Controlling Surface Sensitive Processes in Microelectronics Manufacturing to Improve Wire Bonded Joint Reliability

Validating surface chemical composition and properties of die pad surfaces is crucial for achieving joint reliability in microelectronic wire bonding operations. Die pad surfaces undergo a number of surface sensitive manufacturing steps prior to bonding that will affect joint performance; contact and environmental contaminants from process aids, shipping, handling, storage and out time are all key players in surface degradation. Microelectronics manufacturers may implement cleaning and/or surface activation operations to remediate surfaces from upstream contaminants, however, understanding and quantifying the effect of such processes requires the ability to manipulate and monitor the top few molecular layers of a material responsible for adhesion—the surface. This presentation will investigate surface chemistries of atmospheric plasma cleaned and non-cleaned die pad surfaces as determined by X-ray photoelectron spectroscopy (XPS) and surface energy measurements via contact angle techniques.