A thyristor drive circuit and thyristor chip

Abstract

The present invention belongs to the technical field of semiconductor devices, and provides a thyristor drive circuit and a thyristor chip, wherein the control end of the thyristor drive circuit is a control electrode of the thyristor device, the first electrode of the thyristor device is used as the output end of the thyristor drive circuit, the second electrode of the thyristor device is connected with the cathode of a Zener diode as the power input end of the thyristor drive circuit, the anode of the Zener diode is connected with the cathode of the diode as the compensation signal end of the thyristor drive circuit, and the anode of the diode is used as the ground end of the thyristor drive circuit, thereby providing a thyristor drive circuit with a built-in DC function, and solving the problem of the single function of the current thyristor device.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a thyristor drive circuit and a thyristor chip. Background Art

[0002] Silicon controlled rectifier (SCR) is a high-power electrical component, also known as thyristor, which has the advantages of small size, high efficiency and long life. The current thyristor structures mainly include full plane, single boss, double boss, etc. Its optimization direction is mainly to reduce high temperature leakage, improve voltage change rate and adjust dynamic current when shutting down.

[0003] However, the current thyristor devices are still single thyristors as a whole, and their equivalent circuits can be composed of 8 transistors, which has the problem of single function. Summary of the invention

[0004] The purpose of the present invention is to provide a thyristor drive circuit and a thyristor chip, aiming to solve the problem that the current thyristor device has a single function.

[0005] A thyristor drive circuit provided by the present invention comprises: a thyristor device, a Zener diode and a diode; the control electrode of the thyristor device is the control end of the thyristor drive circuit, the first electrode of the thyristor device serves as the output end of the thyristor drive circuit, the second electrode of the thyristor device and the cathode of the Zener diode are connected together as the power input end of the thyristor drive circuit, the anode of the Zener diode and the cathode of the diode are connected together as the compensation signal end of the thyristor drive circuit, and the anode of the diode serves as the ground end of the thyristor drive circuit.

[0006] Optionally, the thyristor driving circuit further includes a signal compensation circuit, and the signal compensation circuit is arranged between the compensation signal terminal and the anode of the Zener diode.

[0007] Optionally, the signal compensation circuit includes a first resistor and a first capacitor; the first end of the first capacitor is connected to the anode of the Zener diode, the second end of the first capacitor is connected to the first end of the first resistor, and the second end of the first resistor is connected to the compensation signal end.

[0008] Optionally, the thyristor device is a bidirectional thyristor.

[0009] Optionally, the structure of the thyristor device is any one of a full-plane structure, a single-boss structure and a double-boss structure.

[0010] Optionally, the Zener diode includes a substrate, a well region is formed in the substrate, a first doping region and a second doping region with different doping types are formed in the well region, the well region, the first doping region and the second doping region are exposed to the surface of the substrate, the first doping region and the second doping region are arranged laterally and the first doping region and the second doping region are connected, and the connecting area of ​​the first doping region and the second doping region constitutes a pn junction of the Zener diode.

[0011] Optionally, the first doped region includes a first doped body region and a first doped diffusion region laterally connected to the first doped body region, and the second doped region includes a second doped body region and a second doped diffusion region laterally connected to the second doped body region; wherein the first doped diffusion region and the second doped diffusion region are laterally connected, and the connecting area of ​​the first doped diffusion region and the second doped diffusion region constitutes a pn junction of the Zener diode.

[0012] Optionally, the Zener diode is a temperature compensated Zener diode.

[0013] An embodiment of the present application further provides a thyristor chip, comprising a package body and a thyristor drive circuit as described in any one of the above items, wherein the thyristor drive circuit is packaged in the package body.

[0014] Optionally, the thyristor chip includes a main electrode pin, a secondary electrode pin, a control pin, a virtual ground pin and a signal compensation pin; wherein the main electrode pin is connected to the output end of the thyristor drive circuit, the secondary electrode pin is connected to the power input end of the thyristor drive circuit, the control pin is connected to the control end of the thyristor drive circuit, the virtual ground pin is connected to the ground end of the thyristor drive circuit, and the signal compensation pin is connected to the compensation signal end of the thyristor drive circuit.

