JPS58101460A - Photo trigger thyristor - Google Patents

Abstract

PURPOSE:To obtain a photo trigger thyristor which has no erroneous firing without decreasing trigger sensitivity by leading a trigger current terminal from the cathode electrode of an auxiliary SCR and flowing the trigger current at the forcibly firing time. CONSTITUTION:A trigger current terminal 14 is led from the cathode electrode 9 of an auxiliary SCRC in the SCR of the structure similar to the conventional one. When the trigger current terminal is led from the cathode electrode 11 of the second auxiliary SCRd, a large current is improperly required for firing. When the trigger current is flowed to the terminal 14 at the forcibly firing time, the firing can be performed at the suitable magnitude of about several A, thereby preventing erroneous firing and facilitating the firing at the necessary time. Since the photodetecting area of the photodetector is not defected, the phototrigger sensitivity is not decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to improvements in optically triggered thyristors.

At present, there are a wide variety of gate e structures in known optical trigger silices, but relatively often they have a two-stage amplification gate structure.

Figure 1 is a schematic cross-sectional view showing the configuration of a conventional 21-layer amplification gate structure optical trigger silice (11 is a p-type emitter layer (pE layer), [2] is an n-type space layer (n1 layer)
, (3) is the p-type base layer (p, layer), (41 is the main thyristor a (On-type emitter layer (nI III ), 16
) is Il! The anode electrode formed on the S surface of the Σ layer (1), (6) the cathode electrode of the main thyristor a formed on the surface of the n1 layer (4), and 17J the light receiving part on the surface of the pB layer (3). The light-receiving recess provided in (8) is the second stage auxiliary Sirisk Gong layer adjacent to the light-receiving part bK. (91
is the cathode electrode of this S1m auxiliary thyristor 0.
11th layer of thyristor C (91st layer from the surface of 8J)
1) is formed over the surface. The noise is 1Ii2R between jll1 stage auxiliary thyristor C and main thyristor a.
This is the 01 layer of III Suke Sai Risk d. (11) is the cathode electrode of this II two-stage auxiliary cylinder d, and is formed from the surface of the n1 layer of the second-stage auxiliary cylinder d to the surface of the 91st layer (3). α is an anode terminal or a cathode terminal.

The optical trigger of the two-stage amplification game town structure configured in this way
In Thyrisk, a small excitation current generated by the light incident on the light receiving part fires the @1 stage auxiliary thyristor C. As a result, [1st stage auxiliary thyristor C has 4rl]
Lt11a, which becomes the gate current of the second stage auxiliary thyristor d. This 11t current is amplified by the first-stage auxiliary thyristor C, and becomes larger than the excitation current caused by light and sufficient to fire the 82-stage auxiliary thyristor d. In this way @2-stage auxiliary thyristor d
fires. In the same way, *g* auxiliary size screen d
The current amplified by ignites the main thyristor a. In the manner described above, the turn-on of the entire surface of the light-triggered cyrisk is completed.

By the way, some devices that include a cyrisk must forcibly ignite the cyrisk in the event of an accident or the like. There are two methods of forced ignition in such cases, one using light and the other using electric current, but from the standpoint of emergency responsiveness, forced ignition using electric current is often adopted; An electrode is provided on the part, and the current from this electrode causes 1
llJR auxiliary thyristor C is fired, then #Ia
A method has been adopted in which the stage auxiliary thyristor and the main thyristor a are fired in sequence.

However, in the conventional method as described above, since an electrode is provided on the light receiving portion, a portion of the light receiving area is covered with the electrode, reducing the optical trigger sensitivity. (b) Since ignition occurs even with a small current, erroneous ignition is likely to occur. It had drawbacks such as:

This invention has been made in view of the above points, and provides a light with a forced current firing electrode that does not reduce the optical trigger sensitivity, is not overly sensitive to 11atlL firing sensitivity, and does not cause false firing. It is intended to provide trigger risk.

Figure 112 is a schematic cross-section showing the configuration of an embodiment of this invention.
In the t figure, parts equivalent to the conventional example in Fig. 1 are indicated by the same symbols.
It is exactly the same as the conventional example shown in Fig. 1 except that the trigger current terminal (1) is drawn out from the cathode electrode (91) of the first stage auxiliary thyristor C. There is no need to explain the operation of forcibly firing the trigger thyristor.Also, from the point of view of not making the current firing sensitivity too sensitive, the trigger current is Although it would be possible to pull out the terminal, in this case, a large □torque flL (several tens of amperes 411 degrees) is required for ignition, which is inappropriate.

As explained above, the optical trigger thyrisk according to the present invention has a three-stage amplification gate structure, and the trigger current terminal is drawn out from the cathode electrode of the first stage auxiliary thyrisk, and this trigger current terminal is used during forced ignition. Since the trigger current is caused to flow through the trigger, the light-receiving area of the light-receiving section is not lost, and therefore, the optical trigger sensitivity is not reduced. In addition, the trigger current at the time of current ignition is a suitable size (several amperes m degrees), preventing erroneous ignition and facilitating ignition when necessary.

[Brief explanation of the drawing]

FIG. II1 is a schematic cross-sectional view showing the basic structure of a conventional optical trigger thyristor; FIG. 2 is a schematic cross-sectional view showing the structure of an embodiment of the present invention. In the figure, a is the main cylindrical part, and b is the light receiving part. C is the first JI auxiliary thyristor section, (91 is its cathode electrode, (141 is the trigger current terminal, and d is the second stage auxiliary thyristor section. In addition, the same reference numerals in the figure indicate the same or equivalent parts. Agent: Kuzuno Shin - (1 other person)

Claims (1)

[Claims] (1) Light receiving part and 11g 1st stage auxiliary Sailisk 1st!
: A two-stage amplification group consisting of a second-stage auxiliary syringe section and a main auxiliary sys-risk section) has a length of 111m, and a current is passed through the cathode electrode of the first-stage auxiliary sys-risk section during forced ignition to cause the #I second-stage auxiliary sys-risk section to flow. A light-triggered silicate characterized by having a trigger voltage for ignition.