TWI510544B - A thermosetting resin composition and a printed circuit board filled with the resin composition - Google Patents

Description

Thermosetting resin composition and printed circuit board filled with the same

The present invention relates to a thermosetting resin composition, and more particularly to a thermosetting resin composition using a permanent hole-filling material such as a via hole, a through hole or the like in a printed circuit board such as a multilayer substrate or a double-sided substrate. In particular, it relates to a thermosetting resin composition which is excellent in viscosity-increasing viscosity over time and which is excellent in filling property to a hole of a printed circuit board and polishing property after curing.

In recent years, in order to reduce the size and function of electronic devices, it is desirable that printed circuit boards become thinner and shorter. Therefore, it is proposed to use a manufacturing method including a method of manufacturing an insulating layer formed on the upper and lower sides of a core material of a printed circuit board, forming a necessary circuit, and then further forming an insulating layer, forming a circuit, and the like.

In such a printed circuit board, a conductive layer is formed on the inner wall of the surface and a hole such as a through hole or a through hole of a via hole, and a resin composition such as a thermosetting resin is filled in the hole portion by printing or the like. At this time, since the resin is filled so that the hole portion is slightly protruded, the protruding portion is flattened and removed by polishing or the like after curing. Further, the conductive layer of the surface is patterned. (Refer to Patent Document 1)

In general, as the resin composition filled in the hole portion, a thermosetting epoxy resin composition is widely used from the viewpoint of excellent mechanical and electrical properties and chemical properties of the cured product, and good adhesion.

As such a thermosetting epoxy resin composition, a primary aromatic amine or an aromatic secondary amine, an acid anhydride, a tertiary amine, or an imidazole is used as a curing accelerator. Further, from the viewpoint of workability, the epoxy resin and the curing accelerator are mixed and dispersed, and are often used in the form of a co-existing one-liquid composition. The one-liquid type composition may be exemplified by the strict management of the storage conditions of the composition and the short use time. In particular, since the usable time is short, there is a fear that the workability is lowered. Therefore, a resin composition which can be used for a long period of time is desired.

On the other hand, in the method of filling the pores of the thermosetting epoxy resin composition, the printing method is the mainstream. The conditions required for the printing method include fluidity and sagability as an index of the ease of inflow into the pores. The conditions required for removing the outstanding epoxy resin composition by polishing or the like after polishing the epoxy resin composition after curing are exemplified by the polishing property which is easy to carry out polishing and the after polishing. The flatness of the epoxy resin composition.

Patent Document 1: Japanese Patent Laid-Open No. Hei 10-75027

An object of the present invention is to provide a thermosetting tree which is excellent in viscosity-increasing viscosity over time and which is excellent in filling property to a hole of a printed circuit board and polishing property after curing. The fat composition and the printed circuit board containing the same. A main object of the present invention is to provide a thermosetting resin composition which is excellent in viscosity-increasing viscosity over time and which is excellent in the filling property of a hole in a printed circuit board and the polishing property after curing.

More specifically, it is an excellent thermosetting resin composition which is excellent in the filling property of the epoxy resin composition for hole-filling which is unsatisfactory in the prior art and the polishing property after curing, and which can suppress the viscosity increase with time viscosity. .

The inventors have conducted intensive studies to solve the above problems, and have found that (A) an epoxy resin having no alicyclic skeleton, (B) an epoxy resin having an alicyclic skeleton, (C) a curing catalyst, and (D) The thermosetting resin composition characterized by a filler can solve the above problems, thereby completing the present invention.

That is, the thermosetting resin composition of the present invention is characterized in that it is used for filling a hole of a printed circuit board, and contains (A) an epoxy resin having no alicyclic skeleton, and (B) a ring having an alicyclic skeleton. An oxygen resin, (C) a curing catalyst, and (D) a filler.

Further, the printed circuit board of the present invention is characterized in that it has a hole portion filled with a cured product of the thermosetting resin composition.

The epoxy resin composition of the present invention can suppress the passage via (A) an epoxy resin having no alicyclic skeleton, (B) an epoxy resin having an alicyclic skeleton, (C) a curing catalyst, and (D) a filler. Viscosity of the viscosity of the composition during the time of change. As a result, the storage period can be extended, and strict storage management is not required. In addition, since the usable time is also long, it can It is enough to prevent the decrease in operability and can be used stably for a long time. Specifically, since the viscosity is stable even when used for a long period of time, not only the embedding property of the pores is stabilized but also the pores in the pores are increased when the viscosity is increased.

