An automation shift shows how smarter processes reduce inspection and boost value-added work.

Advances in technology offer many ways to improve efficiency and reduce costs without impacting quality through automated inspection tools. The full potential of these tools cannot be fully leveraged without rethinking organization and processes, however. This month, we look at ways SigmaTron International’s facility in Chihuahua, Mexico, is evolving its inspection approach after validating the effectiveness of the automation it has been investing in over the past three years.

Automating inspection in secondary assembly operations.

One of the first lessons in quality management is the difference between quality assurance and quality control. Quality assurance focuses on eliminating defect opportunities before they occur, while quality control focuses on inspection strategies that eliminate defects before they escape the factory. There is universal agreement that quality assurance is more cost effective than quality control. Lean manufacturing principles are based on a quality assurance focus. That said, use of automated inspection equipment has been growing dramatically in recent years because increasing density and complexity in printed circuit board assemblies (PCBAs) is driving the need for a blended quality assurance/quality control approach that includes mass inspection.

Over the past 18 months, SigmaTron International's facility in Tijuana, Mexico, has been exploring the best way to automate inspection and integrate the captured data into real-time corrective action throughout its entire PCBA assembly process. A July 2022 PCD&F/CIRCUITS ASSEMBLY column, "An Industry 4.0 Approach to Employing 3-D AOI on an SMT Line," discussed the journey of integrating Industry 4.0 capabilities in a Lean Six Sigma framework in this facility's SMT area. Once that phase was completed, implementation of 3-D AOI capability began in secondary assembly work cells. Typical secondary assembly operations include soldering cables and components such as switches which can't be reflowed, adding rubber caps and placing QR labels.