With the ability to apply consistent shots as small as 2 nanoliters at speeds up to 150 dots per second, the PICO system is ideal for high-speed, high volume applications that require many small, precise fluid deposits. The narrow design of the valves, with a width of approximately ½ inch, makes them particularly well suited for installations where space is tight or valves need to be mounted close to each other.
Because the valve nozzle does not contact the substrate, the PICO system is also a good choice for applications where controlled amounts of fluid must be applied on surfaces that are not perfectly flat, such as printed circuit boards. Eliminating contact with the substrate also eliminates the need for vertical Z-axis movement and precise height positioning, which can significantly increase production speeds.
The range of possible applications is huge. Sample uses include electronics (bonding cell phone speakers with UV-cure adhesives), life sciences (attaching needles to medical syringes), and precision mechanical applications (jetting small amounts of grease on micro gears).
Jet Valve. The PICO jet valve contains two piezoelectric actuators composed of stacked ceramic coins that expand and contract in response to changes in voltage supplied through the valve driver.
The extremely fast action of the piezoelectric actuators makes it possible to dispense fluid continuously at speeds of up to 150 cycles per second. Depending on the fluid being dispensed, the system can produce consistent shot volumes as small as 2 nanoliters, and the high resolution of the PICO valve controller (0.01 milliseconds) makes it possible to adjust deposit size with exceptional precision.
PICO valves are available in several different configurations to handle fluids ranging from 50 to 500,000 cps. The LV configuration is designed for use with low viscosity fluids from 50 – 1,000 cps; the MV configuration covers a wide range of viscosities from 50 – 200,000 cps; and the HV configuration is specifically designed for fluids with high viscosities of 1,000 – 500,000 cps. Nozzles are available with 150µm, 200µm, 300µm and 400µm orifice diameters to accommodate a wide range of dot sizes.
In order to determine the optimum valve/nozzle combination for specific applications, EFD has set up labs around the world where customers can have their fluid tested according to their process requirements and receive a report with the initial valve driver and controller settings for use as a baseline in the actual production environment.
Most PICO valves, except those used exclusively for low-vicosity fluids, incorporate a heater near the fluid channel in order to thin the fluid to its optimum jetting viscosity. Depending on the rate of consumption, fluid can be supplied to PicoDot valves from syringe barrels, tanks or drum unloader systems.
While PICO valves will dispense a wide variety of fluids, including many particle-filled materials, they are not suitable for use with anaerobics or fluids with a pot life of less than four hours, due to the risk of these materials curing inside the valve.
Valve Controller. The PICO valve controller is available in 2- and 4-channel configurations. Both versions feature a graphical digital display and a user-friendly menu system that makes it easy to set the fluid application parameters for each valve. Complex jetting processes can be easily created on a PC and downloaded via the integrated SD card slot. A password protection feature ensures that standard procedures are not changed accidentally, helping to achieve repeatable results.
The PICO jet dispensing system is a reliable, innovative option for manufacturers seeking to improve process control and reduce costs through exceptional fluid deposit repeatability at high production speeds.
