US Patent Issued on May 20 for "Subtractive method for manufacturing circuit board with fine interconnect" (Taiwanese Inventor)

ALEXANDRIA, Va., June 16 -- United States Patent no. 12,309,938, issued on May 20.

"Subtractive method for manufacturing circuit board with fine interconnect" was invented by Hsu-Tung Chen (New Taipei, Taiwan).

According to the abstract* released by the U.S. Patent & Trademark Office: "A subtractive method for manufacturing a circuit board with fine interconnect includes steps of disposing a resist film on a metal layer on a surface of a wiring substrate, and performing a dry etching process to etch and penetrate the resist film and form a wiring pattern groove in the metal layer, the depth of the wiring pattern groove is less than the thickness of the first metal layer; further wet etching process is performed, and the metal layer is etc...