Ebene Keramiksubstrate und neue Montagetechnologien zum Aufbau hybrid-optischer Systeme
Subject of the thesis are research results concerning the packaging and assembly of hybrid optical systems. The discussed packaging concept is suitable for miniaturized, free-space and two-dimensional optical systems that allow to realize a broad range of optical functions, but it is also capable for the integration of electronical components as well as silicon micromachined parts. Basic idea is to use planar ceramic printed circuit boards (PCB) made of aluminum oxide (Al2O3) or Low Temperature Cofired Ceramics (LTCC) as a system platform for the optical assembly. Ceramic PCB are already well known from electronics manufacturing and by additionally embedding mechanical mounting structures within the substrate optical components can be assembled on top of the platform. The geometrical variety of these mounting structures and their design are the first focus of the thesis. In a second part the assembly technologies are described and evaluated that are necessary to place, adjust and finally join optical components in such mounting structures. Procedures from electronics manufacturing and assembly like "Pick& Place" need to be adapted since positioning and adjustment of optical components often require more than four degrees of freedom. In the thesis two types of assembly strategies that take the issues of optical mounting into account and use mechanical stops or the adjusted optical function for a position representation of the component are evaluated. The investigations were carried out by designing and assembling an optoelectronic demonstrator system. The results show that if the mounting structures within the ceramic PCB are used as mechanical stops for the positioning of optical components the mounting structure accuracies, currently ranging from ±27 µm to ±90 µm, constrain the packaging concept. By using adjustment processes an enhanced positioning accuracy of < ±5 µm was demonstrated. Thus and also concerning the various non-optical functionalities that can be integrated the overall conclusion of the thesis is that ceramic PCB are well suitable for the integration of optics and electronics on a common platform, especially if the demands on the positioning accuracies for the optical components are above 5 µm.