JP2015185642A - Bidirectional photothyristor chip and solid-state relay - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bidirectional photothyristor chip including a PNPN element of a lateral structure and achieving a higher current.SOLUTION: In a bidirectional photothyristor chip, each of a first photothyristor part (42a) and a second photothyristor part on a surface of one semiconductor chip has a PNPN part including an anode diffusion region (43) extending in one direction, a substrate, a gate diffusion region (44), and a cathode diffusion region (45) formed within the gate diffusion region (44). A planar shape of at least any one side selected from among two sides of the anode diffusion region (43) and the gate diffusion region (44), the two sides facing each other, and a side (45a) of the cathode diffusion region (45), the side facing the anode diffusion region (43), is such a shape that concentration of current to a central part in the one direction is relaxed, the current being supplied from the anode diffusion region (43) toward the gate diffusion region (44) and the cathode diffusion region (45).

Description

  The present invention relates to a bidirectional photothyristor chip and a solid state relay (hereinafter abbreviated as SSR) using the bidirectional photothyristor chip.

  Conventionally, some SSRs used in alternating current have a circuit configuration as shown in FIG. The SSR 8 includes a light-emitting coupler 3 including a light-emitting element 1 such as an LED (light-emitting diode) and a bidirectional bidirectional photothyristor 2 and a bidirectional thyristor (hereinafter referred to as a main thyristor) for actually controlling a load. 4) and a snubber circuit 7 composed of a resistor 5, a capacitor 6 and the like.

  Further, an equivalent circuit diagram of the light ignition coupler 3 constituting the SSR 8 is as shown in FIG. The bidirectional photothyristor 2 includes a CH (channel) 1 photothyristor 9 and a CH2 photothyristor 10. The CH1 photothyristor 9 is configured by connecting the base of the PNP transistor Q1 to the collector of the NPN transistor Q2 and connecting the collector of the PNP transistor Q1 to the base of the NPN transistor Q2. Similarly, the photothyristor 10 of CH2 is constructed by connecting the base of the PNP transistor Q3 to the collector of the NPN transistor Q4, and connecting the collector of the PNP transistor Q3 to the base of the NPN transistor Q4.

  Further, on the CH1 side, the emitter of the PNP transistor Q1 is directly connected to the electrode T1. On the other hand, the emitter of the NPN transistor Q2 is connected directly to the electrode T2 via the gate resistor 11 at the base. Similarly, on the CH2 side, the emitter of the PNP transistor Q3 is directly connected to the electrode T2. On the other hand, the emitter of the NPN transistor Q4 is connected directly to the electrode T1 via the gate resistor 12 at the base.

  The light ignition coupler 3 having the above-described configuration operates as follows. That is, in FIG. 16, first, the electrode T1 side is more positive than the electrode T2 side under the condition that a power supply voltage higher than the ON voltage (about 1.5 V) of the element is biased between the electrode T1 and the electrode T2. When the potential is at the potential, when the bidirectional photothyristor 2 receives the optical signal from the LED 1, the NPN transistor Q2 on the CH1 side is turned on. Then, the base current of the PNP transistor Q1 on the CH1 side is drawn, and this PNP transistor Q1 is turned on. Subsequently, the base current is supplied to the NPN transistor Q2 on the CH1 side by the collector current of the PNP transistor Q1, the PNPN portion on the CH1 side is turned on by positive feedback, and the ON state corresponding to the load of the AC circuit from the electrode T1 to the electrode T2 is turned on. Current flows. In that case, on the CH2 side, since the direction of bias application is reverse, positive feedback of the PNPN portion does not occur and only the primary photocurrent flows.

  On the other hand, when the electrode T2 side is more positive than the electrode T1 side, the PNPN section on the CH2 side is turned on by positive feedback operation in the same manner as described above, and only the primary photocurrent is on the CH1 side. Flowing.

  Thus, when the CH1 side PNPN section or the CH2 side PNPN section is turned on, this current flows into the gate of the main thyristor 4 to turn on the main thyristor 4.

  The SSR 8 having a hybrid configuration of the above-described bidirectional photothyristor 2 for triggering light and the main thyristor 4 which is a bidirectional thyristor for actually controlling the load has a feature that the current capacity can be increased. ing. The reason is that since the vertical chip structure is employed, the current path increases in proportion to the area of the PNPN element, so that the chip size can be reduced. In other words, it can be said that the structure is cost-effective.

  On the other hand, there are disadvantages: (1) In order to obtain a vertical chip structure, it is necessary to adopt an isolation or mesa structure, which is difficult to make. (2) The process cost is high due to the above (1). (3) The main thyristor 4 cannot be triggered by light (because the trigger current of the main thyristor 4 requires about 10 mA, and the carrier current generated by photoexcitation is significantly insufficient).

  In recent years, the economic environment surrounding the electronic industry has become increasingly severe, and there has been an increasing demand for reduction in the cost of electronic devices and improvement in convenience. In order to meet such a demand, in the conventional SSR having the configuration as shown in FIG. 15, for example, in order to reduce the number of parts, the main thyristor 4 is omitted and the SSR having the circuit configuration as shown in FIG. Attempts have been made to directly control the load using only the bidirectional photothyristor for light trigger.

  As described above, the bi-directional photothyristor for the optical trigger that can produce an SSR having a circuit configuration in which the main thyristor is omitted and can directly control the load is disclosed in Japanese Patent No. 4065825 (Patent Document 1). There is a photothyristor chip.

  FIG. 17 shows a schematic pattern layout in the bidirectional photothyristor chip disclosed in Patent Document 1. 18 and 19 are schematic cross-sectional views taken along the line B-B 'in FIG. FIG. 18 shows a state when the light is on, and FIG. 19 shows a state when the voltage is reversed (commutation) when the light is off.

  In the conventional bidirectional photothyristor chip, as shown in FIG. 17, in plan view, it is 180 degrees with respect to the intersection of the center line AA ′ and the line segment BB ′ orthogonal to the center line. , That is, a point-symmetric pattern with respect to the intersection. Further, as shown in FIGS. 18 and 19, the cross section is configured to be symmetrical with respect to a vertical line segment C-C ′ orthogonal to the center line A-A ′. Hereinafter, the left photothyristor is referred to as CH1 photothyristor 20a while the right photothyristor is referred to as CH2 photothyristor 20b with respect to the center line A-A 'and line C-C'.

  In FIGS. 17, 18 and 19, 21 is an N-type silicon substrate, 22 is a short diode (channel isolation region) composed of a high-concentration N-type diffusion region 22a and a high-concentration P-type diffusion region 22b, and 23 is an anode. Diffusion region (P type), 24 is a gate diffusion region (P type), 25 is a cathode diffusion region (N type), 26 is a gate resistance region, 27 is a high concentration N type diffusion region as a channel stopper, 23a, 24a, Reference numeral 27a denotes an Al electrode. T1 and T2 are lead frames, 28a, 28b, 28a 'and 28b' are Au wires, and 29 is a Schottky barrier diode.

