Integrated power module and electrical appliance

Abstract

The embodiment of the present specification provides a kind of integrated power module and electric equipment, the power module includes plastic package body, and the rectifying unit and control unit packaged in the plastic package body, wherein the rectifying unit is arranged on ceramic substrate, the control unit is arranged on copper substrate, the ceramic substrate is welded on the copper substrate by laminating mode;The back of the copper substrate is exposed outside the plastic package body, for connecting with radiator.Effectively reduce the overall size of module, improve the integration of power module.Reduce thermal resistance, significantly improve the heat dissipation efficiency.

Description

Technical Field

[0001] The embodiments in this specification relate to the field of semiconductor technology, and in particular to an integrated power module and electrical device. Background Technology

[0002] Currently, electromagnetic heating equipment typically employs a discrete component design, where rectifiers and switching devices are independently mounted on circuit boards. Both types of devices generate significant heat during operation, requiring separate heat sinks for each. Furthermore, sufficient high-voltage isolation distances must be maintained between the components to ensure circuit safety. These factors result in a large circuit board area and a large number of heat dissipation components, making it difficult to reduce the overall size of the device and leading to high material and assembly costs. Therefore, improving equipment integration, reducing overall size, and lowering manufacturing costs have become pressing technical challenges in this field. Utility Model Content

[0003] In view of this, embodiments of this specification provide an integrated power module and electrical device to solve the problems of low integration and insufficient heat dissipation performance of existing integrated power modules.

[0004] According to a first aspect of the embodiments of this specification, an integrated power module is provided, the power module including a plastic package, and a rectifier unit and a control unit encapsulated within the plastic package, wherein... The rectifier unit is disposed on a ceramic substrate, the control unit is disposed on a copper substrate, and the ceramic substrate is welded to the copper substrate in a stacked manner; The back side of the copper substrate is exposed outside the molding compound for connection to the heat sink.

[0005] According to a second aspect of the embodiments of this specification, an electrical device is provided, the electrical device including a main control unit and the power module described above; The main control unit is electrically connected to the power module and is used to control the operation of the electrical equipment through the power module.

[0006] One embodiment of this specification implements a compact integrated structure in the vertical direction by placing the rectifier unit on a ceramic substrate and the control unit on a copper substrate, and then stacking and soldering the ceramic substrate onto the copper substrate. This achieves integrated packaging of the two core functional units without the need for an additional printed circuit board, effectively reducing the overall size of the module and improving the integration of the power module. By exposing the back of the copper substrate outside the molding compound and using it for bonding with the heat sink, a low thermal resistance heat dissipation path is provided for the heat-generating components within the module. The heat generated by the rectifier unit can be directly conducted to the copper substrate via the ceramic substrate, and the heat generated by the control unit can also be directly conducted to the copper substrate. The heat from both substrates converges on the copper substrate and is then directly transferred to the bonded heat sink through the exposed back of the copper substrate. This avoids the thermal insulation barrier of the molding compound, greatly shortens the heat conduction path, effectively reduces thermal resistance, significantly improves heat dissipation efficiency, and ensures the reliability of the module under high-power conditions. Attached Figure Description

[0007] Figure 1 A schematic diagram of the internal planar structure of an integrated power module according to one embodiment of this specification is shown; Figure 2 A schematic diagram of the internal rear structure of an integrated power module according to one embodiment of this specification is shown. Figure 3 A schematic diagram of the rear structure of an integrated power module according to an embodiment of this specification is shown; Figure 4 A three-dimensional structural schematic diagram of an integrated power module according to an embodiment of this specification is shown; Figure 5 A device structure diagram of an electrical device provided according to an embodiment of this specification is shown.

[0008] Figure Labels 1-Molded package; 2-Ceramic substrate; 3-Copper substrate; 4-Rectifier; 5-Switch device; 6-Temperature detection unit; 7-Thermal conductive copper foil; 8-Conductive copper foil area; 9-Rectifier unit; 10-Control unit; 11-Rectifier pin; 12-Temperature sensing pin; 13-Control electrode pin; 14-Second electrode pin; 15-First electrode pin; 16-Heat dissipation hole; 17-Adapter copper foil; 18-Copper strip. Detailed Implementation

[0009] Many specific details are set forth in the following description to provide a full understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed below.

[0010] The terminology used in one or more embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of one or more embodiments of this application. The singular forms “a,” “the,” and “the” used in one or more embodiments of this application and in the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” used in one or more embodiments of this application refers to and includes any or all possible combinations of one or more associated listed items.

[0011] It should be understood that although the terms first, second, etc., may be used to describe various information in one or more embodiments of this application, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first may also be referred to as second without departing from the scope of one or more embodiments of this application, and similarly, second may also be referred to as first. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination."

[0012] First, the terms and concepts involved in one or more embodiments of this application will be explained.

[0013] Molded enclosure: A molded enclosure is a structure formed by injection molding or compression molding using encapsulation materials such as epoxy resin. It is used to isolate internal components from the external environment. The molded enclosure provides mechanical support and electrical insulation protection for the internal components, preventing external factors such as dust and moisture from affecting the internal circuitry.

[0014] Ceramic substrate: A ceramic substrate refers to a substrate with ceramic materials such as alumina, aluminum nitride, or zirconium oxide as the insulating layer, and copper foil layers fixed to its upper and lower surfaces by chemical bonding. Ceramic substrates have high thermal conductivity and excellent electrical insulation properties. In the embodiments of this specification, they can serve as the carrier substrate of the rectifier unit, and also as an insulating and thermally conductive intermediate layer connecting the copper substrate and the rectifier device. Their thickness also limits the high-voltage insulation spacing between the leads and the copper substrate. DBC board (Direct Bonded Copper) refers to a copper-clad ceramic substrate formed by directly bonding copper foil to the surface of a ceramic substrate through a high-temperature sintering process. The ceramic substrate is the DBC board.

[0015] Copper substrate: A copper substrate refers to a conductive and thermally conductive substrate made primarily of copper. Copper substrates have high electrical and thermal conductivity. In the embodiments described in this specification, they serve as the supporting substrate for the control unit and as the main heat dissipation path for the power module. Furthermore, multiple switching chips can be connected in parallel through the copper substrate.

[0016] Lamination welding: Lamination welding refers to the metallurgical bonding of two substrates by stacking them vertically with solder. In the embodiments of this specification, the ceramic substrate is laminated to the upper surface of the copper substrate by high-temperature solder, forming a vertically stacked structure with the copper substrate on the bottom and the ceramic substrate on top, which is different from the side-by-side splicing method.

[0017] Rectifier Unit: A rectifier unit is a circuit functional module formed by soldering rectifier devices onto a conductive copper foil area on the surface of a ceramic substrate. The rectifier unit converts input alternating current (AC) into direct current (DC), providing DC power to subsequent circuits. In the embodiments described in this specification, the rectifier unit is disposed on the front surface (top) of the ceramic substrate, and heat conduction is achieved between the rectifier unit and the copper substrate via thermally conductive copper foil on the back of the ceramic substrate.

[0018] Control Unit: A control unit is a circuit functional module formed by soldering switching devices onto a copper substrate. The control unit performs power switching and voltage regulation functions, converting rectified DC power into high-frequency AC power through high-frequency switching on and off. In the embodiments described in this specification, the control unit is disposed on the upper surface of the copper substrate, adjacent to the ceramic substrate on a plane.

[0019] Switching Devices / Switching Chips: Switching devices refer to power semiconductor devices that have two operating states, on and off, and can be used to control the switching on and off of circuits. In the embodiments of this specification, the switching device may be an IGBT (Insulated-Gate Bipolar Transistor) or a MOSFET (Metal Oxide Semiconductor Field Effect Transistor). When an IGBT is used, its three electrodes are the gate, collector, and emitter; when a MOSFET is used, its three electrodes are the gate, drain, and source.

[0020] Pins: Pins are conductive terminals extending outward from the plastic package, used to achieve electrical connections between internal and external circuits of the module. One end of the pin is soldered to a component or circuit inside the module, while the other end extends out of the plastic package for soldering to an external circuit board by the user. In the embodiments described in this specification, pins include rectifier pins electrically connected to the rectifier unit, control pins electrically connected to the control unit, and temperature sensing pins electrically connected to the temperature detection unit.

[0021] Heat dissipation holes: Heat dissipation holes are openings on the back of the molding compound that expose the back of the internal substrate to the outside of the molding compound. In this specification, the back of the copper substrate is exposed to the outside of the molding compound through heat dissipation holes so that it can be directly attached to the heat sink, thereby avoiding the molding compound from blocking the heat conduction path.

[0022] Thermistor: A thermistor is a resistive temperature sensor whose resistance changes with temperature. In the embodiments of this specification, the thermistor is encapsulated in a plastic package and soldered between the temperature-sensing pin and the first electrode pin of the switching device, used to sense changes in the junction temperature of the switching device. When the temperature of the switching device changes, the resistance of the thermistor changes accordingly, and the external circuit can obtain temperature information by measuring the resistance value between the temperature-sensing pin and the first electrode pin.

[0023] Adapter copper foil: Adapter copper foil refers to the copper foil area fixed on the surface of the ceramic substrate, serving as an intermediate transition connection point between the control electrode pin and the control electrode of the switching device. In the embodiments of this specification, one end of the adapter copper foil is soldered to the control electrode pin, and the other end is connected to the control electrode of the switching device through a copper tie. Its function is to buffer external stress and prevent the control electrode pin from being directly pulled by the copper tie when it deforms, thus avoiding the solder joint of the control electrode of the switching device from falling off.

[0024] With the continuous maturation of electromagnetic heating technology and the increasing market penetration of various electromagnetic heating devices, such as induction cookers and IH (Induction Heating) rice cookers, the electromagnetic heating equipment industry is facing increasingly severe cost competition pressure. Price wars for end products have become the norm, continuously squeezing profit margins, and cost control has become a core issue for the survival and development of manufacturers. At the same time, consumer demand for electromagnetic heating equipment is constantly upgrading, with increasingly clear requirements for small size, high power, and lightweight design, demanding further reduction in overall size while ensuring performance is not compromised. This industry situation makes the shortcomings of traditional technical solutions increasingly prominent, making them unable to meet the current market's dual demands for cost and performance.

[0025] In the power conversion circuits of existing electromagnetic heating equipment, a rectifier unit and a switching control unit are typically required to achieve the power conversion function. The rectifier unit converts the AC mains input into DC power, providing DC power to subsequent circuits. The switching control unit inverts DC power into high-frequency AC power and is the core actuator controlling the output power. Specifically in induction cookers, these two functional units are implemented using a rectifier bridge and an IGBT, respectively. In addition to these two main power devices, to ensure the power devices operate within a safe temperature range, temperature sensing elements such as thermistors are usually placed near the power devices to monitor their temperature rise in real time, providing a basis for over-temperature protection. The rectifier bridge, IGBT, and thermistor are all indispensable components of the induction cooker's power circuit; they must work together to ensure the normal operation and safety of the induction cooker.

[0026] In traditional designs, the rectifier bridge and IGBT are typically mounted separately on the circuit board as discrete components. Since both the rectifier bridge and IGBT are high-heat devices, generating significant heat during operation, separate heatsinks are required to ensure adequate cooling efficiency and prevent overheating damage. Furthermore, the mounting positions of the rectifier bridge, IGBT, and thermistor necessitate the provision of dedicated soldering points and wiring areas on the circuit board for each. Sufficient high-voltage isolation distances must also be maintained between the components to prevent creepage or breakdown hazards. The aforementioned traditional discrete component solution presents the following technical problems: First, because the rectifier bridge, IGBT and thermistor need to occupy independent mounting areas on the circuit board, and high voltage isolation distances need to be reserved between each component, it is difficult to reduce the circuit board area, which in turn makes the overall size of the machine large and cannot meet the market demand for miniaturization of electromagnetic heating equipment.

