JPH11116779A - Resin composition suited rigid printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition which, in spite of a low flame retardant content, can give an insulation material for a rigid printed wiring board having excellent flame retardancy corresponding to UL standard V-0 and good mechanical properties. SOLUTION: This composition comprises 100 pts.wt. fused polycyclic polynuclear aromatic resin obtained by reacting a starting material comprising a fused polycyclic aromatic compound (e.g. naphthalene) or a mixture thereof with a monocyclic aromatic compound (e.g. phenol) with a crosslinking agent comprising an aromatic compound having at least two hydroxymethyl or halomethyl groups (e.g. xylylene glycol) and l-10 pts.wt. at least one compound selected among triphenyl phosphate, antimony trioxide, antimony pentoxide, tetrachlorophthalic anhydride, chlorinated paraffins, brominated bisphenol A and brominated naphthalene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant resin composition suitable for use as a resin for impregnating a rigid printed wiring board, and to a method for producing a rigid printed wiring board using the resin composition. The present invention relates to a prepreg, a copper-clad laminate (or a laminate having another conductor layer) for a rigid printed wiring board manufactured from the prepreg, and a rigid printed wiring board formed from the laminate.

[0002]

2. Description of the Related Art Printed wiring boards are widely used as substrates on which electronic components such as IC packages are mounted. The printed wiring board is a flexible type in which the insulating layer is plain resin,
The insulating layer is roughly classified into a rigid type made of a composite material in which a fiber base material is impregnated with a thermosetting resin and cured. Rigid printed wiring boards are manufactured using a composite material called a prepreg in which a fiber base material is impregnated with a resin and dried.

[0003] In rigid printed wiring boards, the main resins that have been used as resins for impregnating fiber base materials are epoxy resins and phenol resins. Since these resins have high flammability when used alone, it is difficult to use the resin alone as an impregnating material for a fiber base material when safety is taken into consideration. Therefore, in order to impart flame retardancy to these resins, a material system containing a flame retardant such as an antimony compound, a bromine compound or a phosphorus compound is generally used.

The present inventors have previously described a raw material comprising a condensed polycyclic aromatic compound or a mixture of a condensed polycyclic aromatic compound and a monocyclic aromatic compound with at least two hydroxymethyl groups or halomethyl groups. Focusing on the fact that the condensed polycyclic polynuclear aromatic resin obtained by reacting with a crosslinking agent comprising an aromatic compound having a group is a resin having excellent heat resistance and insulation properties, this resin was used as a resin for impregnation. Proposed a rigid printed wiring board (see JP-A-6-224525)
.

[0005]

The composite material obtained by impregnating a glass substrate with the condensed polycyclic polynuclear aromatic resin has high heat resistance of the resin, so that it can be used without blending a flame retardant into the resin. 1.6 is the thickness of the multilayer rigid printed wiring board
It shows excellent flammability equivalent to UL standard V-1 at a plate thickness of mm. However, with the recent trend of emphasizing safety, the insulating material of rigid printed wiring boards has been required to have even higher flammability (flame retardancy) equivalent to UL standard V-0.

In the case of a phenol resin or an epoxy resin, U
In order to achieve flammability equivalent to L standard V-0, a flame retardant must be used.
For example, it was necessary to mix a large amount of 5% by weight or more of the whole material.

An object of the present invention is to provide a resin composition capable of providing an insulating material for a rigid printed wiring board having a flammability equivalent to UL standard V-0 and an excellent mechanical strength with a small amount of a flame retardant. It is to provide.

[0008]

Means for Solving the Problems The present inventors have found that the above problems can be solved by blending a specific flame retardant with the above-mentioned condensed polycyclic polynuclear aromatic resin, and have reached the present invention. .

Here, the present invention is a resin composition comprising a mixture of 100 parts by weight of the following component (A) and 1 to 10 parts by weight of the component (B). (A) a raw material consisting of a condensed polycyclic aromatic compound or a mixture of a condensed polycyclic aromatic compound and a monocyclic aromatic compound, comprising an aromatic compound having at least two hydroxymethyl groups or halomethyl groups; Condensed polycyclic polynuclear aromatic resin obtained by reacting with a crosslinking agent, (B) triphenyl phosphate, antimony trioxide, antimony pentoxide, tetrachlorophthalic anhydride, chlorinated paraffin, brominated bisphenol A, and brominated naphthalene At least one compound selected from the group consisting of:

According to the present invention, a prepreg obtained by impregnating a fiber base material with the above resin composition, and one or more layers of a cured product of the prepreg having conductor layers on both surfaces or one surface thereof. And a rigid printed wiring board formed by forming a circuit on the conductive layer of the laminated body.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The resin component (A) in the resin composition of the present invention is a raw material consisting of a condensed polycyclic aromatic compound or a mixture of a condensed polycyclic aromatic compound and a monocyclic aromatic compound. And a condensed polycyclic polynuclear aromatic resin obtained by reacting with a crosslinking agent comprising an aromatic compound having at least two hydroxymethyl groups or halomethyl groups. This reaction is generally performed in the presence of an acid catalyst.

