer is promoted, and treatment unevenness easily occurs in the surface, which is not preferable. The pH of the aqueous solution can be adjusted by using sulfuric acid, phosphoric acid, hydrochloric acid or the like. As the method of supplying the aqueous solution having the pH of 5 to 9, the spray method is most preferable in terms of the dissolution diffusion rate of the resist layer and the uniformity of the liquid supply. The spray pressure is preferably 0.01 to 0.5 MPa, more preferably 0.02 to 0.3 MPa. The spraying method is preferably sprayed from a direction inclined with respect to a direction perpendicular to the surface of the resist layer in order to efficiently flow the solution on the surface of the resist layer.

After the micelles are removed by an aqueous solution having a pH of 5 to 9, furthermore, the surface of the resist layer and the remaining alkali aqueous solution, which can not be completely removed, are rinsed by washing with water. The spraying method is preferable in terms of the diffusion speed and the uniformity of the liquid supply.

In the drying treatment, it is possible to use both hot air drying and blowing air drying at room temperature. However, a large amount of air is blown by using an air blower, high pressure air is sprayed from the air slit nozzle onto the surface of the resist layer, Is preferable.

Example

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

(Example 1)

A substrate for a printed wiring board (insulating layer 1: glass base epoxy resin, metal layer 7: copper foil having an area of 510 mm x 340 mm, a thickness of copper foil of 12 mu m, a substrate thickness of 0.2 mm, MITSUBISHI GAS CHEMICAL COMPANY, INC (Manufactured by Hitachi Chemical Co., Ltd., trade name: RY3625, thickness: 25 占 퐉) was thermally bonded to the substrate using a laminator for dry film resist, manufactured by Hitachi Chemical Co., Ltd., trade name: CCL-E170) , And a resist layer 3 were formed.

Next, after the carrier film of the dry film resist was peeled off, a 12% by mass sodium carbonate aqueous solution (liquid temperature 25 ° C) was used as the thinning treatment liquid 9, and the length in the transport direction was 500 mm, the width 750 mm, A recovery pipe 21 for guiding the thinning treatment liquid 9 overflowed from the dip tank 10 into the thinning treatment liquid storage tank 13 from the thinned treatment liquid recovery tank 30, A thinning treatment liquid storage tank 13 having a length of 700 mm in the conveying direction, a width of 950 mm and a depth of 600 mm and a recovery pipe outlet (at a height of 350 mm from the bottom of the thinning treatment liquid storage tank 13 A thin film forming process liquid supply pipe 20 introduced along the bottom of the thin film forming process liquid storage tank 13 from the side of the thin film forming process liquid storage tank 13 and a thin film forming process liquid supply pipe 20 provided at the end of the thin film forming process liquid supply pipe 20, The filtration unit 24, which is the inlet for the treatment liquid, The thinning treatment liquid 9 is supplied from the thinning treatment liquid storage tank 13 to the dip tank 10 by the thinning treatment liquid supply pump 14 using the thinning apparatus (Fig. 1 (B) Thereby thinning the resist layer 3 while circulating the thinning treatment liquid 9. The height of the surface 23 of the thinning treatment liquid in the thinning treatment liquid storage tank 13 when the thinning treatment liquid supply pump 14 is operated is set at 250 mm from the bottom surface of the thinning treatment liquid storage tank 13 Respectively. The thinning process liquid supply pipe 20 is a polyvinyl chloride pipe having a diameter of 20 mm and the filtration unit 24 is a rectangular parallelepiped having a length of 20 cm, a width of 30 cm and a height of 10 cm, which is made of a punching metal having many holes having a diameter of 5 mm . The entire upper surface of the filtration part 24 is shielded by a rectangular (non-porous) polyvinyl chloride plate having a length of 20 cm and a width of 30 cm. The ratio of the area of the shielded area 25 to the area of the filtration part 24 seen from the top is 1.

The substrate 8 is conveyed by the conveying roll pairs 12 while being immersed in the thinning treatment liquid 9 for 28 seconds in the direction in which the resist layer 3 is located on the lower surface of the substrate 8, The thickness of the thinned portion of the resist layer 3 after the micelle removal treatment, the water washing treatment, and the drying treatment after measurement was 12 탆.

The surface of the thinned resist layer 3 was observed with an optical microscope, and as a result, it was confirmed that the surface was a smooth surface free from treatment unevenness.

