Thermoelectric devices including thermoelectric elements having off-set metal pads and related structures, methods, and systems
View Patent ↗A thermoelectric device may include a thermoelectric element including a layer of a thermoelectric material and having opposing first and second surfaces. A first metal pad may be provided on the first surface of the thermoelectric element, and a second metal pad may be provided on the second surface of the thermoelectric element. In addition, the first and second metal pads may be off-set in a direction parallel with respect to the first and second surfaces of the thermoelectric element. Related methods are also discussed.
1. A thermoelectric device comprising:
a thermoelectric element including a layer of a thermoelectric material and having opposing first and second surfaces;
a first metal pad on the first surface of the thermoelectric element; and
a second metal pad on the second surface of the thermoelectric element, wherein the first and second metal pads are off-set in a first direction parallel with respect to the first and second surfaces of the thermoelectric element, wherein at least a portion of the first metal pad is non-overlapping with respect to the second metal pad in a second direction that is orthogonal with respect to the first and second surfaces of the thermoelectric element, and wherein at least a portion of the second metal pad is non-overlapping with respect to the first metal pad in the second direction;
wherein a first axis in the second direction extends through the first pad and the first surface of the thermoelectric element, and wherein a second axis in the second direction extends through the second pad and the second surface of the thermoelectric element.
2. A thermoelectric device according to claim 1 further comprising:
a thermally conductive header adjacent the thermoelectric element wherein the second metal pad is mechanically coupled between the thermally conductive header and the thermoelectric element.
3. A thermoelectric device according to claim 2 wherein the thermoelectric element comprises an N-type thermoelectric element, the thermoelectric device further comprising:
a P-type thermoelectric element including a layer of a P-type thermoelectric material and having opposing first and second surfaces;
a third metal pad mechanically coupled between the first surface of the P-type thermoelectric element and the thermally conductive header; and
a fourth metal pad on the second surface of the P-type thermoelectric element, wherein the third and fourth metal pads are off-set in a direction parallel with respect to the first and second surfaces of the P-type thermoelectric element;
wherein an electrically conductive trace of the thermally conductive header provides electrical coupling between the second and third metal pads to define a path of current flow from the first metal pad through the N-type thermoelectric element to the second metal pad through the electrically conductive trace to the third metal pad and through the P-type thermoelectric element to the fourth metal pad.
4. A thermoelectric device according to claim 3 further comprising:
a second thermally conductive header wherein the first metal pad is mechanically coupled between the second thermally conductive header and the N-type thermoelectric element and wherein the fourth metal pad is mechanically coupled between the P-type thermoelectric element and the second thermally conductive header.
5. A thermoelectric device according to claim 1 wherein the thermoelectric material comprises a crystalline semiconductor material.
6. A thermoelectric device according to claim 1 wherein the thermoelectric material comprises a single crystal semiconductor material.
7. A thermoelectric device according to claim 1 wherein the thermoelectric material comprises bismuth telluride.
8. A thermoelectric device according to claim 1 wherein the first and second metal pads are non-overlapping in the second direction.
9. A thermoelectric device according to claim 1 further comprising:
a third metal pad on the second surface of the thermoelectric element wherein the first and third metal pads are off-set in a third direction that is parallel with respect to the first and second surfaces of the thermoelectric element, wherein the second and third metal pads are spaced apart in the first and/or third directions on the second surface of the thermoelectric element, and wherein the second and third metal pads are non-overlapping in the second direction.
10. A thermoelectric device according to claim 1 wherein the thermoelectric element has a first resistivity in the direction parallel with respect to the first and second surfaces of the thermoelectric element that is less than a second resistivity in a direction perpendicular with respect to the first and second surfaces.
11. A method of forming a thermoelectric device, the method comprising:
providing a thermoelectric element including a layer of a thermoelectric material and having opposing first and second surfaces;
forming a first metal pad on the first surface of the thermoelectric element; and
forming a second metal pad on the second surface of the thermoelectric element, wherein the first and second metal pads are off-set in a first direction parallel with respect to the first and second surfaces of the thermoelectric element, wherein at least a portion of the first metal pad is non-overlapping with respect to the second metal pad in a second direction that is orthogonal with respect to the first and second surfaces of the thermoelectric element, and wherein at least a portion of the second metal pad is non-overlapping with respect to the first metal pad in the second direction;
wherein a first axis in the second direction extends through the first pad and the first surface of the thermoelectric element, and wherein a second axis in the second direction extends through the second pad and the second surface of the thermoelectric element.
12. A method according to claim 11 further comprising:
providing a thermally conductive header including an electrically conductive trace thereon; and
electrically and mechanically coupling the second metal pad and the electrically conductive trace.
13. A method according to claim 12 wherein the thermoelectric element comprises an N-type thermoelectric element, the method further comprising:
providing a P-type thermoelectric element including a layer of a P-type thermoelectric material and having opposing first and second surfaces;
forming a third metal pad on the first surface of the P-type thermoelectric element;
electrically and mechanically coupling the third metal pad to the electrically conductive trace of the thermally conductive header so that the third metal pad is electrically and mechanically coupled between the first surface of the P-type thermoelectric element and the electrically conductive trace of the thermally conductive header; and
forming a fourth metal pad on the second surface of the P-type thermoelectric element, wherein the third and fourth metal pads are off-set in a direction parallel with respect to the first and second surfaces of the P-type thermoelectric element;
wherein the electrically conductive trace of the thermally conductive header provides electrical coupling between the second and third metal pads to define a path of current flow from the first metal pad through the N-type thermoelectric element to the second metal pad through the electrically conductive trace to the third metal pad and through the P-type thermoelectric element to the fourth metal pad.
14. A method according to claim 13 further comprising:
providing a second thermally conductive header; and
mechanically coupling the first metal pad to the second thermally conductive header so that the first metal pad is mechanically coupled between the second thermally conductive header and the N-type thermoelectric element; and
mechanically coupling the fourth metal pad to the second thermally conductive header so that the fourth metal pad is mechanically coupled between the second thermally conductive header and the P-type thermoelectric element.
15. A method according to claim 11 wherein the thermoelectric material comprises a crystalline semiconductor material.
16. A method according to claim 11 wherein the thermoelectric material comprises a single crystal semiconductor material.
17. A method according to claim 11 wherein the thermoelectric material comprises bismuth telluride.
18. A method according to claim 11 wherein the first and second metal pads are non-overlapping in the second direction.
19. A method according to claim 11 further comprising:
forming
a third metal pad on the second surface of the thermoelectric element wherein the first and third metal pads are off-set in a third direction that is parallel with respect to the first and second surfaces of the thermoelectric element, wherein the second and third metal pads are spaced apart in the first and/or third directions on the second surface of the thermoelectric element, and wherein the second and third metal pads are non-overlapping in the second direction.
20. A method according to claim 11 wherein the thermoelectric element has a first resistivity in the direction parallel with respect to the first and second surfaces of the thermoelectric element that is less than a second resistivity in a direction perpendicular with respect to the first and second surfaces.
21. A thermoelectric device according to claim 1 wherein centers of the first and second metal pads are off-set in the first direction.
22. A thermoelectric device according to claim 1 wherein portions of the first and second metal pads overlap in the second direction.
23. A method according to claim 11 wherein centers of the first and second metal pads are off-set in the first direction.
24. A method according to claim 11 wherein portions of the first and second metal pads overlap in the second direction.