What is the main focus of the cleaning requirements for soldered assemblies?

The primary goal of the cleaning requirements for soldered assemblies is to remove contaminants that could impact the reliability and performance of the electronic devices. Contaminants such as flux residues, oils, dust, and other foreign materials can lead to a variety of issues, including corrosion, electrical shorts, and poor solder joint integrity. By ensuring that these contaminants are adequately removed, manufacturers can enhance the longevity and reliability of the assemblies, preventing failures in the field and ensuring that the devices function as intended over their expected lifespan.

Focusing solely on aesthetic appearance would not address the potential reliability issues that arise from left-behind contaminants. While visible dirt may be an indicator of poor cleaning practices, the requirement emphasizes the removal of all types of contaminants that might not be visible to the eye. Testing cleaning agents for compliance is also important, but it is just one aspect of a broader approach aimed at ensuring the reliability of soldered connections. The cleaning process needs to be thorough and effective in eliminating anything that can compromise the performance or reliability of the assembly, thus underlining the importance of option B.