Apple is expected to unveil the iPhone 15 in September 2023, with minimal changes anticipated in its PCB design. According to research from TrendForce, the iPhone 16, set to launch in 2024, is projected to adopt the use of RCC (Resin Coated Copper) material for its mainboard to reduce the device’s thickness.

TrendForce’s analysis is as follows:

The iPhone 15 Pro Max will feature RFPCB for its periscope lens, while the iPhone 16 Pro series will utilize RCC for its mainboard.

Looking first at the primary changes in the iPhone 15’s PCB, constrained by factors such as device dimensions and product pricing, only the iPhone 15 Pro Max will incorporate a periscope lens. In contrast to the conventional FPC (Flexible Printed Circuit) used in typical lenses, the iPhone 15’s periscope lens will adopt RFPCB (Rigid-Flex Printed Circuit Board) to better utilize space and control the device’s thickness.

Currently, iPhones employ SLP (Substrate-Like PCB) for their mainboards. To achieve a thinner device profile, Apple is planning to introduce RCC as the mainboard material for the iPhone 16 Pro series, scheduled for the latter half of 2024. This will involve using 2 to 8 layers of RCC within the 18 to 20 layers of SLP.

However, based on supply chain information, RCC has not yet passed drop tests, leading to potential fractures between SLP layers. If this issue persists beyond the end of 2023, the adoption of RCC might be postponed until the introduction of the iPhone 17, which could be expected in 2025.

The SLP architecture is moving closer to ABF substrates, while RCC can only replace a portion of the CCL layers.

Taking a closer look at RCC’s material characteristics, RCC involves applying semi-cured epoxy resin onto copper foil after heating. The main distinction between RCC and standard CCL (Copper Clad Laminate) lies in the absence of glass fiber cloth in RCC. RCC primarily consists of resin and copper foil, and it employs ABF (Ajinomoto Build-up Film) instead of PP (Prepreg) as the insulating material between copper foil layers. RCC is also a material used in ABF substrates, indicating that SLP architecture is moving closer to ABF substrates.

Due to its lack of glass fiber cloth, RCC offers advantages such as reduced thickness and suitability for fine line designs. Its lower Dk (Dielectric constant) and Df (Dissipation Factor) characteristics contribute to high-frequency and high-speed transmission. However, due to its softer nature, RCC has poorer support capabilities, allowing it to only replace certain CCL layers.

It is expected that Ajinomoto will have a monopoly in the iPhone RCC market in 2024, with Taiwanese manufacturers potentially becoming suppliers in 2025.

In the supply chain realm, since ABF substrates also involve RCC, Ajinomoto, a primary ABF supplier, is projected to become the exclusive supplier of iPhone RCC materials in 2024. ITEQ, an early adopter of RCC materials, successfully developed RCC production lines by the end of 2021, making it the first Taiwanese CCL manufacturer to do so. As such, it stands a chance of becoming the second supplier.

EMC is a major supplier of iPhone mainboard CCL materials, with an estimated market share of around 95% in 2023. TSEC also successfully developed RCC materials in 2022, indicating that both ITEQ and EMC have potential to enter the iPhone RCC supply chain in 2025. Other companies, including Japanese firms Mitsubishi Gas Chemical, Panasonic, and Korean company Doosan Electronics, have also developed RCC materials, indicating an interest in becoming part of the iPhone RCC supply chain.

ChatGPT’s debut has sparked a thrilling spec upgrade in the server market, which has breathed new life into the supply chain and unlocked unparalleled business opportunities. Amidst all this, the big winners look set to be the suppliers of ABF (Ajinomoto Build-up Film) substrates, who are poised to reap enormous benefits.

In the previous article, “AI Sparks a Revolution Up In the Cloud,” we explored how the surge in data volumes is driving the spec of AI servers as well as the cost issue that comes with it. This time around, we’ll take a closer look at the crucial GPU and CPU platforms, focusing on how they can transform the ABF substrate market.

NVIDIA’s Dual-Track AI Server Chip Strategy Fuels ABF Consumption

In response to the vast data demands of fast-evolving AI servers, NVIDIA is leading the pack in defining the industry-standard specs.

