KR20080069354A - Resist ink, printed wiring board and method of manufacturing resist ink - Google Patents

Abstract

A resist ink containing various color expression properties, printed wiring board having a cured film and a method of manufacturing resist ink are provided to ensure good stability of dispersion even in the ink using green paint or low density ink using various inks. A resist ink comprises (A) coloring agents, (B) curable resins, (C) reactive diluents, (D) polymerization initiators, and (E) fillers. The coloring agent has a particle average diameter which is measured by a laser diffraction scattering, of 0.01 micrometer or more and 1 micrometer or less, and the standard deviation in particle size distribution is 0.1 to 0.2 micro meter.

Description

RESIST INK, PRINTED WIRING BOARD AND METHOD OF MANUFACTURING RESIST INK

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a graph showing the particle size distribution of a yellow pigment of a yellow rich dispersion liquid used in the solder resist ink of one embodiment of the present invention.

2 is a graph showing the particle size distribution of yellow pigments in a yellow thick dispersion liquid of the comparative example.

3 is a schematic perspective explanatory view of a curtain coater which can be coated using the solder resist ink of one embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

1: Conveyor 2: Printed Wiring Board Finished

3: ink head 4: ink tank

5: ink receiver 6: pump

7: Filter 8A, 8B: Shaft support column roller

9: resist ink 10: curtain coater

TECHNICAL FIELD This invention relates to the soldering resist ink which protects the circuit part which does not require the soldering of the circuit pattern of a printed wiring board, the manufacturing method, and the printed wiring board which has this coating cured film, for example.

A printed wiring board is formed by, for example, a circuit wiring pattern on a copper-clad laminate board, and mounts an electronic component such as a capacitor or a resistor thereon to form one electric / electronic circuit unit thereon. will be.

In order to mount an electronic component in such a printed wiring board, it is made by soldering an electronic component to the predetermined part (land) of the circuit which consists of conductors. As this soldering method, there exists a reflow soldering method or the soldering method by classification. In the soldering part, a circuit portion to avoid contact with solder other than land is coated with a solder resist ink film, which is mainly an insulating film made of resin. This soldering resist ink film also functions as a permanent protective film for preventing the metal material of the conductor constituting the circuit portion from being directly exposed to air and corroded by oxidation or humidity.

As this soldering resist ink composition, after visually inspecting whether the soldering defect exists after soldering an electronic component to a printed wiring board, the thing based on the green color is used so that the coating film may not burden an eye. It is becoming. In order to color such a green color, copper phthalocyanine green is preferable in terms of stable color tone of the ink, but since the halogen formula is present in the molecular formula, after appropriate treatment such as removing an electronic component from a discarded printed wiring board after use, etc. In the case of incineration and industrial waste treatment, there is a problem that toxic dioxins, which are particularly problematic in recent years, arise. In order to avoid this, blue pigments having no single halogen atom, for example, copper phthalocyanine blue and halogen The use of a yellow pigment which does not have an atom is also carried out (see Japanese Patent Application Laid-Open No. 2000-7974). In addition, in the pigment having an azo group as the yellow pigment, there is a fear of elution of amine from the coating film by acid rain or the like, which is also toxic. Because we go to azo without fear It is being conducted also be used in combination with a yellow pigment that do not (see Patent Laid-Open Publication No. 2000-290564).

[Patent Document 1] Japanese Patent Application Laid-Open No. 2000-7974

[Patent Document 2] Japanese Patent Application Laid-Open No. 2000-290564

However, in any solder resist ink using copper phthalocyanine green or using a blue pigment such as copper phthalocyanine blue in combination with a yellow pigment, the average particle diameter of these pigments is 8 to 10 µm (particle diameter by grinding gauge measurement). (In terms of the particle diameter measured by the laser diffraction scattering method (hereinafter referred to as the particle diameter according to this method unless otherwise noted)), the particle diameter is 1 to 8 µm. Dispersibility may worsen, and as a result, there existed a problem that the coloring film deteriorated and the color tone became unstable. The soldering resist ink film which consists of such a coating film does not acquire a clear and uniform color tone, and it does not only have a bad influence on the inspection by said time, but also has a problem that the commodity value of a printed wiring board falls.

When the coating film is formed by the so-called screen printing with respect to the solder resist ink described in Japanese Patent Application Laid-Open No. 2000-290564, the viscosity at the time of printing is good at about 200 dPa · s, so that the phthalocyanine blue of the blue pigment is stably. It is dispersed and is not separated from the yellow pigment, but other examples include a curtain method (coating method in which the ink is flowed down into the curtain shape and applied while moving the coated object to cross the inside) or spray method. In order to apply | coat in a spray form and apply | coating to a to-be-coated object, the viscosity at the time of use should be about 2 dPa * s, and in order to do so, it is necessary to dilute ink with a solvent, for example, 50 dPa * S When diluted below, phthalocyanine blue separates and is easy to float on the surface, so-called color separation causes a predetermined coating film. It tends to be obscured by the steady green uniform.

