Since its customers include military, medical and electronics companies, Ultra Electronics' products must satisfy a number of different cleaning standards, including ESA (European Space Agency), IPC (Institute for Printed Circuits), BS and MIL SPEC. During contamination tests carried out prior to installation, the Kerry plant comfortably surpassed all of these benchmarks.
The Microsolve unit removes flux residue and general contamination from a mixture of through-hole and SMT PCB assemblies. The majority of boards are made from standard FR4, although some feature PTFE, and the largest measures 200mm x 400mm.
The two-tank (four-stage) cleaning process begins with an immersion clean in hydrocarbon Promosol Topklean EL20A and 3M's Novec HFE 71 IPA. This is followed by immersion and vapour rinses, before boards undergo a freeboard dry. According to the type of PCBs being cleaned, the first two stages operate with or without ultrasonics; the boiling action and properties of the co-solvent mixture in the first stage, combined with both rinse stages, ensure that a high level of cleanliness is maintained.
Neil Garbutt, Quality Engineer at Ultra Electronics, outlines the reasons behind his company's decision to install Kerry Ultrasonics' equipment. "When I came to investigate the various cleaning systems available, I found that Kerry offered the leading technology and felt that they could support our business in the future."