In particular, by using (A) an epoxy resin having no alicyclic skeleton, moderate fluidity and hardness of a cured product can be obtained, and thus filling property and polishing property can be obtained. By using (B) an epoxy resin having an alicyclic skeleton, it is possible to suppress the viscosity increase of the composition in the change over time by suppressing the action of the curing reaction of the composition. Therefore, if one of the two is lacking, the full characteristics cannot be obtained.

The (D) filler imparts a stress relieving function to the resin composition by acting as a buffer material when it is contained in heat curing shrinkage. Further, by imparting thixotropy to the resin composition, it is possible to prevent the resin composition from oozing out from the pores after the printing is filled or at the time of curing. Further, by imparting thixotropy, the resin composition can be closely filled with the unevenness of the copper surface in the pores at the time of filling. Through the subsequent curing, the resin composition is uniformly cured with copper, whereby it is possible to obtain stable adhesion.

Therefore, if the (D) filler is absent, all features cannot be obtained.

On the other hand, in the conventional thermosetting resin composition, although the filling property and the polishing property can be obtained, the viscosity increase of the viscosity in the change over time is not sufficient. The reason for this is that, in the conventional thermosetting resin composition, only (A) an epoxy resin having no alicyclic skeleton is used, and a resin composition having high reactivity is designed. For this existing problem, the two-liquid type is The simplest method, but it is necessary to mix 2 liquids during use and cause a decrease in operability. Therefore, it is difficult to stably use it for a long time in the conventional thermosetting resin composition.

In the above-mentioned case, the thermosetting resin composition of the present invention can provide a thermosetting resin composition which is excellent in viscosity-improving viscosity over time and which is excellent in the filling property of the hole of the printed circuit board and the polishing property after curing, and the like. Printed circuit board.

Hereinafter, each constituent component in the thermosetting resin composition of the present invention will be described.

As the epoxy resin (A) having no alicyclic skeleton, a known one may be used as long as it has two or more epoxy groups in one molecule. For example, a compound having two or more epoxy groups in one molecule, such as a bisphenol A type epoxy resin, a bisphenol S type epoxy resin, a dinaphthol type epoxy resin, and a bisphenol F type may be mentioned. Epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, diglycidyl ether of propylene glycol or polypropylene glycol, polytetramethylene glycol diglycidyl ether, glycerol polyglycidyl ether, Trimethylolpropane polyglycidyl ether, phenyl-1,3-diglycidyl ether, biphenyl-4,4'-diglycidyl ether, 1,6-hexanediol diglycidyl ether, ethylene glycol Or diglycidyl ether of propylene glycol, sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, tris(2,3-epoxypropane Isocyanurate, triglycidyl tris(2-hydroxyethyl)isocyanurate, etc., and an amine type epoxy resin, such as tetraglycidylaminodiphenylmethane, tetraglycidyl benzene Dimethylamine, triglycidyl-aminophenol, diglycidylaniline, and diglycidyl o-toluidine, and the like.

For the commercially available products, jER-828 manufactured by Mitsubishi Chemical Corporation can be cited as the bisphenol A type liquid epoxy resin, and jER-807 manufactured by Mitsubishi Chemical Corporation can be cited as the bisphenol F type liquid epoxy resin. Examples of the amine-type liquid epoxy resin include jER-630 manufactured by Mitsubishi Chemical Corporation and ELM-100 manufactured by Sumitomo Chemical Co., Ltd.

Among these, an amine-type liquid epoxy resin which can increase the filling amount of the filler and contains a benzene ring as a heat-resistant skeleton is particularly preferable in the case of producing a paste having a low viscosity. They may be used singly or in combination of two or more.

(A) The compounding ratio of the epoxy resin having no alicyclic skeleton is 4 to 40% by mass, preferably 10 to 38% by mass, and more preferably 20 to 35% by mass based on the total amount of the composition. If it is less than 4% by mass, the reactivity of the composition is deteriorated, and it becomes impossible to have sufficient hardness. As a result, there is a possibility that a problem such as dropping of the composition at the time of polishing may occur. On the other hand, if it is 40% by mass or more, the viscosity increase with time viscosity cannot be suppressed.

