Chosen electrical and stability properties of surface and embedded planar PCB inductors

This paper presents manufacturing process and chosen electrical and stability properties of surface and embedded thin-film inductors made in/on printed circuit boards (PCBs). Such components are made based on Ohmega-Ply resistive-conductive laminates (with 25 or 100 Omega/sq sheet resistance), which permit to create multilayer circuits with integrated resistors, inductors and conductive tracks. Inductance, resistance and quality factor, Q
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are determined in a wide frequency (10 kHz-100 MHz) and temperature (20degC-150degC) range and will be analyzed as a function of inductor geometry (shape and width of conductive tracks width) and embedding process. The stability properties, i.e. fractional inductance and resistance changes after long-term thermal ageing at elevated temperature (150degC) are also investigated and analyzed. The electrical equivalent circuit of investigated will be discussed too.