JPH0739167B2 - Laminated board manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a laminate having a low dielectric constant and excellent heat resistance.

[Background of the Invention]

Conventionally, a laminated board of a phenol resin, an epoxy resin, a polyimide resin or the like has been mainly used as a laminated material for a multilayer printed circuit board. However, in recent years, with the increase in high-speed arithmetic processing of large-scale computers, a printed circuit board having excellent high-frequency electrical characteristics has been required to improve the signal propagation speed. In particular, a printed circuit board having a low dielectric constant is required to shorten the signal propagation delay time and the circuit thickness.
Tetrafluoride ethylene resin (PTFE) laminates, butadiene resin laminates, etc. have been developed as such low dielectric constant laminates. However, since the PTFE laminated plate has a thermoplastic resin, it has problems such as a large coefficient of thermal expansion at high temperatures and insufficient dimensional stability. In particular, there is concern about through-hole reliability when multi-layer bonding is performed. , Is difficult to apply to multilayer printed circuit boards. Further, since PTFE does not have a suitable solvent, a bonding method by heating, melting and pressing is generally used, but it has a drawback that the melting temperature is very high. As described above, PTFE has many difficulties in workability and moldability as compared with the conventional method, and it is necessary to significantly change the manufacturing method.

Also, butadiene resin is a curable type unlike PTFE, but a polymer with good impregnation and curability in a varnish as a varnish is used for work such as winding and laminating, leaving tackiness in the prepreg stage. It often causes trouble. In addition, as a laminated plate, the peeled strength, mechanical strength and heat resistance of the bonded copper foil were unsatisfactory. The tackiness is improved by incorporating a higher molecular weight polymer. However, since the copper foil adhesive strength and other laminated board characteristics depend on the nature of the resin, its improvement must be done by another means. Therefore, a coating layer composed of different kinds of resins having excellent properties in question is provided on the prepreg (see, for example, JP-A-55-55).
No. 74869) has been proposed. However, it is unavoidable that the laminating process becomes complicated, and the obtained laminate has a plurality of resin layers having different characteristics, and it is considered that the properties of the butadiene resin are not fully utilized.

On the other hand, a cured resin of a triazine compound having 2 to 3 polymerizable unsaturated groups bonded thereto is mechanically strong and has excellent heat resistance, and is considered to be applied to a laminated material for a multilayer printed circuit board. However, since the resin is very brittle and lacks flexibility, cracking is likely to occur during lamination and formation of through holes, and it is difficult to use it alone.

In consideration of such circumstances, the present invention has solved the above-mentioned problems by copolymerizing and curing a triazine resin and a butadiene resin.

[Object of the Invention]

The object of the present invention is to provide a low dielectric constant laminated material excellent in mechanical strength, dimensional stability, and heat resistance, which is applied to a multilayer printed circuit board, and a cured material having a low dielectric constant and high copper foil adhesion suitable for the production thereof. Another object of the present invention is to provide a method for producing a laminated board, which is characterized by using a resin composition.

[Outline of Invention]

The present invention will be summarized as follows: 1. (a) The following general formula I or II (Wherein ^each of R ¹ , R ² and R ³ , R ⁴ , R ⁵ and R ⁶ represents a hydrogen atom or an organic group having 6 or less carbon atoms, and at least two of each of the three groups belonging to each formula) Is an organic group containing a polymerizable unsaturated bond) as a repeating unit, and the organic group containing a polymerizable unsaturated bond in the s-triazine compound is homopolymerized or differently polymerizable. An organic solvent-soluble prepolymer obtained by copolymerization in the presence of an unsaturated monomer, and (b)
A step of impregnating a sheet-shaped substrate with a varnish containing 1,2-polybutadiene or a derivative thereof, (c) a radical polymerization initiator, and (d) an organic solvent; a step of drying the impregnated body to obtain a prepreg; The present invention also relates to a method for producing a laminated plate, which comprises the steps of laminating the prepregs and integrally molding them under pressure. In the varnish, S-
The inclusion of a triazine compound as a repeating unit means that the prepolymer is a homopolymer or copolymer of the s-triazine compound represented by the general formula I or II, or the compound and another polymerizable unsaturated monomer. Means a copolymer.

The prepolymer, which is an essential component of the varnish of the present invention, includes the s-triazine compound represented by the general formula I or II as described above and containing at least two polymerizable unsaturated bonds in one molecule (hereinafter referred to as a polymerized compound). A polyfunctional triazine compound) is included as a repeating unit. Specific examples thereof include compounds corresponding to the general formula I: triallyl isocyanurate, diallyl isocyanurate, tris (acryloyloxyethyl) isocyanurate, tris (methacryloyloxyethyl) isocyanurate,
There are tris (acryloyloxymethyl) isocyanurate and the like, and as compounds corresponding to the general formula II, triallyl cyanurate, diallyl cyanurate, diallyl methyl cyanurate, diallyl phenyl cyanurate, dimethacryloyl phenyl cyanurate, tris (Acryloyloxyethyl) cyanurate and the like. These may be used alone or in combination of two or more as desired.

