CN107579150B

CN107579150B - Method for manufacturing planar thermoelectric element

Info

Publication number: CN107579150B
Application number: CN201710803143.XA
Authority: CN
Inventors: 汪元元
Original assignee: Shanghai Cuili Electronic Technology Co ltd
Current assignee: Shanghai Cuili Electronic Technology Co ltd
Priority date: 2017-09-08
Filing date: 2017-09-08
Publication date: 2020-09-15
Anticipated expiration: 2037-09-08
Also published as: CN107579150A

Abstract

The invention discloses a method for manufacturing a planar thermoelectric element, which is characterized by comprising the following steps: the piezoelectric material is used as a substrate, thermoelectric semiconductor material circuits are printed on the plane of the substrate, circuit layers of N-type thermoelectric materials and P-type thermoelectric materials are respectively printed on two surfaces of the substrate, a row of through holes are respectively drilled at two ends of the substrate, metal is plated in the through holes, and the circuit layers on the two surfaces are connected into an N-P-N-P … alternating series circuit structure through the through holes plated with metal at the two ends to obtain the planar thermoelectric element. The invention has the advantages that the planar thermoelectric element circuit manufactured by the method has compact structure and high energy density, utilizes the piezoelectric material substrate to generate electric polarization in the normal direction, can adjust the thermoelectric efficiency and the refrigeration efficiency of the thermoelectric material circuit, and particularly avoids the defect of generating Joule heat by increasing current due to the introduction of a longitudinal electric field when the refrigeration efficiency is improved. In addition, the process is compatible with flexible devices and can be used for preparing flexible thermoelectric conversion elements.

Description

Method for manufacturing planar thermoelectric element

Technical Field

The invention relates to a manufacturing method of a planar thermoelectric element, belonging to the technical field of electronic materials and devices.

Background

The thermoelectric material is a material which realizes mutual conversion between thermal energy and electric energy through the transmission of carriers (holes or electrons) of the thermoelectric material in a solid state. The thermoelectric conversion technology has the characteristics of small volume, no vibration, no noise, no pollution, no abrasion, no moving part, no maintenance, no pollution and the like, and has unique advantages in the aspect of heat energy utilization. Compared with the traditional block TEC refrigerating piece, the planar thermoelectric device manufactured by adopting the film printing process can further reduce the size and improve the integratable performance of the thermoelectric conversion element. The invention patent (201710449930.9) proposes a novel method for manufacturing a flexible thermoelectric element, which results in a flexible thermoelectric conversion element with a planar structure. In refrigeration application, the thermoelectric element utilizes the current in the circuit to realize the change of efficiency in refrigeration and temperature control.

When thermoelectric materials are used for refrigeration in the temperature control process of different temperature points or temperature sections, the refrigeration power needs to be adjusted, but large current can generate a large amount of Joule heat in a circuit during rapid refrigeration, so that the refrigeration effect is greatly limited.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a manufacturing method of a planar thermoelectric element, which is characterized by comprising the following steps: the method comprises the following steps of utilizing a piezoelectric material as a substrate, printing thermoelectric semiconductor circuits on the plane of the substrate, respectively printing circuit layers of N-type thermoelectric materials and P-type thermoelectric materials on two sides of the substrate, respectively drilling a row of through holes at two ends of the substrate, plating metal in the through holes, and connecting the circuit layers on the two sides into an N-P-N-P … alternating series circuit structure through the through holes plated with metal at two ends to obtain a plane thermoelectric element; when the temperature difference exists at the two ends of the substrate, the potential difference is generated in the alternate series circuit structure, the temperature difference can be converted into electric energy, when the current is introduced into the series circuit, one side of the substrate can be refrigerated, and the other side of the substrate can be radiated, so that the temperature difference is formed; the piezoelectric material substrate is used for generating electric polarization in the normal direction, and the thermoelectric efficiency and the refrigeration efficiency of the thermoelectric material circuit can be adjusted.

The substrate is made of an insulating material with piezoelectric properties, and comprises a piezoelectric ceramic material, a piezoelectric crystal material and a piezoelectric polymer material.

The method for generating electric polarization in the normal direction of the piezoelectric material substrate comprises the steps of applying external force to the substrate and polarizing the substrate by an electric field along the normal direction of the substrate, and particularly, the ferroelectric material substrate is polarized and then moved, and the electric field is still kept in a polarization state.

The room temperature electric conductivity of the P-type thermoelectric material is more than 50Scm, and the power factor is more than 10 mu Wm^-1K^-2The room temperature electric conductivity of the N-type thermoelectric material is more than 50Scm, and the power factor is more than 10 mu Wm^-1K^-2The circuit manufacturing mode comprises one of screen printing, mask vacuum evaporation, mask magnetron sputtering, atomic layer epitaxial coating and ink jet printing.

The thermoelectric material comprises (Bi, Sb)₂(Se，Te)₃And one of element doped solid solution thereof, (Pb, Sn) (Se, Te) and element doped solid solution thereof, skutterudite compound, Zintl phase intermetallic compound and element doped solid solution thereof, and conjugated polymer-based composite conductive material.

