Lead-Free Solder Body of Knowledge
POC: Kurt Kessel, NASA TEERM
Principal Center (321-867-8480)
kurt.r.kessel@nasa.gov
Matt Rothgeb, NASA TEERM Principal Center (321-867-8476)
matthew.j.rothgeb@nasa.gov
NASA’s Electronic Parts and Packaging (NEPP) group directed ITB to develop a body of knowledge on lead-free
solder. This effort, contracted through
Marshall Space Flight Center, centered on preparing a guidance
document to assist NASA in determining areas of risk associated with Class III
high reliability electronics. The document would serve to help NASA with the
transition to lead-free by analyzing lead-free test programs, university lead
efforts and supply issues associated with lead-free. ITB completed this project
in the summer of 2005.
Currently there is not enough high-reliability (IPC Class 3) data to understand how lead-free
materials will behave under the harsh environments of space applications. There
are too many variations with lead-free materials including board finishes, part
finishes and solder alloys. Process and performance reliability is tied the
selection of lead-free materials for specific applications. Further
complicating the issue is the fact that process and performance reliability can
vary greatly for the same product supplied by different vendors.
The following risk mitigation strategies are proposed:
1. Ensure that everyone, from
Procurement to Logistics to Technicians, understands the issue and concerns of
lead-free solder and parts that may contain lead-free solder. Making it
everyone’s responsibility will reduce the risk of component or system failure
from the use of lead-free solder.
2. Identify what part manufacturers and
suppliers are doing; which are converting to lead-free, which are going to have
two lines, and what controls will be in place to prevent mix-ups.
3. Modify logistics systems to capture
all possible methods of identifying lead-free products by modifying inventory
system to flag lead-free, RoHS compliant and “Green” products. Be prepared to
conduct a physical inventory for products not changing part numbers
4. Implement internal procedures to
deal with issues of lead-free product re-labeling and non-lead-free return
processes. Clearly defined labeling and parts numbers need to be created for
each product to differentiate it from its leaded counterparts. If the OEM
refuses to make such a differentiation, then the local NASA Quality Assurance
(QA) departments will have to work with technicians requesting the purchases to
ensure that some sort of post-purchase/post-delivery identification system is
set up to keep the leaded parts separate from the lead-free parts.
5. Continue participation in efforts
such as
CALCE,
CAVE, and
JCAA/JGPP
Lead-Free Solder.
The NASA TEERM Office is continuing to get the word out on the Lead-Free Solder (LFS) Body of Knowledge
(BOK). The NASA TEERM Office has been
successful in getting the BOK report on NASA websites. With the report on the
NASA websites, anyone within the agency with an interest in LFS can obtain
access to the report and the valuable information contained within it. The data
gaps identified within the BOK will serve as starting points when discussing new
lead-free (LF) projects which are needed in order to fully understand the
reliably of lead-free electronics possibly operating in space environments. The
NASA TEERM Office will continue to support developing efforts related to LF
electronics as the NASA agency faces the impending transition.
The LFS Body of Knowledge final report and associated appendices is available on the NASA Electronics Parts and Packaging (NEPP) Program:
http://nepp.nasa.gov
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