JPH02286711A - Resin composition for laminate and laminate - Google Patents

Abstract

PURPOSE:To obtain the title composition having excellent heat resistance and alkali resistance and a low dielectric dissipation factor by mixing a specified polyaromatic cyanate, a specified imide compound, a specified epoxy compound, a brominated bisphenol A, a curing agent, and a solvent. CONSTITUTION:This composition is prepared by mixing a polyaromatic cyanate having at least two cyanate groups in the molecule (e.g. a compound of the formula), an imide compound having at least two imide groups in the molecule (e.g. bismaleimide), an epoxy compound having at least two epoxy groups (e.g. brominated epoxy novolac resin), a brominated bisphenol A (e.g. tetrabromobisphenol A), a curing agent (e.g. imidazole), and a solvent (e.g. dimethylformamide).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a resin composition containing a polyaromatic cyanate resin as a main component as a resin component of a laminate used as a printed wiring board.

[Conventional technology]

Resins such as tetrafluoroethylene resin and polyphenylene oxide are being evaluated as resins constituting laminated boards, which are the substrates of printed wiring boards used in the high frequency range, but their glass transition temperatures remain at 180 to 200°C. Poor heat resistance.

In this way, polyaromatic cyanate resins have been newly developed as useful resins in the high frequency range, as they have a high glass transition temperature, a low dielectric constant to shorten signal propagation delay, and a low dielectric loss tangent to reduce power loss. is attracting attention.

However, a laminate that is cured after impregnating a base material with a resin composition mainly composed of polyaromatic cyanate resin,
It has poor heat resistance and alkali resistance, and in the pressure comb test (PCT), the phenomenon of fine cracks and racks occurring in the laminate was observed, leaving some problems for practical use. Therefore, the present inventors developed a resin composition for laminates based on polyaromatic cyanate, which maintains the dielectric constant and dielectric loss tangent and further improves alkali resistance and heat resistance, using imide resin and epoxy resin. It was discovered that a composition containing the following was useful, and based on this composition, a resin composition with a smaller dielectric loss tangent was provided.

[Issues to be solved]

The present invention provides a resin composition for laminates containing polyaromatic cyanate as a main component, which maintains dielectric constant and dielectric loss tangent and further improves alkali resistance and heat resistance. The object of the present invention is to provide a resin composition for laminates.

[Means to solve the problem]

The resin composition for laminates according to the present invention comprises a polyaromatic cyanate having two or more cyanate groups in the molecule, an imide compound having two or more imide groups in the molecule, and a polyaromatic cyanate having two or more cyanate groups in the molecule;
It is characterized in that it contains an epoxy compound having at least three epoxy groups, brominated bisphenol A, a curing agent, and a solvent.

The present invention will be explained in detail below.

First, as the polyaromatic cyanate, a cyanate compound represented by formula (1) is used, and as disclosed in Patent Application Publication No. 1988-50043, this compound has a more hydrolytic action than conventional polytriazine. As a result, (hereinafter margin) (OCN)r (D)t (D)t (D)t <D”)t (
D) t...Formula (1) is known to provide aromatic polytriazine exhibiting excellent thermal stability.

In the cyanate of formula (1), the aromatic group Ar means any group containing an aromatic group, such as benzene, naphthalene, phenanthracene, anthracene, or a bisaromatic group, or a group crosslinked by an alkylene moiety. 2 or more aromatic groups. A13 is preferably a benzene, naphthalene, biphenyl, binaphthyl, or diphenylalkylene group, and particularly a benzene group. B is a polycyclic aliphatic group of 07 to 2o, meaning an aliphatic group containing two or more rings, and the polycyclic aliphatic group has one or more double bonds or triple bonds. May be included.

Suitable polycyclic aliphatic groups include the following.

(In the formula, Y is -CH2--3--3--3 and Dl is a C3-5 alkyl group) Among these, (a) (b)
(c) (d) (e) (f) (g) or (42
) are preferred, and more preferred are (a) (b)
(c) (d) Among (1), (a) is particularly preferred.

