• PWB Solderability: Lead-free alloys will work with Organic Solderability Preservative (OSP) finished boards, but not at the lower 235oC test temperature. At 265oC, the wetting times were considered acceptable. While the wetting forces were improved at 265oC, for lead-free alloys, it took longer to reach.
  • Soldering Processes: Despite the higher reflow soldering temperatures (240oC to 260oC), it is feasible to manufacture lead-free hardware with current reflow soldering and wave soldering equipment. It is recommended that more active solder fluxes and nitrogen be used to improve wetting performance.
  • Circuit Board Assembly Soldering Results: Thermal cycle test results demonstrated that it is feasible, utilizing existing soldering processes and lead-free materials, to achieve acceptable ANSI J-STD-001C Class 2 and Class 3 solder joints capable of meeting high reliability requirements.
  • Tin Whisker Research and Growth: Whisker growth is the result of compressive stress relief. Intermetallic formation appears to play a very significant role in the formation of whiskers.
  • ">

    Advanced Technology Symposium Conference Proceedings


    TEST RESULTS FROM THE LEAD-FREE COMPONENT FOCUS GROUP

    Authors: Lee Whiteman, et al.
    Company: American Competitiveness Inst.
    Date Published: 6/11/2002   Conference: Advanced Technology Symposium


    Seika Machinery, Inc.

    Abstract: In 2000, an industrial component focus group was formed to determine the characteristics of lead-free soldering with respect to component solderability, board solderability, manufacturing and processes, solder joint reliability, and tin whisker growth. The team’s goal was to provide the electronics manufacturing community with data concerning the implementation of lead-free soldering. This was accomplished by performing a limited assessment of lead-free components, board finishes, and solders. These assessments were completed in 2001, and presented at IPC Works 2001, in Orlando, Florida. Among the findings generated from the groups activities were:

  • Component Solderability: Sn, SnCu, and NiPd are acceptable lead-free component termination finishes.
  • Component Moisture Sensitivity: Moisture sensitivity level (MSL/ MRT) capability for "typical" components at 260oC degrades by as much as two (2) or more levels compared to current ANSI J-STD-020A levels.
  • PWB Solderability: Lead-free alloys will work with Organic Solderability Preservative (OSP) finished boards, but not at the lower 235oC test temperature. At 265oC, the wetting times were considered acceptable. While the wetting forces were improved at 265oC, for lead-free alloys, it took longer to reach.
  • Soldering Processes: Despite the higher reflow soldering temperatures (240oC to 260oC), it is feasible to manufacture lead-free hardware with current reflow soldering and wave soldering equipment. It is recommended that more active solder fluxes and nitrogen be used to improve wetting performance.
  • Circuit Board Assembly Soldering Results: Thermal cycle test results demonstrated that it is feasible, utilizing existing soldering processes and lead-free materials, to achieve acceptable ANSI J-STD-001C Class 2 and Class 3 solder joints capable of meeting high reliability requirements.
  • Tin Whisker Research and Growth: Whisker growth is the result of compressive stress relief. Intermetallic formation appears to play a very significant role in the formation of whiskers.


  • Members download articles for free:

    Not a member yet?

    What else do you get when you join SMTA? Read about all of the benefits that go along with membership.

    Notice: Sharing of articles is restricted to just your immediate work group. Downloaded papers should not be stored on an external network or shared on the internet.


    Back


    SMTA Headquarters
    6600 City West Parkway, Suite 300
    Eden Prairie, MN 55344 USA

    Phone +1 952.920.7682
    Fax +1 952.926.1819