The first object of the present invention is to provide a blue-based and yellow-based colorant which does not have a halogen atom in the molecular formula, even in the case of a low viscosity product of an ink using a pigment such as a green pigment alone or an ink using a plurality of pigments together. Also in the case of the mixed low-viscosity article, the dispersion stability is good, and the present invention provides a printed wiring board having a resist ink of a color tone of each color system such as a green system in which both colorants are not separated, a manufacturing method thereof, and a cured film thereof.

The 2nd object of this invention is to provide the resist ink which can obtain the coating film of uniform stable color tone, and the printed wiring board which has the cured film even if it coats with a curtain system or a spray system.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, as a result of earnestly examining, the present inventors grind | pulverizes a coloring agent with a resin component and a solvent component which are the basic components of a resist ink by mechanical means, and makes the coloring agent dispersion liquid, and uses it to make a resist ink. In this case, it is possible to produce a low viscosity colorant dispersion liquid by changing the use ratio of each component in the composition of the colorant dispersion, and for the colorant, for disintegration (or grinding) of colorants such as pigments. When the mechanical means is changed from the conventional three rolls to a fine grinding mill such as a mill dispersion method using a medium (media) such as balls or beads, the pigment particles of the colorant can be further micronized, and the grain boundaries are average particle diameters. When it is less than 1 µm and the standard deviation of the particle size distribution is 0.1 to 0.2 µm, it has been found that the above problems can be solved. The present invention has been completed.

Generally, the zeta potential, pH, particle diameter, specific gravity, etc. of a pigment may be determined as factors for determining the dispersion and aggregation of the pigment. Copper phthalocyanine green itself, or copper phthalocyanine with or without halogen, may be used. Since Blue itself has a low zeta potential and a low specific gravity, when it is contained in a low viscosity composition that is easy to flow, it is easy to float on the liquid surface, whereas the particle diameter of each pigment is less than 1 µm in average particle size and When the standard deviation of the distribution was 0.1 to 0.2 µm, the suspension was reduced or did not occur as compared with the average particle diameter of 1 to 8 µm, and it was found that the value was particularly high for inks of low viscosity products.

Therefore, this invention is the resist ink containing (1), (A) coloring agent, (B) curable resin, (C) reactive diluent, (D) polymerization initiator, and (E) filler, The said (A) coloring agent According to the particle diameter measured by the laser diffraction scattering method, the average particle diameter is 0.05 micrometer or more and less than 1 micrometer, and the standard deviation of a particle size distribution provides the resist ink which is 0.1-0.2 micrometer.

In addition, the present invention is (2), a printed wiring board having a coating film of the resist ink of the above (1), (3), at least in a thick concentration (dispersed) by a pulverizer for fine powder using a colorant and a solvent Prepared a rich colorant dispersion, (A ') the colorant rich dispersion, (B) curable resin, (C) reactive diluent, (D) polymerization initiator and (E) filler, the colorant is laser diffraction scattering method (4), at least the colorant, the solvent, and the whole resin, in which the average particle diameter is 0.05 µm or more and less than 1 µm, and the standard deviation of the particle size distribution is 0.1 to 0.2 µm by the particle diameter measured by When the amount is 100 parts by weight, a colorant-rich dispersion in which the colorant is dispersed in a fine powder using a material containing 1 to 50 parts by weight of the colorant, 20 to 60 parts by weight of the solvent, and 10 to 50 parts by weight of the resin is prepared. A ') The colorant rich dispersion, (B) curable resin, (C) reactive diluent, (D) polymerization initiator and (E) filler are mixed, and the colorant is the average particle by the particle diameter measured according to the laser diffraction scattering method. Provided is a method for producing a resist ink having a diameter of 0.05 µm or more and less than 1 µm and a standard deviation of particle size distribution of 0.1 to 0.2 µm.

(11) and (A) colorants contain a blue colorant having no halogen atom in the (A-1) molecular formula and a yellow colorant having no halogen atom in the (A-2) molecular formula, and the blue colorant The resist ink of the above (1) constituting the green color tone by the yellow colorant, (12), (B) the curable resin is a photocurable resin, (C) the reactive diluent is a photopolymerizable reactive diluent, ( D) The green-type soldering resist ink containing the resist ink of said (11) whose polymerization initiator is a photoinitiator, (13), (A) coloring agent, (F) thermosetting resin, and (E) filler, The said (A) ) The colorant contains a blue colorant which does not have a halogen atom in the (A-1) molecular formula and a yellow colorant which does not have a halogen atom in the (A-2) molecular formula and is green based on the blue colorant and the yellow colorant. Resist ink constituting the tint of (14) to (G) containing the resist ink of any of the above (11) to (13) containing the thermosetting compound, (15) to (H) solvent and / or (I) additive The resist ink of any of (14), (16), the resist ink of any of (11) to (15) above, wherein the yellow colorant of the component (A-2) is a colorant having no azo group in its molecular formula. The resist ink of (6) which is at least 1 sort (s) of the isoindolin type coloring agent and anthraquinone type coloring agent, and the blue coloring agent of (18), (A-1) component It has a cured film of the coating film of the resist ink in any one of said (11)-(17) which is phthalocyanine blue, and the resist ink in any one of said (19) and said (11)-(18), for example, mounting an electronic component It is to provide a printed wiring board before or after the following.

