Active investigation continues on various alloys used to replace lead for soldering in electronics components. Use of lead has dropped since the Restriction of Hazardous Substances Directive took effect in July, 2006. Historically, interconnections in electronic components have been made using tin/lead solder formulations. Those materials melt at 183C, while the thermoset and thermoplastics used in electronics have temperature limits up to 235C. The glass transition temperature of FR-4, a common PCB material, is between 140-175C. The resin softens as temperatures rise. New lead-free alternates such as SAC become liquid at 217C. Other lead-free solders have even higher melting points, causing failures of laminates and thermoplastics. Materials suppliers are struggling to adapt, says James Hall of ITM Consulting, who gave an interesting overview of the issue during a conference session at National Manufacturing Week in Rosemont, IL. “Just increasing cross-linking in the modified epoxies used in laminates is not the way to go,” he says. Cross-linking increases the brittleness of the laminates, creating problems when the boards are drilled. Specialty thermoplastics, such as modified nylons, are also experiencing problems because of the high solder temperatures. Explorations continue on new plastics as well as new solder formulations, including significant use of dopants such as nickel and germanium that provide specific property enhancements for various reasons.
Some of the biggest self-assembled building blocks and structures made from engineered DNA have been developed by researchers at Harvard's Wyss Institute. The largest, a hexagonal prism, is one-tenth the size of an average bacterium.
Arevo Labs' end-production 3D printing technology for carbon composites includes a high-temperature, filament fusion printer head design and firmware for use with the company's new carbon fiber and nanotube reinforced high-temperature matrix polymers like PEEK.
Stratasys will buy Solid Concepts and Harvest Technologies and combine them with its RedEye service business. The plan takes aim at end-production manufacturing and will create one of the biggest commercial 3D printing and AM service bureaus.
The International Federation of Robotics reports that global sales of industrial robots decreased by 4% in 2012 over 2011. The biggest hit was electrical/electronics manufacturing, down by 13%; but by region, the Amerficas did well.
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