JPS5957955A - 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, particularly a porcelain composition that can be sintered at a low temperature of 1000° or less, has a high dielectric constant, low dielectric loss, high insulation resistance, and high mechanical strength. The present invention relates to a composition.

Conventionally, barium titanate (B
It is well known that porcelain containing aTi03) f as its main component is widely put into practical use. However, the main component of barium titanate (BaTi03) is
The sintering temperature is usually a high temperature of 1300 to 1400°C. Therefore, when used in a fully laminated capacitor, it is necessary to use a material that can withstand this sintering temperature for the internal electrode, such as platinum.
The drawback is that expensive precious metals such as palladium must be used, resulting in high manufacturing costs. 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 and nickel 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.

In addition, 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. If cracks occur on the product, it may become damaged. In addition, even in the case of a dip capacitor entirely coated with epoxy resin or the like, cracks may occur in the dip 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, it is of practical importance to increase the mechanical strength of porcelain as much as possible.

The purpose of the present invention is to sinter in the low temperature range of 900 to 1000°C, have excellent electrical properties such as high dielectric constant, low dielectric loss, and high insulation resistance, and also have high mechanical strength and high reliability. There is a whole range of porcelain compositions to offer.

The porcelain composition of the present invention has a main component composition in which the main component blend ratio X of nickel and tungsten is within the range of 030≦X≦0.60, and manganese lead niobate (lead niobate) as a subcomponent. P b, (Mn 1 /3 Nb 2 /3
) 03) in an amount of 0.05 to 8 m relative to the main component composition.
It is characterized by containing 0.01% additive.

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

Lead oxide (PbOλ) with a purity of 99.9% or more is used as a starting material.
Nickel oxide (NtO), tungsten oxide (WOs)
.

Titanium oxide (T 10x ) Niobium oxide (Nb2
Us ) and manganese carbonate (MnCOs ) 2 were used, and each was weighed so that the mixing ratio shown in FIG. 1 was achieved. Next, after wet mixing the weighed materials in a ball mill,
Complete pre-baking at 50-800°C, pulverize this powder with a ball mill, dry it daily, add an organic binder, size it and press it to form 4 discs with a diameter of 15 mm and a thickness of about 2 mm. A cylinder having a diameter of 15 mm and a thickness of approximately IQ mm was prepared.

Next, it was sintered in air at a temperature of 900-1000°C for 1 hour. Silver electrodes were completely baked on the top and bottom surfaces of four sintered disks at 600°C, and a frequency of IKHz, 1 was measured using a digital LCR meter.
Jt, pressure IV r-m-s temperature 20°C for each set.

The dielectric loss was measured and the dielectric constant was calculated. Next, apply a voltage of 50V for 1 minute using a super insulation resistance tester to measure the insulation resistance at a temperature of 2.
It was measured at 0°C and the specific resistance was calculated.

Mechanical properties In order to evaluate the total bending strength, ten rectangular plates each having a thickness Q of 5 mm, a width of 2 mm, and a length of 13 mm were cut out from the sintered cylinder. From the fulcrum distance i9mmVC, (
According to the formula: Kg/cm2), the bending strength r (Kg/cm2)
cm 21 was determined. However, 1 is the distance between the supporting points, t is the thickness of the sample, and W is the width of the sample. Electrical characteristics are disk sample 4
The average value of points, the bending strength is the average value of 10 rectangular plate samples)
I asked for it.

The main component of the porcelain composition thus obtained [Pb(N
i□/2 Wl /2 )03)X ("bTiO
3) Mixing ratio X of □-8, additive amount of subcomponents, dielectric constant, and dielectric loss.

The relationship between specific resistance and bending strength is shown in FIG. Note that sample numbers marked with * are not included in the present invention.

As is clear from these results, according to the present invention, the dielectric constant is as high as 1,200 to 7,000, and the dielectric loss is as high as 0.3 to 2.
It is as small as 2% and has a specific resistance of 5X10” to 4×1013Ω・
It shows a high value of cm, and also has a bending strength of 990 to 1.
A highly reliable and highly practical porcelain composition having a value of 410 kg/Cm, which is sufficiently high for practical use, can be obtained. The magnetic powder of the present invention exhibiting these excellent properties has a sintering temperature of 1000
Since the temperature is low, below ℃, it is possible to reduce the cost of the internal electrodes of multilayer capacitors, and it also has the extremely excellent effect of saving energy and furnace materials. If the main component compounding ratio X is less than 0.30, the Curie temperature will be too high than the practical range, the dielectric constant at room temperature will be small, and the dielectric loss will also be large, which is not practical. If X>0.60, it will not be sintered as porcelain and is not practical. In addition, the subcomponent P b (Mn 1/a Nb 2 /3) 03
If the O addition 710 concentration is less than 0.05 malt%, the effect of improving the bending strength is small, and if it exceeds 8mo7%, the bending strength becomes small, which is not practical.

[Brief explanation of the drawing]

FIG. 1 shows the characteristics of an embodiment of the present invention. Agent Patent Attorney Original Sound Procedural Amendment (Voluntary) Commissioner of the Patent Office 1, Indication of Case 1982 Patent Application No. 1678
No. 22 No. 2, Title of the invention: Porcelain composition 3, Relationship to the amended person's case Applicant: 5-33-1 Shiba, Minato-ku, Tokyo (423) NEC Corporation Representative: Tadahiro Sekimoto 4, Agent: 108 Shiba Go-cho, Minato-ku, Tokyo] 37-8 Resident Mita Building 5, Detailed explanation of the invention column 6 of the specification subject to amendment, Contents of amendment (1) Page 2, line 2 of the specification K Correct ``porcelain te'' to ``porcelain ga''.

Claims (1)

[Claims] Nickel tongue f 7 M (P b(N il
/2W1/2)03) and lead titanate (PbTi03
) as the main component and p b (N I L /2 W 1
/2) 03)X (P b T io 3) 1-
The main component blending ratio X, expressed as X, is 0.30≦X≦0
．． Manganese lead niobate (Pb (Mn1/a Nb2/3)
03) to 0.05 to 8 mO to the main component composition!
A porcelain composition characterized in that it contains an additive.