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34 SMT Magazine • November 2014 Accuracy and repeatability of the procedures are increasing along with the higher degree of automation in the machine which can operate standard SMT components and bottom termi- nated components from 1 x 1 mm to 50 x 50 mm without any special tools for desoldering, solder- ing or placement. No component data needs to be supplied or evaluated; the operator can ex- ecute the rework process starting with the first assembly and the first component. The success rate can easily rise by more than 10% compared to simple, non-automated repair procedures. Automated processes can save up to 30–50 % of the operator's time. The alignment of com- ponents is done by the rework system and the operator can concentrate on other activities with operator generated alignment mistakes re- moved reducing defects during rework. smt references 1. MVTEC: HALCON Functionality; Cam- era calibration, Presentation, Mvtec Software GmbH, 2002. 2. "A computational approach to edge de- tection." IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 8, 1986, p. 690. 3. Workshop "Automatic Learning Systems in Image Processing," Math&Tech Engineering GmbH, 25.02.2013, p. 4. Joerg Nolte is vice president for r&D rework, inspection and tools at erSa Gmbh. When moving through a conductive material in an electric field, electrons tend to follow the path of least resistance--which runs in the direc- tion of that field. But now physicists at MiT and the university of Manchester have found that when a sheet of graphene is placed atop another two-dimen- sional material, electrons instead move sideways, perpendicular to the electric field. What's more, two separate streams of elec- trons would flow in opposite directions, both crosswise to the field, canceling out each other's electrical charge to produce a "neutral, charge- less current," explains leonid levitov, an MiT professor of physics and a senior author of a paper describing these find- ings this week in the journal Science. levitov and co-author an- dre geim at Manchester say this flow could be altered by applying a minute voltage on the gate, allowing the material to function as a transistor. "it is widely believed that new, unconvention- al approaches to information processing are key for the future of hardware," levitov says. "This belief has been the driving force behind a num- ber of important recent developments, in partic- ular spintronics"--in which the spin of electrons, not their electric charge, carries information. in their experiments, levitov, geim, and their colleagues overlaid the graphene on a layer of boron nitride--a two-dimensional material that forms a hexagonal lattice structure, as graphene does. Together, the two materials form a super- lattice that behaves as a semiconductor. Whether or not this effect can be harnessed to reduce the energy used by computer chips remains an open question, lev- itov concedes. The work has great po- tential, guinea adds, because "two-dimensional materials with special topological prop- erties are the basis of new tech- nologies for the manipulation of quantum information." Physicists Find new Way to Push electrons Around new PLacement tecHnoLogy For rework systems continues feaTure