JPH04300952A - Thermosetting resin composition and prepreg and copper-clad laminated board produced by using the same - Google Patents

Abstract

PURPOSE:To provide a composition giving a material for a printed circuit board having low dielectric constant and excellent moisture-absorption, heat-resistance, alkali-resistance, dimensional stability and through-hole plating reliability while keeping low-dielectric constant and low hygroscopicity of a cyanate ester resin and suitable for high-speed computer, satellite communication, etc. CONSTITUTION:The objective composition is produced by compounding (A) a cyanate ester resin expressed by formula I (A is aromatic ring, etc.; B is 7-20C polycyclic alicyclic group; D is substituent free from active hydroxyl group; p, q and r are 0-3; p+q+r is >=2; s is 0-4; o is <=5) (e.g. the compound of formula II) and (B) a polymer having phenolic hydroxyl group, e.g. a compound composed of the recurring unit of formula III and having an average molecular weight of 500-50,000 (e.g. a vinylphenol polymer) at a weight ratio (A:B) of 95:5 to 50:50.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a thermosetting resin composition as a double-sided or multilayer printed wiring board material used in computers, satellite communications, mobile radio communication equipment, measuring equipment, etc., and the use of the resin composition. The present invention relates to prepregs and copper-clad laminates for printed circuit boards.

0002

2. Description of the Related Art Hitherto, epoxy resins, polyimide resins, and the like have been used as resin materials for double-sided or multilayer printed wiring boards used in computers, measuring instruments, and the like. However, in recent years, with the transition to a highly information-oriented society, the amount of information to be processed has increased dramatically, and it is now required to process large amounts of information at higher speeds.

Generally, the signal propagation velocity V is expressed by the following formula:

[Formula 1] (C: speed of light, ε: dielectric constant, K: constant) The smaller the dielectric constant, the faster calculation processing becomes possible. Therefore, attempts have been made to reduce the dielectric constant of printed wiring boards in order to improve the signal propagation speed.

Conventionally, polytetrafluoroethylene (PTFE), thermosetting polyphenylene oxide (PPO), polyolefin, polybutadiene, and the like have been known as low dielectric constant resin materials. In addition to the above, low dielectric constant resin materials include cyanate ester resins containing aromatic or alicyclic compounds in the main chain (Japanese Patent Publication No. 1986-5
No. 00434).

[0005]

[Problem to be solved by the invention] However, PTF
Since E is a thermoplastic resin, it has a large coefficient of thermal expansion in the Z-axis direction, and when it is used as a multilayer printed wiring board material, there is a problem that dimensional stability and through-hole reliability are poor. Furthermore, its melting temperature is 250-3
There were problems such as poor workability due to the high temperature of 50° C., and the need for a complicated treatment process called tetra-etching even when plating copper through-holes. In addition, PPO has poor resistance to organic solvents such as methylene chloride, poor solder heat resistance, and poor flame retardancy, and is UL-944
There was a problem that it was difficult to obtain a VO grade material, and it was unsuitable as a material for multilayer printed wiring boards. Furthermore, regarding polyolefin and polybutadiene,
Since it inherently lacks heat resistance and its use temperature is limited to 120° C. or lower, it is clearly unsuitable for use in high-speed computers.

Furthermore, the cyanate ester resin is
When heat treated in the presence of a catalyst such as organic acid cobalt,
It is possible to obtain a cured product with a triazine ring structure and a high crosslinking density.The obtained cured product has low hygroscopicity, low dielectric constant, and excellent heat resistance and dimensional stability. However, it has been pointed out that the flexibility is poor, and cracks occur during drilling of the laminate, reducing the reliability of through-holes. In order to solve this problem,
-88673 describes the addition of polyhydric phenols, but when these are added, the flexibility and impact resistance are improved, but the dielectric properties are lower than when no additives are added. However, it had the disadvantage of poor chemical resistance.

The present invention has been made in view of the above points, and is capable of maintaining the low dielectric constant and low dielectric loss tangent of cyanate ester resin, as well as high heat resistance and chemical resistance. The object of the present invention is to provide a thermosetting resin composition that has improved properties and impact resistance, thereby increasing the reliability of through-hole plating during drilling of laminates.

