JPH0246537B2 - KEISANSETSUKAIJIKISOSEIBUTSU - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to ceramics, particularly silicate-lime porcelain compositions, used in the electronics field such as high-frequency integrated circuit boards, dielectric resonators, resonator supports, IC packages, and microwave transmission windows. (Prior Art) Lime silicate has been conventionally used as high frequency insulating porcelain. However, compared to alumina porcelain, this porcelain
Due to the large dielectric loss at high frequencies above 1 GHz, there are applications at relatively low frequencies (~10M
Hz). (Problems to be Solved by the Invention) If the drawback of the conventional lime silicate porcelain of large high-frequency dielectric loss can be solved, the range of its use can be expanded, and improvement thereof is strongly desired. (Means for Solving the Problems) The present invention was made in view of the above situation, and by adding a small amount of TiO ₂ to SiO ₂ −CaO, the sintered product can increase the resonance frequency. We have found that not only the temperature coefficient of is small, but also the high frequency dielectric loss can be made extremely small. That is, the gist of the present invention is to calculate the mole fraction in the range surrounded by the quadrilateral area connecting the points A, B, C, and D of the ternary composition diagram in Figure 1 of the attached sheet (which constitutes the quadrilateral). (including on the straight line) SiO ₂ , CaO and
It is a porcelain composition consisting of _TiO2 , with points A, B,
C and D shall be as shown in the following table.

【table】

[Table] Combine the three components in a total amount of 500 g, and add 350 ml of deionized water to a polyethylene ball mill with an internal volume of 1 (20 φ mm, 99.9% alumina ball 1 kg).
and grind and mix for 50 hours. This slurry is freeze-dried to form a powder, which is calcined at 1260°C for 1 hour and passed through a 32-mesh sieve. 300 g of the above calcined powder 200 ml of deionized water 9 g of hydroxypropyl cellulose The above three components were placed in a polyethylene ball mill (20 φ mm, 2 kg of 99.9% alumina balls) with an inner volume of 1, and mixed and ground for 50 hours. The slurry thus obtained was freeze-dried, and the dried powder was passed through a 32-mesh sieve to form a base material. Next, the base material was heated to a pressure of 1500Kg/cm ² and the size was 19φmm×
It was press-molded with a die of 10.2Lmm. This molded body is fired in the air at the optimal temperature in the range of 1280℃ to 1320℃, and the fired product is sized.
Polished to 15φmm x 8Lmm. Both end faces are 0.1S and side faces are 0.3S. Table 1 shows the results of measuring various properties of processed products that were ultrasonically cleaned with acetone for 30 minutes and deionized water for 30 minutes. The measurement was performed using a dielectric cylinder resonance method at a measurement frequency of 9 to 10 GHz.

【table】

[Table] As is clear from Table 1, the dielectric power factor was
The dielectric power factor is a small value of 0.7 to 1.9, whereas the dielectric power factor of a comparative example outside the scope of the present invention is a large value of 7.2 to 7.9. Furthermore, the Q value of the examples of the present invention is as large as 3000 to 4000, whereas that of the comparative example is as small as 900 to 400. Next, in the present invention, SiO ₂ is set to 45.0 mol % to 51.5 mol % because when SiO ₂ is less than 45.0 mol %, both the relative dielectric constant and the temperature coefficient of the resonance frequency become large. This is because the dielectric power factor becomes significantly large. In addition, the reason why CaO is set at 48.0 mol% to 52.0 mol% is because if CaO is less than 48.0 mol%, a sintered body cannot be obtained, and if it exceeds 52.0 mol%, the dielectric power factor tends to be extremely poor. It is. Furthermore, the reason why TiO ₂ is set to 0.5 mol % to 3.0 mol % is that when TiO ₂ is less than 0.5 mol %, although the temperature coefficient of the resonance frequency is extremely excellent, the dielectric power factor is too large; This is because if it exceeds , the dielectric power factor becomes extremely large even though the temperature coefficient of the resonance frequency becomes large. (Effect of the invention) As can be seen from the above explanation, in the present invention, SiO ₂
By creating a composition in which CaO and TiO ₂ are mixed in a specific ratio and sintered, we can take advantage of the small temperature coefficient of resonance frequency of SiO ₂ + CaO in the high frequency range.
The inclusion of TiO ₂ makes it possible to significantly reduce high-frequency dielectric loss, making it possible to provide insulating porcelain that is extremely effective in the field of high-frequency applications.

[Brief explanation of the drawing]

FIG. 1 is a three-component composition diagram showing the basic component ranges of the present invention.

Claims (1)

[Claims] 1. In the ternary composition diagram in which the blending ratio of the ternary porcelain composition consisting of SiO ₂ , CaO and TiO ₂ is expressed in mole fraction, on the line connecting the points below [Table] and this line A silicate lime porcelain composition characterized by being in a composition range surrounded by.