KR920001162B1 - Barium titanate-baseo semi-conductor porcelain - Google Patents

Abstract

No content.

Description

Barium titanate-based semiconductor porcelain and manufacturing method thereof

1 is a characteristic diagram of a temperature-resistance value of barium titanate-based semiconductor porcelain to which zirconium dioxide is added in the first embodiment of the present invention.

2 is a characteristic diagram showing the specific resistance, withstand voltage, and maximum surge current of a magnet on a barium titanate-based peninsula to which antimony trioxide is added in the second embodiment of the present invention.

3 is a characteristic diagram showing a specific resistance value of barium titanate-based semiconductor porcelain added with magnesium to calcium in the third embodiment of the present invention.

4 is a characteristic diagram showing a specific resistance value of barium titanate-based semiconductor porcelain added with magnesium in the sixth embodiment of the present invention.

Table 1 shows the specific resistance ρ (25 ° C) at room temperature and the temperature characteristic ratio R (-20 ° C) when the amounts of magnesium (Mg) and calcium (Ca) added to the semiconductor porcelain were changed using the static characteristic thermistor according to the present invention. ) / R (minimum), R (60 ° C.) / R (minimum).

Table 2 shows the specific resistance ρ (25 ° C) at room temperature and the temperature characteristic ratio R (-20 ° C) / R (minimum value) when the amount of magnesium (Mg) added to the semiconductor porcelain was changed using the static characteristics thermistor according to the present invention. ), R (60 ° C.) / R (minimum).

The present invention relates to a barium titanate-based semiconductor magnetism applied to a static characteristic thermistor and a manufacturing method thereof. In particular, a barium titanate-based semiconductor magnetism having a large withstand voltage value in a low specific resistance area and a small variation in resistance value with respect to temperature And a method for producing the same.

Conventionally, barium titanate-based semiconductor magnets obtained by adding a small amount of rare earth elements to barium titanate have positive resistance temperature characteristics, and are most suitable for protection circuits such as temperature control, temperature compensation, or the like as constant current circuits (PCTs). It is suitably used and can be expected to expand and develop in the future.

Until now, barium titanate-based semiconductor porcelain is usually a rare earth element niobium (Nb), bismuth (Bi), or antimony (Sb) in a barium titanate (BaTiO ₃ ) or a solid solution of barium oxide (BaO) and titanium dioxide (TiO ₂ ). A small amount of yttrium (Y) or the like was added and calcined.

When the barium titanate thus obtained is used as a static characteristic thermistor in which the resistance increases at the same time as the temperature rises, there is a demand to set a low Curie temperature at which the resistance temperature characteristic changes from the negative characteristic to the static characteristic.

In response to this demand, a portion of the barium (Ba) was replaced with strontium (Sr) to set the transition temperature as a static characteristic of the resistance temperature characteristic to near normal temperature (see Japanese Patent Application No. 41-17784).

In addition, oxides such as manganese (Mn), silicon (Si), titanium (Ti) and the like are added to the barium titanate-based semiconductor to give a large slope of resistance temperature characteristics, and to prevent overheating of a solid-state switch or an electrical or electronic device. It is used.

However, conventional barium titanate-based semiconductor magnetics have a high rate of change in resistance to temperature, and when applied to outdoor circuits such as communication line security devices, there is a problem in that they interfere with communication services due to changes in day and night temperatures. .

Furthermore, in the conventional barium titanate-based semiconductor, the withstand voltage value in the low resistance region, for example, 100! &Amp; Cm or less is only 120V and the maximum surge current value is about 120A, for example, in a communication line. There was a problem because of the low protection.

SUMMARY OF THE INVENTION An object of the present invention is to provide a barium titanate-based semiconductor porcelain most suitable for a static characteristic thermistor having a small resistivity at room temperature and excellent characteristics such as withstand voltage characteristics and surge current characteristics. Another object of the present invention is to provide a method for manufacturing a barium titanate-based semiconductor porcelain most suitable for a static characteristic thermistor having a small change in resistance and a low specific temperature resistivity due to temperature change in the vicinity of room temperature.

