Solid state relay and method of manufacturing the same

Abstract

The application discloses a solid-state relay and a manufacturing method thereof, and comprises the following steps: S1, a power component manufacturing process; S2, a printed board component manufacturing process; S3, combining and packaging the power component manufactured through the step S1 and the printed board component manufactured through the step S2 to form an integral whole; the manufacturing method of the solid-state relay provided by the application improves the production efficiency and reduces the cost by separately processing and combining the power component and the printed board component; the solid-state relay provided by the application is reliable and durable according to the above manufacturing method; the solid-state relay provided by the application is provided with a built-in driving circuit, is suitable for AC power grid terminal control, has reliable performance guarantee, and can effectively reduce the conducted disturbance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of relays, in particular to a solid-state relay and a manufacturing method thereof. BACKGROUND

[0002] A solid-state relay is a non-contact switch composed of microelectronic circuits, discrete electronic devices and power electronic power devices. An optical coupling or a pulse signal is used for isolation between a control end and a load end. A small control signal is used for the input end of the solid-state relay to directly drive a large current load.

[0003] Generally, an alternating current solid-state relay uses a silicon controlled rectifier as a switching device, so that the solid-state relay has a very high switching life.

[0004] However, most of the existing manufacturing methods of solid-state relays use a liquid epoxy potting adhesive to encapsulate. The sealing property, heat conductivity and reliability of the solid-state relay manufactured by this method are limited to a certain extent, and the manufacturing cost is relatively high and the production efficiency is relatively low, which is not suitable for mass production.

[0005] The above information disclosed in this section is only for understanding the background of the inventive concept of the present disclosure, and therefore, the above information can include information that does not constitute the prior art. SUMMARY

[0006] The purpose of the present application is to provide a manufacturing method of a solid-state relay, which improves production efficiency and reduces cost by separately processing and combining a power assembly and a printed board assembly.

[0007] To achieve the above purpose, the solution of the present application is as follows: a manufacturing method of a solid-state relay, comprising the following steps:

[0008] S1: a preparation process of a power assembly;

[0009] S1.1: mounting a silicon controlled rectifier on a DBC board in an electrode direction and welding;

[0010] S1.2: aluminum wire bonding of the silicon controlled rectifier;

[0011] S1.3: laminating the DBC board and a bottom plate;

[0012] S1.4: placing gate lead-out sheets and main electrode output terminals corresponding to the silicon controlled rectifier on the DBC board and welding, and welding the DBC board and the bottom plate;

[0013] S1.5: nesting an outer shell around the bottom plate;

[0014] S1.6: sealing the bottom plate and the outer shell with a sealing adhesive;

[0015] S1.7: pouring silicon gel on the surface of the silicon controlled rectifier;

[0016] S2: manufacturing process of the printed board assembly;

[0017] S2.1: tin plating on the pads of the PCB board;

[0018] S2.2: placing the photovoltaic output optocoupler, NPN transistor, PNP transistor, diode, voltage stabilizing diode and resistor on the corresponding pads of the PCB board and reflow soldering;

[0019] S2.3: manually soldering the light emitting diode D1 and the MOS tube;

[0020] S2.4: soldering the corresponding input and output terminals;

[0021] S3: combining the power assembly manufactured by step S1 and the printed board assembly manufactured by step S2 to form a whole;

[0022] S3.1: aligning the hole positions on the printed board assembly with the gate lead-out sheet and the main electrode output terminal of the power assembly;

[0023] S3.2: pressing the printed board assembly tightly on the shell,

[0024] S3.3: soldering the pins of the gate lead-out sheet and the main electrode output terminal on the corresponding pads of the printed board assembly;

[0025] S3.4: pouring epoxy resin on the surface of the printed board assembly;

[0026] S3.5: aligning the cover plate with the shell, clamping the buckle on the cover plate in the corresponding clamping groove of the shell, and finally installing the gasket and screw on the input and output terminals to form a whole.

[0027] Further, the steps S1.1, S1.4 and S1.5 are performed in a vacuum sintering furnace environment.

[0028] Further, the silicon controlled rectifier in step S1 is a bare chip.

[0029] Further, in step S2.1, silk screen printing is used to brush tin paste for tin plating.

[0030] Further, in step S2.3, the light emitting diode and the MOS tube are plug-in components, and the plastic package shell of the light emitting diode and the MOS tube is flatly attached to the bottom layer of the printed board.

[0031] The application also aims to provide a solid-state relay manufactured by the above method, which has reliable performance and can effectively reduce conduction disturbance.