In each of the above inventions, "resist ink" may be "solder resist ink" or "colorant" may be "pigment".

Best Mode for Carrying Out the Invention

As the (A) "coloring agent" used in the present invention, pigments such as chlorinated phthalocyanine green, chrome green, cobalt green, chromium oxide green, brominated phthalocyanine green, cobalt chrome green, titanium nickel cobalt zinc-based green, etc. may be mentioned. have.

As the blue colorant, copper phthalocyanine blue (CI Pigment Blue 15), metal phthalocyanine blue (CI Pigment Blue 16), titanyl phthalocyanine blue, iron phthalocyanine blue, nickel phthalocyanine blue which do not contain a halogen atom in the structure , Aluminum phthalocyanine blue, tin phthalocyanine blue, alkali blue (CI Pigment Blue 1, 2, 3, 10, 14, 18, 19, 24, 56, 57, 61), sulfonated CuPc (CI Pigment Blue 17), CI Pigment Blue 27), Navy (CI Pigment Blue 29), Cobalt Blue (CI Pigment Blue 28), Sky Blue (CI Pigment Blue 35), Co (Al, Cr) ₂ O ₄ (CI Pigment Blue 36), Disazo Pigments such as (CI Pigment Blue 25, 26), indanthrone (CI Pigment Blue 60), and indigo (CI Pigment Blue 63,66) cobalt phthalocyanine (CI Pigment Blue 75).

Moreover, as a yellow coloring agent, monoazo yellow (CI Pigment Yellow 1, 4, 5, 9, 65, 74) which does not contain a halogen atom, bentimidazolone yellow (CI Pigment Yellow 120, 151, 175, 180) , 181, 194), Flavantron Yellow (CI Pigment Yellow 24), Azomethyl Yellow (CI Pigment Yellow 117, 129), Anthraquinone Yellow (CI Pigment Yellow 123, 147), Isoindolin Yellow (CI Pigment Yellow 139 185), disazo yellow (CI Pigment Yellow 155), condensed polycyclic (CI Pigment Yellow 148, 182, 192), iron oxide (CI Pigment Yellow 42), disazomethine (CI Pigment Yellow 101), azo reiki (CI Pigments such as Pigment Yellow 61, 62, 100, 104, 133, 168, 169) and metal complexes (CI Pigment Yellow 150, 153, 177, 179). Among these, as the yellow colorant which is halogen-free and does not have an azo group in the molecular formula, at least one organic colorant of an isoindolin-based colorant and an anthraquinone-based colorant of a yellow system may be mentioned. Isoindolin type colorants have weather resistance, solvent resistance, and heat resistance, and are used for high-quality paints and plastic coloring. Specifically, isoindolin yellow, flavans ron yellow, anthrapyrimidine yellow, titanium yellow, etc. are mentioned.

As a green coloring agent, you may use together the 1 type or multiple types of said halogen-free blue colorant, and the 1 or more type of yellow colorant, and the yellow type isoindolin type colorant and anthraqui as a yellow colorant It is also preferable to use at least 1 type of organic type coloring agent of a non-system colorant.

In order to make such a halogen-free coloring agent into the same color tone as the conventional solder resist ink using phthalocyanine-based green, the blue coloring agent is 0.1 to 10 with respect to the yellow coloring agent 1, and more preferably the blue coloring agent is 1 to 10. It is set to 5.

As a coloring agent, a pigment is preferable.

As for the resist ink of this invention, the coloring agent contained in this has an average particle diameter of 0.01 micrometer or more and less than 1 micrometer, More preferably, 0.05 micrometer or more and less than 1 micrometer by the particle diameter of the measurement by the laser diffraction scattering method, Moreover, the standard deviation of particle size distribution is 0.1-0.2 micrometer, particle diameter is smaller than the conventional pigment (average particle diameter 1-8 micrometers), and particle size distribution is narrow.

