Applications in fluidics or for analytical purposes often require transparent microcomponents to be covered completely or joined. Laser-assisted welding, compared to classical joining techniques, is characterized by its contactless approach. In this process, either a polymer absorbing laser beams is joined to a transparent polymer, or an absorbing layer between transparent polymers is used. However, in most cases, the intermediate layers are very thick (at least 1 µ), thus causing deformation of the microstructures or cracking.In order to allow laser-assisted welding to be used also in microsystems technology, a process was developed in which adjacent microcomponents are joined by means of an absorbing layer only a few nanometers thin, without any expensive positioning of specimens and, consequently, impairment of structural quality. This technique also allows joining several components positioned on top of each other and consisting of nearly any polymer in the stack. The absorbing layers can be applied locally or structured in a highly precise way in order to protect sensitive areas, if necessary, for reasons of sensor integrity or biocompatibility. The combination of laser beam cutting and laser beam welding allows rapid manufacturing of functional components in cycles of minutes.