Methods for forming packaged semiconductor devices including backside power rails and packaged semiconductor devices formed by the same are disclosed. In an embodiment, a device includes a first integrated circuit device including a first transistor structure in a first device layer; a front-side interconnect structure on a front-side of the first device layer; and a backside interconnect structure on a backside of the first device layer, the backside interconnect structure including a first dielectric layer on the backside of the first device layer; and a first contact extending through the first dielectric layer to a source/drain region of the first transistor structure; and a second integrated circuit device including a second transistor structure in a second device layer; and a first interconnect structure on the second device layer, the first interconnect structure being bonded to the front-side interconnect structure by dielectric-to-dielectric and metal-to-metal bonds.

A field-effect transistor includes a substrate, a channel on the substrate including a stem including silicon extending in a vertical direction from the substrate and a number of prongs including silicon extending in a horizontal direction from the stem and spaced apart from each other along the vertical direction, an interfacial layer surrounding the stem and the prongs of the channel, a dielectric layer on the interfacial layer and surrounding the stem and the prongs of the channel, and a metal gate on the dielectric layer and surrounding the stem and the prongs of the channel.

A manufacturing method for a laminated iron core for joining multiple iron core laminae by successively forming multiple spot-shaped welded parts on the multiple iron core laminae that are stacked includes: a first welding step of forming first welded parts, which constitute multiple welded parts, at a first pitch in a stacking direction on a first iron core lamina group composed of a part of the multiple iron core laminae; and a second welding step of forming, after the first welding step, second welded parts, which constitute the multiple welded parts, at a second pitch in the stacking direction on a second iron core lamina group composed of a part of the multiple iron core laminae adjoining the first iron core lamina group, wherein the second pitch is greater than the first pitch.

A manufacturing method for a laminated iron core for joining multiple iron core laminae by successively forming multiple spot-shaped welded parts on the multiple iron core laminae that are stacked includes: a first welding step of forming first welded parts, which constitute multiple welded parts, at a first pitch in a stacking direction on a first iron core lamina group composed of a part of the multiple iron core laminae; and a second welding step of forming, after the first welding step, second welded parts, which constitute the multiple welded parts, at a second pitch in the stacking direction on a second iron core lamina group composed of a part of the multiple iron core laminae adjoining the first iron core lamina group, wherein the second pitch is greater than the first pitch.

A method of manufacturing a compact includes filling a space defined by a die hole in a die and a lower punch with powder, and compressing the powder in the space with the lower punch and an upper punch to form a compact. The compact includes a body, the body being prism-shaped and having a first bottom surface, a second bottom surface opposite to the first bottom surface, and a plurality of side surfaces, a first plate portion provided on the first bottom surface, and a second plate portion provided on the second bottom surface.

A method of manufacturing a compact includes filling a space defined by a die hole in a die and a lower punch with powder, and compressing the powder in the space with the lower punch and an upper punch to form a compact. The compact includes a body, the body being prism-shaped and having a first bottom surface, a second bottom surface opposite to the first bottom surface, and a plurality of side surfaces, a first plate portion provided on the first bottom surface, and a second plate portion provided on the second bottom surface.

A method of manufacturing a motor core includes preparing a plurality of electromagnetic steel sheets, peening an entire surface of at least one of a first and a second main surfaces of an electromagnetic steel sheet selected from the electromagnetic steel sheets, and forming a stack using the electromagnetic steel sheets including the electromagnetic steel sheet peened.

A method of manufacturing a motor core includes preparing a plurality of electromagnetic steel sheets, peening an entire surface of at least one of a first and a second main surfaces of an electromagnetic steel sheet selected from the electromagnetic steel sheets, and forming a stack using the electromagnetic steel sheets including the electromagnetic steel sheet peened.

A rotor (30) for a rotary electric machine, comprising:-at least one permanent magnet (1),-a rotor mass (33) comprising laminations stacked on top of one another, comprising at least one housing (4) accommodating the permanent magnet (1), the housing (4) being delimited by at least one large face (5a) facing a long side (2a) of the permanent magnet (1), at least one lamination (6) comprising at least two cutouts (10) between them creating at least one tab (12) meeting said large face (5a) of the housing (4) and extending into the housing (4), notably in the direction of the air gap, the lamination (6) comprising one or more punches (15) formed in the tab or tabs (12) and enabling the permanent magnet (1) to be held against an opposite face (6b) of the housing (4).

A rotor (30) for a rotary electric machine, comprising:-at least one permanent magnet (1),-a rotor mass (33) comprising laminations stacked on top of one another, comprising at least one housing (4) accommodating the permanent magnet (1), the housing (4) being delimited by at least one large face (5a) facing a long side (2a) of the permanent magnet (1), at least one lamination (6) comprising at least two cutouts (10) between them creating at least one tab (12) meeting said large face (5a) of the housing (4) and extending into the housing (4), notably in the direction of the air gap, the lamination (6) comprising one or more punches (15) formed in the tab or tabs (12) and enabling the permanent magnet (1) to be held against an opposite face (6b) of the housing (4).