To make the particle diameter of the pigment small and to narrow the particle size distribution, for example, a disper, a high speed mixer, a homogenizer, etc., when producing a water suspension of the pigment by dispersing the pigment's press cake or dry pigment in water As a conventional stirring, mixing device, or a pulverizer for fine powder production, a disperser which is given a certain degree of mechanical energy such as a pearl mill, a sand mill, an attritor, or the like may be used, and a series of treatments may be performed using the same apparatus. You can also change the device to proceed. Preparation of the water suspension of a pigment can be performed at temperature higher than room temperature or temperature lower than room temperature. When using a pigment slurry or a press cake, agglomeration of a pigment can be easily loosened to the magnitude | size of a primary particle by providing mechanical energy. In addition, when using a dry pigment, it can be set as suitable particle diameter by providing a larger mechanical energy. The average primary particle diameter can be 0.02 to 1 µm (see Japanese Patent Laid-Open No. 2004-35655), and the standard deviation of the particle size distribution can be 0.1 to 0.2 µm.

In addition, as a pulverizer for fine powder manufacture, a beads mill, a ball mill, a jet mill, etc. can also be used besides the above. Moreover, resin can be used with a solvent.

To reduce the particle diameter and narrow the particle size distribution by using a commercially available pigment, a colorant rich dispersion can be prepared using a colorant, and mixed with other components of the resist ink to obtain a resist ink. The grinding method of the coloring agent in the manufacturing process of the coloring agent rich dispersion liquid is different from that of three roll grinding, and the mill dispersion method using a bead mill, pearl mill, ball mill, jet mill, sand mill, attritor, etc. Adopt. In these mills, a grinding method in which a plurality of media (granular media) are diffused by rotational energy and they are crushed to be crushed by contacting and colliding with each other. It can increase. At this time, the colorant is treated together with at least a solvent, preferably a solvent and a resin together with a grinder. When the total amount is 100 parts by weight, 1 to 50 parts by weight of the colorant, 20 to 60 parts by weight of the solvent, and 10 to 50 parts by weight of the resin are used. It is preferable to use the included material. This includes the case where the sum of the weight parts of the colorant, the solvent, and the resin is less than 100 parts by weight. That is, it can also contain other additives, such as a dispersing agent. In the same composition as 10 parts by weight of the colorant, 80 parts by weight of the resin, and 10 parts by weight of the solvent, microdispersion of the colorant is unlikely to occur, as in the case of conventional dispersion by three rolls.

In addition, the solvent and resin mentioned later can also be used for a solvent and resin.

A dispersant may be used together for dispersing by adding mechanical energy with a disperser. As the dispersant, 0.5-30 wt% of an acrylic polymer dispersant (product of Efca Co.) and a polymer dispersant (pigment derivative) (SOLSPERSE32000 / 36000/39000 (Api) CIA company)) and a modified acrylic copolymer (DOPA-15B / -17 / -33 / -44 (manufactured by Kyo-Eisha Co., Ltd.)), and are preferably used in an amount of 0.1 to 5% by weight based on the colorant.

In this way, the average particle diameter of the particle | grains of a coloring agent is a measurement value by a laser diffraction scattering method, It can be 0.01 micrometer or more and less than 1 micrometer, More preferably, it is 0.05 micrometer or more and less than 1 micrometer, The standard deviation is 0.05 micrometer or more It is possible to obtain a particle having a particle size distribution of 0.5 µm or less, still more preferably 0.1 to 0.2 µm, and mix this with other components to produce a resist ink. When the average particle diameter is larger than 1 µm or the standard deviation value is too large, it is difficult to suppress the deterioration of color development and instability of color tone.

As "(B) curable resin" used by this invention, at least of epoxy acrylate resins, such as the novolak-type epoxy acrylate which made the epoxy resin react with (meth) acrylic acid, etc., and its carboxylic acid addition product (water solubility becomes high) 1 type is mentioned. Although such resin can be made into the photopolymerizable photocurable type by ultraviolet rays etc., it can also be made into a thermosetting type, and may contain "(F) thermosetting resin" in this. Examples of the "(F) thermosetting resin" include an epoxy resin.

As the "(C) reactive diluent" used in the present invention, curing properties such as photocurability and the like of the reaction product of the component (B) are more sufficiently used to obtain a coating film having acid resistance, solvent resistance, heat resistance and the like. . As typical examples thereof, for example, hydroxy (meth) acrylate, 1,4-butanedioldi (meth) acrylate, 1,6-hexanedioldi (meth) acrylate, neopentyl glycol di (meth) acrylate , Polyethylene glycol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, hydroxy piperine acid neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified Dicyclopentenyldi (meth) acrylate, EO-modified phosphate di (meth) acrylate, allyl cyclohexyldi (meth) acrylate, isocyanurate di (meth) acrylate, trimetholpropane tree (meth) Acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, PO modified trimetholpropane Tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) Reactive diluents, such as an acrylate, are mentioned. These reactive diluents can be used either singly or in combination of two or more.

