Electronic assemblies and their manufacture are described. One embodiment relates to a method including depositing an organic thin film layer on metal bumps on a semiconductor wafer, the organic thin film layer also being formed on a surface adjacent to the metal bumps on the wafer. The wafer is diced into a plurality of semiconductor die structures, the die structures including the organic thin film layer. The semiconductor die structures are attached to substrates, wherein the attaching includes forming a solder bond between the metal bumps on a die structure and bonding pads on a substrate, and wherein the solder bond extends through the organic thin film layer. The organic thin film layer is then exposed to a plasma. Other embodiments are described and claimed.