A flexible circuit includes a flexible non-conductive substrate having a first surface and a second surface. A first electrically conductive trace is provided on the first surface and a second electrically conductive trace is provided on the second surface. A passage extends through the substrate from...http://www.google.com/patents/US6211468?utm_source=gb-gplus-sharePatent US6211468 - Flexible circuit with conductive vias having off-set axes
