Title :
Fractographic analysis on the die surface crack of a LOC packaged DRAM
Author :
Mohanbabu, M. ; Khim, Swee Yong ; Durai, Elankovan
Author_Institution :
Texas Instrum. (S) Pte Ltd., Singapore
Abstract :
This paper describes the surface crack on the Silicon die of a LOC packaged DRAM device. Surface crack was found to occur on the die at one edge, after reliability tests. The root cause was found to be the interaction of the LOC tape that exceed the die area covered by the protective PIX, and the scribe structures at the saw street due to thermal stress on the tape. This paper presents the fractographical analysis done on a failed unit to find the root cause, sample preparation needed, and the micrographs of the nature of the crack and the striations observed in the crack site using the optical microscope, SEM and the Laser Scan Microscope (LSM) confocal imaging
Keywords :
DRAM chips; cracks; failure analysis; fractography; integrated circuit packaging; integrated circuit reliability; optical microscopy; scanning electron microscopy; specimen preparation; thermal stress cracking; thermal stresses; LOC packaged DRAM; LSM confocal imaging; SEM; Si; die surface crack; failure; fractographic analysis; laser scan microscopy; optical microscopy; protective PIX; reliability test; sample preparation; saw street; scribe structure; striations; tape; thermal stress; Lab-on-a-chip; Optical microscopy; Packaging; Protection; Random access memory; Scanning electron microscopy; Silicon; Surface cracks; Testing; Thermal stresses;
Conference_Titel :
Physical & Failure Analysis of Integrated Circuits, 1997., Proceedings of the 1997 6th International Symposium on
Print_ISBN :
0-7803-3985-1
DOI :
10.1109/IPFA.1997.638214
