JP2006210811A - Manufacturing method for printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a printed wiring board which has heat resistance sufficient to be adaptive to lead-free solder etc. , can be developed with a sodium carbonate solution etc. , and uses photo-solder resist that does not produce sludges in the developing tank. <P>SOLUTION: On a substrate which has a conductor pattern formed on one surface or both surfaces, a photo-solder resist layer is formed which contains, as principal component, alkali-soluble resin with a bisphenol fluorene skeleton, obtained by making a reactant of an epoxy compound, having a glycidyl ether group as a resin component and (meth)acrylic acid react, saturated dicarboxylic acid or its acid anhydride (a), and unsaturated tetracarboxylic acid or its acid dianhydride (b) react with each other within the range of 0.1 to 10 mol ratio a/b. Then development is carried out with a solution of 1 to 4 wt% sodium bicarbonate to form a pattern, and thus the printed wiring board is manufactured with a resist layer patterned by heat curing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a printed wiring board, and more particularly to a method for producing a printed wiring board capable of developing a photo solder resist with a weak alkaline aqueous solution such as a sodium carbonate aqueous solution.

  Conventionally, when soldering a printed wiring board, as a heat-resistant coating material that prevents solder from sticking to lands and conductor patterns other than lands necessary for soldering, or suppressing short-circuiting during soldering, A photo solder resist is often used as a material for maintaining insulation and protecting the conductor (Japanese Patent Laid-Open No. 61-243869). Here, an example of a general method for forming a photo solder resist will be described.

  First, a photo solder resist is coated on a substrate on which a circuit is formed on one side or both sides, and after drying, a negative film having a desired pattern is brought into close contact, and selectively exposed using an exposure machine. Thereafter, the unexposed portion is dissolved and developed using sodium carbonate or the like as a developer, and finally cured by heat or light. As a result, a printed wiring board on which a solder resist layer having a desired pattern for protecting a circuit is formed can be obtained.

JP 2003-113205 A

Patent Document 1 discloses a photosensitive insulating material for a printed wiring board for the purpose of obtaining electrical insulation reliability, and in the process of developing the photosensitive insulating material when manufacturing the printed wiring board. Examples of the alkaline aqueous solution to be used include sodium carbonate, potassium carbonate, potassium hydroxide, diethanolamine, tetramethylammonium hydroxide and the like. However, these developing solutions must be selected in accordance with the characteristics of the resin layer, and depending on the combination of the developing solution and the resin layer to be used, problems such as accumulation of sludge in a developing tank such as a developing machine arise. In some cases, it is necessary to select an appropriate combination of developer and resin layer.
The sludge here refers to agglomerates mainly of alkali-unnecessary components and compounds produced by deterioration of the developer as aggregates in the developer. When sludge is generated, it adheres to the bottom of the developing tank, the side surface, or the nozzle, causing problems such as deterioration of the developing machine and poor development.

In the production of printed wiring boards, as an alkaline aqueous solution used in the development process of a photo solder resist, an inorganic weak alkaline solution such as sodium carbonate is widely known because of its influence on the environment, and an organic solution such as tetraammonium hydroxide is used. Strong alkaline solutions of the system are gradually being used, although the performance is superior.
On the other hand, solder heat resistance is one of the basic performances required for solder resists. In recent years, the level of requirements has become stricter due to the widespread use of lead-free solder, and there is a need for solder resist materials with higher heat resistance. Patent Document 1 describes a photo solder resist having excellent adhesion and high heat resistance. However, the photo solder resist having a resin structure excellent in heat resistance as disclosed in practice has a problem that an organic alkali such as a tetramethylammonium hydride solution has to be used.

  Accordingly, it is an object of the present invention to have a heat resistance capable of dealing with lead-free solder and the like in the production of a printed wiring board, and can be developed with an inorganic alkali such as a sodium carbonate aqueous solution. Another object of the present invention is to provide a method of manufacturing a printed wiring board using a photo solder resist that does not generate sludge.

