Abstract: A method of making an electrical connection between a first (top) and a second (bottom) surface of a conducting or semi-conducting substrate includes creating a trench in the first surface, and establishing an insulating enclosure entirely separating a portion of the substrate, defined by the trench. Also described is a product usable as a starting substrate for the manufacture of micro-electronic and/or micro-mechanic devices, including a flat substrate of a semi-conducting or conducting material, and having a first and a second surface and at least one electrically conducting member extending through the substrate. The electrically conducting member is insulated from surrounding material of the flat substrate by a finite layer of an insulating material, and includes the same material as the substrate, i.e. it is made from the wafer material.