JPH03166935A - Laminated sheet - Google Patents

Abstract

PURPOSE:To enhance the adhesion with a metal foil and improve the heat resistance while making the best use of the characteristics of a polyphenylene oxide resin by treating the single surface or both surfaces of a double-side roughened metal foil with a coupling agent and integrally laminating a polyphenylene oxide resin base material to the metal foil. CONSTITUTION:A metal clad laminated sheet is prepared by forming a sheet from a polyphenylene oxide resin composition or impregnating base material 1 with said composition to form a prepreg and subsequently integrally laminating other base material, a film, the prepreg and a metal foil 3. In this case, prior to integrally laminating the metal foil 3 to the polyphenylene oxide resin base material, both surfaces of the metal foil 3 are subjected to roughening treatment and the single surface or both surfaces thereof is treated with a coupling agent 2. As the coupling agent, a silane compound having an org. functional group or a hydrolyzable group such as a vinyl group, an epoxy group, an amino group, an acrylic group or mercapto group, for example, a methoxy group, an ethoxy group or an alkyl group is pref.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a metal-clad laminate using polyphenylene oxide resin. More specifically, the present invention relates to a polyphenylene oxide-based resin-metal region laminate that is useful as a wiring board used in electrical equipment, electronic equipment, etc. and has low dielectric constant properties and excellent adhesion to metal foil and its circuits. , relates to a multilayer laminate using this as the inner layer material. (Conventional technology) For wiring boards used in precision instruments, electronic computers, communication equipment, etc., there are increasing demands for faster calculation processing, higher reliability, higher circuit density, and smaller size. In response to this trend, 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 low dielectric constant resin such as fluororesin or polyptadiene resin, and efforts are being made to improve their properties. Progress has been made. For example, in response to higher wiring density, IJrI! Polyphenylene oxide resin is attracting attention as a resin that can be used as a new metal that can be used to stably perform high-speed signal processing with a low dielectric constant and to increase the density of multilayer wiring. The realization of tension laminates is being considered. (Problem to be Solved by the Invention) However, when this polyphenylene oxide resin is used as a base layer in a laminate, the quality deteriorates due to insufficient adhesive strength and heat resistance with the metal foil used for circuit formation. It has been difficult to obtain good 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, etc., but in the case of polyphenylene oxide resins, it is impossible to improve the adhesive strength or improve adhesive strength by conventional means.
Another drawback was that it had insufficient heat resistance. This invention was made in view of the above circumstances, and eliminates the drawbacks of conventional polyphenylene oxide metal-clad laminates, takes advantage of the characteristics of polyphenylene oxide resin, and improves the adhesion with metal foil that tends to occur. The purpose of this paper is to provide an improved metal-clad laminate that can improve strength and heat resistance, and a multilayer printed wiring board using the same. (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a method in which a double-sided metal foil is treated with a coupling agent on one or both sides, and is laminated and integrated with a polyphenylene oxide resin base material. Provided is a multilayer printed wiring board in which a polyphenylene oxide-based metal-clad laminate characterized by:
A preferred embodiment is to use a silane coupling agent. Furthermore, the polyphenylene oxide resin of the present invention is a composition containing polyphenylene oxide, a crosslinkable polymer and/or monomer, and, if necessary, a flame retardant or a flame retardant, a flame retardant aid, a reaction initiator, etc. is considered preferable. The metal-clad laminate is made by forming a sheet and/or prepreg from the above polyphenylene oxide resin composition,
