One or more integrated circuits (ICs) are often implemented as an IC package. During manufacturing of an electronic device, multiple packages may be combined in a package-on-package (PoP) configuration. The PoP manufacturing process typically includes disposing solder balls on an array of contacts on a first package (i.e., a ball grid array (BGA)), placing a second package on the BGA, and reflowing the solder to create electrical and mechanical connections between the two packages. An interposer with at least one BGA may be used to connect two packages. For example, two packages may include BGAs of different solder ball spacing (e.g., solder ball pitch) or different arrangements of solder ball, and an interposer may include a first BGA pitch to connect to a first package, and a second BGA pitch to connect to a second package.
Due to requirements for minimum solder ball spacing (e.g., requirements for minimum pitch), the reduction in size of PoP architecture is limited to minimum requirements for the PoP interconnect pitch. In an example, in order to provide enough standoff height for the die thickness, the solder balls used for PoP interconnect need to be larger than certain minimum solder ball size. This minimum solder ball size limits the density of solder balls (e.g., PoP pitch) that can be placed within an area. Typically, PoP pitch based on through-mold via (TMV) or through-silicon via (TSV) architecture includes a minimum pitch of approximately 350 μm between solder ball contacts. The solder ball size and package heights also result in a minimum PoP z-height. It is desirable to improve the PoP interconnect pitch and reduce the PoP z-height to allow for a further reduction in size of PoP architecture.