An integrated power module for an induction cooker

Abstract

The utility model discloses an integrated power module of electromagnetic stove relates to the field of semiconductor technology, including plastic package body, and the ceramic plate, copper base plate, rectifier, IGBT device and thermistor are encapsulated in plastic package body, and the one side of ceramic plate has heat conduction copper foil, and the other side has conductive copper foil area, and rectifier forms rectifier unit through welding on conductive copper foil area, and IGBT device forms switch control unit through welding to copper base plate, and the plastic package body is fixed with rectification pin, IGBT pin and temperature sensing pin, and thermistor is fixed between temperature sensing pin and IGBT pin, and the plastic package body back has the hole of giving way, and heat conduction copper foil and copper base plate are located in the hole of giving way respectively. The utility model discloses on the basis of cancelling the PCB board, and the radiator can be configured to heat dissipation effectively, can reduce production cost while realizing module volume reduction and promoting integration, and the technical problem of lower integration, larger volume and higher cost of prior art has been solved.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor device technology, specifically to an integrated power module for an induction cooker. Background Technology

[0002] The induction cooker industry is currently at a critical stage of cost competition and low-profit margins: on the one hand, price wars in the end-user market have become the norm, continuously squeezing profit margins and making cost control a core issue for survival and development. On the other hand, consumer demands are constantly upgrading, with increasingly clear requirements for smaller size and higher power induction cookers, demanding effective overall cost control while ensuring performance is not compromised. This industry situation makes the shortcomings of traditional discrete component solutions increasingly prominent, making them unable to meet the current market's dual demands for cost and performance.

[0003] In the core power circuit of an induction cooker, the rectifier bridge and IGBT (Insulated Gate Bipolar Transistor) are two key semiconductor devices, and their functions are indispensable: the rectifier bridge is responsible for rectifying the AC mains power into DC power to supply power to the subsequent circuits; the IGBT undertakes the core functions of power switching and voltage regulation, which directly affects the heating efficiency and stability of the induction cooker.

[0004] In traditional discrete component solutions, the rectifier bridge and IGBT require separate PCB boards and heat sinks, along with separately configured peripheral auxiliary components such as thermistors, leading to the following technical problems: 1. Based on the mounting positions of the rectifier bridge, IGBT, and thermistor, independent soldering points and wiring areas need to be reserved on the PCB board. Furthermore, to ensure circuit safety, high-voltage isolation distances conforming to specifications must be designed between each component. These space requirements make it difficult to reduce the PCB board area, resulting in a larger product size.

[0005] 2. Both the rectifier bridge and IGBT are high-heat-generating devices. In traditional solutions, each requires a separate heatsink to ensure heat dissipation efficiency and prevent damage from overheating, which increases the number of heatsinks required. Furthermore, the cost of a PCB board is positively correlated with its area; a larger PCB board directly increases material costs. The combination of these factors not only increases material procurement costs but also further exacerbates the cost pressure on enterprises.

[0006] Therefore, there is an urgent need for an innovative integration solution that is more integrated, smaller in size, and lower in cost to solve the above-mentioned technical problems. Utility Model Content

[0007] This utility model addresses the shortcomings and defects of the existing technology by proposing an integrated power module for induction cookers. This power module integrates the rectifier bridge, IGBT, and thermistor into one unit using a plastic encapsulation. By eliminating the PCB board, a heat sink can effectively dissipate heat, thereby reducing production costs while achieving a reduction in power module size and an increase in integration. This solves the technical problems of low integration, large size, and high cost in the existing technology.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows: An integrated power module for an induction cooker includes a plastic encapsulation, wherein, The plastic package contains a ceramic plate, a copper substrate, a rectifier, an IGBT device, and a thermistor. The ceramic plate and the copper substrate are spaced apart. A thermally conductive copper foil is fixed on one side of the ceramic plate, and multiple conductive copper foil areas are fixed on the other side of the ceramic plate as needed. The rectifier is formed by welding the conductive copper foil areas to form a rectifier unit, and the IGBT device is formed by welding it to the copper substrate to form a switch control unit. The encapsulation is respectively fixed with a rectifier pin electrically connected to the rectifier unit, an IGBT pin electrically connected to the switch control unit, and a temperature sensing pin electrically connected to the thermistor. The thermistor is fixed between the temperature sensing pin and the IGBT pin through the encapsulation. The back of the encapsulation body has clearance holes corresponding to the thermally conductive copper foil and the copper substrate, respectively, with the thermally conductive copper foil and the copper substrate located inside the clearance holes.

