Resistor assembly and method for determining the temperature of a resistor assembly

Abstract

The invention relates to a resistor assembly (2) comprising at least one connection element (3, 3') and at least one resistor element (4). A coating (5) is applied onto at least one part (411) of the surface (41) of the resistor element (4) as a substrate or onto at least one part (311) of the surface (31) of the connection element (3, 3') as a substrate, said coating having at least one layer (50, 51, 52, 53). According to the invention, the coating (5) is designed such that a metal and a semiconductor are in direct contact at a boundary surface (61) between the substrate and the coating (5) such that a p-n transition is formed at the boundary surface (61), and / or a metal and a semiconductor or a first semiconductor and a second semiconductor are in direct contact at least at a boundary surface (62) between a first layer (50, 51) and a second layer (52) of the coating (5) such that a p-n transition is formed at the boundary surface (62). A layer (50, 51, 52, 53) of the coating (5) and an uncoated part (412, 412') of the surface (41) of the resistor element (4) or an uncoated part (312) of the surface (31) of the connection element (3, 3') or both the first layer (50, 51) as well as another layer (52, 53) of the coating (5) can be contacted in order to detect measurement signals for determining the temperature of the resistor assembly (2).

Description

[0001] Description

[0002] Resistor arrangement and method for determining the temperature of a resistor arrangement

[0003] The invention relates to a resistor arrangement with a coating for measuring the temperature of the resistor arrangement and to a method for determining the temperature of a resistor arrangement.

[0004] Current measurements in electronic circuits are carried out using measuring resistors connected in series with the component to be monitored. The current is determined according to Ohm's law from the voltage drop across the shunt resistor. The resistance value is assumed to be known. Accurate and reliable current measurement is particularly important, for example, in the battery management system of an electric or hybrid vehicle. A resistor assembly comprising such a low-ohm measuring resistor of approximately 10 to 50 pOhm and terminals for connecting the resistor assembly to the circuit can be manufactured from a longitudinally welded composite material. This is known, for example, from document EP 0 605 800 A1.The composite material is manufactured from three metal strips, each of which is joined to one another via a longitudinal seam using an electron beam or laser welding process. The middle metal strip consists of a material with a very low temperature coefficient of resistance. This material forms the actual resistance element of the measuring resistor. The two outer strips are usually made of a material with high electrical conductivity, such as copper. Such materials usually have a high temperature coefficient of resistance compared to the material of the resistance element. These two outer strips form connection elements, via which the measuring resistor can be connected to an electrical circuit.

[0005] Determining the current from the voltage drop across the measuring resistor requires precise knowledge of the resistance value. The influence of temperature on the resistivity of the materials used plays an important role. Therefore, the temperature of the resistor array, which can range between -40 and +170°C during operation, must be known in order to compensate for the temperature-dependent resistance behavior. The temperature of the resistor array can be measured with a temperature sensor, and the resistance value can be corrected based on this information. This is known, for example, from the publications DE 199 06 276 A1 and EP 2 793 034 B1.The temperature of the resistor array is typically determined either using a passive analog sensor, such as an NTC, PT100 temperature sensor, or a thermocouple, or using an active sensor (IC) that features a sensor data evaluation and communication interface. The temperature sensor is an additional component that incurs additional costs and design effort. Furthermore, a temperature sensor reacts to temperature changes with a time delay, which can negatively impact accuracy. This is particularly important when detecting heat generation during short-term peak currents, such as those that occur during extreme acceleration of an electric vehicle. The invention is based on the object of specifying a resistor array that overcomes the disadvantages described above.In particular, the temperature measurement should respond quickly to changes in the temperature of the resistor array. Furthermore, the invention is based on the object of providing a method for measuring the temperature of a resistor array.

[0006] The invention is represented with respect to a resistor arrangement by the features of claim 1 and with respect to a measuring method by the features of claim 17. The further dependent claims relate to advantageous embodiments and developments of the invention.