[0015] In the thyristor drive circuit and thyristor chip provided by the present invention, the control end of the thyristor drive circuit is achieved through the control electrode of the thyristor device, the first electrode of the thyristor device serves as the output end of the thyristor drive circuit, the second electrode of the thyristor device and the cathode of the Zener diode are connected together as the power input end of the thyristor drive circuit, the anode of the Zener diode and the cathode of the diode are connected together as the compensation signal end of the thyristor drive circuit, and the anode of the diode serves as the grounding end of the thyristor drive circuit, thereby providing a thyristor drive circuit with a built-in DC function, solving the problem of the single function of the current thyristor device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the circuit structure of a thyristor drive circuit provided in one embodiment of the present application;

[0017] Figure 2 A schematic diagram of the circuit structure of a thyristor drive circuit provided in another embodiment of the present application;

[0018] Figure 3 A schematic diagram of the circuit structure of a thyristor drive circuit provided in another embodiment of the present application;

[0019] Figure 4 , 5 , 6 are three structures of the thyristor device provided in the embodiments of the present application;

[0020] Figure 7 , Figure 8 A schematic diagram of the structure of a Zener diode provided in an embodiment of the present application;

[0021] Fig. 9 A structural schematic diagram of a thyristor chip is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0023] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0024] See also Figure 1 As shown, the thyristor drive circuit in this embodiment includes: a thyristor device T, a Zener diode Z and a diode D, the control electrode of the thyristor device T is the control end G of the thyristor drive circuit 80, the first electrode of the thyristor device T serves as the output end A of the thyristor drive circuit 80, the second electrode of the thyristor device T and the cathode of the Zener diode Z are connected together as the power input end K of the thyristor drive circuit 80, the anode of the Zener diode Z and the cathode of the diode D are connected together as the compensation signal end Comp of the thyristor drive circuit 80, and the anode of the diode D serves as the ground end GND of the thyristor drive circuit 80.

[0025] In this embodiment, the power input terminal K of the thyristor driving circuit 80 is used to receive a power signal, the compensation signal terminal Comp is used to receive a compensation signal, and the control terminal G is used to receive a control signal. Specifically, when the thyristor driving circuit 80 is working, a control signal is input to the control terminal G to control the conduction or shutdown of the thyristor device T. For example, when the thyristor device T is a bidirectional thyristor, no matter whether a forward voltage or a reverse voltage is applied to the control terminal G, and no matter whether the trigger signal input to the control terminal G is forward or reverse, the thyristor device T can be triggered to turn on.

[0026] In one embodiment, the first end of the thyristor device T serves as the main electrode T2, and the second end of the thyristor device T serves as the secondary electrode. The thyristor device has the following four triggering modes:

[0027] When the voltage applied by the main electrode T2 to the secondary electrode T1 is a positive voltage, the control terminal G also applies a positive trigger signal to the secondary electrode T1. After the bidirectional thyristor is triggered and turned on, the current flows from T2 to T1.

[0028] (2) If the main electrode T2 is still applied with a forward voltage and the trigger signal is changed to a reverse signal, then after the bidirectional thyristor is triggered and turned on, the direction of the on-state current is still from the main electrode T2 to the secondary electrode T1.

[0029] (3) A reverse voltage U12 is applied between the main electrode T2 and the secondary electrode T1, and a forward trigger signal is input. After the bidirectional thyristor is turned on, the current flows from T1 to T2.

[0030] (4) A reverse voltage U12 is still applied between the main electrode T2 and the secondary electrode T1, and a reverse trigger signal is input. After the bidirectional thyristor is turned on, the on-state current still flows from T1 to T2.