  In order to solve the above-mentioned problems, the present inventors have reacted a reaction product of an aromatic epoxy compound derived from bisphenols with (meth) acrylic acid, and a) a saturated dicarboxylic acid or an acid anhydride thereof and b). If a solder resist containing an alkali-soluble component having a bisphenolfluorene skeleton obtained by reacting with an unsaturated tetracarboxylic acid or its acid dihydrate is used, and development is performed using an aqueous sodium carbonate solution, the above problem The present invention has been completed.

  That is, in the present invention, a photo solder resist film layer is formed on a substrate having a conductor pattern formed on one side or both sides, exposed to a predetermined pattern, then developed with an alkaline aqueous solution to form a pattern, and then thermally cured. In the method for producing a printed wiring board having a patterned resist layer, as a resin component in the resin composition constituting the photo solder resist, a reaction product of an epoxy compound having a glycidyl ether group and (meth) acrylic acid A) a bisphenolfluorene skeleton obtained by reacting a saturated dicarboxylic acid or acid anhydride thereof with b) an unsaturated tetracarboxylic acid or acid dihydrate thereof in a range where the molar ratio of a / b is 0.1 to 10. Printed wiring comprising an alkali-soluble resin having a main component as a main component and a developer of 1 to 4% by weight of an aqueous sodium carbonate solution It is a method of manufacture.

  As a resin component in the resin composition constituting the photo solder resist used in the present invention, an alkali-soluble resin having a bisphenolfluorene skeleton (hereinafter also referred to as component (A)) is contained as a main component of the resin component. As the alkali-soluble resin having a bisphenolfluorene skeleton, those represented by the following formula (1) are suitable.

式（I）において、Ｒ₁、Ｒ2、Ｒ₃及びＲ₄は独立に、水素原子、炭素数１〜５のアルキル基、ハロゲン原子又はフェニル基を示し、Ｒ₅は水素原子又はメチル基を示す。また、Aは、下記式(II)で表される9,9-フルオレニル基を示し、Xは4価の不飽和カルボン酸残基を示し、Y₁及びY₂は独立に水素原子又は-OC-Z-COOHで示される飽和カルボン酸残基を示し、nは1〜20の数を示す。

In the formula (I), R ₁ , R 2, R ₃ and R ₄ independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom or a phenyl group, and R ₅ represents a hydrogen atom or a methyl group. . A represents a 9,9-fluorenyl group represented by the following formula (II), X represents a tetravalent unsaturated carboxylic acid residue, and Y ₁ and Y ₂ independently represent a hydrogen atom or —OC A saturated carboxylic acid residue represented by -Z-COOH is represented, and n represents a number of 1 to 20.

  The alkali-soluble resin includes a reaction product of an epoxy compound having two glycidyl ether groups derived from an intermediate 9,9-bisphenolfluorene and (meth) acrylic acid, and a) a saturated dicarboxylic acid or an acid anhydride thereof. And b) obtained by reacting with an unsaturated tetracarboxylic acid or its acid dianhydride. Here, the molar ratio a / b between a) and b) is in the range of 0.1-10.

  The alkali-soluble resin can be obtained by reacting a diol compound obtained by the reaction of a bisphenolfluorene skeleton type epoxy compound and an unsaturated monocarboxylic acid with a saturated or unsaturated polybasic acid anhydride, and has a weight average molecular weight of 3000. Those having an acid value of 50 to 200 mgKOH / g are preferred. In order to obtain an alkali-soluble resin, the diol compound reacted with acid dianhydride has the same reactivity between the two hydroxy groups in the molecule and acid dianhydride from the viewpoint of increasing the molecular weight during the polymerization reaction. Those having a symmetric molecular structure are preferred.

The reaction of the epoxy (meth) acrylate with the polyvalent carboxylic acid or acid anhydride thereof can be performed by a known method.
Further, for the saturated dicarboxylic acid or acid anhydride used, for example, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, malic acid, tartaric acid, diglycolic acid, Examples include saturated linear hydrocarbon compounds such as succinic anhydride, and alicyclic dicarboxylic acids such as hexahydrophthalic acid, cyclobutane dicarboxylic acid, cyclopentane dicarboxylic acid, norbornane dicarboxylic acid, and acid anhydrides thereof. The Among these dicarboxylic acids or anhydrides thereof, succinic anhydride is preferable.
Examples of the unsaturated tetracarboxylic acid or acid anhydride thereof include pyromellitic acid, benzophenone tetracarboxylic acid, biphenyl tetracarboxylic acid, and biphenyl ether tetracarboxylic acid. In addition, aromatic carboxylic acid is 1 type of unsaturated carboxylic acid.
The specification ratio of the above-mentioned a) saturated carboxylic acids and b) unsaturated carboxylic acids is in the range of 0.1 to 10, preferably 0.2 to 1, as the molar ratio of a / b. As the use ratio, a ratio suitable for the effects of optimum molecular weight, alkali developability, light transmittance, heat resistance, solvent resistance, and pattern shape can be selected.

