JPH04202049A - Grain boundary insulated semiconductor porcelain composition - Google Patents

Abstract

PURPOSE:To obtain a grain boundary insulated semiconductor porcelain compsn. having high quality, superior insulation resistance, a high relative dielectric constant, a small dielectric loss and superior temp. characteristics by adding a specified element to a Ti-Sr compsn. CONSTITUTION:This semiconductor porcelain compsn. is represented by a formula xSrO.yTiO2.mNb2O5.nSb2O3.-aSiO2.bCaO.cMgO (where (x) is 90-110mol, (y) is 90-110, (m) is 0.01-0.50, (n) is 0.01-0.50, (a) is 0.01-0.50, (b) is 0.1-1.0 and (c) is 0.01-0.50), the grain boundary has been insulated with at least one among Cu, Bi, Na and Mn and the max. grain diameter is <=200mum.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a grain boundary insulated semiconductor porcelain composition, in particular,
For example, the present invention relates to a grain boundary insulated semiconductor ceramic composition suitable for use as a material for grain boundary insulated semiconductor ceramic capacitors.

Conventional technology In recent years, with the miniaturization, high-density packaging, and stabilization of quality of electronic devices, there are demands for miniaturization and higher quality of electronic components. Therefore, there is a demand for the development of a grain-boundary insulated semiconductor ceramic composition having a small size, large capacity, and low dielectric loss, and the development of a capacitor made from the composition.

To this end, several semiconductor ceramic compositions prepared by adding Nb or the like to strontium titanate have been proposed. However, they were extremely inadequate in one or more electrical properties such as insulation resistance, dielectric constant, dielectric loss, and temperature characteristics.

In particular, insulation resistance and relative permittivity tend to be contradictory, and no semiconductor ceramic composition has hitherto been known that is excellent in both of these properties.

The present invention was made to solve the above-mentioned problems in conventional semiconductor ceramic compositions.
It is an object of the present invention to provide a grain boundary insulated semiconductor ceramic composition which has an unprecedented high quality and has excellent relative dielectric constant, as well as excellent dielectric loss and temperature characteristics.

The grain boundary insulated semiconductor porcelain composition according to the present invention for preparing the amount of
．． 01-0.50, n is 0.01-0.50, a is 0.
01~0.50, b is 0.1~1.0, C is 0.01~
The molar ratio is shown in the range 0.50. ), whose grain boundaries are Cu, Bi, Na, and M
is insulated by at least one of n;
It is characterized in that its maximum particle size is 200 μm or less.

INDUSTRIAL APPLICABILITY The present invention is directed to improving a strontium titanate-based semiconductor ceramic composition, and provides a grain boundary-insulated semiconductor ceramic composition in which Nb and sb are controlled on the diatomic side. In particular, in the present invention, sb and Mg were added because Nb
The main purpose is to lower the specific resistance before insulation treatment by controlling the diatomic side, thereby reducing electrical loss and preventing a decrease in withstand voltage caused by abnormal growth of crystals. Furthermore, in the present invention, the crystal grain boundaries are insulated by at least one of Cu, Bi, Na, and Mn, and the maximum grain size is 200 μm or less.

A capacitor manufactured using the composition according to the present invention has a dielectric constant of 70,000 or more and an insulation resistance of 1,000 MΩ·c.
m or more, dielectric loss of 1% or less, and temperature characteristics of ±15%.

Implementation twist Hereinafter, the present invention will be explained in detail based on examples.

(1) Preparation of porcelain composition Strontium carbonate, titanium dioxide, niobium pentoxide, antimony trioxide, silicon dioxide, calcium carbonate, and magnesium oxide are mixed in predetermined ratios, stirred, and then calcined to obtain the The calcined material was crushed. An organic binder was added to the calcined powder, the particles were sufficiently uniformly sized, and then pressure molded using an IT/C machine.

The obtained molded product was heated at 1350 to 1500° in a hydrogen atmosphere.
The fired beads were fired for 3 to 6 hours at a temperature of C.
After immersion in an aqueous solution consisting of u, Bi and Na ions,
It was dried and then calcined in air at a temperature of 1100-1200°C for 1-2 hours.

The relative dielectric constant, dielectric loss, insulation resistance, and withstand voltage of the thus obtained ceramic composition were measured using an LCR meter and a resistor. Furthermore, temperature characteristics were measured using a constant temperature bath.

The above results are shown in Table 1.

As described above, the grain boundary insulated semiconductor ceramic composition according to the present invention has a high dielectric constant (ε>7000
0), high insulation resistance (100 OMΩ・cm or more), low dielectric loss (tan δ <1%), and good temperature characteristics (25 ± 5
(within ±15% at 5°C).

Claims (1)

[Claims] (1) Composition formula xSrO+yTiO_2+mNb_2O_5+nSb_
2O_3+aSiO_2+bCaO+cMgO (in the formula,
x is 90-110, y is 90-110, m is 0.01-
0.50, n is 0.01-0.50, a is 0.01-0
．． 50, b is 0.1 to 1.0, c is 0.01 to 0.50
The molar ratio is shown in the range of . ), whose grain boundaries are Cu, Bi, Na, and Mn.
A grain boundary insulated semiconductor ceramic composition characterized in that the composition is insulated by at least one of the above, and has a maximum grain size of 200 μm or less.