Integral Capacitors Built as an Embedded Layer in Printed Wiring Boards

摘要

Printed wiring board layers with dielectric constants much greater than typical FR-4 (K≈4.5) can be made by creating, polymer-ceramic composites or dielectric films that can be laminated between or deposited on a copper core. This core can then be integrated as part of a multilayer printed wiring board. Several commercial examples are now available: e.g. the "EmCap~(TM) laminate, which has a dielectric constant of about 50. We will report on the most significant metrics of capacitance/area, temperature and frequency response for some of these new materials and also look at their dielectric performance when made as part of a multilayer printed wiring board. The dielectric performance, leakage currents and breakdown voltages will be compared with standard FR-4 materials and X7R capacitor characteristics. In addition to impedance characteristics, the performance of the embedded dielectric will be evaluated by measuring the amount of charge available in a pulse discharge mode.