The epoxy resin having (B) an alicyclic skeleton is a compound having a cyclic aliphatic skeleton and two or more epoxy groups in the molecule. Among them, the epoxy group of the epoxy resin having (B) an alicyclic skeleton preferably contains no glycidyl ether group. The epoxy group of (B) an epoxy resin having an alicyclic skeleton preferably contains two carbon atoms constituting a cyclic aliphatic skeleton. An epoxy group or an epoxy group directly bonded to a cyclic aliphatic skeleton. The epoxy resin having an alicyclic skeleton as such (B) is produced by oxidizing a corresponding alicyclic olefin compound by an aliphatic percarboxylic acid or the like, and a substance which is basically produced using an anhydrous aliphatic percarboxylic acid has A high epoxidation rate is preferred from this point.

(B) The epoxy resin having an alicyclic skeleton has a linking group, and examples thereof include a single bond, an alkylene group, a carbonyl group (-CO-), an ether group (-O-), and an ester group (-COO-). Amidino group (-CONH-), a carbonate group (-OCOO-), a group formed by these multiple linkages, and the like. Among the preferred linking groups are ether groups (-O-) and ester groups (-COO-). The alkyl group has preferably 1 to 18 carbon atoms, and examples thereof include a straight chain such as a methylene group, a methylmethylene group, a dimethylmethylene group, an exoethyl group, a propyl group, and a trimethyl group. , branched or branched alkyl; 1,2-cyclopentyl, 1,3-cyclopentyl, cyclopentyl, 1,2-extended cyclohexyl, 1,3-cyclohexyl, 1 a 4-valent alicyclic hydrocarbon group (especially a divalent cycloalkylene group) such as a 4-cyclohexylene group and a cyclohexylene group.

(B) An epoxy resin having an alicyclic skeleton is also commercially available, and for example, "Celoxide 2021", "Celoxide 2081" having an ester group as a linking group, and an ether group as a linking group are preferable. "EHPE3150" (all manufactured by DAICEL CHEMICAL INDUSTRIES, LTD.), among which "Celoxide 2021" and "EHPE 3150" are particularly preferable.

(B) The compounding ratio of the epoxy resin having an alicyclic skeleton is 2 to 38% by mass, preferably 4 to 31% by mass, and more preferably 6 to 20% by mass based on the total amount of the composition. If it is less than 2% by mass, the increase in viscosity over time may not be suppressed. sticky. On the other hand, when it is 38% by mass or more, the reactivity of the composition is deteriorated, and sometimes it is impossible to have sufficient hardness. As a result, problems such as falling off of the composition may occur during polishing.

The compounding ratio of (A) epoxy resin which does not have an alicyclic skeleton, and (B) epoxy resin which has an alicyclic skeleton is as follows. In terms of mass ratio (A): (B) = 90: 10 to 20: 80, preferably 85: 15 to 50: 50, more preferably 80: 20 to 60: 40.

Even if (B) the ratio of the epoxy resin having an alicyclic skeleton is high, the characteristics are satisfied, and if (A) the ratio of the epoxy resin having no alicyclic skeleton is high, the curing time can be shortened and the workability is improved, so Expected.

