In the filling stage of epoxy molding compound in IC encapsulation process, high melt viscosity and fast flow can worsen wire sweep problems. A serious defect followed by wire sweep is wire short problems, which happen when a wire deforms and contacts to another wire in the molding process.
Moldex3D provides wire sweep prediction and wire sweep index for user to determine if the setting of processing conditions, the selection of materials, and leadframe layout is appropriate. In figure 2, the position of wire cross over is shown in a closer look. In the wire crossover display, the shape of wires are shown as deformed mesh on true scale, and wires contact each other will be marked in red, while other wires remain theirs original color.