JP2005146009A - Dielectric resin composition and electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a dielectric resin composition which retains good dielectric characteristics such as dielectric constant and dielectric dissipation factor, has a high mechanical strength, is excellent in molding processability and enables downsizing and weight reduction, and an electronic component. <P>SOLUTION: The dielectric resin composition contains a granular inorganic filler having a median size of ≥10 μm such as titanium oxide, a metal titanate, a metal niobate, a metal tantalate and a metal zirconate in a synthetic resin matrix. The proportion of the inorganic filler is preferably 10-95 wt.%. The electronic component is obtained by molding the dielectric resin composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a dielectric resin composition and an electronic component. Specifically, the present invention relates to a dielectric resin composition and an electronic component having a high relative dielectric constant and a low dielectric loss tangent in a high frequency band, high mechanical strength, and excellent molding processability.

  With the recent remarkable spread of mobile communication devices such as mobile phones, cordless phones, and automobile phones, and the remarkable development of satellite communication devices, higher frequency of communication signals and further miniaturization of communication devices are desired. .

  By the way, two kinds of dielectric characteristics, that is, a relative dielectric constant (εr) and a dielectric loss tangent (tan δ) of an antenna substrate incorporated in the communication device, are greatly involved in increasing the frequency of signals and reducing the size of the communication device. The relative dielectric constant is a parameter indicating the degree of polarization in the dielectric body. The higher the relative dielectric constant of the antenna substrate, the shorter the wavelength of the signal propagating through the circuit formed on the substrate. Therefore, if the relative permittivity of the substrate can be set high, the circuit can be shortened and miniaturized. The dielectric loss tangent is a parameter indicating the amount of the signal propagating in the dielectric that is converted into heat and lost, and the lower the value, the smaller the signal loss.

Synthetic resins are used as component materials for general electronic electrical equipment such as home appliances due to their easy moldability. For the purpose of imparting dielectric properties to this resin, a dielectric inorganic filler is used (Patent Document 1, etc.). However, the conventional dielectric inorganic filler can obtain a high relative dielectric constant by increasing the amount of addition to the resin, but the amount of addition increases and the weight of the entire dielectric increases. Moreover, the resin composition which added the conventional filler has a problem in the point of moldability and mechanical strength.
JP-A-8-41247

  An object of the present invention is to provide a dielectric resin composition that has high mechanical strength, excellent molding processability, and can be reduced in size and weight while maintaining good dielectric properties such as dielectric constant and dielectric loss tangent. To provide electronic components.

  As a result of diligent research to achieve the above object, the present inventor has blended and molded granular materials having specific dimensions into a synthetic resin matrix as an inorganic filler, thereby forming dielectric properties such as dielectric constant and dielectric loss tangent. In order to complete the present invention, it is found that a dielectric resin composition and an electronic component can be obtained that have high mechanical strength, excellent molding processability, and can be reduced in size and weight while maintaining good. It came.

  That is, the present invention is a dielectric resin composition characterized by containing a granular inorganic filler having a median diameter of 10 μm or more in a synthetic resin matrix.

  In the present invention, since a granular inorganic filler having a median diameter of 10 μm or more is used, it is possible to obtain good dielectric properties such as a high relative dielectric constant and a low dielectric loss tangent. Moreover, it can be set as the dielectric resin composition which is excellent in moldability and has high mechanical strength. Since it has good dielectric properties, it can be reduced in size, and even if the amount of the granular inorganic filler to be blended is reduced, a high relative dielectric constant can be obtained, so that the weight can be reduced. .

  The electronic component of the present invention is characterized by being formed by molding the dielectric resin composition of the present invention. Examples of the electronic component of the present invention include an antenna, a connector, a capacitor, and a sensor.

  The dielectric resin composition and electronic component of the present invention have good dielectric properties such as a high relative dielectric constant and a low dielectric loss tangent, have excellent molding processability, high mechanical strength, and are reduced in size and weight. be able to.

  The dielectric resin composition and electronic component of the present invention have good signal transmission efficiency in a high frequency band.

  Since the dielectric properties of the dielectric resin composition and the electronic component of the present invention change in correlation with the blending amount of the granular inorganic filler having a specific dimension, the relative dielectric constant can be easily adjusted by adjusting the blending amount. Can be set.

  Since the dielectric resin composition and the electronic component of the present invention can obtain a high relative dielectric constant even if the amount of the granular inorganic filler having a specific dimension is small, it is possible to reduce the size and weight. .

