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 includes a transfer mechanism to transfer an electrically-actuatable element directly from a wafer tape to a transfer location on a circuit trace on a product substrate. The transfer mechanism includes one or more transfer wires. Two or more stabilizers disposed on either side of the one or more transfer wires. A needle actuator is connected to the one or more transfer wires and the two or more stabilizers to move the one or more transfer wires and the two or more stabilizers to a die transfer position.

An apparatus includes a transfer mechanism to transfer an electrically-actuatable element directly from a wafer tape to a transfer location on a circuit trace on a product substrate. The transfer mechanism includes one or more transfer wires. Two or more stabilizers disposed on either side of the one or more transfer wires. A needle actuator is connected to the one or more transfer wires and the two or more stabilizers to move the one or more transfer wires and the two or more stabilizers to a die transfer position.

A semiconductor package includes: a first structure having a first insulating layer disposed on one surface, and first electrode pads and first dummy pads penetrating through the first insulating layer, a second structure having a second insulating layer having the other surface bonded to the one surface and the first insulating layer and disposed on the other surface, and second electrode pads and second dummy pads that penetrate through the second insulating layer, the second electrode pads being bonded to the first electrode pads, respectively, and the second dummy pads being bonded to the first dummy pads, respectively. In the semiconductor chip, ratios of surface areas per unit area of the first and second dummy pads to the first and second insulating layers on the one surface and the other surface gradually decrease toward sides of the first and second structures.

A semiconductor package includes: a first structure having a first insulating layer disposed on one surface, and first electrode pads and first dummy pads penetrating through the first insulating layer, a second structure having a second insulating layer having the other surface bonded to the one surface and the first insulating layer and disposed on the other surface, and second electrode pads and second dummy pads that penetrate through the second insulating layer, the second electrode pads being bonded to the first electrode pads, respectively, and the second dummy pads being bonded to the first dummy pads, respectively. In the semiconductor chip, ratios of surface areas per unit area of the first and second dummy pads to the first and second insulating layers on the one surface and the other surface gradually decrease toward sides of the first and second structures.

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.

A method of removing a substrate, comprising: forming a growth restrict mask with a plurality of striped opening areas directly or indirectly upon a GaN-based substrate; and growing a plurality of semiconductor layers upon the GaN-based substrate using the growth restrict mask, such that the growth extends in a direction parallel to the striped opening areas of the growth restrict mask, and growth is stopped before the semiconductor layers coalesce, thereby resulting in island-like semiconductor layers. A device is processed for each of the island-like semiconductor layers. Etching is performed until at least a part of the growth restrict mask is exposed. The devices are then bonded to a support substrate. The GaN-based substrate is removed from the devices by a wet etching technique that at least partially dissolves the growth restrict mask. The GaN substrate that is removed then can be recycled.

A method of removing a substrate, comprising: forming a growth restrict mask with a plurality of striped opening areas directly or indirectly upon a GaN-based substrate; and growing a plurality of semiconductor layers upon the GaN-based substrate using the growth restrict mask, such that the growth extends in a direction parallel to the striped opening areas of the growth restrict mask, and growth is stopped before the semiconductor layers coalesce, thereby resulting in island-like semiconductor layers. A device is processed for each of the island-like semiconductor layers. Etching is performed until at least a part of the growth restrict mask is exposed. The devices are then bonded to a support substrate. The GaN-based substrate is removed from the devices by a wet etching technique that at least partially dissolves the growth restrict mask. The GaN substrate that is removed then can be recycled.

A semiconductor package includes; a wiring structure including signal wiring and heat transfer wiring, an active chip on the wiring structure, a signal terminal disposed between the wiring structure and the active chip, a first heat transferring terminal disposed between the wiring structure and the active chip and connected to the heat transfer wiring, a passive chip on the wiring structure, a second heat transferring terminal disposed between the wiring structure and the passive chip and connected to the heat transfer wiring, and a heat spreader on the passive chip.