JP5410804B2 - Epoxy resin composition, prepreg, laminate, and multilayer board - Google Patents

Description

  The present invention relates to an epoxy resin composition, a prepreg, a laminated board, and a multilayer board.

  A prepreg used as a material for a printed wiring board is obtained by diluting a resin composition mainly composed of a thermosetting resin such as an epoxy resin with a solvent to obtain a varnish, and impregnating a substrate such as a glass cloth with this varnish. It is produced by drying this to change the resin from an uncured state (A-stage) to a semi-cured state (B-stage).

  And after cutting the prepreg obtained in this way to a predetermined size, the required number of sheets are stacked and a metal foil such as a copper foil is stacked on one or both sides, and this is heated and pressed to form a printed wiring board. A metal-clad laminate to be processed can be produced. At this stage, the resin changes from a semi-cured state (B-stage) to a fully cured state (C-stage), and forms an insulating layer together with the base material.

  Conventionally, an amine curing agent such as dicyandiamide has been used as a curing agent in an epoxy resin composition used for a prepreg for a printed wiring board because it has excellent adhesive strength and toughness with a copper foil or the like (Patent Document 1). reference).

Japanese Patent No. 3216291

  However, in recent years, the mounting temperature of semiconductor elements on printed wiring boards has risen with the use of lead-free solder. However, when amine curing agents are used in epoxy resin compositions, such mounting temperatures are insufficient in heat resistance. May cause problems.

  On the other hand, a phenol curing agent may be used to increase heat resistance corresponding to lead-free solder, but an epoxy resin composition using a phenol curing agent is inferior in adhesive strength and toughness with a copper foil or the like. In some cases, problems may occur when processing printed wiring boards.

  Moreover, the printed wiring board is also required to have flame retardancy, and is required to satisfy the flame retardancy corresponding to UL standard 94V-0.

  The present invention has been made in view of the circumstances as described above, and is excellent in adhesive strength and toughness with a copper foil and the like, and further excellent in heat resistance and flame retardancy, It is an object to provide a prepreg, a laminated board, and a multilayer board.

  The present invention is characterized by the following in order to solve the above problems.

First, the epoxy resin composition of the present invention contains an epoxy resin, an amine curing agent, and a bromine compound having a thermal decomposition temperature of 320 ° C. or higher that is incompatible with the epoxy resin, and the epoxy resin contains an epoxy resin containing no bromine. The bromine content derived from the epoxy resin in the resin component of the epoxy resin composition is 8% by mass or less, and the bromine content in the resin component of the epoxy resin composition is 10% by mass or more. As an epoxy resin, an epoxy resin containing no nitrogen is contained in an amount of 90% by mass or more based on the total amount of the epoxy resin, and 1,2-bis ( Less of pentabromophenyl) ethane, tetradecabromodiphenoxybenzene and decabromodiphenyl oxide It characterized in that it contains one also.

Second, in the first epoxy resin composition, an epoxy resin, characterized by containing 45 to 75 wt% of the difunctional epoxy resin the epoxy resin the total amount.

Third , in the first or second epoxy resin composition, the amine curing agent contains dicyandiamide.

Fourth , the epoxy resin composition according to any one of the first to third features contains an inorganic filler.

Fifth , the prepreg of the present invention is obtained by impregnating a substrate with any of the first to fourth epoxy resin compositions described above and drying.

Sixth , the laminate of the present invention is characterized in that a required number of the above-mentioned fifth prepregs are stacked and heated and pressed to form a laminate.

Seventh , the multilayer board of the present invention is characterized in that the fifth prepreg is laminated on a circuit board for inner layer by heating and pressurizing.

According to the first aspect of the present invention, by using an amine curing agent, the adhesive strength and toughness with copper foil and the like are high, and as an epoxy resin , an epoxy resin not containing bromine and a bromine-containing epoxy resin are used in combination. By using a bromine compound having a thermal decomposition temperature of 320 ° C. or higher that is incompatible with the resin, the heat resistance can be improved and the required flame retardancy can be ensured.

Moreover, as a bromine compound having a thermal decomposition temperature of 320 ° C. or higher that is incompatible with the epoxy resin, a compound having a benzene ring in the molecular structure and having bromine as a substituent of the benzene ring can be used in addition to the above-mentioned effect , Can be particularly improved, and the required flame retardancy can also be ensured.

