Methods for attachment and devices produced using such methods are disclosed. In certain examples, the method comprises disposing a capped nanomaterial on a substrate, disposing a die on the disposed capped nanomaterial, drying the disposed capped nanomaterial and the disposed die, and sintering the dried disposed die and the dried capped nanomaterial at a temperature of 300° C. or less to attach the die to the substrate. Devices produced using the methods are also described.

A metal sintering preparation containing (A) 50 to 90% by weight of at least one metal that is present in the form of particles having a coating that contains at least one organic compound, and (B) 6 to 50% by weight organic solvent. The mathematical product of tamped density and specific surface of the metal particles of component (A) is in the range of 40,000 to 80,000 cm.sup.−1.

A metal sintering preparation containing (A) 50 to 90% by weight of at least one metal that is present in the form of particles having a coating that contains at least one organic compound, and (B) 6 to 50% by weight organic solvent. The mathematical product of tamped density and specific surface of the metal particles of component (A) is in the range of 40,000 to 80,000 cm.sup.−1.

A semiconductor device includes an electrode having a flat part and a non-flat part made up of a concave part, a joint layer being made of a sintered body of metal crystal grains provided on the flat part and the non-flat part of the electrode, and a semiconductor element being joined to the electrode with the joint layer therebetween, wherein the joint layer has a first region sandwiched between the non-flat part and the semiconductor element and a second region sandwiched between the flat part and the semiconductor element, and either one of the first region and the second region having a larger film thickness has a filling rate of the metal crystal grains smaller than the other one of the first region and the second region having a smaller film thickness. The present invention enhances reliability of a joint layer made of a sintered body of metal crystal grains.

A semiconductor device includes an electrode having a flat part and a non-flat part made up of a concave part, a joint layer being made of a sintered body of metal crystal grains provided on the flat part and the non-flat part of the electrode, and a semiconductor element being joined to the electrode with the joint layer therebetween, wherein the joint layer has a first region sandwiched between the non-flat part and the semiconductor element and a second region sandwiched between the flat part and the semiconductor element, and either one of the first region and the second region having a larger film thickness has a filling rate of the metal crystal grains smaller than the other one of the first region and the second region having a smaller film thickness. The present invention enhances reliability of a joint layer made of a sintered body of metal crystal grains.

Disclosed is a method for transient liquid-phase bonding between metal materials using a magnetic force. In particular, in the method, a magnetic force is applied to a transient liquid-phase bonding process, thereby shortening a transient liquid-phase bonding time between the metal materials, and obtaining high bonding strength. To this end, an attractive magnetic force is applied to a ferromagnetic base while a repulsive magnetic force is applied to a diamagnetic base, thereby to accelerate diffusion. This may reduce a bonding time during a transient liquid-phase bonding process between two bases and suppress formation of Kirkendall voids and voids and suppress a layered structure of an intermetallic compound, thereby to increase a bonding strength.

Disclosed is a method for transient liquid-phase bonding between metal materials using a magnetic force. In particular, in the method, a magnetic force is applied to a transient liquid-phase bonding process, thereby shortening a transient liquid-phase bonding time between the metal materials, and obtaining high bonding strength. To this end, an attractive magnetic force is applied to a ferromagnetic base while a repulsive magnetic force is applied to a diamagnetic base, thereby to accelerate diffusion. This may reduce a bonding time during a transient liquid-phase bonding process between two bases and suppress formation of Kirkendall voids and voids and suppress a layered structure of an intermetallic compound, thereby to increase a bonding strength.

A solder material comprising a solder alloy and a thermal conductivity modifying component. The solder material has a bulk thermal conductivity of between about 75 and about 150 W/m-K and is usable in enhancing the thermal conductivity of the solder, allowing for optimal heat transfer and reliability in electronic packaging applications.

A method utilized at a sintered metal layer bonding a semiconductor element and a support substrate together suppresses cracks appearing in the sintered metal layer, and damage to the semiconductor element. A semiconductor device includes a support substrate, a semiconductor element, and a sintered metal layer bonding the support substrate and the semiconductor element. The sintered metal layer has a low porosity region disposed inward of an outer edge of the semiconductor element with the sintered metal layer bonded to the semiconductor element. The region is lower in porosity than the remaining sintered metal layer, and is formed as a wall-shaped structural body having an elongated string and extending from an upper surface to a lower surface of the sintered metal layer. The low porosity region is disposed to surround a region immediately below a center of the semiconductor element along the outer edge of the semiconductor element.

A method utilized at a sintered metal layer bonding a semiconductor element and a support substrate together suppresses cracks appearing in the sintered metal layer, and damage to the semiconductor element. A semiconductor device includes a support substrate, a semiconductor element, and a sintered metal layer bonding the support substrate and the semiconductor element. The sintered metal layer has a low porosity region disposed inward of an outer edge of the semiconductor element with the sintered metal layer bonded to the semiconductor element. The region is lower in porosity than the remaining sintered metal layer, and is formed as a wall-shaped structural body having an elongated string and extending from an upper surface to a lower surface of the sintered metal layer. The low porosity region is disposed to surround a region immediately below a center of the semiconductor element along the outer edge of the semiconductor element.