D in formula (I) means all substituents that can be substituted on the organic hydrocarbon group, but substituents containing active hydrogen atoms are excluded. Active hydrogen atom means a hydrogen atom bonded to an oxygen, sulfur, or nitrogen atom. Each in formula (1) is defined independently, and includes, for example, alkyl, alkenyl, alkynyl, aryl, alkaryl, aralkyl, halo, alkoxy, nitro,
carboxylate, sulfone, sulfide, carbonate, etc., preferably C8~1o alkyl, 01~
1o alkenyl, nitro, halo.

01-3 alkyl, C+-3 alkynyl, bromine,
Chlor is most preferred.

In addition, t in formula (1) is an integer from 0 to 4, preferably an integer of Oll or 2, preferably 0 or 1.
and is optimally 0. Each t in formula (I) is defined independently. q.

r and s are integers of 0.1.2 or 3, and optimally 1. Q+r+3 are each defined independently, but their total is set to be 2 or more. Further X
is a positive number from 0 to 5. The polyaromatic cyanates of formula (I) are found as mixtures of compounds in which X is from O to 5, with X being defined as the average number of this mixture.

A preferred embodiment of the polyaromatic cyanate of formula (I) is represented by the following formula.

Therefore, the aromatic polytriazine obtained from the polyaromatic cyanate of formula (1) shows a low dielectric constant and a low dielectric loss tangent, but on the other hand, when subjected to alkali treatment and a pressure-cutting test, the cured laminate showed fine cracks, ranks, and whitening. Occurrence of the phenomenon and exposure of the grain of the base material are observed. Therefore, the present inventors particularly improved heat resistance and alkali resistance by using an imide compound and an epoxy compound together as resin components in polyaromatic cyanate.

Furthermore, in order to reduce the power loss of the layer and lower the operating voltage of electronic components, in the present invention, in order to further reduce the dielectric loss tangent of the resin composition, bromine is added as a resin component. Bisphenol A1, specifically tetrabromobisphenol A (hereinafter referred to as TBBA)
Blend.

Here, as the imide compound, a compound having two or more imide groups in the molecule is used, and similarly as the epoxy compound, a compound having two or more epoxy groups in the molecule is used. This is because imide compounds and epoxy compounds produce cured products with a crosslinked structure through a ring-opening reaction, because a single imide group or epoxy group does not produce a product with a crosslinked structure and does not increase heat resistance. .

Bismaleimide is used as a typical imide compound, and epoxy novolac resin is used as an epoxy compound. Here, the cyanate in the polyaromatic cyanate resin reacts with the imide group of the imide compound, the epoxy group of the epoxy compound, and the hydroxyl group of TBBA. A reaction occurs to produce a cured product with a dense crosslinked structure. Therefore, the crosslinking density varies depending on the blending ratio of the polyaromatic cyanate, the imide compound, the epoxy compound, and TBBA, which affects heat resistance. By adding TBBA, the dielectric loss tangent can be further reduced.

Specifically, the imide compound is 10 to 40 parts, the epoxy compound is 10 to 40 parts, and the TBBA is 1 to 2 parts by weight, based on 20 to 60 parts by weight of aromatic cyanate (hereinafter simply referred to as parts).
0 parts is appropriate. The reaction of these four components is promoted by imidazoles used as ionic polymerization catalysts. These imidazoles are useful for improving the solubility of the above-mentioned imide compounds, especially bismaleimide compounds, and have the effect of uniformly promoting the curing reaction, and the appropriate amount of addition is 0.001 to 1% by weight based on the total amount of resin components. It is.

Furthermore, the presence of trivalent cobalt ions or divalent zinc ions promotes the above four reactions. These metal ions are in very small amounts and have no effect even if added in large amounts, with a weight ratio of 5 to the polyaromatic cyanate.
A range of 11,000 pp to 11,000 pp is suitable. Examples of trivalent cobalt organic metal salts include cobalt naphthenate and cobalt octylate. In addition, in order to improve the flame retardancy of the cured product obtained by promoting the crosslinking reaction of the resin component, the epoxy compound should have a bromine content of 10% or more based on the total amount of the resin component. Epoxy novolak resins are useful.