This sheet/prepreg base material is laminated and manufactured with metal foil. The polyphenylene oxide of this 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 found that by adding a flame retardant or a flame retardant and a flame retardant to this polyphenylene oxide resin composition, it is possible to improve the flame retardancy while maintaining its low dielectric constant. It has been found that when a flame retardant is included in a resin composition, when a crosslinkable polymer and/or monomer is included, the resin has excellent heat resistance, chemical resistance, processability, and dimensional stability. It has also been done. The polyphenylene oxide used in this invention has, for example, the following general formula (1) [R represents hydrogen or a hydrocarbon group of carbon'I & 1 to 3, and each R may be the same or different. You can. ] Can be used, and one example thereof is poly(2,6-dimethyl-1,4-phenylene oxide). Although the molecular weight is not particularly limited, for example, the weight average molecular weight (M
w) is so, ooo, molecular weight distribution Mw/Mn
=4.2 (Mn is the number average molecular weight). Such polyphenylene oxide is produced by oxidizing 2,6-xylenol with an oxygen-containing gas and methanol in the presence of a catalyst. It can be obtained by coupling reaction. Here,
As a catalyst, copper (I>compound, N,N"-diter
Contains t-butylethylenediamine, butyldimethylamine and hydrogen bromide. Also, based on methanol, 2 to 15 weight 1% of water is added to the reaction mixture system, and the total of methanol and water is 5 to 25 f! % of the polymerization solvent. Examples of crosslinkable polymers include 1,2-polybutadiene, 1,4-polybutadiene, styrene-ptadiene cobolymer, modified 1,2-polyptadiene (maleic-modified, acrylic-modified, epoxy-modified), rubbers, polytriallyl isocyanate, etc. nurate, polytriallyl cyanurate, etc., and each 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 polystyrene having a relatively high molecular weight in order to improve the film's malleability. 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 milder reaction than bulk polymerization, and it is easier to adjust the molecular weight. This can be carried out by dissolving triallyl isocyanurate monomer or triallyl cyanurate monomer in a solvent, mixing a radical initiator, reacting with stirring until a suitable molecular weight is reached, and heating as necessary. 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 a 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 penzoyl peroxide, 2,5-dimethyl-2,5-di(penzoylperoxy)hexane, t-butyl bar. Examples include oxybenzoate and dicumyl peroxide. For example, triallylisocyanurate prepolymer can be synthesized as follows. (
Example 1) Add 11 g of benzoyl peroxide and 1087 g of benzene to triallylisocyanurate monomer 2801,
Using a reactor equipped with a stirrer and a reflux condenser, react for 6 hours while boiling under a nitrogen atmosphere. After recovering benzene under reduced pressure, methanol is added, and the polymer is recovered and dried under reduced pressure to obtain a 139 K polymer. The number average molecular weight is about 10.Goo. (Example 2) Dicumyl peroxide Log and 527 g of toluene were added to 225 g of triallylisocyanurate, and a prepolymer was obtained in the same manner as in Example 1. The number average molecular cap is approximately 4.00
It is 0. For example, the number average molecular weight of triallyl isocyanurate or a single repolymer of triallyl cyanurate that can be synthesized as described above is preferably 10,000 or less. In addition, examples of crosslinking monomers include (i) ester acrylates, epoxy acrylates, urethane acrylates, ether acrylates, melamine acrylates, alkyd acrylates,
Acrylates such as silicone acrylates, polyfunctional monomers such as triallyl cyanurate, trifuryl isocyanurate, ethylene glycol di]acrylate, divinylbenzene, diallyl phthalate, and vinyltoluene such as ethylvinylbenzene, styrene, paramethylnutylene, etc. monofunctional monomers, polyfunctional epoxies, etc. Each can be used alone or in combination of two or more. Among these, triallyl cyanurate and/or triallyl isocyanurate have good compatibility with polyphenylene oxide, have good malleability,
This is preferred because it improves crosslinking properties, heat resistance, and dielectric properties. These triallyl cyanurate and triallyl isocyanurate are chemically structurally isomers and have almost the same processability, compatibility, solubility, reactivity, etc. Or both can be used equally. The above crosslinkable polymers and crosslinkable monomers may be used alone or in combination, but using them in combination is more effective in improving properties. In this case, the relative dielectric constant of the polyphenylene oxide resin composition after adding the flame retardant together with the flame retardant aid can be made 4.0 or less, and the flame retardancy can be reduced to U.