  The resin composition for forming a photo solder resist includes an unsaturated compound (hereinafter referred to as (B) component) containing two or more photopolymerizable ethylenic groups in one molecule together with the alkali-soluble resin (A). It is desirable to use. In particular, in the case where excellent photocurability in addition to alkali solubility, that is, high sensitivity is desired as a solder resist, two or more polymerizable double bonds (bifunctional) per molecule, more preferably It is preferable to blend a resin or monomer having three or more. The amount of component (B) used is preferably in the range of 5 to 50 parts by weight with respect to 100 parts by weight of the alkali-soluble resin component (A).

  In addition to the above components (A) and (B), an epoxy resin (hereinafter also referred to as (C) component) is blended in the resin composition forming the photo solder resist as a part of its constituent components. Can do. Examples of the epoxy resin include phenol novolac type epoxy resins, cresol novolac type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, biphenyl type epoxy resins, and alicyclic epoxy resins. , Phenyl glycidyl ether, p-butylphenol glycidyl ether, triglycidyl isocyanurate, diglycidyl isocyanurate, allyl glycidyl ether, compounds having at least one epoxy group such as glycidyl methacrylate, and the like.

  When the matrix resin is an alkali-soluble resin, the amount of the epoxy resin is preferably blended within a range in which the alkali-soluble property is maintained, and is 5% relative to 100 parts by weight of the component (A). It is preferable to blend in the range of ~ 50 parts by weight.

  A photopolymerization initiator (hereinafter also referred to as “component (D)”) can be blended with the resin composition forming the photo solder resist. Examples of the photopolymerization initiator include radical generating types such as Mihler's ketone, and cation generating types such as triarylsulfonium salts and diaryliodonium salts. These may be used alone or in combination of two or more. The photopolymerization initiator is used in an amount of 0.1 to 15 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the total of the components (A) and (B). If it exceeds 15 parts by weight, the light absorption ratio increases, and light may not penetrate to the bottom.

  Further, when such a photopolymerization initiator is blended, for example, N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, triethanolamine, triethylamine and the like are known. In this case, these photosensitizers can be used alone or in combination of two or more. The photosensitizer is preferably used in the range of 10 to 70% by weight based on the photopolymerization initiator.

  In addition, the solder resist used in the present invention may be made of an inorganic filler such as silica, alumina, titanium oxide, boron nitride, or the like for the purpose of reducing the thermal expansion of the cured product and improving the elastic modulus and hygroscopicity. You may mix | blend 1 type, or 2 or more types of organic fillers, such as coalescence. Moreover, additives, such as an epoxy resin hardening accelerator, a polymerization inhibitor, a plasticizer, a leveling agent, an antifoaming agent, can be mix | blended with the soldering resist used for this invention as needed.

  Examples of the epoxy resin curing accelerator include amine compounds, imidazole compounds, carboxylic acids, phenols, quaternary ammonium salts, and methylol group-containing compounds. Examples of the thermal polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert-butylcatechol, phenothiazine and the like. Examples of the plasticizer include dibutyl phthalate, dioctyl phthalate, tricresyl and the like. Examples of the antifoaming agent and leveling agent include silicon-based, fluorine-based, and acrylic compounds.

  If necessary, the resin composition constituting the solder resist can be blended with a solvent to adjust its viscosity. The solvent is preferably one that dissolves the resin composition and does not react with the resin and additives of the resin composition, and is not particularly limited as long as these conditions are satisfied.