[0032] A solid-state relay comprises a driving circuit for an AC power grid, the driving circuit comprising: a photovoltaic MOSFET response loop, a thyristor self-locking loop, a discharge loop and an AC power grid output port; the output port is connected to the AC power grid and a load loop; the photovoltaic MOSFET response loop is used to turn on the AC power grid output port when a light driving signal is received and the voltage between the output ports is less than the start-up voltage of the thyristor self-locking loop; the thyristor self-locking loop is used to turn on the output port when the voltage between the output ports is greater than or equal to the start-up voltage of the thyristor self-locking loop; and the discharge loop is used to discharge the photovoltaic MOSFET response loop to turn off the photovoltaic MOSFET response loop after receiving a light driving signal.

[0033] Further, the photovoltaic MOSFET response loop comprises a photovoltaic output optocoupler U1, resistors R9 and R10, MOS tubes F1 and F2; the AC power grid output port comprises a first output port and a second output port of the AC power grid; the photovoltaic output optocoupler U1 is connected to a control circuit to obtain a light driving signal; the anode of the photovoltaic output optocoupler U1 is connected to the resistors R9 and R10; the resistor R9 is connected to the gate of the MOS tube F1, and the resistor R10 is connected to the gate of the MOS tube F2; and the cathode of the photovoltaic output optocoupler U1 is connected to the source of the MOS tube F1 and the drain of the MOS tube F2.

[0034] Furthermore, the thyristor self-locking circuit includes: an NPN transistor Q1, a diode D2, unidirectional thyristors Q3 and Q4, and resistors R3, R4, R5, R6, and R7; the anode of the photovoltaic output optocoupler U1 is connected to the collector of the NPN transistor Q1; the cathode of the photovoltaic output optocoupler U1 is connected to the resistor R3, the anode of the diode D2, and the emitter of the NPN transistor Q1; the cathode of the unidirectional thyristor Q3 is connected to the anode of the unidirectional thyristor Q4, the first output port, and resistors R4 and R6; the anode of the unidirectional thyristor Q3 is connected to the second... The output port, the cathode of the unidirectional thyristor Q4, and the resistors R5 and R7 are connected together; the gate of the unidirectional thyristor Q3 is connected to the resistor R6 and the drain of the MOS transistor F1; the gate of the unidirectional thyristor Q4 is connected to the two terminals of the resistor R7 and the source of the MOS transistor F2; the resistors R4 and R5 are respectively connected to the resistor R3, the cathode of the diode D2, and the base of the NPN transistor Q1; the first output port is connected to the drain of the MOS transistor F1 through the resistor R6, and the second output port is connected to the source of the MOS transistor F2 through the resistor R7.

[0035] Furthermore, the discharge circuit includes: a PNP transistor Q2, a diode D6, and resistors R2 and R13; the base of the PNP transistor Q2 is connected to the anode of the diode D6, the resistors R13 and R2, and the anode of the photovoltaic output optocoupler U1; the emitter of the PNP transistor Q2 is connected to the cathode of the diode D6, the resistor R13, and the collector of the NPN transistor Q1; the collector of the PNP transistor Q2 is connected to the resistor R2 and the cathode of the photovoltaic output optocoupler U1.

[0036] Furthermore, it also includes a filtering circuit, which is used to cancel conducted interference caused by current jumps in the photovoltaic MOSFET response circuit, the thyristor self-locking circuit and the discharge circuit.

[0037] Furthermore, the filtering circuit includes: Zener diodes D3 and D4; the anode of Zener diode D3 is connected to the first output port; the cathode of Zener diode D3 is connected to the drain of MOSFET F1; the anode of Zener diode D4 is connected to the second output port; the cathode of Zener diode D4 is connected to the source of MOSFET F2; the filtering circuit further includes: a bidirectional TVS diode T1; one end of the bidirectional TVS diode T1 is connected to the gate of the unidirectional thyristor Q3, and the other end of the bidirectional TVS diode T1... The filter circuit further includes: a varistor MOV1; one end of the varistor MOV1 is connected to the cathode of the unidirectional thyristor Q3, and the other end of the varistor MOV1 is connected to the cathode of the unidirectional thyristor Q4; the filter circuit further includes: a capacitor C2 and a resistor R14; one end of the capacitor C2 is connected to the cathode of the unidirectional thyristor Q3; the other end of the capacitor C2 is connected to the resistor R14; and the resistor R14 is connected to the cathode of the unidirectional thyristor Q4.

[0038] Furthermore, the solid-state relay also includes a control circuit, which includes an input port, a control photovoltaic circuit, and an indicator circuit; the input port receives external voltage action; the control photovoltaic circuit is used to provide a light drive signal to the photovoltaic MOSFET response circuit in response to the external voltage action; and the indicator circuit is used to indicate the working status.

