Processing induced material interactions determining the reliability of LTCC multichip modules

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 electroch emical migration has been well known for several decades. This process is a transport of metal ions between two metallization stripes under bias throu gh 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 ca tastrophic failure. Recent investigations have demonstrated that not only m etallic components, but also oxides from the isolating layers can take part in the formation of migrated shorts, after a chemical reduction process. M aterial design aspects need to clarify the correlation between material com position, processing, chemical bonding state, and electrochemical migration failure rate in isolating compounds: this is the scope of the present stud y. (C) 2000 Elsevier Science Ltd. All rights reserved.