Thermoelectric conversion module and production method therefor

Abstract

A thermoelectric conversion module has a thermoelectric conversion element and an electrode, which are metallurgically bonded together via a porous metal layer. The porous metal layer is made of nickel or silver and has a density ratio of 50 to 90%.

1 . A thermoelectric conversion module having a thermoelectric conversion element and an electrode, which are metallurgically bonded together via a porous metal layer, the porous metal layer being made of nickel or silver and having a density ratio of 50 to 90%. 
     
     
         2 . The thermoelectric conversion module according to  claim 1 , wherein the porous metal layer has a thickness of 10 to 100 μm. 
     
     
         3 . The thermoelectric conversion module according to  claim 1 , wherein the porous metal layer is made by sintering metal powder particles having an average particle diameter of 0.1 to 10 μm, and the metal powder particles are one of nickel powder particles and silver powder particles. 
     
     
         4 . The thermoelectric conversion module according to  claim 1 , wherein the thermoelectric conversion element has an end surface that is covered with a metal, and the end surface is bonded to the electrode via the porous metal layer. 
     
     
         5 . A production method for a thermoelectric conversion module having a thermoelectric conversion element with an end surface and having an electrode,
 the production method comprising:   preparing a paste in which metal powder particles are dispersed, the metal powder particles having an average particle diameter of 0.1 to 10 μm and being one of nickel powder particles and silver powder particles;   applying the paste to the end surface of the thermoelectric conversion element;   abutting the end surface, to which the paste is applied, to the electrode so as to connect the thermoelectric conversion element and the electrode;   heating the paste between the thermoelectric conversion element and the electrode in an inert gas atmosphere, a reducing gas atmosphere, or a vacuum atmosphere, so as to remove the paste except for the metal powder particles and cause the metal powder particles to remain;   sintering the remaining metal powder particles so as to form a porous metal layer; and   diffusion bonding the porous metal layer to the end surface of the thermoelectric conversion element and to the electrode so as to metallurgically bond them,   wherein the sintering and the diffusion bonding are simultaneously performed at a temperature of 650 to 850° C. when the nickel powder particles are used, or at a temperature of 450 to 750° C. when the silver powder particles are used.   
     
     
         6 . The production method for the thermoelectric conversion module according to  claim 5 , wherein the metal powder particles are dispersed in the paste at 30 to 50 volume %. 
     
     
         7 . The production method for the thermoelectric conversion module according to  claim 5 , wherein the paste has a viscosity of 10 to 100 Pa·s. 
     
     
         8 . The production method for the thermoelectric conversion module according to  claim 5 , wherein the paste has a shear strength of not less than 0.1 N/cm 2 . 
     
     
         9 . The production method for the thermoelectric conversion module according to  claim 5 , wherein the end surface of the thermoelectric conversion element is covered with a metal, and the paste is applied to the end surface covered with the metal.