JPS6046966A - 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 The present invention provides a porcelain composition that can be sintered at a low temperature, particularly below 1050'C, has a high dielectric constant, has a high insulation resistance at room temperature and high temperature, and has a mechanical -i! Magnetic 2 with high Ii degree (
The present invention relates to a composition.

Conventionally, barium titanate (B
It is well known that porcelain containing aTiOs as a main component has been widely put into practical use. However, those whose main component is barium titanate (BaTiO3) have a sintering temperature of generally 1300 to 1400°C. Therefore, when this is used in a multilayer capacitor, a fourth material that can withstand this sintering temperature must be used as the internal electrode, such as an expensive blue metal such as platinum or palladium.
The disadvantage is that manufacturing costs are high. In order to make multilayer capacitors more attractive, it is necessary to use porcelain that can be sintered at as low a temperature as possible, especially below 1050°C, so that inexpensive metals mainly composed of silver, nickel, etc. can be used for the internal electrodes.

Furthermore, the electrical properties of the ceramic composition are basically required to have a high dielectric constant, low dielectric loss, and high insulation resistance. Furthermore, regarding the value of insulation resistance, the Military Specification (Mi 1 i tar 7 Specification) is a US Department of Defense standard that requires highly reliable components.
In the MIL-C-55681B of MIL-C-55681B, not only the value at room temperature but also the value at 125°C is specified, and as you can see, in order to obtain a highly reliable ceramic capacitor, only the value at the temperature source is specified. Not,
It is also necessary to have a high insulation resistance at the maximum operating temperature.

However, in the case of multilayer chip capacitors, when the chip capacitor is mounted on a board, mechanical strain is applied to the chip capacitor due to the difference in thermal expansion coefficient between the board and the porcelain that makes up the chip capacitor. Cracks may occur or damage may occur. Furthermore, even in the case of a dip capacitor coated with epoxy resin or the like, cracks may occur in the dip capacitor due to the stress of the coat resin. In either case, the lower the mechanical strength of the porcelain forming the capacitor, the more likely it is to crack and break, resulting in lower reliability. Therefore, increasing the mechanical strength of porcelain as much as possible is a practical and extremely expensive problem.

By the way, Pb(Mg17xWs7JCh PbTiOs
As for porcelain compositions, N.N., Kleinik,
Stingray.

Ai, Maglanovskaya (N, N, Krainik a)
nd A, I.

Agrarovskaya (Fiziko Tverd
ogo Te1a, Vo, 2. No.

1.pp 70-72. Janvara 1960)
), and (SrxPb 1-xTjOs
) a(PbMgo, sWo, 503) B (where x=o~0.10, a=0.35~0.5,
b=0.5 to 0.65, a+b=1), a monolithic capacitor and its manufacturing method are disclosed in JP-A-52-21662, and a dielectric powder composition is disclosed in JP-A-52-21662. It is disclosed in Japanese Patent No. 52-21669. However, none of them discloses any specific resistance, and the practicality of these ceramic compositions has not been clarified.

On the other hand, the present inventors have already been able to simplify the process at a temperature of 910-950°C, and Pb (Mgl/, Wl, ,) □s and Pb T
It consists of a two-component system with iOs, which is combined with [Pb (M
g I/□W, ) 03 ) Engineering (PbTiOs) 1
-2, we proposed a composition in which X is in the range of 0.65<X≦1.00. This composition has excellent electrical properties such as a high value of the product of dielectric constant and specific resistance and low dielectric loss. However, since all of the above compositions have low mechanical strength, their applications have had to be limited to a narrow range.

Also, Pb(Mg17zW17z)Os PbTiOs
For three-component systems including systems, tl, % 1986-1110
In Publication No. 11, Pb(MgniazW+7z)On
PbTiOs Pb(Mg17sNbz7a)Os system was disclosed in JP-A-55-117809 as pb (M
g 1/2 W□7JOs PbTiOs Pb(h7
Ig173Tat7. ) Ox systems are disclosed respectively. However, none of them discloses any specific resistance or mechanical strength, and the practicality of these ceramic compositions has not been clarified.

The present inventors have also already developed Pb (Mg17□Wz7JOs Pb
A Ti03-Pb(Nil/3Nb,,3)On three-component composition has already been proposed. This composition has 900 to 1
It can be sintered in the low temperature range of 050°C, has excellent properties such as high dielectric constant, low dielectric loss, and high insulation resistance at room temperature and high temperature. however,
Since this composition has low mechanical strength, its use has had to be limited to a narrow range.

In view of the above points, the present invention can be sintered in the low temperature range of 900 to 1050°C, has excellent electrical properties such as high dielectric constant, low dielectric loss, and high insulation resistance at room temperature and high temperature. The purpose is to provide a highly reliable porcelain composition with particularly high mechanical strength, and a magnesium tube lead tungstate (Pb(Mg□ztWt/1)O
s), lead titanate (PbTiOs) and nickel.
Lead niobate (Pb (Ni,,,Nb,,)Q,
), a three-component composition consisting of (pb (ml/, wl)
, ) Os ) engineering (PbTiO et al. [pb (Nl 11B
Nb 1/3) Ox ] When expressed as z (however,
X+3'+z=1. OO) In this three-component composition diagram, the following composition points (X=0.693, y=0.297, z=0.
01) (x=0.495, y=o, 495, z
=0.01) (X=0.195, y=0.455
, z=0.35) (X=0.10, V=0.
40, z=0.50) (X=0.06, y=0.
24, z=0.70) and in the composition range surrounded by these five points, manganese lead tantalate [:Pb(Din□/2T
a s/□)0. ] to the main component, 0.05 to 6 m
It is characterized by containing 1% o.

