The finishing industry requires quality control throughout, to ensure standards of the surface finish are high with no defects requiring component rework. There are many types of surface finishing that use different techniques to produce finishes for various different materials.

From course filtration of electrolyte plating fluid with batch process filters to ensure continuity of finish to organics removal with carbon to eliminate pitting on bright finish plating, the finishing industry requires an exacting final product. Pure water gained from either reverse osmosis systems or de-ionised resin treatment also ensures spot free drying of PCB process and decorative items.

Sterner support this market by providing solutions to the filtration and water treatment challenges typically faced by the producers of these items. From the removal of particles and organics and the production of very pure top-up water, Sterner specify and supply filtration and water treatment systems and components tailored to the specific requirements of this market’s applications.

Top-Up Water

Pure water is used widely for preparing chemicals, topping up of the plating baths and for rinsing parts and PCBs to ensure that no spots are present on the finished coating. Different plating industries use different purity levels of water for their applications with the rule of thumb being ‘the purer the better’.

Some will take the water straight from the tap, although this water is made for drinking and not of the purity required for most plating applications. The water quality required for plating involves producing reverse osmosis (RO) quality water or totally de-ionised (DI) water. The quality level of the water is controlled with pure water production reverse osmosis systems, de-ionising resin systems or a combination of both.

Plating Baths

It is important for the quality of the surface finish that the plating solutions are kept free from particulate and build-up of organics does not occur.

Most finishers will have a recirculating loop on the plating bath that includes a particle removal filter such as a bag, depth or surface (pleated) cartridge. Intermittently, a carbon cartridge is used to clear up the organics that build up from environmental conditions and elements directly introduced, such as the components and racks.