Electrovert Ltd.

Donald a. Elliott

Michael T. Mittag

Alan S. Roberts

Alan S Roberts

Donald A Elliott

Michael T Mittag

Raymond J Chartrand

Alfred A Moran

John Gilfta

A method and apparatus for cleaning workpieces, particularly printed circuit boards upon which electrical components have been soldered, is capable of using a potentially flammable or explosive liquid cleaning solvent. In one embodiment, there are two immersion wash stages between which is a spray wash stage. The spray wash stage is formed as a closed chamber which is sealed when the immersion wash stages by liquid seals. To reduce the danger of fire or explosion in the spray wash stage an inert gas such as Nitrogen is introduced into the closed chamber. In another embodiment the spray nozzles are immersed in liquid solvent in a combined immersion/spray wash stage. This reduces atomization of the flammable solvent further reducing the danger of fire or explosion.

Method for cleaning electronic and other devices

A flux density control system controls the density of flux or other liquid by measuring the density and adding a thinner solvent or other liquid with a lower density than the flux. The apparatus includes a tank having an overflow adapted to maintain a set level of liquid in the tank, a liquid container positioned to receive liquid from the overflow in the tank, and a liquid pump adapted to pump liquid from the liquid container to the tank. A thinner container is provided with a thinner pump adapted to pump thinner from the thinner container to the tank. A density probe is positioned in the tank with a controller to turn off the liquid pump when the density of liquid in the tank rises above a predetermined set point, and turn on the thinner pump. The controller also turns off the thinner pump and turns on the liquid pump when the density of liquid in the tank drops below the predetermined set point.

Flux density control system

Growing community of inventors

Pointe Claire, Canada

Alan S Roberts