Patent ID: 8110344

Claim:
A production method of a metal photoetching product having a complex, three-dimensional shape, comprising: coating a photoresist (A) onto a surface of a metal substrate; exposing and developing the photoresist (A) using a first photomask, the first photomask having a first opening pattern with one or more holes, to form one or more first openings in the photoresist (A) according to the first opening pattern; carrying out a first etching of the metal substrate, on which the photoresist (A) having the first openings is provided, to form one or more first cavities on the metal substrate; after removing the photoresist (A) used in the first etching, providing a coating (B) of an electrodeposited resist over the entire surface of the metal substrate; positioning a second photomask having a second opening pattern with one or more holes, the second opening pattern of the second photomask being different from the first opening pattern of the first photomask, to be aligned with the one or more first cavities of the metal substrate produced by the first etching, on which the coating (B) is provided; exposing the coating (B) to light emitted from a parallel light source, which exists above the coating (B), and developing the coating (B) to form one or more second openings on the coating (B) according to the second opening pattern of the second photomask, carrying out a second etching of the metal substrate, on which the coating (B) is provided, to form one or more second cavities on the metal substrate and to form an etched shape of the metal substrate, and removing the coating (B) from the metal substrate, wherein the etched shape includes one or more composite-cavities formed by a combination of the first etching and the second etching, wherein the one or more second cavities are formed in the one or more first cavities, and at least one of etching factors of the one or more composite-cavities is 2.6 or more, the etching factor being obtained by: EF=ED/SE, wherein EF represents the etching factor of the composite-cavity to be evaluated of the metal substrate, the composite-cavity being obtained by a combination of the first etching and the second etching, ED represents an etched depth of the composite-cavity, SE represents a primary side etching which is half the value of the difference between an opening size of the first cavity of the metal substrate formed by the first etching and an opening size of the first opening of the photoresist (A) which is used for forming the first cavity in the first etching, wherein the first etching and the first cavity are used to form the composite-cavity, and when there are two said primary side etchings as a result of photoetching conducted from both the upper and lower surfaces of the metal substrate, and the two primary side etchings are different from each other, SE represents the larger of the two primary side etchings.