Experimentally Investigation of Curing Shrinkage of Extra Low Dilated Epoxy by Fiber Bragg Gratings

Abstract

The bonding adhesion with low shrinkage and coefficient of thermal expansion is really important for packaging of the photonic and optoelectronic elements. Lots of the thermoset glue is thus developed for this packaging. however, the curing shrinkage of the adhesion is relatively large. The silica filler is usually mixed into the epoxy for lowering the curing shrinkage and the CTE. In this study, the filler with negative CTE is derived to decrease the CTE and shrinkage of the composite epoxy. The fiber Bragg gratings is built in the composite of epoxy/filler. The adhesive composite is then put into the temperature cycle chamber for curing. At the meanwhile the FBGs during curing is on-line monitored by the Optical Oscillation Analyzer. Measuring the variation of the central wavelength of FBGs, the curing shrinkage of the composite epoxy with NCTE filler can be is derived. The results show that axial stress is increased drastically during the chemical curing stage. By application of this NCTE filler/epoxy adhesion, the property of the lower shrinkage is expected.