This application claims priority to German Patent Application No. DE 10 2017 217 123.5, filed on Sep. 26, 2017, the contents of which are hereby incorporated by reference in its entirety.
The present invention relates to a method for producing a thermoelectric converter by providing an electrically conductive substrate and equipping the substrate with thermoelectrically active material. The invention, furthermore, relates to a thermoelectric converter produced in such a manner.
The use of thermoelectric converters, which are capable in particular by applying an electric voltage to generate a temperature difference and vice versa becomes increasingly important. Such converters can be employed for example for temperature-controlling various items and/or fluids, in particular in an air-conditioning system, for example of a vehicle. With the increasing importance, the relevance of the production of such converters also increases. It is desirable to produce the converters cost-effectively and/or variably and/or with a high quality.
For producing a thermoelectric converter, thermoelectrically active elements are usually provided, which are each serially interconnected by separate conductor elements, in particular in the form of metal plates. This type of production of thermoelectric converters therefore requires many individual method steps rendering the production complicated and thus expensive. In addition, for producing thermoelectric converters which are distinct from one another, adapted conductor elements and thermoelectrically active elements have to be provided in each case as a result of which the production again becomes elaborate and expensive.
The present invention therefore deals with the object of stating improved or at least other embodiments for a method for producing a thermoelectric converter and for such a thermoelectric converter, which are characterized in particular by a simplified and/or cost-effective production of the converter.
According to the invention, this object is solved through the subject matter of the independent claim(s). Advantageous embodiments are subject of the dependent claim(s).
The present invention is based on the general idea of producing a thermoelectric converter by equipping an electrically conductive substrate with thermoelectrically active material and introducing suitable receptacles and clearances in the substrate equipped with thermoelectrically active material. In this way, the arranging of elements of thermoelectrically active material spaced from one another and the electrical contacting of these elements can be dispensed with, so that the production of the thermoelectric converter can be carried out in a simplified manner and thus more cost-effectively. In addition, differently designed thermoelectric converters can be produced by adapted equipping of the electrically conductive substrate with thermoelectrically active material and/or adapted introduction of the receptacles or clearances in a simple manner and based on the same principle, so that an increased variability for producing different thermoelectric converters can be achieved.
According to the inventive idea, the electrically conductive substrate is initially provided, which preferentially is flat or plate-like, i.e. in particular is formed as a plate. Sides of the substrate facing away from one another are then equipped with thermoelectrically active material. Here, a substrate top side of the substrate is equipped with a first thermoelectrically active material and a substrate bottom side facing away from the substrate top side of the substrate equipped with a second thermoelectrically active material. Following this, a conducting layer of an thermoelectrically conductive material is applied to the respective thermoelectrically active material. This means that on the first thermoelectrically active material an electrically conductive upper conducting layer and on the second thermoelectrically active material an electrically conductive lower conducting layer is applied. When the respective conducting layer is applied, suitable receptacles are introduced on the substrate top side or substrate bottom side in order to produce material sections of the thermoelectrically active material that are spaced from one another in a transverse direction. Here, upper receptacles extending on the substrate top side in a longitudinal direction extending transversely to the transverse direction and which are spaced from one another in the transverse direction are introduced and on the substrate bottom side lower receptacles running in the longitudinal direction and which are spaced from one another in the transverse direction. Following the introduction of the receptacles, an intermediate product is produced which is subsequently processed to form the thermoelectric converter. Here, the receptacles are introduced in such a manner that the upper receptacles overlap in the transverse direction in each case in an overlap section extending in the transverse direction and extending in particular in the longitudinal direction with at least one of the lower receptacles that are adjacent in the transverse direction. In other words, the upper receptacles are spaced from one another in the transverse direction but not spaced from the adjacent lower receptacles. Similar applies analogously to the lower receptacles. Here, the receptacles remove in their associated region in each case the associated thermoelectrically active material, so that adjacent material sections are created in the transverse direction. Thus, the upper receptacles remove the first thermoelectrically active material in their respective associated region so that in the transverse direction adjacent upper material sections are created. Here, because of the abovementioned overlapping arrangement of the receptacles, the upper material sections are arranged in the transverse direction alternately and spaced from one another or offset relative to one another. When the receptacles are introduced, an electrically conductive cover layer is applied to the respective associated side. This means that an electrically conductive upper cover layer is applied to an intermediate product top side of the intermediate product, which is adjacent to the substrate top side or offset relative to the same. Analogously to this, an electrically conductive lower cover layer is applied to an intermediate product bottom side of the intermediate product facing away from the intermediate product top side. The respective cover layer is preferentially applied in such a manner that the previously introduced receptacles are at least partly filled with the cover layer. When the respective cover layer is applied, suitable clearances are introduced into the respective associated side in order to produce the thermoelectric converter. Here, upper clearances extending in the longitudinal direction and which are spaced from one another in the transverse direction are introduced on the intermediate product top side. Analogously to this, bottom clearances which extend in the longitudinal direction and are spaced from one another in the transverse direction are introduced on the intermediate product bottom side, wherein the respective clearance is introduced in one of the overlap sections. Introducing the clearances is effected in such a manner that they remove the associated cover layer in each case the associated region and enter the substrate in order to form a hollow space separating the material sections that are adjacent in the transverse direction. This means that the upper clearances are introduced in such a manner that they remove the upper cover layer in each case in the associated region and enter the substrate so far that the material sections that are adjacent in the transverse direction, i.e. in each case a first material section and a second material section, are separated from one another by a hollow space but are electrically connected. Analogously to this, the lower recesses are introduced in such a manner that they in each case remove the lower cover layer in the associated region and enter the substrate and in each case form a hollow space separating the material sections that are adjacent in the transverse direction, i.e. a second material section and a first material section, but which are electrically contacted with one another.
