A Design and Manufacturing Guide for the Lead Frame Chip Scale Package (LFCSP)

The LFCSP is a near chip scale package (CSP), a plastic encapsulated wire bond package with a copper lead frame substrate in a leadless package format. Perimeter input/output pads are located on the outside edges of the package. Electrical contact to the printed circuit board (PCB) is made by soldering the perimeter pads and exposed paddle on the bottom surface of the package to the PCB. Heat is efficiently conducted from the package by soldering the exposed thermal paddle (see Figure 1) to the PCB. Stable electrical ground connections are provided through down bonds and through conductive die attach material. Wire bonding is provided using gold wires (see Figure 2). Perimeter and thermal pad finish is plated as Sn/Pb solder or 100% Sn. Packaging is in tape and reel or trays.