[0009] The rectifier pins include two AC input pins and two DC output pins. The IGBT pins include a gate pin, a collector pin, and an emitter pin. The thermistor is soldered between the temperature sensing pin and the emitter pin through a plastic encapsulation.

[0010] A separate adapter copper foil is also fixed on the ceramic plate. One end of the adapter copper foil is soldered to the G terminal pin, and the other end is connected to the G terminal of the switch control unit through a soldered copper strip.

[0011] The rectifier pin, IGBT pin, and temperature sensing pin are symmetrically arranged on the upper and lower sides of the plastic package, respectively. The input pin, one of the DC output pins, and the C pin are arranged sequentially on the upper side of the plastic package, while the other DC output pin, the G pin, the temperature sensing pin, and the E pin are arranged sequentially on the lower side of the plastic package.

[0012] The back of the molding compound and the thermally conductive copper foil and copper substrate on the back are all located on the same plane.

[0013] The IGBT device includes at least one IGBT chip. When there are multiple IGBT chips, the multiple IGBT chips are connected in parallel through a copper substrate.

[0014] The minimum distance between the ceramic plate and the copper substrate is 0.8 mm.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. This utility model utilizes a ceramic plate to support the rectifier unit and a copper substrate to support the switch control unit. The thermistor is then integrated with the rectifier unit and the switch control unit through a plastic encapsulation. Compared with the prior art, the PCB board is eliminated, and only one heat sink is needed to effectively dissipate heat for both the rectifier unit and the switch control unit. Furthermore, the built-in thermistor structure reduces the need for separate installation steps, thereby simplifying the wiring structure. It has the advantages of improving product integration, reducing size, and effectively reducing costs.

[0016] In addition, the present invention, through the avoidance hole, allows the thermally conductive copper foil and the back of the copper substrate on the DBC board to be directly exposed, which facilitates connection with the heat sink and enables direct heat transfer, thereby improving the heat dissipation effect.

[0017] 2. This invention uses a plastic encapsulation to solder the thermistor between the temperature sensing pin and the emitter pin. Since the IGBT chip is mounted on the emitter pin via a jumper, the efficient heat transfer between copper components ensures that the temperature measured by the thermistor is closer to the actual junction temperature of the IGBT chip. Furthermore, integrating the thermistor into the module reduces the PCB area and installation steps.

[0018] 3. This invention achieves the lead-out of the gate (G) pin of the switch control unit by using a copper foil and copper tie. Since the G pin is longer and thinner than other pins, if the copper tie is directly soldered to the G pin, the pin deformation under external pressure or during installation can easily cause the copper tie to shift, leading to the detachment of the gate solder joint on the IGBT device and causing the switch control unit to fail. Therefore, using a copper foil as an intermediate transition area between the G pin and the copper tie can effectively reduce stress and improve product reliability.

[0019] 4. The pins of this utility model adopt a relatively symmetrical structure, with a compact arrangement that does not affect the operation of each pin. This results in an aesthetically pleasing and practical design while effectively reducing the impact of parasitic inductance. This reduces the product size while maintaining safe distances between pins. Furthermore, the power pins (such as the collector and emitter) of the IGBT device are the primary heat conduction paths. Symmetrically arranging them on the top and bottom sides of the module facilitates heat dissipation to both sides, preventing heat accumulation on one side and improving overall heat dissipation efficiency.

