JPS58157163A - Photo-driven type semiconductor device - Google Patents

Abstract

PURPOSE:To enable to prevent the erroneous firing due to noises, etc. and enhance the strength to the rate of forward current increase (di/dt), by providing an electric control electrode on the cathode base except for the peripheries of a light receiving part and a main emitter. CONSTITUTION:It is enough to irradiate a light 6 onto the light receiving part 5 to perform firing. Thereby, an auxiliary thyristor constituted of auxiliary emitters 1b, the cathode base 2, an anode base 3, and an anode emitter 4 turns into ''ON'' state. Thereafter, the main thyristor, i.e. the thyristor constituted of the main emitters 1a fires by the same operation as a thyristor of amplifying gate structure in an electric gate system. Where, the electric control electrode 21 is used, in case that the light 6 is not irradiated onto the light receiving part 5 due to the failure in a photo signal system, or at the time of impression of overcurrent, in order to promote the firing of the photo thyristor. In other words, a gate current is supplied into the electric control electrode 21, and thus the photo thyristor is made to fire as the amplifying gate thyristor of normal electric gate system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an optically driven semiconductor device such as an optical trigger thyristor that uses an optical signal as a trigger.

[Technical background of the invention]

Optical trigger thyristors (hereinafter simply referred to as original thyristors) used as triggers for optical signals have many advantages over ordinary electrically triggered thyristors.
-) Excellent electrical insulation between the circuit and the main circuit (the thyristor device body), and extremely little malfunction due to external noise coming in from the D) circuit.1) The entire device can be easily miniaturized and lowered in price. It can be realized, and the reliability is high. Taking advantage of these advantages, optical thyristors can be used to generate high voltage power,
It is often used in conversion devices, etc.

Such party thyristors usually have N as shown in Figure 1.
llNio, Ri1, PM Pace 2, NW Pace J and P
It is a semiconductor element with a four-layer structure consisting of 11 layers and 4 layers.

and the light receiving part of the 0-light thyristor (part of the N-type emitter 1) I
When the light 6 is applied to the anode 1 and the cathode 8 are turned on, a current flows between the anode 1 and the cathode 8, which are turned on.

By the way, when using such an optical thyristor, it is necessary to accelerate the ignition of the thyristor and stop it from breaking down when the optical signal system fails or when an overvoltage is applied. For this reason, a conventional optical thyristor has been proposed in which a light receiving section is provided with an electric control and an electrode (hereinafter simply referred to as an electrode). This optical thyristor usually has an amplifying dart structure, that is, an N-type emitter,
RI (cathode emitter, RI) is earthwork 2. It has an auxiliary thyristor consisting of an auxiliary emitter, an auxiliary emitter, and the above-mentioned light-receiving section (for example, consisting of a P-type base).

Then, as described above, an electrode is provided on the light receiving part, and the electrode is, for example, P? −). Therefore, the S optical thyristor operates as a normal electric f-) type (electric trigger) thyristor, and it is possible to prevent the thyristor from being locally destroyed. . . . [Problem of background collision] However, as described above, the t-light thyristor has the disadvantage that it is easily caused by false firing due to noise or the like. In other words, in order to increase the optical trigger sensitivity, the gate trigger current is increased at the light receiving section!・! When converted to , it is 1 to 2111A. In contrast, the r-)) trigger current IQ of a normal electric r-tonyristor? The driving current ranges from several tens of microns to 200 waA @It, and is generally triggered with a drive current of about 1 micron. Therefore, when the light receiving part is equipped with nine electrodes and operated as a nine electric f-) type cyrisk, even the slightest current such as noise will trigger ψt. When placed around Emi, the Lord of the Evening,
There is a disadvantage that the initial ignition region is narrow and the forward current increase rate (ds/dt) withstand capability is low. In order to obtain high ds/ds withstand capability, if the electrode is made larger, the dirt current IG? This has the disadvantage of increasing.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and provides an optical thyristor having an electric control electrode for promoting ignition of the thyristor in the event of a failure in the original signal system or the application of overvoltage. The purpose of this invention is to provide an optically driven semiconductor shell/device with high noise tolerance.

[Summary of the invention]

That is, in this F14, the electric control electrode is received,
Provided on the cathode paste other than the tip and the periphery of both the cathode and main emitters. From this K, it is possible to increase the as/dt tolerance and the noise tolerance by 1 when promoting the ignition of the thyristor when an overvoltage is applied or the like when the original signal system fails.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows the configuration of the original thyristor according to the present invention, which includes an anode emitter (P emitter) 4, an anode pace <Nf11 base) 3, a cathode base (P type base) 2, and a unipolar emitter.