Hereinafter, the present invention will be explained in detail with reference to Examples.

Lead oxide (PbO) with a purity of 99.9% or more as a starting material
, Cut magnesium (MgO), 4R tungsten (Wo, ), titanium oxide (TiOx), nickel oxide (Nip), niobium oxide (Nb+Os), oxidation tank # (Ta20s) and manganese carbonate (MnCOs)
), and each was weighed to achieve the blending ratio shown in the table. Next, the weighed materials were wet-mixed in a ball mill and pre-baked in stages 75o to soo'c, and this powder was ground in a ball mill, dried, and then added with an organic binder, sized, and then pressed. m'& 16 arm as sample
, four disks with a thickness of about 2 mm and a cylinder with a diameter of 16*s and a thickness of about 10 mm were created. Next, the sample is 900 ~
Sintering was carried out at a temperature of 1050° C. for 1 hour.

Silver electrodes were baked on the top and bottom surfaces of four sintered disks at 60θ℃, and the conductivity, tTi, and loss were measured using a digital LCR meter at frequency IKHz, mpressure IVr, m, and s, and temperature 20℃. The rate was set high. .

Next, a voltage of 50V was applied for 1 minute using a super insulation resistance meter to determine the insulation resistance at temperatures of 20°C and 125°C, and the specific resistance was calculated.

In order to evaluate the mechanical properties in terms of bending stress and tY value, a sintered cylinder with a thickness of 5 mm and a width of 2+11111. Length approximately 1:3
Cut out 10 pieces of my friend's rectangular board. Taking the distance between the fulcrums as 9, and according to the formula kq/ωd], the bending strength τC/ is 9/
cvI].

However, l is the inter-support pressure j, t is the thickness of the sample, W +=
It is the width of the sample. The electrical properties (bow, average value of 4 disk samples, and bending strength were determined from the average value of 10 rectangular plate samples. In this way, Ili et al. 21.
Mg 1/xWx/2)Os )X[P bT i O
s +ly (Pb (Ni, /3Nb, /3)O
s) Mixing ratio X, V+z of 2 and addition amount of subcomponents and 1
The following table shows the relationship among the transmittance, dielectric loss, resistivity at 20°C and 125°C, and bending strength.

As is clear from the results shown in the table, Pb (]VIg
sy□W17□)Os P b T 10s Pb (
Nl 1/3Nb, /3)Os A 3-component composition in which pb (Mn 1/, Ta l/1)03 is added as a subcomponent at a specific ratio has a dielectric constant of 31.
00-13530, high dielectric loss of 0.1-2.2%
The resistivity is as small as 2.0 at 20°C. a x toi
2～1.5 XIQ13Ω・Very high, and 125℃
Also in 1. It shows a high value of I XIO" to 4. I
It can be seen that the porcelain composition has a highly reliable and extremely practical value showing a value of 50 kg/cd, which is sufficiently high for practical use. The porcelain of the present invention exhibiting such excellent properties has a sintering temperature of 1
Since the temperature is 0.050° C. or lower, it is possible to reduce the cost of the internal electrodes of multilayer capacitors, and also has the extremely excellent effect of saving energy and furnace materials. The figure shows the main component composition range of the present invention. The numbers shown in the diagram are
The numbers correspond to the main component blending ratios shown in the table.

In the present invention, the main component composition (pb(Mg, □W1/ρ
on) Engineering (PbTiOs) A I: pb (Ni 173
When expressed as Nb 273) Os :) 2 (where x + Y + z = 1.oO), its composition is the point (x = 0.693, y = 0.297, z = (1
, 01) (x=0.495, 3'=0.495,
z=0.01) (x=0.195, y=0.45
5, z=0.35) (x=0.10, y=o
, 4o, z=0.50) (x=0.06, y
= 0.24, z = 0.70) and the composition range surrounded by these five points, and the added content of subcomponents is limited to 0.05 to 6 mo1% of the main component. . In the three-component composition diagram showing the main component composition range, the resistivity at high temperatures becomes small outside the line connecting composition points 2 and 6 and composition point 17.19, making it impractical. Outside the gland connecting composition points 6゜13 and 17, the single Curie point deviates significantly to the higher temperature side than the practical range, so the dielectric constant becomes small, and outside the line connecting composition points 19 and 2, the single Curie point falls outside the practical range. Since the temperature deviates significantly toward the lower temperature side, the dielectric constant decreases, making it impractical.

In addition, Pb (Mn 172'l'a 1
．． ) If the amount of On added is less than Q, 05 mo, the effect of improving the transverse strength is small, and if it exceeds 6 mo, the transverse strength decreases, which is not practical.

[Brief explanation of the drawing]

The figure is a diagram showing the main component composition range of the present invention and the composition points shown in Examples. Patent applicant: NEC Corporation Pb (NL1/3Nb2/3) 03

Claims (1)

[Claims] (1) Magnesilano, ψ tongue: 1. thea rll
@”l [Pb (Mg, /2)W, /□)03]
, lead titanate CPbTi03) and nickel-lead niobate (pb (Nl l/3Nb 2/3)Os)].
．． ), CPbTi03), CPb(Ni,.Nb273)03]2, (where X
+ y + z = 1.00) Based on this three-component composition diagram,
The following composition points (x=0.693, y=0.297, z=0.01
)(x=(1,495+y:0.495,z=0
．． 01)(x””0.195, 3'=0.455
, z = 0.35 ) (x = 0.10 , y = o, 4
o, z=0.50) (x=0.06, y=0.2
4, z=0.70) and in the composition range surrounded by these five points, manganese-lead tantalate [Pb (Mn I/2Ta 1
72) A porcelain composition comprising 0.05 to 6 mo4 of Os) added to the main component.