Planar transformer structure of integrated control chip

Abstract

The invention relates to the technical field of planar transformers, solves the technical problems that a traditional power module is low in integration level and reuse rate, long in development and design period, high in cost and low in yield, and particularly relates to a planar transformer structure of an integrated control chip. Comprising a planar transformer PCB (printed circuit board), a transformer magnetic core and a patch area reserved outside the planar transformer magnetic core on the planar transformer PCB, a control chip is integrated on the patch area, and the planar transformer PCB and the transformer magnetic core are selectively combined on a power supply bottom plate module to form a power supply module structure. In addition, the crystal nucleus of the control chip can be arranged in the PCB corresponding to the patch area. The power density of the power supply module can be improved, the complexity of production and processing of the power supply module is reduced, design replacement of a chip according to an application scene of the power supply module is facilitated, and the relatively independent processing technology can improve the yield of products and shorten the design time.

Description

Technical Field

[0001] The present invention relates to the technical field of planar transformers, and in particular to a planar transformer structure with an integrated control chip. Background Art

[0002] With the rapid development of portable electronic devices, higher and higher requirements are put forward for the charging speed of charging devices and the reduction of their size. Increasing the switching frequency is an effective means to reduce the size and improve the efficiency, but it will aggravate the EMI problem of the switching power supply.

[0003] Compared with traditional transformers, planar transformers have significant advantages in height, volume and mass. At the same time, it is easier to control parasitic capacitance, which can be used as a path for noise return. The thin structure of the planar transformer conductor can reduce the impact of high-frequency effects, thereby reducing losses.

[0004] However, in the power module, the planar transformer is only an integration of the transformer component part. It cannot achieve modular high integration compared to the power motherboard part and the control circuit part included in the entire power supply. Therefore, a unified design is required for each module, which results in the circuit control part still needing to meet the corresponding space requirements in the power supply. In addition, the various parts cannot be designed and produced independently and modularized, resulting in low reuse rate and matching between modules. At the same time, the development cycle is long, the production cost is high, and the product yield is also reduced. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a planar transformer structure with an integrated control chip, which solves the technical problems of low integration and reuse rate, long development and design cycle, high cost and low yield of traditional power modules.

[0006] To solve the above technical problems, the present invention provides the following technical solutions: a planar transformer structure with an integrated control chip, comprising a planar transformer module that can be optionally combined on a power base plate module to form a power module structure, wherein the planar transformer module comprises a planar transformer PCB that is pre-designed, a coil is integrated on the planar transformer PCB, and a transformer core that is sleeved on the outside of the planar transformer PCB is arranged at a position corresponding to the coil, a patch area connected to the planar transformer module is arranged on the planar transformer PCB, a control chip is integrated on the patch area, or a crystal core of the control chip is integrated in the PCB at the location of the patch area.

[0007] Furthermore, the power baseboard module includes a pre-designed module power PCB, an assembly area for detachably assembling a planar transformer module is provided on the module power PCB, and electrical components are integrated on the module power PCB.

[0008] Furthermore, the control chip is a control circuit integrated in a chip mode and applied in a power module.

[0009] Furthermore, the patch area is arranged on the upper surface of the planar transformer PCB, and the control chip is integrated and pasted on the upper surface of the planar transformer PCB corresponding to the patch area.

[0010] Furthermore, the patch area is arranged inside the planar transformer PCB, and the control chip is embedded in any one layer of the copper clad board in the planar transformer PCB.

[0011] Furthermore, the control chip is arranged on the primary winding of the planar transformer module.

[0012] Furthermore, the control chip is arranged on the secondary winding of the planar transformer module.

[0013] Furthermore, the two control chips are respectively arranged on the primary winding and the secondary winding of the planar transformer module.

[0014] By means of the above technical solution, the present invention provides a planar transformer structure with an integrated control chip, which has at least the following beneficial effects:

[0015] 1. The present invention can reduce the volume of the power module itself by modularly integrating the chip manufacturing on the planar transformer PCB in the form of a patch, thereby expanding its application range, improving the power density of the power module itself, reducing the complexity of the production and processing of the power module, and being more conducive to the design replacement of the chip manufacturing according to the application scenario of the power module. In addition, the relatively independent processing technology can improve the product yield and shorten the design time.

