JPS5832765B2 - Manufacturing method of three-terminal voltage nonlinear resistor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a three-terminal voltage non-linear resistor mainly made of zinc oxide, and its purpose is to manufacture two voltage non-linear resistors using one voltage non-linear resistance element. It is an object of the present invention to provide a three-terminal voltage nonlinear resistor that has the same function as a resistive element and can be made smaller.

Conventionally, voltage nonlinear resistors made of metal oxide sintered bodies containing zinc oxide as a main component have been developed and put into practical use.

This zinc oxide voltage nonlinear resistor is made by adding a small amount of bismuth oxide, lead oxide, barium oxide, etc. to zinc oxide, mixing it uniformly, molding it, and then placing it in air at a temperature of 800 to 15
After sintering at 00° C., forming a pair of electrodes on this sintered body, and connecting lead wires to the electrodes, the entire body can be covered with an organic resin.

This voltage nonlinear resistor has extremely large nonlinearity in voltage-current characteristics, and has been widely used for voltage stabilization, surge absorption, and other protection of electronic equipment.

Normally, two voltage nonlinear resistors, Zl and Z2, are used in the front stage of the electronic equipment to be protected, as shown in FIG. 1, and the midpoint between Zl and Z2 is grounded.

In other words, the surge voltage between the line and the ground is Zl or Z
The surge voltage absorbed by Z2 and generated between the lines is Zl and Z2
I'm planning on absorbing everything I have in the evening.

In order to fully perform the surge absorption function, it is necessary to use a three-terminal type, which requires two voltage nonlinear resistors, which requires a considerable amount of mounting space.
There has been a desire for a voltage nonlinear resistor that can function as two elements with one element and can be miniaturized.

To achieve this purpose, the three-terminal voltage nonlinear resistor of the present invention is made by forming a mixture of raw materials into a thin plate, applying platinum paste on one of its flat surfaces, stacking it, and crimping it. This method attempted to obtain a three-terminal structure.

Hereinafter, a method for manufacturing a three-terminal voltage nonlinear resistor of the present invention will be described in detail using an embodiment shown in FIGS. 2 and 3, which are the accompanying drawings.

In the figure, 1 is a voltage nonlinear resistance element mainly made of zinc oxide, 2 is a platinum electrode, and 3a, 3b, and 3c are metal electrodes made of silver or the like.

First, bismuth oxide Bi2O3 is added to zinc oxide ZnO powder.
, cobalt oxide Co01 manganese oxide Mn01 antimony oxide 5b203, and silicon oxide SiO2 powder in an amount of 0.01 to 10 moles each are added, and to this powder raw material, polyvinyl butyral 3 to 3 as an organic binder is added.
6% by weight, methyl alcohol 25-35% as organic solvent
Add 1 to 10 parts by weight of dibutyl phthalate as a plasticizer and mix for 12 to 24 hours to obtain a slurry.

This slurry is sheeted onto a glass plate or polyester film to a thickness of 0.02 to 2 mm using a blade or the like.

After drawing the sheet, it is dried at 60 to 100°C for 2 to 3 hours.

Thereafter, the mixture is peeled off from the glass plate or film to obtain a thin plate 1 of the mixture.

Next, platinum Pt paste 2 is applied on the thin plate 1, as shown in FIG.
0, and in particular, the opposite side of the side in contact with the peripheral edge of the thin plate 10 is separated by to.

In this case t1 must be greater than the thickness t2 of the thin plate.

The thin plates coated with platinum paste thus obtained are stacked as shown in FIG.

In other words, if the part of a thin plate in one stage where the platinum paste touches the peripheral edge of the thin plate is on the right, the part of the next stage's thin plate where the platinum paste touches the peripheral edge of the thin plate is on the left, and so on. Accumulate.

After stacking the required number of sheets, next several thin sheets 1 to which platinum paste is not applied are piled up.

Next, the required number of thin plates 1 with platinum paste, which were stacked in the lower layer, are stacked on top of them in the same manner.

Next, these are compressed to 300 to 600 kg/c.
A molded body was obtained by crimping with ni.

This molded body is placed in air at a temperature of 800°C to 1500°C.
It was sintered with

Next, of the two sides of this sintered body where the platinum electrode is visible,
- Apply silver paste 3c to the entire surface, and apply silver paste to the upper and lower parts of the other surfaces as shown in 3a and 3b.
Baking was performed in air at 700 to 900°C to form silver electrodes and obtain a three-terminal type voltage nonlinear resistor.

In other words, it is a three-terminal voltage nonlinear resistor in which electrodes 3a and 3b are connected to a power supply line, and electrode 3c is connected to ground.

The varistor voltage of the voltage nonlinear resistor thus obtained is determined by the thickness of one thin plate, and the number of parallel connections is determined by the number of stacked plates, and as the number of plates increases, the actual area increases.

In other words, when a large surge absorption capacity is required, the area of the element is usually increased.In this case, if the element is in the form of a disc, the diameter is increased; I don't like the connection.

In the method of the present invention, since the area is expanded by stacking, there is no problem in practice.

Incidentally, in the present invention, the upper limit of the thickness of the thin plate is 2 mm, and any thickness greater than this must be avoided since cracks may occur in the thin plate itself.

Even when drying after pulling the sheet, the drying time may be too long,
Care must be taken as the thin plate may crack if the temperature is too high.

In the examples, zinc oxide ZnO is replaced by bismuth oxide B i203 , cobalt oxide Co01 manganese oxide M
nO, antimony oxide 5b203 and silicon oxide SiO
Although lead oxide PbO1 calcium oxide CaO, strontium oxide SrO, barium oxide BaO, and uranium oxide UO2 were used, lead oxide PbO1, calcium oxide CaO, strontium oxide SrO, barium oxide BaO, uranium oxide UO2, etc. may also be added, and the voltage non-linearity is generated at the boundary between particles in the zinc oxide sintered body. Any material that forms a layer exhibiting properties is effective.

In addition, aluminum oxide At203, nickel oxide N mill, magnesium oxide MgO, chromium oxide Cr203, tin oxide Sn
O2 or titanium oxide T102 may be added, but even in such cases, the effects of the present invention are not impaired in any way.

[Brief explanation of drawings]

Figure 1 is a wiring diagram showing how to connect a three-terminal voltage non-linear resistor, Figure 2 is a cross-sectional view of a three-terminal voltage non-linear resistor according to an embodiment of the present invention, and Figure 3 is a. FIG. 2 is a plan view and a sectional view of a thin plate of a three-terminal voltage nonlinear resistor of the present invention. 1... Thin plate, 2... Platinum paste.

Claims (1)

[Claims] 1 Bismuth oxide Bi2O3 in zinc oxide ZnO powder,
A mixture of cobalt oxide Co01 manganese oxide MnO, antimony oxide 5b203, and silicon oxide St02 powder in an amount of 0.01 to 10 moles each, and an organic binder and a plasticizer added thereto is made into a thin plate with a thickness of 0.02 to 2 mm. A thin plate and a platinum Pt paste coated on the flat surface of the thin plate were prepared, and the upper and lower parts were coated with platinum Pt paste.
A three-terminal voltage non-contact device characterized by having a stack of thin plates coated with paste, a stack of thin plates without platinum paste coated in the middle part, and crimping these to form a molded body. How to make a linear resistor.