A semiconductor chip includes a chip body and a plurality of solder-including electrodes provided on an element-formation surface of the chip body. A packaging substrate includes a substrate body, and a plurality of wirings and a solder resist layer that are provided on a front surface of the substrate body. The plurality of solder-including electrodes include a plurality of first electrodes and a plurality of second electrodes. The plurality of first electrodes supply a first electric potential, and the plurality of second electrodes supply a second electric potential different from the first electric potential. The plurality of first electrodes and the plurality of second electrodes are disposed alternately in both a row direction and a column direction, in a central part of the chip body. The plurality of wirings include a plurality of first wirings and a plurality of second wirings. The plurality of first wirings connect the plurality of first electrodes, and the plurality of second wirings connect the plurality of second electrodes.

The present disclosure provides a semiconductor package, including a first device having a first joining surface, a first conductive component at least partially protruding from the first joining surface, a second device having a second joining surface facing the first joining surface, and a second conductive component at least exposing from the second joining surface. The first conductive component and the second conductive component form a joint having a first beak. The first beak points to either the first joining surface or the second joining surface.

A fluxless bonding process is provided. An array of micro solder bumps of a first semiconductor structure is aligned to an array of bonding pads of a second semiconductor structure under an applied bonding force. An environment is provided to prevent oxides from forming on the solder bump structures and bonding pads during the bonding process. A scrubbing process is performed at a given scrubbing frequency and amplitude to scrub the micro solder bumps against the bonding pads in a direction perpendicular to the bonding. Heat is applied to at least the first semiconductor structure to melt and bond the micro solder bumps to the bonding pads. The first semiconductor structure is cooled down to solidify the molten solder. Coplanarity is maintained between the bonding surfaces of the semiconductor structures within a given tolerance during the scrubbing and cooling steps until solidification of the micro solder bumps.

A method includes performing a first strike process to strike a metal bump of a first package component against a metal pad of a second package component. A first one of the metal bump and the metal pad includes copper. A second one of the metal bump and the metal pad includes aluminum. The method further includes performing a second strike process to strike the metal bump against the metal pad. An annealing is performed to bond the metal bump on the metal pad.