JPH0565344B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a metal-clad laminate using polyphenylene oxide resin. More specifically, the present invention relates to a polyphenylene oxide resin-metal clad laminate that is useful as a wiring board used in electrical equipment, electronic equipment, etc. and has low dielectric constant properties and excellent metal foil adhesion properties. . (Conventional technology) For wiring boards used in precision instruments, electronic computers, communication devices, etc., there are increasing demands for faster calculation processing, higher reliability, higher circuit density, and smaller size. In order to meet these demands, wiring boards are rapidly becoming more multi-layered and more precisely miniaturized. Conventionally, such wiring boards have been made of epoxy resin, polyimide resin, or
Fluorine resins, polybutadiene resins, and the like have been used as low dielectric constant resins, and efforts have been made to improve their properties. For example, polyphenylene oxide-based resin is attracting attention as a resin that can be used in multilayer wiring boards to meet higher wiring densities. Studies have been underway to realize a new metal-clad laminate that can achieve multi-layer high-density wiring. (Problems to be Solved by the Invention) However, when using this polyphenylene oxide resin as a base layer in a laminate,
Due to insufficient adhesive strength with metal foil for circuit formation,
It has been difficult to obtain high-quality polyphenylene oxide resin metal-clad laminates. Normally, the metal foil used for such metal-clad laminates, such as commercially available electrolytic copper foil or rolled copper foil, has a roughened adhesive surface to improve its adhesion to the resin base layer. Efforts have been made to improve the adhesive strength through treatments, but in the case of polyphenylene oxide resins, there is a drawback in that the adhesive strength cannot be sufficiently improved by conventional means. Furthermore, it was difficult to improve heat resistance. This invention was made in view of the above circumstances, and it solves the drawbacks of conventional polyphenylene oxide metal-clad laminates, takes advantage of the features of polyphenylene oxide resin, and also uses metal foil. The object of the present invention is to provide an improved metal-clad laminate that can improve adhesive strength with the metal-clad laminate and a printed wiring board using the same. (Means for Solving the Problems) This invention solves the above problems by applying a coupling agent treatment to the adhesive surface of the metal foil,
To provide a polyphenylene oxide metal-clad laminate characterized by being integrally laminated with a polyphenylene oxide resin base material, and a printed wiring board formed by forming a circuit using the same. Further, in this invention, it is a preferred embodiment to use a silane coupling agent as the coupling agent. Furthermore, the polyphenylene oxide resin of the present invention includes polyphenylene oxide,
Crosslinkable polymer and/or monomer, and optionally a flame retardant or flame retardant and flame retardant aid;
Compositions containing a reaction initiator and the like are also preferred. The metal-clad laminate is manufactured by forming a sheet and/or prepreg from the above-mentioned polyphenylene oxide resin composition, and laminating and integrating a base material made of this sheet/or prepreg with metal foil. The polyphenylene oxide of the present invention is a resin with a relatively high glass transition point, low dielectric constant, and low dielectric loss, and has attracted attention in recent years because it is inexpensive. It has also been discovered that by adding a flame retardant or a flame retardant and a flame retardant aid to this polyphenylene oxide resin composition, it is possible to improve the flame retardancy while maintaining its low dielectric constant. When adding a flame retardant to a polyphenylene oxide resin composition, if a crosslinkable polymer and/or monomer is added, the resin will have excellent heat resistance, chemical resistance, processability, and dimensional stability. has also been found. The polyphenylene oxide used in this invention has, for example, the following general formula (1): [R represents hydrogen or a hydrocarbon group having 1 to 3 carbon atoms, and each R may be the same or different. ] Those represented by these can be used, and one example thereof is poly(2,6-dimethyl-1,4-phenylene oxide). Although the molecular weight is not particularly limited, it is preferable, for example, that the weight average molecular weight (Mw) is 50,000 and the molecular weight distribution Mw/Mn=4.2 (Mn is the number average molecular weight). Such polyphenylene oxide, for example, the above-mentioned poly(2,6-dimethyl-1,4-phenylene oxide), is produced by oxidizing 2,6-xinol with an oxygen-containing gas and methanol in the presence of a catalyst. It can be obtained by coupling reaction. Here, as a catalyst,