[0016] 2. The present invention greatly shortens the development cycle of the power plant, improves efficiency and development costs, and also reduces manufacturing costs. It has a high degree of integration, greatly reduces the workload of the power plant, reduces the cost of auxiliary materials used, reduces labor, and improves efficiency.

[0017] 3. The present invention aims to improve the consistency of power supply product output. The module, as a highly integrated single component, undergoes strict factory verification to ensure quality. The number of problems that may arise in the production process of the power supply factory will be reduced, reducing quality risks and improving yield.

[0018] 4. The present invention can comprehensively enhance the market competitiveness of power supply factory customers. Its high efficiency, convenience and excellent cost performance enable power supply factories to quickly win the recognition and trust of end customers and seize the market. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0020] Figure 1 This is a schematic diagram of the structure of the power module in the first embodiment of the present invention;

[0021] Figure 2 An exploded view of the power module structure in the first embodiment of the present invention;

[0022] Figure 3 Schematic diagram of the structure of the planar transformer module in the first embodiment of the present invention;

[0023] Figure 4 This is a connection diagram of the control chip integrated into the planar transformer in the first embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the integrated position of the control chip in the planar transformer in the first embodiment of the present invention;

[0025] Figure 6 This is a connection diagram of the control chip integrated into the planar transformer in the second embodiment of the present invention;

[0026] Figure 7 This is a connection diagram of the control chip integrated into the planar transformer in the third embodiment of the present invention;

[0027] Figure 8 Schematic diagram of the integrated position of the control chip in the planar transformer in the fourth embodiment of the present invention.

[0028] In the figure:

[0029] 1. Power baseboard module; 11. Module power PCB; 12. Assembly area; 13. Electrical components;

[0030] 2. Planar transformer module; 21. Planar transformer PCB; 22. Transformer core; 23. SMD area; 24. Control chip. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0032] Embodiment 1

[0033] Please refer to Figure 1-Figure 5, this embodiment proposes a planar transformer structure with an integrated control chip, including a planar transformer module 2 that can be optionally combined on a power base plate module 1 to form a power module structure, the power base plate module 1 includes a pre-designed module power PCB 11, an assembly area 12 for detachably assembling the planar transformer module 2 is provided on the module power PCB 11, and an electrical device 13 is integrated on the module power PCB 11. In this embodiment, the modular design combination between the power base plate module 1 and the planar transformer module 2 can make full use of the special planar structure of the planar transformer module 2 and the close combination of the windings, greatly improve the working state of the switching power supply, and reduce the skin effect loss. In addition, the flat geometry of the planar transformer module 2 also reduces the eddy current loss on the transformer core, so that it performs well in high power density converters. And the modular combination of the two parts is compactly designed, which can achieve high power density in a smaller volume, which makes it particularly suitable for application scenarios requiring high power density. For example, at 270V input and 13.9V / 1.8kW output specifications, the total equivalent leakage inductance of the planar transformer module 2 is about 2μH, which is much smaller than that of a traditional integrated transformer, allowing a high switching frequency to be designed.

[0034] The planar transformer module 2 includes a planar transformer PCB 21 formed by pre-design, a coil is integrated on the planar transformer PCB 21, and a transformer core 22 is set on the outside of the planar transformer PCB 21 at the position corresponding to the coil, and a patch area 23 connected to the planar transformer module 2 is provided on the planar transformer PCB 21, and a control chip 24 is integrated on the patch area 23, or a crystal core of the control chip 24 is integrated in the PCB at the location of the patch area 23. By integrating the crystal core of the control chip 24 into the PCB, the number of peripheral devices can be significantly reduced, thereby simplifying the overall design. It can also reduce external interference and electromagnetic radiation, improve signal integrity, and thus enhance the reliability and durability of the device. In addition, maintenance costs can also be reduced because the use of external components is reduced, and it helps to effectively dissipate heat, prevent overheating and potential damage, which is crucial for applications with thermal problems. Integrating the crystal core of the control chip 24 into the PCB also reduces the need for external components, simplifies the assembly process, reduces the error rate, and improves manufacturing efficiency, which helps save costs, improves processing speed and energy efficiency, and thus improves the performance of the entire system. This makes the design more flexible, and crystal oscillators of different frequencies and packages can be selected as needed to meet the needs of different electronic devices.

