Profile design for wire bonding

A method for analyzing forces acting on a wire during a formation process in which the wire is connected between a first bond and a second bond of a semiconductor device, wherein the second bond has a coordinate (Y1, Z1) relative to the first bond (0,0), comprising:

• (1) designating N sections of the wire each having a length L and respectively having an elastic constant of K1, K2 . . . Kn;
• (2) simulating the trace of a force (P, Q) of a clamp acting on the wire and analyzing deformation θi of the wire moved from the first bond to the second bond and the force (P, Q) of the clamp acting thereon from the following equations which are based on a linkage with springs model:
• L cos θ1+L cos θ2+. . . L cos θN=Z1;
• L sin θ1+L sin θ2+. . . L sin θN=Y1;
• QL sin θi+PL cos θi+Mi+1−Mi=0 for i=1,2, . . . , N;
• Mi=Ke(θi−θi−1)−ke(Δθp1−Δθp) when Δθp2≦Δθi≦Δθp1;
• Mi=Mp when Δθi>Δθp1;
• Mi=−Mp when Δθi<Δθp2;
• wherein θ1. . . θN are deformations at each end of the linkages, Mi is the bending moment value of the i-th spring, Ke is the spring constant in the simulation of elasticity, Mp is the limit bending momentum, Δθp is the angular difference between two linkages, and Δθp1 and θp2 are limit bending angles of recovered springs which are plastically re-deformed;
• and
• (3) calculating the deformation θi and the force (P,Q) of each said section of the wire such that necking and fracture of the wire during the formation process can be avoided thereby providing an optimum design for wire bonding profiles.