JPH0788086B2 - Method for manufacturing metal-clad laminate for high frequency - Google Patents

Description

The present invention relates to a substrate for electronic equipment, particularly a dielectric substrate used in a high frequency region, a dielectric substrate preferably used for microwave reception, and the like. The present invention relates to a high-frequency metal-clad laminate.

[Conventional technology]

Frequencies used in recent fields of the electronic industry and the communication industry are gradually shifting to the high frequency region, and the importance is shifting from the conventionally frequently used region of kilohertz to the region of megahertz or gigahertz. In these high-frequency regions, transmission energy loss tends to be large, and the non-dielectric constant (hereinafter εr) and dielectric loss tangent (hereinafter tan δ)
Smaller dielectric substrates have become desirable.
A planar antenna for microwave reception has a circular or rectangular resonator (radiator) made of copper foil, etc. or a microstrip line on one side of the dielectric layer, and a metal plate or other ground on the other side. It is composed of a plate-shaped substrate on which conductors are arranged, and the resonator is arrayed in order to obtain desired gain and directivity. The dielectric substrate used is required to have small εr and tan δ and good high frequency characteristics. As a substrate satisfying these requirements, the present inventors have proposed Japanese Patent Application No. 61-204062.
Proposed a method in which a powder such as polyolefin is sintered and a dispersed sintered body of powder and air (plastic powder sintered porous body) is used as a dielectric layer. This method has a smaller εr and tan δ than the case where a resin such as polyethylene, polypropylene and polytetrafluoroethylene is used as the dielectric layer, and the high frequency characteristics are good.

[Problems to be Solved by the Invention]

As shown in FIG. 2, the metal-clad laminate using the sintered plastic powder porous body as a dielectric layer has a metal foil (a) on both sides or a metal foil on one side and a metal plate (b) on the other side and an adhesive layer. And a dielectric layer. These metal-clad laminates are produced by forming a plastic powder sintered porous body in advance and pressing or laminating with a metal foil or a metal plate via an adhesive layer. The press molding is performed by a batch method in which constituent materials are cut into a certain size, laminated in a predetermined order, and heated and cooled under pressure, and there is a problem that the number of steps is large. In addition, the laminate molding has a problem in moldability such as wrinkles, wrinkles, and blisters on the metal foil during molding.

The present invention provides an improved method for producing a metal-clad laminate using a plastic powder sintered porous body as a dielectric layer, which does not have these problems.

[Means for Solving the Problems]

According to the present invention, an adhesive layer is provided on a metal foil or a metal plate, plastic powder is sprinkled and supplied on the adhesive layer, and after shaping to a certain thickness, heating and sintering is performed to obtain a plastic powder sintered porous body. The present invention relates to a method for producing a metal-clad laminate, which comprises laminating an adhesive layer and a metal foil or a metal plate on the adhesive layer after the formation. Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 shows an example of an apparatus for forming a plastic powder sintered porous body on a metal foil provided with an adhesive layer, which is obtained by laminating or coating the adhesive layer on a metal foil or a metal plate in advance. Along with the endless metal belt of 6, the metal foil base material with the adhesive layer of 5 was formed into a constant thickness with the plastic powder of 8 on the adhesive layer side of 5 with the cattle-nose coater of 7, and the heating furnace of 9 was used. Heating and sintering are performed, and the sheet 10 having a plastic powder sintered porous body formed on the metal foil with an adhesive layer is wound up. Then, on the wound sheet, an adhesive layer and a metal foil or a metal plate are laminated at the same time, or a sheet obtained by laminating or coating an adhesive layer on the metal foil or a metal plate in advance is laminated or press-molded. To produce a metal-clad laminate. The sheet density of the plastic powder sintered porous body obtained by sintering depends on the sintering temperature and the sintering time. The higher the temperature and the longer the time, the higher the density of the sheet. However, the change in density of the sintered sheet with respect to the sintering time becomes dull as the density increases. Therefore, from the economical point of view, a solid content of 90% or more, that is, a porosity of less than 10% is not preferable because it takes a long time to produce a sheet, requires a large amount of energy, and requires a large manufacturing facility. When used as a dielectric layer of a high-frequency metal-clad laminate, it is required to have low εr and low tan δ, as described above, so the porosity is preferably 10% or more, more preferably 20% or more. 60
%.

