JPH06239663A - Microwave dielectric material porcelain composition and its production - Google Patents

Abstract

PURPOSE:To obtain a micro wave dielectric material porcelain composition maintaining Qu in a practical range, having a high epsilonr of 37-38 and a tauf of approximately zero, and further exhibiting a stable performance even when a calcination temperature and a baking temperature are changed, and to provide a method for producing the same. CONSTITUTION:This porcelain composition is characterized by comprising a composition of the formula: (Zr1-xSnx) TiO4 (wherein 0.1<=x<=0.3) as a main component and further containing MnO2 and ZnO in amounts of 0.1-0.5 pt.wt. and 0.1-1.0 pt.wt., respectively, per 100 pts.wt. of the (Zr1-xSnx) TiO4. The porcelain composition is produced by mixing the powder of the oxides in a prescribed mixing ratio, calcining the mixture at 800-900 deg.C in the atmosphere, adding a prescribed organic binder and water to the calcined powder, grinding the mixture, lyophilizing the ground product, granulating the lyophilized product, molding the granules into a prescribed shape, and subsequently baking the molded product at 1325-1425 deg.C in the atmosphere.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave dielectric porcelain composition, and more specifically, it maintains an unloaded Q (hereinafter referred to simply as "Q") within a practical characteristic range.
It has a high relative dielectric constant of 6 to 38 (hereinafter, simply referred to as ε _r ) and has a temperature coefficient of resonance frequency (hereinafter, simply referred to as τ _f).
Say. ) Is a small value near zero, and shows stable performance even when the calcination temperature and the firing temperature are changed, and a method for producing the same. INDUSTRIAL APPLICABILITY The present invention is utilized for impedance matching of dielectric resonators, microwave integrated circuit substrates, various microwave circuits, etc. in the microwave region.

[0002]

2. Description of the Related Art Microwave dielectric porcelain compositions (hereinafter simply referred to as dielectric porcelain compositions) tend to increase in dielectric loss as the operating frequency becomes higher.
A dielectric ceramic composition having a large Qu in the micro frequency range is desired. As a conventional dielectric porcelain material having a high ε _r , a dielectric porcelain composition mainly containing a predetermined amount of TiO ₂ , ZrO ₂ and SnO ₂ and containing a predetermined amount of ZnO (JP-A-54- No. 35678), a dielectric porcelain composition containing a predetermined amount of ZnO and NiO in the main component (JP-A-55-34526), and a predetermined amount of ZnO and Ta ₂ O ₅ in the main component. Known are dielectric ceramic compositions (Japanese Patent Application Laid-Open No. 61-13326), and dielectric ceramic compositions (Japanese Patent Application Laid-Open No. 3-28162) containing a predetermined amount of ZnO, NiO and MnO ₂ in the main components. Has been.

[0003]

However, the above-mentioned conventional dielectric ceramic compositions are all satisfied in terms of high Qu, high ε _r and τ _f near 0, and a small variation in performance due to manufacturing conditions. is not.

The present invention solves the above-mentioned problems and maintains 36 to 38 while maintaining Qu within a practical characteristic range.
It is an object of the present invention to provide a microwave dielectric ceramic composition having a high ε _r , a small τ _f value near zero, and stable performance even when the calcination temperature and the firing temperature are changed, and a method for producing the same. And

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made it possible to maintain τ _f close to zero in a dielectric ceramic composition while maintaining Qu within a practical characteristic range, and to obtain a calcination temperature and a firing temperature. As a result of various studies on a composition having stable quality even when the temperature was changed, it was found that addition of MnO ₂ and ZnO eliminates this drawback, and the present invention has been completed.

That is, the dielectric ceramic composition of the first invention is
(Zr _1-X Sn _X ) TiO ₄ (where 0.1 ≦ x ≦ 0.
The composition shown in 3) is the main component.
_1-X Sn _X ) TiO ₄ 0.1 to 100 parts by weight
0.5 parts by weight of MnO ₂ and 0.1 to 1.0 parts by weight (hereinafter, these cases are simply referred to as “weight%”) ZnO.
Is added and contained. If the above X is less than 0.1, the sinterability will be insufficient, and if it exceeds 0.3, the characteristics will rapidly deteriorate, which is not preferable. In addition, the above MnO
_{2 If the} addition amount is less than 0.1% by weight, the sinterability is insufficient and ε _r
When it exceeds 0.5% by weight, Qu is lowered, which is not preferable. Further, the amount of ZnO added is 0.1
If it is less than wt%, ε _r is lowered, and if it exceeds 1.0 wt%, Qu is lowered, which is not preferable.

