Method of Electrically Isolating Leads of a Lead Frame Strip by Laser Beam Cutting

摘要

A lead frame strip includes a plurality of connected unit lead frames, each unit lead frame having a die paddle and a plurality of leads connected to a periphery of the unit lead frame. A semiconductor die is attached to each of the die paddles, the unit lead frames are covered with a molding compound after the semiconductor dies are attached to the die paddles, and a laser beam is directed at regions of the periphery of each unit lead frame where the leads are located thereby forming spaced apart cuts in the periphery of each unit lead frame. The spaced apart cuts sever the leads from the periphery of each unit lead frame and extend at least partially into the molding compound in the regions of the periphery where the leads are located so that the molding compound remains intact between the spaced apart cuts.

主权项

1. A method of processing a lead frame strip including a plurality of connected unit lead frames, each unit lead frame having a die paddle and a plurality of leads connected to a periphery of the unit lead frame, the method comprising:
attaching a semiconductor die to each of the die paddles; covering the unit lead frames with a molding compound after the semiconductor dies are attached to the die paddles; directing a laser beam at regions of the periphery of each unit lead frame where the leads are located thereby forming spaced apart cuts in the periphery of each unit lead frame, the spaced apart cuts severing the leads from the periphery of each unit lead frame and extending at least partially into the molding compound in the regions of the periphery where the leads are located so that the molding compound remains intact between the spaced apart cuts; and processing the lead frame strip after the spaced apart cuts are formed in the periphery of each unit lead frame.