In order to achieve the above object, the barium titanate-based semiconductor porcelain according to the present invention is obtained by adding a small amount of rare earth elements, niobium, bismuth, antimony, yttrium and the like to a solid solution of barium titanate or barium oxide and titanium dioxide. To the semiconductor barium titanate composition, 0.0005-0.13 weight percent of antimony trioxide to 0.1-1.3 weight percent of zitconium dioxide is added or a portion of barium is 0.001-0.1 atomic percent of magnesium to 0.01-2.0 atomic percent of Substituted and dissolved with lead from calcium to 0.01-5.0 atomic percent lead.

When at least one of manganese oxide, silicon dioxide, and titanium dioxide is added to the barium titanate composition as an additive, the properties can be improved. By adding antimony trioxide or zitconium phosphate to this barium titanate composition, the breakdown voltage characteristic and the maximum surge current value in a region with a small specific value can be increased. In addition, by substituting and replacing part of barium with magnesium to calcium to lead, it is possible to reduce resistance variations due to temperature changes in the vicinity of room temperature, and to reduce the room temperature specific resistance.

The barium titanate-based semiconductor porcelain according to the present invention will be described in detail with reference to the following examples. First, a barium titanate-based semiconductor ceramic composition is made. This composition comprises a rare earth element to a barium titanate composition obtained by adding strontium (Sr), tin (Sn), or zirconium (Zr) for controlling the Curie point, mainly based on barium titanate (BaTiO ₃ ) or barium titanate. It is a valence control element for semiconductorizing at least one selected from yttrium (Y), niobium (Nb), antimony (Sb), bismuth (Bi), and a crowd.

In addition, the barium titanate-based semiconductor ceramic composition was added with an additive to improve the positive resistance temperature characteristic and increase the resistance temperature. As this subadditive, there are oxides such as manganese (Mn), silicon (Si), aluminum (Al), titanium (Ti) and the like.

In this barium titanate-based semiconductor ceramic composition, 0.01-0.03 weight percent of manganese oxide (MnO), 0.1-1.0 weight percent of silicon dioxide (SiO ₂ ), and titanium dioxide (TiO ₂ ) as a minor additive for changing the positive resistance temperature coefficient ) Can be used in the form of 0.1-1.0% by weight or more.

The reason is that, below the lower limit of each component described above, sufficient static characteristic thermistor (PCT) characteristics are not produced, and above the upper limit, the specific resistance at room temperature is increased.

In the present invention, the barium titanate composition obtained as described above is added with 0.005-0.13 weight percent of antimony trioxide to 0.1-1.3 weight percent of zirconium dioxide or a part of barium from 0.001-0.1 atomic percent of magnesium to 0.01-2.0 Substituted by substitution with lead from calcium on the atomic percent to 0.01 to 5.0 atomic percent.

Next, the barium titanate-based semiconductor of the present invention will be described with reference to Examples.

Example 1

In this embodiment, 0.1-1.3 weight percent of zirconium dioxide (ZrO ₂ ) is added to the barium titanate composition described above to improve the overall properties.

0.1-1.3 weight percent of zirconium dioxide is added to the barium titanate composition described above and calcined by the following production method to obtain a static characteristic thermistor.

After mixing and grinding the semiconductor ceramic composition of the above-mentioned component, it is made to hold for 2 hours at the temperature of about 1100 degreeC, and temporary baking is performed.

After temporary firing, the product is pulverized and dried again, and polyvinyl alcohol is added as a binder to form particles with a particle size of about 150 mesh.

After the particles were made, a disk machine of 10 mm in diameter and 3 mm in thickness was formed by applying a pressure of about 1000 Kg / Cm ² with a press machine, and heated to about 1370 ° C. in an electric furnace, followed by sintering for about 1 hour to sinter the barium titanate-based semiconductor porcelain. do.

