Novel Cu–Cu Bonding Technique: The Insertion Bonding Approach

A novel low-temperature Cu-Cu bonding approach called the insertion bonding technique has been developed. This technique hinges on the introduction of a tangential pressure at the metal-metal interface, which leads to a high localized plastic deformation that is essential for bond formation. Through finite element modeling studies, it is observed that the insertion bonding technique results in a significantly larger plastic deformation in comparison to the conventional bonding technique under the same bonding conditions. First experimental studies of the insertion bonding technique were performed and it is observed that an electrically yielding Cu-Cu joint is achieved at a low bonding temperature of 100^°C. This shows that the insertion bonding technique holds much promise for low-temperature Cu-Cu bonding.