Mitsubishi Chemical launches M‑Filleris™ NTE negative thermal expansion filler
- M‑Filleris™ NTE is a negative thermal expansion filler developed for semiconductor packaging.
- Pilot product sales begin by the end of FY2026; mass-production sales are planned for the second half of FY2027.
- Exhibits negative thermal expansion from room temperature to 400°C and reduces thermal expansion when compounded into epoxy resins.
- Spherical particles with low alpha emission, low water absorption and specific gravity comparable to silica; aimed at encapsulants, underfill and build-up films.
Background
Demand for higher-performance semiconductors driven by AI servers and high-performance computing, and adoption of chiplet and 3D stacking technologies, has increased heat generation and package warpage. With filler content in epoxy resins approaching practical limits, Mitsubishi Chemical developed a negative thermal expansion (NTE) filler that contracts when heated to further reduce thermal expansion.
Product and timing
The company commercialized the material under the brand name M‑Filleris™ NTE. Pilot products will be sold by the end of FY2026, followed by customer evaluations and certifications, with mass-production sales scheduled for the second half of FY2027. The M‑Filleris series will later include other functional fillers for heat dissipation and electrical properties.
Technical features
Developed via inorganic material design technology, the filler provides negative thermal expansion from room temperature to 400°C and significantly reduces CTE when compounded with epoxy resins. It is manufactured as spherical particles for improved fluidity and dispersibility, has specific gravity and low water absorption comparable to silica fillers, and features impurity control to lower alpha particle emission.
Applications and go‑to‑market
Target applications include semiconductor encapsulants, underfill materials and build-up films. Mitsubishi Chemical plans to offer the filler both as a powder and in masterbatches mixed with epoxy resin to shorten customers' material design and development timelines.
Presentations and events
The material was presented at the Electronic Components and Technology Conference 2026 in May 2026 and will be showcased at SEMICON Taiwan, scheduled for September 2–4, 2026.
Source: Mitsubishi