[0039] Furthermore, the input port includes a first input port and a second input port; the control photovoltaic circuit includes a diode D5, a capacitor C1, and resistors R1, R8, and R12; the indicator light circuit includes a light-emitting diode D1 and a resistor R11; the anode of the diode D5 is connected to the first input port; the cathode of the diode D5 is connected to the anode of the light-emitting diode D1, the resistor R12, the capacitor C1, and the anode of the photovoltaic output optocoupler U1; the cathode of the light-emitting diode D1 is connected to the resistor R11; the resistor R12 is connected to the capacitor C1, the cathode of the photovoltaic output optocoupler U1, and the resistor R1; the resistor R1 is connected to the resistor R8; and the second input port is connected to the resistors R8 and R11.

[0040] After adopting the above scheme, the gain effect of the present invention is as follows:

[0041] The solid-state relay manufacturing method provided by this invention improves production efficiency and reduces costs by separately processing and combining power components and printed circuit board components. In particular, it uses silicone gel for filling. Although silicone gel has excellent properties in all aspects, there is very little research on its application in solid-state relay potting, and there is almost no relevant literature.

[0042] Silicone gel has stable physicochemical properties, is not significantly affected by temperature, and can be used over a wide temperature range. It exhibits excellent electrical insulation properties and resistance to high and low temperatures (-50℃ to 200℃). The system is colorless and transparent, and forms a semi-solid state after curing. It has good adhesion and sealing properties to many substrates. When used as a potting material, it allows for easy observation of the internal structure of the potted component and has excellent resistance to thermal cycling.

[0043] Organosilicon gel can physically adhere to the surfaces of most common electronic devices or other materials without the need to spray adhesive onto the bonding surface before curing. No byproducts are generated during the curing process, and there is no shrinkage. It can be cured at room temperature or by heating, and the curing speed increases with higher temperatures. Compared to liquid epoxy resin, which requires baking, this invention improves production efficiency, is suitable for mass production, and has good self-healing ability. The gel is not easy to crack after being stretched by external forces, and it also plays a role in waterproofing and moisture protection without affecting the use effect.

[0044] Due to its high purity and exceptional softness, silicone gel can protect highly sensitive devices, ensuring that electronic components can function normally even under conditions of significant temperature variations and strong vibrations. In contrast, liquid hydrogen peroxide is hard and not shockproof. Encapsulating electronic components with transparent silicone gel not only provides shock and waterproof protection but also allows for visualization of the components and the detection of faults using probes, enabling replacement. Damaged silicone gel can be re-encapsulated for repair. Solid-state relays manufactured using this method exhibit excellent sealing, thermal conductivity, and reliability, and silicone gel is inexpensive, resulting in relatively low manufacturing costs.

[0045] Secondly, the solid-state relay provided by this invention has a built-in drive circuit, suitable for AC power grid terminal control. The drive circuit uses a photovoltaic MOSFET response circuit to connect the output port of the AC power grid when the AC power grid does not meet the triggering condition of the thyristor self-locking circuit. It also uses a thyristor self-locking circuit to connect the output port of the AC power grid in conjunction with the photovoltaic MOSFET response circuit when the triggering condition of the thyristor self-locking circuit is met. Furthermore, a MOSFET discharge circuit is used for rapid discharge to quickly turn off the output port of the AC power grid. This allows the voltage division of R3, R4, and R5 to regulate the opening voltage of the thyristor self-locking circuit, i.e., the zero-crossing voltage of the power grid load. This solid-state relay has guaranteed reliability and can effectively reduce conducted interference. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the manufacturing steps of the solid-state relay provided by the present invention;

[0047] Figure 2 This is an exploded view of the overall assembly of the power component and printed circuit board assembly provided by the present invention.

[0048] Figure 3 This is a schematic diagram of the power component assembly provided by the present invention;

[0049] Figure 4 This is a schematic diagram of side A of the PCB board provided by the present invention;

[0050] Figure 5 This is a schematic diagram of the B side of the PCB board provided by the present invention;

[0051] Figure 6 This is a schematic diagram of the overall structure of the solid-state relay provided by the present invention;

[0052] Figure 7 This is a schematic diagram of the driving circuit and control circuit provided by the present invention. Detailed Implementation

[0053] In the following description, embodiments of the invention will be described more fully. The invention may have various embodiments, and adjustments and changes may be made therein. However, it should be understood that there is no intention to limit the scope of the invention to the specific embodiments disclosed herein, but rather the invention should be understood to cover all modifications, equivalents, and / or alternatives falling within the spirit and scope of the various embodiments of the invention.

