Phonon disruptors for increased thermal resistance without sacrificing electrical signal quality in thermal sensors using alloy and intermetallic materials

Patent metadata

Field	Value
Publication number	US-12320707-B2
Application number	US-202217741185-A
Country	US
Kind code	B2
Filing date	May 10, 2022
Priority date	May 11, 2021
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

Sensor interconnects and supports and methods of making them utilize phonon disruptors for increased thermal resistance while maintaining acceptable electrical signal quality in materials. Phonon disruptors include the use of an electrically conductive alloy material or intermetallic material of at least two or more elements to promote scattering of phonons. These materials are selected to scatter heat carriers while allowing electrons to pass through the material.

First claim

We claim:

1. A thermal sensor device comprising:
a substrate;
read-out circuitry;
a thermal sensor element; and
at least one conductive leg that constitutes a conductive path of enhanced thermal resistance extending between the thermal sensor element and the read-out circuitry configured for conducting an electrical signal between the thermal sensor element and the read-out circuitry, the at least one conductive leg having a thermal resistance and comprising an electrically conductive alloy material or intermetallic material of at least two or more elements having an electrical conductivity (o) no less than about 1.9×10 5 S/m and a thermal conductivity (k) no more than about 22 Wm −1 K −1 .

2. The device of claim 1 , wherein the alloy material or the intermetallic material is a binary alloy composed of only two elements.

3. The device of claim 1 , wherein the alloy material or the intermetallic material is a ternary, quaternary or higher alloy composed of three, four or more elements, wherein the additional element or elements beyond two increase scattering and transport disruption of the phonons through the at least one conductive leg compared to a binary material composed of only two elements.

4. The device of claim 1 , wherein the at least one conductive leg is provided as a homogenous film or a trace.

5. The device of claim 1 , wherein the material is an intermetallic having a B1, B2, B3, B4, B10, B17, B19 or B20 crystal packing structure.

6. The device of claim 1 , wherein the alloy material or the intermetallic material are formed of only metal atoms.

7. The device of claim 1 , wherein the alloy material is clad with a cladding material.

8. The device of claim 1 , wherein the thermal resistance and electrical conductivity of the electrically conductive alloy material or the intermetallic material are determined using the Klemens analytical model and the Nordheim rule, respectively.

9. The device of claim 1 , wherein the phonon mean free path is greater than the electron mean free path through the conductive path of enhanced thermal resistance.

10. A method for forming the thermal sensor device of claim 1 , the method comprising:
selecting an electrically conductive alloy material or intermetallic material of at least two or more elements to promote scattering of phonons; and
forming, as part of the at least one conductive leg extending between the thermal sensor element and the read-out circuitry, the phonon transport disrupting structure from the selected electrically conductive alloy material or intermetallic material for conducting an electrical signal between the thermal sensor element and the read-out circuitry.

11. The device of claim 2 , wherein the material comprises: Ni X Ti 1-X 0.45<x<0.55 , Co X Ga 1-X X≈0.5 , or Al X Fe 1-X X≈0.5 , if an intermetallic, or a-NiTi, CuNi, or TiN, if an alloy.

12. The device of claim 3 , wherein the material comprises: NiTiHf, NiTiCoHf, or hcp-GeSbTe, if an intermetallic, or Fe 0.55 Ni 0.2 Cr 0.25 , Zr 0.55 Al 0.1 Ni 0.05 Cu 0.3 , Pd 0.4 Ni 0.4 P 0.2 , if a binary alloy.

13. The device of claim 8 , wherein the thermal resistance of the electrically conductive alloy material or the intermetallic material is determined according to the following equation:

k
L

k
0

=

tan

-
1

⁢
u

u

,

where
⁢

u

=

(

(

6
⁢

π
5

⁢

V
2

)

1
3

2
⁢

k
B

⁢

v
s

⁢

k
0

⁢
Γ

)

1
/
2

,

where
⁢

Γ

=

〈

Δ
⁢

M
2

_

〉

〈

M
2

_

〉

,

〈

Δ
⁢

M
2

_

〉

is the average mass variance, ( M 2 ) is the average mass squared, k 0 is the thermal conductivity of a pure material, k L is the lattice thermal conductivity of the alloy, V is the volume of a unit cell of the compound, and v s is the average speed of sound in the material.

14. The device of claim 8 , wherein the electrical conductivity of the electrically conductive alloy material or the intermetallic material is determined according to the following equation:

σ
=

1

C
⁢

X

Assignees

• U S Army Combat Capabilities Development Command Army Res Laboratory
• Us Army

Inventors

• Wilson Adam A
• Waldron Dennis L
• Knick Cory R
• Sharar Darin J

Classifications

• G01J2005/0077

  Imaging · CPC title

• G01J2005/202

  Arrays · CPC title

• G01J5/023

  Particular leg structure or construction or shape; Nanotubes · CPC title

• G01J5/046

  Materials; Selection of thermal materials · CPC title

• G01J5/20 Primary

  using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices · CPC title