Contains copper() compounds, N,N'-di-tert-butylethylenediamine, butyldimethylamine and hydrogen bromide. Further, methanol is used by adding 2 to 15% by weight of water to the reaction mixture system so that the total amount of methanol and water is 5 to 25% by weight as a polymerization solvent. Examples of crosslinkable polymers include 1,2-
Examples include polybutadiene, 1,4-polybutadiene, styrene-butadiene copolymer, modified 1,2-polybutadiene (malein-modified, acrylic-modified, epoxy-modified), rubbers, polytriallyl isocyanurate, polytriallyl cyanurate, etc. They can be used alone or in combination of two or more. These polymers may be in the form of elastomers or rubbers. However, when manufacturing the laminate of the present invention using a film formed by the casting method described below, it is preferable to use relatively high molecular weight polystyrene in order to improve the film formability of the film. . Note that the polymer of polytriallyl isocyanurate or polyallyl cyanurate can be synthesized by solution polymerization or bulk polymerization. In this case, solution polymerization has a hidden reaction compared to bulk polymerization, and it is easier to adjust the molecular weight. It can be carried out by dissolving triallyl isocyanurate monomer or triallyl cyanurate monomer in a solvent, mixing a radical initiator, reacting with stirring until an appropriate molecular weight is reached, and heating as necessary. can. At this time, it is preferable to carry out the reaction using a reflux vessel and in an atmosphere free of oxygen. The reaction atmosphere can be, for example, a nitrogen flowing atmosphere. Further, as the solvent, benzene, toluene, xylene, methanol, ethanol, acetone, methyl ethyl ketone, heptane, carbon tetrachloride, dichloromethane, trichloroethylene, etc. can be used. As the radical initiator, any suitable radical initiator can be used, including conventionally known ones, such as benzoyl peroxide, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, and t-butyl peroxide. Examples include oxybenzoate and dicumyl peroxide. For example, triallylisocyanurate prepolymer can be synthesized as follows. (Example 1) 280 g of triallyl isocyanurate monomer, 11 g of benzoyl peroxide, and 1087 g of benzene.
and using a stirrer and a reactor with a reflux condenser,
React for 6 hours while boiling under nitrogen atmosphere. After benzene is recovered under reduced pressure, methanol is added, and the polymer is recovered and dried under reduced pressure. 139 g of polymer was obtained. The number average molecular weight is approximately 10,000. (Example 2) Add 10 g of dicumyl peroxide and 527 g of toluene to 225 g of triallyl isocyanurate, Example 1
A prepolymer is obtained in the same manner as above. The number average molecular weight is approximately 4000. For example, the number average molecular weight of triallyl isocyanurate or triallyl cyanurate prepolymer that can be synthesized as described above is
It is preferable to set it to 10,000 or less. In addition, examples of crosslinking monomers include, for example,
Acrylates such as ester acrylates, epoxy acrylates, urethane acrylates, ether acrylates, melamine acrylates, alkyd acrylates, silicone acrylates, triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, divinylbenzene, Examples include polyfunctional monomers such as diallyl phthalate, monofunctional monomers such as vinyltoluene, ethylvinylbenzene, styrene, and paramethylstyrene, and polyfunctional epoxies, and each can be used alone or in combination of two or more. Among these, triallyl cyanurate and/or triallyl isocyanurate are preferred because they have good compatibility with polyphenylene oxide and improve film-forming properties, crosslinking properties, heat resistance, and dielectric properties. Triallyl cyanurate and triallyl isocyanurate are chemically structurally isomers and have almost the same film-forming properties, compatibility, solubility, reactivity, etc. Both can be used equally. The above crosslinkable polymers and crosslinkable monomers may be used alone or in combination, but their combined use is more effective in improving properties. When using a flame retardant, the relative dielectric constant of the polyphenylene oxide resin composition after adding the flame retardant together with a flame retardant aid can be usually 4.0 or less,
It is preferable to use a material whose flame retardancy can be V-1 or V-0 based on the UL94 flame retardant test method. For example, a brominated diphenyl ether system having the following formula (2) (wherein R represents hydrogen, an aromatic group or an aliphatic group), or a brominated polycarbonate system having the following formula (3), (In the formula, R represents hydrogen, an aromatic group or an aliphatic group.) Or a brominated bisphenol system having the following formula (4), (In the formula, R ¹ and R ² are each hydrogen, an aromatic group, an aliphatic group, or the following formula
