In tabbing and stringing processes in many industries, e.g. in electronics, automotive and solar production the narrow solder-coated copper ribbon used to link the individual cells requires precise flux application to ensure a good connection and prevent discoloration.
Piezoelectric dispensing systems provide a way in production to apply flux at high speed with exceptional accuracy – and without the mess, waste and safety hazards of flux baths and similar application methods.
Nordson EFD’s PICOTM piezoelectric jet dispensing systems incorporate two piezoelectric actuators composed of stacked ceramic coins that expand and contract in response to changes in voltage supplied from the valve driver.
When voltage is applied to the actuators, the rod and sealing ball are raised so the pressurized fluid can flow to the nozzle. When the voltage is changed, the rod and sealing ball descend rapidly to “jet” the fluid out of the nozzle onto the substrate.
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, the system can produce consistent shots as small as 2 nanoliters, and the high resolution (0.01 milliseconds) of the valve controller (described below) makes it possible to adjust the size of the fluid deposit with exceptional precision.
Because the valve nozzle does not contact the substrate, piezoelectric jet dispensing systems are a good choice for applications where controlled amounts of fluid must be applied on surfaces that are not perfectly flat, such as thin photovoltaic wafers. They also eliminate the need for vertical Z-axis movement and precise height positioning, which can significantly increase production speeds on automated production lines.
PICOTM Piezoelectric dispense valves are powered by valve drivers that use an amplifier to generate the signal for the piezoelectric actuators. In addition, they contain a temperature controller for a heater integrated into the valve, to keep the fluid at optimal jetting viscosity.
EFD PICOTM valve controllers are used to set the fluid dispensing parameters for each valve. Graphical displays and user-friendly menus make it simple to create complex jetting processes on a PC, and then download them to the controller via an integrated SD card slot.
Piezoelectric dispensing systems provide a reliable, innovative way for photovoltaic and other manufacturers to improve process control and reduce costs through exceptional accuracy and faster production speeds.
EFD’s PICOTM piezoelectric jet dispensing systems are available through Nordson EFD’s worldwide network operating in over 30 countries.
Nordson EFD is a wholly owned subsidiary of Nordson Corporation. Since 1963 Nordson EFD has designed and manufactured precision dispensing devices for applying controlled amounts of the adhesives, sealants, lubricants and other assembly fluids used in almost every manufacturing process.
Nordson Corporation is one of the world’s leading producers of precision dispensing equipment that applies adhesives, sealants and coatings to a broad range of consumer and industrial products during manufacturing operations. The company also manufactures equipment used in the testing and inspection of electronic components as well as technology-based systems for curing and surface treatment processes. Nordson has direct operations and sales support offices in 32 countries.