[0031] Since the thyristor device T includes multiple PN junctions, for example, from its cathode (i.e., the second electrode) to its anode (the first electrode), it can be regarded as an NPN transistor (BG1) and a PNP transistor (BG2), and the two transistors overlap. Therefore, in a specific application, the thyristor device T can output a large anode current or anode voltage at its anode (i.e., the first electrode) by adding a small current or voltage to its control electrode. For example, a forward voltage Ea is added between the anode and cathode (i.e., the second electrode) of the thyristor device T, and a forward trigger signal is input between its control electrode and cathode, and BG1 will generate A base current Ib is amplified by BG1 to generate a collector current IC1 amplified by β1 times. Since the collector of BG1 is connected to the base of BG2, the collector current IC1 is amplified by β2 times to generate the collector current IC2 and then output to the base of BG1, thereby continuously circulating feedback, so that the thyristor device T can be kept in the on state even when the trigger signal disappears. Only when the power supply Ea is disconnected or Ea is reduced so that the collector current in BG1 and BG2 is less than the minimum value to maintain conduction, can the thyristor device T be turned off. Among them, the amplification factors β1 and β2 depend on the performance parameters of the thyristor device T.

[0032] In one embodiment, see Figure 2 As shown, the thyristor driving circuit 80 further includes a signal compensation circuit 81, and the signal compensation circuit 81 is arranged between the compensation signal terminal Comp and the anode of the Zener diode Z.

[0033] In this embodiment, the signal compensation circuit 81 may be a resistor, a capacitor, or a combination thereof.

[0034] In one embodiment, see Figure 3 As shown, the signal compensation circuit 81 includes a first resistor R1 and a first capacitor C1; the first end of the first capacitor C1 is connected to the anode of the Zener diode Z, the second end of the first capacitor C1 is connected to the first end of the first resistor R1, and the second end of the first resistor R1 is connected to the compensation signal end Comp.

[0035] In one embodiment, the thyristor device T is a bidirectional thyristor.

[0036] In one embodiment, see Figure 4 , Figure 5 as well as Figure 6 As shown, the structure of the thyristor device T is any one of a full-plane structure, a single-convex platform structure and a double-convex platform structure.

[0037] Figure 4 The schematic diagram of the thyristor with double boss structure is shown in Figure 1. Figure 5It is a schematic diagram of a thyristor with a single boss structure. Figure 6 It is a schematic diagram of a full-plane thyristor, wherein P represents a semiconductor doped with a P-type element, N represents a semiconductor doped with an N-type element, Anode represents an anode electrode, Cathode represents a cathode electrode, Gate represents a gate electrode, Oxyde represents an oxide layer, Passivation represents an insulating layer, Metalizationg represents a metal layer, and Glass represents glass filling.

[0038] Generally, the breakdown voltage of a thyristor device is determined by the doping concentration of the substrate layer. Silicon substrates with different doping concentrations are used as the substrate layer according to their breakdown voltages. The higher the doping concentration of the silicon substrate, the lower the breakdown voltage of the prepared thyristor.

[0039] Figure 7 is a schematic diagram of the structure of a Zener diode provided in an embodiment of the present invention, see Figure 7 As shown, the Zener diode Z in this embodiment includes a substrate 201, a well region 202 is formed in the substrate 201, a first doping region 21 and a second doping region 22 with different doping types are formed in the well region 202, the well region 202, the first doping region 21 and the second doping region 22 are exposed to the surface of the substrate 201, the first doping region 21 and the second doping region 22 are arranged laterally and the first doping region 21 and the second doping region 22 are connected, and the connecting area of ​​the first doping region 21 and the second doping region 22 constitutes the pn junction of the Zener diode.

[0040] Specifically, in this embodiment, the doping types of the first doping region 21 and the second doping region 22 are different, so at the junction of the first doping region 21 and the second doping region 22, a lateral pn junction is formed due to the contact of the two doping types. The doping type of the first doping region 21 used in this embodiment is, for example, p-type, and the doping type of the second doping region 22 is, for example, n-type. Correspondingly, the p-type first doping region 21 can be connected to a positive electrode, and the n-type second doping region 22 can be connected to a negative electrode. It should be noted that the doping types of the first doping region 21 and the second doping region 22 can also be n-type and p-type, respectively, then the electrode connected to the corresponding n-type first doping region 21 is the negative electrode, and the p-type second doping region 22 is the positive electrode.

