公开(公告)号：US3610752A

公开(公告)日：1971-10-05

申请号：US3610752D

申请日：1970-01-15

Applicant: ATOMIC ENERGY COMMISSION

Inventor： WILSON FREDERICK C

IPC: G03F1/00 ,  G03F7/20 ,  H05K3/00 ,  G03B41/00

CPC classification number: G03F7/70058 ,  G03F1/00 ,  G03F7/7035 ,  G03F7/70583 ,  H05K3/0002 ,  H05K2201/09363 ,  H05K2203/056

Abstract: An improved process for preparing printed circuit boards in which only the conductor surrounding the circuitry is removed. A refractor is utilized in preparing the circuit board negative to obtain exposure of the film only in the regions directly adjacent the lines representing the circuitry.