Lead-free reflow need not cost the earth

Edited by the Electronicstalk editorial team Apr 6, 2004

A new range of energy efficient solder reflow and curing ovens boasts low delta-T, high performance and low operating costs.

SMT Wertheim, one of Europe's leading solder reflow and curing oven manufacturers, has introduced a complete range of energy efficient ovens, resulting in low delta-T, high performance and low operating costs.

These characteristics are especially relevant today with the introduction of lead-free solder reflow processes, which typically require peak soldering temperatures that are much higher than those used with tin/lead alloys.

To achieve lower peak temperatures, the control of the air distribution within the process chambers is critical and is achieved by an extremely efficient heat transfer system that uses high capacity fans (1600m3/h for each fan) and SMT's patented Slot Nozzle technology in the peak zone, which transfers air to and from the process chamber.

The Slot Nozzles are installed perpendicular to the transport conveyor and act like curtain of hot air that the boards must pass through.

After heat is transferred to the board, the air is sucked back into channels beside the Slot Nozzles for reheating.

This ensures that the distance the air has to travel is very short; thus, little heat is lost.

This results in reduced temperature stress for boards and components, a smaller delta-T between small and large components, lower power consumption, less wear of the oven and the possibility of using lead-free solder paste at normal peak set temperatures of only 260 to 270C.

Running costs are further reduced by increasing the time between maintenance cycles, as all SMT ovens are available with flux filtration systems at their input and output locations, incorporate efficient flux management system in the cooling zone, and are available with an optional process gas cleaning system.

Due to their small footprint, low power consumption, low running costs and efficient filtration systems, SMT ovens not only help to reduce the cost of ownership, but also to protect the environment.