(Nlll Engineering ξ, Evening) Consists of 10PNP Summer 04 layers.
Furthermore, the cathode emitter 1' consists of an earthwork 1a and a plurality of auxiliary emitters Jb.A light receiving portion 5 is formed around the auxiliary emitter 1, for example on the surface of the cathode space 2. When this light receiving section 5 is irradiated with light, the optical thyristor is triggered. And, on the surface of the main emitter 1a and the auxiliary emitter 1b,
A contact cathode electrode 1a+tlb is formed. Furthermore, in addition to the light receiving IIj, the periphery is covered with the auxiliary structure 1b, and a 1 ohm contact electrical control electrode 21 is formed on the surface of the nine cathode paste 2. Further, on the back surface of the anode emitter 4, an acid electrode 7 is placed on the back side of the anode emitter 4. The contact is formed in such a way that it makes contact.

In the light thyristor having such a configuration, in order to ignite it, it is sufficient to irradiate the light receiving part 5 with the light 6.
The auxiliary thyristor consisting of the anode emitter 4 and the anode emitter 4 is turned on.Then, from then on, the main thyristor, that is, the main emitter ,
The thyristor consisting of 11 will fire.

Here, the electric control electrode 21 is used to promote the firing of the one-light thyristor when the light 6 is not irradiated onto the light receiving section 5 due to a failure of the optical signal system or when an overvoltage is applied. That is, by supplying a dart current to the electric control electrode 21, the thyristor is fired as a normal electric dart thyristor. The dart current in this case is
For example, an overvoltage protection device consisting of a Zener diode or the like is provided between the anode and cathode of a thyristor, and the current is input from the overvoltage protection device when an overvoltage is applied.

In this way, the ignition of the optical thyristor can be promoted and local destruction of the thyristor can be prevented. Moreover, in this invention, since the electric control electrode 21 is provided on the surface of the O cathode paste 20 other than the light receiving part 5, the normal dirt trigger current I41? (For example, several tens IIIA to 20
Stable ignition operation can be performed at approximately 0mIA),
Erroneous firing due to noise etc. can be prevented. i9, the electric control electrode 21 has auxiliary emitters other than the vicinity of the main emitter JaO;
Since it is provided on the surface of the cathode paste 20 surrounded by b, the di/as tolerance is high.

r-) When the current is input, the PN around the main entrant 1a
It is possible to reliably prevent local destruction such as the destruction of @Aiku.

FIGS. 3 and 4 each show other embodiments, and the optical thyristor shown in 1E31EIK is a case where the light receiving part 5 is the auxiliary engine of the auxiliary thyristor. That is, this optical thyristor becomes a thyristor with a three-stage amplification dart structure. Note that the other configurations and effects are the same as those of the above embodiment, so explanations thereof will be omitted.

Furthermore, in the optical thyristor shown in FIG. 4, the electrical control electrode 2
1 is provided at the same position as the side gate structure. That is, the main emitter 1a is placed between the auxiliary two constant vines 1b.
The electric control electrode 21 is provided on the surface of the cathode space 20 via the earthwork ξ, the auxiliary emitter and the ray 1b on the outer side of the earthwork ξ and the ray JaO with respect to the light receiving part JK in the center.

Even in this case, the operation and effects are the same as in the above embodiment, so explanation W14 will be omitted.

In the above embodiment, the electric control electrode 11 is an independent electrode provided on the surface of the cathode paste 2. The electrode 8k on the surface of the auxiliary emitter 1b, which is in contact with a part of the cathode paste 2, may also be used as the electric control electrode 21. However, it goes without saying that a part of the cathode paste 2 in the case of a cylindrical case is a part other than the periphery of both the light receiving part 5 and the main emitter 11.

〔Effect of the invention〕

As explained in detail above, according to the WAK with K-0 firing, by passing a gate current through the electrical control electrode, it is possible to
can promote ignition of the thyristor when overvoltage is applied. Moreover, by providing electrical control electrodes on the polar pace at # other than around 0 of both the light receiving part and the main emitter, it is possible to prevent erroneous single firing due to noise etc., and to increase the forward current increase rate (at/dt) tolerance. You can increase your humanity. As a result, it is possible to provide a semiconductor device that operates stably.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional optically triggered thyristor, FIG. 2 is a block diagram of a light-driven semiconductor device according to an embodiment of the present invention, and FIGS. 3 and 4 are respectively other embodiments of the present invention. It is a configuration diagram of a light-driven semiconductor device according to 1...1llk pole emitter, 2... cathode paste, 3
...Positive false pace, 4...Anode emitter, ri, 5...Light receiving part, 6...light, 7...Anode electrode, 8 River cand electrode, 1a...main emitter, ri, 1b...Auxiliary Emi,
ri, 8a. 8b...Cathode electrode, 21 river electric control electrode. Applicant's agent Patent attorney Takehiko Suzue Figure 1 6 Figure 3 o V

Claims (1)

[Claims] In an optical thyristor, the cathode emitter is composed of four layers: an anode emitter, an anode paste, a cathode paste, and a PNPN which is a cathode emitter, and has a light receiving part that receives an optical trigger signal. What is claimed is: 1. A light-driven semiconductor device comprising an electrical control electrode on the cathode space other than around both the main emitter, the light receiving section and the light receiving section.