Electrolube Cleaning Guide

Experience has shown that the cleaning of PCBs, stencils and electronic assemblies is vital to ensure long term performance. Electrolube has developed a comprehensive range of cleaning products which provide high reliability at minimum unit cost.

The range includes products that will remove fluxes, solder paste, grease and other general contaminants to recognised international cleanliness standards. Products are also available for degreasing precision metal parts in a huge variety of cleaning applications.

Electrolube can provide flammable and non-flammable solvent cleaners and water based cleaners.

The Safewash Range

Electrolube’s Safewash range is the most effective family of aqueous cleaning products available. It is currently in use by major manufacturers in a wide variety of cleaning machines. It provides superior cleaning performance to military and commercial standards at minimal cost – both financial and environmental.

The Safewash Range is effective in all equipment types including batch ultrasonics, in-line spray, dishwasher and also by hand. Products are available for use with sensitive metals such as aluminium, copper and alloys, whilst compatibility with plastics and rubbers is assured.

The benefits of Safewash include excellent cleaning performance at room temperature, low odour, very low toxicity, and it continues to clean effectively over long time periods.

Eventually, as Safewash continues to absorb flux, its efficiency begins to decline. The exact time when replacement is required is dependent upon the type and amount of flux used, the surface area cleaned and the cleanliness level required. Methods to determine the status of the Safewash include electrical conductivity and pH measurement.

Solvents

Solvents, as defined here, are fast evaporating, organic materials. For ease of discussion they may be split into flammable and non-flammable solvents.

Flammable solvents are characterised by relatively low toxicity, good materials compatibility together with a wide range of evaporation rates and flashpoints. (Ultraclens cleaning solvent (ULC), Ultrasolve cleaning solvent (ULS), Electronic cleaning solvent plus (ECSP))

Non-flammable solvents fall into two groups, traditional chlorinated solvents are characterised by relatively high levels of toxicity, poor materials compatibility but are fast drying. The new non-flammable fluorinated solvent blends exhibit excellent solvency, fast drying and relatively low toxicity with good materials compatibility. (Non Flammable Contact Cleaner (CCC), Flux Remover (FRC), Degreaser (DGC), Switch Cleaner Lubricant (SWC))

The use of solvent based cleaners may be necessary when the PCB or assembly contains unsealed components or water sensitive devices.

Both solvent types generally require specialist equipment for their use in high volume manufacturing to protect against toxicity or problems associated with their flashpoint. This specialist equipment is relatively expensive and running costs are high in comparison with aqueous systems. However, hydrocarbon solvents are particularly effective for small scale production and bench rework as they clean effectively, and remove a wide range of soils. They dry extremely quickly, are easy to use and leave no residues.

Electrolube has developed a range of hydrocarbon solvents to meet the requirements of many applications. In general, the faster the evaporation rate, the lower the flashpoint; i.e. the higher the flammability risk.

Low VOC

The definition of a Volatile Organic Compound by the EU Solvent Emissions Directive is "any organic compound having at 20°C a vapour pressure of 0.01kPa or more, or having a corresponding volatility under the particular conditions of use."

The emissions of solvents are being limited, but why?

Emissions need to be controlled because many solvents undergo chemical reactions in the atmosphere, which cause a number of indirect effects, in particular the formation of ozone. Elevated concentrations of ozone in air can impair human health and can damage some building materials, forests, vegetation and crops. The European Solvent Emissions Directive (1999/13/EC) of 11 March 1999 aims for a 57% reduction on the 1999 figures for solvent emissions by the specified solvent-using industries by 2007.

As environmental concerns increase and the pace quickens towards the transition to solvent-free and low-VOC materials, practical solutions need to be found. Electrolube, as a responsible manufacturer, is continually investing in R&D so that our product range evolves to meet and exceed our customer's expectations through this period of change.

Benefits of Cleaning

The effective cleaning of PCBs and metal parts increases the reliability of the assemblies and allows coating and encapsulating operations to be carried out with full confidence.

The primary benefit of cleaning is that all contamination is removed from the assembly ensuring high reliability and long life. Shiny solder joints and contaminant free products enhances the manufacturer’s reputation.

Typical Application

Cleaning has been used for many years within the electronics industry to remove potentially corrosive flux and other residues from PCBs.

Today, even though ‘no-clean’ fluxes have been introduced, many electronics manufacturers still clean their PCBs. Screens and stencils always need cleaning to ensure accurate solder and adhesive printing.

Applications are extremely varied, but the following list does give some indication of the main areas of use:

The common feature of these applications is the requirement for high reliability. Manufacturers are under constant pressure to provide exceptional reliability at low cost.

The Electrolube cleaners in small packs include products for hand cleaning PCBs, screens and stencils, glass, contacts, ink removal and general degreasing. Drying cloths are also available as well as impregnated wipes in sachets and tubs.

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