  According to the above configuration, the commutation characteristic, which is an important design parameter in the bidirectional photothyristor, can be greatly improved. Therefore, the main thyristor can be omitted by using the bidirectional photothyristor as the SSR light spot coupler.

  Here, the “commutation characteristic” is a characteristic representing the maximum operating current value Icom that can be controlled without causing commutation failure. The bidirectional photothyristor chip disclosed in Patent Document 1 has a short diode 22 on the surface side of the N-type silicon substrate 21. Accordingly, as shown in FIG. 19, the minority carriers 30 in the N-type silicon substrate 21 are recovered by the short diode 22 at the time of commutation. As a result, the malfunction (commutation failure) in which the CH2 photothyristor 20b is turned on by the positive feedback action on the CH2 side is suppressed, and the commutation characteristics are improved.

  As described above, the bi-directional photothyristor chip disclosed in Patent Document 1 is a bi-directional photothyristor for the purpose of optical triggering, and is also produced for the purpose of a driver element for actually controlling a load. And has a lateral structure suitable for those purposes. Therefore, there is an advantage that the planar structure is easy to manufacture and the process cost is low.

  However, the bidirectional photothyristor chip disclosed in Patent Document 1 has the following problems.

  That is, in the case of a lateral PNPN element such as the bidirectional photothyristor chip, the current paths are the anode diffusion region (P type) 23, the gate diffusion region (P type) 24, and the cathode that are opposed to each other. One side located in the region of the CH1 photothyristor 20a or CH2 photothyristor 20b in the composite with the diffusion region (N-type) 25 (hereinafter referred to as "gate diffusion region 24 / cathode diffusion region 25"). And, depending on the width (depth), there is a problem that the current efficiency with respect to the chip size (cost) is poor.

  Therefore, in the bidirectional photothyristor disclosed in Patent Document 1, it is necessary to increase the current.

  In order to increase the current, the chip size of the bidirectional photothyristor is increased, and the distance of the surface into which the current flows (the width of the anode diffusion region 23, the gate diffusion region 24, and the cathode diffusion region 25) is increased. It will be possible. However, the chip cost will increase.

Japanese Patent No. 4065825

  SUMMARY OF THE INVENTION An object of the present invention is to provide a bidirectional photothyristor chip having a lateral PNPN element and capable of increasing the current, and an SSR using the bidirectional photothyristor chip.

In order to solve the above problems, the bidirectional photothyristor chip of the present invention is:
A first photothyristor portion and a second photothyristor portion formed on the surface of one semiconductor chip so as to be separated from each other;
Each of the photothyristor sections includes an anode diffusion region extending in one direction and having one conductivity type of N type or P type, a substrate having the other conductivity type of N type or P type, and the anode A PNPN portion including a gate diffusion region having the one conductivity type facing the diffusion region, and a cathode diffusion region formed in the gate diffusion region facing the anode diffusion region and having the other conductivity type Have
The planar shape of at least one of the two sides opposite to each other in the anode diffusion region and the gate diffusion region and the side opposite to the anode diffusion region in the cathode diffusion region is: The current supplied from the anode diffusion region toward the gate diffusion region and the cathode diffusion region has a shape that relaxes concentration in the central portion of the one direction that is the extending direction of the anode diffusion region. It is characterized by being.

The SSR of the present invention is
A light spot coupler composed of the bidirectional photothyristor chip of the present invention and an LED;
It is characterized by comprising a snubber circuit.

  As is clear from the above, in the bidirectional photothyristor chip of the present invention, the current supplied from the anode diffusion region toward the gate diffusion region and the cathode diffusion region is concentrated in the central portion in the one direction. Can be relaxed. That is, when a surge current that is an inrush current flows between the anode diffusion region and the gate diffusion region / the cathode diffusion region, it is possible to reduce the concentration of the current in the central portion in the one direction. .

  Therefore, according to the present invention, the breakdown of the gate diffusion region / the cathode diffusion region can be prevented to increase the inrush current surge withstand voltage, and the bidirectional photothyristor chip having a lateral PNPN element can be increased in current. As a result, current efficiency can be improved.

  Further, the SSR of the present invention increases current efficiency even when a bidirectional photothyristor chip having a lateral PNPN element is used to directly control a load according to an optical signal from an LED. It is possible to use a light ignition coupler. Therefore, the main thyristor for controlling the load can be omitted, and an inexpensive and high-performance SSR with a small number of parts can be realized.

It is a figure which shows the schematic pattern layout in the bidirectional | two-way photothyristor chip | tip of this invention. It is DD 'arrow sectional drawing in FIG. It is DD 'arrow sectional drawing of FIG. 1 which shows the state at the time of light ON. It is DD 'arrow sectional drawing of FIG. 1 which shows the state at the time of the commutation which is the time of light-off. It is a pattern schematic diagram of an anode diffusion region, a gate diffusion region, and a cathode diffusion region. It is a figure which shows the relationship between the surge tolerance of inrush current, and a chip area. FIG. 6 is a schematic pattern diagram different from FIG. 5. FIG. 8 is a schematic pattern diagram different from FIGS. 5 and 7. FIG. 9 is a pattern schematic diagram different from FIGS. 5, 7, and 8. FIG. 10 is a schematic pattern diagram different from FIGS. 5 and 7 to 9. FIG. 11 is a schematic pattern diagram different from FIGS. 5 and 7 to 10. FIG. 12 is a schematic pattern diagram different from FIGS. 5 and 7 to 11. FIG. 13 is a schematic pattern diagram different from FIGS. 5 and 7 to 12. It is a circuit diagram of SSR which abbreviate | omitted the main thyristor. It is a circuit diagram of SSR used by alternating current. FIG. 16 is an equivalent circuit diagram of a light ignition coupler constituting the SSR shown in FIG. 15. It is a figure which shows the schematic pattern layout in the conventional bidirectional photothyristor. It is BB 'arrow sectional drawing of FIG. 17 which shows the state at the time of light ON. FIG. 18 is a cross-sectional view taken along the line BB ′ in FIG.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

First Embodiment FIG. 1 shows a schematic pattern layout in a bidirectional photothyristor chip of this embodiment, and FIG. 2 is a schematic cross-sectional view taken along the line DD ′ in FIG.

  As shown in FIGS. 1 and 2, the bidirectional photothyristor chip of the present embodiment includes a first photothyristor 42a of CH1 formed on the surface of an N-type silicon substrate 41 constituting the chip so as to be separated from each other. The second photothyristor 42b of CH2.

  The first photothyristor 42 a and the second photothyristor 42 b include a P-type anode diffusion region 43, a P-type gate diffusion region 44 facing the anode diffusion region 43, and an anode diffusion region in the gate diffusion region 44. 43 has an N-type cathode diffusion region 45 formed so as to be opposed to 43. Thus, a PNPN portion is formed from the anode diffusion region 43 toward the cathode diffusion region 45. Reference numeral 46 denotes a gate resistance region.

