JP5144323B2 - Method for manufacturing printed wiring board - Google Patents

Description

The invention, for example, relates to the production how the printed wiring board sheet required a flexible printed circuit board or flexible.

  Due to recent rapid advances in semiconductor components, electronic devices are becoming smaller, lighter, higher performance, and multifunctional, and the printed wiring board is becoming increasingly dense following these trends. In response to this high density, BGA (ball grid array), CSP (chip) instead of IC packages called QFP (quad flat pack package), SOP (small outline package), etc. An IC package called “Scale Package” has appeared. In such a package substrate or an in-vehicle printed wiring board, a solder resist is used to apply gold plating or the like to improve the reliability in the opening of the pad or the like on the package substrate connected to a semiconductor or the like. It is done.

  Furthermore, the core material used for such printed wiring boards and package substrates has been made thinner. For example, TAB (Tape Auto Bonding), T-BGA (Tape Ball Grid Array), T-CSP ( Tape chip scale package), UT-CSP (Ultra Thin Chip Scale Package), etc. have appeared. As described above, as the core material becomes thinner, warping due to curing shrinkage of the solder resist has been a problem. And when using the core material on such a tape, the roll-to-roll method is used, From the viewpoint of workability, reliability, film thickness accuracy, and smoothness, There is a demand for a dry film type solder resist. Such a dry film type solder resist is supplied in the form of a sheet or a roll, and it is necessary to contain a resin component excellent in flexibility and film-forming property in the resin composition due to the characteristics in the form.

  Examples of such resin components having excellent flexibility and film-forming properties include rubbery compounds, compounds having at least one carboxyl group and two hydroxyl groups in one molecule, diol compounds, and polyisocyanate compounds. And a photosensitive resin obtained by reacting a compound having a polymerizable unsaturated group, a carboxyl group and at least one hydroxyl group in one molecule with the terminal isocyanate compound of the reaction product (for example, Patent Document 1) To 4).

However, when such a resin component with excellent flexibility and film-forming property is blended with a solder resist, the developability is lowered, a development residue is generated in an opening such as a fine pad, and adhesion such as gold plating is deteriorated. As a result, there is a problem that yield and reliability are lowered. Therefore, there are cases where the residue can be removed by repeating development, but there is a problem that productivity is lowered.
JP 2003-192760 A (Claims etc.) JP 2002-162739 A (Claims etc.) JP 2004-252485 A (Claims etc.) JP 2007-71966 A (Claims etc.)

The present invention has been made in view of such problems of the prior art, and its purpose is to remove development residues and the like in openings such as fine pads formed in predetermined portions of an alkali development type solder resist layer. by suppressing, to improve plating adhesion, high reliability, is to provide a manufacturing how a printed wiring board capable of obtaining productivity.

  In order to achieve the above-mentioned problems, the development residue can be suppressed by changing the washing water after development in the case of using an alkali development type solder resist excellent in flexibility and film-forming properties used in UT-CSP. Found that is possible.

That is, according to one aspect of the present invention, a step of forming an alkali development type solder resist layer containing a carboxyl group-containing urethane (meth) acrylate compound as a carboxyl group-containing resin on a substrate surface on which a conductor pattern is formed ; The step of exposing the alkali development type solder resist layer with a predetermined opening pattern, the step of developing the alkali development type solder resist layer exposed in this step with a dilute alkaline aqueous solution , and the alkali development type solder resist developed in this step removing the development residue layer with wash water containing 30~1000ppm divalent metal ions, an alkali development type solder resist layer was removed development residue in this process and a step of thermally curing, the alkali To form an opening at a predetermined position of the development type solder resist layer And butterflies.

  The unit of metal ion concentration, ppm, is a unit representing the mg number of metal ions contained in 1 liter of sample.

  According to the present invention, development residue in an opening such as a fine pad formed at a predetermined portion of an alkali development type solder resist layer is suppressed, plating adhesion is improved, and high reliability and productivity are obtained. It is possible to provide a printed wiring board that can be used.

  Hereinafter, the best embodiment of the present invention will be described in detail.

  First, the printed wiring board manufacturing method of the present invention uses an alkali development type solder resist for a printed wiring board having a minute pad portion (for example, having an opening diameter of 20 to 100 μm) that is difficult to develop. It is suitably used when performing gold plating or the like.

  In the method for producing a printed wiring board of the present invention, an alkali development type solder resist layer containing a carboxyl group-containing urethane (meth) acrylate compound as a carboxyl group-containing resin is formed on a substrate surface on which a conductor pattern is formed. The development type solder resist layer is exposed with a predetermined opening pattern, developed with a dilute alkaline aqueous solution, washed with water containing 30 to 1000 ppm of divalent metal ions, and then thermally cured to obtain an alkali development type. An opening is formed at a predetermined position of the solder resist layer.

  That is, the manufacturing method of the printed wiring board of this embodiment has the following processes.

1. 1. forming an alkali developing type solder resist layer on the surface of the substrate on which the conductor pattern is formed; 2. Exposure step 3. Development step with dilute alkaline aqueous solution 4. A washing step using washing water containing 30 to 1000 ppm of divalent metal ions. 5. Rinse flush water (if necessary) Step of drying the substrate (generally, steps 3 to 6 are collectively referred to as a development step)
7). Through these steps, a printed wiring board having an alkali development type solder resist layer having an opening formed at a predetermined position is formed on the surface of the substrate on which the conductor pattern is formed.

  First, an alkali development type solder resist layer to be described later is formed on the surface of the substrate on which the conductor pattern is formed. The substrate on which the conductor pattern is formed in this step is, for example, paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven cloth epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, fluorine / polyethylene / PPO・ Copper-clad laminates for high-frequency circuits using cyanate esters, etc. Conductive for copper-grade laminates of all grades (FR-4, etc.), other polyimide films, PET films, glass substrates, ceramic substrates, wafer plates, etc. A substrate on which a pattern is formed can be mentioned.

  In the step of forming an alkali development type solder resist layer on such a substrate surface, there are a method using a liquid alkali development type solder resist and a method using a dry film having an alkali development type solder resist layer.

  When using a liquid alkali development type solder resist, the viscosity is adjusted to an application method with an organic solvent (D-1) described later, and a dip coating method, a flow coating method, The entire surface is applied by a roll coating method, bar coater method, screen printing method, curtain coating method or the like. Then, the organic solvent (D-1) contained in the alkali development type solder resist is volatilized and dried (temporarily dried) at a temperature of about 60 to 100 ° C. In this way, a tack-free alkali development type solder resist layer can be formed.

  The dry film having an alkali development type solder resist layer is a solder resist layer obtained by applying and drying a carrier film and an alkali development type solder resist on a carrier film (or cover film), and a solder resist layer. It has a peelable cover film.

  As the carrier film, a polyester film such as PET having a thickness of 10 to 150 μm, a polyimide film, or the like is used.

  The alkali development type solder resist layer is prepared by lowering the viscosity of the alkali development type solder resist with an organic solvent (D-1) so that it can be applied to a carrier film or a cover film, and then blade coater, lip coater, comma coater, film coater. For example, the film is uniformly applied to a carrier film (or cover film) with a thickness of 10 to 150 μm and dried.

  As the cover film, a polyethylene film, a polypropylene film, or the like can be used, but it is preferable that the adhesive force with the alkali development type solder resist layer is smaller than that of the carrier film.

