EP3763167B1 - Flat electric component and method for manufacturing - Google Patents

Description

The invention relates to a surface electrical component, a sheet metal strip composite material for a surface electrical component and a method for producing a surface electrical component. The invention further relates to devices such as containers, protective walls and roof, wall, ceiling and floor panels for buildings, which include a surface electrical component, for example in the form of a surface heating and/or a surface deformation sensor.

Currently, heaters or sensors are integrated as separate units in flat components such as walls of containers or building wall surfaces if a corresponding functionality (heating of the environment, detection of environmental influences) is desired. For example, it is known to attach heating wires, heating coils, heating mats or heating coatings to surface elements or to provide pressure sensors in walls.

When using heating wires, it has proven to be disadvantageous that a large amount of space is required combined with high costs and, in many cases, a structurally complex coupling of the heating wires to the component to be heated is required. Heating coatings require large layer thicknesses to conduct current in the layer plane and expensive fillers (e.g. silver) as well as complex electrode structures to achieve the required electrical conductivity. If the heating coatings are to be applied to an electrically conductive substrate, this must be electrically insulated from the heating coating, for example by pre-painting, which leads to high disposal costs when scrapping in large-area applications.

Out of WO 2013/156162 A2 a heating device is known in which a heating layer and a second contacting layer are applied to a substrate forming a first contacting layer via a sequence of coating processes. The heating layer can be applied by spraying, rolling or doctoring.

EP 2 457 412 B1 describes a high-temperature heater that uses heating element layers formed from a flowable base material and carbon nanotubes dispersed therein.

US 2016/0113065 A1 describes an electrical heating mat that is constructed from two conductors and a heating element arranged between them that includes an electrically conductive material.

KR 2011 0088934 A describes a surface heating element which contains two conductors made of a metal foil and an electrically conductive element in between.

One task on which the invention is based can be seen in creating a surface electrical component that has an integral, surface electrical functionality, such as heating or sensors, and can be produced inexpensively. In particular, the surface electrical component should have a high structural suitability for a variety of applications and areas of use. Furthermore, an object on which the invention is based can be seen in creating a cost-effective sheet metal strip composite material for a flat electronic component and in specifying methods which are used to produce a sheet metal strip composite material as a preliminary product of the flat electronic component.

The task is solved by the features of the independent claims. Exemplary embodiments and further developments are the subject of the subclaims.

Accordingly, a surface electrical component comprises a first sheet metal panel, a second sheet metal panel and an electrically conductive adhesive layer which is arranged between mutually facing surfaces of the first sheet metal panel and the second sheet metal panel. The first sheet metal panel forms a first electrode of the surface electrical component, the second sheet metal panel forms a second electrode of the surface electrical component and, during operation, a current flows from the first sheet metal panel to the second sheet metal panel through the electrically conductive adhesive layer in the direction perpendicular to the adhesive layer plane. The two sheet metal panels, which can be blanks made from a rolled sheet metal strip, are held together by the electrically conductive adhesive layer. The first sheet metal panel is made of a steel material. The second sheet metal panel consists of a steel material or an aluminum material. The electrically conductive adhesive layer is based on a baking varnish.

The electrically conductive adhesive layer is therefore a chemically curable adhesive layer in which the first and second sheet metal panels are bonded via activation of the chemically curable adhesive layer. The electrical conductivity of the adhesive layer can be brought about, for example, by an electrically conductive filler material (e.g. metal particles, carbon particles, such as conductive carbon black, graphite particles or nano-carbon particles, such as nanotubes) or by using an intrinsically conductive polymer adhesive.

The current flow direction perpendicular to the layer plane of the adhesive layer ensures that the layer material only has to have a relatively low electrical conductivity compared to arrangements in which the current flow takes place in the layer plane. In this respect, a relatively low fill factor of conductive particles may be sufficient to produce the desired electrical layer properties. In addition, the vertical flow of current enables a high level of reliability of the surface electrical component, since an interruption of the current flow can practically not occur due to the large cross section.

Since the current is coupled in via sheet metal panels, a high level of mechanical and/or structural stability of the surface electrical component can be guaranteed. As a result, a high degree of reliability of the surface electrical component can be achieved in the event of mechanical stress against short circuits.

The electrically conductive adhesive layer is an adhesive layer based on chemical curing (crosslinking). The chemical hardening of the adhesive layer also contributes to the robustness of the surface electrical component and thus to its reliability.

The electrically conductive adhesive layer is based on a baking varnish. Baked varnish layers are chemically curable adhesive layers specially developed for electrical core construction, which offer high mechanical and thermal (long-term) stability as well as high corrosion protection.

To increase the corrosion resistance of the surface electrical component and thus to expand its area of application It can be provided that one or both of the mutually facing surfaces of the two electrical panels are covered with a metallic corrosion protection layer, for example a corrosion protection layer based on zinc and / or aluminum.

