The use temperature of quartz glass in semiconductor industrial equipment is often in the high temperature state of 1000 ℃ to 1300 ℃. In this state, the devitrification phenomenon occurs due to the attachment of impurities. The devitrification part is the crystallization of quartz, and the devitrification point is 275 ℃. When the quartz glass drops from the high temperature to the devitrification temperature, the surface devitrification part is the same as the high temperature of quartz glass itself α Phase and low temperature β Different interphase expansion coefficients produce opaque peel shape under rapid cooling, which will lead to fracture when it is more serious.
In order to make quartz products can be used longer, we must pay attention to prevent the causes of quartz impermeability, and the pollution sources causing impermeability are alkali metals, alkaline earth metals, sweat, saliva, oil stain, dust, etc.
And 0.1mg/cm2l}k will cause dozens of times or hundreds of times of devitrification. Therefore, to prevent these pollution sources from adhering to the quartz surface, in addition to not directly holding the quartz with empty hands, cleaning must be done before high-temperature operation to ensure the cleanliness of the quartz surface. Generally, the cleaning of quartz requires some procedures. First, wash the surface with pure water, and then soak it in the pickling tank for some time. After taking it out, rinse it with pure water and dry it.
1. It smells like a very natural stone, defective quartz pieces, and formaldehyde containing glue is added in the production process of quartz stone.
2. If there are pores, whether there are pores on the surface of the quartz tube.
3. Not significant for good goods, splices and gaps.
4. The scratch is deep and marked as unqualified, key or pencil sharpener.
5. The simple falling stone powder is unqualified and polished with sand paper below 200 mesh.
6. If there is a cut crack, it is unqualified and the upper and lower edges of the cut surface.