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US 2017/0365765 A1Published application
Method of manufacturing a sealed thermoelectric module
AssigneeTegma AS
InventorsTorleif A. TOLLEFSEN, Marianne Aanvik ENGVOLL
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Abstract
The present invention relates to a method for manufacturing a thermoelectric module which utilises the concept of solid-liquid interdiffusion bonding for both forming the metallization, interconnection and bonding between the thermoelectric elements and the electric contacts and the forming of a hermetically sealing of the thermoelectric module.
Claims19
A method manufacturing a thermoelectric module, characterised in that the method comprises:
- 1) pre-processing a first and second electrically nonconductive cover substrate, each having a first and second surface, for electrical connection and sealing by:
- i) attaching a stratified layered metallic electric contact element consisting of a first bonding layer of metal A and an optional second bonding layer of metal B onto each location of the first side of the first and the second cover substrate where an electric contact with a thermal element is to be formed, the electric contact element is attached with its first bonding layer facing the first side of the respective cover substrate, and
- ii) attaching an equally dimensioned stratified layered metallic sealing frame consisting of a first bonding layer of a metal C and an optional second bonding layer of metal D along the periphery of the first side of both the first and the second cover substrate such that the first bonding layer of each metal frame is facing the first side of the respective cover substrate,
- 2) preparing the formation of the electrical connections between the electrical contact elements and a number of p-doped and a number of n-doped thermoelectric elements, where each p-doped and n-doped thermoelectric element has on a first side and on a second side opposite the first side, a first bonding layer of the metal A and a second bonding layer of the metal B directly onto the first bonding layer, by:
- j) selecting one of either the first or the second cover substrate:
- jj) placing a p-doped thermoelectric element with its second bonding layer on its first side facing either the first or the optional second bonding layer of the respective electric contact element on each location where an electrical connection between the p-doped thermoelectric element and the electric contact element is to be formed on the selected cover substrate, and
- jjj) placing a n-doped thermoelectric element with its second bonding layer on its first side facing either the first or the optional second bonding layer of the respective electric contact element on each location where an electrical connection between the n-doped thermoelectric element and the electric contact element is to be formed on the selected cover substrate,
- 3) preparing a hermetically sealing of the thermoelectric module by:
- k) placing a sealing element having on a first side and on a second side opposite the first side a first bonding layer of a metal C and a second bonding layer of a metal D, with its second bonding layer facing either the first or the optional second bonding layer of the sealing frame of the selected cover substrate, and
- 4) forming both the electrical contacts and the hermetically sealing of the thermoelectric module by:
- l) placing the non-selected cover substrate such that facing either the first or the optional second bonding layer of its sealing frame and its attached electric contact elements obtains physical contact with the respective second bonding layer of the second side of the sealing element and the respective p- doped and n-doped thermoelectric element placed onto the selected cover substrate, and
- ll) applying a gentle pressure pressing the first and second cover substrate against each other and annealing to a temperature at which the metal A and metal B and the metal C and D bonds all bonding layers in contact with each other together by solid-liquid interdiffusion,
- and
- wherein the melting point of metal A is higher than metal B and the melting point of metal C is higher than metal D, and the metals A and B and metals C and D are chemically reactive towards each other and forms one or more intermetallic compounds by solid-liquid interdiffusion when subject to heating above the melting point of metals B and D.
11 more elements
A thermoelectric module, comprising:
- a number of thermoelectric elements of semiconducting thermoelectric conversion material doped to n-type conductivity and a number of thermoelectric elements of semiconducting thermoelectric conversion material doped to p-type conductivity,
- a number electric contact elements comprising a first bonding layer of a metal A, and optionally, a second bonding layer of a metal B deposited directly onto the first bonding layer,
- a sealing system comprising a first sealing frame, a sealing element, and a second sealing frame, where the first and second sealing frame comprises a first bonding layer of a metal C, and optionally, a second bonding layer of a metal D deposited directly onto the first bonding layer
- and
- a first cover substrate in thermal contact with a heat reservoir and second cover substrate in thermal contact with a heat sink,
- where
- the thermoelectric elements of n-type conductivity and the thermoelectric elements of p-type conductivity are electrically connected in series by the electric contact elements,
- each electric contact element is on a first side bonded to at least one thermoelectric element, and on a second side opposite the first side bonded to one of the first and second cover substrate,
- wherein
- each thermoelectric element of n-type conductivity and each thermoelectric element of p-type conductivity has on both its first and second surface:
- i) a first adhesion layer of a first metal deposited directly onto the first and second surfaces,
- ii) a diffusion barrier layer of a non-metallic compound of a second metal deposited directly onto the first adhesion layer on the first and second surfaces,
- iii) a second adhesion layer of a third metal deposited directly onto the diffusion barrier layer of the non-metallic compound of the second metal on the first and second surfaces,
- iv) a first bonding layer of a metal A deposited directly onto the second adhesion layer on the first and second surfaces, and
- v) a second bonding layer of a metal B deposited directly onto the first bonding layer the on the first and second surfaces, and
- the sealing element has on a first side and a second side opposite the first side:
- vi) an adhesion layer of Cu,
- vii) a first bonding layer of a metal C deposited directly onto the adhesion layer on the first and second sides, and
- viii) a second bonding layer of a metal D deposited on the first bonding layer,
- the first sealing frame is at a first side of the first bonding layer attached to the first cover substrate and on the side opposite of the first side bonded to the sealing element by solid liquid interdiffusion bonding, and
- the second sealing frame is at a first side of the first bonding layer attached to the second cover substrate and on the side opposite the first side bonded to the sealing element by solid liquid interdiffusion bonding, and where
- the non-metallic compound of the second metal is either a nitride or an oxide of the second metal,
- the melting point of metal A is higher than metal B and the melting point of metal C is higher than metal D, and the metals A and B and metals C and D are chemically reactive towards each other and forms one or more inter metallic compounds by solid-liquid interdiffusion when subject to heating above the melting point of metal B and D, and
- the solid liquid interdiffusion bonds are formed by laying the second bonding layer of metal B of the thermoelectric elements and optionally,
- the electric contact elements, respectively, facing and contacting each other followed by an annealing which causes metal B of the second bonding layer to melt and reacting with metal A of the first bonding layer.
22 more elements
Dependencies are inferred from the claim text.