As the (C) curing catalyst, any conventionally known one which can be used as a curing catalyst of (A) an epoxy resin having no alicyclic skeleton and (B) an epoxy resin having an alicyclic skeleton can be used. Specific examples include an imidazole such as 2E4MZ, C11Z, C17Z, and 2PZ, an AZINE compound such as 2MZ-A or 2E4MZ-A, and a product name of 2MZ-OK and 2PZ-OK. Isocyanurate such as imidazole, imidazole hydroxymethyl ester such as 2PHZ or 2P4MHZ (the above-mentioned trade names are all manufactured by Shikoku Chemicals Co., Ltd.), dicyandiamide and its derivatives, melamine and its derivatives, diamine Kimalyl nitrile and its derivatives, di-ethyltriamine, tri-ethylidene tetraamine, tetraethylamamine, bis(hexamethyl)triamine, triethanolamine, diaminodiphenylmethane An amine such as an organic acid diterpene, an octanoate of 1,8-diazabicyclo[5,4,0]undecene-7, a sulfonate (trade name: DBU, manufactured by SAN-APRO Co., Ltd.), 3 , 9-bis (3-amino group Propyl)-2,4,8,10-tetraoxaspiro[5,5]undecane (trade name: ATU, manufactured by Ajinomoto Co., Ltd.), or triphenylphosphine, tricyclohexylphosphine, tributyl An organic phosphine compound such as a phosphine or a methyl diphenylphosphine. These are matched with the requirements for improving the characteristics of the coating film, and may be used singly or in combination of two or more. In addition, tetrapropenyl succinic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, dodecenyl succinic anhydride, methyl endomethylene tetrahydrophthalic acid can also be used. A known acid anhydride such as an acid anhydride. Among these curing catalysts, in particular, imidazole is preferable because it has excellent heat resistance and chemical resistance in a cured product of an epoxy resin, and is also capable of obtaining hydrophobicity, thereby suppressing moisture absorption. In addition, dicyandiamide, melamine, methyl decylamine, benzoguanamine, 3,9-bis[2-(3,5-diamino-2,4,6-triazaphenyl)ethyl] Indoleamines such as 2,4,8,10-tetraoxaspiro[5,5]undecane and derivatives thereof, and organic acid salts, epoxy adducts and the like thereof are known to have adhesion to copper. The properties and rust preventive properties can be suitably used not only as a curing agent for an epoxy resin but also to prevent discoloration of copper on a printed circuit board.

For the compounding amount of the (C) curing catalyst, a ratio of the amount generally used is sufficient, for example, per 100 parts by mass of the aforementioned (A) epoxy resin having no alicyclic skeleton and (B) having an alicyclic skeleton. The total amount of the epoxy resin is 0.05 parts by mass or more and 140 parts by mass or less is suitable. It is preferably 0.1 part by mass or more and 120 parts by mass or less, more preferably 0.3 part by mass or more and 100 parts by mass or less. If it is less than 0.05 parts by mass, a cured product having sufficient hardness cannot be obtained. As a result, there is a possibility that a problem such as dropping of the composition at the time of polishing may occur. in case In the case of 140 parts by mass or more, in addition to the inability to suppress the viscosity increase with time viscosity, the pre-curing speed of the resin composition is usually too fast, and voids are likely to remain in the cured product, which is not preferable.

(D) The filler is used to relax the stress caused by curing shrinkage, adjust the linear expansion coefficient, and impart thixotropy to the resin composition, and may be any material as long as it is used in a general resin composition. Conventional non-conductive material. Specific examples thereof include cerium oxide, barium sulfate, calcium carbonate, barium nitride, aluminum nitride, boron nitride, aluminum oxide, magnesium oxide, aluminum hydroxide, magnesium hydroxide, titanium oxide, mica, and talc. , organic bentonite, kaolin, Sillitin, sintered kaolin clay, sintered talc, sintered non-metallic fillers such as Neuburg alumina, and copper, gold, silver, palladium, rhodium, etc. Metal filler. These are matched with the requirements for improving the characteristics of the coating film, and may be used singly or in combination of two or more. Among them, cerium oxide and calcium carbonate are preferred from the viewpoint of properties and operation.

(D) The shape of the filler may be a spherical shape, a needle shape, a sheet shape, a scaly shape, a hollow shape, an amorphous shape, a hexagonal shape, a cubic shape, a sheet shape, or the like, and may be any shape.

(D) The average particle diameter of the filler may be any particle diameter as long as it can be paste-formed without a particularly suitable range, and desired properties can be obtained.

Further, the surface treatment of the (D) filler may be treated with or without treatment.

The compounding ratio of the (D) filler is preferably from 30 to 90% by mass, more preferably from 40 to 70% by mass based on the total amount of the composition. When the compounding ratio of the inorganic filler is less than 30% by mass, the obtained cured product cannot exhibit sufficiently low expandability, and Abrasiveness and adhesion also become insufficient. On the other hand, in the case of more than 90% by mass, paste formation becomes difficult, and printability, hole filling property, and the like cannot be obtained.

In the thermosetting resin composition of the present invention, when a liquid epoxy resin at room temperature is used, it is not always necessary to use a diluent solvent, but a diluting solvent may be added in order to adjust the viscosity of the composition. Examples of the diluent solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; methyl cellosolve, butyl cellosolve, and methyl carbitol; Ethyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monoethyl ether and other glycol ethers; ethyl acetate, butyl acetate, and the above glycol ethers of acetic acid Esters such as esters; alcohols such as ethanol, propanol, ethylene glycol, and propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, naphtha, hydrogenated naphtha, and solvent naphtha. Organic solvents. They may be used singly or in combination of two or more.

