Development of sealing glass and fiber type sealant for laser sealing

The sealing method using a laser has been widely used since laser beams supplied locally the necessary energy to allow the formation of a hermetic bonding. The most common sealing techniques using a glass frit and a screen printer have some problems such as pores, non-uniform height, imperfect hermetic sealing. To reach high quality of laser sealing, the difference of coefficient thermal expansion (CTE) between the laser sealing glass and glass substrate should be lower than 1.0 x 10(-6)/K. In order to prove the feasibility of novel laser sealing glass as a fiber type sealant, PbO-SiO2-Al2O3B2O3 based glass system was drawn with fiber types ranging from 180 lam to 1000 lam in diameter. CuO and Na2CO3 were added into PbO-SiO2-Al2O3-B2O3 glass system in order to tuning the CTE. The thermo mechanical and thermal properties were investigated for correlations the CuO and Na2CO3 concentrations with PbO-SiO2-Al2O3-B2O3 glass system. The lwt% CuO and lwt% Na2CO3 co-doped PbO-SiO2-Al2O3-B2O3 glass system shows the CTE of 9.53 x 10(-6)/K. In this study, the FTO-coated glass substrate with a CTE of 10.23 x 10(-6)/K was sealed with fiber type sealant made of the CuO and Na2CO3 co-doped PbO-SiO2-Al2O3-B2O3 glass system. These results indicate that the fiber type sealant is feasible as laser sealing material in the packaging industry.