[0054] The following is in conjunction with the appendix Figures 1-7 The present invention will be described in detail.

[0055] This invention provides a method for manufacturing a solid-state relay, comprising the following steps:

[0056] S1: Manufacturing process of power component 001;

[0057] S2: Manufacturing process of printed circuit board assembly 002;

[0058] S3: The power component 001 obtained in step S1 and the printed circuit board assembly 002 obtained in step S2 are combined and packaged into a whole.

[0059] Specifically, step S1 includes:

[0060] S1.1: Mount the thyristors Q3 and Q4 onto the DBC board 0011 according to the electrode direction and then solder them;

[0061] S1.2: Bond the thyristors Q3 and Q4 with aluminum wire;

[0062] S1.3: Attach the DBC board 0011 to the base plate 0012;

[0063] S1.4: Place and solder the gate leads and main electrode output terminals corresponding to the thyristors Q3 and Q4 on the DBC board 0011;

[0064] S1.5: Weld the DBC board 0011 to the base plate 0012;

[0065] S1.6: Nest the outer shell 0013 around the base plate 0012;

[0066] S1.7: Use sealant to seal the base plate 0012 and the outer casing 0013;

[0067] S1.8: Encapsulate the surfaces of the silicon controlled rectifiers Q3 and Q4 with silicone gel;

[0068] Specifically, step S2 includes:

[0069] S2.1: Apply solder to pad 0021 on the PCB board;

[0070] S2.2: Place the photovoltaic output optocoupler U1, NPN transistor Q1, PNP transistor Q2, diodes D2 and D6, Zener diodes D3 and D4, and resistors R2, R3, R6, R7, R9, R10, and R13 onto the corresponding pads on PCB board 0021 for reflow soldering.

[0071] S2.3: Manually solder the LED D1, MOSFETs F1 and F2;

[0072] S2.4: Weld the corresponding input and output terminals;

[0073] Specifically, step S3 includes:

[0074] S3.1: Align the printed circuit board assembly 002 with the gate lead and main electrode output terminal of the power assembly 001;

[0075] S3.2: Press down to make the printed circuit board assembly 002 press tightly onto the housing 0013.

[0076] S3.3: Press the pins of the gate lead-out piece and the main electrode output terminal onto the corresponding pads of the printed circuit board assembly 002 for soldering;

[0077] S3.4: Encapsulate and cover the surface of the printed circuit board assembly 002 with a layer of epoxy resin;

[0078] S3.5: Align the cover plate 003 with the housing 0013, snap the buckle 0031 on the cover plate 003 into the corresponding slot 00131 on the housing 0013, and finally install the gasket 0032 and screw 0033 on the input and output terminals to secure them together to form a whole.

[0079] Specifically, steps S1.1, S1.4 and S1.5 are performed in a vacuum sintering furnace environment.

[0080] Specifically, in step S1, the thyristors Q3 and Q4 are bare dies.

[0081] Specifically, in step S2.1, screen printing is used to apply tin.

[0082] Specifically, in step S2.3, the light-emitting diode D1, the MOSFETs F1 and F2 are connectors, and the plastic encapsulation shells of the light-emitting diode D1, the MOSFETs F1 and F2 are flush with the bottom layer of the printed circuit board.

[0083] The present invention also provides a solid-state relay, which is obtained by the above-described method for manufacturing a solid-state relay.

[0084] This invention provides a drive circuit for reducing electromagnetic interference for an AC power grid, comprising: a photovoltaic MOSFET response circuit, a thyristor latching circuit, a discharge circuit, a filter circuit, and an output AC power grid port; the AC power grid port is connected to the AC power grid and a load circuit; the photovoltaic MOSFET response circuit is used to turn on the output port when a light-driven signal is received and the voltage between the AC power grid ports is less than or equal to the turn-on voltage of the thyristor latching circuit; the thyristor latching circuit is used to cooperate with the photovoltaic MOSFET response circuit to turn on the output port when the voltage between the AC power grid ports is greater than the turn-on voltage of the thyristor latching circuit; the discharge circuit is used to discharge the photovoltaic MOSFET response circuit to turn it off when the voltage between the AC power grid ports is greater than the turn-on voltage of the thyristor latching circuit; and the filter circuit is used to cancel conducted interference caused by current jumps in the photovoltaic MOSFET response circuit, the thyristor latching circuit, and the discharge circuit.

[0085] Specifically, the AC ports include a first AC mains port and a second AC mains port.

