JP2005089659A - Resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition capable of providing a cured product which can exhibit not only excellent insulating property and heat resistance, but also excellent plating resistance and being cured by light and/or heat. <P>SOLUTION: The resin composition comprises (A) a bismaleimide compound, (B) a photopolymerization initiator, (C) a photopolymerizable compound having an ethylenic unsaturated bond, (D) a thermosetting resin and (E) a triazole compound having an amino group or a mercapto group and the resin composition is cured by light and/or heat. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a resin composition, in particular, a resin composition that is cured by light and / or heat.

  Thermoelectric resins such as epoxy resin, phenol resin, melamine resin, and bismaleimide are generally used as electrically insulating organic materials that constitute insulating layers and protective films in laminated boards used for electronic components such as printed wiring boards. Has been used. Among these, in particular, bismaleimide is a material that can exhibit excellent insulating properties and heat resistance, and is considered to be extremely useful for the above-described applications.

  However, since this bismaleimide is expensive, the cost tends to increase when it is used in a large amount, and the unsaturated bond of bismaleimide has low reactivity. Its use has not always been easy, such as requiring long-time heating. For this reason, bismaleimide has often been used as a laminated material for substrates in laminated boards and printed wiring boards, and has been rarely used for other applications.

In recent years, in order to further utilize the properties of bismaleimide such as insulation and heat resistance, a resin composition having excellent thermosetting and photocuring properties is prepared by combining bismaleimide with a predetermined curing component. Attempts have been made to use this as an interlayer insulating material or solder resist for printed wiring boards (see, for example, Patent Document 1).
JP 11-100409 A (page 2-7)

  By the way, the protective film such as solder resist formed on the printed wiring board prevents the adhesion of solder to unnecessary places during soldering, as well as maintaining the insulation from the outside and protecting the wiring pattern. As an object, the wiring board is formed on a surface having a wiring pattern. Here, in the production of a printed wiring board, after these protective films are formed, nickel plating or gold plating is generally performed for the purpose of forming a terminal for an electrode at a predetermined site. It is. In addition, these platings are often performed by electroless plating in order to cope with the recent increase in the density of printed wiring boards. In this case, since electroless plating tends to have a lower deposition rate than conventional electroplating, plating is usually performed under a high temperature condition of 85 to 98 ° C. in order to increase the deposition rate.

  However, when electroless plating is carried out under high temperature conditions in the production of a printed wiring board in this way, if the conventional resin composition containing bismaleimide is applied to the protective film, discoloration or penetration occurs in the protective film. It tended to be easy. If it becomes like this, a protective film will deteriorate and the tolerance with respect to a plating solution will become inadequate.

  The present invention has been made in view of the above circumstances, and can be cured by light and / or heat to obtain a cured product that can exhibit not only excellent insulation and heat resistance but also excellent plating resistance. An object is to provide a composition.

  As a result of intensive studies, the present inventors have found that the metal (mainly copper) forming the wiring pattern in contact with the protective film is discolored or penetrated into the protective film such as solder resist on the printed wiring board. It was found that it was caused by oxidation during plating. Thus, it has been found that if the metal oxidation that occurs during plating can be suppressed, the plating resistance of the protective film can be improved, and the present invention has been completed.

  That is, the resin composition of the present invention is (A) a bismaleimide compound, (B) a photopolymerization initiator, and (C) a photopolymerizable compound having an ethylenically unsaturated bond (hereinafter referred to as “photopolymerizable compound”). ), (D) a thermosetting resin, and (E) a triazole compound having an amino group or a mercapto group (hereinafter referred to as “triazole compound”), and is cured by light and / or heat.

  The resin composition of the present invention contains a triazole compound having an amino group or a mercapto group in the composition, and according to the knowledge of the present inventors, this triazole compound is added to other resin components, etc. When it is brought into contact with a metal in a mixed state, the oxidation reaction of the metal can be remarkably suppressed. Therefore, a protective film such as a solder resist formed from such a resin composition is a metal film forming a wiring pattern even when electroless plating is performed on a printed wiring board provided with the resin composition under high temperature conditions. Oxidation can be greatly suppressed. As a result, these protective films are very unlikely to undergo discoloration or penetration during plating. Moreover, since the said resin composition contains bismaleimide in a composition, the protective film which is the hardened | cured material will be extremely excellent in insulation and heat resistance. Furthermore, since this resin composition contains a photopolymerization compound and a photopolymerization initiator at the same time, the curability by light is extremely high, and a protective film can be easily formed.