  When using such a dry film of an alkali development type solder resist, the cover film is peeled off, and the alkali development type solder resist layer on the carrier film is overlaid on the substrate on which the conductor pattern is formed. Then, by laminating using a laminator or the like, an alkali development type solder resist layer can be formed on the substrate on which the conductor pattern is formed. At this time, the carrier film may be peeled off either before exposure or after exposure. Lamination is performed by a heating laminator, usually at 60 to 110 ° C. and at 0.4 MPa or more. At this time, generation of voids can be suppressed by using a vacuum laminator.

  Next, the alkali development type solder resist layer thus formed is exposed with a predetermined opening pattern. In this exposure process, a contact or non-contact exposure machine using a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp or a metal halide lamp is generally used as an active energy ray irradiation light source. Furthermore, a laser direct imaging apparatus using laser light can be used.

  The alkali development type solder resist layer thus exposed is developed using a dilute alkaline aqueous solution as a developer. In this development step, a dipping method, a shower method, a spray method, or the like can be used, but it is preferable to use a spray method in consideration of a subsequent water washing step.

  As the developer, for example, a dilute alkaline aqueous solution containing a monovalent alkali metal salt or ammonium salt such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines is used. can do.

  The alkali development type solder resist layer just developed in this way is washed with water containing 30 to 1000 ppm of divalent metal ions.

Examples of the divalent metal ions contained in the washing water used in this washing step include calcium ions (Ca ²⁺ ), magnesium ions (Mg ²⁺ ), strontium ions (Sr ²⁺ ), barium ions (Ba ²⁺ ) and the like. . As these metal ions, those having no adverse effect on the insulating properties of the printed wiring board are preferably used, and calcium ions and magnesium ions are particularly preferable.

  Examples of compounds containing these divalent metal ions include chlorides, hydroxides, sulfates, phosphates, nitrates, acetates, etc., but chlorides and salts that do not adversely affect the printed wiring board. Hydroxides are preferably used.

The concentration of these divalent metal ions needs to be 30 to 1000 ppm. When the concentration of the divalent metal ion is less than 30 ppm, the effect of removing the development residue of the alkali development type solder resist is low, and the development residue is generated. On the other hand, when it exceeds 1000 ppm, the agglomeration of the alkali development type solder resist dissolved in a minute amount in the washing water occurs and reattaches to the pad portion or the like. Preferably, it is 50-1000 ppm. Incidentally, strontium ions ^{(Sr 2+)} as divalent metal ions, in the case of using barium ion ^{(Ba 2+),} and more preferably 100 to 1000 ppm.

  The concentration of these divalent metal ions can be managed by measurement using atomic absorption spectrophotometry, inductively coupled plasma emission spectrometry (ICP method), ion chromatography, or the like. A simple water quality test kit can also be used.

  By providing such a washing step, it is possible to reduce development residues. The reason is considered as follows.

  An alkali development type solder resist containing a carboxyl group-containing urethane (meth) acrylate compound excellent in flexibility and film-forming property is hardly dissolved and becomes an alkali metal salt when developed with a dilute alkaline aqueous solution such as sodium carbonate. . Then, since the alkali metal salt is sticky due to the action of water, it is considered that a development residue is generated without being removed at the minute opening where the spray pressure of the developing machine is not transmitted.

  By diluting the alkali metal salt (usually a sodium salt) of the carboxyl group-containing (meth) acrylate compound having a stickiness with water containing 30 to 1000 ppm of a divalent metal ion, the divalent metal is washed. It is considered that the substance is changed into a water-insoluble substance by the exchange reaction with salt and salt crosslinking, and is dispersed and removed in washing water. At this time, some divalent metal ions remain in a slight amount near the surface of the alkali development type solder resist layer.

  Here, the divalent metal ions remaining in the vicinity of the surface of the alkali development type solder resist layer can be analyzed, for example, by the following procedure. First, the alkali developing type solder resist layer is separated by scraping or the like, and heat-treated at 100 to 120 ° C. for 4 to 8 hours in pure water having an electric conductivity of 18 MΩ or more, for example, to extract the ionic component by heat. Then, the divalent metal ion component remaining in the vicinity of the surface of the alkali development type solder resist layer can be identified by analyzing the extract using ion chromatography (model DION Chromatography, manufactured by DIONEX).

  The carboxyl group-containing urethane (meth) acrylate compound is a generic term for a carboxyl group-containing urethane acrylate compound, a carboxyl group-containing urethane methacrylate compound, and a mixture thereof, and the same applies to other similar expressions.

  Further, secondary cleaning (rinsing) is performed with ion-exchanged water as necessary.

  The alkali development type solder resist layer thus washed with water (secondary washing as necessary) is dried and then thermally cured.

  In such a thermosetting process, for example, a hot air circulation drying furnace, a far infrared curing furnace, or the like is used, and the heating is performed at a temperature of about 140 to 180 ° C., for example. And the carboxyl group contained in the alkali development type solder resist reacts with thermosetting components such as epoxy resin, and has excellent properties such as heat resistance, chemical resistance, moisture absorption resistance, adhesion, and electrical characteristics. A cured coating film can be formed.

  Moreover, in order to improve plating tolerance etc., you may perform hardening by ultraviolet irradiation before thermosetting or after thermosetting. For example, an ultraviolet irradiation conveyor furnace can be used to cure photosensitive groups such as acrylate groups that remain unreacted during exposure. However, since there are problems such as a decrease in the adhesion of the marking ink and a decrease in the modulus of elasticity of the coating film, an appropriate curing method may be selected in consideration of the application.

  Through these steps, an opening for forming gold plating or the like was formed on the surface of the substrate on which a conductor pattern such as a copper foil was normally formed on a portion to be a pad portion or the like in a printed wiring board. A printed wiring board provided with an alkali development type solder resist layer is formed.

  At this time, the diameter of the opening is preferably 20 to 100 μm. If the thickness is less than 20 μm, it is difficult to form the opening with high precision because the resolution at the time of exposure cannot be sufficiently obtained. On the other hand, if it exceeds 100 μm, the chip size to be mounted becomes large, and the merit of using CSP and UT-CSP is impaired.

  When forming such a small-diameter opening, it is difficult for the water flow to reach the opening during washing, and development residues are likely to occur. However, by using the rinsing water in the present embodiment, it is possible to suppress development residue even when a small-diameter opening is formed.

  The printed wiring board thus formed is further degreased and washed with, for example, an acidic degreasing solution, and then immersed in a catalyst solution to give a catalyst. And a pad is formed in an opening by performing electroless nickel plating and electroless gold plating.

In the alkali development type solder resist layer formed in such a printed wiring board manufacturing method, for example,
(A) Carboxyl group-containing resin (B) Photopolymerization initiator (C) Alkali development containing a thermosetting component (D) diluent having two or more cyclic ether groups and / or cyclic thioether groups in one molecule A type solder resist is used.

  As the carboxyl group-containing resin (A), a resin compound containing a carboxylic acid in the molecule can be used. Further, from the viewpoint of photocurability and development resistance, it is preferable to use a carboxyl group-containing photosensitive resin (A ′) having an ethylenically unsaturated double bond in the molecule.