In the method for producing a dielectric ceramic composition according to the second aspect of the present invention, ZrO ₂ powder, SnO ₂ powder and TiO ₂ powder are converted into (Zr _1-X Sn _X ) TiO ₄ (where 0.1 ≦ x ≦ 0.
The composition formula 3) is used, and the MnO ₂ powder is added in an amount of 0.1 to 0.5 parts by weight (% by weight) based on 100 parts by weight of the above (Zr _1-X Sn _X ) TiO ₄ , and ZnO powder 0.1
To 1.0 part by weight (wt%), and then calcinated in an air atmosphere at a temperature of 800 to 900 ° C. Then, the calcinated powder is mixed with a predetermined organic binder. And pulverizing by adding water, and then granulating the pulverized product by freeze-drying, and then molding the granulated powder into a predetermined shape, and calcining at 1325 to 1425 ° C. in an air atmosphere. Is characterized by. The calcination temperature is set to 800-9
The reason for limiting the temperature to 00 ° C. is that when the temperature is lower than 800 ° C., for example, when the addition amount of MnO ₂ is large, any of the performances may deteriorate and the variation may become large. This is because τ _f decreases.

When MnO ₂ is added, Qu tends to decrease (FIG. 1), ε _r and τ _f tend to increase (FIGS. 2 and 3), and the sintered density does not change much (Table 2). ). In particular, the amount of MnO ₂ added is 0.1% by weight, Z
In a typical case where the added amount of nO is 0.5% by weight, the calcination temperature is 900 ° C., and the firing temperature is 1375 ° C., as shown in Table 1, ε _r is 37.6, Qu is 3500, τ _f is +0.71 ppm / ° C, which shows excellent characteristics. Furthermore, the amount of MnO ₂ added, the amount of ZnO added, and the firing temperature are the same as above, and even if the calcination temperature is changed to 800 to 900 ° C., ε _r is 37.6 ± 0 and Qu is 3500 ±.
0, τ _f is +0.71 to +0.72 ppm / ° C,
The variation in each performance is extremely small (Table 1). When the firing temperature is 1325 to 1425 ° C. (other than above, the same conditions as above), ε _r is 37.4 to 37.7 and Qu is 316.
0 to 3500, τ _f is -0.18 to +0.71 ppm /
C., and even in this case, the variation in each performance is extremely small. Moreover, τ _f becomes a small value around 0 ppm / ° C.

Further, as shown in Table 3, when ZnO is added, ε _r decreases, Qu also decreases, and τ _f slightly shifts to the minus side. Further, as shown in Table 4, X is 0.
When changing to 1-0.3, ε _r decreases and Qu increases,
τ _f shifts to the minus side, but τ _f is X = 0.2
Showed the value closest to zero. In addition, as shown in Table 5,
Even if the type (purity) of ZrO ₂ is changed, the variation in each performance is small as compared with the case where only ZnO is added (MnO _{2 is} not added). From the above, as shown in FIGS. 1 to 3 and Tables 1 to 5, by adding an appropriate amount of MnO ₂ and ZnO, even when firing in a wide temperature range (calcination temperature, firing temperature), the performance is excellent and It is possible to manufacture a sintered body with stable performance and high sintering density.

[0010]

EXAMPLES The present invention will be specifically described below with reference to test examples and examples. (1) Relationship between Addition Amount of MnO ₂ and ZnO, Calcination Temperature and Firing Temperature and Performance ZrO ₂ powder (purity; 99.35%), SnO ₂ powder (purity; 99.7%), TiO ₂ powder ( Purity; 99.9
8%), ZnO powder (purity; 99.5%), and MnO ₂ powder (purity; 94%) as starting materials. Then, as shown in Tables 1 to 3 and FIGS. 1 to 3, the amount of MnO ₂ added was changed in the range of 0.1 to 0.5% by weight, and as shown in Table 3. Then, a predetermined amount (total amount of about 600 g) was weighed and mixed so that the composition was changed in the range of 0.2 to 0.7% by weight of ZnO.