It is preferable to use one that has a characteristic of V-1 or ■10 based on the L94II flammability 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), (wherein R represents hydrogen, an aromatic group, or an aliphatic group), or a brominated bisphenol system having the following formula (4), ( In the formula, R and R2 each represent hydrogen, an aromatic group, an aliphatic group, or a group represented by any of the following formulas <i> to <yi>. <i -o-ctt2 - Ctl = CH2 <ii> 10- CO- CH= CH2 <iy> -0-Cl2-C}l2 10- CO- CH= CH2 <yi> -0-CH2 -CH-CI1 \ /2 0 ) Furthermore , Brominated cyanuric acid having the following formula (5) can be used. These flame retardants may be used alone or in combination. Such flame retardants may be used as needed. Flame retardant aids can be used in combination with flame retardants, thereby producing a synergistic effect on flame retardancy. Examples of flame retardant aids include antimony oxide (antimony trioxide, antimony pentoxide), zirconium oxide, etc. These flame retardant aids may be used alone or in combination.These flame retardant aids may be used alone or in combination as a flame retardant.In addition, When using antimony oxide, it is preferable to disperse it in an organic solvent for ease of handling. As the initiator, the following two types can be selected depending on whether the polyphenylene oxide resin composition is an ultraviolet curing type or a thermosetting type, but the initiator is limited to these. Examples of UV-curable photoinitiators (that is, those that generate radicals upon UV irradiation) include benzoin, benzyl, allyldiazonium fluoroborate, penzyl methyl ketal, and 2,2-diethoxyacetophenone. , penzoylisobutyl ester, p-tert-butyltrichloroacetophenone, benzyl(0-ethoxycarbonyl)-alpha-1, monooxime, biacetyl, acetophenone, penzophenone, Michler's ketone, tetramethylthiuram sulfide, azobisisobutyronitrile, etc. In addition, as a thermosetting initiator (that is, one that generates radicals by heat), dicumyl peroxide, t
ert-butyl cumyl peroxide, penzoyl peroxide, 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-isoprobyl)benzene [1,4《or 1,3》-bis(
peroxides such as 1-hydroxycyclohexyl phenyl edone, 2-hydroxy-2-methyl-1
-7enylpropan-11-one, 1-《4-yne 1
Lopylphenyl》-2-hydroxy-2-methylpropan-1-one, 2-chlorothioxanthone, methylbenzoylformate, 4,4-bisdimethylaminobenzophenone (Michler's ketone), benzoin methyl ether, methyl 101-peizoyl benzoate, α-acyloxime ester, Nippon Oil & Fats ■'s biscumyl, etc. can be used. Each of these initiators may be used alone or in combination with two
More than one species may be used together. Furthermore, it is possible to use a combination of an ultraviolet ray initiator and a thermal initiator. The blending ratio of the polyphenylene oxide, crosslinkable polymer and/or monomer, flame retardant or flame retardant and flame retardant aid, and reaction initiator is usually preferably 5 to 95% by weight of polyphenylene oxide, Crosslinkable polymer/monomer 1-95% by weight, flame retardant 1-90% by weight,
The flame retardant aid should be 1 to 50% by weight. In addition, the blending ratio of the reaction initiator to be included in addition to such a blend is 0 to 10
It is preferable to express it in 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 ceramics, barium titanate ceramics, lead titanate ceramics, strontium titanate ceramics,
Calcium titanate ceramics, lead zirconate ceramics, etc. can be used alone or in combination. Such a polyphenylene oxide resin composition is
Usually, it is dissolved in a solvent, dispersed, and mixed. In this case, the amount of solvent used is a 5 to 50% by weight solution of the polyphenylene oxide resin composition. range). As the solvent, halogenated hydrocarbons such as trichloroethylene, trichloroethanechloroform, methylene chloride, and chlorobenzene, aromatic hydrocarbons such as benzene, toluene, and xylene, acetone, and carbon tetrachloride can be used, with trichloroethylene being particularly preferred. Each of 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, a prepreg is formed by forming a sheet from the polyphenylene oxide resin composition or impregnating it into a base material, and then forming a prepreg as required. It can be manufactured by manufacturing core materials etc. from base material layer forming materials such as sheets and prepregs, and then laminating and integrating them with other base materials, films, prepregs, metal foils, etc. according to conventional methods. The same applies to multilayering. 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.

