Transcript Slideset () - Journal of Electronic Packaging

Date of download: 4/2/2017
Copyright © ASME. All rights reserved.
From: Monitoring Fatigue Cracking in Interconnects in a Ball Grid Array by Measuring Electrical Resistance
J. Electron. Packag. 2012;134(3):031006-031006-7. doi:10.1115/1.4006708
Figure Legend:
Diagram of shear fatigue test apparatus with specimen
Date of download: 4/2/2017
Copyright © ASME. All rights reserved.
From: Monitoring Fatigue Cracking in Interconnects in a Ball Grid Array by Measuring Electrical Resistance
J. Electron. Packag. 2012;134(3):031006-031006-7. doi:10.1115/1.4006708
Figure Legend:
Reflow temperature (°C) profile measured at the top of the components placed on the 23 mm board locations. The timescale is in
minutes (from 0 to 6) and there are seven heating zones. This was measured 4 times. The top figure is a schematic of the daisy
chain electrically connected array with 288 ball grid interconnections.
Date of download: 4/2/2017
Copyright © ASME. All rights reserved.
From: Monitoring Fatigue Cracking in Interconnects in a Ball Grid Array by Measuring Electrical Resistance
J. Electron. Packag. 2012;134(3):031006-031006-7. doi:10.1115/1.4006708
Figure Legend:
Cross-section diagram of an individual interconnect with nominal dimensions shown
Date of download: 4/2/2017
Copyright © ASME. All rights reserved.
From: Monitoring Fatigue Cracking in Interconnects in a Ball Grid Array by Measuring Electrical Resistance
J. Electron. Packag. 2012;134(3):031006-031006-7. doi:10.1115/1.4006708
Figure Legend:
(A) Photo of a fatigue test with real-time resistance data with the installed collection equipment. (B) Circuit diagram of in situ
resistance measurement experiment.
Date of download: 4/2/2017
Copyright © ASME. All rights reserved.
From: Monitoring Fatigue Cracking in Interconnects in a Ball Grid Array by Measuring Electrical Resistance
J. Electron. Packag. 2012;134(3):031006-031006-7. doi:10.1115/1.4006708
Figure Legend:
The monotonic shear stress versus shear strain response of a BGA sample containing 288 interconnects. All deformation from
sources other than the interconnects were subtracted. The plot also shows real-time resistance versus total shear strain.
Date of download: 4/2/2017
Copyright © ASME. All rights reserved.
From: Monitoring Fatigue Cracking in Interconnects in a Ball Grid Array by Measuring Electrical Resistance
J. Electron. Packag. 2012;134(3):031006-031006-7. doi:10.1115/1.4006708
Figure Legend:
Shows maximum shear stress and electrical resistance for each cycle near beginning and ending cycles. The shear stress does not
give distinct signal of initial interconnect failure whereas real-time electrical resistance does.
Date of download: 4/2/2017
Copyright © ASME. All rights reserved.
From: Monitoring Fatigue Cracking in Interconnects in a Ball Grid Array by Measuring Electrical Resistance
J. Electron. Packag. 2012;134(3):031006-031006-7. doi:10.1115/1.4006708
Figure Legend:
Calculated crack area propagation rates in a fatigue test. Three crack stages appear to be delineated. Although in stage II the crack
rate decreases temporarily, these results may be interpreted to show the crack may have temporarily stopped at a void before final
rapid propagation toward failure, or burnishing may have caused better electrical contact (reducing the resistance at crack
surfaces).
Date of download: 4/2/2017
Copyright © ASME. All rights reserved.
From: Monitoring Fatigue Cracking in Interconnects in a Ball Grid Array by Measuring Electrical Resistance
J. Electron. Packag. 2012;134(3):031006-031006-7. doi:10.1115/1.4006708
Figure Legend:
Crack area determined from maximum stress versus number of cycles. The change in maximum stress measures change in crack
area for the total number of interconnects. Five zones of differing total crack propagation rates versus cycle number, labeled by
numbers, are shown on the figure.
Date of download: 4/2/2017
Copyright © ASME. All rights reserved.
From: Monitoring Fatigue Cracking in Interconnects in a Ball Grid Array by Measuring Electrical Resistance
J. Electron. Packag. 2012;134(3):031006-031006-7. doi:10.1115/1.4006708
Figure Legend:
The equivalent crack length was calculated using the resistivity data assuming a thumbnail shaped crack. A fit of the Paris’ law to
the crack growth data gave da/dN = C (ΔK)m, C = 6.7 × 10− 20 and m = 2.25.