JPS58130163A - 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 relates to a porcelain composition, for example, a porcelain composition that can be sintered at a low temperature of 1000°C or less, has a high dielectric constant, has high insulation resistance at room temperature and high temperature, and has high mechanical strength. It is related to.

Conventionally, barium titanate (B
It is well known that porcelain whose main component is aTiOs3 is widely used in practical use.However, porcelain whose main component is barium titanate (BaTiO3) is sintered at a high temperature of usually 1300 to 1400°C. It is. Therefore, when using this in a multilayer capacitor, a material that can withstand this sintering temperature must be used for the internal electrode, such as an expensive noble metal such as platinum or palladium.
The disadvantage is that manufacturing costs are high. In order to manufacture multilayer capacitors at low cost, it is necessary to use porcelain that can be sintered at as low a temperature as possible, especially below 1000°C, so that inexpensive metals mainly composed of silver, nickel, etc. can be used for the internal electrodes.

In addition, the electrical properties of the porcelain composition include a high dielectric constant,
Basically, it is required to have low dielectric loss and high insulation resistance. Furthermore, when considering the life characteristics of ceramic capacitors, in general, the lower the value of insulation resistance, the shorter the life is. In addition, it is necessary to have a high insulation resistance at the maximum operating temperature.

In addition, in the case of a multilayer chip capacitor, when the chip capacitor is mounted on a board, mechanical strain is applied to the chip capacitor due to the difference in thermal tensile coefficient k between the board and the porcelain that makes up the chip capacitor. Chip capacitors may crack or be damaged.

Also, in the case of a dilag capacitor coated with epoxy resin or the like, cracks may occur in the dilag capacitor due to the stress of the coating 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 extremely important in practical terms. , Agranovskaya (Fujico Toperdogo)
Terra Vo1.2. t@1.70p 1960)
N, N.

Krainik and A, 1. Agranovs
Kaya (Fizik.

Ti03)a (Pb Mtzos Wo,s 0a)
b (However, X = O ~ 0.10. a is 0.35
~0.5, b is 0.5 to 0.65, and a
Regarding +b-1), q as a monolithic powder composition
#Disclosed in JP-A-52-21699. However, none of them disclosed any specific resistance, and the practicality of these porcelain compositions was not clear◇In addition, the present inventors have already found that they can be sintered at temperatures of 910°C to 950°C, and Pb (MgHWM)Os and PbTi0a system consists of two components, which is CPb(MgMWM)Os:lx
(PbTiOs) When expressed as 1-x, X is O-6S
〈A composition in the range of x-1-00 is proposed. This composition has a high product of dielectric constant and specific resistance, and has excellent electrical properties with low dielectric loss. However, since all of the above compositions have low mechanical strength, their applications are limited to a narrow range and r1 was not obtained.

In addition, a three-component EC system including Pb('hk314W%)Oi-prebTjO, system is used.
Pb(Mg3AW%)σ1-PbT in 10111c
iOsPb(MgHNb)i)Ox system is published in JP-A
In 55-117809, pb work W54) Oa
-PbTiOsPb(MgHTaN)Ox systems are disclosed, respectively. However, none of them discloses any specific resistance, and the practicality of these ceramic compositions is unclear.
Os-PbTiOa-Pb(MgKTaVa
) The sintering temperature of the Q system (Japanese Patent Application Laid-open No. 55-117809) is
Because of the high temperature of 1,000 to 1,150° C., it has been difficult to use inexpensive metals mainly composed of silver, nickel, etc. as internal electrodes. Furthermore, in JP-A-56-48004, PbZrQs-Pb(Mg3ANb)'a)O
Although the x-Pb(MgM WS2)Ox system is disclosed, since the sintering temperature is a high temperature of 1000 to 1150°C, it is difficult to use cheap metals mainly composed of silver, nickel, etc. as internal electrodes. It was difficult.

In addition, the present inventors have already discovered that Pb (Mg I W3A) 03-P
A ternary composition bTi03-PbZrOa has already been proposed. This composition can be sintered in the low temperature range of 900 to 1000°C, and has a high dielectric constant and a high product of dielectric constant and specific resistance.
, has excellent characteristics of low dielectric loss. However, since this composition has low mechanical strength, its application has to be limited to a narrow range.

In view of the above points, the present invention can be sintered in a low temperature range of 900 to 1000°C, has a high dielectric constant, and has a small dielectric loss.
The purpose is to provide a porcelain composition that has excellent electrical properties such as high insulation resistance at room temperature and high temperature, and also has high mechanical strength and reliability. Pb(W3f to Mg)Oa)
s A three-component composition consisting of lead titanate [PbTi0a] and lead zirconate [PbZr0a] is [Pb(Mg%W34)O3)! (PbTiOa)
When expressed as y (PbZr03)z (however,
x+y+z-1,00).

In this three-component composition diagram (x=0.72, y-0.08, z=0.20
) (x-0,792, y=0.198, z-0
,01) (x=0.396, y=oj94,
z=0.01 )(!-0,15,y-035,z-
0,50) (x=o:27, y-0-03, z
-0,70), and add manganese-lead niobate (Pb(MnX Nb%)Os) as a blue component to the main component composition in the composition range surrounded by these five points. The I# image is obtained by adding O, OS to 10(2)l- to the main component.

