JP3447971B2 - Dielectric porcelain composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric ceramic composition suitable for use as a filter, an antenna, a wiring board, and the like in a high-frequency field. 2. Description of the Related Art As frequency bands used in various communication fields become higher in frequency, there is a demand for dielectric ceramic materials having a low relative dielectric constant of less than 10 for applications such as filters, antennas, and wiring boards. Is growing. [0003] The dielectric porcelain material used for such applications is required to have a high Q and good temperature characteristics. It was normal. SUMMARY OF THE INVENTION The present invention is to provide a dielectric ceramic composition having a low dielectric constant, a high Q, and a good temperature characteristic which can be used in a high frequency range. is there. The present invention solves the above-mentioned problems by employing a novel material composition. That is, 61.5 mol% or more of
1% or less, 30.5 mol% or more and 32.5 mol% or less as SiO ₂ , Al ₂
0.1 mol% or more and 2.0 mol% or less as O ₃ , 1.0 mol as SrO
% To 3.0 mol%, 1.0 mol% to 3.0 mol% as ZrO ₂
The following (however, MgO + SiO ₂ + Al ₂ O ₃ + SrO + ZrO ₂ = 100 mol
%). The temperature coefficient (τf) can be reduced by setting the above composition range. Further, by setting the calcining temperature of the material to 1150 ° C. or more, the characteristic (Q) can be further improved. An embodiment of the present invention will be described below. A predetermined amount of each raw material is weighed, wet-mixed in a ball mill for 16 hours, and dried. The powder thus obtained was calcined in an electric furnace, and the calcined powder was wet-mixed with a ball mill for 20 hours and dried. An appropriate amount of the PVA solution was mixed with the dried product, granulated using a sieve, and dried. This granulate
It was formed into a cylinder at a pressure of ² ton / cm ² and fired at 1320-1380 ° C. The dielectric porcelain was measured by the Hakki & Coleman method, and its electrical characteristics and temperature characteristics were measured. Table 1 shows the results when each sample was calcined at 1150 ° C. In each case, while maintaining a high value of Q, a small temperature coefficient was maintained. [Table 1] As a comparative example, samples having the above composition were calcined at 1150 ° C. and measured similarly. Table 2 shows the results. All of them have large temperature coefficients and have practical problems. [Table 2] In order to confirm the difference due to the calcination temperature, a part of the sample having the composition shown in Table 1 was measured in the same manner with the calcination temperature set at 1000 ° C. Table 3 shows the results. It has been confirmed that a large difference occurs in Q depending on the calcination temperature even with the same composition. [Table 3] As described above, by adopting the material composition according to the present invention, a high-frequency low-permittivity dielectric ceramic material having good temperature characteristics can be obtained. By setting the calcination temperature to about 1150 ° C. or more, Q can be improved from 50% to 100%, and a dielectric ceramic composition having not only good temperature characteristics but also good Q can be obtained. .

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-5-262562 (JP, A) JP-A-7-33516 (JP, A) JP-A-6-333429 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H01B 3/12 C04B 35/16 C04B 35/495

Claims (1)

(57) Patent Claims 1. A 65.0Mol% or more 61.5Mol% as MgO or less, 30.5mol% or more 32.5Mol% as SiO ₂ or less, 0.1 mol% or more 2.0 mol% or less as Al ₂ O ₃ A dielectric ceramic composition characterized by containing 1.0 mol% or more and 3.0 mol% or less as SrO and 1.0 mol% or more and 3.0 mol% or less as ZrO ₂ (however, MgO + SiO ₂ + Al ₂ O ₃ + SrO + ZrO ₂ = 100 mol%). .