As "(D) polymerization initiator" used by this invention, the photoinitiator generally used is mentioned in a photopolymerizable composition. Typical examples thereof include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2 , 2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl Ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propane-1-one, benzophenone, 4,4-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthra Quinone, 2-ethylanthraquinone, 2-tertiary-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethyl thi Oxanthone, 2,4-diethyl thioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, P-dimethylamino benzoic acid ethyl ester and the like, and the like can be used alone or in combination. All.

As the "(E) filler" used in the present invention, for example, silica, talc, clay, magnesium carbonate, calcium carbonate, natural mica, synthetic mica, aluminum hydroxide, precipitated barium sulfate, barium titanate, iron oxide, nonfibrous glass, Inorganic pigments such as asbestos, mineral wool, aluminum silicate, calcium silicate, galvanized steel and titanium oxide. The filler can be used either alone or in a mixed system.

In the present invention, a "(G) thermosetting compound" can be used, for example, (propylene, polypropylene) glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, 2-ethylhexyl glycy Dil ether, phenylglycidyl ether, p-tertiarybutylphenylglycidyl ether, lauryl alcohol glycidyl ether, glycerol polyglycidyl ether, trimethyrol propane polyglycidyl ether, resorcin diglycidyl Ether, 1,6-hexanediol diglycidyl ether, (ethylene, propylene) glycol diglycidyl ether, sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, pentaerythritol polyglycidyl ether, tris Epoxy compounds, such as (2, 3- epoxypropyl) isocyanurate and triglycidyl tris (2-hydroxyethyl) isocyanurate, melamine, such as methylated melamine, butylated melamine, and hexamethoxy methylol melamine A compound, another phenol compound, a polyester compound, etc. are mentioned, These can be used individually or in combination.

In addition, in this invention, "(H) solvent" can be used, For example, ethylene glycol monoalkyl ether or its acetate, diethylene glycol mono or dialkyl ether, propylene glycol monoalkyl ether or its Acetates, dipropylene glycol mono or dialkyl ethers, methyl carbitol, butyl carbitol, butyl cellosolve acetate, carbitol acetate, ethyl methyl ketone, cyclohexane, toluene, xylene, tetramethylbenzene, petroleum ether, petroleum Naphtha, solvent naphtha, etc. are mentioned, These can be used individually or in combination.

In addition, in this invention, "(I) additive" can be used, For example, dispersing agents, such as antifoamers, such as a silicone type, a hydrocarbon type, an acryl type, coupling agents, such as a silane type, a titanate type, and an alumina type, are mentioned. , Boron trifluoride-amine complex, dicyandiamide (DICY) and derivatives thereof, organic acid hydrazide, diaminomaleonitrile (DAMN) and its derivatives, melamine and its derivatives, guanamine and its derivatives, amineimide (AI ), Latent curing agents such as salts of polyamines, metal salts of acetylacetone such as acetylacene Zn, acetylaceite Cr, enamine, octylic acid tin, quaternary sulfonium salts, triphenylphosphine, 1,8-dia Thermosetting accelerators such as Xavicyclo (5,4,0) undecene-7 and 2-ethylhexanoate and phenol salts, imidazole, imidazolium salt, triethanolamine borate, and the like, and these alone or in combination It is available.

The resist ink of the present invention obtained by mixing the above components may have a halogen content of less than 1000 ppm, more preferably less than 500 ppm, and an amine elution amount of the cured product may be less than 100 ppm, more preferably less than 10 ppm. .

To obtain a solder resist film using the resist ink of the present invention as solder resist ink, three methods can be applied.

The first method is used as a photopolymerizable resin composition for photocuring such as ultraviolet light, and forms a coating liquid film of a pattern of a portion which does not require soldering of a circuit pattern by coating means such as screen printing. For example, by photosensitive with an ultraviolet curing furnace, the cured film of the coating film of the target soldering resist can be formed. In addition, although the 2nd method is used for photocuring, such as an ultraviolet-ray, as a photopolymerizable resin composition, when performing post-exposure image development, after apply | coating soldering resist ink to a board | substrate, it is 60-80 degreeC for 15 to 60 minutes. After heating to volatilize the organic solvent, the dry coating film is brought into contact with the negative film of the desired pattern, and then irradiated with light such as ultraviolet rays, and then developed by removing the non-exposed area using a rare alkali aqueous solution. Way. As a rare alkali aqueous solution used here, 0.5-5.0 weight% of sodium carbonate aqueous solution is common, but other alkaline aqueous solution can also be used. The developed coating film is postcure about 30 minutes, for example with a 150 degreeC hot-air circulation type dryer, and can form the cured film of the coating film of the target soldering resist. And the 3rd method is a case where it uses when it uses for thermosetting as a resin composition for thermosetting, after forming said pattern by application means, such as a screen printing method, thermosetting by heating means, such as a far-infrared curing furnace or a hot air drying furnace, The cured film of the coating film of the target soldering resist can be formed.

Although the above is a negative type using a negative film of a pattern, the resist ink of this invention can be applied also to the positive type using a positive film of a pattern.

