Material Gains
Materials Supply Chain Security
Between counterfeits and improper handling, the potential for consequences is rampant.
I’m a huge fan of the connected world. I’ve commented previously on the many potential benefits for communities everywhere. Like many good things, however, it poses its own set of challenges. One of these is the “democratization” of cyber-crime. The spread of the IoT means we are all vulnerable in our connected homes, our connected cars, or when enjoying the efficiencies of connected infrastructures and smart services. The potential consequences of cyber-attacks are no longer an issue only for banks, governments or large corporations. The consequences of a hacked car or medical device can be personal, real-time, and in some instances life-threatening.

IoT software protocols and hardware-device security down to the silicon level are being developed to counter a host of potential attacks that can range from stealing stored passwords or intellectual property to taking over devices and systems using malicious firmware. This will be an ongoing battle of “arms versus armor.” Other potential security threats such as counterfeiting are more mature, less fast-paced, but costly and potentially dangerous. Counterfeit electronic components are reckoned to cost the industry billions of dollars every year, although the Semiconductor Industry Association points out that the safety implications and potential threat to life posed by rogue components often worth only a few cents each make this a far more serious issue than financially larger black markets such as those for counterfeit high-value luxury goods.

Threats from substandard materials. When it comes to printed circuit boards and materials, counterfeiting can be a problem, but there are other issues to look out for too. The variety of different grades of substrate materials has proliferated enormously in recent years, as many subtly different formulas have been developed to help designers optimize and fine-tune more and more parameters to push performance to the limit. There is often no visible difference between materials of various grades, although properties can vary enormously between special high-end formulas such as low-loss substrates and those for more general-purpose applications. Sometimes the system requirements are so substrate-dependent that even one grade lower can be enough to impair system performance.

Malice or mistake? Not only must materials used be genuine, but fabricators should select the correct grade during manufacture. Incorrect materials could be used through simple errors or poor stock-handling practices, if not an outright desire to cut costs and boost profits.

Products built on low-loss substrates are likely to fail production tests if materials of the wrong grade are used. However, incorrectly specified IMS materials could be less easy to spot immediately. Recently, the number of different IMS grades offered by leading manufacturers has grown enormously due to trends such as LED lighting and e-mobility. Ventec, for example, has 12 different grades of IMS materials to meet a variety of thermal management challenges. The issue here is that system reliability is closely linked to operating temperatures, so if, for example, the emitter for an automotive LED headlamp is built with a lower grade IMS than the manufacturer specified – say a 1.0W/m.K product in place of 3.0 or 3.6W/m.K chosen by the system designers – the error may not be discovered until long into the life of the vehicle. Automotive lighting is no longer designed for easy replacement because LED reliability is presumed to be extremely high. If large numbers of units fail before the warranty period expires, the resulting extra costs could seriously damage the lighting supplier’s reputation.

On the other hand, poor handling of materials could result in using over-specified materials, hence unnecessarily higher costs. In either case, the LED emitters will not operate at the design temperature, which could result in unpredictable chromaticity. An operating point just 10% higher could cause a noticeable difference, creating a highly visible quality issue. Other systems deployed in high-temperature environments, such as under-the-hood electronics, including engine management or mechatronic modules, can also be at risk of compromised reliability due to incorrect IMS products.

So, it’s important to keep supply chains secure. It’s also important for board shops to ensure correct management of their materials and maintain adequate traceability. Materials suppliers can help to some extent by providing services such as indelible marking to help verify both the authenticity and performance grade of the materials supplied.

It’s worth mentioning that some engineering problems may indicate the wrong materials are in use, when in fact the underlying reason is somewhat different. We recently helped a customer troubleshoot an RF product that had run into problems. The board design was marginal to get the necessary range and sensitivity for the desired signal strength and power consumption. We traced the problem to circuits built on panels fabricated at right angles to the master sheet used in the original design. The difference in fibers per inch between one orientation and the other was enough to cause signal loss, resulting in a failure to meet the loss budget. It’s just one more illustration showing the value of keeping proper control over processes and materials.

Alun Morgan
Alun Morgan
is technology ambassador at Ventec International Group (ventec-group.com); alun.morgan@ventec-europe.com.