Stacked-die package structure

A stacked-die package structure, comprising:

• a carrier having an upper surface and a back surface opposite to the upper surface;
• a plurality of dies stacked one by one on the upper surface of the carrier, and a plurality of bonding pads located on a top surface of each die along the periphery of each die;
• at least one spacer located between two adjacent dies, wherein a top surface and a bottom surface of the spacer face the two adjacent dies, respectively, and the spacer is made of material having a thermal expansion coefficient approximate to the thermal expansion coefficient of the dies;
• a plurality of adhesive layers located between the spacers, the dies, the carrier, wherein at least along a periphery of the top surface, a bottom surface or both surfaces of each die, and a side surface of the spacer are not covered by the adhesive layers;
• a plurality of conducting lines respectively electrically connecting the bonding pads to the carrier;
• and
• a mold compound formed over the upper surface of the carrier, for encapsulating the spacers, the dies and the adhesive layers.