In addition, at least one of 1,2-bis (pentabromophenyl) ethane , tetradecabromodiphenoxybenzene, and decabromodiphenyl oxide is used as a bromine compound having a thermal decomposition temperature of 320 ° C. or higher that is incompatible with the epoxy resin. Thus, in addition to the above effects , the heat resistance can be particularly improved, and the required flame retardancy can also be ensured.

Moreover, in addition to said effect , especially high heat resistance is acquired by using what does not contain nitrogen as an epoxy resin in the quantity of said specific range.

According to the second aspect, a bifunctional epoxy resin by using an amount of a particular range of the epoxy resin, in addition to the effect of the first invention, the glass transition temperature is obtained and particularly high toughness.

According to the third invention, by using dicyandiamide as the amine curing agent, in addition to the effects of the first or second invention, the adhesive strength and toughness with the copper foil or the like can be made particularly high. .

According to the fourth invention, by containing the inorganic filler, in addition to the effects of the first to third inventions, the heat resistance can be further improved.

According to the fifth invention, since the epoxy resin composition of the first to fourth inventions is impregnated into a base material and dried, the adhesive strength and toughness with a copper foil or the like are high. Furthermore, the heat resistance is high and the required flame retardancy can be ensured.

According to the sixth invention, the required number of the prepregs of the fifth invention are stacked and heated and pressed to form a laminate, so that the adhesive strength and toughness with copper foil and the like are high, and the heat resistance is also high and required. It is also possible to ensure flame retardancy.

According to the seventh aspect of the invention, the prepreg of the fifth aspect of the invention is laminated on a circuit board for inner layer by heating and pressurization, and has a high adhesive force and toughness with a copper foil and the like, and further has heat resistance. Therefore, the required flame retardancy can be secured.

  Hereinafter, the present invention will be described in detail.

  In the present invention, the epoxy resin can be used without particular limitation as long as it has two or more epoxy groups in one molecule. Specific examples of such an epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, biphenyl type epoxy resin, and alicyclic type. Examples thereof include epoxy resins, diglycidyl ether compounds of polyfunctional phenols, diglycidyl ether compounds of polyfunctional alcohols, and bromine-containing epoxy resins. These may be used alone or in combination of two or more.

  In this invention, it is preferable that the epoxy resin which does not contain nitrogen is 90 mass% or more in all the epoxy resins from the point from which high heat resistance is acquired.

  Moreover, it is preferable that the ratio of a bifunctional epoxy resin is 45-75 mass% with respect to the epoxy resin whole quantity. By setting the ratio of the bifunctional epoxy resin within the range, toughness can be increased without lowering the glass transition temperature. If the ratio of the bifunctional epoxy resin is less than 45% by mass, the toughness may decrease. If the proportion of the bifunctional epoxy resin exceeds 75% by mass, the glass transition temperature may be lowered.

  The epoxy resin composition of the present invention contains an amine curing agent as a curing agent. By using an amine curing agent, the adhesive strength and toughness with a copper foil or the like can be increased. As the amine curing agent, dicyandiamide is preferable.

  The content of the amine curing agent is preferably adjusted so that the equivalent ratio with respect to the epoxy resin is 0.3 to 1.0, particularly 0.4 to 0.7. When the equivalent ratio of the amine curing agent to the epoxy resin is outside this range, curing may be insufficient or physical properties may be deteriorated.

  The epoxy resin composition of the present invention contains a bromine compound having a thermal decomposition temperature of 320 ° C. or higher, preferably 330 ° C. or higher, which is incompatible with the epoxy resin. By using a bromine compound having a thermal decomposition temperature of 320 ° C. or higher that is incompatible with the epoxy resin, high heat resistance can be obtained even if an amine curing agent is used.

  As the bromine compound having a thermal decomposition temperature of 320 ° C. or higher that is incompatible with the epoxy resin, a compound having a benzene ring in the molecular structure and having bromine as a substituent of the benzene ring is preferably used. Among them, a compound having 2 to 4 benzene rings, in which the benzene rings are directly bonded to each other or bonded through a hetero atom such as a carbon atom or an oxygen atom is preferable. In particular, a compound having a tetrasubstituted or pentasubstituted benzene ring structure in which all hydrogen in the benzene ring is substituted with bromine is preferable. Examples of such bromine compounds include 1,2-bis (pentabromophenyl) ethane, tetradecabromodiphenoxybenzene, decabromodiphenyl oxide, and the like.

