Package structure interaction induced molding issues in MCM packages

As we move forward to newer silicon technologies that requiring MCM dual pad leadframe design and packaging solutions with tighter process margins, it is becoming imperative to resolve ppm wire sweep failure which is critical in transfer molding process as excessive results in shorting of wires, current leakage and electrical failure. Wire sweep has been proved to be closely related to bond span, wire length, height, mold flow direction, mold gate design…etc. With the MCM dual pad leadframe design, architecture dependent mold flow phenomena and race track profile are observed and impact on wire sweep failure rate. Although the impact could be positive on wire sweep, it is considered not acceptable as it would restrict the package design and could introduce incomplete filled or void issues. Besides, it could not meet today's zero ppm mindset in the automotive and critical applications industry.