  A high-concentration N-type diffusion region 47 as a channel stopper is formed along the periphery of the chip. Further, an Al electrode 47a is formed on the high-concentration N-type diffusion region 47 as indicated by a broken line. Also, an Al electrode (broken line display) 43a is formed so as to cover the anode diffusion region 43, and an Al electrode (broken line display) 44a is formed so as to cover the gate diffusion region 44, the cathode diffusion region 45 and the gate resistance region 46. Yes.

  As shown in FIG. 1, the bidirectional photothyristor has a rotational symmetry of 180 degrees with respect to the intersection of a center line EE ′ and a line segment DD ′ orthogonal to the center line. That is, it has a substantially point-symmetric pattern with respect to the intersection point. Further, as shown in FIG. 2, the cross section is substantially symmetrical with respect to a vertical line segment F-F ′ orthogonal to the center line E-E ′. That is, the left photothyristor is the CH1 first photothyristor 42a and the right photothyristor is the CH2 second photothyristor 42b with respect to the center line E-E 'and the line segment F-F'.

  Further, the Al electrode 43a on the anode diffusion region 43 of the first photothyristor 42a of CH1 and the Al electrode 44a on the cathode diffusion region 45 of the second photothyristor 42b of CH2 are lead frames by Au wires 48a and 48b. Connected to T1. Further, the Al electrode 44a on the cathode diffusion region 45 in the first photothyristor 42a of CH1 and the Al electrode 43a on the anode diffusion region 43 in the second photothyristor 42b of CH2 are lead by Au wires 48a 'and 48b'. Connected to the frame T2. Thus, the first photothyristor 42a of CH1 and the second photothyristor 42b of CH2 are wired in antiparallel with wire bonds.

  Further, in the bidirectional photothyristor chip, in the first photothyristor 42a and the second photothyristor 42b, the longitudinal direction of the anode diffusion region 43 and the cathode diffusion region 45 is the first direction, and the direction perpendicular to the first direction. When the second direction is a direction substantially parallel to the surface of the N-type silicon substrate 41, the dicing surface that faces the gate diffusion region 44 in the outermost dicing surface of the chip and the gate diffusion in the second direction. The distance X to the region 44 is set within 400 μm.

  Hereinafter, the reason why the commutation characteristic Icom is improved in the region of X ≦ 400 μm will be described with reference to FIGS. 3 and 4. 3 and 4 are schematic cross-sectional views taken along the line DD ′ of FIG. 1 as in FIG. 2, and the distance X is “X ≦ 400 μm”. However, FIG. 3 shows a state when the light is on, and FIG. 4 shows a state when the voltage is reversed (commutation) when the light is off.

  As shown in FIG. 3, the minority carrier 49 generated when the first photothyristor 42a on the CH1 side is turned on is caused by the potential gradient of the bidirectional photothyristor during the commutation shown in FIG. It is recovered in the anode diffusion region 43 in 42a or the gate diffusion region 44 in the second photothyristor 42b of CH2. In this case, when the amount of minority carriers collected in the gate diffusion region 44 on the CH2 side exceeds a certain critical value, the NPN transistor constituting the PNPN part in the second photothyristor 42b of CH2 is turned on, The positive feedback of the second photothyristor 42b is urged, and the second photothyristor 42b is turned on, causing the “commutation failure”.

  Therefore, in order to suppress the “commutation failure”, it is necessary to increase the critical value Icom of the operating current as much as possible. In order to increase Icom, it is necessary to suppress the amount of minority carriers collected in the gate diffusion region 44 on the CH2 side.

  Here, when the distance X between the dicing surface on the outer periphery of the chip and the gate diffusion region 44 in the first photothyristor 42a of CH1 is reduced, the minority carriers 49 generated on the CH1 side when turned on as shown in FIG. Before moving to the CH2 side, as shown in FIG. 4, it is collected on the dicing surface on the CH1 side.

  Therefore, the distance X between the dicing surface on the outer periphery of the chip and the gate diffusion layer 44 is reduced to the maximum while satisfying characteristics (for example, characteristics such as withstand voltage) other than the commutation characteristics in the bidirectional photothyristor. It is desirable to do. In particular, it is desirable that X ≦ 400 μm.

  As described above, in the present embodiment, the first photothyristor 42a and the second photothyristor 42b have the distance X between the dicing surface on the outermost periphery of the chip and the gate diffusion region 44 in the second direction. It is set within 400 μm.

  Therefore, for example, the minority carriers 49 generated on the CH1 side when turned on are collected on the dicing surface on the CH1 side as shown in FIG. 4 before moving to the CH2 side. As a result, the commutation characteristics can be greatly improved without the Schottky barrier diode and the channel isolation region.

  Therefore, an inexpensive bi-directional photothyristor chip can be obtained that has the function of controlling the load by suppressing the increase in the chip area and controlling the load in a single chip and omitting the SSR main thyristor. is there.

  By the way, in the bidirectional photothyristor chip configured as described above, in order to increase the current, it is necessary to increase the surge current resistance of the inrush current and increase the rated current value. In general, an inrush current surge resistance of 10 times the rated current value is required. For example, in the case of a rated product having a rated current value of 0.3 A, an inrush current surge resistance of 3 A is required. .

  In the pattern layout of the bidirectional photothyristor chip shown in FIG. 1, an anode diffusion region 43 and a gate diffusion region 44 having straight sides opposite to each other in the first photothyristor 42a of CH1 or the second photothyristor 42b of CH2. When a surge current, which is an inrush current, is caused to flow between the cathode diffusion region 45 and the cathode diffusion region 45, a current flowing in the lateral direction (lateral direction) from the side of the anode diffusion region 43 is caused to flow as shown in FIG. / Junction breakdown occurs at the central portion of the cathode diffusion region 45 in the first direction. Therefore, in order to increase the current of the bidirectional photothyristor chip, it is necessary to alleviate the current concentration at the center in the first direction of the chip.

  The present invention is intended to alleviate current concentration at the center in the first direction of the chip by changing the pattern structure of the anode diffusion region 43, the gate diffusion region 44, and the cathode diffusion region 45.

  First, in the present embodiment, by changing the shape of the side of the cathode diffusion region 45 facing the anode diffusion region 43, current concentration at the central portion in the first direction of the chip is alleviated.

  FIG. 5 shows a schematic pattern diagram of the anode diffusion region 43, the gate diffusion region 44, and the cathode diffusion region 45 on the first photothyristor 42a side in the pattern layout shown in FIG. In FIG. 5, the patterns of the anode diffusion region 43 and the gate diffusion region 44 are rectangular as in the case of the pattern layout shown in FIG. On the other hand, in the pattern of the cathode diffusion region 45, a rectangular cutout portion 50 is formed at the central portion in the first direction of the side 45a facing the anode diffusion region 43.

