| 摘要 |
<p>Single and multilayer circuit boards (10) are provided which boards (10) have rigid portions (16) and at least one flexible portion (18). The method involves the use of printed circuit techniques to fabricate the board (10) with flexibility being obtained by windowing interconnect layers (22) for the boards (10) and for at least one embodiment, some but not all of the substrates (12) in the flexible area (18). Where only interconnect layers (22) are provided, at least one, but not all, of such layers (22) are windowed in the flexible area (18). A flexible encapsulant (30) is preferably provided over any portion of a substrate (12) having circuitry thereon at least in the flexible portion (18) thereof. A composite material having aramid fibres encapsulated in a resin is utilized for substrates (12) and interconnecting layers (22) for embodiments where large numbers of flexures may be required and/or where high temperature stability is required. Enhanced performance with changes in temperature is also achieved by having all layers formed of substantially the same material and having all circuit bearing layers of substantially the same thickness. Sequential layering may also be provided to enhance flexibility.</p> |
