JP2015117300A - Preparation method for thermosetting resin composition varnish, and prepreg, laminate and circuit board using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preparation method for thermosetting resin composition varnish that has a high tolerance against desmear treatment and that realizes a low thermal expansion, and to provide a prepreg using the same, and a laminate and circuit board using said prepreg.SOLUTION: The thermosetting resin composition varnish is prepared by: obtaining a thermosetting resin (b) by subjecting a compound (a) comprising at least 2 or more cyanate groups in one molecule to 40 to 70 mol% triazine cyclization reaction in organic solvent; and formulating a compound (c) comprising at least 2 or more epoxy groups in one molecule during the period while the ratio of the reaction conversion of the thermosetting resin is 20 to 80% of the final reaction conversion.

Description

  The present invention relates to a thermosetting resin composition varnish having low thermal expansion and high resistance to desmear treatment, and a prepreg, a laminate and a wiring board using the same.

  Thermosetting resin compositions have a cross-linked structure and exhibit high heat resistance and dimensional stability, and are therefore widely used in the fields of electronic devices and the like. In particular, it is used as a printed wiring board on which wirings and circuit patterns are printed, a prepreg constituting a copper-clad laminate in which printed wiring boards are multilayered, and an interlayer insulating material.

  In recent years, electronic devices have become smaller and lighter, and the operating frequency has been increased, and printed wiring and circuit patterns have been highly integrated. As high integration methods, proposals have been made for miniaturization of printed wiring and circuit patterns formed on a printed wiring board, multilayering of circuit boards on which circuit patterns are formed, or a combination thereof.

  In addition, with the high integration of printed wiring, low thermal expansion is particularly required for printed wiring boards. Patent Documents 1, 2 and 3 disclose resin compositions comprising a cyanate compound and an inorganic filler and exhibiting a low thermal expansion property. However, since these exhibit a low thermal expansion property, the blending amount of the inorganic filler is disclosed. However, when used as a copper clad laminate or an interlayer insulating material, there are problems such as insufficient drillability and formability. In addition, there is a problem that resistance to desmear treatment for removing smear generated during drilling is insufficient.

JP 2003-268136 A JP 2003-73543 A JP 2002-285015 A

  An object of the present invention is to provide a method for producing a thermosetting resin composition varnish having high resistance to desmear treatment and exhibiting low thermal expansion, a prepreg using the same, and a laminate and a wiring board using the prepreg To do.

As a result of investigations to solve the above-mentioned problems, the present inventors have obtained a thermosetting resin (b) obtained by subjecting a compound (a) having at least two cyanate groups in one molecule to a triazine cyclization reaction, and In the resin composition having the compound (c) having at least two epoxy groups in one molecule, the reaction rate of the compound having at least two cyanate groups in one molecule is 40 to 70 mol%. Thermosetting resin (b), a compound having at least two epoxy groups in one molecule when the reaction rate ratio of the thermosetting resin is 20 to 80% of the target final reaction rate It discovered that the tolerance with respect to a desmear process became high by using the varnish produced by mix | blending.
The present invention has been completed based on such findings.

The present invention includes the following contents.
(1) A thermosetting resin (b) obtained by subjecting a compound (a) having at least two cyanate groups in one molecule to a 40 to 70 mol% triazine cyclization reaction in an organic solvent, the thermosetting resin A thermosetting resin composition varnish characterized by blending a compound (c) having at least two epoxy groups in one molecule when the resin reaction rate ratio is 20 to 80% of the final reaction rate Manufacturing method.
(2) The method for producing a thermosetting resin composition varnish according to the above (1), wherein the compound (c) having at least two epoxy groups in one molecule has an aromatic ring.
(3) The method for producing a thermosetting resin composition varnish according to the above (1), wherein the compound (c) having at least two epoxy groups in one molecule has a polycyclic compound. .
(4) The method for producing a thermosetting resin composition varnish according to the above (1), wherein the compound (c) having at least two epoxy groups in one molecule has a biphenyl structure.
(5) The method for producing a thermosetting resin composition varnish as described in (1) above, wherein the compound (c) having at least two epoxy groups in one molecule has a naphthalene structure.
(6) A prepreg obtained by impregnating the substrate with the thermosetting resin composition varnish according to any one of (1) to (5) and drying it.
(7) A laminate obtained by molding the prepreg according to (6).
(8) A wiring board obtained by forming wiring on the laminated board according to (7).

