Do multiple single-spray-nozzle conformal coaters outperform a three-nozzle machine for volume builds?

Electronics manufacturing services (EMS) providers often have to evaluate equipment selection tradeoffs on more stringent standards than original equipment manufacturers due to their needs for flexible capacity across multiple clients.

How does AI contribute to continuous improvement?

Depending on whom you talk to, artificial intelligence (AI) is likely to open amazing possibilities or lead to the end of humanity as we know it. The reality is that when appropriately used, AI eliminates a lot of repetitive tasks that have high levels of variation and cost when done manually. In the quality realm, this opens the door to a discussion about whether a truly automated inspection process is a non-value-added or necessary non-value-added activity.

Manual inspection is costly, and accuracy can vary widely among operators, the time of day the activity is performed, or even the day of the week the activity is performed. Quality philosophy has long held that it is better to prevent defect opportunities (quality assurance) than to try to inspect them out (quality control). If a printed circuit board assembly (PCBA) can be 100% visually inspected by machines during SMT and secondary assembly processes without significant throughput time, however, does it make sense to do so? Let’s look at the pros and cons:

Non-value activities are sometimes unavoidable.

One challenge for electronics manufacturing services (EMS) providers implementing Lean manufacturing practices can be customer buy-in. While an original equipment manufacturer (OEM) can design a process with minimal non-value-added activity, customer requirements may revive some necessary non-value-added activity and it is up to the EMS provider to find a compromise that satisfies the customer requirements while minimizing the cost of resources associated with the non-value activity.

A recent example of this occurred in SigmaTron International’s Chihuahua, Mexico, facility. A consumer product customer added conformal coating to a product experiencing field failures related to operating environment issues. An automated selective coating machine is used that controls conformal coating deposition areas and application thickness. The customer wanted an automated visual inspection step added to ensure any overspray or missed coating was caught.

Which process offers fewer steps – and less contamination?

In a perfect world, the electronics industry would have migrated to 100% SMT by now. Unfortunately, through-hole remains a required technology for some products. In particular, through-hole connectors are often preferred over their SMT counterparts due to the robust solder joints they provide.

From a Lean perspective, a requirement for mixed technology can open the door to several of the seven wastes, as it can drive the need for processes not required for a 100% SMT printed circuit board assembly (PCBA). In particular, the wastes of transport and processing can occur when separate solder processes are required for the same PCBA. The need to do multiple thermal cycles when processing via reflow and wave solder also potentially adds to the waste of defects, as it can plant the seeds for premature component failure and handling damage.