The resin composition used in the present invention can be produced, for example, by the following method.
That is, the alkali-soluble resin (A), an unsaturated compound (B) containing two or more photopolymerizable ethylenic groups in one molecule, an epoxy resin (C), a photopolymerization initiator (D), and other necessary Additives are added accordingly, a solvent is added to obtain an appropriate viscosity, and the mixture is stirred for an appropriate time with a stirrer equipped with a stirring blade to obtain a resin composition containing the above components. In this case, when a filler is added, the resin component in which the filler is well dispersed can be obtained by adjusting the stirring speed and stirring time. In this case, in order to make the particle size range uniform, it is preferable to perform filtration using a filter in an appropriate range after mixing with the resin. The range of the filter used for filtration is preferably in the range of 0.5 to 5 μm. If the diameter of the filter is smaller than 0.5 μm, not only the secondary aggregation is subdivided but also the filtration resistance is increased, which is not preferable. If it is larger than 5 μm, secondary aggregates remain and mechanical properties are lowered, which is not preferable.

  The method for using this resin composition is as follows: 1) After preparing as a varnish, this is applied to a substrate on which a conductor pattern as a target object is formed and dried to form a solder resist layer. And 2) a method in which a solution of the resin composition is previously applied onto a support substrate to be peeled and removed later, a solvent-removed (dry film) laminate is formed, and the laminate is laminated on a substrate.

  When used as a varnish, for example, a resin composition prepared in a varnish form is applied onto a substrate by means of spin coating, curtain coating or the like, and a pattern is formed by drying, exposure and development, followed by thermosetting Is mentioned. In addition, when a laminate is used in advance, a method in which the resin composition is uniformly applied onto a supporting substrate, the solvent is dried by hot air drying or the like, and then wound up with a protective film as necessary. Is exemplified. The drying temperature is preferably 80 ° C. to 120 ° C. in consideration of the thermal stability and productivity of the unsaturated compound. In addition, it is desirable to raise the temperature in multiple stages in order to prevent skinning and foaming of the coating film surface during drying.

  Although the organic solvent often remains in the resin layer after drying, the content is desirably 15% by weight or less, preferably 10% by weight or less. The content referred to here is a weight% that is reduced when the weight of the resin layer after drying is 100% by weight and the absolute dry weight is obtained after drying again at 200 ° C. for 30 minutes. If this exceeds 15% by weight, cold flow tends to occur.

  The thickness of the resin layer after drying varies depending on the application, but is 5 to 100 μm for circuit boards. The thinner the resin layer is, the higher the resolution is, and it is possible to form vias and fine lines equal to or less than the thickness of the resin layer.

  As a support base material (film) which apply | coats a resin composition, the transparent thing which permeate | transmits active light is desirable. Examples of the support layer that transmits active light include known polyethylene terephthalate films, polyacrylonitrile films, optical polypropylene films, and cellulose derivative films. The thinner the film, the more advantageous in terms of image forming property and economy, but a film having a thickness of 10 to 30 μm is generally used because the strength needs to be maintained. Moreover, in this laminated body for solder resists, a protective film can be laminated on the surface of the resin composition that is not in contact with the support base, if necessary. It is desirable that this protective film has sufficiently smaller adhesion with the resin composition than the support film and can be easily peeled off. An example of such a film is a polyethylene film.

  Next, an example of the development process in creating a circuit board when using a laminate in which a base material and a protective film are provided on a resin composition that becomes a solder resist will be described. When there is a protective film, first, the protective film is peeled off, and then the resin composition to be a solder resist is heat-pressed and laminated on a substrate having a conductor pattern formed on one or both sides with a hot roll laminator or the like. The heating temperature at this time is 70-120 degreeC, Preferably it is 80-110 degreeC. When the temperature is lower than 70 ° C., the adhesion to the substrate is inferior, and when the temperature is higher than 120 ° C., the resin component protrudes from the side edge and the film thickness accuracy is liable to be impaired. Next, the supporting base material is peeled off, and image exposure is performed with active light through a mask to prepare a substrate before development. In the method of preparing a varnish and then applying it to a substrate and drying it to form a solder resist layer, a process of forming an substrate before development by image exposure with active light through a mask is performed. Is called.

