In Case You Missed It
Environmental Compliance
“RoHS vs. REACH: What Does This Mean to IT Hardware Companies and Data Management?”
Authors: Jackie Adams, et al; jackiea@us.ibm.com.
Abstract: When preparing to meet EU REACH requirements for IT electronics hardware, the focus is on tracking, communication and notification of certain substances in articles, while RoHS focuses on eliminating or restricting the use of heavy metals and other substances in homogeneous materials. Because of the larger number of potential chemicals involved (Substances of Very High Concern, SVHC, candidates), and the fact that there are no exemptions applicable to hardware products, the REACH requirements can be a challenging task for companies. With EU REACH, if the stated concentration level of SVHC candidates in articles (e.g., hardware products) is exceeded, producers and importers in the EU are subject to communication and possibly notification requirements. This drives extensive information requests throughout the supply chain. These regulations drive requirements for quantitative and qualitative chemical data and an increased need for the surveillance of emerging regulations as they are being formulated, so that one can design compliance processes that are ahead of what will become firm requirements. This paper outlines data collection options the electronics industry can deploy in connection with their supply chain and with clients to develop material composition information systems necessary to comply with both RoHS and REACH requirements. (SMTAI, October 2009)
Failure Modes
“Head-and-Pillow SMT Failure Modes”
Authors: Dudi Amir, Raiyo Aspandiar, Scott Buttars, Wei Wei Chin and Paramjeet Gill; dudi.amir@intel.com.
Abstract: Head-and-pillow is an SMT non-wetting defect. This defect is hard to detect after SMT assembly and most likely will fail in the field. There are a number of causes for this type of defect. They can be categorized into process issues, material issues, and design-related issues. This paper examines different causes for the head-and-pillow defect and the mechanism behind it. The paper also describes critical factors that affect head-and-pillow, how to identify the root cause, and potential solutions for prevention. (SMTAI, October 2009)
Laminates
“Conductive Anodic Filament Study: Laminates and Pb-Free Processing”
Author: Randal L. Ternes; randal.l.ternes@boeing.com.
Abstract: This work evaluated the conductive anodic filament (CAF) growth susceptibility of three common PWB laminate systems under eutectic SnPb reflow and Pb-free reflow conditions. CAF test boards fabricated from three resin types were reflowed five times, following either eutectic Sn-Pb or Pb-free profiles. The boards were subjected to a 600 hr., 100VDC CAF test. CAF failures were detected in all laminates and in both reflow profiles. Pb-free processing caused twice the CAF failures than did eutectic SnPb processing. Pb-free epoxy laminate was substantially more CAF-resistant than either high Tg epoxy or polyimide. CAF failures were strongly dependant on hole spacing, and ranged from nearly 0% at 0.035˝ (0.089 cm) hole spacing to 100% at 0.010˝ (0.025 cm) hole spacing, regardless of laminate type. (SMTAI, October 2009)
Nanotechnology
“All Optical Metamaterial Circuit Board at the Nanoscale”
Authors: Andrea Alů and Nader Engheta, andreaal@ee.upenn.edu.
Abstract: Optical nanocircuits may pave the way to transformative advancements in nanoscale communications. This work introduces the concept of an optical nanocircuit board, constituted of a layered metamaterial structure with low effective permittivity, over which specific traces that channel the optical displacement current may be carved out, allowing the optical “local connection” among “nonlocal” distant nanocircuit elements. This may provide “printed” nanocircuits, realizing an all-optical nanocircuit board over which specific grooves may be nanoimprinted within the realms of current nanotechnology. (Physical Review Letters, September 2009)