[0007] The invention relates to a resistor arrangement comprising at least one connection element for connecting the resistor arrangement to an electrical circuit and at least one resistance element. The resistance element is electrically connected to the connection element via a contact surface. The extension of the resistance element in the direction perpendicular to the contact surface is referred to as the length. The at least one resistance element, on the one hand, and the at least one connection element, on the other hand, consist of different electrically conductive materials, preferably metallic materials. The specific electrical resistance of the material of the resistance element can be at least a factor of 10 greater than the specific electrical resistance of the material of the connection element.On the other hand, the magnitude of the temperature coefficient of resistance of the terminal element material is much larger, typically at least a factor of 80, than the magnitude of the temperature coefficient of resistance of the resistive element material. In particular, the magnitude of the temperature coefficient of resistance of the resistive element material can be less than 5 10'. 5 1 / K, while the resistance temperature coefficient of the material of the connecting element is approximately 4 10' 31 / K. The connection element of the resistor arrangement can be made of copper, a preferably low-alloy copper alloy, aluminum, or a preferably low-alloy aluminum alloy, or can comprise at least one of these materials. The resistor element can be made of a copper alloy that is commonly used as a resistor alloy. The at least one connection element can have means for connecting the resistor arrangement to an external circuit, for example, a bore. The resistor arrangement can preferably have two connection elements, between which the resistor element is arranged.

[0008] A coating comprising at least one layer is applied to at least part of the surface of the resistance element as a substrate or to at least part of the surface of the connection element as a substrate. The coating can comprise one or more layers. The term "layer" refers here to a spatial arrangement of a uniform material, wherein the extent of the material in the spatial direction perpendicular to the surface of the substrate, i.e., the thickness of the layer, is significantly smaller than the extent of the material in the spatial directions parallel to the surface of the substrate.

[0009] According to a first aspect of the invention, the coating is designed such that a metal and a semiconductor are in direct contact at an interface between the substrate and the coating, so that a pn junction is formed at this interface. Preferably, the material of the substrate forms the metal, and the layer of the coating that is in direct contact with the substrate is designed as a semiconductor. Both a layer of the coating, on the one hand, and an uncoated part of the surface of the substrate, on the other hand, i.e., the resistance element or the connection element, can be contacted to detect measurement signals for determining the temperature of the resistance arrangement.If the coating is applied to the resistance element, then both at least one layer of the coating on the one hand and an uncoated part of the surface of the resistance element on the other hand can be contacted to record measurement signals for determining the temperature of the resistance arrangement. If the coating is applied to the connection element, then both at least one layer of the coating on the one hand and an uncoated part of the surface of the connection element on the other hand can be contacted to record measurement signals for determining the temperature of the resistance arrangement. Preferably, the layer of the coating that is in direct contact with the substrate is contactable.

[0010] According to a second aspect of the invention, the coating is designed such that at least at one interface between a first layer of the coating and a second layer of the coating, a metal and a semiconductor are in direct contact, or a first semiconductor and a second semiconductor are in direct contact, so that a pn junction is formed at this interface. Both the first layer of the coating, on the one hand, and at least one further layer of the coating, in particular the second layer of the coating in direct contact with the first layer, on the other hand, can be contacted directly or indirectly to detect measurement signals for determining the temperature of the resistor arrangement.

[0011] The invention is based on the idea of ​​using the temperature behavior of the current-voltage characteristic of a pn junction to directly determine temperature. The current-voltage characteristic of a pn junction can be described like a diode characteristic using the Shockley equation. The Shockley equation contains temperature-dependent quantities, namely temperature voltage and reverse current. The current-voltage characteristic of a pn junction thus changes with temperature. If the current flowing through the pn junction and the voltage drop across the pn junction are known, the temperature prevailing at the pn junction can be determined based on the assumed temperature dependence of the current-voltage characteristic.The measurement of such a pn junction as a temperature sensor can be carried out, for example, using discrete components such as a constant current source and an operational amplifier or analog-to-digital converter (ADC) or alternatively in an integrated circuit (IC).

