Processing induced material interactions determining the reliability of LTCC multichip modules

摘要

Metals can exhibit dendritic short-circuit growth caused by electrochemical migration in conductor-insulator structures, which may result in failures and reliability problems in microcircuits. The classical model of electrochemical migration has been well known for several decades. This process is a transport of metal ions between two metallization stripes under bias through a continuous aqueous electrolyte. Due to the electrochemical deposition at the cathode, dendrites and dendrite-like deposits are formed. Ultimately, such a deposit can lead to a short circuit in the device and can cause catastrophic failure. Recent investigations have demonstrated that no only metallic components, but also oxides from the isolating layers can take part in the formation of migrated shorts, after a chemical reduction process. Material design aspects need to clarify the correlation between material composition, processing, chemicla bonding state, and electrochemicla migration failure rate in isolating compounds: this is the scope of the present study.