Performance assessment of a modular device for micro-sphere singularization

A wide variety of mechatronic products undergoes major changes to miniaturize them and integrate a larger number of functions. They require advanced technologies for their manipulation and assembly, that become even more challenging due to the different properties and tiny size of their components. Innovative devices are necessary to enable the automation of such operations, such as sorting and feeding systems able to singularize and deliver micro-parts precisely and reliably at high-speed. To this aim, an original “Store&Place device” was developed for micro-sphere singularization and deposition (Fontana et al., 2018) [3], based on the novel operating principle proposed in Fontana et al. (2017) [1]. A potential application of this device concerns the automatic rework of electronic components, more specifically the reballing of Ball Grid Array packages, that basically consists in restoring their electrical connection to the board by attaching new solder balls. When the release of a single solder ball is commanded, the device singularizes it from a storage of identical balls and places it onto the corresponding circular land on the package. The paper presents the assessment of the device performance resulting from a structured experimental analysis on the manipulation of micro-spheres with diameter of 300 μm. It was applied to highlight the main process parameters influencing its performance, optimize them, and enhance the tool use. The performance indices to quantitatively evaluate the precision of the micro-sphere release were calculated according to Ruggeri et al. (2019) [5], and merged with other indices related to the reliability of the release and the time needed to execute it.