ALEXANDRIA, Va., June 19 -- United States Patent no. 12,331,386, issued on June 17, was assigned to Mitsubishi Materials Corp. (Tokyo).
"Pure copper plate" was invented by Hirotaka Matsunaga (Aizuwakamatsu, Japan), Yuki Ito (Ageo, Japan), Hiroyuki Mori (Tsukuba, Japan), Norihisa Iida (Sakai, Japan) and Motohiro Hitaka (Sakai, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A pure copper sheet of the present invention has a composition including 99.96 mass % or more of Cu, 0.01 mass ppm or more and 3.00 mass ppm or less of P, 3.0 mass ppm or more of a total content of Ag and Fe, and inevitable impurities as a balance, in which an average crystal grain size of crystal grains on a rolled surface is 10 micr...