Method for stacking serially-connected integrated circuits and multi-chip device made from same
View Patent ↗A multi-chip device and method of stacking a plurality substantially identical chips to produce the device are provided. The multi-chip device, or circuit, includes at least one through-chip via providing a parallel connection between signal pads from at least two chips, and at least one through-chip via providing a serial or daisy chain connection between signal pads from at least two chips. Common connection signal pads are arranged symmetrically about a center line of the chip with respect to duplicate common signal pads. Input signal pads are symmetrically disposed about the center line of the chip with respect to corresponding output signal pads. The chips in the stack are alternating flipped versions of the substantially identical chip to provide for this arrangement. At least one serial connection is provided between signal pads of stacked and flipped chips when more than two chips are stacked.
1. A multi-chip device including a stacked pair of integrated circuit chips comprising:
a top chip having:
one or more input signal pads for connection to external input signals;
one or more common connection signal pads, each common connection signal pad being symmetrically disposed about a center line of the top chip with respect to a duplicate common connection signal pad;
one or more output signal pads symmetrically disposed about the center line of the top chip with respect to respective input signal pads;
a bottom chip having a substantially identical signal pad arrangement as the top chip, the bottom chip being flipped in orientation with respect to the top chip;
a parallel connection through-chip via connecting a top chip common connection signal pad in parallel with its duplicate common connection signal pad; and
a serial connection through-chip via connecting a top chip output signal pad in series with its respective input signal pad on the bottom chip.
2. The device of claim 1 wherein the one or more input signal pads, the one or more common connection signal pads and the one or more output signal pads are disposed along a single edge of the top chip.
3. The device of claim 1 further comprising a plurality of serial connection through-chip vias connecting top chip output signal pads in series with their respective input signal pads on the bottom chip.
4. The device of claim 1 further comprising a plurality of parallel connection through-chip vias connecting top chip common connection signal pads in parallel with their duplicate common connection signal pads on the bottom chip.
5. The device of claim 1 wherein the one or more input signal pads are disposed on the same side of the center line of the top chip.
6. The device of claim 1 wherein the top chip and the bottom chip are aligned so there is substantially no offset.
7. The device of claim 6 wherein an edge of the top chip lines up vertically with a corresponding edge of the bottom chip.
8. The device of claim 1 wherein the top chip and the bottom chip face the same direction as one another.
9. The device of claim 8 wherein a side of the top chip having selected signal pads faces the same direction as a side of the bottom chip having the same selected signal pads.
10. A multi-chip device comprising:
a plurality of substantially identical chips including a top chip, an even number of intermediate chips and a bottom chip, each chip comprising:
one or more input signal pads;
one or more common connection signal pads, each common connection signal pad being symmetrically disposed about a center line of the chip with respect to a duplicate common connection signal pad;
one or more output signal pads symmetrically disposed about the center line of the chip with respect to respective input signal pads;
a parallel connection through-chip via connecting corresponding common connection signal pads on each chip together in parallel; and
a serial connection through-chip via connecting an output signal pad on one chip in series with its respective input signal pad on another chip,
the top chip having the one or more input signal pads for connection to external input signals, the common connection signal pads for connection to external common signals, and the one or more output signal pads connected to respective input signal pads of an adjacent chip,
the bottom chip having the one or more output signal pads for connection to external output signals, the common connection signal pads for connection to the external common signals and the one or more input signal pads connected to respective output signal pads of an adjacent chip,
at least one of the intermediate chips having the one or more output signal pads connected serially to respective one or more input signal pads of an adjacent intermediate chip, and
the plurality of substantially identical chips being provided in a stack, each alternating chip in the stack being flipped in orientation with respect an adjacent chip, each chip having substantially identical signal pad arrangements.
11. The device of claim 10 wherein the even number of intermediate chips comprises a multiplicity of intermediate chips having the one or more output signal pads connected to respective one or more input signal pads of a plurality of adjacent intermediate chips.
12. The device of claim 10 further comprising an insulator disposed between pads of adjacent intermediate chips to prevent contact between selected adjacent pads.
13. The device of claim 12 wherein the parallel connection through-chip via extends through the insulator and through the corresponding common connection signal pads of the intermediate chips.
14. The device of claim 12 further comprising a through-pad via extending through the insulator to connect the one or more output signal pads of one of the intermediate chips to respective one or more input signal pads of an adjacent intermediate chip.
15. The device of claim 12 further comprising:
a controller for controlling access to the plurality of substantially identical chips;
controller input connections to connect output signal pads from the bottom chip to an input side of the controller; and
controller output connections to connect an output side of the controller to the input pads of the top chip.
16. The device of claim 15 wherein the controller is placed below the stacked chips, and the controller output connections comprise wire bonding.
17. The device of claim 15 wherein the controller is placed above the stacked chips, and the controller input connections comprise wire bonding.
18. A multi-chip device comprising:
a plurality of substantially identical chips including a top chip and a bottom chip, the top and bottom chips having substantially identical signal pad arrangements, the bottom chip being flipped in orientation with respect to the top chip;
at least one serial through-chip via to connect at least one output signal pad of the top chip to a respective input signal pad of the bottom chip; and
at least one parallel through-chip via to connect at least one common connection signal pad on the top chip to at least one duplicate common connection signal pad on the bottom chip.
19. A multi-chip device comprising:
a plurality of substantially identical chips including a top chip, an even number of intermediate chips and a bottom chip, each chip in the device having substantially identical signal pad arrangements, the plurality of chips being provided in a stack, each alternating chip in the stack being flipped in orientation with respect an adjacent chip;
at least one parallel through-chip via;
at least one serial through-chip via; and
at least one serial connection between output and input signal pads of two of the intermediate chips.
20. A multi-chip package comprising:
a plurality of substantially identical chips including a top chip, an even number of intermediate chips and a bottom chip, each chip in the device having substantially identical signal pad arrangements, the plurality of chips being provided in a stack, each alternating chip in the stack being flipped in orientation with respect an adjacent chip;
at least one parallel through-chip via;
at least one serial through-chip via;
at least one serial connection between output and input signal pads of two of the intermediate chips;
package input connectors for connection to external input signals; and
package output connectors for connection to external output signals.