This fused polycyclic polynuclear aromatic resin is superior to polyimide in terms of long-term heat resistance, has a lower dielectric constant, and has a very low water absorption when compared with polyimide which is a typical heat-resistant resin. It has characteristics and characteristics suitable for an insulating substrate material for a printed wiring board.

As the condensed polycyclic aromatic compound as a raw material used in the synthesis of this resin, naphthalene, acenaphthene,
Examples include fused polycyclic hydrocarbons such as phenanthrene, anthracene, and pyrene, and hydroxy-containing derivatives such as naphthol and its alkyl-substituted product. Examples of the monocyclic aromatic compound which can be used as a raw material by mixing with the condensed polycyclic aromatic compound include phenols such as phenol, alkylphenol and resorcinol, and alkylbenzene.

Further, two or more aromatic units derived from the above-mentioned condensed polycyclic or monocyclic aromatic compound may be a single bond, an oxy group, a thio group, a methylene group, a phenylene group, a xylylene group or the like. An aromatic compound having a polynuclear structure linked by a group can also be used as a polycyclic or monocyclic raw material. Further, coal-based or petroleum-based heavy oils and pitches containing an aromatic compound as a main component as described above can also be used as a raw material.

The crosslinking agent to be reacted with the raw material is an aromatic compound having at least two hydroxymethyl groups or halomethyl groups, that is, a monocyclic or condensed polycyclic aromatic compound such as benzene, xylene, naphthalene, anthracene or the like. Hydroxymethyl or halomethyl substituted derivatives of hydrocarbon compounds such as alkyl derivatives thereof. It is preferable to use hydroxymethyl compounds such as dihydroxymethylbenzene (xylylene glycol), dihydroxymethylxylene, trihydroxymethylbenzene, and dihydroxymethylnaphthalene.

The acid catalyst used for the reaction between the raw material and the cross-linking agent is preferably sulfonic acid, and particularly preferably a sulfonic acid that is reactive with at least one of the raw material and the cross-linking agent, or is water-insoluble.

The reactive sulfonic acid group-containing acid catalyst suitable for the catalyst includes aromatic sulfonic acids (eg, sulfonic acids having a naphthalene nucleus or phenol nucleus, or carboxyls) which react with a hydroxymethyl group or a halomethyl group of a crosslinking agent. Aromatic sulfonic acid having a functional group such as a group, an amino group, an epoxy group, or an unsaturated hydrocarbon group), and an organic aromatic sulfonic acid having a hydroxymethyl group, a halomethyl group, or a formyl group that reacts with a starting aromatic compound
(Eg, hydroxymethylbenzenesulfonic acid, chloromethylbenzenesulfonic acid, formylbenzenesulfonic acid, naphthalene derivatives thereof and the like).

Examples of the water-insoluble sulfonic acid suitable for the catalyst include a polystyrene sulfonic acid resin obtained by crosslinking a styrene polymer with divinylbenzene and then sulfonating, phenol sulfonic acid, naphthalene sulfonic acid and the like to an aldehyde or at least two hydroxy sulfonic acids. Examples thereof include a phenolsulfonic acid resin condensed with a crosslinking agent comprising an aromatic compound having a methyl group or a halomethyl group, or a sulfonated product of a condensed polycyclic polynuclear aromatic resin. Also,
Water-insoluble sulfonic acids having a hydrophobic group such as dinonylnaphthalenesulfonic acid and didodecylbenzenesulfonic acid can also be used as the catalyst.