[0012] According to the invention, such a pn junction is realized by a coating on the resistor arrangement. The coating is thin compared to the substrate and has only a low thermal mass. At the same time, the thermal coupling of the coating to the substrate occurs over a large area. Therefore, the temperature at the pn junction is always, to a very good approximation, identical to the temperature of the substrate. Even rapid temperature changes are detected without a significant time delay. The coating can be applied either to the resistor element or to a terminal element. Accordingly, the temperature of the resistor element or the terminal element can be determined.

[0013] The pn junction can be realized directly at the interface between substrate and coating. The electrically conductive, preferably metallic substrate acts as the n-part of the pn junction due to the free electrons. The layer of the coating in direct contact with the substrate must then be selected so that, in combination with the substrate, it acts like a semiconductor, i.e., has a lack of free electrons compared to the substrate. It then forms the p-part of the pn junction. A resistor arrangement featuring such a pn junction can be manufactured by depositing or building up a copper-based material, preferably an oxide, as a layer on a surface of the resistor arrangement. The selected material pairing creates a pn junction with a specific current-voltage characteristic.

[0014] Alternatively, the pn junction can be realized at an interface between a first layer and a second layer of the coating, i.e., by a suitable layer structure of the coating. At this interface, either a metal and a semiconductor or a first semiconductor and a second semiconductor are in direct contact with each other.

[0015] Suitable material combinations for which the described semiconductor properties are known and which use copper as a starting material include Cu / Cu(I)O, p-Cu2O / n-ZnO, SnF2:SnO2 / CuAlC, or p-Cu2O / n-Cu2O. The oxides mentioned as examples exhibit semiconductor properties. They can be referred to as "oxide semiconductors." In such oxides, the energetic separation between the valence band and conduction band (band gap) is on the same order of magnitude as in semiconductors, i.e., in the range of a few electron volts (eV). Through thermal excitation, electrons can be lifted from the valence band into the conduction band. Therefore, the electrical conductivity of the oxides increases with temperature. The material pairings mentioned form a material junction with a current-voltage characteristic that, like a semiconductor diode, can be described by the Shockley equation.Based on the examples mentioned, other material pairings can be found that exhibit similar properties. In such material pairings, oxides act like semiconductors and can therefore fall under the term "semiconductor" in the context of this invention.

[0016] The particular advantage of the invention is that the temperature sensor formed by the coating is applied to the resistor array not at a point, but across the entire surface. This ensures good thermal coupling between the sensor and the object whose temperature is to be measured. Furthermore, the coating has only a very low inherent heat capacity, allowing the temperature sensor to react very quickly to temperature changes in the substrate. In other words, due to its very low thermal mass, the coating has very low thermal inertia and can thus detect temperature changes in the substrate very quickly.

[0017] Within the scope of one embodiment of the invention, the coating can have at least one layer formed from or comprising a doped semiconductor. Doping can specifically adjust the properties of the semiconductor. In particular, doping can influence the current-voltage characteristic of the pn junction. In this way, for example, the accuracy of temperature measurement can be improved. Both p-doping and n-doping of the same base material, such as p-Cu2O / n-Cu2O, can be considered. Doping can take place during the coating process.

[0018] Within the scope of a further embodiment of the invention, the coating can have at least two layers, which are selected such that the pn junction is part of an npn junction or a pnp junction. In this way, a bipolar layer sequence is realized. The third material of the layer sequence can be either a third layer of the coating or the substrate, i.e. one of the electrically conductive materials of the resistor arrangement. The measurement accuracy can be significantly improved with such an arrangement, because an npn junction or a pnp junction has a significantly higher temperature consistency than a pn junction. In a particularly preferred embodiment of this embodiment, all three materials of the bipolar layer sequence, in particular all three layers of the bipolar layer sequence, can be contactable for detecting measurement signals for determining the temperature of the resistor arrangement.This makes it possible to create a circuit that corresponds to a bipolar transistor connected as a diode.

[0019] In a further embodiment of the invention, the coating can be applied only to a portion of the surface of the resistance element. This makes it possible to determine the temperature at critical points on the resistance element, for example, at points of particularly high temperature.

