Die stacks and methods of making die stacks with very thin dies are disclosed. The die surfaces remain flat within a 5 micron tolerance despite the thinness of the die and the process steps of making the die stack. A residual flux height is kept below 50% of the spacing distance between adjacent surfaces or structures, e.g. in the inter-die spacing.

Die stacks and methods of making die stacks with very thin dies are disclosed. The die surfaces remain flat within a 5 micron tolerance despite the thinness of the die and the process steps of making the die stack. A residual flux height is kept below 50% of the spacing distance between adjacent surfaces or structures, e.g. in the inter-die spacing.

An integrated circuit assembly including a substrate having a surface including at least one area including contact points operable for connection with an integrated circuit die; and at least one ring surrounding the at least one area, the at least one ring including an electrically conductive material. A method of forming an integrated circuit assembly including forming a plurality of electrically conductive rings around a periphery of a die area of a substrate selected for attachment of at least one integrated circuit die, wherein the plurality of rings are formed one inside the other; and forming a plurality of contact points in the die area.

An integrated circuit assembly including a substrate having a surface including at least one area including contact points operable for connection with an integrated circuit die; and at least one ring surrounding the at least one area, the at least one ring including an electrically conductive material. A method of forming an integrated circuit assembly including forming a plurality of electrically conductive rings around a periphery of a die area of a substrate selected for attachment of at least one integrated circuit die, wherein the plurality of rings are formed one inside the other; and forming a plurality of contact points in the die area.

In an embodiment, a device includes: a back-side redistribution structure including: a metallization pattern on a first dielectric layer; and a second dielectric layer on the metallization pattern; a through via extending through the first dielectric layer to contact the metallization pattern; an integrated circuit die adjacent the through via on the first dielectric layer; a molding compound on the first dielectric layer, the molding compound encapsulating the through via and the integrated circuit die; a conductive connector extending through the second dielectric layer to contact the metallization pattern, the conductive connector being electrically connected to the through via; and an intermetallic compound at the interface of the conductive connector and the metallization pattern, the intermetallic compound extending only partially into the metallization pattern.

In an embodiment, a device includes: a back-side redistribution structure including: a metallization pattern on a first dielectric layer; and a second dielectric layer on the metallization pattern; a through via extending through the first dielectric layer to contact the metallization pattern; an integrated circuit die adjacent the through via on the first dielectric layer; a molding compound on the first dielectric layer, the molding compound encapsulating the through via and the integrated circuit die; a conductive connector extending through the second dielectric layer to contact the metallization pattern, the conductive connector being electrically connected to the through via; and an intermetallic compound at the interface of the conductive connector and the metallization pattern, the intermetallic compound extending only partially into the metallization pattern.

In an embodiment, a package includes: an interposer having a first side; a first integrated circuit device attached to the first side of the interposer; a second integrated circuit device attached to the first side of the interposer; an underfill disposed beneath the first integrated circuit device and the second integrated circuit device; and an encapsulant disposed around the first integrated circuit device and the second integrated circuit device, a first portion of the encapsulant extending through the underfill, the first portion of the encapsulant physically disposed between the first integrated circuit device and the second integrated circuit device, the first portion of the encapsulant being planar with edges of the underfill and edges of the first and second integrated circuit devices.

Flexible devices including conductive traces with enhanced stretchability, and methods of making and using the same are provided. The circuit die is disposed on a flexible substrate. Electrically conductive traces are formed in channels on the flexible substrate to electrically contact with contact pads of the circuit die. A first polymer liquid flows in the channels to cover a free surface of the traces. The circuit die can also be surrounded by a curing product of a second polymer liquid.

Flexible devices including conductive traces with enhanced stretchability, and methods of making and using the same are provided. The circuit die is disposed on a flexible substrate. Electrically conductive traces are formed in channels on the flexible substrate to electrically contact with contact pads of the circuit die. A first polymer liquid flows in the channels to cover a free surface of the traces. The circuit die can also be surrounded by a curing product of a second polymer liquid.

A semiconductor device includes a substrate having a plurality of pads on a surface of the substrate, a semiconductor chip that includes a plurality of metal bumps connected to corresponding pads on the substrate, a first resin layer between the surface of the substrate and the semiconductor chip, a second resin layer between the substrate and the semiconductor chip and between the first resin layer and at least one of the metal bumps, and a third resin layer on the substrate and above the semiconductor chip.