[0041] In addition, since the breakdown voltage of the Zener diode in this embodiment depends on the lateral pn junction in the connecting area of ​​the first doped region 21 and the second doped region 22, and the conductive path of the lateral pn junction does not need to pass through the well region 202, there is no special requirement for the doping type of the well region 202. Furthermore, the well region 202 can also be arbitrarily selected as n-type or p-type.

[0042] It is worth noting that since the Zener diode in this embodiment forms a lateral pn junction, there is no vertical stacking structure of the p region and the n region in the vertical pn junction. Furthermore, in the preparation process, it is not necessary to use an additional mask to form a vertically stacked pn junction. The specific reasons will be explained in detail in the preparation method and will not be repeated here. Therefore, the Zener diode with a lateral pn junction of the present invention can save mask costs and preparation costs.

[0043] As a preferred solution, the first doped region 21 includes a first doped body region 210 and a first doped diffusion region 211 laterally connected to the first doped body region 210, and the second doped region 22 includes a second doped body region 220 and a second doped diffusion region 221 laterally connected to the second doped body region 220;

[0044] The first doped diffusion region 211 and the second doped diffusion region 221 are laterally connected, and the connecting region of the first doped diffusion region 211 and the second doped diffusion region 221 constitutes a pn junction of the Zener diode.

[0045] In one embodiment, the first doped diffusion region 211 is formed by diffusion of doped ions in the first doped body region 210 , and the second doped diffusion region 221 is formed by diffusion of doped ions in the second doped body region 220 .

[0046] Specifically, in this embodiment, the first doped region 21 and the second doped region 22 are not directly formed in one process step, but the first doped body region 210 and the second doped body region 220 are first formed in the substrate 201, and then the first doped body region 210 is diffused to form the first doped diffusion region 211, and the second doped body region 220 is diffused to form the second doped diffusion region 221 by using a diffusion process. Therefore, the first doped diffusion region 211 and the second doped diffusion region 221 can be regarded as extensions of the first doped body region 210 and the second doped body region 220, respectively, so that by controlling the process conditions for forming the first doped diffusion region 211 and the second doped diffusion region 221, the depletion region and concentration distribution of the pn junction can be controlled, thereby adjusting the breakdown voltage of the Zener diode.

[0047] In one embodiment, the reverse breakdown voltage of the Zener diode increases with the increase of the sum of the lateral lengths of the first doped diffusion region 211 and the second doped diffusion region 221; wherein the sum of the lateral lengths is the sum of the lengths of the first doped diffusion region 211 and the second doped diffusion region 221 along the lateral diffusion direction.

[0048] There are two possible breakdown situations in the Zener diode. The first is Zener breakdown. When the doping concentration of the pn junction is high, the width of its depletion region is correspondingly small, and the built-in electric field strength is large. Therefore, only a small reverse voltage is applied to obtain a large electric field, which destroys the covalent bonds of neutral atoms in the depletion region, thereby converting valence electrons into free electrons, exciting a large number of carriers, and forming Zener breakdown; the second is avalanche breakdown. When the doping concentration of the pn junction is low, a large reverse voltage is applied, so that the carriers obtain greater kinetic energy, and the high-energy carriers collide with neutral atoms, thereby destroying the covalent bonds and releasing carriers. The newly generated carriers will also repeat the above situation, thereby forming an avalanche growth of carriers, and the reverse current increases sharply, resulting in avalanche breakdown. It can be seen that the different widths of the pn junction depletion region will lead to different breakdowns. Zener diode is another name for voltage regulator diode, not just voltage regulator diode that works on the Zener breakdown principle. However, generally speaking, the voltage regulator diodes used in integrated circuits mostly use the Zener breakdown principle to obtain a relatively small breakdown voltage.

