Tellurite glass thin film was successfully bonded on a silicate glass substrate by the direct-bonding (DB) method. Glass film (thickness 1-3 μm) was fabricated by the glassblowing technique and the DB process was performed at room temperature at relative humidity (RH) of 62% or 15%. The surface adhesive strengths of the glass films bonded at 15% and 62% RH were measured as 250 and 96 mJ/m 2 , respectively, by the Obreimoff-Metsik method. The hydroxyl (-OH) functional groups on the interface between the film and silicate glass were analyzed by Fourier-transform infrared spectroscopy. The major bonding forces between the tellurite thin film and silicate glass were hydrogen bonds at 62% RH and bonds between Te on the tellurite glass and O on the silicate glass were concerned at 15% RH. These forces, contributed by Si-OH, were important for bond formation at 62%. The large amounts of water and OH groups on the silicate glass, determined by thermogravimetric analysis, indicated a weaker bonding process at 62% RH. This work will contribute toward reliable, high-integrity components for integrated optical circuits, which are increasingly needed for high-throughput data transfer. K E Y W O R D Sadhesive strength, direct bonding, glass thin film, hydroxyl group, tellurite glass

Freestanding ultrathin glass film (UGF) of 45S5 bioglass was successfully bonded on a Ti substrate by the room-temperature bonding method. 45S5 UGFs with a thickness of 1~4 μm were fabricated by the glass-blowing technique, and the UGF was attached on the Ti plate at room temperature with a water layer between them. The bonding strength was about 370 mJ/m 2 just after bonding, and it increased during storing in the ambient atmosphere at room temperature and reached about 900 mJ/ m 2 after 9 hours storage. The interfaces of the UGF and Ti substrate during the bonding process were analyzed by an X-ray photoelectron spectroscopy. The as-prepared UGF was found to have surface layers with a high content of Na 2 O and low content of SiO 2 , and the dissolution of Na 2 O-rich component into water layer induced depolymerization and polymerization of SiO 2 network to form Si-O-Si bonds between the UGF and Ti plate and then to increase the bonding strength during storage. This work presents the simple technique to laminate the bioactive glass layer on the surface of the metal without post heat treatment.

No abstract

No abstract