Here is the abstract you requested from the NHP_2012 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Moisture Failures in Electronic Devices|
|Keywords: Moisture, Hermeticity, Failure Modes and Mechanisms|
|Electronic devices are sealed in hermetic enclosures to protect them from contamination, especially moisture. Yet RGA database reviews show that 10-14% of hermetic enclosures do not comply to the internal water vapor limit of 5000 ppmv. About half of the noncompliances are due to moisture volatilizing from materials into sealed package headspace, and half are due to moisture ingress through package seal defects. While the noncompliance rate is high (>100,000 ppm!), the rate of actual moisture-caused failure in hermetics remains relatively low. This paper reviews some prominent moisture-caused failures that have occurred in hermetic packages over the past five decades. It identifies reasons why field-failure rates are low despite the high rate of internal water vapor noncompliance. However, if hermetic packages have such a high rate of noncompliance for moisture control, how much more could moisture affect the reliability of packages that are not intended to be hermetic to begin with? Are there materials and process factors that could cause failure rates for nonhermetics to mushroom over that of hermetics because the devices they enclose are potentially subject to a greater extent of moisture exposure than in hermetics? To provide context for nonhermetic packaging technology, and the establishment of standards by which to qualify nonhermetics, this paper extrapolates the concerns for moisture in hermetic packages to nonhermetic packages of both the cavity and flip-chip or encapsulated style.|
|Robert K. Lowry, Consultant
Electronic Materials Characterization