Embodiments include an electronic system and methods of forming an electronic system. In an embodiment, the electronic system may include a package substrate and a die coupled to the package substrate. In an embodiment, the electronic system may also include an integrated heat spreader (IHS) that is coupled to the package substrate. In an embodiment the electronic system may further comprise a thermal interface pad between the IHS and the die. In an embodiment the die is thermally coupled to the IHS by a liquid metal thermal interface material (TIM) that contacts the thermal interface pad.

A system includes a semiconductor substrate having a first cavity. The semiconductor substrate forms a pedestal adjacent the first cavity. A device overlays the pedestal and is bonded to the semiconductor substrate by metal within the first cavity. A plurality of second cavities are formed in a surface of the pedestal beneath the device, wherein the second cavities are smaller than the first cavity. In some of these teachings, the second cavities are voids. In some of these teachings, the metal in the first cavity comprises a eutectic mixture. The structure relates to a method of manufacturing in which a layer providing a mask to etch the first cavity is segmented to enable easy removal of the mask-providing layer from the area over the pedestal.

Liquid metal thermal interface materials and their uses in electronics assembly are described. In one implementation, a semiconductor assembly includes: a semiconductor die; a heat exchanger; and a thermal interface material (TIM) alloy bonding the semiconductor die to the heat exchanger without using a separate metallization layer on a surface of the semiconductor die or a surface of the heat exchanger. The TIM alloy may be formed by placing a TIM material between the semiconductor die and the heat exchanger, the TIM material comprising a first liquid metal foam in touching relation with the surface of the semiconductor die, a second liquid metal foam in touching relation with the surface of the heat exchanger.

A method for wafer bonding includes: providing a semiconductor wafer having a first main face; fabricating at least one semiconductor device in the semiconductor wafer, wherein the semiconductor device is arranged at the first main face; generating trenches and a cavity in the semiconductor wafer such that the at least one semiconductor device is connected to the rest of the semiconductor wafer by no more than at least one connecting pillar; arranging the semiconductor wafer on a carrier wafer such that the first main face faces the carrier wafer; attaching the at least one semiconductor device to the carrier wafer; and removing the at least one semiconductor device from the semiconductor wafer by breaking the at least one connecting pillar.

The present disclosure relates to a microelectronics package with significantly reduced delamination/cracking at solder joints, and a process for making the same. The disclosed microelectronics package includes a carrier, a solder joint region over the carrier, a top intermetallic (IMC) layer over the solder joint region, and a device die over the top IMC layer. Herein, the device die includes a substrate, an active device over the substrate, a top barrier layer underneath the substrate, and a backside metal layer vertically between the top IMC layer and the top barrier layer. The backside metal layer is formed of gold (Au) with a thickness at least 0.5 μm. The top IMC layer comprises gold nickel tin (AuNiSn) or gold platinum tin (AuPtSn), and the solder joint region comprises an Au-rich gold-tin (Au.sub.5Sn) and gold-tin (AuSn) eutectic mixture.

Solid metal foam thermal interface materials and their uses in electronics assembly are described. In one implementation, a method includes: applying a thermal interface material (TIM) between a first device and a second device to form an assembly having a first surface of the TIM in in touching relation with a surface of the first device, and a second surface of the TIM opposite the first surface in touching relation with a surface of the second device, the TIM comprising a solid metal foam and a first liquid metal; and compressing the assembly to form an alloy from the TIM that bonds the first device to the second device.

A system includes a semiconductor substrate having a first cavity. The semiconductor substrate forms a pedestal adjacent the first cavity. A device overlays the pedestal and is bonded to the semiconductor substrate by metal within the first cavity. A plurality of second cavities are formed in a surface of the pedestal beneath the device, wherein the second cavities are smaller than the first cavity. In some of these teachings, the second cavities are voids. In some of these teachings, the metal in the first cavity comprises a eutectic mixture. The structure relates to a method of manufacturing in which a layer providing a mask to etch the first cavity is segmented to enable easy removal of the mask-providing layer from the area over the pedestal.

A system includes a semiconductor substrate having a first cavity. The semiconductor substrate forms a pedestal adjacent the first cavity. A device overlays the pedestal and is bonded to the semiconductor substrate by metal within the first cavity. A plurality of second cavities are formed in a surface of the pedestal beneath the device, wherein the second cavities are smaller than the first cavity. In some of these teachings, the second cavities are voids. In some of these teachings, the metal in the first cavity comprises a eutectic mixture. The structure relates to a method of manufacturing in which a layer providing a mask to etch the first cavity is segmented to enable easy removal of the mask-providing layer from the area over the pedestal.

A thermal interface structure may be formed comprising a thermally conductive substrate having a first surface and an opposing second surface, a first liquid metal layer on the first surface of the thermally conductive substrate, and a second liquid metal layer on the second surface of the thermally conductive substrate. The thermal interface structure may be used in an integrated circuit assembly or package between at least one integrated circuit device and a heat dissipation device.

A system includes a semiconductor substrate having a first cavity. The semiconductor substrate forms a pedestal adjacent the first cavity. A device overlays the pedestal and is bonded to the semiconductor substrate by metal within the first cavity. A plurality of second cavities are formed in a surface of the pedestal beneath the device, wherein the second cavities are smaller than the first cavity. In some of these teachings, the second cavities are voids. In some of these teachings, the metal in the first cavity comprises a eutectic mixture. The structure relates to a method of manufacturing in which a layer providing a mask to etch the first cavity is segmented to enable easy removal of the mask-providing layer from the area over the pedestal.