HOT-ROLLING COPPER PLATE

摘要

PROBLEM TO BE SOLVED: To provide a hot-rolling copper plate which is excellent in processability and a fatigue characteristic even if it is produced by hot rolling, and which can satisfactorily suppress abnormal discharge even when being used for a sputtering target.SOLUTION: A hot-rolling copper plate comprises pure copper in which purity is at least 99.99 mass%, and is characterized in that an average crystal grain size is at most 40 μm, and (&Sgr;3+&Sgr;9) grain boundary length fraction (L(&sgr;3+&sgr;9)/L) that is the fraction of the total crystal grain boundary length L to the sum L(&sgr;3+&sgr;9) of &Sgr;3 grain boundary length L&sgr;3 and &Sgr;9 grain boundary length L&sgr;9 measured by an EBSD method is made at least 28%.