| 摘要 |
<p>PROBLEM TO BE SOLVED: To stably reduce the thermal expansion coefficient of a shadow mask by applying residual stress thereto. SOLUTION: In this producing method, by applying residual stress by cooling treatment or pressurizing treatment, a shadow mask in which the average thermal expansion coefficient at 20 to 100 deg.C is regulated to <1.20×10<-6> / deg.C can be obtd. After shaping into a thin sheet stock in an ordinary production, blackening treatment is executed at about 600 deg.C, and by a cooling stage in this blackening treatment, the cooling rate is controlled. The cooling rate is preferably regulated to >=1000 deg.C/hr. Namely, by the rapid cooling, residual strains by thermal stress are generated. Furthermore, in the case of pressurizing treatment, after the blackening treatment, it is pressurized under >=200kgf/cm<2> by cold hydrostatic pressing (CIP) or the like to apply strains thereto and to generate residual stress therein. Then, it is required that treatment causing deterioration in the residual internal stress is not executed after that.</p> |
