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 semiconductor device includes a first substrate, a second substrate spaced apart from the first substrate in a first direction, a first metal layer on the first substrate, a second metal layer on the first substrate and spaced apart from the first metal layer in a second direction, a first semiconductor element, and a second semiconductor element. The second substrate includes a main wiring and a signal wiring. The first semiconductor element includes a first electrode on the first metal layer, a second electrode connected to the main wiring, and a first gate electrode connected to the signal wiring. The second semiconductor element includes a third electrode on the second metal layer, a fourth electrode connected to the main wiring, and a second gate electrode connected to the signal wiring. During operation, current flows in wiring layers of the main wiring in opposite directions.

A semiconductor device includes a first substrate, a second substrate spaced apart from the first substrate in a first direction, a first metal layer on the first substrate, a second metal layer on the first substrate and spaced apart from the first metal layer in a second direction, a first semiconductor element, and a second semiconductor element. The second substrate includes a main wiring and a signal wiring. The first semiconductor element includes a first electrode on the first metal layer, a second electrode connected to the main wiring, and a first gate electrode connected to the signal wiring. The second semiconductor element includes a third electrode on the second metal layer, a fourth electrode connected to the main wiring, and a second gate electrode connected to the signal wiring. During operation, current flows in wiring layers of the main wiring in opposite directions.

In a method of manufacturing a semiconductor package, information with respect to a downward warpage of a reference package substrate, which may be bent with respect to a long axis and/or a short axis of the reference package substrate in applying heat to the reference package substrate to which a plurality of semiconductor chips may be attached using a die attach film (DAF), may be obtained. A package substrate, which may include a first surface to which the semiconductor chips may be attached using the DAF and a second surface opposite to the first surface, may be rotated with respect to the long axis or the short axis at an angle selected based on the information. The heat may be applied to the package substrate to cure the DAF and correct a warpage of the package substrate. Thus, warpage of the package substrate may be corrected for.

In a method of manufacturing a semiconductor package, information with respect to a downward warpage of a reference package substrate, which may be bent with respect to a long axis and/or a short axis of the reference package substrate in applying heat to the reference package substrate to which a plurality of semiconductor chips may be attached using a die attach film (DAF), may be obtained. A package substrate, which may include a first surface to which the semiconductor chips may be attached using the DAF and a second surface opposite to the first surface, may be rotated with respect to the long axis or the short axis at an angle selected based on the information. The heat may be applied to the package substrate to cure the DAF and correct a warpage of the package substrate. Thus, warpage of the package substrate may be corrected for.

A die bonding apparatus includes: a mounting base including a mounting area on which a first member is mounted; a heater arranged below the mounting base; a side wall configured to surround the mounting area; a collet configured to hold a second member by vacuum-chucking at an end portion; a lid including a hole, the lid being mounted on the side wall; a moving structure configured to move the collet to transport the second member held by the collet through the hole for bonding the second member to the first member; and a gas-supplying tube arranged on the side wall and configured to supply a heating gas to a heating space formed by the side wall and the lid. The lid contains a material capable of: reflecting an infrared radiation caused by the heater and the heating gas; or absorbing and re-radiating the infrared radiation.

A method of fabricating a semiconductor device is disclosed. In one aspect, the method includes placing a first semiconductor chip on a carrier with the first main surface of the first semiconductor chip facing the carrier. A first layer of soft solder material is provided between the first main surface and the carrier. Heat is applied during placing so that a temperature at the first layer of soft solder material is equal to or higher than a melting temperature of the first layer of soft solder material. A second layer of soft solder material is provided between the first contact area and the second main surface. Heat is applied during placing so that a temperature at the second layer of soft solder material is equal to or higher than a melting temperature of the second layer of soft solder material. The first and second layers of soft solder material are cooled to solidify the soft solder materials.

A method of fabricating a semiconductor device is disclosed. In one aspect, the method includes placing a first semiconductor chip on a carrier with the first main surface of the first semiconductor chip facing the carrier. A first layer of soft solder material is provided between the first main surface and the carrier. Heat is applied during placing so that a temperature at the first layer of soft solder material is equal to or higher than a melting temperature of the first layer of soft solder material. A second layer of soft solder material is provided between the first contact area and the second main surface. Heat is applied during placing so that a temperature at the second layer of soft solder material is equal to or higher than a melting temperature of the second layer of soft solder material. The first and second layers of soft solder material are cooled to solidify the soft solder materials.

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 terminal case formed by integrally molding a lead frame and a case that has internally an inner face on which the lead frame is mounted and has externally a step portion fixed to a circuit block having an insulating substrate and semiconductor chips formed on the insulating substrate. An opening portion is formed between the step portion and the inner face so as to extend through them, and the opening portion is filled with an adhesive to bond the insulating substrate to the step portion. Since a connecting area to which a bonding wire of the lead frame is ultrasonically bonded is fixed, it is possible to reduce the bonding failures of the lead frames.