0
Research Papers

Effects of Cycling Parameters on the Thermal Fatigue Life of Mixed SnAgCu/SnPb Solder Joints

[+] Author and Article Information
M. Meilunas

 Universal Instruments Corporation, Conklin, New York 13904 e-mail: meilunas@uic.com

P. Borgesen

Department of Systems Science and Industrial Engineering,  Binghamton University, P.O. Box 6000, Binghamton, New York 13902-6000 e-mail: pborgese@binghamton.edu

J. Electron. Packag 133(2), 021001 (Jun 22, 2011) (5 pages) doi:10.1115/1.4003863 History: Received September 27, 2009; Revised February 03, 2011; Published June 22, 2011; Online June 22, 2011

The mandated switch of the overwhelming part of microelectronics assembly to lead-free soldering has left the manufacturers of many high reliability products, which are still exempt from the requirement to change, with a choice between imperfect alternatives. One of these involves the inclusion of lead-free BGAs and CSPs in a eutectic SnPb solder paste based reflow process. In order to assess the consequences of this for reliability it is not enough to subject samples to common accelerated tests. Mixing of the alloys is almost certain to affect the acceleration factors so that comparisons of test results may not reflect relative performances under service conditions. This was illustrated with for a set of model BGA components with 20 mil (0.5 mm) diameter SAC305 solder balls, which were reflow soldered onto printed circuit boards using a eutectic SnPb solder paste and tested in thermal cycling together with controls soldered with a SAC305 paste. Mixed joints were found to outperform pure SAC305 in −40/125°C tests but not in 0/100°C, and general trends suggest that mixed joints may compare more poorly in service.

FIGURES IN THIS ARTICLE
<>
Copyright © 2011 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Cross section schematic of model BGA, not to scale

Grahic Jump Location
Figure 2

Typical fatigue crack. Sample subjected to 4000 cycles of 0/100°C with 10 min dwells

Grahic Jump Location
Figure 3

Life, N63 , versus dwell time in 0/100°C cycling for component TV64A with mixed SAC305/SnPb and pure SAC305 joints

Grahic Jump Location
Figure 4

Life, N63 , versus dwell time in 0/100°C cycling for component TV64B with mixed SAC305/SnPb and pure SAC305 joints

Grahic Jump Location
Figure 5

Life, N63 , versus dwell time in 0/100°C cycling for component TV64C with mixed SAC305/SnPb and pure SAC305 joints

Grahic Jump Location
Figure 6

Life, N63 , for the three components with mixed SAC305/SnPb and pure SAC305 joints in −40/125°C cycling with two different dwell times

Grahic Jump Location
Figure 7

Dwell time dependence versus strain range in −40/125°C cycling for mixed SAC305/SnPb and pure SAC305 joints

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In