Thermoelectric device and method of manufacture

Abstract

A thermoelectric device containing at least one thermoelement formed by powder metallurgical techniques including, but not limited to: hot pressing, hot isostatic pressing, press and sinter and mechanical alloying.

1 . A thermoelectric device containing at least one thermoelement formed by powder metallurgical techniques wherein each thermoelement has a leg length range, in centimeters, equal to: (K+0.026 centimeters) to (K+0.061 centimeters), wherein K is the thermoelement material's thermal conductivity value, given in watts/centimeter per degree Celsius.  
     
     
         2 . A thermoelectric device design, providing at least one wafer containing at least two through-hole cavities to accept thermoelements, wherein the wafer thickness is equal to or less than 0.125 centimeters.  
     
     
         3 . A thermoelectric device design, as in  claim 2 , wherein the wafer is composed of a metallic material.  
     
     
         4 . A thermoelectric device design, as in  claim 2 , wherein the wafer is composed of a non-ferrous metallic material.  
     
     
         5 . A thermoelectric device design, as in  claim 2 , wherein the walls of the wafer through-holes are coated with an electrically conductive material.  
     
     
         6 . A thermoelectric device design, as in  claim 2 , wherein the walls of the wafer cavities are oxidized to mitigate the formation of an intermetallic layer on the thermoelements.  
     
     
         7 . A method of manufacturing a thermoelectric device, including at least one thermoelement, one heat rejecting interconnection member, one heat absorbing interconnection member, one wafer containing at least two through holes, each containing dissimilar thermoelectric material comprising the steps of: 
 a. Simultaneously dispensing one type of thermoelectric element materials to at least two wafer through holes;    b. Simultaneously cold compacting more than one thermoelement with the wafer;    c. Covering each wafer face with a heat resistant material;    d. Apply hot isostatic pressure to the entire covered wafer;    e. Removing the covering;    f. Cleaning and electrochemically activating the entire wafer surface including the exposed faces of each thermoelement;    g. Plating the entire wafer surface including all exposed faces of each thermoelement;    h. Bonding a metallic sheet to each face of the wafer via the plated layer;    i. Chemically removing part of each metallic sheet and all of the wafer material;    j. Mounting the completed device to a substrate.    
     
     
         8 . A method of manufacture, as in  claim 7 , wherein the wafer is a metallic material.  
     
     
         9 . A method of manufacture, as in  claim 7 , wherein the thermoelement material is in powder form.  
     
     
         10 . A method of manufacture as in  claim 7 , wherein the thermoelement materials is in tablet form.  
     
     
         11 . A method of manufacture, as in  claim 7 , wherein step (a) involves the use of a squeegie for the dispensation of the thermoelement powders.  
     
     
         12 . A method of manufacture, as in  claim 7 , wherein the step (c) covering is a metallic foil.  
     
     
         13 . A method of manufacturing, as in  claim 7 , wherein the thermoelement material in step (a) is a mixture of metallic elements which, following step (d) will become the resultant P and N-type thermoelement compounds.  
     
     
         14 . A method of manufacture, as in  claim 7 , wherein step (d) involves the use of pressureless sintering (heat only).  
     
     
         15 . A method of manufacture, as in  claim 7 , wherein step (g) utilizes a metallic spraying process in lieu of the electroplating and/or metallic sheet in steps (g) and (h) respectively.  
     
     
         16 . A method of manufacture, as in  claim 7 , which utilizes a conversion coated (anodized) substrate.  
     
     
         17 . A method of manufacturing a thermoelectric device, including at least one thermoelement, an envelope or covering, one wafer containing at least two through holes, each containing dissimilar thermoelectric material wherein a pressurized liquid gas is utilized to compact the thermoelements by applying pressure against the envelope which is in direct contact with each thermoelement.  
     
     
         18 . A method of manufacturing a thermoelectric device, including at least one perforated metallic substrate with two or more through holes (filled with dissimilar thermoelement material) in which the completed device is bonded to a perforated metallic substrate.  
     
     
         19 . A method of manufacture, as in  claim 18 , which utilizes a conversion coated (anodized) substrate.  
     
     
         20 . A method of manufacture, as in  claim 18 , in which the bonding is accomplished through the use of an adhesive.  
     
     
         21 . A method of manufacturing a thermoelectric device, including at least one thermoelement, reusable magnetic mask material and at least one wafer wherein the prepatterned magnetic mask is placed on each face of the wafer for subsequent chemical processing.  
     
     
         22 . A method of manufacturing a thermoelectric device, including at least one thermoelement, one wafer containing at least two through-holes, each containing thermoelement material and at least one sheet of deformable material wherein the wafer and sheet of deformable material are stacked, such that the deformable material interfaces the exposed thermoelement faces, and subjected to heat and pressure, thereby causing the deformable material to deform and compress the thermoelement material into the wafer through-holes.  
     
     
         23 . A method of manufacturing a thermoelectric device, as in  claim 22 , wherein the sheet of deformable material is comprised of aluminum.  
     
     
         24 . A method of manufacturing a thermoelectric device, including at least one thermoelement, one wafer containing at least two through-holes, each containing P and N-type thermoelement material wherein both the P and N-type thermoelement materials are hot isostatic pressed simultaneously.  
     
