DocumentCode :
2357821
Title :
Die crack mechanism study and improvement on 54ld SOIC EP package
Author :
ZhiJie, Wang ; Lim, Tony ; YingWei, Jiang ; ChangLiang, Zhang ; BaoGuan, Yin ; XiaoWei
fYear :
2010
fDate :
8-10 Dec. 2010
Firstpage :
217
Lastpage :
223
Abstract :
There are multiple die crack incidents reported on 54ld SOIC EP (Exposed pad) packages from one SMT customer. Various analytical methods were employed in order to find the root cause of the die crack, including CSAM, X-Ray, 4 point bend test, SEM & fractography analysis, TherMorie analysis and digital modeling. A series of experimentations on silicon, packaging process and SMT PCB board design were carried out. The root cause of the die crack is concluded as that SMT process and PCB board design generate high thermo-mechanical stress onto EP package, exceeding low end of die strength distribution. Anti die crack solutions were identified including: improving silicon mechanical strength and reducing thermal mechanical stress of SMT process. Optimizing dicing saw process, adding Diama flow additive, changing dicing sequence reduced die crack ppm by 50%, adding SEZ etching after wafer backgrinding can further reduce die crack ppm by 99.8%. TherMorie measurement on different PCB designs indicated full flag solder pad design generates less thermal mechanical stress than 4 solder bar solder pad design with 60% package warpage reduction.
Keywords :
cracks; integrated circuit packaging; printed circuit design; 4 point bend test; 54ld SOIC EP package; CSAM, X-Ray; Diama flow additive; SEM; SMT PCB board design; TherMorie analysis; die crack mechanism; digital modeling; exposed pad packages; fractography analysis; silicon mechanical strength; small-outline integrated circuit; thermal mechanical stress; thermo-mechanical stress;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Electronics Packaging Technology Conference (EPTC), 2010 12th
Conference_Location :
Singapore
Print_ISBN :
978-1-4244-8560-4
Electronic_ISBN :
978-1-4244-8561-1
Type :
conf
DOI :
10.1109/EPTC.2010.5702636
Filename :
5702636
Link To Document :
بازگشت