| 摘要 |
PURPOSE: To obtain a lead frame having high pin count by setting a flat width narrower than that of a bonding face, providing flat parts over the entire region in the direction of flat width on the bonding face, and forming the flat part to include a snaking shape. CONSTITUTION: The rear flat part 20 at the forward end 10 of an inner lead is formed narrower than the surface flat part and snaked along the direction of the inner lead. The cross-section part C1-C2 at the rear surface part 20 is located on the left side of the lateral center of inner lead, the cross-section part B1-B2 is located in the center and the cross-sectional part A1-A2 is located on the right side. This structure provides a wide gap ID between the inner leads while decreasing the pitch IP thereof at the time of etching work. At the time of bonding work, the cross-sectional parts A1-A2, B1-B2, and C1-C2 support the inner lead which is thereby protected against tumbling. |