The amount of the sulfonic acid catalyst used depends on the reactivity of the raw material, the reaction temperature and the like, but is generally required to be 0.2% by weight or more based on the mixture of the raw material and the crosslinking agent, preferably from 1 to 20%. % By weight. The mixing ratio of the cross-linking agent and the raw material to be cross-linked (raw material + acid catalyst) is preferably from 0.7 to 6, particularly preferably from 1 to 3, in molar ratio. The reaction temperature is about 50-200 ° C,
Preferably it is 80-180 ° C. The reaction pressure is usually from normal pressure to slightly increased pressure, but the reaction can be carried out under reduced pressure in order to remove the condensed water generated as a result of the reaction from the reaction system and to increase the reaction efficiency. The reaction is easy to carry out in a molten state, but can also be carried out using a suitable solvent or dispersion medium.

As the reaction proceeds, the viscosity of the reaction product increases, and a thermosetting resin (B-stage resin or prepolymer) is obtained. When the reaction is further heated and the reaction proceeds, an insoluble and infusible cured product is formed, and thus a B-staged thermosetting condensed polycyclic polynuclear aromatic resin that can be melted and solution-molded is obtained. Stop at the stage.

The condensed polycyclic polynuclear aromatic resin (A) is added to (B)
As components, triphenyl phosphate, antimony trioxide, antimony pentoxide, tetrachlorophthalic anhydride,
At least one compound selected from chlorinated paraffin, brominated bisphenol A, and brominated naphthalene is blended. All of the compounds constituting the component (B) are known as flame retardants.

The amount of the component (B) (the total amount when two or more compounds are used) is 1 to 10 parts by weight based on 100 parts by weight of the condensed polycyclic polynuclear aromatic resin of the component (A). It is. If the amount is less than 1 part by weight, the flammability level of UL standard V-0 cannot be achieved, and if the amount exceeds 10 parts by weight, the strength becomes noticeable and sufficient mechanical strength cannot be obtained.

The preferred blending amount of the component (B) is as follows.
0 to 1 to 5 parts by weight, more preferably 1 to 5 parts by weight.
３3 parts by weight. It is a great advantage of the present invention that the UL standard V-0 can be achieved even with a small amount of the flame retardant component (B). For example, in the case of polyimide resin, epoxy resin, and phenol resin, it is necessary to add about 5 to 10 parts by weight of a flame retardant per 100 parts by weight of the resin in order to make the flame retardant to UL standard V-0. Was less than 5 parts by weight, it was difficult to achieve flame retardancy up to V-0.
The present invention requires only a small amount of the flame retardant, which is advantageous in all of cost, safety and mechanical properties.

Of the above-mentioned component (B), triphenyl phosphate, antimony pentoxide, brominated bisphenol A, and brominated naphthalene have better dispersibility in the resin solution or are soluble in the resin solution. It is preferable because of its existence.

There are many compounds known to be flame retardants other than the compound used as the component (B) in the present invention. However, when such another compound is used as a flame retardant, the mechanical strength is greatly reduced, which makes the compound unsuitable for practical use.

The mixing of the condensed polycyclic polynuclear aromatic resin (A) and the flame retardant compound (B) may be carried out according to a conventional method. For example, a method in which the flame retardant compound (B) is mixed with a solution in which the resin component (A) is dissolved in an appropriate solvent, a method in which the resin component (A) is heated to a temperature lower than the curing initiation temperature to form a low-viscosity melt, and A method of mixing the combustible compound (B) and the like are possible. Flame retardant compounds
When (B) is an organic substance, it may be mixed with the resin component (A) after dissolving it in a common solvent. Examples of the solvent include, but are not limited to, methyl ethyl ketone, acetone, toluene, dioxane, and tetrahydrofuran. The resin composition of the present invention comprising the mixture of the component (A) and the component (B) thus obtained in a solution state can be used as it is for impregnation of a fiber base material for producing a prepreg.

The resin composition of the present invention may comprise, in addition to the condensed polycyclic polynuclear aromatic resin (A) and the flame retardant compound (B), one or more kinds of additives to be added to the prepreg composition. An agent may be contained. Examples of such additives include coupling agents (e.g.,
(Silane coupling agent, titanate coupling agent),
It is a curing accelerator, a coloring agent such as a pigment or a dye. The addition amount is not particularly limited as long as it is within a usual range.

A prepreg can be produced from the resin composition of the present invention, and a rigid printed wiring board can be produced from the prepreg. Known methods can be used for the production of the prepreg and the rigid printed wiring board.

The prepreg is generally produced by a solvent method or a hot melt method. In the solvent method, a resin solution (varnish) in which the resin composition of the present invention is dissolved in an appropriate organic solvent is impregnated into a fiber base material, and the solvent is removed by heating to obtain a prepreg. In the hot melt method, at least one of the two release sheets is coated with the resin composition of the present invention, and the resin is melted by passing the fiber base material between the sheets and passing them between heating rolls. After the fiber base material is impregnated, the release sheet is peeled off to obtain a prepreg.

