JPH04192489A - Prepreg and copper-clad laminated board - Google Patents

Abstract

PURPOSE:To obtain a prepreg and a copper-clad laminated board whose permittivity is low and which are excellent in a heat-resistant property by a method wherein a cloth obtained by treating the surface of a woven cloth of silicate fibers with a silane coupling agent is impregnated with a specific resin varnish. CONSTITUTION:A cloth obtained by treating, with a silane coupling agent, the surface of a woven cloth formed by weaving silicate fibers whose content of SiO2 is at 98wt.% or higher, whose specific gravity is at 1.8 to 2.0, whose tensile strength is at 20 to 82kg/mm<2> and whose modulus of elasticity is at 1000 to 8200kg/mm<2> is impregnated with a resin varnish obtained by polymerizing a cyanate ester resin expressed by Formula I. In Formula I, A represents an aromatic ring or a group including an aromatic ring, B represents a polycyclic alicyclic group of C7 to C20, D represents a substitution group which does not contain an active hydrogen group individually and independently (p) to (r) represent an integer of 0 to 3 individually and independently, the total of (p) to (r) is at 2 or higher, (s) represents an integer of 0 to 4 individually and independently and (x) represents an integer of 0 to 5. Thereby, it is possible to obtain a prepreg and a copper-clad laminated board whose permittivity is low and which are excellent in a solder heat-resistant property.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a prepreg and a copper-clad laminate using the same, and more specifically, to improving the signal processing speed of a printed circuit wiring board. This invention relates to a low dielectric constant prebrig and a copper clad laminate using the same.

(Prior Art) In recent years, with the transition to a highly information-oriented society, in the computer field that supports this society, there has been an increasing demand for improvements in the signal processing speed of printed wiring boards.

Generally, the signal propagation velocity (2) is expressed by the following equation, and the smaller the dielectric constant, the higher the speed of calculation processing. Therefore, attempts have been made to reduce the dielectric constant of printed wiring boards in order to improve the signal propagation speed.

v=KC/f7 (C: speed of light, ε: dielectric constant, N: constant) As a means to lower the dielectric constant, that is, to improve high frequency characteristics, quartz glass, aramid cloth, and ordinary epoxy resin have been used. , a combination with polyimide resin has been proposed (JP-A-59-130365, JP-A-62
-204589).

Furthermore, for the purpose of lowering the dielectric constant, polytetrafluoroethylene (PTFE) (Japanese Patent Application Laid-Open No. 63-159442,
(Japanese Patent Application Laid-Open No. 63-154748).

Polyphenylene oxide (PPO) (Special Publication No. 51-25
No. 394, Japanese Patent Publication No. 52-17880).

Polybutadiene (Special Publication No. 58-21925, Special Publication No. 6
Some printed wiring boards using resins such as Japanese Patent Publication No. 3-6088) and heat-resistant polyolefins (Japanese Patent Publication No. 60-49422, Japanese Patent Application Laid-Open No. 63-236638) have also been put into practical use.

However, there are still three problems that need to be solved in these reports.

For example, when 9 quartz glass or aramid cloth is used, drill workability is difficult, and it has not yet been put into practical use. In addition, products using PTFE have been put into practical use by several companies, but multi-layer It is not preferable as a substrate for use. Furthermore, products using PPO, polybutadiene, and heat-resistant polyolefin resins have heat resistance,
It has problems in terms of chemical resistance, dimensional stability, flame retardance, etc., and is clearly unsuitable for use in high-speed computers.

(Problem to be solved by the invention) On the other hand, as an alternative to these, JP-A-63-2
No. 89032 and JP-A No. 63-289033 disclose a method in which a glass cloth or a glass mat made of a low dielectric constant glass composition containing 65 to 90% of Si0□ and 82037 to 30% is impregnated with a low dielectric constant resin. Prepreg and copper-clad laminates are described. However, these low dielectric constant glass compositions are commonly referred to as D glasses, and are not only insufficient in terms of low dielectric constant.

