JPH0588558B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a circuit board used in a high frequency electric circuit. [Background Art] The development of electronic devices in recent years, especially in the field of telecommunications, has been remarkable. And its development is nothing but the accumulation of efforts to develop higher frequencies, or in other words, shorter wavelengths. That is, when electromagnetic waves are used for communication, the use of higher frequency waves allows for a wider frequency band and therefore allows for the transmission of a larger amount of information. Another advantage is that as the frequency increases, the wavelength decreases inversely, making it possible to create smaller, higher-performance antennas. By the way, the substrate of such an electric circuit intended for high frequencies is required to be made of a heat-resistant material with a low dielectric constant and low dielectric loss. In other words, at high frequencies, the propagation speed of an electric signal increases as the dielectric constant of the circuit board decreases, and the attenuation of the electric signal requires a material with low dielectric loss and heat resistance for the circuit board. That is, at high frequencies, the propagation speed of an electrical signal becomes faster as the dielectric constant of the circuit board is smaller, and the attenuation of the electrical signal becomes smaller as the dielectric loss of the circuit board becomes smaller. Therefore, the smaller the dielectric constant and dielectric loss of the material, the higher the speed and the lower the SN. In addition, in the process of manufacturing electrical circuits, temperatures exceeding 200°C are applied during solder dipping and soldering operations, so it is required to have enough heat resistance to prevent deformation even at such temperatures. Under these circumstances, substrates using various materials are currently being proposed, including substrates made of fluororesin, epoxy resin, polyimide, polypropylene, and the like. However, fluororesin has problems in that it has poor adhesion to the metal that forms the conductive layer, has low rigidity, and is extremely expensive. Epoxy resins or polyimides have conventionally been used as circuit boards for low frequencies and medium waves, but their dielectric constant and dielectric loss are too large to be used for high frequencies, making them unsuitable. Although polypropylene has excellent dielectric constant and dielectric loss, it lacks heat resistance and is easily deformed. As described above, the high-frequency electric circuit boards that have been proposed in the past have advantages and disadvantages, and no one is known that exhibits excellent performance in all aspects. [Problems to be Solved by the Invention] Therefore, the present inventor investigated the possibility of providing an electric circuit board suitable for high frequency use, and found that the purpose could be achieved by using a specific polymer as the board material. . [Means for Solving the Problems] That is, the present invention provides a polymer layer containing at least a monomer component represented by formula (1) and having a structure represented by formula (2) in which the monomer component is conductive. This is a high frequency electric circuit board made up of laminated layers.

【formula】 [Effect]

The polymer constituting the circuit board of the present invention contains a monomer component represented by the above-mentioned formula (1), and in the polymer, the monomer component mainly has a structure represented by formula (2). It's on. A preferred embodiment of such a polymer is a copolymer comprising the monomer component of formula (1) and an α-olefin and/or a cyclic olefin other than formula (1). formula as a component
Examples include those containing the monomer (1) and ethylene. In the polymer, the monomer component of formula (1) is at least 2
It should contain mol% or more, but when ethylene is coexisting, the molar ratio of ethylene/monomer component of formula (1) is preferably in the range of 5/95 to 95/5, particularly 40/60 to 90/10, Furthermore, when α-olefins or chain dienes other than ethylene, or cyclic olefins or cyclic dienes other than formula (1) such as ethylidene norbornene, dicyclopentadiene, etc. are present, the total amount of these monomers/monomer component of formula (1) molar ratio of 5/95 to 95/5, especially 30/70 to 90/
A range of 10 is preferred. In addition, in the present invention, formula (1)
Of course, the monomer component may not only be used alone, but also a mixture of a plurality of components represented by formula (1) may be used. Specific examples of the monomer component represented by formula (1) include the following; however, the examples shown here are extremely limited; Anything can be a monomer component of the present invention.

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[Formula] Among these, n=1 in formula (1), that is, formula (3),

Monomer components represented by the following formula are preferred in terms of ease of monomer availability or monomer synthesis. In order to produce the above-mentioned monomer components, it is possible to apply, for example, the method disclosed in US Pat. For example, to produce the monomer component of formula (3), cyclopentadiene is condensed with norbornene as shown in the following formula.

