JPS61217240A - Manufacture of metallic foil-lined laminated board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for producing a metal foil-clad laminate having excellent dielectric properties in the so-called ultra-high frequency region, such as the X-hand (10GH2) region of satellite communications.

[Background technology]

X hand (IOGH2) w4 used for satellite communication etc.
Laminated plates used in the so-called ultra-high frequency range are required to have excellent high frequency properties, especially excellent dielectric properties.In other words, they are required to have excellent dielectric constant and loss over a wide frequency range, temperature range, and humidity range. The material must have constant and preferably low properties.These properties are not due to the composition of the laminate, but are inherent to the material, so it is important to materials must be selected.

Conventionally, polytetrafluoroethylene, alumina ceramic, cross-linked polyethylene, etc. have been used for such applications, but alumina ceramic has difficulties in forming three circuits (copper cladding method), etc. , poly(4-fluorinated) ethylene, and cross-linked polyethylene all have low glass transition points, so they have the disadvantage that their dielectric constant and dielectric loss change significantly near practical conditions.Furthermore, their nonpolar nature makes it difficult to form circuits. It has the disadvantage that the adhesive strength with metal foil is insufficient.

Low dielectric constant materials with relatively high glass transition points include polyethersulfone, polyetherimide, and polyphenylene oxide. Polysulfone, etc., but most of these are thermoplastic resins, and even if they can be used to bond metal foil under normal conditions, they have the drawback of poor properties such as soldering heat resistance. It is well known that crosslinking is the most effective and reliable means to improve However, it cannot be crosslinked (cured) by a simple procedure as with ordinary thermosetting resins. Therefore, methods such as using special catalysts and blending thermosetting resins have been proposed.

As an example of the former, there is a proposal to use a metal alcoholade, and as an example of the latter, there is a proposal to mix a polyfunctional maleimide or a polyfunctional cyanate ester with an epoxy compound. (Japanese Unexamined Patent Publication No. 143320/1983). However, especially in the latter method, there were drawbacks such as deterioration of the intended performance and poor adhesion to metal foil.

Radiation crosslinking has been attempted as a crosslinking method different from the above. There are already published documents regarding this technology, and it has also been summarized by Mitsuyuki Yamagami (Osaka Central Research Institute for Radiation Research). However, there are limits to the resins that can be crosslinked by radiation, and not all resins can be crosslinked. Therefore, there have been no successful cases of producing a resin that has satisfactory performance from the viewpoints of adhesion to metal foil and high frequency properties and is capable of radiation crosslinking.

Under these circumstances, conventionally it has not been possible to easily obtain a metal foil-clad laminate with excellent high frequency characteristics and heat resistance.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a metal foil-clad laminate that can easily produce a metal foil-clad laminate with excellent high frequency characteristics and heat resistance.

[Disclosure of the invention]

The inventors decided to use polyphenylene oxide as a material, which is not crosslinked by radiation but has excellent high frequency properties, and without impairing the properties of this material,
Research has been carried out in an attempt to achieve the above objective by improving heat resistance.

As a result, we decided to use a sheet made of polyphenylene oxide, a resin with good radiation crosslinking properties for polyphenylene oxide, and a resin composition containing a radiation crosslinking aid, and after heat lamination molding of this sheet and metal foil,
They discovered that it is sufficient to cause a crosslinking reaction by irradiating them with radiation, and have now completed this invention.

Therefore, this invention provides polyphenylene oxide,
The gist is a method for producing metal foil-clad laminates in which a sheet and metal foil made of a resin composition containing a resin with good radiation crosslinking properties and a radiation crosslinking aid for polyphenylene oxide are heated and laminated, and then radiation is irradiated. .

The present invention will be explained in detail below.

Here, polyphenylene oxide (hereinafter, FPPOJ
For example, poly (2,6-cymethyl-1,4
-phenylene oxide).