  According to the present invention, it is possible to provide a prepreg, a laminated board, and a wiring board having a low thermal expansion coefficient and high resistance to desmear treatment.

Hereinafter, embodiments of the present invention will be described in detail.
[Thermosetting resin composition]
(Composition of (a) and (c))
The thermosetting resin composition varnish of the present invention comprises a thermosetting resin (b) obtained by subjecting a compound having at least two cyanate groups in one molecule to a triazine cyclization reaction in an organic solvent, and 1 A compound (c) having at least two epoxy groups in the molecule is blended. The final reaction rate of the compound having at least two cyanate groups in one molecule needs to be 40 to 70 mol%, and among them, the reaction rate is preferably terminated at 45 to 65 mol%. When the reaction rate is less than 40 mol%, the fluidity of the obtained prepreg becomes too large, and when it exceeds 70 mol%, the fluidity of the obtained prepreg is lowered. When the reaction rate ratio is 20 to 80% of the final reaction rate, preferably 30 to 70% of the final reaction rate, the compound (c) having at least two epoxy groups in one molecule is blended. . For example, when the final reaction rate is 50 mol%, the compound (c) having at least two epoxy groups in one molecule when the reaction rate is 10 to 40 mol% (50 × 20/100 to 50 × 80/100) Is blended. When the compound (c) having at least two epoxy groups in one molecule is added when the reaction rate ratio is less than 20% of the final reaction rate, the resistance to desmear treatment is not improved, and the reaction When the rate ratio exceeds 80% of the final reaction rate, a compound (c) having at least two epoxy groups in one molecule and a reactant of a compound having at least two cyanate groups in one molecule; This is not preferable because the compatibility is reduced.

(Organic solvent)
The organic solvent used for the triazine cyclization reaction of the compound having at least two cyanate groups in one molecule is not particularly limited, and examples thereof include toluene, mesitylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and the like. Mesitylene is preferable because of high solubility of the compound (a) having at least two cyanate groups in one molecule.

(catalyst)
In order to obtain a cyanate resin (thermosetting resin (b)) by subjecting compound (a) having at least two cyanate groups in one molecule to a 40 to 70 mol% triazine cyclization reaction in an organic solvent, a catalyst is used. It is preferable to use it. As a catalyst, it is preferable to mix a metal catalyst. The metal-based catalyst has a function of accelerating the self-polymerization reaction of the component (a), and examples thereof include metal salts of transition metals or group 12 metals and chelate complexes. Examples of the metal include copper, cobalt, manganese, iron, nickel, and zinc. Examples of these salts include metal salts such as carboxylates (preferably 2-ethylhexanoate and naphthenate). Examples of the chelate complex include an acetylacetone complex. These metal catalysts may be used alone or in combination of two or more.
The amount of the metal-based catalyst is preferably 1 to 300 ppm, more preferably 1 to 200 ppm, and particularly preferably 2 to 150 ppm by weight with respect to the component (a). In this range, when a metal catalyst is blended, the reactivity is sufficient, and the addition of the metal catalyst may be performed all at once or in a plurality of times.

