WO2019165253A1 - Thermoelectric module with an array of elements for a flexible circuit assembly - Google Patents

Abstract

A thermoelectric module has a base, a first thermoelectric couple, and a second thermoelectric couple. The first thermoelectric couple includes a first thermoelectric element, a second thermoelectric element and a first bus bar electrically connecting the first and second thermoelectric elements. The second thermoelectric couple includes a third thermoelectric element, a fourth thermoelectric element and a second bus bar electrically connecting the third and fourth thermoelectric elements. The first, second, third and fourth thermoelectric elements are set in the base and electrically isolated by the base. The base is used to protect the thermoelectric elements. Multiple thermoelectric modules may be mounted to and connected by conductors on a flexible circuit panel to create a flexible thermoelectric circuit assembly for cooling, heating and/or power generating applications.

Description

THERMOELECTRIC MODULE WITH AN ARRAY OF ELEMENTS FOR A FLEXIBLE CIRCUIT ASSEMBLY

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. provisional patent application No. 62/633,812, filed February 22, 2018, which is incorporated herein by reference. Application no. PCT/US18/17409 also is incorporated herein by reference.

TECHNICAL FIELD

[0002] Example embodiments relate to a discrete thermoelectric module and a flexible thermoelectric circuit assembly incorporating the discrete thermoelectric modules. The thermoelectric module and flexible thermoelectric circuit assembly may be used for various cooling, heating and/or power generating applications.

BACKGROUND

[0003] Thermoelectric circuits may be used for cooling, heating and/or power generating applications due to the Peltier effect whereby passing a current through the junction of two different conductive materials causes a heating or cooling effect. The conductive materials suitable for thermoelectric circuits are typically rigid and relatively fragile or brittle materials.

SUMMARY

[0004] The present invention has important benefits over previous flexible thermoelectric circuit assemblies. For example, the present invention allows for significant cost savings. By placing multiple thermoelectric couplers in a single module, production costs can be reduced because fewer modules are required for each device. In addition, by putting multiple thermoelectric couples into one module, fewer modules are needed to assemble the device, which increases the speed and efficiency of the assembly process. The present invention also provides mechanical advantages because the modules allow for improved adhesion to the underlying flexible circuit, which in turn, increases the reliability and durability of the device.

[0005] According to one embodiment, there is provided a thermoelectric module, which comprises a base, a first thermoelectric couple, and a second thermoelectric couple. The first thermoelectric couple comprises a first thermoelectric element, a second thermoelectric element and a first bus bar electrically connecting the first and second thermoelectric elements. The second thermoelectric couple comprises a third thermoelectric element, a fourth thermoelectric element and a second bus bar electrically connecting the third and fourth thermoelectric elements. The first, second, third and fourth thermoelectric elements are set in the base and electrically isolated by the base.

[0006] According to another embodiment, there is provided a flexible thermoelectric circuit assembly, which comprises a flexible circuit panel and a thermoelectric module. The flexible circuit panel comprises a plurality of circuit conductors. The thermoelectric module comprises a base, a first thermoelectric couple, and a second thermoelectric couple. The first thermoelectric couple comprises a first thermoelectric element, a second thermoelectric element and a first bus bar electrically connecting the first and second thermoelectric elements. The second thermoelectric couple comprises a third thermoelectric element, a fourth thermoelectric element and a second bus bar electrically connecting the third and fourth thermoelectric elements. The first, second, third and fourth thermoelectric elements are set in the base and electrically isolated by the base.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein : [0008] Figure 1 is a top perspective view of a thermoelectric module in accordance with one embodiment of the present disclosure;

[0009] Figure 2 is a bottom perspective view of the thermoelectric module of Figure 1;

[0010] Figure 3 is a front cross-sectional view of the thermoelectric module of Figure 1;

[0011] Figure 4 is a side cross-sectional view of the thermoelectric module of Figure 1;

[0012] Figure 5 is a top perspective view of the thermoelectric module of Figure 1 with a heat sink;