[0020] 5. The entire back of this module is a flat surface without any uneven steps. This maximizes the effective contact area and the cross-sectional area of ​​the heat conduction path when the module is installed on the heat sink, thereby effectively reducing thermal resistance and improving overall heat dissipation efficiency and reliability. Furthermore, when fixing the molded body with screws at both ends, if the surface is uneven, the raised copper substrate will bear most of the installation stress, potentially causing the molded body to crack or internal connections to be damaged. Simultaneously, the coplanar design ensures that pressure is evenly distributed across the entire back of the module, and the flat surface allows the thermal paste to be easily pressed into a uniform, bubble-free thin layer. Attached Figure Description

[0021] Figure 1 This is a plan view of the internal structure of this utility model; Figure 2 This is a plan view of the back of the present invention; Figure 3 This is a three-dimensional structural diagram of the present invention.

[0022] The following are labeled in the diagram: 1. Molded enclosure, 2. Ceramic plate, 3. Copper substrate, 4. Rectifier, 5. IGBT device, 6. Thermistor, 7. Thermally conductive copper foil, 8. Conductive copper foil area, 9. Rectifier unit, 10. Switch control unit, 11. Rectifier pin, 12. Temperature sensing pin, 13. Gate pin, 14. Collector pin, 15. Exit pin, 16. Clearance hole, 17. Adapter copper foil, 18. Copper tie. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0024] See Figures 1-3 This utility model provides an integrated power module for an induction cooker, which includes a plastic encapsulation 1, wherein... The encapsulated body 1 encapsulates a ceramic plate 2, a copper substrate 3, a rectifier 4, an IGBT device 5, and a thermistor 6. The ceramic plate 2 and the copper substrate 3 are spaced apart, with a minimum spacing of 0.8 mm, to ensure a safe distance for high-voltage isolation. The ceramic plate 2 has two parallel sides. One side is chemically bonded to a thermally conductive copper foil 7, and the other side is chemically bonded to multiple conductive copper foil areas 8 as needed. The rectifier 4 includes multiple rectifier diode chips, conductive connecting pieces, etc., and is soldered onto the conductive copper foil areas 8 to form a rectifier unit 9. The IGBT device 5 includes an IGBT chip, conductive connecting pieces, etc., and is soldered onto the copper substrate 3 to form a switch control unit 10.

[0025] The plastic package 1 is respectively fixed with a rectifier pin 11 that is electrically connected to the rectifier unit 9, an IGBT pin that is electrically connected to the switch control unit 10, and a temperature sensing pin 12 that is electrically connected to the thermistor 6. The other end of each pin extends out of the plastic package 1. The thermistor 6 is fixed between the temperature sensing pin 12 and the IGBT pin through the plastic package 1, which improves the integration of the module and avoids the need for separate wiring to connect the thermistor 6.

[0026] It should be noted that the thermistor 6 primarily measures the temperature rise of the IGBT device 5. The emitter (E) terminal of the IGBT device 5 is connected to the emitter pin 15 via a jumper, and the thermistor 6 is soldered between the temperature sensing pin 12 and the emitter pin 15. At this point, the heat from the IGBT chip is transferred to the thermistor 6 through the copper conductor. By observing the change in resistance between the temperature sensing pin 12 and the emitter pin 15, the junction temperature of the IGBT chip can be obtained. Furthermore, the thermistor acts as a temperature acquisition device, integrated inside the product, closer to the heat source, resulting in more accurate results.

[0027] The back of the molding compound 1 has two clearance holes 16, which correspond to the thermally conductive copper foil 7 and the copper substrate 3, respectively. The thermally conductive copper foil 7 and the copper substrate 3 are located within the clearance holes 16, and both are exposed through the clearance holes 16, facilitating direct connection between the thermally conductive copper foil 7 and the copper substrate 3 and the heat sink. When the module is working, the heat from the rectifier 4 can be directly transferred to the heat sink through the ceramic plate 2 and the thermally conductive copper foil 7 for heat dissipation, and the heat generated by the IGBT device 5 can be directly transferred to the heat sink through the copper substrate 3 for heat dissipation.

