A New Approach For a Planar Miniaturized PCB Based High Sensitivity Fluxgate Sensor Design

摘要

In many sensor applications, for example proximity switches, current-, torque-, angle- or position sensors, Hall-effect elements are used. Such devices require strong magnetic fields in the order of millitesla to generate a valid output signal. In that context Fluxgate sensors are a better choice as they can detect much weaker fields, but are limited by current technology to large and heavy sensor heads and show high power consumption. State of the art Fluxgate sensors are constructed from solid ferromagnetic cores and copper wire-wound coils. The presented innovative new planar sensor design, just uses standard PCB laminates combined with different magnetic materials, which is fabricated using subtractive PCB etching technology with trace widths and line spaces as small as 75μm making it possible to build up sensor devices with dimensions of just 18×6 mm~2, while obtaining large sensitivities of up to 4.5mV/μT.