Lab validation

Notes

Lab findings such as marginal eye diagrams often trace back to package or board design rather than the die.

Overview

Lab validation is the bench-top testing of real chips, mounted on validation or evaluation boards and connected to laboratory instruments and real peripherals, to confirm that the silicon meets its specification and works in the systems it is designed for. It sits alongside production test on automatic test equipment (ATE) but has a different job: deep, flexible investigation of a small number of parts rather than fast screening of every part. It is the hands-on core of post-silicon validation, which also includes system-level and software-driven checks.

How it works

A validation set-up typically combines a board that carries the device and its supporting parts, instruments wired to the device's inputs and outputs, equipment to drive it into different modes and environmental extremes, and a controller running test scripts. Depending on the block under test, the instruments may include power supplies and electronic loads, signal sources, oscilloscopes, protocol analysers and temperature forcing systems.

The work falls into several strands. Electrical validation checks interfaces against their specifications, such as signal timing and quality on high-speed links or regulation and efficiency on power management parts. Functional and system validation runs the chip with real memory, peripherals and software, which production ATE generally cannot do because it does not attach those components. Characterisation sweeps voltage, temperature and frequency to find the real operating window, and pre-compliance testing checks behaviour before formal certification.

Automation matters because the number of measurements per product keeps growing. Teams script their instruments, share common test software across sites and products, and share results so that design, validation and test engineers work from the same data. Bench versions of DFT tools also let engineers run scan, memory self-test and embedded instrument procedures on a board through a small adapter, without waiting for tester time.

Lab validation is slow and expensive per part, so it is used on samples rather than on every part, and its findings feed back into the production test programme, errata and the next design revision.

Examples

• Measuring a high-speed serial interface on a validation board with an oscilloscope and checking the results against the interface specification.
• Testing a power management IC across load currents and temperatures with programmable loads and a thermal forcing unit.
• Booting an operating system on a new SoC with real memory and peripherals attached, something a production tester cannot do.

Related terms

• Post-silicon validation
• Interoperability testing
• Compliance testing
• Bring-up

Where it appears on the Hub

Used on 7 pages of the Hub. In each group, the pages that mention it most come first.