  Thus, when an inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / cathode diffusion region 45 (a composite of the gate diffusion region 44 and the cathode diffusion region 45), anode diffusion Of the current supplied from the region 43 to the gate diffusion region 44 / cathode diffusion region 45, a part of the current concentrated in the central portion in the first direction is P gate junction surface rather than the central wall 50a in the notch 50. It flows toward both side walls 50b and 50c that are close to each other. The “P gate junction surface” is a junction surface with the N-type silicon substrate 41 in the P-type gate diffusion region 44, and is a side surface facing the anode diffusion region 43 of the gate diffusion region 44.

  Thus, the current concentrated in the first direction central portion of the gate diffusion region 44 / cathode diffusion region 45 is distributed to the side walls 50b and 50c, thereby reducing the current concentration in the first direction central portion. Is done. As a result, the breakdown of the gate diffusion region 44 / cathode diffusion region 45 is prevented, and the inrush current surge breakdown voltage can be increased.

  Here, in the breakdown of the junction between the gate diffusion region 44 and the cathode diffusion region 45, the cathode diffusion region 45 having the shallowest junction is destroyed in the initial operation of the destruction, and then the destruction spreads to the gate diffusion region 44. The location of the gate diffusion region 44 / cathode diffusion region 45 to which the junction breakdown proceeds depends on the amount of inrush current, and the breakdown of the cathode diffusion region 45 alone may cause the junction breakdown to remain.

FIG. 6 shows the relationship between the surge resistance of inrush current and the chip area of the bidirectional photothyristor chip. By using the pattern of the cathode diffusion region 45 in the present embodiment, the chip area is at 1mm ² ~8mm ^2, it is possible to increase the surge resistance. The surge withstand does not increase in proportion to the chip area. The reason is that there is a bias in the current concentration location.

  As described above, in the present embodiment, the bidirectional photothyristor chip has a center line EE ′ and a line segment DD ′ orthogonal to the center line as shown in FIG. 2 has a rotational symmetry of 180 degrees with respect to the intersection point, that is, a point-symmetric pattern with respect to the intersection point, and is perpendicular to the center line EE ′ as shown in FIG. It is configured symmetrically with respect to the direction line segment FF ′. The first photothyristor 42a of CH1 is formed on the left side with respect to the center line E-E 'and the line segment F-F', and the second photothyristor 42b of CH2 is formed on the right side.

  The first photothyristor 42a and the second photothyristor 42b include a P-type anode diffusion region 43, a P-type gate diffusion region 44 facing the anode diffusion region 43, and an anode in the gate diffusion region 44, respectively. An N-type cathode diffusion region 45 formed to face the diffusion region 43 is provided. In the second direction, the distance X between the dicing surface on the outermost periphery of the chip and the gate diffusion region 44 is set within 400 μm.

  Therefore, for example, the minority carrier 49 generated on the CH1 side at the time of turning on can be collected on the dicing surface on the CH1 side before moving to the CH2 side. As a result, the SSR main thyristor can be omitted without increasing the chip area, and an inexpensive bidirectional photothyristor chip can be obtained.

  Further, the pattern of the cathode diffusion region 45 is formed with a rectangular cutout portion 50 at the central portion in the first direction of the side 45 a facing the anode diffusion region 43. Therefore, when an inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / cathode diffusion region 45, the current supplied from the anode diffusion region 43 to the gate diffusion region 44 / cathode diffusion region 45 is The current concentrated in the central portion in the first direction can be distributed to both side walls 50b and 50c of the notch 50, and the current concentration in the central portion in the first direction of the gate diffusion region 44 / cathode diffusion region 45 is achieved. Can be relaxed.

  Therefore, the breakdown of the junction between the gate diffusion region 44 and the cathode diffusion region 45 can be prevented, the inrush current surge withstand voltage can be increased, and the current can be increased.

  In the present embodiment, a rectangular notch 50 is formed at the central portion in the first direction of the side 45a of the cathode diffusion region 45. However, the shape of the notch is not limited to a rectangle, and may be a semicircle or an ellipse. The point is that the distance in the second direction from the P-gate junction surface to the side 45a in the gate diffusion region 44 may be a shape that maximizes at the central portion in the first direction.

Second Embodiment The basic pattern layout in the bidirectional photothyristor chip of the present embodiment is the same as the pattern layout shown in FIG. 1 in the first embodiment. Further, the basic longitudinal sectional view is the same as the sectional view taken along the line DD ′ shown in FIG. 2 in the first embodiment.

  Therefore, the bidirectional photothyristor chip according to the present embodiment also has a function of controlling the load by suppressing the increase of the chip area and controlling the load with a single chip, so that the SSR main thyristor can be omitted. A simple bidirectional photothyristor chip can be obtained.

  In addition, the above-mentioned thing is the same also in all the following embodiments.

  In the present embodiment, as in the case of the first embodiment, by changing the shape of the side of the cathode diffusion region 45 facing the anode diffusion region 43, the center of the chip in the first direction is changed. This alleviates current concentration in the part.

  FIG. 7 is a schematic pattern diagram of the anode diffusion region 43, the gate diffusion region 44, and the cathode diffusion region 45 on the first photothyristor 42a side in the pattern layout shown in FIG. In FIG. 7, the patterns of the anode diffusion region 43 and the gate diffusion region 44 are rectangular as in the case of the pattern layout shown in FIG. On the other hand, the pattern of the cathode diffusion region 45 is divided into two parts 51a and 51b at the center in the first direction. The distance between the end faces 52a and 52b becomes closer to the end faces 52a and 52b, which are the divided surfaces facing each other in the first cathode diffusion area 51a and the second cathode diffusion area 51b, as the distance from the P gate junction face is closer. The slope is widened. That is, the distance between both end faces 52a and 52b is reduced in inverse proportion to the distance from the P gate junction surface.

  By doing so, the length of the cathode junction surface which is the junction surface with the gate diffusion region 44 in the cathode diffusion region 45 can be efficiently increased. When the inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / cathode diffusion region 45, the current out of the current supplied from the anode diffusion region 43 to the gate diffusion region 44 / cathode diffusion region 45 is A part of the current concentrated in the central portion in the first direction is a P gate junction in which the end face 52a of the first cathode diffusion region 51a and the end surface 52b of the second cathode diffusion region 51b have a short distance from the P gate junction surface. It flows toward the area on the surface side.

  Thus, the current concentrated in the first direction central portion of the gate diffusion region 44 / cathode diffusion region 45 is spread and dispersed in the region on the P gate junction surface side in the both end surfaces 52a and 52b, Current concentration at the central portion in the first direction is alleviated. As a result, the breakdown of the gate diffusion region 44 / cathode diffusion region 45 is prevented, and the inrush current surge breakdown voltage can be increased.

  As described above, in the present embodiment, the bidirectional photothyristor chip can omit the SSR main thyristor without increasing the chip area as in the case of the first embodiment, and the inexpensive bidirectional photothyristor chip can be omitted. A thyristor chip can be obtained.

