ABSTRACT - Laminated substrates are used widely in the manufacture of multichip modules (MCM-L) by the electronic packaging industry. Of late, the thrust has been towards higher density circuitry to achieve improved performance and reduced size. This has led to the use of finer lines and spacings, smaller drilled holes and buried vias in organic laminates leading to reliability issues such as electrochemical migration.

One of the forms of electrochemical migration is known as conductive filament formation. Conductive filament formation is an electrochemical process. In accelerated environments of temperature and humidity, organic laminates can develop a loss of insulation resistance between conductors, eventually resulting in loss of electrical function of the circuit. The paper aims at discussing electrochemical migration in general, and conductive filament formation in particular. and its impact on the reliability of MCM-L.