Dielectric ceramic composition, stacked ceramic capacitor using the same, and method of manufacturing the same

Abstract

A stacked ceramic capacitor that includes a ceramic body formed by stacking dielectric ceramic layers and internal electrodes mainly composed of Ni; and an external electrode formed on an outer surface of ceramic body. The dielectric ceramic layers are formed by using a dielectric ceramic composition that includes a main ingredient expressed by (K.sub.aNa.sub.bLi.sub.cM2.sub.d)(Nb.sub.wTa.sub.xMg.sub.yM4.sub.z)O.sub.3, where M2 is at least one of Ca, Sr and Ba, M4 is at least one of Zr, Hf and Sn, and a, b, c, d, w, x, y, and z satisfy predetermined relationships; and includes 2 to 15 molar parts of Mn with respect to 100 molar parts of a total content of Nb, Ta, Mg, and M4.

Claims

1. A dielectric ceramic composition comprising: a main ingredient expressed by (K.sub.aNa.sub.bLi.sub.cM2.sub.d)(Nb.sub.wTa.sub.xMg.sub.yM4.sub.z)O.sub.3, where M2 is at least one of Ca, Sr and Ba, M4 is at least one of Zr, Hf and Sn, w+x+y+z=1, 0.07a0.92, 0b0.81, 0c0.09, 0.57a+b+c0.95, 0.1d0.4, 0.95a+b+c+d1.05, 0.73w+x0.93, 0x/(w+x)0.3, 0.02y0.07, and 0.05z0.2; and 2 to 15 molar parts of Mn with respect to 100 molar parts of a total content of Nb, Ta, Mg, and M4.

2. A stacked ceramic capacitor comprising: a ceramic body including a plurality of stacked dielectric ceramic layers and a plurality of internal electrodes comprising Ni along an interface between said dielectric ceramic layers; and an external electrode on an outer surface of said ceramic body, wherein said dielectric ceramic layers comprise the dielectric ceramic composition as recited in claim 1.

3. A method of forming a stacked ceramic capacitor, the method comprising: forming a plurality of ceramic green sheets from a dielectric ceramic composition; forming an internal electrode patterns comprising Ni on respective ceramic green sheets of the plurality of ceramic green sheets; stacking the plurality of ceramic green sheets such that the internal electrode patterns are at an interface between adjacent ceramic green sheets to form a stacked body; and firing the stacked body in a reducing atmosphere to obtain a ceramic body, wherein the dielectric ceramic composition comprises: a main ingredient expressed by (K.sub.aNa.sub.bLi.sub.cM2.sub.d)(Nb.sub.wTa.sub.xMg.sub.yM4.sub.z)O.sub.3, where M2 is at least one of Ca, Sr and Ba, M4 is at least one of Zr, Hf and Sn, w+x+y+z=1, 0.07a0.92, 0b0.81, 0c0.09, 0.57a+b+c0.95, 0.1d0.4, 0.95a+b+c+d1.05, 0.73w+x0.93, 0x/(w+x)0.3, 0.02y0.07, and 0.05z0.2; and 2 to 15 molar parts of Mn with respect to 100 molar parts of a total content of Nb, Ta, Mg, and M4.

4. The method of forming a stacked ceramic capacitor according to claim 3, the method further comprising: applying a conductive paste to an end surface of the ceramic body and baking the conductive paste to form an external electrode.

5. The method of forming a stacked ceramic capacitor according to claim 3, wherein the stacked body is fired at 1000 C. to 1160 C. in the reducing atmosphere at an oxygen partial pressure of 10.sup.11 to 10.sup.10 MPa.

6. The dielectric ceramic composition according to claim 1, wherein 1.4d/z3.0.

7. The stacked ceramic capacitor according to claim 2, wherein 1.4d/z3.0.

8. The method of forming a stacked ceramic capacitor according to claim 3, wherein 1.4d/z3.0.

9. The dielectric ceramic composition according to claim 1, wherein 0.5d/z8.0.

10. The stacked ceramic capacitor according to claim 2, wherein 0.5d/z8.0.

11. The method of forming a stacked ceramic capacitor according to claim 3, wherein 0.5d/z8.0.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view showing a stacked ceramic capacitor as the background art of the present invention.

