Patent ID: 6178540
Filing Date: 2001-01-23
Classification: G06F,H01L

Abstract:
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 .theta..sub.i 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 .theta..sub.1 +L cos .theta..sub.2 +. . . L cos .theta..sub.N =Z1;L sin .theta..sub.1 +L sin .theta..sub.2 +. . . L sin .theta..sub.N =Y1;QL sin .theta..sub.i +PL cos .theta..sub.i +M.sub.i+1 -M.sub.i =0 for i=1,2, . . . , N;M.sub.i =K.sub.e (.theta..sub.i -.theta..sub.i-1)-k.sub.e (.DELTA..theta..sub.p1 -.DELTA..theta..sub.p) when .DELTA..theta..sub.p2.ltoreq..DELTA..theta..sub.i.ltoreq..DELTA..theta.. sub.p1 ;M.sub.i =M.sub.p when .DELTA..theta..sub.i >.DELTA..theta..sub.p1 ;M.sub.i =-M.sub.p when .DELTA..theta..sub.i <.DELTA..theta..sub.p2 ;wherein .theta..sub.1. . . .theta..sub.N are deformations at each end of the linkages, M.sub.i is the bending moment value of the i-th spring, K.sub.e is the spring constant in the simulation of elasticity, M.sub.p is the limit bending momentum, .DELTA..theta..sub.p is the angular difference between two linkages, and .DELTA..theta..sub.p1 and .theta..sub.p2 are limit bending angles of recovered springs which are plastically re-deformed; and(3) calculating the deformation .theta..sub.i 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.