Abstract: This invention realizes the improvement of the surface properties and the magnetic characteristics in such a way that a large amount of Si of 3.1-4.5% is incorporated into a raw material, a small amount of Al and a very small amount of S or Se are used as inhibitor together with Mo, and the slab heating is so performed at a temperature of not lower than 1,270.degree. C. that the scale loss may reach 2.7-5.0%, whereby the inhibitor is fully dissociated and solid-solved to conspicuously strengthen the growth inhibiting effect against the primary recrystallization grains in the secondary recrystallization annealing for promoting the growth of the secondary recrystallization grains in the {110}<001> orientation, thereby forming the secondary recrystallization texture extremely strongly arranged in the {110}<001> orientation, so that a high magnetic flux density and a low iron loss is attained with effectively preventing cracks in hot rolling after slab soaking.

Abstract: A substrate for print circuit board comprising a steel sheet, a forsterite film layer formed on at least one surface of the steel sheet, and an insulating film layer formed on the forsterite film layer by baking a coating solution mainly consisting of a phosphate and colloidal silica. A print circuit board having a conductive pattern on the insulating film layer of the substrate for print circuit board, and methods of manufacturing the substrate and the print circuit board. One of typical methods of manufacturing the substrate for print circuit board comprises steps of applying an annealing separator mainly consisting of MgO on the steel sheet and annealing it to form a forsterite film layer, applying and baking a coating solution mainly consisting of the phosphate and colloidal silica onto the forsterite film layer to form an insulating film layer. The print circuit board is obtained by bonding the conductive pattern to the insulating film layer and annealing at a temperature range of not lower than 300.