JPS58209807A - Dielectric porcelain composition - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention achieves high insulation resistance and specific current visit rate by sintering in a reducing or neutral atmosphere and then heat treating in an acidic and arsenic atmosphere. Regarding the reduction and reoxidation type dielectric ceramic composition that becomes a dielectric with low loss, furthermore, a green sheet is coated with a conductive paste containing nickel Y as a main component.
This invention relates to a dielectric ceramic composition that is ideal for manufacturing ceramic multilayer capacitors by coating and sintering.

Conventional laminated porcelain capacitors are made of dielectric raw sheet (f I
J-7 sheet) Printed conductive paste Y of precious metals such as platinum and palladium.Multiple sheets are stacked and crimped, fired at a high temperature of 1100 to 1400°C in an oxidizing atmosphere, and then provided with external lead-out electrodes. It is manufactured by. but.

Because electrode materials such as platinum and palladium are expensive.

It has been impossible to provide the inexpensive multilayer porcelain capacitors required by consumer equipment. In order to solve this type of problem, attempts have been made to form internal electrodes of multilayer ceramic capacitors using conductive paste containing nickel Y as a main component. However, nickel oxidizes when heated at about 300°C in an oxidizing atmosphere, making it impossible to use it as an electrode. It must be fired in a reducing atmosphere. For this reason.

A dielectric ceramic composition that can be sintered in a neutral or reducing atmosphere is required.

On the other hand, when manufacturing multilayer porcelain capacitors.

It is necessary to form external lead-out electrodes by applying silver paste, etc., and it may also be necessary to form thick film resistors and the like. When forming external push-out electrodes, extraction electrodes, etc., it is generally necessary to perform heat treatment at 800 to 000°C in an oxidizing atmosphere. Therefore, even for dielectric ceramic compositions, FJ in a neutral or reducing atmosphere]]00~]40
Firing at 0℃.

A heat treatment at about 800 to 1000° C. in an oxidizing atmosphere is necessarily performed. Therefore, there is a need for a dielectric ceramic composition that can stably obtain a dielectric ceramic having desired characteristics through the above two heat treatments.

Therefore, one object of the present invention is to provide a dielectric ceramic composition that satisfies the above requirements.

To achieve the above object, the present invention provides ((Bax-x
5rx) O) k-tTi, -yzr, )it f)
mK-style te expression n and before! li:8x, y, k are 0.0
2≦X≦0.30.0.01≦y≦0.26. ．． 1.0
The invention relates to a dielectric ceramic composition characterized in that the value is in the range of 01≦ to 1.03.

According to the above invention, about 1100 in a neutral or reducing atmosphere.
About 800-10 when fired at ~1400℃ and in an oxidizing atmosphere
By heat treatment at 00℃, the relative permittivity ε is 55
It becomes possible to obtain a dielectric material with a dielectric loss tan δ of 2% pJ or less over 0 OAJ. Also.

In the preferred range, ε8 is 20,000 or more and tan
It is possible to obtain a dielectric with δ of 2%.

Further, it becomes possible to stably and mass-produce dielectrics. Therefore, it is possible to provide a dielectric ceramic composition suitable for a laminated ceramic capacitor in which internal electrodes are formed from a conductive paste containing 1% nickel as a main component.

Embodiment fIIVc of the present invention will be described below.

Example] BaC0++, 5rCO with purity of 99 degrees or higher
s, Tilt.

Each powder of ZrO was prepared as a starting material and the composition formula was 1%.
The raw materials were weighed and wet mixed so that the formula % 1-x, x, 1-y, and y had the values shown in Table 1 (3) and (2). Next, this mixture is dehydrated and dried, polyvinyl alcohol is added and granulated, and the granulated material is produced at 1000 kg/crr? Pressure molded. Next, it is fired in an oxidizing atmosphere to 600°C using an electric furnace, and then the volume ratio mountain/N2 = 1.5/1oo
5 as shown in the column of sintering temperature in Table 1 in a reducing atmosphere of
] Raise the temperature to a temperature in the range of 330°C to 1386°C and maintain this temperature for 3 hours to make a sail with a diameter of 3.2 mm and a thickness of 8.
A 4 mm disc-shaped sintered body was manufactured.

