Abstract: In a liquid cleaning process and apparatus where work pieces such as printed circuit boards are cleaned in an isolated enclosure, there is provided an inert gas purging system within the enclosure and a recycling condenser within the isolated enclosure to recycle all vapors from cleaning tanks within the enclosure. The apparatus has a cleaning tank and a water tank, an isolated enclosure extends between the tanks and has liquid seal dividers that extend down into the tanks. The work pieces pass on a conveyor through the cleaning tank, under a first divider, and into the enclosure where cleaning occurs. The work pieces then pass through the water tank under the second divider. A condenser is positioned above the isolated enclosure which condenses vapors rising from the enclosure and the condensate is recirculated to the cleaning tank and the water tank.

Abstract: A wave soldering apparatus and process occurs in an atomsphere which substantially excludes oxygen. By providing a gas blanket over the solder, reduction in dross occurs and improved soldering results avoiding the necessity of removing flux residues. Gas diffusers are provided on both sides of a solder wave in an enclosure, the diffusers are placed below the path of the element to be soldered and a further gas diffuser is positioned above the element to be soldered. The gas diffusers supply a calm gas blanket over the solder wave so no turbulent movement of gas occurs within the enclosure.

Abstract: A dryer system for a liquid cleaning apparatus has a dehumidifier to remove vapors, droplets of liquid cleaning agent and recirculate dry gas onto workpieces moving on a conveyor. The dryer is particularly useful for removing solvents and restricts solvents escaping from the cleaning apparatus. The dryer has an enclosed tunnel from an enclosed liquid containing tank, a conveyor passes from the tank through the tunnel towards an exit. A dehumidifier is associated with the tunnel to remove vapor and liquid particles from atmosphere above the tank and in the tunnel, and supplies dry gas to assist in drying workpieces leaving the tank and passing through the tunnel.

Abstract: A cooling and exhaust unit for an IR reflow soldering machine is arranged to be mounted on the soldering machine after the last heating zone. The unit has fans which direct cold air downwardly on to the conveyor and this cooling air divides into two streams, one moving with the conveyor and one counter to the movement of the conveyor. An exhaust inlet is provided near the front and the rear of the machine, the exhaust inlets being connected through an exhaust chamber to an exhaust outlet. To minimize the amount of hot process air sucked out of the soldering machine into the nearer exhaust inlet an additional cold air inlet is provided, this being located intermediate the rear end of the unit (i.e., the end abutting the soldering machine) and the nearer exhaust inlet.