【Company Information】Announcement of expansion of large-diameter isotropic graphite products


Toyo Tanso Co., Ltd. (hereinafter called "Toyo Tanso") announces that it has decided to make capital investments to increase the manufacturing capacity of large diameter graphite products at its Takuma Plant (Mitoyo City, Kagawa Prefecture) in order to prepare for increased demand for isotropic graphite products used in the electronics field, such as in the manufacturing process of silicon wafers.

1. Background of Investment

Our Advanced Materials business is engaged in the manufacture and sale of graphite products, which are used as structural components in the manufacturing process of silicon wafers for semiconductors.
Silicon wafers, which form the basis of semiconductor devices in preparation for the increase in demand for semiconductors due to the development of the IoT, AI and other technologies, are becoming larger in diameter to improve productivity, and demand for large-diameter isotropic graphite products is increasing.
Under these circumstances, as part of our global growth strategy, we will expand our building and add graphite materials and processing facilities to strengthen our manufacturing capabilities for large-diameter graphite products.

Takuma plant(Mitoyo city, Kagawa prefecture)

2. Outline of Investment

Investment Place: Takuma plant (Mitoyo city, Kagawa Prefecture)
Investment Contents: Investment in equipment for the manufacture and processing of isotopic graphite
Investment Amount: approximately JPY 3.5billion
Operation Time:August, 2021

About Isotropic Graphite product for Monocrystalline silicon manufacturing equipment

When pulling monocrystalline silicon, melting temperature is extremely high at approximately 1500°C, but isotropic graphite's excellent thermal durability helps extend product life.
Isotropic Graphite products in Monocrystalline silicon manufacturing equipment (cross section model)


  • Excellent thermal durability
  • Excellent thermal conductivity
  • High density
  • High strength
  • Lightweight
  • Little variation in characteristics enables stable use
  • Ultra-high-purity treatment possible
  • Product examples


    To protect the quartz crucible used in the manufacture of single crystal silicon, many manufacturers are using our high purified isotropic graphite as it provides high strength and minimal wear.


    Graphite can be purified down to the ppm order as well as easily machined to complicated forms. It is an absolutely necessary material for the heating elements used in semiconductor manufacture.