Electrolube Clean Up With Safewash Total

Since its launch to the market just over a year ago, it has become one of the most successful additions to the Safewash range, and indeed to the portfolio.

Safewash Total provides superior cleaning performance to military and commercial standards, at minimal financial and environmental cost. It is a specially formulated blend of non-flammable solvents, which form a micro-emulsion when mixed with water. Designed for cleaning printed circuit boards, it is ideal for the removal of leaded, lead-free and no-clean flux residues. The cleaner is also suitable for the removal of pastes and adhesives from screens, stencils, boards and accessories as well as general degreasing applications.

Safewash Total is a low foam cleaner, suitable for use in dishwasher and in-line pressure systems, as well as Ultrasonic and spray under immersion applications. Supplied as a concentrate, the product has an inbuilt corrosion inhibitor allowing for the safe cleaning of sensitive metals, including copper and aluminium. It is also harmless to plastics in typical application temperatures and cycle times, although testing is always advised in the specific application prior to large scale use.

Cleaning efficiency can be maintained, even after many uses, by regularly filtering the Safewash Total solution to remove contaminants. A variety of methods including refractive index, pH and electrical conductivity can be used to determine the contamination level of the solution. The most suitable method will depend on the type of residue being removed.

The benefits of Safewash Total include excellent cleaning performance, in a wide variety of applications, even at low temperatures. It has the versatility to allow cleaning using an array of different equipment and methods and being surfactant free, it is also extremely easy to rinse.

It is currently in use by Chiltern Connections (CCL), a leading independent conformal coating sub-contractor. Peter Woollcott, Technical Director said: “We started to use SWAT about two years ago after trialling and comparing with other cleaning chemistries and found it to be a very effective product.

“As part of the services that Chiltern Connections provide, cleanliness of PCB assemblies prior to conformal coating is a very important aspect to ensure good adhesion between coating and the assembly surface, as is the coating appearance and aesthetic appeal of the finished coated product. Poor preparation due to poor cleaning can lead to many problems later on in the conformal coating process.

“As a company that provides conformal coating sub-contract services, we deal with many types of assemblies all produced using a multitude of varying solders, fluxes, photoresists and solder resists on many types of substrates. Therefore, we needed a cleaning chemistry that had the capability and capacity to cater for this complexity of assembly build. At our facility in Wallingford, the cleaning system we use is the excellent Aqueous Technology SMT1000LD Batch cleaner. This unit has the facility to be programmed and retain a wide range of varying cleaning programs which were initially designed for individual assemblies and specific customer. However, due to the cleaning efficacy of SWAT we have found the number of programs we now use greatly reduced, as in most cases just one or two programs are now sufficient for the majority of applications.

“It is important to remember that in many applications the cleanliness level of the assembly must be of a certain standard, and as we often deal with assemblies that are used in aerospace, communications and military level requirements, the cleanliness level will therefore be aimed at the military standard of <1.5 µgm/cm2 NaCl. The batch cleaner provides us with an automatic status of cleanliness level achieved at the conclusion of the cleaning process and we can also verify this via an independent ionograph unit to ensure the cleanliness level is continually met. Electrolube SWAT reliably helps us meet these standards.

“Another important fact has been that due to the good cleaning provided by SWAT we have been able to reduce the temperature profile quite dramatically, the cleaning wash program operating around 32ºC combined with a much shorter program time of around 16 minutes. Therefore, environmentally and cost wise this move to SWAT has been a good economic decision.

“As well as conformal coating, CCL also provides an assembly cleaning service for a number of companies who do not have their own cleaning facility. These companies send us their assemblies for a clean only process in order for them to provide either themselves or their customer with a clean assembly. And again, we have the same issues with the use of a wide range of solder flux residues, both no-clean types and standard resin based materials; once again SWAT copes extremely well with all of these challenges.

“CCL is very pleased and delighted with the decision to use the Electrolube SWAT and would recommend its use for all cleaning and conformal coating preparation applications.”

Cleaning has been an essential stage within electronics manufacturing processes for many years, to remove potentially harmful contaminants that could lead to PCB failure. Such contaminants include flux, solder and adhesive residues, and other more general contaminants such as dust and fingerprints present from various stages of manufacture. As the developing electronics market sees modern assemblies getting smaller and smaller, the requirement for high performance and reliability is stronger than ever. In order to achieve good insulation resistance, and ensure adhesion of conformal coatings and encapsulants, cleanliness of the electronic assemblies is essential.

With environmental concerns at an all time high many electronics manufacturers are moving away from traditional solvent cleaners with ozone depleting chemicals and high VOC content, and replacing them with safer alternatives. Safewash Total has several advantages including non-flammable properties, low odour, low VOC and very low toxicity. The product has been designed to ensure that assembly performance and reliability will not be compromised, and can in fact be improved.

In the past, the specific choice of cleaner has been dependant on the equipment choice, whether it is ultrasonic, spray under immersion or dishwasher type application. The use of Safewash Total now allows the use of a single product for all types of processing. Versatility is partially due to the cleaner being supplied as a concentrate, allowing flexibility in terms of the application concentration in addition to temperature. At approximately 20% concentration the solution has low foaming properties, particularly at the elevated temperatures commonly used during spray application such as dishwasher and in-line cleaning. Used in immersion applications such as ultrasonic, Safewash Total will remove residues from screens, stencils, boards and accessories at concentrations as low as 10%.

These factors have made Safewash Total into the success story it is today over a very short period of time, and its popularity is continuing to grow rapidly within the market place.