The LED industry has grown its production capacity at a remarkable speed since LEDs were first used in commercial illumination products barely 20 years ago. In that time, virtually, the lighting industry has shifted from relying on filament bulbs and other incandescent light sources to LEDs, a type of semiconductor device. Today, across the commercial, residential, automotive, and specialty lighting segments, many billions of LEDs are assembled into new lighting fixtures every year.

Lumileds, based in Silicon Valley, pioneered the design and production of LEDs for lightings and today is one of the world’s top five manufacturers. Maintaining its leadership position requires the implementation of advanced manufacturing technologies and methods that enable it to continually improve product performance and quality while reducing the cost of operations.

Big Data Reveals Patterns Across Billions of Production Units

Lumileds counts its annual production volumes in the billions of units. The quality across this production output is stratospherically high. The brand value of Lumileds depends on maintaining its leadership position in quality; customer shipments have a typical defect rate of fewer than 20 parts per billion.

An important innovation in production operations that help the company to continually improve this defect rate is the application of artificial intelligence (AI) to the vast data sets generated by testing and inspection of raw epitaxy, finished wafers, and packaged LEDs. ‘Maverick detection’ is the process for analyzing Lumileds’ ‘big data’ – establishing the recurring patterns which characterize good units, and identifying the outliers, or maverick units, which do not match the good pattern.

“AI enables the AVI technology to recognize distinctive visual signatures of potentially defective units. The AVI system is both more accurate and faster than the previous human inspection process, and requires far fewer people to perform repetitive tasks.”

This computerized process enables Lumileds to automatically find and destroy mavericks before they are included in customer shipments.

Seeing Better: the Application of Automated Visual Inspection

In common with many other production environments, an LED factory uses visual inspection to monitor the quality of production output. As little as 10 years ago, a Lumileds factory would have housed rooms full of manufacturing technicians hunched over microscopes to examine batches of production units.

Today, this process is performed by machines using automated visual inspection (AVI) technology. Here too, AI is in use: in this case, AI enables the AVI technology to recognize distinctive visual signatures of potentially defective units. The AVI system is both more accurate and faster than the previous human inspection process, and requires far fewer people to perform repetitive tasks.

This is the perfect example of a technology that improves quality and reduces cost.

Quality and Performance Embedded in the Culture

Beyond big data, AI, and AVI, perhaps the next biggest differentiator for Lumileds is not a technology at all – it is the way that its people operate in the factory. This is conditioned by Lumileds’ company culture in which quality and continuous improvement are prime values.

This culture is promoted through formal programs such as ‘TCPI2’ (Total Continuous Process Improvement and Innovation). This ambitious initiative is aligned with the company’s safety, quality, and efficiency policies, and has three goals:
• Zero accidents
• Zero defects
•  Zero waste

These high-level goals are backed by formal elements of business operations – procedures, data repositories, training, and education – but equally by a company-wide understanding. This is passed down from generation to generation of workers in a company that still counts on its payroll, numerous veterans of the early years of the company.

As critical as technology and equipment, it is this shared commitment to quality and improvement which will ensure that Lumileds maintains its position as the premium manufacturer of high-performance LEDs.