[Chemical formula] The monomer components shown by formula (1) other than formula (3) are basically applications of the above condensation reaction, and the only difference is in the starting materials. The α-olefin that can be copolymerized with the monomer component of formula (1) has 2 to 20 carbon atoms, preferably 2
~10 α-olefins, such as ethylene, propylene, 1-butene, 3-methyl-1-
Butene, 1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene,
1-octene, 1-decene, 1-dodecene, 1-
Examples include tetradecene, 1-hexadecene, and 1-icosene. Among these, ethylene is particularly preferred from the viewpoint of copolymerizability, and can also be used when copolymerizing other α-olefins (having 3 or more carbon atoms) or cyclic olefins or cyclic dienes described below with the monomer component of formula (1). , copolymerizability is better in the presence of ethylene. Cyclic olefins and cyclic dienes other than formula (1) which are other components that can be copolymerized with the monomer component of formula (1), such as cyclopentene, cyclohexene, 3,4-dimethylcyclopentene, 3-methylcyclohexene, 2-( 2-methylbutyl)-1
-Cyclohexene, styrene, α-methylstyrene, 3a,5,6,7a-tetrahydro-4,7-
Methanol-1H-indene, dicyclopentadiene,
Examples include ethylidenenorbornene and vinylnorbornene. Furthermore, in addition to the monomer components described above, the polymer may contain a small amount of other copolymerizable monomer components within a range that does not impair the object of the present invention. The polymer is produced by polymerizing the monomer component of formula (1) or the monomer component of formula (1) and α-olefin and/or cyclic olefin, etc., which have been explained in detail above, using a well-known Ziegler catalyst, particularly a vanadium-based Ziegler catalyst. Manufactured by More details are disclosed in the applicant's prior patent application (for example, Japanese Patent Application No. 16995/1982). A feature of the polymer is that the monomer component of formula (1) mainly has the structure shown by formula (2) in the polymer, and as a result, the iodine value of the polymer is usually 5 or less.
Many are 1 or less. Also, taking this structure
This is also supported by ¹³ C-NMR.

〔effect〕

The high-frequency electric circuit board of the present invention having the above-described structure has a small dielectric constant, which increases the propagation speed of high-frequency electric signals, and a small dielectric loss, which reduces the attenuation of electric signals, thereby increasing the speed of information transmission. can be achieved, and high-sensitivity reception of weak signals can also be achieved. Because it has high heat resistance, it does not soften, melt, or deform during the heating and pressing process in circuit board manufacturing. Therefore, the thickness of the circuit board can be accurately controlled. Excellent solder resistance. It has low water absorption and can stably exhibit excellent electrical properties over a long period of time. Excellent dimensional stability. It has the following characteristics. Therefore, various circuit boards, flat antennas,
Can be used for housing-integrated boards, flexible boards, etc. [Example] Examples of the present invention will be shown below, including preferred examples, but unless otherwise specified, the content of the present invention will be as follows.
The invention is not limited to these examples in any way. Example 1 Using a two-glass polymerization vessel equipped with stirring blades,
Continuously ethylene and 2-methyl-1,4,5,8
-dimethano-1,2,3,4,4a,5,8,8a
- A copolymerization reaction of octahydronaphthalene (hereinafter abbreviated as M-DMON) was carried out. That is, a toluene solution of M-DMON is added at 0.9 g/hour so that the concentration of M-DMON in the polymerization vessel is 60 g/hour from the top of the polymerization vessel.
, the vanadium concentration in the polymerization vessel is 0.5 mmol/
A toluene solution of VO(OC ₂ H ₅ )Cl is added at a rate of 0.7 per hour so that the aluminum concentration in the polymerization vessel is
A toluene solution of ethylaluminum sesquichloride (Al(C ₂ H ₅ ) _1.5 Cl _1.5 ) was continuously fed into each polymerization vessel at a rate of 0.4 mmol/hour. On the other hand, the polymer solution is continuously drawn out from the lower part of the polymerization vessel so that the polymerization liquid is always at 1 level in the polymerization vessel. Additionally, ethylene is supplied from the top of the polymerization reactor at a rate of 23 mph and nitrogen at a rate of 80 mph. The copolymerization reaction was carried out at a controlled temperature of 10°C using a refrigerant. A small amount of methanol was added to the polymer polymerization liquid taken out from the bottom of the polymerization vessel to stop the polymerization reaction, and the resulting copolymer was poured into a large amount of inpropyl alcohol to precipitate the resulting copolymer, which was washed with isopropyl alcohol. At this time, the copolymer was obtained at a rate of 30 g/hour. After drying under reduced pressure at 130℃ overnight, 0.1wt% of Irganox 1010 was added as a stabilizer.
Zinc stearate was added at 0.07wt% and granulated at 260°C using a 20mmφ extruder manufactured by Thermoplastics. The ethylene composition of the copolymer according to ¹³ C-NMR analysis was 53 mol%, and the intrinsic viscosity [η] measured in decalin at 135°C was 1.05 dl/g.
Glass transition temperature (Tg) measured by mechanical analyzer (DMA) is 145℃, dielectric constant and dielectric loss tangent (1M
Hz) were 2.1 and 1.1×10 ^-4 , respectively, and the thermal decomposition temperature (Td) was 380°C. The density was 1.032g/cm ³ . The resin obtained in this way was heated to
A sheet with a thickness of 1.5 mm and a width of 20 cm was produced at 280°C. Electrolytic copper foil (35 μm thick) manufactured by Mitsui Kinzoku Mining Co., Ltd. was pasted on both sides of this sheet (10 cm x 10 cm).
It was fused using a press molding machine at ℃. The dielectric constant and dielectric loss of double-sided copper clad plate are respectively
2.1, 1.2×10 ^-4 and the peel strength was 1.0 Kg/cm. This copper-clad plate was coated with a photoresist (Fuji Gosei Kagaku Kenkyusho No. 200), and a fine pattern was formed in an alkaline developer and etching treatment (saturated ferric chloride solution). As a result, a fine pattern of 1 μm or less could be formed. Example 2 1,4,5,8-dimethano-1.2.3.4.4a,5, instead of M-DMON in the polymerization of Example 1
8,8a-octahydronaphthalene

