Abstract: Reflow solder oven gas management system introduces an inert gas into and removes contaminated gas from a reflow oven tunnel (42) at predetermined points (6, 8) to influence the oven tunnel gas flow and to dilute and expel excess oxygen. The contaminated gas is ducted to a flux separation system (34) to be cleaned, for example remove flux vapors, and returned in part to the tunnel (42) for recirculation and with the remainder routed to end baffle boxes (54) for tunnel end pressurization and exhaust. The system has sufficient pressure to supply end baffle boxes (54) with clean gas to create a gas barrier to effectively seal off the tunnel ends from air infiltration or migration into the tunnel making the system insensitive to external pressure and/or temperature variations. The invention also includes alternative embodiments, low flow oxygen bleed valves (72) to maintain low oxygen content in the oven process tunnel.

Abstract: Reflow solder oven gas management system introduces an inert gas into and removes contaminated gas from a reflow oven tunnel (42) at predetermined points (6, 8) to influence the oven tunnel gas flow and to dilute and expel excess oxygen. The contaminated gas is ducted to a flux separation system (34) to be cleaned, for example remove flux vapors, and returned in part to the tunnel (42) for recirculation and with the remainder routed to end baffle boxes (54) for tunnel end pressurization and exhaust. The system has sufficient pressure to supply end baffle boxes (54) with clean gas to create a gas barrier to effectively seal off the tunnel ends from air infiltration or migration into the tunnel making the system insensitive to external pressure and/or temperature variations. The invention also includes alternative embodiments, low flow oxygen bleed valves (72) to maintain low oxygen content in the oven process tunnel.