Electrodes exhibiting ohmic contact are attached to both surfaces of the barium titanate-based semiconductor porcelain molded into a disc shape to form a static characteristic thermistor (PCT).

The static characteristic thermistor thus obtained has a high withstand voltage value and a surge current value in a region having a low room temperature specific resistance. The results of the test of the specific resistance p, withstand voltage Vw and the maximum surge current Is while varying the amount of ZrO ₂ added to the semiconductor porcelain using the above-described static characteristics thermistor are shown in FIG. In addition, as static characteristics the dust mist, the diameter about 7.5 mm and the thickness about 2.0 mm were used.

In the ZrO ₂ addition amount of the magnetic semiconductor is near the 0.1 percent by weight of the specific resistance ρ of the ZrO ₂ amount showing a rising trend indicates a tendency to increase the specific resistance ρ more than 100Ω.Cm range as shown in Figure 1, AC withstand voltage value Vw It became 120V or more, and the maximum surge current Is value of 20x200 mA became 140A or more.

The reason why the withstand voltage Vw in the low resistance region and the maximum surge current Is value respectively increased is considered to be that the ideal grain growth of the grain diameter was suppressed, the grain diameter was uniform, and the grains and grain boundaries were well controlled.

Example 2

The barium titanate-based semiconductor porcelain of Example 1 to which 0.1-1.3 weight percent of zirconium dioxide (ZrO ₂ ) used for improving various properties was added as a composition, and again, antimony trioxide (Sb ₂ O ₃ ) was used for improving overall characteristics. ) Is added 0.005-0.13 weight percent.

The results of testing the specific resistance p, withstand voltage Vw, and the maximum surge current Is by changing the amount of Sb ₂ O ₃ addition of the semiconductor porcelain by using the static characteristic thermistor obtained by plastic molding the above components in the above-described manufacturing method It is shown in the figure.

As apparent from FIG. 2, when the antimony trioxide (Sb ₂ O ₃ ) was added to the barium titanate composition in an amount of 0.005-0.13 weight percent, it was calcined. In the region of low temperature specific resistance, the withstand voltage was increased and the surge current was increased. The characteristics of the thermistor can be significantly improved.

Example 3

In this embodiment, the barium titanate-based semiconductor ceramic composition has barium titanate (BaTiO 3) or barium titanate as a main component, and strontium (Sr), tin (Sn), or zirconium (Zr) is added to control the Curie point. To a barium titanate composition obtained by adding a rare-earth element, yttrium (Y), niobium (Nb), antimony (Sb), and at least one selected from the group of bismuth (Bi) as a small amount additive as a valence control element for semiconductorization. . In addition, the above-mentioned barium titanate-based semiconductor ceramic composition was added with an additive for improving the positive resistance temperature characteristic and giving a large resistance temperature gradient. As this subadditive, there are oxides such as manganese (Mn), silicon (Si), aluminum (Al), titanium (Ti) and the like.

A characteristic of the barium titanate-based semiconductor porcelain in this embodiment is that part of barium (Ba) is co-substituted and dissolved in a portion of 0.001-0.1 atomic percent magnesium (Mg) and 0.01-2.0 atomic percent calcium (Ca). Here, magnesium (Mg) is a factor which improves a temperature characteristic ratio, and the influence is not seen below the lower limit of the said component, and above the upper limit, the specific resistance in normal temperature becomes high significantly, or it becomes difficult to obtain a favorable sintered compact.

This is because the calcium (Ca) is a factor for lowering the specific resistance value at room temperature, and the lowering effect of the component is not seen below the lower limit value of the component, and the specific resistance value is lowered above the upper limit value, but the temperature characteristic ratio is increased, thereby departing from the original purpose. Thus, to form the barium titanate-based semiconductor porcelain having the above composition, a predetermined amount of BaCO ₃ , SrCO ₃ , MgCO ₃ , Y ₂ O ₃ , TiO ₂ , MnO, SiO ₂ , ZrO ₂ , Sb ₂ O ₃ , CaO ₃ It is weighed, weighed, dried, and then calcined at a temperature of about 1100 ° C. for 2 hours.

