JPH10208548A - Composite dielectric material composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable specific dielectric constant and dielectric loss to be adjusted to a desired value by blending a high-frequency ceramic material with a polymeric material obtained by polymerizing a monomer composition containing at least monomer of fumaric acid diester. SOLUTION: A fumarate-based polymer having a repetition unit induced from a fumaric acid diester by polymerization of a monomer composition containing a fumaric acid diester has good adhesive property with a metal conductor layer and a glass fiber, low dielectric loss tangent, and low dielectric rate. This composition in which a Ti-Ba-Na based material of 60 to 90wt.% or a Pb-Ca based material of 60 to 90wt.% are preferably added thereto as a high frequency ceramics material has a dielectric constant of at least 5.0 and a Q value of at least 200 in a high-frequency bandwidth of 30MHz or more. Preferably, a film of 30 micrometers or more in film thickness in which a solution of this composition is impregnated in a reinforce fiber such as glass fiber and a film made of two layers of 60 micrometers or more formed by lamination of a coated film thereto are employed as a substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-ceramic composite dielectric material composition particularly suitable for use in a high frequency range and a substrate for electronic parts using the same, and particularly to a flat antenna. And a low-loss composite dielectric material composition having a specific dielectric constant.

[0002]

2. Description of the Related Art With the recent development of electronic technology,
Various performances are also required for insulating materials used for electronic devices. In particular, printed wiring boards are used for a very wide range of applications, and the characteristics required for the boards are also increasingly diverse. Under such circumstances, there are many demands for dielectric properties.

Hitherto, low permittivity wiring boards have been developed for the purpose of high-speed propagation in printed wiring boards, high characteristic impedance, thinning of wiring boards, reduction of crosstalk, and the like. Circuits and other circuit boards with delay circuits, low-impedance circuit board characteristic impedance matching, finer wiring patterns, high-permittivity substrates due to the need for integrated circuits with elements that have a capacitor effect on the substrate itself. Is needed.

[0004] With the recent development of information communication systems, the frequency band of radio waves used for portable mobile communications such as car phones and digital cellular phones and satellite communications is in the mega- to giga-frequency range. Have been. With the rapid development of communication equipment used as these communication means,
As housings and electronic components are being miniaturized and mounted with high density, equivalent requirements are being placed on antennas used for them. A planar antenna used as a high-frequency antenna by forming a microstrip line on a dielectric substrate Is used.

The planar antenna has a relatively low relative dielectric constant (εr) as a dielectric substrate, and is made of Teflon (εr = 2.2 to 2.2).
7/1 GHz) and BT resin (εr = 3.3-3.5 /
Although materials such as (1 GHz) have been used, miniaturization is difficult, and deformation due to heat or change in relative dielectric constant (εr) due to temperature is likely to occur, so that it is difficult to obtain high reliability.

Therefore, a dielectric substrate used in such an application needs to have a high dielectric constant and low loss characteristics in order to reduce the size of the planar antenna.

Therefore, a high dielectric constant ceramic powder is added to a conventional phenol resin, epoxy resin, or the like for a laminated board or a printed wiring board, or a fluororesin or polyphenylene ether resin, which is a low dielectric constant resin, to form a glass cloth or glass. There has been proposed a high dielectric constant substrate formed by laminating and molding a prepreg obtained by impregnating and drying a nonwoven fabric.

[0008]

However, simply adding a high-permittivity high-frequency ceramic to a conventional thermosetting resin such as a phenolic resin or an epoxy resin for a conventional laminated board or printed wiring board results in a low dielectric loss tangent. Not be.

When a filler having a high dielectric constant is added to a resin such as a fluororesin having a low dielectric constant or a polyphenylene ether resin, the dielectric loss tangent becomes low. The amount increases, and problems such as a decrease in drill workability and cutting workability of the laminate and an increase in dimensional change occur. Therefore, the present invention proposes a dielectric composite material having a high dielectric constant and a low dielectric loss tangent and a dielectric substrate in which these disadvantages are improved.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has the following features. That is, the present invention provides (1) a composite dielectric material composition obtained by mixing a high-frequency ceramic material with a polymer material obtained by polymerizing a monomer composition containing at least a fumaric acid diester as a monomer.

(2) The composite dielectric material composition according to (1), wherein the high-frequency ceramic material contains at least one material selected from the group consisting of titanium-barium-neodymium and lead-calcium, and has a frequency of 30 MHz or more. A composite dielectric material composition having a relative dielectric constant of at least 5.0 and a Q value of at least 200 in a high-frequency band.