[0008]

[Means for Solving the Problems] The present invention provides (1) general formula [1]

[Formula 2] (wherein A is an aromatic ring or a group containing an aromatic ring, B is a C7-
C20 polycyclic alicyclic group, D is each independently a substituent containing no active hydrogen group, p, q, r are each independently an integer of 0 to 3, provided that the total of p, q, r is 2 That's all. Furthermore, each s is an integer from 0 to 4, and x is an integer from 0 to 5.
is an integer up to . ) A thermosetting resin composition characterized by blending a polymer having a phenolic hydroxyl group with a cyanate ester resin represented by (2) a woven or nonwoven fabric of inorganic fibers or organic fibers; A prepreg characterized by impregnating 30 to 70% by weight of the thermosetting resin composition according to claim 1; This is a copper-clad laminate characterized in that prepregs obtained by impregnating 30 to 70% by weight of a composition are laminated and copper foil is bonded to the surface.

The present invention will be explained in detail below.

[0010] As the cyanate ester resin represented by the general formula [1] used in the present invention,
0434 can be used. That is, this special cyanate ester resin provides a polytriazine that has lower hygroscopicity than polytriazine derived from conventional bisphenol A type cyanate ester resin, is extremely stable against hydrolytic action, and has excellent heat resistance. It is something.

In the general formula [1], A means any group containing an aromatic ring, specifically, a phenylene group, a naphthylene group, anthrylene group, a biphenylene group, a binaphthylene group, or an alkylene group. It is a group containing two or more bonded aromatic rings, and among them, a phenylene group and a naphthylene group are preferable, and a phenylene group is particularly preferable.

[0012] Furthermore, in formula [1], B is C7 to C2
0 represents a polycyclic alicyclic group, which means an alicyclic group containing two or more rings, and a polycyclic alicyclic group contains one or more double bonds or triple bonds. It's okay. Specific examples include the following, among which (a) and (b)
, (c), (d), and (e) are preferred, and (a) is particularly preferred.

[Formula 3] (wherein, Y is CH2, S, S=O, O=S=O,
D' is a C1-C5 alkyl group. )

[0013]
In formula [1], each D is independently a substituent containing no active hydrogen group, and substituents containing active hydrogen atoms are excluded. The active hydrogen atom herein means a hydrogen atom bonded to an oxygen, sulfur, or nitrogen atom. Specific examples include hydrogen atoms, C1-C10 alkyl groups, C1-C10 alkenyl groups, C1-C5 alkynyl groups, C1-C5 alkoxy groups, nitro groups, carboxyl groups, halogen atoms, etc. A hydrogen atom, a C1-C3 alkyl group, and a halogen atom are preferred, and a hydrogen atom and a bromine atom are particularly preferred.

In formula [1], s is an integer from 0 to 4, preferably an integer from 0 to 1, and particularly preferably 0. Moreover, p, q, and r are each independently an integer of 0 to 3, and 1 is particularly preferable among them. However, p, q
, r is set to be 2 or more. moreover,
x is an integer from 0 to 5, and the cyanate ester resin of formula [1] is found as a mixture of compounds where x is from 0 to 5.

A preferred specific example of the cyanate ester resin represented by formula [1] is represented by the following formula, which is available as QUATREX 7187 (manufactured by Dow Chemical Company).

[C4]

However, the polytriazine obtained by heating the cyanate ester resin of formula [1] in the presence of a catalyst has low hygroscopicity (water absorption rate of 0.5% or less) and low dielectric constant (ε2
．． (around 8), low dielectric loss tangent (tan δ around 0.003)
It also has excellent properties as a resin constituting a printed wiring board having high heat resistance (Tg 250° C. or higher).

The polymer having a phenolic hydroxyl group used in the present invention is used to improve impact resistance without impairing dielectric properties and chemical resistance when curing the cyanate ester resin. , an average molecular weight of 500 to 50, in which the repeating unit is represented by the general formula [2],
000 compounds are mentioned.

