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 method of soldering includes providing a substrate having a first metal joining surface, providing a semiconductor die having a second metal joining surface, providing a solder preform having a first interface surface and a second interface surface, arranging the solder preform between the substrate and the semiconductor die such that the first interface surface faces the first metal joining surface and such that the second interface surface faces the second metal joining surface, and performing a mechanical pressure-free diffusion soldering process that forms a soldered joint between the substrate and the semiconductor die by melting the solder preform and forming intermetallic phases in the solder. One or both of the first interface surface and the second interface surface has a varying surface profile that creates voids between the solder preform and one or both of the substrate and the semiconductor die before the melting of the solder preform.

A method of using a processing oven may include disposing at least one substrate in a chamber of the oven and activating a lamp assembly disposed above them to increase their temperature to a first temperature. A chemical vapor may be admitted into the chamber above the at least one substrate and an inert gas may be admitted into the chamber below the at least one substrate. The temperature of the at least one substrate may then be increased to a second temperature higher than the first temperature and then cooled down.

A method of using a processing oven may include disposing at least one substrate in a chamber of the oven and activating a lamp assembly disposed above them to increase their temperature to a first temperature. A chemical vapor may be admitted into the chamber above the at least one substrate and an inert gas may be admitted into the chamber below the at least one substrate. The temperature of the at least one substrate may then be increased to a second temperature higher than the first temperature and then cooled down.

A method of using a solder reflow oven can include disposing at least one substrate including solder in a chamber of the oven. The method can include decreasing a pressure of the chamber to a first pressure between about 0.1-50 Torr. After decreasing the pressure of the chamber, the temperature of the at least one substrate can be increased to a first temperature. Formic acid vapor can be admitted into the chamber above the at least one substrate while nitrogen is discharged into the chamber below the at least one substrate. The method can also include removing at least a portion of the formic acid vapor from the enclosure. After the removing step, the temperature of the at least one substrate can be further increased to a second temperature higher than the first temperature. The at least one substrate can be maintained at the second temperature for a first time. And then, the at least one substrate can be cooled.

A method of using a solder reflow oven can include disposing at least one substrate including solder in a chamber of the oven. The method can include decreasing a pressure of the chamber to a first pressure between about 0.1-50 Torr. After decreasing the pressure of the chamber, the temperature of the at least one substrate can be increased to a first temperature. Formic acid vapor can be admitted into the chamber above the at least one substrate while nitrogen is discharged into the chamber below the at least one substrate. The method can also include removing at least a portion of the formic acid vapor from the enclosure. After the removing step, the temperature of the at least one substrate can be further increased to a second temperature higher than the first temperature. The at least one substrate can be maintained at the second temperature for a first time. And then, the at least one substrate can be cooled.

A multilayer electronics assembly and associated method of manufacture are provided. The multilayer electronics assembly includes a plurality of stacked substrate layers. Each of the substrate layers is fusion bonded to at least an adjacent one of the plurality of substrate layers. A first discrete electrical circuit component is bonded to a first layer of the plurality of layers. A bonding material is interposed between the discrete electrical circuit component and the first layer. The bonding material has a reflow temperature at which the bonding material becomes flowable that is higher than a fusion bonding temperature of the substrate layers.

A method of soldering includes providing a substrate having a first metal joining surface, providing a semiconductor die having a second metal joining surface, providing a solder preform having a first interface surface and a second interface surface, arranging the solder preform between the substrate and the semiconductor die such that the first interface surface faces the first metal joining surface and such that the second interface surface faces the second metal joining surface, and performing a mechanical pressure-free diffusion soldering process that forms a soldered joint between the substrate and the semiconductor die by melting the solder preform and forming intermetallic phases in the solder. One or both of the first interface surface and the second interface surface has a varying surface profile that creates voids between the solder preform and one or both of the substrate and the semiconductor die before the melting of the solder preform.

There is provided a bonding paste capable of forming a uniform bonding layer by reducing occurrence of voids at edges even when a bonding area is large, and bonding method using the paste, and provides a metal paste for bonding containing at least metal nanoparticles (A) having a number average primary particle size of 10 to 100 nm, wherein a cumulative weight loss value (L.sub.100) when a temperature is raised from 40° C. to 100° C. is 75 or less, and a cumulative weight loss value (L.sub.150) when a temperature is raised from 40° C. to 150° C. is 90 or more, and a cumulative weight loss value (L.sub.200) when a temperature is raised from 40° C. to 200° C. is 98 or more, based on 100 cumulative weight loss value (L.sub.700) when the paste is heated from 40° C. to 700° C. at a heating rate of 3° C./min in a nitrogen atmosphere.

There is provided a bonding paste capable of forming a uniform bonding layer by reducing occurrence of voids at edges even when a bonding area is large, and bonding method using the paste, and provides a metal paste for bonding containing at least metal nanoparticles (A) having a number average primary particle size of 10 to 100 nm, wherein a cumulative weight loss value (L.sub.100) when a temperature is raised from 40° C. to 100° C. is 75 or less, and a cumulative weight loss value (L.sub.150) when a temperature is raised from 40° C. to 150° C. is 90 or more, and a cumulative weight loss value (L.sub.200) when a temperature is raised from 40° C. to 200° C. is 98 or more, based on 100 cumulative weight loss value (L.sub.700) when the paste is heated from 40° C. to 700° C. at a heating rate of 3° C./min in a nitrogen atmosphere.