Therefore, low-volume orders using components with unique properties and insufficient packaging or documentation should be manually assembled by a skilled technician.
In general, for efficiency it is best practice to manually assemble boards with a volume limit of 10 or less (like prototype builds), simple technology, and when there are a few individual components per board. Best practices for effective productivity cannot be discussed without addressing safeguards for quality.
SMT lines are preferred for large-volume assembly because they consistently produce quality PCBs and reduce the margin of error associated with manual assembly. The key to ensuring quality of manual assembled boards is having a well-defined manual process with failsafe quality checks that hold hand and automated orders to the same standards. This is typically implemented by limiting manual elements to placement of components on the board.
Before starting your project, we strongly advise consulting with your PCB service provider regarding your PCB assembly options.