JPS582003Y2 - Thick film varistor device - Google Patents

Description

[Detailed description of the invention] This invention is a thick film varistor device that obtains unique voltage and current characteristics by arranging resistor films in parallel in a thick film varistor, and exhibits functions that cannot be obtained with a varistor alone. Regarding.

The voltage-current characteristics of a thick film varistor are as shown in (2) in FIG. 1, and by utilizing these characteristics, it is being put into practical use for purposes such as voltage stabilization, pulse suppression, and surge absorption in circuits.

Generally, the larger the nonlinear index, the better the varistor.

However, when applied to various fields, it may be advantageous for the overall performance of the varistor to operate as a fixed resistor and consume a certain amount of power when a relatively low voltage is applied.

Furthermore, the residual waveform after the surge absorption can be controlled.

Such a function is obtained when the device has voltage-current characteristics as shown by the solid line in FIG. 1, such that it operates as a fixed resistor in a relatively low voltage region and as a varistor when a high voltage is applied.

However, it is difficult to manufacture a single thick film varistor that exhibits such voltage-current characteristics.

The present invention has a resistor characteristic R as shown in FIG.
This invention discloses a means for obtaining a thick film varistor device that exhibits voltage-current characteristics as shown by the solid line, which is a combination of the characteristics (1) and (2) of the varistor.

The present invention will be explained below based on examples.

Thick film varistor V and thick film resistor R are equivalently arranged side by side as shown in Figure 2 to obtain composite characteristics, and each performance setting (resistance value setting) The resistance value of the resistor is set to be low, and the dynamic resistance of the thick film varistor is set to be low in a high voltage region.

FIG. 3 shows a cross-sectional view of a sandwich-type thick film varistor. In the figure, 1 is a heat-resistant insulating substrate, 2 is a lower electrode on the substrate 1, and 3 and 4 are formed on the lower electrode 2. 5 is an upper electrode provided to cover the varistor film and resistor film, and 5 is an upper electrode provided to cover the varistor film and the resistor film. has been cut.

That is, a single lower electrode 2 is placed on a single heat-resistant insulating substrate 1.
is printed and baked, and varistor paste 3 and resistor paste 4 are printed and baked thereon, respectively.

Further, on the formed varistor film 3 and resistor film 4, maintaining a certain distance so as not to contact the lower electrode 2,
The upper electrode 5 is printed and baked to cover.

If necessary, cover with solder resist, insulating resin, etc.

The current path of the device obtained in this way is
perpendicular to .

Next, FIG. 4 shows an example of a planar type thick film varistor. Reference numeral 9 denotes a varistor film and a resistor film arranged in parallel across the two electrodes 6 and 7.

That is, electrodes 6 and 7 are printed on the heat-resistant insulating substrate 1 at a predetermined interval and baked.

Varistor paste 8 and resistor paste 9 are then printed and baked between electrodes 6 and 7, respectively.

If necessary, cover with solder resist, insulating resin, etc.

The current path of the device obtained in this way is
horizontal to

In addition to the above two methods, the characteristics of the present invention can also be obtained by forming the thick film varistor into a sandwich type and forming the thick film resistor into a planar type, or vice versa.

An example of the former is shown in FIG.

In the figure, 1 is a heat-resistant insulating substrate, 10 is a lower electrode provided on the substrate 1, 11 is a varistor film provided on the electrode 10, and 12 is an upper electrode provided on the varistor film 11. , one end of which extends above the substrate 1.

13 is a resistor film provided across the extended upper electrode 12 and lower electrode 10.

Of course, in this embodiment as well, measures are taken to prevent the electrodes 10 and 12 from being short-circuited.

When the device thus obtained is applied, for example, in the low voltage range, energy is consumed due to the characteristics of the fixed resistor, and in the event of an abnormally high voltage, the high voltage can be suppressed to a sufficiently low level using the characteristics of the varistor. It has a useful function.

In addition, the device having voltage-current characteristics according to the present invention can shorten the residual voltage waveform after suppressing abnormal high voltage, especially the time width, and can be used to protect governor contacts of mechanical governor type micromotors. It can be said that it is an ideal device.

In addition, since the thick film varistor device of the present invention has a thick film varistor and a thick film resistor arranged side by side on a single insulating substrate, the varistor and resistor are less affected by their self-heating. This structure is effective in preventing deterioration of characteristics due to heat.

Furthermore, the thick film varistor and the thick film resistor can be simultaneously formed on the insulating substrate using the same method, which has the advantage of significantly reducing the number of steps and improving workability.

As described above, the thick film varistor device according to the present invention has the combined performance of a fixed resistor and a voltage dependent resistor, has unique characteristics, and expands the field of application of thick film varistors.

[Brief explanation of the drawing]

Figure 1 is a composite voltage-current characteristic diagram of a thick film varistor and a thick film resistor, Figure 2 is a parallel circuit diagram of a thick film varistor and a thick film resistor,
FIG. 3 is a sectional view of one embodiment of the thick film varistor device according to the present invention, and FIG. 4 a, l) is a plan view of the second embodiment and its A.
-A' line sectional view, Figures 5a and 5l) are a plan view of the third embodiment and its BB' line sectional view. 1...Single insulating substrate, 2...Lower electrode, 3,8.11...Varistor film, 4,9.13
. . . Resistor film, 5 . . . Upper electrode, 6.
7...Electrode, 10...Lower electrode, 12
...Top electrode.

Claims (4)

[Scope of utility model registration request] (1) A thick film varistor device characterized in that a thick film varistor and a thick film resistor are arranged side by side and integrated on a single insulating substrate. (2) A utility model registration claim in which a varistor film and a resistor film are formed on a single lower electrode on a single insulating substrate, and an upper electrode is provided to cover both the varistor film and the resistor film. The thick film varistor device according to item (1). (3) The thick-film varistor device according to claim (1), in which a varistor film and a resistor film are arranged side by side across two electrodes spaced apart on a single insulating substrate. (4) forming a varistor film on a single lower electrode on a single insulating substrate, and providing an upper electrode to cover the varistor film;
The thick film according to claim 1, wherein the upper electrode is extended on the single insulating substrate, and a resistor film is provided spanning between the extended upper electrode and the lower electrode. barista equipment.