(Comparative Example 1)

A thinning treatment liquid supply pipe 20 introduced at a height of 10 cm from the bottom of the thinning treatment liquid storage tank 13 from the side of the thinning treatment liquid storage tank 13 instead of the filtration unit 24, The resist layer 3 was thinned in the same manner as in Example 1 except that a thinning apparatus (Fig. 9) provided with a thinning treatment liquid inlet port 17 with an end portion 5 cm downward was used. The thickness of the thinned portion of the resist layer 3 was measured and found to be 12 占 퐉. As a result of observing the surface of the thinned resist layer 3 with an optical microscope, numerous unevenness in processing, which is thought to be caused by adhesion of bubbles, has occurred.

(Example 2)

A non-porous polyvinyl chloride plate for shielding the upper surface of the filtration part 24 was formed into a rectangular shape having a length of 5 cm and a width of 30 cm and the ratio of the area of the shielding area 25 to the area of the filtration part 24 0.25, the resist layer 3 was made thinner in the same manner as in Example 1. [ The thickness of the thinned portion of the resist layer 3 was measured and found to be 12 占 퐉. The surface of the thinned resist layer 3 was observed with an optical microscope, and as a result, unevenness in treatment, which is considered to be caused by adhesion of bubbles, occurred at two points.

(Example 3)

A non-porous polyvinyl chloride plate for shielding the upper surface of the filtration part 24 is formed into a rectangle having a length of 7 cm and a width of 30 cm and a ratio of the area of the shielded area 25 to the area of the filtration part 24 The resist layer 3 was thinned in the same manner as in Example 1, except that a thin film forming apparatus of 0.35 was used. The thickness of the thinned portion of the resist layer 3 was measured and found to be 12 占 퐉. The surface of the thinned resist layer 3 was observed with an optical microscope, and as a result, there was no treatment unevenness.

(Example 4)

A non-porous polyvinyl chloride plate for shielding the upper surface of the filtration part 24 is formed into a rectangular shape having a length of 9 cm and a width of 30 cm and a ratio of the area of the shielded area 25 to the area of the filtrated part 24 The resist layer 3 was thinned in the same manner as in Example 1, except that a thin film forming apparatus of 0.45 was used. The thickness of the thinned portion of the resist layer 3 was measured and found to be 12 占 퐉. The surface of the thinned resist layer 3 was observed with an optical microscope, and as a result, there was no treatment unevenness.

(Example 5)

A non-porous polyvinyl chloride plate for shielding the upper surface of the filtration part 24 was formed into a rectangle having a length of 16 cm and a width of 30 cm and a ratio of the area of the shielded area 25 to the area of the filtrated part 24 The resist layer 3 was thinned in the same manner as in Example 1 except that a thin film forming apparatus of 0.80 was used. The thickness of the thinned portion of the resist layer 3 was measured and found to be 12 占 퐉. The surface of the thinned resist layer 3 was observed with an optical microscope, and as a result, there was no treatment unevenness.

The apparatus for thinning a resist layer according to the present invention can be applied to the production of a circuit board in a printed wiring board or a lead frame or in the production of a package substrate having a connection pad for flip chip connection .

1: insulating layer
2: Conductor wiring
3: resist layer
4: Photomask
5: active ray
6: Connection pad
7: metal layer
8: substrate
9: Thinning treatment liquid
10: Deep bath
11: Thinning treatment liquid supply port
12: conveying roll pair
13: Thinning treatment liquid storage tank
14: Thinning treatment liquid supply pump
15: Bubble
16: bubble induction plate
17: Thinning treatment liquid inlet
18: bubble induction plate
19: bubble induction plate
20: thinning process liquid supply pipe
21: Recovery pipe
22: Return tube outlet
23: Liquid phase of thinning treatment liquid
24:
25: Shielding area
30: Thinning treatment liquid recovery tank

Claims (2)

In a thin film forming apparatus for a resist layer provided with a thinning processing unit,
Wherein the thinning treatment unit comprises a thinning treatment liquid storage tank for storing a thinning treatment liquid containing a thinning treatment liquid and an overflowed thinning treatment liquid overflowed from the dip tank, a thinning treatment liquid intake port formed in the thinning treatment liquid storage tank, And a thinning treatment liquid supply pump for supplying the thinning treatment liquid sucked from the thinning treatment liquid intake port to the dip tank,
Wherein the filtration section is provided in the thin-film processing liquid inlet port, and the upper surface side of the filtration section is shielded. The method according to claim 1,
Wherein the ratio of the area of the shielded area to the area of the filtration part viewed from above is 0.25 or more and 1 or less.

Images