A device is disclosed. The device includes a first die, a plurality of chiplets above the first die, a first underfill material beneath the chiplets, and a gap fill material between the chiplets. The gap fill material is different from the first underfill material. An interface region is formed between the first underfill material and the gap fill material.

A device is disclosed. The device includes a first die, a plurality of chiplets above the first die, a first underfill material beneath the chiplets, and a gap fill material between the chiplets. The gap fill material is different from the first underfill material. An interface region is formed between the first underfill material and the gap fill material.

A device is disclosed. The device includes a first die, a plurality of chiplets above the first die, a first underfill material beneath the chiplets, and a gap fill material between the chiplets. The gap fill material is different from the first underfill material. An interface region is formed between the first underfill material and the gap fill material

A device is disclosed. The device includes a first die, a plurality of chiplets above the first die, a first underfill material beneath the chiplets, and a gap fill material between the chiplets. The gap fill material is different from the first underfill material. An interface region is formed between the first underfill material and the gap fill material

Embodiments include an encapsulation material, one or more semiconductor packages, and methods of the semiconductor packages. A semiconductor package including dies disposed on a package substrate. The semiconductor package also includes at least one of an underfill layer, a mold layer, and a dielectric layer on or in the package substrate. The semiconductor package further includes an encapsulation material having a fluorescent chemical compound and an epoxy. The encapsulation material may be incorporated into at least one of the underfill layer, the mold layer, and/or the dielectric layer on or in the package substrate. The fluorescent chemical compound of the encapsulation material may include at least one of a poly(vinylcarbazole) (PVCz), a 1,4-Bis(5-phenyl-2-oxazolyl) benzene (POPOP), and/or a plurality of conjugated, aromatic molecules and polymers. The encapsulation material may include at least one of a hardener, a filler, an additive, and/or a polymer.

Embodiments include an encapsulation material, one or more semiconductor packages, and methods of the semiconductor packages. A semiconductor package including dies disposed on a package substrate. The semiconductor package also includes at least one of an underfill layer, a mold layer, and a dielectric layer on or in the package substrate. The semiconductor package further includes an encapsulation material having a fluorescent chemical compound and an epoxy. The encapsulation material may be incorporated into at least one of the underfill layer, the mold layer, and/or the dielectric layer on or in the package substrate. The fluorescent chemical compound of the encapsulation material may include at least one of a poly(vinylcarbazole) (PVCz), a 1,4-Bis(5-phenyl-2-oxazolyl) benzene (POPOP), and/or a plurality of conjugated, aromatic molecules and polymers. The encapsulation material may include at least one of a hardener, a filler, an additive, and/or a polymer.