(3) The composite dielectric material composition according to (2), wherein the high-frequency ceramic material contains a titanium-barium-neodymium-based material in an amount of 60 wt% to 90 wt%.

(4) The composite dielectric material composition according to claim 2, wherein the high-frequency ceramic material contains 85 to 90 wt% of a lead-calcium-based material.

(5) A film having a thickness of 30 μm or more, characterized by impregnating reinforcing fibers with the composite dielectric material composition according to any one of (1) to (4).

(6) The film according to (5), wherein glass fiber is used as the reinforcing fiber.

(7) A substrate provided by laminating the films described in (5) and (6) is provided.

(8) A film having a film thickness of 60 μm or more, which is obtained by uniformly applying the composite dielectric material composition according to any one of claims 1 to 4 to the film described in (5) or (6). provide.

(9) A film having a thickness of 30 μm or more obtained by impregnating Teflon fiber or glass fiber with a polymer material obtained by polymerizing a monomer composition containing at least a fumaric acid diester as a monomer. A film having a thickness of 60 μm or more, wherein the composite dielectric material composition according to any one of (1) to (4) is uniformly applied.

(10) A substrate obtained by laminating the films described in (8) to (9).

[0020]

Embodiments of the present invention will be described below in detail.

The present invention relates to a low dielectric polymer material obtained by polymerizing a monomer composition containing at least a fumaric acid diester as a monomer, and a fumarate having a repeating unit derived from the fumaric acid diester. A high-frequency ceramic material is mixed with a system polymer to obtain a dielectric composite material composition having a high dielectric constant and a low dielectric loss tangent.

Here, a low dielectric polymer material obtained by polymerizing a monomer composition containing at least a fumaric acid diester as a monomer is disclosed in Japanese Patent Application No. 8-42073 (not disclosed). As proposed in the above, it has good adhesion or adhesion to the metal conductor layer and glass fiber and also has the ability to form a thin film, and has a low dielectric loss tangent and excellent insulation,
Furthermore, it is a polymer material having excellent heat resistance and weatherability. Since the dielectric loss tangent in the high-frequency region increases with an increase in the frequency, the material used in the high-frequency region needs to have a small dielectric loss tangent. It can be said that the obtained low dielectric polymer material is most suitable for a dielectric material for high frequency.
However, since it has a low dielectric constant, it is not suitable for use in producing a high dielectric substrate.

Therefore, in order to produce the dielectric composite material according to the present invention, dicyclohexyl fumarate is used as a low dielectric polymer material obtained by polymerizing a monomer composition containing at least a fumaric acid diester as a monomer. Rate / diisopropyl fumarate copolymer (CDIP) or dicyclohexyl fumarate / disec-butyl fumarate copolymer (CDSB) (εr = 2.4-2.
8, Q = 200-600 / 1 GHz) is dissolved in a solvent such as toluene so as to form a 10-20 wt% solution. Thereafter, a dielectric ceramic (εr = 85 to 100, Q = 2500 to 6000 / 1G) was mixed with a mixing stirrer.
Hz) powder and mix. At that time, if the dielectric ceramics is titanium-barium-neodymium, it will be 60 watts.
t-90wt%, 85w for lead-calcium system
It is desirable to contain t% to 90 wt%.

Further, the mixture is mixed and pulverized at least twice with three rolls. Toluene was further added to the dielectric composite material thus formed for viscosity adjustment, and 10
And stir for 20 minutes. At this time, it is desirable to stir while degassing. Thereby, a composite dielectric material composition solution having a film forming ability of 1 μm or more can be obtained.

The dielectric ceramic material used here is not particularly limited, but has a relative dielectric constant (εr) of 1
0 or more is desirable, more desirably 30 or more,
Those having a dielectric loss tangent (tan δ) of 0.005 or less are preferred.

Examples of such materials include titanium-barium-neodymium ceramics, lead-calcium ceramics, titanium dioxide ceramics, barium titanate ceramics, lead titanate ceramics, strontium titanate ceramics, Calcium titanate ceramics, bismuth titanate ceramics, magnesium titanate ceramics,
And lead zirconate ceramics. Furthermore, CaWO4 ceramics, Ba (Mg, Nb) O
Examples include ternary ceramics, Ba (Mg, Ta) O3 ceramics, Ba (Co, Mg, Nb) O3 ceramics, and Ba (Co, Mg, Ta) O3 ceramics. These may be used alone or in combination of two or more.

The above-mentioned titanium dioxide-based ceramic is a system containing only titanium dioxide or a system containing a small amount of other additives in titanium dioxide, and the crystal structure of the main component titanium dioxide is maintained. Is what is being done.