[Formula 5] (wherein, X and Y represent a hydrogen atom, an alkyl group or an aryl group which may have a substituent, and Z represents a halogen atom, an alkyl group or an aryl group which may have a substituent) represents a group, n is an integer of 1 to 3, m is 0 or 1 to 3
represents an integer. )

Specific examples thereof include (1) vinylphenol polymer, vinylbromophenol polymer, vinyl t-butylphenol polymer, vinylphenol/methyl methacrylate copolymer, vinylphenol/styrene copolymer, vinylphenol/2 - Polymers derived from vinylphenol such as hydroxyethyl methacrylate copolymer and vinylphenol-phenylmaleimide copolymer, ■ Phenols such as phenol, cresol, xylenol, resorcinol, and pyrogallol, and formaldehyde, acetaldehyde, benzaldehyde, acetone,
Examples include compounds obtained by reaction with aldehydes or ketones such as methyl ethyl ketone and acetophenone.

The blending ratio of the above compound [1] and the polymer having a phenolic hydroxyl group is 95:5 to 50:5 by weight.
It may be within the range of 0. If this blending ratio is greater than 95:5, the cured product will lack flexibility and will have poor solder heat resistance and chemical resistance after moisture absorption treatment. Also, this blending ratio is 5
If the ratio is less than 0:50, hygroscopicity becomes large and the characteristics as a low dielectric constant material are not fully exhibited, which is not preferable.

Next, a method for manufacturing a prepreg for printed wiring boards and a copper-clad laminate using the resin composition of the present invention will be explained.

[0021] When making prepreg, first of all, the cyanate ester resin of the above formula [1] and the formula [
A varnish is prepared by dissolving the polymer having a phenolic hydroxyl group shown in 2], a flame retardant, a reaction catalyst, etc. in an organic solvent. Next, this varnish is impregnated into a woven or nonwoven fabric of inorganic fibers or organic fibers, which is commonly used as a fiber base material for printed wiring boards, and then heated and dried. At this time, the amount of varnish impregnated into the fiber base material is
It is preferable to set the ratio of resin solid content (combined resin of formula [1], polymer having a phenolic hydroxyl group, and flame retardant) to the total weight after drying to be 30 to 70% by weight. . The heating drying conditions when producing prepreg are influenced by the amount of reaction catalyst added, but for example, when the heating temperature is 150°C, the heating time is 3 to 1
By setting the time to about 0 minutes, it is possible to obtain a desired prepreg stroke gel time.

[0022] The flame retardant used in producing the present prepreg may be any compound containing halogen, but specifically, tetrabromobisphenol A, decabromodiphenyl oxide, halogen-substituted aromatic Group polycarbonate oligomers, e.g.
A tribromophenoxy-terminated tetrabromobisphenol A carbonate oligomer shown in [3] can be used.

[C6] (In the formula, n is an integer from 1 to 20.)

These flame retardants can be used alone or in combination, but the cyanate ester resin of formula [1] and the cyanate ester resin of formula [2]
The content of Br is 1 for the total amount of polymer and flame retardant.
It is preferable to adjust the content to 0 to 15% by weight.

As the reaction catalyst, imidazoles, amines, organic acid metal salts, etc. can be used, and organic acid metal salts such as cobalt naphthenate, cobalt octylate, and manganese octylate are particularly preferred. The amount of reaction catalyst added is not particularly limited, but for example,
When using organic acid cobalt salts, the weight ratio of the metal to the weight of the cyanate ester resin represented by formula [1] is 20 depending on the desired gel time of the prepreg.
It is blended in a range of ~500 ppm.

Furthermore, the organic solvent is not particularly limited as long as it dissolves the cyanate ester resin represented by formula [1] and the flame retardant and does not adversely affect the reaction.
For example, ketones such as acetone and methyl ethyl ketone,
Polar amide solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone are used, and these can be used alone or in combination. The amount of organic solvent added is generally adjusted so that the solid content concentration in the varnish is 50 to 70% by weight.

[0026] As the above-mentioned fiber base material, those generally used as laminated materials for printed circuit boards can be used. For example, as the inorganic fiber base material, SiO2 or Al2
There are E-glass, D-glass, C-glass, S-glass, etc. whose main component is O3 etc., and there are also woven fabrics and non-woven fabrics of glass fibers such as silica glass whose main component is SiO2. In addition, examples of the organic fiber base material include woven fabrics or nonwoven fabrics of aramid fibers containing aromatic polyamide as a main component.

