Semiconductor device packages having dummy block leads and tie bars with extended portions to prevent formation of air traps in the encapsulate

摘要

A semiconductor device package is equipped with devices for preventing the formulation of air traps in its encapsulated package body. These devices include dummy block leads formed on the outermost inner lead of each row of inner leads, and extended portions formed on each tie bar. Each dummy block lead extends from the end of an outermost inner lead and is integrally formed therewith. The tie bar extended portions are separated into several parts defined by spaces between the parts, and the several parts are formed integral with each other and with the tie bar. The dummy block leads and the tie bar extended portions may be formed so as to be inclined relative to horizontal and with jagged edges at their side surfaces. The dummy block leads and tie bar extended portions serve to reduce the velocity of the potting resin which forms the encapsulate, as it enters the die cavity for encapsulation, but before the resin actually contacts the chip or the inner leads. Thereby, the flow velocity at various points within the mold cavity is uniform, and formation of air traps is prevented.