[0013] Figure 6 is a side cross-sectional view of a portion of the thermoelectric module and heat sink of Figure 5;

[0014] Figure 7 is a side cross-sectional view of a portion of a flexible thermoelectric circuit assembly including the thermoelectric module and heat sink of Figure 5;

[0015] Figure 8 is a bottom perspective view of one embodiment of a flexible thermoelectric circuit assembly;

[0016] Figure 9 is the flexible thermoelectric circuit assembly of Figure 8 with the heat sinks removed;

[0017] Figure 10 is the flexible thermoelectric circuit assembly of Figure 9 showing the circuit path through the thermoelectric modules;

[0018] Figure 11 is a front cross-sectional view of a portion of one embodiment of the flexible thermoelectric circuit assembly mounted within a padding layer for a vehicle seat;

[0019] Figure 12 is a top perspective view of a thermoelectric module in accordance with another embodiment of the present disclosure; [0020] Figure 13 is a bottom perspective view of the thermoelectric module of Figure 12;

[0021] Figure 14 is a side cross-sectional view of the thermoelectric module of Figure 12;

[0022] Figure 15 is a top perspective view of a thermoelectric module in accordance with another embodiment of the present disclosure;

[0023] Figure 16 is a bottom perspective view of the thermoelectric module of Figure 15;

[0024] Figure 17 is a top view of a thermoelectric module in accordance with another embodiment of the present disclosure;

[0025] Figure 18 is a bottom view of the thermoelectric module of Figure 17;

[0026] Figure 19 is a top view of a portion of a flexible thermoelectric circuit assembly including the thermoelectric module of Figure 17;

[0027] Figure 20 is a top view of a thermoelectric module in accordance with another embodiment of the present disclosure;

[0028] Figure 21 is a bottom view of the thermoelectric module of Figure 20;

[0029] Figure 22 is a top view of a portion of a flexible thermoelectric circuit assembly including the thermoelectric module of Figure 20;

[0030] Figure 23 is a side view of the flexible thermoelectric circuit assembly of Figure 22 with heat sinks;

[0031] Figure 24 is a side view of the flexible thermoelectric circuit assembly of Figure 22 without heat sinks; [0032] Figure 25 is a top view of a thermoelectric module in accordance with another embodiment of the present disclosure;

[0033] Figure 26 is a bottom view of the thermoelectric module of Figure 25;

[0034] Figure 27 is a top view of a portion of a flexible thermoelectric circuit assembly including the thermoelectric module of Figure 25;

[0035] Figure 28 is a top view of a thermoelectric module in accordance with another embodiment of the present disclosure;

[0036] Figure 29 is a bottom view of the thermoelectric module of Figure 28;

[0037] Figure 30 is a top view of a portion of a flexible thermoelectric circuit assembly including the thermoelectric module of Figure 28; and

[0038] Figure 31 is a top view illustrating how the thermoelectric module in accordance with the present disclosure may be increased in size.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0039] Figures 1 to 31 illustrate various thermoelectric modules and flexible thermoelectric circuit assemblies incorporating the thermoelectric modules according to embodiments described herein. Directional references employed or shown in the description, figures or claims, such as top, bottom, upper, lower, upward, downward, lengthwise, widthwise, left, right, and the like, are relative terms employed for ease of description and are not intended to limit the scope of the invention in any respect. For example, the figures illustrate thermoelectric modules and flexible thermoelectric circuit assemblies with heat sinks extending towards the bottom or towards the top of the figure. It will be readily apparent that the thermoelectric modules and flexible thermoelectric circuit assemblies according to the present disclosure may be oriented in any direction. Further, cross section views of the thermoelectric modules and flexible thermoelectric circuit assemblies are shown to illustrate their layers and components but such views are not necessarily to scale.