(2) FIG. 2 is an illustration showing an internal structure of the stacked ceramic capacitor shown in FIG. 1.

(3) FIG. 3 is an illustration showing a part of a process for manufacturing the stacked ceramic capacitor shown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) A dielectric ceramic composition of the present invention is used to fabricate stacked ceramic capacitor 10 shown in FIGS. 1 and 2. In order to obtain such a dielectric ceramic composition, K.sub.2CO.sub.3, Na.sub.2CO.sub.3, Li.sub.2CO.sub.3, Nb.sub.2O.sub.5, Ta.sub.2O.sub.5, MgCO.sub.3, CaCO.sub.3, SrCO.sub.3, BaCO.sub.3, ZrO.sub.2, SnO.sub.2, HfO.sub.2, MnO and the like are prepared as ceramic raw materials.

(5) Then, in order to obtain the dielectric ceramic composition expressed by (K.sub.aNa.sub.bLi.sub.cM2.sub.d)(Nb.sub.wTa.sub.xMg.sub.yM4.sub.z)O.sub.3, the aforementioned ceramic raw materials are weighed. Here, M2 is at least one of Ca, Sr and Ba, and M4 is at least one of Zr, Hf and Sn. The ceramic raw materials are weighed to satisfy the relationships of w+x+y+z=1, 0.07a0.92, 0b0.81, 0c0.09, 0.57a+b+c0.95, 0.1c0.4, 0.95a+b+c+d1.05, 0.73w+x0.93, 0x/(w+x)0.3, 0.02y0.07, and 0.05z0.2 in the aforementioned general formula and to include 2 to 15 molar parts of Mn with respect to 100 molar parts of a total content of Nb, Ta, Mg, and M4.

(6) These weighed materials are put into a ball mill together with a solvent and they are wet mixed. The obtained mixture is dried and calcined to obtain a calcined material. The calcined material is crushed, and thereafter, the calcined material is put into the ball mill together with a binder, a dispersant and pure water and they are wet mixed sufficiently to obtain a ceramic slurry. The obtained ceramic slurry is molded in accordance with the doctor blade method to obtain ceramic green sheet 20 as shown in FIG. 3.

(7) Next, a conductive paste for internal electrodes, in which a base metal such as Ni is used as a conductive material, is prepared. By using this conductive paste for the internal electrodes, internal electrode patterns 22 shown in FIG. 3 are formed on ceramic green sheet 20 in accordance with the screen printing method. Then, a plurality of ceramic green sheets 20 each having internal electrode patterns 22 formed thereon are stacked, and ceramic green sheets 20 having no internal electrode patterns formed thereon are stacked so as to sandwich the plurality of ceramic green sheets 20. These ceramic green sheets 20 are pressure-bonded to obtain mother stacked body 24.

(8) Next, mother stacked body 24 is cut such that internal electrode patterns 22 adjacent to each other in the stack direction are alternately led out to both end surfaces, and a crude stacked body chip is formed. This stacked body chip is fired at 1000 C. to 1160 C. in the reducing atmosphere at an oxygen partial pressure of 10.sup.11 to 10.sup.10 MPa, to obtain ceramic body 12 including dielectric ceramic layers 14 and internal electrodes 16.

(9) A conductive paste for an external electrode is applied and baked onto the end surface of ceramic body 12 to which internal electrodes 16 are led out, thereby forming external electrode 18 connected to the portion where internal electrodes 16 are led out. External electrode 18 is plated with Ni, Sn and the like as needed. Stacked ceramic capacitor 10 having a capacitance formed between two external electrodes 18 is thus obtained.