The polymerizable polyfunctional triazine compound can be made into a soluble prepolymer by a polymerization reaction. Since the prepolymer generally undergoes a crosslinking reaction very quickly, cracks and the like may easily occur in the formed product during the curing process. In such a case, in preparing the prepolymer, two or more polymerizable polyfunctional triazine compounds may be copolymerized or a polymerizable unsaturated monomer different from the compound may be copolymerized. Preferably, thereby, the crosslinking rate of the prepolymer can be relaxed and the moldability of the resin composition can be improved. The polymerizable unsaturated monomer used at that time is represented by the general formula III R-Ar-R ¹ (wherein Ar represents a divalent aromatic group, and R represents an organic group having a polymerizable unsaturated bond). , R ¹ represents a hydrogen atom or an organic group), and diallyl isophthalate, diallyl terephthalate, bisphenol diallyl ethers, styrene, allylbenzene, α-methylstyrene, etc. are useful. The molar ratio of the polymerizable polyfunctional triazine compound and the polymerizable unsaturated compound is 75:25 to 25:75,
Copolymerization may be performed in the presence or absence of a solvent.

The 1,2-polybutadiene component in the resin composition of the present invention includes 1,2-polybutadiene homopolymer, cyclized 1,2-polybutadiene, and terminal epoxidized 1,2.
-Polybutadiene 1,2-Polybutadiene glycol, 1,2
-Polybutadiene dicarboxylic acid, urethane modified 1,2-polybutadiene, maleinized 1,2-polybutadiene, terminal acrylic modified 1,2-polybutadiene, terminal ester modified
Derivatives such as various polymers and copolymers containing 1,2-polybutadiene having a vinyl side chain group such as 1,2-polybutadiene as a basic component can be used.

The compounding ratio (weight) of the prepolymer containing the polymerizable polyfunctional triazine compound as a repeating unit and 1,2-polybutadiene is selected from the range of 80:20 to 20:80, and the content ratio of the former is more than that. If the amount is too large, the dielectric constant and brittleness of the cured resin are increased. If the amount is too small, the effect of the prepolymer containing the triazine compound on the tack-free property of the prepreg, the adhesion to the copper foil and other properties of the laminate is significant. Disappear. A particularly preferred ratio of both components is approximately 30:70 to 3
It is 0:70.

Next, a general method for manufacturing a laminated board in the present invention will be described.

First, a prepolymer obtained by polymerization or copolymerization of a polymerizable polyfunctional triazine compound and 1,2-polybutadiene or a derivative thereof are dissolved in an organic solvent to prepare a varnish. At this time, for the purpose of promoting dissolution, it may be heated at a temperature of 80 ° C. or lower for about 30 minutes.

Examples of organic solvents include acetone, methyl ethyl ketone, toluene, xylene, 2-methoxyethanol, 3-
Methoxypropanol, N, N-Dimethylformamide, N-
There are methyl-2-pyrrolidone, dimethylsulfoxide, trichloroethylene, 1,1,2-trichloroethane and the like, and any solvent which can uniformly mix the above component polymers can be used without limitation. A radical polymerization initiator is added to the prepared varnish to prepare an impregnating varnish. Typical examples of radical polymerization initiators are benzoyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, t-butyl perbenzoate, t-butyl peroxylaurate, di-t-butyl peroxyphthalate, dibenzyl peroxide. Oxide, etc., resin composition 10
Add 0.1 to 10 parts by weight to 0 parts by weight. Then, the sheet-like base material is impregnated with the obtained impregnating varnish and applied at room temperature to 170 ° C.
Dry at ℃ to obtain a tack-free prepreg. The selection of the drying temperature at this time depends on the solvent and the initiator used. Stack the required number of prepregs obtained at the end, 100-2
A heat curing reaction is carried out at 50 ° C. under a pressure of 1 to 100 kgf / cm ² to obtain a laminate.

Example of Invention

Example 1 Triallyl isocyanurate prepolymer (manufactured by Nippon Kasei): number-average molecular weight of 550 and 1,2-polybutadiene (molecular weight of about 1.5 × 10 ⁵ , side chain vinyl group content of 90% or more) in methyl ethyl ketone at 60 ° C. Heat and dissolve for 30 minutes, polymer compounding ratio 5:
A varnish with a weight ratio of 5 and a solid content of 40% was obtained. Further, 5 parts by weight of dicumyl peroxide was added as a radical polymerization initiator to 100 parts by weight of the varnish, and the varnish was impregnated and coated on a glass cloth cloth (E-glass manufactured by Nitto Boseki, thickness 0.1 mm). Dried-free prepreg was obtained by drying in constant temperature air for 20 minutes at ℃. Next, 10 sheets of the prepreg are stacked and heated at a pressure of 30 kgf / cm ² and a temperature of 130 ° C. for 30 minutes, and further 17
The temperature was raised to 0 ° C., the adhesive curing reaction was carried out in the press for 1 hour, and after-cure was added in constant temperature air at 220 ° C. for 2 hours to produce a laminated plate.

