Integrated fan-out structure with guiding trenches in buffer layer

摘要

A bottom package includes a molding compound, a buffer layer over and contacting the molding compound, and a through-via penetrating through the molding compound. A device die is molded in the molding compound. A guiding trench extends from a top surface of the buffer layer into the buffer layer, wherein the guiding trench is misaligned with the device die.

主权项

1. A method comprising:
forming a first package comprising:
forming a through-via over a dielectric buffer layer;placing a device die over the dielectric buffer layer;encapsulating the device die and the through-via in an encapsulating material;planarizing the encapsulating material to expose the through-via and a metal pillar of the device die; andforming redistribution lines overlying and electrically coupling to the through-via and the metal pillar; flipping the first package upside-down; forming openings in the dielectric buffer layer to expose the through-via; and forming a guiding trench in the dielectric buffer layer.