(10) This dielectric ceramic composition used to manufacture stacked ceramic capacitor 10 does not easily become a semiconductor and an insulation resistance thereof does not easily decrease, even when the dielectric ceramic composition is fired in the reducing atmosphere. Therefore, the stacked body chip can be fired in the reducing atmosphere and the easily-oxidizable base metal material such as Ni can be used as the conductive material of the conductive paste for the internal electrodes. Namely, it is possible to co-fire the internal electrode patterns formed by using the conductive paste made of the inexpensive base metal material and the ceramic green sheets formed by using the dielectric ceramic composition of the present invention.

(11) In addition, in dielectric ceramic layers 14 formed by using this dielectric ceramic composition, a rate of change in dielectric constant with respect to temperature change is small, and stacked ceramic capacitor 10 having a small capacitance-temperature change rate can be obtained. Therefore, stacked ceramic capacitor 10 can be used in a place where the temperature changes greatly, and can be used as, for example, vehicle-mounted stacked ceramic capacitor 10.

Example 1

(12) First, the ceramic raw materials described above were prepared. Then, in order to obtain dielectric ceramic compositions expressed by (K.sub.aNa.sub.bLi.sub.cM2.sub.d)(Nb.sub.wTa.sub.xMg.sub.yM4.sub.z)O.sub.3 and having the compositions shown in Tables 1 and 2, these raw materials were weighed. In Tables 1 and 2, an amount of addition of Mn indicates an amount of addition (molar part) with respect to 100 molar parts of a total amount of Nb, Ta, Mg, and M4 (Zr, Hf, Sn). In Sample No. in Tables 1 and 2, the mark of * indicates outside the scope of the present invention.