It was not satisfactory because it had inferior heat resistance compared to other glass fibers.

Therefore, it is an object of the present invention to provide a prepreg and a copper-clad laminate having a low dielectric constant and excellent heat resistance.

(Means for Solving the Problems) The present inventors have discovered that the specific content of SiO□ proposed earlier,
A cloth in which the surface of a woven fabric of silicic acid fibers having specific physical properties is treated with a silane coupling agent (Japanese Patent Application No. 1-258561)
The present inventors have discovered that the above-mentioned problems can be solved by impregnating a specific resin face into the material (No. 1).

That is, the content of SiO□ is 98% by weight or more.

Specific gravity 1.8-2.0. Tensile strength 20-82 kg/mm
A cyanate ester resin represented by the general formula [I] was applied to a cloth whose surface was treated with a silane coupling agent by weaving silicic acid fibers with an elastic modulus of 1,000 to 8,200 kg/mm. Burepurig is characterized by being impregnated with a resin face obtained by polymerization. The gist of this paper is a copper-clad laminate using the same.

(OCN).

(NCO)p-A-(B-A)X-B-A-('0C
N)q (1)l II II (D), (D), (D)s(D)s(D)s (wherein, A
is an aromatic ring or a group containing an aromatic ring, B is a C1-C2° polycyclic alicyclic group, D is each independently a substituent that does not contain an active hydrogen group,
p, q, r are each independently integers of 0 to 3, and p, q
, r is 2 or more. Furthermore, each S is independently O
It is an integer of ~4, and X is an integer of 0-5. ) The following is a detailed explanation of the present invention.

The content of SiO□ used in the present invention is 98% by weight or more,
Specific gravity 1.8-2. O9 tensile strength 20-82kg/Kaku22
A cloth made by weaving silicic acid fibers with an elastic modulus of 1,000 to 8,200 kg/mm and whose surface is treated with a silane coupling agent is described in Japanese Patent Application No. 1258561. The silicic acid fibers are produced by dry spinning soda water glass, wicking away moisture and solidifying the fibers, extracting and removing the soda content from the fibers with an aqueous solution of acid or salt, and then incinerating at high temperatures in some cases. The water in the fibers has been removed and the micropores have disappeared.

Next, after weaving this, the spinning binder and weaving paste adhering to the surface are removed by appropriate means such as heat treatment, and then immersed in a silane coupling agent solution.
By drying, the silane coupling agent is bonded to the surface of the glass and crosslinked.

In the present invention, since the woven fabric has a large 5in2 content of fibers, it exhibits excellent low dielectric properties, and has a light specific gravity, making it convenient to handle. Also.

Because the tensile strength and modulus of elasticity are within the above ranges.

It also has excellent mechanical properties as a reinforcing material.

The single fiber diameter of the silicic acid fiber used in the present invention is 3 to 15 μm.
is preferable, and the thickness of the cloth is preferably in the range of 20 to 250 μm. If the single yarn diameter is smaller than 3 μm, it may break easily and become difficult to handle. On the other hand, if it exceeds 15 μm, it is difficult to satisfy the smoothness of the cloth surface required for normal double-sided printed wiring boards. Drillability also tends to decrease. Also, the thickness of the cloth is 20
If it is thinner than μm, the strength of the cloth will be weakened and it will be difficult to process it.

May be difficult to handle during treatment processes.

On the other hand, if it is thicker than 250 μm, the impregnability of the resin face will decrease, and it will be necessary to use fibers with a large single diameter to ensure the thickness, and the smoothness of the cloth surface will deteriorate.
Drill workability also tends to deteriorate.

As the cyanate ester resin represented by the general formula (r) used in the present invention, those disclosed in Japanese Patent Publication No. 61-500434 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 formula (1), A means any group having an aromatic ring, specifically, 2 bonded by a phenylene group, naphthylene group, anthrylene group, biphenylene group, biphelene group, or alkylene group. The group includes a group containing at least three aromatic rings, and among these, a phenylene group and a naphthylene group are preferable, and a phenylene group is particularly preferable.

