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50 SMT007 MAGAZINE I JUNE 2018 Amendment 1, Qualification and Performance Specification for Flexible Printed Boards. As long as the FPC has the correct design, it can be reasonably used in the manufacturing process. "Some applications are very hard to realize; and some applications cannot be processed in the reflow. Some applications may be unsuit- able for condensation soldering systems. So, the manufacturer of flex circuits should consider the manufacturing processes, the whole step," he explains. "Ordinarily, we are just support- ing the applications in general. When we're having issues and the customers cannot solve it, this very point that's just mentioned, maybe the manufacturer of such boards should come with the equipment suppliers earlier in the stage. That will be much more helpful. Also, having them early at the design stage, to fit it in the whole process chain, will make it easier to manufacture the flex circuit assemblies." Wagenfuehr also stresses the importance of communication with their customers and users. "There are a lot of limits that they should consider—limits in the design, in preparation of the fixtures—to ensure proper soldering. We can support our customers in applica- tions where we have certain expe- riences, such as in mobile phone manufacturing, for instance. We also have to know more about our customers issues. We are happy to help in the process steps. We have a rich experience and we can also consider the early design stage with our application teams in China and Germany." In fact, Wagenfuehr notes that they will be willing to join forums to address these issues. "It will be nice if it is focused on soldering flex printed circuits. There is not much forums happening in manufacturing in this front. It's always driven by the designers—that's the problem. They don't ever consider the equip- ment. They just do the designs, which, some- times are impossible or quite challenge to manufacture. It will be good if forums will be created to bring the designers and equipment manufacturers together to discuss the issues. That will be helpful in the future." SMT007 A Northwestern University research team has found ways to stabilize a new battery with a record-high charge capacity. Based on a lithium-manganese-oxide cath- ode, the breakthrough could enable smart phones and battery-powered automobiles to last more than twice as long between charges. The study was published online in Science Advances. A French research team first reported the large-capac- ity lithium-manganese-oxide compound in 2016. But it was not without its challenges—the battery's perfor- mance degraded significantly within the first two cycles that researchers did not consider it commercially viable. They also did not fully understand the chemical origin of the large capacity or the degradation. After composing a detailed, atom-by-atom picture of the cathode, Christopher Wolverton, the Jerome B. Cohen Professor of Materials Science and Engineer- ing in Northwestern's McCormick School of Engineering, and his team discovered the reason behind the material's high capacity: It forces oxygen to participate in the reac- tion process. By using oxygen—in addition to the transition metal—to store and release electrical energy, the battery has a higher capacity to store and use more lithium. The Northwestern team turned its focus to stabilizing the battery to prevent its swift degradation. The compu- tations pinpointed two elements: chromium and vana- dium. The team predicts that mixing either element with lithium-manganese-oxide will produce stable compounds that maintain the cathode's unprecedented high capacity. Next, Wolverton and his collaborators will exper- imentally test these theoretical compounds in the laboratory. Northwestern Researchers Predict Materials to Stabilize Record-high Capacity Lithium-ion Battery Ralf Wagenfuehr

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