The fiber base material used for producing the prepreg can be composed of any insulating fibers. A glass fiber web obtained by processing glass fibers into a web such as cloth, mat, or tape is generally used, but a web of organic fibers such as aramid fibers or a web of inorganic fibers other than glass fibers such as quartz fibers can also be used. The content of the resin in the prepreg is preferably in the range of 20 to 80% by weight. The thickness of one prepreg is usually about 50 to 200 μm.

A copper-clad laminate for a rigid printed wiring board is formed by laminating a plurality of prepregs cut to a predetermined size so as to have a predetermined thickness as necessary, and placing copper foil on one or both surfaces (usually both surfaces). It can be manufactured by hot pressing. Instead of copper foil, another conductor layer can be used. By hot pressing, the condensed polycyclic polynuclear aromatic resin in the prepreg is thermoset at the same time that the prepreg and the prepreg-copper foil are thermocompression bonded, and a copper-clad laminate having the required strength is obtained. Suitable hot pressing conditions are temperature
120 ~ 230 ℃, applied pressure 25 ~ 100 kgf / cm ² , holding time 10 ~
120 minutes. If necessary, it may be post-cured by further heating.

The copper foil can be bonded to the prepreg using an adhesive. Further, as another prepreg manufacturing method, a copper layer (or other conductive metal layer) can be formed by electrolytic plating on the surface of the obtained laminate after hot-pressing the prepreg without placing a copper foil. .

After applying a photoresist to the copper-clad laminate and exposing it through a mask having a wiring pattern,
When a circuit is formed on the copper foil layer (conductor layer) by developing the photoresist and etching the copper foil, a printed wiring board is obtained. If necessary, further processing such as formation of through holes and plating of through holes is performed. Thermocompression bonding of two or more laminates with a circuit formed on the conductor layer,
Alternatively, a multilayer printed wiring board can be formed by forming an insulating layer and a wiring layer in multiple layers on a copper wiring.

[0034]

EXAMPLES The production of a prepreg and a copper-clad laminate using the resin of the present invention will be described below by way of examples. In the examples, parts and% are parts by weight and% by weight unless otherwise specified.

The fused polycyclic polynuclear aromatic resin used in the examples was SK resin SKR-NM manufactured by Sumikin Kako. This condensed polycyclic polynuclear aromatic resin is a B-stage brown transparent resin obtained by reacting naphthalene and para-xylene glycol in the presence of a β-naphthalene sulfone catalyst,
Melt viscosity at 70 ° C is 16,500 cps, number average molecular weight is 58
It was 0.

Example 1 Antimony pentoxide (Sb ₂ O ₅ ) was added to a 50% solution of a fused polycyclic polynuclear aromatic resin dissolved in methyl ethyl ketone with respect to 100 parts of the fused polycyclic polynuclear aromatic resin.
It was added in the range of 0.1-20 parts. Antimony pentoxide
It was uniformly dispersed in this solution.

Thereafter, a glass cloth having a thickness of 0.18 mm was immersed in the solution to impregnate the resin, and dried at 100 ° C. for 10 minutes to obtain a prepreg. Eight of the obtained prepregs were laminated, and were hot-pressed while sandwiched between copper foils having a thickness of 35 μm to obtain a copper-clad laminate. The hot pressing conditions are
The pressure was 12 kgf / cm ² at 180 ° C. for 60 minutes and at 230 ° C. for 60 minutes. The resin content of this prepreg was 45% by weight.

After cutting the obtained copper-clad laminate, the copper foil was completely removed by etching, and the flammability and bending strength of the remaining insulating layer (pre-preg laminate cured product) were measured according to JIS C648.
The measurement was performed based on the method described in 1. Table 1 shows the measurement results.

[0039]

[Table 1] Flammability is V when the amount of antimony pentoxide is 1 part by weight or more.
It turned out to be equivalent to −0. Further, the bending strength of the laminate hardly decreased when the amount of antimony pentoxide added was up to 10 parts by weight, but when it exceeded that, the decrease became noticeable and sufficient mechanical strength could not be obtained. From this,
It was found that the material to which antimony pentoxide was added in the range of 1 to 10 parts by weight had excellent flammability equivalent to V-0 and sufficient mechanical strength.

Example 2 Example 1 was repeated, except that the flame retardant component was changed from antimony pentoxide to brominated naphthalene. Table 2 shows the measurement results of flammability and bending strength.

