Prepreg mica tapes are semi-cured tape made with calcined muscovite mica paper impregnated with heat resistant epoxy resin. They are bonded to various supporting materials such as glass cloth,polyester film and polyester fleece. When the prepreg mica tape is subjected to heat and pressure after it is wound on coils,the resin flows and then hardens to form a void-free insulating material. Since it is in semi-cured form,it is necessary to store at below 10℃ and used within 3 months.