Denka Company Limited

Koki Ikarashi

Koji Nishimura

Hideki Hirotsuru

Toshikatsu Mitsunaga

Shuhei Nonaka

Taiki Nishi

Mitsuru Shiiba

Junichi Tatami

Saori Inoue

Makoto Takeda

Midori Sotokawa

Kouji Miyata

Fumiya Kobayashi

A resin-impregnated boron nitride sintered body having superior thermal conductivity and superior strength, and a resin-impregnated boron nitride sintered body having superior conductivity and small anisotropy of thermal conductivity are provided. A resin-impregnated boron nitride sintered body, including: 30 to 90 volume % of a boron nitride sintered body having boron nitride particles bonded three-dimensionally; and 10 to 70 volume % of a resin; wherein the boron nitride sintered body has a porosity of 10 to 70%; the boron nitride particles of the boron nitride sintered body has an average long diameter of 10 &#x3bc;m or more; the boron nitride sintered body has a graphitization index by powder X-ray diffractometry is 4.0 or less; and an orientation degree of the boron nitride particles of the boron nitride sintered body by I.O.P is 0.01 to 0.05 or 20 to 100; and a resin-impregnated boron nitride sintered body, including: 30 to 90 volume % of a boron nitride sintered body having boron nitride particles bonded three-dimensionally is provided.

Resin-impregnated boron nitride sintered body and use for same

There is provided a method for producing hexagonal boron nitride, including a heating step of heating a mixture containing boron carbide and an alkaline earth metal compound under an ammonia atmosphere at 1300-1500&#xb0; C. to obtain a product containing hexagonal boron nitride, wherein a molar ratio of the boron carbide to the alkaline earth metal compound in the mixture is 0.5-2.0.

Method for producing hexagonal boron nitride, and heat dissipation sheet

Provided is a boron-nitride powder that is suitable for use in a resin composition for transmitting heat from a heat-producing electronic component such as a power device to a heat-dissipating member. The boron-nitride powder reduces thermal-conductivity anisotropy and thermal contact resistance, resulting in high thermal conductivity, and contains boron-nitride particles each consisting of hexagonal boron-nitride primary particles joined together. The boron-nitride powder, which is an aggregate of said boron-nitride particles, exhibits a mean sphericity of at least 0.70, a mean particle diameter of 20-100 &#x3bc;m, a porosity of 50-80%, a mean pore diameter of 0.10-2.0 &#x3bc;m, a maximum pore diameter of at most 10 &#x3bc;m, and a calcium content of 500-5,000 ppm. Under X-ray powder diffraction, the graphitization index of the boron-nitride powder is preferably between 1.6 and 4.0, inclusive, and the peak intensity ratio (I(002)/I(100)) between the (002) plane and the (100) plane is preferably at most 9.0.

Boron-nitride powder and resin composition containing same

A boron nitride/resin composite circuit board having high heat dissipation characteristics and high reliability is provided. A boron nitride/resin composite circuit board, including: a plate-shaped resin-impregnated boron nitride sintered body having a plate thickness of 0.2 to 1.5 mm, the plate-shaped resin-impregnated boron nitride sintered body including 30 to 85 volume % of a boron nitride sintered body having boron nitride particles bonded three-dimensionally, the boron nitride particles having an average long diameter of 5 to 50 &#x3bc;m, and 70 to 15 volume % of a resin; and a metal circuit adhered onto both principal planes of the plate-shaped resin-impregnated boron nitride sintered body, the metal circuit being copper or aluminum, wherein: a ratio of a linear thermal expansion coefficient in a plane direction of the resin-impregnated boron nitride sintered body at 40 to 150&#xb0; C. (CTE1) and a linear thermal expansion coefficient of the metal circuit at 40 to 150&#xb0; C. (CTE2) (CTE1/CTE2) is 0.5 to 2.0.

Boron nitride/resin composite circuit board, and circuit board including boron nitride/resin composite integrated with heat radiation plate

Growing community of inventors

Omuta, Japan

Koki Ikarashi