Insulating sheet and method for its preparation and the insulating sheet exhibiting power module

Insulating sheet, which comprises: - an inner portion (7c) comprising a thermosetting resin; and - an adhesive surface portion (7b) to at least one side of the interior region (7c), wherein the inner area (7c) and the adhesive area (7b) comprise a filler member, which includes either a flattened filler (71) and a granular filler (72) or has a flattened filler (71), and - wherein the insulating sheet (7) is formed by a continuous layer such that the concentrations of the Fullstoffelements stepwise or gradually in a direction from the adherent surface area (7b) increases the insulating sheet to an inside thereof, and wherein the insulating sheet (7) is a laminate in the A or B-stage.