Design World

June 2023 Issue: Test & Measurement Handbook

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Test goes beyond the bench

Many, if not most, design engineers use bench test equipment — oscilloscopes, multimeters, spectrum analyzers, function generators, and so on. Test doesn’t, however, end at your bench; it goes onto the production floor. In production, test is about making sure that the manufacturing process operates within tolerances. That is, if the product is built correctly, it should pass production tests.

That’s the big change we’ve brought to the 2023 Test & Measurement Handbook. We’ve added articles relating to production and manufacturing test for systems and subsystems. So far, we haven’t touched on semiconductor test, but we might just do that online over the coming year.

Test engineers have different priorities than design engineers. For example, test engineers must consider throughput, costs of test, automation, and footprint. Throughput relates directly to the cost of test. If your facility produces, say, thousands of products every day, throughput needs to be as quick as possible. To achieve high throughout, you need to automate the process of applying test signals to your DUT and measuring the results. That means software: test executives, test routines, instrument drivers, databases, test reports, and the like. Furthermore, test systems need to be easy to operate.

If you’re not familiar with manufacturing test and need some background, look to the following articles:

  • “How test executives automate equipment and processes” provides a top-level view of test software.
  • “How modularity benefits test systems” looks at automated test hardware such as PXI.
  • “What is an instrument driver and why do I need one?” explains how test executives and individual test routines communicate directly with test instruments, be they modular or boxed. Chances are, you’ll need both configurations in a production test station.

    • Do you work with high-speed digital signals? If you do, then you understand the importance of signal integrity. Without quality signals, bits get lost resulting in bit errors. That’s something nobody wants. Power integrity, a subset of signal integrity, is the study of how power and its issues — droops, dips, ripples, and noise — affect signal integrity. Today’s oscilloscopes include software written specifically for measurements on power planes. “Measurements verify power integrity” and “How to make fast and accurate power integrity measurements” explain why you need to measure power integrity and how to do it.

    While EE World focuses on modern test equipment and how to use it, we still appreciate vintage equipment. Sure, you can find all kinds of vintage test equipment online, but there’s nothing quite like seeing it in person. Here’s an oscilloscope I photographed at a monthly swapfest (swapfest.us) on the MIT campus in Cambridge, Mass. It needs some cleaning, and it might even still work.

    Martin Rowe
    Senior Technical Editor

    Filed Under: DIGITAL ISSUES • EE WORLD

     

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