[0020] In particular, in this embodiment, the resistance element can have a length perpendicular to the contact surface located between the resistance element and the connection element, and the coating can be applied centrally on the surface of the resistance element relative to the length of the resistance element. The coating is thus positioned in the region of the resistance element that is furthest from the contact surfaces to the connection elements. The highest temperature occurs in this region. The average temperature of the resistance arrangement can be determined from the highest temperature.

[0021] Preferably, the extension of the coating in the direction perpendicular to the contact surface can be at least 1 mm, particularly preferably at least 1.5 mm, and at most 4 mm, particularly preferably at most 2.5 mm. By selecting the dimensions of the coating in this range, the electrical quantities to be measured are set within a favorable range.

[0022] Furthermore, within the scope of a particular embodiment of the invention described above, the coating can be applied across the entire width of the resistance element. The width of the resistance element is understood to be its extension along the contact surface, i.e., transverse to the direction of the electrical current. In this particular embodiment of the invention, a temperature is measured that is averaged across the entire width of the resistance element.

[0023] Within the scope of a further particular refinement of the above-described embodiment of the invention, a first measuring tap can contact the coating, i.e., a layer of the coating, and a second measuring tap can contact the uncoated part of the surface of the resistance element, i.e., be mounted on the uncoated part of the surface of the resistance element. Using this arrangement of measuring taps, the voltage drop that occurs at the pn junction at the interface between the resistance element as the substrate and the coating can be detected.

[0024] In an alternative embodiment of the invention, the coating can be applied only to a portion of the surface of the connecting element, directly adjacent to the contact surface of the resistance element. With this positioning of the coating, the temperature of the connecting element is measured in close proximity to the resistance element. From this measured temperature, the temperature of the resistance element can then be determined with sufficient accuracy. Depending on the choice of materials, it may be easier to apply the coating to the connecting element than to the resistance element.

[0025] Within the scope of a particular embodiment of this embodiment of the invention, a first measuring tap can contact the coating, i.e., a layer of the coating, and a second measuring tap can contact the uncoated part of the surface of the connecting element, i.e., be mounted on the uncoated part of the surface of the connecting element. Using this arrangement of measuring taps, the voltage drop that occurs at the pn junction at the interface between the connecting element as the substrate and the coating can be detected.

[0026] Within the scope of a further embodiment of the invention, the coating can have a layer which is in direct contact with the substrate and which comprises or is an oxide of the material of the substrate. Due to the material relationship between the substrate and the material of the coating which is in direct contact with the substrate, particularly favorable conditions arise for the formation of a pn junction. For example, if the coating is applied to a connection element made of copper, the layer which is in direct contact with the connection element can be made of Cu(I)O or contain Cu(I)O. Analogously, if the coating is applied to a resistance element made of a copper-manganese alloy, the layer which is in direct contact with the resistance element can be made of CuMnO2 or contain CuMnO2.

[0027] In an alternative embodiment of the invention, a barrier layer can be present between the substrate and the coating. A first measuring tap contacts a first layer of the coating, and a second measuring tap contacts another layer of the coating. The barrier layer creates a physical separation between the substrate and the coating, but not a thermal separation. The substrate therefore has no material influence on the coating processes. Thus, the coating can be selected within a wide range, independent of the substrate material. This allows the coating to be optimized with regard to its function as a temperature sensor. The barrier layer can be made of nickel, for example.

[0028] Within the scope of a further embodiment of the invention, the coating may further comprise a layer that serves to passivate the coating and to electrically contact a non-metallic layer of the coating. This passivation layer is preferably a metallic layer. Such a layer may be the layer of the coating that is at the greatest distance from the substrate.

[0029] Within the scope of a further embodiment of the invention, the coating can have at least one layer whose thickness is at least 50 nm, preferably at least 70 nm, and at most 100 μm, preferably at most 10 μm. In particular, each layer of the coating can have a thickness that lies within the range specified above and in particular within its preferred subranges. A coating comprising one or more layers within the specified ranges is particularly well suited for implementing a temperature sensor based on a pn junction.