The hollow spaces are each practically formed in such a manner that material sections that are adjacent in the transverse direction are electrically and mechanically connected in series. This means that material sections that are adjacent in the transverse direction form an electrical and mechanical series arrangement.
It is to be understood that the method steps stated above can also be performed in other sequences provided they lead to the same result. It is possible, for example, to equip the substrate top side with the first thermoelectrically active material, to provide the same with the upper conducting layer, introduce the upper receptacles, apply the upper cover layer and introduce the upper clearances before the corresponding steps are performed on the substrate bottom side.
Basically, the respective conducting layer can be configured in any way. In particular, the respective line layer can be in multiple layers, wherein the individual layers can be applied one after the other.
The respective conducting layer is preferentially configured in such a manner that it results in an improved adhesion of the subsequently applied associated cover layer. Accordingly, the conducting layer can also be referred to as contact layer. For this purpose, the respective conducting layer can at least partly consist of a mixture of different components. This means in particular that individual layers of the conducting layer can consist of a mixture or comprise a mixture.
The respective thermoelectrically active material is preferentially equipped in such a manner that the associated side of the substrate is entirely equipped with the thermoelectrically active material. On the one hand, the entire substrate is used for producing the thermoelectric converter. On the other hand, subsequent steps for producing the converter can be easily performed. Analogously to this it is preferred when the respective conducting layer and/or the respective cover layer entirely cover/s the associated side.
Preferred are embodiments, with which the upper receptacles are introduced in such a manner that they each remove the upper conducting layer and the first electrically active material in the associated region, so that the upper material sections spaced in the transverse direction are created. Analogously to this it is preferred when the lower receptacles are introduced in such a manner that they each remove the lower conducting layer and the second thermoelectrically active material in the associated region in order to produce the lower material sections that are spaced in the transverse direction. It is advantageous, furthermore, to introduce the upper clearances in such a manner that they each remove the upper cover layer in the associated region, enter the substrate and each form one of the hollow spaces separating the material sections that are adjacent in the transverse direction. It is particularly preferred when the upper clearances are introduced in such a manner that they enter the cover layer located opposite, i.e. the lower cover layer however without removing the same. By way of this, undesirable electric currents between adjacent material sections are prevented so that the efficiency of the thermoelectric converter is improved. An improved thermal separation between adjacent material sections is additionally effected by way of this, so that the efficiency of the thermoelectric converter is again improved. It is preferred, furthermore, when the bottom clearances are introduced in such a manner that they each remove the lower cover layer in the associated region, enter the substrate and each form one of the hollow spaces separating the material sections that are adjacent in the transverse direction. In order to achieve and/or further increase the aforementioned advantages, the bottom clearances should preferably enter the cover layer located opposite, i.e. the upper cover layer, however without removing the same.
Embodiments in which the substrate following the introduction of the clearances by the introduction of at least one cut extending obliquely to the longitudinal direction is divided into at least two separate parts prove to be advantageous, wherein the respective part forms a thermoelectric converter. This means that the previously produced thermoelectric converter is separated into multiple parts in such a manner that the respective part again forms a thermoelectric converter.
Prior to the equipping of the turned-away substrate side of the substrate with the thermoelectrically active material it is conceivable to provide at least one of the conducting layers with an electrically insulating insulating layer. By way of this it is prevented in particular that the conducting layer, to which the insulating layer is applied, is provided with the thermoelectrically active material which has to be applied to the turned-away side. It is conceivable, for example, to provide the upper conducting layer, before equipping the substrate bottom side with the second thermoelectrically active material with an upper electrically insulating insulating layer in order to prevent in particular that during the equipping of the substrate with the second thermoelectrically active material the second thermoelectrically active material reaches the upper conducting layer. By way of this, undesirable currents between the thermoelectrically active materials are thus prevented and consequently a quality and/or efficiency of the thermoelectric converter improved. Similar applies when the lower conducting layer prior to equipping the substrate top side with the first thermoelectrically active material is provided with an electrically insulating bottom insulating layer.