(13) TABLE-US-00001 TABLE 1 Amount of Sample d Breakdown of M2 x/ Addition No. a b c a + b + c (=d + d) M2-(1) d M2-(2) d a + b + c + d w x w + x w + x y M4 z Mn of 1* 0.41 0.41 0.05 0.87 0.13 Ca 0.03 Ba 0.10 1.00 0.94 0.00 0.94 0.00 0.03 Zr 0.03 5 2* 0.41 0.41 0.05 0.87 0.13 Ca 0.04 Ba 0.09 1.00 0.93 0.00 0.93 0.00 0.03 Zr 0.04 5 3* 0.45 0.45 0.07 0.97 0.10 Ca 0.05 Ba 0.05 1.07 0.93 0.00 0.93 0.00 0.02 Zr 0.05 5 4* 0.45 0.45 0.00 0.90 0.08 Ca 0.03 Ba 0.05 0.98 0.93 0.00 0.93 0.00 0.02 Zr 0.05 5 5 0.45 0.45 0.05 0.95 0.10 Ca 0.05 Ba 0.05 1.05 0.93 0.00 0.93 0.00 0.02 Zr 0.05 5 6 0.45 0.45 0.00 0.90 0.10 Ca 0.05 Ba 0.05 1.00 0.93 0.00 0.93 0.00 0.02 Zr 0.05 5 7 0.40 0.40 0.05 0.85 0.15 Ca 0.05 Ba 0.10 1.00 0.92 0.00 0.92 0.00 0.03 Zr 0.05 5 8 0.38 0.38 0.05 0.81 0.19 Ca 0.10 Ba 0.09 1.00 0.87 0.00 0.87 0.00 0.03 Zr 0.10 5 9 0.34 0.34 0.04 0.72 0.28 Ca 0.20 Ba 0.08 1.00 0.77 0.00 0.77 0.00 0.03 Zr 0.20 5 10 0.26 0.26 0.08 0.60 0.40 Ca 0.20 Ba 0.20 1.00 0.73 0.00 0.73 0.00 0.07 Zr 0.20 5 11 0.26 0.26 0.05 0.57 0.40 Ca 0.20 Ba 0.20 0.97 0.73 0.00 0.73 0.00 0.07 Zr 0.20 5 12* 0.26 0.26 0.08 0.60 0.40 Ca 0.20 Ba 0.20 1.00 0.71 0.00 0.71 0.00 0.09 Zr 0.20 5 13* 0.26 0.26 0.08 0.60 0.43 Ca 0.23 Ba 0.20 1.03 0.73 0.00 0.73 0.00 0.07 Zr 0.20 5 14* 0.26 0.26 0.03 0.55 0.40 Ca 0.20 Ba 0.20 0.95 0.73 0.00 0.73 0.00 0.07 Zr 0.20 5 15* 0.34 0.34 0.04 0.72 0.28 Ca 0.20 Ba 0.08 1.00 0.74 0.00 0.74 0.00 0.03 Zr 0.23 5 16* 0.38 0.38 0.05 0.81 0.19 Ca 0.10 Ba 0.09 1.00 0.87 0.00 0.87 0.00 0.03 Zr 0.10 1 17 0.38 0.38 0.05 0.81 0.19 Ca 0.10 Ba 0.09 1.00 0.87 0.00 0.87 0.00 0.03 Zr 0.10 2 18 0.38 0.38 0.05 0.81 0.19 Ca 0.10 Ba 0.09 1.00 0.87 0.00 0.87 0.00 0.03 Zr 0.10 15 19* 0.38 0.38 0.05 0.81 0.19 Ca 0.10 Ba 0.09 1.00 0.87 0.00 0.87 0.00 0.03 Zr 0.10 20 20* 0.40 0.40 0.05 0.85 0.15 Ca 0.10 Ba 0.05 1.00 0.89 0.00 0.89 0.00 0.01 Zr 0.10 5 21 0.39 0.39 0.05 0.83 0.18 Ca 0.10 Ba 0.08 1.01 0.87 0.00 0.87 0.00 0.03 Zr 0.10 5 22 0.33 0.33 0.04 0.70 0.30 Ca 0.10 Ba 0.20 1.00 0.83 0.00 0.83 0.00 0.07 Zr 0.10 5 23* 0.28 0.28 0.04 0.60 0.40 Ca 0.10 Ba 0.30 1.00 0.80 0.00 0.80 0.00 0.10 Zr 0.10 5 24* 0.95 0.00 0.00 0.95 0.10 Ca 0.05 Ba 0.05 1.05 0.93 0.00 0.93 0.00 0.02 Zr 0.05 5