After temporary firing, it is pulverized and dried again, and polyvinyl alcohol is added as a binder to produce a particle size of about 150 mesh.

After the particle size was made, a disk machine of 10 mm diameter and 3 mm thickness was formed by applying a pressure of about 1000 Kg / Cm ² with a press machine, and heated to about 1370 ° C. in an electric furnace, followed by sintering for about 1 hour to fire the barium titanate-based semiconductor porcelain. do.

As described above, a positive characteristic thermistor is formed by attaching electrodes showing ohmic contact to both surfaces of a barium titanate-based semiconductor porcelain molded into a disc shape.

The specific resistance ρ (25 ℃) at room temperature and the temperature characteristic ratio R (-20 ℃) / R (when the amounts of magnesium (Mg) and calcium (Ca) added to the semiconductor porcelain were changed by using such static characteristic thermistor. Minimum) and R (60 ° C.) / R (minimum) are shown in Table 1. Moreover, the characteristic diagram of a temperature-resistance value is shown in FIG. 3, a solid line in a figure shows a present Example, and a dotted line shows a conventional example.

In Table 1, samples # 1-# 2 are conventional barium titanate-based semiconductor porcelain, and samples # 3-# 13 are of the present invention.

Example 4

A characteristic of the barium titanate-based semiconductor magnetism in the fourth invention is that a part of barium (Ba) is co-substituted and dissolved in a portion of lead (Pb) of 0.01-5.0 atomic percent and calcium (Ca) of 0.01-2.0 atomic percent. Here, the above-mentioned lead (Pb) is a factor for improving the temperature characteristic ratio, and it is not known that it has been improved below the lower limit of the above-mentioned components, and above the upper limit, the specific resistance at room temperature is remarkably high or a good sintered body can be obtained. none.

Thus, to form the barium titanate-based semiconductor in the fourth invention, a predetermined amount of BaCO ₃ , SrCO ₃ , PbO, Y ₂ O ₃ , TiO ₂ , MnO, SiO ₂ , ZrO ₂ , Sb ₂ O ₃ , CaCO ₃ is specified. After attaching to the balance, the barium titanate-based semiconductor porcelain having characteristics similar to those of FIG. 3 can be obtained by carrying out the same molding process as in Example 3 described above.

Example 5

The barium titanate-based semiconductor porcelain described here is characterized in that a part of barium (Ba) is contained in 0.001-0.1 atomic percent magnesium (Mg), 0.01-0.1 atomic percent lead (Pb), and 0.01-2.0 atomic percent calcium (Ca). Co-substituted and employed.

In order to form the barium titanate-based semiconductor porcelain according to the fifth invention, a predetermined amount of BaCO ₃ , SrCO ₃ , PbO, Y ₂ O ₃ , TiO ₂ , MnO, SiO ₂ , ZrO ₂ , Sb ₂ O ₃ , and CaCO ₃ is prescribed. By attaching the balance to the balance, the barium titanate-based semiconductor porcelain having characteristics similar to those of the third embodiment can be obtained by performing the same molding process as in the third embodiment.

Example 6

The barium titanate-based semiconductor porcelain according to the sixth invention employs a portion of barium (Ba) substituted with 0.001-0.1 atomic percent magnesium (Mg) at the same time.

To form the barium titanate-type semiconductor porcelain according to the sixth invention, BaCO ₃ , SrCO ₃ , MgCO ₃ , Y ₂ O ₃ , TiO ₂ , MnO, SiO ₂ , ZrO ₂ , and Sb ₂ O ₃ are weighed by a predetermined amount. After the addition, the barium titanate-based semiconductor porcelain can be obtained by undergoing the molding process as in Example 3.

By using such static characteristic thermistor, the specific resistance value rho (25 degreeC), the temperature characteristic ratio R (-20 degreeC) / R (minimum value), R at normal temperature, when the addition amount of magnesium (Mg) of a semiconductor magnet are changed, respectively (60 degreeC) / R (minimum value) is shown in Table 2, (sample # 14-17), and the characteristic diagram of the temperature-resistance value is shown in FIG.

