{'fraction_non_alphanumeric': 0.021760633036597428, 'fraction_numerical': 0.003956478733926805, 'mean_word_length': 5.170731707317073, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Ion Channeling Contrast Imaging of Aluminum Wire Bonds

Bond formation in metallic solids can occur by diffusion when metal atoms acquire enough energy to overcome the activation barrier. In ultrasonic wirebonding, the bond is formed by introduction of ultrasonic energy while applying a clamping force. It has been proposed that the ultrasonic “scrubbing” action breaks up surface oxides and contaminants, allowing atomically clean metals to come in direct contact and form a bond at relatively low temperatures (well below the melting temperatures of the constituents). It is also proposed that localized heating during the process is not sufficient to play a substantial role in the bonding process [2]. Ultrasonic power, clamping pressure, and time are the key process variables. In this study, bonds formed under two sets of parameters were evaluated. Test sample preparation consisted of mounting Si die on PWB hybrids and bonding with 32-micrometer diameter aluminum (Al 1% Si) wire under two conditions.