Influence of crystallization inside glass frit on seal stress in ceramic metal halide lamps

Thus, the coefficient of thermal expansion of the glass frit containing the crystalline phase was found to influence the seal stress. Furthermore, the crystallization in the glass frit was found to influence crack propagation. Therefore, formation of cracks inside the glass frit can be prevented by optimizing these factors, which can be achieved by changing the cooling rate in the sealing process without changing the specifications of the glass frit (composition, composition ratio, etc.).