In the development process using the substrate, a sodium carbonate aqueous solution is used as a developer, and unexposed portions are removed for patterning. For example, when a 1% Na ₂ CO ₃ aqueous solution is used as a developing solution in the developing step, the temperature of the developing solution is in the range of 25 to 35 ° C., preferably 28 to 35 ° C. When the temperature is lower than 25 ° C., the solubility of the unexposed resist in the developer is lowered, which causes development defects such as scum. On the other hand, when the temperature exceeds 35 ° C., the solubility of the resist in the developer increases, and the exposed area deteriorates.

  The pressure of the developer against the substrate is preferably 0.2 to 0.3 MPa. When the pressure is less than 0.2 MPa, unexposed portions remain on the substrate and development failure occurs. If the pressure exceeds 0.3 MPa, there is a high possibility that the resist line patterned by high water pressure will blow away. The development time is 40 to 150 seconds, preferably 60 to 150 seconds. If the development time is too short, it is difficult to open a small via, and it is likely to cause a development failure. If the development time is long, it is easy to form a small via, but the exposed portion deteriorates and undercuts. Etc. occur.

  As a process after development, it is cured by heat to form a solder resist layer, but heat curing in the range of 150 to 200 ° C. is preferable in order to impart heat resistance, hardness, weather resistance and the like of the solder resist.

The method for developing a printed wiring board according to the present invention uses a solder resist mainly composed of an alkali-soluble resin having a bisphenolfluorene skeleton obtained by reacting an acid anhydride with a saturated dicarboxylic acid or an acid anhydride thereof. Even if a 1% Na ₂ CO ₃ aqueous solution is used, the development time can be shortened because the break point becomes faster. Moreover, by repeating the developing process, sludge generated in the developing tank in the automatic developing apparatus is dispersed in the entire liquid, and the particle diameter is reduced, thereby reducing the resulting sludge. Since these are good in mass productivity and can suppress deterioration of the developing machine in the development process of the printed wiring board, the industrial utility value is extremely high.

Hereinafter, the present invention will be described in detail with reference to synthesis examples, examples, and comparative examples. Moreover, evaluation of the alkali-soluble resin in the following synthesis examples is as follows unless otherwise noted.
Solid content concentration: About 1 g of the resin composition solution was impregnated into a glass filter W ₀ (g), weighed W ₁ (g), and heated at 160 ° C. for 2 hours, from weight W 2 (g) It calculated | required by following Formula.
Solid content concentration (% by weight) = 100 × (W ₂ −W ₀ ) / (W ₁ −W ₀ )
Acid value: The resin composition was dissolved in dioxane, and titrated with a 1/10 N-KOH aqueous solution using phenolphthalein as an indicator.
Molecular weight: Determined by gel permeation chromatography (GPC) equipped with an RI (refractive index) detector using tetrahydrofuran as a developing solvent. The molecular weight shown is the polystyrene equivalent weight average molecular weight (Mw) of the carboxyl group-containing copolymer portion excluding the unreacted raw material.

The abbreviations used in the synthesis examples are as follows.
FHPA: Equivalent reaction product of fluorene bisphenol type epoxy resin and acrylic acid (ASF-400 manufactured by Nippon Steel Chemical Co., Ltd .; in Formula 1, A is a 9,9-fluorenyl group, and R _{1 to} R ₅ are either Is also a hydrogen atom, acid value 1.28mgKOH / g, epoxy equivalent 21300)
BPDA: Biphenyltetracarboxylic dianhydride
SA: Succinic anhydride
THPA: Tetrahydrophthalic anhydride
PGMEA: Propylene glycol monomethyl ether acetate
TPP: Triphenylphosphine
BHT: 2,6-ditertiary butyl-P-cresol

Synthesis example 1
In a 500 mL four-necked flask equipped with a reflux condenser, 238.0 g of a 50% PGMEA solution of FHPA, 9.81 g of SA, 28.8 g of BPDA, 0.456 g of TPP, 0.0365 g of BHT and 10.36 g of PGMEA were charged, and 120 to 125 under a nitrogen atmosphere The mixture was heated and stirred for 1 hour in an oil bath at ° C, and then stirred for 6 hours in an oil bath at 75 to 80 ° C. The solid content of the obtained resin was 55 wt%, the acid value (resin solid content conversion) was 112.2 mgKOH / g, the area of alkali-soluble resin (A) -1 in the resin solution by GPC analysis was 91%, and Mw was 2800. there were.