Practically, the respective insulating layer is removed before the coating of the associated side with the cover layer. By way of this, a continuous electrical connection between the conducting layer and the associated cover layer is created, so that undesirable electrical contacting of adjacent material sections is improved.
The respective thermoelectrically active material can be applied to the associated substrate side generally in any way. Here it is preferred when the thermoelectrically active material is coated onto the associated substrate side.
Considered advantageous are embodiments, with which at least one of the thermoelectrically active material is applied to the associated substrate side in particular by way of physical vapour deposition (PVD). Because of this, a large-area application of the respective thermoelectrically active material with low contaminations and in a high quality is possible.
It is advantageous when at least one of the conducting layers and/or at least one of the cover layers is applied by a vacuum-based deposition method, in particular deposited. By way of this, the relevant conducting layer or cover layer can be applied over a large area and/or with low contamination and/or in a high quality. When for applying the thermoelectrically active materials and/or the conducting layers and/or the cover layers, the same deposition method is employed, producing the thermoelectric converter can be carried out particularly cost-effectively and/or with a particularly high quality.
It is conceivable to provide at least one of the conducting layers and/or one of the cover layers with a protective layer for preventing or at least reducing the oxidation of the conducting layer or the cover layer. The protective layer, which can also be referred to as oxidation protection layer, can consist in particular of a precious metal, for example gold or comprise such a metal. The protective layer is preferentially thin compared with the remaining applied layers, in order to achieve in particular an improved efficiency of the converter or reduce the efficiency by as little as possible. When the protective layer is applied to the conducting layer, the protective layer can be removed prior to applying the associated cover layer. Generally, this results in an improved adhesion of the cover layer to the conducting layer. However it is also conceivable to apply the cover layer to the protective layer in the region of the conducting layer.
It is obviously conceivable to also perform other method steps between the stated method steps, such as for example a cleaning, an attachment and the like.
It is to be understood that besides the method for producing the thermoelectric converter such a converter also forms part of the scope of this invention.
Here, the converter can be employed in particular as a Peltier element, which when energised with an electric current, exchanges heat between at least two regions, in particular pumps heat.
A possible use of the thermoelectric converter, in particular of the Peltier element, is in an air-conditioning system for example of a vehicle.
Further important features and advantages of the invention are obtained from the subclaims, from the drawings and from the associated figure description by way of the drawings.
It is to be understood that the features mentioned above and still to be explained in the following cannot only be used in the respective combination stated but also in other combinations or by themselves without leaving the scope of the present invention.
It shows, in each case schematically,
For producing a thermoelectric converter 1, in particular a Peltier element 2, as is visible for example in
According to
According to
The thermoelectrically active materials 10, 15, the conducting layers 13, 18 and the protective layers 14, 19 are each applied with a substantially constant thickness extending in the height direction 7. A material thickness 20 of the respective thermoelectrically active material 10, 15 can be between 10 μm and 100 μm. A conductor thickness 21 of the respective conducting layer 13, 18 can be between 10 μm and 100 μm. The respective protective layer 14, 19 preferentially has a protective layer thickness 22, which is smaller than the associated material thickness 20 and/or conductor thickness 21. The protective layer thickness 22 can be for example between 10 nm and 100 nm. Compared with this, the substrate 3 has a substrate thickness 23 that is greater than the material thicknesses 20, the conductor thicknesses 21 and the protective layer thicknesses 22, for example between 0.1 mm and 1 mm. The respective conducting layer 13, 18 is preferably produced from a metal or from a metal-containing material, in particular from aluminium or an aluminium alloy.
The respective thermoelectrically active material 10, 15, the respective conducting layer 13, 18 and the respective protector layer 14, 19 are advantageously applied with the help of a vacuum-based deposition method, in particular by physical gas phase depositions.
Following the application of the thermoelectrically active material 10, 15 located opposite and/or after the method steps explained in the following, the respective layer 14, 19 is removed. As shown in
To this end, as shown in
As shown in
When the converter 1, in particular the Peltier element 2, is energised, a first thermal side 43, for example a cold side, materialises in the region of the upper cover sections 40, and a second thermal side 45, for example a warm side 46, of the converter 1 or of the Peltier element 2 in the region of the lower cover sections 41.
Number | Date | Country | Kind |
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102017217123.5 | Sep 2017 | DE | national |