[0040] The thermoelectric modules described herein are discrete cooling, heating and/or power generating blocks or components which may be mounted to a flexible circuit panel to create a flexible thermoelectric circuit assembly. Alternatively, the thermoelectric modules may be electrically connected with wires, adhesives, foils, etc. to create a flexible thermoelectric circuit assembly. Each thermoelectric module is rigid to protect the thermoelectric materials contained therein, but the distribution of several thermoelectric modules over a flexible circuit panel results in a flexible thermoelectric circuit assembly. The flexible circuit panel may be sized and shaped to target a specific cooling, heating and/or power generating application. The flexible circuit panel also may be configured to support suitable numbers and locations or patterns of thermoelectric modules electrically connected in series and/or in parallel to achieve the desired thermoelectric performance. For example, as shown in Figure 8 and described later herein, the thermoelectric modules may be used along with heat sinks to create a flexible thermoelectric circuit assembly for heating and/or cooling a seat of a vehicle. It will be appreciated that other flexible thermoelectric circuit assemblies may be configured with different patterns using the same thermoelectric modules in order to target different seat assemblies. The same thermoelectric modules also may be used in flexible thermoelectric circuit assemblies configured for different vehicle parts such as steering wheels, or other seats, parts, or applications not limited to vehicles. The thermoelectric module thus provides a standard component which may be used across many applications, reducing the cost and complexity of flexible thermoelectric circuit assemblies.

[0041] Figures 1-4 illustrate one embodiment of a thermoelectric module 10 of the present disclosure. The thermoelectric module 10 includes a base 12 and two thermoelectric couples 14, 16. Thermoelectric couple 14 includes two thermoelectric elements 18, 20 and a bus bar 22, and thermoelectric couple 16 includes two thermoelectric elements 24, 26 and a bus bar 28. Thermoelectric elements 18, 20, 24, 26 are set in the base 12.

[0042] The base 12 is a rigid substrate which operates to protect the thermoelectric elements 18, 20, 24, 26. The base 12 may comprise a phenolic resin, epoxy resin, or glass-reinforced epoxy laminate material such as flame-retardant composite materials. For example, the base 12 may be made from NEMA (National Electrical Manufacturers Association) FR-1, FR-2 or FR4 laminate materials which are typically used to manufacture rigid printed circuit boards. Other rigid materials may be used for the base 12 provided that the material is electrically isolative and has minimal thermal conductivity. The base 12 may be formed by an injection molding process with a liquid substrate which is cured or set to provide the rigid base. The injection molding process allows for low cost and flexibility of design. The base may be formed from a material or combination of materials including but not limited to polyetherimide (PEI), polyester terephthalate (PET), polybutylene terephthalate (PBT), or nylon, and may include glass to add strength and heat resistance. The shape of the base may vary depending on the application. For example, the base may be rectangular, square, cylindrical or oval. The base may include rounded edges 32 to protect surrounding components from sharp edges or stress concentrations. The base 12 preferably has a thermal conductivity below 0.25 W/mK.

