Electrical supply and signal bus=bar - uses metallic and dielectric films with conducting and non-conducting adhesives in high capacitance strip for printed circuit boards

摘要

The layered supply line has electrodes in the form of flat foil strips, which are separated by a sandwich of 2n+2 metallised films separated by 2n+1 dielectric layers. A dielectric film (5) of thickness not exceeding 5 microns, metallised on both sides (6,7) is sandwiched in serpentine fashion between the electrode strips (1,2) which are of tinned copper covered with a layer of conductive adhesive (11,12). Non-conducting films (3,4) separate the metal films to giVe a structure with a capacitance (2 nanofarads per centimetre) three times that of a similar two-electrode form. With non-conducting adhesive, film defects causing pinhole short circuits can be self-healed by the application of a suitable potential. Signal frequencies from d.c. to several hundred megahertz can be transmitted. The structure is flexible, mechanically robust and is suitable for printed circuit boards.