Ajinomoto holds a bottleneck in the AI chip supply chain due to ABF film shortage

Ajinomoto, the Japanese company best known for monosodium glutamate (MSG), is emerging as a critical bottleneck in the global AI chip supply chain. As AI infrastructure investment accelerates, shortages of Ajinomoto’s key semiconductor material—ABF (Ajinomoto Build-up Film)—are increasingly seen as a limiting factor for high-end chip production.

What ABF is and why it matters

ABF is a thin insulating film that bridges the silicon core of a chip and the traces on the motherboard. Without this film, high-end chips cannot reach the dense interconnect density and stable signal transmission needed at tens of gigahertz—requirements associated with AI accelerators such as NVIDIA’s Blackwell and Rubin platforms, which operate under demanding conditions.

The ABF supply chain involves multiple steps. Ajinomoto Fine-Techno supplies the base film material, after which chip substrate makers—including Ibiden in Japan and Unimicron in Taiwan—produce the final product. However, Ajinomoto is described as the bottleneck control point: without ABF, AI chips cannot leave the factory.

Chip demand rises, ABF scarcity intensifies

The shortage risk increases as AI chip demand grows. For an AI accelerator, ABF usage is reported to be 15 to 18 times higher than that of ordinary components such as consumer GPUs. Each chip package requires 8 to more than 16 ABF layers depending on design size. Larger chips—such as those referenced for NVIDIA’s Rubin and Rubin Ultra—require more ABF layers, making ABF more likely to constrain the entire production line.

While Ajinomoto has expanded its plants, the decision to add capacity is constrained by market absorption risk. Overspending on production that demand cannot absorb is described as a non-trivial concern. As a result, manufacturers such as Ibiden are often short on supply. In addition, advanced interconnect technology (SAP) is said to increase defect risk in the multi-layer process, which can affect yields.

Big customers race to secure supply

To reduce exposure during shortages, large cloud infrastructure operators have reportedly pre-placed orders with Ajinomoto. This support is intended to help Ajinomoto expand additional production lines and sign long-term supply contracts. Even so, during shortage cycles, supply cannot meet all demand, and only limited quantities of ABF and the corresponding chips can be secured.

Forecast and expected timeline

According to DigiTimes, ABF demand is forecast to grow at a double-digit pace annually. The shortage cycle is expected to last at least three more years, positioning ABF as one of the semiconductor industry’s most significant chokepoints as AI infrastructure expands globally.