Package on package structures and methods for forming the same

摘要

The described embodiments of mechanisms of forming a package on package (PoP) structure involve bonding with connectors with non-solder metal balls to a packaging substrate. The non-solder metal balls may include a solder coating layer. The connectors with non-solder metal balls can maintain substantially the shape of the connectors and control the height of the bonding structures between upper and lower packages. The connectors with non-solder metal balls are also less likely to result in bridging between connectors or disconnection (or cold joint) of bonded connectors. As a result, the pitch of the connectors with non-solder metal balls can be kept small.

主权项

1. A method of forming a semiconductor device package, comprising:
providing a substrate with a contact pad; bonding a metal ball to the contact pad to form a first bonding structure, wherein the metal ball comprises a non-solder material, wherein the bonded metal ball includes a solder layer over a surface of the non-solder material and an intermediate layer between the solder layer and the non-solder material, and the intermediate layer is configured to prevent formation of an intermetallic compound (IMC), wherein the non-solder material includes copper, aluminum, silver, gold, nickel, tungsten, alloys thereof, or combinations thereof, and the intermediate layer comprises titanium; bonding a semiconductor die to the substrate, wherein the semiconductor die is disposed next to the first bonding structure; bonding a die package, having a connector, to a surface of the substrate bonded with the semiconductor die, wherein the bonding the die package forms a second bonding structure between the connector on the die package and the metal ball bonded to the substrate; forming a molded underfill (MUF) on the substrate; and singulating a semiconductor device including the die package and the semiconductor die bonded to the substrate from a remaining portion of the substrate.