[0030] Within the scope of a further embodiment of the invention, the coating can be applied using a CVD process or a PVD process. CVD processes and PVD processes are well suited for applying coatings of the type described above. In particular, these processes enable the doping of semiconductor layers applied using these processes.

[0031] Within the scope of a further embodiment of the invention, the coating can be applied in a depression in the surface of the substrate or on an area raised above the surface of the substrate. In some applications, it can be advantageous to apply the coating in a depression in the surface of the substrate in order to protect it from environmental influences, for example mechanical attacks. In contrast, in some applications it can be advantageous to apply the coating on an area raised above the surface of the substrate. This can, for example, facilitate contact with measuring taps. Within the scope of a further embodiment of the invention, the resistor arrangement can be contacted by means of a connector, a circuit board, or a cable to detect the measurement signals. These components enable the measurement signals that must be detected to determine the temperature to be detected in a simple and cost-effective manner.

[0032] With regard to further technical features and advantages of the resistor arrangement according to the invention, reference is hereby explicitly made to the explanations in connection with the method according to the invention for determining the temperature of a resistor arrangement as well as to the figures, the description of the figures and the exemplary embodiments.

[0033] A further aspect of the invention relates to a method for determining the temperature of a resistor arrangement. The resistor arrangement has a coating as described above. The coating is selected such that a pn junction is formed at the contact surface between the substrate and the coating or at a contact surface between two layers of the coating. According to the invention, the electrical current flowing through the pn junction and the electrical voltage dropping across the pn junction are determined. From these two measured variables, the temperature of the resistor arrangement is determined using the temperature-dependent current-voltage characteristic of the pn junction. According to a further aspect of the invention, a coating as described above is used to determine the temperature of a resistor arrangement.

[0034] With regard to further technical features and advantages of the method according to the invention for determining the temperature of a resistor arrangement and the use according to the invention of a coating for determining the temperature of a resistor arrangement, reference is hereby explicitly made to the explanations in connection with the resistor arrangement according to the invention as well as to the figures, the description of the figures and the exemplary embodiments.

[0035] Embodiments of the invention are explained in more detail with reference to the schematic, not-to-scale drawings. In these drawings:

[0036] Fig. 1 shows a resistor arrangement with a coating on the resistor element,

[0037] Fig. 2 shows a resistor arrangement with a coating in a recess of the resistor element,

[0038] Fig. 3 shows a resistor arrangement with a coating on a raised area of ​​the resistor element,

[0039] Fig. 4 shows a resistor arrangement with a coating on a connection element,

[0040] Fig. 5 a resistance element with a coating with a first layer structure,

[0041] Fig. 6 a resistance element with a coating with a second layer structure,

[0042] Fig. 7 a resistance element with a coating having a third layer structure.

[0043] Corresponding parts are provided with the same reference numerals in all figures.

[0044] Fig. 1 shows a resistor arrangement 2 with two connection elements 3, 3' and a resistance element 4 arranged between the two connection elements 3, 3'. The resistance element 4 is electrically connected to the two connection elements 3, 3' via contact surfaces 34, 34'.

[0045] The length of the resistance element 4 between the two contact surfaces 34, 34' is designated as length L. For the sake of simplicity, in the illustrated embodiment, the resistance element 4 is drawn such that its width B, i.e., its length along the contact surfaces 34, 34', is as large as the length of the connecting elements 3, 3' in this direction. Typically, the length of the resistance element 4 along the contact surfaces 34, 34' is somewhat smaller than the length of the connecting elements 3, 3' in this direction. Means for connecting the resistance arrangement 2 to an external circuit, such as holes in the connecting elements 3, 3', are not shown for the sake of simplicity.

[0046] The resistance element 4 has a freely accessible surface 41. A coating 5 in the form of a narrow strip is applied to a part 411 of the surface 41 of the resistance element 4. The

[0047] Coating 5 is applied centrally between the two contact surfaces 34, 34', so that an uncoated part 412, 412' of the surface 41 of the resistance element 4 is present between the coating 5 and a respective connection element 3, 3'. The coating extends over the entire width B of the resistance element 4. Alternatively, it is also possible for the coating 5 to extend only over part of the width B of the resistance element 4. A pn ​​junction (not shown in detail) is formed at the interface 61 between the coating 5 and the resistance element 4.

