Abstract: A method of welding includes providing first and second joining partners, providing a welding apparatus that includes a sonotrode comprising a structured working surface, arranging the first and second joining partners to contact one another, and forming a welded connection between the first and second joining partners by contacting the first joining partner with the structured working surface and vibrating the sonotrode at an ultrasonic frequency, wherein the structured working surface comprises a plurality of apexes, a plurality of nadirs between immediately adjacent ones of the apexes, and planar sidewalls that extend between the nadirs and the apexes, and wherein for each of the apexes the planar sidewalls on either side of the respective apex extend along first and second planes that intersect one another at an acute angle.

Abstract: A power semiconductor device includes: at least one substrate; at least one power semiconductor die arranged over the at least one substrate; a first leadframe arranged over the at least one power semiconductor substrate and over the at least one power semiconductor die, the first leadframe being arranged at least partially in a first plane and including one or more connecting portions extending out of the first plane in a first direction; and a second leadframe at least partially arranged in a second plane above or below the first plane and including one or more attachment sites. The one or more connecting portions extend into the second plane at the one or more attachment sites. The one or more connecting portions are arranged at a non-zero distance from the second leadframe, the non-zero distance being bridged by weld seams at the one or more attachment sites.

Abstract: A method of welding includes providing first and second joining partners, providing a welding apparatus that includes a sonotrode comprising a structured working surface, arranging the first and second joining partners to contact one another, and forming a welded connection between the first and second joining partners by contacting the first joining partner with the structured working surface and vibrating the sonotrode at an ultrasonic frequency, wherein the structured working surface comprises a plurality of apexes, a plurality of nadirs between immediately adjacent ones of the apexes, and planar sidewalls that extend between the nadirs and the apexes, and wherein for each of the apexes the planar sidewalls on either side of the respective apex extend along first and second planes that intersect one another at an acute angle.

Abstract: An ultrasonic welding apparatus includes a sonotrode comprising a structured working surface that comprises a plurality of apexes, a plurality of nadirs between immediately adjacent ones of the apexes, and planar sidewalls that extend between the nadirs and the apexes, and for each of the apexes the planar sidewalls on either side of the respective apex extend along first and second planes that intersect one another at an acute angle.

Abstract: A method for calibrating a second bonding machine based on a calibrated first bonding machine is disclosed. The first bonding machine includes a first ultrasonic transducer. The second bonding machine includes a second ultrasonic transducer and a power supply. The method includes providing a first electrical calibration supply that causes the first ultrasonic transducer to oscillate at a first calibration amplitude when it is damped by a mechanical damping, providing a second electrical calibration supply that causes the second ultrasonic transducer to oscillate at the same calibration amplitude when it is damped by the same mechanical damping.

Abstract: An ultrasonic welding apparatus includes a sonotrode comprising a structured working surface that comprises a plurality of apexes, a plurality of nadirs between immediately adjacent ones of the apexes, and planar sidewalls that extend between the nadirs and the apexes, and for each of the apexes the planar sidewalls on either side of the respective apex extend along first and second planes that intersect one another at an acute angle.

Abstract: A method for calibrating a second bonding machine based on a calibrated first bonding machine is disclosed. The first bonding machine includes a first ultrasonic transducer. The second bonding machine includes a second ultrasonic transducer and a power supply. The method includes providing a first electrical calibration supply that causes the first ultrasonic transducer to oscillate at a first calibration amplitude when it is damped by a mechanical damping, providing a second electrical calibration supply that causes the second ultrasonic transducer to oscillate at the same calibration amplitude when it is damped by the same mechanical damping.