Abstract: Flexible multilayer printed circuit boards are disclosed which utilize adhesiveless laminates interconnected in a generally superposed relationship by a conductive adhesive. In one embodiment, the adhesiveless laminates have relatively thin conductive layers and metallized through holes which exhibit high delamination resistance. The metallized through holes preferably have a thickness of at most about 25 microns, yet they are capable of withstanding multilayer assembly processes. High flexibility, reliability, packaging density, and environmental resistance are consequently available in a thin multilayer construction. In a further embodiment, adhesiveless dielectric layers are interposed between adhesiveless laminates to electrically insulate portions thereof. The adhesiveless dielectric layers may define relatively small apertures therein, thus providing greater packaging density for a multilayer printed circuit board.

Abstract: A printed wiring board includes a photoimageable dielectric material (PID) utilized as the base dielectric substrate therefor. The photoimageable dielectric material may be utilized in many conventional PWB designs, and improved resolution and registration precision of access apertures and through holes is generally realized through the use thereof. Moreover, less costly and complex manufacturing processes are required to deposit, image, develop and cure the PID material.