With the casting method, a cured product can be obtained at low temperatures without using the costly calendering 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. with a coating of, for example, 5-700 (preferably 5-700). Casting (or coating) to a thickness of 500 μm
The sheet is then obtained by thoroughly drying and removing the solvent. The carrier film for casting is not particularly limited, but polyethylene terephthalate (
(hereinafter abbreviated as rPETJ) film, polyethylene film, polypropylene film, polyester film, polyimide film, etc., which are insoluble in the above-mentioned solvents are preferable, and those which have been subjected to mold release treatment are preferable. Drying is performed by air drying or hot air drying. The temperature range in this case must have an upper limit lower than the boiling point of the solvent, or
It is preferable to set the temperature lower than the heat resistance temperature of the carrier film for casting (when drying is performed on the carrier film for casting), and the lower limit shall be determined depending on the drying time and processability. For example, when using trichlorethylene as a solvent and PET
When the film is used as a carrier film for casting, it is preferably kept at a temperature ranging from room temperature to 80°C. Note that drying time can be shortened by increasing the temperature within this range. 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 dipping the base material in a solvent dispersion of the polyphenylene oxide resin composition. The solvent is then removed by drying or semi-cured to bring it to the B stage. In this case, the amount of impregnated polyphenylene oxide resin composition is not particularly limited, but is 3.
It is preferably 0 to 80% by weight. The base material may be a cloth material that can be impregnated with resin such as glass cloth, aramid cloth, polyester cloth, or nylon cloth, a mat material made of these materials, and/or a fibrous material such as nonwoven fabric.
Paper such as kraft paper and linter paper can be used, but is not limited to these. As the metal foil for circuit formation used in the stage for 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 provides that, prior to laminating and integrating these metal foils with a polyphenylene oxide resin base material, both sides of the metal foils are roughened, and one or both sides of the metal foils are treated with a coupling agent in advance. This treatment improves the adhesion and heat resistance to the polyphenylene oxide resin base material, which are not sufficiently achieved by ordinary means such as surface roughening. This laminate can then be circuitized to form the inner layer material. 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. It can be exemplified as an example. After applying an aqueous solution of this coupling agent, etc., dry it to remove moisture. Such a coating treatment greatly improves the metal foil peeling strength of the metal area laminate after lamination and integration, and significantly increases the reliability of printed wiring boards using this laminate. As a method for manufacturing a metal-clad laminate, for example, the method shown in FIG. 1 can be used. That is, a predetermined number of appropriately dried base materials (1) made of the above-mentioned sheets and/or pre-regs are combined so as to have a predetermined design thickness, and after roughening both sides, a coupling agent (2) is applied to one or both sides. The treated metal foils (3) are combined and laminated, and heated and pressed to form a laminate. If the heating at this time causes a crosslinking reaction by the reaction initiator, even stronger adhesion can be obtained. Such crosslinking reactions include photocrosslinking such as ultraviolet irradiation, thermal crosslinking,
This is done by cross-linking through radiation irradiation, etc. The temperature during heat-pressing depends on the combination of metal foil, film, sheet, or prepreg, but for example, the lamination-pressing temperature is 160~160°C.
Preferably, the temperature is in the range of about 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, so the heating temperature and heating time are selected depending on the type of initiator. For example, temperature 150~300℃, time 10~
The duration is approximately 60 minutes. Select the clamping conditions as necessary. For example, the pressure can be set to about 40 to 80 kg/1. In the heat-pressing method described above, a predetermined number of base materials of the film and/or prepreg are heated and laminated in advance, a metal foil is superimposed on one or both sides of the film, and then heat-pressing is performed again. It's okay. Next, the metal foil (3) of the obtained laminate is processed by etching or the like to form a circuit, thereby obtaining an inner layer material (4) for a multilayer printed wiring board. Using this inner layer material (4), a base material (1) made of a sheet and/or prepreg and a metal foil (3) treated with the above-mentioned coupling agent <<2>> after surface roughening are further provided on the outside thereof. Then, heat and press to form a layer. By doing this, a multilayer laminate is obtained. By forming a circuit on this outermost layer, a multilayer printed wiring board is manufactured. As for the inner layer material (4), it goes without saying that only one side of the metal foil <3> may be treated with a coupling agent. C Effect} The polyphenylene oxide-based metal-clad laminate and multilayer printed wiring board of the present invention maintain the excellent heat resistance, dimensional stability, chemical resistance, and low dielectric constant properties of the polyphenylene oxide-based resin composition, In addition to exhibiting flame retardancy and resin properties for printed wiring boards, treatment of the metal foil with a coupling agent can significantly improve adhesive strength with the resin base material and heat resistance. Therefore, the polyphenylene oxide-based laminate of the present invention is easy to process 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 further explain the metal-clad laminate of the present invention. {Example} Example 1 Polyphenylene oxide (GE) was added to a reactor equipped with a pressure reduction device.
