Experiment and numerical analysis for edge and corner bonded PoP bottom package assemblies under four-point bending
This paper presents the four-point bend test results for edge and corner bonded 0.5mm pitch lead-free package stackable very thin fine pitch ball grid arrays (PSvfBGAs) as package-on-package (PoP) bottom packages on a standard IPC/JEDEC bend test board. The tests were carried out based on the above...
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Published in | Microelectronics and reliability Vol. 51; no. 9-11; pp. 1850 - 1855 |
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Main Authors | , , |
Format | Journal Article Conference Proceeding |
Language | English |
Published |
Kidlington
Elsevier Ltd
01.09.2011
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | This paper presents the four-point bend test results for edge and corner bonded 0.5mm pitch lead-free package stackable very thin fine pitch ball grid arrays (PSvfBGAs) as package-on-package (PoP) bottom packages on a standard IPC/JEDEC bend test board. The tests were carried out based on the above standard with a 30mm loading span, 90mm support span and 7.5mm/s crosshead speed. The daisy chain resistance, strain, crosshead displacement and load of each PSvfBGA were measured and a 20% increase in the resistance was used as the failure criterion. Materials used in this study were a UV-cured acrylic edge bond adhesive, a thermal-cured epoxy edge bond adhesive and a thermal-cured epoxy corner bond adhesive. The test results show that all of them can improve the bend performance significantly; especially the edge bond high module epoxy increased the crosshead displacement, strain and bending force when mechanical damage occurred by 33.46%, 26.74% and 3.05% respectively. Failure analysis indicated that the predominant failure site was PCB pad lift/cratering regardless of with or without adhesives. The 3D quarter finite element model was also built to further study the improvement mechanism of bend performance by these adhesives. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0026-2714 1872-941X |
DOI: | 10.1016/j.microrel.2011.07.087 |