[0028] It should be noted that the aforementioned IGBT device 5 includes at least one IGBT chip. When there are multiple IGBT chips, the multiple IGBT chips are connected in parallel through the copper substrate 3. Furthermore, the structures of the aforementioned rectifier unit 9 and switch control unit 10 are both existing conventional technologies, which can be directly obtained by those skilled in the art and will not be described in detail here.

[0029] See Figures 1-3 The rectifier pin 11 includes two AC input pins and two DC output pins. The IGBT pins include a gate pin 13, a collector pin 14 and an emitter pin 15. The thermistor 6 is soldered and fixed between the temperature sensing pin 12 and the emitter pin 15 through a plastic encapsulation 1.

[0030] See Figure 1 The ceramic plate 2 is also separately fixed with an adapter copper foil 17. One end of the adapter copper foil 17 is soldered to the G pole pin 13, and the other end is connected to the G pole of the switch control unit 10 through the soldered copper connecting piece 18.

[0031] It should be noted that, compared to other pins, the gate pin 13 is relatively long and thin. In this case, the copper strip 18 is directly soldered onto the gate pin 13. Under significant external pressure or during installation, deformation of the pin can easily cause the copper strip 18 to shift, leading to the detachment of the gate solder joint on the IGBT device 5 and causing the switch control unit to fail. Therefore, by using a transition copper foil as the intermediate transition area between the gate pin 13 and the copper strip 18, stress can be effectively reduced, and product reliability can be improved.

[0032] See Figures 1-3 The rectifier pin 11, IGBT pin, and temperature sensing pin 12 are symmetrically arranged on the upper and lower sides of the molded body 1, respectively. The input pin, one DC output pin, and collector pin 14 are arranged sequentially on the upper side of the molded body 1, while the other DC output pin, gate pin 13, temperature sensing pin 12, and emitter pin 15 are arranged sequentially on the lower side of the molded body 1. The arrangement of the pins is relatively compact, yet does not affect their respective operation. This reduces the product size while ensuring safe distances between pins, effectively reducing the impact of parasitic inductance. Furthermore, the power pins (such as collector and emitter pins) of the IGBT device are the main heat conduction paths; symmetrically arranging them on the upper and lower sides of the module facilitates heat dissipation to both sides, preventing heat accumulation on one side and improving overall heat dissipation efficiency.

[0033] See Figure 2 In practical applications, the thermally conductive copper foil 7 and the copper substrate 3 are directly fixed to the heat sink. Therefore, this invention sets the back of the molding compound 1 and the thermally conductive copper foil 7 and copper substrate 3 on the same plane, enabling the back of the molding compound 1, the thermally conductive copper foil 7, and the copper substrate 3 to fit tightly against the mounting surface of the heat sink, thus reducing product size and improving heat dissipation.

[0034] Currently, the size of a single commercially available rectifier bridge is approximately 20 mm * 30 mm, while the size of this utility model, based on the above-mentioned integrated structure, can be as small as 19 mm * 26 mm. It can be seen that this utility model can improve the integration level and reduce the size of the product while integrating more components and increasing functions, thus making it more practical.

[0035] Please see Figure 1In this invention, the rectifier unit 9 converts the AC power input from the mains into DC power. In the induction cooker, the upper rectifier pin 11 is connected to the positive terminals of the two AC input terminals and the DC output terminal, while the lower rectifier pin 11 is connected to the negative terminal of the DC output terminal. When the input AC current is in the positive half-cycle, it enters the rectifier diode chip located in the upper left corner through the first rectifier pin 11. After passing through the conductive copper foil area 8, it flows out from the positive terminal of the DC output. After passing through the external load, the current returns to the lower rectifier pin 11, i.e., the negative terminal of the DC output. At this time, the current flows through the rectifier diode chip located in the lower right corner and finally returns to the upper second rectifier pin 11 through the jumper. Similarly, when the input AC current is in the negative half-cycle, it enters the rectifier diode chip located in the upper right corner through the second rectifier pin 11. After passing through the conductive copper foil area 8, it flows out from the positive terminal of the DC output. After passing through the external load, the current returns to the lower rectifier pin 11. At this time, the current flows through the rectifier diode chip located in the lower left corner and returns to the upper first rectifier pin 11 through the jumper between the chips. After one rectification cycle, the sinusoidal AC current is converted into DC current with only positive voltage. A filter circuit is then needed to correct the current, thereby achieving the purpose of converting the input AC current into DC current.