  In this invention, it does not restrict | limit especially as a synthetic resin used as a matrix, A well-known thing can be used. Specifically, for example, polyethylene, polypropylene, chlorinated polyolefin, 5-methylpentene resin, cyclic polyolefin, polystyrene, modified polystyrene, syndiotactic polystyrene, polyphenylene ether, ABS resin, polyamide, acrylic resin, methacrylic resin, polyacetal, Polycarbonate, thermoplastic polyimide, polyetherimide, polyamideimide, ionomer resin, polyetherketone, polyethernitrile, polyphenylene sulfide, polysulfone, polyester, aromatic polyester, liquid crystal polyester, polyethylene terephthalate, polybutylene terephthalate, heat-melting fluororesin Such as thermoplastic resin, phenol resin, urea resin, melamine resin, guanamine resin, amino resin, Saturated polyester resins, diallyl phthalate resins, epoxy resins, silicone resins, urethane resins, thermosetting polyphenylene ether, triazine resins, and thermosetting resins such as polyimide. As the thermoplastic resin, cyclic polyolefin, polyetherimide, liquid crystal polyester, polyphenylene ether, modified polystyrene, hot-melting fluororesin, polyphenylene sulfide, thermoplastic polyimide, 5-methylpentene resin, syndiotactic polystyrene, and the like are preferable. As the thermosetting resin, an epoxy resin, a thermosetting polyphenylene ether, a triazine resin, a polyimide, or the like is preferable. Among these, those having a dielectric loss tangent of 0.01 or less in a high frequency band of 1 GHz or more are particularly preferable. Specifically, cyclic polyolefin, polyetherimide, polyphenylene ether, syndiotactic polystyrene, 5-methylpentene resin, Examples include polyphenylene sulfide, liquid crystal polyester, and heat-meltable fluororesin.

  Synthetic resins can be used alone or in combination of two or more.

  In this invention, what has a specific dimension is used as a granular inorganic filler. By using such specific granular inorganic filler, synthetic resin is given high relative dielectric constant and low dielectric loss tangent, molding processability is improved, mechanical strength is high, and signal transmission efficiency in high frequency band Will be better.

  The granular inorganic filler in the present invention has a median diameter of 10 μm or more. Preferably, it is 20 micrometers or more, More preferably, it is 20-500 micrometers or more. If the median diameter is less than 10 μm, high dielectric constant and low dielectric loss tangent cannot be obtained, and mechanical strength is low, and it is difficult to obtain a dielectric resin composition and electronic component that are reduced in size and weight. It is. In the present invention, the median diameter of the granular inorganic filler can be measured by a laser diffraction particle size distribution measuring apparatus. The median diameter is the cumulative diameter at 50% by volume.

  The blending amount of the particulate inorganic filler is not particularly limited and can be appropriately selected from a wide range according to the set value of the relative dielectric constant and dielectric loss tangent and the use of the composition, but is usually about 10 to 95% by weight of the total amount of the composition. Preferably, it is about 30 to 90% by weight, and more preferably about 50 to 85% by weight.

  The particulate inorganic filler that can be used in the present invention is not particularly limited as long as it has the above specific dimensions. For example, titanium oxide, metal titanate, metal niobate, metal tantalate, zirconate A metal salt etc. are mentioned.

  Specific examples of the metal titanate include alkalis such as barium titanate, calcium titanate, magnesium titanate, strontium titanate, barium strontium titanate, barium calcium titanate, barium magnesium titanate, and calcium magnesium titanate. Alkali earth metal salts such as earth metal salts, barium bismuth titanate, barium neodymium titanate, etc. substituted with other metals, metal titanate, lead zirconate titanate, lead magnesium titanate niobate, etc. The titanic acid metal salt etc. which a part of titanic acid substituted by the other metal etc. can be mentioned, 1 type can be used individually or in combination of 2 or more types.

  Among the above-mentioned metal titanates, alkaline earth metal titanates are preferred, and two or more of strontium titanate, barium strontium titanate, barium calcium titanate, barium magnesium titanate, calcium magnesium titanate, etc. Those containing the alkaline earth metal are particularly preferred.

  Specific examples of the metal niobate include sodium niobate, lithium niobate, potassium niobate, lead niobate, cadmium niobate, etc., and one kind can be used alone or two or more kinds can be used in combination. Can be used.

  Specific examples of the metal tantalate include, for example, lithium tantalate, sodium tantalate, potassium tantalate, rubidium tantalate, lead tantalate and the like, and one kind can be used alone or two or more kinds can be used in combination. Can be used.