In particular,
(1) Carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid and one or more other compounds having an unsaturated double bond (2) unsaturated carboxylic acid Carboxyl group-containing resin obtained by partially adding an ethylenically unsaturated group as a pendant (for example, adding glycidyl methacrylate) to a copolymer of an acid and another compound having an unsaturated double bond (3) A second product produced by reacting a compound having an epoxy group and an unsaturated double bond in one molecule with a copolymer of another compound having an unsaturated double bond with an unsaturated monocarboxylic acid. Carboxyl group-containing resin obtained by reacting a saturated hydroxyl group with a saturated or unsaturated polybasic acid anhydride (4) a polyfunctional epoxy compound and an unsaturated monocarboxylic acid And a carboxyl group-containing resin (5) obtained by reacting the produced hydroxyl group with a saturated or unsaturated polybasic acid anhydride (5) a polyfunctional epoxy compound, an unsaturated monocarboxylic acid, and at least one per molecule. Carboxyl group-containing resin obtained by reacting a saturated or unsaturated polybasic acid anhydride with a reaction product of an alcoholic hydroxyl group and a compound having one reactive group other than an alcoholic hydroxyl group that reacts with an epoxy group (6) A polyfunctional epoxy compound is reacted with an unsaturated monocarboxylic acid, the resulting hydroxyl group is reacted with a saturated or unsaturated polybasic acid anhydride, and an epoxy group and an unsaturated double group in one molecule such as glycidyl methacrylate. Carboxyl group-containing resin (7) obtained by reacting a compound having a bond with the hydroxyl group of the bisphenol type bifunctional epoxy compound. Linear carboxyl group-containing resin obtained by reacting a saturated or unsaturated polybasic acid anhydride with a reaction product of a bisphenol type polyfunctional epoxy compound obtained by reacting rhohydrin and an unsaturated monocarboxylic acid ( 8) Obtained by alternately polymerizing a bifunctional epoxy compound such as a bisphenol type epoxy resin and an aromatic compound having two phenolic hydroxyl groups or a compound having two carboxyl groups, and reacting an epihalohydrin with the resulting hydroxyl group In one molecule of a linear carboxyl group-containing resin (9) obtained by reacting a reaction product of a polyfunctional linear epoxy compound with an unsaturated monocarboxylic acid with a saturated or unsaturated polybasic acid anhydride Reaction of a compound having two or more phenolic hydroxyl groups with an alkylene oxide or cyclocarbonate compound The reaction product obtained is reacted with an unsaturated group-containing monocarboxylic acid, and the resulting reaction product is reacted with a polybasic acid anhydride. (10) Carboxyl group-containing resin (10) Hydroxyl group-containing (meth) Compound obtained by reacting acrylate compound (a), dimethylolalkanoic acid (b), and diisocyanate compound (c), or further carboxyl group-containing urethane (meth) acrylate obtained by reacting polymer polyol (d) Examples thereof include resins such as compounds.

  Since such a carboxyl group-containing resin (A) has a large number of free carboxyl groups in the side chain of the backbone polymer, development with a dilute alkaline aqueous solution is possible.

  Among these, the carboxyl group-containing photosensitive resins (5) to (10) are particularly preferably used for package substrates such as UT-CSP. Among these, by containing the carboxyl group-containing urethane (meth) acrylate compound (10), it is possible to form a highly flexible printed wiring board suitable for a package substrate such as UT-CSP. And it is preferable that 35 mass parts or more of this carboxyl group containing urethane (meth) acrylate compound is contained with respect to 100 mass parts of carboxyl group containing resin (A) at the point of provision of a softness | flexibility.

  Such carboxyl group-containing resins (A) can be used alone or in combination. In order to impart flexibility, a carboxyl group-containing rubber-like compound such as carboxyl group-terminated butadiene acrylonitrile (CTBN) may be used. From the viewpoint of imparting flexibility, the carboxyl group-containing rubber-like compound, the linear carboxyl group-containing photosensitive resin (7), (8), the carboxyl group-containing urethane (meth) acrylate compound (10), It is preferable to contain 15-85 mass% (15-85 mass parts in 100 mass parts of carboxyl group-containing resin) with respect to the total amount of containing resin (A).

  Such a carboxyl group-containing urethane (meth) acrylate compound and the like are liable to produce a sticky development residue when developed with a dilute alkaline aqueous solution. However, it is possible to suppress development residue by using the washing water in the present embodiment.

  Moreover, it is preferable that the acid value of carboxyl group-containing resin (A) is the range of 40-200 mgKOH / g. When the acid value of the carboxylic acid-containing resin is less than 40 mgKOH / g, alkali development becomes difficult. On the other hand, when the acid value exceeds 200 mgKOH / g, dissolution of the exposed area by the developer proceeds, so that the line becomes thinner than necessary. In some cases, the exposed portion and the unexposed portion are dissolved and separated with a developer without distinction, and it becomes difficult to draw a normal resist pattern. More preferably, it is the range of 45-120 mgKOH / g.

  Moreover, although the weight average molecular weight of carboxyl group-containing resin (A) changes with resin frame | skeletons, the thing of 2,000-150,000 is generally preferable. When the weight average molecular weight is less than 2,000, the tack-free performance may be inferior, the moisture resistance of the coated film after exposure may be poor, and the film may be reduced during development, and the resolution may be greatly inferior. On the other hand, when the weight average molecular weight exceeds 150,000, developability may be remarkably deteriorated, and storage stability may be inferior. More preferably, it is in the range of 5,000 to 100,000.

  It is preferable that the mixture ratio of such carboxyl group-containing resin (A) is 20-60 mass% in the whole composition. When it is less than 20% by mass, it is difficult to obtain sufficient coating strength. On the other hand, when it is more than 60% by mass, the viscosity becomes high, and the coating property and the like are lowered. More preferably, it is 30-50 mass%.

  Examples of the photopolymerization initiator (B) include benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy Acetophenones such as 2-phenylacetophenone and 1,1-dichloroacetophenone; 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino- 1- (4-morpholinophenyl) -butanone-1, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, etc. Aminoacetophenones; 2-methyla Anthraquinones such as traquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone; 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone, etc. Thioxanthones; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzyl and benzophenone; or xanthones; (2,6-dimethoxybenzoyl) -2,4,4-pentylphosphine oxide, bis (2, 4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl-2,4,6-trimethylbenzoyl Phosphine oxides such as phenyl phosphinate, (2- (acetyloxyiminomethyl) thioxanthen-9-one), (1,2-octanedione, 1- [4- (phenylthio)-, 2- ( O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) It is done.

  These photopolymerization initiators (B) can be used alone or in combination. The mixing ratio of these photopolymerization initiators (B) is suitably 0.01 to 30 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin (A). When the usage-amount of a photoinitiator (B) is less than 0.01 mass part, photocurability will fall, and when more than 30 mass parts, a cured coating film characteristic will fall. In the case of an oxime photopolymerization initiator, the blending ratio is 0.01 to 20 parts by mass, more preferably 0.01 to 5 parts by mass.

  Furthermore, a tertiary amine compound or a benzophenone compound can be contained as a photoinitiator aid. Examples of such tertiary amines include ethanolamines, 4,4′-dimethylaminobenzophenone (Nisso Cure MABP manufactured by Nippon Soda Co., Ltd.), ethyl 4-dimethylaminobenzoate (Kayacure EPA manufactured by Nippon Kayaku Co., Ltd.), 2- Ethyl dimethylaminobenzoate (Quantacure DMB manufactured by International Bio-Synthetics), ethyl 4-dimethylaminobenzoate (n-butoxy) Quantacure BEA manufactured by International Bio-Synthetics, isoamyl p-dimethylaminobenzoate Ethyl ester (Kayacure DMBI manufactured by Nippon Kayaku Co., Ltd.), 2-Ethylhexyl 4-dimethylaminobenzoate (Esolol 507 manufactured by Van Dyk), 4,4'-diethylaminobenzophenone (Hodogaya Chemical) Company made EAB) and the like.

  These tertiary amine compounds can be used alone or as a mixture of a plurality of them. A particularly preferred tertiary amine compound is 4,4'-diethylaminobenzophenone, but is not particularly limited thereto. As long as it absorbs light in the wavelength region of 300 to 420 nm and exhibits a sensitizing effect when used in combination with a hydrogen abstraction type photopolymerization initiator, it is not limited to the photopolymerization initiator (B) and photoinitiator aid. These can be used alone or in combination.