[0086] Specifically, the photovoltaic MOSFET response circuit includes: a photovoltaic output optocoupler U1, resistors R9 and R10, and MOSFETs F1 and F2. The anode of the photovoltaic output optocoupler U1 is connected to the resistors R9 and R10. Resistor R9 is connected to the gate of MOSFET F1. Resistor R10 is connected to the gate of MOSFET F2. The cathode of the photovoltaic output optocoupler U1 is connected to the source of MOSFET F1 and the drain of MOSFET F2. The drain of MOSFET F1 is connected to the first AC mains port. The source of MOSFET F2 is connected to the second AC mains port.

[0087] Specifically, the thyristor self-locking circuit includes: an NPN transistor Q1, a diode D2, unidirectional thyristors Q3 and Q4, resistors R3, R4, R5, R6, and R7. The anode of the photovoltaic output optocoupler U1 is connected to the collector of the NPN transistor Q1. The cathode of the photovoltaic output optocoupler U1 is connected to resistor R3, the anode of diode D2, and the emitter of NPN transistor Q1. The cathode of unidirectional thyristor Q3 is connected to the anode of unidirectional thyristor Q4. The first AC mains port is connected to resistors R4 and R6. The anode of the unidirectional thyristor Q3 is connected to AC port 2, the cathode of the unidirectional thyristor Q4, and resistors R5 and R7. The gate of the unidirectional thyristor Q3 is connected to resistor R6 and the drain of MOSFET F1. The gate of the unidirectional thyristor Q4 is connected to resistor R7 and the source of MOSFET F2. Resistors R4 and R5 are connected to resistor R3, the cathode of diode D2, and the base of NPN transistor Q1.

[0088] Specifically, the discharge circuit includes: a PNP transistor Q2, a diode D6, and resistors R2 and R13; the base of the PNP transistor Q2 is connected to the anode of the diode D6, resistors R13 and R2, and the anode of the photovoltaic output optocoupler U1; the emitter of the PNP transistor Q2 is connected to the cathode of the diode D6, resistor R13, and the collector of the NPN transistor Q1; and the collector of the PNP transistor Q2 is connected to resistor R2 and the cathode of the photovoltaic output optocoupler U1.

[0089] Specifically, it also includes a filtering circuit, which is used to cancel conducted interference caused by current jumps in the photovoltaic MOSFET response circuit, the thyristor self-locking circuit, and the discharge circuit.

[0090] Specifically, the filter circuit includes Zener diodes D3 and D4. The anode of Zener diode D3 is connected to AC mains output port 1, and the cathode of Zener diode D3 is connected to the drain of MOSFET F2. The anode of Zener diode D4 is connected to AC mains output port 2, and the cathode of Zener diode D4 is connected to the drain of MOSFET F2.

[0091] Specifically, the filtering circuit also includes a bidirectional TVS diode T1, one end of which is connected to the gate of a unidirectional thyristor Q3, and the other end of which is connected to the gate of a unidirectional thyristor Q4.

[0092] Specifically, the filter circuit also includes a varistor MOV1, one end of which is connected to the cathode of the unidirectional thyristor Q3, and the other end of which is connected to the cathode of the unidirectional thyristor Q4.

[0093] Specifically, the filter circuit also includes a capacitor C2 and a resistor R14. One end of the capacitor C2 is connected to the cathode of the unidirectional thyristor Q3, and the other end of the capacitor C2 is connected to the resistor R14. The resistor R14 is connected to the cathode of the unidirectional thyristor Q4.

[0094] The present invention also provides a solid-state relay 000, comprising a housing 100, a PCB board 200, a DBC board 300, a control circuit 400, and a driving circuit 500 as described in any one of claims 1-9. In the driving circuit 500, a photovoltaic output optocoupler U1, MOSFETs F1 and F2, unidirectional thyristors Q3 and Q4, an NPN transistor Q1, a PNP transistor Q2, diodes D2 and D6, Zener diodes D3 and D4, a bidirectional TVS diode T1, a varistor MOV1, a capacitor C2, and resistors R2, R3, R4, R5, R6, R7, R9, R10, R13, and R14 are electrically connected through the PCB board and / or the DBC board.

[0095] Specifically, the control circuit includes an input port, a control photovoltaic circuit, and an indicator light circuit; the input port receives external voltage input; the control photovoltaic circuit provides a light drive signal to the photovoltaic MOSFET response circuit in response to the external voltage input; and the indicator light circuit indicates the operating status.