[0043] Thermoelectric elements 18, 20, 24, 26 may comprise various thermoelectric materials including but not limited to bismuth telluride (Bi₂Te₃), lead telluride (PbTe), or magnesium stannide (Mg₂Sn). One thermoelectric element 18, 24 from each thermoelectric couple 14, 16 is a P-type semiconductor, and the other thermoelectric element 20, 26 is an N-type semiconductor, as is well known in the art. For ease of reference and illustration purposes, all embodiments of the thermoelectric couples are described and illustrated herein with the first thermoelectric element being a P-type semiconductor and the second thermoelectric element being an N-type semiconductor. [0044] In one embodiment, the base 12 defines apertures 30 which receive the thermoelectric elements 18, 20, 24, 26. The thermoelectric elements 18, 20, 24, 26 and apertures 30 in the base 12 may be generally rectangular. In other embodiments, the base 12 may define different sizes and shapes of apertures 30 for receiving different sizes and shapes of thermoelectric elements 18, 20, 24, 26. This may include but is not limited to square, cylindrical or oval apertures 30 in the base 12 which receive corresponding square, rectangular or oval shaped thermoelectric elements 18, 20, 24, 26. Alternatively, the thermoelectric module 10 may have square or rectangular cuboid thermoelectric elements 18, 20, 24, 26 set in round or oval apertures 30 in the base 12. In one embodiment, the thermoelectric elements 18, 20, 24, 26 are generally free-floating within the apertures 30. Spaces may exist within the apertures 30 between the base 12 and the thermoelectric elements 18, 20, 24, 26, The thermoelectric elements 18, 20, 24, 26 may have generally the same thickness as the base 12 such that top surfaces of the thermoelectric elements 18, 20, 24, 26 are coplanar or nearly coplanar with a top surface of the base 12. Similarly, the thermoelectric elements 18, 20, 24, 26 may have respective bottom surfaces which are coplanar or nearly coplanar with a bottom surface of the base 12. In some embodiments, a unique size and/or shape may be provided for one of the apertures 30 in order to serve as an indication for the orientation and installation of the thermoelectric module 10 on the flexible circuit panel. In another embodiment the P-type thermoelectric elements 18, 24 may have a different cross section from the N-type thermoelectric elements 20, 16 to distinguish parts from each other.

[0045] Bus bar 22 is coupled to the base 12 and electrically connected to thermoelectric elements 18, 20, and bus bar 28 is coupled to the base 12 and electrically connected to thermoelectric elements 24, 26. In some embodiments, bus bars 22, 28 also mechanically link or connect the base 12 and the thermoelectric elements 18, 20, 24, 26. [0046] Bus bars 22, 28 include electrically conductive materials, such as copper or aluminum. As illustrated in Figures 3-4, bus bar 22 may be joined by solder 34, 36 to the bottom surface of thermoelectric elements 18, 20, and bus bar 28 may be joined by solder 38 to the bottom surface of thermoelectric element 24. Alternatively, an electrically conductive adhesive may be used. Such adhesives include but are not limited to epoxies, resins or silicones, each filled with silver, copper, aluminum, or iron. Bus bars 22, 28 may be attached or mounted to the bottom surface of the base 12 with an adhesive 40, which may be the same adhesive used for the thermoelectric elements, or may be a different adhesive such as a structural adhesive, including but not limited to Loctite® 3616 or Epotek® H70E-4.

[0047] As depicted in Figures 5 and 6, thermoelectric module 10 may be attached to a heat sink 42 to remove or dissipate excess heat from the thermoelectric module 10. Alternatively, one or both bus bars 22, 28 may be attached to a heat sink. For some heating, cooling and/or power generating applications, heat sink 42 is not necessary. Heat sink 42 comprises any suitable material typically used for heat sinks, such as copper, aluminum, or graphite, and may be extruded, stamped or folded. The heat sink 42 may be rigid or flexible and configured with various fins, sizes, and shapes. As depicted in Figures 6 and 7, a dielectric barrier 44, 46 may electrically isolate heat sink 42 from one or both bus bars 22, 28. Preferably, dielectric barrier 44, 46 comprises a thermally conductive epoxy or adhesive. Alternatively, the dielectric barrier 44, 46 may comprise a sheet material with adhesive on both sides. In some embodiments (not shown), one or both bus bars 22, 28 of the thermoelectric module 10 may be configured as a heat sink.

[0048] Figure 7 illustrates a cross section of a portion of a flexible thermoelectric circuit assembly 48 incorporating the thermoelectric module 10 of Figure 1. The flexible thermoelectric circuit assembly 48 includes a flexible circuit panel 50 which is configured with multiple circuit conductors (not shown) for mounting and connecting the thermoelectric modules 10. Flexible circuit panel 50 provides electrical circuits between the thermoelectric modules 10. The conductors in the flexible circuit panel 50 may be electrically connected to the thermoelectric elements 18, 20, 24, 26 with solder 52, 54. Alternatively, an electrically conductive adhesive may be used. Such adhesives include but are not limited to epoxies, resins or silicones, each filled with silver, copper, aluminum, or iron. The flexible circuit panel 50 may be attached or mounted to the top surface of the base 12 with an adhesive 56. Each thermoelectric couple 14, 16 in the thermoelectric module 10 is electrically connected individually to the flexible circuit panel 50. Thermoelectric couples 14, 16 may be connected in series or in parallel, or may be incorporated individually to achieve the desired thermoelectric performance.