(14) TABLE-US-00002 TABLE 2 Amount of Sample d Breakdown of M2 x/ Addition No. a b c a + b + c (=d + d) M2-(1) d M2-(2) d a + b + c + d w x w + x w + x y M4 z of Mn 25 0.92 0.00 0.00 0.92 0.10 Ca 0.05 Ba 0.05 1.02 0.93 0.00 0.93 0.00 0.02 Zr 0.05 5 26 0.76 0.00 0.05 0.81 0.19 Ca 0.10 Ba 0.09 1.00 0.87 0.00 0.87 0.00 0.03 Zr 0.10 5 27 0.08 0.68 0.05 0.81 0.19 Ca 0.10 Ba 0.09 1.00 0.87 0.00 0.87 0.00 0.03 Zr 0.10 5 28 0.07 0.81 0.00 0.88 0.12 Ca 0.07 Ba 0.05 1.00 0.91 0.00 0.91 0.00 0.02 Zr 0.07 5 29* 0.05 0.81 0.00 0.86 0.12 Ca 0.07 Ba 0.05 0.98 0.91 0.00 0.91 0.00 0.02 Zr 0.07 5 30* 0.07 0.83 0.00 0.90 0.12 Ca 0.07 Ba 0.05 1.02 0.91 0.00 0.91 0.00 0.02 Zr 0.07 5 31 0.41 0.41 0.00 0.82 0.19 Ca 0.10 Ba 0.09 1.01 0.87 0.00 0.87 0.00 0.03 Zr 0.10 5 32 0.36 0.36 0.08 0.82 0.19 Ca 0.10 Ba 0.09 1.01 0.87 0.00 0.87 0.00 0.03 Zr 0.10 5 33 0.35 0.35 0.09 0.79 0.21 Ca 0.06 Ba 0.15 1.00 0.89 0.00 0.89 0.00 0.05 Zr 0.06 5 34* 0.35 0.35 0.14 0.84 0.21 Ca 0.06 Ba 0.15 1.05 0.89 0.00 0.89 0.00 0.05 Zr 0.06 5 35 0.38 0.38 0.05 0.81 0.19 Ca 0.10 Ba 0.09 1.00 0.63 0.24 0.87 0.28 0.03 Zr 0.10 5 36 0.38 0.38 0.05 0.81 0.19 Ca 0.10 Ba 0.09 1.00 0.61 0.26 0.87 0.30 0.03 Zr 0.10 5 37* 0.38 0.38 0.05 0.81 0.19 Ca 0.10 Ba 0.09 1.00 0.55 0.32 0.87 0.37 0.03 Zr 0.10 5 38 0.38 0.38 0.05 0.81 0.19 Ba 0.19 1.00 0.87 0.00 0.87 0.00 0.03 Zr 0.10 5 39 0.38 0.38 0.05 0.81 0.19 Sr 0.10 Ba 0.09 1.00 0.87 0.00 0.87 0.00 0.03 Zr 0.10 5 40 0.38 0.38 0.05 0.81 0.19 Ca 0.19 1.00 0.87 0.00 0.87 0.00 0.03 Hf 0.10 5 41 0.38 0.38 0.05 0.81 0.19 Ca 0.10 Sr 0.09 1.00 0.87 0.00 0.87 0.00 0.03 Sn 0.10 5 42* 0.36 0.36 0.02 0.74 0.19 Ca 0.10 Ba 0.09 0.93 0.87 0.00 0.87 0.00 0.03 Zr 0.10 5 43 0.36 0.36 0.04 0.76 0.19 Ca 0.10 Ba 0.09 0.95 0.87 0.00 0.87 0.00 0.03 Zr 0.10 5 44 0.36 0.36 0.05 0.77 0.19 Ca 0.10 Ba 0.09 0.96 0.87 0.00 0.87 0.00 0.03 Zr 0.10 5 45 0.40 0.40 0.05 0.85 0.19 Ca 0.10 Ba 0.09 1.04 0.87 0.00 0.87 0.00 0.03 Zr 0.10 5 46 0.40 0.40 0.06 0.86 0.19 Ca 0.10 Ba 0.09 1.05 0.87 0.00 0.87 0.00 0.03 Zr 0.10 5 47* 0.40 0.40 0.08 0.88 0.19 Ca 0.10 Ba 0.09 1.07 0.87 0.00 0.87 0.00 0.03 Zr 0.10 5