  The thermosetting component (C) having two or more cyclic ether groups and / or cyclic thioether groups in one molecule is used for improving the heat resistance of the cured product.

  As the thermosetting component (C) having two or more cyclic ether groups and / or cyclic thioether groups in one molecule, three, four or five-membered cyclic ether groups or cyclic thioether groups in one molecule A compound having two or more of any one or two kinds of groups, for example, a compound having at least two epoxy groups in one molecule, that is, a polyfunctional epoxy compound (C-1), at least in one molecule Examples thereof include a compound having two or more oxetane groups, that is, a polyfunctional oxetane compound (C-2), a compound having two or more thioether groups in one molecule, that is, an episulfide resin.

  As the polyfunctional epoxy compound (C-1), for example, Epicoat 828, Epicoat 834, Epicoat 1001, Epicoat 1004 manufactured by Japan Epoxy Resin, Epicron 840, Epicron 850, Epicron 1050 manufactured by Dainippon Ink & Chemicals, Inc. Epicron 2055, Epototo YD-011, YD-013, YD-127, YD-128 manufactured by Toto Kasei Co., Ltd., D.C. E. R. 317, D.E. E. R. 331, D.D. E. R. 661, D.E. E. R. 664, Ciba Specialty Chemicals' Araldide 6071, Araldide 6084, Araldide GY250, Araldide GY260, Sumitomo Chemical Industries Sumi-Epoxy ESA-011, ESA-014, ELA-115, ELA-128, Asahi Kasei Corporation A. E. R. 330, A.I. E. R. 331, A.I. E. R. 661, A.I. E. R. Bisphenol A type epoxy resin such as 664 (all trade names); Epicoat YL903 manufactured by Japan Epoxy Resin, Epicron 152, Epicron 165 manufactured by Dainippon Ink & Chemicals, Epototo YDB-400, YDB- manufactured by Tohto Kasei Co., Ltd. 500, D.C. E. R. 542, Araldide 8011 manufactured by Ciba Specialty Chemicals, Sumi-epoxy ESB-400, ESB-700 manufactured by Sumitomo Chemical Co., Ltd., and A.D. E. R. 711, A.I. E. R. Brominated epoxy resins such as 714 (all trade names); Epicoat 152 and Epicoat 154 manufactured by Japan Epoxy Resin Co., Ltd., D.C. E. N. 431, D.D. E. N. 438, Epicron N-730, Epicron N-770, Epicron N-865, Etototo YDCN-701, YDCN-704 from Toto Kasei Co., Ltd., Araldide ECN1235 from Ciba Specialty Chemicals, Araldide ECN1273, Araldide ECN1299, Araldide XPY307, Nippon Kayaku Co., Ltd. EPPN-201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306, Sumitomo Chemical Industries Sumi-epoxy ESCN-195X, ESCN- 220, manufactured by Asahi Kasei Corporation. E. R. Novolak type epoxy resins such as ECN-235, ECN-299, etc. (both are trade names); Epicron 830 manufactured by Dainippon Ink and Chemicals, Epicoat 807 manufactured by Japan Epoxy Resin, Epototo YDF-170 manufactured by Toto Kasei Co., Ltd. -175, YDF-2004, bisphenol F type epoxy resin such as Araldide XPY306 manufactured by Ciba Specialty Chemicals (all trade names); Epotot ST-2004, ST-2007, ST-3000 manufactured by Toto Kasei Hydrogenated bisphenol A type epoxy resin, such as Epicoat 604 manufactured by Japan Epoxy Resin Co., Ltd., Epotot YH-434 manufactured by Tohto Kasei Co., Ltd., Araldide MY720 manufactured by Ciba Specialty Chemicals Co., Ltd., Sumitomo Chemical Co., Ltd. Epoxy ELM-1 Glycidylamine type epoxy resins such as 0 (all trade names); Hydantoin type epoxy resins such as Araldide CY-350 (trade name) manufactured by Ciba Specialty Chemicals; Celoxide 2021 manufactured by Daicel Chemical Industries, Ciba Specialty Alicyclic epoxy resins such as Araldide CY175 and CY179 manufactured by Chemicals (both are trade names); YL-933 manufactured by Japan Epoxy Resin; E. N. , EPPN-501, EPPN-502, etc. (all trade names) such as trihydroxyphenylmethane type epoxy resin; Japan Epoxy Resin YL-6056, YX-4000, YL-6121 (all trade names), etc. Xylenol type or biphenol type epoxy resins or mixtures thereof; bisphenol S type such as EBPS-200 manufactured by Nippon Kayaku Co., Ltd., EPX-30 manufactured by Asahi Denka Kogyo Co., Ltd., EXA-1514 manufactured by Dainippon Ink & Chemicals, Inc. Epoxy resin; Bisphenol A novolak type epoxy resin such as Epicoat 157S (trade name) manufactured by Japan Epoxy Resin; Epicoat YL-931 manufactured by Japan Epoxy Resin, Araldide 163 manufactured by Ciba Specialty Chemicals, etc. Name) Tetraphenylo Luethane type epoxy resin; Araldide PT810 manufactured by Ciba Specialty Chemicals Co., Ltd., and heterocyclic epoxy resin such as TEPIC manufactured by Nissan Chemical Industries Co., Ltd. (all trade names); Diglycidyl phthalate resin such as Bremer DGT manufactured by Nippon Oil &Fats; Tetraglycidylxylenoylethane resins such as ZX-1063 manufactured by Tohto Kasei Co., Ltd .; Naphthalenes such as ESN-190 and ESN-360 manufactured by Nippon Steel Chemical Co., Ltd., HP-4032, EXA-4750, and EXA-4700 manufactured by Dainippon Ink & Chemicals, Inc. Group-containing epoxy resin; Epoxy resin having a dicyclopentadiene skeleton such as HP-7200 and HP-7200H manufactured by Dainippon Ink &Chemicals; Glycidyl methacrylate copolymer epoxy such as CP-50S and CP-50M manufactured by Nippon Oil & Fats Co., Ltd. Resin; further cyclohex Copolymerized epoxy resin of rumaleimide and glycidyl methacrylate; epoxy-modified polybutadiene rubber derivative (for example, PB-3600 manufactured by Daicel Chemical Industries, Ltd.), CTBN-modified epoxy resin (for example, YR-102, YR-450 manufactured by Toto Kasei Co., Ltd.) However, it is not limited to these. These epoxy resins can be used alone or in combination. Among these, a novolac type epoxy resin, a heterocyclic epoxy resin, a bisphenol A type epoxy resin or a mixture thereof is particularly preferable.

  Examples of the polyfunctional oxetane compound (C-2) include bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, bis [(3-ethyl-3-oxetanylmethoxy) methyl] ether, 1,4-bis [ (3-Methyl-3-oxetanylmethoxy) methyl] benzene, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl In addition to polyfunctional oxetanes such as -3-oxetanyl) methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate and oligomers or copolymers thereof, and oxetane Novolac resin, poly (p-hydroxystyrene), cardo-type bisphenol Le ethers, calixarenes, calix resorcin arenes, or the like ethers of a resin having a hydroxyl group such as silsesquioxane and the like. In addition, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate is also included.

  Examples of the compound having two or more cyclic thioether groups in one molecule include bisphenol A type episulfide resin YL7000 manufactured by Japan Epoxy Resins. Moreover, episulfide resin etc. which replaced the oxygen atom of the epoxy group of the novolak-type epoxy resin with the sulfur atom using the same synthesis method can be used.