Synthesis example 2
In a 500 mL four-necked flask equipped with a reflux condenser, 238.0 g of 50% PHPEA solution of FHPA, 14.9 g of SA, 21.3 g of BPDA, 0.456 g of TPP, 0.0365 g of BHT, and 8.4 g of PGMEA were charged. Resin (A) -2 was synthesized. The solid content of the obtained resin is 55.4 wt%, the acid value (resin solid content conversion) is 120.0 mgKOH / g, the area of the alkali-soluble resin (A) -2 in the resin solution by GPC analysis is 90%, and Mw is 2400. Met.

Synthesis example 3
In a 500 mL four-necked flask equipped with a reflux condenser, 238.0 g of a 50% PHPEA solution of FHPA, 14.9 g of THPA, 28.8 g of BPDA, 0.456 g of TPP, 0.0365 g of BHT, and 14.8 g of PGMEA were charged. Resin (B) was synthesized. The solid content of the obtained resin was 56.5 wt%, the acid value (resin solid content conversion) was 100.0 mgKOH / g, the area of the alkali-soluble resin (A) -3 in the resin solution by GPC analysis was 90%, and Mw was 4800. Met.

Example 1
30 parts by weight (total of about 55 parts by weight) of the alkali-soluble resin (A) -1 obtained in Synthesis Example 1 in terms of resin solids, trimethylolpropane triacrylate (manufactured by Nippon Kayaku Co., Ltd., TMPTA) 12 parts by weight, crosslinked rubber having an average particle size of 0.07 μm as a crosslinked elastic polymer (15% solution of XSR-91-MEK dispersion of JSR Corporation) 7 parts by weight in terms of solid content, 2-methyl-1 as a photoinitiator -[4- (Methylthio) phenyl] -2-monoforinopropane-1 (Chiba Specialty Chemicals Co. Ltd., Irgacure 907) 2 parts by weight, epoxy resin (Japan Epoxy Resin Co., Ltd., YX4000HK) 12 parts by weight , 0.04 parts by weight of a sensitizer (Hodogaya Chemical Co., Ltd., EABF), 1.6 parts by weight of other additives, and 100 parts by weight of PGMEA are mixed, and a stirring blade with a wind speed of 0.5 m / sec at the blade tip is used. After preparing the resin composition solution by dispersing the solvent for a period of time, it is filtered under pressure using a filter with a pore system of 1 μm. A resin composition solution was prepared.

  The resin composition solution prepared as described above was applied to a polyester film having a thickness of 25 μm and a width of 600 mm by a die coater, and dried in a continuous four-stage drying oven set at a temperature range of 80 to 120 ° C., with a residual solvent ratio of 2.3. %, A resin composition layer having a thickness of 35 μm was obtained. A 60 μm thick polyethylene protective film was laminated on the dried coating film to prepare a dry film laminate.

After blackening the conductor circuit pattern on a commercially available 0.8mm thick glass epoxy substrate, the protective film is peeled off from the dry film laminate, the resin composition layer surface is 80 ° C, transfer pressure is 5kgf / cm ² G, transfer speed After laminating at 25 cm / min, the polyester film was cooled and peeled to obtain a substrate on which a 35 μm thick solder resist layer was formed on the conductor circuit pattern.

Next, UV light was applied under the condition of 250 mJ / cm ^{2 with} an ultra-high pressure mercury lamp (Hitech, illuminance 11 mJ / cm ² , I-line standard) through a negative mask with a via hole pattern on the solder resist layer. Exposure by irradiation was performed.

Using the exposed substrate as a test piece, a horizontal automatic processor (YAMAGATA MACHINERY EX-25D) is filled with a 1% Na ₂ CO ₃ aqueous solution as a developer, temperature 30 ± 1 ° C, pressure 0.2 MPa, time 40 to 150 seconds. Development was performed under the conditions of

The following evaluation was performed under the development conditions described above.
Resolution evaluation
A substrate exposed with a negative mask provided with a via hole pattern of 10 to 100 μm was developed with a horizontal automatic developing machine under the above development conditions, and the minimum via diameter at each development time was measured. Here, “×” indicates that the via could not be formed, and although the via could be formed, and “Δ” was added and evaluated when a part of the residue remained. The results are summarized in Table 1.
In Example 1 using succinic anhydride, vias could be formed up to 75 μm with a development time of 40 seconds and up to 60 μm between 60 and 150 seconds.