[0096] Specifically, the input ports include input port 3 and input port 4; the control photovoltaic circuit includes diode D5, capacitor C1, resistors R1, R8, and R12; the indicator light circuit includes light-emitting diode D1 and resistor R11; the anode of diode D5 is connected to input port 3, the cathode of diode D5 is connected to the anode of light-emitting diode D1, resistor R12, capacitor C1, and the anode of photovoltaic output optocoupler U1, the cathode of light-emitting diode D1 is connected to resistor R11, resistor R12 is connected to capacitor C1, the cathode of photovoltaic output optocoupler U1, and resistor R1, resistor R1 is connected to resistor R8, and input port 4 is connected to resistors R8 and R11.

[0097] Solid-state relay working principle:

[0098] The grid voltage is a sinusoidal AC voltage, which is connected to both ends of the drive module. That is, the voltage across the drive circuit is also a sinusoidal AC voltage that changes with time.

[0099] The AC grid is connected to both ends of the AC grid output port. The AC grid provides sinusoidal AC power. When the input port of the control circuit receives external voltage, the control photovoltaic circuit and indicator light circuit are turned on, and the photovoltaic output optocoupler U1 is turned on. At this time, the other end of the photovoltaic output optocoupler U1 will generate an 8V AC voltage.

[0100] When the voltage between the ports of the AC power grid changes to less than the turn-on voltage of the thyristor self-locking circuit, i.e., the zero-crossing voltage: the base potential of the NPN transistor Q1 in the thyristor self-locking circuit is insufficient to turn on the transistor Q1, i.e., the transistor Q1 is turned off. As a result, the gate voltages of MOSFETs F1 and F2 in the photovoltaic MOSFET response circuit meet the requirements for MOSFETs F1 and F2 to turn on. The junction voltages at the source and drain ends of MOSFETs F1 and F2 are small and cannot trigger the unidirectional thyristors Q3 and Q4 to turn on. Thyristors Q3 and Q4 are turned off. At this time, the loop current of the driving circuit is provided by the photovoltaic MOSFET response circuit, i.e., when the thyristor is turned off, the photovoltaic MOSFET response circuit ensures that the loop current does not momentarily become zero.

[0101] When the voltage between the AC grid ports changes to a value greater than or equal to the turn-on voltage of the thyristor self-locking circuit (i.e., zero-crossing voltage): the base potential of the NPN transistor Q1 in the thyristor self-locking circuit satisfies the condition that transistor Q1 enters the conduction state, i.e., transistor Q1 is turned on. This causes the gate voltage of MOSFETs F1 and F2 in the photovoltaic MOSFET response circuit to be insufficient for MOSFETs F1 and F2 to turn on. The junction voltage at the source and drain ends of MOSFETs F1 and F2 is sufficient to trigger the unidirectional thyristors Q3 and Q4 to turn on. When thyristors Q3 and Q4 are turned on, the loop current of the driving circuit is provided by the thyristor self-locking circuit, i.e., the photovoltaic MOSFET response circuit does not provide loop current when the thyristor is turned on.

[0102] In summary, the output voltage of the AC grid is a sinusoidal AC current, which changes periodically to be less than the zero-crossing voltage and greater than or equal to the AC voltage. The photovoltaic MOSFET response circuit and the thyristor self-locking circuit also provide loop current alternately periodically. Compared with only the thyristor self-locking circuit providing current, the loop current changes more smoothly with the AC grid voltage.

[0103] In this invention, resistors R3, R4, and R5 in the thyristor self-locking circuit act as zero-crossing resistors, determining the level of the thyristor self-locking circuit's turn-on voltage, i.e., the zero-crossing voltage. Resistors R6 and R7 control the magnitude of the thyristor's conduction current. This can prevent the solid-state relay from jumping due to interference when it conducts at the zero-crossing point, thereby reducing conducted electromagnetic interference.

[0104] The diode D5 in the control circuit protects the control circuit from reverse connection.

[0105] The function of the TVS transistor T1 in the photovoltaic MOSFET response circuit is that when there is a surge voltage at the output terminals and the voltage exceeds the operating voltage of the TVS, the TVS will activate, triggering the thyristor at the output terminals to conduct, thus preventing the thyristor from being damaged due to overvoltage and providing protection.

[0106] The function of the varistor MOV1 in the filter circuit is to activate when there is a surge voltage at the output terminals, and the surge voltage exceeds the operating voltage of the varistor. The varistor absorbs the energy of the surge voltage and converts it into heat, thus preventing overvoltage breakdown of the forward and reverse modules and providing protection. The capacitor C2 and resistor R14 are connected in series to form an RC absorption circuit, which protects the unidirectional thyristors Q3 and Q4 in the unidirectional thyristor circuit. In order to suppress the impact of the instantaneous voltage change dV / dt on the devices in the circuit, in an inductive load, if the magnetic flux of the inductive load is not zero at the moment the switching device is turned off, a self-induced electromotive force will be generated according to Lenz's law, which stores energy in the external magnetic field. For simplicity, an RC absorption circuit is used to dissipate this energy as heat.

