Commercialization of a New Negative Thermal Expansion Filler that Suppresses Warpage of Semiconductor Packages —Launch of 'M-Filleris™ NTE,' a new material that contributes to[...]

■ Background In recent years, with the spread of AI servers and high-performance computing (HPC), demand for even more powerful semiconductors is growing. Semiconductor packages are increasingly adopting advanced packaging technologies such as chiplet technology and 3D stacking technology, and increased heat generation due to high-density chip packaging has become an issue. Currently, epoxy resins and silica fillers are the primary materials used in semiconductor packaging and high filler content is increasingly being used to suppress warpage caused by thermal expansion. However, in recent years, filler content has been approaching its limit, so in order to further reduce thermal expansion, we developed a negative thermal expansion filler that contracts when heated.

Examples of dimensional changes caused

Comparison of the coefficient of thermal expansion (CTE) of cured epoxy resin

■ Features
This product was developed using the inorganic material design technology that we have cultivated over many years. It overcomes problems found in conventional negative thermal expansion materials-such as narrow operating temperature range, non-spherical shape, high specific gravity, and high water absorption-thus enabling its application in semiconductor packaging. Its main features include:

• Significantly reduces thermal expansion when compounded in epoxy resins, etc.
• Negative thermal expansion characteristics over a wide temperature range from room temperature to 400°C
• Excellent fluidity and dispersibility due to its spherical shape
• Low alpha particle emission through impurity control (reduction of soft errors)
• Specific gravity and low water absorption comparable to general semiconductor fillers (silica fillers)
• Applications to semiconductor encapsulants, underfill materials, build-up film materials, etc.

Furthermore, by leveraging synergies with our existing epoxy resin business, we plan to not only offer fillers individually, but also in masterbatches mixed with epoxy resin, etc. This will also help shorten our customers' material design and development timelines.

Through this product, we will provide new solutions in the semiconductor materials market-which is expected to grow as demand for AI and data centers expands-and contribute to the sustainable development of society.

■ Reference information
· Product Website
https://www.m-chemical.co.jp/en/products/departments/mcc/nes/product/1216976_9004.html
· The Company presented this material at Electronic Components and Technology Conference 2026, an international conference in the semiconductor packaging field that was held in Orlando, Florida, USA in May 2026.
· The Company will be exhibiting at "SEMICON Taiwan 2026," a semiconductor industry trade show to be held in Taipei, Taiwan, from September 2 to 4, 2026, and will showcase this material at the event.
https://www.semicontaiwan.org/en