JPS5913301A - Semiconductor porcelain 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 An industrial field of application The present invention relates to a semiconductor ceramic composition, and relates to a semiconductor ceramic composition having a positive temperature resistance coefficient of 1%. This invention relates to a device in which the negative slope is reduced in a temperature range having the following negative characteristics.

Problems to be solved by the prior art and the invention A semiconductor ceramic composition made by adding a small amount of semiconductor elements to barium titanate to make it a semiconductor has a positive humidity resistance coefficient, and when it heats up to a certain point, the current is suppressed to a small value. Because of this, it is used in heating elements, overcurrent prevention elements, etc.

When using this as a heating element, it is required to increase the heat generation flow rate.1 For example, by adding lead to barium titanate, or by converting barium titanate to lead titanate VcR, It is known that (Tc) can be moved to the Takabuchi side.

However, in this case, as the amount of movement toward the high temperature side increases, the negative slope of the N 1' C region also tends to increase. If the Curie point becomes higher, the inrush current will increase even with the same current resistance, and changes over time during intermittent tests will increase. Further, due to the substitution of lead titanate, the positive characteristics also become steep, and the temperature range in which positive I retention can be sustained is narrow. Therefore, it had many disadvantages when used.

Purpose of the Invention The purpose of the present invention is to improve the above-mentioned problems.
It is an object of the present invention to provide a semiconductor ceramic composition having positive resistance-temperature characteristics that does not cause a large inrush current and exhibits small changes over time in intermittent tests and the like. Another object of the present invention is to provide a semiconductor ceramic composition having good positive resistance conditioning characteristics as a heating element.

Means for Solving the Problem In order to achieve this object, the semiconductor ceramic composition of the present invention contains 1 to 50 mol% of barium in barium titanate.
It is characterized in that 0.1 to 3.0 mol % of an element for semiconductor formation is added to a composition in which 1 to 1.0 mol % of lead and o are simultaneously replaced with magnesium.

Example In the present invention, barium carbonate B a CO3 is used as the starting charge.
゜Titanium dioxide TJO, lead oxide pbo, magnesium carbonate MgC0, silicon dioxide 810. ．． Manganese nitrate solution Mn (NOx)2, alumina dioxide Al, O
S, yttrium oxide Y, Os, etc., all of high purity, were weighed so that the final composition was as shown in Table 1, and after wet mixing in a ball mill for about 16 hours, the water was removed from the mixture. After drying to 7 circles, 1000 to 120
The mixture was heated to a temperature of 0° C. at a temperature gradient of 250° C./hour, calcined for about 2 hours, and then slowly cooled. The calcined product obtained by further heating was wet-pulverized again using a ball mill, dehydrated and dried, and then about 2 μ% of a PVA aqueous solution was added in terms of solid content.

Then, after 50 meshes were granulated and granulated, 2
Diameter 16.5MX thickness 3.5 at a pressure of 000Kp/cm
A disk-shaped molded body of Maro was obtained, heated to 1200 to 1350°C at a temperature increase rate of 250°C/hour, held at this temperature for 1 hour, and then slowly cooled to room temperature at a rate of 150°C/hour. In this way, porcelain with a diameter of 14 m and a thickness of 3.0 m was obtained.The specific resistance ρ2o, the Curie point Tc, β, and the resistance change in the intermittent life test of each sample of porcelain obtained in this way. When the ratio was measured, the characteristics shown in Table 1 were obtained.

Here, β is calculated by the following formula, where the resistance value at a temperature of 20°C is R20* and the minimum resistance value at one Curie point is Rmln. It is easy to use.

In addition, the resistance change rate in the intermittent life test is 1 when the applied voltage is 120
It shows the rate of change in resistance with respect to the initial value after repeating this for 1000 cycles by turning it on for one minute and then turning it off for the next minute,
Again, the smaller the value, the less the change over time.

The reason for the numerical limitation in the present invention is as follows.

+11 MgJl upper limit If it exceeds 1.0 mol%, sample Nα9 in Table 1,
Nα47. The Ke edge is closed as evidenced by Nα81 and the like.

When the lower 11uO is less than 1 mol%, sample No. 1 in Table 1, Nn 32-40. As is clear from Nα82 to 85, etc., the resistance change rate in the resistance change, β, and intermittent life tests are poor, and it becomes an insulator, and there is no so-called additive effect, and no improvement in characteristics is observed.

(2) If the upper limit of the amount of elements for semiconductor formation is 3.0 mol %, the specific resistance at room temperature will be extremely high and it will be impractical.

If the lower limit does not reach 0.1 mol%, the addition has no effect.

Do not use semiconductors.