Solid lines in the figures show the present embodiment, and dotted lines show the conventional example.

Example 7

A feature of the barium titanate-based semiconductor porcelain according to the seventh invention is that a part of barium (Ba) is simultaneously substituted and employed by 0.01-5.0 atomic percent lead (Pb).

In order to form the barium titanate-type semiconductor porcelain according to the seventh invention, BaCO ₃ , SrCO ₃ , PbO, Y ₂ O ₃ , TiO ₂ , MnO, SiO ₂ , ZrO ₂ , and Sb ₂ O ₃ are added to the balance by a predetermined amount. After the month, the barium titanate-based semiconductor porcelain (Samples # 18- # 22 in Table 2) having characteristics similar to those of Example 4 can be obtained by carrying out the same molding process as in Example 3 described above.

Example 8

A feature of the barium titanate-based semiconductor porcelain in the eighth invention is that part of barium (Ba) is co-substituted and substituted with 0.001-0.1 atomic percent magnesium (Mg) and 0.01-5.0 atomic percent lead (Pb).

In order to form the barium titanate-type semiconductor porcelain according to the eighth invention, BaCO ₃ , MgCO ₃ , SrCO ₃ , PbO, Y ₂ O ₃ , TiO ₂ , MnO, ZrO ₂ , and Sb ₂ O ₃ are attached to a predetermined amount scale. After this, the barium titanate-based semiconductor porcelain can be obtained by performing the same molding process as in Example 3.

In this way, the barium titanate-based semiconductor porcelain (Samples # 23- # 24 in Table 2) having characteristics similar to those of FIG. 4 can be obtained in the same manner as in Example 6.

In Examples 3 to 8 described above, a positive characteristic thermistor is formed by attaching electrodes having ohmic contacts to both surfaces of a barium titanate-based semiconductor porcelain shaped into a disc shape.

A portion of barium (Ba) is substituted by either magnesium (Mg) to calcium (Ca) to lead (Pb) to one or both at the same time so as to exhibit an R minimum value as shown in FIGS. 3 to 4 The NTC characteristics could be suppressed in the thermistor (NTC) region. In other words, a static characteristic thermistor with little resistance value variation was obtained over a wide temperature range of about ± 40 ° C at the R minimum value.

Specifically, the conventional value shown in Sample # 1 of Table 1 was able to suppress 1.30 or more to 1.20 or less. Moreover, by substituting and solidifying a part of barium (Ba) with calcium (Ca) simultaneously, as shown in Table 2, the room temperature resistance value could be lowered.

Usually, you can think of it as use environment temperature of -20 degrees Celsius-60 degrees Celsius range, and temperature characteristic ratio [R (-20 degrees Celsius) / R (minimum value). R (60 degrees Celsius / R (minimum value)) In other words, it is possible to obtain a stable static characteristics thermistor having a small resistance variation and a low normal temperature specific resistance.

Thus, even if the environmental temperature fluctuates within the temperature change range of the operating environment, the resistance of the thermistor does not fluctuate as much as in the conventional example. Moreover, the specific resistance of the room temperature can be suppressed to a low level. It is possible to provide a highly reliable static characteristics thermistor which is required as a component of a security device used for contact prevention.

As described above, withstand voltage characteristics, surge current characteristics, and other static characteristics in a low region in which a specific resistance of the room temperature is suppressed by substituting a part of barium of the barium titanate-based semiconductor porcelain with solid solution of antimony trioxide or zirconium dioxide. The characteristics of the MR can be significantly improved.

In addition, by substituting and substituting part of barium of barium titanate-based semiconductor porcelain with magnesium and calcium, or by simultaneously substituting with magnesium, lead and calcium, it is possible to suppress the change of resistance due to temperature change in the temperature range of the use environment and at room temperature Since the resistivity value can be suppressed low, reliability can be improved by using this barium titanate-based semiconductor porcelain as a component of a communication line security device.

