Programmable stitch chaining of die-level interconnects for reliability testing
View Patent ↗A method includes fabricating a set of die in a production run, each die comprising a set of pads at a periphery of a top metal layer, a first set of fuse elements, and a second set of fuse elements. Each fuse element of the first set of fuse elements couples a corresponding pad of the set to a corresponding bus when in a conductive state, and each fuse element of the second set couples a corresponding subset of pads of the set together when in a conductive state. The method further includes selecting a subset of the die of the production run for testing, and configuring each die of the subset for testing by placing each fuse element of the first set in a non-conductive state and placing each fuse element of the second set in a conductive state.
1. An integrated circuit (IC) die comprising:
a set of pads at a periphery of a top metal layer;
a first set of fuse elements, each fuse element of the first set of fuse elements coupling a corresponding pad of the set to a corresponding power bus when in a conductive state;
a second set of fuse elements, each fuse element coupling a corresponding subset of pads of the set together when in a conductive state;
wherein the fuse elements of the first set comprise electronic fuses;
wherein the fuse elements of the second set comprise electronic anti-fuses; and
wherein the die further comprises:
an activation pad at the top metal layer, the activation pad electrically coupled to each electronic fuse of the first set and each electronic anti-fuse of the second set.
2. The IC die of claim 1 , wherein the electronic fuses of the first set and the electronic anti-fuses of the second set are located in a keep-out zone of the die.
3. A method comprising:
electrically isolating a set of pads of a die and which are located at a periphery of the die from corresponding busses of the die by rendering non-conductive each fuse element of a first set of fuse elements of the die, the first set of fuse elements coupling the sets of pads to the respective busses;
electrically coupling subsets of pads of the set of pads by rendering conductive each fuse element of a second set of fuse elements of the die, the second set of fuse elements coupling the pads of each subset;
bonding the die to a substrate to form an integrated circuit (IC) device, the substrate having one or more interconnects coupling corresponding pairs of subsets of pads of the die so as to electrically connect the set of pads into an electrically-continuous chain that stitches between the die and the substrate; and
testing the IC device by monitoring a resistance across the chain.
4. The method of claim 3 , wherein the fuse elements of the first set comprise at least one of: sacrificial fuses; and electronic fuses.
5. The method of claim 3 , wherein the fuse elements of the second set comprise at least one of: sacrificial anti-fuses; and electronic anti-fuses.
6. The method of claim 3 , wherein the set of pads are located at a corner of the die.
7. The method of claim 3 , further comprising:
locating at least one of the first set of fuse elements and the second set of fuse elements in a keep-out zone of the die.
8. The method of claim 3 , further comprising:
fabricating a set of die as a production run intended for inclusion in saleable integrated circuit devices; and
selecting the die from the set of die as a test die for the production run.
9. The method of claim 3 , further comprising:
rendering non-conductive each fuse element of the first set of fuse elements by applying a voltage to each pad of the first set via a probe pin, wherein the fuse elements of the first set comprise sacrificial fuses; and
rendering conductive each fuse element of the second set of fuse elements by applying a voltage to each pad of the first set via a probe pin, wherein the fuse elements of the second set comprise sacrificial anti-fuses.
10. The method of claim 3 , further comprising:
rendering non-conductive each fuse element of the first set of fuse elements by applying a voltage to an activation pad of the die via a probe pin, the activation pad electrically coupled to each electronic fuse of the first set and to each electronic anti-fuse of the second set, wherein the fuse elements of the first set comprise electronic fuses and the fuse elements of the second set comprise electronic anti-fuses; and
rendering conductive each fuse element of the second set by applying a voltage to the activation pad via a probe pin.
11. An integrated circuit (IC) device comprising:
a die comprising:
a set of pads at a periphery of a top metal layer;
a set of busses;
a first set of non-conductive fuse elements electrically isolating the set of pads from corresponding busses of the set of busses;
a second set of conductive fuse elements electrically coupling subsets of pads of the set of pads; and
a substrate bonded to the die, the substrate comprising one or more interconnects coupling corresponding pairs of subsets of pads of the die so as to electrically connect the set of pads into an electrically-continuous chain that stitches between the die and the substrate.
12. The IC device of claim 11 , wherein the set of pads are located at a corner of the die.
13. The IC device of claim 11 , wherein at least one of the first set of fuse elements and the second set of fuse elements is located in a keep-out zone of the die.
14. The IC device of claim 11 , wherein:
the fuse elements of the first set comprise electronic fuses;
the fuse elements of the second set comprise electronic anti-fuses; and
the die further comprises:
an activation pad at the top metal layer, the activation pad electrically coupled to each electronic fuse of the first set and each electronic anti-fuse of the second set.