(Compound (a) having at least two cyanate groups in one molecule)
Examples of the compound (a) having at least two cyanate groups in one molecule include novolak type cyanate resin, bisphenol A type cyanate resin, bisphenol E type cyanate resin, bisphenol F type cyanate resin, and tetramethylbisphenol F type. Cyanate resin etc. are mentioned, Among these, 1 type or 2 or more types can be mixed and used. Among these, bisphenol A type cyanate resin or novolac type cyanate resin is preferable from the viewpoints of dielectric properties, heat resistance, flame retardancy, low thermal expansion, and low cost. Although the average repeating number of novolak-type cyanate resin is not specifically limited, 1-30 are preferable and 1-25 are more preferable. If it is less than 1, it may be easily crystallized and may be difficult to handle. On the other hand, if it exceeds 30, the cured product may become brittle.
As a commercial product of the bisphenol A type cyanate resin that can be used as the compound (a) having at least two cyanate groups in one molecule, Lonza Japan Co., Ltd., trade name Arocy B-10 can be mentioned. Moreover, as a commercial item of a novolak-type cyanate resin, Lonza Japan Co., Ltd. make, brand name Primaset PT-30 (weight average molecular weight 500-1,000), brand name Primaset PT-60 (weight average molecular weight 2,000) ~ 3,000).

If the reaction rate of the compound (a) having at least two cyanate groups in one molecule is less than 40 mol%, the fluidity of the prepreg obtained by coating may become too high. Moreover, when the reaction rate of the compound (a) which has at least 2 or more cyanate group in 1 molecule exceeds 70 mol%, the fluidity | liquidity of the prepreg obtained by coating may fall.
In addition, the reaction rate of the compound (a) which has at least 2 or more cyanate groups in 1 molecule is calculated | required from the measurement result of GPC measurement. Specifically, a pre-reaction solution in which a compound (a) having at least two cyanate groups in one molecule is blended and a solution after reacting this solution appear near a predetermined retention time. Compare the peak areas of the cyanate resin. The disappearance rate of the peak area of the solution after the reaction relative to the peak area of the solution before the reaction corresponds to the reaction rate (mol%).

(Compound (c) having at least two epoxy groups in one molecule)
The compound (c) having at least two epoxy groups in one molecule used in the present invention may be any compound as long as it has two or more epoxy groups in one molecule. Examples of the compound (c) having biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl aralkyl type epoxy resin, phenol novolac type epoxy resin, cresol novolak type epoxy resin, etc. Can be mentioned.
Examples of the polycyclic compound include naphthalene type epoxy resins, naphthalene novolac type epoxy resins, anthracene type epoxy resins, dihydroanthracene type epoxy resins, and the like.
In particular, it is preferable to have a naphthalene structure or a biphenyl structure such as a naphthalene novolac type epoxy resin or a biphenyl aralkyl type epoxy resin. These compounds may have any molecular weight, and several types may be used in combination. The compounding amount of the compound (c) having at least two or more epoxy groups in one molecule is 10 to 100 parts by mass with respect to 100 parts by mass of the compound (a) having at least two or more cyanate groups in one molecule. The amount is preferably 10 to 80 parts by mass, particularly preferably 15 to 50 parts by mass. If it is less than 10 parts by mass, the adhesive strength with the copper foil is poor, and if it exceeds 100 parts by mass, the low thermal expansibility does not appear.

(Inorganic filler)
In the thermosetting resin composition of the present invention, an inorganic filler may be blended, for example, crushed silica, fused silica, mica, talc, short glass fiber or fine powder and hollow glass, calcium carbonate, quartz powder, Examples thereof include metal hydrates. The blending amount is preferably 10 to 300 parts by mass, more preferably 100 to 250 parts by mass, and 150 to 250 parts by mass in terms of solid content with respect to 100 parts by mass of the thermosetting resin composition. It is particularly preferred. If it is 10-300 mass parts, sufficient rigidity of a base material, moisture heat resistance, a flame retardance, the tolerance with respect to the erosion by a plating solution, etc. will be obtained. The filler may be treated with a commercially available surface treatment agent such as a coupling agent, a three-roller, a bead mill, a nanomizer, or the like to improve the dispersibility of the inorganic filler.

