DE1954056B2 - PROCESS FOR PRODUCING A VOLTAGE DEPENDENT RESISTANCE - Google Patents

Description

Zinc oxide, 0.1 to 3.0 mole percent barium oxide In conventional varistors, the germanium

and 0.1 to 3.0 mole percent of an oxide belonging to the group: or containing silicon p-n bridge diodes, it is Consists of stionium oxide, lead oxide and cobalt oxide. difficult to get the C-value over a wide range

7. The method according to claim 1, characterized in that it is regulated because the voltage-dependent property shows that the mass essentially consists of 35 of these varistors, not the block volume, but Zinc oxide, 0.05 to 10.0 mole percent barium oxide, attributed to the p-n bridge. on the other hand 0.05 to 8.0 mole percent bismuth oxide and 0.05 to 0.05 to silicon carbide varistors have voltage dependent ones 8.0 mole percent of an oxide belonging to the group: Stron properties due to contact of the through a tium oxide and lead oxide. ceramic binder interconnected

8. The method according to claim 1, characterized in 40 silicon grains, and the C value is determined by changing indicates that the mass consists essentially of a dimension in a direction in which the

,, Zinc oxide, 0.1 to 3.0 mol percent barium oxide, ι, current flows through the varistors, regulated. the

However, 0.1 to 3.0 mole percent bismuth oxide and 0.1 to silicon carbide varistors have a different

3.0 mole percent of an oxide of the group: current ratio low «value and are through

tium oxide and lead oxide. ,, 45 burning in a non-oxidizing atmosphere,

9. The method according to claim 1, characterized gekenri- in particular with the aim of a low C value draws that the mass is essentially made from to obtain.

Zinc oxide, 0.05 to 10.0 mole percent barium oxide, resistor materials which include zinc oxide and oxides

0.05 to 8.0 mol percent lead oxide and 0.05 to contain metals are, for example, from dei

8.0 mole percent of an oxide belonging to the group: Stroh 5 ° USA. Patent 2,887,632 known. In detail

tium oxide and cobalt oxide. ". relates to U.S. Patent 2,887,632 Materials

10. The method according to claim 1, characterized with a low specific resistance or one indicates that the mass consists essentially of zinc- improved contact rectifier or transistor, oxide, 0.1 to 3.0 mole percent barium oxide, 0.1 to which have a zinc oxide plate as the base plate, which 3.0 mole percent lead oxide and 0.1 to 3.0 mol%, a low resistivity material percent of an oxide of the group: is strontium oxide. However, all of the U.S. Patents and cobalt oxide. 2 887 632 proposed materials ohmic cons

Stand properties on.

The object of the present invention was to provide a method for producing a voltage-dependent

Ceramic resistor with non-ohmic property

to find businesses that unite in particular high κ-value due to the mass of the same is marked and can be checked in the C-value

The invention relates to a method for production 65 The underlying object was dadurcl a voltage-dependent resistance ceramic, which solved that one essentially made of zinc oxic consists essentially of zinc oxide and one and 0.05 to 10.0 mole percent of barium oxide ' possesses non-ohmic resistance. Mass at a temperature of 1000 to 1450 ° (

3 4

sinters. Such a voltage-dependent resistance is that the mass consists essentially of zinc oxide, because of its mass, has a non-ohmic 0.1 to 3.0 mole percent barium oxide, 0.1 to 3.0 mole resistance. Hence, its C value can be changed, percent lead oxide and 0.1 to 3.0 mole percent of one without worsening the «value by separating the oxides from the group: strontium oxide and cobalt oxide exists between the opposing surfaces, which is advantageous for this voltage-dependent will change. A shorter distance leads to a resistance that is an extremely high value lower C-value. can be obtained.

One aspect of the invention is to make these and other objects of the invention

that the mass consists essentially of zinc oxide and is explained in the following description as well as on hand

0.1 to 3.0 mole percent barium oxide. On this io of the drawing, in which the only illustration is a

voltage-dependent resistance, it is advantageous to have a partial cross-sectional view of a chip according to the invention

that a higher «value can be obtained. voltage-dependent resistor body represents.