[0027] Secondly, the rectifier bridge and IGBTs each require independent heat sinks, resulting in a large number of heat dissipation components inside the device. These independent heat sinks not only increase material procurement costs but also complicate the internal structure, adding assembly steps and further increasing manufacturing costs. Simultaneously, the larger circuit board area directly increases the material cost of the PCB board. Combined with the multiple heat sink configuration, both overall material and assembly costs are high.

[0028] Third, the thermistor, as an independent component, is mounted separately on the circuit board and needs to be connected to the external control circuit through additional wires, which increases the wiring complexity and installation process. In addition, there is an air gap between the thermistor and the heat-generating device and thermal barrier from the circuit board medium, resulting in a lag in temperature measurement response, which affects the timeliness and accuracy of over-temperature protection.

[0029] Furthermore, when expanding the power or iterating products in electromagnetic heating equipment, traditional discrete device solutions require reselecting different rectifier bridges and IGBT devices for different power levels, and redesigning the circuit board layout and heat dissipation. This results in poor product development flexibility and scalability, and prolongs the product development cycle.

[0030] Therefore, how to improve the layout and connection structure of existing rectifier units, switch control units and temperature detection elements while ensuring the power conversion performance and reliability of electromagnetic heating equipment, so as to improve integration, reduce overall size, reduce manufacturing costs and optimize heat dissipation performance, has become an urgent technical problem to be solved in this field.

[0031] Based on this, an integrated power module and electrical device are provided in the embodiments of this specification to solve the problems of low module integration, insufficient heat dissipation performance, and poor temperature monitoring accuracy in the prior art. These will be described in detail in the following embodiments.

[0032] See Figure 1 , Figure 1 A schematic diagram of the internal planar structure of an integrated power module according to an embodiment of this specification is shown. The power module includes a plastic package, and a rectifier unit and a control unit encapsulated within the plastic package. The rectifier unit is disposed on a ceramic substrate, and the control unit is disposed on a copper substrate. The ceramic substrate is laminated onto the copper substrate. The back side of the copper substrate is exposed outside the plastic package for connection to a heat sink.

[0033] Among them, the stacked welding method refers to the metallurgical bonding of ceramic substrates and copper substrates by stacking them one on top of the other using high-temperature solder. The welding between the ceramic substrate and the copper substrate is fixed and connected by a solder layer, forming a stacked structure with the copper substrate on the bottom and the ceramic substrate on top, which is different from the side-by-side splicing method.

[0034] Exposed refers to the back of the copper substrate not being covered by the molding compound and being directly exposed to the external environment. With the back of the copper substrate exposed outside the molding compound, it can be directly bonded to the heat sink without the need for additional thermal conductive media or penetration through the molding compound layer, thus enabling direct heat conduction from the copper substrate to the heat sink.

[0035] In practical applications, the rectifier unit and the switching control unit are usually mounted separately on a PCB board as discrete components, each requiring an independent heat sink for heat dissipation. In the embodiments described in this specification, the rectifier unit and the control unit are integrated into a single molding compound, forming a single module from the two core functional units. This lays the foundation for solving the problem of low integration in existing power conversion modules. Furthermore, by placing the rectifier unit on a ceramic substrate and the control unit on a copper substrate, and then bonding the ceramic substrate to the copper substrate in a stacked manner, the heat generated by the rectifier unit on the ceramic substrate can be directly conducted to the copper substrate, and the heat generated by the control unit on the copper substrate can also be directly conducted to the same copper substrate. The heat from both substrates converges on the copper substrate and is then uniformly conducted outwards. This creates the condition that only one heat sink is needed to simultaneously meet the heat dissipation needs of both heat-generating units.

[0036] Furthermore, by exposing the back of the copper substrate outside the molding compound and using it to connect with the heat sink, a direct physical channel is provided for heat to be transferred from the copper substrate to the heat sink, avoiding the blockage of the heat conduction path by the molding compound, and providing a structural basis for solving the problem of insufficient heat dissipation performance in the prior art.

[0037] In specific implementation, such as Figure 1 As shown, the power module includes a molding compound 1, within which a ceramic substrate 2 and a copper substrate 3 are encapsulated. The ceramic substrate 2 is laminated to the upper surface of the copper substrate 3, forming a stacked structure with the copper substrate 3 at the bottom and the ceramic substrate 2 on top. A rectifier unit 9 is disposed on the ceramic substrate 2, and a control unit 10 is disposed on the copper substrate 3. The rectifier unit 9 and the control unit 10 are arranged side-by-side in the planar direction of the module. Specifically, the rectifier unit 9 is located in the left area of ​​the module, and the control unit 10 is located in the right area of ​​the module. The molding compound 1 also has multiple pins for electrical connection between the internal circuitry and the external circuitry. Multiple pins are provided on the upper and lower sides of the molding compound 1, respectively. The pin electrically connected to the rectifier unit 9 is the rectifier pin 11, and the pins electrically connected to the control unit 10 are the control electrode pin 13, the second electrode pin 14, and the first electrode pin 15.

[0038] See Figure 2 , Figure 3 and Figure 4 , Figure 2 This diagram shows a schematic internal rear structure of an integrated power module according to one embodiment of the present specification. Figure 3 A schematic diagram of the rear structure of an integrated power module according to an embodiment of this specification is shown. Figure 4 A three-dimensional structural schematic diagram of an integrated power module according to an embodiment of this specification is shown. (In conjunction with...) Figure 2 , Figure 3 and Figure 4 The back side of the copper substrate 3 is exposed outside the molding compound 1. Specifically, heat dissipation holes 16 are formed on the back side of the molding compound 1, and the back side of the copper substrate 3 is exposed outside the molding compound 1 through the heat dissipation holes 16. The exposed back side of the copper substrate 3 is used for bonding and connection with the heat sink. In some embodiments, the back side of the molding compound 1 and the back side of the copper substrate 3 are located on the same plane, so that the exposed back side of the copper substrate 3 can form a tight surface contact with the mounting surface of the heat sink, reducing contact thermal resistance and improving heat dissipation efficiency.

[0039] In some embodiments of this specification, the back side of the copper substrate being exposed outside the molding compound can be achieved in various ways. One method, as described in this embodiment, involves creating heat dissipation holes on the back side of the molding compound, allowing the back side of the copper substrate to be exposed outside the molding compound through these holes. Another method involves the molding compound itself employing a semi-encapsulated structure, meaning that the back side of the molding compound is not sealed during injection molding, allowing the back side of the copper substrate to be naturally exposed without being covered by the molding compound. Both methods achieve the effect of exposing the back side of the copper substrate and allowing it to be bonded to the heat sink.

[0040] In some embodiments of this specification, the lamination and welding between the ceramic substrate and the copper substrate can be achieved using high-temperature solder paste through a reflow soldering process.

[0041] In some embodiments of this specification, the connection between the exposed back side of the copper substrate and the heat sink can be achieved in various ways. A common method is to apply thermally conductive silicone grease or a phase-change thermally conductive material to the back of the copper substrate, and then press and fix the copper substrate to the heat sink using screws. In other embodiments, thermally conductive double-sided tape or snap-fit ​​connections can also be used to achieve a bonding connection between the copper substrate and the heat sink.

[0042] In some embodiments of this specification, the power module described above is not only applicable to induction cookers, but can also be widely used in various electromagnetic heating devices, such as household cooking appliances like IH rice cookers and electromagnetic heating pressure cookers, as well as commercial kitchen equipment like high-power commercial induction cookers. Furthermore, this power module can also be used in the field of industrial induction heating, such as the heating power supply section of industrial equipment like small metal smelting equipment and high-frequency quenching machines.

[0043] In a specific embodiment of this specification, taking an induction cooker application scenario as an example, the power module is the core power component inside the induction cooker used to convert AC mains power into high-frequency AC power to drive the coil to heat up. The power module's encapsulation is formed by injection molding using epoxy resin material, and the encapsulation completely encapsulates the internal ceramic substrate, copper substrate, rectifier unit, and control unit. The rectifier unit is formed by welding multiple rectifier diode chips to the conductive copper foil area on the surface of the ceramic substrate through conductive connecting pieces, and the back of the ceramic substrate is welded to the upper surface of the copper substrate. The control unit is formed by welding IGBT chips to the upper surface of the copper substrate, and the IGBT chips and the rectifier unit on the ceramic substrate are arranged side by side in the planar direction of the copper substrate. The back of the copper substrate is exposed outside the encapsulation body through heat dissipation holes on the back of the encapsulation body. During installation, the exposed back of the copper substrate is directly attached to an independent heat sink inside the induction cooker and fixed by applying thermal grease and tightening with screws. When the induction cooker is powered on, the rectifier unit rectifies the input 220V AC power into DC power. The IGBT chip in the control unit inverts the DC power into high-frequency AC power to supply the induction cooker's coil, causing the cookware to heat up. During this process, the heat generated by the rectifier unit is conducted to the copper substrate via the ceramic substrate, and the heat generated by the IGBT chip is also directly conducted to the same copper substrate. After the two parts of heat converge on the copper substrate, they are directly transferred to the heat sink through the exposed back of the copper substrate, and the heat sink dissipates the heat into the surrounding environment.

[0044] Based on this, by integrating the rectifier unit and control unit into the same molding compound, and placing the rectifier unit on a ceramic substrate and the control unit on a copper substrate, with the ceramic substrate stacked and soldered onto the copper substrate, the two core functional units form a compact integrated structure in the vertical direction. This achieves integrated packaging without the need for an additional PCB board, significantly improving the integration of the power module. Simultaneously, by exposing the back of the copper substrate outside the molding compound for bonding with the heat sink, a low-thermal-resistance common heat dissipation path is provided for both the rectifier unit and the control unit. Heat from the rectifier unit is conducted to the copper substrate via the ceramic substrate, and heat from the control unit is directly conducted to the same copper substrate. The heat from both substrates converges on the copper substrate and is then directly transferred to the heat sink through the exposed back, avoiding the thermal insulation barrier of the molding compound, greatly shortening the heat conduction path, effectively reducing thermal resistance, significantly improving heat dissipation efficiency, and ensuring the reliability and stability of the module under high-power conditions.

[0045] Furthermore, the rectifier unit includes a rectifier device located on the ceramic substrate, and the control unit includes a switch device located on the copper substrate; the molding compound is provided with a rectifier pin electrically connected to the rectifier device and a switch pin electrically connected to the switch device.

[0046] In this specification, a rectifier device refers to a power semiconductor element used to convert alternating current (AC) to direct current (DC). In the embodiments described herein, the rectifier device includes multiple rectifier diode chips and conductive connecting pieces. The multiple rectifier diode chips are connected via the conductive connecting pieces according to a preset circuit topology, such as a rectifier bridge circuit, to form a complete rectifier functional unit.

[0047] A switching device is a power semiconductor device that has two operating states: on and off, and can be used to control the switching on and off of a circuit. In the embodiments of this specification, the switching device may be a power switching transistor such as an IGBT or a MOSFET. The switching device inverts rectified DC power into high-frequency AC power through high-frequency on / off switching, and is the core actuator for energy conversion in a power module.