(Other ingredients)
In the thermosetting resin composition of the present invention, it is desirable to use a curing accelerator in order to improve heat resistance, flame retardancy, copper foil adhesion, and the like. Examples of curing accelerators include organometallic salts such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, imidazoles and their derivatives, tertiary amines and quaternary ammonium salts. .
In addition, known thermoplastic resins, elastomers, flame retardants, organic fillers and the like can be used in combination.
Examples of the thermoplastic resin that can be blended in the thermosetting resin composition of the present invention include polytetrafluoroethylene, polyethylene, polypropylene, polystyrene, polyphenylene ether resin, phenoxy resin, polycarbonate resin, polyester resin, polyamide resin, and polyimide resin. , Xylene resin, petroleum resin and silicone resin.
Examples of elastomers that can be blended in the thermosetting resin composition of the present invention include polybutadiene, acrylonitrile, epoxy-modified polybutadiene, maleic anhydride-modified polybutadiene, phenol-modified polybutadiene, and carboxy-modified acrylonitrile.
Examples of organic fillers that can be blended in the thermosetting resin composition of the present invention include organic powders such as silicone powder, polytetrafluoroethylene, polyethylene, polypropylene, polystyrene, and polyphenylene ether.
Examples of flame retardants that can be blended in the thermosetting resin composition of the present invention include triphenyl phosphate, tricresyl phosphate, trisdichloropropyl phosphate, phosphate ester compounds, phosphazenes, red phosphorus, and other phosphorus flame retardants And inorganic flame retardant aids such as antimony trioxide and zinc molybdate.
In addition, the thermosetting resin composition of the present invention may appropriately contain compounding agents such as an ultraviolet absorber, an antioxidant, a photopolymerization initiator, a fluorescent whitening agent, and an adhesion improver.
Examples of compounding agents that can be incorporated into the thermosetting resin composition of the present invention include ultraviolet absorbers such as benzotriazoles, antioxidants such as hindered phenols and styrenated phenols, benzophenones, benzyl ketals, Examples thereof include photopolymerization initiators such as thioxanthone, fluorescent brighteners such as stilbene derivatives, urea compounds such as urea silane, and adhesion improvers such as silane coupling agents.

(Prepreg)
The prepreg of the present invention is obtained by impregnating or coating the above-mentioned thermosetting resin composition varnish on a sheet-like reinforcing base material, drying, and forming a B-stage. The well-known thing used for the laminated board for various electrical insulation materials can be used as a sheet-like reinforcement base material of a prepreg. Examples of the material include inorganic fibers such as E glass, D glass, S glass, and Q glass, organic fibers such as polyimide, polyester, and polytetrafluoroethylene, and mixtures thereof. These base materials have, for example, shapes such as woven fabric, non-woven fabric, robink, chopped strand mat, and surfacing mat, but the material and shape are selected depending on the intended use and performance of the molded product, and if necessary, A single material or two or more materials and shapes can be combined.
The thickness of the sheet-like reinforcing base material is not particularly limited, and for example, about 0.03 to 0.5 mm can be used, and the surface treatment with a silane coupling agent or the like or mechanical fiber opening treatment is performed. What was given is suitable from the surface of heat resistance, moisture resistance, and workability. After impregnating or coating the base material so that the amount of the resin composition attached to the base material is 20 to 90% by mass in terms of the resin content of the prepreg after drying, the temperature is usually 100 to 200 ° C. Can be heated and dried for 1 to 30 minutes and semi-cured (B-stage) to obtain the prepreg of the present invention.

(Laminated board and wiring board)
The laminate of the present invention is formed using a prepreg. For example, it can be manufactured by stacking 1 to 20 prepregs and laminate-molding them with a configuration in which a metal foil such as copper and aluminum is disposed on one or both sides thereof. The metal foil is not particularly limited as long as it is used for electrical insulating material applications.
The molding conditions can be applied to a laminate for an electrical insulating material and a multilayer board, for example, using a multistage press, a multistage vacuum press, continuous molding, an autoclave molding machine, etc., at a temperature of 100 to 250 ° C., a pressure of 0.2 to It can be molded in a range of 10 MPa and a heating time of 0.1 to 5 hours.
Further, the prepreg of the present invention and the inner layer wiring board can be combined and laminated to produce a multilayer board.
The wiring board according to the present invention is manufactured by forming a circuit on the surface of the laminated board. That is, the conductor layer of the laminated board according to the present invention is processed by wiring by a normal etching method, or a plurality of laminated boards processed by wiring through the above-described prepreg are stacked and subjected to hot press processing to be multilayered at once. . Then, a multilayer printed wiring board can be manufactured through formation of a through hole or blind via hole by drilling or laser processing and formation of an interlayer wiring by plating or conductive paste.

