A method of soldering elements together includes providing a substrate having a metal die attach surface, providing a semiconductor die that is configured as a power semiconductor device and having a semiconductor body, a rear side metallization, and a front side layer stack, the front side layer stack having a front side metallization and a contaminant protection layer, arranging the semiconductor die on the substrate with a region of solder material between the die attach surface and the rear side metallization, and performing a soldering process that reflows the region of solder material to form a soldered joint between the metal die attach surface and the rear side metallization, wherein the soldering process comprises applying mechanical pressure to the front side metallization.

A semiconductor assembly includes a substrate including a metal die attach surface, a semiconductor die that is arranged on the substrate, the semiconductor die being configured as a power semiconductor device and comprising a semiconductor body, a rear side metallization, and a front side layer stack, the front side layer stack comprising a front side metallization and a contaminant protection layer that is between the front side metallization and the semiconductor body, and a diffusion soldered joint between the metal die attach surface and the rear side metallization, the diffusion soldered joint comprising one or more intermetallic phases throughout the diffusion soldered joint, wherein the contaminant protection layer is configured to prevent transmission of contaminants into the semiconductor body.

A method of soldering elements together includes providing a substrate having a metal die attach surface, providing a semiconductor die that is configured as a power semiconductor device and having a semiconductor body, a rear side metallization, and a front side layer stack, the front side layer stack having a front side metallization and a contaminant protection layer, arranging the semiconductor die on the substrate with a region of solder material between the die attach surface and the rear side metallization, and performing a soldering process that reflows the region of solder material to form a soldered joint between the metal die attach surface and the rear side metallization, wherein the soldering process comprises applying mechanical pressure to the front side metallization, and wherein the contaminant protection layer is configured to prevent transmission of contaminants into the semiconductor body after the soldering process is completed.

Provided are a sintered material excellent in both thermal stress and bonding strength; a connection structure comprising the sintered material; a composition for bonding with which the sintered material can be produced; and a method for producing the sintered material. The sintered material comprises a base portion, one or more buffer portions, and one or more filling portions. The buffer portions and the filling portions are dispersed in the base portion. The base portion is a metal sintered body, each buffer portion is formed from at least one of a pore and a material that is not the same as that of the sintered body, and each filling portion is formed from at least one of particles and fibers. The sintered material satisfies A>B, where A is the kurtosis of volume distribution of the base portions in a three-dimensional image of the sintered material, and B is the kurtosis of volume distribution of the base portions in a three-dimensional image of the sintered material from which the filling portions are removed.

Provided are a sintered material excellent in both thermal stress and bonding strength; a connection structure comprising the sintered material; a composition for bonding with which the sintered material can be produced; and a method for producing the sintered material. The sintered material comprises a base portion, one or more buffer portions, and one or more filling portions. The buffer portions and the filling portions are dispersed in the base portion. The base portion is a metal sintered body, each buffer portion is formed from at least one of a pore and a material that is not the same as that of the sintered body, and each filling portion is formed from at least one of particles and fibers. The sintered material satisfies A>B, where A is the kurtosis of volume distribution of the base portions in a three-dimensional image of the sintered material, and B is the kurtosis of volume distribution of the base portions in a three-dimensional image of the sintered material from which the filling portions are removed.

A sintered material excellent in thermal stress and bonding strength; a connection structure containing the sintered material; a composition for bonding with which the sintered material can be produced; and a method for producing the sintered material. The sintered material has a base portion, buffer portions, and filling portions. The buffer portions and filling portions are dispersed in the base portion. The base portion is a metal sintered body, each buffer portion is formed from a pore and/or material that is not the same as the sintered body, and each filling portion is formed from particles and/or fibers. The sintered material satisfies A>B. A is the kurtosis of volume distribution of the base portions in a three-dimensional image of the sintered material. B is the kurtosis of volume distribution of the base portions in a three-dimensional image of the sintered material from which the filling portions are removed.

A sintered material excellent in thermal stress and bonding strength; a connection structure containing the sintered material; a composition for bonding with which the sintered material can be produced; and a method for producing the sintered material. The sintered material has a base portion, buffer portions, and filling portions. The buffer portions and filling portions are dispersed in the base portion. The base portion is a metal sintered body, each buffer portion is formed from a pore and/or material that is not the same as the sintered body, and each filling portion is formed from particles and/or fibers. The sintered material satisfies A>B. A is the kurtosis of volume distribution of the base portions in a three-dimensional image of the sintered material. B is the kurtosis of volume distribution of the base portions in a three-dimensional image of the sintered material from which the filling portions are removed.

A mount structure includes two members that are bonded to each other with a bonding material layer having a first interface layer and a second interface layer at the interfaces with the two members. The bonding material layer contains a first intermetallic compound and a stress relaxation material. The first intermetallic compound has a spherical, a columnar, or an oval spherical shape, and the same crystalline structure as the first interface layer and the second interface layer, and partly closes the space between the first interface layer and the second interface layer. The stress relaxation material contains tin as a main component, and fills around the first intermetallic compound.

A semiconductor assembly includes a substrate including a metal die attach surface, a semiconductor die that is arranged on the substrate, the semiconductor die being configured as a power semiconductor device and comprising a semiconductor body, a rear side metallization, and a front side layer stack, the front side layer stack comprising a front side metallization and a contaminant protection layer that is between the front side metallization and the semiconductor body, and a diffusion soldered joint between the metal die attach surface and the rear side metallization, the diffusion soldered joint comprising one or more intermetallic phases throughout the diffusion soldered joint, wherein the contaminant protection layer is configured to prevent transmission of contaminants into the semiconductor body.

A mount structure includes two members that are bonded to each other with a bonding material layer having a first interface layer and a second interface layer at the interfaces with the two members. The bonding material layer contains a first intermetallic compound and a stress relaxation material. The first intermetallic compound has a spherical, a columnar, or an oval spherical shape, and the same crystalline structure as the first interface layer and the second interface layer, and partly closes the space between the first interface layer and the second interface layer. The stress relaxation material contains tin as a main component, and fills around the first intermetallic compound.