[0048] A first measuring tap 71 is mounted so that it directly contacts the coating 5. A second measuring tap 72 is mounted so that it contacts an uncoated portion 412 of the surface 41 of the resistance element 4. Using these two measuring taps 71, 72, the voltage drop across the pn junction can be determined. In the case not shown in Fig. 1, in which the coating 5 extends only over part of the width B of the resistance element 4, the uncoated part 412, 412' of the surface 41 of the resistance element 4 also comprises an area which is the same distance from the connection elements 3, 3' as the coating 5. Thus, when current flows through the resistance element 4, this area is at the same electrical potential as the coating 5. In this case, the second measuring tap 72 can advantageously be arranged in this area of ​​the uncoated part 412, 412' of the surface 41 of the resistance element 4.Particularly preferably, the second measurement tap 72 can be positioned such that it is at the same distance from the two connection elements 3, 3' as the first measurement tap 71, which contacts the coating 5. Measurement value distortions are thus reduced.

[0049] Fig. 2 shows a preferred embodiment of a resistor arrangement 2. The embodiment shown in Fig. 2 differs from the embodiment shown in Fig. 1 in that the coating 5 is located in a recess 8 of the resistor element 4. All other features of the resistor arrangement 2 shown in Fig. 2 correspond to those of the resistor arrangement 2 shown in Fig. 1. As explained in connection with Fig. 1, it is also possible for the coating 5 and the recess 8 to extend only over part of the width B of the resistor element 4 or for only the coating 5 to extend over part of the width B of the resistor element 4, while the recess 8 extends over the entire width B of the resistor element 4. In these cases, the second measuring tap 72 can advantageously be positioned as described in connection with Fig. 1.

[0050] Fig. 3 shows a further preferred embodiment of resistor arrangement 2, in which the coating 5 is applied to a raised region 9 of the resistor element 4. All other features of the resistor arrangement 2 shown in Fig. 3 correspond to those of the resistor arrangement 2 shown in Fig. 1. As explained in connection with Fig. 1, it is also possible for the coating 5 and the raised region 9 to extend only over part of the width B of the resistor element 4 or for only the coating 5 to extend over part of the width B of the resistor element 4, while the raised region 9 extends over the entire width B of the resistor element 4. In these cases, the second measuring tap 72 can advantageously be positioned as described in connection with Fig. 1.

[0051] Fig. 4 shows an alternative embodiment of a resistor arrangement 2. The basic structure of this resistor arrangement 2 with regard to the connection elements 3, 3' and the resistor element 4 corresponds to the embodiment shown in Fig. 1. The connection element 3 has a freely accessible surface 31. A coating 5 in the form of a narrow strip is applied to a part 311 of the surface 31 of the connection element 3, directly at the transition to the resistor element 4. Thus, the surface 31 of the connection element 3 has an uncoated part 312. The coating extends over the entire extent of the connection element 3 in the direction longitudinal to the contact surfaces 34, 34'. Alternatively, it is also possible for the coating 5 to extend only over part of the extent of the connection element 3 in the direction longitudinal to the contact surfaces 34, 34'.At the interface 61 between the coating 5 and the connection element 3, a pn junction (not shown in detail) is formed. A first measuring tap 71 is arranged such that it directly contacts the coating 5. A second measuring tap 72 is arranged such that it contacts the uncoated part 312 of the surface 31 of the connection element 3. Using these two measuring taps 71, 72, the voltage drop across the pn junction can be determined. In the case (not shown in Fig. 4) in which the coating 5 extends only over part of the width B of the connection element 3, the uncoated part 312 of the surface 31 of the connection element 3 also comprises a region that is the same distance from the resistance element 4 as the coating 5. Thus, when current flows through the resistance arrangement 2, this region has the same electrical potential as the coating 5.In this case, the second measuring tap 72 can advantageously be arranged in this region of the uncoated part 312 of the surface 31 of the connecting element 3. Particularly preferably, the second measuring tap 72 can be positioned such that it is at the same distance from the resistance element 4 as the first measuring tap 71, which contacts the coating 5.