The compounding ratio of the diluent solvent is preferably 10% by mass or less based on the total amount of the thermosetting resin composition. When the compounding ratio of the diluent solvent exceeds 10% by mass, bubbles and cracks are likely to be generated in the pore portion due to the evaporation of the volatile component during curing. More preferably, it is 5% by mass or less.

Further, in the thermosetting resin composition of the present invention, a known conventional coloring agent such as phthalocyanine blue, phthalocyanine green, iodine green, bisazo yellow, crystal violet, titanium oxide, carbon black or naphthalene black may be blended as needed. And a known conventional thermal polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, tert-butylcatechol, pyrogallol or phenothiazine for imparting storage stability during storage, clay, kaolin, and Conventional tackifiers or thixotropic agents such as bentonite and montmorillonite, antifoaming agents and/or leveling agents such as organic lanthanides, fluorine-based polymers, and polymers, imidazoles, thiazoles, triazoles, and decanes. A well-known and customary additive such as a coupling agent such as a coupling agent.

The thermosetting resin composition of the present embodiment is filled with a printed circuit board in which a conductive layer such as copper is formed on the wall surface of the surface and the hole portion by a known patterning method such as a screen printing method, a roll coating method, or a die coating method. The hole. At this time, it is completely filled so that the hole portion slightly protrudes. Next, the printed circuit board in which the hole portion is filled with the thermosetting resin filler is heated, for example, at 150 ° C for 60 minutes, whereby the thermosetting resin filler is cured to form a cured product.

Next, an unnecessary portion of the cured product protruding from the surface of the printed circuit board is removed by a known physical polishing method to perform planarization. Next, the conductive layer on the surface is patterned in a predetermined pattern to form a predetermined circuit pattern. Further, if necessary, the surface of the cured product may be roughened by a potassium permanganate aqueous solution or the like, and then a conductive layer may be formed on the cured product by electroless plating or the like.

Example

The present invention will be described in more detail by way of examples and comparative examples, but the technical scope of the invention and its embodiments are not limited thereto. The "parts" or "%" in the examples and comparative examples are based on weight unless otherwise specified. The property value test of the composition of the present example was carried out by the method described below.

(Preparation of paste)

The thermosetting resin compositions of Examples 1-4 and Comparative Examples 1-5 were prepared by premixing the components shown in Table 1 in a respective compounding ratio (parts by mass) via a stirrer and then dispersing them in a three-roll mill.

Epoxy Resin A-1 without alicyclic skeleton: bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, "jER-828")

Epoxy Resin A-2 without alicyclic skeleton: bisphenol F-type epoxy resin (manufactured by Mitsubishi Chemical Corporation, "jER-807")

Epoxy Resin A-3 without an alicyclic skeleton: p-aminophenol type epoxy resin (manufactured by Mitsubishi Chemical Corporation, "jER-630")

Epoxy resin B-1 having an alicyclic skeleton: 3', 4'-epoxycyclohexanecarboxylic acid 3,4-epoxycyclohexylmethyl ester (manufactured by DAICEL CHEMICAL INDUSTRIES, LTD., "Celoxide 2021P")

Epoxy resin B-2 having an alicyclic skeleton: 1,2-epoxy-4-(2-oxiranyl)cyclohexane of 2,2-bis(hydroxymethyl)-1-butanol Adduct (manufactured by DAICEL CHEMICAL INDUSTRIES, LTD., "EHPE3150")

Curing catalyst C-1: imidazole (manufactured by Shikoku Chemical Industry Co., Ltd., "2MZ-A")

Curing catalyst C-2: tetrapropenyl succinic anhydride (manufactured by Nippon Chemical and Chemical Co., Ltd., "RIKACID DDSA")

Curing catalyst C-3: octanoate of DBU (manufactured by SAN-APRO, "U-CATSA-102")

Filler D-1: calcium carbonate (particle size D50: 2.0 μm)

Filler D-2: cerium oxide (particle size D50: 1.5 μm)

Performance evaluation: (1) Viscosity

Each of the thermosetting resin compositions of the above Examples 1 to 4 and Comparative Examples 1 to 5 was allowed to stand in an environment of 30 ° C for 168 hours, and the viscosity before and after the standing was measured, and the viscosity-increasing ratio was determined by the following formula. The viscosity was measured by using 0.2 ml of each thermosetting resin composition, using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.) at 25 ° C and a rotation speed of 5 rpm / min.

