Elimination of island formation and contact resistance problems during electroetching of blanket or patterned thin metallic layers on insulating substrate

A method of electrochemically micromachining a metal film having a surface at least partially covered with an insulating mask having a plurality of openings and said method comprising the steps of:

• calculating a numerical relationship along a plurality of values including, a, h and L wherein the insulating mask has a thickness h and at least one of said plurality of openings has a width 2L and is spaced a distance 2a apart from another one of said plurality of openings wherein the numerical relationship among a, h, and L is calculated and h is varied to at least partially prevent undercut of said metal film;
• forming the insulating mask on the surface of the metal film according to the calculated numerical relationship;
• and
• electrochemically micromachining the metal film.

A method of electrochemically micromachining a metal film having a surface at least partially covered with an insulating mask having a plurality of openings, said method comprising the steps of:

• determining three of a plurality of variables including a, b, h, and L where the metal film has a thickness b, the insulating mask has a thickness h and at least one of said plurality of openings has a width 2L and is spaced a distance 2a apart from another one of said plurality of openings;
• calculating another of a, b, h, and L according to a numerical relationship;
• forming the metal film and the insulating mask according to said respective determining and calculating of a, b, h, and L;
• and
• electrochemically micromachining the metal film,
• wherein said another of a, b, h, and L is calculated and one of b and h is varied to prevent island formation during electrochemical micromachining of the metal film.

A method of electrochemically micromachining a metal film having a surface at least partially covered with an insulating mask having a plurality of openings, said method comprising the steps of:

• determining three of a plurality of variables including a, b, h, and L where the metal film has a thickness b, the insulating mask has a thickness h and at least one of said plurality of openings has a width 2L and is spaced a distance 2a apart from another one of said plurality of openings;
• calculating another of a, b, h, and L according to a numerical relationship;
• wherein said another of a, b, h and L is calculated and one of b and h is varied to prevent undercut of said metal film;
• forming the metal film and the insulating mask according to said respective determining and calculating of a, b, h, and L;
• and
• electrochemically macromachining the metal film.