［式中Ｒ^１、Ｒ^２及びＲ^３は、それぞれ独立に水素原子、アミノ基、メルカプト基、カルボキシル基又はヒドラジノ基を示す。ただし、Ｒ^１、Ｒ^２及びＲ^３のうち少なくとも１つはアミノ基又はメルカプト基である。］ Here, the triazole compound is preferably a triazole compound represented by the following general formula (1a) or (1b).

[Wherein R ¹ , R ² and R ³ each independently represents a hydrogen atom, an amino group, a mercapto group, a carboxyl group or a hydrazino group. However, at least one of R ¹ , R ² and R ³ is an amino group or a mercapto group. ]

  More specifically, as the triazole compound, 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, 3-amino-1,2,4-triazole-5-carbon Acid, 3-mercapto-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, 3-amino-5-mercapto-1,2,4-triazole, 4-amino-3- And at least one compound selected from the group consisting of hydrazino-5-mercapto-1,2,4-triazole.

  By using these compounds as the triazole compound, the plating resistance of the protective film formed tends to be further improved.

［式中、Ｒ^２１は、水素原子、ハロゲン原子又はアルキル基、Ｒ^２２はアルキレン基、アリーレン基及びオキシ基からなる群より選ばれる基を一つ以上有していてもよい２価の基を示し、ｒは１〜４、ｍは０又は１の整数を示す。なお、複数存在するＲ^２１はそれぞれ同一でも異なっていてもよい。］ Furthermore, as the bismaleimide compound, a bismaleimide compound represented by the following general formula (2) is preferable.

[Wherein R ²¹ represents a hydrogen atom, a halogen atom or an alkyl group, and R ²² represents a divalent group which may have one or more groups selected from the group consisting of an alkylene group, an arylene group and an oxy group. R is 1-4, m is an integer of 0 or 1. A plurality of R ²¹ may be the same or different. ]

  By using such a compound as the bismaleimide compound, not only the heat resistance and insulation of the obtained cured product are further improved, but also the mechanical strength of the protective film made of the cured product is improved.

  Further, the thermosetting resin is preferably at least one resin selected from the group consisting of epoxy resins, resins having phenolic hydroxyl groups, melamine resins, and cyanate ester resins. By containing these resins in the resin composition, the resulting resin composition exhibits good thermosetting properties and is more convenient.

  According to the resin composition of the present invention, after a protective film such as a solder resist such as a printed wiring board is formed, even if the printed wiring board is plated under high temperature conditions, the color changes to the protective film. There is very little occurrence of soaking. Further, the protective film thus formed has excellent insulating properties and heat resistance.

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

  The resin composition of the present invention contains the components (A) to (E) described above as essential components, and is particularly suitable as a material for forming a protective film such as a solder resist in a laminated board such as a printed wiring board. It is. Hereinafter, each of these components will be described.

(Bismaleimide compound)
(A) As a bismaleimide compound, the bismaleimide compound containing one or more aromatic rings is mentioned, The compound represented by the said General formula (2) is mentioned as a more suitable example.

In the compound represented by the general formula (2), when R ²¹ is a halogen atom, a bromo group is preferable, and when it is an alkyl group, a methyl group or an ethyl group is preferable. The alkylene group of R ²² is preferably an alkylene group having 1 to 3 carbon atoms, and the arylene group is preferably a phenylene group which may have a substituent, and may have one or more of these groups. As the valent group, a group represented by —O—Ph—R ²³ —Ph—O— is preferable. Ph represents an optionally substituted phenylene group, and R ²³ represents an alkylene group having 1 to 3 carbon atoms.

  Examples of the bismaleimide include m-di-N-maleimidylbenzene, bis (4-N-maleimidylphenyl) methane, 2,2-bis (4-N-maleimidylphenyl) propane, 2,2 -Bis (4-N-maleimidyl-2,5-dibromophenyl) propane, 2,2-bis [4- (4-N-maleimidylphenoxy) phenyl] propane, 2,2-bis (4-N- And maleimidyl-2-methyl-5-ethylphenyl) propane. These can be used alone or in combination.