(15) These weighed materials were put into the ball mill and wet mixed for about 90 hours by using ethanol as a solvent. The obtained mixture was dried, and thereafter, was calcined at a temperature of 750 C. to obtain a calcined material. This calcined material was crushed, and the calcined material was put into the ball mill together with a binder, a dispersant and pure water and they were wet mixed sufficiently to obtain a ceramic slurry. This ceramic slurry was molded in accordance with the doctor blade method to obtain a ceramic green sheet having a thickness of 100 m.

(16) Next, a conductive paste for internal electrodes, in which Ni was used as a conductive material, was prepared. By using this conductive paste for the internal electrodes, internal electrode patterns having a prescribed shape were formed on the ceramic green sheet in accordance with the screen printing method. 11 ceramic green sheets each having the internal electrode patterns formed thereon were stacked, and ceramic green sheets having no internal electrodes formed thereon were stacked so as to sandwich the 11 ceramic green sheets. Then, a pressure of about 2.4510.sup.7 Pa was applied to pressure-bond these ceramic green sheets, and a mother stacked body was thus obtained. This mother stacked body was cut to obtain a crude stacked body chip.

(17) The obtained stacked body chip was fired for two hours at a temperature of 1100 C. in the reducing atmosphere adjusted to attain an oxygen partial pressure of 3.810.sup.11 MPa, and a ceramic body having dielectric ceramic layers and internal electrodes was thus obtained. The obtained ceramic body had a 2012 size, the dielectric ceramic layer had a thickness of 1010.sup.6 m, the internal electrode had a thickness of 2.010.sup.6 m, and a portion where the internal electrodes faced each other (portion where a capacitance was formed) had an area of 1.710.sup.6 m.sup.2.

(18) Next, a conductive paste for an external electrode, in which Ag was used as a conductive material, was prepared. Then, the conductive paste for the external electrode was applied and baked at 900 C. onto a portion of the obtained ceramic body where the internal electrodes were led out. The external electrode was thus formed.

(19) Electrical characteristic evaluation was performed on the stacked ceramic capacitor thus obtained. For the electrical characteristic evaluation, 20 stacked ceramic capacitors including the dielectric ceramic composition having each composition shown in Table 1 and 20 stacked ceramic capacitors including the dielectric ceramic composition having each composition shown in Table 2 were prepared. For these stacked ceramic capacitors, a capacitance C was measured under the conditions of 1 kHz, 1 Vrms and 25 C. by using an automatic bridge-type measuring instrument, and an average value of dielectric constants of the dielectric ceramic layers was calculated. In addition, by using the capacitance of the stacked ceramic capacitor at 25 C. as a reference, a capacitance-temperature change rate was measured, with the temperature being changed in a range of 55 C. to 250 C. The capacitance-temperature change rate was calculated by measuring the capacitance of the stacked ceramic capacitor under the conditions of 1 MHz and 1 Vrms. The capacitance-temperature change rate of the stacked ceramic capacitor corresponds to a rate of change in dielectric constant of the dielectric ceramic layers with respect to the temperature. The measurement results were shown in Tables 3 and 4.

(20) TABLE-US-00003 TABLE 3 Dielectric Constant Maximum Sample Dielectric Increase Maximum Capacitance-Temperature Change Rate (%) No. Constant at 25 C. Rate (%) Decrease Rate (%) 55 C. 40 C. 0 C. 85 C. 105 C. 125 C. 150 C. 200 C. 250 C. 1* low resistance 2* sintering is impossible 3* sintering is impossible 4* low resistance 5 6405 6.0 41.6 22.7 18.0 4.9 6.0 5.5 2.4 4.6 23.7 41.6 6 4351 17.8 28.0 28.0 22.8 8.9 14.3 16.8 17.8 16.6 2.3 19.6 7 4684 0.0 79.6 62.5 50.4 16.1 11.7 26.4 42.6 59.2 76.0 79.6 8 1088 0.4 61.3 11.6 7.8 0.4 14.6 22.0 29.6 38.4 52.5 61.3 9 632 13.4 52.3 13.4 12.2 7.0 20.2 26.5 32.4 38.7 47.4 52.3 10 409 17.3 26.7 17.3 14.0 5.5 8.1 10.9 13.0 15.7 21.1 26.7 11 427 15.9 25.5 15.9 12.6 5.3 7.4 10.2 12.4 15.1 20.6 25.5 12* low resistance 13* 389 24.0 25.2 24.0 19.3 6.6 7.1 9.9 12.1 14.9 20.3 25.2 14* 405 22.5 23.9 22.5 17.9 6.4 6.5 9.3 11.5 14.2 19.7 23.9 15* low resistance 16* low resistance 17 592 0.0 49.4 9.7 6.8 0.0 12.1 18.9 25.9 34.1 46.8 49.4 18 927 0.0 73.4 26.9 19.1 1.4 24.5 36.1 46.6 56.6 68.7 73.4 19* low resistance 20* 786 39.7 28.8 28.8 23.6 9.9 30.1 36.5 39.7 38.4 21.3 4.6 21 1110 3.0 48.5 34.7 27.9 9.9 3.0 0.0 5.2 13.9 33.1 48.5 22 768 20.0 60.4 20.0 17.9 9.7 25.9 33.4 40.0 46.6 56.5 60.4 23* 663 30.3 58.0 30.3 25.9 11.8 27.1 34.4 40.3 46.2 54.0 58.0 24* 3268 33.3 30.3 30.3 25.2 10.7 23.0 30.2 33.3 31.9 15.7 9.0