[0049] Figures 8-10 illustrate a flexible circuit assembly 58 having a plurality of thermoelectric modules 60 mounted to heat sinks 62 aligned in single rows on a flexible circuit panel 64. Figure 9 illustrates the flexible circuit assembly 58 with the heat sinks 62 removed. Each thermoelectric module 60 includes two thermoelectric couples 60a, 60b, where the first thermoelectric couple 60a for each thermoelectric module 60 is connected in series, and the second thermoelectric couple 60b for each thermoelectric module 60 is connected in series. When designed in this manner, current flows in one direction 66a through the first set of thermoelectric couples 60a, and current flows in the other direction 66b through the second set of thermoelectric couples 60b as shown in Figure 10.

[0050] Figure 8 illustrates a bottom view of the flexible thermoelectric circuit assembly 58. When inverted and mounted to a vehicle seat or mattress, the thermoelectric modules 60 and heat sinks 62 attached thereto, may be configured to extend downwardly within channels of the seat cushion or padding. As shown in the embodiment of Figure 11, for example, each thermoelectric module 60 is mounted to flexible circuit panel 64 such that, when assembled with a seat cushion or padding 70, each thermoelectric module 60 sits within a channel 68 defined by padding 70 of the seat assembly or mattress. The fins of each heat sink 62 extend within each channel 68. In the embodiments shown in Figure 11, air may be forced or drawn through the channels 68 by fans or blowers (not shown) to further accelerate the cooling of the seat or mattress by removing excess heat from the heat sinks 62.

[0051] The locations of the thermoelectric modules 60 and the connectivity created by circuit conductors of the flexible circuit panel 64 may be configured to target the heating and/or cooling of a specific vehicle seat or mattress based on the size of the seat or mattress and the pressure distribution created by an occupant of the seat or mattress. Although the thermoelectric modules 60 described herein may be used for heating and/or cooling applications by changing the current flow through the flexible thermoelectric circuit assembly 58, it will be appreciated that other means may exist for heating applications. Thus, in some embodiments, the thermoelectric modules 60 and flexible thermoelectric circuit assemblies 58 described herein may target primarily cooling applications or applications in which heating and cooling for specific temperature control are required. In some embodiments, a resistive heating element may be combined with and/or controlled by the flexible thermoelectric circuit assembly 58 to provide heat more effectively. For example, a continuous loop of conductive material (not shown) may be included to add a resistive heating element to a flexible thermoelectric circuit assembly.

[0052] Figures 12-14 illustrate another embodiment of a thermoelectric module 72. The thermoelectric module 72 includes a base 74 comprising standard circuit board material or a laminate (such as FR1 or FR4), which includes a nonconductive layer 76 (e.g., fiberglass) with a thin layer of a conductive material 78a, 78b (e.g., copper) laminated to one or both sides of the nonconductive layer 76. The thermoelectric module 72 also includes two thermoelectric couples 80, 82. Thermoelectric couple 80 includes two thermoelectric elements 84, 86 electrically connected to a bus bar 88, and thermoelectric couple 82 includes two thermoelectric elements 90, 92 electrically connected to a bus bar 94. Thermoelectric elements 84, 86, 90, 92 are set in apertures 98 defined by the base 12. Portions of the conductive layer 78a are etched to expose nonconductive layer 76a to ensure that the thermoelectric elements 84, 86, 90, 92 are electrically isolated from each other when the thermoelectric module 72 is attached to a flexible circuit panel of the flexible thermoelectric circuit assembly. If the conductive layer 78a, 78b is laminated to both sides of the nonconductive layer 76, portions of the conductive layer 78b on the second side are etched to expose nonconductive layer 76b to ensure that the bus bars 88, 94 are electrically isolated from each other. A poke-yoke 96 (e.g., a hole) may be etched into the conductive layer 76a in order to serve as an indication for the orientation and installation of the thermoelectric module 72 on the flexible circuit panel.