In addition to or instead of the corrosion protection layer, it can also be provided that one or both of the mutually facing surfaces of the two electrical panels are covered with an electrically conductive lacquer layer whose specific electrical resistance is smaller than a specific electrical resistance of the adhesive layer. This can ensure that the electrode surface adjacent to the electrically conductive adhesive layer (which is formed by the surface of the electrically conductive lacquer layer) has uniform and defined electrical properties and the underlying electrode materials (for example the metallic corrosion protection layer or the sheet material of the sheet metal panels) are protected from reactions ( e.g. oxidation) are protected with ambient media (e.g. air).

For example, the adhesive layer can be arranged in the form of a pattern that partially covers the mutually facing surfaces. By only applying the adhesive layer to partial areas, cost savings can be achieved by reducing the amount of adhesive required (if necessary with a corresponding amount of filling material).

Furthermore, it can be provided that spacers are arranged between the mutually facing surfaces. The spacers increase the reliability of the surface electrical component and can, especially in combination with a An adhesive layer that is only applied to part of the surface can result in cost savings.

The sheet metal panels can be comparatively large and have side lengths in one or both dimensions equal to or greater than 1.0 m, 2.0 m, 3.0 m or 4.0 m, etc.

The surface electrical component can, for example, have an electrical functionality as an electrical surface heating and/or as an electrical surface deformation sensor. These or other electrical functionalities can also be used together. As will be explained in more detail below by way of example, this results in a variety of applications and possible uses. In particular, applications are possible in which high mechanical stability, load-bearing capacity and robustness and/or large areas are required and/or high corrosion resistance or resistance to environmental influences are required.

Products that consist of or can have the surface electrical component described here are therefore, for example, containers, roof, wall, ceiling and/or floor panels for buildings as well as protective walls with integrated breakthrough protection and/or integrated impact detection.

A further aspect relates to a method for producing a surface electrical component, which involves separating a sheet metal strip, over one surface of which an electrically conductive adhesive layer is applied, into first sheet metal panels, and bonding the first sheet metal panels using the adhesive layer to second sheet metal panels, in such a way that first sheet metal panel, a first electrode of the surface electrical component and the second sheet metal panel, a second electrode of the surface electrical component form, includes. It is again provided that the current flow between the sheet metal panel via the electrically conductive adhesive layer takes place perpendicular to the adhesive layer plane. The first sheet metal panel is made of a steel material. The second sheet metal panel consists of a steel material or an aluminum material. The electrically conductive adhesive layer is based on a baking varnish and is applied over a surface of the sheet metal strip.

In the method, the first sheet metal panels can be glued to the second sheet metal panels in a pressing station using surface pressure and an energy supply to activate the adhesive layer.

The process can, for example, be carried out entirely at the customer's site, i.e. after delivery of the sheet metal strip with the electrically conductive adhesive layer applied thereon by the steel producer. It is also possible, for example, for the step of separating the sheet metal strip to be carried out by the steel producer and the remaining steps by the customer.

Another aspect relates to a method for producing a sheet metal strip composite material, which is intended as a preliminary product for the production of a surface electrical component according to the above description. The method includes producing a rolled sheet metal strip from a steel material and applying an electrically conductive adhesive layer based on a baking varnish over a surface of the rolled sheet metal strip.

The method can also produce a metallic corrosion protection layer, in particular a corrosion protection layer based on zinc and/or aluminum, over the surface of the rolled sheet metal strip before applying the electrically conductive adhesive layer and/or producing an electrically conductive lacquer layer over the surface of the rolled sheet metal strip before applying the electrically conductive adhesive layer. The specific electrical resistance of the electrically conductive lacquer layer can be smaller than a specific electrical resistance of the adhesive layer.

A cost-effective way of applying the electrically conductive adhesive layer is to apply it by roller application or by a printing process, in particular screen printing.

Both the production process and the creation of the (optional) metallic corrosion protection layer and/or the (optional) electrically conductive paint layer can be carried out entirely at the steel producer, i.e. for example on site in the steelworks.