[0107] The rapid discharge of resistor R13 and diode D6 in the discharge circuit enables the circuit to be turned off quickly.

[0108] In the thyristor self-locking circuit, diode D2 serves as reverse protection for transistor Q1, and resistor R3 acts as a voltage divider for transistor Q1 in the circuit.

[0109] In summary, the driving circuit provided by this invention uses a photovoltaic MOSFET response loop to connect the output port of the AC power grid when the AC power grid does not meet the triggering conditions of the thyristor self-locking circuit, thus providing loop current. The driving circuit also uses a thyristor self-locking circuit to connect the output port of the AC power grid when the AC power grid meets the triggering conditions of the thyristor self-locking circuit, in conjunction with the photovoltaic MOSFET response loop, thus providing loop current. Furthermore, the driving circuit uses a MOSFET discharge loop for rapid discharge to quickly turn off the output port of the AC power grid. It also uses a filter loop to reduce electromagnetic interference. The solid-state relay provided by this invention has the advantages of the above driving circuits and can be used in applications with EMI requirements. The solid-state relay also uses a control loop to cooperate with the above driving circuits, ensuring safety and reliability. Finally, the driving circuit and solid-state relay provided by this invention utilize the voltage division of resistors R3, R4, and R5 to adjust the turn-on voltage (zero-crossing voltage) of the thyristor self-locking circuit.

[0110] In summary, the solid-state relay manufacturing method provided by this invention improves production efficiency and reduces costs through the separate processing and combination of power components and printed circuit board components; the solid-state relay provided by this invention, manufactured according to the above method, is reliable and durable; the solid-state relay provided by this invention has built-in control circuit and drive circuit, and is suitable for AC power grid terminal control; the drive circuit provided by this invention uses a photovoltaic MOSFET response circuit to achieve conduction and connection to the AC power grid output port when the AC power grid does not meet the triggering condition of the thyristor self-locking circuit; the drive circuit provided by this invention uses a thyristor self-locking circuit to achieve conduction and connection to the AC power grid output port in conjunction with the photovoltaic MOSFET response circuit when the AC power grid meets the triggering condition of the thyristor self-locking circuit; the drive circuit provided by this invention uses a MOSFET discharge circuit for rapid discharge to quickly turn off the AC power grid output port; the drive circuit provided by this invention uses a filter circuit to reduce electromagnetic interference; the drive circuit and solid-state relay provided by this invention utilize the voltage division of R3, R4 and R5 to regulate the turn-on voltage of the thyristor self-locking circuit, i.e., the zero-crossing voltage of the power grid load.

[0111] The above description is only a preferred embodiment of the present invention and is not intended to limit the design of this case. All equivalent changes made based on the key design features of this case shall fall within the protection scope of this case.

Claims

1. A method for manufacturing a solid-state relay, characterized in that, Includes the following steps: S1: Manufacturing process of power components; S1.1: The thyristor is mounted on the DBC board according to the electrode direction and then soldered. S1.2: Bond the thyristor with aluminum wire; S1.3: Attach the DBC board to the base plate; S1.4: Place and solder the gate lead and main electrode output terminal corresponding to the thyristor on the DBC board, and solder the DBC board to the base plate at the same time; S1.5: An outer shell is nested around the base plate; S1.6: Use sealant to seal the base plate and the outer shell; S1.7: Encapsulate the surface of the silicon controlled rectifier with silicone gel; S2: Manufacturing process of printed circuit board assembly; S2.1: Apply solder to the pads on the PCB board; S2.2: Place the photovoltaic output optocoupler, NPN transistor, PNP transistor, diode, Zener diode and resistor on the corresponding pads on the PCB board and perform reflow soldering; S2.3: Manually solder the LED D1 and the MOSFET; S2.4: Weld the corresponding input and output terminals; S3: The power component obtained in step S1 and the printed circuit board assembly obtained in step S2 are combined and packaged into a whole. S3.1: Align the holes on the printed circuit board assembly with the gate leads and main electrode output terminals of the corresponding power components; S3.2: Press down to press the printed circuit board assembly onto the housing and tighten it. S3.3: Press the pins of the gate lead-out piece and the main electrode output terminal onto the corresponding pads of the printed circuit board assembly for soldering; S3.4: Encapsulate and cover the surface of the printed circuit board assembly with a layer of epoxy resin; S3.5: Align the cover plate with the housing, snap the clips on the cover plate into the corresponding slots on the housing, and finally install washers and screws on the input and output terminals to form a whole.

