JPS61281062A - Ceramic 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 (Field of Industrial Application) The present invention provides a ceramic composition that can be sintered at a low temperature, particularly 1050° C. or lower, has a high dielectric constant, and has a small dielectric loss.

The present invention relates to a ceramic composition suitable for laminated capacitors with high insulation resistance and high mechanical strength, and capacitors.

(Prior art) Conventionally, barium titanate (8
aTi03) It is well known that porcelain containing f as the main component has been widely put into practical use. However, those whose main component is barium titanate (BaTiOs) have a sintering temperature of usually 1300 to 1400°C. Therefore, when using this in a multilayer capacitor, a material that can withstand this sintering temperature must be used for the internal electrodes, such as an expensive noble metal such as platinum, rose, or dium.
Because of this, there is a need for porcelain that can be sintered at as low a temperature as possible, allowing the use of inexpensive metals mainly composed of silver or nickel. Therefore, Pb(Pe'3'3WQ)Os pb
(pe%Nb5)o, (Special Publication No. 55-34962) and (
There are many proposals such as Sr-Pb)Pie and -Pb(Mg)Os (Japanese Unexamined Patent Publication No. 52-21699).

The present inventors searched for a new porcelain composition different from these, and found that P b (N i /3N b%) 0. and Pb
(NiSouW”/1) 3 consisting of Os and PbTiOs
The component composition can be sintered at a low temperature of 1050°C or less and has a high dielectric constant.

It was discovered that the dielectric loss was small and the resistivity was high, and it was proposed as *a No. 193806/1983. However, since the three-component porcelain composition described above has low mechanical strength, its use has to be limited to a narrow range.Practical improvements have been desired. It is an object of the present invention to provide a ceramic composition for a multilayer capacitor that can be sintered at a low temperature of 1050°C or lower, has a high dielectric constant, low dielectric loss, high specific resistance, and high mechanical strength.

(Structure of the Invention) The main component breaker composition of the present invention is (P b (N 1hNb
name) 0,] [Pb(Ni!/2WX/2)0. ] [Pb
TiO3] when expressed as N
Y (however, x+y+ z=1.o O) blending ratio x* Y e z is the following composition point A in the ternary composition diagram: (x=0.89. y=o, ol, z=
Q, IQ) B: (x=o, oO, y=0.60.z
= 0.40) C: (x = 0.OO, y = 0.30.
z=0.70)D: (z=Q, 5Q, y=
0.05. z=0.45) (however, the line connecting B and C is excluded according to the earlier patent application No. 57-167820) and the range surrounded by this line, with niobium (Nb) as a subcomponent. The present invention will be described in Examples below. This will be explained in detail in . Lead oxide (PbO), nickel oxide (Nip), niobium oxide (NbtosL, tungsten oxide (WO), titanium oxide (Ti02), and manganese carbonate (MnCOs) with a purity of 99.9% or higher are used as starting materials, and the specified Weigh according to the mixing ratio.Next, wet mix in a ball mill and then mix at 750℃~
Prebaked at 825°C. After that, it is crushed in a ball mill, and after drying, an organic binder is added and the particles are sized.

Pressed. Four disks each having a diameter of 16 mm and a thickness of approximately 2 mm and a cylinder having a diameter of 16 mm and a thickness of approximately 10 mm were prepared. Next, it was sintered in air at 900-1050°C for 1 hour. Silver electrodes were baked on the top and bottom of the sintered disk at 600° C., and the capacitance and dielectric loss (tan δ) were measured using a digital LCR meter at a frequency of IKH4 and a voltage of IVrms, and the dielectric constant was calculated. Next, a voltage of 50 V (7) was applied for 1 minute using a super insulation resistance needle to measure insulation resistance, and specific resistance was calculated. In order to evaluate the mechanical properties by bending strength, we used a sintered cylinder with a thickness of 0.5 mm, a width of 2 mm, and a length of about 1 mm.
A 3mm rectangular plate was cut into lθ pieces, and the distance between the 0 fulcrums was 9m.
Using the three-point method, the fracture load PmCW4) is determined by the rupture strength τ[
~/crn2] where l is the distance between the fulcrums, t is the thickness of the sample, and W is the width of the sample.The electrical properties are the average values of 4 disk samples, and the bending strength is the 10 rectangular plate samples. It was calculated from the average value of the points. The main component of the porcelain thus obtained (P
b(Ni!'3Nb%)0. ]8(Pb(Ni 3w
3) Mixing ratio xTYe of o, ) Cpb'rio, ),
The following table shows the relationship between the amounts of 2 and subcomponents added and the dielectric constant, dielectric loss, specific resistance, and bending strength.

Below is a blank space (effects of the invention) As is clear from the results shown in the figure, the present invention
″/3Nb%) 03-Pb (Ni-sou W glaze) Os Pb
Nb, Ta, S as subcomponents in Ti0.3 component system
By containing 0.02 to 3 atoms of at least one of b, the flexural strength is greatly improved, and the dielectric constant and specific resistance are also high. Moreover, because it can be sintered at low temperatures, it provides an excellent material for highly reliable ceramic compositions for multilayer capacitors.

Claims (1)

[Claims] Nickel lead niobate [Pb (Ni_1_/_3Nb
_2_/_3)O_3], nickel-lead tungstate [Pb(Ni_1_/_2W_1_/_2)O_3] and lead titanate [PbTiO_3].
3]_x[Pb(Ni_1_/_2W_1_/_2)O
When expressed as _3]_y[PbTiO_3]_z (where x+y+z=1.00), the compounding ratio x, y, z is the following composition point A in this ternary composition diagram: (x=0.89 y=0. 01 z=0.10)B
:(x=0.00 y=0.60 z=0.40)C:
(x=0.00 y=0.30 z=0.70) D:(
x = 0.50 y = 0.05 z = 0.45) (excluding the line connecting B and C) and within the composition range surrounded by this line, niobium is added as a subcomponent. (Nb), tantalum (Ta), and antimony (
A porcelain composition characterized in that at least one element selected from Sb) is added and contained in an amount of 0.02 to 3 atomic % based on the main component.