Material Gains
New IPC Standards Emphasize Performance over Composition
Changes in standards and supply chain are making high-performance materials more accessible.
5G is expected to revolutionize many aspects of work and life, as a critical enabler for connected cars and self-driving vehicles, autonomous factories, remote medical surgery and the diffusion of smart “things” throughout cities, infrastructures and our homes.

Within the automotive sector alone, its influence will be huge thanks to attributes like ultra-low latency that will enable time-critical use cases such as V2X. The 5G Automotive Association (5GAA) is excited about the prospects for cellular V2X (C-V2X) to consolidate vehicle-to-vehicle, vehicle-to-infrastructure, vehicle-to-pedestrian, and vehicle-to-network modes, combining direct communication, communication with cell towers, and links to cloud services.

For a country to delay 5G rollout risks compromising standards of living and economic competitiveness. On the other hand, US concerns about foreign involvement in such a pervasive infrastructure are widely reported. While the UK has decided to grant Huawei access to noncritical parts of the network – against the counsel of the Trump administration – it has been proposed the US consider the outright purchase of equipment companies such as Nokia as a way of keeping pace while also staying in control.

We all understand what’s at stake. The fear of falling behind is driving the search for solutions. Moreover, in the race to unleash the benefits of 5G for life, work and everything else, we can expect increasing pressure on the pace of intellectual-property development, as well as demand for the high-performance components and materials needed to make it real.

The PCB substrate materials capable of satisfying 5G technical specifications are esoteric, high-performance formulations characterized by very low losses. Tightly controlled dielectric constant (Dk) and low dissipation factor (Df) are needed to ensure signal integrity and minimize power demand and heat dissipation. Low passive intermodulation and good thermal stability are also required. The materials are technically specialized; few companies can produce them, and supply can be limited. 5G infrastructure rollouts have barely hit their stride and already there is talk of shortages that could delay and disrupt projects ongoing around the world. Applications like 77GHz automotive radar are also set for explosive growth and will compete for a share of the supply.

Part of the problem is manufacturers of substrate materials are managing complex, globalized supply chains that are difficult to control. There are many variables, and some companies in these chains may have conflicting business interests. I have explained before how a wholly owned supply chain provides protection against some of these hazards. Such arrangements can keep lines of communication short and untethered to supply-chain management skills of third-party companies.

No company has unlimited resources or flexibility to ignore the effects of global supply shortages that coincide with surging customer demand. However, complete control over the means of production and distribution makes it easier to make relatively small but influential adjustments to handle the situation. Production capability and capacity can be raised in targeted locations, increasing inventories of the most affected products, which in turn can be distributed in strategic locations globally. On the other hand, the understanding and cooperation of customers is vital to be completely confident of delivering the required products to the right place, at the time they are needed. Ideally, this should extend to automated electronic cooperation between the supplier’s and customer’s enterprise resource-planning software tools. Letting the machines share the information they need automatically is the most effective and efficient way to ensure customers’ needs are communicated properly to be fulfilled at the right time.

On the other hand, human interaction is very much needed at the cutting edge of product development. The technical demands in cellular infrastructure are always ahead of the standards-making processes, so equipment designers need to work extremely closely with their material suppliers to leverage the newest and best materials and make their products as good as they can be.

An important change in the standards landscape, however, concerns the latest IPC-4103 specification covering low-loss materials for use in printed circuits for microstrip, stripline, and high-speed digital circuits. Unlike IPC-4101 and IPC-4921, which were derived from NEMA specifications first published in the 1960s, IPC-4103 characterizes materials based on their Dk and Df at different frequencies, without concern for chemical composition. Materials covered by this specification typically have Df less than 0.005 and include state-of-the-art styles as low as 0.002.

As the performance of modern PCBs has advanced significantly since the 1960s, it makes sense to bypass the constraints of 1960s’ thinking when it comes to material grades. Emphasizing performance over composition enables a pragmatic approach to material selection that should make all our lives easier.

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