Substrate with conducting vias

A component for electrical or electronic use comprises a laminar substrate 1 having first and second opposed major surfaces with at least one electrically conductive path or via 9 extending therebetween, said path being provided by a through substrate hole 7 extending between the first and second surfaces, electrically conductive material filling said hole or providing a conductive layer 9 over the internal surface of the hole and extending across the base of said hole at the first surface, wherein an electrically insulating stop layer 4 extends over the first surface but is pierced by at least one access hole 12 allowing external contact with said conductive material, leaving at least a portion of the base of said through substrate hole covered by the insulating layer 4. One application is the provision of a detector array, where the detectors are mounted on the second surface and readout circuitry is mounted on the first surface.