A method for attaching a semiconductor die to a substrate includes providing a substrate that includes an attachment layer at a surface of the substrate. The attachment layer is covered by a protective flash plating layer. The protective flash plating layer has a reflow temperature less than or equal to a reflow temperature of the attachment layer. The method further includes preheating the substrate to a temperature greater than or equal to a reflow temperature of the attachment layer, attaching a semiconductor die to the attachment layer, and cooling the substrate and semiconductor die.

A method for attaching a semiconductor die to a substrate includes providing a substrate that includes an attachment layer at a surface of the substrate. The attachment layer is covered by a protective flash plating layer. The protective flash plating layer has a reflow temperature less than or equal to a reflow temperature of the attachment layer. The method further includes preheating the substrate to a temperature greater than or equal to a reflow temperature of the attachment layer, attaching a semiconductor die to the attachment layer, and cooling the substrate and semiconductor die.

A method for bonding two superconducting integrated circuits (“chips”), such that the bonds electrically interconnect the chips. A plurality of indium-coated metallic posts may be deposited on each chip. The indium bumps are aligned and compressed with moderate pressure at a temperature at which the indium is deformable but not molten, forming fully superconducting connections between the two chips when the indium is cooled down to the superconducting state. An anti-diffusion layer may be applied below the indium bumps to block reaction with underlying layers. The method is scalable to a large number of small contacts on the wafer scale, and may be used to manufacture a multi-chip module comprising a plurality of chips on a common carrier. Superconducting classical and quantum computers and superconducting sensor arrays may be packaged.

A method for bonding two superconducting integrated circuits (“chips”), such that the bonds electrically interconnect the chips. A plurality of indium-coated metallic posts may be deposited on each chip. The indium bumps are aligned and compressed with moderate pressure at a temperature at which the indium is deformable but not molten, forming fully superconducting connections between the two chips when the indium is cooled down to the superconducting state. An anti-diffusion layer may be applied below the indium bumps to block reaction with underlying layers. The method is scalable to a large number of small contacts on the wafer scale, and may be used to manufacture a multi-chip module comprising a plurality of chips on a common carrier. Superconducting classical and quantum computers and superconducting sensor arrays may be packaged.

A method of making an assembly can include juxtaposing a top surface of a first electrically conductive element at a first surface of a first substrate with a top surface of a second electrically conductive element at a major surface of a second substrate. One of: the top surface of the first conductive element can be recessed below the first surface, or the top surface of the second conductive element can be recessed below the major surface. Electrically conductive nanoparticles can be disposed between the top surfaces of the first and second conductive elements. The conductive nanoparticles can have long dimensions smaller than 100 nanometers. The method can also include elevating a temperature at least at interfaces of the juxtaposed first and second conductive elements to a joining temperature at which the conductive nanoparticles can cause metallurgical joints to form between the juxtaposed first and second conductive elements.

Microelectronic assemblies, related devices, and methods are disclosed herein. In some embodiments, a microelectronic assembly may include a die having a first surface and an opposing second surface; a capacitor having a surface, wherein the surface of the capacitor is coupled to the first surface of the die; and a conductive pillar coupled to the first surface of the die. In some embodiments, a microelectronic assembly may include a capacitor in a first dielectric layer; a conductive pillar in the first dielectric layer; a first die having a surface in the first dielectric layer; and a second die having a surface in a second dielectric layer, wherein the second dielectric layer is on the first dielectric layer, and wherein the surface of the second die is coupled to the capacitor, to the surface of the first die, and to the conductive pillar.

Microelectronic assemblies, related devices, and methods are disclosed herein. In some embodiments, a microelectronic assembly may include a die having a first surface and an opposing second surface; a capacitor having a surface, wherein the surface of the capacitor is coupled to the first surface of the die; and a conductive pillar coupled to the first surface of the die. In some embodiments, a microelectronic assembly may include a capacitor in a first dielectric layer; a conductive pillar in the first dielectric layer; a first die having a surface in the first dielectric layer; and a second die having a surface in a second dielectric layer, wherein the second dielectric layer is on the first dielectric layer, and wherein the surface of the second die is coupled to the capacitor, to the surface of the first die, and to the conductive pillar.

A method of forming a semiconductor package is provided. The method includes forming a metallization stack over a semiconductor die. Polymer particles are mounted over the metallization stack. Each of the polymer particles is coated with a first bonding layer. A heat spreader lid is bonded with the semiconductor die by reflowing the first bonding layer. A composite thermal interface material (TIM) structure is formed between the heat spreader lid and the semiconductor die during the bonding. The composite TIM structure includes the first bonding layer and the polymer particles embedded in the first bonding layer.

A method of forming a semiconductor package is provided. The method includes forming a metallization stack over a semiconductor die. Polymer particles are mounted over the metallization stack. Each of the polymer particles is coated with a first bonding layer. A heat spreader lid is bonded with the semiconductor die by reflowing the first bonding layer. A composite thermal interface material (TIM) structure is formed between the heat spreader lid and the semiconductor die during the bonding. The composite TIM structure includes the first bonding layer and the polymer particles embedded in the first bonding layer.

A packaged semiconductor includes an electrically insulating encapsulant body having an upper surface, a first semiconductor die encapsulated within the encapsulant body, the first semiconductor die having a main surface with a first conductive pad that faces the upper surface of the encapsulant body, a second semiconductor die encapsulated within the encapsulant body and disposed laterally side by side with the first semiconductor die, the second semiconductor die having a main surface with a second conductive pad that faces the upper surface of the encapsulant body, and a first conductive track that is formed in the upper surface of the encapsulant body and electrically connects the first conductive pad to the second conductive pad. The encapsulant body includes a laser activatable mold compound.