Kester specifically engineered Ultra-sphere solder spheres to resist surface-darkening induced by transit tumbling and ball-placement systems, for more accuracy in vision systems. Surface-darkening can lead to false missing-ball readings with detection devices. The spheres support high-yield ball-attach processes. The company claims that the product eliminates excessively large- or small-sized balls. Diameters range from 0.15 to 0.889 mm for ball grid array (BGA) and chip scale package (CSP) attach. The spheres are available in a variety of alloys, including high-lead for ceramic BGAs and lead-free to meet RoHS regulations. Kester, Des Plaines, IL, www.kester.com.