Example 1

"Part" in an Example means a "weight part", and is as follows.

(Production of Blue Colorant Rich Dispersion)

250 parts of epoxy acrylate resin (THPA and GMA (glycidyl methacrylate) addition resin) (made by Nippon Ink Chemical Co., Ltd.), 250 parts of lionol blue FG-7351 (copper phthalocyanine blue manufactured by Dongyang Ink Co., Ltd.) , 500 parts of propylene glycol monomethyl ether acetate (PMA) (manufactured by Samyang Chemicals) were weighed and stirred and mixed by a dissolver (manufactured by Turbo Industries, Ltd.) (rotational speed 300 ± 50 rpm, mixing time: 2 minutes ± 1 minute, content temperature 10-35 degreeC), pre-dispersion, and 1000 parts of pre-dispersion liquids are obtained.

Then, 1 mm of zirconia beads are added to the preliminary dispersion, and dispersed six times using a lateral wet sand mill (manufactured by Shinmar Enterprise Co., Ltd.) at a driving speed of 20 m / sec at a circumferential speed. , A blue colorant rich dispersion is obtained.

About this blue colorant rich dispersion liquid, the particle diameter of the measurement by the laser diffraction scattering method particle size distribution measuring apparatus (product name; BECKMAN COUNTER type; LS230) was less than 1 micrometer in average particle diameter, and the standard deviation was 0.182 micrometer.

(Production of Yellow Colorant Rich Dispersion)

In the same manner as above, 1000 parts of a yellow colorant-rich dispersion was obtained in the same manner except that flavansrone yellow (compound (C.I. PIGMENT YELLOW 24) represented by [Formula 1] below) was used instead of lionol blue FG-7351.

About this yellow colorant rich dispersion liquid, the particle size distribution of the measurement by the said measuring apparatus can be shown in FIG. 1, The particle diameter was 0.118 micrometers in average particle diameter, The standard deviation was 0.016 micrometer.

[Equation 1]

(Manufacture of Solder Resist Ink)

8.0 parts of dipentaerythritol hexaacrylates and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one 8.0 to 100 parts of carboxylic acid addition novolak-type epoxy acrylate resins Part, 8.0 parts of triglycidyl tris (2-hydroxyethyl) isocyanurate (thermosetting compound), 1.2 parts of the above-mentioned blue colorant rich dispersion, 1.2 parts of the above yellow colorant dispersion, 0.3 parts of dicyandiamide, polymer antifoaming agent After 0.5 part, 20 parts of fused silica, and 30 parts of precipitated barium sulfate were mixed and dispersed by three rolls, the viscosity was adjusted to 2 dPa * s with the propylene glycol monomethyl ether acetate.

(Application to the printed wiring board)

The photo- and thermosetting solder resist inks thus obtained are coated on the entire surface of the printed wiring board after the surface treatment by a bar coater (thickness of 80 µm of the undried coating film), followed by preliminary drying (80 ° C., 20 minutes). Then, the negative film on which the pattern was formed was brought into contact with each other for exposure (500 mJ / cm ² ), followed by development (immersed in 1% sodium carbonate aqueous solution for 60 seconds), followed by post cure (150 ° C., 30 minutes), followed by heat. It hardened | cured and the coating film of the pattern which hardened | cured by light and heat was formed, and the printed wiring board which formed the cured film of the coating film of green soldering resist ink by this was obtained.

Comparative example  One

In the manufacture of the blue colorant rich dispersion liquid in Example 1, the manufacture of the yellow colorant rich dispersion liquid, 800 parts of THPA and GMA (glycidyl methacrylate addition resin), 100 parts of lionol blue FG-7351, propylene glycol 100 parts of monomethyl ether acetate (PMA) was used, and instead of using a pearl mill, it was dispersed using three rolls of iron, and this was carried out twice. At first, the maximum particle diameter was 19 µm and the average particle diameter was 15 µm. Secondly, a blue colorant-rich dispersion liquid was prepared in the same manner as in Example 1 except that the maximum particle diameter was 12 µm and the average particle diameter was 10 µm (the particle diameter was 0 to 25 µm using a grind gauge). In the blue colorant rich dispersion, the average particle diameter was larger than 1 m and the standard deviation was larger than 0.2 m in the blue colorant rich dispersion.

In addition, 1000 parts of yellow colorant rich dispersion liquids were obtained similarly except using flavansrone yellow (compound (C.I. PIGMENT YELLOW 24) represented by said [formula 1]) instead of lionol blue FG-7351.

About this yellow colorant rich dispersion liquid, the particle size distribution of the measurement by the said measuring apparatus can be shown in FIG. 2, The particle diameter was 0.205 micrometer in average particle diameter, The standard deviation was 0.249 micrometer.