[0048] A rectifier pin is a conductive terminal fixed to the plastic package and electrically connected to the rectifier device. One part of it is located inside the plastic package and forms an electrical connection with the rectifier device, while the other part extends out of the plastic package and is used to electrically connect the rectifier unit to external circuits such as AC input terminals and DC load terminals.

[0049] A switch pin is a conductive terminal that is fixed on a plastic package and electrically connected to a switching device. One part of it is located inside the plastic package and forms an electrical connection with the switching device, while the other part extends out of the plastic package and is used to electrically connect the control unit to external circuits such as drive circuits and loads.

[0050] In practical applications, existing discrete component solutions involve soldering rectifiers and switches to different areas of a PCB board, each connected to external circuits via independent pins or pads. This results in complex PCB wiring and a large PCB area. In the embodiments described in this specification, rectifier and switch pins are uniformly placed on the molding compound, allowing the integrated rectifier unit and control unit within the module to directly connect to external circuits via their respective pins. This eliminates the need for separate wiring for each component on the PCB, simplifying system-level design and assembly. Furthermore, by placing the rectifier on a ceramic substrate and the switch on a copper substrate, the two types of devices are positioned on substrates that match their characteristics. The ceramic substrate provides high-voltage insulation protection for the rectifier, while the copper substrate provides a low-thermal-resistance heat dissipation path for the switch, thus achieving integration while maintaining the performance and reliability of each component.

[0051] like Figure 1 As shown, the rectifier unit 9 includes a rectifier device 4 disposed on a ceramic substrate 2. Specifically, multiple conductive copper foil regions 8 are chemically bonded to the surface of the ceramic substrate 2, and the rectifier device 4 is fixed to the conductive copper foil regions 8 by soldering to form the rectifier unit 9. The control unit 10 includes a switching device 5 disposed on a copper substrate 3. Specifically, the switching device 5 is fixed to the upper surface of the copper substrate 3 by soldering to form the control unit 10. The rectifier unit 9 and the control unit 10 are arranged side by side in the planar direction of the module. Specifically, the rectifier unit 9 is located in the left region of the module, and the control unit 10 is located in the right region of the module.

[0052] The molding compound 1 has rectifier pins 11 electrically connected to the rectifier device 4. The rectifier pins 11 include multiple pins, specifically two pins located on the upper side of the molding compound 1 and one pin located on the lower side of the molding compound 1. These pins are used to connect the AC input terminal and the DC output terminal, respectively. The molding compound 1 also has switch pins electrically connected to the switching device 5. The switch pins include a control electrode pin 13, a second electrode pin 14, and a first electrode pin 15, wherein the second electrode pin 14 is located on the upper side of the molding compound 1, and the control electrode pin 13 and the first electrode pin 15 are located on the lower side of the molding compound 1.

[0053] In a specific implementation, the rectifier device includes multiple rectifier diode chips and conductive connecting pieces. The multiple rectifier diode chips are soldered onto multiple conductive copper foil areas on the surface of the ceramic substrate through the conductive connecting pieces to form a full-bridge rectifier circuit. In the embodiments of this specification, the rectifier device is not limited to a single-phase full-bridge rectifier circuit composed of four diodes. In other embodiments, it can also be configured as a half-bridge rectifier circuit or other rectifier topologies according to application requirements. The number and connection method of the rectifier diodes can be adjusted accordingly based on specific circuit design requirements.

[0054] In some embodiments of this specification, the switching device may be an IGBT, or other types of power switching devices such as a MOSFET. When an IGBT is used, the switching pins include a gate pin (control pin), a collector pin (second electrode pin), and an emitter pin (first electrode pin). When a MOSFET is used, the switching pins include a gate pin (control pin), a drain pin (second electrode pin), and a source pin (first electrode pin). The switching device is electrically connected to its corresponding switching pins through its three electrodes, where the control pin is used to receive external drive signals, and the other two electrodes are the main current paths of the power circuit.

[0055] In some embodiments of this specification, the number and arrangement of rectifier pins and switch pins are not limited to the specific forms shown in the accompanying drawings. The number of rectifier pins depends on the circuit topology of the rectifier device; for example, a full-bridge rectifier typically requires two AC input pins and two DC output pins. The number of switch pins depends on the type of switching device; for example, a three-terminal switch typically requires three pins. The specific arrangement of each pin on the plastic package can be adaptively adjusted according to the internal layout of the module and the connection requirements of external systems.

[0056] In a specific embodiment of this specification, taking an induction cooker application scenario as an example, the rectifier device in the power module includes four rectifier diode chips and corresponding conductive connecting pieces. These four rectifier diode chips are soldered onto the conductive copper foil area on the surface of the ceramic substrate through the conductive connecting pieces, forming a full-bridge rectifier circuit. The rectifier pins include two AC input pins and two DC output pins. The two AC input pins are used to connect to the mains power, and the two DC output pins are used to output rectified DC power. The switching device uses IGBT chips, which are soldered onto the upper surface of the copper substrate. The gate, collector, and emitter of the IGBT chip are electrically connected to the switching pins through corresponding conductive connecting pieces. The collector and emitter pins are used to connect to the induction cooker coil, and the gate pin is used to receive control signals from the external drive circuit. When the induction cooker is working, AC power is input from the rectifier pins, rectified by the rectifier device, and output as DC power. Under the control of the drive signal, the IGBT chip is turned on and off at high frequency, inverting the DC power into high-frequency AC power to supply the coil. The portions of the rectifier pins and switch pins that extend beyond the plastic package are used for insertion or soldering to external circuit boards or wires to achieve electrical connection between the module and the entire induction cooker system.

[0057] Based on this, by defining the rectifier unit as including rectifier devices located on a ceramic substrate and the control unit as including switching devices located on a copper substrate, the rectifier devices and switching devices are respectively placed on substrates that match their characteristics. The ceramic substrate provides high-voltage insulation protection for the rectifier devices, and the copper substrate provides a low thermal resistance heat dissipation path for the switching devices. This achieves high integration while ensuring the reliability and heat dissipation performance of each device. Furthermore, by setting rectifier pins electrically connected to the rectifier devices and switching pins electrically connected to the switching devices on the molding compound, the rectifier unit and control unit inside the module can directly form electrical connections with external circuits through their respective pins, eliminating the need for additional PCB boards for wiring. This simplifies system-level circuit design and assembly processes, further reducing the overall material and assembly costs.

[0058] Furthermore, one side of the ceramic substrate is provided with a thermally conductive copper foil, and the other side is provided with multiple conductive copper foil areas; the rectifier device includes multiple rectifier diodes and conductive connecting pieces; the multiple rectifier diodes in the rectifier device are welded to the multiple conductive copper foil areas through the conductive connecting pieces; the ceramic substrate is welded to the copper substrate through the thermally conductive copper foil.

[0059] The thermally conductive copper foil refers to a copper foil layer fixed to the back of a ceramic substrate through chemical bonding. Covering the back of the ceramic substrate, the thermally conductive copper foil serves as a thermally conductive and soldering interface between the ceramic substrate and the copper substrate. A tight thermal contact is formed between the thermally conductive copper foil and the ceramic substrate; heat from the front of the ceramic substrate can be conducted through the ceramic substrate body to the thermally conductive copper foil on the back, and then through the thermally conductive copper foil to the copper substrate. Simultaneously, the thermally conductive copper foil acts as a soldering interface, achieving metallurgical bonding with the copper substrate through a solder layer.

[0060] The conductive copper foil area refers to multiple isolated copper foil regions fixed to the front side of the ceramic substrate by chemical bonding. These conductive copper foil areas are insulated from each other and each serves as an independent electrical pad and conductive line. In the embodiments of this specification, the conductive copper foil areas are used to carry rectifier devices. Rectifier diodes and conductive connecting pieces are fixed to the corresponding conductive copper foil areas by soldering to achieve the electrical connection of the rectifier circuit.

[0061] Conductive connectors are sheet-shaped connectors made of conductive materials such as copper, used to achieve electrical connections between rectifier diodes or between rectifier diodes and conductive copper foil areas. The conductive connectors are fixed to the conductive copper foil areas by welding, connecting multiple rectifier diodes according to a preset circuit topology to form a complete rectifier circuit.

[0062] In practical applications, existing discrete device solutions typically use rectifier diodes soldered onto a PCB board in independent packages. Electrical connections between diodes are achieved via copper traces on the PCB, requiring significant PCB area and resulting in complex wiring. In the embodiments described in this specification, multiple conductive copper foil areas are directly disposed on the surface of a ceramic substrate, and the rectifier diodes and conductive connecting pieces are soldered onto these areas. This forms a complete rectifier circuit directly on the ceramic substrate surface, achieving rectification without the need for an additional PCB board and saving wiring space. Simultaneously, by placing a thermally conductive copper foil on the back of the ceramic substrate and soldering it to a copper substrate, a large-area heat conduction channel is established between the ceramic and copper substrates. This allows heat generated by the rectifier devices on the front of the ceramic substrate to be efficiently transferred to the copper substrate, providing a concrete structural basis for integrated design and efficient heat dissipation.

[0063] like Figure 1 As shown, one side (back side) of the ceramic substrate 2 is provided with a thermally conductive copper foil 7, and the other side (front side) of the ceramic substrate 2 is provided with multiple conductive copper foil areas 8. The rectifier device 4 includes multiple rectifier diodes and conductive connecting pieces. The multiple rectifier diodes are soldered to the multiple conductive copper foil areas 8 via the conductive connecting pieces. Specifically, the conductive copper foil areas 8 serve as independent electrical pads. The pins of the rectifier diodes are soldered to the conductive copper foil areas 8, and the conductive connecting pieces are soldered between different conductive copper foil areas 8 or between rectifier diodes, thereby connecting the rectifier diodes together according to a preset rectifier circuit topology to form a complete rectifier unit 9. Figure 2 As shown, a thermally conductive copper foil 7 is provided on the back side of the ceramic substrate 2, and the ceramic substrate 2 is soldered to the copper substrate 3 through the thermally conductive copper foil 7. Specifically, the thermally conductive copper foil 7 covers the back side of the ceramic substrate 2, and a solder layer is disposed between the thermally conductive copper foil 7 and the copper substrate 3. The ceramic substrate 2 and the copper substrate 3 are fixedly connected as a whole through processes such as reflow soldering.

[0064] In practice, the number and distribution of the multiple conductive copper foil areas on the front side of the ceramic substrate are determined according to the topology of the rectifier circuit. For example, in a full-bridge rectifier circuit, four diodes and corresponding AC / DC input / output nodes are usually required. Therefore, at least four or more mutually isolated conductive copper foil areas are required, serving as two AC input terminals, a DC positive output terminal, and a DC negative output terminal, respectively.

[0065] In some embodiments of this specification, the rectifier diodes can be connected according to different circuit topologies via conductive connectors. For example, in a full-bridge rectifier circuit, four rectifier diodes are connected in a bridge configuration via conductive connectors, where the connection point of two diodes serves as the AC input terminal, and the connection point of the other two diodes serves as the DC output terminal. The specific shape and number of conductive connectors are adjusted according to the actual circuit layout and pin positions.

[0066] In some embodiments of this specification, the thermally conductive copper foil on the back side of the ceramic substrate can be a continuous copper foil layer covering the entire back side area of ​​the ceramic substrate to provide the largest possible thermally conductive area. When the ceramic substrate is soldered to the copper substrate via the thermally conductive copper foil, a high-temperature solder paste can be used in a reflow soldering process. The solder layer is uniformly filled between the thermally conductive copper foil and the copper substrate, forming a tight metallurgical bond that ensures both thermal conductivity and connection strength.