  Note that “incompatible with the epoxy resin” means that a fine sea-island structure is formed between the epoxy resin and the bromine compound and does not mix with each other at the molecular level. On the other hand, heat resistance cannot be improved even if a bromine compound that is molecularly compatible with an epoxy resin without forming a cluster is used.

  In the present invention, the bromine content derived from the epoxy resin in the resin component of the epoxy resin composition is 8% by mass or less, and the bromine content in the resin component of the epoxy resin composition is 10% by mass or more. By adjusting the amount of bromine compound that is not compatible with epoxy resin and having a pyrolysis temperature of 320 ° C or higher and making the bromine content within this range, heat resistance can be improved and the required flame retardancy can be secured. it can.

  The epoxy resin composition of the present invention can contain a curing accelerator. Specific examples of the curing accelerator include imidazoles such as 2-ethyl 4-methylimidazole, 2-methylimidazole, and 2-phenylimidazole. These may be used alone or in combination of two or more.

  The epoxy resin composition of the present invention can contain an inorganic filler. Heat resistance can be improved by containing an inorganic filler.

  Specific examples of the inorganic filler include aluminum hydroxide, silica, magnesium hydroxide and the like. These may be used alone or in combination of two or more. The size of the inorganic filler particles is not particularly limited, but for example, those having an average particle diameter of 0.1 to 5 μm are used.

  The content of the inorganic filler is preferably 5 to 120% by mass with respect to the total amount of the epoxy resin composition. By containing an inorganic filler within this range, heat resistance can be enhanced without impairing other physical properties.

  The epoxy resin composition of this invention can mix | blend said epoxy resin, an amine hardening | curing agent, a bromine compound, and another component as needed, and can prepare it as a varnish. When preparing as a varnish, you may dilute with a solvent. Specific examples of the solvent include amides such as N, N-dimethylformamide (DMF), ethers such as ethylene glycol monomethyl ether, ketones such as acetone and methyl ethyl ketone, alcohols such as methanol and ethanol, benzene, toluene and the like. And aromatic hydrocarbons.

  When producing the prepreg of the present invention, the base material is impregnated with an epoxy resin composition prepared as a varnish. And the prepreg made into the semi-hardened state (B-stage) can be produced, for example by performing heat drying for 3 to 15 minutes at 130-170 degreeC in dryer.

  As the substrate, glass fibers such as glass cloth, glass paper, and glass mat can be used, and craft paper, natural fiber cloth, organic synthetic fiber cloth, and the like can also be used.

  The laminated plate of the present invention is formed by laminating a required number of the prepregs obtained as described above, for example, by heating and pressing under conditions of 140 to 200 ° C., 0.5 to 5.0 MPa, 40 to 240 minutes. Can be produced.

  At this time, a metal-clad laminate can be produced by stacking a metal foil on the outermost layer prepreg on one side or both sides and laminating these by heating and pressing. As the metal foil, copper foil, silver foil, aluminum foil, stainless steel foil or the like can be used.

  The multilayer board of the present invention can be produced as follows. By forming a circuit for the inner layer on the metal foil on one or both sides of the metal-clad laminate in advance by the additive method or subtractive method, etc., and by applying a blackening treatment to the surface of this circuit using an acid solution, the inner layer A circuit board is prepared.

  Then, the required number of the above prepregs are stacked on one or both sides of the circuit board for the inner layer, and further, metal foil is stacked on the outer surface as necessary, and this is heated and pressed to form a multilayer board. can do.

  Then, a circuit is formed on one or both sides of the laminated board or multilayer board produced as described above by an additive method, a subtractive method, etc., and if necessary, holes are made by laser processing, drilling, etc. A printed wiring board or a multilayer printed wiring board can be produced by performing a process such as plating to form via holes or through holes.

