In order to provide a reflow process for lead-free solder joints requiring high-temperature uniform heating, two types of equipment, an "RA" air-reflow oven and an "RN" N{sub}2-reflow oven have been developed by using the "dual-sided matrix jet circulation heating method". The heating system consists of two sets of the same hot-air circulation system, each of which blows hot air on the top and bottom surfaces of a PC board with blow nozzles and suction nozzles arranged alternately in a matrix fashion for the circulation of hot air. By employing this design, the peak temperature variations on a board can be reduced for reflow soldering of lead-free solder material, which has a higher melting point than that of conventional lead-based eutectic solder. Further, the thermal damage on the mounted components for providing highquality reflow soldering can be eliminated.
展开▼
