Preparation method of a thin power device

A preparation method of a thin power device comprising the steps of:

• step S1, providing a substrate comprising a first set of first contact pads and a second set of second contact pads arranged at a front surface and a back surface of the substrate respectively, wherein each first contact pad of the first set of contact pads is electrically connected with a respective second contact pad of the second set of contact pads via a respective interconnecting structure formed inside the substrate;
• and a through opening formed in the substrate aligning with a third contact pad attached to the back surface of the substrate, wherein the third contact pad is not electrically connected with the first set of contact pads;
• step S2, embedding a semiconductor chip into the through opening, wherein a back metal layer at a back surface of the semiconductor chip is attached to the third contact pad;
• and
• filling an underfill material in a gap between edges of the through opening and a periphery of the semiconductor chip;
• and
• step S3, electrically connecting a respective electrode of a plurality of electrodes at a front surface of the semiconductor chip with said each first contact pad of the first set of contact pads via a respective conductive structure of a plurality of conductive structures;
• and
• electrically connecting a selected electrode of the plurality of electrodes at the front surface of the semiconductor chip with a selected first contact pad in the first set of contact pads closest to the selected electrode via an aerosol jet printed strip positioned atop the front surface of the substrate, a top surface of the underfill material and a passivation layer at the front surface of the semiconductor chip.