Forming sacrificial composite materials for package-on-package architectures and structures formed thereby
Methods of forming a microelectronic packaging structure are described. Those methods may include forming a solder paste comprising a sacrificial polymer on a substrate, curing the solder paste below a reflow temperature of the solder to form a solid composite hybrid bump on the conductive pads, forming a molding compound around the solid composite hybrid bump, and reflowing the hybrid bump, wherein the sacrificial polymer is substantially decomposed.
1. A structure comprising:
a solder disposed on a conductive pad of a substrate;
a polymer disposed in contact with a surface of the solder;
a molding compound disposed on the substrate and spaced apart from the surface of the solder;
wherein the polymer has a thermal decomposition temperature that is no greater than a reflow temperature of the solder; and
wherein the surface of the solder is separated from the molding compound by the polymer.
2. The structure of claim 1 , wherein the polymer comprises a curable polymer, and has a cure temperature that is less than a reflow temperature of the solder.
3. The structure of claim 1 , wherein the polymer comprises a polynorbornene material.
4. The structure of claim 1 , wherein the polymer comprises a polycarbonate material.
5. The structure of claim 1 , wherein the polymer has a density that is lower than that of the solder.