  The present invention will be described more specifically with reference to examples, but these examples do not limit the present invention in any way.

Production Example 1: Production of compatibilized resin (1-1) At least two cyanate groups in one molecule in a reaction vessel having a volume of 3 liters which can be heated and cooled with a thermometer, a stirrer and a reflux condenser. Bisphenol A type cyanate resin (manufactured by Lonza Japan Co., Ltd .; trade name Primaset BADCy): 800.0 g and toluene: 1000.0 g were added as the compound (a) having the following. Next, the temperature was raised to the reflux temperature (about 116 ° C.) while stirring, and after confirming that the resin solid content was dissolved into a uniform solution, 0.01 g of an 8% by mass mineral spirit solution of zinc naphthenate was added. The mixture was added and reacted at about 110 ° C. for 2 hours. Then, it cooled to room temperature (25 degreeC) and the solution of the compatibilizing resin (1-1) was obtained. A small amount of this reaction solution was taken out and subjected to GPC measurement (polystyrene conversion, eluent: tetrahydrofuran, column: HZ2000, HZ3000 manufactured by Tosoh Corporation), and a bisphenol A, a synthetic raw material, whose elution time appears around 12.4 minutes. The ratio of the peak area of the type cyanate resin compared to the peak area of the bisphenol A type cyanate resin at the start of the reaction is reduced by the reaction rate (mol%) of a compound having at least two cyanate groups in one molecule. ). The reaction rate calculated according to the above was 25 mol%. Moreover, the peak of the product of the thermosetting resin which appears at about 10.9 minutes vicinity and 8.0-10.0 vicinity was confirmed. Next, as a compound (c) having at least two epoxy groups in one molecule, a biphenyl type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd .; trade name YX-4000, epoxy equivalent; 186): 200.0 g is added, and about Reaction was performed at 110 degreeC for 2 hours. Thereafter, GPC measurement was performed, and it was confirmed that the reaction rate of the compound having at least two cyanate groups in one molecule was 50 mol%, and the reaction was terminated and cooled to room temperature. Since the reaction rate before introducing the epoxy compound is 25 mol% and the reaction rate after introducing the epoxy compound is 50 mol%, the ratio of the reaction rate to the final reaction rate is 50%. By the above method, a thermosetting resin composition varnish having a reaction rate ratio of 50% was prepared.

Production Example 2: Production of compatibilized resin (1-2) The reaction time before introducing the epoxy resin is 1 hour, the reaction rate of the compound having at least two cyanate groups in one molecule is 13 mol%, and the epoxy compound The reaction rate when the epoxy compound was added in the same manner as in Production Example 1 except that the reaction time after addition was 3 hours and the reaction rate of the compound having at least two cyanate groups in one molecule was 50 mol%. Ratio: 26% thermosetting resin composition varnish was produced.

Production Example 3: Production of compatibilizing resin (1-3) The reaction time before introducing the epoxy resin is 3 hours, the reaction rate of the compound having at least two cyanate groups in one molecule is 38 mol%, and the epoxy compound The reaction rate when the epoxy compound was added in the same manner as in Production Example 1 except that the reaction time after the addition was 1 hour, and the reaction rate of the compound having at least two cyanate groups in one molecule was 50 mol%. Ratio: 76% of a thermosetting resin composition varnish was produced.

Production Example 4: Production of compatibilized resin (1-4) The reaction time after adding the epoxy resin was 3 hours, and the reaction rate of the compound having at least two cyanate groups in one molecule was 63 mol%. In the same manner as in Production Example 1, a thermosetting resin composition varnish having a reaction rate ratio of 40% when an epoxy compound was added was prepared.

