Lead-Free Electronics

Lead-Free Electronics [Suggest Change]

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Primary Functional Area : Life Cycle Logistics

Tin Whiskers

 

Definition [Suggest Change]

The term 'lead free', when applied to solder or electronics usually implies a lead content that meets specifications of the European Union's Restriction of Hazardous Substance (ROHS) directive, initiated in 2006, or the related Waste Electrical and Electronic Equipment Directive, intended to minimize hazardous wastes in electronics disposal. These mandates, along with others impacting both US domestic and international trade and manufacturing, were initiated to improve personal and environmental safety, since even minute amounts of lead can pose a significant health risk.


Although there are exemptions to such mandates that might provide limited reprieve for the more demanding defense applications, the prevalence of COTS and increasing blending of commercial products and suppliers with military applications and providers and maintenance is problematic for DOD. Traditionally, only leaded solder provides the reliability and peak performance demanded of critical DOD systems. Many component and parts suppliers in the DOD supply chains are primarily commercial manufacturers who routinely operate lead free processes and this, coupled with a much faster technology refresh rate than is typical for DOD systems, creates ongoing system performance and DMSMS issues for DOD. Not only does low volume DOD demand not drive events in the global manufacturing and supply chains, but increasing costs means alternative technologies and mil spec options for DOD are less viable.


Driven by such trends in the civilian/industrial manufacturing sectors, more DOD weapons systems increasingly face reduced system availability and reduced system capability, as well as climbing DMSMS and sustainment costs as a result of the civilian movement toward lead-free manufacturing.

General Information/Narrative [Suggest Change]

Leaded solder has been in use for decades, and has a proven technical performance record.  It is reliable, available and low cost and, from an engineering standpoint, it is known and well understood. It provides solid performance in military applications that are more severe than civilian applications, and include temperature and humidity extremes, high altitude, vibration and shock, immersion, and so forth.


Unfortunately, lead is a serious health hazard and an environmental risk, resulting in the recent and sustained emphasis on alternate substances and solders in civilian industry and manufacturing.  While those alternatives, typically tin solder, are safer, and seemingly appropriate for consumer applications, the DOD has experienced reduced joint integrity and reduced component reliability, and increased failures and maintenance costs. Often this is a function of reduced joint pliability, or of 'tin whiskers', which are tiny hairs or physical abnormalities that 'grow' over time, spontaneously, from lead free tin-based finishes. These naturally occurring conductive, crystalline structures can create shorts, fires, and system or optics failures over long periods of time (or in some cases quite rapidly!). While such risks may be acceptable in some applications, or when judged purely from an ESOH standpoint, the resultant reliability issues have been felt in DOD for years.


A study done at the U.S. Naval Air Warfare Center indicates that about 25 percent of air- and surface-launched weapons, such as the Tomahawk and Sidewinder missiles, and the  Joint Direct Attack Munition (JDAM) have experienced component failures due to tin whisker issues. Through 2002, at least six satellites sustained partial or complete loss due to tin whiskers, and there have also been problems reported with the F-15 jet fighter radar, the Patriot missile, and the Airborne Warning and Control System (AWACS) aircraft, and even the space shuttle. That time period, as the civilian industries were just ramping up compliance with new international mandates such as the ROHS, suggests there may be yet more difficulties to come for DOD as tin solder becomes more predominant. Although both DOD and industry, in a joint effort, are working to address the concerns, so far the DOD has no effective and accepted tests to determine the susceptibility of plating to whiskering.  And no mitigation technique guarantees the protection that the Defense Department requires for high-reliability systems except the reintroduction of small amounts of lead to the tin; the lead free transition is uncontrolled from DOD's perspective, but is proceeding regardless of military preparedness or availability of alternatives.


Other problems include disposal of leaded components as they are phased out, viability of technician training for new materials, reliability and engineering data for standardized lead-free alloys, and lack of overall DOD policy on the matter are metallurgical phenomenon caused by thermal, compressive or other stresses and which can cause short circuit,plasma vapor arc, or visual/physical contamination.

Defense Acquisition Guidebook, Policies, Directives, Regulations, Laws [Suggest Change]

  • GEIA-STD-0005-1, "Performance Standard for Aerospace and High Performance Electronic Systems Containing Lead-free Solder"
  • GEIA-STD-0005-2, "Standard for Mitigating the Effects of Tin Whiskers in Aerospace and High Performance Electronic Systems"
  • GEIA-HB-0005-1, "Program Management / Systems Engineering Guidelines for Managing the Transition to Lead-Free Electronics"
  • GEIA-HB-0005-2, "Technical Guidelines for Aerospace and High Performance Electronic Systems Containing Lead-Free Solder and Finishes"

Best Practices, Lessons Learned, Stories, Guides, Handbooks, Templates, Examples, Tools [Suggest Change]


For example, the Roadmap for Lead Free Implementation sub-committee has conducted Gap Analysis that has lead to three specific projects in Lead Free Implementation that will help assure a joint DoD response to this worldwide movement. Recommendations for DoD or multi-service joint investment have been incorporated into a white paper available on the site. There also is a discussion forum addressing new changes in Lead Free Electronics issues and postings of the latest Lead Free electronics developments, A Lead Free frequently asked questions (FAQ) section, Lead Free case studies and papers, as well as tin whiskers studies and tech tips.


Training Resources [Suggest Change]

Communities [Suggest Change]

Life Cycle Logistics
Performance Based Logistics
Production, Quality & Manufacturing
Program Management
Reliability, Availability & Maintainability
Risk Management
Systems Engineering

Related Articles [Suggest Change]

Diminishing Manufacturing Sources and Material Shortages (DMSMS)
Supply Chain Management (SCM)
Supportability Requirements
System Safety
Systems Engineering in Engineering and Manufacturing Development Phase
Systems Engineering in Materiel Solution Analysis
Systems Engineering in Operations and Support
Systems Engineering in Production and Deployment
Systems Engineering in Technology Maturation and Risk Reduction
Systems Engineering Plan (SEP)
Systems Engineering Process
Defense Logistics Agency (DLA)
Supportability Design Objectives
Integrated Product Support (IPS) Element - Sustaining Engineering
Supportability Testing (Logistics Test & Evaluation)

Attachments [Suggest Change]

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Page Views 5,582
Created on 10/1/2012
Modified on 5/11/2016
Last Reviewed 5/3/2016