[0053] Solder may be used to connect bus bars 88, 94 to thermoelectric elements 84, 86, 90, 92 and to connect bus bars 88, 94 to the conductive layer 78b on base 74. Alternatively, an adhesive may be used to connect bus bars 88, 94 to the conductive layer 78b on base 74. If the conductive layer 78b is not laminated to the second side of the nonconductive layer 76, an adhesive may be used to connect the bus bars 88, 94 directly to the base 74.

[0054] When the thermoelectric module 72 is mounted to a flexible circuit panel, the conductive layer 78a and thermoelectric elements 84, 86, 90, 92 may be soldered to conductors on a flexible circuit panel. Alternatively, an electrically conductive adhesive or a combination of solder connections and adhesives may be used. Circuit conductors on the flexible circuit panel may be sized larger than is needed for an electrical and thermal connection in order to also provide a physical connection between the flexible circuit panel and the thermoelectric module 72.

[0055] Figures 15-16 illustrate another embodiment of a thermoelectric module 100 according to the present disclosure. This embodiment includes a circular base 102 and two thermoelectric couples 104, 106. Thermoelectric couple 104 includes two thermoelectric elements 108, 110 electrically connected to a bus bar 112, and thermoelectric couple 106 includes two thermoelectric elements 114, 116 electrically connected to a bus bar 118. Thermoelectric elements 108, 110, 114, 116 are set in apertures 120 defined by the base 102. Although depicted as a circular base 102, the shape may vary depending on the application.

[0056] Figures 17-18 illustrate another embodiment of a thermoelectric module 122 according to the present disclosure. This embodiment includes a rectangular base 124 and two thermoelectric couples 126, 128.

Thermoelectric couple 126 includes two thermoelectric elements 130, 132 electrically connected to a bus bar 134, and thermoelectric couple 128 includes two thermoelectric elements 136, 138 electrically connected to a bus bar 140. Thermoelectric elements 130, 132, 136, 138 are arranged in a single row, and are set in apertures 142 defined by the base 124. Figure 19 illustrates a portion of a flexible thermoelectric circuit assembly 144 incorporating the thermoelectric module 122 of Figures 17-18. The flexible thermoelectric circuit assembly 144 includes three conductors 146 from a flexible circuit panel connected to the thermoelectric module 122.

[0057] The present invention may include more than two thermoelectric couples within each thermoelectric module. For example, Figures 20-21 illustrate an embodiment of a thermoelectric module 148 according to the present disclosure which includes a rectangular base 150 and three thermoelectric couples 152, 154, 156. Thermoelectric couple 152 includes two thermoelectric elements 158, 160 electrically connected to a bus bar 162, thermoelectric couple 154 includes two thermoelectric elements 164, 166 electrically connected to a bus bar 168, and thermoelectric couple 156 includes two thermoelectric elements 170, 172 electrically connected to a bus bar 174. Thermoelectric elements 158, 160, 164, 166, 170, 172 are arranged in a single row, and are set in apertures 176 defined by the base 150.

[0058] The single row thermoelectric modules may be combined to form a string of modules that can flex in one direction. For example, Figures 22-24 depict a portion of a flexible thermoelectric circuit assembly 178 that includes a plurality of single row thermoelectric modules 122 connected by a plurality of flexible circuit panels 180. Each of the thermoelectric modules 122 may (Figure 23) or may not (Figure 24) include heat sinks 182. The flexible thermoelectric circuit assembly 178 can flex in one direction, as illustrated in Figure 23. This flexible thermoelectric circuit assembly 178 is ideal for wearable power generation applications, such as a watchband or a headband for wireless headphones.

