Improvements in or relating to lead frames

摘要

A method of fabricating a lead frame. The method includes providing an electrically conductive layer (11) having a pair of opposing major surfaces. A pattern is etched in the layer extending partially through the layer to form cavities (15) with sidewalls in the layer. A patterned mask is (17) provided on the etched layer including masking of the sidewalls. The layer is again etched (21) within the cavities. The patterned mask is preferably a liquid photo resist and the electrically conductive layer is preferably one of a copper or copper-based material or ALLOY 42. The etch can take place from both major surfaces.