[0027] Then, by stacking a plurality of sheets of the prepreg prepared in this manner, and further layering copper foil on both the upper and lower surfaces and molding them under heat and pressure, the cyanate ester resin in the prepreg and the formula [2] are combined. A copper-clad laminate can be produced by laminating and bonding copper foil on both sides of an insulating substrate formed by polymerizing and curing a compound. The molding conditions at this time are a heating temperature of 170-230℃ and a pressure of 25-50kg.
/cm2 and the time is generally set to about 1 to 2 hours. Moreover, when after-curing at 220 to 230°C after molding, a molding temperature of 170 to 180°C is sufficient.

In order to produce a multilayer printed wiring board, an inner layer board is produced by etching the copper foil of the copper clad laminate produced by the method described above to form a circuit, and then this inner layer A shield plate, which is a multilayer printed circuit board, can be produced by stacking the plates via a plurality of the prepregs, stacking copper foil on the outermost layer, and heat-forming this. The double-sided copper-clad laminate and shield board thus obtained can be made into printed wiring boards using the following known methods.

[0029]

EXAMPLES The present invention will now be explained in detail by way of examples.

Reference Example 1 A cloth was woven using waterglass-derived fibers manufactured by AKZO as silicic acid fibers. The number of single yarns used was 120.
The diameter of the single yarn was 9.0 μm, and the count was 17 tex. The physical properties of this yarn are: SiO2 content 99.5%, specific gravity 2.0, tensile strength 70kg/mm2, elastic modulus 5.20.
It was 0 kg/mm2.

Next, a polyvinyl alcohol-based sizing agent was applied to the yarn, and after drying, the sizing agent-coated yarn was woven using a rapier loom. The resulting cloth was placed in a batch incinerator for 40 minutes.
After heat treatment at 0°C and incineration to remove the spinning binder and sizing agent on the fiber surface, aminosilane coupling agent (SZ-6
032, manufactured by Toray Silicone Co., Ltd.) immersed in a solution of 140
A glass cloth treated with a silane coupling agent was obtained by heating and drying at °C. The density of this cloth is 62 warps/25mm, 64 latitudes/25mm, and the thickness is 96μ.
It was m.

Reference Example 2 D-glass fiber DCE 270 1/0 manufactured by Nippon Electric Glass Co., Ltd., number of single yarns: 160, single yarn diameter: 8.7 μm, count: 2
E-glass cloth was woven using E-glass cloth (0.6 tex). Hereinafter, a glass cloth treated with a silane coupling agent was obtained in the same manner as in Reference Example 1. The density of the obtained cloth is 64 pieces/25 mm in diameter, 58 pieces/25 mm in latitude, and 100 pieces thick.
It was μm.

Reference Example 3 E-glass fiber 225 1/0 (manufactured by Nippon Electric Glass Co., Ltd., number of single threads: 2) commonly used for printed wiring boards
00 pieces, single yarn diameter 7.0 μm, count 22.4 tex) were used to weave a cloth. Hereinafter, a glass cloth treated with a silane coupling agent was obtained in the same manner as in Reference Example 1. The density of this cloth is 61 warp/25mm, 58 latitude/
It was 25 mm and 97 μm thick.

Reference Example 4 Aramid fiber Twaron (manufactured by ENKA, number of single yarns: 2)
After weaving a cloth using 50 pieces, a single yarn diameter of 20 μm, and a single yarn denier of 1.5), a cloth was obtained by subjecting it to low-temperature plasma treatment. The density of the obtained cloth is 41 warps/
The length was 25 mm, the latitude was 31/25 mm, and the thickness was 180 μm.

Example 1 As the cyanate ester resin represented by the general formula [1], 85 g of QUATREX 7187 (manufactured by Dow Chemical Company) was used.
, vinyl phenol polymer (Maruka Linker-M, manufactured by Maruzen Petrochemical Co., Ltd.,
15g of molecular weight 2000-2500) and 1 of methyl ethyl ketone (MEK) and dimethylformamide (DMF)
A resin liquid was obtained by dissolving in 67 g of a :1 mixed solvent.