[0041]

[Table 2] When brominated naphthalene was added, the same tendency as when antimony pentoxide was added was exhibited. When the addition amount of brominated naphthalene is 1 part by weight or more, flammability equivalent to V-0 is obtained, and the bending strength of the laminated board hardly decreases until the addition amount of brominated naphthalene decreases to 10 parts by weight, but exceeds that. And the decrease became noticeable, and sufficient mechanical strength could not be obtained. Again, when the amount of brominated naphthalene was in the range of 1 to 10 parts by weight, the flammability was as excellent as V-0 and sufficient mechanical strength was obtained.

Example 3 The flame retardant component was changed to another compound within the scope of the present invention, and the compounding amount was fixed at 1 part by weight and 10 parts by weight based on 100 parts of the condensed polycyclic polynuclear aromatic resin. Then, Example 1 was repeated. Table 3 shows the measurement results of flammability and bending strength.

[0043]

Table 3 Combustibility Flexural strength (kgf / cm ² ) Flame retardant component 1 part by weight 10 parts by weight 1 part by weight 10 parts by weight Triphenis phosphate V-0 V-0 35 35 Antimony trioxide V-0 V-0 37 37 Tetrachlorophthalic anhydride V-0 V-0 37 36 Chlorinated paraffin V-0 V-0 35 35 Brominated bisphenol A V-0 V-0 36 34 The amount of the flame retardant component is also 1 part by weight. It can be seen from Table 3 that excellent flammability equivalent to V-0 was obtained and that the strength was not significantly reduced up to 10 parts by weight.

(Comparative Example 1) The flame retardant component was changed to a compound outside the scope of the present invention, and the compounding amount was fixed at 1 part by weight and 10 parts by weight with respect to 100 parts of the condensed polycyclic polynuclear aromatic resin. Example 1 was repeated. Table 4 shows the measurement results of flammability and bending strength.

[0045]

[Table 4] Flammability component ( flammable flexural strength (kgf / cm ² )) 1 part by weight of flame retardant component 1 part by weight 1 part by weight 10 parts by weight Aluminum hydroxide No laminate is formed (The thermosetting reaction does not proceed) Zinc borate laminate No plate is formed (The thermosetting reaction does not proceed) Brominated diphenyl ether V-0 V-0 20 15 Brominated cyclododecane V-0 V-0119 17 Chlorinated polyethylene V-0 V- 0115 15 Nitrogenated guanidine V-0 V-0 17 16 Even when the compounding amount of the flame retardant was as small as 1 part by weight, excellent flammability equivalent to V-0 was obtained, but the bending strength was significantly reduced as compared with Examples 1-3. . That is, when a compound out of the range of the present invention is used as a flame retardant, the decrease in mechanical strength is large.

[0046]

According to the present invention, a condensed polycyclic ring which has heat resistance comparable to polyimide, and is superior to polyimide in terms of insulation and water absorption, and is suitable as an insulating material for rigid printed wiring boards. By using a polynuclear aromatic resin and reducing the mechanical strength, U
Excellent flammability equivalent to L standard V-0 can be provided.

As a result, a very high-performance rigid printed wiring board which satisfies the demand for flammability currently required for printed wiring boards and has other performances equal to or superior to conventional polyimides can be produced at low cost. This contributes to higher functionality and lower cost of rigid printed wiring boards.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08K 5:02 5: 136 5: 095)

Claims (4)

[Claims] (1) 100 parts by weight of the following component (A) and component (1)
A resin composition comprising a mixture with 10 parts by weight. (A) a raw material consisting of a condensed polycyclic aromatic compound or a mixture of a condensed polycyclic aromatic compound and a monocyclic aromatic compound, comprising an aromatic compound having at least two hydroxymethyl groups or halomethyl groups; Condensed polycyclic polynuclear aromatic resin obtained by reacting with a crosslinking agent, (B) triphenyl phosphate, antimony trioxide, antimony pentoxide, tetrachlorophthalic anhydride, chlorinated paraffin, brominated bisphenol A, and brominated naphthalene At least one compound selected from the group consisting of: 2. A prepreg obtained by impregnating a fiber base material with the resin composition according to claim 1. 3. A laminate for a rigid printed wiring board, comprising a conductor layer on one or both sides of one or more layers of the cured product of the prepreg according to claim 2. 4. A rigid printed wiring board comprising a circuit formed on the conductor layer of the laminate according to claim 3.