A solder resist ink was prepared in the same manner as in Example 1 except that the obtained blue colorant rich dispersion and the yellow colorant rich dispersion were used instead of the corresponding colorant rich dispersion, and were applied to the printed wiring board in the same manner as in Example 1. did.

The following experiment was performed about the printed wiring board and soldering resist ink before electronic component mounting obtained in the said Example 1 and the comparative example 1.

(1) solder heat resistance

About the cured film of the coating film of the soldering resist ink of each obtained printed wiring board, it immersed in 260 degreeC molten solder accommodated in the solder tank for 30 second according to the test method of JIS C 6481, and the cellophane tape (brand name) is hardened after that The so-called peeling test, which is rubbed off with a finger on a film, is carried out, and one test is used as one cycle, which is performed up to three cycles in the same portion. Table 1 shows the results of visually observing the degree of peeling of the cured film and evaluating it according to the following criteria.

◎: No change in coating after 3 cycles

(Circle): what changes very little after 3 cycles.

(Triangle | delta): What changes after 2 cycles

X: causing peeling after 1 cycle

(2) chemical resistance

About the cured film of the coating film of the soldering resist ink of each obtained printed wiring board, after immersing in 10% hydrochloric acid aqueous solution for 30 minutes, the state of a cured film is visually observed and the result evaluated by the following reference | standard is shown in Table 1. .

◎: A change is not fully recognized

○: very slightly changing

△: remarkably changing

X: The coating film swelled and peeled off

(3) solvent resistance

About the cured film of the coating film of the soldering resist ink of each obtained printed wiring board, after immersing in methylene chloride for 30 minutes, the state of a cured film is visually observed and the result evaluated by the following reference | standard is shown in Table 1.

◎: Not fully recognized for change

○: very slightly changing

△: remarkably changing

X: The coating film swelled and peeled off

(4) electrical characteristics

On the cured film of the coating film of the soldering resist ink of each obtained printed wiring board, the comb-shaped electrode of IPC-SM-840B B-25 test coupon was put in DC (direct current) in the constant temperature and humidity chamber of 60 degreeC and 90% RH (relative humidity). 100V was applied and the grade of discoloration of the copper foil of the insulation resistance and a circuit pattern after 500 hours was investigated. The measured value of the insulation resistance is shown in Table 1, and the coating degree of the copper foil is visually observed, and the result evaluated by the following criteria is shown in Table 1

◎: not discolored at all

○: lightly discolored

△: remarkably discolored

×: black pressed

(5) Amine elution amount

The sample for measurement is prepared by scraping and fine-pulverizing the cured film of the coating film of the soldering resist ink of each obtained printed wiring board, and detecting by ion chromatography.

The measured value is shown in Table 1.

(6) viscosity stability of solder resist ink

Each obtained soldering resist ink was filled into a polypropylene container and sealed, and it accommodated in a 70 degreeC hot-air circulation test machine, the degree of the viscosity increase was measured with a viscometer, and the result evaluated by the following reference | standard is shown in Table 1 Indicates.

(Double-circle): The thing which a viscosity rise is not seen more than seven days is seen

(Circle): Viscosity rises or gelatinizes twice or more in 5-6 days.

(Triangle | delta): The viscosity rises or gelatinizes 2 or more times in 3 to 4 days.

X: viscosity rises or gelatinizes 2 times or more in 1-2 days

(7) suspension of blue pigment

Each obtained soldering resist ink was put into a beaker, it sealed, it left to stand at 25 degreeC for 72 hours, the state was visually observed, and the result evaluated by the following reference | standard is shown in Table 1.

◎: No floating of blue pigment

(Circle): Floating of a blue pigment is seen a little

×: blue pigment floating on the surface

(B) color separation test

The viscosity was adjusted by adding PMA (propylene glycol monomethyl ether acetate) so that 300 g of the soldering resist ink which concerns on an Example and a comparative example became 25% in a beaker, and ink viscosity was measured by 70S (Iwatacap NK-2) )

While stirring this ink at low speed with the stirrer (SRS 311HA by ADVANTEC company), the aging change is observed every 24 hours for 24 hours, and the result evaluated by the following reference | standard is shown in Table 1.

○: without color separation

△: color separation is visible

×: severe color separation

As a result, as shown in the table, in the examples, even after 24 hours, it is "(circle)", there is no separation of the pigment, the dispersibility of the pigment is maintained, and both the color tone and the color development are good, whereas the solder resist ink of the comparative example is After 12 hours, it was "Δ", and after 24 hours, it was "x", and the dispersibility of the pigment deteriorated with each passing of time (more specifically, color separation occurred, and after 24 hours, the blue pigment was suspended and the centrifugal force The larger particles are on the outside, the smaller particles are on the inside, and a double concentric shape with a diameter ratio of about 1: 5 (the inner circle is the circle of particles, the outer circle is 1/5 of the outside, and gradually It became a rounded circle that became thinner toward the inside, and the tendency could be clearly discerned after 12 hours), and the color tone and color development were also deteriorated.In grapes is set narrower, the resist ink using the same, good dispersibility of the pigment, is also holding the dispersion. Also, as a result, it can be seen that even hard to deteriorate the color forming property and color tone.

