Multilayer PCB Voice Coil for Flat-Panel Speaker Output

The voice coil is divided into multiple separate PCB layers, each functioning as an independent coil segment. By stacking multiple PCB layers (4-layer or more even-numbered layers) and connecting them in series, the total number of turns is effectively increased across layers while maintaining manageable resistance per layer. This segmentation allows the system to achieve high induced electromotive force without concentrating all turns in a single layer where resistance would become unmanageable.

The design transitions from a single-plane coil to a multi-layer three-dimensional structure. By utilizing the vertical dimension through PCB stacking, the voice coil achieves increased turn count and induced electromotive force while distributing the resistance across multiple layers. The series connection of layers multiplies the effect of turns without proportionally increasing the resistance in any single layer, resolving the contradiction between electromotive force and resistance.

The PCB serves multiple functions simultaneously: it acts as the structural base, the electrical connection medium, and the voice coil itself through printed conductive patterns. This multi-functionality eliminates the need for separate winding processes and additional connection components, reducing overall device complexity despite the multi-layer structure. The standardized PCB manufacturing process handles the complexity of multi-layer construction automatically.

The same PCB pattern design is replicated across multiple layers with identical trace layouts and dimensions. This copying approach ensures consistency in electrical characteristics and simplifies the design process, as the same pattern can be reused across layers. The repetition of proven patterns reduces design complexity while achieving the desired increase in turns and induced electromotive force.