TABLE 1

TABLE 2

Claims (13)

Semiconductorizing at least one selected from the group of rare earth elements, yttrium, niobium, antimony and bismuth in a barium titanate composition obtained by adding strontium, tin, or zirconium for controlling the Curie point mainly based on barium titanate or barium titanate 0.1-1.3 weight percent of zirconium dioxide or antimony trioxide 0.005- to a barium titanate-based semiconductor ceramic composition which is added as an additive for the addition and as addition of manganese oxide, silicon dioxide, and at least one of titanium dioxide as an additive. A barium titanate-based semiconductor porcelain fired by adding 0.13% by weight. The barium titanate-based semiconductor porcelain according to claim 1, wherein manganese oxide is added in an amount of 0.01-0.03 weight percent, silicon dioxide 0.1-1.0 weight percent, and titanium dioxide 0.1-1.0 weight percent. The barium titanate-based semiconductor magnetic composition is composed of a barium titanate composition obtained by adding strontium, tin, or zirconium for controlling the Curie point, mainly containing barium titanate or barium titanate, from a rare earth element, yttrium, niobium, antimony, and bismuth. In the barium titanate-based semiconductor porcelain added as a micro additive for at least one selected semiconductor, a part of the barium is 0.001-0.1 atomic percent magnesium to 0.01-5.0 atomic percent lead to 0.01-2.0 atomic percent calcium Barium titanate-based semiconductor porcelain formed by simultaneous substitution solid solution with. 4. The barium titanate-based semiconductor porcelain according to claim 3, wherein a part of barium is dissolved in magnesium, which is 0.001-0.1 atomic percent. 4. The barium titanate-based semiconductor porcelain according to claim 3, wherein a portion of the barium is solid-substituted with lead which is 0.01-5.0 atomic percent. 4. The barium titanate-based semiconductor porcelain according to claim 3, wherein a part of barium is solid-substituted with 0.001-0.1 atomic percent magnesium and 0.01-5.0 atomic percent lead. 4. The barium titanate-based semiconductor porcelain according to claim 3, wherein a part of barium is solid-substituted with 0.001-0.1 atomic percent magnesium and 0.01-2.0 atomic percent calcium. 4. The barium titanate-based semiconductor porcelain according to claim 3, wherein a part of barium is solid-substituted with 0.01 to 5.0 atomic percent lead and 0.01 to 2.0 atomic percent calcium. 4. The barium titanate-based semiconductor porcelain according to claim 3, wherein a part of barium is solid-substituted with 0.001-0.1 atomic percent magnesium and 0.01-5.0 atomic percent lead. The barium titanate-based semiconductor porcelain according to claim 3, wherein at least one of manganese, silicon, aluminum, and titanium is added as a minor additive to give a large resistance temperature gradient. At least one selected from the group of rare earth elements, yttrium, niobium, antimony and bismuth is semiconductorized to a barium titanate composition obtained by adding barium titanate or barium titanate as a main component and adding strontium, tin or zirconium for controlling the Curie point. At the same time, as an additive, manganese oxide, silicon dioxide, and at least one of titanium dioxide are added to form a barium titanate-based semiconductor ceramic composition: 0.1-1.3 weight percent of zirconium dioxide or antimony trioxide. A method for producing a barium titanate-based semiconductor porcelain obtained by adding at 0.005-0.13 weight percent and firing. 12. The obtained barium titanate composition is calcined and then dried to hold the calcined composition at a temperature of about 1370 ° C. for 2 hours to be temporarily calcined, and then calcined and dried to add polyvinyl alcohol as a binder. A method for producing a barium titanate-based semiconductor porcelain, wherein the composition is made into particles and calcined at a temperature of about 1370 ° C. under a pressure of about 1100 Kg / Cm ² . The method for manufacturing a barium titanate-based semiconductor porcelain according to claim 11 or 12, wherein a positive characteristic thermistor is formed by ohmic connection of an electrode to the semiconductor porcelain.

Images