Patent ID: 7498074

Claim:
A metal photoetching product comprising: at least one large cavity of minor axis W 1 S, major axis W 1 L and depth D 1 in a surface of the product, wherein at least two cavities are included inside at least one of the at least one large cavity, and a smallest hole among the cavities has minor axis of W 2 S, major axis W 2 L, and depth D 2 ; and D 1+ D 2=plate thickness D, 0.02 mm≦ D≦ 2 mm, 0.4× D<W 1 S<D , and 0.2× D<W 2 S< 0.8× D ; and at least one combination of the large cavity and the smallest hole formed in the large cavity has an etching factor of 2.6 or more, where the etching factor is EF=ED/SE wherein EF represents the etching factor, ED represents an etched depth of a cavity to be evaluated, SE represents a primary side etching which is a half of a difference between a dimension of an opening of the cavity formed by primary etching and a dimension of an opening of a photoresist pattern used for the primary etching, and when there are two primary side etchings as a result of photoetching conducted from both upper and lower surfaces of a metal substrate, SE represents the larger one.