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74 SMT Magazine • February 2016 print volume was much better with the plastic film adhesive-backed stencil. Also, because the plastic film stencil is single use that is not subject to the "plugging" of the metal stencil apertures, its print consistency was found to be more stable than its metal counterpart. SMT references 1. Farrell, Robert and Shea, Chrys, "Sten- cil and Solder Paste Inspection Evaluation for Miniaturized SMT Components," SMTA Journal Volume 27 Issue 2, 2014. 2. Haerter, Stefna; Franke, Joerg; and Laentzsch, Carmina, "Fundamental Study on Secure Printing Process using Nanowork Sten- cils for 01005 Components," Proceedings of SMTA International September 28–Oct 2, 2014, Rosemont, Il. bob Wettermann is the principal of bEST inc., a contract rework and repair facility in Chicago. 3. Tonkay, Gregory; Storer, Robert; Sallade, Ronald; and Leandri, David, "Critical Variables of Solder Paste Stencil Printing for Micro-BGA and Fine-Pitch QFP," IEEE Transactions on Elec- tronics Packaging Manufacturing, Volume 27, No 2, April 2004. 4. Garcia, Omar, et. al, "Selective Reflow Re- work Process," IPC APEX EXPO Proceedings, 2015. The next great technological advance in smartphone screens and solar cells could come from an unex - pected source—giant clams. New research from uc Santa barba- ra shows some species of these large bivalves produce their white coloration via color- mixing techniques akin to those used in reflective displays. Appearing in the journal optica, the study focuses on two species of giant clam and the symbiotic photosynthetic algae with which they cohabitate. Iridescent cells on the inside edge of the clams' shells where the algae live pro- duce a dazzling array of colors, including blues, greens, golds and—more rarely—white, which the animals mix in different ways. Both clam species create white by mixing clus - ters of colors in much the same way that the elec- tronic displays found in televisions, smartphones and electronic billboards combine red, blue and green pixels to make white. However, most of to- day's displays gener- ate light using LEDs or another light source, while the clams re- quire only sunlight. "If we could create and control structures similar to those that generate color in the clams, it might be possible to build color-reflective displays that work with ambi- ent light sources such as sunlight or normal in- door lighting. Producing color the way giant clams do could lead to smartphone, tablet and TV screens that use less power and are easier on the eyes," said lead author Amitabh Ghoshal, a postdoctoral fellow at ucSb's institute for collabora- tive biotechnologies (icb). Ghoshal worked with Daniel Morse, a professor emeritus in the campus's Department of Molecular, Cellular, and Developmental Biology and director of this research, and ucSb alumna Elizabeth Eck, now a graduate student at uc berkeley. Bioinspired Technology reWork site PriNtiNg usiNg miNi steNcils—Plastic adHesiVe Vs. metal