| 摘要 |
PROBLEM TO BE SOLVED: To provide high luminous efficiency which is stable at high temperatures by forming a thermal radiation body made of carbon material, having fine nonlinear continuous holes with an average hole diameter and porosity in a specific range. SOLUTION: An average hole diameter is 0.1-5μm, and a porosity is 30-80%. A polyimide precursor is deposited and increased in porosity by abutting a film of a precursor solution of polyimide on a solidifying solvent via a solvent substitution speed adjustment material. It is formed into a polyimide film having fine continuous holes, thereafter carbonized by processing it at a high temperature and is further graphatized, so that this heat radiator is provided. It is desirable that the temperature for carbonizing and further graphatizing the polymer be 2,900 deg.C or higher, and the high-temperature processing is carried out in an anaerobic atmosphere such as nitrogen, argon or helium. The polyimide precursor is a polyamic acid obtained by polymerizing a tetracarboxylic acid constituent and a diamine constituent, desirably a monomer belonging to an aromatic compound, or a substance obtained by partially converting it into an imide. It is formed into a polyimide resin by closing a ring through heat treatment.
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