| 摘要 |
PURPOSE:To improve adhesiveness between a resin layer and a steel plate by a method wherein a specific plating layer is applied to the surface of the steel plate and a chromate treatment is applied to the plating layer and a metal foil is laminated with the insulating layer between. CONSTITUTION:A plating layer 2 of one or two metals among Gr, Cu, Ni, Zn and Sn is formed on the surface of a steel plate 1 and a chromate layer 3 is formed on it and a metal foil 5 is laminated on the chromate layer 3 with an insulating layer 4 between to constitute an iron board. The steel plate with a thickness of 0.3-2.0mm is used. If the thickness is less than 0.3mm, heat radiation is not sufficient. If the thickness exceeds 2.0mm, satisfactory motor characteristics can not be obtained when the iron board is used as a magnetic path of a miniature motor. As for the composition of the steel plate, if only the heat radiation and the mechanical strength are to be considered, common steel is good enough. But, if the iron board is used as the magnetic path of the miniature motor, a silicon-steel plate containing 0.5-3. 5% of silicon is employed. One or two metals among Cr, Cu, Zn, Ni and Sn are applied to the surface of such steel plate with a thickness of 0.5g/m<2>-3.0g/m<2> by electrolytic plating and a chromate treatment is applied to the plating with a thickness of 10-100mg/m<2> in metal chrome conversion. With this constitution, adhesiveness between the resin layer and the steel plate 1 can be improved. |
