Here is the abstract you requested from the wirebonding_2014 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Ball Bond Reliability: Simulation of Pull and Shear Test|
|Keywords: bond pull strength, bond shear, bond pad struccture|
|This academic study simulates the elements of typical reliability sample testing in ball bond assembly, namely Bond Pull Strength (BPS) and Bond Shear (BS). A variety of 3D bond pad models developed for finite element studies at Brigham Young University Idaho are used, some which are expected to crack or crater easily in harsh ball bonding. Upward force at various angles (pull test) or lateral force (shear test) is applied in static and in dynamic simulations. Stress and strain during pull test is simulated to the point at which a 25µ gold (Au) or copper (Cu) wire may be expected to experience a “span break”, assuming a strong bond. Simulation for shear test is done with the force expected to shear the Au of a well-bonded ball, or the force that may break the pad structure for a well-bonded Cu ball. Pull and shear forces are applied to a variety of pad Al film thicknesses to study the stress differences. Simulated stresses are also compared with the stress applied during the ball bonding process itself.|
|Stevan Hunter, Sr. Principal Reliability Engineer