Comparative Production Example 1: Production of Comparative Compatibilized Resin (2-1) In a reaction vessel having a volume of 3 liters that can be heated and cooled with a thermometer, a stirrer, and a reflux condenser, at least two or more in one molecule As a compound having a cyanate group, bisphenol A type cyanate resin (Lonza Japan Co., Ltd .; trade name Primaset BADCy): 800.0 g and biphenyl type epoxy resin (Japan Epoxy Resin Co., Ltd .; trade name YX-4000, epoxy equivalent); 186): 200.0 g was added, and toluene: 1000.0 g was added. Next, the temperature was raised to the reflux temperature (about 116 ° C.) while stirring, and after confirming that the resin solid content was dissolved into a uniform solution, 0.01 g of an 8% by mass mineral spirit solution of zinc naphthenate was added. The reaction was carried out at about 110 ° C. for 4 hours. Then, it cooled to room temperature and obtained the solution of compatibilizing resin (2-1). A small amount of this reaction solution was taken out and subjected to GPC measurement (polystyrene conversion, eluent: tetrahydrofuran). As a result, the peak area of the bisphenol A type cyanate resin, which is a synthetic raw material and the elution time appears around 12.4 minutes, is the start of the reaction. Compared with the peak area of the bisphenol A type cyanate resin at the time, the disappearance rate (reaction rate) of the peak area was 50 mol%. Moreover, the peak of the product of the thermosetting resin which appears at about 10.9 minutes vicinity and 8.0-10.0 vicinity was confirmed, and the comparative compatible resin (2-1) varnish was produced.

Comparative Production Example 2: Production of Comparative Compatibilized Resin (2-2) Comparative Production Example, except that the reaction time was 5 hours and the reaction rate of the compound having at least two cyanate groups in one molecule was 63 mol%. Comparative Compatibilized Resin (2-2) Varnish was prepared in the same manner as in Example 1.

Comparative Production Example 3: Production of Comparative Compatibilized Resin (2-3) The reaction time before introducing the epoxy resin is 0.5 hours, and the reaction rate of the compound having at least two cyanate groups in one molecule is 8 mol. Epoxy compound in the same manner as Comparative Production Example 1 except that the reaction time after addition of the epoxy compound was 3.5 hours, and the reaction rate of the compound having at least two cyanate groups in one molecule was 50 mol%. The ratio of the reaction rate when charging was added: A compatibilized resin (2-3) varnish with 16% was prepared.

Comparative Production Example 4: Production of Comparative Compatibilized Resin (2-4) The reaction time before introducing the epoxy resin is 3.5 hours, and the reaction rate of the compound having at least two cyanate groups in one molecule is 44 mol. %, The reaction time after addition of the epoxy compound was 0.5 hours, and the reaction rate of the compound having at least two cyanate groups in one molecule was 50 mol%. The ratio of the reaction rate when sucrose was added: A comparatively compatibilizing resin (2-4) varnish with 88% was produced, but it was not compatibilized and separated.

Manufacture of varnish for inner layer Silica: 700 g of SO-G1 (trade name, manufactured by Admatex Co., Ltd.) and 7 g of KMB-903 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., 3-aminopropyltriethoxysilane) were added. The mixture was added to 300 g of methyl isobutyl ketone solution with stirring to prepare a methyl isobutyl dispersion of silica. 762 g of a comparative compatibilizing resin (2-1) was added to a methyl isobutyl dispersion solution of silica, and stirred for 2 hours to prepare a varnish (2-5).

The varnish (2-5) obtained in the production of the varnish for the inner layer is impregnated on an E glass cloth having a thickness of 0.1 mm and dried by heating at 160 ° C. for 10 minutes to obtain a prepreg having a resin content of 55% by mass. It was. Next, four sheets of this prepreg were stacked, and an electrolytic copper foil having a thickness of 18 μm was placed on top and bottom, and pressed at a pressure of 25 kg / cm ² and a temperature of 185 ° C. for 90 minutes. The copper foil of the obtained copper-clad laminate was removed by etching to produce an etched substrate.

