Integrated Circuit Package and Method

A device comprising:

• an interposer;
• a first integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds;
• a second integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds;
• a buffer layer around the first integrated circuit device and the second integrated circuit device, the buffer layer comprising a stress reduction material having a first Young's modulus;
• and
• an encapsulant around the buffer layer, the first integrated circuit device, and the second integrated circuit device, the encapsulant comprising a molding material having a second Young's modulus, the first Young's modulus less than the second Young's modulus.

A device comprising:

• an interposer;
• a first integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds;
• a second integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds;
• a buffer layer having a gap portion and fillet portions, the gap portion disposed between the first integrated circuit device and the second integrated circuit device, the fillet portions disposed along outer edges of the first integrated circuit device and the second integrated circuit device;
• and
• an encapsulant around the buffer layer, the first integrated circuit device, and the second integrated circuit device, the encapsulant having a different Young's modulus, a different coefficient of thermal expansion, a different filler load, and a different average filler particle size, and a different elongation than the buffer layer.