A STUDY ON THERMAL-STRESS-RELIABILITY OF SI-BASED PLC SUBSTRATE

Planar lightwave technology is rapidly advancing and promises excellen t performance as economical opto-electro-devices. To confirm its feasi bility, it is very important to estimate its mechanical reliability es pecially against the thermal stresses caused by the difference of the thermal expansion coefficients of Silicon and silica glass, This paper examines the thermal strain and stress distribution on silicon-based Planar-Lightwave-Circuits (PLC) substrates and the stress concentratio n on silicon terrace structures prepared for mounting active optical d evices, Experimental data on the fracture strength of silicon obtained by three-point-bending tests are given, Finally, the thermal-stress-r eliability of PLC substrates based on probabilistic analysis is calcul ated and it is confirmed that the PLC substrate, even its present form , is reliable enough for a new family of optical components.