DoD Counterfeit Rules Subpar, Expert Tells Congress (UPDATED)

WASHINGTON -- A leading committee member of one of the largest electronics industry trade groups testified to Congress that new rules governing counterfeit components might be too onerous and have unintended consequences that overwhelm the goals of the statute.

As part of the National Defense Authorization Act of 2012, the US Congress directed the Department of Defense to implement certain practices to prevent fake parts from entering the supply chain.

Robert Metzger of Rogers Joseph O'Donnell, vice chair of TechAmerica'ssupply chain subcommittee, said the DoD rules mandating procurement of parts from OEMs or their authorized dealers cannot be followed because of the vast number of systems and the scarcity of available components in the supply chain.

Metzger also argued that the DoD rules fails to adequately define whether certain distributors should be qualified suppliers, and does not distinguish between OEM parts that fail quality inspections versus parts that are fake.

The rule should also provide more guidance on purchasing decisions where parts are determined to be obsolete or otherwise unavailable from trusted suppliers, he added.

Metzger, an attorney who also works on an American Bar Association committee that studies counterfeit parts rules, said his comments were his own views and not necessarily those of TechAmerica or ABA.

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Hot Alternative Energy News Stories | AltEnergyMag

Hot Alternative Energy News Stories | AltEnergyMag:

One of the issues that came out of the Roadmap was the rising cost of energy being of concern, not only to make more efficient products, but also the manufacturing costs involved.  Could we make something of this piece in that sense?

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Soldering Practices Are Insane | EE Times

Soldering Practices Are Insane | EE Times:

I think this would be an interesting article to include, perhaps paraphrasing & trying to induce some conversation?

He makes a number of interesting points.  Perhaps also point out that Soldertec used to teach a course on the metallurgy of soldering at the onset of Lead free


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EMSNow - NEW WHITE PAPER - Voiding Behavior in Mixed Solder Alloy Systems

EMSNow - NEW WHITE PAPER - Voiding Behavior in Mixed Solder Alloy Systems:

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NEW WHITE PAPER - Voiding Behavior in Mixed Solder Alloy Systems

By Yan Liu, Derrick Herron, Joanna Keck, and Ning-Cheng Lee.

Jun 21, 2013

The voiding behavior of mixed solder alloy systems using a nitrogen reflow atmosphere during BGA assembly was investigated. 

The solder joints were comprised of a combination of Sn62/Pb36/Ag2 (Sn62), Sn63/Pb37 (Sn63), Sn98.5/Ag1/Cu0.5 (SAC105), and Sn96.5/Ag3/Cu0.5 (SAC305) as the solder ball or solder paste, except for the SnPb solder ball, which used lead-free solder pastes. Assembly of each BGA employed a high temperature (HT) profile for lead-free and mixed systems, and a low temperature (LT) profile for mixed and SnPb systems. 

Mixed systems had higher voiding than lead-free systems when reflowed at HT. SnPb systems had a wider voiding range when compared with mixed systems reflowed at LT. Voiding was found to decrease with reduced alloy surface tension; earlier melting of the bottom solder paste; a narrower pasty range; smaller joint overheating; when the top ball remained solid during reflow; and by using flux alone instead of solder paste.

SMTONLINE Surface Tension and Load-Carrying Capacities of Solder

SMTONLINE Surface Tension and Load-Carrying Capacities of Solder: "
Surface Tension and Load-Carrying Capacities of Solder"

Reflow soldering on both sides of a board is standard procedure in the SMT manufacturing process. When the second component side is soldered, the components hang upside-down on the PCB. When the reflow process reaches its peak range, the possibility of remelting previously finished solder joints cannot be ruled out, which leaves the component hanging directly from the molten solder. 

Manufacturers count on the load-carrying capacity of molten solder millions of times a day. Figure 1 shows a component hanging from a drop of solder. Molten solder is entirely capable of bearing considerable component weight.

Read the full article here.


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Review on microstructure evolution in Sn-Ag-Cu solders and its effect on mechanical integrity of solder joints

Scopus - Document details: "The use of Pb-bearing solders in electronic assemblies is avoided in many countries due to the inherent toxicity and environmental risks associated with lead. Although a number of "Pb-free" alloys have been invented, none of them meet all the standards generally satisfied by a conventional Pb-Sn alloy. A large number of reliability problems still exist with lead free solder joints. Solder joint reliability depends on mechanical strength, fatigue resistance, hardness, coefficient of thermal expansion which are influenced by the microstructure, type and morphology of inter metallic compounds (IMC). In recent years, Sn rich solders have been considered as suitable replacement for Pb bearing solders. The objective of this review is to study the evolution of microstructural phases in commonly used lead free xSn-yAg-zCu solders and the various factors such as substrate, minor alloying, mechanical and thermo-mechanical strains which affect the microstructure. A complete understanding of the mechanisms that determine the formation and growth of interfacial IMCs is essential for developing solder joints with high reliability. The data available in the open literature have been reviewed and discussed. "

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Extending the fatigue life of Pb-free SAC solder joints under thermal cycling

Scopus - Document details:

This paper reports on the dependence of the thermal fatigue life of Pb-free solder (Sn-3.0Ag-0.5Cu) joints on the points at which the printed circuit board (PCB) is fixed to a rigid support. Elastic-plastic finite element analysis under various thermal cycling conditions was performed. For the analysis, the mechanical boundary conditions around a solder joint bonded silicon chip were varied by changing the points at which the PCB was attached to its support. From the results of the analysis, it was found that the accumulated strain in the solder joints decreased when the PCB was fixed at points placed diagonally with respect to the silicon chip. The thermal fatigue life could therefore be expected to be extended by the choice of fixing points. Using a special support with a thermal expansion coefficient of less than 1.5 × 10-6 K-1, we demonstrated, experimentally, that the accumulated strain and the failure site of the solder joints could indeed be controlled by the positions at which the printed circuit board was fixed. © 2013 Elsevier Ltd. All rights reserved.

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