Fluid Delivery
Non-contact adhesive application is achieved by utilizing a high-speed pneumatic or piezoelectric actuator to eject droplets of fluid from a nozzle without contacting the substrate. In electronic manufacturing, jet dispensing allows the precise placement of underfill materials, surface-mount adhesives, and conductive inks onto dense circuit boards. This method eliminates the need for vertical Z-axis motion during fluid deposition, which increases processing speed.
Metrological Control
Qualification of high-speed fluid valves involves measuring both the individual droplet mass and the consistency of the dot pattern. Precision jet dispensing systems utilize integrated weight scales to automatically calibrate the volume of fluid dispensed per pulse. Drift in fluid temperature or pressure directly alters the dot diameter, which requires continuous closed-loop feedback adjustments to the actuator pulse profile.
The dispensing tolerance is verified by optical inspection systems.
Nozzle Configuration
Selection of the appropriate nozzle diameter and stroke length determines the minimum achievable dot size on the target. If the stroke length is set too high, the fluid experiences excessive shear force and splits into multiple micro-droplets.
Viscosity Management
Industrial fluids exhibit non-Newtonian flow behavior under the high shear rates experienced within the valve nozzle. To maintain consistent jet dispensing performance, the system must control fluid viscosity by heating the nozzle assembly to a stable temperature. Sourcing stable fluid formulations prevents batch-to-batch variation from degrading the placement accuracy of the droplets.
This control is necessary for preventing dispensing failures during continuous shifts.
