The Nuts and Bolts of Advanced Packaging

Estimated reading time: 3 minutes

The I-Connect007 Editorial Team asked IPC Chief Technologist Matt Kelly: Will you help us understand what advanced packaging means? This informative conversation touched on topics for both assembly and board fabrication. To that end, we will present this conversation in two parts. In this issue of SMT007 Magazine, Matt helps define not only what advanced packaging is, but the approach EMS companies must take when looking ahead. Think it’s about just adding some new equipment and software? Think again. There are logistics, onboarding, and so much more.

To read an excerpt from this interview that was previously published in the November 2022 issue of PCB007 Magazine, click here.

Nolan Johnson: Matt, I was on the exhibition floor at a technical conference recently and heard a lot of questions about advanced packaging: What is it, how does it apply, what does it mean to EMS providers, etc.? Would you help to define and provide a framework about advanced packaging?

Matt Kelly: There are two terms to define. An advanced package is an electronic component; it’s as simple as that. It has a few elements—it’s comprised of a semiconductor chip (typically silicon) and an interposer and/or substrate—followed by interconnection and assembly of the component. Advanced packaging is the process by which these elements are integrated, assembled, and tested. Advanced packages represent a very specific class of electronic components called active devices. They are called active devices because they contain silicon that provides compute, memory, or other logical device functions. Advanced packaging is critical because the combination of performance, reliability, cost, and functionality that future consumers are demanding can only be met by integrating silicon chips through an advanced packaging process.

Keep in mind this is just one of many different components in a system. While these components are important—they’re the brain of a system—they’re still just one of many different component types. Advanced packaging is a very specific component type. But what types of components are they? These advanced packages have different functions, the first of which is compute. It’s the Intel chip inside your laptop (CPU), graphics accelerators (GPU), AI-based neuro-network chips (NPU). It’s also the solid-state memory (DRAM, NVRAM, NAND Flash) within your phones and computers. These packages can also serve as sensors, analog, mixed signal, and system integration functions. Basically, they are actively doing something within the circuit design. Those are the main functions of an advanced package.

There’s also a difference between definitions of advanced packaging in the past, what it means today, and what it will mean in the future. For example, for at least 50 years, there’s been an active type of component called monolithic silicon, a single chip that is mounted to a substrate and then packaged into a component. A class of those are called multi-chip modules (MCM) and have been in use for decades.

As we move forward with the monolithic silicon, the idea of Moore’s Law becomes less economically viable and advanced packaging is morphing.

For example, when you think about a circuit card from the past, you typically had a compute chip and DRAM (memory banks), which were two different things connected on a printed circuit board. Those are now merging using chiplet-based heterogeneous integration architectures that are now integrating compute and high bandwidth memory (HBM) together within the same electronic package. The result is faster speeds and reduced latencies within a single component package. The resurgence in advanced packaging is driving increased functionality, performance, and speeds within a single device.

Johnson: Increased functionality, increased speed, and an overall smaller package means leaving more real estate available to further integrate more things.

Kelly: Absolutely. For example, if you look at images of a recent Apple Watch teardown, it’s unbelievable what can be accomplished in these small spaces. There are numerous small chips performing many functions within a very small area. Next generation designs continue driving miniaturization, increased functionality, and speeds. On the downside, these configurations are power hungry, meaning there are more power and thermal needs—thus challenges—that need to be addressed with these architectures.

To read this entire conversation, which appeared in the January 2023 issue of SMT007 Magazine, click here.