• Figur 1 zeigt in Längsschnittdarstellung beispielhaft ein Flächenelektrobauteil gemäß einer ersten Ausführungsform.
• Figur 2 zeigt ein elektrisches Ersatzschaltbild des Flächenelektrobauteils der Figur 1.
• Figur 3A ist eine Detaildarstellung des Details D1 aus Figur 1 gemäß einem ersten Beispiel.
• Figur 3B ist eine Detaildarstellung des Details D1 aus Figur 1 gemäß einem zweiten Beispiel.
• Figur 3C ist eine Detaildarstellung des Details D1 aus Figur 1 gemäß einem dritten Beispiel.
• Figur 4 zeigt in Längsschnittdarstellung beispielhaft ein Flächenelektrobauteil gemäß einer zweiten Ausführungsform.
• Figur 5A zeigt in perspektivischer Ansicht ein teilweise aufgeschnittenes Flächenelektrobauteil mit einer teilflächigen Klebstoffschicht in Form eines Gittermusters.
• Figur 5B zeigt in perspektivischer Ansicht ein teilweise aufgeschnittenes Flächenelektrobauteil mit einer teilflächigen Klebstoffschicht in Form eines Streifenmusters.
• Figur 5C zeigt in perspektivischer Ansicht ein teilweise aufgeschnittenes Flächenelektrobauteil mit einer teilflächigen Klebstoffschicht in Form eines Punktemusters.
• Figur 6A zeigt eine Detaildarstellung des Details D2 aus Figur 4 gemäß einem ersten Beispiel.
• Figur 6B zeigt eine Detaildarstellung des Details D2 aus Figur 4 gemäß einem zweiten Beispiel.
• Figur 7 zeigt den Einsatz von Flächenelektrobauteilen als Wand- und Deckenpaneele für bedachte Aufenthaltsbereiche.
• Figur 8 zeigt die Verwendung von Flächenelektrobauteilen als Wandung eines Aufbewahrungsbehälters für flüssige, gasförmige oder feste Stoffe.
• Figur 9 zeigt die Verwendung von Flächenelektrobauteilen als Wandung eines Aufbewahrungsbehälters für eine Elektrobatterie.
• Figur 10 zeigt die Verwendung von Flächenelektrobauteilen als Schutzwand mit integriertem Durchbruchschutz und/oder integrierter Aufpralldetektion.
• Figur 11 zeigt die Verwendung von Flächenelektrobauteilen als robuster Zähler.
• Figur 12A zeigt einen beispielhaften Prozess des Auftragens einer elektrisch leitfähigen, chemisch aushärtbaren Klebstoffschicht über eine Oberfläche eines gewalzten Blechbandes.
• Figur 12B zeigt einen Querschnitt eines Blechband-Verbundmaterials, wie es beispielsweise durch den in Figur 12A dargestellten Prozess produziert werden kann.
• Figur 13 zeigt ein beispielhaftes Verfahren zur Herstellung eines Flächenelektrobauteils aus Blechband-Verbundmaterial.

Exemplary embodiments and further developments are explained below in an exemplary manner using the schematic drawings, with a different level of detail being used in some of the drawings. The same reference numbers designate the same or similar parts.

• Figure 1 shows an example of a surface electrical component according to a first embodiment in a longitudinal section.
• Figure 2 shows an electrical equivalent circuit diagram of the surface electrical component Figure 1 .
• Figure 3A is a detailed representation of detail D1 Figure 1 according to a first example.
• Figure 3B is a detailed representation of detail D1 Figure 1 according to a second example.
• Figure 3C is a detailed representation of detail D1 Figure 1 according to a third example.
• Figure 4 shows an example of a surface electrical component according to a second embodiment in a longitudinal section.
• Figure 5A shows a perspective view of a partially cut open surface electrical component with a partial adhesive layer in the form of a grid pattern.
• Figure 5B shows a perspective view of a partially cut open surface electrical component with a partial adhesive layer in the form of a stripe pattern.
• Figure 5C shows a perspective view of a partially cut open surface electrical component with a partial adhesive layer in the form of a dot pattern.
• Figure 6A shows a detailed representation of detail D2 Figure 4 according to a first example.
• Figure 6B shows a detailed representation of detail D2 Figure 4 according to a second example.
• Figure 7 shows the use of surface electrical components as wall and ceiling panels for covered lounge areas.
• Figure 8 shows the use of surface electrical components as the wall of a storage container for liquid, gaseous or solid substances.
• Figure 9 shows the use of surface electrical components as the wall of a storage container for an electric battery.
• Figure 10 shows the use of surface electrical components as a protective wall with integrated breakthrough protection and/or integrated impact detection.
• Figure 11 shows the use of surface electrical components as a robust meter.
• Figure 12A shows an exemplary process of applying an electrically conductive, chemically curable adhesive layer over a surface of a rolled sheet metal strip.
• Figure 12B shows a cross section of a sheet metal strip composite material, such as that shown in Figure 12A the process shown can be produced.
• Figure 13 shows an exemplary method for producing a surface electrical component made of sheet metal strip composite material.

Terms such as "applying" or "applying" as well as similar terms (e.g. "applied" or "applied") in this description are not to be understood as meaning that the applied or applied layers are in direct contact with the surface on which they are applied or must be applied. There may be intervening elements or layers between the "applied" or "applied" elements or layers and the underlying surface to be available. However, the above-mentioned or similar terms in this disclosure may also have the specific meaning that the elements or layers are in direct contact with the underlying surface, that is, that there are no intervening elements or layers.

