JPH06215626A - Microwave dielectric porcelain composition and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a microwave dielectric porcelain composition which is provided with a high Qu-value and a high dielectric constant (epsilonr) of 37 to 38 and the temperature coefficient of a small value near to zero, and further shows stable performance even when the kind (purity) of a ZrO2 component material is changed, and also the manufacture thereof. CONSTITUTION:A ZrO2 powder, an SnO2 powder and a TiO2 powder are mixed so as to produce a composition as represented by the following composition formula: (Zr1-xSnx)TiO4 (however, 0.1<=x<=0.3) and also a MnO2 power is mixed so as to have a mixture rate of 0.2 to 0.8 parts by weight relative to the foregoing (Zr1-xSnx)TiO4 of 100 parts by weight. After that, primary heating (provisional heating) is applied to the composition at a temperature of 900 to 1100 deg.C in the atmosphere, and a predetermined organic binder and water are added to a powder to which the primary heating has been applied and then the powder is ground, and the ground powder is dried and granulated, and the granulated powder is molded into a predetermined shape. Next, the molded product is baked at a temperature of 1300 to 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 permittivity of 7 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 the microwave dielectric ceramic composition exhibits stable performance even when the raw material (purity) of the ZrO ₂ component is changed, and a method for producing the same. The present invention relates to a dielectric resonator in the microwave region,
It is used for impedance matching of microwave integrated circuit boards and various microwave circuits.

[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. Particularly, in the one disclosed in JP-A-54-35678, which is a typical one of the above-mentioned ZnO-based dielectric ceramic composition, as shown in Table 5, the type (for example, purity) of the ZrO ₂ component raw material Due to
There are large variations in both performances.

The present invention solves the above-mentioned problems and maintains 37 to 38 while maintaining Qu within a practical characteristic range.
A microwave dielectric ceramic composition having a high ε _r , a small τ _f value near zero, and stable performance even when the type (purity) of the ZrO ₂ component raw material is changed, and a method for producing the same. The purpose is to

[0005]

DISCLOSURE OF THE INVENTION In the dielectric ceramic composition, the present inventors have made it possible to bring τ _f close to zero while maintaining Qu within a practical characteristic range, and to provide a calcination / firing temperature. As a result of various studies on a composition having stable quality even when the type of the ZrO ₂ component raw material was changed, the inventors found that the addition of MnO ₂ eliminates this drawback, and thus completed the present invention. is there.

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
It is characterized in that 1.0 part by weight of MnO ₂ was additionally contained. If the above X is less than 0.1, the sinterability becomes insufficient,
When it exceeds 0.3, the characteristics are rapidly deteriorated, which is not preferable. Further, if the amount of MnO ₂ added is less than 0.1, the sinterability is insufficient and ε _r decreases, and if it exceeds 1.0, Q
This is unfavorable because it lowers u.

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 0.1 to 1.0 parts by weight of MnO ₂ powder is added to 100 parts by weight of the above (Zr _1-x Sn _x ) TiO ₄ (hereinafter, this case is simply referred to as ""% By weight"), and then calcinated in an air atmosphere at a temperature of 900 to 1100 ° C, and then added a predetermined organic binder and water to the calcined powder. It is characterized in that the pulverized product is granulated by freeze-drying, then granulated by freeze-drying, then molded into a predetermined shape using the granulated powder, and fired at 1350 to 1425 ° C. in the air atmosphere. . The calcination temperature is 900 to 1100 ° C.
The reason why it is limited to
If the addition amount of O ₂ is small, ε _r may decrease and the variation may increase, and if it exceeds 1100 ° C,
This is because, particularly when the amount of MnO ₂ added is large, ε _r and Qu are greatly reduced, and variations may be increased.

In particular, the amount of MnO ₂ added is 0.3 to
When 0.8 wt% of high-purity ZrO ₂ is used and the calcination temperature is 900 ° C. and the firing temperature is 1350 to 1400 ° C., ε _r is 37.9 as shown in Tables 1 to 3. ~ 3
8.6, Qu is 2940 to 3780, and τ _f is -0.95.
It is +0.87 ppm / ° C, and the variation in the performance is extremely small. Further, the addition amount of MnO ₂ is 0.3 to
0.8% by weight, high-purity and low-purity ZrO ₂ is used, the calcination temperature is 1000 ° C., and the firing temperature is 1350 ° C.
As an example, as shown in Tables 1 to 3, the difference in performance between the high-purity product ZrO ₂ and the low-purity product ZrO ₂ is Δε _r ; , ΔQu; 20
To 80, .DELTA..tau _f is 0.17~0.35ppm / ℃, even changing the type of ZrO _2, variation in the performance is extremely small.