Example 2 A polybutadiene component composed of 1,2-polybutadiene used in Example 1 and a lower molecular weight 1,2-polybutadiene (molecular weight 3 × 10 ³ , manufactured by Nippon Soda), and triallyl isocyanurate-diallyl isophthalate. (Molar ratio 3: 7)
A copolymer prepolymer: a number average molecular weight of 380 was heated and dissolved in xylene at 80 ° C. for 30 minutes to prepare a varnish having a polymer compounding ratio of 5: 5 (weight) and a solid content of 40%.

Subsequent steps were performed in the same manner as in Example 1 to obtain a laminated board.

Example 3 The 1,2-polybutadiene used in Example 1 and tris (2-
(Hydroxyethyl) Isocyanuric acid / acrylic acid esterified product (weight ratio 4: 6, number average molecular weight 6200) is heated and dissolved in xylene at 80 ° C for 30 minutes, and polymer blend ratio 7: 3 (weight), solid content 40 % Varnish was obtained. Subsequent steps manufactured the laminated board by the method similar to Example 1.

Example 4 Terminal epoxy-modified 1,2-polybutadiene (Nippon Soda EPB
-42M) and triallyl isocyanurate-bisphenol F diallyl ether (molar ratio 7: 3) copolymer prepolymer are dissolved in xylene by heating at 80 ° C for 30 minutes,
A varnish having a polymer compounding ratio of 5: 5 (weight ratio) and a solid content of 40% was obtained. Subsequent steps were performed in the same manner as in Example 1 to produce a laminated board.

Example 5 A diallyl cyanurate and a triallyl cyanurate (weight ratio 5: 5) copolymer prepolymer were dissolved in xylene, and the polybutadiene used in Example 1 was mixed at a weight ratio of 5: 5 to give a resin content of 40. A varnish for impregnation was obtained in%. Subsequent steps were performed in the same manner as in Example 1 to produce a laminated board.

Comparative Example A laminate was prepared in the same manner as in Example 1 except that the triallyl isocyanurate prepolymer described in Example 1 was not mixed and only 1,2-polybutadiene was used.

The table below shows the main characteristics of the laminates according to the examples and comparative examples and the heat resistance of the cured resin.

EFFECTS OF THE INVENTION The present invention uses a novel varnish to apply a conventional apparatus as it is, to easily manufacture a tack-free prepreg from a known base material, and further improve the copper It is possible to provide a method for producing a laminate having a low dielectric constant, which has foil adhesion strength, mechanical strength, and heat resistance.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location C08F 220/58 MNJ 226/06 MNL (72) Inventor Masahiro Ono 3-chome, Saiwaicho, Hitachi, Ibaraki No. 1 in Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Ritsuro Tada 3-1-1, Saiwaicho, Hitachi City, Ibaraki Hitachi Incorporated Hitachi Research Laboratory in Hitachi (72) Motoyo Wajima Hitachi City, Ibaraki Prefecture 3-1, 1-1 Sachimachi Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Toshikazu Narahara 3-1-1 1-1 Sachimachi Hitachi City, Ibaraki Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Keiko Tawara 3-1, 1-1 Sachimachi, Hitachi, Ibaraki, Ltd., Hitachi Research Laboratory, Hitachi Ltd. (56) References JP-A-51-125483 (JP, A) JP-A-59-71320 (JP) A)

Claims (1)

[Claims] (A) The following general formula I or II: (Wherein ^each of R ¹ , R ² and R ³ , R ⁴ , R ⁵ and R ⁶ represents a hydrogen atom or an alkyl group having 6 or less carbon atoms, and each of at least 2 of the 3 groups belonging to each formula) Each of which is an allyl group, an acryloyl group, a methacryloyl group) as a repeating unit, and the allyl group, acryloyl group in the s-triazine compound,
An organic solvent-soluble prepolymer obtained by polymerization of a methacryloyl group or copolymerization in the presence of a different type of polymerizable unsaturated monomer; and (b) 1,2-polybutadiene or a derivative thereof, (c) Radical polymerization initiator, (d)
A step of impregnating a sheet-shaped substrate with a varnish containing an organic solvent, a step of drying the impregnated body into a prepreg,
And a method for producing a laminated plate, which comprises a step of laminating the prepregs and integrally molding them under pressure.