Patent ID: 6238845
Filing Date: 2001-05-29
Classification: G03F,H01L

Abstract:
A method of making a lead frame with fine pitch leads, comprising the steps of:applying a photoresist layer to a first side of a lead frame material;developing the photoresist layer applied to the first side of the lead frame material to define a lead frame pattern;etching partially through the first side of the lead frame material to provide a partially etched first side of the lead frame material;removing the patterned photoresist from the first side of the lead frame material;applying a coating material solely over said partially etched first side of the lead frame material such that the coating material does not fill etched areas within the lead frame material;applying a photoresist layer to a second side of the lead frame material;developing the photoresist layer applied to the second side of the lead frame material using the lead frame pattern developed in association with the first side of the lead frame material;etching the second side of the lead frame material to completely etch through to the partially etched first side to form a lead frame;removing patterned photoresist layer from the second side of the lead frame; and plating the lead frame.