  Further, the pattern of the cathode diffusion region 45 is divided into 51a and 51b at the center in the first direction, and the end surface 52a of the first cathode diffusion region 51a and the end surface 52b of the second cathode diffusion region 51b facing each other. A slope is provided so that the distance between the both end faces 52a and 52b becomes smaller in inverse proportion to the distance from the P gate junction surface.

  Therefore, when an inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / cathode diffusion region 45, it is concentrated at the center in the first direction of the gate diffusion region 44 / cathode diffusion region 45. The current can be spread and dispersed in the region on the P gate junction surface side of the both end faces 52a and 52b, and the current concentration at the central portion in the first direction can be reduced.

  As a result, the breakdown of the junction between the gate diffusion region 44 and the cathode diffusion region 45 can be prevented to increase the inrush current surge withstand voltage, and the current can be increased.

Third Embodiment In the present embodiment, as in the case of the first embodiment, the tip of the cathode diffusion region 45 is changed by changing the shape of the side facing the anode diffusion region 43. To alleviate current concentration in the central portion in the first direction.

  In FIG. 8, the pattern of the anode diffusion region 43 and the gate diffusion region 44 on the first photothyristor 42a side is rectangular as in the case of the pattern layout shown in FIG. On the other hand, the pattern of the cathode diffusion region 45 is such that the side 45a facing the anode diffusion region 43 has a longer distance from the P gate junction surface at the center in the first direction than at both ends in the first direction. In addition, the center portion has an arcuate shape.

  Thus, when an inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / cathode diffusion region 45, the anode diffusion region 43 is supplied to the gate diffusion region 44 / cathode diffusion region 45. A part of the current concentrated in the central portion in the first direction of the current flows toward the both end portions having a short distance from the P gate junction surface in the cathode diffusion region 45.

  Thus, the current concentrated in the central portion in the first direction of the gate diffusion region 44 / cathode diffusion region 45 is spread and dispersed to the both end portions of the cathode diffusion region 45, whereby the central portion in the first direction. Current concentration to the part is eased. As a result, the breakdown of the gate diffusion region 44 / cathode diffusion region 45 is prevented, and the inrush current surge withstand voltage can be increased. As a result, a high current can be achieved.

  That is, according to the present embodiment, it is possible to obtain a bidirectional photothyristor chip that suppresses an increase in chip area, is inexpensive, and can achieve a high current.

Fourth Embodiment In the present embodiment, the current concentration at the central portion in the first direction of the chip is changed by changing the shape of the side 44b facing the anode diffusion region 43 in the gate diffusion region 44. Is to ease.

  In FIG. 9, the pattern of the anode diffusion region 43 and the cathode diffusion region 45 on the first photothyristor 42a side is rectangular as in the case of the pattern layout shown in FIG. In contrast, the pattern of the gate diffusion region 44 is such that the side 44b facing the anode diffusion region 43 has a longer distance from the cathode junction surface at the center in the first direction than at both ends in the first direction. The arcuate shape is projected from the central portion.

  Thus, when an inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / cathode diffusion region 45, the anode diffusion region 43 is supplied to the gate diffusion region 44 / cathode diffusion region 45. The current is concentrated at the central portion in the first direction that is closer to the anode diffusion region 43. A part of the current concentrated in the central portion in the first direction flows toward the both end portions where the distance from the P gate junction surface in the cathode diffusion region 45 is short.

  Thus, the current concentrated in the central portion in the first direction of the gate diffusion region 44 / cathode diffusion region 45 is spread and dispersed to the both end portions of the cathode diffusion region 45, whereby the central portion in the first direction. Current concentration to the part is eased. As a result, the breakdown of the gate diffusion region 44 / cathode diffusion region 45 is prevented, and the inrush current surge withstand voltage can be increased. As a result, a high current can be achieved.

  That is, according to the present embodiment, it is possible to obtain a bidirectional photothyristor chip that suppresses an increase in chip area, is inexpensive, and can achieve a high current.

Fifth Embodiment In the present embodiment, the first side of the chip is changed by changing the shape of the sides 44b and 45a facing the anode diffusion region 43 in the gate diffusion region 44 and the cathode diffusion region 45. This is to alleviate current concentration in the center of the direction.

  In FIG. 10, the pattern of the anode diffusion region 43 on the first photothyristor 42a side is rectangular as in the case of the pattern layout shown in FIG. On the other hand, the pattern of the gate diffusion region 44 and the cathode diffusion region 45 is such that the side 44b and the side 45a facing the anode diffusion region 43 have a distance from the anode diffusion region 43 at the center in the first direction. The central part has an arcuate shape that is recessed so as to be longer than both ends in one direction. However, the distance from the P gate junction surface on the side 45a of the cathode diffusion region 45 is substantially equal over the entire region in the first direction.

  By doing so, the distance from the anode diffusion region 43 in the gate diffusion region 44 and the cathode diffusion region 45 smoothly changes from the “long” at the central portion in the first direction toward the “short” at both ends. Therefore, when an inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / cathode diffusion region 45, the current supplied from the anode diffusion region 43 to the gate diffusion region 44 / cathode diffusion region 45 is It becomes substantially uniform in the first direction, and the current concentration at the center in the first direction is alleviated.

  Therefore, the breakdown of the gate diffusion region 44 / cathode diffusion region 45 can be prevented, the inrush current surge withstand voltage can be increased, and the current can be increased.

  That is, according to the present embodiment, it is possible to obtain a bidirectional photothyristor chip that suppresses an increase in chip area, is inexpensive, and can achieve a high current.

Sixth Embodiment In the present embodiment, the current concentration in the central portion in the first direction of the chip is changed by changing the shape of the side 43b facing the gate diffusion region 44 in the anode diffusion region 43. Is to ease.

  In FIG. 11, the pattern of the gate diffusion region 44 and the cathode diffusion region 45 on the first photothyristor 42a side is rectangular as in the pattern layout shown in FIG. On the other hand, in the pattern of the anode diffusion region 43, the side 43b facing the gate diffusion region 44 has a distance from the gate diffusion region 44 at the center in the first direction that is longer than both ends in the first direction. In addition, the center portion has an arcuate shape.

  As a result, the distance from the gate diffusion region 44 in the anode diffusion region 43 smoothly changes from the “long” at the central portion in the first direction toward the “short” at both ends. When an inrush current flows between the region 43 and the gate diffusion region 44 / cathode diffusion region 45, the current supplied from the anode diffusion region 43 to the gate diffusion region 44 / cathode diffusion region 45 is substantially in the first direction. It becomes uniform and current concentration at the central portion in the first direction is reduced.

  Therefore, the breakdown of the junction between the gate diffusion region 44 and the cathode diffusion region 45 can be prevented, the inrush current surge withstand voltage can be increased, and the current can be increased.

  That is, according to the present embodiment, it is possible to obtain a bidirectional photothyristor chip that suppresses an increase in chip area, is inexpensive, and can achieve a high current.

