Orlando, Fl-based nScrypt is meeting the challenge of flexible hybrid electronics (FHE) and 3D printed electronics by precision microdispensing solder and adhesive dots with volumetric control, in the 50 micron range.
Microdispensing is an additive method of dispensing pastes, inks, and other fluid materials, typically in the picoliter to nanoliter range. Compared to other methods, such as jetting, microdispensing gets closer to the surface of the substrate. The closer the nozzle can get to the surface, the finer the features that can be printed.
Using nScrypt’s SmartPumpTM, a conical pen tip, Heraeus SAC305-8XM8-D Type IX solder paste, and a silicone adhesive, the team controlled the SmartPump valve opening, dispensing gap (distance between the nozzle and substrate), lateral print speed (5 dots per second or 18000 per hour), dispense time (the amount of time the valve is open), and pump air pressure to achieve consistent results. The team’s goal was to test the consistency and repeatability of ~50µm Type IX solder dots and adhesive dots. The tests yielded consistent average dot diameter of 51.24 microns with a standard deviation of 6.42 microns, or 13%.
Such results support 3D manufacturing (also known as direct digital manufacturing, or DDM) of 3D printed electronics. DDM enables printing to both planar substrates, as in PCBs and FHE, and also the non-planar world of Printed Circuit Structures, in which the 3D manufacturing platform prints the structure or housing of an electronic device, which could be doubly curved, and also prints or picks and places the electronics conformally into such structures. In other words, 3D manufacturing enables printing high density solder and adhesive dots on complexly shaped substrates.
nScrypt’s SmartPumpTM microdispensing tool head eliminates drooling with pico-liter volumetric control and boasts the widest range of materials available for any microdispensing system: more than 10,000 commercially available materials, ranging from a few centipoise (like water) to millions of centipoise (much thicker than peanut butter). The SmartPump’s™ pen tip has the smallest commercially available diameter, 10 microns. The internal valve, or valve rod, of the nScrypt SmartPump sets this pump apart from other microdispensing tool heads.
The team plans a larger solder and adhesive dot study to test long-term reliability, frequency of clogging, and required downtime.
The team’s results are reported in a paper entitled “High-Density Microdispensing Solder And Adhesives Onto FHE And Conformal Substrate Assemblies,” authored by nScrypt’s Sam LeBlanc, Jasmine Hammonds, and Mike Newton.