  The blending ratio of the thermosetting component (C) having two or more cyclic ether groups and / or cyclic thioether groups in one molecule is 1 equivalent to the total amount of carboxyl groups of the carboxyl group-containing resin (A). On the other hand, it is preferably 0.5 to 2.0 equivalents. When the blending ratio of the thermosetting component (C) having two or more cyclic ether groups and / or cyclic thioether groups in one molecule is less than 0.5 equivalent, a carboxyl group remains, heat resistance, alkali resistance, Electrical insulation properties will be reduced. On the other hand, when it exceeds 2.0 equivalents, the thermosetting component (C) having two or more cyclic ether groups and / or cyclic thioether groups remains in one molecule having a low molecular weight, and thereby the strength of the coating film is increased. Etc. will fall. More preferably, it is the range used as 0.8-1.5 equivalent.

  Further, in the alkali development type solder resist used in the present embodiment, a diluent (D) is used for the synthesis of the carboxyl group-containing resin (A), the adjustment of the composition, or the improvement of the photocurability. As the diluent (D), an organic solvent (D-1) can be used as a non-reactive diluent, or a polymerizable monomer (D-2) can be used as a reactive diluent.

  Examples of the organic solvent (D-1) include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum solvents, and the like. More specifically, ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl Glycol ethers such as ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether; dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol butyl ether acetate, etc. Glycol ether acetates; ethyl acetate, butyrate And esters such as acetates of the above glycol ethers; alcohols such as ethanol, propanol, ethylene glycol, and propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent Petroleum solvents such as naphtha. Such an organic solvent (D-1) is used alone or as a mixture.

  The blending ratio of these organic solvents (D-1) is not particularly limited, and can be determined in consideration of the coating property and securing the film thickness of the dried coating film, but the carboxyl group-containing resin (A) And 300 mass parts or less are preferable with respect to 100 mass parts of total amounts of a carboxyl group-containing urethane (meth) acrylate compound.

  Moreover, as the polymerizable monomer (D-2) which is a reactive diluent, hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, propylene Mono- or diacrylates of glycols such as glycol; acrylamides such as N, N-dimethylacrylamide, N-methylolacrylamide, N, N-dimethylaminopropylacrylamide; N, N-dimethylaminoethyl acrylate, N, N-dimethyl Aminoalkyl acrylates such as aminopropyl acrylate; hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, tris-hydroxyl Polyhydric alcohols such as ethyl isocyanurate or polyhydric acrylates such as these ethylene oxide adducts or propylene oxide adducts; phenoxy acrylate, bisphenol A diacrylate, and ethylene oxide adducts or propylene oxide adducts of these phenols Acrylates such as: glycerin diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, acrylates of glycidyl ether such as triglycidyl isocyanurate; and melamine acrylate and / or methacrylates corresponding to the above acrylates, etc. Is mentioned. Among these, a polyfunctional (meth) acrylate compound which is a compound having two or more ethylenically unsaturated groups in the molecule is particularly preferable because of excellent photocurability.

  Furthermore, polyfunctional epoxy resins such as bisphenol A, bisphenol F type epoxy resins, phenol and cresol novolac type epoxy resins, and epoxy acrylate resins obtained by reacting acrylic acid, and further to the hydroxyl groups of the epoxy acrylate resins, pentaerythritol triacrylate And an epoxy urethane acrylate compound obtained by reacting a half urethane compound of a diisocyanate such as isophorone diisocyanate. Such an epoxy acrylate resin can improve photocurability without deteriorating the touch drying property.

  It is preferable that the mixture ratio of such a polymerizable monomer (D-2) is 120 mass parts or less with respect to 100 mass parts of carboxyl group-containing resin (A). When the blending ratio of the polymerizable monomer (D-2) exceeds 120 parts by mass, the electrical insulation property is lowered or the coating film becomes brittle. More preferably, it is 10-70 mass parts.

  The alkali development type solder resist used in this embodiment is a thermosetting component (C) having a carboxyl group of the carboxyl group-containing resin (A) and two or more cyclic ether groups and / or cyclic thioether groups in one molecule. It is preferable to add a curing catalyst in order to accelerate the curing reaction.

  Examples of such a curing catalyst include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, Imidazole derivatives such as 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N- Amine compounds such as dimethylbenzylamine, 4-methyl-N, N-dimethylbenzylamine, hydrazine compounds such as adipic acid hydrazide and sebacic acid hydrazide; phosphorus compounds such as triphenylphosphine, Example For example, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (both trade names of imidazole compounds) manufactured by Shikoku Kasei Kogyo Co., Ltd. Compound trade names), DBU, DBN, U-CATSA102, U-CAT5002 (both bicyclic amidine compounds and salts thereof). In particular, it is not limited to these, as long as it is a thermosetting catalyst for an epoxy resin or an oxetane compound, or a catalyst that promotes the reaction between an epoxy group and / or an oxetanyl group and a carboxyl group, either alone or in combination. You can use it. Guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-4,6-diamino-S-triazine, 2 S-triazine derivatives such as -vinyl-4,6-diamino-S-triazine / isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-S-triazine / isocyanuric acid adduct can also be used, Preferably, a compound that also functions as an adhesion promoter is used in combination with a thermosetting catalyst.

  A usual quantitative ratio of the curing catalyst is sufficient. For example, it is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the total resin composition. When the blending ratio of the curing catalyst is less than 0.1 parts by mass, the curing time becomes longer, workability is lowered, and oxidation of the copper foil and the like becomes intense. On the other hand, when the blending ratio of the curing catalyst exceeds 20 parts by mass, the electrical characteristics are deteriorated or the standing life after temporary drying is shortened. More preferably, it is the ratio of 0.5-15.0 mass parts.

  In addition, the alkali developing type solder resist used in the present embodiment can be blended with an inorganic filler for the purpose of further improving properties such as adhesion of the cured product, mechanical strength, and linear expansion coefficient. For example, inorganic fillers such as barium sulfate, barium titanate, silicon oxide powder, finely divided silicon oxide, amorphous silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, and mica powder can be used. The blending ratio is preferably 0 to 80% by mass of the resin composition.

  Further, if necessary, colorants such as phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black, hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, Thermal polymerization inhibitors such as pyrogallol and phenothiazine, thickeners such as fine silica, organic bentonite and montmorillonite, defoamers and / or leveling agents such as silicone, fluorine and polymer, imidazole, thiazole and triazole Additives such as a silane coupling agent such as a system can be blended.

  And the printed wiring board formed in this way is used suitably as a board | substrate of packages, such as CSP and UT-CSP.

  The CSP functions as an intermediate board (interposer) for mounting an IC chip on a printed wiring board, and its size is almost the same as that of the IC chip. The UT-CSP is obtained by further reducing the thickness of the CSP.

  Such a CSP or UT-CSP is manufactured and mounted as follows, for example.

  First, an alkali development type solder resist layer having openings is formed on both surfaces of a substrate on which a conductor pattern is formed, and pads for connection with an IC chip and pads for connection with a printed wiring board are provided. A package substrate having the same is formed.

  Next, the IC chip is connected to the IC chip connection surface of the package substrate using a wire bonding method or a flip chip method. Then, the IC chip is fixed to the package substrate with a sealing material (underfill if necessary).

  Furthermore, a solder ball is adhered to the printed circuit board connection surface of the package substrate to form a CSP (UT-CSP).

  The formed CSP (UT-CSP) is installed on a printed wiring board, and when passed through a reflow furnace, the solder ball is melted and connected to the printed wiring board at the opening where the gold plating is applied. Implemented by.

