JPS6386318A - Dielectric ceramic composition - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dielectric ceramic composition suitable as a dielectric for a temperature-compensating multilayer ceramic capacitor whose internal electrodes are made of a base metal such as nickel.

[Prior art] Japanese Patent Application Laid-open No. 59-227789 describes ((Sr C
a) 1-×x O) Basic component consisting of kTi02 and L i 20 and 5
i02 and MO (however, MO is BaO1CaO and SrO
Disclosed is a dielectric ceramic composition containing an additive component consisting of at least one metal oxide of the following. Since this ceramic composition can be sintered in a non-oxidizing atmosphere, it can be used to provide a temperature-compensating multilayer ceramic capacitor in which internal electrodes are made of a base metal such as nickel. By the way, in order to improve the performance and reduce the size of temperature-compensating ceramic capacitors, a dielectric ceramic composition having a high Q and a high resistivity ρ is required, and the dielectric ceramic composition disclosed in the above-mentioned publication is required. In materials, Q is less than 4400 in the range of temperature coefficient (TC) of dielectric constant from +350 to -1000 (DplB/"C), and sufficient Q cannot necessarily be obtained.Therefore, the applicant of the present application Special application 1986-29800
In Specification No. 4, ((Sr 1-x-y Ca ,
My) O) k(Ti1-zZr)o2 (where M is Mg or zn), and B2O
3 and SiO2 and MO (Ba 01Mg01Zn O,S
A new dielectric ceramic composition comprising an additive component consisting of at least one of r O and CaO is disclosed. According to this new dielectric ceramic composition, the temperature coefficient (TC) is within and outside the range of +350 to -1ooo < pp1/°C), has a Q of 4500 or more, and has a Q of 1.0 at 20°C. OX10
A resistivity ρ of 7MQ·01 or more can be obtained.

[Problems to be Solved by the Invention] The dielectric ceramic composition disclosed in the above specification can be used as a dielectric substrate of a capacitor used under normal environmental conditions (for example, -25°C to +85°C). Although fully usable, it has been found to be insufficient as a dielectric substrate for capacitors that may be used in harsh environmental conditions (eg, 125° C.). That is, in the dielectric ceramic composition disclosed in the above specification, the resistivity ρ at high temperature (for example, 125°C) is set to 1. OX105
It is impossible or difficult to make it more than MQcm. Therefore, the object of the present invention is to obtain a material that can be obtained by firing in a non-oxidizing atmosphere at 1200'C or less, and has a Q of 5000.
Above, the resistivity ρ at 125'C is 1. “Oxlo”
It is an object of the present invention to provide a dielectric ceramic composition having a diameter of MO.cm or more.

[Means for solving problems].

The present invention for solving the above problems and achieving the above objects consists of 100 parts by weight of a basic component and 0.2 to 15.0 parts by weight of an additive component, wherein the basic component is N Ma
Mb) 01 k(Ti 1-w-v Zr
.

1-V'/Si)02 (However, Ma is at least one metal selected from sr (strontium) and Ca (calcium), and Mb is at least one metal selected from + (magnesium) and Zn (zinc). At least one metal, y, k, W, ■ is 0.005≦y≦0.100.1.00≦≦1.2
0o, o, oos≦W≦o, ioo, o, oo1≦
V≦o, ioo), and the additive components are B2O3 and S i O2) (however, M
O is BaO, Mg01ZnO1SrO1 and CaO
In the triangular diagram showing the composition with at least one metal oxide of
0 mol%, point (A) where the MO is 19 mol%, and the point B
O is 1 mol%, the SiO2 is 39 mol%, the M
A point (B) where O is 60 mol%, a point (C) where the B2O3 is 30 mol%, the 5in2 is 0 mol%, and the MO is 70 mol%, and the B2O3 is 90 mol% and the Sio2
is 0 mol%, the MO is 10 mol%, point (E) is 90 mol%, the 5in2 is 10 mol%, the MO is 0 mol%, and the B203 is 2o
mol%, the S i O2 is 80 mol%, the MO is 0
This relates to a dielectric ceramic composition within a region surrounded by six straight lines sequentially connecting points (F) of mol %.