Viscosity increase = (viscosity after 168 hours - initial viscosity) ÷ initial viscosity

The evaluation criteria are as follows.

○: viscosity increase rate of 20% or less

×: viscosity increase rate exceeds 20%

(2) Fillability

Each of the thermosetting resin compositions of the above Examples 1 to 4 and Comparative Examples 1 to 5 was filled into the through holes by screen printing, and then placed on the glass epoxy substrate in which the through holes were formed by plate plating in advance. The sample was subjected to photocuring at 150 ° C for 1 hour in a hot air loop drying oven to obtain a sample to be evaluated. The sample to be evaluated was physically polished by a grinder equipped with a High Cut Buff 19 (SFBR-#320 Sumitomo 3M Limited), and the cross section of the hole portion was observed under an optical microscope (100 times). The evaluation criteria are as follows.

○: No crack/void/peeling was observed at all the through holes.

×: voids/cracks/peeling were confirmed in any of the holes.

(3) Abrasiveness

Each of the thermosetting resin compositions of the above Examples 1 to 4 and Comparative Examples 1 to 5 was filled into a through hole by a screen printing method, and then placed on a glass epoxy substrate in which through holes were formed by plate plating in advance, and then placed in a through hole. The sample was subjected to photocuring at 150 ° C for 1 hour in a hot air loop drying oven to obtain a sample to be evaluated. The sample to be evaluated was physically ground using a grinder equipped with a High Cut Buff 19 (SFBR-#320 Sumitomo 3M Limited) to visually observe the surface of the surface by an optical microscope. state. The evaluation criteria are as follows.

○: The paste protruding on the surface was removed by polishing using the number of times of polishing.

△: The paste protruding on the surface was removed by grinding twice using the number of times of polishing.

X: The residue of the thermosetting resin composition was observed between the periphery of the through hole or the adjacent through hole, or the thermosetting resin composition in the through hole was peeled off.

The results of the above tests are shown in Table 2.

In view of the above, it was found that the thermosetting resin composition prepared in Example 1-4 can be obtained by suppressing the viscosity increase with time viscosity, and is excellent in the filling property to the pores of the printed circuit board and the polishing property after curing. Thermosetting resin composition. On the other hand, in Comparative Examples 1 and 2, since the reactivity was high, the viscosity increase rate was high, and the hardness of the cured product was high. If the polishing conditions were not set, the polishing could not be performed, and thus the polishing property was insufficient. Comparative Example 3 using only (B) an epoxy resin having an alicyclic skeleton, although lacking in reactivity, suppressed sticking, but the strength and hardness of the cured product were insufficient, and peeling of the resin composition in the pore and the interface of copper occurred. The cured product in the pores is also peeled off during the grinding, and the surface of the cured product is not up to standard after grinding, so it is not filled. Filling and abrasive. In Comparative Example 4, the viscosity was not inhibited due to high reactivity. In Comparative Example 5, since the reactivity was high, the viscosity of the viscosity was not suppressed, and since the influence of the filler was not contained, the stress relaxation of the resin composition was insufficient to cause cracking, and thus the filling property was not obtained.

Claims (5)

A thermosetting resin composition for filling a hole of a printed circuit board, wherein the thermosetting resin composition contains (A) an amine type liquid epoxy resin having a benzene ring, and (B) an alicyclic skeleton. Epoxy resin, (C) curing catalyst, and (D) filler. The thermosetting resin composition according to the first aspect of the invention, wherein the ratio of the (A) amine-type liquid epoxy resin having a benzene ring is 4 to 40% by mass based on the total amount of the composition. The thermosetting resin composition according to the first aspect of the invention, wherein (B) the epoxy resin having an alicyclic skeleton has a compounding ratio of 2 to 38% by mass based on the total amount of the composition. The thermosetting resin composition according to the first aspect of the invention, wherein (A) an amine-type liquid epoxy resin having a benzene ring and (B) an epoxy resin having an alicyclic skeleton are ratios by mass ratio ( A): (B) = 90: 10 ~ 20: 80. A printed circuit board having a hole portion of a cured product filled with the thermosetting resin composition according to any one of claims 1 to 4.