In formula 2 [I], B is C7 to Ca. 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. Good too.

Specific examples include the following, among which (a)
, (b), (c), (d), and (e) are preferred, and (a) is particularly preferred.

(In the formula, Y is CHHz, S, S=O, 0=S=O.

and Do is a C3-C3 alkyl group. )formula〔
I], D is each independently a substituent containing no active hydrogen group, and substituents containing an active hydrogen atom are excluded.

The active hydrogen atom herein means an atom bonded to an oxygen, sulfur, or nitrogen atom.

Specific examples thereof include hydrogen atoms, C, -C, and so on. an alkyl group of C+ to CIO, an alkynyl group of CI-Cs, an alkoxy group of C, -C, a nitro group,
These include carboxyl groups and halogen atoms.

Among these, a hydrogen atom, an 01-C3 alkyl group, and a halogen atom are preferred, and a hydrogen atom and a pro-broad 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, the total of IP, q, and r is set to be 2 or more. Further, X is an integer from 0 to 5, and the cyanate ester resin of formula [I] is found as a mixture of compounds where X is 0 to 5, and X is expressed as the average number of this mixture. It is something.

A preferred specific example of the cyanate ester resin represented by formula (1) is one represented by the following formula, which is available as XU-71787 (manufactured by Dow Chemical Company).

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

Next, a method of manufacturing a bleep lig and a copper clad laminate using the above-mentioned cloth and resin in the present invention will be explained.

When making a prebrig, first, a varnish is prepared by dissolving the cyanate ester resin of the formula (1) in an organic solvent along with a flame retardant, a reaction catalyst, and the like. Next, the cloth of the present invention is impregnated with this varnish and dried by heating.

At this time, the amount of varnish impregnated into the cloth is set so that the ratio of resin solid content (combined resin of formula (1) and flame retardant) to the total weight after drying is 40 to 60% by weight. is preferable. The heating and drying conditions when producing prepreg are influenced by the amount of catalyst added for one reaction.9 For example, when the heating temperature is 150°C, the heating time is
By setting the time to about 10 minutes, it is possible to obtain the desired stroke gel time for the prep league.
□Ru.

The flame retardant used in the production of this prepreg may be any compound containing halogen, but specifically, tetrabromobisphenol A, halogen-substituted aromatic polycarbonate oligomers, such as those of formula 2 (If) The phenoxy-terminated tetrabromobisphenol A carbonate oligomer shown can be used.

(In the formula, n is an integer of 1 to 20.) These flame retardants can be used alone or in combination, but one formula (
It is preferable to adjust the Br content to 10 to 15% by weight based on the total amount of the cyanate ester resin and flame retardant in 1).

In addition, as 2-reaction catalysts, imidazoles, amines,
Although organic metal salts etc. can be used.

Especially cobalt naphthenate and cobalt octylate.

Organometallic salts such as manganese octylate are preferred.

The amount of the reaction catalyst added is not particularly limited; for example, when organic cobalt salts are used.

1 set depending on the desired prebrig gel time [1]
The metal is blended in a weight ratio of 100 to 1 + 000 ppm based on the weight of the cyanate ester resin.

Furthermore, the organic solvent is not particularly limited as long as it dissolves the cyanate ester resin and flame retardant represented by Formula 9 [■] and does not have an adverse effect on the 9 reaction.1 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. What is the amount of organic solvent to add?

It is common to prepare the varnish so that the solid content concentration in the varnish is 50 to 70% by weight.

Then, the cyanate ester resin in the prepreg is polymerized and cured by stacking a plurality of sheets of the prepreg prepared in this way, and then layering copper foil on the upper and lower screens and molding them under heat and pressure.

A copper-clad laminate can be produced in which copper foil is laminated and bonded to both sides of an insulating substrate. What are the molding conditions at this time?