The term "over" as used in reference to an element or layer of material formed or applied "over" a surface may be used herein to mean that the element or layer of material is "indirectly on" the Surface is attached, wherein intermediate elements or layers may be present between the surface and the element or layer of material. However, the term "over" may also have the specific meaning that the element or layer of material that is applied or applied "over" a surface is applied "directly on", i.e., for example, in direct contact with the surface in question. The same applies to similar terms such as "above", "below", "underneath", etc.

Figure 1 shows an exemplary surface electrical component 100 according to a first embodiment. The surface electrical component 100 contains a first sheet metal panel 110, a second sheet metal panel 120 and an electrically conductive adhesive layer 130, which is arranged between mutually facing surfaces 110A and 120B of the first sheet metal panel 110 and the second sheet metal panel 120, respectively.

The sheet metal panels 110, 120 can be shaped blanks that were produced from a continuous sheet metal strip, for example by dividing it transversely. The first and second sheet metal panels 110, 120 can, for example have a thickness equal to or greater than 0.5 mm, 0.75 mm, 1.0 mm, 1.5 mm, 2.0 mm or 2.5 mm. The thickness and the material (for example steel) of the sheet metal panels 110, 120 can depend on the intended purpose of the surface electrical component 100, that is to say in particular depend on the mechanical and/or structural stability that is required of the surface electrical component 100 in the respective application.

According to one exemplary embodiment, both sheet metal panels 110, 120 are made of a steel material. However, it can advantageously also be a combination of two different metallic materials for the two sheet metal panels, i.e. the sheet metal panel 110 can consist of a different metallic material than the sheet metal panel 120. In this case, the sheet metal panel 110 is made of a steel material to ensure sufficient mechanical and/or structural stability, and the second sheet metal panel 120 is made of an aluminum material. The thermal insulation properties can advantageously be improved here, since in particular the emissivity values (measure of the heat radiation that a material exchanges with its surroundings) can be kept low when using aluminum. In such a case, the thickness of the aluminum material would advantageously be less than or equal to 0.1 mm.

The electrically conductive adhesive layer 130 can consist of a chemically curable adhesive which is present in a cured form in the finished surface electrical component 100. The electrically conductive adhesive layer 130 thus bonds the two sheet metal panels 110, 120. The adhesive can be, for example, a polymerization adhesive, a polycondensation adhesive or a polyaddition adhesive.

Furthermore, the electrically conductive adhesive layer 130 is made on the basis of a baking varnish layer. Well-known baking varnish layers are epoxy resin-based baking varnish layers with latent hardener. An advantageous composition can result if the organic material of the (dried) baking varnish layer contains, for example, 7.5 to 10.5% by volume of latent hardener and, for example, 89.5 to 92.5% by volume of epoxy resin. In addition to the organics, the baking varnish contains fillers (e.g. electrically conductive particles made of carbon (e.g. soot particles, carbon nanotubes, etc.) or metal particles) in order to adjust the electrical conductivity according to the specific intended use in the product, and the rest can be used in the (dried ) Baking varnish layer may also contain possible impurities.

The electrical conductivity of the electrically conductive adhesive layer 130 can be achieved by fillers (for example by adding electrically conductive particles as mentioned above), or it is possible to use an intrinsically conductive organic adhesive.

The layer thickness of the electrically conductive adhesive layer 130 can, for example, be equal to or greater than 30 μm, 50 μm, 75 μm, 100 μm or 150 μm. Larger layer thicknesses in the range of over 200 pm, 300 µm, 400 µm are also possible.

The ratio of the thickness of at least one of the first and second sheet metal panels 110, 120 to the layer thickness of the electrically conductive adhesive layer 130 can, for example, be equal to or greater than 5, 10, 15 or 20.

The first sheet metal panel 110 forms a first electrode of the surface electrical component 100 and the second sheet metal panel 120 forms a second electrode of the surface electrical component 100. A current flow from the first sheet metal panel 110 to the second sheet metal panel 120 (or vice versa) occurs perpendicular to the plane of the electrically conductive adhesive layer 130.

The surface electrical component 100 can have different electrical functionalities. In a first example it is used as surface heating. In this case, the two electrodes (first and second sheet metal panels 110, 120) are connected to a power source (SQ). The current is coupled into the surface electrical component 100 via the two sheet metal panels 110, 120. The electrically conductive adhesive layer 130 acts as a heating coating in which the heat development takes place.

According to a further example, the surface electrical component 100 can also serve as a sensor. In this case, the two electrodes (sheet metal panels 110, 120) are connected to a measuring device M. The measuring device M evaluates an electrical quantity at its input. For example, an electrical resistance is measured or monitored. A change in resistance may indicate a structural change (e.g. deformation, damage, destruction, etc.) of the surface electrical component 100.