  Examples of the present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

<Synthesis of carboxyl group-containing resin>
2200 g of cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., EOCN-104S, softening point 92 ° C., epoxy equivalent 220), 134 g of dimethylolpropionic acid, 648.5 g of acrylic acid, 4.6 g of methylhydroquinone, 1131 g of carbitol acetate and 484.9 g of solvent naphtha was charged, heated to 90 ° C. and stirred to dissolve the reaction mixture. Next, the reaction solution was cooled to 60 ° C., charged with 13.8 g of triphenylphosphine, heated to 100 ° C., and reacted for about 32 hours to obtain a reaction product having an acid value of 0.5 mgKOH / g. Next, 364.7 g of tetrahydrophthalic anhydride, 137.5 g of carbitol acetate, and 58.8 g of solvent naphtha were charged into this, heated to 95 ° C., reacted for about 6 hours, cooled, and the solid acid value of 40 mgKOH / g. A carboxyl group-containing photosensitive resin having a nonvolatile content of 65% was obtained. Hereinafter, this reaction solution is referred to as varnish (A-1).

<Synthesis of carboxyl group-containing urethane (meth) acrylate compound>
In a 5 L separable flask equipped with a thermometer, a stirrer, and a reflux condenser, 1,245 g of polycaprolactone diol (PLACCEL 208, molecular weight 830, manufactured by Daicel Chemical Industries) as a polymer polyol, dimethylol propion as a dihydroxyl compound having a carboxyl group 201 g of acid, 777 g of isophorone diisocyanate as a polyisocyanate, 119 g of 2-hydroxyethyl acrylate as a (meth) acrylate having a hydroxyl group, and 0.5 g each of p-methoxyphenol and di-t-butyl-hydroxytoluene did. The mixture was stopped by heating to 60 ° C. while stirring, and 0.8 g of dibutyltin dilaurate was added. When the temperature in the reaction vessel starts to decrease, the mixture is heated again and stirred at 80 ° C., and the reaction is terminated after confirming that the absorption spectrum of the isocyanate group (2280 cm ⁻¹ ) has disappeared in the infrared absorption spectrum. A viscous liquid urethane acrylate compound was obtained. This was adjusted to a non-volatile content = 50 mass% using carbitol acetate to obtain a carboxyl group-containing urethane (meth) acrylate compound having a solid acid value of 47 mgKOH / g and a non-volatile content of 50%. Hereinafter, this reaction solution is referred to as varnish (A-2).

<Preparation of alkali development type solder resist>
Using the obtained varnish (A-1) and varnish (A-2), the following blending components were kneaded with a three-roll mill to obtain an alkali developing type solder resist.

77 parts of varnish (A-1)
Varnish (A-2) 100 parts
2,4,6-trimethylbenzoyl
10 parts of diphenylphosphine oxide
3 parts of melamine
Dipentaerythritol
Hexaacrylate 20 parts
RE-306
(Nippon Kayaku novolak epoxy resin) 25 parts
Phthalocyanine green 2 parts
Viscosity adjusting solvent
Propylene glycol monomethyl ether
Acetate 10 parts <Preparation of evaluation substrate>
1. Formation of Alkali Development Type Solder Resist Layer Using an FR-4 substrate with a conductor pattern appropriately formed and buffing this, the prepared alkali development type solder resist was printed on the entire surface by a screen printing method at 80 ° C. , Dried for 30 minutes to form a tack-free alkali development type solder resist layer.

2. Exposure process Using a contact exposure machine (EXP-2960 manufactured by ORC) equipped with an alkali development type solder resist layer in advance and a high pressure mercury lamp, Kodak No. The exposure amount which becomes 6 steps with the step tablet of 2 was obtained.

  And the negative film of the predetermined pattern was mounted on the board | substrate with which the alkali image development type soldering resist layer was formed, it set to the calculated | required exposure amount, and it exposed with the said contact exposure machine.

3. Development Step The exposed substrate was developed using a 1 mass% sodium carbonate aqueous solution at 30 ° C. with a developing machine having a spray pressure of 0.2 MPa to form a pattern. The washing apparatus attached to the developing machine was stopped and the substrate was taken out after development.

4). Flushing process (preparation of flush water)
Calcium chloride (molecular weight = 110.98, containing 36.11% by mass of calcium) was used as a source of calcium ions, and 2.769 mg of calcium chloride (CaCl ₂ ) was dissolved in 1 liter of ion-exchanged water. Washing water containing 1 ppm of ions was prepared. Similarly, washing water containing calcium ions of 10, 20, 30, 100, 500, 1000, and 10,000 ppm was prepared.

  In addition, ion-exchanged water containing no calcium ions was prepared.

(Washing)
The above-mentioned washing water and stirrer were placed in a 2 liter beaker, and the washing water was stirred with a magnetic stirrer to obtain a water flow. The substrate for evaluation after development was put into a beaker containing the washing water which was being stirred, and washed with water.

  Then, the rinse process was abbreviate | omitted, and it was made to dry after removing a water | moisture content with a waste cloth.

5). Thermosetting process The dried substrate was put in a hot air circulation drying oven set at 150 ° C. for 60 minutes to cure the alkali development type solder resist layer.

  Thus, an evaluation substrate on which an alkali development type solder resist layer provided with an opening was formed was produced.

<Evaluation of substrate>
(1) Evaluation of development residue An alkali development type solder resist layer is formed, and after exposure and development using a negative pattern on which a dot pattern for producing a dummy pad with a diameter of 80 μm is drawn, each rinse is washed with water. About the dried evaluation board | substrate before thermosetting, the development residue etc. were evaluated on the following references | standards using the scanning electron microscope (SEM). The results are shown in Table 1.

  ○: No development residue or deposit.

  Δ: Slightly developed residue or deposits.

  X: There are development residues or deposits, which causes poor adhesion of plating.

(2) Evaluation of solder heat resistance After forming an alkali development type solder resist layer, exposure and development, washing with each washing water, drying and thermosetting, a rosin-based flux is applied to the substrate for evaluation at 260 ° C. Was immersed in a solder bath for 30 seconds. After washing the substrate with propylene glycol menomotyl ether, the state of the coating film was evaluated according to the following criteria. The results are also shown in Table 1.

  ○: No abnormality such as swelling, peeling or discoloration of the coating film.

  X: Remarkable blistering, peeling, discoloration, etc. are observed.

(3) Evaluation of gold plating adhesion An alkali developing type solder resist layer was formed, exposed and developed, then washed with each washing water, dried and heat-cured, and an evaluation degreasing solution (Japan) It was degreased by immersion for 3 minutes in a 20 vol% aqueous solution of Metex L-5B manufactured by McDermid Co., Ltd., and then immersed in running water for 3 minutes and washed with water. Then, it was immersed in a 14.3 wt% ammonium persulfate aqueous solution at room temperature for 3 minutes, subjected to soft etching, and then immersed in running water for 3 minutes and washed with water. The substrate for evaluation was immersed in a 10 vol% sulfuric acid aqueous solution at room temperature for 1 minute, and then immersed in running water for 30 seconds to 1 minute and washed with water. Furthermore, after being immersed in a 30 ° C. catalyst solution (Meltex Co., 10 vol% aqueous solution of metal plate activator 350) for 7 minutes to give the catalyst, it was immersed in running water for 3 minutes and washed with water.