(Photopolymerization initiator)
(B) A photoinitiator is a component which mainly initiates the polymerization reaction of a photopolymerizable compound, which will be described later, and thereby accelerates the curing reaction of the resin composition by light. As the photopolymerization initiator, a known component having a property of initiating a polymerization reaction by light can be used without particular limitation, and for example, a radical initiator is preferable. Examples of the radical initiator include benzophenone, 4,4-bisdimethylaminobenzophenone, 3,3-dimethyl-4-methoxybenzophenone, 3,3,4,4-tetra (t-butylperoxycarbonyl) benzophenone, Aromatic ketones such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-dimethoxy-1-phenylpropan-1-one, benzoin ethyl ether, benzoin butyl ether, benzoin Benzoin ethers such as isobutyl ether, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, thioxanthone compounds such as 2,4-dimethylthioxanthone, 1,2-di 9-acridinylethane, 1,3-di-9-acridinylpropane, 1,4-di-9-acridinylbutane, 1,7-di-9-acridinylheptane, 1,8-di Examples include acridinin derivatives such as -9-acridinyloctane, benzoin compounds such as methylbenzoyl formate, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane, azobisisobutylnitrile, and the like.

(Photopolymerizable compound)
(C) The photopolymerizable compound is a compound having a property of being polymerized by light irradiation, and is a component capable of improving the photocurability of the resin composition. The photopolymerizable compound preferably has one or more ethylenically unsaturated groups in the molecule, and the unsaturated group is a compound that can contribute to the polymerization reaction by light. Examples of such photopolymerization compounds include (meth) acrylate monomers or oligomers that are alkyl esters of 1 to 8 carbon atoms of (meth) acrylic acid, and epoxy acrylates that are (meth) acrylic acid adducts of bisphenol diglycidyl ether. Or the acrylic modified novolak epoxy resin etc. which added acrylic acid to the novolak-type epoxy resin can be illustrated. In addition, (meth) acrylic acid means acrylic acid or methacrylic acid, and (meth) acrylate means acrylate or methacrylate.

  Especially, as a photopolymerizable compound, it is preferable to use an acrylate monomer or an acrylate oligomer. As the acrylate oligomer, a low molecular weight oligomer (for example, an oligomer having a polymerization degree of 2 to 10) is more preferable. These compounds have the property of imparting appropriate flexibility to the resin composition, and the handleability of the resin composition is improved by using these compounds.

(Thermosetting resin)
(D) The thermosetting resin is a thermosetting component excluding the bismaleimide compound in the resin composition, and imparts a suitable thermosetting property to the resin composition of the present invention and improves the strength after curing. It has the characteristics that can be made. As the thermosetting resin to be contained in the resin composition, those not having reactivity with the bismaleimide compound are preferable, for example, a group consisting of an epoxy resin, a resin having a phenolic hydroxyl group, a melamine resin, and a cyanate ester resin. Examples thereof include at least one resin selected from the above.

  Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, bisphenol AD type epoxy resin, phenol novolac type epoxy resin, cresol type epoxy resin, aliphatic Examples include epoxy resins, cycloaliphatic epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, heterocyclic epoxy resins, and epoxidized polybutadiene resins.

  Moreover, the acid-modified product of the epoxy resin mentioned above can also be used preferably. Such an acid-modified product is preferably a modified product modified with an unsaturated acid. Examples of the unsaturated carboxylic acid that is a preferable example of the unsaturated acid include maleic anhydride, tetrahydrophthalic anhydride, itaconic anhydride, acrylic acid, and methacrylic acid. The acid-modified product of this epoxy resin can be obtained by reacting an equivalent amount or an equivalent amount or less of an unsaturated carboxylic acid to the epoxy group in the epoxy resin.

  When acid-modified products of these epoxy resins are used as the thermosetting resin, development using an inexpensive developer such as an alkaline developer or an aqueous developer is possible, making the production of printed wiring boards easier. Can be implemented. On the other hand, even when an epoxy resin that is not acid-modified is used, development is possible by using a solvent such as cyclohexanone or butyl carbitol.

  Examples of the resin having a phenolic hydroxyl group include a phenol resin, an alkylphenol resin, a novolac phenol resin, an acid-modified novolac phenol resin, bisphenol A, and tetrabromobisphenol A. One or more of these may be used. Can do.

  Furthermore, as thermosetting resins other than those described above, melamine resins, cyanate ester resins and the like can also be used, and these may be used in combination with the above-described phenol resins.

