Study on the Influence of Au Content and Bonding Parameters on the Free Air Ball Morphology and Bonding Reliability of Ag-Au-Pd Alloy Wire

Abstract

This article conducts wire bonding tests and cold/hot-cycle tests using φ 0.025 mm Ag-Au alloy wires and Ag-Au-Pd alloy wires with different specifications. The results show that, due to the addition of the alloying element Pd, under the same bonding parameters, the fracture strength and ball-bonded point shear force of the Ag-Au-Pd alloy wires are significantly higher than those of the Ag-Au alloy wires. After the cold/hot-cycle tests, the failure probability of the Ag-Au-Pd alloy wires is approximately half that of the Ag-Au alloy wires. Among Ag-Au-Pd alloy wires, 92% break at the ideal positions, while 77% of the Ag-Au alloy wires break at the necks. As the Au content increases, the Free Air Ball (FAB) morphology of the Ag-Au-Pd alloy wires becomes more and more regular, gradually transitioning from a pointed ball to an ellipsoid and finally presenting a spherical shape.

Keywords

• bonding parameters
• FAB characteristics
• failure probability