(9) Application test by curtain coater

3 is a schematic diagram showing a known curtain coater 10. As shown in Fig. 3, the surface-preprinted printing is carried out by the conveyor 1, which is wound around the shaft support main rollers 8A and 8B by a motor (not shown) and moved linearly in the direction of the arrow A. While conveying the wiring board 2 one by one, the photo-thermosetting solder resist ink obtained above is flown from the ink head 3, and is apply | coated. In the ink head 3, ink transferred by the pump 6 from the ink tank 4 through the ink receiver 5 is circulated and supplemented as the photo-thermosetting solder resist ink through the filter 7 and reused. .

In this way, it coated on the whole surface of this printed wiring board, and it processed on the conditions similar to the case of the coating by said bar coater below, and obtained the printed wiring board which formed the cured film of the coating film of green soldering resist ink by this.

Also in the case of application by the curtain coater 10, the photo-thermosetting solder resist ink can improve the dispersibility and retention, and the color development is also stabilized, so that a uniform stable color film can be obtained. In addition, since color separation does not occur even in the ink tank at the time of manufacture (when mass production), and the ink receiver 5 can be enlarged, the equipment of the entire curtain coater 10 can be enlarged and a more stable color tone It is possible to increase the production efficiency of a printed wiring board having a resist ink coating method of the present invention, and furthermore, to reduce not only the cost of the product but also to prevent color problems in advance.

TABLE 1

Example 1 Comparative Example 1 Solder heat resistance ◎ ◎ Chemical resistance ◎ ◎ Solvent resistance ◎ ◎ Electrical characteristics Insulation Resistance × 10 ¹² (Ω) 2.5 2.5 discoloration ◎ ◎ Viscosity stability ◎ ◎ Amine elution amount (ppm) <5 <5 Floating of blue pigment ○ × Color separation test ○ ×

[Industry availability]

The resist ink of the present invention can be used as a resist ink such as solder resist ink applied to a printed wiring board or the like.

According to the present invention, since a resist ink using a colorant having an average particle diameter of less than 1 m and a standard deviation of particle size distribution of 0.1 to 0.2 m can be provided, uniform dispersion of the colorant particles in the ink and good color development It is possible to provide a resist ink such as a solder resist ink having a, and a hue stability, and particularly hard to impair such performance even in a low viscosity product.

In addition, since the printed wiring board before or after mounting the electronic component having the cured film of the coating film of the resist ink can be provided, the coating film has a good color development and color tone stability, and is not only visually burdened, but also the product value. It can increase.

In addition, since the colorant was dispersed using a pearl mill or the like, the dispersed particles can be less than 1 µm in average particle diameter, and the standard deviation of the particle size distribution can be set to 0.1 to 0.2 µm. It can be made easier by making a pigment and a solvent ratio high.

And even if it coats by a curtain system or a spray system, even if the line is paused or the said coating apparatus is enlarged, the printed circuit board which has the resist ink which can obtain a uniform stable color tone, and its cured film can be provided.

Claims (4)

In the resist ink containing (A) a coloring agent, (B) curable resin, (C) reactive diluent, (D) polymerization initiator, and (E) filler, the said (A) coloring agent measured particle | grains by the laser diffraction scattering method. The resist ink whose average particle diameter is 0.01 micrometer or more and less than 1 micrometer by diameter, and the standard deviation of a particle size distribution is 0.1-0.2 micrometer. The printed wiring board which has a coating film of the resist ink of Claim 1. A colorant-rich dispersion in which the colorant is dispersed in a rich manner using a pulverizer for fine powder production, using at least a colorant and a solvent, is prepared. ) The polymerization initiator and (E) filler are mixed, and the said coloring agent has an average particle diameter of 0.01 micrometer or more and less than 1 micrometer by the particle diameter measured by the laser diffraction scattering method, and the standard deviation of particle size distribution is 0.1-0.2 micrometer. Process for producing in resist ink. When at least 100 parts by weight of the colorant, the solvent, and the resin were used, the colorant was concentrated in a fine powder mill using a material containing 1 to 50 parts by weight of the colorant, 20 to 60 parts by weight of the solvent, and 10 to 50 parts by weight of the resin. A colorant rich dispersion is prepared, (A ') the colorant rich dispersion, (B) curable resin, (C) reactive diluent, (D) polymerization initiator and (E) filler, and the colorant is laser diffraction scattering method The manufacturing method of the resist ink whose average particle diameter is 0.05 micrometer or more and less than 1 micrometer, and the standard deviation of a particle size distribution is 0.1-0.2 micrometer by the particle diameter measured by.

Images