Rigid-flexible PCB with flexible circuit foil mfg. - having flexible PCB in flexible region with fracture lines in rigid outer layers along rigid-flexible transition allowing rigid part to be removed along fracture lines after processing

摘要

The method involves mfg. rigid/flexible PCBs with a single or multilayer, with a separately prepared flexible PCB (1) only in the flexible region. Fracture lines (23) are made in rigid outer layers (2) along a rigid/flexible transition. The flexible board is then laid between the rigid layers. The connection leads (12) of the flexible board end in terminal eyes corresp. to the ends of the conductive tracks of the rigid regions. The flexible board is bigger around the eyes than the flexible region and has non-fluid adhesive layers (14) in the eye region on both sides. The adhesive only covers the edges and not the flexible region. The layers are connected by prepregs (3) with recesses 0.1 - 1.5 mm bigger than the flexible board. The number of these is such that the uncompressed thickness is about 0.1 - 0.5 mm greater than the flex. board and adhesive. The construction is compressed to a lamina by heat and pressure. The circuit parts are connected to each other and to the flexible board. After processing the rigid part (24) is removed along the fracture lines. ADVANTAGE - Several circuits can be made in flexible region.