Heating temperature: 170-230°C2 Pressure: 25-50kg
/c111. It is common to set the time to about 1 to 2 hours. In addition, when after-curing at 220-230°C after molding, the molding temperature is 170-180°C.
is sufficient.

Also, to produce multilayer printed wiring boards.

The F4 foil of the copper-clad laminate produced by the above method is etched to form a circuit to produce an inner layer board. Next, this inner layer board is stacked via a plurality of the above-mentioned bleep leagues, and the outermost layer is A shield plate, which is a multilayer printed circuit board, can be produced by stacking copper foils and heat-forming them. The double-sided copper-clad laminate and shield board thus obtained can be made into a printed wiring board using a known method.

(Example) The present invention will be specifically explained below using examples.

Reference Example 1 A cloth was woven using water glass-derived fibers manufactured by AKZO as silicic acid fibers. The number of single yarns used was 241.
The diameter of the single yarn was 9.6 μm, and the number 9 yarn was 35.7 tex. The physical properties of this yarn include 5i0z content of 99.6%.
, specific gravity 2.0. Tensile strength 52kg/+11ffl 2.
The elastic modulus was 5,500 kg/stroke 2.

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.

This cloth was heat-treated at 400'C in a Hatchi-type incinerator to remove the spinning binder and sizing agent on the fiber surface by incineration, and then immersed in an aminosilane coupling agent (S Z-6032, manufactured by Toshi Silicone Co., Ltd.) solution. By heating and drying at 140°C, a cloth treated with a silane coupling agent was obtained. The density of this cloth is 40 lengths and 725m
m.

The latitude was 32 lines/25 mm, and the thickness was 124 μm.

Reference Example 2 Silicate fibers derived from water glass manufactured by AKZO were woven in the same manner as in Reference Example 1. The number of single yarns of the removed yarn was 120, the single yarn diameter was 9.0 μm, and the first count was 17 textures. In addition, the physical properties of this yarn are as follows: Si0g content: 9
9.5%, specific gravity 2.0. Tensile strength 70 kg/mm2.
The elastic modulus was 5,220 kg/11 m2.

Thereafter, cloth treated with a silane coupling agent was obtained in the same manner as in Reference Example 1. The density of this cloth is 64 warps/
25 mm, 62 wefts/25 lines thickness was 96 μm.

Reference example 3 E-glass fiber 2 commonly used for printed wiring boards
25 l10 (number of single threads 200, single thread diameter 7.0 μm
A cloth was woven using a 22.4-texture (22.4 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 this cross is 6
1 line/25mm, latitude 58 lines/25mm.

The thickness was 97 μm.

Example 1 As a cyanate ester resin represented by general formula (T), 100 g of XU-71787 (manufactured by Dow Chemical Company) was mixed with methyl ethyl ketone (MEK) and dimethyl formamide (D
A resin solution with a solid content of 63% by weight was prepared by dissolving it in a 1:I mixed solution of MF), and cobalt octylate was added as a reaction catalyst to the cyanate ester resin at a weight ratio of 600%. A varnish was prepared by adding it in ppm. A prepreg was prepared by impregnating the cloth prepared in Reference Example 1 with this varnish so that the solid content was 50% by weight, and drying it by heating at 150"C for 5 minutes.

Next, 10 sheets of this prepreg were stacked, and 35g thick copper foil was stacked on both sides, and the molding temperature was 177°C.
After molding under the conditions of a molding pressure of 30 kg/cffl and a molding time of 60 minutes, a single-sided copper-clad tank laminate was obtained by further after-curing at 225°C for 2 hours.

Example 2 Except for using 80 g of XU-71787 as a resin component and 20 g of phenoxy-terminated tetrabromobisphenol A carbonate oligomer (BC-58° manufactured by Great Lakes) as a flame retardant.

A copper-clad laminate was obtained in the same manner as in Example 1.

