Method for post-treating a substrate having an electrically conductive coating and at least one isolating line in the production process, wherein a) a substrate is provided having: - an electrically conductive coating on at least one surface of the substrate, - at least one isolating line in the electrically conductive coating, - at least one first subregion (2.1) and one second subregion (2.2) of the coating, between which the isolating line runs, - at least one defect (3.1) of the isolating line, in the region of which the local sheet resistance is lower than the sheet resistance of the isolating line outside the defect (3.1) b) a first electric contact (4.1) is electrically conductingly connected to the first subregion (2.1) and a second electric contact (4.2) is electrically conductingly connected to the second subregion (2.2) of the electrically conductive coating, c) a voltage U n is applied between the first electric contact (4.1) and the second electric contact (4.2), d) a measurement is taken using the first electric contact (4.1) and the second electric contact (4.2) whether an electric current is flowing between the first subregion (2.1) and the second subregion (2.2), e) if a current is flowing between the first subregion (2.1) and the second subregion (2.2), the steps c) and d) are repeated with a voltage greater than or equal to U n, until, in step d), a current can no longer be measured between the first subregion (2.1) and the second subregion (2.2), wherein the areal proportion of the defect (3.1) to the total surface area of the isolating line is less than 10%, wherein the electric current causes a thermal decomposition of the electrically conductive coating in the region of the defect (3.1). a) a substrate is provided having: - an electrically conductive coating on at least one surface of the substrate, - at least one isolating line in the electrically conductive coating, - at least one first subregion (2.1) and one second subregion (2.2) of the coating, between which the isolating line runs, - at least one defect (3.1) of the isolating line, in the region of which the local sheet resistance is lower than the sheet resistance of the isolating line outside the defect (3.1) - an electrically conductive coating on at least one surface of the substrate, - at least one isolating line in the electrically conductive coating, - at least one first subregion (2.1) and one second subregion (2.2) of the coating, between which the isolating line runs, - at least one defect (3.1) of the isolating line, in the region of which the local sheet resistance is lower than the sheet resistance of the isolating line outside the defect (3.1) b) a first electric contact (4.1) is electrically conductingly connected to the first subregion (2.1) and a second electric contact (4.2) is electrically conductingly connected to the second subregion (2.2) of the electrically conductive coating, c) a voltage U n is applied between the first electric contact (4.1) and the second electric contact (4.2), d) a measurement is taken using the first electric contact (4.1) and the second electric contact (4.2) whether an electric current is flowing between the first subregion (2.1) and the second subregion (2.2), e) if a current is flowing between the first subregion (2.1) and the second subregion (2.2), the steps c) and d) are repeated with a voltage greater than or equal to U n, until, in step d), a current can no longer be measured between the first subregion (2.1) and the second subregion (2.2), wherein the areal proportion of the defect (3.1) to the total surface area of the isolating line is less than 10%, wherein the electric current causes a thermal decomposition of the electrically conductive coating in the region of the defect (3.1).