Abstract: An easier and cheaper way to obtain multilayer circuit board is by using a flexible circuit board and folding it in an organized pattern. Flexible circuit has the unique property of being a three-dimensional circuit that can be shaped in multiplanar configurations, rigidized in specific areas, and molded to backer boards for specific applications. The folded circuit is fabricated from a series of foldable circuit board strips and rigid circuit board strips which are interconnected, folded, and bonded into a composite structure. The foldable strips may have prefolds arranged so that a group of upper foldable strips and lower foldable strips are folded in opposite directions. A plurality of intermediate portions are stacked on each other by the folding the foldable strips in opposite directions. The folded circuit, can be bonded after a first fold, or folded further to achieve a greater reduction in area and subsequently be bonded as a composite multilayer structure.