A row of through holes are drilled at two ends of the piezoelectric material substrate respectively, metal is plated in the through holes, the process mode is electroplating, the metal comprises one of copper, silver and gold, and metal coatings in the through holes are respectively connected and conducted with the N-type thermoelectric circuit and the P-type thermoelectric circuit on two sides of the substrate.

A plurality of piezoelectric material substrates with P-type thermoelectric material circuits and N-type thermoelectric material circuits on two sides are bonded to form a multilayer circuit board, and the circuits on the circuit boards are connected through drilling through holes and plating metal in the holes, so that higher thermoelectric conversion efficiency is obtained.

The invention has the advantages that: the planar thermoelectric element circuit manufactured by the method has a compact structure and high energy density, can generate a longitudinal electric field through polarization to adjust the carrier concentration of the thermoelectric material, further optimizes the thermoelectric conversion efficiency, and particularly avoids the defect that joule heat is generated by increasing current due to the introduction of the longitudinal electric field when the refrigeration efficiency is improved. In addition, the process is compatible with flexible devices and can be used for preparing flexible thermoelectric conversion elements.

While the invention has been disclosed in the foregoing description with reference to specific embodiments thereof, the foregoing description is directed to only certain specific embodiments of the invention and many more specific features of the invention may be employed than as disclosed herein. Therefore, the scope of the present invention should not be limited to the disclosure of the embodiments, but should include all combinations of the contents embodied in different parts, and various substitutions and modifications without departing from the present invention, and are covered by the claims of the present invention.

Drawings

FIG. 1 is a schematic plan view of a planar thermoelectric device fabricated according to the present invention. 1-a piezoelectric material substrate; 2-front N-type thermoelectric material circuit; 3-back P-type thermoelectric material circuit; 4-through holes, and the through holes are plated with metal.

FIG. 2 is a schematic cross-sectional view of a planar thermoelectric element fabricated according to the present invention. 1-a piezoelectric material substrate; 2-front N-type thermoelectric material circuit; 3-back P-type thermoelectric material circuit; 4-through holes, wherein the through holes are plated with metal; p, P' -external pressure.

FIG. 3 is a schematic cross-sectional view of a planar thermoelectric element fabricated according to the present invention. 1-a flexible piezoelectric material substrate; 2-front N-type thermoelectric material circuit; 3-back P-type thermoelectric material circuit; 4-through holes, wherein the through holes are plated with metal; f, F' -external tension.

FIG. 4 is a schematic cross-sectional view of a planar thermoelectric element fabricated according to the present invention. 1-a ferroelectric material substrate; 2-front N-type thermoelectric material circuit; 3-back P-type thermoelectric material circuit; 4-through holes, wherein the through holes are plated with metal; e-applying a longitudinal electric field.

Detailed Description

Example 1:

n-type Bi adopting lead zirconate titanate piezoelectric ceramic as substrate and magnetron sputtering on front surface through mask_0.5Sb_1.5Te₃The back of the circuit layer of thermoelectric material is magnetically controlled by a maskSputtered P-type Bi₂Te_2.7Se_0.3The circuit layer of thermoelectric material is drilled with through holes at the ends of the circuit and electroplated with copper to form an alternating series circuit structure of N-P-N-P …, the planar structure is shown in FIG. 1. When the series circuit is electrified, one side of the substrate can be refrigerated, and the other side of the substrate can be radiated to form temperature difference; when the temperature difference exists at the two ends of the substrate, the potential difference is generated in the alternate series circuit structure, and the temperature difference can be converted into electric energy to be output outwards. Normal pressure is applied to the substrate in the thermoelectric or electrothermal conversion working process, and the schematic cross-sectional view is shown in fig. 2, so that a longitudinal polarization electric field is generated, the carrier characteristics of the thermoelectric material can be regulated and controlled, and the thermoelectric or electrothermal conversion efficiency is optimized.

Example 2:

the lead magnesium niobate piezoelectric ceramic is used as a substrate, a circuit layer of an N-type PbTe thermoelectric material is vacuum-evaporated on the front surface through a mask, a circuit layer of a P-type PbSe thermoelectric material is vacuum-evaporated on the back surface through a mask, through holes are drilled at the end parts of the circuits, copper is electroplated in the through holes, and an N-P-N-P … alternating series circuit structure is formed, wherein the plane structure is shown in figure 1. When the series circuit is electrified, one side of the substrate can be refrigerated, and the other side of the substrate can be radiated to form temperature difference; when the temperature difference exists at the two ends of the substrate, the potential difference is generated in the alternate series circuit structure, and the temperature difference can be converted into electric energy to be output outwards. Normal pressure is applied to the substrate in the thermoelectric or electrothermal conversion working process, and the schematic cross-sectional view is shown in fig. 2, so that a longitudinal polarization electric field is generated, the carrier characteristics of the thermoelectric material can be regulated and controlled, and the thermoelectric or electrothermal conversion efficiency is optimized.