[0035] The control chip 24 is a control circuit integrated in a chip mode and used in a power module. For example, this embodiment is applicable to various power topologies such as Flyback topology (flyback topology), QR-Flyback topology (QR flyback topology), LLC topology, CLLC topology, Buck topology (buck topology), Boost topology (boost topology), Buck-Boost topology (buck-boost topology), Forward topology (forward topology), Push-Pull topology, Half-Bridge topology, Full-Bridge topology, SEPIC and Cuk topology. In this embodiment, the corresponding control chip can be selected according to different power topologies, and no limitation is made here.

[0036] Among them, the patch area 23 is set on the upper surface of the planar transformer PCB 21, and the control chip 24 is integrated and pasted on the upper surface of the planar transformer PCB 21 corresponding to the patch area 23. The control chip 24 is set on the primary winding of the planar transformer module 2. In this embodiment, by modularly integrating the control chip 24 on the planar transformer PCB 21 in the form of a patch, the volume of the power module itself can be reduced, making its application range wider, while improving the power density of the power module itself, reducing the complexity of the production and processing of the power module, and the modular integration method is more conducive to the design replacement of the control chip 24 according to the application scenario of the power module, and the relatively independent processing technology can improve the product yield and shorten the design time.

[0037] At the same time, the development cycle of the power supply plant is greatly shortened. The original power supply development cycle needs to go through EVI->DVT->PVT+safety application, which generally takes 3 to 6 months to complete. The implementation method proposed in the present invention can be shortened to 2 to 3 months, which improves efficiency and development costs. It also reduces manufacturing costs. The original LLC resonance or AHB asymmetric dual-tube solution has many discrete components. The implementation method proposed in this embodiment has half the number of main components of the QR flyback solution, high integration, and greatly reduces the workload of the power supply plant. The cost of auxiliary materials used is reduced, labor is reduced, and efficiency is improved. The comprehensive manufacturing cost can be reduced by 5 to 20%.

[0038] In addition, the consistency of power supply product output is improved. As a highly integrated single component, the module undergoes strict factory verification to ensure quality. The number of problems that may arise in the production process of the power supply plant will be reduced, reducing quality risks and improving yield.

[0039] Finally, it can comprehensively enhance the market competitiveness of power supply factory customers. The high efficiency, convenience and excellent cost performance enable power supply factories to quickly win the recognition and trust of end customers and seize the market.

[0040] Embodiment 2

[0041] This embodiment proposes this embodiment 2 on the basis of the embodiment 1, and the parts that are the same or similar to the embodiment 1 can refer to each other. In this embodiment, the secondary winding of the planar transformer module 2 is generally used to improve the current carrying capacity by using multiple winding layers in parallel, and because its current is relatively high, the secondary side is placed on the top to increase the heat dissipation conditions. In addition, in the design of the planar transformer, the secondary winding is generally located on the top of the PCB board to facilitate heat dissipation and optimize the design. Therefore, the control chip 24 is set on the secondary winding of the planar transformer module 2 to effectively manage the current and temperature and ensure the stable operation of the system. Please refer to Figure 6 In this embodiment, the control chip 24 is arranged on the secondary winding of the planar transformer module 2. This embodiment has the following advantages:

[0042] Improving heat dissipation conditions: Since the secondary winding current of planar transformer module 2 is relatively high, placing it on the top can improve heat dissipation conditions, thereby helping to reduce temperature rise and improve system stability and life.

[0043] Optimizing design and reducing parasitic effects: By optimizing the distance between the secondary windings, parasitic effects can be reduced and the efficiency of the planar transformer module 2 can be improved. This design can also adapt to the needs of large currents and ensure the stability of output voltage and current.

