Methods of manufacturing and operating die-to-die inductive communication devices

Patent metadata

Field	Value
Publication number	US-9362987-B2
Application number	US-201514812242-A
Country	US
Kind code	B2
Filing date	Jul 29, 2015
Priority date	Dec 12, 2013
Publication date	Jun 7, 2016
Grant date	Jun 7, 2016

Abstract

Embodiments of inductive communication devices include first and second IC die and an inductive coupling substrate. The first IC die has a first coil. The inductive coupling substrate has a second coil and a first signal communication interface (e.g., a third coil or a contact). The second IC die has a second signal communication interface (e.g., a fourth coil or a contact). The first IC die and the inductive coupling substrate are arranged so that the first and second coils are aligned across a gap between the first IC die and the inductive coupling substrate. A dielectric component is positioned within the gap between the first and second coils to galvanically isolate the first IC die and the inductive coupling substrate. During operation, signals are conveyed between the first and second IC die through inductive coupling between the coils and communication through the signal communication interfaces.

First claim

What is claimed is:

1. A method of manufacturing an inductive communication device, the method comprising the steps of:
coupling together a first integrated circuit (IC) die, an inductive coupling substrate, a second IC die, and one or more dielectric structures, wherein
the first IC die includes a first semiconductor substrate, a first coil proximate to a first surface of the first IC die, and a plurality of first bond pads, wherein the plurality of first bond pads are electrically coupled to the first coil,
the inductive coupling substrate includes a second coil and a first signal communication interface, wherein the second coil is proximate to a first surface of the inductive coupling substrate, and the second coil is electrically coupled to the first signal communication interface,
the second IC die includes a second semiconductor substrate, a second signal communication interface, and a plurality of second bond pads electrically coupled to the second signal communication interface,
the first IC die, the inductive coupling substrate, and the second IC die are arranged within the device so that the first surface of the first IC die faces the first surface of the inductive coupling substrate, the first surface of the inductive coupling substrate faces a first surface of the second IC die, and the first coil and the second coil are aligned with each other across a gap between the first IC die and the and the inductive coupling substrate,
the first IC die and the inductive coupling substrate are galvanically isolated from each other, and
the one or more dielectric structures are positioned within the gap directly between the first coil and the second coil.

2. The method of claim 1 , further comprising:
electrically connecting the plurality of first bond pads of the first IC die to first package leads; and
electrically connecting the plurality of second bond pads of the second IC die to second package leads.

3. The method of claim 2 , wherein:
electrically connecting the plurality of first bond pads of the first IC die to first package leads includes electrically connecting first wirebonds between the plurality of first bond pads and the first package leads; and
electrically connecting the plurality of second bond pads of the second IC die to second package leads includes electrically connecting second wirebonds between the plurality of second bond pads and the second package leads.

4. The method of claim 2 , further comprising:
coupling a second surface of the first IC die to a support structure; and
coupling a second surface of the second IC die to the support structure, wherein the support structure and the first and second package leads form portions of a leadframe.

5. The method of claim 1 , further comprising:
forming the first IC die by forming, over the first semiconductor substrate, a plurality of first patterned conductive layers, wherein the first coil is formed from multiple substantially-concentric first conductive rings of the first patterned conductive layers and first conductive vias between the first patterned conductive layers; and
forming the inductive coupling substrate die by forming a plurality of second patterned conductive layers, wherein the second coil is formed from multiple substantially-concentric second conductive rings of the second patterned conductive layers and second conductive vias between the second patterned conductive layers.

6. The method of claim 1 , wherein:
the first signal communication interface of the inductive coupling substrate comprises a third coil proximate to the first surface of the inductive coupling substrate and spatially separated from the second coil;
the second signal communication interface of the second IC die comprises a fourth coil proximate to the first surface of the second IC die;
the third coil and the fourth coil are aligned with each other across a gap between the second IC die and the inductive coupling substrate;
the second IC die and the inductive coupling substrate are galvanically isolated from each other; and
the dielectric structure also is positioned directly between the third coil and the fourth coil.

7. The method of claim 6 , wherein:
the third coil is formed from a plurality of third patterned conductors in a plurality of third metal layers that are separated by one or more third dielectric layers; and
the fourth coil is formed from a plurality of fourth patterned conductors in a plurality of fourth metal layers that are separated by one or more fourth dielectric layers.

8. The method of claim 1 , wherein:
the first signal communication interface of the inductive coupling substrate comprises a first electrical contact proximate to the first surface of the inductive coupling substrate and spatially separated from the second coil;
the second signal communication interface of the second IC die comprises a second electrical contact proximate to the first surface of the second IC die; and
the method further comprises forming an electrical connection between the first and second electrical contacts.

9. The method of claim 1 , further comprising:
forming the first IC die by forming first communication circuitry between the plurality of first bond pads and the first coil; and
forming the second IC die by forming second communication circuitry between the plurality of second bond pads and the second signal communication interface.

10. The method of claim 1 , further comprising:
forming the first IC die to include first communication circuitry coupled to the first coil, wherein the first communication circuitry is selected from transmitter circuitry, receiver circuitry, and transceiver circuitry; and
forming the second IC die to include second communication circuitry coupled to the second signal communication interface, wherein the second communication circuitry is selected from transmitter circuitry, receiver circuitry, and transceiver circuitry.

11. The method of claim 1 , wherein the one or more dielectric structures include one or more of:
a material selected from polyimide, polytetrafluorethylene, and benzocyclobutene; a portion of a dielectric layer overlying the first coil; a portion of a dielectric layer overlying the second coil; and an air gap.

12. The method of claim 1 , wherein the one or more dielectric structures includes a dielectric material with a thickness in a range of about 25 micrometers to about 400 micrometers.

13. The method of claim 1 , wherein the one or more dielectric structures include a dielectric structure having a first surface and an opposing second surface, wherein the first surface of the dielectric structure is coupled to the first surface of the first IC die, the second surface of the dielectric structure is coupled to the first surface of the inductive coupling substrate, and the dielectric structure extends beyond edges of the inductive coupling substrate.

14. The method of claim 1 , wherein:
the first IC die further includes one or more additional first coils proximate to the first surface of the first IC die;
the inductive coupling substrate further includes one or more additional second coils proximate to the first surface of the inductive coupling substrate, and one or more additional first signal communication interfaces electrically coupled to the additional second coils, wherein each of the additional first coils is aligned with a corresponding one of the additional second coils across the gap;
the second IC die further includes one or more additional second signal communication interfaces electrically coupled to the plurality of second bond pads; and
the one or more dielectr

Assignees

• Freescale Semiconductor Inc

Inventors

• Brauchler Fred T
• Gray Randall C

Classifications

• H10W90/293

  characterised by non-galvanic coupling between the chips, e.g. capacitive coupling · CPC title

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title

• H10W72/877

  Bump connectors and die-attach connectors · CPC title

• H10W72/865

  Die-attach connectors and bond wires · CPC title