Custom Flat Enameled Wire Coils for Automotive Wireless Charging Modules

An automotive electronics supplier was developing a wireless charging module for installation inside a vehicle center console. The customer wanted to keep the module thin while maintaining stable charging performance when the phone was placed slightly away from the center of the charging area.

The initial round-wire coil occupied too much vertical space. When the coil thickness was reduced, charging efficiency became less stable and the component temperature increased during extended charging. Nearby metal brackets and the center-console structure also affected the magnetic coupling between the transmitter coil and the receiver coil.

Golden Eagle reviewed the center-console drawing, available installation height, charging power, operating frequency, coil dimensions, ferrite shielding, surface material, controller design, and allowable phone-position deviation. The objective was to develop a coil that could fit the compact structure while maintaining suitable electrical and thermal performance.

A flat enameled wire structure was evaluated to improve conductor utilization within the limited space. Compared with a standard round-wire structure, flat wire can provide a larger conductor cross-section in a controlled height, but the forming process requires careful control. Excessive bending, sharp corners, winding pressure, or insulation damage may affect the final reliability of the coil.

The engineering team adjusted the coil outline, winding position, lead direction, and ferrite shielding arrangement according to the center-console structure. The coil was then tested with the customer's charging controller and representative housing rather than only being tested as an independent component.

The customer evaluated charging efficiency at different phone positions, coil temperature, surface temperature, long-duration charging, nearby-metal influence, vibration, temperature cycling, and assembly tolerance. For automotive-related projects that require operation above 85°C, the actual thermal range, materials, and test conditions should be confirmed according to the final product design.

Golden Eagle supports custom CNC processes, OEM/ODM coil development, and rapid prototyping for suitable projects. The company highlights 15 years of R&D experience, approximately 3–5 days of sample development for suitable projects, and a production defect-rate target below 0.5%. These figures should be verified through project records and inspection reports before being used as formal customer claims.

The customized flat-wire coil helped the customer create a more compact charging module and provided a clearer basis for evaluating alignment, heat generation, shielding, and assembly consistency. It also allowed the customer to assess the wireless charging system before finalizing the center-console structure.

When requesting a custom automotive wireless charging coil, buyers should provide the center-console drawing, coil height, charging power, operating frequency, ferrite requirements, surface material, distance between the coil and phone, temperature range, vibration requirements, and expected annual quantity.

Golden Eagle can support wireless charging coil development for automotive interiors, smart devices, and other compact charging products. Final charging efficiency, thermal performance, and compliance status should always be confirmed through the complete terminal product.