Figure 2 shows a simplified representation of an equivalent circuit diagram of the surface electrical component 100. Shown are an electrical device SQ/M (e.g. current source and/or measuring device) and the sheet resistance R _KS of the electrically conductive adhesive layer 130. The equivalent circuit diagram refers to a design in which the electrical sheet resistance R _KS of the electrically conductive adhesive layer 130 is significantly greater than the electrical resistance of the sheet metal panels 110, 120.

wobei ρ_KS der spezifische Widerstand (in Ωm), SD die Schichtdicke (in m) der elektrisch leitfähigen Klebstoffschicht 130 und A die Kontaktfläche (in m²) zwischen den Blechpaneelen 110 bzw. 120 und der elektrisch leitfähigen Klebstoffschicht 130 ist.The following applies to the sheet resistance R _KS $${\mathrm{R}}_{\mathrm{KS}}={\mathrm{\rho }}_{\mathrm{KS}}\cdot \mathrm{SD}/\mathrm{A},$$

where ρ _KS is the specific resistance (in Ωm), SD is the layer thickness (in m) of the electrically conductive adhesive layer 130 and A is the contact area (in m ² ) between the sheet metal panels 110 or 120 and the electrically conductive adhesive layer 130.

Values for ρ _KS can vary over a wide range depending on the application and can, for example, be equal to or larger or smaller than 20 kΩm, 60 kΩm, 200 kΩm, 800 kΩm, 1000 kΩm or 3000 kΩm. In general, values in the range from kΩm to several MΩm can be expected.

For example, with a desired surface heating output of, for example, 150 W/m ² , a contact area A of, for example, 1 m ² (corresponds to the panel size with a degree of coverage of, for example, 100%) and an operating voltage of, for example, 60 V, a sheet resistance R _KS = 24 Ω. For a layer thickness SD of, for example, 30 µm, this would result in a value for ρ _KS of 800 kΩm.

If the surface electrical component 100 is a surface heating system, the heating output of the surface electrical component 100 results from the equation $$\mathrm{P}=\mathrm{U}\cdot \mathrm{I}={\mathrm{<figure-callout\; id="2"\; label="U"\; filenames="imgf0003.png"\; state="\{\{state\}\}">U</figure-callout>}}^2/{\mathrm{R}}_{\mathrm{KS}}.$$

P denotes the power (in W), U denotes the operating voltage (in V) and I denotes the current (in A). It is clear that a desired heating output of the surface electrical component 100 can be set as desired by selecting suitable values for A and/or SD and/or ρ _KS .

Figure 3A shows a detail D1 Figure 1 . A metallic corrosion protection layer 111 (for example corrosion protection layer based on zinc and/or aluminum) is arranged above the surface 110A of the first sheet metal panel 110, which thus runs between the adhesive layer 130 and the base material (for example steel) of the first sheet metal panel 110. The corrosion protection layer 111 can completely cover the surface 110A of the first sheet metal panel 110.

Figure 3B shows a second example of detail D1, which differs from that in Figure 3A The example shown differs only in that an electrically conductive lacquer layer 112 is provided between the metallic corrosion protection layer 111 and the adhesive layer 130. The electrically conductive paint layer 112 can consist of an organic conductive paint, increase corrosion protection and create an electrode contact surface for the adhesive layer 130 that is improved in terms of electrical and structural properties. The electrically conductive lacquer layer 112 can have a significantly higher specific electrical conductivity than the adhesive layer 130. The thickness of the electrically conductive lacquer layer 112 can be significantly less than the thickness of the electrically conductive adhesive layer 130 and, for example, be equal to or less than 20 μm, 15 μm or 10 μm. The electrically conductive lacquer layer 112 can have a high flatness and act as an electrode finish that improves the electrode surface.

Figure 3C shows another example of detail D1 Figure 1 , in which compared to the example of Figure 3B the metallic corrosion protection layer 111 is dispensed with. Otherwise they are too Figures 3A and 3B information provided on the in Figure 3C Example shown transferable.

It should be noted that the second electrode of the surface electrical component 100 comprising the second sheet metal panel 120 is analogous to that in Figures 3A to 3C shown layer sequences can be realized.

Figure 4 shows an exemplary surface electrical component 400 according to a second embodiment. The surface electrical component 400 differs from the surface electrical component 100, for example, only in that a protective layer 410 or 420 is applied to one or both outer surfaces of the sheet metal panels 110, 120 (ie on a surface 110B or a surface 120A). The protective layers 410, 420 can consist of a polymer material, for example. For example, a polyester material can be used.

The protective layers 410, 420 can cause electrical insulation of the electrodes from the outside. In addition, the protective layers 410, 420 can enable the surface electrical component 400 to have a desired appearance, such as is required, for example, for wall, floor or ceiling surfaces on the outside or inside of buildings. The protective layers 410, 420 can be highly scratch-resistant and/or highly UV-resistant surface layers, which are already used, for example, for facade applications on coated steel facades. The thickness of the protective layers 410, 420 can, for example, be equal to or smaller or larger than 15 μm, 25 μm, 35 μm or 50 μm. In this way, surface electrical components 400 can be produced, which are electrically insulated from the outside and can be used in the same way as known wall structures based on coated steels, but in contrast to these have an integrated electrical functionality.