A further embodiment of the invention is before a detailed description of the

characterized in that the mass essentially depends on the voltage sought by the invention

Borrowed from zinc oxide, 0.05 to 10.0 mole percent barium 15 resistors should be referenced to their structure

oxide and 0.05 to 8.0 mole percent calcium oxide. the aforementioned illustration of the drawing explained

The advantage of this voltage-dependent resistor will be that with 10 a voltage-dependent resistor

is that stability for ambient temperatures is referred to as whole resistance, as active

and the electrical stress endurance test improve a sintered body having a pair of elements

leaves. 20 contains electrodes 2 and 3, which are connected to the opposite

Another embodiment of the invention consists of lying surfaces of the same applied. This

in that the mass consists essentially of zinc oxide, sintered body 1 is in a yet to be explained

0.1 to 3.0 mole percent barium oxide and 0.1 to 3.0 mole manner and has any shape like that

percent calcium oxide. a round, square or rectangular plate.

The advantage of this voltage-dependent resistor is that lead wires 5 and 6 are conductive on the electrodes

stand is that the stability for ambient temperatures 2 and 3 attached by a connecting means 4 like

ren and the electrical endurance test apart from soldering or the like.

is properly improved. The sintered body 1 can by as such

Another embodiment of the invention is known ceramic technology can be produced. the

characterized in that the mass is essentially 30 starting materials in the above

Lichen zinc oxide, 0.05 to 10.0 mole percent barium slide masses are in a wet mill

oxide and 0.05 to 8.0 mole percent of an oxide of the mixed so that homogeneous mixtures are produced

Group: Strontium Oxide, Lead Oxide and Cobalt Oxide. The mixtures are dried and in

consists. What is advantageous about this voltage-dependent form is the desired dimensions and shape

Resistance that the η value is increased. 35 pressed at a pressure of 100 to 1000 kg / cm ^2. the

Another embodiment of the invention consists in being pressed in the air at a body

in that the mass consists essentially of zinc oxide, given temperature and sintered for 1 to 3 hours

0.1 to 3.0 mole percent barium oxide and 0.1 to 3.0 mole - then in the oven to room temperature (about 15 to 30 ° C)

percent of an oxide of the group: strontium oxide, cooled.

Is made up of lead oxide and cobalt oxide. Advantage of this 40 The available sintering temperature is in view of

voltage-dependent resistance is that of the electrical resistivity that

/ j value can be increased further. Non-linearity and stability determine and lie in

Another embodiment of the invention is the range from 1000 to 1450 ° C.

characterized in that the mass is essentially The mixtures can be introduced at 700 to 1000 ° C

borrowed from zinc oxide, 0.05 to 10.0 mol percent barium-45 calcined and for easier processing in the post

oxide, 0.05 to 8.0 mole percent bismuth oxide and 0.05 in the following pressing step. That too

up to 8.0 mole percent of an oxide of the group: Stron- pressing mixture can be mixed with a suitable

tium oxide and lead oxide. Advantages of this binding agent such as water, polyvinyl alcohol, etc.

voltage-dependent resistance is that are mixed in combination.

nation a high η value and a low C value 50 It is advantageous if the sintered body to

is obtained. the opposite surfaces through a grinding

Another embodiment of the invention consists of powder such as silicon carbide with a particle size

'in that the mass of zinc oxide, essentially 300 to 1500 mesh, is abraded.

0.1 to 3.0 mol percent barium oxide, 0.1 to 3.0 mol- The sintered bodies are at their opposite-

percent bismuth oxide and 0.1 to 3.0 mole percent of one of the surfaces with electrodes is an available oxide from the group consisting of strontium oxide and lead oxide. ^: and suitable manner such as by electroplating

The advantage of this voltage-dependent resistor is process, vacuum evaporation process, metal

that the C-value is lowered and the -value is removed by spraying or silver

is increased properly. painting process.

A further embodiment of the invention is thereby 60 The voltage-dependent properties will be

characterized in that the mass is essentially not due to the electrodes used

Zinc oxide, 0.05 to 10.0 mole percent barium oxide, types influenced, but by the thickness of the sintered

0.05 to 8.0 mole percent lead oxide and 0.05 to 8.0 mole percent. In particular, the C value fluctuates in

Percentage of an oxide of the group strontium oxide and ratio to the thickness of the sintered body, true

.Cobalt oxide consists. The advantage of this tension 65 is that the 77 value is almost independent of the thickness. the

dependent resistance is that also a high means with certainty that the voltage dependent

ntyert can be obtained. Property on the block volume itself and not au

"' ⁰ EiIJe further embodiment of the invention, the electrode is due.:

Lead wires can be attached to the electrodes in a conventional manner by conventional solder be attached with a low melting point. It is convenient to use a conductive one Adhesive that contains silver powder and resin in an organic solvent to secure the lead wires to connect to the electrodes.