Such a PPO may be, for example, USP 4.05
It can be synthesized by the method disclosed in No. 9568. Although not particularly limited, for example, the molecular weight (MW) is 50000, M w 7M n = 4
．． 2 polymers are preferably used.

Examples of resins with good radiation crosslinking properties for PPO include, but are not limited to, 1-2-
Polybutadiene, 1,4-polybutadiene, styrene-butadiene copolymer, modified 1,2-polybutadiene (malein-modified, acrylic-modified, epoxy-modified), rubbers, etc., and resins with particularly excellent radiation crosslinking properties include, for example, Examples include polyethylene, polyvinyl acetate, polyacrylate, polybutadiene, nylon, polyparamethylstyrene, and the like. Among these, when polyparamethylstyrene is used, a laminate with excellent properties can be obtained. In addition, as a radiation crosslinking aid,
For example, ■Ester acrylates, epoxy acrylates, urethane acrylates, and ether acrylates.

Acrylic acids such as melamine acrylates, alkyd acrylates, silicone acrylates, ■Multifunctional monomers such as triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, divinylhenzene, diallyl phthalate, ■vinyltoluene, ethylvinyl Examples include monofunctional monomers such as benzene di-styrene and polyparamethylstyrene, and polyfunctional epoxy monomers, but are not particularly limited to these.

As a radiation crosslinking aid, triallyl cyanurate or triallyl isocyanurate is used for PPO.
The radioactive crosslinking aid used here, such as triallylisocyanurate, has very good radiation crosslinking properties, and is preferable in terms of film forming properties, crosslinking properties, heat resistance, and dielectric properties. 50 M r a d
The degree of crosslinking increases to 90% by irradiation of . Since polyphenylene oxide is not a crosslinked type, crosslinking does not occur alone. By using a resin with good radiation crosslinkability and a radiation crosslinking aid in combination with ppo, a radiation crosslinkable resin composition can be obtained.

The blending ratio of the above raw materials is not particularly limited, but it is preferable that the proportion of the resin with good radiation crosslinking properties is 5 to 80% by weight and the radiation crosslinking aid is 1 to 20% by weight to 20 to 90% by weight of polyphenylene oxide. preferable. Further, although not particularly limited, it is preferable to use a resin having good radiation crosslinkability in a ratio of 20 parts by weight or less per 1 part by weight of the radiation crosslinking aid.

In addition, an initiator is usually used in the resin composition. As an initiator, dicumyl peroxide, ter
t-butylcumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di-tert
er tert-butylperoxyhexane-3,2,5-dimethyl-2,5-diter t-butylperoxyhexane, α・α′-bis(tert-butylperoxy-m-isopropyl)benzene [1・4 (or 1・
3)-Bis(tert-butylbaronitrifluoride diisopropyl) Hensen] peroxide. In addition, hengeine, hensyl, allyl diazonium fluorophosphate, hensyl methyl ketal, 2,2-she 1
-xyacetophenone, hendyl isobutyl ether, p-tert-butyltrichloroacetophenone, hensyl (0-ethoxycarbonyl)-α-monoxime, hyacetyl, acetophenone, hensyphenone, tetramethylthiuram sulfite, azobisisobutyronitrile, hensyl Peroxide, 1-hydroxycyclohexylphenyledone, 2-hydroxy-2=methyl-1-phenyl-propan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1- 1, 2-chlorothioxanthone, methylhenzoyl formate, 4,4-bisdimethylaminohensiphenone (Michler's ketone), henzoin methyl ether, methyl-〇-henzoylhenzoate, α-
Examples include aziroxime ester. A commercially available initiator that is not a peroxide is ``Biscumil'' manufactured by NOF, which is prepared by the following formula. This one has a temperature of 3.
It is 30°C.

The resin composition is usually obtained from the raw materials by blending or solution mixing. Blen 1' is 260~
Preferably it is carried out at a temperature of 300°C. The means used for blending is not limited, but examples include a Banbury mixer, a single-screw or twin-screw extruder, and a heating kneader. The kneading time in these devices is usually about 2 to 15 minutes. However, the kneading time is not limited to this.