Represents a group represented by either <>. 〈〉 −O−CH ₂ −CH=CH ₂ 〈〉 −O−CO−CH=CH ₂ 〈〉 −O−CH ₂ −CH ₂ −O−CO−CH=CH ₂ Furthermore, a brominated cyanuric acid system having the following formula (5) can be used. These flame retardants may be used alone or in combination. In the present invention, a flame retardant aid may be used together with such a flame retardant as necessary, thereby producing a synergistic effect on flame retardation. As the flame retardant aid, for example, antimony oxide (antimony trioxide, antimony pentoxide), zirconium oxide, etc. can be used. These flame retardant aids may be used alone or in combination. These flame retardant aids may be used alone or in combination as flame retardants. In addition, when using antimony oxide, it is preferable to disperse it in an organic solvent for ease of handling. When the polyphenylene oxide is made to contain the above-mentioned crosslinkable polymer and/or monomer, flame retardant, or flame retardant and flame retardant aid, an initiator can be further used. As the initiator, the following two types can be selected depending on whether the polyphenylene oxide resin composition is to be an ultraviolet curing type or a thermosetting type, but the initiator is not limited to these. Examples of ultraviolet curing photoinitiators (that is, those that generate radicals when exposed to ultraviolet rays) include benzoin, benzyl, allyldiazonium fluoroborate, benzyl methyl ketal, 2,2-diethoxyacetophenone, benzoyl isobutyl ether, p-tert-butyltrichloroacetophenone, benzyl (o-ethoxycarbonyl)-
α-Monoxime, biacetyl, acetophenone, benzophenone, Michler's ketone, tetramethylthiuram sulfide, azobisisobutyronitrile, and the like can be used. In addition, examples of thermosetting initiators (that is, those that generate radicals by heat) include dicumyl peroxide, tert-butylcumyl peroxide, benzoyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl -2,5-
di-(tert-butylperoxy)hexyne-3,
2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, α,α'-bis(tert-butylperoxy-m-isopropyl)benzene [1,4 (or 1,3)- bis(tert-butylperoxyisopropyl)benzene], 1-hydroxycyclohexyl phenyl edone, 2-hydroxy-2-methyl-1-
Phenyl-propan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 2-chlorothioxanthone, methylbenzoylformate, 4,4-bisdimethylaminobenzophene Non (Michler Ketone), Benzoin Methyl Ether, Methyl-o-
Bayzoyl ate, α-acyloxime ester,
Biscum mill from Nippon Oil & Fats Co., Ltd. can be used. Each of these initiators may be used alone or in combination with two
More than one species may be used in combination. Further, an initiator using ultraviolet rays and an initiator using heat may be used in combination. The blending ratio of the above polyphenylene oxide, crosslinkable polymer and/or monomer, flame retardant or flame retardant and flame retardant aid, and further reaction initiator is usually preferably 5
-95% by weight, 1-95% by weight of crosslinkable polymer/monomer, 1-90% by weight of flame retardant, and 1-50% by weight of flame retardant aid. Moreover, the blending ratio of the reaction initiator to be included in addition to such a blend is preferably 0 to 10% by weight. Furthermore, properties such as the dielectric constant of the resin may be changed by incorporating various inorganic fillers. Examples of such inorganic fillers include titanium dioxide-based ceramics, barium titanate-based ceramics, lead titanate-based ceramics, strontium titanate-based ceramics, calcium titanate-based ceramics, lead zirconate-based ceramics, etc., singly or in combination. Can be used together. Such polyphenylene oxide resin compositions are usually dissolved in a solvent, dispersed, and mixed. In this case, the amount of solvent used is 5 to 50% by weight solution of the polyphenylene oxide resin composition ( Alternatively, it is preferable that the resin solid content is in the range of 10 to 30% by weight based on the solvent. As a solvent, trichlorethylene, trichloroethane,
Halogenated hydrocarbons such as chloroform, methylene chloride, chlorobenzene, benzene, toluene,
Aromatic hydrocarbons such as xylene, acetone, carbon tetrachloride, etc. can be used, and trichlorethylene is particularly preferred. These can be used alone or in a mixture of two or more. When manufacturing the metal-clad laminate of the present invention using this polyphenylene oxide resin,
Form a sheet from a polyphenylene oxide resin composition, or impregnate a base material with this to form a prepreg, and if necessary, manufacture a core material etc. from the base material layer forming material such as the sheet or prepreg, Then, it can also be manufactured by laminating and integrating it with other base materials, films, prepregs, metal foils, etc. in accordance with conventional methods. Multi-layering is also possible. When forming a sheet from a resin composition,
For example, a casting method can be used. The casting method is a method in which a resin mixed with a solvent is formed into a thin layer by casting or coating, and then the solvent is removed to form a cured product.