[0052] The embodiment of a resistor arrangement 2 shown in Fig. 4 can be modified by applying a coating 5 in the form of a narrow strip to both connection elements 3, 3' directly at the respective transition to the resistance element 4. Thus, the respective temperature of the two connection elements 3, 3' can be measured in the immediate vicinity of the respective contact surfaces 34, 34'. Based on these temperatures, the thermoelectric voltages that arise at the respective transitions between the resistance element 4 and the connection elements 3, 3' can be estimated.

[0053] Fig. 5 shows a resistance element 4 with a coating 5 having a first layer structure. The resistance element 4 shown can be part of a resistance arrangement 2 according to Figs. 1 to 3. For the sake of simplicity, connection elements 3, 3', which contact the resistance element 4 on both sides, are not shown. The coating 5 consists of a first layer 50, which is in direct contact with the resistance element 4, and a further layer 59, which serves to passivate the coating 5 and to electrically contact the first layer 50. The first layer 50 can preferably be made of an oxide of the material of the resistance element 4 or comprise such an oxide. The further layer 59 consists of a metal and represents the uppermost layer 59 of the coating 5, i.e. the layer furthest away from the substrate.A pn junction (not shown) is formed at the interface 61 between the first layer 50 of the coating 5 and the resistance element 4. A first measuring tap 71 contacts the

[0054] Coating 5 by being in contact with the uppermost layer 59 of coating 5. In this way, the first layer 50 of coating 5 is electrically contacted. A second measuring tap 72 contacts the resistance element 4 in an uncoated area 412 of its surface 41. Using these two measuring taps 71, 72, the voltage drop across the pn junction can be determined.

[0055] Fig. 6 shows a resistance element 4 with a coating 5 having a second layer structure. The resistance element 4 shown can be part of a resistance arrangement 2 according to Figs. 1 to 4. For the sake of simplicity, connection elements 3, 3', which contact the resistance element 4 on both sides, are not shown. The coating 5 consists of a barrier layer 58, which is applied directly to the resistance element 4, an uppermost layer 59, which serves to passivate and contact the coating 5, and two further layers 51, 52, which are arranged between the barrier layer 58 and the uppermost layer 59. The first layer 51 of these two layers is applied to the barrier layer 58. The second layer 52 of these two layers is in direct contact with the uppermost layer 59. The first layer 51 can be a p-doped semiconductor. In this case, the second layer 52 is an n-doped semiconductor.However, it is also possible for the first layer 51 to be an n-doped semiconductor and the second layer 52 to be a p-doped semiconductor. In both cases, a pn junction (not shown) is formed at the interface 62 between the first layer 51 and the second layer 52 of the two further layers. A first measuring tap 71 contacts the first layer 51 of the two further layers. A second measuring tap 72 contacts the coating 5 by being in contact with the uppermost layer 59 of the coating 5. In this way, the second layer 52 of the further layers of the coating 5 is electrically contacted. Using these two measuring taps 71, 72, the voltage drop across the pn junction can be determined.

[0056] Fig. 7 shows a resistance element 4 with a coating 5 having a third layer structure. The resistance element 4 shown can be part of a resistance arrangement 2 according to Figs. 1 to 4. For the sake of simplicity, connection elements 3, 3', which contact the resistance element 4 on both sides, are not shown. The coating 5 consists of a barrier layer 58, which is applied directly to the resistance element 4, an uppermost layer 59, which serves to passivate and contact the coating 5, and three further layers 51, 52, 53, which are arranged between the barrier layer 58 and the uppermost layer 59. The first 51 of these three layers is applied to the barrier layer 58. The third 53 of these three layers is in direct contact with the uppermost layer 59. The second 52 of these three layers is arranged between the first 51 and the third 53 layer. The first layer 51 may be a p-doped semiconductor.In this case, the second layer is an n-doped semiconductor and the third layer 53 can be a p-doped semiconductor. However, it is also possible for the first layer 51 to be an n-doped semiconductor, the second layer 52 a p-doped semiconductor and the third layer 53 an n-doped semiconductor. A pn ​​junction (not shown) is formed at the interface 62 between the first layer 51 and the second layer 52 of the three further layers. A pn ​​junction (not shown) is also formed at the interface 62' between the second layer 52 and the third layer 53 of the three further layers, so that the three further layers 51, 52, 53 represent a bipolar layer sequence of the npn or pnp type. A first measuring tap 71 contacts the first layer 51 of the three further layers. A second measuring tap 72 contacts the coating 5 by being in contact with the uppermost layer 59 of the coating 5.In this way, the third layer 53 of the three remaining layers of coating 5 is electrically contacted. Furthermore, an optional third measuring tap 73 contacts the second layer 52. The combination of the three measuring taps 71, 72, 73 creates a circuit in which two pn junctions can be used to measure the temperature. Such a circuit corresponds to a diode-connected bipolar transistor.

