JPH02106904A - Complex function element - Google Patents

Abstract

PURPOSE:To obtain a high absorptivity of a high-speed noise and improve the voltage dependent nonlinearity by making a semiconductor porcelain composition, the principal component of which is SrTiO3 and containing at least one oxide selected from a group composed of oxides of rare earth elements, Nb, W, and Ta, by using semiconductor porcelain of a glass composition. CONSTITUTION:At least one of Bi, Pb, and Zn glass oxides, one or both of B and Si glass oxides, and at least one of Fe, Mn, Co, Ni, Cr, and V glass oxides are diffused in a grain boundary. Therefore, varistor voltage can be easily controlled by adjusting the diffusion quantity to easily obtain a varistor available under low voltage. Besides, excellent voltage dependent nonlinearity can be obtained with SrTiO3 semiconductor porcelain maintaining large capacitance. Therefore, a high-speed noise can be effectively absorbed and a complex function element having high absorptivity of a high-frequency noise and a surge wave front can be obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is directed to a multifunctional device having varistor and capacitor functions, which is mainly composed of 5rTIO semiconductor ceramic and has a high resistance layer formed at its grain boundaries. Regarding improvements.

[Conventional technology]

In recent years, micro combinators have been installed in various electronic devices, and in such cases, malfunction of the devices due to noise has become a major problem. Therefore,
Demand for varistors to absorb voltage noise is increasing.

Semiconductor porcelain in which a high-resistance oxide layer is formed at the grain boundaries is known as a variable material, and conventionally, ZnO-based,
SiC-based and 5rTiOs-based materials are used.

[Technical problem to be solved by the invention] However,
ZnO-based varistors, which are being put into practical use, have excellent voltage nonlinearity, but have problems in that they have poor response to high-speed noise and are less effective in absorbing static electricity noise and the like.

On the other hand, SiC-based materials do not have very good voltage non-linearity, and may not be able to fully absorb noise voltage.

Therefore, 5rTjOj-based varistors are attracting attention.The most important feature of varistors using #SrTi03-based semiconductor porcelain is that they have a large capacitance, and Zn
It has a capacitance nearly 10 times that of O-based semiconductor ceramics.

Therefore, it has excellent ability to absorb high-speed noise.

However, in terms of varistor characteristics, that is, voltage nonlinearity, 5rTiOs-based semiconductor porcelain has about twice the performance as SiC-based semiconductor porcelain, but is inferior to ZnO at 172 to 115. Therefore, the voltage suppression effect is small, which has been a big problem when considering the use of 5rTiCh semiconductor ceramics.

Furthermore, the driving voltage of a microcomputer is approximately 3 to 5 µm, and currently there are no varistors that can handle this low driving voltage.Therefore, it is desired that a varistor that can handle such a low driving voltage be developed. ing.

Therefore, an object of the present invention is to provide a high-speed noise absorption system with excellent absorption ability for high-speed noise;
The present invention also aims to provide a 5rTiO-based multifunctional device which has improved voltage non-linearity and can obtain a desired varistor voltage in a compact manner.

[Means for solving technical problems]

The multifunctional device of the present invention has 5rTiO as a main component,
For a semiconductor ceramic composition containing at least 111 selected from the group consisting of rare earth elements, Nb, W, and Ta oxides as a semiconductor agent, a semiconductor diffused in the grain boundaries of the following glass composition. It is characterized by being constructed using porcelain.

This glass oxide contains at least one of Bi%Pb and Zn, at least 171% of B and Si, and F
At least I of e, Mn, Go, Ni, C'' and V
including ll.

Preferably, the weight of the glass composition is less than 1% by weight based on the semiconductor porcelain, and contains Fe, Mn, Co, Ni, C.
r and V are Fe and O, respectively.

, Mn01C010x, NIO, Crz03 and Vies are added and contained in the glass composition in an amount of 1 to 30% by weight.

The reason why rare earth elements, Nb, W, and Ta oxides are included in the above structure is to form a high resistance layer at the grain boundaries of the 5rTiO1-based porcelain to make it a semiconductor.

(Operations and Effects of the Invention) Conventionally, when producing semiconductor porcelain mainly composed of 5rTiO, S r Ti O
It was known that S-type varistors and capacitors could be created.

Therefore, the inventors of the present application made extensive studies to utilize the characteristics of such 5rTiO1-based semiconductor ceramics to obtain a multifunctional device with even better voltage nonlinearity. The present inventors discovered that a multifunctional device with better voltage nonlinearity could be obtained by diffusing it into the grain boundaries, leading to the present invention.

