Patterned conductive microstructures within a heat shrinkable substrate

Patent metadata

Field	Value
Publication number	US-11638348-B2
Application number	US-202016934951-A
Country	US
Kind code	B2
Filing date	Jul 21, 2020
Priority date	Jul 6, 2018
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

A conductive interconnect structure comprises a polymeric substrate (e.g., a thermoplastic) and a plurality of compliant conductive microstructures (e.g., conductive carbon nanofibers) embedded in the polymeric substrate. The microstructures can be arranged linearly or in a grid pattern. In response to heating, the polymeric substrate transitions from an unshrunk state to a shrunken state to move the microstructures closer together, thereby increasing an interconnect density of the compliant conductive microstructures. Thus, the gap or pitch between adjacent microstructures is reduced in response to heat-induced shrinkage of the polymeric substrate to generate finely-pitched microstructures that are densely pitched, thereby increasing the current-carrying capacity of the microstructures. The polymeric material can be heated to conform or form-fit to planar and non-planar surfaces/geometries, and can be selectively heated at various portions to tailor or customize the interconnect density of the microstructures at selected portions. Associated electrical conducting assemblies and methods are provided.

First claim

What is claimed is:

1. A conductive interconnect structure, comprising:
a polymeric substrate shrinkable from an unshrunk state to a shrunken state; and
a plurality of compliant conductive microstructures attached to the polymeric substrate, each compliant conductive microstructure comprising a plurality of micro elements,
wherein, in response to selective application of heat, at least a portion of the polymeric substrate transitions from the unshrunk state to the shrunken state to increase an interconnect density of the plurality of compliant conductive microstructures, and
wherein an unshrunk portion of the polymeric substrate defines a first interconnect density region, and wherein a shrunk portion of the polymeric substrate defines a second interconnect density region, wherein a first section of the compliant conductive microstructures associated with the first interconnect density region extend continuously to a second section of the compliant conductive microstructures associated with the second interconnect density region.

2. The conductive interconnect structure of claim 1 , wherein the plurality of micro elements comprises a plurality of compliant conductive nanofibers, and wherein the polymeric substrate comprises a thermoplastic material.

3. The conductive interconnect structure of claim 1 , wherein the plurality of compliant conductive microstructures is arranged in a grid pattern.

4. The conductive interconnect structure of claim 1 , wherein at least some of the compliant conductive microstructures define a first pitch when in the shrunken state, and wherein, when in the unshrunk state, at least some of the compliant conductive microstructures define a second pitch, the first pitch being less than the second pitch.

5. The conductive interconnect structure of claim 4 , wherein the polymeric material is comprised of a thermoplastic material that is shrinkable to a fraction of its unshrunk size in response to the application of heat.

6. The conductive interconnect structure of claim 1 , wherein a first portion of the polymeric substrate comprises a first curved profile, and wherein a second portion of the polymeric substrate comprises a second curved profile different from the first curved profile.

7. The conductive interconnect structure of claim 1 , wherein the polymeric substrate is formed from a polymeric film and a polymeric base substrate that embed the compliant conductive microstructures.

8. The conductive interconnect structure of claim 1 , wherein a first end portion of the conductive interconnect structure defines a first interconnect density and is coupleable to a first electronics component, a second end portion of the conductive interconnect structure defines a second interconnect density and is coupleable to a second electronics component, and a middle portion of the conductive interconnect structure defined between the first and second end portions comprises a third interconnect density, and wherein the first and second interconnect densities are each higher than the third interconnect density.

9. An electrical conducting assembly, comprising:
a support body comprising a support surface;
a conductive interconnect structure carried by the support body about the support surface,
the conductive interconnect structure comprising:
a polymeric substrate shrinkable from an unshrunk state to a shrunken state; and
a plurality of compliant conductive microstructures attached to the polymeric substrate, each conductive microstructure comprising a plurality of micro elements,
wherein, in response to selective application of heat, at least a portion of the polymeric substrate transitions from the unshrunk state to the shrunken state to increase an interconnect density of the plurality of compliant conductive microstructures, thereby conforming the conductive interconnect structure to the support surface of the support body, and
wherein an unshrunk portion of the polymeric substrate defines a first interconnect density region, and wherein a shrunk portion of the polymeric substrate defines a second interconnect density region, wherein a first section of the compliant conductive microstructures associated with the first interconnect density region extend continuously to a second section of the compliant conductive microstructures associated with the second interconnect density region.

10. The assembly of claim 9 , wherein the plurality of micro elements comprises a plurality of compliant conductive nanofibers, and wherein the polymeric substrate comprises a thermoplastic material, the thermoplastic material configured to shrink to a fraction its original shape and size in response to the application of heat.

11. The assembly of claim 9 , wherein the plurality of compliant conductive microstructures are arranged in a grid pattern, wherein at least a portion of the support surface comprises a curved surface.

12. The assembly of claim 9 , wherein the support body comprises a first curved support surface and a second curved support surface, wherein a first section of the compliant conductive microstructures is conformed to the first curved support surface, and wherein a second section of the compliant conductive microstructures is conformed to the second curved support surface, wherein the first section comprises an interconnect density that is higher than an interconnect density of the second section.

13. The assembly of claim 12 , wherein the first section of the compliant conductive microstructures is electrically coupled to a processor, and wherein the second section of compliant conductive microstructures is electrically coupled to at least one electronics component.

14. The assembly of claim 9 , wherein a first section of the compliant conductive microstructures define a first pitch and is coupled to a first electronics component, and wherein a second section of the compliant conductive microstructures define a second pitch and is coupled to a second electronics component, and wherein a middle section of the compliant conductive microstructures defined between the first and second sections comprises a third pitch, wherein the first and second pitches are each less than the third pitch.

15. The assembly of claim 9 , wherein a first section of the compliant conductive microstructures defines a first pitch and is coupled to a first electronics component, wherein a second section of the compliant conductive microstructures defines a second pitch and is coupled to a second electronics component, and wherein a middle section of the compliant conductive microstructures defined between the first and second sections defines a third pitch, wherein the first and second pitches are each higher than the third pitch.

Assignees

• Raytheon Co

Inventors

• Grosse Kyle L
• Trent Catherine

Classifications

• H05K2201/0129

  Thermoplastic polymer, e.g. auto-adhesive layer; Shaping of thermoplastic polymer · CPC title

• H05K2203/1105

  Heating or thermal processing not related to soldering, firing, curing or laminating, e.g. for shaping the substrate or during finish plating · CPC title

• H05K2201/09245

  Crossing layout · CPC title

• H05K1/09

  Use of materials for the {conductive, e.g. } metallic pattern · CPC title

• H05K2201/026

  Nanotubes or nanowires · CPC title