JPS6019603B2 - composite dielectric - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite dielectric material, and more particularly to a composite dielectric material made of MgTi0
The present invention relates to a composite dielectric that can be used as a microwave composite dielectric or a microcapacitance capacitor material, which is made of a 3-CaTi03-based dielectric ceramic powder and an insulating polymer material.

In recent years, with the development of communication in the microwave region, efforts have been made to integrate microwave circuits.

Conventionally, a substrate for integration, a so-called microwave substrate (M
The dielectric material (IC board) used was a dielectric material such as tetrafluoroethylene resin or polystyrene resin coated with copper on both sides, and circuits were formed by etching the steel plate. There are cases where the dielectric constant of resin is used as part of the circuit configuration. However, since the dielectric constant of this resin is 2 to 3, for example, when forming a resonant circuit, if the dielectric constant of the resin is small, the shape of the conductive pattern must be enlarged, which becomes an obstacle to miniaturization. was. Therefore, there has been a demand for a microwave substrate with an even higher dielectric constant. On the other hand, the application of dielectric ceramics to microwave communication equipment is progressing, and materials with high Q values in the microwave band and excellent temperature stability are being developed.

However, when attempting to perform processing such as drilling or cutting on ceramic, it is difficult to process because ceramic is inherently hard, and it also has the drawback of chipping and cracking. Therefore, the present invention aims to provide a composite dielectric material that utilizes the flexibility of resin and the excellent electrical properties of microwave dielectric ceramic.

Further, the present invention aims to provide a composite dielectric material that has a high Q value in the microwave region, has stable temperature characteristics of relative permittivity, and has a relative permittivity larger than that of general polymer materials. .

Furthermore, it is an object of the present invention to provide a composite dielectric material that is more flexible and easier to process than microwave dielectric ceramics.

That is, the gist of the present invention is that MgTi03
-CaTi03-based dielectric ceramic 10-70% by capacity,
Preferably 30-5 kon capacity% and insulating polymeric material 9
It is a composite dielectric material having a capacity of 0 to 3%, preferably 70 to 5%.

Among those constituting the composite object of the present invention, MgTi0
3-CaTi03-based material has a component ratio of MgTi03
80-100 mol% and CaTi030-20 mol%
with a Q of 3000 to 20 at 7GHz.
000, a relative dielectric constant of 17 to 27, and a temperature characteristic of the relative permittivity of -100 to 1100 ppm/00.

In addition, it is also permissible to add Ti02 to further increase the dielectric constant. In addition, as the insulating polymer material, fluorine-containing polymers such as single or copolymers of tetrafluoroethylene are particularly preferable, but other dielectric loss polymers such as polyethylene or polyolefin polymers, Polymers can be used.

Among these, homopolymers of tetrafluoroethylene are particularly preferred. Examples of copolymers that can be used include copolymers of ethylene tetrafluoride and ethylene, propylene, propylene hexafluoride, vinyl fluoride, vinylidene fluoride, ethylene trifluoride, and the like. The mixing ratio of the crab body ceramic and the insulating polymer material is generally 10:90 to 70.
:30, and the reason why this range is preferable is as follows. In other words, if the dielectric ceramic has a capacity of less than 1.5% and the insulating polymer material has a capacity of more than 9.0%, no increase in the relative dielectric constant is observed and a composite effect cannot be obtained. Furthermore, if the dielectric ceramic exceeds 7% by weight and the insulating polymer material becomes less than 3% by capacity, the amount of dielectric ceramic increases, so even if mixed with the insulating polymer material, a homogeneous composite dielectric You won't be able to get a body.
Therefore, flexibility is lost and workability is also deteriorated. To manufacture the composite dielectric of the present invention, the insulating polymer material and dielectric ceramic are uniformly mixed in powder form, and then molded under polymer material molding conditions.

For example, in the case of polytetrafluoroethylene, the mixed powder is compression molded under pressure to about 100 to 700 k9/kg, and then fired at a temperature of about 330 to 420 qC to form a compact. The present invention will be explained in detail below according to examples.

Example Dielectric ceramic powder (80 mesh pass) consisting of 95 mol% MgTiQ and 35 mol% CaTi and polytetrafluoroethylene resin powder were mixed uniformly at the ratio shown in the first picture. After compression molding under pressure, it was heated and fired at a temperature of 0° C. for 3 hours to obtain a cylindrical composite dielectric material with a diameter of 56 ribs and a height of 8 capes.

The resulting composite dielectric was subjected to 8. dielectric resonator method using the daughter motion method. The relative permittivity and Q value at &Hz were measured, and the temperature characteristics of the relative permittivity were also measured at IMHz.

The measurement results are also shown in Table 1. Table 1 In Table 1, sample number 1 is outside the scope of this invention, and all others are within the scope of this invention.

As is clear from Table 1, the composite dielectric material according to the present invention has a large dielectric constant under microwaves and also exhibits a high Q value.

In addition, the temperature characteristics of the relative dielectric constant are pm/. It exhibits characteristics centered around 0, and has stable characteristics against temperature changes.

In addition, the composite dielectric material according to the present invention has flexibility and can be easily perforated and cut, and has the advantage that, for example, when used as a microwave substrate, conduction treatment between the front surface and the back surface can be easily performed. has.

Claims (1)

[Scope of Claims] 1. A composite dielectric consisting of 10-70% by volume of MgTiO_3-CaTiO_3-based dielectric ceramic and 90-30% by volume of insulating polymer material. 2 MgTiO_3-CaTiO_3-based dielectric ceramic contains MgTiO_380 to 100 mol% and CaTi
The composite dielectric material according to claim 1, comprising O_30 to 20 mol%. 3 MgTiO_3-CaTiO_3-based dielectric ceramic has a Q of 3000 to 20000 at 7 GHz, a relative dielectric constant of 17 to 27, and a temperature characteristic of the relative permittivity of -100 to +
The composite dielectric material according to claim 1 or 2, which has a temperature of 100 ppm/°C. 4. The composite dielectric material according to claim 1, wherein the insulating polymer material is a monopolymer or a copolymer of tetrafluoroethylene.