Lead containing solders have been used as an interconnecting and surface coating material in various electrical and electronic applications for decades. Ever since the introduction of the lead free solder paste the question has been, how advanced should a reflow oven be? The success of a reflow oven is not measured in its size or the amount of heating zones, it is determined by the ability to create every possible reflow profile. A simple calculation will help to explain what is needed. For most lead free reflow profiles the board needs about three to five minutes in the process chambers. For those companies that produce only small batches of boards, the speed of the conveyor is of no big importance. Therefore, if the oven runs at 20 cm per minute a tunnel length of maximum 100 cm (20 cm x 5 min) is required, or if the oven runs at 40 cm per minute, a tunnel length of a maximum of 200 cm (40 cm x 5 min) is required.
The amount of zones is a similar story. The high throughput ovens are using many zones, but in practice several zones are set at the same temperature. Dividing one long zone into several smaller zones makes it easier to keep the temperature uniform over a longer distance. In theory only three zones plus one cooling zone is required (ramp-soak-peak), but in practice it is easier to create an ideal profile when adding one extra heating zone.
Both DIMA’s Breeze and Solano reflow oven offer a powerful convection heating irrespective of the size and mass of the components. The unlimited variation of temperature profiles is achieved by the tunnel design that includes 4 top heating and 4 bottom heating zones. To eliminate the possibility of damage caused by static, the Breeze and Solano include an air ioniser in the cool down zone as standard equipment. Breeze and Solano offer full forced hot air heating to maintain consistent edge-to-edge temperatures, regardless of component size or density.
EPP EUROPE 419
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