[0059] The present invention may include more than one row of thermoelectric couples within each thermoelectric module. For example, Figures 25-26 illustrate an embodiment of a thermoelectric module 184 according to the present disclosure which includes a rectangular base 186 and two rows of three thermoelectric couples 188, 190, 192. Thermoelectric couple 188 includes two thermoelectric elements 194, 196 electrically connected to a bus bar 198, thermoelectric couple 190 includes two thermoelectric elements 200, 202 electrically connected to a bus bar 204, and thermoelectric couple 192 includes two thermoelectric elements 206, 208 electrically connected to a bus bar 210. Thermoelectric elements 194, 196, 200, 202, 206, 208 are set in apertures 212 defined by the base 186. Figure 27 illustrates a portion of a flexible thermoelectric circuit assembly 214 incorporating the thermoelectric module 184 of Figures 25-26. The flexible thermoelectric circuit assembly 214 includes four conductors 216 from a flexible circuit panel connected to the thermoelectric module 184.

[0060] The present invention may include more than three thermoelectric couples within each double row thermoelectric module. For example, Figures 28-29 illustrate an embodiment of a thermoelectric module 218 according to the present disclosure which includes a rectangular base 220 and four thermoelectric couples 222, 224, 226, 228. Thermoelectric couple 222 includes two thermoelectric elements 230, 232 electrically connected to a bus bar 234, thermoelectric couple 224 includes two thermoelectric elements 236, 238 electrically connected to a bus bar 240, thermoelectric couple 226 includes two thermoelectric elements 242, 244 electrically connected to a bus bar 246, and thermoelectric couple 228 includes two thermoelectric elements 248, 250 electrically connected to a bus bar 252. Thermoelectric elements 230, 232, 236, 238, 242, 244, 248, 250 are set in apertures 254 defined by the base 220. Figure 30 illustrates a flexible thermoelectric circuit assembly 256 incorporating the thermoelectric module 218 of Figures 28-29. The flexible thermoelectric circuit assembly 256 includes five conductors 258 from a flexible circuit panel connected to the thermoelectric module 218.

[0061] Similar to the single row thermoelectric modules, the double row thermoelectric modules 184, 218 may be combined to form a string of modules that can flex in one direction.

[0062] As illustrated in Figure 31, the size of a thermoelectric module in accordance with the present invention may be increased by adding thermoelectric couples in either direction to the array. Fewer thermoelectric couples within each module will result in smaller modules, which will allow more flexibility of the flexible thermoelectric circuit assembly. In some applications, it may be desirous to have fewer modules and target flexibility at key locations.

[0063] The invention has been described in an illustrative manner, and it is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced other than as specifically described.

Claims

1. A thermoelectric module comprising : a base; a first thermoelectric couple comprising a first thermoelectric element, a second thermoelectric element and a first bus bar electrically connecting the first and second thermoelectric elements; and a second thermoelectric couple comprising a third thermoelectric element, a fourth thermoelectric element and a second bus bar electrically connecting the third and fourth thermoelectric elements; wherein the first, second, third and fourth thermoelectric elements are set in the base and electrically isolated by the base.

2. The thermoelectric module of claim 1 wherein the base defines a first aperture extending through the base for receiving the first thermoelectric element, a second aperture extending through the base for receiving the second thermoelectric element, a third aperture extending through the base for receiving the third thermoelectric element, and a fourth aperture extending through the base for receiving the fourth thermoelectric element.

3. The thermoelectric module of claim 2 wherein the first thermoelectric element is adjacent to the second and fourth thermoelectric elements, and the third thermoelectric element is adjacent to the second and fourth

thermoelectric elements, and wherein the base comprises a square shape.

4. The thermoelectric module of claim 2 wherein the first thermoelectric element is adjacent to the second and fourth thermoelectric elements, and the third thermoelectric element is adjacent to the second and fourth

thermoelectric elements, and wherein the base comprises a circular shape.