     
         25 . A method of manufacturing a thermoelectric device, as in  claim 24 , wherein both the P and N-type thermoelement materials are hot pressed simultaneously.  
     
     
         26 . A method of manufacturing a thermoelectric device, including at least one thermoelement, in which the surface preparation of each thermoelement for interconnection bonding comprises: 
 a. Immersion of the thermoelements into an alkaline solution;    b. Making the thermoelements anodic through the application of an external positive polarity voltage to the thermoelements;    c. Completing the electrical circuit within the alkaline solution by applying the external negative voltage polarity to a metallic member, now made cathodic;    d. Removal of thermoelements from the alkaline solution and removal of their remaining surface layer residue chemically.    
     
     
         27 . A method of manufacturing, as in  claim 26 , wherein the alkaline solution is a solution containing chromic acid.  
     
     
         28 . A method of manufacturing a thermoelectric device, including at least one thermoelement, in which the surface preparation of each thermoelement for interconnection bonding comprises: 
 a. Immersion of the thermoelements into an acidic solution;    b. Making the thermoelements cathodic through the application of an external negative polarity voltage to the thermoelements;    c. Completing the electrical circuit within the alkaline solution by applying the external positive voltage polarity to a metallic member, now made anodic;    d. Plating a metallic layer on each surface of the thermoelements.    
     
     
         29 . A method of manufacturing, as in  claim 28 , wherein the acidic solution is a solution containing sulfuric acid.  
     
     
         30 . A method of manufacturing, as in  claim 28 , where the thermoelement surfaces are subjected to a current density greater than 150 amps per square foot of negatively charged surface area in the solution.  
     
     
         31 . A method of manufacturing, as in  claim 28 , wherein the electrical potential applied to the thermoelements in steps (a) through (d) is applied prior to immersion of the thermoelements into each solution.  
     
     
         32 . A method of manufacturing a thermoelectric device, including at least one thermoelement comprising: 
 a. Depositing a bismuth layer on each junction face of the P and N-type thermoelements;    b. Melting and solidifying the bismuth layer;    c. Depositing a metallic layer on the bismuth layer.    
     
     
         33 . A method of manufacturing, as in  claim 32 , wherein step (a) utilizes plating to deposit the bismuth layer.  
     
     
         34 . A method of manufacturing a thermoelectric device, including at least one thermoelement, in which the removal of surface layers between the hot and cold junctions of each thermoelement comprises: 
 a. Immersion of the thermoelements into a corrosive solution;    b. Making the thermoelements anodic through the application of an external positive polarity voltage to the thermoelements;    c. Completing the electrical circuit within the corrosive solution by applying the external negative voltage polarity to a metallic member, now made cathodic;    d. Removal of thermoelements from the corrosive solution and removal of their remaining surface layer residue chemically.    
     
     
         35 . A method of manufacturing, as in  claim 34 , wherein the solution contains chromic acid.  
     
     
         36 . A method of manufacturing, as in  claim 34 , wherein step (b) polarity is negative and the step (c) polarity is positive.  
     
     
         37 . A method of manufacturing a thermoelectric device, including at least one thermoelement, wherein the thermoelement materials, in powder form, are coated with boric acid prior to thermal processing (sintering, hot pressing, etc.) to getter surface oxides.  
     
     
         38 . A wearable thermoelectric-based heating and cooling therapy apparatus design, including at least one thermoelectric device and a thermal storage medium wherein one face of the thermoelectric device interfaces the source to be heated or cooled (wearer) and the opposite face of the thermoelelctric device interfaces a thermal storage medium.  
     
     
         39 . A wearable thermoelectric-based heating and cooling therapy apparatus design, as in  claim 38 , wherein the thermal storage medium is a polymer-based material.  
     
     
         40 . A wearable thermoelectric-based heating and cooling therapy apparatus design, as in  claim 38 , wherein the thermal storage medium is a elastomer-based material.  
     
     
         41 . A wearable thermoelectric-based heating and cooling therapy apparatus design, as in  claim 38 , wherein the thermal storage medium is a ceramic-based material.  
     
     
         42 . A wearable thermoelectric-based heating and cooling therapy apparatus design, as in  claim 38 , wherein the thermal storage medium comprises a phase change material.  
     
     
         43 . A thermoelectric-based system design for conditioning the ambient air drawn through an enclosure comprising: 
 a. Establishing an airflow through the enclosure;    b. Conditioning the input airstream to the enclosure with a thermoelectric device.    
     
     
         44 . A thermoelectric-based system design for conditioning the ambient air drawn through an enclosure, as in  claim 43 , wherein the enclosure houses heat generating electronics.  
     
     
         45 . A thermoelectric-based system design for conditioning the ambient air drawn through an enclosure, as in  claim 43 , wherein the enclosure houses heat generating electronics.  
     
     
         46 . A thermoelectric-based system design for conditioning the ambient air drawn through an enclosure, as in  claim 43 , wherein the enclosure's airstream exhaust, or discharge air, is directed over one face of the thermoelectric device.