Technologies to connect humans and their environment
|With the recent sophistication of hand-held devices such as smartphones, there are growing needs for multilayer flexible printed circuits (FPCs) that have both reliability and implementability. Multilayer FPCs have three or more copper conductor layers. It is an advanced form of FPC that integrates different designs: a multilayer structure on which components are mounted and a single- or double-sided structure that serves as a connector or bending part.
The manufacturing process laminates single- and double-sided FPCs on which circuits are formed, prepares adhesion layers using bonding sheets, and creates a multilayer FPC by thermo-compression.
A single FPC can provide three-dimensional wiring that runs along the interior, small-footprint (space-saving) wiring, and wiring at folding parts within the limited space of a small electronic device such as a smartphone.
Recent designs use high-density wiring that contains impedance-control circuits, which cannot be implemented with double-sided boards due to space limitations. Multilayer FPCs find many applications in such areas.