[0067] In some embodiments of this specification, the thermally conductive copper foil and the conductive copper foil area are bonded to the ceramic substrate by chemical bonding, that is, the copper foil is directly bonded to the surface of the ceramic substrate by a high-temperature sintering process, which has higher bonding strength and better thermal conductivity compared to adhesive bonding.

[0068] In a specific embodiment of this specification, taking an induction cooker application scenario as an example, the ceramic substrate uses a DBC board. Six mutually isolated conductive copper foil areas are fixed to its front side via chemical bonding, and a full-surface thermally conductive copper foil is fixed to its back side via chemical bonding. The rectifier device includes four rectifier diode chips and three conductive connecting pieces. The four rectifier diode chips are respectively soldered to their corresponding conductive copper foil areas, and the three conductive connecting pieces are respectively soldered between different conductive copper foil areas, connecting the four rectifier diodes into a full-bridge rectifier circuit. Two conductive copper foil areas serve as AC input terminals, connected to two AC input pins respectively; the other two conductive copper foil areas serve as DC output terminals, connected to two DC output pins respectively. The thermally conductive copper foil on the back side of the ceramic substrate is soldered to the copper substrate using high-temperature solder, forming a tightly integrated whole between the ceramic substrate and the copper substrate. When the induction cooker is operating, the heat generated by the rectifier diodes is transferred from the rectifier diode chips through the solder layer to the conductive copper foil areas, then through the ceramic substrate body to the thermally conductive copper foil on the back side, and finally through the solder layer to the copper substrate. The entire heat conduction path is short and efficient.

[0069] Based on this, by setting multiple conductive copper foil areas on one side of the ceramic substrate and directly soldering multiple rectifier diodes from the rectifier device to these conductive copper foil areas via conductive connecting pieces, the rectifier circuit is formed directly on the surface of the ceramic substrate. This eliminates the need for an additional PCB board, achieving complete rectification functionality, saving wiring space, and simplifying the circuit structure. Simultaneously, by setting a thermally conductive copper foil on the other side of the ceramic substrate and soldering the ceramic substrate to a copper substrate through this thermally conductive copper foil, a large-area, low-thermal-resistance thermal conduction channel is established between the ceramic and copper substrates. This allows the heat generated by the rectifier device on the front side of the ceramic substrate to be efficiently transferred to the copper substrate via the conductive copper foil areas, the ceramic substrate body, the thermally conductive copper foil, and the solder layer. The heat is then dissipated to the heat sink through the exposed back side of the copper substrate. The entire heat conduction path is short and direct, significantly improving the heat dissipation efficiency of the rectifier unit and ensuring the reliability of the rectifier device under high-current conditions.

[0070] Furthermore, the power module also includes a temperature detection unit; the temperature detection unit is encapsulated within the plastic package.

[0071] The temperature detection unit refers to a component used to sense temperature changes within the power module. In the embodiments of this specification, the temperature detection unit can be a thermistor. The resistance value of a thermistor changes significantly with temperature, and the corresponding temperature information can be obtained by measuring its resistance value. The temperature detection unit is encapsulated inside a plastic package and integrated with the rectifier unit and control unit. It is used to monitor the operating temperature of the power module in real time, especially the junction temperature changes of the switching devices, providing a basis for over-temperature protection of the system. Types of temperature detection units include positive temperature coefficient (PTC) thermistors and negative temperature coefficient (NTC) thermistors. NTC thermistors have a decreasing resistance value as the temperature increases, while PTC thermistors have a increasing resistance value. Both types can be selected according to actual application requirements.

[0072] Encapsulated within the plastic package means that the temperature sensing unit, along with the rectifier and switching devices, is encapsulated together to form an integrated packaging structure. The temperature sensing unit is located inside the plastic package and is not exposed to the external environment, thus avoiding the influence of external environmental factors (such as airflow, dust, and moisture) on the temperature measurement accuracy.

[0073] In practical applications, existing discrete component solutions typically use thermistors mounted separately on a PCB board as independent components, arranged adjacent to the rectifier bridge or IGBT device via wires for temperature detection. This external approach not only increases the number of components and installation steps, but also introduces air gaps and PCB board dielectric barriers between the thermistor and the device under test. Heat transfer from the heat-generating device to the thermistor requires passing through multiple thermal interfaces, resulting in a delayed temperature response and an inability to reflect the actual junction temperature changes of the power device in real time, affecting the timeliness and accuracy of over-temperature protection. In the embodiments described in this specification, the temperature detection unit is directly encapsulated within a plastic package, integrating it with the rectifier unit and control unit into the same module. This eliminates the need for separate temperature sensing elements on the PCB board, simplifying the number of system-level components and installation steps. Furthermore, the temperature detection unit, located inside the plastic package, is closer to the heat source, enabling faster sensing of internal module temperature changes. This provides a more timely and accurate source of temperature information for system temperature monitoring and over-temperature protection, thereby improving the reliability and safety of the power module.

[0074] like Figure 1As shown, the power module also includes a temperature detection unit 6, which is encapsulated within a plastic package 1. Specifically, the temperature detection unit 6 is located between the rectifier unit 9 and the control unit 10, within the internal region of the plastic package 1, and is encapsulated together with the rectifier device 4 and the switching device 5. The temperature detection unit 6 is positioned close to the switching device 5 in its planar layout to more accurately sense temperature changes in the switching device 5. The plastic package 1 also has a temperature sensing pin 12 electrically connected to the temperature detection unit 6. One end of the temperature detection unit 6 is electrically connected to the temperature sensing pin 12, and the other end is electrically connected to the corresponding electrode pin of the switching device, enabling the external temperature detection circuit to obtain the resistance change of the temperature detection unit 6 through the temperature sensing pin 12, thereby monitoring the internal operating temperature of the module in real time.

[0075] In practical implementation, the temperature detection unit can use a negative temperature coefficient thermistor, a positive temperature coefficient thermistor, or other types of temperature sensors, such as thermocouples or integrated digital temperature sensors. Different types of temperature detection units have different electrical characteristics and interface methods, and can be selected according to actual temperature measurement accuracy requirements and cost requirements. In the embodiments of this specification, a thermistor is selected as the temperature detection unit because of its low cost, fast response, and simple interface, making it suitable for cost-sensitive consumer products such as electromagnetic heating equipment.

[0076] In some embodiments of this specification, the arrangement of the temperature sensing unit within the plastic package can be adjusted according to actual temperature measurement requirements. For example, the temperature sensing unit can be positioned close to the switching device to prioritize monitoring the junction temperature of the switching device. Switching devices generate significant heat and experience rapid temperature fluctuations during operation, making them the components in the power module that most require real-time temperature monitoring.

[0077] In some embodiments of this specification, the power module may be equipped with only one temperature detection unit, or multiple temperature detection units may be set up as needed, respectively arranged near the rectifier unit and near the switching device, so as to realize separate monitoring of the temperature of different areas within the module.

[0078] In some embodiments of this specification, the temperature sensing unit is fixed to a conductive structure inside the plastic package by welding, for example, fixed to a conductive copper foil area or connected via conductive connecting pieces. The welding process of the temperature sensing unit can be performed simultaneously with the welding processes of the rectifier and switching devices, without adding any additional process steps.

[0079] In a specific embodiment of this specification, taking an induction cooker application scenario as an example, the temperature detection unit uses a negative temperature coefficient thermistor, whose resistance decreases as the temperature rises. The thermistor is soldered onto a conductive structure inside the module, with one end electrically connected to a temperature-sensing pin on the encapsulation body and the other end electrically connected to the first electrode pin of the switching device. The thermistor and the switching device are arranged adjacent to each other, forming a heat conduction path between them through a thermally conductive medium such as a copper substrate and conductive connecting pieces. When the induction cooker is working, the switching device generates a large amount of heat during continuous switching on and off, causing the chip junction temperature to rise. The heat is quickly transferred to the thermistor through the copper substrate and conductive connecting pieces, causing the thermistor's resistance value to change accordingly. The external control circuit detects the thermistor's resistance value in real time through the temperature-sensing pin and calculates the current temperature value according to a preset resistance-temperature correspondence. When the detected temperature exceeds a preset safety threshold, the control circuit immediately reduces the power or stops working to prevent the switching device from being damaged due to overheating.

[0080] Based on this, by encapsulating the temperature detection unit inside a plastic package, the temperature detection unit is integrated with the rectifier unit and control unit, eliminating the need for separate temperature sensing elements on the PCB board. This reduces the number of components and installation steps, further improving the integration of the power module and lowering material and assembly costs. Simultaneously, with the temperature detection unit encapsulated inside the plastic package, it is closer to the heat source. The heat transfer path from the rectifier or switching devices to the temperature detection unit is shorter and the thermal resistance is lower, allowing the temperature detection unit to sense internal temperature changes more quickly, significantly shortening the temperature response time. This enables the external control circuit to execute over-temperature protection strategies based on more timely and accurate temperature information. When the internal temperature of the module rises abnormally, it can quickly respond, reduce power, or cut off the output, effectively preventing power devices from failing due to overheating, thus improving the operational reliability of the power module and the overall safety of the device.

[0081] Furthermore, the switch pin includes a first electrode pin, and the molding compound is also provided with a temperature sensing pin; the temperature detection unit is connected between the first electrode pin and the temperature sensing pin.

[0082] The first electrode pin refers to one of the two power electrode pins of the switching device. When the switching device is an IGBT, the first electrode is the emitter; when the switching device is a MOSFET, the first electrode is the source. The first electrode pin extends out of the plastic package and is used to form an electrical connection with an external load circuit. In the embodiments of this specification, the first electrode pin, in addition to being part of the power circuit, also serves as a connection terminal for the temperature detection unit, enabling the temperature detection unit to form a detection circuit with the external circuit through this pin.

[0083] The temperature sensing pin is a conductive terminal specifically designed for the temperature detection unit. One end is inside the plastic package and electrically connected to the temperature detection unit, while the other end extends out of the package to electrically connect the temperature detection unit to an external temperature detection circuit. The temperature sensing pin provides an independent signal output channel for the temperature detection unit, allowing external circuitry to obtain changes in the electrical parameters of the temperature detection unit through this pin.

[0084] The connection between the first electrode pin and the temperature sensing pin means that one end of the temperature detection unit is electrically connected to the first electrode pin inside the plastic package, and the other end is electrically connected to the temperature sensing pin inside the plastic package. The temperature detection unit is connected in series in the electrical path between the first electrode pin and the temperature sensing pin. The external temperature detection circuit applies a detection current or voltage to the temperature detection unit through the temperature sensing pin and measures the resistance value or other electrical parameters of the temperature detection unit to obtain temperature information.

[0085] In practical applications, existing external temperature detection solutions involve mounting the thermistor on a PCB board. One end is connected to a reference voltage or ground, while the other end is connected to the control circuit via a separate trace. This requires consuming PCB board wiring and interface resources, and multiple thermal resistances exist between the thermistor and the device under test, resulting in slow temperature response and low accuracy. In the embodiments described in this specification, the temperature detection unit is connected between the first electrode pin and the temperature sensing pin. The first electrode pin of the switching device serves as both a power electrode and a connection point for the temperature detection unit, allowing the temperature detection unit to directly acquire the temperature information of the switching device through the first electrode pin. Since the first electrode pin and the switching device are directly connected on the copper substrate via soldering, the heat conduction path between them is extremely short and the thermal resistance is extremely low. The heat generated by the switching device can be quickly transferred to the vicinity of the first electrode pin, thus being sensed by the temperature detection unit. Furthermore, connecting the temperature detection unit to the external circuit via a separate temperature sensing pin ensures that the external circuit does not interfere with the power circuit while acquiring the temperature detection signal, guaranteeing the accuracy and reliability of temperature detection.