Figure 5A shows a perspective view of a partially cut open surface electrical component 500. The surface electrical component 500 can be constructed according to one or more of the previously described examples, but with the modification that the electrically functional adhesive layer 130 is arranged as a pattern that only partially covers the surfaces 110A and 120B.

In the Figure 5A A grid-shaped adhesive pattern is shown. The Figures 5B and 5C show surface electrical components 500 with a stripe pattern or an adhesive pattern consisting of dots. The representations in the Figures 5A to 5C are merely examples and a variety of other pattern shapes can be realized.

In all examples of partial coverage shown, the degree of coverage of the adhesive layer 130 can be equal to or less than 80%, 60%, 40% or 20% of the surface of the base. By covering only partial areas, savings in adhesive are achieved, which enables significant cost advantages, particularly for larger layer thicknesses SD (see the values mentioned).

Side lengths L1 and/or L2 of the sheet metal panels 110, 120 can be equal to or greater than 1.0 m, 2.0 m, 3.0 m or 4.0 m for all surface electrical components 100, 400, 500 described here as examples.

To increase the structural stability and electrical functional reliability of the surface electrical components 100, 400, 500, spacers can be provided between the sheet metal panels 110, 120. Figure 6A illustrated in the form of a detailed representation of detail D2 in Figure 4 a first example in which spacers 610_1 are inserted, for example in the form of an insert structure, between the sheet metal panels 110, 120 before they are glued together. Figure 6B illustrates another possibility in which spacers 610_2 in the form of beads, for example glass beads, are introduced between the sheet metal panels 110, 120 together with the adhesive (ie dispersed in them). Both options can be used with both full-surface adhesive layers 130 and partially patterned adhesive layers 130 (see Figures 5A-5C ) can be used. The spacers 610_1, 610_2 can have a thickness (or average diameter) of, for example, equal to or smaller or larger than 30 pm, 50 µm, 75 pm, 100 µm, 125 µm, 150 µm, 175 µm or 200 µm.

Figure 7 shows an example of the use of surface electrical components 100, 400, 500 as wall and ceiling panels for a covered lounge area, for example a bus stop. Many other indoor and outdoor applications are possible, for example as floor heating or wall heating in buildings or as radiant heat sources in halls or churches (where convection heating is expensive) or outdoors.

Figure 8 shows by way of example the use of surface electrical components 100, 400, 500 as the walls of storage containers 800. The storage containers can be, for example, containers for liquid, gaseous or solid, in particular free-flowing substances, for example large-volume storage containers for gases or liquids, or silos . The Surface electrical components 100, 400, 500 can be operated here, as in many other applications, as a heater, as a pressure or deformation sensor or as both. In particular, it is possible for the complete wall structure to be realized from surface electrical components 100, 400, 500 that are optionally welded together, so that, for example, no further flat stiffening elements are required to ensure the structural stability of the wall.

Figure 9 shows an example of the use of surface electrical components 100, 400, 500 as the wall of a storage container (electric box) 900 for an electric battery, for example a battery in the field of electromobility. The same statements as for Figure 8 apply accordingly to this application, although here too the combination of heatability and/or deformation sensors as well as structural stability and robustness can be very important.

Figure 10 shows an example of the use of surface electrical components 100, 400, 500 as a protective wall 1000 with integrated breakthrough protection and/or integrated impact detection. For example, the protective wall 1000 can be a guardrail in road traffic.

Figure 11 shows an example of the use of surface electrical components 100, 400, 500 as a robust counter 1100. Here, a floor area, for example of a road, consists of a surface electrical component, which is used as a sensor for motor vehicles or other movable goods driving over it. As a result of the (slight) deformation of the surface electrical component 100, 400, 500 when loaded by, for example, a motor vehicle, a measurement variable is generated which can be detected and verified by the measuring device M.

It should be noted that for the functionality of the surface electrical components 100, 400, 500 as a sensor, an evaluation of electrical signals from the electrodes in a measuring device does not necessarily have to take place. For example, it is also possible, alternatively or additionally, to detect spatially resolved deformations of the surface electrical components 100, 400, 500 using, for example, a thermal imaging camera, since the local heating power is influenced by a local change in the layer thickness SD of the electrically conductive adhesive layer 130. For example, material fatigue processes can be localized at an early stage and then remedied appropriately.

Figure 12A shows, in an exemplary form, a process for producing a sheet metal strip composite material intended as a preliminary product for the production of a surface electrical component.