That is, according to the present invention, at least 1f of Bi%Pb and Zn! 1! , B, at least one of Si,
In addition, since each glass oxide of at least one of Fe, Mn, Co, Ni, Cr, and V is diffused into the grain boundaries, the varistor voltage can be accurately controlled by adjusting the expansion +1k ffi. be able to. Therefore, a varistor compatible with low voltage can be obtained in a compact size.

Moreover, excellent voltage nonlinearity is achieved while maintaining the large capacitance characteristic of 5rTiO1 semiconductor ceramics. Therefore, it is possible to obtain a multifunctional element that can effectively absorb high-speed noise and has excellent high-frequency noise absorption properties and surge wave front absorption effects.

(Explanation of Examples) 5rCOs and Tie were mixed in a ratio to obtain SrTiOs, and a mixture was prepared in which 0.0. The mixture thus prepared was heated to 1000″
It was precalcined at a temperature of C-1200'C for about 3 hours and then ground. Polyvinyl alcohol was mixed as an organic binder into the obtained fine powder raw material and granulated.

Next, the granulated powder is molded at a pressure of about 500 Kg/cj to 2 tons/c4, and a diameter of 1aa and a wall thickness of 0°5-
A disk-shaped molded body was obtained. This molded body was heated to 1100℃~1
It was calcined in air at a temperature in the range of 200°C, and further calcined for 3 hours at a temperature of 1400°C-1500°C in a reducing atmosphere of N, :H□-95 mol%:5 mol%.

A glass oxide obtained by vitrifying the oxide having the composition shown in Table 1 below was applied to the surface of the obtained sintered body.
% and heat treated at a temperature of 900°C to 1200°C for 2 hours. Finally, an indium-gallium alloy is applied to the surface of this unit as an electrode material, and the varistor voltage (vi
sa), voltage nonlinear coefficient (α), capacitance! (C),
The induced 111tl loss (tan δ) was measured. The results are also shown in Table 1.

In addition, items listed in Table 1 are B i Ox and P bo.

The proportions of ZnO, SiO, and B2O are in mol%, and the proportions of Fe
w o3 , MnO, Cow Ox , Ni01
C'20 and VtOs are shown in weight %. Also, ΔVIaA represents the rate of change in V1+aA after applying two 8×20 μsec, 500 A peak pulses at 5 minute intervals.

As is clear from Table 1, Fe, O, 'MnO, C
r, O, and v! 0. It can be seen that the varistor voltage increases as the amount added increases. On the other hand,
In this case, the capacitance does not change much, so
It can be seen that only the varistor voltage can be controlled by the amount of additive.

In addition, Cozol and NiO have the effect of lowering the varistor voltage, and in this case, it can be seen that the capacitance increases with addition (data for sample numbers 9 to 12 and sample numbers 13 to 16). Please refer).

Therefore, Fe, Os, Mn01CrtOx and/or V! Addition amount of O, Co, O, and/or NiO
It can be seen that by adjusting the amount of addition, the varistor voltage can be easily controlled and the surge resistance can be slightly improved.

However, no matter which glass oxide is used, when the amount added exceeds 30% by weight and 50mff1%, the voltage nonlinear coefficient α decreases significantly, and α becomes less than 10. Therefore, the amount of each oxide of Fe, Mn, CO%Ni, Cr, or V added is preferably 30% by weight or less based on the total glass oxide.

Next, for each unit using sample number 2.14.22 in Table 1, Fe, Mn%Co, and Ni.

Varistor voltage was measured while varying the amounts of Cr and V additives. The results are shown in Figure 1.As is clear from Figure 1, the addition ratio of these is 1% by weight of glass oxide.
It can be seen that when the voltage is increased by 1, the voltage nonlinear coefficient α becomes smaller and the varistor characteristics deteriorate.

In addition, the solid line in the figure shows the varistor voltage, and the broken line shows the voltage nonlinear coefficient.

[Brief explanation of the drawing]

FIG. 1 shows the varistor voltage and voltage nonlinear coefficient in an example of the present invention, as well as Fe, Mn5Co, and Ni. It is a diagram showing the relationship between the amount of oxide added and V.

Claims (2)

[Claims] (1) Main component is SrTiO_3, rare earth elements, Nb
, W, and Ta as a semiconductor agent, and Bi, Pb, and Zn.
at least one of B and Si
1. A multi-functional device constructed using semiconductor porcelain in which a glass composition containing seeds and at least one of Fe, Mn, Co, Ni, Cr and V is diffused in grain boundaries. (2) The amount of the glass composition is 1 for the semiconductor porcelain.
weight% or less, and Fe, Mn, Co, Ni, Cr and Vv are Fe_2O_3, MnO, Co_2O_3, Mm
2. The multifunctional device according to claim 1, wherein 1 to 30% by weight of O, Cr_2O_3 and V_2O_5 are added to the glass composition.