5. The thermoelectric module of claim 2 wherein the first, second, third and fourth thermoelectric elements are arranged in a single row.

6. The thermoelectric module of claim 2 wherein the base comprises a first conductive layer laminated to a nonconductive layer wherein the first conductive layer surrounds the first aperture and the first and second bus bars are coupled to a side of the base opposite the first conductive layer.

7. The thermoelectric module of claim 6 wherein the base further comprises a second conductive layer laminated to the nonconductive layer on the same side as the first conductive layer, wherein the second conductive layer surrounds the second aperture and is electrically isolated from the first conductive layer.

8. The thermoelectric module of claim 7 wherein the base further comprises a third conductive layer laminated to the nonconductive layer opposite the first and second conductive layers, wherein the third conductive layer surrounds the first and second apertures and the first bus bar is coupled to the third conductive layer.

9. The thermoelectric module of claim 1 wherein the first bus bar is coupled to the first and second thermoelectric elements by an electrically conductive adhesive or a solder connection, and wherein the first bus bar is coupled to the base by an electrically conductive adhesive or a solder connection.

10. The thermoelectric module of claim 1 wherein the first bus bar is coupled to the first and second thermoelectric elements by an electrically conductive adhesive or a solder connection, and wherein the first bus bar is coupled to the base with an adhesive.

11. The thermoelectric module of claim 1 further comprising a heat sink coupled to the first bus bar.

12. The thermoelectric module of claim 8 further comprising a dielectric layer between the heat sink and the first bus bar.

13. The thermoelectric module of claim 1 further comprising a third thermoelectric couple comprising a fifth thermoelectric element, a sixth thermoelectric element and a third bus bar electrically connecting the fifth and sixth thermoelectric elements, wherein the fifth and sixth thermoelectric elements are set in the base and electrically isolated from each other and from the first, second, third, and fourth thermoelectric elements by the base.

14. The thermoelectric module of claim 1 wherein the base has a thermal conductivity substantially lower than thermal conductivities of the first and second thermoelectric elements.

15. The thermoelectric module of claim 1 wherein the first and third thermoelectric elements comprise a P-type thermoelectric element and wherein the second and fourth thermoelectric elements comprise an N-type thermoelectric element.

16. A flexible thermoelectric circuit assembly comprising : a flexible circuit panel comprising a plurality of circuit conductors; and a thermoelectric module comprising : a base; a first thermoelectric couple comprising a first thermoelectric element, a second thermoelectric element and a first bus bar electrically connecting the first and second thermoelectric elements; and a second thermoelectric couple comprising a third thermoelectric element, a fourth thermoelectric element and a second bus bar electrically connecting the third and fourth thermoelectric elements; wherein the first, second, third and fourth thermoelectric elements are set in the base and electrically isolated by the base; wherein one of the plurality of circuit conductors is coupled to the first thermoelectric element and the thermoelectric module is mounted on the flexible circuit panel.

17. The flexible thermoelectric circuit assembly of claim 16 wherein a second of the plurality of circuit conductors is coupled to the second thermoelectric element.

18. The flexible thermoelectric circuit assembly of claim 16 further comprising a second thermoelectric module comprising : a second base; a third thermoelectric couple comprising a fifth thermoelectric element, a sixth thermoelectric element and a third bus bar electrically connecting the fifth and sixth thermoelectric elements; and a fourth thermoelectric couple comprising a seventh thermoelectric element, an eighth thermoelectric element and a fourth bus bar electrically connecting the seventh and eighth thermoelectric elements; wherein the fifth, sixth, seventh and eighth thermoelectric elements are set in the second base and electrically isolated by the second base; wherein a second of the plurality of circuit conductors is coupled to the fifth thermoelectric element and the second thermoelectric module is mounted on the flexible circuit panel.

19. The flexible thermoelectric circuit assembly of claim 16 wherein the flexible thermoelectric circuit assembly comprises a cooling thermoelectric circuit assembly for a vehicle seat, a mattress, a watchband or a headband for wireless headphones.