Mastering Miniaturization: Custom Coils for TWS And Smart Rings

The wearable technology market—comprising TWS earbuds, smartwatches, and smart rings—is defined by its constraints. Engineers must fit sophisticated power management and wireless charging circuitry into spaces measured in millimeters. In these applications, the size and Q-factor (quality factor) of the inductors and coils are the primary bottlenecks for battery life and signal clarity.

The Challenge: Shrinking the Footprint without Losing Power

A global consumer electronics brand (an OEM partner of Fuying) was designing a next-gen TWS earbud with active noise cancellation (ANC). The original inductor choice was too bulky, taking up 20% of the internal PCB space, and had a high DCR that drained the battery prematurely. They needed a micro-coil that was 30% smaller but maintained the same inductive performance.

The Fuying Micro-Precision Approach

Fuying Electronics utilized its specialized Ultra-Fine Wire Winding capabilities. We employed wire diameters as thin as 0.015mm—significantly thinner than a human hair.

To meet the space constraints, we developed an "irregular-shaped" coil design that fits perfectly around the earbud's internal battery housing. Our 100% automated optical inspection (AOI) ensured that despite the minute scale, each coil maintained a defect rate of <0.5%, a critical metric for high-volume consumer product launches.

The Outcome: Longer Playback and Compact Design

The new micro-coil design allowed the client to reclaim valuable PCB space for a larger battery, increasing playback time by 12%. Fuying's dual production bases provided the scalability needed for a global launch, shipping 1 million units in the first month. Our 3-5 day sampling cycle allowed the client to complete three design iterations in record time.