A printed circuit board comprising: a top conductive layer; a bottom conductive layer; a plurality of electronic components (40, 42, 44) arranged on at least one of the top conductive layer or the bottom conductive layer; and a heater layer interposed between the top conductive layer and the bottom conductive layer and configured to generate and transfer heat to at least one of the electronic components; the heating layer comprising an input via and an an output via; the printed circuit board comprising a plurality of heating layers (81,82) comprising the heating layer, the heating layers being interposed between the top conductive layer and the bottom conductive layer; the printed circuit board being characterised in that the pluralty of heating layers comprises: a horizontal heating layer comprising a horizontal conductive pattern, the horizontal conductive pattern comprising a plurality of conductive traces arranged in substantially parallel lines along a horizontal direction of the printed circuit board and electrically coupled in series between the input viia and the output via by a plurality of connecting traces; and a vertical heating layer comprising a vertical conductive pattern, the vertical conductive pattern comprising another plurality of conductive traces arranged in substantially parallel lines along a vertical direction of the printed circuit board and electrically coupled in series between the input via and the output via by another plurality of connecting traces; wherein the horizontal heating layer and the vertical heating layer are arranged so that one of the horizontal heating layer or the vertical heating layer overlaps the other to form a heater grid. a top conductive layer; a bottom conductive layer; a plurality of electronic components (40, 42, 44) arranged on at least one of the top conductive layer or the bottom conductive layer; and a heater layer interposed between the top conductive layer and the bottom conductive layer and configured to generate and transfer heat to at least one of the electronic components; the heating layer comprising an input via and an an output via; the printed circuit board comprising a plurality of heating layers (81,82) comprising the heating layer, the heating layers being interposed between the top conductive layer and the bottom conductive layer; the printed circuit board being characterised in that the pluralty of heating layers comprises: a horizontal heating layer comprising a horizontal conductive pattern, the horizontal conductive pattern comprising a plurality of conductive traces arranged in substantially parallel lines along a horizontal direction of the printed circuit board and electrically coupled in series between the input viia and the output via by a plurality of connecting traces; and a vertical heating layer comprising a vertical conductive pattern, the vertical conductive pattern comprising another plurality of conductive traces arranged in substantially parallel lines along a vertical direction of the printed circuit board and electrically coupled in series between the input via and the output via by another plurality of connecting traces; wherein the horizontal heating layer and the vertical heating layer are arranged so that one of the horizontal heating layer or the vertical heating layer overlaps the other to form a heater grid. a horizontal heating layer comprising a horizontal conductive pattern, the horizontal conductive pattern comprising a plurality of conductive traces arranged in substantially parallel lines along a horizontal direction of the printed circuit board and electrically coupled in series between the input viia and the output via by a plurality of connecting traces; and a vertical heating layer comprising a vertical conductive pattern, the vertical conductive pattern comprising another plurality of conductive traces arranged in substantially parallel lines along a vertical direction of the printed circuit board and electrically coupled in series between the input via and the output via by another plurality of connecting traces; wherein