2. The method for manufacturing a solid-state relay as described in claim 1, characterized in that, Steps S1.1, S1.4, and S1.5 are performed in a vacuum sintering furnace environment.

3. The method for manufacturing a solid-state relay as described in claim 1, characterized in that, In step S1, the thyristor is a bare die.

4. The method for manufacturing a solid-state relay as described in claim 1, characterized in that, In step S2.1, screen printing is used to apply solder paste.

5. A method for manufacturing a solid-state relay as described in claim 1, characterized in that, In step S2.3, the light-emitting diode and the MOSFET are connectors, and the plastic casings of the light-emitting diode and the MOSFET are flush with the bottom layer of the printed circuit board.

6. A solid-state relay, characterized in that, A solid-state relay manufactured by any one of claims 1-5 comprises a drive circuit for use with an AC power grid. The drive circuit includes a photovoltaic MOSFET response circuit, a thyristor latching circuit, a discharge circuit, and an AC power grid output port. The output port is connected to the AC power grid and a load circuit. The photovoltaic MOSFET response circuit is used to turn on the AC power grid output port when a light-driven signal is received and the voltage between the output ports is less than the turn-on voltage of the thyristor latching circuit. The thyristor latching circuit is used to turn on the output port when the voltage between the output ports is greater than or equal to the turn-on voltage of the thyristor latching circuit. The discharge circuit is used to discharge the photovoltaic MOSFET response circuit to turn it off after receiving a light-driven signal.

7. A method for manufacturing a solid-state relay as described in claim 6, characterized in that, The photovoltaic MOSFET response circuit includes: a photovoltaic output optocoupler U1, resistors R9 and R10, and MOSFETs F1 and F2; the AC grid output port includes a first output port and a second output port of the AC grid; the photovoltaic output optocoupler U1 is connected to an external control circuit to obtain a light drive signal; the anode of the photovoltaic output optocoupler U1 is connected to the resistors R9 and R10; the resistor R9 is connected to the gate of the MOSFET F1, and the resistor R10 is connected to the gate of the MOSFET F2; the cathode of the photovoltaic output optocoupler U1 is connected to the source of the MOSFET F1 and the drain of the MOSFET F2.

8. A method for manufacturing a solid-state relay as described in claim 7, characterized in that, The thyristor self-locking circuit includes: an NPN transistor Q1, a diode D2, unidirectional thyristors Q3 and Q4, and resistors R3, R4, R5, R6, and R7; the anode of the photovoltaic output optocoupler U1 is connected to the collector of the NPN transistor Q1; the cathode of the photovoltaic output optocoupler U1 is connected to the resistor R3, the anode of the diode D2, and the emitter of the NPN transistor Q1; the cathode of the unidirectional thyristor Q3 is connected to the anode of the unidirectional thyristor Q4, the first output port, and resistors R4 and R6; the anode of the unidirectional thyristor Q3 is connected to the second output terminal. The first output port is connected to the cathode of the unidirectional thyristor Q4, and resistors R5 and R7; the gate of the unidirectional thyristor Q3 is connected to the drain of the MOS transistor F1 via resistor R6; the gate of the unidirectional thyristor Q4 is connected to the source of the MOS transistor F2 via resistor R7; resistors R4 and R5 are respectively connected to resistor R3, the cathode of the diode D2, and the base of the NPN transistor Q1; the first output port is connected to the drain of the MOS transistor F1 via resistor R6; and the second output port is connected to the source of the MOS transistor F2 via resistor R7.

9. A method for manufacturing a solid-state relay as described in claim 6, characterized in that, The discharge circuit includes: a PNP transistor Q2, a diode D6, and resistors R2 and R13; the base of the PNP transistor Q2 is connected to the anode of the diode D6, the resistors R13 and R2, and the anode of the photovoltaic output optocoupler U1; the emitter of the PNP transistor Q2 is connected to the cathode of the diode D6, the resistor R13, and the collector of the NPN transistor Q1; the collector of the PNP transistor Q2 is connected to the resistor R2 and the cathode of the photovoltaic output optocoupler U1.

10. A method for manufacturing a solid-state relay as described in claim 6, characterized in that, It also includes a filtering circuit, which is used to cancel conducted interference caused by current jumps in the photovoltaic MOSFET response circuit, the thyristor self-locking circuit and the discharge circuit.

Images