Electronic devices are manufactured using a collective (wafer-scale) fabrication process. Electronic chips are mounted onto one face of a collective substrate wafer. A collective flexible sheet made of a heat-conductive material comprising a layer containing pyrolytic graphite is fixed to extend over a collective region extending over the electronic chips and over the collective substrate wafer between the electronic chips. The collective flexible sheet is then compressed. A dicing operation is then carried out in order to obtain electronic devices each including an electronic chip, a portion of the collective plate and a portion of the collective flexible sheet.