Provided are a package structure and a method of forming the same. The package structure includes a first die, a second die group, an interposer, an underfill layer, a thermal interface material (TIM), and an adhesive pattern. The first die and the second die group are disposed side by side on the interposer. The underfill layer is disposed between the first die and the second die group. The adhesive pattern at least overlay the underfill layer between the first die and the second die group. The TIM has a bottom surface being in direct contact with the first die, the second die group, and the adhesive pattern. The adhesive pattern separates the underfill layer from the TIM.

Provided are a package structure and a method of forming the same. The package structure includes a first die, a second die group, an interposer, an underfill layer, a thermal interface material (TIM), and an adhesive pattern. The first die and the second die group are disposed side by side on the interposer. The underfill layer is disposed between the first die and the second die group. The adhesive pattern at least overlay the underfill layer between the first die and the second die group. The TIM has a bottom surface being in direct contact with the first die, the second die group, and the adhesive pattern. The adhesive pattern separates the underfill layer from the TIM.

A semiconductor device includes: a semiconductor die having a metal region; a substrate having a metal region; and a soldered joint between the metal region of the semiconductor die and the metal region of the substrate. One or more intermetallic phases are present throughout the entire soldered joint, each of the one or more intermetallic phases formed from a solder preform diffused into the metal region of the semiconductor die and the metal region of the substrate. The soldered joint has the same length-to-width aspect ratio as the semiconductor die.

A semiconductor device includes: a semiconductor die having a metal region; a substrate having a metal region; and a soldered joint between the metal region of the semiconductor die and the metal region of the substrate. One or more intermetallic phases are present throughout the entire soldered joint, each of the one or more intermetallic phases formed from a solder preform diffused into the metal region of the semiconductor die and the metal region of the substrate. The soldered joint has the same length-to-width aspect ratio as the semiconductor die.

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 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 joining a semiconductor die to a substrate includes: applying a solder preform to a metal region of the semiconductor die or to a metal region of the substrate, the solder preform having a maximum thickness of 30 μm and a lower melting point than both metal regions; forming a soldered joint between the metal region of the semiconductor die and the metal region of the substrate via a diffusion soldering process and without applying pressure directly to the die; and setting a soldering temperature of the diffusion soldering process so that the solder preform melts and fully reacts with the metal region of the semiconductor die and the metal region of the substrate to form one or more intermetallic phases throughout the entire soldered joint, each intermetallic phase having a melting point above the melting point of the preform and the soldering temperature.

A method of joining a semiconductor die to a substrate includes: applying a solder preform to a metal region of the semiconductor die or to a metal region of the substrate, the solder preform having a maximum thickness of 30 μm and a lower melting point than both metal regions; forming a soldered joint between the metal region of the semiconductor die and the metal region of the substrate via a diffusion soldering process and without applying pressure directly to the die; and setting a soldering temperature of the diffusion soldering process so that the solder preform melts and fully reacts with the metal region of the semiconductor die and the metal region of the substrate to form one or more intermetallic phases throughout the entire soldered joint, each intermetallic phase having a melting point above the melting point of the preform and the soldering temperature.

Provided are a package structure and a method of forming the same. The package structure includes a first die, a second die group, an interposer, an underfill layer, a thermal interface material (TIM), and an adhesive pattern. The first die and the second die group are disposed side by side on the interposer. The underfill layer is disposed between the first die and the second die group. The adhesive pattern at least overlay the underfill layer between the first die and the second die group. The TIM has a bottom surface being in direct contact with the first die, the second die group, and the adhesive pattern. The adhesive pattern separates the underfill layer from the TIM.

Provided are a package structure and a method of forming the same. The package structure includes a first die, a second die group, an interposer, an underfill layer, a thermal interface material (TIM), and an adhesive pattern. The first die and the second die group are disposed side by side on the interposer. The underfill layer is disposed between the first die and the second die group. The adhesive pattern at least overlay the underfill layer between the first die and the second die group. The TIM has a bottom surface being in direct contact with the first die, the second die group, and the adhesive pattern. The adhesive pattern separates the underfill layer from the TIM.