According to the casting method, a cured product can be obtained at a low temperature without using the costly calendar method. To explain this casting method more specifically, a polyphenylene oxide resin composition mixed with a solvent is placed on a mirror-treated iron plate or a carrier film for casting, etc. Preferably 5~
A sheet is obtained by casting (or coating) to a thickness of 500 μm and thoroughly drying to remove the solvent. The carrier film for casting is not particularly limited, but it is preferable to use one that is insoluble in the above solvents, such as polyethylene terephthalate (hereinafter abbreviated as "PET") film, polyethylene film, polypropylene film, polyester film, and polyimide film. ,and,
It is preferable to use a mold release treatment. Drying is performed by air drying or hot air drying. In this case, it is preferable that the upper limit of the temperature range be lower than the boiling point of the solvent or lower than the heat-resistant temperature of the carrier film for casting (when drying is performed on the carrier film for casting). . The lower limit shall be determined depending on drying time and processability. For example, when trichlorethylene is used as a solvent and PET film is used as a carrier film for casting,
Preferably, the temperature is up to 80°C. Note that by increasing the temperature within this range, the drying time can be shortened. When manufacturing a prepreg by impregnating a base material with a polyphenylene oxide resin composition, the following method can generally be used. That is, the polyphenylene oxide resin composition is impregnated and adhered to the base material by immersing (dipping) the base material in a solvent dispersion of the polyphenylene oxide resin composition. Then, the solvent is removed by drying or the like, or semi-cured to bring it to the B stage. The amount of the polyphenylene oxide resin composition impregnated in this case is not particularly limited, but is preferably 30 to 80% by weight. The base material can be a cloth-like material that can be impregnated with resin such as glass cloth, aramid cloth, polyester cloth, or nylon cloth, a pine-like material made of these materials and/or a fibrous material such as nonwoven fabric, or paper such as kraft paper or linter paper. etc., but is not limited to these. As the metal foil for circuit formation used in forming the metal-clad laminate of the present invention, a wide variety of metal foils commonly used for wiring boards can be used. For example, metal foil such as copper foil or aluminum foil can be used. The present invention is characterized in that the adhesion surface of these metal foils is previously treated with a coupling agent prior to lamination and integration with the polyphenylene oxide resin base material. This improves the adhesion to the polyphenylene oxide resin base material, which is not sufficient by ordinary means such as surface roughening. The coupling agent in this case is preferably a silane compound having an organic functional group such as a vinyl group, an epoxy group, an amino group, an acrylic group, a mercapto group, or a hydrolyzable group, such as a methoxy group, an ethoxy group, or an alkyl group. This can be exemplified as an example. After applying an aqueous solution of this coupling agent, etc., it is dried to remove moisture. By such coating treatment, the metal foil peeling strength of the metal-clad laminate after lamination and integration is greatly improved, and the reliability of a printed wiring board using this laminate is significantly improved. Moreover, heat resistance also becomes good. As a method for manufacturing a metal-clad laminate, for example, the following method can be used. That is, a predetermined number of suitably dried base materials made of the above-mentioned sheets and/or prepregs are combined so as to have a predetermined design thickness, metal foil is combined and laminated, and the laminate is heated and pressed to form a laminate. If the heating at this time causes a crosslinking reaction by the reaction initiator, very strong adhesion can be obtained. Such a crosslinking reaction can be carried out by photocrosslinking such as ultraviolet irradiation, thermal crosslinking, crosslinking by radiation irradiation, and the like. The temperature during hot pressing depends on the combination of metal foil, film, sheet, prepreg, etc., but for example, the lamination pressing temperature is preferably in the range of about 160 to 300°C. In addition, when crosslinking is carried out by heating in a dryer, etc., the crosslinking reaction depends on the reaction temperature of the initiator used, etc., so the heating temperature and heating time are selected depending on the type of initiator. For example, temperature
