US Patent Issued to NGK INSULATORS on Oct. 20 for "Wafer placement table" (Japanese Inventors)

ALEXANDRIA, Va., Oct. 21 -- United States Patent no. 12,770,841, issued on Oct. 20, was assigned to NGK INSULATORS Ltd. (Nagoya, Japan).

"Wafer placement table" was invented by Taro Usami (Kasamatsu-Town, Japan) and Yohei Kajiura (Nagoya-City, Japan).

According to the abstract* released by the U.S. Patent & Trademark Office: "A wafer placement table includes a ceramic plate having a wafer placement surface on an upper surface, and a cooling plate provided on a lower surface of the ceramic plate. The cooling plate is made of a material having a lower thermal conductivity than Al. A length between an upper surface of a refrigerant flow path and the wafer placement surface is not constant and varies as being long in one part and short in ano...