[0044] Reduce copper loss: The improved secondary winding structure can expand the conduction area and reduce the current density, thereby reducing the equivalent AC resistance generated by high-frequency current and avoiding additional winding losses, effectively reducing the copper loss of the transformer.

[0045] Improve system stability: Through decoupling technology, the two coils can be decoupled, thereby improving the stability and transmission efficiency of the system. This design ensures that the current change of one coil will not affect the other coil, thereby enhancing the overall performance of the system.

[0046] Embodiment 3

[0047] This embodiment proposes this embodiment 3 on the basis of the embodiment 1. The same or similar parts as the embodiment 1 can be referred to each other. In this embodiment, the planar transformer module 2 includes a primary winding and a secondary winding, and these windings can be distributed on a multi-layer PCB to form a vertical structure. In addition, the design of the planar transformer module 2 allows for separate PCB design on the primary side and the secondary side, which provides the possibility of installing control chips on different sides, thereby optimizing the performance and function of the transformer. Please refer to Figure 7 In this embodiment, two control chips 24 are respectively arranged on the primary winding and the secondary winding of the planar transformer module 2. This embodiment has the following advantages:

[0048] Improve system stability and transmission efficiency: By setting the control chip 24 on the primary side and the secondary side respectively, the two windings can be independently controlled, thereby optimizing the overall performance of the system. For example, by adjusting the size of the overlapping area of ​​the two windings, the two coils can be decoupled, reducing the impact of the current change of one coil on the other coil, thereby improving the stability of the system.

[0049] Optimizing leakage inductance and electromagnetic interference (EMI): Placing the control chip 24 on the primary side and the secondary side separately helps to better manage leakage inductance and electromagnetic interference. Since the design of the planar transformer module 2 allows for increased insulation between the winding layers, this helps to reduce leakage inductance and related AC losses. In addition, by placing the control chip 24 on different sides, parasitic parameters such as leakage inductance can be more effectively controlled, thereby further reducing EMI.

[0050] Reducing manufacturing costs: Separating the primary and secondary windings and providing the control chip 24 separately can simplify the manufacturing process and reduce production costs. This design method is conducive to adjusting the leakage inductance, and due to the application of PCB technology, it is easier to achieve mechanical processing and consistency control.

[0051] Improved efficiency and consistency: The planar transformer module 2 uses PCB technology to make the winding more consistent and repeatable, which is very important for the placement of the control chip 24 and the implementation of the control strategy. By setting the control chip 24 on different sides, the advantages of PCB technology can be better utilized to improve the overall efficiency and consistency of the planar transformer module 2.

[0052] Embodiment 4

[0053] This embodiment proposes this embodiment 4 on the basis of the embodiment 1. The parts that are the same or similar to the embodiment 1 can be referred to each other. In this embodiment, since the control chip 24 is integrated and attached to the upper surface of the planar transformer PCB 21, although this integration method can facilitate the selection of control chips 24 with different performances according to the specific application scenario of the power module, it is also easy to weld and integrate the control chip 24. However, the control chip 24 will also be exposed to the external environment, which will make the control chip 24 vulnerable to external factors such as vibration, moisture and dust, and will also have different degrees of influence on its electrical performance. In order to solve this technical defect, please refer to Figure 8 In this embodiment, the patch area 23 is arranged inside the planar transformer PCB 21, and the control chip 24 is embedded in any layer of the copper clad board in the planar transformer PCB 21, so that it has advantages in size, performance, reliability, cost and other aspects.

[0054] Furthermore, since the planar transformer module 2 in the prior art faces the problem of increased parasitic capacitance when operating at high frequencies, this may cause electromagnetic interference (EMI) problems and may damage the switching devices. Parasitic capacitance resonates with inductance, which may affect the stability and performance of the planar transformer module 2. In this embodiment, by embedding the control chip 24 in the planar transformer PCB 21, the thickness of the planar transformer PCB 21 can be increased. At the same time, the copper foil winding has a larger conductor thickness selection range, allowing a larger conductor to be selected to limit or reduce the complex parallel layers related to the skin depth, and the layer spacing can be adjusted, thereby alleviating the problem of parasitic capacitance. Experimental results show that after using a planar transformer PCB 21 with a thickness greater than 0.4 mm, the resonant frequency increases from 1.27 MHz to 1.63 MHz.