The temperature is 150-300°C and the time is about 10-60 minutes. Pressing conditions are selected as necessary. For example, the pressure can be about 40 to 80 kg/cm ² . In the heat-pressing method described above, a predetermined number of base materials made of the film and/or prepreg are heat-laminated in advance, metal foil is superimposed on one or both sides of the base material, and then heat-pressing is performed again. It's okay if it's hot. (Function) The polyphenylene oxide metal-clad laminate of the present invention maintains the excellent heat resistance, dimensional stability, chemical resistance, and low dielectric constant properties of the polyphenylene oxide resin composition, and In addition to exhibiting flammability and resin properties for printed wiring boards, treatment of the metal foil with a coupling agent can improve adhesive strength with the resin base material and heat resistance. Therefore, the polyphenylene oxide-based laminate of the present invention can be easily processed with high precision, is suitable for high-speed signal processing, and can realize high-density multilayering. A high quality printed wiring board is realized. Next, examples will be shown to explain the metal-clad laminate of the present invention in more detail. (Example) Example 1 100 g of polyphenylene oxide (GE PPO), 40 g of styrene-butadiene copolymer (Asahi Kasei Corporation; Solplain T406),
Triallylisocyanurate (Nippon Kasei Co., Ltd.:
TAIC) 40g, dicumyl peroxide (NOF: Percmil D) 2g, and trichlorethylene (Toagosei Chemical Co., Ltd.: Triclean) 750g
was added, sufficiently stirred until a homogeneous solution was obtained, and defoamed to obtain a polyphenylene oxide resin composition. A glass cloth (Nitto Boseki: WE-116E) was impregnated with this polyphenylene oxide resin composition so that the amount of resin was 50% by weight. 80
It was dried at ℃ for 30 minutes to obtain a prepreg sheet. On the other hand, the adhesive surface of a 35 μm thick copper foil (Furukawa Circuit Film Co., Ltd.) was roughened, and then an aminosilane coupling compound (Toshiba Silicone Co., Ltd.) was applied.
Apply 1 g/aqueous solution of TSL8331) to the copper foil,
Dry at 80°C for 30 minutes to remove moisture. The copper foil after this treatment is laminated with the four prepreg sheets described above, and heat-pressed at 200° C. and a pressure of 30 kg/cm ² . The obtained metal-clad laminate was evaluated for peel strength and soldering heat resistance at 260°C. As a result, as shown in Table 1, the peel strength was more than doubled and the heat resistance was greatly improved compared to the case without coupling treatment (comparative example). Examples 2 to 5 Four types of metal-clad laminates were manufactured in the same manner as in Example 1 using coupling agents as shown in Table 1. The physical properties of the obtained laminate were evaluated in terms of room temperature peel strength and soldering heat resistance. The results are also shown in Table 1. Comparative Example A metal foil laminate was produced in the same manner without treating the metal foil with a coupling agent. In addition, the physical properties of the laminate were measured. The peel strength was low, and the heat resistance was also far inferior to that of the Examples.

[Table] (Effects of the invention) As explained in detail above, this invention makes use of the features of polyphenylene oxide resin,
Excellent dimensional stability, chemical resistance, and good workability.
Moreover, a laminate with a low dielectric constant and excellent flame retardancy has been realized, and furthermore, a metal-clad laminate with improved adhesive strength and heat resistance between metal foil and these resin base materials can be provided. . Therefore, the polyphenylene oxide laminate of the present invention can be processed with high precision as a wiring board.
In addition to being heat resistant during mounting, it is advantageous as a highly reliable printed wiring board.

Claims (1)

[Claims] 1. Applying a coupling agent treatment to the adhesive surface of the metal foil,
A polyphenylene oxide metal-clad laminate characterized by being formed by laminating and integrating a polyphenylene oxide resin base material. 2. A metal foil for laminates, which is obtained by applying a coupling agent treatment to the adhesive surface of the metal foil to the base material. 3. The laminate or metal foil for a laminate according to claim 1 or 2, wherein the coupling agent is a silane coupling agent. 4. A printed wiring board formed by forming a circuit on the laminate according to claim 1. 5. The laminate according to claim 1 or 4, wherein a polyphenylene oxide resin base material comprising polyphenylene oxide, a crosslinkable polymer and/or a monomer, and further a reaction initiator as required is laminated and integrated. board or printed wiring board.