[Operations and Effects of the Invention] The dielectric ceramic composition of the invention described above is provided in a non-oxidizing atmosphere, 12
Since it can be obtained by firing at temperatures below 00°C, it is suitable as a dielectric for temperature-compensating multilayer ceramic capacitors in which the base metal of a nickel cap is used as an internal electrode. According to this dielectric ceramic composition, the relative dielectric constant ε is 151 to 323, and the Q is 5000.
Above, the temperature coefficient of dielectric constant TC is -690 to -31oOp
pn/'C1 resistivity ρ is 20'Crl, o xlo
MQ ・cn or more, 125℃r1. o X10”MO
・Big difference between the dielectric ceramic composition disclosed in the above-mentioned Japanese Patent Application No. 60-298004 and the dielectric ceramic composition of the present invention, which can obtain a temperature-compensating ceramic capacitor of 0.01 or higher. maintains a Q of 5000 or more and becomes 1
The resistivity ρ at 25° C. can be set to 1.0′×10 5 MΩ·C1 or more. The reason why it is possible to suppress the decrease in resistivity ρ at high temperatures while maintaining such a high Q is because Si (silicon) is included as a basic component.

As the value of $1 in the basic components increases, the resistivity ρ at high temperatures increases, but if it increases too much, it is not possible to obtain a dense sintered body.Dielectric with a large resistivity ρ at high temperatures according to the present invention By using a porcelain composition, the distance between the electrodes of the container can be shortened, so that a temperature-compensating porcelain container used under high-temperature conditions can be made smaller. Further, since it is possible to provide a ceramic capacitor having a high Q despite the large resistivity ρ, it is possible to improve the performance of electronic circuits using the ceramic capacitor.

[Examples] Next, examples (including comparative examples) of the present invention will be described. Test fINo in Table 1, k of 1 = 1.00, X =
0.28.3. =0.01, w=0.05, v=0.0
More specifically, Ma = Sr CaO, 99
Since 0,710,28゛Mb = Zn, 0.01 0.01 (s r c az n > o (T
r o, 940.71 0.28 0.01 Zr Si )0 0.05 0.01 2 5rC03 (strontium carbonate) with a purity of 99.0% or more, Ca C03 (
calcium carbonate), Zn0 (zinc oxide), 'ri02
(Titanium oxide>nZro2 (zirconium oxide), 5
Prepare iO7 (silica) as a starting material and add Sr C0486.38g (equivalent to 0.71 mole part) without adding impurities.
Ca Co 129.94g (equivalent to 0.28 mole part) Zn O3.78g (equivalent to 0.01-1 nyl part) T i O2348.53g (equivalent to 0.94 mole part) Z r 0228.59 (1 (0, Equivalent to 0.05 mol part> S i O22,799 (equivalent to 0.01 mol part) was weighed, and 2.59 mol of water was added to these raw materials to make 15
Mixed time-wise.

Next, this raw material mixture was dried at 150°C for 4 hours, and then ground. Next, this ground material was dried at 1100°C.
It was calcined in the air for 2 hours to obtain a powder having the basic components of the above composition formula. On the other hand, in order to obtain the additive components of sample No. 1 in Table 2, B2O31,01 (1 (1 mol%) S i O70,05g (80 mol%) B a CO8
,49c+ (3,8 mol%)M(l 0
2.23 (1 (3,8 mol%) Zn O4,51!+
(3.8 mol%) S r CO8.17g
(3,8-t-nyl%)Ca CO5,54(+ (
3.8 mol%) and add 300% alcohol to this.
cc was added and stirred for 10 hours using an alumina ball in a polyethylene pot, then pre-calcined in the air at 1000°C for 2 hours, placed in an alumina pot with 300cc of water, crushed with an alumina ball for 15 hours, and then rear,
After drying at 150°C for 4 hours, B203 was 1 mol%, 5
i02 is 80 mol%, MO is 19 mol%, (BaO3,
A powder of additive components having a composition of 8 mol % + M (1 2 O3, 8 mol % + Zn O 3, 8 mol % + 5r0 3.8 mol % + Ca O 3, 8 mol %) was obtained.

Next, 30 g (3 parts by weight) of the above additive component powder was added to 1000 (1 (100 parts)) of the basic component powder, and an organic compound consisting of an aqueous solution of acrylic acid ester polymer, glycerin, and condensed phosphate was added. 15% by weight of binder is added to the total weight of the basic components and additive components, and 50% of water is added, and these are crushed and mixed in a ball mill to create a slurry of porcelain raw materials. did.

Next, the above slurry is put into a vacuum defoaming machine to defoam, and this slurry is put into a reverse roll coater, which is used to form a thin film based on the slurry on a polyester film, and this thin film is applied onto the film. The mixture was heated to 100° C. and dried to obtain a green sheet (unsintered porcelain sheet) with a thickness of about 25 μm. This sheet is long and is used by punching out a 10cm square.

