Contoured package-on-package joint

摘要

A contoured package on package joint and a method for making the same are disclosed herein. A method for forming a device comprises providing a substrate having a package land and forming a mounting stud on the package land. A molded underfill is applied to the substrate and in contact with the mounting stud. A contoured stud surface is formed on the mounting stud is contoured and connecting member attached to the contoured stud surface with a second package attached to the connecting member. The connecting member may be solder and have a spherical shape. The contoured stud surface may be etched or mechanically formed to have a hemispherical shape conforming to the connecting member shape.

主权项

1. A device, comprising:
a package land disposed on a first side of a substrate; a mounting stud disposed on and in electrical contact with the package land, the mounting stud having a recessed contoured stud surface extending from a first sidewall to a second sidewall of the mounting stud, wherein the first sidewall is straight; and a molded underfill (MUF) disposed at the first side of the substrate and covering at least a portion of the mounting stud, the MUF extending along sidewalls of the mounting stud, the recessed contoured stud surface extending lower than an uppermost surface of the MUF.