INEMI PROJECT FOCUSES ON METHODOLOGIES FOR QUALIFYING NEW ELECTRONIC DEVICE PACKAGING
New integrated circuit (IC) package technologies are typically qualified using procedures and test conditions based on experience with the most similar technology previously qualified. Doing so, however, does not take into account the characteristics of new technologies and may result in overlooking new failure modes. At the same time, there is a general lack of understanding of the assembly processes, application environments, and use conditions in which the new package technologies will be used. This information gap poses challenges when developing the appropriate reliability test plans for new package technologies and materials.
A thorough qualification methodology is necessary to identify reliability weaknesses and prevent reliability escapes when qualifying new package technologies and materials. Moreover, field failures are rarely fed back to the original qualification team to allow for failure mode validation, root cause analysis, and improvements to the test plan; nor are the developers of new package technologies and materials rushing to help industry standards groups develop new test methods or qualification standards for their new technologies and materials.
iNEMI's New Packaging Technology Qualification Methodology project plans to develop guidelines for relevant and cost-effective testing for qualifying new package technologies. The team conducted two industry surveys to assess potential gaps in existing package qualification practices. Survey respondents included the entire electronics supply chain, from device users to device suppliers, fabless device suppliers, design houses, package suppliers (OSAT), and fab suppliers. Topics such as new package materials and technologies, end-user concerns, test conditions, new application spaces, and new qualification requirements were included in the survey.
The first survey provided key insights into current industry practices and validated the gaps identified by iNEMI. A second survey helped gather more detailed information in five areas:
1) test methods
2) qualification standards
3) application temperatures (both use and junction)
4) new application spaces
5) package qualification methodology tools and best practices
Both surveys highlighted a discrepancy between supplier and customer knowledge about the use of new technologies and materials, indicating a need for greater information sharing — from end use conditions to qualification results — between companies. The awareness of what failure mechanisms could occur with new package technology and how best to test for those mechanisms can be improved, and would greatly benefit from industry guidelines for best practices.
The second survey explored the differences between field use conditions and the qualification stress conditions required to support the use conditions. Respondents indicated that application use temperatures are rising, with some going higher than the current 150°C upper limits and a few going below the -65°C lower limits. The fact that survey respondents are extending their test durations indicates an awareness that improvements need to be made in test methods and requirements used in qualification standards.
The New Packaging Technology Qualification Methodology project plans to develop a white paper with recommendations for package qualification for new technologies and materials, leveraging industry test methods, qualification standards, and best practices.
“Benchmarking of Qualification Methodologies for New Package Technologies and Materials,” presented by Feng Xue (IBM Singapore), iNEMI Session at ICEP 2019, April 17, 2019, Niigata, Japan. This paper discusses the findings from the project team's two surveys and presents a roadmap for developing a methodology to qualify new package technology that will address the gaps identified in the surveys.
“iNEMI New Package/Material Qualification Methodology Project,” presentation from webinar reviewing survey results (July 9, 2019).