METHOD AND DEVICE FOR CONTROLLING THE GENERATION OF ULTRASONIC WIRE BONDS

摘要

The invention relates to a method for generating a wire bond between a wire (3) and an electrical contact member (4), the method comprising the steps of: pressing a first surface (A(t)) of a portion (3a) of the wire (3) against a second surface (S) of the electrical contact member (4) with a first force (F_nb) normal to the second surface while vibrating the portion of the wire along the second surface in order to generate a bond; measuring the time dependent vibration amplitude (a(t)) of the portion (3a) of the wire (3) at a number of discrete time steps during the generation of the bond; measuring the time dependent deformation (z(t)) of said portion of the wire due to said applied first force and said vibration at a number of discrete time steps during the generation of the bond; and generating a time dependent first signal (F_s(t)) from at least said vibration amplitude and said deformation at a number of discrete time steps during the generation of the bond that is a direct measure of the stability of the bond at the respective time step. The invention also relates to a device for generating this kind of bonds, wherein an analysing device (9) is provided that is adapted to generate a time dependent first signal (F_s(t)) from at least said vibration amplitude and said deformation of the wire at a number of discrete time steps during generation of the bond, wherein said first signal is a direct measure of the stability of the bond at the respective time step.