(21) TABLE-US-00004 TABLE 4 Dielectric Constant Dielectric Maximum Sample Constant Increase Maximum Capacitance-Temperature Change Rate (%) No. at 25 C. Rate (%) Decrease Rate (%) 55 C. 40 C. 0 C. 85 C. 105 C. 125 C. 150 C. 200 C. 250 C. 25 3884 18.8 32.8 32.8 26.5 10.2 15.2 17.7 18.8 18.8 6.5 13.1 26 996 0.1 11.8 11.8 8.0 0.1 14.0 21.5 29.1 38.0 52.2 61.1 27 1016 0.4 11.6 11.6 7.8 0.4 14.6 22.0 29.6 38.4 52.5 61.3 28 4015 18.7 29.0 29.0 23.8 9.1 15.2 17.7 18.7 17.5 0.9 23.3 29* 3528 33.7 31.4 31.4 26.5 10.1 24.5 30.6 33.7 31.6 7.2 21.6 30* 3586 31.1 29.4 29.4 24.3 9.7 21.1 27.4 31.1 27.3 1.7 25.3 31 1326 9.1 63.0 8.9 9.1 6.7 23.5 31.2 38.2 45.7 56.3 63.0 32 1198 0.0 58.2 16.9 13.2 3.1 8.4 15.0 22.3 31.7 47.8 58.2 33 1229 0.0 51.7 20.0 16.2 6.0 1.1 6.2 13.0 22.4 39.4 51.7 34* sintering is impossible 35 964 19.7 57.2 19.7 18.4 8.6 23.8 31.4 37.6 43.8 52.8 57.2 36 945 21.0 58.0 21.0 19.6 9.8 24.0 32.1 38.3 44.4 53.8 58.0 37* 849 46.5 56.0 46.5 37.8 14.2 26.4 32.3 37.7 43.4 51.5 56.0 38 1116 1.0 62.2 11.0 7.1 1.0 15.3 22.7 30.3 39.1 53.3 62.2 39 1092 0.9 61.8 11.1 7.2 0.9 15.0 22.4 30.0 38.8 52.9 61.8 40 1078 0.4 61.3 11.6 7.8 0.4 14.6 22.0 29.6 38.4 52.5 61.3 41 1139 1.6 62.5 10.5 6.6 1.6 15.7 23.1 30.7 39.5 53.7 62.5 42* low resistance 43 1176 2.1 59.8 10.1 6.2 2.1 14.9 22.2 29.8 38.0 50.8 59.8 44 1150 2.4 61.7 9.9 5.9 2.4 15.5 22.8 30.3 39.0 53.0 61.7 45 1003 0.9 61.5 11.2 7.3 0.9 14.2 21.7 29.6 38.4 52.7 61.5 46 988 0.0 58.2 12.1 8.3 0.7 14.4 21.3 29.2 37.8 51.1 58.2 47* sintering is impossible

(22) In Tables 3 and 4, low resistance indicates that a resistance value was equal to or lower than 10 k. This is presumed to be because the dielectric ceramic layers became a semiconductor due to firing in the reducing atmosphere.

(23) As can be seen from Tables 3 and 4, when the dielectric ceramic composition of the present invention is used, the resistance value of the dielectric ceramic layers does not easily decrease even when firing is performed in the reducing atmosphere. Moreover, it is possible to obtain a stacked ceramic capacitor having such an excellent capacitance-temperature characteristic that a maximum increase rate is within +22% and a maximum decrease rate is within 82% with respect to the capacitance at 25 C. in the temperature range of 55 C. to 250 C.

REFERENCE SIGNS LIST

(24) 10 stacked ceramic capacitor; 12 ceramic body; 14 dielectric ceramic layer; 16 internal electrode; 18 external electrode; 20 ceramic green sheet; 22 internal electrode pattern; 24 mother stacked body.