When MnO ₂ is added, Qu tends to decrease (FIG. 1), ε _r tends to increase (FIG. 2), τ _f does not change so much, and 0 ppm / ° C.
Before and after (Fig. 3), it is very preferable. Also, the sintered density does not change much (Fig. 4). Furthermore, the calcination temperature is 900-
At 1000 ° C., ε _r , Qu and τ _f are all stable (FIGS. 5-7). Further, the firing temperature is 1350 to 14
In case of 00 ° C (for example, the composition formula is [(Zr _0.8 Sn _0.2 ))
TiO ₄ +0.3 parts by weight MnO ₂ ], calcination temperature is 100
At 0 ° C., when using a high-purity product ZrO ₂ ), ε _r is 3
The value is 8.0 to 38.1, the Qu is 3550 to 3620, and the τ _f is −0.88 to +0.31 ppm / ° C., and the variation is extremely small. From the above, as shown in FIGS. 1 to 7 and Tables 1 to 4, by adding an appropriate amount of MnO ₂ , ZrO ₂
Even if the type of raw material is changed, a wide temperature range (calcination temperature,
Even when fired at a firing temperature, 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 MnO ₂ Addition Amount, Calcination Temperature and Firing Temperature and Performance ZrO ₂ powder (purity; 99.35%, also called low-purity product) or ZrO ₂ powder (purity; 99.95%, high) Purified product), SnO ₂ powder (purity: 99.7)
%), TiO ₂ powder (purity; 99.98%), MnO ₂
Prepare powder (purity; 96%) as a starting material. Then, as shown in Tables 1 to 3 and FIGS. 1 to 7, a predetermined amount (the total amount is about 600 g) is adjusted so that the composition is changed in the range of 0.3 to 0.8% by weight of MnO _2. ) Was weighed and mixed.

Then, dry mixing (20
˜30 minutes) and primary pulverization, and then calcination in the atmosphere at a temperature of 1000 ° C. for 2 hours. Then, to this calcined powder, 29 g of an appropriate amount of an organic binder (type; polyvinyl alcohol type) and 500 to 650 g of water are added, and 20 mm
It was crushed with a φ alumina ball at 90 rpm for 23 hours. Then, vacuum freeze-drying (about 0.4 Torr, -35
Granulation at about 50 ° C. for about 23 hours) and using the granulated raw material at a pressing pressure of 1000 kg / cm ² for 19 m
It was formed into a cylindrical shape of mφ × 10 mmt (thickness).

Next, the molded body was placed in the atmosphere at 650 ° C. for 2 hours.
After degreasing for 3 hours, it is baked at each temperature in the range of 1350 to 1400 ° C for 3.5 hours, and finally both end surfaces are about 16
The dielectric sample (Nos. 1 to 9 in Tables 1 to 3) was polished into a cylindrical shape of mmφ × 8 mmt (thickness). Then, for each sample, the parallel conductor plate type dielectric cylinder resonator method (TE ₀₁₁
MODE, etc., ε _r , Qu, and τ _f , and the sintered density was measured by the Archimedes method. The measurement frequency was 4.2 GHz to 4.3 GHz, and the value converted to 4.5 GHz was shown. Further, τ _f is measured in a temperature range of 20 ° C. to 80 ° C., and τ _f = (f ₈₀ −f ₂₀ ) / (f ₂₀ × ΔT),
It was calculated at ΔT = 80−20 = 60 ° C. The results are shown in Tables 1 to 3 and FIGS. Incidentally, Zr in Tables 1 to 3
O ₂ (1) indicates a high-purity product, and ZrO ₂ (2) indicates a low-purity product. 2% by weight of HfO ₂ is contained in these high and low purity products.
included. Further, in FIGS. 1 to 7, ◯ indicates a high-purity product, and ● indicates a low-purity product.

[0013]

[Table 1]

[0014]

[Table 2]

[0015]

[Table 3]

(2) Composition ratio of Zr and Sn As shown in Table 4, the calcination temperature is 900 ° C. and the firing temperature is 1.
350 ° C., composition formula (Zr _1-X Sn _X ) TiO ₄
Each porcelain composition was manufactured in the same manner as in the above-mentioned Test Example except that X in 0.1 was 0.2, 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 with Prior Art As shown in Table 5, the composition formula (Zr _0.8 Sn _0.2 ) TiO 2
₄ + 0.3 wt% MnO ₂ of high-purity product (Example 1) and low-purity product (Example 2) of ZrO ₂ was used.
Characteristic values of the porcelain composition produced under the conditions of calcination and firing shown in are shown in the same table. Comparative Example 1 is a composition formula (Zr _0.8 Sn
_0.2 ) TiO ₄ +0.3 wt% ZnO, using high-purity ZrO ₂ , Comparative Example 2 shows the composition formula (Zr
_0.8 Sn _0.2 ) TiO ₄ +0.3 wt% ZnO, which is a low-purity product of ZrO ₂ .