Next, an In-Ga alloy was applied to both sides of this sintered body to form a pole on the entire surface, and this was used as a sample for measuring the specific resistance of the sintered body in a reducing atmosphere.
was applied for 1 minute, the insulation resistance was measured, and the specific resistance p1 before the oxidation treatment was determined by conversion.

As a result, ρ1 of each sample was the value shown in Table 1.

The housing was a sintered body (In-Gat) manufactured in the same manner as above.
The sintered compact (without electrodes before oxidation) is placed in an electric furnace.

All samples were subjected to oxidation firing for 1 hour at 800°C in an oxidizing atmosphere, and In
- Form a Qa alloy electrode, use it as a sample to measure the specific resistance p after oxidation, measure the insulation resistance after applying DC50■ for 1 minute at 20°C, and calculate the specific resistance (p,) by conversion. Ta. As a result, the specific resistance ρ of each sample was the value shown in Table 1.

In addition, after firing in a reducing atmosphere similar to the above, a silver base coat was applied to both main surfaces of the sintered body (sintered body before oxidation), and heat treatment was performed at 800°C for ] hours in an oxidizing atmosphere. The same process was applied to all samples to form a 1 mm electrode, and this was used as a sample for measuring relative dielectric constant ε8 and dielectric loss tan δ,
When εS and tana were measured at a frequency of 1 kHz, the results shown in Table 1 were obtained.

As is clear from Table 1 above, sample numbers 2 to 6.8.
According to the compositions according to Nos. 12 to 15 and 17 to 20, dielectric ceramics having a dielectric constant εS of 5500 or more and a tan δ of 2% or less are fired in a reducing atmosphere.

It can be obtained both by firing in an oxidizing atmosphere. - 10,000, as shown in sample number 9 (when , cannot be used as a dielectric ceramic composition.Therefore, ε, tanJ of this sample were not measured.

As shown in sample number 11C (x is greater than 0.3).
32 (when Sr is 0.32 mol), e, and t
Both anδ are good values, but εS is low at 3300.
This makes it impossible to achieve the purpose of the invention.

Also, as shown in sample number 10, when y is 0 (when Zr has no additive H), K is a Pm is L5
Ll-crH is too low to be used as a dielectric ceramic Mi composition. Therefore, εB and tan δ of this sample were not measured. In addition, as shown in sample number 7 (if y becomes 0.27, which is above 0.26 kl, cs becomes low and the object of the present invention cannot be achieved. Sample number 1). As (the value of k is smaller than 1.001 In3
．． When it becomes 00, %p becomes 5 When it becomes .04, sintering becomes impossible.

Therefore, the preferred range for x and y is from X=0.02 to
0.30, Y = 0.0 ] ~ 0.26, k-1
,001 to 1.03. That is, it can be seen that the preferred range of Sr is 02 to 0.30 mol, the preferred range of Zr is 0.01 to 0.26 mol, and the preferred range of 1.001 to 1.03. .

According to the composition of sample number 6 and ]2, the sample number was 1%.

It is possible to obtain a very excellent dielectric material with a high εS of 20,000 or more and a low tan δ of 2% or less. Therefore, a more preferable range of X is about 0.] to 0.2,
A more preferred range of y is about 0.1 to 0.2.

Regarding sample number 4, the temperature was varied in the range of -25 to +85 using a constant temperature bath, and the specific resistance ρ after oxidation was
2. When we investigated the changes in relative dielectric constant ss and tan δ, we found that
As shown in Figures 1 to 3.

However, ε and VC are shown in FIG. 2 as a rate of change. From this result, it is clear that ρ2 tends to decrease as the temperature increases, as is the case with TI. However, at +85°C p.

is 9-1 x ] OMLL-am, which is a sufficient value for soil. ε3 peaks at 12°C and rapidly decreases around this point. However, the variation between -25°C and +85°C ranges from +20% to -80% and is customizable. Furthermore, tan δ tends to increase as the temperature decreases. However, since it is 3% at -25°C, it is custom-made with enough soil. Also, for samples other than sample number 4 within the scope of the present invention.

p is greater than ]OMΩ"cm at +85℃, and tan
ll was 3% or less at -25°C. In addition, it was confirmed that the temperature customization of εS can be used for various purposes, although it differs slightly depending on the composition.

