Some remarks to the effectiveness of the cleaning in electronics production process

This paper deals with research of the cleaning methods efficiency measurement in the sector of electronics assembly technologies. The cleaning is a necessary technological step whose importance is increasing with the development towards smaller resolution. Increased miniaturization, higher speeds and tighter board space highlights that need, as well as request for a higher reliability in some types of applications (automotive, medical, military etc.). Moreover, with introduction of new environmental regulations (WEEE, RoHS) and eco-design (EuP) rules the cleaning becomes to be more and more in the centre of attention. The cleaning process is important for various parts of technological processes, including lead-free solders process. Any various contaminants such as ionic or non-ionic flux residues, etching residues, handling contamination, fingerprints etc. can cause a decrease of lifetime could reduce lifetime and cause fatal failures. Therefore cleanliness is only the only way how to achieve acceptable reliability of electronic circuits and assemblies. But there is not enough information on which method to choose and how to arrange parameters. Described in this paper is the new method for measurement of cleaning efficiency by optical valuation, and some obtained results are discussed.