Mobile-Menu

Production Testing of MicroLEDs Optical Characterization at the Emitter Level

From Dipl.-Ing. (FH) Hendrik Härter | Translated by AI 2 min Reading Time

Related Vendors

FAULHABER Drive Systems
SIMTOS (Seoul International Machine Tool Show)

MicroLED arrays for AR displays or optical chip-to-chip interconnects consist of millions of individual emitters. Characterizing these individually during mass production is challenging due to the high throughput. With the “Iris 100,” Teradyne is introducing a system designed to adapt the requirements of laboratory measurement technology to fab conditions.

The "Iris 100" test system for high-precision volume production of microLEDs uses a spectrometer and a high-resolution camera.(Image: Teradyne)
The "Iris 100" test system for high-precision volume production of microLEDs uses a spectrometer and a high-resolution camera.
(Image: Teradyne)

Teradyne views MicroLED technology as a foundation for future augmented reality (AR) microdisplays and as a building block for optical data interconnects in AI data center architectures. Such architectures increasingly require optical connections, as purely copper-based solutions are reaching their physical limits. The metrological challenge with these components lies in their high integration density: a single array can contain hundreds of thousands to millions of individual emitters.

For quality assurance purposes, it is necessary to precisely characterize each of these emitters. While benchtop optical testers can perform this task in the laboratory, Teradyne states that they do not achieve the throughput per component required for cost-effective high-volume production. However, the manufacturer does not provide exact figures on throughput.

Integration of Optical and Electrical Testing

The new “Iris 100” testing system is designed to meet the demands of high-precision volume production. The system uses a combination of a spectrometer and a high-resolution camera to measure the spectral response, luminance, and uniformity at the level of individual emitters.

To handle the required throughput for millions of MicroLEDs, the system relies on parallel testing and specific image-processing algorithms. A key aspect of its integration into manufacturing is its compatibility with existing infrastructure: The “Iris 100” can be directly integrated into Teradyne’s widely used UltraFLEXplus platform, enabling combined optical and electrical testing within a single test cell.

Software Integration and Calibration

The system is controlled using Teradyne’s IG-XL software. It is designed to detect optical defects—such as dead or stuck pixels, as well as cluster defects—early in the manufacturing process, both during wafer testing and final testing. A NIST-traceable calibration workflow for absolute measurements ensures the comparability of measurement results across different lots, wafers, and manufacturing sites.

Expansion of Photonics Testing

The unveiling of the Iris 100 follows the introduction of the “Photon 100” for silicon photonics and co-packaged optics testing, as well as the 2025 acquisition of Quantifi Photonics. Teradyne is thus expanding its portfolio to meet the diverse testing requirements in the field of optoelectronics. The roadmap also calls for future support of photodetector testing within the same test step. 

Subscribe to the newsletter now

Don't Miss out on Our Best Content

By clicking on „Subscribe to Newsletter“ I agree to the processing and use of my data according to the consent form (please expand for details) and accept the Terms of Use. For more information, please see our Privacy Policy. The consent declaration relates, among other things, to the sending of editorial newsletters by email and to data matching for marketing purposes with selected advertising partners (e.g., LinkedIn, Google, Meta)

Unfold for details of your consent

Related content