US Patent 9337135 Pop joint through interposer

A package includes a package component and an interposer over and bonded to the package component. The package component includes a solder region. The interposer includes a core dielectric material, a conductive pipe penetrating through the core dielectric material, with the first solder region in contact with a bottom end of the conductive pipe, and a through-opening in a center region of the interposer.