Next, 25 g of tribromophenoxy-terminated tetrabromobisphenol A carbonate oligomer (PO-64P, manufactured by Great Lakes) as a flame retardant and cobalt octylate as a reaction catalyst were added to the cyanate ester resin. Co is 100p by weight
pm to prepare a varnish with a resin concentration of 65% by weight. A prepreg was prepared by impregnating the glass cloth prepared in Reference Example 1 with this varnish so that the resin content was 50% by weight, and heating and drying it at 150° C. for 4 minutes. Next, 8 sheets of this prepreg were stacked, and 35 μm thick copper foil was layered on both sides, and molded at a molding temperature of 177°C, a molding pressure of 30 kg/cm2, and a molding time of 60 minutes, and then at 225°C for another 1 hour. A double-sided copper-clad laminate was obtained by after-curing.

Example 2 Example 1 except that 15 g of vinyl bromophenol polymer (Maruka Linker MB, manufactured by Maruzen Petrochemical Co., Ltd., molecular weight 6,000-7,000) was used as the polymer having a phenolic hydroxyl group. A copper-clad laminate was obtained in the same manner.

Example 3 As a polymer having a phenolic hydroxyl group, a vinylphenol/styrene copolymer (molecular weight 5,000 to 6,0
A copper-clad laminate was obtained in the same manner as in Example 1 except that 00) was used.

Example 4 As the cyanate ester resin represented by the general formula [I], QUATREX 7187 (manufactured by Dow Chemical Company) 8
0g, as a polymer having a phenolic hydroxyl group, θ-
Cresol novolac resin (Pryophen ZA-1
165 (manufactured by Dainippon Ink and Chemicals) and 10 g of methyl ethyl ketone (MEK) and dimethyl formamide (DM).
A resin liquid was obtained by dissolving in 82 g of a 1:1 mixed solvent of F). Next, 10 g of tetrabromobisphenol A (BA-59P, manufactured by Great Lakes) as a flame retardant and cobalt naphthenate as a reaction catalyst were added to this in a weight ratio of 50 pp by weight to the cyanate ester resin.
A varnish with a resin concentration of 55% by weight was prepared by adding the resin in an amount of 55% by weight. This varnish was impregnated into the glass cloth prepared in Reference Example 3 so that the resin content was 45% by weight,
A prepreg was prepared by heating at 140°C for 5 minutes. Next, 8 sheets of this prepreg were stacked, and 18 μm thick copper foil was stacked on both sides, and the molding temperature was 18 μm.
After molding under the conditions of 0°C, molding pressure of 35 kg/cm2, and molding time of 60 minutes, a double-sided copper-clad laminate was obtained by further after-curing at 215°C for 1 hour.

Example 5 A copper-clad laminate was prepared in the same manner as in Example 4, except that 10 g of phenol novolak resin (Barcam, TD-2093, manufactured by Dainippon Ink & Chemicals) was used as the polymer having a phenolic hydroxyl group. I got it.

Example 6 A copper-clad laminate was obtained in the same manner as in Example 4, except that a vinylbromophenol polymer (Maruka Linker MB, manufactured by Maruzen Petrochemical Co., Ltd.) was used as the polymer having phenolic hydroxyl groups. Ta.

Example 7 A copper-clad laminate was obtained in the same manner as in Example 1, except that the glass cloth produced in Reference Example 2 was used as the fiber base material.

Example 8 A copper-clad laminate was obtained in the same manner as in Example 1, except that the aramid cloth produced in Reference Example 4 was used as the fiber base material.

Comparative Example 1 Q
A copper-clad laminate was obtained in the same manner as in Example 1, except that 100 g of UATREX 7187 was used.

Comparative Example 2 Q
A copper-clad laminate was obtained in the same manner as in Example 4, except that 100 g of UATREX 7187 was used.

The obtained laminate was evaluated as a laminate by the method described below.