The starting product of the process is a rolled sheet metal strip 1210, as is produced in a steelworks using known process steps (for example hot rolling, cold rolling, galvanizing, etc.). The sheet metal strip 1210 can be, for example, a steel strip. For example, cold-rolled steel strips, electrolytically galvanized steel strips, hot-dip galvanized steel strips or hot-dip galvanized steel strips with zinc-magnesium-aluminum (ZM) coating can be used. Possible coatings (e.g. metallic corrosion protection layer(s) and/or electrically conductive paint layer) have been described previously and are in Figure 12A not shown.

The sheet metal strip 1210 is fed to a coating station 1250. In the coating station 1250, an electrically conductive adhesive layer 130 'is applied over a surface (corresponds to in the Figure 1 the surface 110A of the first sheet metal panel 110 or the surface 120B of the second sheet metal panel 120).

The electrically conductive adhesive layer 130' can be applied, for example, by roller application, a screen printing process, possibly roller screen printing, or by a spraying process, in which case in all cases either a full-surface or partial-surface patterned coverage of the sheet metal strip 1210 with the electrically conductive adhesive layer 130' can be achieved can.

At the same time, before or later, on the opposite surface of the sheet metal strip 1210 (corresponds to in the Figure 4 the surface 110B of the first sheet metal panel 110 or the surface 120A of the second sheet metal panel 120) optionally a protective layer 410, 420 can be applied, as is the case in connection with Figure 4 has already been explained.

The sheet metal strip 1210 coated with the electrically conductive adhesive layer 130 'can then be guided through a drying station 1260. In the drying station 1260, the electrically conductive adhesive layer 130' is dried so that subsequent handling processes, such as winding into a coil or stacking coated sheet metal panels, become possible. However, during drying in the drying station 1260, the electrically conductive adhesive layer 130' is not yet activated, i.e. the chemical reaction (for example crosslinking) of the adhesive is not initiated.

Figure 12B shows an example through the in Figure 12A Sheet metal strip composite material produced by the process 1200. It can contain, in a manner not shown, all of the previously described additional layers (e.g. metallic corrosion protection layer 111, electrically conductive lacquer layer 112) and/or can be implemented, for example, without a protective layer 410. The layer thicknesses of the not yet activated electrically conductive adhesive layer 130 'can be in the range of the same values as those mentioned above for the layer thickness SD of the electrically conductive adhesive layer 130 in the surface electrical component 100, 400, 500. The same applies to the remaining information on the electrically conductive adhesive layer 130, in particular for the values of the specific electrical resistance ρ _KS , which can also be transferred to the not yet activated electrically conductive adhesive layer 130 '.

Figure 13 illustrates in an exemplary manner a method for producing a surface electrical component 100, 400, 500 from sheet metal strip composite material 1200. The sheet metal strip composite material 1200 can, for example, be in the form of a coil (winding) which was delivered from a steelworks to a customer.

In a following process step, the sheet metal strip 1200 is separated in a separating station 1350. The sheet metal strip composite material 1200 can be separated either at the steel manufacturer, or after delivery of the sheet metal strip composite material 1200 at the customer. In the first case, either sheet metal panels 110, 120 are delivered already cut to size or sheet metal panels are delivered that are brought into the final shape in a subsequent shape cutting at the customer's premises.

Two sheet metal panels 110, 120 are then glued to form a surface electrical component 100, 400, 500 using the adhesive layer 130'. For this purpose, two sheet metal panels 110, 120 are used at 1360 mutually facing electrically conductive adhesive layers 130 'arranged one above the other and pressed together in a bonding station 1370 using surface pressure (F) and supplying energy. This activates the electrically conductive adhesive layer 130', which can be based on a chemical reaction, for example a 3-dimensional crosslinking of the adhesive.

During curing, high adhesive forces are usually achieved, which ensure the mechanical stability and integrity of the surface electrical component 100, 400, 500. The hardenable adhesive layer 130' can be hardened by heating the pressed sheet metal panels 110, 120, for example in an oven or a heatable press, to a temperature T that is higher than the ambient temperature, whereby the hardened electrically conductive adhesive layer 130 is formed. Other activation processes, which can be based, for example, on the use of radiant energy, are also conceivable. After a bonding period t, the surface electrical component 100, 400, 500 is mechanically completed and can be removed from the bonding station 1370 (e.g. oven or press).

After the electrodes (first and second sheet metal panels 110, 120) have been electrically contacted, the surface electrical component 100, 400, 500 can optionally be installed and put into operation.

Instead of the in Figure 13 Using the example of two sheet metal panels 110, 120 with identical layer structure, different sheet metal panels can also be glued. For example, an electrically conductive adhesive layer 130' can only be provided on one of the two sheet metal panels and/or it is possible for different electrically conductive lacquer layers, protective layers and/or different panel thicknesses to be used. For example, one of the two sheet metal panels (eg the sheet metal panel forming an outer wall) can be significantly thicker (for example the same or more than 2, 3, 4 times as thick) as the other sheet metal panel. It is also possible, for example, for the two protective layers 410, 420 to be different, since one protective layer (for example, the inner wall of a container) is exposed to different attacks than, for example, the protective layer on an outer wall of the container, or because, for example, different optical requirements (visible surface/not -visible surface).