(Triazole compound)
(E) A triazole compound is a compound in which at least one amino group or mercapto group is substituted at a substitutable site of triazole. As the triazole compound, either 1,2,4-triazole or 1,2,3-triazole may be used, but 1,2,4-triazole is more preferable, and in particular, the above general formula (1a) or The triazole compound represented by (1b) is preferable.

  Examples of the triazole compound represented by the general formula (1a) or (1b) include 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, and 3-amino-1,2 , 4-triazole-5-carboxylic acid, 3-mercapto-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, 3-amino-5-mercapto-1,2,4- Examples include triazole and 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole. Among these, at least one triazole compound is preferably used.

  By adding such a triazole compound to the resin composition, a metal (for example, copper) that is in contact with the solder resist when the resin composition is applied to a protective film such as a solder resist of a printed wiring board Thus, it becomes possible to greatly suppress the discoloration and penetration that are likely to occur in the protective film during plating.

  Next, the compounding amount of each component will be described.

  (A) The blending amount of the bismaleimide compound is preferably 5 to 90% by weight and preferably 10 to 60% by weight based on the total weight of the bismaleimide compound, the photopolymerization initiator and the photopolymerizable compound. Is more preferable. When the blending amount of the bismaleimide compound is less than 5% by weight, the characteristics of the bismaleimide are not sufficiently exhibited and the electric insulation and heat resistance of the cured product tend to be lowered, and the yellow hue is insufficient. Therefore, the photosensitivity tends to decrease. Moreover, when it exceeds 90 weight%, a resin composition may shrink | contract at the time of hardening, and the brittleness of hardened | cured material may fall.

  The blending amount of the (B) photopolymerization initiator is preferably 0.1 to 10% by weight based on the total weight of the bismaleimide compound, the photopolymerization initiator and the photopolymerizable compound, More preferably, it is made into 5 weight%. Furthermore, it is preferable that the compounding quantity of (C) photopolymerizable compound shall be 2 to 50 weight% on the basis of the total weight of a bismaleimide compound, a photoinitiator, and a photopolymerizable compound. If the amount of the photopolymerizable compound is less than 2% by weight, the resin composition tends to be insufficiently cured by light irradiation. If it exceeds 50% by weight, shrinkage may occur during curing or the resin may be cured. Things tend to be fragile.

  Furthermore, it is preferable that the compounding quantity of (E) triazole compound is 0.01-5 weight part with respect to the total weight of a bismaleimide compound, a photoinitiator, and a photopolymerizable compound, 0.05-3 More preferred are parts by weight. When the blending amount of the triazole compound is less than 0.01 part by weight, the heat resistance of the cured product tends to decrease, and when it exceeds 5 parts by weight, the storage stability of the resin composition tends to decrease.

  The resin composition of the present invention may further contain other components. For example, as a filler, silica, fused silica, talc, alumina, hydrated alumina, barium sulfate, aluminum hydroxide, magnesium hydroxide, Inorganic fine particles such as calcium hydroxide, airgel, calcium carbonate, powdered epoxy resin, powdered polyimide particles, powdered Teflon (registered trademark) particles, etc., in an amount of 2 to 70% by weight in the total solid weight of the resin composition Preferably, 5 to 50 parts by weight can be added. In addition, these fillers may be subjected to a coupling treatment in advance, and dispersion in these resin compositions may be performed by a kneading method such as a kneader, a ball mill, a bead mill, or a three roll. it can.

  Moreover, a polymerization stabilizer, a leveling agent, a pigment, dye, an adhesive improvement agent etc. can be contained about 0.01 to 10 weight% in the total weight of a resin composition as needed.

  When the resin composition of the present invention is applied to a protective film or the like of a printed wiring board, the protective film is a resin layer made of the resin composition of the present invention on a substrate on which a wiring pattern of the printed wiring board is formed. After forming, the resin layer can be cured.

  As a method for forming a resin layer on a substrate, first, a method of drying a resin composition solution or varnish as described later after coating on the substrate can be mentioned. Examples of the method for applying the solution or varnish on the substrate include a dip coating method, a roll coating method, a flow coating method, a screen printing method, a spray method, and an electrostatic spray method. The thickness of the resin layer formed by these methods is preferably about 5 to 100 μm.

