In a method of determining the distance (d) between an integrated circuit (1) and a substrate (2) emitted light enters the at least semi transparent substrate (2), passes through the substrate (2) and an at least semi transparent material (8), is reflected by the integrated circuit (1), passes again through the material (8) and the substrate (2), and leaves the substrate (2). The at least semi transparent material (8), particularly is an at least semi transparent adhesive, provided between the substrate (2) and the integrated circuit (1). The distance (d) between the substrate (2) and the integrated circuit (1) is determined by evaluating the intensities of the light leaving and entering the substrate (2), particularly by evaluating the ratio between the intensities of the light leaving and entering the substrate (2).