[0055] Specifically, the implementation method proposed in the fourth embodiment can improve space efficiency and compactness. Embedding the control chip 24 on any layer of the copper-clad board in the planar transformer PCB 21 can significantly reduce the overall size of the power module, making the power module more compact and portable. It not only saves assembly space, but also allows designers to implement more complex functions in a limited space.

[0056] At the same time, the signal integrity and electrical performance can be improved. The control chip 24 embedded in the planar transformer PCB 21 can shorten the signal path, reduce parasitic capacitance and inductance, and thus improve signal integrity and overall electrical performance. This is especially important for high-frequency applications because they can reduce signal degradation and interference. In addition, the present embodiment can also achieve the following beneficial effects, namely:

[0057] Enhanced reliability and durability: Since the control chip 24 is shielded within the PCB layer, it is less susceptible to external factors such as vibration, moisture and dust, thereby improving the reliability and durability of the device. In addition, by reducing solder joints and external connections, the number of failure points is also reduced, improving the stability of the system.

[0058] Improved thermal management: The proximity of the control chip 24 to the PCB layer helps to effectively dissipate heat, preventing overheating and potential damage. For example, by embedding a thermally conductive structure in the PCB, heat can be directly conducted to the thermal plane of the external layer, thereby reducing thermal resistance.

[0059] Reduce manufacturing costs and simplify design: Integrating the control chip 24 into a PCB reduces the number and types of external components, reduces system costs, simplifies the design and assembly process of the PCB, reduces the possibility of errors, and improves manufacturing efficiency.

[0060] Improve system integration and functional complexity: By integrating more functional modules into one chip, more complex functions can be realized and the processing speed and efficiency of the system can be improved.

[0061] Reduced Electromagnetic Interference (EMI): External noise coupling can be reduced by integrating EMI shielding, even eliminating the need for additional surface-mount shielding in some applications. This is especially important for devices that require high electromagnetic compatibility.

[0062] Each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the above embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0063] The above implementation methods have been described in detail. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A planar transformer structure with an integrated control chip, characterized in that: The invention comprises a planar transformer module (2) which is optionally combined on a power base plate module (1) to form a power module structure, wherein the planar transformer module (2) comprises a pre-designed planar transformer PCB (21), a coil is integrated on the planar transformer PCB (21), and a transformer core (22) sleeved on the outside of the planar transformer PCB (21) is arranged at a position corresponding to the coil, and a patch area (23) connected to the planar transformer module (2) is arranged on the planar transformer PCB (21), a control chip (24) is integrated on the patch area (23), or a crystal core of the control chip (24) is integrated in the PCB at the position of the patch area (23).

2. The planar transformer structure according to claim 1, characterized in that: The power baseboard module (1) comprises a pre-designed modular power PCB (11), an assembly area (12) for detachably assembling a planar transformer module (2) is provided on the modular power PCB (11), and an electrical device (13) is integrated on the modular power PCB (11).

3. The planar transformer structure according to claim 1, characterized in that: The control chip (24) is a control circuit integrated in a chip mode and used in a power module.

4. The planar transformer structure according to claim 1, characterized in that: The patch area (23) is arranged on the upper surface of the planar transformer PCB (21), and the control chip (24) is integrated and pasted on the upper surface of the planar transformer PCB (21) corresponding to the patch area (23).

5. The planar transformer structure according to claim 1, characterized in that: The patch area (23) is arranged inside the planar transformer PCB (21), and the control chip (24) is embedded in any one layer of the copper-clad board in the planar transformer PCB (21).

6. The planar transformer structure according to claim 1, characterized in that: The control chip (24) is arranged on the primary side winding of the planar transformer module (2).

7. The planar transformer structure according to claim 1, characterized in that: The control chip (24) is arranged on the secondary winding of the planar transformer module (2).

8. The planar transformer structure according to claim 1, characterized in that: The two control chips (24) are respectively arranged on the primary winding and the secondary winding of the planar transformer module (2).

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