A method of making a fusion bonded circuit structure. Each major surface of an LCP substrate is provided with a seed layers of a conductive material. Resist layers are deposited on the seed layers. The resist layers are processed to create recesses corresponding to a desired circuitry layers on each side of the LCP substrate. The recesses expose portions of the seed layers of conductive material. The LCP substrate is electroplated to simultaneously create conductive traces defined by the first recesses on both sides of the LCP substrate. The resist layers are removed to reveal the conductive traces. The LCP substrate is etched to remove exposed portions of the seed layers adjacent the conductive traces. LCP layers are fusion bonded to the major surfaces of the LCP substrate to encapsulate the conductive traces in an LCP material. The LCP layers can be laser drilled to expose the conductive traces.