[Formula] DMON) was used in the same manner. As a result, the ethylene composition was 55 mol%, [η] 0.95
dl/g, Tg140℃, dielectric constant, 2.1, dielectric loss tangent 1.0×
10 ^-4 , Td 370°C, and density 1.048 g/cm ³ . In addition, the peel strength of the double-sided copper clad board is 0.9Kg/cm, the dielectric constant is 2.1,
The dielectric loss tangent was 1.1×10 ^-4 . Example 3 6-ethylbicyclo[2,2,1]hept-2 instead of M-DMON in the polymerization of Example 1
−en (

[Formula] EBH) was used in the same manner. As a result, ethylene 60 mol%, [η] 1.3
dl/g, Tg 102°C, and density 1.021 g/cm ³ . The dielectric constant and dielectric loss tangent were 2.1 and 1.2×10 ^-4 , respectively, and Td was 390°C. The peel strength of the double-sided copper clad plate was 0.9 Kg/cm, the dielectric constant was 2.1, and the dielectric loss tangent was 1.3×10 ^-4 . Example 4 Maleic anhydride was graft copolymerized to the polymer of Example 1 to obtain a modified product having a maleic anhydride content of 1.5 wt%. This polymer was replaced with the polymer of Example 1,
It was mixed at 10wt%, formed into a sheet, and fused with copper foil on both sides. The dielectric constant of double-sided copper clad plate is 2.2, and the dielectric loss tangent is
It was 4.4×10 ^-4 . In addition, the peel strength is 1.3Kg/cm
It was hot. Example 5 The modified product of Example 4 was applied to the back surface (uneven surface) of copper foil.
It was coated to a thickness of 10 μm (coating was done with a cyclohexane solution). This copper foil was fused to the sheet of Example 1 using a press molding machine. The dielectric constant of the double-sided copper foil plate was 2.1, and the dielectric loss tangent was 1.8×10 ^-4 . Moreover, the peel strength was 2.1 kg/cm. Example 6 The polymer of Example 1 was dissolved in cyclohexane,
Glass cloth for printed circuit boards was impregnated and dried. 6 layers of polymer-impregnated glass cloth,
Press bonded at 260℃, Young's modulus is 8x at thickness 1.5mm
A highly rigid body of 10 ¹⁰ dyne/cm ² was obtained. Thereafter, copper foil treated as described in Example 5 was adhered to both sides of the laminate. As a result, the dielectric constant of double-sided copper clad plate is 2.8,
The dielectric loss tangent was 5.3×10 ⁻⁴ and the peel strength was 2.1 Kg/cm. Example 7 Using the sheet of Example 1, a circuit was formed by screen printing using a conductive paint (Dotite FA-705) manufactured by Fujikura Kasei Co., Ltd., and cured at 130° C. for 1 hour. Adhesion was sufficiently high. Example 8 The polymer of Example 1 was grafted with aleic acid (2.0 wt%), dissolved in a cyclohexane/toluene = 50/50 Vol% solution with copper powder (approximately 400 mesh), an antioxidant, and a viscosity modifier to form a paint. And so. This paint was printed on the sheet of Example 1 (20μ thick) by screen printing. After drying, the peel strength was measured and found to have sufficient strength. Example 9 Using the circuit board formed in Example 8, a 2 μ thick copper layer was further formed on the paint by electroless plating.
For the plating liquid, use the copper plating liquid manufactured by Okuno Pharmaceutical Co., Ltd.
℃ for 20 minutes. In this case, when the dielectric constant and dielectric loss tangent were measured, they were 2.2 and 1.6×10 ⁻⁴ .

Claims (1)

[Scope of Claims] 1. A high-frequency electric device comprising a conductive layer laminated on a polymer layer containing at least a monomer component represented by formula (1) and in which the monomer component has a structure represented by formula (2). circuit board. [Formula] [Formula] (In the formula, R ¹ to ^{R 12} are hydrogen, an alkyl group, or a halogen, and each may be the same or different, and
R ⁹ or R ¹⁰ and R ¹¹ or R ¹² may mutually form a ring. n is 0 or a positive number of 1 or more, and R ⁵ to ^{R 8}
When repeated multiple times, these may be the same or different. )