The present invention will be explained in detail below using examples.

As a starting material, lead oxide (Pb
0) Magnesium oxide (MgO), tungsten oxide (
W) 3) Using titanium oxide (TiOx), zirconium oxide (ZrO2) + niobium oxide (Nb103), and manganese carbonate (MnCOa), each is weighed so as to have the compounding ratio shown in the table. Next, the weighed ingredients were wet-mixed in a ball mill, pre-baked at 750-800℃, and this powder was ground in a ball mill. Then, four disks with a diameter of 16 square meters and a thickness of approximately -1 and a cylinder with a diameter of 16 square meters and a thickness of approximately 10 m were prepared.

Next, it was sintered in air at a temperature of 900 to 1000°C for 1 hour. Silver electrodes were baked at 600°C on the top and bottom of four sintered disks, and the frequency was measured using a digital LCR meter at a frequency of IKHz and a voltage of I.
The capacitance and dielectric loss were measured at Vr, m, and s at a temperature of 20° C., and the dielectric constant was calculated. Next, measure the voltage of 50μ with a layer insulation resistance meter.
The insulation resistance was measured at temperatures of 20° C. and 125° C., and the specific resistance was calculated. In order to evaluate the mechanical properties by bending strength, the thickness of the sintered cylinder was 0.5 mm, @2 mm, and the length was 1 mm.
Ten rectangular plates of size 3 were cut out. Using the distance between the fulcrums as 9■, measure the breaking load Pm (each) using the three-point method, and Pn
According to the formula, bending strength r [:
Kg/ml] was determined. However, 1 is the distance between the supports, t
is the thickness of the sample, and W is the width of the sample.The electrical properties were determined from the average value of 4 disk samples, and the bending strength was determined from the average value of 10 rectangular plate samples. The main component of the ia device thus obtained is CPb(Mg !A W34 )On )x(PbTi
Os)y (PbZrOs)z blending ratio
The relationship between specific resistance and bending strength at 25°C is shown in the following table.

As is clear from the results shown in the table, Pb(Mg3fW
3A') Ox PbT10g-PbZrOn A ternary composition in which Pb (Wb% to Mn)Os is added as an accessory component and is within the scope of the present invention has a dielectric constant of 107.
High dielectric loss of 0-3750, 0.1'll-4.9
Small as s, specific resistance at 20℃ &Nr, 3-7X
101L - 6.4
It can be seen that the ceramic composition has a high value of 0.013 Ω·α and also has a bending strength of 99G −1430%, which is sufficiently high for practical use, making it a highly reliable and extremely practical ceramic composition. The porcelain of the present invention, which exhibits these excellent characteristics, is sintered at a low temperature of 1000°C or less, making it possible to reduce the cost of internal electrodes of multilayer capacitors, and also to save energy and furnace materials. Effects also occur.

Note that the main component IIt of the present invention is [Pb(Mg3
(Wi)Oa)x (PbTiOa))' (PbZr
When expressed as Oi:lz (however, ! + y
+ zuta 1-00) Its composition is shown in the ternary composition diagram as NIL3.6.16.18.5.

3: (x-0,72,y-0,08',z-
0,20)6: (x=0.792.y-0,1
98,z-0,01)16: (x-0,396,y
=0.594, z-0,01)18: (X
=0.15, y-035, z-OjO)5:
(x=0.27, y-value 0.03, z
-0,70) on the line connecting each point, and the composition range surrounded by these five points, and the added content of subcomponents is 0.05 to 10(2)1% of the main component. Limited.

In the three-component composition diagram showing the main component composition range, point 6.
Outside the line connecting 3.5.18.16, the dielectric constant becomes small and it is not practical. Outside the - connecting points 6.16, the resistivity at high temperatures becomes small and is not practical.

Furthermore, if the addition amount of Pb (Mn%Nb)os, which is a subcomponent, is less than 0.05 mol, the effect of improving the bending strength is small, and if it exceeds 10 mol, the bending strength becomes small, which is not practical.

The figure shows the composition range of the main components of the present invention.

The numbers shown in the EIC correspond to the numbers of the main component blending ratios shown in the table.

[Brief explanation of drawings]

The figure is a diagram showing the main component composition range of the present invention and the composition points shown in Examples. 'FhlyOs

Claims (1)

[Claims] Magnesium lead tungstate (Pb(Mg34W3)
A) (%), Lead titanate (PbTi0a:)
The three-component composition consisting of lead zirconate [PbZr0a] and lead zirconate [PbZr0a] is CPb(Mg54WM)Os]
When expressed as z (PbTiOs]y(PbZrOa)z, (however, z 4 - y + z = 1.0
0) In this three-component composition diagram (x-0,72, y-0,08, z-020) (x=0
．． 792, y-0,198,z-0,01)(x
-0,396,y-0,594,z=0.01)(X
=0.15, y-0,35, z=0.50)
(x=0.27-, y-0,03, z-0,70
) on the line connecting each point and within the composition range between these 5 points, add manganese lead niobate [Pb(Mn3ANbVS)03] as a subcomponent to the main component composition at 0.05 to 10 moH1 relative to the main component. Porcelain composition characterized by containing additives◎