  The evaluation substrate thus provided with the catalyst was immersed in an 85 ° C. nickel plating solution (Meltex Ni-865M, 20 vol% aqueous solution, pH 4.6) for 20 minutes, and electroless nickel plating was performed. Went. Then, after being immersed in a 10 vol% sulfuric acid aqueous solution for 1 minute at room temperature, it was immersed in running water for 30 seconds to 1 minute and washed with water. Next, after electroless gold plating was performed by immersing in a gold plating solution at 95 ° C. (Meltex Co., an aqueous solution of Aurolectroles UP15 vol% and 3 vol% potassium cyanide, pH 6) for 10 minutes, It was immersed for a minute and washed with water, and further immersed in warm water at 60 ° C. for 3 minutes and washed with hot water. After sufficiently washing with water, water was thoroughly drained, dried, and an evaluation substrate subjected to electroless gold plating was obtained.

  The obtained evaluation substrate was observed with an SEM and evaluated according to the following evaluation criteria. The results are also shown in Table 1.

  ○: No problem in gold plating adhesion due to development residue.

  X: A problem in gold plating adhesion due to development residue.

(4) Evaluation of PCT resistance An alkali development type solder resist layer was formed, exposed and developed, then washed with each washing water, dried and thermally cured, and the evaluation substrate was 121 ° C., 2 atm, and humidity 100%. It was placed in a high-temperature, high-pressure, high-humidity tank for 168 hours, the state change of the cured coating film was visually observed, and evaluated according to the following criteria. The results are also shown in Table 1.

  ○: No noticeable swelling or discoloration.

  Δ: Slight swelling and discoloration are observed.

  X: Remarkable swelling and discoloration are observed.

(5) Evaluation of migration state after HAST (Highly accelerated temperature and stress stress test) Using an FR-4 substrate on which comb-type electrodes (line / space = 50 μm / 50 μm) are formed, an alkali development type solder resist layer After the exposure, development, and washing with each washing water, drying and thermosetting, the evaluation substrate was subjected to HAST for 168 hours by applying DC 5 V in an atmosphere of 130 ° C. and humidity 85%. . Thereafter, the occurrence of migration was observed with an optical microscope and evaluated according to the following criteria. The results are also shown in Table 1.

  ○: No significant migration was observed.

  Δ: Slight migration is observed.

  X: A remarkable migration is observed.

(6) Evaluation of warpage As a substrate, a high heat-resistant adhesive insulating material (manufactured by Hitachi Chemical Co., Ltd.) having a thickness of 60 μm and 400 mm × 300 mm was used to form an alkali development type solder resist layer, and after exposure and development, The evaluation substrate washed with water, dried and thermally cured was placed on a flat surface, and the heights of the four corners of the test piece were measured. Then, the total was taken as the amount of warpage deformation, and warpage was evaluated from the amount of deformation according to the following criteria. The results are also shown in Table 1.

  ○: Warpage deformation is less than 20 mm.

X: The amount of warp deformation is 20 mm or more.

  As is apparent from the results shown in Table 1, those washed with water containing 30 to 1000 ppm of calcium ions were not recognized as a development residue after being washed once, and resolution, gold plating adhesion, PCT resistance, The state of occurrence of migration was good, the solder heat resistance was good, and no warping was observed.

  On the other hand, when the ion-exchanged water and the water treated with 20 ppm or less of washing water with calcium ions are used, a development residue remains in one washing, and there is a problem in resolution and gold plating adhesion. Further, the PCT resistance and the migration occurrence state were inferior. In addition, even when the calcium ion concentration exceeded 1000 ppm, a development residue remained and there was a problem in resolution and gold plating adhesion. This is considered to be because the alkali-developable solder resist that had been dissolved in the washing water aggregated.

(7) Measurement of change in ion concentration in washing water Using washing water containing 100 ppm of calcium ions, changes in the treatment area and ion concentration of the substrate per liter of washing water were measured. The result is shown in FIG.

As shown in FIG. 1, in washing water containing 100 ppm of calcium ions, calcium ions decrease with an increase in treatment area, but about 30 ppm of calcium ions remain when treated with about 1 m ² per liter, It was confirmed that water could be washed without problems up to a substrate area of about 1 m ² per liter without replenishing calcium ions. Therefore, it can be seen that the water washing process can be performed with high productivity.

  A substrate for evaluation was prepared in the same manner as in Example 1, and the divalent metal ions contained in the washing water were changed to magnesium ions and washed with water. The magnesium ion concentration of washing water was adjusted to 50 ppm, and as a comparative example, a magnesium ion concentration of 10 ppm and 10,000 ppm was prepared. About the evaluation board | substrate before thermosetting which dried this, development residue etc. were evaluated using SEM.

  FIG. 2 shows an electron micrograph of the pad portion when washed with washing water containing 50 ppm of magnesium ions. As shown in the figure, development residues and the like were not recognized.

  FIG. 3 shows an electron micrograph of the pad portion as a comparative example when washed with water containing 10 ppm of magnesium ions. It can be seen that an adhesive development residue remains on the periphery of the land and the outer periphery of the pad bottom.

  FIG. 4 shows, as a comparative example, an electron micrograph of the pad portion when washed with rinsing water containing 10000 ppm of magnesium ions. It can be seen that a resinous material is adhered on the pad.

  An alkali development type solder resist was prepared as follows, and an evaluation substrate was prepared in the same manner as in Example 1.

<Synthesis of carboxyl group-containing urethane (meth) acrylate compound>
In a reaction vessel equipped with a stirrer, a thermometer, and a condenser, 2400 g (3 mol) of polycarbonate diol derived from 1.5-pentanediol and 1.6-hexanediol (manufactured by Ube Industries, PDCL800, number average molecular weight 800). ), 402 g (3 mol) of dimethylolpropionic acid as a dihydroxyl compound having a carboxyl group, 1554 g (7 mol) of isophorone diisocyanate as a polyisocyanate, and 238 g (2.05 mol) of 2-hydroxyethyl acrylate as a monohydroxyl compound. When the temperature in the reaction vessel starts to decrease while heating to 60 ° C. while stirring, the mixture is heated again and stirred at 80 ° C., and the absorption spectrum of the isocyanate group (2280 cm ⁻¹ ) in the infrared absorption spectrum. The reaction was terminated after confirming disappearance of the product, and a viscous liquid urethane acrylate compound was obtained. And carbitol acetate was added so that solid content might be 50 mass%, and the number average molecular weight 22,000 (The value converted into polystyrene using gel carrier liquid chromatography (GPC-1 by GPC Showa Denko KK)). The acid value of the solid content was 46 mg KOH / g of a carboxyl group-containing urethane (meth) acrylate compound (varnish A-3).

<Synthesis of carboxyl group-containing resin>
119.4 parts of a novolac type cresol resin (trade name “Shonol CRG951”, Showa Polymer Co., Ltd., OH equivalent: 119.4) in an autoclave equipped with a thermometer, a nitrogen introduction device / alkylene oxide introduction device and a stirring device. Then, 1.19 parts of potassium hydroxide and 119.4 parts of toluene were charged, the inside of the system was replaced with nitrogen while stirring, and the temperature was increased by heating. Next, 63.8 parts of propylene oxide was gradually added dropwise and reacted at 125 to 132 ° C. and 0 to 4.8 kg / cm ² for 16 hours. Thereafter, the reaction solution was cooled to room temperature, and 1.56 parts of 89% phosphoric acid was added to and mixed with the reaction solution to neutralize potassium hydroxide. The nonvolatile content was 62.1% and the hydroxyl value was 182.2 g / eq. A novolak-type cresol resin propylene oxide reaction solution was obtained. This was an average of 1.08 moles of alkylene oxide added per equivalent of phenolic hydroxyl group.

