TEERM NASA Lead-Free Electronics

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TEERM=20 Active = Project

NASA-DOD Lead-Free Electronics = (Project=20 2)

POC: Kurt Kessel, (321-867-8480) = kurt.r.kessel@nasa.gov
&nbs= p; =20 Greg Krivdo, (321-867-0492) mailto:Gregory.T.Krivdo@nasa.go= v

Background
NASA=92s=20 earlier lead-free=20 solder high-reliability testing effort = helped shed=20 light on the reliability of circuit cards = manufactured=20 with lead-free solders. However, that project = was not=20 able to fully explore rework and solder = mixing. As=20 the transition to lead-free becomes an = ever-closer=20 reality for military and aerospace applications, = it will=20 be critical to fully understand the implications = of=20 rework and solder mixing.

This joint = project of=20 DoD, NASA and defense and space contractor=20 representatives will build on the results from = the=20 former NASA-led lead-free solder project. = The new=20 effort will focus on the rework of tin-lead and=20 lead-free solder alloys and will include the = mixing of=20 tin-lead /lead-free & lead-free/ tin-lead = solder=20 alloys.

Objective
In response to concerns = about=20 risks from lead-free induced faults to high = reliability=20 products, NASA has outlined a multi-year project = to=20 provide manufacturers and users with data to = clarify the=20 risks of lead-free materials in their = products. =20 The project will also be of potential interest = to=20 component manufacturers supplying to high = reliability=20 markets. The project was launched in = November=20 2006. The primary technical objective of = the=20 project is to undertake comprehensive testing to = generate information on failure modes/criteria = to better=20 understand the reliability of packages (e.g., = Thin Small=20 Outline Package, Ball Grid Array, Plastic Dual = Inline=20 Package) assembled and reworked with lead-free = alloys=20 and with mixed (lead/lead-free) = alloys.

The=20 assembled boards will be subjected to = accelerated=20 testing (e.g., thermal, vibration) to understand = solder=20 joint reliability. Results from the = project will=20 be available during the duration of the project = allowing=20 advance information to assist organizations in = their own=20 implementation or mitigation strategies.

Period of = Performance=20

November 2006 to September=20 2010.

Stakeholders
NASA = Centers=20 (Kennedy Space Center, Jet Propulsion = Laboratory,=20 Marshall Space Flight Center, Johnson Space = Center,=20 Goddard Space Flight Center, Ames Research = Laboratory),=20 NASA contractors (United Space Alliance-Solid = Rocket=20 Booster, Boeing-Orbiter), major commercial and = defense=20 aerospace contractors (BAE Systems, Boeing, = Lockheed=20 Martin, Raytheon, Rockwell Collins), Air Force, = Army,=20 Navy, Marines, Dept. of Energy and other private = entities.

Benefits

Project will fast-track since it builds = off of the=20 previous NASA lead-free project=20
Data generated from this project is = required to=20 gain a better understanding of how lead-free=20 electronics will perform in high-reliability = aerospace=20 applications=20
Even though NASA and the aerospace = community are=20 exempt from lead-free laws and regulations, = there may=20 not be enough suppliers available to meet = needs=20
Military and aerospace contractors are = receiving=20 unwanted electronics components with lead-free = finishes.

Document Status

Joint Test Protocol - Final - = October 8,=20 2007 (NLFE Project JTP = October-08-2007.pdf, 666KB,=20 36 pages, October 8, 2007)=20
Project Plan =96 Final - = November 17,=20 2008 (NASA-DoD LFE Project Plan = Nov-17-2008.pdf,=20 9MB, 74 pages, November 17, 2008) =

Recent=20 Progress=20

Test vehicle rework is currently in=20 progress.
Test vehicles being reworked by NSWC Crane = have=20 been completed and shipped to BAE Systems for = thermal=20 aging.

Milestones

The Joint Test Protocol was finalized on = October=20 8, 2007. JTP testing activities being=20 coordinated include:
- Thermal cycling: -20^oC to=20 +80^oC=20
- Thermal cycling: -55^oC to=20 +125^oC=20
- Vibration=20
- Combined environments testing=20
- Drop testing=20
- Mechanical shock=20
- Integrated stress testing=20
- Copper dissolution
Test vehicle assembly was completed August = 2008 by=20 BAE Systems Irving, Texas =20

Near-Term Goals

Receive Joint Test Protocol endorsement = letters=20 from all stakeholders=20
Complete test vehicle rework =

