Mitsui Metals to mass-produce semiconductor thermal expansion suppression materials

Mitsui Metal & Chemical Corporation will begin mass production of a “thermal expansion-suppressing material” for cutting-edge semiconductors in 2026-2027. This material suppresses thermal expansion. By incorporating it into the packaging materials used in graphics processing units (GPUs) from companies like NVIDIA, it can offset thermal expansion and prevent cracking or deformation in the semiconductor packages. This move aims to address the rapidly growing demand for semiconductors driven by the advancement of artificial intelligence (AI).

The drive to improve semiconductor performance requires not only miniaturization of circuits within individual chips but also integration of multiple chips onto substrates. While high-density integration increases semiconductor size, packaging materials are more susceptible to cracking and deformation due to heat. To ensure a stable supply of cutting-edge semiconductors, corresponding material countermeasures are also necessary.

Mitsui Metal & Chemical Corporation will mass-produce a compound called a “negative thermal expansion material.”

The company has nearly completed the development of technology for incorporating this compound into packaging materials to suppress the thermal expansion of resins and is currently awaiting certification from packaging material manufacturers. If all goes well, production will begin as early as 2026 at the plant in Omuta City, Fukuoka Prefecture.

Previously, the semiconductor packaging industry has used “low thermal expansion materials” such as spherical silica. However, even when spherical silica is mixed in, the package will still expand slightly.

In contrast, Mitsui Kinzoku’s negative thermal expansion material achieves a shrinkage rate approximately seven times that of other manufacturers’ materials, making it a promising alternative to existing low thermal expansion materials. Furthermore, the material possesses the insulating properties required for packaging.