In this invention, a laminate is made using a sheet (including a film) made of the resin composition as described above. The sheet is
For example, it can be made by a casting method.

To describe the casting method in detail, the resin composition is mixed with a single or mixed solvent selected from 1 to chlorinated hydrocarbons such as ricrene, chloroporum, carbon tetrachloride, and methylene chloride, and/or xylene, toluene, Hensen, and acetone. The solution is completely dissolved in a proportion of ~50% by weight, spread on a mirror-treated iron plate or casting film to a thickness of 5 to 500 μm, and thoroughly dried to obtain a PPO sheet. The casting film is preferably one that is insoluble in the solvent, such as a polyester film or a polyimide film, and that has been subjected to a mold release treatment.

Sheets of a predetermined thickness formed by a casting method or the like are laminated together with a predetermined number of metal foils to achieve a predetermined design thickness, and the resin is melted by heating and pressing, etc., so that the sheets are bonded together.
The sheet and metal foil are adhered to each other to obtain a laminate. Strong adhesion is obtained by this fusion, but even stronger adhesion can be obtained by subsequent radiation irradiation. As the metal foil, copper foil, aluminum foil, etc. are used.

Since pressing is performed to join the metal foil and sheet and to adjust the thickness, the pressing conditions are selected as necessary. For example, temperature 150-300℃, pressure 50kg/cm"
, the time is about 10 to 60 minutes.

Alternatively, a predetermined number of sheets may be heated and laminated in advance, metal foil may be superimposed on one or both sides of the sheets, and the sheets may be heated and pressed again.

The overall thickness of the laminate obtained in this way is not particularly limited, but it is preferably about 0.2 to 2 x*, and about 0.6 to 0.8 m1
It is more desirable for circuit design.

Radiation (β rays, γ rays,
rays, etc.) to cause a crosslinking reaction. The amount of radiation irradiated is preferably 10 to 70 Mrad, preferably 40 to 60 Mrad, although it depends on the resin composition. Here, since the metal foil usually has a thickness of about 18 to 50 μm, it has almost no effect on irradiation. In order to take advantage of the excellent thermal adhesive properties of polyphenylene oxide, the adhesive interface can also be crosslinked by heat-sealing the metal foil to the sheet in advance and then irradiating it with radiation η-j rays. Therefore, adhesion with excellent heat resistance can be realized between the sheet 1- and the metal foil.

The metal foil-clad laminate thus obtained does not impair the properties of polyphenylene oxite, has excellent high frequency properties such as dielectric properties, and has excellent heat resistance. The manufacturing operation is also simple as described above.

Next, Example 1 to explain Examples and Comparative Examples
11 and Comparative Examples 1 to 5, resin compositions containing the raw materials shown in Tables 1 and 2 were used. In Tables 1 and 2, SBS is styrene-butadiene copolymer, 1,2-PBu is 1,2-polybutadiene, TAIc is triallylisocyanure-+-, r
) CP is dicumyl peroxide, A is tert-butyl cumyl peroxide, B is di-tert-phthyl peroxide [-10 is 2,5-dimethyl-2,5-
Di-tert-butylperoxyhexane-3,D is 2,5-dimethyl-2,5-di-tert-butylperoxyhexane, E is α・α′-bis(tert-butylperoxy-m- isopropyl) Hensen respectively. SBS is Asaprene manufactured by Asahi Kasei Industries, Ltd.]
・2-P B IJ is manufactured by Nippon Soda Co., Ltd., T
AIC manufactured by Nippon Kasei Co., Ltd. was used.

(Margin below) A resin composition was produced as follows. The blended raw materials were dissolved in trichlene to make a 30% by weight solution, and the mixture was sufficiently stirred in a reactor equipped with a defoaming device until a homogeneous solution was obtained. Thereafter, defoaming was performed to obtain a solution blend.

