Embedded passives technology for bluetooth application in multi-layer printed wiring board (PWB)

This study was to investigate the use of special high dielectric constant (Hi-DK) material for embedded passives in bluetooth system module. The stack structure of module substrate was comprised by three kinds of material, such as Hi-DK, low loss-tangent and general organic material. Both experimental circuit and embedded passives can be implemented in this substrate for normal printed wiring board (PWB) lamination process. Area of electrodes of embedded capacitors can be reduced considerably by taking the advantage of Hi-DK material. After considering of electrical character that was carefully simulated, SMT matching network inductors could be replaced with solenoid or spiral embedded layout structure. With embedded passives built into Bluetooth substrate, this design can shrink area at least 14%, 38% reduction was also realized by double-side package layout design.