Seventh Embodiment In the present embodiment, the side 43b facing the gate diffusion region 44 in the anode diffusion region 43 and the side facing the anode diffusion region 43 in the gate diffusion region 44 and the cathode diffusion region 45 are described. By changing the shapes of 44b and 45a, current concentration at the central portion in the first direction of the chip is alleviated.

  In FIG. 12, the pattern of the anode diffusion region 43 on the first photothyristor 42a side has an arcuate shape in which the side 43b facing the gate diffusion region 44 is depressed in the center. Similarly, the pattern of the gate diffusion region 44 and the cathode diffusion region 45 has an arcuate shape in which the side 44b and the side 45a facing the anode diffusion region 43 are recessed in the central portion. However, the distance from the P gate junction surface on the side 45a of the cathode diffusion region 45 is substantially equal over the entire region in the first direction.

  By doing so, the distance between the anode diffusion region 43 and the gate diffusion region 44 / cathode diffusion region 45 is smoothly changed from the “long” at the central portion in the first direction toward the “short” at both ends. In addition, since it is greatly changed from the fifth embodiment and the sixth embodiment, when an inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / cathode diffusion region 45, the anode The current supplied from the diffusion region 43 to the gate diffusion region 44 / cathode diffusion region 45 becomes more uniform in the first direction, and the current concentration in the central portion in the first direction is alleviated.

  Therefore, the breakdown of the junction between the gate diffusion region 44 and the cathode diffusion region 45 can be prevented, the inrush current surge withstand voltage can be increased, and the current can be increased.

  The present embodiment corresponds to the case where the pattern configuration of the anode diffusion region 43 in the sixth embodiment is applied to the pattern of the gate diffusion region 44 and the cathode diffusion region 45 in the fifth embodiment. Yes. However, the present invention is not limited to the fifth embodiment, and may be applied to any one of the first to fourth embodiments.

Eighth Embodiment In the present embodiment, the tip of the chip is changed according to the position where the Au wires 48a and 48a ′ are connected to the Al electrode 43a on the anode diffusion region 43 and the Al electrode 44a on the cathode diffusion region 45. The current concentration at the central portion in the first direction is alleviated.

  FIG. 13 shows a schematic pattern diagram of the anode diffusion region 43, the gate diffusion region 44, and the cathode diffusion region 45 on the first photothyristor 42a side in the pattern layout shown in FIG. Here, the pattern of the anode diffusion region 43, the gate diffusion region 44, and the cathode diffusion region 45 in the present embodiment has the same pattern as the pattern shown in FIG. 5 in the first embodiment. Therefore, the current concentrated in the central portion in the first direction of the cathode diffusion region 45 can be distributed to the both side walls 50b and 50c of the notch 50, and the current concentration in the central portion in the first direction of the cathode diffusion region 45 can be achieved. Can be relaxed.

  Furthermore, in the present embodiment, a line segment passing through the center in the first direction and parallel to the line segment DD ′ (see FIG. 1) in the chip of the N-type silicon substrate 41 is defined as a chip center line CL. When the shortest distance among the distances from the chip center line CL to both end faces 45b, 45c of the cathode diffusion region 45 is L, the distance from the chip center line CL is L / 2, and the chip center line CL Consider parallel line segments GG ′ and line segments HH ′. Then, the Al electrode 43a (see FIG. 1) on the anode diffusion region 43 is placed on the lead frame T1 (see FIG. 1) at the intersection position of the line segment GG ′ and the line segment HH ′ in the anode diffusion region 43. Metal balls 53a and 53b for Au wire 48a to be wire-bonded are formed. Similarly, an Al electrode 44a (see FIG. 1) on the cathode diffusion region 45 is connected to the lead frame T2 (see FIG. 1) at the intersection between the line segment GG ′ and the line segment HH ′ in the cathode diffusion region 45. The metal balls 54a and 54b for the Au wire 48a 'to be wire-bonded are formed.

  That is, in the present embodiment, the connection of the anode diffusion region 43 to the lead frame T1 and the connection of the cathode diffusion region 45 to the lead frame T2 are connected from the chip center line CL on both sides of the chip center line CL to L. This is done at two locations at a distance of / 2.

  Therefore, according to the present embodiment, the current supply position from the lead frame T1 to the anode diffusion region 43 and the current outflow position from the cathode diffusion region 45 to the lead frame T2 are determined on the chip center line CL. It is possible to disperse the chip center lines CL on two sides at an equal distance of L / 2 from the chip center line CL.

  That is, in the present embodiment, a rectangular notch 50 is formed in the first direction central portion of the side 45 a in the cathode diffusion region 45, and the cathode diffusion region 45 is formed in the first direction central portion. In addition to distributing the concentrated current to both side walls 50b and 50c of the cutout portion 50, the current supply position to the anode diffusion region 43 and the current outflow position from the cathode diffusion region 45 are determined in the first direction. It is made to disperse | distribute to two places of the distance of L / 2 from a center part. Therefore, when an inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / cathode diffusion region 45, the current supplied from the anode diffusion region 43 to the gate diffusion region 44 / cathode diffusion region 45 is Concentration in the central portion in the first direction can be further prevented, and current concentration in the central portion in the first direction can be further alleviated.

  In the present embodiment, ball bonding has been described as an example, but the same applies to wedge bonding.

  In the present embodiment, the anode diffusion region 43 is connected to the lead frame T1 and the cathode diffusion region 45 is connected to the lead frame T2 from the chip center line CL on both sides of the chip center line CL. The case where the configuration performed at two locations at a distance of 2 is applied to the first embodiment has been described as an example. However, the present invention is not limited to this, and may be applied to any of the second to seventh embodiments.

Ninth Embodiment This embodiment is a light spot coupler using a bidirectional photothyristor chip according to any one of the first embodiment to the eighth embodiment, and the light spot coupler. It relates to SSR using.

  FIG. 14 shows a circuit configuration of the SSR in the present embodiment. The SSR in the present embodiment is obtained by omitting the main thyristor 4 in the conventional SSR having the configuration shown in FIG. 15 in order to reduce the number of parts, for example. Therefore, in FIG. 14, the same members as those in the SSR shown in FIG.

  As the bidirectional photothyristor 2 for optical trigger in the present embodiment, any one of the first embodiment to the eighth embodiment having a lateral PNPN element capable of achieving a high current. The bidirectional photothyristor chip in the embodiment is used. Therefore, the light ignition coupler 3 composed of the bidirectional photothyristor 2 and the light emitting element 1 has a lateral PNPN element in order to directly control the load according to the optical signal from the light emitting element 1. Even when the photothyristor chip 2 is used, the current efficiency can be increased.

  Further, the SSR 8 in the present embodiment uses a light-current ignition coupler 3 having a high current efficiency and a snubber circuit 7 that can directly control a load in accordance with the optical signal from the light-emitting element 1. ing. Therefore, the main thyristor for controlling the load can be omitted, and an inexpensive and high-performance SSR 8 with a small number of parts can be realized.