+31 810. Jll If the upper limit exceeds 3.0w1%, dense porcelain will be obtained: it will not leak and will have a high specific resistance at room temperature. If the lower limit is less than 0.1 wt%, the firing temperature range will be narrow and uniform porcelain will not be obtained.

+41 Mn3% Upper limit If it exceeds 0.03 wt%, the specific resistance at room temperature becomes high and it lacks practicality.

When the lower limit of 0.002wt%Ic is not reached, there is no effect of improving characteristics over time.

+51 Pb blade upper limit If it exceeds 50 mol%, it becomes difficult for Mg9 to form a solid solution, and there is no property improvement effect. (Sample No. 59, 40
, 54, etc.) If the lower limit is less than 1 mol %, the temperature Tc at which PTC characteristics begin will not shift to the high flow side, and no improvement in lrk property will be observed, resulting in poor practicality.

(Upper limit of 6i ke2os amount: If it exceeds 1.0w1%, the specific resistance at room temperature will increase and the effect of improving the characteristics will not be seen.

When the lower limit of 0.1 wt% is not reached, no characteristic improvement effect is observed.

+71 TlO2.

Upper limit: 2.0 W; When it exceeds 2.0 W, the specific resistance increases and is impractical.

If the lower limit is less than 0.1 wt%, no property improvement effect is observed.

Further, the characteristics of the conventional example and the present invention are shown in the accompanying drawings.

At'i shows the conventional example, and Table 1 shows the characteristics of sample Nn83, and B shows the characteristics of sample Nα79 of the present invention.

(Ba 89.4 Pb 10.OMg 0.6) T
lo, + Y2030.7 mat! %＋' S lo
z O,7+ Mn O,01+ T lo* 0.3
It has a composition of +h120s 0.5. Here I3a
, Pb, Mg indicate mol%, others are W
[Indicates %.

As is clear, the conventional type has a small Rmin, so the inrush current is large, and the temperature range in which it exhibits positive characteristics is also narrow, but the present invention has greatly improved the characteristics, making it easier to use. I understand that.

Adding Mg to Naori aTIOsK has been reported in 2 For example, [Experimental Research on Barium Titanate Semiconductors] (Sabaketsu) and I), J, BROWN, F, A, W, SLY a.
nd G, AR'111-UR [The Effect
of Oxide Impuritiell o
n the Electrical Re5lstiv
lty o(La-doped BaTl0jIInt
national research and
Development Co.

Lid Newcastle upon Tyne 6
etc., but it has been clearly stated that these require a large amount of MgKi semiconducting agent.
(IlaPbMg)TIO.

Furthermore, the present applicant has filed a patent application for a barium titanate semiconductor [containing Mg and Pb (Japanese Unexamined Patent Application Publication No. 55-1979).
46524), the amount of iLF'iMg is completely different from that of the present invention, and moreover, unlike the present invention, it does not have the effect of suppressing the sudden current.

Effects According to the present invention, the negative slope of the resistance temperature characteristic in the humidity range below the Curie point vortex (NTC region) can be controlled to be small. And the inrush current can be kept smaller than this trap. Also, the PTC temperature is higher than the curri point temperature.
The positive gradient in the region becomes gentle, and the temperature range in which the positive characteristics persist expands, and the usage requirements as a 2-heating element also expand. With K like this, the change over time is also small, right? It has thus become possible to provide a high power heating element during aging.

[Brief explanation of the drawing]

The accompanying drawings show characteristic curves of a conventional semiconductor ceramic composition and an embodiment of the semiconductor ceramic composition of the present invention. Patent applicant Tokyo Denki Kagaku Kogyo Co., Ltd. Representative Patent Attorney
Akira Yamatani Sakae T#++ r(su

Claims (1)

[Claims] 1. 1 to 50 of barium in barium titanate VC
In a composition in which mol% is replaced with lead and 0.1 to 1.0% with magnesium, 0.1 to -
3. A semiconductor ceramic composition whose IPf characteristic is that o mol % is added. 2. Yttrium as the semiconductor element. Antimony, niobium, tantalum 1. At least one of dystopdium, gadolinium, neodymium, and samarium
2. The semiconductor ceramic composition according to claim 1, characterized in that: 5. sio, 0.1-5. The semiconductor ceramic composition according to claim 1, further comprising Owt-%. 4. The semiconductor ceramic composition according to claim 1, further comprising 0.002 to 0.05 wt% of Wygan. 5, 810. 0.1 to 3. Owt%, Mn 0.002-0.03wt%2 people 603 0.1-1.
2. The semiconductor ceramic composition according to claim 1, further comprising 0.1 to 2.0 wt% of TiO2.