On the other hand, the conductive paste for internal electrodes has an average particle size of 1.5 μm.
10g of nickel powder of I and 0.9g of ethyl cellulose
was dissolved in 9.1 g of butylcarpitol, and the mixture was placed in a stirrer and stirred for 10 hours. Use this conductive paste to form 5 patterns of length 141 IO 1 width 71.
After printing on one side of the green sheet through a screen having 0 screens, it was dried.

Next, two green sheets were laminated with the printed side facing up. At this time, adjacent upper and lower sheets are arranged so that their printed surfaces are shifted by about half in the longitudinal direction of the pattern, and four 60 μm thick green sheets are laminated on each of the upper and lower surfaces of this laminate. did. Next, this laminate was compressed at a temperature of about 5° C. by applying a pressure of about 40 tons in the thickness direction. Thereafter, this laminate was cut into a grid shape to obtain approximately 50 laminate chips.

Next, this laminate chip was placed in a furnace capable of firing in an atmosphere, and the temperature was raised to θOO″C at a rate of 100° C./h in an air atmosphere to burn the organic binder.

After that, the atmosphere of the furnace is changed from the atmosphere to H22 volume % + N29.
The atmosphere was changed to 8% by volume. Then, while maintaining the reducing atmosphere in the furnace as described above, the heating temperature of the stacked chips was increased from 600°C to the sintering temperature of 1190°C.
The temperature was raised at a rate of 1190°C/h and held at 1190°C (maximum temperature) for 3 hours, then the temperature was lowered to 600°C at a rate of 100°C/h, the atmosphere was changed to air (oxidizing atmosphere), and the temperature was increased to 600°C. The oxidation treatment was carried out by maintaining the temperature at °C for 30 minutes, and then cooling to room temperature to obtain sintered chips.

Next, a conductive paste consisting of zinc, glass frit, and vehicle is applied to the side surface of the sintered chip where the electrodes are exposed, dried, and baked in the air at a temperature of 550°C for 15 minutes to form a zinc electrode. A layer is formed, copper is deposited on top of this by electroless plating, and then P is deposited on top of this by electroplating.
A b-3n solder layer was provided to form a pair of external electrodes.

As a result, as shown in Fig. 1, the dielectric ceramic layer (1)
, (2), (3), and internal electrodes (4), (5),
A multilayer ceramic capacitor (10) consisting of external electrodes (6) and (7) was obtained. The thickness of the dielectric ceramic layer (2) of this capacitor (10) is 0.02 rare, and the facing area of the internal electrodes (4-inch (5)) is 511 m x 5 m.
n=25 n12.

Moreover, the composition of the porcelain layer (1) (203) after sintering is substantially the same as the mixed composition of the basic component and the additive component before sintering, and
Basic component of mold structure (Sr Ca Zn O, 710, 280, 01) 0 (T' 0.94Zr
5i (1,050, (11)02) Between the crystal grains are B2031 mol%, S + 0280 mol%, BaO3, 8 mol%, 1103.8 mol%, and Zn.
A homogeneous distribution of the additive components consisting of 8 mol % O3, 3.8 mol % 5r0 and 8 mol % CaO3 is obtained.

Next, the dielectric constant ε3, temperature coefficient TC, Q, and resistivity ρ of the completed multilayer ceramic capacitor were measured. As shown in sample Na 1 in Table 3, ε is 241 and TC is -166.
0ppn/'C2Q is 11000, ρ is 3.
1 xlo MΩ・clN, 2.2 x at 125°C
It was 105MΩ·CIm. Note that the above electrical characteristics were measured in the following manner.

(A) The relative permittivity ε is at a temperature of 20°C and a frequency of 1MH.
2. Measure the capacitance under the condition of AC voltage (effective value > 0.5V, and combine this measurement value with the thickness of porcelain N (2) 0.05 + 11
Calculated from 111.

(B) The temperature coefficient (TC) is the capacitance (C
85) and the capacitance (C20) at 20°C, and (
C) Q is the frequency I MHz at a temperature of 20°C,
Voltage [actual value] Measured with a Q meter at 0.5 V AC.

(D> Resistivity ρ (MΩ・cm) is determined by measuring the resistance value between a pair of external electrodes (607) after applying DC 50V for 1 minute at a temperature of 20″C and 125°C, and calculating this measured value and the dimensions. It was calculated based on.

Above, we have described the preparation method of sample No. 011 and its characteristics, but the compositions of basic components and additive components, their ratios, and the firing temperature in a reducing atmosphere (non-oxidizing atmosphere) are also explained for other samples Nα2 to Nα2 to 92. A multilayer ceramic capacitor was manufactured in exactly the same manner as in Test FINα1, except that the values were changed as shown in Tables 1, 2, and 3, and the electrical characteristics were measured in the same manner.

