In copper wire bonding (e.g., using the Kulicke & Soffa Copper Kit), forming gas (e.g., 5% Hydrogen/95%
Nitrogen) is typically used to facilitate the proper and robust wire bonding process and prevent oxidation of the
heated copper wire. Extensive experimentation and testing have shown that the small percentage of hydrogen
mixed with nitrogen performs better than pure nitrogen alone. This note is provided in response to customer
questions on the subject; however, it provides general guidance only. Before designing an actual production
environment for wire bonding using forming gas (e.g., copper wire bonding), appropriate environmental
engineers or other experts in air quality should be consulted.