The voltage-dependent resistors invention have a high temperature resistance and service life at full load, the test is carried out at 7O ⁰ C with a load 500 hours. The / j-value and C-value do not change noticeably after the heating cycles and the full load life test. In order to achieve high resistance to moisture, it is advantageous that the voltage-dependent resistors obtained are embedded in a moisture-proof resin such as an epoxy resin and phenolic resin in a manner known per se.

Preferred illustrative embodiments of the invention follow.

example 1

A mixture of zinc oxide and barium oxide in a composition given in Table 1 is mixed for 3 hours in a wet mill. The mixture is dried and then calcined at 700 ° C. for 1 hour. The calcined mixture is pulverized by the motor-driven ceramic mortar for 30 minutes and then pressed in a mold into a molding 17.5 mm in diameter and 2.5 mm in thickness at a pressure of 500 kg / cm ^a.

The pressed body is sintered 1 hour in air at 1350 ° C and then furnace cooled to room temperature (about 15 to 30 ⁰ C). The sintered disk is abraded on the opposite surfaces thereof by silicon carbide having a particle size of 600 mesh. The sintered disk obtained has a size of 14 mm in diameter and 1.5 mm in thickness. Commercially available silver point electrodes are brush attached to the opposing surfaces of the sintered disk. Then, lead wires are attached to the silver electrodes by soldering. The electrical properties of the resistors obtained are shown in Table 1. It is easy to see that the zinc oxide sintered bodies containing barium oxide incorporated in an amount of 0.05 to 10.0 mole percent can be used for voltage resistance, and particularly the addition of barium oxide in an amount of 0.1 to 3 .0 mole percent makes the stress nonlinear property more excellent.

Table 1

(Mol
percent) C.
(at
ImA) 3.2
5.4
6.2
7.0
6.4 (Mol
percent) C.
(at
ImA) R. 0.05
0.1
0.2
0.5
1 420
280
70
40
65 2
3
5
8th
10 90
120
200
285
380 5.7
5.2
4.6
3.9
3.3

Example 2

Starting materials composed of 99.5 mole percent zinc oxide and 0.5 mole percent barium oxide are mixed, dried, calcined and pulverized in the same manner as in Example 1. The pulverized Mixture is in a mold into a molding 17.5 mm in diameter and 5 mm thick in a

ίο Pressed pressure of 500 kg / cm ² .

The pressed body is sintered in air at 1350 ° C. for 1 hour and then in an oven to room temperature cooled down. The sintered disc becomes a thickness on its opposing surfaces as shown in Table 2, abraded by silicon carbide having a particle size of 600 mesh. the The ground disc is made with the electrodes and lead wires on the opposite surfaces in a manner similar to that in Example 1.

The electrical properties of the resistors obtained are shown in Table 2; the C values vary approximately in relation to the thickness of the sintered disk, while the η value essentially is independent of the thickness. It is easy to understand that the stress nonlinear properties of the resistances are ascribed to the sintered body itself.

Table 2

Thickness (mm) 35 Beginning (4.1) C (at 1 mA) η 3.5 3.0 107 7.1 40 2.5 93 7.0 2.0 79 6.9 1.5 65 7.2 1.0 53 7.0 40 7.0 26th 6.9

Example 3

Zinc oxide, to which barium oxide and calcium oxide is incorporated in a composition given in Table 3, is processed into the voltage-dependent resistors by the same method as in Example 1. The resistors obtained are tested by the methods used in the electronic components. The service life test at full load is carried out at an ambient temperature of 70 ° C and a load of 0.5 watt for 500 hours. The heat cycle test is held by Smaliges repeating the cycle, wherein these resistances at 85 ⁰ C ambient temperature for 30 minutes, rapidly cooled to -20 ⁰ C and 30 minutes, maintained at this temperature is performed. Table 3 shows a difference in C value and value between resistors before and after the load life test. It can be readily seen that the combination of barium oxide and calcium oxide is effective as an additive for electrical and environmental strength.