  Specific examples of the metal zirconate include, for example, barium zirconate, calcium zirconate, strontium zirconate, magnesium zirconate and the like, and can be used alone or in combination of two or more.

  The granular inorganic filler may be treated with a surface treatment agent for the purpose of enhancing the dispersibility of the filler in the synthetic resin. A well-known thing can be used as a surface treating agent, For example, coupling agents, such as a silane coupling agent and a titanate coupling agent, can be mentioned. The amount of the surface treatment agent to be used is not particularly limited, but is usually within a range that does not impair the dielectric properties and physical properties of the composition of the present invention.

  A known resin additive may be added to the dielectric resin composition and the electronic component of the present invention as long as the dielectric properties and physical properties thereof are not impaired. Specific examples of the additive include, for example, a reinforcing material, an ultraviolet absorber, an antistatic agent, a surface treatment agent, a compatibilizer, a heat conduction improver, a lubricity improver, a colorant, a dye, an antioxidant, a plasticizer. Agents, surfactants, flame retardants, plating property improvers and the like.

  The electronic component of the present invention can be produced by mixing and molding the above synthetic resin and a granular inorganic filler having a specific size according to a known method. For example, an electronic component having a desired shape can be obtained according to a known method such as injection molding, extrusion molding, compression molding, or cast molding.

  In the dielectric resin composition and the electronic component of the present invention, for example, by appropriately changing the blending amount of the granular inorganic filler having a specific dimension, it can be set to a desired relative dielectric constant and dielectric loss tangent, In general, the relative dielectric constant is preferably 20 or more and the dielectric loss tangent is preferably 0.05 or less.

In addition, when the dielectric resin composition and the electronic component of the present invention are applied to applications requiring heat resistance, it is preferable to set the deflection temperature under a load of 18.5 kg / cm ² to 130 ° C. or higher. .

[Synthesis Examples 1-3]
A ball mill using three types of powders (Ba / Sr / Ti = 0.5 / 0.5 / 1 molar ratio) of 56.83 g of barium carbonate, 42.51 g of strontium carbonate, and 46.02 g of titanium oxide. For 24 hours. The powder dispersion after mixing was separated from the powder, balls and ethanol, and the powder was dried at 110 ° C. for 12 hours and used as a raw material. The dried powder was put into an alumina crucible and baked at 1300 ° C. for 24 hours using an electric furnace. The baked powder was passed through a sieve while being pulverized in an alumina mortar to obtain a powder with adjusted particle size as shown in Table 1. The results are shown in Table 1.

[Synthesis Examples 4 to 7]
In the same manner as in Synthesis Example 1, barium carbonate, strontium carbonate, and niobium oxide are used as raw materials, mixed at a mixing ratio (Ba / Sr / Nb = 0.5 / 0.5 / 2 molar ratio), and fired. After pulverization, the size of the particles was adjusted with a sieve. The results are shown in Table 1.

[Synthesis Examples 8 to 10]
In the same manner as in Synthesis Example 1, calcium carbonate and titanium oxide were mixed at a mixing ratio (Ca / Ti = 1/1 molar ratio), fired and pulverized, and the size of the particles was adjusted with a sieve. The results are shown in Table 1.

[Examples 1-7 and Comparative Examples 1-3]
Samples were prepared by adding the granular inorganic fillers of Synthesis Examples 1 to 10 to polyethylene using a Laboplast mill (manufactured by Toyo Seiki Seisakusho Co., Ltd.) so that the amount was 80 wt%. The dielectric properties of the obtained sample were measured by a cavity resonator method using a network analyzer. The results are shown in Table 2.

  As shown in Table 2, in Examples 1 to 7 containing a granular inorganic filler having a median diameter of 10 μm or more, a higher relative dielectric constant is obtained than in Comparative Examples 1 to 3. Moreover, when it is going to obtain a high dielectric constant as shown in Examples 1-7 by mix | blending a large amount of the granular inorganic filler used for the comparative example 1, a dielectric loss tangent will become higher than the thing of an Example. Therefore, according to the present invention, a dielectric resin composition having a high relative dielectric constant and a low dielectric loss tangent can be obtained.

