Thermoelectric Module Bonding Layer for High-Temperature Stability
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Solution Overview
Problem
Conventional thermoelectric modules face challenges in operating stably at high temperatures due to the limitations of soldering techniques, which have low melting points, making them unsuitable for temperatures above 200°C for Sn-based solder paste and 300°C for Pb-based solder paste.
Innovation Solution
A thermoelectric module with a bonding layer composed of a sintered metal compound, including metals like Ni and Sn, formed through transient liquid phase sintering, which provides high bonding strength and stability up to 500°C, and optionally includes a metallized layer and a NiP layer for enhanced performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If solder paste (Sn-based or Pb-based) is used to bond electrode with thermoelectric element, then bonding process is simple and widely used, but the thermoelectric module cannot operate at high temperatures due to low melting point of solder
Solution Approach 1:
The invention changes the bonding material from conventional solder paste to a paste containing metal powders of two or more classes (e.g., Ni, Sn, Fe, Cu, Al, Zn, Bi, Ag, Au, Pt). This material parameter change enables the bonding layer to withstand high temperatures (above 300°C) while maintaining bonding strength, thus resolving the contradiction between ease of manufacture and temperature resistance.
Solution Approach 2:
The invention uses a composite paste material comprising multiple metal powders (at least two different classes) that form a sintered body with high-temperature stability. This composite approach combines the advantages of different metals to achieve both manufacturability and high-temperature operation capability, overcoming the limitations of single-material solder paste.
2Ease of manufacture
If conventional soldering is used for bonding, then manufacturing is easy and cost-effective, but bonding strength at high temperatures deteriorates
Solution Approach 1:
The invention modifies the bonding material composition to include metal powders of two or more classes with specific properties that maintain bonding strength at high temperatures. The paste is designed to form a sintered body with enhanced thermal stability, preserving bonding strength above 300°C while keeping the manufacturing process accessible and cost-effective.
Solution Approach 2:
The invention replaces the conventional soldering mechanism (reliant on low-melting-point alloys) with a sintering-based bonding mechanism. The paste is sintered to form a dense, strong bonding layer that mechanically and metallurgically bonds the electrode to the thermoelectric element, providing superior high-temperature strength while maintaining manufacturing simplicity.
3Temperature
If metal powders of two or more classes are sintered to form bonding layer, then high-temperature stability is achieved, but manufacturing process becomes more complex
Solution Approach 1:
The invention incorporates all necessary metal powder components into a pre-mixed paste formulation before application. This preliminary preparation ensures that the correct proportions of different metal classes are uniformly distributed, simplifying the subsequent sintering process and reducing manufacturing complexity despite the multi-component nature of the bonding material.
Solution Approach 2:
The paste serves as an intermediary carrier that facilitates the introduction of multiple metal powders into the bonding interface. By formulating the paste with appropriate binders and dispersants, the invention enables easy application and uniform distribution of complex multi-metal compositions, thereby reducing process complexity while achieving high-temperature stability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The module achieves stable operation at high temperatures, with bonding strengths exceeding 10 MPa and specific resistances suitable for thermoelectric performance, enabling its use in power-generation applications.
Implementation Method 1
The bonding layer may be formed in such a way that a paste including the metal powders of two or more classes is sintered in a transient liquid phase sintering (TLPS) manner and the metal powders of two or more classes are transformed into the metal compound.
Implementation Method 2
If there is a temperature difference between both ends of a solid material, a concentration difference of carriers (electrons or holes) having thermal dependence occurs, leading to an electric phenomenon called a thermal electromotive force, that is, a thermoelectric effect.
Implementation Method 3
the metallized layer may have a function of preventing oxidation of a surface of the thermoelectric element
Data Source
AI summary
The present disclosure discloses a thermoelectric module to which a bonding technique for stably driving the thermoelectric module at high temperatures is applied and a method of manufacturing the thermoelectric module. The thermoelectric module according to the present disclosure includes thermoelectric elements including a thermoelectric semiconductor, an electrode which includes a metal material and is connected between the thermoelectric elements, and a bonding layer which is interposed between the thermoelectric element and the electrode to bond the thermoelectric element with the electrode and includes a metal compound including metals of two or more classes as a sintered body of a paste including metal powders of two or more classes.