Tabel

BaO CaO Life test
at stress Λ «(%) Heating cycle test Δη {"ld (Mole percent) (Mole percent) ■ dCCYo) -9.2 -8.6 0.05 0.05 -8.5 -6.2 -9.0 -6.2 0.05 0.5 -7.2 -6.0 -7.1 -5.9 0.05 8th -7.0 -8.7 -5.9 -8.7 0.5 0.05 -6.2 -8.6 -7.9 -8.8 0.5 8th -7.0 -7.1 -8.0 -7.1 10 0.05 -6.9 -6.5 -6.2 -6.3 10 0.5 -6.7 -9.3 -5.9 -9.0 10 8th -9.0 -4.3 -8.7 -4.2 0.1 0.1 -4.2 -2.9 -4.8 -2.2 0.1 0.5 -3.8 -3.7 J, Δ -4.0 0.1 3 -4.1 -4.5 -3.3 -3.0 0.5 0.1 -2.6 -4.4 -4.6 -2.6 0.5 3 -2.7 -3.6 -4.7 -2.8 3 0.1 -3.0 -2.9 -3.4 -3.0 3 0.5 -3.7 -4.8 -3.6 -3.9 3 3 -4.9 -1.1 -4.0 -1.3 0.5 0.5 1 9 -0.8

Example 4

Zinc oxide with the additions from Tables 4 and 5 becomes voltage-dependent resistors according to processed using the same procedure as in Example 1. The «values of the resistances obtained are in Tables 4 and 5 reproduced. It's easy to

see the combination of barium oxide with one of the following oxides: strontium oxide, cobalt oxide and lead oxide as additives leads to an excellent stress nonlinear property Remarkably excellent value can be obtained by additional combination of barium oxide and lead oxide with strontium oxide or cobalt oxide.

Tabel

BaO SrO CoO PbO C. η (Mole percent) (Mole percent) (Mole percent) (Mole percent) (at 1 mA) 5.0 0.05 0.05 600 9.2 0.05 0.5 - - 330 4.9 0.05 8th - - 590 10 0.5 0.05 - - 60 9.5 0.5 8th - - 58 5.0 10 0.05 - - 540 10 10 0.5 - - 350 4.9 10 8th - - 525 10 0.1 0.1 - - 300 15th 0.1 0.5 - - 290 11th 0.1 3 - - 320 14th 0.5 0.1 - - 50 14th 0.5 3 - - 48 11th 3 0.1 - - 135 16 3 0.5 - - 120 11th 3 3 - - 150 18th 0.5 0.5 - - 42 4.8 0.05 - 0.05 - 520 9.0 0.05 - 0.05 - 300 5.0 0.05 - 8th - 570 9.5 0.5 - 0.05 - 57 9.7 0.5 - 8th - 56 4.5 10 - 0.05 - 500 9.8 10 - 0.5 - 325 4.7 10 - 8th - 500 9 0.1 - 0.1 - 285 14th 0.1 - 0.5 - 310 10 0.1 - 3 - 300

209 530/488

Table 5

ίο

SrO (Continuation from table 4) C. 13th BaO (Mole percent) CoO PbO (at 1 inA) 13th (Mole percent) (Mole percent) (Mole percent) 47 10 0.5 - 0.1 46 15th 0.5 - 3 - 110 10 3 - 0.1 - 125 16 3 - 0.5 .— 130 5.3 3 - 3 - 40 9.0 0.5 - 0.5 - 700 4.8 0.05 - - 0.05 350 9.7 0.05 - - 0.5 620 9.7 0.05 - - 8th 72 5.0 0.5 - - 0.05 63 11th 0.5 - 8th 570 5.4 10 - - 0.05 385 11th 10 - - 0.5 550 15th 10 - - 8th 325 10 0.1 - - 0.1 310 13th 0.1 - - 0.5 350 13th 0.1 - - 3 65 11th 0.5 - - 0.1 53 14th 0.5 - 3 150 10 3 . - 0.1 135 16 3 - - 0.5 170 3 - - 3 48 0.5 - 0.5

BaO SrO CoO PbO C. η (Mole percent) (Mole percent) (Mole percent) (Mole percent) (at 1 mA) 8.0 0.05 0.05 0.05 600 7.9 0.05 0.05 - 8th 340 6.1 0.05 8th - 0.05 570 8.0 0.05 8th - 8th 550 7.9 10 0.05 - 0.05 530 8.3 10 0.05 - 8th 515 8.0 10 8th - 0.05 500 8.4 10 8th - 8th 490 13th 0.1 0.1 0.1 275 14th 0.1 0.1 3 290 14th 0.1 3 0.1 300 14th 0.1 3 - 3 300 15th 3 0.1 - 0.1 125 17th 3 0.1 3 110 14th 3 3 0.1 135 14th 3 3 3 150 25th 0.5 0.5 - 0.5 39 8.3 0.05 - 0.05 0.05 490 8.4 0.05 - 0.05 8th 480 8.3 0.05 - 8th 0.05 500 7.8 0.05 8th 8th 520 7.0 10 - 0.05 0.05 480 8.1 10 - 0.05 8th 450 6.4 10 - 8th 0.05 450 7.0 10 - 8th 8th 500 12th 0.1 - 0.1 0.1 270 12th 0.1 - 0.1 3 285 12th 0.1 - 3 0.1 280 14th 0.1 3 3 270 13th 3 - 0.1 0.1 100 15th 3 - 0.1 3 105 12th 3 3 0.1 125 15th 3 - 3 3 115 24 0.5 - 0.5 0.5 35

