Planar Transformer Revealed: Ideal for High Performance and High Density Power Conversion??

Planar Trasnformer, as the name suggest are also known as Flat transformers, which are a flat type of transformer. In recent years, with the increasing and high efficiency, Planar transformer are becoming a popular solution in power electronics design due ti their excellent performance. Below,we will introduce the main advanstages, core desgin difference and winding process of planar transformers in detail.

1. Core benefits of flat transformers

Flat-panel transformers have the following significant advantages:

• Large surface area, excellent heat dissipation:

The larger surface area facilitates rapid heat dissipation, allowing the transformer to carry greater current and power density.

?? Enhances system stability and reliability.

• Low loss and high efficiency

Low loss, universal efficiency up to 98% or more.

?? Energy efficient and environmentally friendly, ideal for high efficiency power systems.

• Excellent magnetic coupling design

Adopts thin sheet stacking design to improve magnetic coupling between windings and low leakage inductance.

?? Improve overall inductor performance and reduce system interference.

• Compact and thin structure

?? Low height and small size, typically 8 to 10 times smaller than conventional wire-wound transformers.

?? Space-saving and easy to integrate into a wide range of modern electronic equipment.

• Supports high switching frequencies

Can be applied in working scenarios above 700KHz to meet the demand for high-speed conversion.

?? Promote the development of high-frequency applications.

2. Key differences between flat transformers and conventional transformers

Core Design

Flat-panel transformers utilize cores with large widths and low heights, such as the EIR, EE, EI, and POT models.

Commonly used material is 95 material, with wide temperature, wide frequency, high BS and low loss characteristics, to meet the needs of high power and high density applications.

Winding design

Flat transformers are wound in various ways and can be categorized according to their structure:

Flat coil

Usually spiral wound, different sizes and wire diameters require special winding fixtures and higher development costs.

The pins usually need to be stripped of paint on all sides, and it is recommended to open holes for soldering through the tin, to enhance the reliability of soldering.

The design should pay attention to the width-to-thickness ratio of the wire: the conventional selection of the width-to-thickness ratio of 10 to 12, if it is greater than 15, it is prone to inner diameter line wrinkles, which may cause insulation damage.

Multi-layer PCB board winding

Commonly used substrate for FR4 copper-clad plate, copper thickness 1OZ ~ 5OZ (1OZ about 0.035mm), metallized pad hole copper thickness should be greater than 25μm, 30OZ or more than the thickness of copper holes copper thickness should be greater than 35μm.

Multi-layer board pad hole surface should use immersion gold process, gold thickness 0.05 ~ 0.075μm.

Copper sheet winding

Pure copper strip cutting or mold stamping, commonly used copper grade C1100 or T2 copper, molding is usually nickel-plated or tin-plated treatment.

In order to ensure the insulation performance, the surface of the copper sheet will also be coated with polyimide film, and through the high temperature and high pressure curing molding, in order to meet the requirements of voltage resistance.

3. Design considerations for practical applications

Flat-panel transformers require special attention to the following points in their design and manufacture:

• Heat Dissipation and Power Density: Large surface area design ensures excellent heat dissipation and supports high power density.
• Efficiency & Loss: Optimized sheet stacking and magnetic coupling design effectively reduces loss and ensures high efficiency.
• Size and Integration: Compact design allows it to take up less space in modern electronic devices.
• High-frequency applications: supports switching frequencies above 700KHz to meet high-frequency conversion requirements.

4. concluding remarks

Flat-panel transformers show great advantages in the field of modern power conversion thanks to their flat, thin, lightweight and highly efficient design. High power density, low losses, excellent magnetic coupling, and perfect adaptation to high-frequency switching make them the ideal power conversion solution.

Meanwhile, as a professional supplier of electronic components, LPEMA is committed to providing customers with the highest quality and most reliable transformer solutions. We specialize in the research, development and production of high frequency transformers and flat transformers, with advanced manufacturing process and strict quality control, to protect your design. If you have more questions about flat transformers or need technical support, please feel free to contact us!

?? WhatsApp Direct: +86 15171571200

?? Email: [email protected]

?? Official Site: www.lpema.com