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Enhanced Cu pillar design to reduce thermomechanical stress induced during flip chip assembly
- Source :
- Microelectronics Reliability. 87:97-105
- Publication Year :
- 2018
- Publisher :
- Elsevier BV, 2018.
-
Abstract
- In this work a Cu pillar design that combines a stiff metal pedestal with a soft polymer as buffer layer has been integrated in a dedicated test vehicle to investigate the thermo mechanical stress induced during flip chip assembly. In-situ electrical measurements of dedicated stress sensors during a Bump Assisted BEOL Stability Indentation (BABSI) test were performed to assess the strength of the bump designs. Furthermore, the package induced stress was monitored in different regions of the test chips by measuring and comparing the ION current of the stress sensors before and after packaging. By combining in-situ electrical measurements and finite element modeling it was possible to quantify the stress level induced in the Si die after packaging. Additionally, the package out of plane deformation has been measured after flip chip to laminate and after molding. The results show that the use of a stiff pedestal is very efficient to mitigate packaging induced stress. It has also been shown that the out of plane deformation is independent of the Cu pillar design.
- Subjects :
- 010302 applied physics
Materials science
Deformation (mechanics)
02 engineering and technology
Molding (process)
021001 nanoscience & nanotechnology
Condensed Matter Physics
01 natural sciences
Atomic and Molecular Physics, and Optics
Finite element method
Die (integrated circuit)
Surfaces, Coatings and Films
Electronic, Optical and Magnetic Materials
Pedestal
Indentation
0103 physical sciences
Electrical measurements
Electrical and Electronic Engineering
Composite material
0210 nano-technology
Safety, Risk, Reliability and Quality
Flip chip
Subjects
Details
- ISSN :
- 00262714
- Volume :
- 87
- Database :
- OpenAIRE
- Journal :
- Microelectronics Reliability
- Accession number :
- edsair.doi...........e4b86bec3e7091c85fd07ff5fc905077
- Full Text :
- https://doi.org/10.1016/j.microrel.2018.06.004