The Micro-Dot pump is a refined dispense pump based on auger technology. The Micro-Dot pump works very well for pastes and glues that need to be dispensed in very small volumes, like dots smaller than 0.010" (0.25 mm).
The pump works with the following method. Fluid is fed into the auger cartridge from a syringe reservoir pressurized with air. When the auger rotates, fluid moves through the cartridge and is funneled through the dispense tip to the substrate.
The rotation of the auger is precisely controlled by a brushless DC motor with an encoder that can be programmed with specific dispense parameters. The encoder provides more than 57,000 counts per 360 degrees of auger rotation, thereby providing the precision control required for micro volume dispensing. For the smallest of dispenses, we offer a high resolution option attaining 200,000 counts for a single revolution.
The Micro-Dot pump can span a wide range of dispense processes with its ability to use a range of auger dimensions.
The depth of the auger grooves range over 5 octaves with designation from Ultra Shallow to Ultra Deep.
Your type of dispense process defines the type of nozzle to be used. Standard nozzles for the Micro-Dot have been designed for enhanced flow rate in order to funnel fluid with reduced pressure to eliminate clogging of the nozzle tip. Precision nozzles are available in a variety of lengths and in either ceramic or machined stainless steel. Micro-Dot augers are also compatible with Luer nozzles for simpler applications.
Auger Customization when Needed
Standard clearance between the auger and cartridge wall is 0.0003" (7 micron). Tolerances are set very high to avoid spheres of solder or other particles from shearing between the auger and cartridge wall. When particles shear, they become deformed and can either lead to clogging of the nozzle or can accumulate on the wall of the cartridge leading to binding. However you look at it, the results aren't good.
To overcome this issue, we customize an auger to allow for fillers to float without being damaged. The customization process is typically used with solder pastes from type 5 or 6 and higher. After customization, no binding or nozzle clogging will be evident.