[0086] like Figure 1As shown, the switch pins include a first electrode pin 15, and a temperature sensing pin 12 is also provided on the plastic package 1. A temperature detection unit 6 is connected between the first electrode pin 15 and the temperature sensing pin 12. Specifically, one end of the temperature detection unit 6 is electrically connected to the temperature sensing pin 12 inside the plastic package 1, and the other end of the temperature detection unit 6 is electrically connected to the first electrode pin 15 inside the plastic package 1. The external temperature detection circuit can obtain the resistance change of the temperature detection unit 6 through the temperature sensing pin 12 and the first electrode pin 15, thereby monitoring the internal operating temperature of the module in real time. Since the first electrode pin 15 and the switch device 5 are located on the same copper substrate 3 and are directly connected through a conductive structure, the heat generated by the switch device 5 can be quickly transferred to the first electrode pin 15, enabling the temperature detection unit 6 to accurately sense the junction temperature change of the switch device 5.

[0087] In practical implementation, the temperature detection unit is connected between the first electrode pin and the temperature sensing pin, based on the thermal coupling relationship between the switching device and the first electrode pin on the copper substrate. Since the first electrode pin is directly connected to the switching chip on the copper substrate via a conductive connector, the temperature of this electrode pin can reflect the actual junction temperature change of the switching chip in real time. The temperature detection unit is directly connected to the first electrode pin, making the detected temperature closer to the actual junction temperature of the switching chip.

[0088] In some embodiments of this specification, the connection between the temperature sensing unit and the first electrode pin and the temperature sensing pin is achieved by soldering. Specifically, one end of the temperature sensing unit is soldered to the inner end of the first electrode pin inside the plastic package, and the other end is soldered to the inner end of the temperature sensing pin inside the plastic package. Soldering ensures a reliable electrical connection and good thermal contact between the temperature sensing unit and the pin.

[0089] In some embodiments of this specification, the temperature sensing pin is a dedicated pin independently mounted on the plastic package, with one end extending out of the package for connection to an external temperature detection circuit. The placement of the temperature sensing pin isolates the signal from the power circuit, improving the signal-to-noise ratio and interference immunity of the signal detection.

[0090] In some embodiments of this specification, the connection between the temperature detection unit and the first electrode pin utilizes the existing electrode pin of the switching device itself as part of the temperature measurement circuit, eliminating the need to set up two new pins for the temperature detection unit, thereby achieving the built-in temperature detection function without significantly increasing the number of pins.

[0091] In a specific embodiment of this specification, taking an induction cooker application scenario as an example, the switching device is an IGBT chip, whose three electrode pins are the gate pin (control pin), collector pin (second electrode pin), and emitter pin (first electrode pin). An independent temperature sensing pin is also provided on the molding compound. The temperature detection unit uses a negative temperature coefficient thermistor, with one end soldered to the inner end of the emitter pin and the other end soldered to the inner end of the temperature sensing pin. When the induction cooker is working, the IGBT chip generates a large amount of heat during continuous high-frequency switching on and off. This heat is transferred from the IGBT chip through the solder layer to the copper substrate, and then through the copper substrate to the emitter pin. The thermistor, positioned close to the emitter pin, can quickly sense the temperature change at the emitter pin, and this temperature has a direct correlation with the actual junction temperature of the IGBT chip. The external control circuit applies a constant detection current to the thermistor through the temperature sensing pin and measures the voltage drop between the temperature sensing pin and the emitter pin to calculate the current resistance value of the thermistor. Then, based on a preset resistance-temperature curve, the current junction temperature of the IGBT chip can be deduced. When the junction temperature exceeds the safety threshold, the control circuit immediately reduces the heating power of the induction cooker or stops heating to protect the IGBT chip from overheating damage.

[0092] Based on this, by connecting the temperature detection unit between the first electrode pin and the temperature sensing pin, and utilizing the existing first electrode pin of the switching device as the connection terminal for the temperature detection unit, the temperature detection unit can directly acquire the temperature information of the switching device through thermal coupling with the first electrode pin. This results in fast temperature response and accurate and reliable temperature information. Simultaneously, by leading the signal from the temperature detection unit to the external circuit through a separate temperature sensing pin, mutual interference between the temperature detection signal and the power circuit signal is avoided, improving the accuracy and anti-interference capability of temperature detection. Furthermore, the temperature detection unit does not require additional component mounting space; electrical connection can be achieved solely through existing pins within the module, effectively utilizing the module's internal space and facilitating further improvements in integration and reduction in module size.

[0093] Furthermore, the switch pin includes a control electrode pin, and the ceramic substrate is also provided with a transition copper foil; one end of the transition copper foil is electrically connected to the control electrode pin, and the other end of the transition copper foil is electrically connected to the control electrode of the switching device through a copper tie.

[0094] The control pin refers to the conductive terminal that is electrically connected to the control electrode of the switching device. When the switching device is an IGBT, the control electrode is the gate, and the control pin is the gate pin; when the switching device is a MOSFET, the control electrode is the gate, and the control pin is also the gate pin. Part of the control pin is located inside the plastic package and forms an electrical connection with the transition copper foil, while the other part extends out of the plastic package to receive the drive signal provided by the external drive circuit and control the switching device to turn on and off.

[0095] The transition copper foil refers to the copper foil area fixed to the surface of the ceramic substrate, which belongs to the same copper foil structure as the conductive copper foil area on the front side of the ceramic substrate. The transition copper foil is positioned adjacent to the control electrode pin, serving as an intermediate transition connection point between the control electrode pin and the copper tie. One end of the transition copper foil is electrically connected to the inner end of the control electrode pin via soldering, while the other end is electrically connected to the control electrode of the switching device via the copper tie. The function of the transition copper foil is to extend and transition the electrical connection path of the control electrode, eliminating the need for the control electrode pin to be directly soldered to the copper tie.

[0096] A copper connector is a sheet-like connector made of conductive materials such as copper, used to achieve electrical connection between a transfer copper foil and the control electrode of a switching device. One end of the copper connector is soldered to the transfer copper foil, and the other end is soldered to the control electrode of the switching device. The drive signal is transmitted from the transfer copper foil to the control electrode of the switching device through the copper connector.

[0097] In practical applications, if a direct connection method is used, that is, the copper tie is directly soldered from the control electrode of the switching device to the control electrode pin, the following problems will occur: First, the control electrode pin is thinner and longer than other power pins, and has lower mechanical strength. When a large external stress is applied, the deformation of the pin can easily cause the copper tie to shift. Second, the control electrode of the switching device is usually a gate structure, which is relatively fragile. When the copper tie shifts, it directly pulls on the control electrode solder joint of the switching device, which can easily lead to the control electrode solder joint falling off or the gate structure being damaged, causing the switching control unit to fail. At the same time, when the internal layout of the module is relatively compact, if the copper tie directly crosses the area between the rectifier unit and the control unit, it may interfere with adjacent rectifier units or conductive structures, affecting the overall performance and reliability of the product. In the embodiments of this specification, an adapter copper foil is set on the ceramic substrate, so that the control electrode pin is first soldered to the adapter copper foil, and then connected to the control electrode of the switching device through the adapter copper foil via the copper tie. The control electrode pin and the copper tie are indirectly connected through the adapter copper foil. When external stress causes deformation of the control electrode pin, the stress generated by the pin deformation is absorbed and buffered by the copper foil fixed on the ceramic substrate due to its high structural strength. It will not be directly transmitted to the copper tie, thus avoiding the pulling of the control electrode solder joint of the switching device by the copper tie offset, and effectively protecting the control electrode structure of the switching device.

[0098] like Figure 1 As shown, the switch pins include a control electrode pin 13, and a connecting copper foil 17 is also provided on the ceramic substrate 2. One end of the connecting copper foil 17 is electrically connected to the control electrode pin 13, and the other end of the connecting copper foil 17 is electrically connected to the control electrode of the switching device 5 through a copper connector 18. Specifically, the control electrode pin 13 is located on the lower side of the molding compound 1, and its inner end extends into the molding compound 1 and is soldered to one end of the connecting copper foil 17. The connecting copper foil 17 is fixed to the surface of the ceramic substrate 2 and is on the same level as the conductive copper foil area 8 on the front side of the ceramic substrate 2. The other end of the connecting copper foil 17 extends to a position close to the switching device 5 and forms an electrical connection with the control electrode of the switching device 5 through the copper connector 18. One end of the copper connector 18 is soldered to the connecting copper foil 17, and the other end is soldered to the control electrode of the switching device 5. With the above connection method, after the external drive signal is input from the control pin 13, it is transmitted to the control electrode of the switching device 5 through the adapter copper foil 17 and the copper connecting piece 18 in sequence, so as to realize the conduction and turn-off control of the switching device 5.

[0099] In practice, the adapter copper foil and the conductive copper foil area on the front side of the ceramic substrate are fixed to the ceramic substrate surface on the same layer by chemical bonding. An interval is formed between the adapter copper foil and the conductive copper foil area through etching or cutting to achieve mutual insulation.

[0100] In some embodiments of this specification, the shape of the transition copper foil can be adapted to the internal layout of the module. For example, the transition copper foil can be rectangular, L-shaped, or other shapes, with one end extending near the control electrode pin and the other end extending near the control electrode of the switching device.

[0101] In some embodiments of this specification, the soldering between the copper strip, the transition copper foil, and the control electrode of the switching device can be completed simultaneously using a reflow soldering process. The two ends of the copper strip are respectively fixedly connected to the transition copper foil and the control electrode pad of the switching device via solder layers.

[0102] In some embodiments of this specification, the inner end of the control electrode pin extending into the plastic package is provided with a bent portion or a flat portion to increase the welding area with the transition copper foil and improve the welding strength and reliability.

[0103] In a specific embodiment of this specification, taking an induction cooker application scenario as an example, the switching device is an IGBT chip, and its controller pin is the gate. The controller pin is the gate pin, and the portion extending out of the plastic package is used for soldering to the corresponding pad on the external drive circuit board. A transition copper foil is chemically bonded to the surface of the ceramic substrate inside the gate pin. This transition copper foil is isolated from other conductive copper foil areas on the front side of the ceramic substrate, forming an independent electrical node. The inner end of the gate pin is fixed to one end of the transition copper foil by soldering. One end of a copper tie is fixed to the other end of the transition copper foil by soldering, and the other end of the copper tie is fixed to the gate pad of the IGBT chip by soldering. The drive signal output from the external drive circuit enters the module through the gate pin and is transmitted to the gate of the IGBT chip sequentially through the transition copper foil and the copper tie, controlling the high-frequency turn-on and turn-off of the IGBT chip. When the induction cooker is in operation, if the gate pin is subjected to external vibration or impact and undergoes slight deformation, the stress generated by the pin deformation is absorbed by the transfer copper foil because the transfer copper foil is fixed to the surface of the ceramic substrate and the ceramic substrate and the copper substrate are welded together to form a whole with high structural strength. The copper foil will not move with the pin deformation, and the gate solder joint of the IGBT chip will always remain stable and unaffected by stress.