Presentations

NASA-DoD Lead-Free Electronics = Project (NASA_DoD LFE Project = Details_Jul-17.pdf,=20 5 MB, 33 pages, July 17, 2008)=20
Printed Trace Testing = Report=20 (Printed Trace Testing _Final.pdf, 629KB, 8 = pages,=20 March 16, 2008)=20
Value-add Solutions for the = BGA Supply=20 Chain (Premier BGA Presentation = 7-28-08.pdf,=20 669KB, 39 pages, July 28, 2008)

Additional = Activities

Investigation of=20 printed traces
The NASA-DoD Lead-Free = Electronics=20 Project is investigating printed trace = technology as a=20 possible rework procedure for printed wiring=20 assemblies. The deposition or prototyping=20 technologies used for creating printable = electronics=20 emerged from a Defense Advanced Research = Projects Agency=20 (DARPA) program titled Mesoscale Integrated = Conformal=20 Electronics (MICE). The program ran from 1998 = through=20 2003 and developed a number of advanced direct = write=20 technologies. The Center for Accelerated = Applications at=20 the Nanoscale (CAAN) at the South Dakota School = of Mines=20 and Radiance Technologies are working to further = refine=20 the technologies for DoD applications.

IST coupon Deposition brief = - February=20 12, 2008 (IST Coupon Deposition=20 Test-Radiance.pdf, 646KB, 6 pages, February = 12,=20 2008)=20
Final Printed Trace = Testing =20 (Printed Trace Testing _Final.pdf, 629KB, 8 = pages,=20 March 16, 2008) =

New Mexico=20 Tech Lead-Free Solder Research
The=20 Microelectronics Testing and Technology = Obsolescence=20 Program (METTOP) is a small microelectronics = testing and=20 research facility located at New Mexico Tech, in = Socorro, NM. The facility recently started a = lead-free=20 solder research program, to assist in mitigating = Diminishing Manufacturing Sources and Material = Shortages=20 (DMSMS) issues and concerns regarding=20 reliability-information, or the lack there of, = on=20 lead-free solders for use in Military and = Aerospace=20 applications. METTOP joined with Naval Surface = Warfare=20 Center (NSWC) Crane and Purdue University on = their=20 Project 1722-Impact of Lead-Free Components on = Military=20 Repair. The purpose of this project is to = develop with=20 NAVSEA Crane a technical team of industry, = academia and=20 military to evaluate existing data and recommend = strategy for DOD on military electronics = affected by the=20 lead-free initiative. Emphasis is placed in four = areas:=20 tin whiskers, solder joint reliability, copper=20 dissolution and cross-contamination. METTOP has = focused=20 on the issue of solder joint reliability, = particularly=20 in the area of vibration testing.

New Mexico Tech Lead-Free = Solder=20 Research - Paper (NMT_NASA_paper.pdf, = 569KB, 62=20 pages, May 2008)=20
New Mexico Tech Lead-Free = Solder=20 Research - Presentation=20 (NASA_NMT_presentation.pdf, 1MB, 30 pages, = May 2008)=20

Completed Activities

Area Array X-Ray Analysis

Once test vehicle assembly = was=20 completed, all test vehicles were shipped to = Lockheed=20 Martin for x-ray analysis of the area array = components,=20 BGA and CSP. The QFN components were = analyzed as=20 well. Percentage of voiding as well as = ball shape=20 were documented.

Automated X-Ray of Circuit Card=20 Assemblies (NASA-DoD Lead-Free Electronics = Project=20 X-Ray Results.pdf, 7 pages,=20 1MB)

Interconnect Stress Test = (IST); =20 PWB Interconnect Solutions Inc.
IST has = the=20 capability of effectively/rapidly quantify the = integrity=20 of both the Plated Through Hole (PTH) and the = unique=20 ability to identify the presence & levels of = post=20 separations within the multilayer board (MLB). = IST both=20 compliments and/or dramatically reduces the = levels of=20 microsection analysis required for PWB = interconnect=20 quality assessment.

The IST principles = are unique=20 in that they simultaneously quantify the = integrity of=20 both the PTH and its interconnections to the = internal=20 layers (posts) throughout accelerated stress = testing.=20 IST creates a uniform strain from within the = substrate,=20 the interconnects ability to distribute and = redistribute=20 this strain provides an indication of integrity. = The=20 plated barrels and inner layer junctions are = =93exercised=94=20 until the initial failure mode/mechanism is = uncovered.

Thermal Distribution in an = IST=20 Coupon (Thermal Distribution in an IST=20 Coupon.pdf, 464KB, 7 pages, April 29, 2008)=20
NASA-DoD_IST = Coupons_set-1=20 (NASA-DoD_IST Coupons_set-1.pdf, 2MB, 37 = pages,=20 March 28, 2008)

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Last Updated: = 12/31/2008