The invention relates to a metal layer stack for use in electronic components, in particular as a spacer in power electronic components, comprising n bulk metal layers and n or n+1 contact material layers, wherein the bulk metal layers and the contact material layers are stacked in an alternating manner and n is at least two. Additionally, the invention relates to a process for preparing the metal layer stack and a semiconductor module comprising such a metal layer stack.

A method for assembling a first substrate and a second substrate via metal adhesion layers, the method including: depositing, on a surface of each of the first and second substrates, a metal layer with a thickness controlled to limit surface roughness of each of the deposited metal layers to below a roughness threshold; exposing the metal layers deposited on the surface of the first and second substrates to air; directly adhering the first and second substrates by placing the deposited metal adhesion layers in contact, the surface roughness of the contacted layers being that obtained at an end of the depositing. The adhesion can be carried out in the air, at atmospheric pressure and at room temperature, without applying pressure to the assembly of the first and second substrates resulting from directly contacting the deposited metal adhesion layers.

A method for assembling a first substrate and a second substrate via metal adhesion layers, the method including: depositing, on a surface of each of the first and second substrates, a metal layer with a thickness controlled to limit surface roughness of each of the deposited metal layers to below a roughness threshold; exposing the metal layers deposited on the surface of the first and second substrates to air; directly adhering the first and second substrates by placing the deposited metal adhesion layers in contact, the surface roughness of the contacted layers being that obtained at an end of the depositing. The adhesion can be carried out in the air, at atmospheric pressure and at room temperature, without applying pressure to the assembly of the first and second substrates resulting from directly contacting the deposited metal adhesion layers.

A semiconductor device provided with a substrate made of material except for semiconductors and having thermal conductivity greater than that of the semiconductor material. The semiconductor device provides, on the support, a metal layer, a primary mesa, and electrodes formed on the primary mesa. The metal layer, which is in contact with the primary mesa, may be made of at least one of tungsten (W), molybdenum (Mo), and tantalum (Ta) with a thickness of the 10 to 60 nm.

A semiconductor device provided with a substrate made of material except for semiconductors and having thermal conductivity greater than that of the semiconductor material. The semiconductor device provides, on the support, a metal layer, a primary mesa, and electrodes formed on the primary mesa. The metal layer, which is in contact with the primary mesa, may be made of at least one of tungsten (W), molybdenum (Mo), and tantalum (Ta) with a thickness of the 10 to 60 nm.

Provided is a semiconductor package in which a bonding structure is formed using metal grains included in metal powder layers having a coefficient of thermal expansion (CTE) similar with those of a substrate and a conductor so as to minimize generation of cracks and to improve reliability of bonded parts.

Provided is a semiconductor package in which a bonding structure is formed using metal grains included in metal powder layers having a coefficient of thermal expansion (CTE) similar with those of a substrate and a conductor so as to minimize generation of cracks and to improve reliability of bonded parts.

Embodiments include semiconductor packages and methods of forming such packages. A semiconductor package includes a die on a package substrate, an integrated heat spreader (IHS) on the package substrate and above the die, and a solder thermal interface material (STIM) coupling the die to the IHS. The semiconductor package includes a low-temperature solder (LTS) paste comprising an alloy of tin and bismuth (Bi), and the LTS paste on a bottom surface of the package substrate having a ball grid array. The LTS paste may have a weight percentage of Bi greater than 35% and a melting point less than or equal to a melting point of the STIM, where the STIM includes indium. The weight percentage of Bi may be between approximately 35% to 58%. The semiconductor package may include a solder ball coupling the LTS paste on the package substrate to the LTS paste on a second package substrate.

Embodiments include semiconductor packages and methods of forming such packages. A semiconductor package includes a die on a package substrate, an integrated heat spreader (IHS) on the package substrate and above the die, and a solder thermal interface material (STIM) coupling the die to the IHS. The semiconductor package includes a low-temperature solder (LTS) paste comprising an alloy of tin and bismuth (Bi), and the LTS paste on a bottom surface of the package substrate having a ball grid array. The LTS paste may have a weight percentage of Bi greater than 35% and a melting point less than or equal to a melting point of the STIM, where the STIM includes indium. The weight percentage of Bi may be between approximately 35% to 58%. The semiconductor package may include a solder ball coupling the LTS paste on the package substrate to the LTS paste on a second package substrate.

Provided is a semiconductor package in which a bonding structure is formed using metal grains included in metal powder layers having a coefficient of thermal expansion (CTE) similar with those of a substrate and a conductor so as to minimize generation of cracks and to improve reliability of bonded parts.