Claims (16)

1. Flat electrical component, comprising:

   a first sheet metal panel (110);

   a second sheet metal panel (120); and

   an electrically conductive adhesive layer (130) disposed between facing surfaces of the first sheet metal panel (110) and the second sheet metal panel (120), wherein

   the first sheet metal panel (110) forms a first electrode of the flat electrical component,

   the second sheet metal panel (120) forms a second electrode of the flat electrical component, and

   a current flow occurs from the first sheet metal panel (110) through the electrically conductive adhesive layer (130) to the second sheet metal panel (120) perpendicular to the adhesive layer plane, characterized in that the first sheet metal panel (110) is made of a steel material, the second sheet metal panel (120) is made of a steel material or of an aluminum material and the electrically conductive adhesive layer (130) is constructed on the basis of a baking varnish.
2. Flat electrical component according to claim 1, wherein at least one or both of the mutually facing surfaces are covered with a metallic corrosion protection layer (111).
3. Flat electrical component according to claim 1 or 2, wherein at least one or both of the surfaces facing each other are covered with an electrically conductive lacquer layer (112), the specific electrical resistance of which is smaller than a specific electrical resistance of the electrically conductive adhesive layer (130).
4. Flat electrical component according to any one of the preceding claims, wherein a specific electrical resistance of the electrically conductive adhesive layer (130) is equal to or greater than 20 kΩm, 60 kΩm, 200 kΩm, 800 kΩm, 1000 kΩm or 3000 kΩm.
5. Flat electrical component according to one of the preceding claims, wherein spacers (610_1, 610_2) of a thickness equal to or greater than 30 pm, 50 pm, 75 pm, 100 pm, 125 pm, 150 pm, 175 µm or 200 µm are arranged between the surfaces facing each other.
6. Flat electrical component according to any one of claims 1 to 4, wherein the thickness of the electrically conductive adhesive layer (130) is equal to or greater than 30 pm, 50 pm, 75 pm, 100 µm or 150 µm.
7. Flat electrical component according to any one of the preceding claims, wherein the thickness of at least one or both of the sheet metal panels (110, 120) is equal to or greater than 0.5 mm, 0.75 mm, 1.0 mm, 1.5 mm, 2.0 mm or 2.5 mm.
8. Flat electrical component according to one of the preceding claims, wherein at least one or both of the sheet metal panels (110, 120) have a side length equal to or greater than 1.0 m, 2.0 m, 3.0 m or 4.0 m, 3.0 m or 4.0 m.
9. Flat electrical component according to any one of the preceding claims, which is an electrical surface heater or an electrical surface deformation sensor.
10. Container (800, 900) with a wall comprising a flat electrical component according to claim 9.
11. Roof, wall, ceiling and/or floor panels for buildings and/or covered living areas, comprising a flat electrical component according to one of claims 1 to 8, which is an electrical surface heating.
12. Protective wall (1000) with integrated breakthrough protection and/or integrated impact detection, comprising a flat electrical component according to any one of claims 1 to 8, which is an electrical surface deformation sensor.
13. Method of manufacturing a flat electrical component, comprising:

    separating (1350) a sheet metal strip (1210) into first sheet metal panels (110); and

    bonding of the first sheet metal panels (110) by means of an adhesive layer (130) to respective second sheet metal panels (120) in such a way that

    the first sheet metal panel (110) forms a first electrode of the flat electrical component,

    the second sheet metal panel (120) forms a second electrode of the flat electrical component, and wherein

    a current flow occurs from the first sheet metal panel (110) via the electrically conductive adhesive layer (130) to the second sheet metal panel (120) perpendicular to the adhesive layer plane, characterized in that

    the first sheet metal panel (110) is made of a steel material,

    the second sheet metal panel (120) is made of a steel material or of an aluminum material, and

    the electrically conductive adhesive layer (130) is constructed on the basis of a baking varnish and is applied over a surface of the metal strip (1210).
14. Method according to claim 13, wherein
    the bonding takes place in a pressing station (1370) using surface pressure and an energy supply to activate the electrically conductive adhesive layer.
15. Method of producing a sheet metal strip composite material which is provided as a precursor for the manufacture of a flat electrical component according to claim 13, the method comprising:

    producing a rolled sheet metal strip (1210) from a steel material; and

    applying an electrically conductive adhesive layer (130) based on a baking varnish over a surface of the rolled sheet metal strip (1210).
16. Method according to claim 15, wherein the application of the electrically conductive adhesive layer (130) is carried out by a roller application or by a printing process, in particular screen printing.

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