PPO) 100 g, styrene butadiene cobolima (
Asahi Kasei ■; Solprene T406) 40g, triallylisocyanurate (Nippon Kasei ■: T A I C)
40 g, dicuminol liver oxide (NOF:
2 g of Bark Mill D) and 750 t of trichlorethylene (Toagosei Kagaku Kogyo @: Trichlene) were added, thoroughly stirred until a homogeneous solution was obtained, and defoamed to obtain a polyphenylene oxide resin composition. A glass cloth (Nittobo 11: WE-116B) was impregnated with this polyphenylene oxide resin composition so that the resin amount was 50% by weight. It was dried at 80°C for 30 minutes to obtain a prepreg sheet. On the other hand, a 35 μm thick copper foil (Furukawa Sarki Gamma Tofilm Co., Ltd.) was subjected to surface roughening treatment on both sides, and then treated with an aminosilane coupling compound (Toshiba Silicone Co., Ltd.: TSL8331).
Coat a copper foil with an aqueous solution of g/1 and dry at 80°C for 30 minutes to remove moisture. The copper foil after this treatment was laminated with the four sheets of Bripreg described above, and heat-pressed at 200°C and a pressure of 30 kg/1. Regarding the obtained metal-clad laminate, beer strength and 26
The soldering heat resistance at 0°C was evaluated. As a result, as shown in Table 1, the beer strength was more than doubled and the heat resistance was greatly improved compared to the case without coupling treatment (comparative example). Next, a circuit was formed on the metal foil to produce a multilayer printed wiring board as shown in Figure 1. At this time, the laminated shape was '', the temperature was 200°C, and the pressure was 30kg/1. The characteristics of the inner layer circuit in the multilayer elliptical structure were evaluated in the same manner as above. Equivalent characteristics were obtained. Examples 2 to 5 Four types of metal-clad laminates were manufactured in the same manner as in Example 1 using the coupling agents as shown in Table 1. The physical properties of the obtained laminate were evaluated in terms of room temperature beer 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. We also measured the physical properties of the laminate. The beer strength was low, and the MS properties were also far inferior to those of the Examples. <Effects of the Invention> As explained in detail above, this invention makes use of the features of polyphenylene oxide resin to achieve excellent dimensional stability, chemical resistance, good processability, low dielectric constant, and flame retardancy. It is possible to realize a laminate with excellent properties in terms of imparting properties, and furthermore, it is possible to provide a metal-clad laminate with improved adhesive strength and heat resistance between the metal foil and these resin base materials. Therefore, the polyphenylene oxide-based laminate of the present invention can be processed with high precision as a wiring board, has heat resistance during mounting, and is advantageous as a highly reliable multilayer printed wiring board.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view illustrating the process of forming a laminate according to the present invention. 1... Sheet and/or prepreg base material 2...
Coupling agent 3...Metal foil 4...Inner layer material

Claims (5)

[Claims] (1) A polyphenylene oxide metal-clad laminate, characterized in that it is formed by applying a coupling agent treatment to one or both sides of a double-sided roughened metal foil and laminating it integrally with a polyphenylene oxide resin base material. (2) The laminate according to claim (1), wherein the coupling agent is a silane coupling agent. (3) A multilayer laminate or a printed wiring board thereof, characterized in that a circuit is formed on the laminate according to claim (1), and this serves as an inner layer material. (4) The multilayer laminate or printed wiring board thereof according to claim (3), wherein the adhesive surface of the outermost layer metal foil is also treated with a coupling agent. (5) Claims (1) or (3) wherein a polyphenylene oxide resin base material comprising polyphenylene oxide, a crosslinkable polymer and/or monomer, and optionally a reaction initiator is laminated and integrated. laminate board or its printed wiring board.