Summary
Semiconductor and photonics manufacturers continue to face increasing pressure to validate more devices, at higher speeds, with tighter requirements than ever before. When a renowned international science and research center needed a fully automated, high‑throughput photodiode test system capable of handling their unique TO (Transistor Outline) case packaging and exacting test specifications, they turned to DMC for a state-of-the-art turnkey solution that would scale with their technology roadmap.
The customer required parallel test execution, rigorous low‑noise measurement performance, and an overall test platform flexible enough to support new photodiode assemblies and test requirements without costly redesign. DMC delivered a PC‑based solution with a custom LabVIEW/TestStand software stack, achieving throughput well beyond the customer’s 300‑units‑per‑hour target while reducing operator burden and ensuring long‑term extensibility.
This case study highlights how DMC engineered a turnkey production‑ready automated test platform that combines speed, precision, and flexibility with research-grade accuracy and signal-to-noise ratio, key requirements for any organization testing semiconductor‑class optoelectronic devices.
Custom fixturing mounts for photodiodes
Customer Benefits
- High capacity – Test throughput exceeded the required 300 units/hour
- User-friendly interface – A clean and organized custom operator interface made it very easy for the operator to control the test system
- High efficiency – Providing multiple DUT fixturing trays, allowing for preloading of trays, provides continuous testing of devices, and more time available to the operator
- Flexibility – Flexible hardware setup allows for the testing of other device types in the future, without a test equipment or software redesign
Technologies
Hardware
- Pickering LXI chassis
- Pickering LXI/PXI multiplexer and relay modules
- VPC Icon connectors
- Keysight 34461A Multimeter
- Keithley 6485 Picoammeter
- TDK Lambda Z230 Power Supply
Software
- NI LabVIEW (desktop application)
- NI TestStand (sequence engine)
Solution (System Description)
Hardware
To meet the customer’s testing requirements, DMC designed, developed, programmed, and assembled a custom, PC-based, turnkey test system. DMC’s embedded team led the development of custom electro-mechanical enclosures to house all of the devices under test (DUTs). DUT test fixtures were connected to the test system using VPC iCon connectors for fast, easy, and reliable changeover of the DUT trays. To meet the customer’s throughput requirements, DMC designed the system with two independent sets of carefully selected test equipment, which each operate in parallel to increase test capacity, while being controlled from a single, unified control PC and test application for ease of use. Each set of test instrumentation is switched and connected to test a specific DUT in the fixturing through a series of LXI-controlled multiplexers and relay banks.
Software
A LabVIEW-based custom desktop application provided a single operator interface for the test system. The foundation of the test application is DMC’s CORTEX platform, which is built in LabVIEW and readily integrates sequencing through NI TestStand. The application allows for both automatic operation of test equipment and a separate manual or engineering mode for specific one-off testing and/or debugging. The operator can run two asynchronous test sequences in parallel to optimize their setup time and maximize testing throughput. The application uses TestStand’s user management features, allowing users with different roles and privileges to log in and access only parts of the application available to their role in the testing workflow.
The automatic test mode (Auto Mode) lets the operator minimize their involvement and inputs to the software, focusing on unloading and reloading the DUT trays. As soon as one tray finishes testing, the operator can load the next tray of DUTs and continue testing with the click of a button (or a key press). The user interface shows a color-coded overview of all DUTs in the currently loaded tray, allowing the operator to see the testing status of all DUTs at a quick glance. Further, the specific photodiode currently being tested has its results displayed in a neatly organized manner, with measured current, voltage, and resistance values, as well as whether the individual tests passed or not. In addition, the operator can click on any of the DUTs in the overview to see the test results of that DUT in a separate box. At the end of the test sequence in Auto Mode, a test report is generated along with a results CSV file customized per the customer’s format specifications.
Instead of testing an entire tray of photodiodes at a time, our application also has a separate Manual Mode to run a specific test on a photodiode in any specific slot of the DUT tray. This was designed for several purposes:
- If a photodiode tests as defective, more specific tests can be performed to dig deeper
- Samples of new photodiodes can be tested for quick benchmarking or for R&D purposes
- If there is a hardware issue (such as a specific socket on the DUT tray not working), that can be confirmed or characterized
The operator is guided through the selection of test parameters and the photodiode to be tested, and is presented with a quick summary of results (measurements and pass/fail status) at the end, so they can easily review. The results are also saved on disk for later reference.
Conclusion
DMC’s turnkey test system approach—spanning mechanical design, electrical engineering, software development, and integration—enabled our customer to move from concept to a fully deployed, production‑ready photodiode test platform without needing to coordinate multiple vendors. The delivered system exceeded throughput requirements, provided a clean and intuitive operator experience, and introduced a hardware/software architecture ready to support future device generations.
For semiconductor and photonics manufacturers facing growing test volumes, tighter specifications, or increasingly complex DUT variants, this project demonstrates how a well‑architected automated test system can dramatically improve throughput while lowering total cost of ownership. DMC brings deep experience in NI-based test systems, precision measurement, and scalable software frameworks—allowing customers to move quickly and confidently from prototype to production.
If your team is exploring next‑generation test automation, expanding capacity, or replacing legacy fixtures, DMC can help. Learn more about DMC’s Test & Measurement Turnkey Systems expertise or contact us for your next project.