Abstract
Beside the possibilities low temperature co-fired ceramics (LTCC) offer for electric devices they also enable the fabrication of micro fluidic elements like channels and embedded cavities. Hence, LTCC facilitate the realization of complex and integrated micro fluidic systems. Examples can be applied in many areas like micro fuel cells and reaction chambers for synthesis of chemical compounds. However, for many applications it is necessary to have an optically transparent interface to the surroundings. The integration of optical windows in LTCC opens up a wide field of new and innovative applications such as the observation of chemiluminescent reactions. These chemical reactions emit electromagnetic radiation and thus offer a method for noninvasive detection. The optical windows consist of thin glasses (≤ 500 μm) bonded by thermocompression onto a LTCC substrate. As the bonding agent, a low temperature sealing glass paste was used. Borosilicate glasses and fused silica as well as silicon were successfully bonded onto LTCC. In order to bond materials with a large CTE mismatch (i.e. fused silica) to LTCC, it is necessary to limit the heat input to the bond interface. Therefore, a heater structure was integrated into the LTCC substrate beneath the bond interface. This bonding process provides a vacuum proof and gas tight optical port (< 5 × 10−10 mbar·l/sec) with a high bond strength.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call