Sludge evaluation A resin composition (abbreviated as a solder resist or a resist) containing an alkali-soluble resin was laminated on a glass substrate whose weight had been measured in advance, and the weight of the applied resist was measured. Then, adjust the weight ratio of the measured solder resist and 1% Na ₂ CO ₃ aqueous solution to 1: 300, dissolve the resist in a container containing 1% Na ₂ CO ₃ aqueous solution, and stir for about 15 minutes. After that, a small amount was collected in a sample bottle, and the particle size, dispersion, and sedimentation of the sludge after standing for one day were observed and evaluated. Regarding the evaluation of the sludge, in the case of the solder resist containing the alkali-soluble resin (A) -1, the solder resist component was uniformly dispersed throughout the developer, the sludge particle size was small, and the sediment component was very small.

Evaluation of Break Point The substrate after lamination was developed with the horizontal automatic developing machine, and observed from the top of the developing machine to measure the time for all the solder resist to flow down from the substrate. The results are summarized in Table 2. When SA is used as an acid anhydride, the break point is faster than that using conventional THPA.

Solder heat resistance evaluation After laminating a solder resist film on a glass epoxy substrate and exposing it to ultraviolet rays through a predetermined negative mask, it was developed by the horizontal automatic processor above, at 180 ° C for 90 minutes. In accordance with the test method of JIS C-6481, the test piece cured with JIS C-6481 is immersed in a solder bath at 260 ° C for 30 seconds, and the peeling test with a cellophane tape is taken as one cycle, and this is repeated 1-3 times. The state was visually observed and evaluated according to the following criteria. The results are summarized in Table 2.
A: No abnormality in the coating film even after 3 cycles. O: A slight change is observed in the coating after 3 cycles. Δ: A change is observed in the coating after 2 cycles.
×: Change is observed in the coating after one cycle is repeated

Example 2
The same procedure as in Example 1 was conducted except that the type of the alkali-soluble resin of the resin composition constituting the solder resist was changed from (A) -1 to (A) -2.
As a result of the evaluation, as in Example 1, all of the resolution, sludge evaluation, break point, and solder heat resistance were good results. In particular, in the evaluation of resolution and breakpoint, results were better than those of Example 1.

Comparative Example 1
The same procedure as in Example 1 was conducted except that the type of the alkali-soluble resin of the resin composition constituting the solder resist was changed from (A) -1 to (A) -3.
As a result of the evaluation, the solder heat resistance was good. However, in the evaluation of the resolution, since THPA was used as the acid anhydride, a via could not be formed at a development time of 40 to 60 seconds. Even if the time was increased to ˜150 seconds, a 100 μm via could not be formed completely. Also in the sludge evaluation, most of the components were not dispersed, the particle size of the sludge was extremely large, and most of the components were precipitated at the bottom.

Claims (2)

  After a photo solder resist film layer is formed on a substrate having a conductor pattern formed on one or both sides, it is exposed to a predetermined pattern, then developed with an aqueous alkaline developer to form a pattern, and is thermally cured and patterned. In the method for producing a printed wiring board having a resist layer, as a resin component in the resin composition constituting the photo solder resist, a reaction product of an epoxy compound having a glycidyl ether group and (meth) acrylic acid, a) Alkali having a bisphenolfluorene skeleton obtained by reacting a saturated dicarboxylic acid or acid anhydride thereof with b) an unsaturated tetracarboxylic acid or acid dianhydride in a range where the molar ratio of a / b is 0.1 to 10. A method for producing a printed wiring board comprising a soluble resin as a main component and a developer of 1 to 4% by weight of an aqueous sodium carbonate solution .   2. The method for producing a printed wiring board according to claim 1, wherein the development with the alkaline aqueous solution is performed at a liquid temperature of 30 ± 5 ° C. and a development time of 40 to 150 seconds.