Then, dry mixing (20
˜30 minutes) and primary pulverization, and then calcinated in the air atmosphere at a temperature of 800 to 900 ° C. for 2 hours. Then, 29 g of an appropriate amount of an organic binder (kind; polyvinyl alcohol compound) and 450 to 550 g of water are added to this calcined powder, and an alumina ball of 20 mmφ is used, and 90 rpm, 23
Crushed for hours. After that, vacuum freeze-drying (about 0.4 Tor
r, about 23 hours, freezing temperature -20 ° C, drying temperature 50 ° C)
Granulated by, and using this granulated raw material, 1000k
It was molded into a cylindrical shape of 19 mmφ × 10 mmt (thickness) with a pressing pressure of g / cm ² .

Next, the molded body was placed in the atmosphere at 650 ° C. for 3 days.
Degreasing is performed for a period of time, and then firing is performed at each temperature in the range of 1325 to 1425 ° C. for 3.5 hours, and finally both end surfaces are about 16
It was polished into a cylindrical shape of mmφ × 8 mmt (thickness) to obtain dielectric samples (Nos. 1 to 6 in Table 1, Nos. 1 to 2 in Table 2 and Nos. 1 to 3 in Table 3). Then, for each sample, by the parallel conductive plate type dielectric cylindrical resonator method (TE ₀₁₁ MODE) or the like, epsilon _r, Qu and tau _f, further, was measured sintered density by the Archimedes method. The measurement frequency is 4.2GH
A value converted to 4.5 GHz was shown at z to 4.5 GHz. Also, τ _f is measured in the temperature range of 30 ° C to 80 ° C,
τ _f = (f ₈₀ −f ₃₀ ) / (f ₃₀ × ΔT), ΔT = 80−
It was calculated at 30 = 50 ° C. The results are shown in Tables 1 to 3 and FIGS. HfO is contained in these ZrO _2.
2 is contained by 2% by weight. Further, in FIGS. 1 to 3, ◯ indicates that MnO ₂ and 0.5 wt% ZnO were added to the main component composition, and ▲ indicates that only MnO ₂ was added (without ZnO).

[0013]

[Table 1]

[0014]

[Table 2]

[0015]

[Table 3]

(2) Composition ratio of Zr and Sn: The calcination temperature is 900 ° C. and the firing temperature is 1350 ° C.
_{X in the} composition formula (Zr _1-X Sn _X ) TiO ₄ is 0.
Each porcelain composition was manufactured in the same manner as in the above-mentioned test example except that it was 1, 0.2 and 0.3. The performance of this composition was evaluated in the same manner, and the results are shown in Table 4.

[0017]

[Table 4]

(3) Comparison of high-purity ZrO ₂ powder with low-purity product and comparison with conventional porcelain composition As shown in Table 5, the composition formula (Zr _0.8 Sn _0.2 ) TiO 2
The characteristic values of the porcelain composition, which is ₄ + 0.5 wt% ZnO + 0.1 wt% MnO ₂ and is manufactured under the conditions of calcination and firing shown in Table 5, are shown in the same table. High-purity product (Purity: 99.97
% In Example 1, low purity product (purity; 99.
35%) was used as Example 2. Note that 2% by weight of HfO ₂ is contained in these high and low purity products. As Comparative Example 1, the composition formula (Zr _0.8 Sn _0.2 ) TiO _{4 was used.}
+0.5 wt% ZnO (not containing MnO ₂ ) and using high-purity ZrO ₂ , Comparative Example 2 uses the same composition as Comparative Example 1 and low-purity ZrO ₂ . The comparative example 3 has a composition formula (Zr _0.8 Sn _0.2 ) TiO ₄
+0.3 wt% MnO ₂ (without ZnO) and using high-purity ZrO ₂ , Comparative Example 4 uses the same composition as Comparative Example 3 and low-purity ZrO ₂ . It was what I had.

[0019]

[Table 5]

(4) Effects of Test Examples and Examples According to the results of Table 1, addition of MnO ₂ does not significantly change ε _r , but Qu becomes slightly small, and conversely τ.
_f tends to be large. Therefore, MnO ₂ of 0.1
When the calcination temperature is 800 to 900 ° C and the firing temperature is 1325 to 1425 ° C, Qu (31
It is possible to maintain ε _r at 37 or more (37.2 to 38.0) and suppress τ _f to 0 pp while suppressing the decrease of 0 to 3500).
It can be maintained around m / ° C (-0.34 to +1.28 ppm / ° C).

