Printed circuit boards are often coated after they are stuffed and soldered to protect the thin metal traces between components from damage and to protect the traces and soldered joints from corrosion. When the boards need servicing to the component level, this coating must be removed to successfully unsolder and replace a defective component and return the board to service.
Previous practice has involved the use of solvents to dissolve and remove the coating. The solvents are expensive, because they must be formulated carefully to remove the coating without damaging the components or the board itself. The work area needs expensive fume control to protect workers. The used solvent presents a hazmat disposal problem.
Dry ice blast cleaning uses pellets of dry ice, propelled by compressed air, to remove coatings.
The size of the pellets and force of the air stream can be controlled precisely for the most efficient coating removal with minimal damage to component markings or silk-screened information on the circuit board. Dry ice is solid carbon dioxide, which sublimates into carbon dioxide gas upon contact with the surface to be cleaned. Both thermal shock and mechanical force combine to loosen and remove the coating.
Solvents can cause the dissolved coating to creep into through-holes in the circuit board that are used to mount components. This creep can make resoldering of the replacement component difficult. Dry ice blast cleaning simply removes the coating. No fumes, no hazmat waste disposal, no solvent drying time for workers to wait to begin rework. Expensive bench time is saved and output per work-hour is increased. Do observe all the dry ice safety precautions.
Contact Continental Carbonic Products for complete information about using dry ice cleaning for your project. Please see this map to find the dry ice location nearest to you.
See all Dry Ice Blasting News...
