Predicting the Shear Strength of a Wire Bond Using Laser Vibration Measurements

Wedge/wedge bonding with AlSi-1 wire on semiconductor chips with aluminum metallization has been investigated. The scope of the article is the modeling of the wedge bond. The description of the bonding process by a physical model shall predict the change of bond quality, depending on a change in bonding parameters. The physical model is based on measurements of the vibration amplitude, induced into the assembly by the ultrasonic (US) power. The model is derived by measurements of the shear strength for various bond times. By fitting the calculation to the measurements, details of the bonding process can be clarified.. By using the model shear force can be calculated by estimation of the deformation of the wire material, the amplitude of the tool, sigma and the transversal force during bonding