Methods For Thick Films Thermoelectric Device Fabrication

摘要

Solid state thermoelectric energy conversion devices can provide electrical energy from heat flow, creating energy, or inversely, provide cooling through applying energy. Thick film methods are applied to fabricate thermoelectric device structures using microstructures formed through deposition and subsequent thermal processing conditions. An advantageous coincidence of material properties makes possible a wide variety of unique microstructures that are easily applied for the fabrication of device structures in general. As an example, a direct bond process is applied to fabricate thermoelectric semiconductor thick films on substrates by printing and subsequent thermal processing to form unique microstructures which can be densified. Bismuth and antimony are directly bonded to flexible nickel substrates.

主权项

1. A fabrication process for producing a thick film with a precursor microstructure of relatively large free-volume comprising the steps of:
Forming a powder comprised of elements, alloys, or compounds, with particle sizes of the initial constituents such size that a layer of the mixture can be formed on a surface; Combining said powder with a vehicle which is capable of being volatilized at an elevated temperature without residue, and a thinning agent, also capable of being volatilized, to form a paste of desired viscosity as a means of depositing said powder, where the volume ratio of powder and vehicle allows of particles of the powder in said paste allows most of the particles to be in partial contact with one another; Depositing said paste to form a layer by screen printing, stencil printing, spraying, or by any other suitable means that can form a layer of the particles within the vehicle on a surface with said vehicle capable of being volatilized; Drying said layer at a relatively low temperature to volatilize and remove the thinning agent; Sintering said layer in while simultaneously volatilizing and removing said vehicle in the paste such that, most if not all the vehicle, within the paste leaves free volume within the layer, and whereas said particles become an interconnected microstructure within the layer, and thereby capable of supporting itself structurally in layered form, and is of sufficient structural stability for further processing; Pressing said sintered layer at desired and sufficient pressure so as to provide a desired densification in the layer to obtain desired material properties after densification, greatly reducing the high free volume.