[0104] Based on this, by setting an adapter copper foil on the ceramic substrate, the control electrode pin is first soldered to the adapter copper foil, and then connected to the control electrode of the switching device via a copper tie, forming an indirect connection between the control electrode pin and the copper tie. When the control electrode pin deforms under external stress, the adapter copper foil, fixed to the surface of the ceramic substrate, has high structural strength and stability. The stress generated by the pin deformation is absorbed and buffered by the adapter copper foil and will not be directly transmitted to the copper tie. This effectively avoids the pulling of the control electrode solder joint of the switching device by the copper tie, protects the integrity of the control electrode structure of the switching device, and significantly improves the reliability and service life of the power module under external mechanical stress. At the same time, the setting of the adapter copper foil allows the lead-out position of the control electrode pin to be flexibly adjusted according to the overall layout of the module, which is beneficial to optimize the internal space utilization and wiring design of the module and further improve the integration.

[0105] Furthermore, the rectifier pin includes a first AC input pin, a second AC input pin, a first DC output pin, and a second DC output pin, and the switch pin further includes a second electrode pin; the first AC input pin, the second AC input pin, the first DC output pin, and the second electrode pin are disposed at one end of the molding compound; the second DC output pin, the temperature sensing pin, the control electrode pin, and the first electrode pin are disposed at the other end of the molding compound.

[0106] The first AC input pin and the second AC input pin are the two pins in the rectifier pins used to connect to the AC power supply. Alternating current has the characteristic of alternating positive and negative half-cycles. The two AC input pins are connected to the two ends of the AC power supply, namely the live wire and the neutral wire, respectively. The AC current enters the rectifier unit for rectification and conversion through these two pins.

[0107] The first DC output pin and the second DC output pin are the two pins in the rectifier used to output DC power. The rectifier unit rectifies the AC power and outputs DC power with fixed positive and negative polarities. The first DC output pin is the positive DC output terminal, and the second DC output pin is the negative DC output terminal. These two DC output pins are connected to the subsequent switching control unit or other load circuits.

[0108] The second electrode pin is the other of the two power electrode pins of the switching device. When the switching device is an IGBT, the second electrode is the collector; when the switching device is a MOSFET, the second electrode is the drain. The second electrode pin extends out of the plastic package and is used to connect to an external load.

[0109] One end and the other end of the molding compound refer to the two opposite sides of the molding compound in the planar direction. In the embodiments of this specification, one end and the other end are specifically the upper side and the lower side of the molding compound, and each pin is arranged on the upper edge and the lower edge of the molding compound, forming a compact and symmetrical pin arrangement.

[0110] In practical applications, existing discrete device solutions have the pins of the rectifier bridge and IGBT independently distributed on their respective packages. The positions and arrangements of these pins are independent and lack unified planning, resulting in wiring across large areas on the circuit board, long traces, and significant parasitic inductance, affecting the electromagnetic compatibility performance and switching reliability of the circuit. In the embodiments described in this specification, the second electrode pin of the rectifier and switch pins is placed at one end of the plastic package, while the second DC output pin, temperature sensing pin, control pin, and first electrode pin of the rectifier pin are placed at the other end. This creates a compact and symmetrical arrangement of pins on the upper and lower sides of the plastic package. Specifically, the upper pins include two AC input pins, one DC output pin, and a second electrode pin, while the lower pins include another DC output pin, a temperature sensing pin, a control pin, and a first electrode pin. This symmetrical layout ensures uniform spacing between pins and short traces, reducing parasitic inductance and mutual interference between units during independent operation, while also facilitating wiring connections to external circuits.

[0111] like Figure 1As shown, the rectifier pins include a first AC input pin, a second AC input pin, a first DC output pin, and a second DC output pin. All rectifier pins are marked as 11. The switch pins also include a second electrode pin 14. Each pin is located on the upper and lower sides of the molding compound 1. Specifically, the upper side of the molding compound 1 has the first AC input pin, the second AC input pin, the first DC output pin, and the second electrode pin 14 arranged sequentially; the lower side of the molding compound 1 has the second DC output pin, the temperature sensing pin 12, the control electrode pin 13, and the first electrode pin 15 arranged sequentially. The three rectifier pins on the upper side are electrically connected to the corresponding electrical nodes of the rectifier unit 9, and the second electrode pin 14 is electrically connected to the second electrode of the control unit 10. The second DC output pin on the lower side is electrically connected to the DC negative output terminal of the rectifier unit 9, the temperature sensing pin 12 is electrically connected to the temperature detection unit 6, the control electrode pin 13 is electrically connected to the control electrode of the switching device 5 via the adapter copper foil 17 and the copper connecting piece 18, and the first electrode pin 15 is electrically connected to the first electrode of the switching device 5.

[0112] In practice, the arrangement of the pins on the top and bottom sides of the plastic package can be adjusted appropriately according to the internal layout of the module. For example, the order of the AC input pins and DC output pins can be adjusted according to the structure of the internal circuit of the rectifier unit.

[0113] In some embodiments of this specification, one end and the other end of the molding compound are specifically the upper and lower sides, but in other embodiments, the pins may also be arranged on the left and right sides of the molding compound, depending on the overall packaging design of the module and the connection requirements of the external system.

[0114] In some embodiments of this specification, since the back of the copper substrate is exposed outside the plastic package and bonded to the heat sink, the copper substrate is at the same potential as the second electrode of the switching device during operation, while the other pins are electrically insulated from the copper substrate by a ceramic substrate. The thickness of the ceramic substrate, if not less than 0.98 mm, defines the longitudinal insulation distance between each pin and the copper substrate, ensuring electrical safety under high-voltage conditions.

[0115] In some embodiments described in this specification, the leads are made of copper and may be tin- or silver-plated to improve solderability and conductivity. The portion of the leads extending beyond the plastic casing may be bent and shaped as needed to accommodate different mounting methods.

[0116] In a specific embodiment of this specification, taking an induction cooker application scenario as an example, the first AC input pin of the three rectifier pins on the upper side of the encapsulation is connected to the mains live wire, the second AC input pin is connected to the mains neutral wire, and the first DC output pin is connected to the positive input terminal of the subsequent circuit; the second electrode pin on the upper side of the encapsulation is connected to one end of the induction cooker coil. Of the four pins on the lower side of the encapsulation, the second DC output pin is connected to the negative input terminal of the subsequent circuit; the temperature sensing pin is connected to an external temperature detection circuit; the control pin is connected to the output terminal of an external drive circuit; and the first electrode pin is connected to the other end of the induction cooker coil, forming a complete load current loop with the collector pin.

[0117] On the circuit board of the induction cooker, each of the aforementioned pins is connected to its corresponding circuit node via solder pads. During operation, AC power enters the module through the two AC input pins, is rectified, and outputs DC power from the two DC output pins. A drive signal is input from the control pin to control the switching action of the IGBT chip. High-frequency current flows from the collector pin to the emitter pin and through the external coil, achieving the electromagnetic heating function. The symmetrical layout of the upper and lower pins allows the traces on the external circuit board to be led out from both sides without crossing, resulting in a clean and clear wiring design.

[0118] Based on this, by placing two AC input pins, one DC output pin, and the second electrode pin at one end of the molding compound, and placing the other DC output pin, temperature sensing pin, control electrode pin, and first electrode pin at the other end, the pins are arranged in a compact and symmetrical manner on the top and bottom sides of the molding compound. The uniform spacing between the pins and short traces effectively reduce parasitic inductance, minimize mutual interference between units during independent operation, and improve the electromagnetic compatibility performance and switching reliability of the power module. Simultaneously, the two AC input pins and two DC output pins are positioned at opposite ends of the molding compound, creating natural physical isolation between the AC input and DC output terminals, which helps reduce parasitic coupling between the AC and DC sides. The second electrode pin and the first electrode pin are located at opposite ends of the molding compound, ensuring a symmetrical distribution of the main current path of the switching device within the module. This promotes uniform current flow and heat dissipation to both sides, preventing heat accumulation on one side and further improving the heat dissipation efficiency and long-term operational reliability of the power module.

[0119] Furthermore, the back of the molding compound is provided with heat dissipation holes; the back of the copper substrate is connected to the heat sink through the heat dissipation holes; the back of the molding compound and the back of the copper substrate are located on the same plane.

[0120] The heat dissipation hole refers to an opening structure on the back of the molding compound, which allows the back of the copper substrate to be exposed outside the molding compound through the opening. During injection molding, a corresponding protrusion structure is set in the mold, so that after injection molding, an opening is formed in this area that penetrates the back of the molding compound. The back of the copper substrate is exposed to the external environment through this opening, so that it can directly contact the heat sink without penetrating the molding compound material.

[0121] The back side of the molding compound refers to the surface facing the heat sink when the power module is installed. During the encapsulation process, the back side of the molding compound corresponds structurally to the back side of the copper substrate. In the embodiments described in this specification, the back side of the molding compound corresponds to the position of the internal copper substrate by providing ventilation holes. The back side of the molding compound and the back side of the copper substrate are flush in the height direction, forming a flat mounting surface together. Because the back side of the molding compound and the back side of the copper substrate are on the same plane, there is no height difference between the exposed back side of the copper substrate and the contact surface of the heat sink, enabling a tight surface contact.

[0122] In practical applications, in existing discrete device solutions, power devices contact the heat sink through the surface of their package. Heat must first pass through the plastic encapsulation layer of the package to be transferred to the heat sink. The thermal conductivity of the plastic encapsulation material is much lower than that of metal materials, resulting in high thermal resistance and low heat dissipation efficiency. Furthermore, if the back of the copper substrate has a depression or protrusion relative to the back of the plastic encapsulation, an air gap or point contact will form between it and the heat sink, further increasing contact thermal resistance. Even with modular packaging, although the copper substrate is exposed outside the plastic encapsulation and connected to the heat sink, if there is a height difference between the exposed surface and the back of the plastic encapsulation, uniform adhesion is still difficult to achieve after applying thermal grease, affecting heat dissipation. In the embodiments of this specification, by creating heat dissipation holes and controlling the height consistency between the back of the plastic encapsulation and the back of the copper substrate during injection molding, they form a coplanar structure, enabling a tight fit with the mounting surface of the heat sink. This achieves direct heat transfer from the copper substrate to the heat sink, avoiding the thermal barrier of the plastic encapsulation and greatly shortening the heat conduction path.

[0123] like Figure 3As shown, the back of the molding compound 1 has heat dissipation holes 16, which are through openings on the back of the molding compound 1. The back of the copper substrate 3 is exposed outside the molding compound 1 through the heat dissipation holes 16, and the exposed back of the copper substrate 3 is connected to the heat sink through the heat dissipation holes 16. The back of the molding compound 1 and the back of the copper substrate 3 are on the same plane, that is, the surface of the back of the molding compound 1, except for the area of ​​the heat dissipation holes 16, is flush with the exposed back of the copper substrate 3 in the height direction. This coplanar design allows the exposed back of the copper substrate 3 and the back of the molding compound 1 to simultaneously form a tight, gapless contact with the mounting surface of the heat sink when the heat sink is installed. When the power module is actually installed on the heat sink, the back of the molding compound 1 and the back of the copper substrate 3 together form a flat contact surface, which is tightly attached to the surface of the heat sink using thermal grease and locking screws. See Figure 3 The specific location of the heat dissipation hole 16 corresponds to the position of the copper substrate 3 inside the molding compound 1. The opening shape and size of the heat dissipation hole 16 are adapted to the shape and size of the back side of the copper substrate 3, so that the entire back side area of ​​the copper substrate 3 is exposed outside the molding compound 1, thereby maximizing the heat dissipation area.

