A packaged integrated circuit device includes a substrate having a surface thereon. A spacer and a first semiconductor chip are provided at spaced-apart locations on a first portion of the surface of the substrate. This first portion of the surface of the substrate has a lateral area equivalent to a sum of: (i) a lateral footprint of the spacer, (ii) a lateral footprint of the first semiconductor chip, and (iii) an area of an entire lateral space between the spacer and the first semiconductor chip. A stack of second semiconductor chips is provided, which extends on the spacer and on the first semiconductor chip. The stack of second semiconductor chips has a lateral footprint greater than the lateral area of the first portion of the surface of the substrate so that at least a portion of the stack of second semiconductor chips overhangs at least one sidewall of at least one of the spacer and the first semiconductor chip, which extend between the stack of second semiconductor chips and the surface of the substrate.

Methods for bonding substrates used, for example, in substrate-level packaging, are provided herein. In some embodiments, a method for bonding substrates includes: performing electrochemical deposition (ECD) to deposit at least one material on each of a first substrate and a second substrate, performing chemical mechanical polishing (CMP) on the first substrate and the second substrate to form a bonding interface on each of the first substrate and the second substrate, positioning the first substrate on the second substrate so that the bonding interface on the first substrate aligns with the bonding interface on the second substrate, and bonding the first substrate to the second substrate using the bonding interface on the first substrate and the bonding interface on the second substrate.

Methods for bonding substrates used, for example, in substrate-level packaging, are provided herein. In some embodiments, a method for bonding substrates includes: performing electrochemical deposition (ECD) to deposit at least one material on each of a first substrate and a second substrate, performing chemical mechanical polishing (CMP) on the first substrate and the second substrate to form a bonding interface on each of the first substrate and the second substrate, positioning the first substrate on the second substrate so that the bonding interface on the first substrate aligns with the bonding interface on the second substrate, and bonding the first substrate to the second substrate using the bonding interface on the first substrate and the bonding interface on the second substrate.

A semiconductor package includes a semiconductor chip including a chip pad on a first surface thereof, an external pad electrically connected to the chip pad of the semiconductor chip, an external connection terminal covering the external pad, and an intermediate layer between the external pad and the external connection terminal, the intermediate layer including a third metal material that is different from a first metal material included in the external pad and a second metal material included in the external connection terminal.

A semiconductor package includes a semiconductor chip including a chip pad on a first surface thereof, an external pad electrically connected to the chip pad of the semiconductor chip, an external connection terminal covering the external pad, and an intermediate layer between the external pad and the external connection terminal, the intermediate layer including a third metal material that is different from a first metal material included in the external pad and a second metal material included in the external connection terminal.

A semiconductor package including a first semiconductor chip having a first thickness, a second semiconductor chip on the first semiconductor chip and having a second thickness, the second thickness being smaller than the first thickness, a third semiconductor chip on the second semiconductor chip and having a third thickness, the third thickness being smaller than the second thickness, a fourth semiconductor chip on the third semiconductor chip and having a fourth thickness, the fourth thickness being greater than the third thickness, and a fifth semiconductor chip disposed on the fourth semiconductor chip and having a fifth thickness, the fifth thickness being greater than the fourth thickness may be provided.

A semiconductor package including a first semiconductor chip having a first thickness, a second semiconductor chip on the first semiconductor chip and having a second thickness, the second thickness being smaller than the first thickness, a third semiconductor chip on the second semiconductor chip and having a third thickness, the third thickness being smaller than the second thickness, a fourth semiconductor chip on the third semiconductor chip and having a fourth thickness, the fourth thickness being greater than the third thickness, and a fifth semiconductor chip disposed on the fourth semiconductor chip and having a fifth thickness, the fifth thickness being greater than the fourth thickness may be provided.

A multi-chip unit suitable for chip-level packaging may include multiple IC chips that are interconnected through a metal redistribution structure, and that are directly bonded to an integrated heat spreader. Bonding of the integrated heat spreader to the multiple IC chips may be direct so that no thermal interface material (TIM) is needed, resulting in a reduced bond line thickness (BLT) and lower thermal resistance. The integrated heat spreader may further serve as a structural member of the multi-chip unit, allowing a second side of the redistribution structure to be further interconnected to a host by solder interconnects. The redistribution structure may be fabricated on a sacrificial interposer that may facilitate planarizing IC chips of differing thickness prior to bonding the heat spreader. The sacrificial interposer may be removed to expose the RDL for further interconnection to a substrate without the use of through-substrate vias.

A multi-chip unit suitable for chip-level packaging may include multiple IC chips that are interconnected through a metal redistribution structure, and that are directly bonded to an integrated heat spreader. Bonding of the integrated heat spreader to the multiple IC chips may be direct so that no thermal interface material (TIM) is needed, resulting in a reduced bond line thickness (BLT) and lower thermal resistance. The integrated heat spreader may further serve as a structural member of the multi-chip unit, allowing a second side of the redistribution structure to be further interconnected to a host by solder interconnects. The redistribution structure may be fabricated on a sacrificial interposer that may facilitate planarizing IC chips of differing thickness prior to bonding the heat spreader. The sacrificial interposer may be removed to expose the RDL for further interconnection to a substrate without the use of through-substrate vias.

Disclosed is a method for transient liquid-phase bonding between metal materials using a magnetic force. In particular, in the method, a magnetic force is applied to a transient liquid-phase bonding process, thereby shortening a transient liquid-phase bonding time between the metal materials, and obtaining high bonding strength. To this end, an attractive magnetic force is applied to a ferromagnetic base while a repulsive magnetic force is applied to a diamagnetic base, thereby to accelerate diffusion. This may reduce a bonding time during a transient liquid-phase bonding process between two bases and suppress formation of Kirkendall voids and voids and suppress a layered structure of an intermetallic compound, thereby to increase a bonding strength.