As a resin component, a polyaromatic cyanate, an imide compound, an epoxy compound, and TBB represented by the above formula (1) are used.
A. A varnish is prepared by dissolving imidazole and others as a reaction catalyst in an organic solvent. The organic solvent may be any solvent as long as it dissolves the polyaromatic cyanate, imide compound, epoxy compound, or pre-reactant of TBBA and does not adversely affect the reaction.
Alcohol, ketone, amide, etc. are not particularly limited.

For example, toluene, acetone, methyl ethyl ketone, dimethyl formamide, methyl cellosolve, etc. can be used alone or in combination of two or more. The concentration of the varnish is generally adjusted so that the solid content is 50 to 70% by weight.

In manufacturing prepreg, the base material is not particularly limited, but it is common to use glass fiber woven or non-woven fabric, and this base material is impregnated with varnish and dried by heating. do. The amount of varnish impregnated into the base material is preferably set to be 45% or more based on the total amount of resin components and other additives in the base material. The dielectric constant level is affected by the resin content, and when the base material is made of E glass cloth, a dielectric constant of 4.0 or less can be achieved with impregnation of 45% by weight or more. Further, when the base material is formed of D glass cloth, a dielectric constant of 3.5 or less can be achieved by impregnation of 45% by weight or more. The heating drying conditions when preparing prepreg are influenced by the amount of reaction catalyst blended, etc., but for example, if the heating temperature is 160°C, the desired heating time can be set by setting the heating time for about 3 to 10 minutes. Prepreg stroke gel time can be obtained. The stroke gel time of prepreg varies depending on molding conditions, etc., but is generally about 2 to 10 minutes at 170'C. Then, by layering multiple sheets of prepreg prepared in this way, then layering metal foil such as copper foil on both or one side of the top and bottom, and molding this under heat and pressure, the polyaromatic cyanate in the prepreg is cured by reaction. It is possible to create a double-sided metal foil-clad or single-sided metal-clad laminate in which metal foil is laminated and bonded on both sides or one side of an insulating substrate.

The molding conditions are: heating temperature of 170'C to 230°C, maximum pressure of about 30 to 40 kg/cJ, and time of 90 to 230°C.
Generally, it is set to about 120 minutes. 22 after molding
In the case of after-curing at a temperature of about 0 to 230°C, a molding temperature of about 170 to 180°C is sufficient.

This laminate maintains alkali resistance and dielectric constant, and has even better performance in terms of dielectric loss tangent than when cured with a three-component resin consisting of polyaromatic cyanate, imide compound, and epoxy compound. The printed circuit board obtained by forming a circuit by etching the metal foil of the laminated board created in 2015 is suitable for mounting electronic components with a lower operating voltage to reduce power loss. .

〔Example] Hereinafter, the present invention will be explained in detail with reference to Examples and Comparative Examples.

Example 1 contains 50 parts of polyaromatic cyanate (XU-71787, manufactured by Daumical) represented by the following formula, 30 parts of bismaleimide, 19 parts of brominated epoxy novolac (YDB-400, manufactured by Tobu Kasei), and 1 part of TBBA. , cobalt octylate 500 ppm as imidazole 2 E
A resin composition was obtained by dissolving 0.5 part of 4M Z in 70 parts of dimethylformamide with stirring.

A prepreg was prepared by impregnating a 2×16 type E glass substrate (116E, manufactured by Nittobo Co., Ltd.) with this varnish so that the solid content was 45% by weight, and heating and drying it at 150° C. for 14 minutes.

Next, four sheets of this prepreg were stacked, and copper foil with a thickness of 35μ and roughened on both sides was stacked on both sides, and this was laminated and molded at a molding temperature of 170°C and a molding pressure of 40kg/c+fl for 90 minutes. After molding, the film was cured at 230°C for 12 hours in an electric open oven to a thickness of 0.
A 4 mm double-sided body-bonded laminate was obtained.

Example 2 was carried out in the same manner as in Example 1 except that 5 parts of TBBA and 15 parts of brominated epoxy novolak were used.

