JPS6057239B2 - Amorphous semiconductor switch element - Google Patents

Description

[Detailed description of the invention] The present invention relates to an amorphous semiconductor switching element.

Amorphous semiconductors, such as Si12, α1O, AS3O,
Te48 has current-voltage characteristics as shown in Figure 1,
It is well known that the chair has a loose switch characteristic. The voltage that starts the switch in this switch phenomenon,
In other words, it is also known that the value of the threshold voltage decreases as the temperature rises, as shown in Figure 2, and the temperature dependence of the threshold voltage is similar to that when an amorphous semiconductor is used as a general switching element. has become a major obstacle. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an amorphous semiconductor switching element that can be switched at a constant voltage without being affected by ambient temperature.

FIG. 4 shows an embodiment of the present invention, in which 1 is an amorphous semiconductor, 2,
3 is an electrode that holds the semiconductor; 4 and 5 are lead terminals connected to the electrodes 2 and 3, respectively; 6 is the amorphous semiconductor 1 and the electrode 2;
, 3 and a case made of glass for protecting and fixing the lead terminals 4 and 5; 7 is a nonlinear resistance heating element that is attached to the entire inner surface of the case 6 and is connected to the lead terminals 4 and 5 at both ends of the case 6; It is.

Here, the amorphous semiconductor 1 and the nonlinear resistance heating element 7 are connected in parallel between the pair of lead terminals 4 and 3.
The nonlinear resistance heating element 1 has, for example, aluminum oxide as its main component, and as shown in the voltage-current characteristics in FIG. It has the property of generating strong heat at temperatures, and its voltage-current characteristics hardly change with temperature. The nonlinear resistance heating element itself is well known. In the above-mentioned switch element, the threshold voltage of the amorphous semiconductor 1 is set to a value higher than the limit temperature of the operating temperature range of the switch element.

For example, if the operating temperature range is 00C to 700C and the desired gate voltage is 100V, the threshold voltage of the semiconductor 1 at a temperature of 70C is set to 100V as much as possible.
That is, the threshold voltage of semiconductor 1 is 100°C at a temperature lower than 70°C.
The value is higher than V. In addition, the setting of such a leap value voltage is performed using electrode 2,
This can be done by selecting the distance between 3 and the composition of the semiconductor 1. Furthermore, in the switch element, the large current operating voltage D of the nonlinear resistance heating element 7 is set to be approximately the same as the threshold voltage of the semiconductor, and the heating element 7 lowers the temperature of the semiconductor 1 during its large current operation. In order to raise the temperature of the semiconductor 1 and lower its threshold voltage, the temperature of the semiconductor 1 is raised to 70°C or more at an ambient temperature within the above operating temperature range.
The amount of heat generated by the heating element 7 is set so as to reduce the threshold voltage to 100V or less.

The amount of heat generated can be set based on the resistance value and shape of the heating element 7, as well as the heat capacity of the entire switch element. Therefore, according to the above switch element, even if a voltage lower than 100V is applied between the lead terminals 4 and 5, the semiconductor 1 cannot be heated because the nonlinear resistance heating element 7 is in the small current region.
Therefore, as long as the operating temperature is within the above operating temperature range, the switching element will not conduct, regardless of the ambient temperature, and if a voltage of 100 V or more is applied, the nonlinear resistance heating element 7 will enter the large current region, and the above operating temperature will be exceeded. As long as the temperature of the semiconductor 1 rises above 70°C and its open voltage falls below 100V, regardless of the ambient temperature, as long as the applied voltage is within 10V.
At 0■, the switch element becomes conductive when the temperature reaches 70°C.

That is, the open value voltage as a switching element is always constant at 100 cm regardless of the ambient temperature. Furthermore, once the switching element passes, the voltage across the semiconductor 1 drops, so the nonlinear resistance heating element 17 enters a small current region, and therefore, the power consumption in the heating element 7 is extremely small while the switching element is conducting. If the resistance of the heating element 7 during high current operation is very small and a sufficient amount of heat cannot be obtained, as shown in another embodiment of FIG. A nonlinear resistor 9 having the characteristics shown in FIG. 3 is further provided on the remaining entire surface of the inner surface of the case 6. That is, the nonlinear resistor 9 and the resistance heating element 8 are connected in series, and it is clear that the same operation as in the case of FIG. 4 is achieved in this case as well. Thus, according to the present invention, in a two-terminal type amorphous semiconductor switching element, the threshold voltage can be made constant regardless of the ambient temperature, and high reliability can be obtained, and the threshold voltage can be kept constant. The control power for controlling the switching element is also consumed only until the switching element becomes conductive after the threshold voltage is applied, which is extremely advantageous.

[Brief explanation of the drawing]

1 and 2 are characteristic curve diagrams of an amorphous semiconductor, FIG. 3 is a characteristic curve diagram of a nonlinear resistor, and FIGS. 4 and 5 are sectional views of different embodiments of the present invention. 1... Amorphous semiconductor, 4, 5... Lead terminal, 7.
...Nonlinear resistance heating element, 8...Resistance heating element, 9...
Nonlinear resistor.

Claims (1)

[Claims] 1. A switch element is configured by connecting in parallel a first circuit including an amorphous semiconductor between a pair of lead terminals and a second circuit having a resistance heating action and a nonlinear resistance action, and the threshold voltage of the semiconductor is set to the switch element. In addition to setting the value at a predetermined temperature above the upper limit of the operating temperature range of the element, the large current operating voltage in the nonlinear resistance action of the second circuit is made to almost match the threshold voltage, and furthermore, the voltage of the second circuit is An amorphous semiconductor switch element in which the temperature of the semiconductor is increased to above the predetermined temperature during large current operation.