A hearing instrument uses an MID (Molded Interconnect Device) to replace a complexly folded and expensive flexible PCB (Printed Circuit Board) inside hearing aids and enables the use of complex MID frames in hearing instruments. An additional routing building block is provided for the very complex routing around active electronic components, e.g. chips or ASICs and small passive electronic components. It includes a small, preferably rigid mini PCB provided for the complex routing. A large Flex-PCB is therefore replaced by a combination of an MID circuit frame and a mini PCB. The mini PCB enables complex routing of conducting paths and thus helps to increase integration while the MID circuit frame provides for a mechanical structure that enables and alleviates placing and connecting components such as microphones or receivers at respective mounting positions, e.g. at openings of a hearing aid housing.