Table 1 shows the values for determining the compositional formula (% formula) of the basic components of each sample, x, y, w, v, that is, the numerical value indicating the ratio of the number of atoms of each element, and the content of Mb. and,
Table 2 shows the amount (11 parts) of additive components added to 100 parts by weight of the basic component of each sample and the composition of the additive components.
The proportion of n 01sr o, caO is shown in mol %. Table 3 shows the firing temperature (!! is high temperature) for sintering in a reducing atmosphere and the electrical properties of each sample.

As is clear from Tables 1 to 3, in the samples according to the present invention, when fired in a non-oxidizing atmosphere at 1200°C or lower, the relative dielectric constant ε is 151 to 323, the Q is 5000 or more, and the temperature coefficient of the dielectric constant TC is -690 to -3100pp11/℃
The range is . Also, the resistivity ρ is 160×10 at 20℃
Ma-C1 or higher, 1. at 125°C. OxlO5MΩ-C
It will be 11 or more.

On the other hand, sample 7.8.9.10.29.33.34.3
8.43.44.49.53.54.58.59.63
．． 68, 69, 75, 76, 82 cannot achieve the purpose of the present invention, and therefore they are outside the scope of the present invention.

Next, the reasons for limiting the composition will be described.

When the amount of the additive component is zero, as is clear from sample 76, a dense sintered body cannot be obtained even if the firing temperature is 1300°C, but as shown in sample 77, when the amount added is 100 parts by weight, 119 in the case of 0.2 parts by weight based on the basic component of
A sintered body having desired electrical properties can be obtained by firing at 0°C. Therefore, the lower limit of the additive component is 0.2 parts by weight. On the other hand, as shown in sample No. 82, when the amount added is 18 parts by weight, Q becomes less than 5000, which is worse than the desired properties, but when the amount added is 15 parts by weight, as shown in sample NQ81, the desired characteristics are characteristics can be obtained. Therefore, the upper limit of the amount added is 15 parts by weight.

The value of X is, for example, between samples, 24.25.26.27.2
As shown in 8, desired electrical characteristics can be obtained with any value from 0 to 0.995. Therefore, the value of X includes all values from 0 to 0.995.

In addition, when x is 0.995 as shown in sample spacing 28,
x+y=l, and S' is zero after all. Therefore, the contents of Ma in the general formula according to the present invention are Sr, Ca, Sr
+Ca.

If the value of y is <0.002 as shown in Sample Interval 29.34, the effect of adding Mb (Mg and/or Zn) is not seen, but the y value as shown in Sample Interval 30.35.39 is 0
, 005, desired electrical characteristics can be obtained.

Therefore, the lower limit of the value of y is o, oos. On the other hand, if the value of y is <0.12 as shown in sample NQ33.38.43, a dense sintered body cannot be obtained, but as shown in sample NQ32.37.
42, desired electrical characteristics can be obtained when the value of y is 0.10. Therefore, the upper limit of the value of y is 0.10.

If the value of W is < 0.002 as shown in 44 for the sample, then ρ at 125°C is 1. The effect of adding 02 is not seen, but the difference between samples is lower than OX2O3MΩ・CI.
5, desired electrical characteristics can be obtained when the value of W is o or oos. Therefore, the lower limit of the value of W is 0.0
It is 05. On the other hand, when the value of W is 0°12, a dense sintered body of less than m cannot be obtained as shown in 49, but when the value of W is 0.10 as shown in 48, Desired electrical characteristics can be obtained.

As shown in the sample interval 54.59 (if the value of
Although the effect of adding 02 was not seen, the amount of sample material was 55.6
As shown in 0.64, desired electrical characteristics can be obtained when the value of ■ is o or ooi. Therefore, the lower limit of the value of V is 0.
It is 001. - As shown in sample NQ53.58.63.68, when the value of v is 0.12, a dense sintered body cannot be obtained, but as shown in sample NQ52.57.62.67, v
When the value of is 0.10, desired electrical characteristics can be obtained.

Therefore, the upper limit of the value of V is 0.10. For example, as shown in 50.51.52 for the sample, if the value of ■ is gradually increased, ρ at 125°C also gradually increases
It can be seen that i contributes to an increase in resistivity ρ at high temperatures.

If the value of k is <0.99 as shown in sample Nα69,
ρ is 5.3 x 10' at 20℃ and 125℃, respectively.
1.2 x 101MΩ・CIl, and Q is also significantly lower at 450, but as shown in sample NQ70, the value of k is 1.
．． In the case of 00, desired electrical characteristics can be obtained. Therefore, the lower limit of the value of k is 1.00. On the other hand, the value of k is
If k<1.25 as shown in 75, a dense sintered body cannot be obtained, but if the sample has a k value of 1.2 as shown in 74,
In the case of 0, desired electrical characteristics can be obtained. Therefore, the upper limit of the value of k is 1.20.