The same applies to other ceramics. Titanium dioxide is a substance represented by TiO2 and has various crystal structures. Among them, the one used as a dielectric ceramic has a rutile structure.

The particle diameter of the dielectric ceramic is about 50 μm.
m or less can be used, but preferably 0.1 m or less.
It is in the range of 1 to 20 μm, more preferably 0.5 to 7 μm. This is because if the particle size is large, uniform dispersion and mixing in the resin becomes difficult, and if the particle size is small, handling becomes difficult.

The composite dielectric material composition solution thus produced is poured into a mold to evaporate the solvent, whereby a film having a uniform thickness can be obtained. By such a so-called casting method, various thicknesses can be obtained according to the intended use.
mm. In the present invention, examples of a mold used for forming a film by a casting method include a glass plate, a silicone rubber plate, and a metal plate. The film can be obtained by evaporating the solvent at room temperature (temperature of about 15 to 30 ° C.) as described above, but may be dried at a temperature of about 40 to 60 ° C. if necessary.

In the present invention, a film of the dielectric composite material may be formed on a resin film substrate such as polyethylene terephthalate (PET) to form a film. Even in this case, the thickness of the coating film can be 1 μm or more.
A film having a thickness of about 0 μm can be obtained.

The coating method may be any known method, such as a doctor blade coating method, a spin coating method, a dip coating method, or a screen printing coating method. So you can be more productive.

The film having such a coating film formed thereon may be laminated for each film substrate. The lamination may be performed with the solvent remaining and lamination may be performed, or the film may be dried and then bonded using a fumaric acid diester resin as an adhesive.

It is also possible to laminate a metal conductor film or the like.

The composite dielectric material composition of the present invention can be formed into a film by impregnating reinforcing fibers such as glass fibers. At this time, the solvent used for the solution for reinforcing fiber impregnation needs to show good solubility in the dielectric composite material composition according to the present invention, but has an adverse effect in consideration of control of the evaporation rate and the like. Can be used in combination. Examples of solvents used include methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ketone solvents such as acetone, benzene, aromatic hydrocarbon solvents such as toluene, methyl cellosolve, butyl cellosolve, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, Various glycol ether solvents such as dipropylene glycol monomethyl ether and diethylene glycol monobutyl ether, ester solvents such as butyl cellosolve acetate, methyl cellosolve acetate and ethyl acetate, N, N-dimethylacetamide, N, N-dimethylformamide, N-methyl- 2-
Amide solvents such as pyrrolidone, alcohol solvents such as methanol and ethanol, and tetrahydrofuran (TH
It can be obtained by dissolving in a solvent such as F), decalin, dimethyl sulfoxide, butyl chloride, trichlorotrifluoroethane, trifluorotoluene and the like. These can be used in combination of several types.

The content of the dielectric composite material composition in the impregnating liquid may be 60 to 85% by weight from the viewpoint of operability and the like.
The viscosity in this case is preferably 500 to 30,000 under normal conditions.
It is about cps.

In the above, not only glass fibers but also Teflon fibers and any insulating fibers conventionally used in the production of rigid substrates can be used as reinforcing fibers.
Glass fibers are preferred. It is particularly preferable to use glass fibers having low dielectric properties (low dielectric constant, low dielectric loss tangent). As the glass fiber, any of reinforcing fibers such as a glass woven fabric and a glass nonwoven fabric can be used.

The content of the dielectric composite material composition in the glass fiber-containing film is suitably from 10 to 70% by weight. This results in a film or substrate having sufficient strength, low dielectric properties, and heat resistance. Such a content can be determined by adding a dielectric composite material composition-containing solution (usually 60 to 8) as a resin paste when laminating a film or laminating a substrate.
(5% by weight solution).

Further, a coating film of the dielectric composite material may be formed on a film obtained by impregnating a glass fiber with a solution of the dielectric composite material composition to form a two-layer film. In this case, a film having a thickness of 60 μm or more including the thickness of the coating film can be obtained. Similarly, a film obtained by impregnating a polymer material solution obtained by polymerizing a monomer composition containing at least a fumaric acid diester as a monomer into Teflon fiber or glass fiber, preferably impregnating glass fiber A film of the above-mentioned dielectric composite material may be formed on the obtained film to form a film having a two-layer structure.

Alternatively, the substrate having the two-layer structure may be laminated with the remaining solvent remaining, and after lamination, the solvent may be removed to form a substrate.

Further, it is also possible to laminate a metal conductor film or the like. A film obtained by impregnating a glass fiber with a solution of a dielectric composite material composition is further laminated on both surfaces of the laminated film. A substrate that is stable in strength can be produced.

