Method for connecting a die assembly to a substrate in an integrated circuit

A method for connecting a die assembly to a substrate in an integrated circuit, the method comprising:

• attaching the die assembly to the substrate, the die assembly comprising a first die and a second die;
• locating a flexible strip over the substrate and the die assembly, the flexible strip carrying one or more conducting routing circuits terminated at each end with a solder-on pad;
• and
• establishing electrical contact between the first die of the die assembly and the second die of the die assembly and between the first and second dies of the die assembly and the substrate via the one or more routing circuits carried on the flexible strip, wherein establishing electrical contact comprises applying an ultrasonic process to the flexible strip, the die assembly and the substrate to fuse solder on the solder-on pads with one or more bond pads on each die of the die assembly and one or more bond fingers on the substrate.

A method for connecting a die assembly to a substrate in an integrated circuit, the method comprising:

• attaching the die assembly to the substrate, the die assembly comprising a first die and a second die;
• locating a flexible strip over the substrate and the die assembly, the flexible strip carrying one or more conducting routing circuits terminated at each end with a solder-on pad;
• and
• establishing electrical contact between the first die of the die assembly and the second die of the die assembly and between the first and second dies of the die assembly and the substrate via the one or more routing circuits carried on the flexible strip, wherein locating the flexible strip over the substrate and the die assembly comprises locating one or more apertures in the flexible strip on one or more projections on a holder retaining the substrate in position.

A method for connecting a die assembly to a substrate in an integrated circuit, the method comprising:

• attaching the die assembly to the substrate, the die assembly comprising a first die and a second die;
• locating a flexible strip over the substrate and the die assembly, the flexible strip carrying one or more conducting routing circuits terminated at each end with a solder-on pad;
• and
• establishing electrical contact between the first die of the die assembly and the second die of the die assembly and between the first and second dies of the die assembly and the substrate via the one or more routing circuits carried on the flexible strip;
• applying a template to the flexible strip after locating the flexible strip over the substrate and the die assembly to clamp the strip in position during the step of establishing electrical contact.

A method of forming a semiconductor device, the method comprising:

• placing a first die over a substrate, the substrate having substrate contacts on a first top surface of a first area, the first die having first bonding pads on a second top surface of a second area, the second area being smaller than the first area;
• placing a second die over the first die, the second die having second bonding pads on a third top surface of a third area, the third area being smaller than the first area;
• placing a flexible strip over the second die;
• and
• electrically coupling the first die with the second die using the flexible strip, wherein first routing circuits disposed within the flexible strip couple the first bonding pads with the substrate contacts, and wherein second routing circuits disposed within the flexible strip couple the first bonding pads with the second bonding pads, wherein the flexible strip is placed by positioning and retaining the flexible strip over the substrate, the first die and the second die using a removable template.

A method of forming a semiconductor device, the method comprising:

• placing a die assembly comprising a first die and a second die over a substrate, the substrate having substrate contacts on a first top surface of a first area, the first die having first bonding pads on a second top surface of a second area, the second area being smaller than the first area, wherein the second die is over the substrate and the first die, wherein the second die comprises second bonding pads on a third top surface of a third area, the third area being smaller than the first area;
• locating a flexible strip over the second die of the die assembly after placing the die assembly to the substrate, the flexible strip having a fourth area;
• and
• electrically coupling the first die with the second die using the flexible strip, wherein first routing circuits disposed within the flexible strip couple the first bonding pads with the substrate contacts, and wherein second routing circuits disposed within the flexible strip couple the first bonding pads with the second bonding pads, wherein the die assembly comprising the first and the second dies is physically separate from the flexible strip before the electrical coupling.