What constitutes an “unacceptable defect” in solder joints according to IPC-A-610?

An "unacceptable defect" in solder joints, according to IPC-A-610, is defined as any joint that fails to meet the established visual and dimensional standards. This standard serves as a guideline for quality assurance in electronic assemblies, ensuring that all solder joints are not only visually sound but also meet specific functional criteria for robustness and reliability.

When a joint does not conform to these standards, it may compromise the electrical connectivity or mechanical stability required for the electronic device to function properly. This includes defects such as insufficient solder, cold solder joints, or excessive solder that could lead to short circuits or other operational failures. Therefore, adhering to these standards is essential for ensuring product quality and longevity in electronic assemblies.