A substrate using the thus obtained dielectric composite material composition was prepared to have a length of 100 mm, a width of 2 mm, and a width of 1.2 m.
m, and a relative permittivity (εr) and a dielectric loss tangent (ta) at 1 GHz and 2 GHz are obtained by a perturbation method.
nδ), and the result of calculating the value of Q is shown in the embodiment of FIG.

As shown in FIG. 3 (a), a film of the dielectric composite material was formed on a film obtained by impregnating a glass fiber with a solution of the dielectric composite material composition, and was laminated. The substrate obtained by the A lamination method is used to impregnate glass fibers with a polymer material solution obtained by polymerizing a monomer composition containing at least a fumaric acid diester as a monomer as shown in FIG. A coating film of the dielectric composite material was formed on the film thus obtained, and the obtained substrate was laminated by a B lamination method.

Further, the relative dielectric constant (εr), dielectric loss tangent (tan δ), and Q value of a substrate using a conventionally used material are shown in the comparative example of FIG. 1 by the same test method.

FIG. 2 shows changes in the relative dielectric constant (εr) and the value of Q, with the content of the dielectric ceramics, particularly the mixed dielectric ceramics as a parameter.

The dielectric composite material composition according to the present invention comprises:
A low dielectric polymer material obtained by polymerizing a monomer composition containing at least a fumaric acid diester as a monomer, and a high frequency ceramic material containing a fumarate-based polymer having a repeating unit derived from the fumaric acid diester. , It is possible to adjust the relative dielectric constant (εr) and the dielectric loss (tan δ) in the high-frequency region to arbitrary values. As a high-frequency ceramic material, 60 to 90 wt.
%, 85-90 wt% for lead-calcium ceramics
%, A high dielectric constant substrate in a high frequency region,
In particular, the relative permittivity (ε, which is a value required by a high-permittivity substrate used for a planar antenna for which miniaturization is required in recent years, is required.
r) It is understood that the condition of 5.0 or more and the value of Q is 200 or more are satisfied.

[0047]

The present invention is a low dielectric polymer material obtained by polymerizing a monomer composition containing at least a fumaric acid diester as a monomer, and a fumarate-based polymer having a repeating unit derived from the fumaric acid diester. By mixing a high-frequency ceramic material into the union, the relative dielectric constant (ε
r) and dielectric loss (tan δ) can be adjusted to arbitrary values, and a dielectric substrate that can be used in a high-strength high-frequency region with an arbitrary thickness by a technique such as lamination can be provided. it can.

[Brief description of the drawings]

FIG. 1 is a table showing the dielectric properties of a dielectric composite material composition according to the present invention.

FIG. 2 is a diagram showing a change in characteristics of a dielectric composite material composition according to the present invention depending on a mixing amount of high-frequency ceramics.

FIG. 3 is a sectional view showing a laminated structure of a substrate according to the present invention.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideaki Ninomiya 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation

Claims (10)

[Claims] 1. A composite dielectric material composition obtained by mixing a high-frequency ceramic material with a polymer material obtained by polymerizing a monomer composition containing at least a fumaric acid diester as a monomer. 2. The composite dielectric material composition according to claim 1, wherein the high-frequency ceramic material contains at least one material selected from the group consisting of titanium-barium-neodymium and lead-calcium, and has a high frequency of 30 MHz or more. A composite dielectric material composition having a dielectric constant of at least 5.0 and a Q value of at least 200 in the band. 3. The composite dielectric material composition according to claim 2, wherein the high-frequency ceramic material contains a titanium-barium-neodymium-based material in an amount of 60 wt% to 90 wt%. 4. A lead-free ceramic material as the high-frequency ceramic material.
3. The composite dielectric material composition according to claim 2, wherein the composition contains 85 to 90 wt% of a calcium-based material. 5. A film having a thickness of 30 μm or more, wherein a reinforcing fiber is impregnated with the composite dielectric material composition according to any one of claims 1 to 4. 6. The film according to claim 5, wherein glass fiber is used as the reinforcing fiber. 7. A substrate obtained by laminating the films according to claim 5 and 6. 8. A film having a thickness of 60 μm or more, wherein the composite dielectric material composition according to claim 1 is uniformly applied to the film according to claim 5 or 6. 9. A film having a thickness of 30 μm or more obtained by impregnating a Teflon fiber or a glass fiber with a polymer material obtained by polymerizing a monomer composition containing at least a fumaric acid diester as a monomer. A film having a film thickness of 60 μm or more, wherein the composite dielectric material composition according to claim 1 is uniformly applied. 10. A substrate obtained by laminating the films according to claim 8.