The plastic powder is used as it is without being dispersed in a liquid dispersion medium.

The plastic powder used includes thermoplastic resin powder and thermosetting resin powder. For example, polyethylene,
Homopolymer such as polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene-propylene copolymer, ethylene-1-butene copolymer, propylene-1-butene copolymer, ethylene- Polyolefin resin such as polyolefin copolymer such as vinyl acetate copolymer, polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkoxyethylene copolymer, trifluorochloroethylene -Tetrafluoroethylene copolymer, polyvinylidene fluoride, polyvinyl fluoride and other fluorine-based resins, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, polycarbonate, polymethylmethacrylate Various acrylate etc., polyvinyl butyral, polyvinyl formal, polyimide, polyamide, polyamideimide, polyphenylene sulfide, polyether sulfone, polysulfone, polyarylate, polyether ether ketone, polyphenylene oxide, polyether amides, polyether imides,
Polyisobutylene, polyoxybenzylene, polybutylene terephthalate, polybutadiene, polyester, polyvinyl chloride, polyvinylidene chloride, urea resin, melamine resin, benzoguanamine resin, phenol resin, epoxy resin, silicone resin, formalin resin, xylene resin, furan resin , Diallyl phthalate resin, polyisocyanate resin, phenoxy resin and the like, which may be appropriately modified. Further, a mixture or a copolymer of these composites may be used, and if necessary, a crosslinking agent, a curing agent and an additive may be used as a main component. Further, these plastic powders can be used by being coated with another resin.

Plastic powders are also used as a mixture of several types.

The thermosetting resin may have any degree of curing as long as it does not hinder the adhesion to the adjacent particles.

Thus, either thermoplastic or thermosetting can be used, but thermoplastic resins are preferred. This is because adjacent powder particles are easily fused by heating.

When used as a dielectric layer of a high frequency metal-clad laminate, a polyolefin resin having a small number of polar groups and a low εr or tan δ is preferable. For example, polyethylene, polypropylene, or their cross-linked products, modified products, and copolymers are preferable.

Metal foils and plates are conductors with low electrical resistance, such as gold, silver,
Copper, aluminum, nickel and the like are preferable, and copper and aluminum are preferable. Further, a metal foil or a metal plate whose both surfaces are smooth is preferable.

When the adhesive layer contains many polar groups in its structure, εr and tan δ
Can be high. In such a case, it is desirable that the thickness of the adhesive layer be the minimum necessary.

Examples of the adhesive for the adhesive layer include acrylic resin, polyester resin, polyurethane resin, phenol resin, epoxy resin, chloroprene rubber, nitrile rubber, epoxy phenol, butyral phenol, and nitrile phenol. Further, as an adhesive film, (I) ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, ethylene-acrylic acid copolymer, ethylene-maleic acid copolymer, ethylene-maleic anhydride grafted copolymer Α, β-unsaturated carboxylic acid to polyolefin such as polymer, ethylene-glycidyl methacrylate-vinyl acetate terpolymer, ionomer polymer, etc.
Or a copolymer obtained by ordinary copolymerization or graft copolymerization of an ester thereof, an anhydride thereof or a metal salt thereof, or a saturated organic carboxylic acid, (II) a mixture of a polyolefin and the copolymer (I), ( III) Adhesive compounds obtained by compounding a polyolefin with a tackifier and the like.

In particular, the adhesive layer is preferably an adhesive film that is easy to handle.

[Action]

Compared with the conventional method of manufacturing a metal-clad laminate by press molding by forming a plastic powder sintered porous body on a metal foil with an adhesive layer or a metal plate, the time required to cut the constituent materials of the laminate into a certain size Can be simplified, the number of steps can be reduced, and foreign matter such as fiber waste adhering to the material when cutting can be reduced. Further, in laminating molding, the phenomenon such as wrinkles, wrinkles, and blistering that occurs during lamination is eliminated, and the moldability is improved. This is because the number of laminated layers is reduced, the inclusion of air, which causes blistering, is eliminated, and the plastic powder-sintered porous body, the adhesive layer, and the metal foil or metal plate are pre-laminated. There are no wrinkles or blisters on the surface, and when laminating this with an adhesive layer or metal foil or metal plate to be further laminated, the laminating pressure may be small, so the ironing by the laminating roll is small and wrinkles and wrinkles do not occur. Disappear.

