Core Viewpoint - Mitsui Mining & Smelting is set to mass-produce a negative thermal expansion material that can achieve a shrinkage rate approximately seven times greater than existing low thermal expansion materials, addressing the growing demand for semiconductors driven by AI advancements [2][6]. Group 1: Product Development - The negative thermal expansion material is designed to suppress thermal expansion in semiconductor packaging, which has been a challenge with traditional materials like spherical silica [2][5]. - The company has completed the technical development of mixing this compound into packaging materials to mitigate resin thermal expansion and is awaiting certification from packaging manufacturers [5]. Group 2: Market Context - The semiconductor industry requires not only the miniaturization of individual chip circuits but also the integration of multiple chips onto substrates, which increases the risk of cracking and deformation due to thermal effects [4]. - The introduction of this new material aims to ensure stable supply and performance of advanced semiconductors, particularly in high-density integration scenarios [4].