Outer leads are buried in a package. At least the contact portions of the outer leads which are connected to a circuit board are exposed from the package and the exposed portions make the same flat surfaces as the package surface. When forming the package, the outer leads are used as the side wall of...http://www.google.com/patents/US5493151?utm_source=gb-gplus-sharePatent US5493151 - Semiconductor device, lead frame and method for manufacturing semiconductor devices
