Innovative Corrosion Inhibitors for ECAs on Leadfree Surfaces


Background: Modified electrically conductive adhesives (MECAs) and methods of making MECAs are disclosed. The MECAs include a corrosion inhibitor additive. The corrosion inhibitor additive can act as a barrier layer between the metal surface and the environment by forming a film over the metal surfaces and therefore reducing or preventing corrosion of the metal over an extended time frame. In general the corrosion inhibitor additive is a material that reduces or prevents the oxidation and corrosion of metal surfaces and stabilizes contact resistance of MECAs during elevated temperature and humidity. The cured composition has a contact resistance that changes less than about 20% after 500 hours\' aging at C./85% relative humidity. Technology Description: The MECAs of the present disclosure are capable of being used to bond electrical components in power ground and signal transmissions in electrical packaging. In short the MECAs could replace tin/lead solder in electrical packaging. For example the MECAs of the present disclosure can find application in interconnection technologies such as but not limited to pin-through-hole (PTH) surface mount technology (SMT) ball grid array (BGA chip scale package (CSP)) and flip chip technology. The MECAs can find application in consumer electronic devices such as but not limited to computers video displays cell phones pagers PDAs electronic toys electronic gaming machines and the like. The MECAs of the present disclosure are advantageous because they are environmentally friendly relatively inexpensive easy to process low thermo-mechanical stress and fine pitch capability. In addition embodiments of the MECAs may provide superior characteristics over currently used MECAs. For example after curing MECAs of the present disclosure have higher conductivity lower bulk resistivity a lower contact resistance shift over time a higher glass transition temperature enhanced mechanical properties and a lower coefficient of thermal expansion (CTE). Applications: Due to the improved interconnections the adhesives can be used in a wide variety of applications from flip chip technology to consumer electronic devices.


1) Corrosion inhibitors that also act as electrically conductive adhesives 2) Stabilized contact resistance on a variety of non-noble metal surfaces 3) Lead-free interconnections

Date of release