〔Example〕

Example Using the apparatus shown in FIG. 1, an adhesive film, Nucrel 0908C (trade name of Mitsui DuPont Chemical Co., Ltd.), which serves as an adhesive layer on an oxygen-free copper foil OFC-ACE foil (trade name of Hitachi Cable Co., Ltd.) of 35 μm in advance. A base material 5 laminated with ethylene methacrylic acid copolymer resin, 25 μm is placed along a stainless steel belt (width 800 mm) 6, and a plastic powder 8 is applied to a constant thickness on the adhesive layer of 5 with a cow-nose coater 7. A sheet in which a plastic powder-sintered porous body is formed on a metal foil with an adhesive layer by shaping and heating in a heating furnace 9 and sintering.
Rolled up 10. As the plastic powder 8, polyolefin resin powder, MIPERON XM-220 (ultra high molecular weight polyethylene powder, trade name of Mitsui Petrochemical Industry Co., Ltd.,
An average particle size of 0.03 mm and a melting point of 136 ° C.) was used, and the density of the sintered plastic powder porous body was 0.5 g / cm ³ and the thickness was 0.7 mm. As shown in FIG. 3 (a), the wound sheet 10 has an adhesive film, Nucrel 0908, as an adhesive layer.
An aluminum plate (1 mm ^t ) which is a metal plate was preliminarily laminated with C and laminated to obtain a metal-clad laminate.

Comparative Example Using the device shown in FIG. 1, plastic powder (Mipelon XM-220) 8 was directly applied onto the stainless steel belt 6.
Was molded into a uniform thickness, heated in a heating furnace 9 and sintered to produce a plastic powder sintered porous body sheet having a density of 0.5 g / cm ³ and a thickness of 0.7 mm. As shown in Fig. 3 (b), this sheet is a 35 μm oxygen-free copper foil OFC-ACE foil and adhesive film, Nucrel 0908C and an aluminum plate (1 m
adhesive film m ^t), a 4-layer although laminated with NUCREL 0908C, to obtain a laminated metal-clad laminate under the same conditions as in Example.

Table 1 shows the number of occurrences of 50 cm square metal-clad laminates, 50 blisters, wrinkles, and lines produced in Examples and Comparative Examples, respectively.

[Effects of the Invention] According to the production method of the present invention, since the plastic powder sintered porous body is formed on the metal foil with an adhesive layer, when producing a metal-clad laminate by laminating, blisters and wrinkles are formed. It is possible to efficiently produce a metal-clad laminate having a good appearance with almost no generation of streaks. Also,
In press molding, according to the present invention, three layers of the metal foil or metal plate, the adhesive layer, and the plastic powder sintered porous body are formed, so that the labor of cutting into a certain size can be simplified and the number of steps can be reduced. At the same time, it is possible to reduce the inclusion of foreign matter such as fiber waste adhering to the material at the time of cutting, and prevent the deterioration of the appearance and the characteristics due to the inclusion of foreign matter.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an apparatus for producing a plastic powder sintered porous body, FIGS. 2 (a) and 2 (b) are configuration diagrams of a metal-clad laminate, and FIGS. 3 (a) and 3 (b). [Fig. 3] is a schematic diagram for producing a metal-clad laminate by a laminating method. Explanation of symbols 1. Metal foil, 2. Adhesive layer (adhesive film) 3. Plastic powder sintered porous body 4. Metal plate, 5. Metal foil base material with adhesive layer 6. Metal belt, 7. Cattle-nose coater 8 .Plastic powder 9. Heating furnace 10. Sheet of plastic powder sintered porous material formed on metal foil with adhesive layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Arai 1500 Ogawa, Shimodate, Ibaraki Shimodate Research Laboratory, Hitachi Chemical Co., Ltd. Shimodate factory

Claims (3)

[Claims] 1. A plastic powder sintered porous body comprising a metal foil or a metal plate provided with an adhesive layer, spraying and supplying plastic powder on the adhesive layer, shaping the adhesive powder to a predetermined thickness, heating and sintering. The method for producing a metal-clad laminate, which comprises laminating an adhesive layer and a metal foil or a metal plate thereon after forming the. 2. The method for producing a metal-clad laminate according to claim 1, wherein the plastic powder is a polyolefin resin. 3. The method for producing a metal-clad laminate according to claim 1, wherein the adhesive layer is an adhesive film.