11th

Example 5

Zinc oxide with the additions from Table 6 becomes voltage-dependent resistors according to the same

are shown in Table 6. It is easy to see that the combination of barium oxide and Bismuth oxide with lead oxide or strontium oxide as additives to make a remarkably excellent one W d lihii

Procedure processed as in Example 1. The elec- 5 «value and at the same time to a lower C value SscherEilensIaften of the resistances obtained leads.

Table 6

BaO ■ ——
Bi ₂ O ₃ PbO SrO C. Il (Mole percent) (Mole percent) (Mole percent) (Mole percent) (at 1 mA) 7.0 0.05 0.05 0.05 400 6.9 0.05 0.05 8th - 420 6.8 0.05 8th 0.05 - 430 6.0 0.05 8th 8th - 450 6.5 10 0.05 0.05 - 300 7.0 10 0.05 8th - 310 7.2 10 0.05 - 305 7.4 10 8th 8th - 325 13th 0.1 0.1 0.1 - 195 12th 0.1 0.1 3 - 200 11th 0.1 3 0.1 - 200 11th 0.1 3 3 - 210 13th 3 0.1 0.1 - 95 14th 3 0.1 3 - 98 12th 3 3 0.1 - 110 13th 3 3 3 - 120 20th 0.5 0.5 0.5 - 25th 7.0 0.05 0.05 0.05 380 7.2 0.05 0.05 8th 390 6.9 0.05 8th - 0.05 350 6.0 0.05 8th - 8th 400 7.2 10 0.05 - 0.05 380 7.1 10 0.05 - 8th 375 7.2 10 8th - 0.05 350 6.8 10 8th - 8th 310 12th 0.1 0.1 - 0.1 200 13th 0.1 0.1 - 3 195 12th 0.1 3 - 0.1 180 13th 0.1 - 3 200 13th 3 0.1 - 0.1 85 13th 3 0.1 - 3 95 12th 3 3 - 0.1 80 13th 3 3 - 3 90 26th 0.5 0.5 - 0.5 25th

1 sheet of drawings

? 448

Claims (6)

Various voltage-dependent resistors such as silicon carbide varistors, selenium rectifiers and germanium or silicon p-bridge diodes are widely used to stabilize the voltage or 1. Process for the production of a ceramic S of the current used in electrical circuits. Resistance, characterized by the electrical properties of such a voltage, that one is essentially zinc oxide voltage-dependent resistance through the and 0.05 to 10.0 mole percent barium oxide relationship standing mass at a temperature of 1000 to _ / V \ " 145O ⁰ C sinters, whereby the ceramic obtained io ¹ ~ \ ~ q \ receives a voltage-dependent resistance. ^v ' 2. The method according to claim 1, characterized in that V is the voltage across the counter that the mass essentially consisted of zinc, the current flowing through the resistor, oxide and 0.1 to 3.0 mole percent barium oxide C one of which is voltage at a given current. 15 corresponding constant and the exponent η a 3. The method according to claim 1, characterized in that the number is greater than 1. The value of η is characterized by the fact that the mass is essentially calculated from the following equation: Zinc oxide, 0.05 to 10.0 mole percent and 0.05 to 8.0 mole percent calcium oxide. , 4. The method according to claim 1, characterized in that 20 n— ——
records that the mass is essentially log ™
Zinc oxide, 0.1 to 3.0 mole percent barium oxide and 0.1 to 3.0 mole percent calcium oxide. where V ₁ and V _{2 are} the voltages given 5. The method according to claim 1, characterized in that currents I ₁ and I ₂ are marked. The desired value of C indicates that the mass consists essentially of zinc-25 depends on the type of application in which the counter-oxide, 0.05 to 10.0 mole percent barium oxide and stand is to be used. Usually 0.05 to 8.0 mole percent of an oxide of the group: is desired that the value of η consists of strontium oxide, lead oxide and cobalt oxide as large as possible. is, as this exponent determines the extent, up to 6. The method according to claim 1, characterized in which the resistances are drawn from the ohmic inherent, that the mass essentially differ from 30 shafts.