Curtiss-Wright’s Instrumentation & Control (I&C) Group is leveraging Environmental Stress Screening (ESS) to address the challenges posed by ongoing global supply chain bottlenecks. In industries like nuclear, where production levels are still recovering, we recognize the need for innovative solutions that offer shorter lead-times without compromising reliability.

Functional Testing and Burn-In

Before any I&C component reaches our customers, it undergoes rigorous functional testing. However, the philosophy around adequate functional testing has not kept up with demands for increased reliability. That’s where ESS comes into play.

As part of our testing process, Curtiss-Wright performs burn-in on modules containing electronic components. Burn-in involves connecting these modules to a power source in order to identify assembly issues or early component failure. The burn-in time varies based on customer requirements and product specifics. Some burn-in periods last 24 hours (1 day), while others may require 100 hours (4 days) or even as much as 336 hours (14 days).

ESS Methodology

ESS is the process of using rapid thermal cycling to induce a failure in components. It involves placing the module in an environmental chamber and subjecting it to extreme temperature fluctuations. This rapid cycling allows us to calculate the probability of finding a defective component if an anomaly is present that could cause a premature failure. Since implementing ESS, our team has seen ESS to be a much stronger screen than a high temperature burn-in or ambient temperature burn-in.

Recent I&C successes utilizing Curtiss-Wright’s ESS process include:

(A) NUS-710 Master Trip Unit

Curtiss-Wright received a PO for NUS-710 Master Trip Unit with an aggressive delivery schedule. Due to the deadline, there would not be sufficient time to perform a standard 100-hour burn-in. The standard test would also only return a Screen Strength (SS) of 68%, that is, there is 68% confidence that the standard burn-in will cause a component to fail if that component contains a fatal anomaly.

With ESS, the testing period was significantly reduced—a 68% SS could be achieved in roughly 35 minutes and a 99% SS could be achieved in just over 3 hours

(B) DAM503

Standard lead-time projects can also benefit from ESS. For example, the normal burn-in for a DAM503 module is 48 hours (2 days) at ambient temperature. Even if no early failure occurred, the test would only yield a SS of 40%.

With ESS, Curtiss-Wright was able to achieve 42% SS in just 45 minutes! More impressively, 99% SS could be achieved in 4.5 hours. With the traditional testing process, the same SS would have taken 441 hours (18 days) to achieve!

In summary, ESS offers the following benefits

• Maximizes efficiency of functional testing.

• Increases reliability of I&C equipment

• Reduces lead-time to customers

• Does not reduce the life or degrade the equipment tested

• Available for many types of I&C equipment

For more information about ESS or our other I&C solutions, contact us at [email protected] or +1.208.497.3333.