Abstract: A variety of leadless packaging arrangements and methods of packaging integrated circuits in leadless packages are disclosed. The described lead frames are generally arranged such that each device area has a plurality of contacts but no die attach pad. With this arrangement, the back surface of the die is exposed and coplanar with the exposed bottom surface of the contacts. A casing material (typically plastic) holds the contacts and die in place. In one aspect of the invention, the back surface of the die is metallized. The metallization forms a good attachment surface for the package and serves as a good thermal path to transfer heat away from the die. In another aspect, at least some of the contacts have a top surface, a shelf, and a bottom surface. The die is wire bonded (or otherwise electrically connected) to the shelf portions of the contacts. The described package is quite versatile.
Type:
Grant
Filed:
October 31, 2002
Date of Patent:
April 20, 2004
Assignee:
National Semiconductor Corporation
Inventors:
Nghia Tu, Shaw Wei Lee, Sadanand R. Patil