The demand for products that last is innovating design, processes and materials.
As the technology in our pockets, homes and offices becomes increasingly critical to our daily missions as individuals, we all value the reliability of these complex electronic devices. We depend on smartphones, communication networks, home office equipment, automobiles, contactless payment terminals and more to be ready for action every time we call on them. To meet our expectations, these systems must deliver high reliability.
Product manufacturers and brand owners understand the market value gained from establishing a reputation for reliability. They also understand that product reviews and social media channels give consumers immense power to make or break that reputation.
In general, the reliability of consumer-grade and industrial products has improved remarkably as the electronics industry has matured. This is due to a number of important factors. Component and interconnect technologies have improved enormously. Digital electronics offer much greater repeatability and robustness to changing operating conditions than ancient, predominantly analog circuits. And opening the enclosure of almost any consumer device typically reveals a tidy and minimalist assembly as integrated components internalize many interconnections and functions. On top of this, standardization of specialized functions such as RF transceivers as plug-and-play modules has made complex systems much easier to design and build using hardware that’s already proven in existing designs. Moreover, the vendors continually refine and improve these modules from one generation to the next.
Another influential trend is the extensive automation of today’s manufacturing, which has largely driven variability out of mass-produced items. Subsequently, testing has become highly automated, faster and more rigorous, comprising multiple techniques including optical inspection, boundary-scan, in-circuit testing and functional testing.
Alongside these advancements, I would argue that specialization is also an extremely important and influential factor in improving reliability. Bringing more or less any product to life in today’s world demands the skills of multiple specialists to deliver a result that is both credible and competitive in the marketplace. This is true at every stage and every level of engineering, including PCB design. There are few general board shops now, compared to the many specialists that focus on high-performance, low-loss boards or on demanding applications such as automotive, medical or aerospace. With deep knowledge to apply, these organizations can prevent design errors during development and thus minimize early failures.
On the other hand, while growing into the global, professional phenomenon that employs many of us today, the industry has learned a huge amount about failure mechanisms and, as a result, how to minimize or prevent these by design. Materials technologists have developed enhanced filler systems that have been a major move forward in relieving mismatches in thermal expansion to minimize mechanical stresses on solder joints.
We have also seen rapid evolution in insulated metal substrates (IMS) materials to handle demands for greater thermal performance and increased reliability. Early IMS products aimed primarily at LED-lighting applications have provided a springboard into today’s sophisticated suites of materials that offer differentiated properties to satisfy a wide range of requirements. IMS is now routinely deployed in cutting-edge applications such as power conversion, renewable energy and e-mobility. As well as greatly enhancing reliability, these are helping to boost power density and minimize BoM costs.
Other improvements in materials science are helping increase the reliability of equipment exposed to harsh environmental conditions such as high humidity, mitigating effects such as conductive anodic filament (CAF) formation. Realizing such improvements is essential as our growing dependence on advanced technology drives complex electronic systems into challenging locations exposed to hazards such as rain, salt water, industrial chemicals and extreme temperature fluctuations.
On the other hand, applications traditionally considered “high reliability” remain special and are seeing big changes as commercial opportunities like the “New Space” market bring competitive pressures. Private spaceflight is heavily supporting deployments of low-cost, small satellites typically launched into low earth orbits (LEO) or geostationary orbits for purposes such as commercial telecom or Internet access, earth observation and weather monitoring. Several categories of small satellites are now recognized, from extremely tiny femto satellites (femtosats) weighing less than 100g to mini satellites (minisats) up to 500kg.
Rapid growth in the New Space market is placing more and more extreme time and cost pressures to design, build, test and deploy new satellites. Where satellites and instruments used to be designed and built slowly and expensively using specially screened parts in radiation-hardened (rad-hard) ceramic packages, commercialization is driving the emergence of a new category of space-enhanced plastic (Space EP) technology that permits competitively priced, radiation-tolerant components that are ideal for commercial LEO operations or missions that require a short lifetime. In addition to saving costs, these plastic packages can also be smaller and lighter than ceramic parts, and the internal circuitry uses techniques such as modular redundancy to minimize the impact of ionizing single-event effects. The device construction also utilizes material sets that use flip-chip assembly or gold bond wires instead of copper, and are tested to meet minimum outgassing specifications.
While a lack of reliability data has historically exempted aerospace electronics from the transition to lead-free mandated for consumer applications, supply-chain issues are now moving the industry in this direction. As the availability of components with tin-lead terminations has become severely restricted, initiatives such as the Lead-free Transition for the European Space Sector (LETTERSS) are now driving the emergence of new lead-free compatible materials that will meet reliability targets.
Today’s tech may need to survive for many years outdoors, several years in space, three years in our pocket or even just a few hours in a smart tag on its way through the supply chain. Designers have many tools at their disposal, including materials systems, process knowledge and manufacturing and testing capabilities, to achieve the necessary reliability while meeting stringent commercial constraints.
Alun Morgan is technology ambassador at Ventec International Group (venteclaminates.com); This email address is being protected from spambots. You need JavaScript enabled to view it.. His column runs monthly.