  293.0 parts of an alkylene oxide reaction solution of the obtained novolak-type cresol resin, 43.2 parts of acrylic acid, 11.53 parts of methanesulfonic acid, 0.18 part of methylhydroquinone and 252.9 parts of toluene were mixed with a stirrer and a temperature. A reactor equipped with a meter and an air blowing tube was charged, air was blown at a rate of 10 ml / min, and the reaction was carried out at 110 ° C. for 12 hours while stirring. 12.6 parts of water was distilled from the water produced by the reaction as an azeotrope with toluene. Thereafter, the reaction solution was cooled to room temperature, neutralized with 35.35 parts of a 15% aqueous sodium hydroxide solution, and then washed with water. Thereafter, toluene was distilled off while substituting 118.1 parts of diethylene glycol monoethyl ether acetate with an evaporator to obtain a novolak acrylate resin solution.

  Next, 332.5 parts of the obtained novolak acrylate resin solution and 1.22 parts of triphenylphosphine were charged into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was supplied at a rate of 10 ml / min. While blowing and stirring, 60.8 parts of tetrahydrophthalic anhydride was gradually added, reacted at 95 to 101 ° C. for 6 hours, cooled and taken out. Thus, a carboxyl group-containing resin (varnish A-4) having a nonvolatile content of 70.6% and a solid acid value of 87.7 mgKOH / g was obtained.

<Preparation of alkali development type solder resist>
Using the carboxyl group-containing resin containing the obtained carboxyl group-containing urethane (meth) acrylate compound and novolak acrylate compound, the following blending components were kneaded with a three-roll mill to obtain an alkali developing type solder resist.

170 parts of urethane acrylate (varnish A-3)
23 parts of novolak acrylate (varnish A-4)
2,4,6-trimethylbenzoyl
10 parts of diphenylphosphine oxide
0.2 parts of phenothiazine
3 parts of melamine
Dipentaerythritol hexaacrylate 20 parts
25 parts of RE-306
First Gen Blue 0.6 parts
Chromophthal yellow 0.6 parts
10 parts of propylene glycol monoethyl ether acetate Using the prepared alkali development type solder resist, an evaluation substrate was prepared in the same manner as in Example 1, and the divalent metal ions contained in the washing water were changed to strontium ions and barium ions. Then, washing with water was performed by changing the ion concentration. In addition, as a comparative example, washing was performed using washing water containing aluminum ions that are trivalent ions. And the development residue etc. were evaluated using SEM about the board | substrate for evaluation before thermosetting which dried these.

  FIG. 5 shows an electron micrograph of the pad portion when washed with water containing 115 ppm of strontium ions. As shown in the figure, development residues and the like were not recognized.

  As a comparative example, FIG. 6 shows an electron micrograph of the pad portion when washed with water containing 12 ppm of strontium ions. It can be seen that an adhesive development residue remains on the outer periphery of the pad bottom.

  FIG. 7 shows an electron micrograph of the pad portion as a comparative example when washed with water containing 23000 ppm of strontium ions. It can be seen that a resinous material is adhered on the pad.

  FIG. 8 shows an electron micrograph of the pad portion when washed with rinsing water containing 240 ppm of barium ions. As shown in the figure, development residues and the like were not recognized.

  FIG. 9 shows, as a comparative example, an electron micrograph of the pad portion when washed with water containing 12 ppm of barium ions. It can be seen that an adhesive development residue remains on the outer periphery of the pad bottom.

  As a comparative example, FIG. 10 shows an electron micrograph of the pad portion when washed with water containing 24000 ppm of barium ions. It can be seen that a resinous material is attached on and around the pad.

  FIG. 11 shows, as a comparative example, an electron micrograph of the pad portion when washed with water containing 5 ppm of trivalent aluminum ions. It can be seen that an adhesive development residue remains on the outer periphery of the pad bottom. If the concentration is lower than 5 ppm, it is considered possible to wash with water without generating a development residue. However, in practice, it is difficult to control such a low concentration with high accuracy and obtain good productivity during mass production.

  Thus, in the water washing after the development of the alkali development type solder resist, by using the water for washing containing 30 to 1000 ppm of divalent metal ions, the water can be washed once with a predetermined portion of the alkali development type solder resist layer. It is possible to suppress a development residue or the like in an opening such as a formed fine pad. Therefore, it is possible to provide a printed wiring board that can improve plating adhesion and the like and can obtain high reliability and productivity.

The figure which shows the relationship between the calcium ion at the time of using the washing water containing 100 ppm of calcium ions, and the treatment area per liter of washing water. The electron micrograph of the pad part when wash | cleaning with the washing water which contains 50 ppm of magnesium ions which concern on 1 aspect of this invention. The electron micrograph of a pad part when wash | cleaning with the washing water containing 10 ppm of magnesium ions which concern on a comparative example. The electron micrograph of the pad part when it wash | cleans with the washing water containing 10000 ppm of magnesium ions which concern on a comparative example. The electron micrograph of a pad part when wash | cleaning with the washing water which contains 115 ppm of strontium ion which concerns on 1 aspect of this invention. The electron micrograph of a pad part when wash | cleaning with the washing water which contains 12 ppm of strontium ion which concerns on a comparative example. The electron micrograph of the pad part when it wash | cleans with the washing water containing 23000 ppm of strontium ion which concerns on a comparative example. The electron micrograph of the pad part when it wash | cleans with the washing water containing 240 ppm of barium ion which concerns on 1 aspect of this invention. The electron micrograph of a pad part when wash | cleaning with the washing water containing 12 ppm of barium ion which concerns on a comparative example. The electron micrograph of a pad part when wash | cleaning with the washing water which contains 24000 ppm of barium ion which concerns on a comparative example. The electron micrograph of a pad part when wash | cleaning with the washing water containing 5 ppm of aluminum ions which concern on a comparative example.

Claims (8)

Forming an alkali development type solder resist layer containing a carboxyl group-containing urethane (meth) acrylate compound as a carboxyl group-containing resin on the substrate surface on which the conductor pattern is formed ;
The step of exposing the alkali development type solder resist layer with a predetermined opening pattern ;
Developing the alkali-developable solder resist layer exposed in this step with a dilute alkaline aqueous solution ;
A step of removing the development residue from the alkali development type solder resist layer developed in this step using washing water containing 30 to 1000 ppm of divalent metal ions ;
A method for producing a printed wiring board comprising: forming an opening at a predetermined position of the alkali development type solder resist layer, comprising the step of thermally curing the alkali development type solder resist layer from which development residues have been removed in this step . The method for producing a printed wiring board according to claim 1, wherein the divalent metal ion is at least one metal ion selected from Ca ²⁺ , Mg ²⁺ , Sr ²⁺ , and Ba ²⁺ .   The method for producing a printed wiring board according to claim 1, wherein 35 parts by mass or more of the carboxyl group-containing urethane (meth) acrylate compound is contained with respect to 100 parts by mass of the carboxyl group-containing resin. . Diameter of the opening, a manufacturing method of the printed wiring board according to claim 1, characterized in that a 20 to 100 [mu] m. 2. The printed wiring board according to claim 1, wherein the alkali-developable solder resist layer is formed by applying an alkali-developable solder resist on the surface of the substrate on which the conductor pattern is formed, and drying the resist pattern. Method. The formed substrate surface of the conductor pattern by laminating a dry film consisting of alkali development type solder resist, printed circuit board according to claim 1, characterized in that to form the alkali development type solder resist layer Manufacturing method.   The method for manufacturing a printed wiring board according to claim 1, wherein the conductor pattern includes Cu.   The method for manufacturing a printed wiring board according to claim 1, wherein the opening is formed on the conductor pattern.