The thermosetting resin composition varnishes obtained in Production Examples 1 to 4 and Comparative Production Examples 1 to 3 were each impregnated and applied to E glass cloth having a thickness of 0.1 mm and dried at 160 ° C. for 10 minutes. A prepreg having a resin content of 55% by mass was obtained. Next, one prepreg prepared on both sides of the etching substrate prepared above was stacked, 18 μm electrolytic copper foil was placed up and down, and pressed at a pressure of 25 kg / cm ² and a temperature of 185 ° C. for 90 minutes. 1-4 and the copper clad laminated board of Comparative Examples 1-3 were obtained. Using the copper-clad laminate thus obtained, resistance to desmear treatment was evaluated as a desmear weight reduction amount. Table 1 shows examples and Table 2 shows comparative examples.

<Measurement of desmear weight loss>
The produced copper clad laminates of Examples 1 to 4 and Comparative Examples 1 to 3 were etched and cut to a size of 50 × 50 mm, desmeared under the conditions shown below, and the weight loss from the weight change before and after desmearing. Was calculated.
Treatment solution (alkaline permanganate) manufactured by Rohm & Haas
Swelling (MLB-4125): 80 ° C / 5 minutes Roughening (MLB-213): 80 ° C / 5 minutes Neutralization (MLB-216-2): 40 ° C / 5 minutes

  Examples 1 to 3 in Table 1 regarding the reaction rate when the compound (c) having an epoxy group with a final reaction rate of 50 mol% of the compound (a) having at least two cyanate groups in one molecule is blended From the comparison of Comparative Example 1 in Table 2, it can be confirmed that the desmear weight reduction amount is small when the reaction rate is 20 to 80%, and the resistance to desmear treatment is improved. Similarly, from the comparison of Example 4 in Table 1 and Comparative Example 2 in Table 2 with respect to the reaction rate when (c) is blended when the final reaction rate of (a) is 63 mol%, the resistance to desmear treatment is similarly improved. You can see that On the other hand, it can be seen from Comparative Example 3 in Table 2 that when the reaction rate is as low as 16% from 20 to 80%, there is no effect in improving resistance to desmear treatment. Further, from Comparative Example 4 in Table 2, when the reaction rate is 88%, which is higher than 20 to 80%, the compatibility is poor and the varnish cannot be formed. Therefore, it turns out that it is effective for the tolerance improvement with respect to a desmear process to make it 20 to 80% of reaction rate of this invention.

  By adjusting the reaction rate of the present invention and producing a thermosetting resin composition varnish, it is possible to provide a copper-clad laminate having excellent resistance to desmear treatment, and for producing printed wiring boards for electronic devices. Useful.

Claims (8)

  A thermosetting resin (b) obtained by subjecting a compound (a) having at least two cyanate groups in one molecule to a 40 to 70 mol% triazine cyclization reaction in an organic solvent, the reaction of the thermosetting resin A method for producing a thermosetting resin composition varnish comprising blending a compound (c) having at least two epoxy groups in one molecule when the rate ratio is 20 to 80% of the final reaction rate .   The method for producing a thermosetting resin composition varnish according to claim 1, wherein the compound (c) having at least two epoxy groups in one molecule has an aromatic ring.   The method for producing a thermosetting resin composition varnish according to claim 1, wherein the compound (c) having at least two epoxy groups in one molecule has a polycyclic compound.   The method for producing a thermosetting resin composition varnish according to claim 1, wherein the compound (c) having at least two epoxy groups in one molecule has a biphenyl structure.   The method for producing a thermosetting resin composition varnish according to claim 1, wherein the compound (c) having at least two epoxy groups in one molecule has a naphthalene structure.   A prepreg obtained by impregnating a base material with the thermosetting resin composition varnish according to claim 1 and drying it.   A laminate obtained by molding the prepreg according to claim 6.   A wiring board obtained by forming wiring on the laminated board according to claim 7.