Integrated fan-out structure with openings in buffer layer

摘要

A package includes a molding compound, a through-via penetrating through the molding compound, a device die molded in the molding compound, and a buffer layer on and contacting the molding compound. An opening is through the buffer layer to the through-via. The buffer layer has ripples in a plane parallel to an interface between the molding compound and the buffer layer and around a circumference of the opening. Other embodiments contemplate an additional package bonded to the package, and methods for forming the package.

主权项

1. A structure comprising: a first package comprising: a molding compound; a through-via penetrating through the molding compound; a device die molded in the molding compound; and a buffer layer on and contacting the molding compound, an opening being through the buffer layer to the through-via, the buffer layer having ripples in a plane parallel to an interface between the molding compound and the buffer layer and around a circumference of the opening, wherein a peak and a valley of the ripples are both disposed in the plane parallel to the interface between the molding compound and the buffer layer, and a guiding trench, wherein the guiding trench forms a ring, and wherein the guiding trench completely encircles a center portion of the buffer layer in a top-down view of the structure, with the center portion of the buffer layer overlapping an entirety of the device die.