The preferred composition of the additive components is B2B203-8i in Figure 2.
It can be determined based on a triangular diagram showing the composition ratio of O2-. Point (A) of the triangular diagram is the BOI mol% of 1 between samples,
5iO2 shows a composition of 80 mol % and MO 19 mol %, and point (B) is sample No.

82031 mol% of 2, S! 0239 Mol%, M
The composition of O60 mol% is shown, and point (C) is sample N013 with B 20330 mol%, Si 020 mol%, MO7
It shows a composition of 0 mol%, and point (D) is B2 of sample No. 4.
0390 mol%, S i 020 mol%, MOIO-
11% composition, point (E) is the sample amount, B2 of 5
0390 mol%, SiO2 10 mol%, MO 10 mol%, and point (F) is sample No. 820 of 6.
The composition is 320 mol%, 5i080 mol%, and MOO mol%.

The composition of the additive component of the sample that falls within the scope of the present invention is within the area surrounded by six straight lines connecting the first to sixth points (A) to (F) in the triangular diagram in order. . If the composition is within this range, desired electrical characteristics can be obtained. In addition, as is clear from samples Nα86 to 92 in the triangular diagram, S
Even if one of i O2 and M O is omitted, the characteristics targeted by the present invention can be obtained.

On the other hand, if the composition of the additive component is outside the range specified in the present invention, as in sample Nα7.8.9.10, a dense sintered body cannot be obtained. , 11.12.13.14.15 as shown in BaO
, Mgo, Zno, sr 01CaO-
or in appropriate proportions as shown in other samples.

[Modifications] Although the embodiments of the present invention have been described above, the present invention is not limited thereto, and, for example, the following modifications are possible.

(a) Further, appropriate amounts of other substances may be added to the basic components and additive components as necessary.

(b) The starting material for obtaining the basic component may be, for example, an oxide or hydroxide such as Sr 2 O, Ca 2 O, or another compound other than those shown in the examples. Also,
Other compounds such as oxides and hydroxides may be used as starting materials for the additive components.

(C) The # formation temperature may be set to a temperature lower than the sintering temperature other than 600°C (preferably 1000°C or less).

That is, it is possible to make many changes in consideration of the electrode made of nickel or the like and the oxidation of the ceramic.

(d) The firing temperature in a non-oxidizing atmosphere can be varied depending on the electrode material.

(e) Sintering may be performed in a neutral atmosphere.

(f) It is of course applicable to general ceramic capacitors other than IF layer ceramic capacitors.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a multilayer ceramic capacitor according to an embodiment of the present invention, and FIG. 2 is a triangular diagram showing the composition range of additive components. (1)(2)(3)...Dielectric ceramic layer, (4)(5)
...Internal electrode, (607)...External electrode.

Claims (1)

[Claims] (1) Consists of 100 parts by weight of a basic component and 0.2 to 15.0 parts by weight of additional components, and the basic component is {(Ma
_1_-_yMb_y)O}_k(Ti_1_-_w_
-_vZr_wSi_v)O_2 (However, Ma is at least one metal among Sr and Ca, Mb is at least one metal among Mg and Zn,
y, k, w, v are 0.005≦y≦0.100, 1.
00≦k≦1.20, 0.005≦w≦0.100, 0
．． 001≦v≦0.100), and the additive components are B_2O_3, SiO_2, and MO (however,
In the triangular diagram showing the composition of MO (at least one metal oxide of BaO, MgO, ZnO, SrO, and CaO), the B_2O_3 is 1 mol%, the SiO_2 is 80 mol%, and the MO is 19 Point (A) of mol% and the above B_2
The point (B) where O_3 is 1 mol%, the SiO_2 is 39 mol%, and the MO is 60 mol%, and the B_2O_3 is 3
0 mol%, the SiO_2 is 0 mol%, the MO is 70
Point (C) of mol% and the above B_2O_3 is 90 mol%,
Point (D) where the SiO_2 is 0 mol% and the MO is 10 mol%, and the point (D) where the B_2O_3 is 90 mol% and the SiO
A point (E) where _2 is 10 mol% and the MO is 0 mol%,
The B_2O_3 is 20 mol%, and the SiO_2 is 80 mol%.
mol%, connect the point (F) where the MO is 0 mol% in order 6
Dielectric porcelain compositions that are within the area enclosed by straight lines in the book.