[0124] In practice, the number and location of the heat dissipation holes on the back of the molding compound are determined based on the number and location of the internal copper substrate. In this specification, the copper substrate is a single integral structure; therefore, a corresponding heat dissipation hole is opened on the back of the molding compound, so that the entire back of the copper substrate is exposed outside the molding compound.

[0125] In some embodiments of this specification, the opening shape of the heat dissipation hole is rectangular, adapted to the shape of the copper substrate. The opening area of ​​the heat dissipation hole is equal to or slightly smaller than the back surface area of ​​the copper substrate, so that the back surface of the copper substrate is completely exposed, but the molding compound can still cover and fix the copper substrate at the edges. The specific size and shape of the heat dissipation hole can be adjusted according to the module packaging design.

[0126] In some embodiments of this specification, the back surface of the molding compound and the back surface of the copper substrate are located on the same plane through mold design and process parameter control during the injection molding process. During injection molding, parameters such as mold closing pressure, injection temperature, and holding time are controlled to ensure that the molding compound remains flat with the back surface of the copper substrate after curing. In other embodiments, the back surface of the molding compound can also be processed through a post-injection grinding process to make the back surface of the molding compound and the back surface of the copper substrate coplanar.

[0127] In some embodiments of this specification, the copper substrate is connected to the heat sink by applying thermal grease and then securing it with screws. Mounting holes are provided on the power module's molding compound; screws pass through these holes and are tightened into the threaded holes of the heat sink, ensuring a tight fit between the exposed back of the copper substrate and the mounting surface of the heat sink. In other embodiments, the copper substrate and heat sink can also be connected using thermally conductive double-sided tape or welding.

[0128] In some embodiments of this specification, since the back of the copper substrate is exposed outside the plastic package and the IGBT chip is directly soldered onto the copper substrate, the copper substrate and the collector of the IGBT chip are at the same potential. Therefore, the copper substrate carries a high voltage when powered on. During the assembly of the induction cooker, the heat sink, after being bonded to the copper substrate, also carries a high voltage. However, in the application scenario of the induction cooker, the heat sink is located inside the entire unit and is not in direct contact with human hands; corresponding insulation and protection measures are already in place in the overall design.

[0129] In a specific embodiment of this specification, taking an induction cooker application scenario as an example, the molding compound is made of epoxy resin material through injection molding. In the injection mold, a raised stop structure is provided in the mold area corresponding to the back of the copper substrate. After injection molding, this position forms a heat dissipation hole penetrating the back of the molding compound. The back of the copper substrate is exposed through this heat dissipation hole, and the exposed back of the copper substrate is flush with the back of the molding compound in the height direction. During the assembly of the induction cooker, a uniformly thick layer of thermally conductive silicone grease is applied to the exposed back of the copper substrate of the power module. Then, the power module is placed on the mounting surface of the heat sink, so that the exposed back of the copper substrate and the back of the molding compound simultaneously adhere to the mounting surface of the heat sink. By passing screws through the mounting holes on the molding compound and tightening them into the threaded holes of the heat sink, the power module is fixedly connected to the heat sink. Since the back of the molding compound and the back of the copper substrate are coplanar, after tightening, a uniform thin layer of thermally conductive silicone grease is formed between the exposed back of the copper substrate and the surface of the heat sink, with no air gaps and minimal contact thermal resistance. When the induction cooker is working, the heat generated by the rectifier and switching devices is directly transferred from the exposed back of the copper substrate to the thermal grease layer, and then to the heat sink substrate, where the heat sink fins dissipate the heat into the air.

[0130] Based on this, by creating heat dissipation holes on the back of the molding compound, the back of the copper substrate can be exposed outside the molding compound and directly connected to the heat sink. Heat from the copper substrate can be directly transferred to the heat sink through its exposed back surface without passing through the molding compound material. This avoids the low thermal conductivity of the molding compound hindering heat conduction, significantly shortening the heat conduction path, effectively reducing the total thermal resistance of the heat dissipation path, and significantly improving the heat dissipation efficiency of the power module, ensuring the module's reliability under high-power conditions. Simultaneously, the back of the molding compound and the back of the copper substrate are on the same plane, allowing for a tight fit between the exposed back of the copper substrate and the mounting surface of the heat sink. This avoids air gaps and increased contact thermal resistance caused by height differences, further improving thermal conductivity and heat dissipation consistency, and making the module's installation more stable and reliable.

[0131] Furthermore, the switching device includes at least one switching chip; if there are multiple switching chips, the multiple switching chips are connected in parallel on the copper substrate.

[0132] In this context, a switching chip refers to the core power semiconductor chip that constitutes a switching device, specifically the bare die of a power switching transistor. A switching chip has a control electrode and two power electrodes, achieving power conversion through high-frequency switching on and off. Switching chips can be IGBT chips or MOSFET chips, with the appropriate chip type and specifications selected based on the specific application requirements. The switching chips are directly soldered to the upper surface of a copper substrate, with the copper substrate providing electrical connections and thermal conductivity between the chips.

[0133] Parallel connection refers to the electrical connection of multiple switching chips in parallel, meaning that the first electrodes, second electrodes, and control electrodes of all switching chips are interconnected. In the embodiments of this specification, multiple switching chips form a parallel structure through a copper substrate, which serves as a common electrode plate. The control electrode of each switching chip is connected to the control electrode pin through its respective copper connecting piece and transition copper foil. The first electrode of each switching chip is connected to the first electrode pin through a conductive connecting piece, thereby forming a parallel circuit of multiple switching chips.

[0134] In practical applications, existing discrete device solutions require the selection of power switching transistors with different current ratings to meet the application requirements of different power levels. When the current capability of a single switching transistor is insufficient, additional external parallel devices are needed. This not only increases the circuit board area but also increases the complexity of parallel wiring and the inconsistency of parasitic parameters. In the embodiments of this specification, by placing multiple switching chips on the same copper substrate and connecting them in parallel, when high power output is required, the total current can be distributed across multiple switching chips. The current passing through each switching chip is reduced, and the conduction loss caused by its saturation voltage drop is correspondingly reduced, which helps to lower the junction temperature of a single chip. Simultaneously, when products with different power levels are needed, only the number of parallel switching chips needs to be increased or decreased for adaptation, without the need to customize switching devices with larger current ratings or change the overall package size and pin definitions of the module. This allows for a standardized and scalable approach to meet the needs of electromagnetic heating equipment with different power levels.

[0135] like Figure 1 As shown, the control unit 10 includes a switching device 5. The switching device 5 includes at least one switching chip, which is located on a copper substrate 3. In other embodiments, the switching device 5 may include multiple switching chips. When there are multiple switching chips, they are connected in parallel on the copper substrate 3. Specifically, the first electrode and second electrode of each of the multiple switching chips are respectively connected to a common first electrode pin and second electrode pin through corresponding conductive connecting pieces. The copper substrate 3 serves as a common connecting plate for the second electrodes of each switching chip, electrically connecting the second electrodes of the multiple switching chips into a single unit. The control electrode of each switching chip is connected to a common control electrode pin 13 through its respective copper connecting piece 18 and transition copper foil 17, thus electrically connecting the control electrodes of each switching chip into a single unit.

[0136] In specific implementations, in some embodiments of this specification, the switching chip can be an IGBT chip. An IGBT chip has a gate, a collector, and an emitter, wherein the collector is located on the back of the chip and is directly connected to the copper substrate via soldering, and the collector is at the same potential as the copper substrate.

[0137] In some embodiments of this specification, the parallel connection of multiple switching chips on a copper substrate is as follows: the second electrode of each switching chip, such as the collector of an IGBT, is connected to the copper substrate through its respective solder layer, with the copper substrate serving as a common second electrode plate for all switching chips; the first electrode of each switching chip, such as the emitter of an IGBT, is connected to a common first electrode pin through its corresponding conductive connecting piece; and the control electrode of each switching chip, such as the gate of an IGBT, is connected to a common control electrode pin through its corresponding copper tie and transition copper foil. This structure enables a true parallel connection of multiple switching chips.

[0138] In some embodiments of this specification, multiple switch chips are arranged side by side on the copper substrate in the same plane direction, with uniform spacing between each switch chip, to ensure consistency in heat dissipation conditions and electrical parameters among the chips.

[0139] In some embodiments of this specification, when multiple switching chips are connected in parallel, the specifications and models of each switching chip must be consistent. The external gate resistors of each switching chip are set independently to reduce the impact of parameter differences between the switching chips on current sharing in parallel. At the same time, a symmetrical design is adopted in the internal layout of the module to make the parasitic parameters of the leads of each switching chip as consistent as possible, so as to ensure that the current can be evenly distributed among the parallel switching chips during dynamic switching.

[0140] In a specific embodiment of this specification, taking an induction cooker application scenario as an example, the switching device is an IGBT device, comprising two IGBT chips. The two IGBT chips are soldered side-by-side onto the upper surface of a copper substrate. The copper substrate serves as the common collector of the two IGBT chips, and the collectors of the two IGBT chips are electrically connected as one unit through the copper substrate and connected to the collector pin through the copper substrate. The emitters of the two IGBT chips are respectively connected to the common emitter pin through their respective conductive connecting pieces. The gates of the two IGBT chips are respectively connected to the common gate pin through their respective copper connecting pieces and transition copper foil. The drive signal output from the external drive circuit is simultaneously transmitted to the gates of the two IGBT chips through the gate pins, causing the two IGBT chips to be turned on or off simultaneously. During operation, the total current flowing through the two IGBT chips is evenly distributed, with each IGBT chip only bearing half of the total current. For an induction cooker with an input power of 2200W, using a single IGBT chip may result in a peak current approaching the chip's current limit, leading to severe overheating. However, by using two IGBT chips in parallel, the current of each chip is only half of the original, significantly reducing conduction losses, overall heat generation, and reliability. When applied to higher-power commercial induction cookers, the number of IGBT chips connected in parallel can be further increased, for example, using three or four IGBT chips in parallel to meet the demand for higher current output.

[0141] Based on this, by setting the switching device to include at least one switching chip, and when there are multiple switching chips, connecting them in parallel on a copper substrate, the power level scalability of the power module is achieved. When it is necessary to meet the requirements of electromagnetic heating equipment with different power levels, only the number of parallel switching chips needs to be increased or decreased, without changing the overall package size and pin definition of the module, nor is it necessary to customize different specifications of switching devices for different power levels, thus reducing product development costs and inventory management difficulties. At the same time, after multiple switching chips are connected in parallel, the total current is distributed across multiple chips, reducing the current passing through each chip, and the conduction loss caused by its saturation conduction voltage drop is correspondingly reduced, which helps to reduce the junction temperature of individual chips and the overall heat generation, improving the efficiency and reliability of the power module in high-power application scenarios. In addition, the copper substrate, as the common connection plate of each switching chip, provides a uniform heat dissipation plane while realizing the parallel connection. The heat generated by each switching chip can be quickly conducted to the copper substrate and dissipated to the heat sink through the exposed back side, ensuring temperature uniformity and thermal stability when multiple chips are connected in parallel.

