Journal of SMT Article

EFFECTS OF NEMI Sn/Ag/Cu ALLOY ASSEMBLY REFLOW ON PLATED THROUGH HOLE PERFORMANCE

Author: John J. Davignon
Company: Merix Corporation
Date Published: 10/1/2000   Volume: 13-4

Abstract: At the present time there is a major thrust to evaluate which of the many lead free solder alloys to use for assembling packages. Many of the newer alloys have higher eutectic temperatures and require higher reflow temperatures than the existing Sn/Pb reflow temperature. This paper evaluates the changes in PTH performance and laminate material properties for several epoxy-based laminate systems caused by the thermal reflow requirements of the NEMI higher temperature alloy. Although the epoxy systems evaluated will discolor at the higher temperatures, the glass transition temperatures (Tg) and the Z-axis coefficient of thermal expansion (CTE) are not greatly affected. Time to delamination (T-260) was lowered in 2 of the 3 systems but not to a level to cause concern. The PTH performance for the standard FR-4 epoxy and the high Tg epoxy was significantly degraded, while the PPO/epoxy blend did not significantly change.

Keywords: This paper will discuss the effects on the plated-through-hole (PTH) performance and epoxy-based laminate material properties caused by the higher temperature assembly reflow profiles required for the new NEMI 95.5Sn/3.8Ag/0.7Cu alloy. PTH performance was evaluated by the Interconnect Stress Test (IST) method.



Cost to download:

  Members: Free! (Log on to receive the member rate)
  Non-Members: $10

Why become an SMTA member?

Not a member yet? Join SMTA today!

Notice: Sharing of articles is prohibited. Downloaded papers must only be stored on a local hard drive and not in a shared repository either internal or external.


Back


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

Phone 952.920.7682
Fax 952.926.1819
Home
Site Map
Update Your Info
Related Links
Send Us Feedback
Contact Us
Privacy Policy
↑ Top