Amkor Electronics, Inc.

Frank J Johnson

Lead frames for microchips and other integrated circuit dies are produced by a continuous manufacturing method and apparatus in which silver spot plating is done prior to etching away unwanted portions of the lead frame substrate. A flexible substrate of a metal alloy is fed continuously from a reel, then spot plated with silver, coated with a photosensitive material, and exposed to intensive light in an exposure chamber using a photoresist or masking tool of predetermined design. The exposed photosensitive material is developed chemically, etched in acid, and placed in a chemical solution to remove any remaining unwanted material. The strip is then dried, cut to predetermined lengths and boxed for shipment. If necessary, the strip is downset and taped before packaging. In a presently preferred process, the metal alloy substrate is 42 alloy (Fe+Ni), and the selective spot plating is silver 100 to 150 microinches thick. The silver does not dissolve in the etchants and therefore has to be removed from exposed areas, preferably by 'reverse' plating techniques.

Method of and apparatus for producing a strip of lead frames for

A slitter machine for slitting a film sheet wound on a core in a roll to obtain desired widths of film sheet for laminating onto metallic substrates of semiconductor devices comprises a main frame, notches on the main frame for rotatably supporting the roll on the frame, a rotatable knife blade for slitting the roll sheet into a strip of desired width, a tiltable knife blade mounting plate on the frame for mounting the knife blade on the frame, guide tracks adjusting the lateral position of the knife blade to adjust the width of the strip being cut, an air cylinder for pressing the knife blade into the rolled sheet to cut the sheet into strips of the desired width, and a sensing roller for limiting the depth of the cut.

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Santa Cruz, CA, United States of America

Frank J Johnson