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

The following were used as a compounding component of the epoxy resin composition of an Example and a comparative example.
(Epoxy resin)
-"N690" manufactured by DIC Corporation, epoxy equivalent 190-240 g / eq, bromine content 0 mass%, average intramolecular epoxy group content 5-3, epoxy resin containing neither nitrogen nor bromine in the molecule-DIC stock “Epiclon 1050” manufactured by company, epoxy equivalent 450-500 g / eq, bromine content 0 mass%, average molecular epoxy group content 2 pieces, epoxy resin made by Dow Chemical Co., Ltd. that contains neither nitrogen nor bromine in the molecule DER514L ", epoxy equivalent 479-495 g / eq, bromine content 21.5 mass%, intramolecular average epoxy group content 2 pieces, epoxy resin containing bromine without nitrogen in the molecule
- "Epiclon 153" manufactured by DIC Corporation, epoxy equivalent 390-410 g / eq, bromine content 48 mass%, intramolecular average epoxy group content 2, epoxy resin containing bromine without containing nitrogen in the molecule ( Hardener)
Amine curing agent (dicyandiamide, equivalent 21 g / eq)
・ Phenol curing agent (phenol novolac resin, “TD2090” manufactured by DIC Corporation, hydroxyl equivalent 105 g / eq)
(Bromine compound)
1,2-bis (pentabromophenyl) ethane, “SAYTEX8010” manufactured by Albermarle, thermal decomposition temperature of 344 ° C.
Tetradecabromodiphenoxybenzene, “SAYTEX120” manufactured by Albermarle, thermal decomposition temperature of 402 ° C.
Decabromodiphenyl oxide, “SAYTEX102E” manufactured by Albermarle, thermal decomposition temperature of 326 ° C.
Tetrabromobisphenol A, “SAYTEXCP-2000” manufactured by Albermarle, thermal decomposition temperature 241 ° C.
(Curing accelerator)
・ 2-Ethyl-4methylimidazole, “CURESOL 2E4MZ” manufactured by Shikoku Kasei Kogyo Co., Ltd.
(Inorganic filler)
Aluminum hydroxide, “C-303” manufactured by Sumitomo Chemical Co., Ltd., average particle diameter of about 4 μm
[Preparation of resin varnish]
The above blending components were blended in the blending amounts (parts by mass) shown in Table 1, and the mixture diluted with a solvent was stirred and homogenized with a disper or the like. At this time, the amount of the solvent was adjusted so that the compounding components (epoxy resin, solid content including the curing agent) other than the solvent were 60 to 75% by mass, and the epoxy resin compositions of Examples and Comparative Examples were obtained as varnishes. . In addition, when mix | blending an inorganic filler, after adding predetermined compounding quantity, it stirred for 2 hours with the disper, and obtained the epoxy resin composition.
[Prepreg production conditions]
As a base material, a glass cloth (“7628 type cloth” manufactured by Nitto Boseki Co., Ltd.) was used, and this glass cloth was impregnated with a varnish of an epoxy resin composition at room temperature, and then about 130 by a non-contact type heating unit. By heating at ˜170 ° C., the solvent in the varnish was removed by drying, and the epoxy resin composition was semi-cured to prepare a prepreg. The amount of resin in the prepreg was adjusted to be 100 parts by mass of resin (50% by mass of resin) with respect to 100 parts by mass of glass cloth.
[Copper-clad laminate molding conditions]
Four prepregs (340 mm × 510 mm) produced above are sandwiched between roughened surfaces of two copper foils (thickness 35 μm, JTC foil, manufactured by Nikko Gouldfoil Co., Ltd.) for 90 minutes at 170 ° C. and 2.94 MPa. Lamination was performed to obtain a copper-clad laminate.
[Resin plate molding conditions]
After removing the resin component from the prepreg produced above to obtain resin powder, a required amount of resin powder is put into a 20 cm × 20 cm mold, and a copper foil (thickness 35 μm, JTC foil, manufactured by Nikko Gouldfoil Co., Ltd.) The resin plate was obtained by being laminated between the roughened surfaces at 170 ° C. and 2.94 MPa for 90 minutes.
<Thermal decomposition temperature>
Using a thermogravimetric change measuring device (TG-DTA), the copper foil of the copper clad laminate prepared above was peeled off and measured (temperature increase rate 5 ° C./min), and the weight loss was 5% of the initial value. This temperature was defined as the thermal decomposition temperature.
<Oven heat resistance>
The copper-clad laminate having a thickness of about 0.4 mm prepared above was heated in an oven for 60 minutes, and then evaluated at the limit (maximum) oven temperature at which there was no blistering or peeling.
<Adhesive strength>
After processing the non-roughened surface of the copper foil of the copper clad laminate produced above with BO200 manufactured by McDermid, the copper foil of the copper clad laminate molded with the prepreg sandwiched between the inner layer treated surfaces is peeled off, and JIS C6481 The 90 degree peel was measured according to
<Toughness>
A bending test was performed according to JIS C6481 using the resin plate having a thickness of 1.2 mm produced above, and the fracture distance [mm] was defined as toughness.
<Glass-transition temperature>
About the copper clad laminated board produced in the above, the glass transition temperature (Tg) was measured by TMA method (Thermo-mechanical analysis) according to JIS C6481.
<Flame retardance>
Evaluation was performed according to the UL method using the copper-clad laminate prepared above.

