Shielded multilayer printed wiring board, high frequency, high isolation

A shielded printed wiring board which isolates signal layers thereon said wiring board comprising:

• a signal layer including a fiat conductor;
• a first non-conductive layer having a sheet of controlled dielectric material with top and bottom surfaces, said signal layer being defined on the top surface of said first non-conductive layer;
• a second non-conductive layer having a sheet of controlled dielectric material with top and bottom surfaces, said signal layer and top surface of said first non-conductive layer being laminated to the bottom surface of said second non-conductive layer;
• a conductive base layer extending across the bottom surface of said first non-conductive layer;
• first and second grooves routed along the sides of said signal layer and displaced therefrom, said grooves having walls extending through said first and second non-conductive layers and at least to said conductive base layer;
• a conductive coating encapsulating the plurality of layers and grooves of said wiring board thereby providing a conductive shielding surrounding the signal layer;
• and
• access means for accessing said signal layer to form electrical connection therewith.

A circuit board comprising:

• an electrically conductive base layer;
• a first layer of non-conductive material disposed on top of said conductive base layer;
• an electrically conductive signal transmission line disposed on top of a portion of said first layer of non-conductive material;
• a second layer of non-conductive material disposed on top of said signal transmission line and said first layer of non-conductive material, said first and second layers of non-conductive material extending beyond opposite sides of said signal transmission line;
• conductive grooves formed along opposite sides of said signal transmission line and separated therefrom, said grooves having walls extending through said first and second layers of non-conductive material at least to said conductive base layer and providing electrical contact therewith;
• and
• an electrically conductive material substantially covering the top of said second layer of non-conductive material and said walls so as to form a conductive shield substantially surrounding said signal transmission line.