A manufacturing method of a grain-oriented electrical steel sheet according to an embodiment of the present invention includes producing a cold-rolled plate; forming a groove in the cold-rolled plate; performing primary recrystallization annealing to the cold-rolled plate; and applying an annealing separator to the primary-recrystallized cold-rolled plate and performing secondary recrystallization annealing, wherein a weight ratio of SiO.sub.2/Fe.sub.xSiO.sub.y of the surface layer part of the cold-rolled plate is 0.3 to 3 after the primary recrystallization annealing of the cold-rolled plate. (Here, x is an integer from 1 to 2, and y is an integer from 2 to 4.)

A manufacturing method of a grain-oriented electrical steel sheet according to an embodiment of the present invention includes producing a cold-rolled plate; forming a groove in the cold-rolled plate; performing primary recrystallization annealing to the cold-rolled plate; and applying an annealing separator to the primary-recrystallized cold-rolled plate and performing secondary recrystallization annealing, wherein a weight ratio of SiO.sub.2/Fe.sub.xSiO.sub.y of the surface layer part of the cold-rolled plate is 0.3 to 3 after the primary recrystallization annealing of the cold-rolled plate. (Here, x is an integer from 1 to 2, and y is an integer from 2 to 4.)

A grain oriented electrical steel sheet comprising a grain oriented electrical steel sheet having a surface and a forsterite film formed on the surface of the steel sheet, wherein a total area percentage of defective parts scattered on the forsterite film is less than 1.5% relative to a surface area of the forsterite film when viewed from above the surface, and methods for evaluating a grain oriented electrical steel sheet comprising a grain oriented electrical steel sheet having a surface and a forsterite film formed on the surface of the steel sheet.

A grain oriented electrical steel sheet comprising a grain oriented electrical steel sheet having a surface and a forsterite film formed on the surface of the steel sheet, wherein a total area percentage of defective parts scattered on the forsterite film is less than 1.5% relative to a surface area of the forsterite film when viewed from above the surface, and methods for evaluating a grain oriented electrical steel sheet comprising a grain oriented electrical steel sheet having a surface and a forsterite film formed on the surface of the steel sheet.

A pre-coating agent composition for a grain-oriednted electrical steel sheet, a grain-oriednted electrical steel sheet including the same, and a manufacturing method thereof are provided. Particularly, a pre-coating agent composition for a grain-oriednted electrical steel sheet including an acid containing boron (B); and a solvent, a grain-oriednted electrical steel sheet including the same, and a manufacturing method thereof are provided.

A linear groove formation method including forming a coated resist on a surface of a steel sheet, irradiating two or more laser beams onto the surface of the steel sheet while scanning the laser beams in a direction intersecting the rolling direction of the steel sheet cyclically in a rolling direction of the steel sheet, and forming linear grooves by etching portions of the steel sheet. In the laser irradiating process, the coated resist is removed continuously in a sheet transverse direction of the steel sheet by using the laser beams irradiated from respective ones of two or more laser irradiation devices arranged in the sheet transverse direction, and the laser beams are irradiated by shifting centers of two of the laser beams irradiated from two of the laser two of the laser irradiation devices adjacent to each other in the sheet transverse direction.

Provided are a composite sheet for shielding a magnetic field and an electromagnetic wave, and an antenna module using the same, which can block influence of a magnetic field on a main body and a battery of a mobile terminal block device, and the like, and simultaneously shield an electromagnetic wave, by significantly reducing a loss due to an eddy current by flaking an amorphous ribbon sheet. The composite sheet includes: a magnetic sheet; and a conductor sheet stacked on the magnetic sheet for shielding an electromagnetic wave and radiating heat. The magnetic sheet includes: an amorphous ribbon sheet which is thermally treated, flaked, and then separated into a plurality of fine pieces; a protective film bonded to one side surface of the amorphous ribbon sheet; and an adhesive tape bonded to the other side surface of the amorphous ribbon sheet.

Provided are a composite sheet for shielding a magnetic field and an electromagnetic wave, and an antenna module using the same, which can block influence of a magnetic field on a main body and a battery of a mobile terminal block device, and the like, and simultaneously shield an electromagnetic wave, by significantly reducing a loss due to an eddy current by flaking an amorphous ribbon sheet. The composite sheet includes: a magnetic sheet; and a conductor sheet stacked on the magnetic sheet for shielding an electromagnetic wave and radiating heat. The magnetic sheet includes: an amorphous ribbon sheet which is thermally treated, flaked, and then separated into a plurality of fine pieces; a protective film bonded to one side surface of the amorphous ribbon sheet; and an adhesive tape bonded to the other side surface of the amorphous ribbon sheet.

An embodiment of the present invention provides an electrical steel sheet including: an upper adhesive layer positioned on an upper surface of an electrical steel sheet; and an lower adhesive layer positioned on a lower surface of the electrical steel sheet, wherein the upper adhesive layer has a pencil hardness of F or lower, and the lower adhesive layer has a pencil hardness of H or higher.

A manufacturing method of a grain-oriented electrical steel sheet according to an embodiment of the present invention includes: manufacturing a cold-rolled sheet; forming a groove in the cold-rolled sheet; removing an Fe—O oxide formed on a surface of the cold-rolled sheet; primary recrystallization annealing the cold-rolled sheet; and applying an annealing separating agent to the primary recrystallized cold-rolled sheet, and secondary recrystallization annealing it, wherein a close contacting property coefficient calculated by Formula 1 below is 0.016 to 1.13.

close contacting property coefficient (S.sub.ad)=(0.8×R)/H.sub.hill-up  [Formula 1] (In Formula 1, R represents the average roughness (μm) of the surface of the cold-rolled sheet after the removing of the oxide, and H.sub.hill-up represents the average height (μm) of the hill-up present on the surface of the cold-rolled sheet after the removing of the oxide.)