(1) Dielectric constant and dielectric loss tangent JIS
According to C-6481, the value at 1 MHz was measured using LP Impedance Analyzer 4194A (manufactured by Yokogawa Heuretsu Packard Co., Ltd.).

(2) Bending strength A sample of a predetermined size was prepared according to JIS C-6481, and measured using a precision universal material testing machine model 2020 (manufactured by Intesco) at a distance of 50 mm between fulcrums.

(3) Peel strength A sample of a predetermined size was prepared according to JIS C-6481, and measured using a precision universal material testing machine model 2020 (manufactured by Intesco).

(4) Insulation resistance A comb-shaped electrode with a width of 375 μm was prepared according to IPC-B25, and a vibrating lead electrometer T was prepared.
Insulation resistance was measured using R-84M (manufactured by Takeda Riken Co., Ltd.) when 500 V DC was applied.

(5) Glass transition temperature (Tg) 15 mg of a powder sample was taken and measured using DSC-2C (manufactured by PerkinElmer) at a heating rate of 20° C./min.

(6) Flame retardancy Evaluation was performed by the vertical method according to the UL-94 standard.

(7) Inner wall roughness of the through-hole surface and reliability of the through-hole The through-hole was drilled using a 0.9 mmφ drill bit at a rotation speed of 40,000 rpm and a feed rate of 50 μm/rev per rotation. condition, then
Electroless plating and electrolytic plating were performed.

The inner wall roughness of the obtained through-hole was measured by observing the cross-section of the through-hole with a microscope, and the reliability of the through-hole was determined by observing the cross-section of the through-hole with a microscope. Evaluation was made by measuring the depth of penetration of the liquid.

(8) Using a sample with a thermal expansion coefficient of 6 mm x 6 mm, the temperature was raised at 2° C./min using TMA-50 (manufactured by Shimadzu Corporation) to a temperature of 50 to 250° C.
The coefficient of thermal expansion in the Z-axis direction was determined from the thermal expansion curve in the range of °C.

(9) Pressure treatment of the heat-resistant laminate (121° C., 3 atm under 2 atm)
time), then immersed in a 260℃ solder bath for 60 seconds,
The appearance and properties were evaluated by visual observation. …No abnormality ×…Whitening phenomenon occurred

0057
] (10) Add caustic soda 10 to the alkali-resistant laminate
After being immersed in a wt% aqueous solution at 80° C. for 10 minutes, the appearance and properties were evaluated by visual observation. ...No abnormality, ×...Whitening phenomenon occurred The results obtained are shown in Table 1.

[Table 1]

[0058]

[Effects of the Invention] As described above, according to the present invention, the formula [1
] By blending the cyanate ester resin with a polymer having phenolic hydroxyl groups, it has low hygroscopicity, low dielectric constant, and low dielectric loss tangent, which are the advantages of cyanate ester resin.
In addition, it is possible to produce laminates with good heat resistance, chemical resistance, and dimensional stability, and they can be used for printed circuits of high-speed computers. At the same time, by relaxing the crosslinking density during curing, Flexibility and impact resistance can be improved, cracks can be prevented from occurring during through-hole processing, and the reliability of through-hole plating can be increased.

Claims (3)

[Claims] Claim 1 General formula [1] [Formula 1] (wherein A is an aromatic ring or a group containing an aromatic ring, B is a C7-
C20 polycyclic alicyclic group, D is each independently a substituent containing no active hydrogen group, p, q, r are each independently an integer of 0 to 3, provided that the total of p, q, r is 2 That's all. Furthermore, each s is an integer from 0 to 4, and x is an integer from 0 to 5.
is an integer up to . 1. A thermosetting resin composition characterized in that a cyanate ester resin represented by the following formula is blended with a polymer having a phenolic hydroxyl group. 2. The thermosetting resin composition according to claim 1 is applied to a woven or non-woven fabric made of inorganic fibers or organic fibers.
A prepurig characterized by being impregnated with 0% by weight. 3. The thermosetting resin composition according to claim 1 is applied to a woven or nonwoven fabric of inorganic fibers or organic fibers in an amount of 30 to 70%.
By laminating the prepregs obtained by impregnating 0% by weight,
Copper-clad laminates are characterized by having copper foil laminated on the surface.