Example 3 was carried out in the same manner as in Example 1 except that 10 parts of TBBA and 10 parts of brominated epoxy novolak were used.

Example 4 was carried out in the same manner as in Example 1 except that TBBA was changed to 20 parts and brominated epoxy novolak was not blended.

Example 5 was carried out in the same manner as in Example 1 except that TBBA was changed to 25 parts and brominated epoxy novolak was not blended.

Comparative Example 1 was carried out in the same manner as in Example 1, except that TBBA was not blended and 20 parts of brominated epoxy novolak was blended.

0.0 of Examples 1 to 5 and Comparative Example 1 obtained as described above.
The electrical properties and heat resistance of the 4 mm thick laminate were measured, and the results are shown in Table 1.

In Table 1, dielectric constant, dielectric loss tangent, and oven heat resistance were measured based on JIS, C6481, and alkali resistance was measured by immersing the laminate in a 10% by weight aqueous solution of caustic soda at 80°C for 3 to 10 minutes. After immersion, the appearance was visually observed, and cases in which fine whitening due to rack occurred were marked as ×, and cases in which no change in appearance was observed even after 40 minutes of immersion were marked as ○.

(Margins below) Table 1 As seen in the results in Table 1, T according to Examples 1 to 5
The laminate using the polyaromatic cyanate resin composition blended with BBA has a further reduction in dielectric loss tangent compared to the laminate using the polyaromatic cyanate resin composition not containing TBBA according to Comparative Example 1. It could be confirmed. The reason why the content of TBBA is limited to 1 to 20 parts per 100 parts of the resin component is that from the results in Table 1, adding 1 part of TBBA is effective in reducing the dielectric loss tangent, and 20 parts or more of TBBA reduces the dielectric loss tangent. This is because there is no reduction in heat resistance, but rather only a decrease in heat resistance, which is undesirable.

(Effects of the Invention) As described above, according to the present invention, the dielectric loss tangent of the polyaromatic cyanate resin can be further reduced.

Claims (8)

[Claims] (1) Polyaromatic cyanates having two or more cyanate groups in the molecule, imide compounds having two or more imide groups in the molecule, epoxy compounds having two or more epoxy groups in the molecule, brominated A resin composition for a laminate comprising bisphenol A, a curing agent, and a solvent. (2) The resin composition for a laminate according to claim 1, wherein the brominated bisphenol A is tetrabromobisphenol A. (3) The resin composition for a laminate according to claim 1 or 2, wherein the polyaromatic cyanate is represented by formula (1). ▲There are mathematical formulas, chemical formulas, tables, etc.▼...Formula (I) (In the formula, Ar is aromatic. B is a polycyclic aliphatic group of C_7 to _2_0. D is each independently a substituent that does not contain active hydrogen. q, r, s are each independently an integer of 0, 1, 2 or 3, provided that the sum of q, r, s is greater than 2 or 2.
be equivalent to. t is an integer from 0 to 4, each independently. (X is a number from 0 to 5) (4) The resin composition for a laminate according to any one of claims 1 to 3, wherein the imide compound is bismaleimide. (5) The resin composition for a laminate according to any one of claims 1 to 4, wherein the epoxy compound is a brominated epoxy novolak resin. (6) The resin composition for a laminate according to any one of claims 1 to 5, further comprising an organic metal salt of trivalent cobalt or divalent zinc. (7) 20 to 60 parts by weight of the above polyaromatic cyanate, 10 to 40 parts by weight of the imide compound, 10 to 40 parts by weight of the epoxy compound, and 1 part by weight of tetrabromobisphenol A.
The resin composition for a laminate according to any one of claims 1 to 6, wherein the resin composition is blended in a proportion of 20 parts by weight. (8) Polyaromatic cyanates having two or more cyanate groups in the molecule, imide compounds having two or more imide groups in the molecule, epoxy compounds having two or more epoxy groups in the molecule, tetrabromobisphenol A laminate, characterized in that a resin composition formed by blending A, a curing agent, and a solvent contains a resin that is reacted and cured in a base material.