Devitrifing solder glasses in a specific group of glass ceramic materials are extensively used in hermetically sealing alumina electronics packages. Preferred frit glass compositions of this study consist of 37~40wt% PbO, 35~40wt% ZnO, 18~20wt% B2O3, 1~3wt% SiO2, 0~6wt% TiO2. The coated frit glasses crystallize during firing and form a strong hermetic seal. DTA and X-ray diffraction were used to characterize crystallization of the glass frit. Frit seal containing 2wt% TiO2 has crystallization temperature of 550~57$0^{circ}C$ with surface nucleation. Frit seal containing 6wt% TiO2 has crystallization temperature of 515~5$25^{circ}C$ with bulk nucleation, and the main crystalline phase was perovskite lead titanate having minus expansion coefficient. The average activation energy for the crystallization calculated from Ozawa equation was 65$pm$10kcal/mol.