Even if the calcination temperature is 800, 900 ° C. (Z
nO 0.5 wt%, MnO ₂ 0.1 wt%, firing temperature 1
There is almost no difference in performance even at 375 ° C.) [Qu: Δ (variation is shown, the same applies below) 0, ε _r : Δ 0, τ _f :
Δ0.01], indicating stable performance. Furthermore, even if the firing temperature is varied in the range of 1325 to 1425 ° C. (ZnO 0.5% by weight, MnO ₂ 0.1% by weight, calcination temperature 900 ° C.), the variation in each performance is extremely small (Qu:
Δ340, ε _r : 0.3, τ _f : Δ 0.89), and τ _f is as small as −0.18 ppm / ° C. to +0.71 ppm / ° C., so a small value near 0 ppm / ° C. can be adjusted very easily. . According to Table 2 results, the calcining temperature, changing the firing temperature and MnO ₂ added amounts stable sintered density (5
Above; 5.030 to 5.092) is obtained. According to the results shown in Table 3, ε _r was decreased by adding ZnO and Qu
Also decreases, and τ _f shifts to the negative side.

Further, according to the results of Table 4, SnO ₂ (X
= Within the range of 0.1 to 0.3), ε _r decreases and Qu increases, but τ _f shifts to the negative side and X
Was 0.2 and τ _f was about 0 ppm / ° C. Further, according to the results in Table 5, even when the type (purity) of ZrO _{2 in} Examples 1 and 2 is changed, it is compared with the case where only MnO ₂ is added (ε _r : Δ0.79, τ _f : Δ0). However, when only ZnO is added (ε _r : Δ1.24, τ
_f : Δ5.45), the variation in each performance is small (ε _r : Δ1.02, τ _f : Δ1.19).

The present invention is not limited to the specific examples described above, and various modifications may be made within the scope of the present invention depending on the purpose and application. That is,
Various calcination conditions such as the calcination temperature and the calcination conditions such as the calcination temperature can be selected. Further, as for the oxide, it is possible to use another compound which becomes an oxide by heating.

[0024]

In the dielectric ceramic composition of the present invention,
By adjusting the amount of MnO ₂ added, Qu and ε
_While maintaining _r in a practical (high) characteristic range, τ _f can be brought close to zero or adjusted to desired values on the plus side and minus side centered on zero, so a very good performance balance. Excellent in. Further, it shows extremely stable performance even if the calcination temperature and the calcination temperature are changed. According to the production method of the present invention, the porcelain composition which is stable and has an excellent performance balance can be easily produced.

[Brief description of drawings]

FIG. 1 [(Zr _0.8 Sn _0.2 ) TiO ₄ + (0.1-
0.5) wt% MnO ₂ +0.5 wt% ZnO] A ceramic composition showing the relationship between the amount of MnO ₂ and Qu.

2] In the porcelain composition shown in FIG.
5 is a graph showing the relationship between 0.5 wt% MnO ₂ amount and ε _r .

3] In the porcelain composition shown in FIG.
5 is a graph showing the relationship between 0.5% by weight) MnO ₂ amount and τ _f .

Claims (2)

[Claims] 1. (Zr _1-X Sn _X ) TiO ₄ (provided that 0.
1 ≦ x ≦ 0.3) as a main component, and 0.1 to 0.5 parts by weight of MnO ₂ and 0 based on 100 parts by weight of the above (Zr _1-x Sn _x ) TiO ₄ 1 to 1.0 parts by weight of ZnO is added to the microwave dielectric ceramic composition. 2. ZrO ₂ powder, SnO ₂ powder and TiO _2.
2 powders (Zr _1-X Sn _X ) TiO ₄ (where 0.1 ≦ x
≦ 0.3), and 0.1 to 0.5 parts by weight of MnO ₂ powder with respect to 100 parts by weight of (Zr _1-X Sn _x ) TiO ₄ and 0 of ZnO powder. 1-1.
The mixture is mixed so as to have a blending ratio of 0 parts by weight, and then calcined at a temperature of 800 to 900 ° C. in an air atmosphere, and then a predetermined organic binder and water are added to the calcined powder and the powder is ground. , Then granulate this crushed product by freeze-drying,
Then, the granulated powder is molded into a predetermined shape and fired at 1325 to 1425 ° C. in an air atmosphere, which is a method for producing a microwave dielectric ceramic composition.