The so far achieved results show that laser assisted joining of dissimilar materials is possible for the cases shown above. However the development is still in progress with the aim to improve joint strength and reliability. Moreover, it is necessary for applications in hybrid microsystems to reduce the size of joint geometries. In order to understand the processes and bonding mechanism occurring in laser joining the examination of the interfacial region is approached from a materials science viewpoint paying special attention towards mechanical strength and fluid tightness as mentioned above. Further experiments will deal with the application of coupling agents and structuring of the silicon substrate in order to increase the interfacial strength of silicon-polymer joints. Mechanical testing of specimen can give information about the influence of process parameters and changes in materials structure. Finally bonding and interfacial states will be examined with spectroscopic methods (Raman, FTIR, XPS) giving information about the way, how dissimilar materials bond together.