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ABSTRACT In-field operation Reliability is key for manufacturers in the automotive, aerospace and space industries and while the suppliers of PCBs and populated boards invest heavily in inspection to eliminate defective products this generally fails to identify boards which have latent defects and will fail in the field especially in harsh environments. Particulate contamination is a major contributor to this type of defect and efforts must be made to eliminate contamination at every stage of the assembly process. In recent years, driven by the automotive industry, various Standard Authorities have produced documents designed to establish the risk of any particles causing a defect together with ways to mitigate them. One such document is VDA 19 which is in two parts. Part 1 is titled Inspection of Technical Cleanliness: particulate contamination of functionally relevant automotive parts while Part 2 covers Technical Cleanliness in assembly. While the methodology in both parts of VDA 19 Part 1is fundamentally good, it has a limitation for high volume production of populated PCBs in that it is a very time consuming sampling process. This means that although one sample meets the Technical Cleanliness requirements the rest of the batch may not, increasing the possibility of particles of contamination progressing through the rest of the process and causing latent defects. Most PCB manufacturers, supplying in accordance with VDA 19 will have cleaned the boards before packing. However after transport to the start of the SMT line and unpacking particles may have been generated either from the packaging itself or from the boards rubbing together. This paper will explain how, using the VDA 19 Part 1 methodology, Contact Cleaning installed before solder paste print can overcome the limitations of the proscribed sampling technique, by removing unattached particles from every PCB. It will also demonstrate the effectiveness of particle capture from the PCBs This greatly reduces the risk of latent defects thus improving system reliability