Armstrong, Westerman, Hattori, McLeland & Naughton
Printed circuit plates
 A method for manufacturing printed circuit plates, which includes laminating an aluminum rolled leaf on a surface of an insulator base, forming an etching resist coat film on the surface of the aluminum rolled leaf, and then dissolving and removing an unnecessary aluminum leaf in the non-resist area with an etching liquid. The etching liquid is an aqueous solution containing (1) 0.1 to 15 mol/liter of acid of an amine hydrofluoride and (2) 0.02 to 10 mol/liter of a hydrogen peroxide, wherein the amine is one of an aliphatic amine having 12 carbon atoms or less and a heterocyclic amine, the amine having no other acid group or basic group than amino group, the etching liquid having a pH within the range from 4 to 9, wherein the hydrogen peroxide oxidizes aluminum into an aluminum oxide which is dissolved by the amine hydrofluoride. 
Oogi Chemical Industry Co., Ltd. Sharp Kabushiki Kaisha
Y C C
Y10S C23F C23F
additional inventional inventional
Hiroya Masakatu Kiyoshi Ichiro Hideaki
Ito Takaishi Kondo Kohara Ishitobi