This contrasts with standard GPU servers, where one CPU backs 2 to 6 GPUs. Instead, NVIDIA’s AI servers, geared towards DL(Deep Learning) and ML(Machine Learning), typically support 2 CPUs and 4 to 8 GPUs, thus doubling the ABF substrate usage compared to conventional GPU servers.

NVIDIA has devised a dual-track chip strategy, tailoring their offerings for international and Chinese markets. The primary chip for ChatGPT is NVIDIA’s A100. However, for China, in line with U.S. export regulations, they’ve introduced the A800 chip, reducing interconnect speeds from 600GBps (as on the A100) to 400GBps.

Their latest H100 GPU chip, manufactured at TSMC’s 4nm process, boasts an AI training performance 9 times greater than its A100 predecessor and inferencing power that’s 30 times higher. To match the new H100, H800 was also released with an interconnect speed capped at 300GBps. Notably, Baidu’s pioneering AI model, Wenxin, employs the A800 chip.

To stay competitive globally in AI, Chinese manufacturers are expected to aim for the computational prowess on par with the H100 and A100 by integrating more A800 and H800 chips. This move will boost the overall ABF substrate consumption.

With the ChatBot boom, it is predicted a 38.4% YoY increase in 2023’s AI server shipments and a robust CAGR of 22% from 2022 to 2026 – significantly outpacing the typical single-digit server growth, according to TrendForce’s prediction.

AMD, Intel Server Platforms Drive ABF Substrate Demand

Meanwhile, examining AMD and Intel’s high-end server platforms, we can observe how spec upgrades are propelling ABF substrate consumption forward.

• AMD Zen 4:

Since 2019, AMD’s EPYC Zen 2 server processors have used Chiplet multi-chip packaging, which due to its higher conductivity and cooling demands, has consistently bolstered ABF substrate demand.

• Intel Eagle Stream:

Intel’s advanced Eagle Stream Sapphire Rapids platform boasts 40-50% higher computation speed than its predecessor, the Whitley, and supports PCIe5, which triggers a 20% uptick in substrate layers. This platform employs Intel’s 2.5D EMIB tech and Silicon Bridge, integrating various chips to minimize signal transmission time.

The Sapphire Rapids lineup includes SPR XCC and the more advanced SPR HBM, with the latter’s ABF substrate area being 30% larger than the previous generation’s. The incorporation of EMIB’s Silicon Bridge within the ABF substrate increases lamination complexity and reduces overall yield. Simply put, for every 1% increase in Eagle Stream’s server market penetration, ABF substrate demand is projected to rise by 2%.

As the upgrades for server-grade ABF substrates continue to advance, production complexity, layer count, and area all increase correspondingly. This implies that the average yield rate might decrease from 60-70% to 40-50%. Therefore, the actual ABF substrate capacity required for future server CPU platforms will likely be more than double that of previous generations.

ABF Substrate Suppliers Riding the Tide

By our estimates, the global ABF substrate market size is set to grow from $9.3 billion in 2023 to $15 billion in 2026 – a CAGR of 17%, underscoring the tremendous growth and ongoing investment potential in the ABF supply chain.

Currently, Taiwanese and Japanese manufacturers cover about 80% of the global ABF substrate capacity. Major players like Japan’s Ibiden, Shinko and AT&S, along with Taiwan’s Unimicron, Nan Ya, and Kinsus all consider expanding their ABF substrate production capabilities as a long-term strategy.

As we analyzed in another piece, “Chiplet Design: A Real Game-Changer for Substrates,” despite the recent economic headwinds, capacity expansion of ABF substrate can still be seen as a solid trend, which is secured by the robust growth of high-end servers. Hence, the ability to precisely forecast capacity needs and simultaneously improve production yields will be the key to competitiveness for all substrate suppliers.

Read more:

• HBM Supply Leader SK Hynix’s Market Share to Exceed 50% in 2023 Due to Demand for AI Servers, Says TrendForce
• Shipments of AI Servers Will Climb at CAGR of 10.8% from 2022 to 2026, Says TrendForce

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