In Examples 1 to 11 and Comparative Examples 1 to 13, films (sheets) were made using the resin compositions in the following manner. First, it was coated onto a polyethylene terephthalate (PET) film to a thickness of 400 μm using a coating machine. It was air-dried as it was and dried at 50°C. The produced film was peeled off from the PET film and further heated at 120°C for 30
After drying for a minute, the film-like resin solidified product (thickness approximately 100μ
m) was obtained. In Comparative Examples 14 and 15, a film could not be obtained even if the same operation was performed.

In Examples 1 to 11, 10 films obtained as described above were laminated and formed into a size of 200 x 200 ml, and then copper foil with a thickness of 35 μm was layered on the top and bottom surfaces, and the temperature was 240° C. and the pressure was 50 kg. / cm” for 30 minutes.The obtained laminate was then compressed with 30 Mr.
A double-sided copper-clad laminate was obtained by irradiating with ad electron beams (β rays). In Comparative Examples 1 to 13, double-sided copper-clad laminates were obtained in the same manner as in Examples 1 to 11, except that the electron beam was not irradiated.

The physical properties of the copper-clad laminates obtained in Examples 1 to 11 and Comparative Examples 1 to 13, including resistance to cold beer, solder heat resistance, insulation resistance, dielectric constant, and dielectric loss tangent, were measured. The dielectric constant and dielectric loss tangent were according to the US Army Inspection Standard (MIL).

The measurement results are shown in Tables 1 and 2.

From Tables 1 and 2, when comparing sheets using the same type of sheets, the copper-clad laminates obtained in Examples 1 to 11 were found to be as follows: It can be seen that although the high frequency characteristics of dielectric constant and dielectric loss tangent, and insulation resistance were at the same level, the soldering heat resistance and room temperature beer resistance were improved due to radiation irradiation.

〔Effect of the invention〕

The method for manufacturing a metal foil-clad laminate according to the present invention involves heat lamination molding of a sheet made of a resin composition containing polyphenylene oxide, a resin with good radiation crosslinking properties for polyphenylene oxide, and a radiation crosslinking aid, and a metal foil. Since the method is irradiated with radiation, a metal foil-clad laminate with excellent high frequency characteristics and heat resistance can be easily obtained.

Claims (5)

[Claims] (1) A sheet made of polyphenylene oxide, a resin with good radiation crosslinking properties for polyphenylene oxide, and a resin composition containing a radiation crosslinking aid, and a metal foil are heat laminated and then irradiated with radiation. Manufacturing method. (2) The method for producing a metal foil-clad laminate according to claim 1, wherein the sheet is produced by a casting method. (3) The resin composition contains 20% polyphenylene oxide.
The metal foil-clad laminate according to claim 1 or 2, which contains a resin with good radiation crosslinking properties in a proportion of ~90% by weight, a resin with good radiation crosslinking properties in a proportion of 5 to 80%, and a radiation crosslinking aid in a proportion of 1 to 20% by weight. Manufacturing method. (4) The resin with good radiation crosslinkability is at least one selected from the group consisting of 1,2-polybutadiene, 1,4-polybutadiene, styrene-butadiene copolymer, modified 1,2-polybutadiene, and rubbers. A method for manufacturing a metal foil-clad laminate according to any one of claims 1 to 3. (5) The radiation crosslinking aid is ester acrylates, epoxy acrylates, urethane acrylates, ether acrylates, melamine acrylates, alkyd acrylates, silicone acrylates, triallyl cyanurate, triallyl isocyanurate, ethylene glycol di Claims 1 to 4 are at least one selected from the group consisting of methacrylate, divinylbenzene, diallylphthalate, vinyltoluene, ethylvinylbenzene, styrene, polyparamethylstyrene, and polyfunctional epoxies. A method for producing a metal foil-clad laminate according to any of the preceding paragraphs.