[0142] See Figure 5 , Figure 5 A device structure diagram of an electrical device according to an embodiment of this specification is shown. The electrical device 500 includes a main control unit 502 and the aforementioned power module 504; the main control unit is electrically connected to the power module and is used to control the operation of the electrical device through the power module.

[0143] In this context, "electrical equipment" refers to electrical devices that require a power source to operate and perform specific functions. In the embodiments of this specification, the electrical equipment can be an electromagnetic heating device, i.e., an appliance that works using the principle of electromagnetic induction heating, such as an induction cooker, an IH rice cooker, or an electromagnetic heating pressure cooker. The electrical equipment converts AC mains power into high-frequency AC power through a power module, driving a coil to generate a high-frequency alternating magnetic field. This causes eddy currents to form at the bottom of a ferromagnetic pot placed above the coil, resulting in heating and thus achieving the heating function. In other embodiments, the electrical equipment can also be other electrical devices that require converting AC power to DC power and performing high-frequency power conversion.

[0144] The main control unit (MCU) is the circuit module in an electrical device responsible for overall operation control and logical decision-making. It typically includes a microcontroller and its peripheral circuits such as crystal oscillators, reset circuits, and power management components. The MCU generates and outputs control signals, such as PWM drive signals, receives and processes feedback signals, such as temperature detection signals, current detection signals, and voltage detection signals, and executes preset control algorithms to control the operating state of the electrical device. The MCU is electrically connected to the power module, controlling the switching devices in the power module by outputting drive signals, and performing real-time temperature monitoring and over-temperature protection by receiving temperature detection signals from the power module.

[0145] An electrical connection refers to the formation of an electrical path between two components through a conductive medium, enabling the transmission of electrical signals or energy between them. In the embodiments of this specification, the electrical connection between the main control unit and the power module includes a drive signal transmission path and a detection signal feedback path. The drive signal transmission path is used to transmit the drive signal output by the main control unit to the control pin of the power module to control the on and off states of the switching devices; the detection signal feedback path is used to transmit the temperature detection signal from the temperature sensing pin of the power module to the main control unit to achieve temperature monitoring and over-temperature protection.

[0146] In practical applications, existing electrical equipment requires the main control unit to be electrically connected to multiple discrete components such as independent rectifier bridges, IGBT devices, and thermistors. The transmission paths for drive and detection signals are dispersed and complex, consuming significant I / O resources and PCB layout space. Furthermore, the individual heat dissipation requirements of these discrete components necessitate multiple heat sinks or a large-area heat sink within the entire device, limiting further reductions in overall size and cost. In the embodiments described in this specification, by applying the highly integrated power module to the electrical equipment, the main control unit only needs to be electrically connected to one module to achieve overall control of the rectifier unit, switch control unit, and temperature detection unit. This eliminates the need to connect multiple discrete components separately, simplifying the overall circuit layout and reducing the I / O interface resources and drive circuitry required by the main control unit. Meanwhile, the high integration and efficient heat dissipation characteristics of the power module mean that the electrical equipment does not need to set up separate heat dissipation areas for multiple power devices in the overall design. Only one heat sink is needed to meet the heat dissipation requirements of the entire power module, effectively reducing the internal space occupied by the whole machine. This provides a structural basis for the miniaturization and lightweighting of electrical equipment, enabling electrical equipment such as induction cookers to reduce the overall size and material costs while maintaining or improving heating performance. This better meets the current market demand for small-sized, cost-effective electromagnetic heating products.

[0147] In practice, the electrical equipment includes, but is not limited to, household cooking appliances such as induction cookers, IH rice cookers, electromagnetic heating pressure cookers, multi-functional cooking pots, and electric frying pans, as well as commercial high-power induction cookers, buffet warming stations, and industrial induction heating equipment. In all of these electrical devices, the power module serves as the core power conversion component, converting the input AC power into high-frequency AC power to drive the heating load.

[0148] In some embodiments of this specification, the electrical connection between the main control unit and the power module can be achieved by soldering wires, by routing copper foil traces on the PCB board, or by using connectors and ribbon cables for plug-in connection. The PWM drive signal output by the main control unit usually needs to be amplified by the gate driver chip for voltage and current enhancement before being transmitted to the control pin of the power module to ensure that the drive signal has sufficient driving capability to enable the switching devices to turn on and off quickly.

[0149] In some embodiments of this specification, the electrical device further includes a heat sink, which is bonded to the back of the copper substrate in the power module. The connection between the heat sink and the copper substrate is as follows: thermal grease is evenly applied to the exposed back of the copper substrate; the power module is placed on the heat sink mounting surface; and screws are passed through mounting holes on the plastic encapsulation and tightened into the threaded holes of the heat sink, ensuring a tight fit between the copper substrate and the heat sink. The heat sink is typically made of aluminum or copper, and its structure includes a substrate and multiple heat dissipation fins. The fins are oriented in the same direction as the fan airflow to improve convection cooling efficiency.

[0150] In some embodiments of this specification, the main control unit executes the over-temperature protection strategy in the following ways: when the temperature of the power module is detected to reach a first preset threshold, the main control unit reduces the duty cycle of the PWM drive signal to reduce the heating power; when the temperature continues to rise and reaches a second preset threshold, the main control unit stops outputting the PWM drive signal to stop the power module from working; when the temperature falls back to below a third preset threshold, the main control unit automatically resumes the output of the PWM drive signal to restore the power module to normal operation.

[0151] In a specific embodiment of this specification, an induction cooker is used as the electrical appliance. The induction cooker includes a main control unit and a power module. The main control unit uses a microcontroller chip and its peripheral circuitry, and is mounted on the main control PCB board of the induction cooker. The power module is the aforementioned integrated power module, which is fixed to an aluminum heat sink inside the induction cooker by screws. The fins of the heat sink face the fan outlet of the induction cooker, and the fan forces airflow for cooling. Two AC input pins of the power module's rectifier pins are connected to the power input terminals of the induction cooker, and two DC output pins are connected to the DC bus capacitor. The second electrode pin and the first electrode pin of the power module's switching pins are connected to the coil and resonant capacitor of the induction cooker. The control electrode pin of the power module is connected to the PWM output port of the main control unit through a drive resistor. The temperature sensing pin of the power module is connected to the ADC sampling port of the main control unit.

[0152] After the user sets the heating power via the buttons or touchscreen on the induction cooker panel, the main control unit calculates and generates a PWM drive signal with a corresponding duty cycle based on the user-set power level and the currently detected cookware status. This signal is transmitted to the gate of the IGBT chip in the power module via the control pin, controlling the high-frequency switching of the IGBT chip. When the IGBT chip is on, the DC bus current flows through the coil, storing magnetic field energy. When the IGBT chip is off, the coil releases energy through the resonant capacitor, forming a high-frequency oscillating current. By adjusting the duty cycle and switching frequency of the PWM drive signal, the output power of the coil can be precisely controlled, thereby achieving precise control of the cookware heating temperature. Simultaneously, the main control unit detects the resistance value of the thermistor in the power module in real time via the temperature sensing pin, calculating the current junction temperature of the IGBT chip based on the relationship between resistance and temperature. When the detected junction temperature exceeds the preset safety threshold, the main control unit immediately stops outputting the PWM drive signal, the IGBT chip turns off, heating stops, and the main control unit controls the induction cooker panel to display a fault code or issue an alarm. The system automatically resumes operation after the temperature returns to a safe range.

[0153] Based on this, by applying the highly integrated power module to electrical equipment, the main control unit only needs to be electrically connected to one power module to achieve overall control of the rectifier unit, switch control unit, and temperature detection unit. This eliminates the need to connect multiple discrete components separately, simplifying the overall circuit wiring, reducing the I / O interface resources and the number of peripheral drive circuits required by the main control unit, and lowering the complexity and development cycle of the overall circuit design. Simultaneously, the high integration of the power module eliminates the need for separate heat sinks for multiple power devices; a single heat sink is sufficient to meet the cooling needs of the entire module, effectively reducing the internal space occupied by the entire device. This provides a structural basis for the miniaturization, lightweighting, and compact design of the electrical equipment, and helps reduce overall material and assembly costs. Furthermore, the temperature detection unit integrated within the power module can sense the internal operating temperature of the module in real time and feed the temperature signal back to the main control unit. This allows the main control unit to execute a graded over-temperature protection strategy based on accurate temperature information, promptly reducing power or stopping heating in case of abnormal temperatures, effectively preventing damage to power devices due to overheating, and significantly improving the operational safety and long-term reliability of the electrical equipment.

[0154] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0155] The foregoing has described specific embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0156] It should be noted that, for the sake of simplicity, the foregoing embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0157] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0158] The preferred embodiments disclosed above are merely illustrative of this application. The optional embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this application. These embodiments are selected and specifically described in this application to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to better understand and utilize this application. This application is limited only by the claims and their full scope and equivalents.

Claims

1. An integrated power module, characterized in that, The power module includes a plastic package, and a rectifier unit and a control unit encapsulated within the plastic package, wherein... The rectifier unit is disposed on a ceramic substrate, the control unit is disposed on a copper substrate, and the ceramic substrate is welded to the copper substrate in a stacked manner; The back side of the copper substrate is exposed outside the molding compound for connection to the heat sink.

2. The power module according to claim 1, characterized in that, The rectifier unit includes a rectifier device located on the ceramic substrate, and the control unit includes a switching device located on the copper substrate; The encapsulation has rectifier pins electrically connected to the rectifier device and switch pins electrically connected to the switch device.

3. The power module according to claim 2, characterized in that, One side of the ceramic substrate is provided with a thermally conductive copper foil, and the other side is provided with multiple conductive copper foil areas; the rectifier device includes multiple rectifier diodes and conductive connecting pieces; The plurality of rectifier diodes in the rectifier device are soldered to the plurality of conductive copper foil areas through the conductive connecting piece; The ceramic substrate is welded to the copper substrate via the thermally conductive copper foil.

4. The power module according to claim 2, characterized in that, The power module also includes a temperature detection unit; The temperature detection unit is encapsulated within the plastic casing.

5. The power module according to claim 4, characterized in that, The switch pin includes a first electrode pin, and the plastic package also has a temperature sensing pin; The temperature detection unit is connected between the first electrode pin and the temperature sensing pin.

6. The power module according to claim 5, characterized in that, The switch pins include control electrode pins, and the ceramic substrate is also provided with a transition copper foil. One end of the adapter copper foil is electrically connected to the control electrode pin, and the other end of the adapter copper foil is electrically connected to the control electrode of the switching device through a copper strip.

7. The power module according to claim 6, characterized in that, The rectifier pin includes a first AC input pin, a second AC input pin, a first DC output pin, and a second DC output pin; the switch pin also includes a second electrode pin. The first AC input pin, the second AC input pin, the first DC output pin, and the second electrode pin are disposed at one end of the plastic package. The second DC output pin, the temperature sensing pin, the control electrode pin, and the first electrode pin are disposed at the other end of the encapsulation.

8. The power module according to claim 1, characterized in that, The back of the encapsulation body is provided with heat dissipation holes; The back side of the copper substrate is connected to the heat sink through heat dissipation holes; The back side of the molding compound is on the same plane as the back side of the copper substrate.

9. The power module according to any one of claims 2-7, characterized in that, The switching device includes at least one switching chip; When there are multiple switch chips, the multiple switch chips are connected in parallel on the copper substrate.

10. An electrical appliance, characterized in that, The electrical equipment includes a main control unit and a power module as described in any one of claims 1-9; The main control unit is electrically connected to the power module and is used to control the operation of the electrical equipment through the power module.

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