[0049] In this embodiment, the breakdown mode of the Zener diode is, for example, Zener breakdown. The diffusion process is used to diffuse the doped ions in the first doped body region 210 and the second doped body region 220 to form the first doped diffusion region 211 and the second doped diffusion region 221. The doped ion concentration distribution of the first doped diffusion region 211 and the second doped diffusion region 221 will be limited by their lateral diffusion length, that is, the sum of the lengths of the first doped diffusion region 211 and the second doped diffusion region 221 along the lateral diffusion direction. In this embodiment, the sum of the lengths of the first doped diffusion region 211 and the second doped diffusion region 221 along the lateral diffusion direction actually refers to the lateral spacing between the first doped body region 210 and the second doped body region 220. The reason is that, under the condition that the total concentration of the doped ions remains unchanged, the longer the diffusion distance of the doped ions, the lower the ion concentration obtained by diffusion, and then the excessively long diffusion region makes the doped ion concentrations on both sides of the pn junction formed after diffusion low, and also causes the width of the depletion region of the pn junction to increase. Obviously, when the depletion region increases, the built-in electric field strength in the depletion region decreases accordingly, resulting in a corresponding increase in the external voltage required to achieve Zener breakdown. It can be seen that the reverse breakdown voltage of the Zener diode in this embodiment increases with the increase in the sum of the lateral lengths of the first doped diffusion region 211 and the second doped diffusion region 221. And, in order to prevent the Zener diode from failing to undergo Zener breakdown due to the sum of the lateral lengths being too large, the sum of the lateral lengths of the first doped diffusion region 211 and the second doped diffusion region 221 in this embodiment is less than or equal to 0.4 μm to ensure that the Zener diode in this embodiment can work normally.

[0050] In one embodiment, the second doping region 22 is a ring-shaped region and laterally surrounds the first doping region 21 .

[0051] Specifically, Figure 7 The cross-sectional structure of the Zener diode in this embodiment is only schematically shown in FIG. 1 . In order to more clearly and comprehensively illustrate the structure of the Zener diode in this embodiment, this embodiment also provides Figure 8 , Figure 8 is a top view schematic diagram of the Zener diode structure in the first embodiment of the present invention, Figure 8 The schematic diagram shows that the second doping region 22 is an annular region and surrounds the first doping region 21. At this time, since the connecting region between the first doping region 21 and the second doping region 22 is also an annular region, the first doping diffusion region 211 and the second doping diffusion region 221 are also annular regions, and thus the second doping region 22 surrounds the second doping diffusion region 221, the second doping diffusion region 221 surrounds the first doping diffusion region 211, and the first doping diffusion region 211 surrounds the first doping region 21. Since the connecting area between the first doping region 21 and the second doping region 22 is increased, the pn junction cross-sectional area of ​​the Zener diode is effectively increased.

[0052] In one embodiment, the Zener diode is a temperature compensated Zener diode.

[0053] The present application also provides a thyristor chip, see Fig. 9 As shown, the thyristor chip in this embodiment includes a package body 82 and a thyristor drive circuit as described in any one of the above items, and the thyristor drive circuit is packaged in the package body 82.

[0054] In one embodiment, the thyristor chip can be divided into three types according to its packaging form: metal package thyristor, plastic package thyristor and ceramic package thyristor. Among them, metal package thyristor is divided into bolt type, flat plate type, round shell type and other types; plastic package thyristor is divided into two types with heat sink and without heat sink.

[0055] In one embodiment, the thyristor chip includes a main electrode pin A, a secondary electrode pin K, a control pin G, a virtual ground pin GND and a signal compensation pin Comp; wherein the main electrode pin A is connected to the output terminal A of the thyristor drive circuit, the secondary electrode pin K is connected to the power input terminal K of the thyristor drive circuit, the control pin G is connected to the control terminal G of the thyristor drive circuit, the virtual ground pin GND is connected to the ground terminal GND of the thyristor drive circuit, and the signal compensation pin Comp is connected to the compensation signal terminal Comp of the thyristor drive circuit.

