PURPOSE: To eliminate the variation of the fusing time of organic semiconductor and facilitate impregnating capacitor elements immediately after the fusion of the organic semiconductor in a short time by a method wherein the mixed solution of primary liquid composed of inert high boiling point organic compound and secondary liquid composed of inert low boiling point organic compound whose boiling point is lower than the former one is employed.
CONSTITUTION: Primary liquid 2 composed of inert high boiling point organic compound and secondary liquid 3 composed of inert low boiling point organic compound whose boiling point is lower than the former one are poured into a cylindrical vessel 1 with a bottom to constitute mixed solution 4. The mixed solution 4 is heated and the liquid 3 is vaporized first and cooled by a coil 7 and a secondary vapor layer 8 is formed. Then the liquid 2 is vaporized and cooled by a coil 6 and the vapor layer 8 and a primary vapor layer 9 is formed. At that time, the vapor layer 9 is always covered with the vapor layer 8. If a metal plate 11 is dipped into the vapor layer 9, TCNQ salt 12 absorbs vaporization latent heat before its temperature reaches the vapor temperature and is fused and liquefied almost simultaneously. Further, capacitor elements 13 are dipped into the vapor layer 9 and put into cases 10 to be impregnated with TCNQ salt 12.