초록 ▼

A method for producing a lead frame having outer leads and inner leads, for use in constructing a resin-sealed semiconductor package comprises etching processes for etching a blank. A first resist pattern having a first opening and a second resist pattern having second openings are formed on the fir

A method for producing a lead frame having outer leads and inner leads, for use in constructing a resin-sealed semiconductor package comprises etching processes for etching a blank. A first resist pattern having a first opening and a second resist pattern having second openings are formed on the first and the second major surfaces of a blank. The first and the second major surfaces of the blank are etched through the first and the second resist pattern by a first etching process using a first etchant to form a first recess corresponding to the first opening and second recesses corresponding to the second recesses in the first and the second major surfaces, respectively. The first recess is filled up with an etch-resistant layer. The second major surface is etched through the second resist pattern by a second etching process using a second etchant so that portions of the blank corresponding to the second openings of the second resist pattern are etched through to form the tips of the inner leads.

대표청구항 ▼

A method for producing a lead frame having a plurality of outer leads and a plurality of inner leads respectively having tips, for a resin-sealed semiconductor package, comprising: coating a first and a second major surface of a blank for a lead frame with a first and a second photoresist layer, res

A method for producing a lead frame having a plurality of outer leads and a plurality of inner leads respectively having tips, for a resin-sealed semiconductor package, comprising: coating a first and a second major surface of a blank for a lead frame with a first and a second photoresist layer, respectively; forming a first resist pattern having a first opening on the first major surface of the blank by exposing the first photoresist layer through a first pattern mask and a second resist pattern having second openings on the second major surface of the blank by exposing the second photoresist layer through a second pattern mask; applying a first etchant to at least the first major surface of the blank to form an etched recess; cleaning the surface of the etched recess formed in the first major surface of the blank after applying the first etchant; pickling the cleaned surface of the etched recess to remove oxides and hydroxides tarnishing the surface of the etched surface; forming a protective film over the pickled surface of the etched recess to prevent oxidation and hydraulic; forming an etch-resistant layer of an etch-resistant material to fill the etched recess in the first major surface of the blank; applying a second etchant to the second major surface of the blank to etch through remaining portions of the blank; and removing the etch resistant layer, the first resist pattern and the second resist pattern from the resulting lead frame and cleaning the lead frame.