Example 3:

the method adopts P (VDF-TrFE) piezoelectric polymer as a substrate, and the front surface of the substrate is printed with N-type poly-3, 4 ethylenedioxythiophene by screen printing: the back of the circuit layer of the poly (diallyldimethylammonium chloride) thermoelectric material is filled with the circuit layer of the poly (phenylpyrrole) thermoelectric material through the screen-printed P-type graphene, through holes are drilled at the end parts of the circuit, copper is electroplated in the through holes, and an N-P-N-P … alternating series circuit structure is formed, wherein the plane structure is shown in figure 1. When the series circuit is electrified, one side of the substrate can be refrigerated, and the other side of the substrate can be radiated to form temperature difference; when the temperature difference exists at the two ends of the substrate, the potential difference is generated in the alternate series circuit structure, and the temperature difference can be converted into electric energy to be output outwards. In the thermoelectric or electrothermal conversion process, a tensile force is applied to the substrate, the schematic cross-sectional view is shown in fig. 3, and a longitudinal polarization electric field is generated by the tensile force on the P (VDF-TrFE) substrate, so that the carrier characteristics of the thermoelectric material can be regulated and controlled, and the thermoelectric or electrothermal conversion efficiency is optimized.

Example 4:

the barium strontium titanate ferroelectric ceramic is used as a substrate, a circuit layer of an N-type Bi thermoelectric material is formed by magnetron sputtering through a mask on the front side, a circuit layer of a P-type BiSb thermoelectric material is formed by magnetron sputtering through a mask on the back side, through holes are drilled at the end parts of the circuits, copper is electroplated in the through holes, and an N-P-N-P … alternating series circuit structure is formed, wherein the plane structure is shown in figure 1. When the series circuit is electrified, one side of the substrate can be refrigerated, and the other side of the substrate can be radiated to form temperature difference; when the temperature difference exists at the two ends of the substrate, the potential difference is generated in the alternate series circuit structure, and the temperature difference can be converted into electric energy to be output outwards. Before use, the electric field with the cross-sectional schematic view as shown in fig. 4 is adopted for polarization, when the electric field is removed during work, the barium strontium titanate ferroelectric ceramic substrate still keeps a longitudinal polarization electric field, the carrier characteristic of the thermoelectric material can be regulated and controlled, and the thermoelectric or electrothermal conversion efficiency is optimized.

Claims

1. A method for manufacturing a planar thermoelectric element, comprising: the method comprises the following steps of utilizing a piezoelectric material as a substrate, printing thermoelectric semiconductor circuits on the plane of the substrate, respectively printing circuit layers of N-type thermoelectric materials and P-type thermoelectric materials on two sides of the substrate, respectively drilling a row of through holes at two ends of the substrate, plating metal in the through holes, and connecting the circuit layers on the two sides into an N-P-N-P … alternating series circuit structure through the through holes plated with metal at two ends to obtain a plane thermoelectric element; when the temperature difference exists at the two ends of the substrate, the potential difference is generated in the alternate series circuit structure, the temperature difference can be converted into electric energy, when the current is introduced into the series circuit, one side of the substrate can be refrigerated, and the other side of the substrate can be radiated, so that the temperature difference is formed; the piezoelectric material substrate is used for generating electric polarization in the normal direction, and the thermoelectric efficiency and the refrigeration efficiency of the thermoelectric material circuit can be adjusted.

2. The method of claim 1, wherein the substrate is made of an insulating material having piezoelectric properties, and comprises a piezoelectric ceramic material, a piezoelectric crystal material and a piezoelectric polymer material.

3. The method of claim 1, wherein the generating of the electric polarization in the normal direction of the piezoelectric material substrate comprises applying an external force to the substrate and polarizing the electric field in the normal direction of the substrate.

4. The method of claim 1, wherein the P-type thermoelectric material has a room temperature conductivity of > 50Scm, and a power factor of > 10 μ Wm^-1K^-2The room temperature electric conductivity of the N-type thermoelectric material is more than 50Scm, and the power factor is more than 10 mu Wm^-1K^-2The circuit manufacturing mode comprises one of screen printing, mask vacuum evaporation, mask magnetron sputtering, atomic layer epitaxial coating and ink jet printing.

5. The method of claim 1, wherein the thermoelectric material comprises (Bi, Sb)₂(Se，Te)₃And one of element doped solid solution thereof, (Pb, Sn) (Se, Te) and element doped solid solution thereof, skutterudite compound, Zintl phase intermetallic compound and element doped solid solution thereof, and conjugated polymer-based composite conductive material.

6. The method of claim 1, wherein a row of through holes are drilled in each of two ends of the substrate, the through holes are plated with a metal, the metal is selected from copper, silver and gold, and the metal plating in the through holes is respectively connected to and conducted with the N-type thermoelectric circuit and the P-type thermoelectric circuit on the two sides of the substrate.

7. The method of claim 1, wherein a plurality of piezoelectric material substrates each having a P-type thermoelectric material circuit and an N-type thermoelectric material circuit on both sides thereof are bonded to form a multilayer wiring board, and the circuits on the plurality of wiring boards are connected by drilling through holes and plating the holes, thereby obtaining higher thermoelectric conversion efficiency.

8. A planar thermoelectric element manufactured by the method of manufacturing a planar thermoelectric element according to any one of claims 1 to 7.