[0056] In one embodiment, the thyristor chip is packaged in any one of a TO-220 package structure, a TO-3P package structure, and a TO-263 package structure.

[0057] In the thyristor drive circuit and thyristor chip provided by the present invention, the control end of the thyristor drive circuit is achieved through the control electrode of the thyristor device, the first electrode of the thyristor device serves as the output end of the thyristor drive circuit, the second electrode of the thyristor device and the cathode of the Zener diode are connected together as the power input end of the thyristor drive circuit, the anode of the Zener diode and the cathode of the diode are connected together as the compensation signal end of the thyristor drive circuit, and the anode of the diode serves as the grounding end of the thyristor drive circuit, thereby providing a thyristor drive circuit with a built-in DC function, solving the problem of the single function of the current thyristor device.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A thyristor drive circuit, characterized in that: include: Thyristor devices, Zener diodes and diodes; The control electrode of the thyristor device is the control end of the thyristor drive circuit, the first electrode of the thyristor device is used as the output end of the thyristor drive circuit, the second electrode of the thyristor device and the cathode of the Zener diode are connected together as the power input end of the thyristor drive circuit, the anode of the Zener diode and the cathode of the diode are connected together as the compensation signal end of the thyristor drive circuit, and the anode of the diode is used as the ground end of the thyristor drive circuit; The thyristor driving circuit also includes a signal compensation circuit, and the signal compensation circuit is arranged between the compensation signal terminal and the anode of the Zener diode.

2. The thyristor drive circuit according to claim 1, characterized in that: The signal compensation circuit includes a first resistor and a first capacitor; the first end of the first capacitor is connected to the anode of the Zener diode, the second end of the first capacitor is connected to the first end of the first resistor, and the second end of the first resistor is connected to the compensation signal end.

3. The thyristor drive circuit according to claim 1, characterized in that: The thyristor device is a bidirectional thyristor.

4. The thyristor drive circuit according to claim 1, characterized in that: The structure of the thyristor device is any one of a full-plane structure, a single-convex platform structure and a double-convex platform structure.

5. The thyristor drive circuit according to claim 1, characterized in that: The Zener diode includes a substrate, a well region is formed in the substrate, a first doping region and a second doping region with different doping types are formed in the well region, the well region, the first doping region and the second doping region are exposed to the surface of the substrate, the first doping region and the second doping region are arranged laterally and the first doping region and the second doping region are connected, and the connecting area of ​​the first doping region and the second doping region constitutes a pn junction of the Zener diode.

6. The thyristor drive circuit according to claim 5, characterized in that: The first doped region includes a first doped body region and a first doped diffusion region laterally connected to the first doped body region, and the second doped region includes a second doped body region and a second doped diffusion region laterally connected to the second doped body region; wherein the first doped diffusion region and the second doped diffusion region are laterally connected, and the connecting area of ​​the first doped diffusion region and the second doped diffusion region constitutes a pn junction of the Zener diode.

7. The thyristor drive circuit according to claim 1, characterized in that: The Zener diode is a temperature compensated Zener diode.

8. A thyristor chip, characterized in that: It comprises a packaging body and the thyristor drive circuit according to any one of claims 1 to 7, wherein the thyristor drive circuit is packaged in the packaging body.

9. The thyristor chip according to claim 8, characterized in that: The thyristor chip includes a main electrode pin, a secondary electrode pin, a control pin, a virtual ground pin and a signal compensation pin; wherein the main electrode pin is connected to the output end of the thyristor drive circuit, the secondary electrode pin is connected to the power input end of the thyristor drive circuit, the control pin is connected to the control end of the thyristor drive circuit, the virtual ground pin is connected to the ground end of the thyristor drive circuit, and the signal compensation pin is connected to the compensation signal end of the thyristor drive circuit.

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