  Table 1 shows the results of the above measurements and evaluations performed on Examples and Comparative Examples.

From Table 1, the amine curing agent as a blending component of the epoxy resin composition, and in Examples 1-9 using epoxy resin incompatible with the thermal decomposition temperature of 320 ° C. or more bromine compounds, adhesion between the copper foil and High toughness, heat resistance (thermal decomposition temperature, oven heat resistance) was also high, and the required flame retardancy could be secured. In particular, Examples 1 to 9 containing 90% by mass or more of an epoxy resin containing no nitrogen with respect to the total amount of the epoxy resin had high heat resistance. Especially, in Examples 1-5, 8 , and 9 which contain 45-75 mass% of bifunctional epoxy resins with respect to the epoxy resin whole quantity, toughness was high and the glass transition temperature was also high. In particular, in Examples 1 to 5 and 9, in which bromine compounds having a thermal decomposition temperature of 330 ° C. or higher that are incompatible with the epoxy resin were used, the heat resistance was high.

On the other hand, in Comparative Example 1 in which the bromine content was the same as that of Examples 1 to 9 by using only the epoxy resin without blending a bromine compound having a thermal decomposition temperature of 320 ° C. or higher that is incompatible with the epoxy resin, the heat resistance decreased. did. And when the bromine content derived from the epoxy resin in the resin component of the epoxy resin composition exceeded 8% by mass, the same tendency was observed.

  In Comparative Example 2 using a phenol curing agent instead of an amine curing agent as the curing agent, although heat resistance was obtained, adhesive strength and toughness with copper foil and the like were reduced.

  A bromine compound 1,2-bis (pentabromophenyl) ethane having a thermal decomposition temperature of 320 ° C. or higher that is incompatible with the epoxy resin was blended in the same amount as in Example 3, but the total bromine content with the epoxy resin was 10% by mass. In Comparative Example 3, which was less than the required flame retardancy, the required flame retardancy was not obtained.

  In Comparative Example 4 in which a compound that reacts with and is compatible with the epoxy resin during curing is used as the bromine compound, the heat resistance is greatly reduced.

Claims (7)

An epoxy resin, an amine curing agent, and a bromine compound having a thermal decomposition temperature of 320 ° C. or higher that is incompatible with the epoxy resin , the epoxy resin includes a bromine-free epoxy resin and a bromine-containing epoxy resin, and an epoxy resin composition The epoxy resin-derived bromine content in the resin component of the product is 8 mass% or less, the bromine content in the resin component of the epoxy resin composition is 10 mass% or more, and the epoxy resin does not contain nitrogen As a bromine compound having a thermal decomposition temperature of 320 ° C. or higher that is incompatible with the epoxy resin and is 90% by mass or more based on the total amount of the epoxy resin, 1,2-bis (pentabromophenyl) ethane, tetradecabromodiphenoxybenzene, and Containing at least one of decabromodiphenyl oxide Epoxy resin composition.   The epoxy resin composition according to claim 1, wherein the epoxy resin contains 45 to 75% by mass of a bifunctional epoxy resin based on the total amount of the epoxy resin.   The epoxy resin composition according to claim 1, comprising dicyandiamide as the amine curing agent.   The epoxy resin composition according to any one of claims 1 to 3, further comprising an inorganic filler.   A prepreg obtained by impregnating a base material with the epoxy resin composition according to any one of claims 1 to 4 and drying it.   A laminate comprising the prepreg according to claim 5 which is laminated by heating and pressing.   A multilayer board, wherein the prepreg according to claim 5 is laminated on an inner layer circuit board by heating and pressing.