[0036] Regarding heat dissipation testing, the inventors compared the integrated module of this invention with existing conventional single-unit devices, testing the temperature of the epoxy surfaces of both under the same operating conditions. The test results showed that the temperatures of both were essentially at the same level. Furthermore, this invention can be adapted to smaller heat sinks, reducing costs. Therefore, this invention reduces the overall weight of the induction cooker while achieving system miniaturization, weight reduction, and cost reduction.

[0037] The above description is only a specific embodiment of this utility model. Any feature disclosed in this specification may be replaced by other equivalent features unless otherwise specified. All features or steps in all methods or processes disclosed may be combined in any way except for mutually exclusive features and / or steps.

Claims

1. An integrated power module for an induction cooker, comprising a plastic encapsulation (1), characterized in that: The encapsulation (1) contains a ceramic plate (2), a copper substrate (3), a rectifier (4), an IGBT device (5), and a thermistor (6). The ceramic plate (2) and the copper substrate (3) are spaced apart. A thermally conductive copper foil (7) is fixed on one side of the ceramic plate (2), and multiple conductive copper foil areas (8) are fixed on the other side of the ceramic plate (2) as needed. The rectifier (4) is formed into a rectifier unit (9) by welding onto the conductive copper foil area (8), and the IGBT device (5) is formed into a switch control unit (10) by welding onto the copper substrate (3). The encapsulation (1) is respectively fixed with a rectifier pin (11) electrically connected to the rectifier unit (9), an IGBT pin electrically connected to the switch control unit (10), and a temperature sensing pin (12) electrically connected to the thermistor (6). The thermistor (6) is fixed between the temperature sensing pin (12) and the IGBT pin through the encapsulation (1). The back of the encapsulation body (1) is provided with clearance holes (16) corresponding to the thermally conductive copper foil (7) and the copper substrate (3), respectively, and the thermally conductive copper foil (7) and the copper substrate (3) are located in the clearance holes (16).

2. The integrated power module for an induction cooker according to claim 1, characterized in that: The rectifier pin (11) includes two AC input pins and two DC output pins. The IGBT pin includes a gate pin (13), a collector pin (14) and an emitter pin (15). The thermistor (6) is soldered between the temperature sensing pin (12) and the emitter pin (15) through a plastic package (1).

3. The integrated power module for an induction cooker according to claim 2, characterized in that: A separate adapter copper foil (17) is fixed on the ceramic plate (2). One end of the adapter copper foil (17) is soldered to the G pole pin (13), and the other end is connected to the G pole of the switch control unit (10) through the soldered copper connecting piece (18).

4. The integrated power module for an induction cooker according to claim 2, characterized in that: The rectifier pin (11), IGBT pin and temperature sensing pin (12) are symmetrically arranged on the upper and lower sides of the plastic package (1), and the input pin, one of the DC output pins and the C pin (14) are arranged on the upper side of the plastic package (1), while the other DC output pin, the G pin (13), the temperature sensing pin (12) and the E pin (15) are arranged on the lower side of the plastic package (1).

5. An integrated power module for an induction cooker according to any one of claims 1-4, characterized in that: The back of the encapsulated body (1) is on the same plane as the thermally conductive copper foil (7) and the copper substrate (3) on the back.

6. The integrated power module for an induction cooker according to claim 1, characterized in that: The IGBT device (5) includes at least one IGBT chip. When there are multiple IGBT chips, the multiple IGBT chips are connected in parallel through a copper substrate (3).

7. The integrated power module for an induction cooker according to claim 1, characterized in that: The minimum distance between the ceramic plate (2) and the copper substrate (3) is 0.8 mm.

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