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.

An apparatus comprising a substrate with multiple electronic devices. An interconnect structure formed on a first side of the substrate interconnects the electronic devices. Dummy TSVs each extend through the substrate and form an alignment mark on a second side of the substrate. Functional TSVs each extend through the substrate and electrically connect to the electronic devices. A redistribution layer (RDL) formed on the second side of the substrate interconnects ones of the dummy TSVs with ones of the functional TSVs. Step heights of the RDL over the functional TSVs are less than a predetermined value, whereas step heights of the RDL over the dummy TSVs are greater than the predetermined value.

An apparatus comprising a substrate with multiple electronic devices. An interconnect structure formed on a first side of the substrate interconnects the electronic devices. Dummy TSVs each extend through the substrate and form an alignment mark on a second side of the substrate. Functional TSVs each extend through the substrate and electrically connect to the electronic devices. A redistribution layer (RDL) formed on the second side of the substrate interconnects ones of the dummy TSVs with ones of the functional TSVs. Step heights of the RDL over the functional TSVs are less than a predetermined value, whereas step heights of the RDL over the dummy TSVs are greater than the predetermined value.

A semiconductor structure includes: a first base having a first face, a second base having a second face and a welded structure. The first base is provided with an electrical connection column protruding from the first face. A conductive column is provided in the second base, and a first groove and a second groove are further provided at the second face. The first groove is located above the conductive column, and the second groove exposes at least part of a side surface of the conductive column. The protruding portion of the electrical connection column is located in the second groove, and part of a side surface of the electrical connection column and part of the side surface of the conductive column overlap in staggered way in a direction perpendicular to the first face or the second surface. At least part of the welded structure is filled in the first groove.

A bonding element and a method for manufacturing the same thereof are provide, wherein the method comprises the following steps: providing a carrier substrate; forming a first metal layer on the carrier substrate; forming a first insulating layer on the first metal layer, wherein the first insulating layer includes a first through hole; forming a first passivation layer and a first conductive layer in the first through hole, wherein the first passivation layer and the first conductive layer in the first through hole form a first connecting bump; forming a first substrate on the first connection bump and the first insulating layer; removing the carrier substrate and the first metal layer to form a first sub-bonding element; and connecting the first sub-bonding element and a second sub-bonding element with a surface of the first passivation of the first connection bump to form the bonding element.

A bond tip for thermocompression bonding a bottom surface includes a die contact area and a low surface energy material covering at least a portion of the bottom surface. The low surface energy material may cover substantially all of the bottom surface, or only a peripheral portion surrounding the die contact area. The die contact area may be recessed with respect to the peripheral portion a depth at least as great as a thickness of a semiconductor die to be received in the recessed die contact area. A method of thermocompression bonding is also disclosed.

Embodiments include semiconductor packages and methods to form the semiconductor packages. A semiconductor package includes a plurality of first dies on a substrate, an interface layer over the first dies, a backside metallization (BSM) layer directly on the interface layer, where the BSM layer includes first, second, and third conductive layer, and a heat spreader over the BSM layer. The first conductive layer includes a titanium material. The second conductive layer includes a nickel-vanadium material. The third conductive layer includes a gold material, a silver material, or a copper material. The copper material may include copper bumps. The semiconductor package may include a plurality of second dies on a package substrate. The substrate may be on the package substrate. The second dies may have top surfaces substantially coplanar to top surface of the first dies. The BSM and interface layers may be respectively over the first and second dies.

Embodiments include semiconductor packages and methods to form the semiconductor packages. A semiconductor package includes a plurality of first dies on a substrate, an interface layer over the first dies, a backside metallization (BSM) layer directly on the interface layer, where the BSM layer includes first, second, and third conductive layer, and a heat spreader over the BSM layer. The first conductive layer includes a titanium material. The second conductive layer includes a nickel-vanadium material. The third conductive layer includes a gold material, a silver material, or a copper material. The copper material may include copper bumps. The semiconductor package may include a plurality of second dies on a package substrate. The substrate may be on the package substrate. The second dies may have top surfaces substantially coplanar to top surface of the first dies. The BSM and interface layers may be respectively over the first and second dies.

A semiconductor structure and a method for manufacturing a semiconductor structure are provided. The semiconductor structure includes: a first base with a first surface, in which a conductive pillar is arranged in the first base, the first surface includes a first groove, and the first groove exposes a top surface and a portion of a sidewall of the conductive pillar; a second base with a second surface, in which the first surface is bonded to the second surface, the second surface includes a second groove, an electrical connection pillar is arranged in the second base, the electrical connection pillar is located in the second groove, and the electrical connection pillar protrudes from the second surface; and an electrical connection structure, in which the electrical connection structure and a portion of the electrical connection pillar are embedded into the first groove.