  The resin composition solution or varnish described above is obtained by dissolving or dispersing the above-described resin composition of the present invention in a predetermined solvent. Examples of the solvent used at this time include ketone compounds such as methyl ethyl ketone, acetone and cyclohexanone, aromatic hydrocarbon compounds such as xylene and toluene, and amide compounds such as N, N-dimethylformamide and N, N-dimethylacetamide. Depending on the solubility of the resin, a solvent such as ethylene glycol monoethyl ether or ethyl ethoxypropionate can be used, and a solvent in which these are combined with other solvents as described above is also suitable. These may be used alone or in combination.

  The amount of the solvent added when preparing the resin composition solution or varnish is preferably 10 to 200 parts by weight, preferably 30 to 100 parts by weight, based on 100 parts by weight of the solid content of the resin composition. Is more preferable. If the blending amount is less than 10 parts by weight, the viscosity becomes high and uniform mixing becomes difficult, and the handleability tends to decrease. When the amount exceeds 200 parts by weight, the viscosity becomes low, and therefore, when forming a resin layer comprising a resin composition, it tends to be difficult to control the thickness of the layer, and due to an increase in the amount of solvent used. There is a risk of increasing costs.

  Moreover, as another method of forming a resin layer on a substrate, there is a method of laminating a film-like cured product composed of the resin composition of the present invention on a substrate. In this lamination method, it is more preferable to use the following resin film.

  The resin film includes a support and a resin layer made of the resin composition of the present invention formed on the support, and may further include a protective film on the resin layer. . If the resin film having such a configuration has a protective film, after removing the protective film, the resin layer is disposed so as to contact the substrate, and these are laminated by using a hot roll laminator or the like. A resin layer can be formed on the substrate. In this case, the thickness of the resin layer is preferably 5 to 100 μm.

  The resin film has a uniform thickness on a support by, for example, applying a resin composition solution or varnish as described above to a uniform coater, blade coater, lip coater, rod coater, squeeze coater, reverse roll coater, transfer roll coater, or the like. It can be formed by applying, volatilizing the solvent by heating and drying.

  As the support used for the resin film, a film of polyethylene terephthalate, polyester, polyimide, polyamideimide, polypropylene, polystyrene or the like can be used. In addition, as the protective film, a film such as polyethylene, polypropylene, Teflon (registered trademark), or surface-treated paper can be used. As the protective film, one that can be easily peeled off from the resin layer in the resin film is preferable. For this purpose, a protective film having an adhesive force with the resin layer smaller than that between the support and the resin layer may be selected.

  A protective film can be formed on a substrate such as a printed wiring board by curing the resin layer by irradiating (exposure) actinic light or heating the resin layer formed on the substrate by these methods. it can. In the case of curing by exposure, an ultra-high pressure mercury lamp or a high-pressure mercury lamp is preferable as the light source for actinic rays, and the resin layer is cured by irradiating the resin layer with light from these light sources. At this time, when the support existing on the resin layer is transparent to the active light, the active light can be irradiated through the support, and when the support is light-shielding, the support is supported. After removing the body, the resin composition layer is irradiated with actinic rays.

  The protective film formed as described above is a protective film having a predetermined pattern by irradiating the resin layer with actinic rays through a predetermined negative mask pattern at the time of exposure, and then developing to remove unexposed portions. It can also be a membrane. In this way, for example, only the electrode terminals and the like on the printed wiring board can be in a state not covered with the protective film, thereby connecting the external device while protecting the wiring pattern on the printed wiring board. It will be able to plan. In this case, development can be performed using a developer capable of dissolving or dispersing the resin layer in the unexposed area. Examples of the developer include an alkali developer, a semi-aqueous developer, and a solvent developer, and can be appropriately selected and used depending on the resin composition constituting the resin layer.

  As the developer, for example, an emulsion developer containing water and an organic solvent described in JP-A-7-234524 is suitable, and as such an emulsion developer, propylene glycol monomethyl ether acetate as an organic solvent component, Examples include emulsion developers containing 10 to 40% by weight of ethylene glycol ethyl ether acetate, 2,2-butoxyethoxyethanol, butyl lactate, cyclohexyl lactate, ethyl benzoate, 3-methyl-3-methoxybutyl acetate, and the like. . Moreover, when performing alkali development, it is preferable to use the emulsion developing solution which combined alkaline aqueous solution, such as sodium hydroxide and sodium tetraborate, and the above-mentioned organic solvent component.