  In each of the above-described embodiments, as shown in FIGS. 1 and 2, both the first photothyristor 42a of CH1 and the second photothyristor 42b of CH2 have an anode diffusion region 43 formed by a gate diffusion region 44. Is also arranged on the center line EE ′ side.

  However, according to the present invention, the anode diffusion region 43 is not necessarily arranged on the center line E-E ′ side than the gate diffusion region 44. In both the CH1 first photothyristor 42a and the CH2 second photothyristor 42b, the gate diffusion region 44 may be disposed closer to the center line E-E 'than the anode diffusion region 43.

  In this case as well, as in the case of the bidirectional photothyristor chip shown in FIGS. 1 and 2, by setting the distance X between the dicing surface on the outermost periphery of the chip and the gate diffusion region 44 within 400 μm, for example, Sometimes, minority carriers generated on the CH1 side are collected on the dicing surface on the CH1 side before moving to the CH2 side. Therefore, even without the Schottky barrier diode and the channel isolation region, the commutation characteristics can be greatly improved.

  In each of the above-described embodiments, the pattern of the anode diffusion region 43, the gate diffusion region 44, and the cathode diffusion region 45 on the first photothyristor 42a side is described. This is the same as the one photothyristor 42a side.

As described above, the bidirectional photothyristor chip of the present invention is
Provided on the surface of one semiconductor chip is a first photothyristor portion 42a and a second photothyristor portion 42b that are formed apart from each other,
Each of the photothyristor portions 42a and 42b extends in one direction and has an anode diffusion region 43 having one conductivity type of N type or P type, and a substrate having the other conductivity type of N type or P type. 41, a gate diffusion region 44 having the one conductivity type opposite to the anode diffusion region 43, a gate diffusion region 44 formed in the gate diffusion region 44 opposite to the anode diffusion region 43 and the other conductivity type. A PNPN portion including a cathode diffusion region 45 having
At least one of two sides 43b and 44b facing each other in the anode diffusion region 43 and the gate diffusion region 44 and a side 45a facing the anode diffusion region 43 in the cathode diffusion region 45. The planar shape of one side is such that the current supplied from the anode diffusion region 43 toward the gate diffusion region 44 and the cathode diffusion region 45 is the center of the one direction in which the anode diffusion region 43 extends. It is characterized by a shape that eases concentration on the part.

  According to the above configuration, the current supplied from the anode diffusion region 43 toward the gate diffusion region 44 and the cathode diffusion region 45 can be reduced from being concentrated in the central portion in the one direction. That is, when a surge current, which is an inrush current, flows between the anode diffusion region 43 and the gate diffusion region 44 / the cathode diffusion region 45, the current is reduced from being concentrated in the central portion in the one direction. be able to.

  Therefore, according to the present invention, the breakdown of the gate diffusion region 44 / the cathode diffusion region 45 can be prevented to increase the inrush current surge withstand voltage, and the bidirectional photothyristor chip having the lateral structure PNPN element can be improved. The current efficiency can be improved by increasing the current.

In the bidirectional photothyristor chip of one embodiment,
The planar shape of the first side 45a facing the anode diffusion region 43 in the cathode diffusion region 45 is such that the first side 45a facing the anode diffusion region 43 in the gate diffusion region 44 is from the first side 44b. The distance to the side 45a in the other direction orthogonal to the one direction is such that the distance in the central portion of the one direction is maximized.

  According to this embodiment, the distance from the second side 44b of the gate diffusion region 44 to the first side 45a of the cathode diffusion region 45 is maximized at the central portion in the one direction. ing. Therefore, when an inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / the cathode diffusion region 45, the anode diffusion region 43 supplies the gate diffusion region 44 / the cathode diffusion region 45. Part of the current concentrated in the central part in the one direction is the side part where the distance from the second side 44b to the first side 45a is closer than the central part in the one direction. The current concentration at the central part in the one direction is relaxed.

  As a result, the junction breakdown of the gate diffusion region 44 / the cathode diffusion region 45 is prevented, and the inrush current surge withstand voltage can be increased.

In the bidirectional photothyristor chip of one embodiment,
The cathode diffusion region 45 is divided into two at the central portion in the one direction, and the division surfaces 52a and 52b facing each other are spaced apart from each other on the second side of the gate diffusion region 44. An inclination is provided so as to decrease in accordance with the distance in the other direction from the side 44b.

  According to this embodiment, the two divided surfaces 52a and 52b facing each other in the cathode diffusion region 45 divided into two at the central portion in the one direction are on the second side of the gate diffusion region 44. An inclination that opens toward the side of 44b is provided. Therefore, when an inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / the cathode diffusion region 45, the gate diffusion region 44 / the cathode diffusion region 45 is located at the center of the one direction. The concentrated current can be dispersed so as to spread in the region on the second side 44b side of the gate diffusion region 44 in the divided surfaces 52a and 52b, so that the current concentration can be reduced.

In the bidirectional photothyristor chip of one embodiment,
The planar shape of the first side 45a in the cathode diffusion region 45 is such that the distance from the second side 44b of the gate diffusion region 44 to the other direction in the central portion in the one direction is the one direction. The central part has an arcuate shape that is recessed so as to be longer than both ends.

  According to this embodiment, the distance from the second side 44b of the gate diffusion region 44 in the first side 45a of the cathode diffusion region 45 is maximum at the central portion in the one direction. ing. Therefore, when an inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / the cathode diffusion region 45, the anode diffusion region 43 supplies the gate diffusion region 44 / the cathode diffusion region 45. Part of the current concentrated in the central portion in the one direction is applied to the both end portions of the cathode diffusion region 45 that are short from the second side 44b of the gate diffusion region 44. The current concentration can be relaxed by spreading so as to spread.

In the bidirectional photothyristor chip of one embodiment,
The planar shape of the second side 44b in the gate diffusion region 44 is such that the distance from the anode diffusion region 43 to the other direction at the central portion in the one direction is longer than both end portions in the one direction. , The central part has a concave arc shape,
The other of the arc-shaped first side 45a in which the central portion in the cathode diffusion region 45 is depressed and the arc-shaped second side 44b in which the central portion in the gate diffusion region 44 is depressed. The distance in the direction is equal over the entire area in the one direction.

  According to this embodiment, the planar shape of the second side edge 44b in the gate diffusion region 44 is an arc shape with the central portion in the one direction being depressed, and the cathode diffusion region 45 has the shape described above. The distance between the arcuate first side 45a and the second side 44b having a depressed central portion is equal over the entire area in the one direction. Therefore, when an inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / the cathode diffusion region 45, the anode diffusion region 43 supplies the gate diffusion region 44 / the cathode diffusion region 45. Current is substantially uniform in the one direction, and current concentration in the central portion in the one direction is alleviated.

In the bidirectional photothyristor chip of one embodiment,
The planar shape of the third side 44 b facing the anode diffusion region 43 in the gate diffusion region 44 is from the fourth side facing the anode diffusion region 43 in the cathode diffusion region 45. The central portion protrudes in an arc shape so that the distance in the other direction orthogonal to the one direction is longer than both end portions in the central portion in the one direction.