Example 3 Using 80 g of XU-71787 as a resin component and 20 g of phenoxy-terminated tetrabromobisphenol A carbonate oligomer (BC-58° manufactured by Great Lake) as a flame retardant, and using the cloth prepared in Reference Example 2 as a cloth. A copper-clad laminate was obtained in the same manner as in Example 1 except for the above.

Comparative Example 1 Except for using the glass cloth prepared in Reference Example 3,
A copper-clad laminate was obtained in the same manner as in Example 1.

Comparative Example 2 A copper-clad laminate was produced in the same manner as in Example 1, except for using 80 g of XU-71787 as a resin component and 20 g of tetrabromobisphenol A as a flame retardant, and using the glass cloth prepared in Reference Example 3. Obtained.

Comparative Example 3 A copper-clad laminate was obtained in the same manner as in Example 1, except that 100 g of tetrabrominated bisphenol A type epoxy resin and 5 g of dicyandiamide were used as resin components.

Table 1 shows the characteristics of the laminates produced in Examples 1 to 4 and Comparative Examples 1 to 3. Note that the evaluation method for the characteristics of the laminate is as follows.

(1) Dielectric constant and dielectric loss tangent Values at IMHz were measured using LP Zein-Dance Analyzer 4194A (manufactured by Yokogawa Hewlett-Baccard) in accordance with JIS C-6481.

(2) Bending strength According to JIS C-6481, a sample of a predetermined size was taken out and measured using a precision universal material testing machine 2° 20 model (manufactured by Intesco) at a distance of 50 mm between fulcrums.

(3) Beer strength According to JIS C-6481, a sample of a predetermined size was taken out and measured using a precision universal material testing machine 2°20 model (manufactured by Intesco).

(4) Insulation resistance I A comb-shaped electrode with a width of 375 μm was prepared according to PC-825, and the insulation resistance was measured when 500 V DC was applied using a pipe-rating lead electrometer TR-84M (manufactured by Tagada Riken).

(5) Glass transition temperature (Tg) 15 micrometers of powdered sample was taken and measured by heating it at 20'C/min using DSC-2C (manufactured by PerkinElmer).

(6) Thermal decomposition onset temperature (Td) Powdered sample 5 was collected and heated at 20°C/min in a N2 stream using TGA7 (manufactured by PerkinElmer) to measure the thermal loss. It was determined from the temperature at which the weight loss started.

(7) Flame retardant Evaluation was made by the vertical method according to the UL-94 standard.

(Effect of the invention) The prepreg of the present invention and a copper-clad laminate using the same,
It has a low dielectric constant of, for example, 3.4 or less, a high glass transition temperature of 250° C. or more, and has excellent solder heat resistance, so it is suitable as an insulating material for electronic devices. In addition, a printed circuit board formed using the copper-clad laminate of the present invention has a dielectric constant of 3.4 or less, for example, and is much smaller than conventionally used glass epoxy substrates and glass polyimide substrates. , it has the effect of significantly increasing the signal propagation speed, and is excellent for use in printed circuits such as high-speed electronic computers.

Claims (2)

[Claims] (1) SiO_2 content is 98% by weight or more, specific gravity 1.
The surface of a woven fabric made of silicic acid fibers with a tensile strength of 20-2.0, a tensile strength of 20-82 kg/mm^2, and an elastic modulus of 1.000-8.200 kg/mm^2 was treated with a silane coupling agent. A prepreg characterized in that a cloth is impregnated with a resin varnish obtained by polymerizing a cyanate ester resin represented by the general formula [I]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, A is an aromatic ring or a group containing an aromatic ring, B is C_7~
C_2_0 polycyclic alicyclic group, D is each independently a substituent that does not contain an active hydrogen group, p, q, r are each independently an integer of 0 to 3, and the total of p, q, r is 2 or more It is. moreover,
s is each independently an integer of 0 to 4, and x is an integer of 0 to 5. ) (2) A copper-clad laminate, characterized in that the prepreg according to claim (1) is laminated and a copper foil is pasted on the surface.