Full Content is available to subscribers

Subscribe/Learn More  >

Mechanical Reliability Evaluation of Stripped and Replated Component Termination Finishes

[+] Author Affiliations
Guhan Subbarayan, Pei Fang Tsai, Krishnaswami Srihari

State University of New York - Binghamton, Binghamton, NY

Robert Kinyanjui

Sanmina-SCI Corporation, Huntsville, AL

Paper No. IPACK2007-33666, pp. 43-49; 7 pages
  • ASME 2007 InterPACK Conference collocated with the ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference
  • ASME 2007 InterPACK Conference, Volume 1
  • Vancouver, British Columbia, Canada, July 8–12, 2007
  • Conference Sponsors: Electronic and Photonic Packaging Division
  • ISBN: 0-7918-4277-0 | eISBN: 0-7918-3801-3
  • Copyright © 2007 by ASME


The termination finish of Small Output Integrated Circuit (SOIC) and Small Output Transistor (SOT) chip components were converted from Pb-free to Sn-Pb (backward conversion) and vice versa (forward conversion). The motivation for these conversions is due to a combination of factors such as the supply chain constraints on component availability, European Union’s (EU) legislation on “Restriction of Hazardous Substances” (or RoHS), and the growth of tin whiskers on matte tin finish components. The conversions were performed using a “Robotic Stripping and Solder Dipping Process”, and the mechanical reliability of the converted components was evaluated through lead pull testing. In this experiment, a 100% (all finishes are given in weight percentage unless otherwise specified) matte tin finish was first stripped and re-plated with an eutectic Sn-Pb finish. Then, components with 100% matte tin and eutectic Sn-Pb termination finish were replaced with a Pb-free Sn-3.5%Ag-0.5%Cu (SAC305) finish. Three Printed Circuit Board (PCB) surface finishes namely Immersion Silver (ImAg), Organic Solderable Preservative (OSP), and Electroless Nickel/Immersion Gold (ENIG), were evaluated with Sn-Pb and Pb-free processes. All the assembled boards were subjected to an initial analysis, which includes visual inspection with an optical microscope and X-Ray analysis. Subsequently, a time zero analysis was performed which includes cross sectioning, Scanning Electron Microscope (SEM) analysis and lead pull testing. The pull testing was performed on a Chatillon TCM 201-SS equipment. All the leads were pulled orthogonal to the surface of the PCB. After isothermal aging at 150°C for a time period of 10 days (240 hours), cross sectioning and pull testing were performed to study its effect on Intermetallic Compound (or IMC) growth and reliability.

Copyright © 2007 by ASME
Topics: Reliability , Finishes



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

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 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