Chiplet Design: A Real Game-Changer for Substrates

2023-04-26 Semiconductors editor

In the post-Moore’s Law era, chiplet design has been burgeoning as the mainstream architecture.

With the widespread adoption of EUV technology by foundries on process nodes of 5nm and below, the cost of semiconductor fabrication has skyrocketed. The cost of the 5nm process has grown by almost 1x compared to the 7nm process, and the 3nm process is expected to increase by almost 1x compared to the 5nm process.

To address this issue, IC design companies have started to split chip components or connect multiple chips and adopt advanced packaging such as 2.5D/3D IC to integrate multiple chips together.

Compared to traditional chip design methods, chiplet design has superior characteristics such as shorter upgrade cycles, lower costs, and higher yields, which is one of the reasons why chiplet technology is gaining popularity.

AMD’s chiplet design is a representative example. Through close collaboration with TSMC, AMD has fully transitioned its CPUs to chiplets since the 7nm process, with the Ryzen 7000 series CPU and Radeon RX 7000 series graphics cards released in 2022. The latter uses the RDNA 3 architecture and integrates the GCD and MCD produced by the 5nm and 6nm processes respectively, as a result improving overall performance, with a 54% increase in RDNA 3’s Performance per Watt.

Under the leadership of industry leaders such as AMD and Intel, chiplet design has had a significant impact on the entire semiconductor industry – substrates manufacturers in particular.

ABF Substrates Set to Soar

Aside from CPUs, developments in AMD and Intel’s server platforms indicate that the trend towards higher-layer-count and larger-area ABF substrates is expected to continue.

Given the server shipment volume is expected to remain stable and grow steadily in the mid to low single digits for the next 3-5 years, the growth momentum of ABF substrates mainly comes from the increase in layer count and area brought by 2.5D/3D packaging adoption in servers.

Starting in 2020, ABF substrates saw a surge in demand due to the pandemic. The supply-demand gap peaked in 2021, and in the first half of 2022, ABF substrate prices increased while volume increased and gross profit margins hit new highs.

Due to the impact of shortage in ABF substrates in 2020-2021, major substrate manufacturers have initiated large-scale expansion plans, with the expectation that demand for ABF substrates would continue to grow with the upcoming releases of new server platforms and the integration of 2.5D packaging for PC CPUs.

Growing demands with Some Hiccups

However, the moves have been put on hold for now. Since the second half of 2022, due to inventory correction in the overall semiconductor industry and the delayed production time of Intel’s new server platform, there’s been a supply glut in ABF substrates.

Therefore, Unimicron has taken the lead in adjusting its capital expenditure plans, reducing its planned capacity increase for 2023 from about 20% to only 3.5%. AT&S has also tentatively postponed the significant increase in capacity planned for the end of 2024. It is unclear when the expansion will resume or whether the expansion will be scaled back.

This indicates that current substrate manufacturers have not only lowered their demand projections for 2023, but also for 2025-2026. Further adjustments to the expansion plans of other manufacturers will also affect the future market supply-demands dynamics.

Back on Track for Major Growth in 2024

Looking into the future, things are looking up for the ABF substrate industry. In the second quarter of 2023, we can expect the release of new server platforms from AMD and Intel, as well as the completion of PC inventory adjustments.

With expansion plans in place, it’s predicted that global ABF substrate production capacity will only increase by 15-20% in the latter half of 2023, continuing to put pressure on substrate manufacturers, according to TrendForce.

Things are expected to pick up in 2024 with the release of AMD and Intel’s next-generation server platforms, Zen 5 and Birch Stream. Plus, the anticipated introduction of 2.5D packaging for PC CPUs will drive a new wave of demand for ABF substrates. All in all, we can expect a significant rebound for the ABF substrate industry in 2024.