In this study, polymeric/metallic yarns were fabricated by using the micrometric copper multifilament and the polymer multifilament to create electrically conductive, thin, flexible composite yarn structures. The main aim is to realize the circuit board by using fabricated conductive yarns in the needle position of the embroidery machine and to integrate electronic components on textile structures by the soldering process. In the embroidery machine, the usage of the yarn in the needle gives a chance to create a tailored design according to the specified application. Mechanical and electrical properties of fabricated yarns were investigated. Meanwhile, a benchmark test has been done by using other commercial conductive yarns. Their embroidery performances were tested by investigating the possible harms during the stitching process. Finally, several embroidered circuit boards have been realized to show the versatility of fabricated yarns for different circuit designs.