One of the fundamental innovations in the field of mechatronics is the direct material integration of mechanical and electronic functions using Molded Interconnect Devices (MID technology). Unlike conventional circuit boards, they are not limited to two dimensions but offer the possibility to arbitrarily lay printed circuit traces on the surfaces of the 3D carrier, traditional 2D routing function in EDA cannot be directly applied in MID design. In this paper, two new 3D automatic routing methods are introduced. One method is based on a grid graph and extends Hadlock’s minimum detour algorithm; the other is gridless and combines the A*-algorithm and an extension of Hightower’s algorithm. The related 3D routing functions, which are not supported by conventional MCAD und ECAD systems, are integrated in the design system MIDCAD. With these 3D routing functions, MIDCAD enables a more effective product design based on the MID technology.