Tuning built-in oscillation loops in SMD technology or HF filter - using air-cored coil whose inductivity is adjusted by altering winding spacing to achieve desired frequency.

摘要

The tuning method involves using an air coil encased by an impregnating element which softens and flows-off at the soldering temperature. The air coil is mounted using conventional SMD-technology assembly devices e.g. suction pipette. The inductivity of the air coil is adjusted by altering the winding spacing to achieve the desired frequency. If necessary after adjusting the inductivity, the windings are fixed in their adjusted position by forming a second impregnating element, to avoid microphony. USE/ADVANTAGE - For e.g. oscillating circuits built in SMD technology for car radio. Enables insertion of adjustable air coil in SMD circuit which can be handled by conventional SMD technology assembly equipment.