A power module (1) is disclosed, comprising: first and second substrates (10), each substrate patterned layer of electrically conductive material (12), a plurality of pre-packed power cells (20), positioned between the substrates, each cell comprising: an electrically insulating core (21) embedding at least one power die (22), and two external layers (23) of electrically conductive material on opposite sides of the electrically insulating core (21), said external layers being respectively connected to each patterned layers of the substrates, wherein each external layer of a pre-packed power cell comprises a contact pad (230) connected to a respective contact (220) of the power die through connections arranged in the electrically insulating core (21), said contact pad having a surface area greater than the surface area of the power die electrical contact to which it is connected.