Practicability 2 The same composition as Sample No. 4 of Example M1 was used, except that only the firing conditions were changed as shown in Table 2. Similarly, ρ weight, εs, t
When anδ and PR were measured, the results shown in Table 2 were obtained. The sintering temperature in a neutral or reducing atmosphere was 340°C for each sample, and the heating temperature in an acid injection atmosphere was 800°C for both samples. Furthermore, the firing atmosphere H and C in Table 2 indicate the volume ratio 7 in a neutral or reducing atmosphere.

Table 2 As is clear from the results in Table 2, the specific resistance before oxidation firing h&'! -The stronger the reducing atmosphere, the smaller the size, but after oxidation firing, 3. OX] OMΩ・cm or more,
It can be quenched depending on the strength of the reducing atmosphere. Ty,
:, et*tanJ both have good values. Therefore, according to the dielectric ceramic composition of the present invention, it is possible to obtain a sintered body without being affected by variations in sintering conditions due to a reducing atmosphere.

It becomes possible to mass produce capacitors with uniform characteristics.

Example 3 The same composition as Sample No. 4 in Example was calcined.

A 15% by weight aqueous solution of acrylic ester, t' IJ mama water-soluble binder, glycerin, and condensed phosphate was added to this calcined raw material, and the mixture was ground and mixed with 50% by weight of water in a ball mill to form a slip. After making and degassing, a 60 μm thick ceramic green sheet was made using a doctor blade method, and after drying, it was punched out into a rectangular shape using a press, and one side K of the punched ceramic green sheet.

Ni powder bed 9] wt%, MnO powder], 0 wt%, Pb0
A conductive paste consisting of 8.0 wt. 1% -BaO-5ill glass was printed, and 20 of the above green sheets were stacked so that the printed portions faced each other and bonded by thermocompression.

The thus-integrated product is heated in air at 600°C to burn the binder and achieve the primary VcH! /N
, = 1.5/100 in a reducing aW atmosphere at a rate of 100°C/h to 1340°C, held at this temperature for 2 hours, and then cooled to 800°C at a rate of 100°C/hr'). Thereafter, this atmosphere was maintained to room temperature and allowed to cool naturally. Silver paste is applied to the laminated sintered body of the arrow as an electrode for external extraction.

Sintered at 800°C for about 1 hour in an oxidizing atmosphere to bake the silver base and oxidize the sintered body, each having a width of 4.8 mm.
A ceramic multilayer capacitor with a length of 5.6 mm and a thickness of 0 mm was completed. When we measured the characteristics of this capacitor, we found that the capacitance C was 1.34μF []kHz).
Dielectric loss (tanJ) is 2.50% (1kHz)
, and the specific resistance was 4XlOMΩ-cm (20°C).

As described above, according to the composition of the present invention, it is possible to use a conductive paste containing nickel as a main component, to obtain a sintered body by heat treatment simultaneously with this paste, and to form an external lead-out electrode. At the same time, the sintered body was heated with #f during heat treatment,
Ceramic multilayer capacitors can be completed. Therefore, it is an optimal composition for multilayer capacitors having internal electrodes mainly composed of nickel.

The embodiments of the present invention have been described above, but the present invention is as follows.
However, the present invention is not limited to the above (1) and can be modified in any way without departing from the gist of the present invention.

For example, At and H! in a neutral or reducing atmosphere! The same effects as in Example] can be obtained by using a combination or a combination atmosphere of CO3 and CO. Also, within the scope of satisfying the customization aimed at by the present invention.

Trace amount of Mnoffi, Fetus -Altos-
5ift, clay, etc. may be added as a mineralizing agent, for example, to the composition of the present invention, Mnot is 0.1 to 0.0.
By adding clay in an amount of 0.2 to 0.7% by weight, the sinterability can be improved without affecting the electrical properties.

[Brief explanation of the drawing]

Figures 1, 2, and 3 are p3. FIG. 3 is a characteristic diagram showing changes in εg and tanδ depending on temperature. In the symbols used in the drawings, e is the specific resistance after reoxidation, εS is the relative dielectric constant, and tan δ is the dielectric loss.

Claims (1)

[Claims] (tBa Sr)0)k-(Ti, -yZry
) Ox1-X X and the x, y, k are 0.02≦X
A dielectric ceramic composition having a value in the range of ≦0.30 0.0]≦y≦0.26 LOOI≦≦1.03.