  According to this embodiment, the distance from the anode diffusion region 43 in the third side 44b facing the anode diffusion region 43 of the gate diffusion region 44 is minimum at the central portion in the one direction. It has become. Therefore, when an inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / the cathode diffusion region 45, the anode diffusion region 43 supplies the gate diffusion region 44 / the cathode diffusion region 45. The current that is applied is concentrated in the central portion in the one direction that is closer to the anode diffusion region 43. A part of the current concentrated in the central portion in the first direction flows toward the both end portions where the distance from the gate diffusion region 44 in the cathode diffusion region 45 is short. As a result, current concentration at the central portion in the one direction is alleviated.

In the bidirectional photothyristor chip of one embodiment,
The planar shape of the fifth side 43 b facing the gate diffusion region 44 in the anode diffusion region 43 is from the sixth side facing the anode diffusion region 43 in the gate diffusion region 44. The center part has an arcuate shape in which the center part is recessed so that the distance in the other direction is longer than both end parts in the center part in the one direction.

  According to this embodiment, the distance from the sixth side of the gate diffusion region 44 in the fifth side 43b of the anode diffusion region 43 is maximized at the central portion in the one direction. Yes. Therefore, when an inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / the cathode diffusion region 45, the current is supplied from the anode diffusion region 43 to the gate diffusion region 44 / the cathode diffusion region 45. Current is substantially uniform in the one direction, and current concentration at the center in the one direction is alleviated.

In the bidirectional photothyristor chip of one embodiment,
Set a chip center line LC passing through the center of the one direction in the semiconductor chip and extending to the other,
L is the shortest distance among the distances from the tip center line LC to both end faces of the cathode diffusion region 45;
A first line segment GG ′ and a second line segment H− that are parallel to the chip center line LC and are separated from the chip center line LC by a distance L / 2 in the one direction. When H 'is set,
The crossing position of the first line segment GG ′ and the second line segment HH ′ in the anode diffusion region 43 is set to the tip of the wire when wire bonding is performed to the anode diffusion region 43. While the connection position to connect
The crossing position of the first line segment GG ′ and the second line segment HH ′ in the cathode diffusion region 45 is the tip of the wire when wire bonding is performed to the cathode diffusion region 45. Is the connection position to connect.

  According to this embodiment, the wire connection position when wire bonding is performed on the anode diffusion region 43 is set to a position separated from the center in the one direction by a distance L / 2. On the other hand, the wire connection position when performing wire bonding to the cathode diffusion region 45 is a position that is separated from the center in the one direction by a distance L / 2. Therefore, the current supply position through the wire to the anode diffusion region 43 and the current outflow position through the wire to the cathode diffusion region 45 are dispersed at two equidistant locations from the center in the one direction. Can do.

  That is, in the present embodiment, when an inrush current flows between the anode diffusion region 43 and the gate diffusion region 44 / the cathode diffusion region 45, the anode diffusion region 43 and the gate diffusion region 44 / The current supplied to the cathode diffusion region 45 can be prevented from being concentrated in the central portion in the one direction, and the current concentration in the central portion in the one direction can be further reduced.

The light spot coupler of the present invention is
It is characterized by comprising the bidirectional photothyristor chip of the present invention and an LED.

  According to the above configuration, a bidirectional photothyristor chip having a lateral PNPN element capable of increasing the current is used. Therefore, according to the present light ignition coupler, even when a bidirectional photothyristor chip having a lateral PNPN element is used in order to directly control the load according to the optical signal from the LED, It becomes possible to increase current efficiency.

The SSR of the present invention is
The present invention is characterized in that it comprises the light spot coupler of the present invention and a snubber circuit.

  According to the above configuration, the light ignition coupler that enables the load to be efficiently controlled directly according to the optical signal from the LED is used. Therefore, the main thyristor for controlling the load can be omitted, and an inexpensive and high-performance SSR with a small number of parts can be realized.

1 ... Light emitting element (LED),
2. Bidirectional photothyristor,
3 ... Light-on-light coupler,
7 ... snubber circuit,
41 ... N-type silicon substrate 42a ... first photothyristor 42b ... second photothyristor 43 ... P-type anode diffusion region 43a, 44a, 47a ... Al electrode 43b ... side 44 of anode diffusion region ... P-type gate diffusion region 44b ... Side 45 of gate diffusion region ... N-type cathode diffusion region 45a ... side 46 of cathode diffusion region ... P-type gate resistance region 47 ... High concentration N-type diffusion regions 48a, 48b, 48a ', 48b' ... Au wire T1, T2 ... lead frame 49 ... minority carrier 50 ... notch 50a ... center wall 50b, 50c of notch ... both side walls 51a of notch ... first cathode diffusion region 51b ... second cathode diffusion region 52a, 52b ... end face 53a, 53b, 54a, 54b ... Metal balls for Au wire

Claims (5)

A first photothyristor portion and a second photothyristor portion formed on the surface of one semiconductor chip so as to be separated from each other;
Each of the photothyristor sections includes an anode diffusion region extending in one direction and having one conductivity type of N type or P type, a substrate having the other conductivity type of N type or P type, and the anode A PNPN portion including a gate diffusion region having the one conductivity type facing the diffusion region, and a cathode diffusion region formed in the gate diffusion region facing the anode diffusion region and having the other conductivity type Have
The planar shape of at least one of the two sides opposite to each other in the anode diffusion region and the gate diffusion region and the side opposite to the anode diffusion region in the cathode diffusion region is: The current supplied from the anode diffusion region toward the gate diffusion region and the cathode diffusion region has a shape that relaxes concentration in the central portion of the one direction that is the extending direction of the anode diffusion region. A bidirectional photothyristor chip characterized by The bidirectional photothyristor chip according to claim 1,
The planar shape of the first side opposite to the anode diffusion region in the cathode diffusion region is the one from the second side opposite to the anode diffusion region to the first side in the gate diffusion region. A bidirectional photothyristor chip characterized in that the distance to another direction orthogonal to the direction is maximized at the central portion in the one direction. The bidirectional photothyristor chip according to claim 2,
The cathode diffusion region is divided into two at the central portion in the one direction, and the division surfaces facing each other have an interval between the division surfaces in the other direction from the second side of the gate diffusion region. 2. A bidirectional photothyristor chip characterized in that an inclination is provided so as to become smaller according to the distance. The bidirectional photothyristor chip according to claim 2,
The planar shape of the first side in the cathode diffusion region is such that the distance from the second side of the gate diffusion region in the central portion in the one direction to the other direction is more than the both ends in the one direction. A bidirectional photothyristor chip, characterized in that the center portion has an arcuate shape that is recessed so as to be long. A light spot coupler comprising a bidirectional photothyristor chip according to any one of claims 1 to 4 and a light emitting diode;
Solid state relay, which is composed of a snubber circuit.

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