  The protective film formed as described above is preferably subjected to actinic ray exposure (post-exposure) and / or heat treatment (post-heating) at 80 to 200 ° C. Such post-exposure or post-heating can further improve the adhesion, heat resistance, solvent resistance, etc. of the solder resist. In addition, when performing both post-exposure and post-heating, the order of both is not limited.

  Thus, the protective film such as a solder resist formed on the substrate of the printed wiring board is formed by curing the resin composition of the present invention, and therefore has excellent insulation and heat resistance. In addition, even when nickel plating or gold plating is performed after the formation of the protective film, since the protective film is less likely to be discolored or penetrated, it is extremely excellent as a permanent protective film for printed wiring boards. It has characteristics.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.

[Preparation of resin composition]
(Preparation Example 1)
The resin composition was prepared by blending the components shown in the following (a) to (h).
(A) 40 parts by weight of tetrahydroxyphthalic anhydride-modified epoxy resin (PCR-1050, manufactured by Nippon Kayaku Co., Ltd., cyclohexanone solution having a solid content of 60% by weight),
(B) 20 parts by weight of an acrylate-modified epoxy resin (YDV-1011, manufactured by Toto Kasei Co., Ltd., cyclohexanone solution having a solid content of 60% by weight),
(C) 5 parts by weight of a photoinitiator (Irgacure 651, manufactured by Ciba-Gaigi)
(D) 10 parts by weight of 2,2-bis [4- (4-N-maleimidinylphenoxy) phenyl] propane (bismaleimide compound, manufactured by Hitachi Chemical Co., Ltd.)
(E) 2.5 parts by weight of perhexine 25B (manufactured by NOF Corporation),
(F) Isocyanuric acid ethylene dioxide modified triacrylate (M-315, manufactured by Toa Gosei Co., Ltd.) 10 parts by weight,
(G) 0.5 part by weight of 3-mercapto-1,2,4-triazole (manufactured by Kanto Chemical Co., Inc.)
(H) 20 parts by weight of methyl ethyl ketone.

(Comparative Preparation Example 1)
(G) A resin composition was obtained in the same manner as in Preparation Example 1, except that 3-mercapto-1,2,4-triazole was not used.

[Create evaluation board]
Example 1a
An evaluation substrate was produced according to the following steps (A) to (E).
(A) A glass cloth base epoxy resin double-sided copper-clad laminate MCL-E-679 (manufactured by Hitachi Chemical Co., Ltd., copper foil type: double-sided roughened foil, copper foil thickness: 18 μm) A laminate having a wiring pattern in the part was prepared.
(B) The resin composition obtained in Preparation Example 1 was applied on the laminate of (A), and then dried at 80 ° C. for 20 minutes to form a 30 μm resin layer.
(C) Development with 10 wt% 2,2-butoxyethoxyethanol and 8 g / L sodium tetraborate after UV exposure of the resin layer at an exposure amount of 300 mJ / cm ² through a photomask The unexposed portion was removed by performing a spray treatment at 30 ° C. for 1 minute using the liquid, and a cured film having a comb-shaped test pattern with a line width / space width of 20 μm / 20 μm, respectively, was formed.
(D) Using a metal halide lamp type conveyor type exposure machine (lamp output: 80 W / cm ² , lamp height: 80 cm, no cold mirror, conveyor speed: 1.5 m / min), an exposure amount of 2000 mJ / cm on the cured film ^The post-exposure was carried out by further irradiating with ultraviolet rays at ² .
(E) The cured film was further heated at 170 ° C. for 2 hours and then heated to form a protective film.

(Example 1b)
In the step (C), an evaluation substrate was produced in the same manner as in Example 1a, except that a via hole having a diameter of 100 μm was formed instead of the comb-shaped test pattern.

Example 2a
In the step (B), an evaluation substrate was prepared in the same manner as in Example 1a, except that a resin layer was formed on the laminate as described below. In the formation of the resin layer, first, the resin composition obtained in Preparation Example 1 was applied on a polyethylene terephthalate film (PET film) and then dried at 80 ° C. for 20 minutes to prepare a resin film. Next, after arrange | positioning this resin film on a laminated board so that a resin layer might contact copper foil, both were bonded together using the laminator. Thereafter, the PET film in the resin film was peeled off to form a resin layer having a thickness of 30 μm on the laminate.