[Examples 8 to 14 and Comparative Examples 4 to 6]
As a polyphenylene sulfide (PPS) resin, the trade name “Fortron W203A” (sold by Polyplastics Co., Ltd.) was used. Barium strontium titanate produced in Synthesis Example 3, calcium titanate produced in Synthesis Example 10, and The barium strontium titanate produced in Synthesis Example 1 was mixed so as to have the blending ratios shown in Tables 3 and 4, respectively. Specifically, using a twin-screw extruder (manufactured by Nippon Steel Works, TEX44), after melting Fortron W203A at a cylinder temperature of 320 ° C., a method of adding each filler halfway (side feed) Strand cutting was performed to prepare each resin pellet. These pellets were injection molded at a cylinder temperature of 320 ° C. and a mold temperature of 150 ° C. using an injection molding machine (manufactured by Nissei Plastic Industry Co., Ltd., FS-150), and the physical properties of each molded product were evaluated. The results are shown in Table 3 (Examples) and Table 4 (Comparative Examples).

  The relative dielectric constant and dielectric loss tangent shown here were measured by a cavity resonator method using a network analyzer.

  Tensile strength was measured according to JIS K-7113, bending strength and flexural modulus were measured according to JIS K-7203, and Izod impact strength (notched) was measured according to JIS K-7110.

  From Table 3, it can be seen that the relative dielectric constant increases drastically as the amount of the granular inorganic filler in the resin increases. From this, it is understood that a dielectric resin composition and an electronic component having an arbitrary relative dielectric constant can be obtained by adjusting the filling amount of the granular inorganic filler.

  From Table 3 and Table 4, when the same filling amount is compared, it can be seen that the barium strontium titanate of the example has a higher relative dielectric constant and higher mechanical strength than the barium strontium titanate of the comparative example. From this, when trying to obtain electronic components with the same relative dielectric constant, the use of the dielectric resin composition of the example requires a small amount of inorganic filler and realizes weight reduction of the electronic components. I understand that I can do it.

[Examples 15 to 17]
As a thermosetting resin, phenol type epoxy resin (Dainippon Ink Chemical Co., Ltd., EPCLOON850) was used, and barium strontium titanate produced in Synthesis Example 3 was mixed so as to have a blending ratio shown in Table 5, respectively. After sufficiently stirring and dispersing, 15 phr (15 parts by weight with respect to 100 parts by weight of epoxy resin) of metasyringeamine was added as a curing agent, followed by vacuum degassing after stirring. Next, the obtained resin composition was cast on a fluororesin sheet around a spacer having a thickness of 3 mm and allowed to stand at room temperature for 3 hours, and then cured at 130 ° C. for 3 hours. Dielectric characteristics of the obtained cured product were measured. The results are shown in Table 5.

[Examples 18 to 21]
Using the resin compositions of Examples 9, 10, 13, and 14, the patch antenna shown in FIG. 1 was prepared so that the resonance frequency was in the 430 MHz band. In FIG. 1, 1 indicates a dielectric substrate, and 2 indicates a feeding point. Table 6 shows the dimensions of the antenna. For manufacturing an antenna, using a network analyzer to measure the resonant frequency f ₀ and the voltage standing wave ratio VSWR. Table 6 shows the measurement results.

  As is clear from the results shown in Table 6, it can be seen that by using the dielectric resin composition of the present invention, an electronic component such as an antenna substrate having a high relative dielectric constant can be obtained. Therefore, it can be seen that a small antenna, which was difficult to manufacture with the conventional resin composition, can be manufactured.

[Examples 22 to 26 and Comparative Examples 7 to 8]
Using the fillers of Synthesis Examples 1 to 7, the molded product of the resin composition obtained by mixing these fillers with the polyphenylene sulfide (PPS) resin used in Examples 8 to 14 (molded product dimensions: 90 mm × 50 mm × 3 mm) was blended so that the relative dielectric constant (εr) was 20. Table 7 shows the weight of the molded product at this time.

  As is clear from the results shown in Table 7, it can be seen that the weight can be reduced by using a granular inorganic filler having a median diameter of 10 μm or more according to the present invention.

The perspective view which shows the patch antenna produced in the Example of this invention.

Explanation of symbols

1 ... Dielectric substrate 2 ... Feed point

Claims (5)

  A dielectric resin composition comprising a synthetic resin matrix containing a granular inorganic filler having a median diameter of 10 μm or more.   2. The granular inorganic filler is one or more selected from titanium oxide, metal titanate, metal niobate, metal tantalate, and metal zirconate, according to claim 1. Dielectric resin composition.   The dielectric resin composition according to claim 1 or 2, wherein the amount of the granular inorganic filler is 10 to 95% by weight.   An electronic component formed by molding the dielectric resin composition according to claim 1. The electronic component according to claim 4, wherein the electronic component is an antenna, a connector, a capacitor, or a sensor.