Method for manufacturing grain-oriented electrical steel sheet

1. A method for manufacturing a grain-oriented electrical steel sheet comprising the steps of:

forming a film on one surface or both surfaces of a steel sheet; and

performing etching on the steel sheet where the film is formed such that a groove depth of the steel sheet is 10 μm to 30 μm, and an erosion length of the steel sheet under the film is 2 to 4.5 times of the groove depth,

wherein a steel sheet exposed portion where a portion of the steel sheet is exposed is formed in the film, and

the steel sheet exposed portion has a first region oriented in a sheet width direction, and a plurality of second regions starting from the first region, widths of the first region and the second regions being 20 μm to 100 μm, and a distance from an end portion of one of the second regions to an end portion of another of the second regions adjacent thereto being 60 μm to 570 μm.

2. The method for manufacturing a grain-oriented electrical steel sheet according to claim 1 , wherein the etching is electrolytic etching, the electrolytic etching being performed by using a sodium chloride aqueous solution having a concentration of 10 mass % to 20 mass % as an etching solution under such conditions that a solution temperature is 40° C. to 50° C., a current density is 0.1 A/cm 2 to 10 A/cm 2 , and an electrolytic time length is 10 s to 500 s.

3. The method for manufacturing a grain-oriented electrical steel sheet according to claim 1 , wherein the etching is non-electrolytic etching, the non-electrolytic etching being performed by using a ferric chloride aqueous solution having a concentration of 30 mass % to 40 mass % as an etching solution under such conditions that a solution temperature is 40° C. to 50° C., and an immersion time length is 10 min to 25 min.