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Transformer PCB (printed circuit board transformer) is a new type of transformer technology. It replaces the winding structure in traditional transformers by printing conductive materials on PCB to form coils, achieving high integration and miniaturization, and providing strong support for the miniaturization and efficiency of electronic equipment.
1. Technical principle of transformer PCB
Electromagnetic principle
The design of transformer PCB is based on Faraday's law of electromagnetic induction, that is, when the current in the coil changes, an induced electromotive force will be generated in the adjacent coil. This is the basis for the operation of the transformer. In the transformer PCB, the primary coil and the secondary coil are magnetically coupled through the magnetic core to achieve voltage and current conversion.
Material selection
Transformer PCB usually uses magnetic materials as the core, such as ferrite or soft magnetic composite materials. These materials have high magnetic permeability and low loss characteristics, which help to improve the efficiency of the transformer. In addition, the PCB board needs to have good electrical and mechanical properties, and the winding material needs to select the appropriate wire diameter and material according to the current size and frequency characteristics.
Coil design
The coil is the main component of the transformer PCB, and they are printed on the PCB in a specific pattern. The design of the coil needs to consider the current density, the number of coil turns, and the layout of the coil to ensure that the performance of the transformer meets the design requirements. There are "through holes" between the layers of the PCB for the windings to be interconnected, and the turns between the windings are connected in series or parallel through the "through holes".
Coupling coefficient and frequency response
The coupling coefficient is an indicator of the efficiency of energy transfer between the primary and secondary coils of the transformer. In the transformer PCB design, the coupling coefficient is improved by optimizing the layout and turns ratio of the coil. The frequency response depends on the physical size of the transformer PCB and the electrical characteristics of the coil. The operating frequency needs to be considered during design to ensure that the transformer has good performance within the required frequency range.
Thermal management and integration
Since the transformer PCB generates heat when it is working, thermal management needs to be considered. When designing, it may be necessary to add a heat sink or use a high thermal conductivity material to help dissipate heat. One advantage of the transformer PCB is its high integration. It can be integrated on the same PCB with other electronic components, thereby reducing the volume and weight of the entire system.
transformer PCB
2. Manufacturing process of transformer PCB
The manufacturing process of transformer PCB is a complex and precise process, which involves multiple steps, including design, material selection, cutting, winding, assembly, welding and testing.
Design: First, the planar transformer needs to be designed according to the specifications and requirements. This includes determining the number of layers, the size and shape of the transformer, the winding pattern and other design parameters.
Material selection: PCB planar transformers can be composed of independent standard stacked circuits or small multi-layer PCB board components, or integrated into the power multi-layer PCB board. The selected materials need to meet the requirements of multi-layer (4-12 layers), low height (2-3mm) and high current of the winding.
Cutting and assembly: Silicon steel sheets are the core material of the transformer. After pre-processing, they need to be cut and assembled according to the design requirements. In this process, workers need to use precision cutting tools and equipment to ensure that the size and shape of the silicon steel sheets meet the requirements.
Winding: Winding is another important component of the transformer. Planar transformers generally use E-type, RM-type, EC, ETD and EER-type cores made of high-frequency power ferrite soft magnetic materials. During the winding process, the tension and winding speed of the coil should be controlled to ensure the uniformity and tightness of the coil.
Insulation treatment: After the winding is completed, insulation treatment is required to ensure the safety and reliability of the transformer. This usually includes measures such as applying insulating paint, using insulating tape or insulating paper.
Assembly welding: Assemble the wound coil and the core together and weld them to ensure the firmness of the connection.
Testing and debugging: Finally, the transformer needs to be tested and debugged to ensure that its performance meets the design requirements. This includes thermal resistance test, leakage inductance test and power density test, etc.
Quality inspection: Only after strict process control and quality inspection can high-quality transformer products be produced.
3. Design points of transformer PCB
Layout design
In the 6kW high-power inverter PCB design, the layout of the transformer is crucial. The transformer should be arranged as close to the power supply part as possible to reduce the length of the power line, reduce the influence of resistance and inductance, and improve efficiency. At the same time, good heat dissipation design should be considered, such as a suitable heat sink or heat dissipation area. The layout around the transformer should consider electromagnetic shielding and reduce radio frequency interference to avoid affecting the system and surrounding electronic equipment.
Heat dissipation design
The transformer will generate a lot of heat when running at high power, so enough space should be reserved to install the heat sink or ensure good air flow around to avoid overheating of the transformer. Copper-based PCB or heat sink can be used to ensure that the heat can be effectively conducted and dissipated.
Wiring and shielding
The input and output ends of the transformer should use wide and short PCB wires as much as possible to reduce resistance and inductance and reduce losses. If conditions permit, consider arranging a ground plane and a shielding cover around the transformer to effectively reduce electromagnetic radiation and reception interference.
4. Application prospects of transformer PCB
Transformer PCB has broad application prospects in many fields due to its small size, light weight, high integration and stable performance.
Portable electronic devices: With the popularization of portable electronic devices, the requirements for miniaturization and high efficiency of power supplies are getting higher and higher. Transformer PCB can meet this demand and provide stable power supply for mobile phones, tablets and other devices.
New energy vehicles: New energy vehicles have extremely high requirements for the efficiency and reliability of the power system. Transformer PCB can be applied to the charging system, motor drive system, etc. of new energy vehicles to improve the performance and stability of the power system.
Renewable energy systems: In renewable energy systems such as solar energy and wind energy, transformer PCBs can be used to achieve voltage and current conversion and improve energy conversion efficiency.
Industrial automation: In the field of industrial automation, transformer PCBs can be used in motor control, sensor power supply, etc. to improve the performance and reliability of equipment.