US Patent 11031364 Nanoparticle backside die adhesion layer

In described examples, a microelectronic device includes a microelectronic die with a die attach surface. The microelectronic device further includes a nanoparticle layer coupled to the die attach surface. The nanoparticle layer may be in direct contact with the die attach surface, or may be coupled to the die attach surface through an intermediate layer, such as an adhesion layer or a contact metal layer. The nanoparticle layer includes nanoparticles having adjacent nanoparticles adhered to each other. The microelectronic die is attached to a package substrate by a die attach material. The die attach material extends into the nanoparticle layer and contacts at least a portion of the nanoparticles.