Millimeter-wave systems increasingly are entering into commercial systems, both for communication and sensors for traffic or industrial applications. In many cases, circuit technology of the involved front-ends includes monolithic and hybrid integrated circuits and even waveguide components like filters or antenna feeds. In addition to the standard technical and environmental requirements, these front-ends have to be fabricated in large quantities at very low cost. After a short review of the problems and some general interconnect and packaging techniques for mm-wave front-ends, achievements of a research program will be presented at the example of components for a 28 GHz communication front-end. Emphasis is put on a novel feed-through structure using multilayer carrier substrates for mm-wave circuits, some advances in electromagnetic field coupling for interconnects to mm-wave MMICs, and the realization of packages including waveguide components by plastic injection molding and electroplating. Results of filters and a diplexer produced in this way are shown, including pretuning of the filters to compensate the shrinking of the plastic parts during cooling.