(Example 2b)
In the step (C), an evaluation substrate was produced in the same manner as in Example 2a, except that a via hole having a diameter of 100 μm was formed instead of the comb-shaped test pattern.

(Comparative Example 1a)
Instead of the resin composition obtained in Preparation Example 1, an evaluation substrate was produced in the same process as in Example 1 except that the resin composition obtained in Comparative Preparation Example 1 was used.

(Comparative Example 1b)
In the step (C), an evaluation substrate was produced in the same manner as in Comparative Example 1a except that a via hole having a diameter of 100 μm was formed instead of the comb-shaped test pattern.

[Evaluation of insulation]
After measuring the insulation resistance of the evaluation substrates of Examples 1a, 2a and Comparative Example 1a, each was treated for 500 hours under conditions of a temperature of 130 ° C., a humidity of 85% RH and a voltage of 5 V, and the insulation resistance after the treatment was determined. It was measured. Table 1 shows the insulation resistance values before and after the treatment.

[Evaluation of plating resistance]
The evaluation substrates of Examples 1b and 2b and Comparative Example 1b were electroless nickel plating solutions having a pH of 5.0 (solution temperature: 90) containing nickel chloride (33 g / L) and sodium hypophosphite (12 g / L). And a nickel plating layer having a thickness of 5 μm was formed on the copper foil exposed by the via hole. The electroless gold plating solution further containing potassium gold cyanide (2.5 g / L), ammonium chloride (70 g / L), sodium citrate (45 g / L), and sodium hypophosphite (12 g / L). It was immersed in (liquid temperature: 95 ° C.) for 30 seconds to form a gold plating layer having a thickness of 0.05 μm on the nickel plating layer.

  The evaluation of plating resistance was performed by observing before and after nickel plating and gold plating of each evaluation substrate with a metal microscope, and visually confirming whether discoloration occurred around the via hole after plating. The obtained results are shown in Table 2. In Table 2, those having discoloration were shown, and those having no discoloration were shown as nothing.

  From Table 1, it was found that the evaluation substrates of Examples 1a and 1b showed less deterioration in insulation when a voltage was applied for a long time at a high temperature and high humidity compared to the evaluation substrate of Comparative Example 1b. Further, from Table 2, the evaluation substrate of Comparative Example 1b showed discoloration around the via hole after plating, whereas the evaluation substrates of Examples 1b and 2b showed no discoloration after plating. It was found that the protective film on the evaluation substrates of Examples 1b and 2b was excellent in plating resistance.

Claims (5)

  (A) a bismaleimide compound, (B) a photopolymerization initiator, (C) a photopolymerizable compound having an ethylenically unsaturated bond, (D) a thermosetting resin, and (E) an amino group or a mercapto group A resin composition comprising a triazole compound and cured by light and / or heat. The resin composition according to claim 1, wherein the triazole compound is a triazole compound represented by the following general formula (1a) or (1b).

[Wherein R ¹ , R ² and R ³ each independently represents a hydrogen atom, an amino group, a mercapto group, a carboxyl group or a hydrazino group. However, at least one of R ¹ , R ² and R ³ is an amino group or a mercapto group. ]   The triazole compound is 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, 3-amino-1,2,4-triazole-5-carboxylic acid, 3-mercapto- 1,2,4-triazole, 3,5-diamino-1,2,4-triazole, 3-amino-5-mercapto-1,2,4-triazole and 4-amino-3-hydrazino-5-mercapto- 3. The resin composition according to claim 1, wherein the resin composition is at least one triazole compound selected from the group consisting of 1,2,4-triazole. The resin composition according to any one of claims 1 to 3, wherein the bismaleimide compound is a bismaleimide compound represented by the following general formula (2).

[Wherein R ²¹ represents a hydrogen atom, a halogen atom or an alkyl group, and R ²² represents a divalent which may have one or more groups selected from the group consisting of an alkylene group, an arylene group and an oxy group. Represents a group, r represents 1 to 4, and m represents an integer of 0 or 1. A plurality of R ²¹ may be the same or different. ]   The thermosetting resin is at least one thermosetting resin selected from the group consisting of an epoxy resin, a resin having a phenolic hydroxyl group, a melamine resin, and a cyanate ester resin. The resin composition according to claim 1.