[0019]

[Table 5]

(4) Effects of Test Examples and Examples According to the results of Tables 1 to 3, the addition of MnO ₂ caused τ _f
Although it does not change much, Qu tends to be slightly smaller, and conversely, ε _r tends to be larger. Therefore, by adding 0.3 to 0.8 wt% of MnO ₂ , it is possible to maintain ε _r of 37 or more while suppressing the decrease of Qu, and τ _f of 0 ppm.
Can be maintained near / ° C. The calcination temperature is 900 to 10
00 ° C. is preferable, and at 1100 ° C., variations in performance may occur, and particularly when 0.8% by weight of MnO ₂ is added, the variations may occur. Furthermore, even if the firing temperature is changed in the range of 1350 to 1400 ° C., τ _f
And the variation of ε _r (especially τ _f ) is small,
A small value around 0 ppm / ° C can be adjusted very easily. Further, even if the raw material powders in which the type (purity) of ZrO ₂ is changed are used, the variation in each performance is remarkably small as compared with the comparative example. From the above, the calcination temperature is 900 to 1000 ° C.
If the amount is set to a certain level, a porcelain composition having stable performance can be produced even if the type (purity) of ZrO ₂ , the firing temperature, and the appropriate addition amount of MnO ₂ are changed.

Further, according to the results in Table 4, ε _r decreases and Qu increases with increasing SnO ₂ , but τ _f shifts to the negative side. On the other hand, due to the decrease of SnO ₂ ,
ε _r improves, Qu decreases, and τ _f shifts to the positive side. In addition, according to the results of Table 5, the porcelain composition of the present invention (Examples 1 and 2) was compared with the conventional ZnO-based porcelain composition (Comparative Examples 1 and 2) to determine the type of ZrO ₂ component raw material. Even if changed, the difference between each performance (especially ε _r and τ _f ) is small,
Of these, τ _f is particularly small. Furthermore, the SE of the sintered body
According to M analysis (not shown), remarkable grain growth was observed regardless of whether the high-purity ZrO ₂ product or the low-purity ZrO ₂ product was used. The one with high powder activity) is stronger. Further, when the low-purity ZrO ₂ was used, many cracks were observed in the sintered body (not shown). This is due to the composition densification (SE
It is considered that the time of firing (when the temperature was lowered) was entered by M analysis.

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.

[0023]

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, even if the type of powder of the ZrO ₂ component raw material is changed, extremely stable performance is exhibited. 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 + ( _{0.3 to}
0.8) wt% MnO ₂ ] In the porcelain composition, MnO
It is a graph which shows the relationship between ₂ quantity and Qu.

FIG. 2 shows the porcelain composition shown in FIG.
8 is a graph showing the relationship between the amount of MnO ₂ (0.8 wt%) and ε _r .

3] In the porcelain composition shown in FIG.
8 is a graph showing the relationship between the amount of MnO ₂ (0.8 wt%) and τ _f .

4] In the porcelain composition shown in FIG.
8 is a graph showing the relationship between the amount of MnO ₂ (0.8 wt%) and the sintered density.

FIG. 5 [(Zr _0.8 Sn _0.2 ) TiO ₄ + ( _{0.3 to}
8 is a graph showing the relationship between the calcination temperature and Qu in a 0.8) wt% MnO ₂ ] porcelain composition.

6 is a graph showing the relationship between calcination temperature and ε _r in the porcelain composition shown in FIG.

7 is a graph showing the relationship between calcination temperature and τ _f in the porcelain composition shown in FIG.

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 1.0 part by weight of MnO ₂ is added to 100 parts by weight of the above (Zr _1-x Sn _x ) TiO _4. A microwave dielectric porcelain composition characterized by being contained. 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 the compounding ratio of MnO ₂ powder is 0.1 to 1.0 parts by weight with respect to 100 parts by weight of (Zr _{1 -X} Sn _x ) TiO ₄ described above. As described above, and then calcinated in the atmosphere at a temperature of 900 to 1100 ° C., and then pulverized by adding a predetermined organic binder and water to the calcinated powder, and then freeze the pulverized product. A method for producing a microwave dielectric ceramic composition, which comprises granulating by drying, then shaping the granulated powder into a predetermined shape, and firing at 1350 to 1425 ° C. in an air atmosphere.