NOVEL CIRCUIT BOARD

PURPOSE: To provide a circuit board which can be formed in an extremely thin board by constituting the circuit board of a complex body, composed of an insulator substrate containing one or a plurality of syntactic films and an electronic circuit provided on the substrate. CONSTITUTION: A printed circuit board 7, containing a plurality of electronic parts 7 stuck with an adhesive or mechanically, is provided on at least one top face of outer layers 5. Each layer 5 is made of a fiber-reinforced complex body containing a thermosetting resin or thermoplastic polymer as a matrix. A layer 3 held between the layers 5 is a synthetic film layer containing very small rigid hollow balls surrounded by a complementary thermosetting resin or thermoplastic polymer material to the matrix of the layers 5 as a matrix component. At the time of manufacturing this circuit board complex, insulating complexes are manufactured before an electronic circuit is stuck to and mounted on one or more of the insulating complexes.