PCBs must be of extremely high quality, since any malfunction in a car or medical device could seriously harm the user. Since consumer safety is critical, solid inspection strategies are required to detect potential failures. Fortunately, the latest advancements in smart factory technologies can help PCB manufacturers dramatically improve their quality control.
What equipment is involved in PCB manufacturing?
PCBs are produced on what’s known as a surface-mount technology (SMT) line, which is generally composed of six machines that each juggle their own data. These machines include:
- a printer, which manages the paste and stencil placement,
- a solder paste inspection machine, which measures the amount of applied paste, alignment, and defects,
- a pick-and-place system, which tracks part orientation, placement, and nozzle used,
- a pre-reflow inspection system, which measures part orientation, placement, and defects,
- a reflow oven, which maintains precise temperature profiles,
- and a post-reflow inspection system, which measures part orientation, placement, and solder defects.
Correlating the data from these systems helps engineers with troubleshooting. Given the importance of consistent quality, limited data tracking solutions like manufacturing execution systems (MESs) are available, and many vendor-provided solutions help engineers review inspection data from multiple machines throughout the line simultaneously.
However, this data is seldom correlated enough to pinpoint precise machine issues or predict potential failures. It’s even less common for machines to talk directly to one another without additional software or human intervention. This is generally because different vendors are responsible for different machines, and few communication standards exist.
Smart technology helps engineers pinpoint highly specific sources of failure
In our recent white paper titled “The impact of smart factory solutions on PCB manufacturing,” we take a look at two cases in which process quality software helped engineers precisely determine when a defect was created and take steps toward prevention. This software made use of data coming from all components of the SMT line.
In one case, the software indicated that around 1% of samples exhibited a common shift defect involving a specific chip capacitor that had either shifted or been lifted off of the solder pad. The solution involved replacing a 1.0mm nozzle with a slightly smaller one that would allow the pick-and-place to repeatedly grab and place the component correctly.