[0057] The coatings 5 ​​shown in Fig. 5, Fig. 6 and Fig. 7 can be applied not only to the resistance element 4, but also in an analogous manner to a connection element 3, as shown in Fig. 4, or to both connection elements 3, 3', as explained in connection with Fig. 4.

[0058] List of reference symbols

[0059] 2 Resistor arrangement

[0060] 3, 3' connecting element

[0061] 31 Surface

[0062] 311 coated part

[0063] 312 uncoated part

[0064] 34, 34' contact area

[0065] 4 resistance element

[0066] 41 Surface

[0067] 411 coated part

[0068] 412, 412' uncoated part

[0069] 5 Coating

[0070] 50, 51 , 52, 53 Location

[0071] 58 barrier layer

[0072] 59 Location

[0073] 61 , 62, 62' interface

[0074] 71 , 72, 73 measuring tap

[0075] 8 Deepening

[0076] 9 raised area

[0077] L length

[0078] B Width

Claims

Patent claims 1. A resistor arrangement (2) comprising at least one connection element (3, 3') for connecting the resistor arrangement (2) to an electrical circuit and at least one resistance element (4), wherein the resistance element (4) is electrically conductively connected to the connection element (3, 3') via a contact surface (34, 34'), wherein the at least one resistance element (4) on the one hand and the at least one connection element (3, 3') on the other hand are made of different, electrically conductive materials, and wherein a coating (5) is applied to at least a part (411) of the surface (41) of the resistance element (4) as a substrate or to at least a part (311) of the surface (31) of the connection element (3, 3') as a substrate, said coating having at least one layer (50, 51, 52, 53), characterized in that the coating (5) is designed such thatthat at an interface (61) between the substrate and the coating (5), a metal and a semiconductor are in direct contact, so that a pn junction is formed at the interface (61) and / or that at least at one interface (62, 62') between a first layer (50, 51) of the coating (5) and a second layer (52) of the coating (5), a metal and a semiconductor are in direct contact, or a first semiconductor and a second semiconductor are in direct contact, so that a pn junction is formed at the interface (62, 62'), wherein both at least one layer (50, 51, 52, 53) of the coating (5) on the one hand and an uncoated part (412, 412') of the surface (41) of the resistance element (4) or an uncoated part (312), the surface (31) of the connection element (3, 3') on the other hand or both the first layer (50, 51) on the one hand and at least one further layer (52, 53) of the coating (5) on the other hand can be contacted for detecting measuring signals for determining the temperature of the resistor arrangement (2).

2. Resistor arrangement (2) according to claim 1, characterized in that the coating (5) has at least one layer (51, 52, 53) which is formed from or comprises a doped semiconductor.

3. Resistor arrangement (2) according to claim 1 or 2, characterized in that the coating (5) has at least two layers (50, 51, 52, 53) which are selected such that the pn junction is part of an npn junction or a pnp junction.

4. Resistor arrangement (2) according to one of claims 1 to 3, characterized in that the coating (5) is applied only to a part (411) of the surface (41) of the resistance element (4).

5. Resistor arrangement (2) according to claim 4, characterized in that the resistance element (4) has a length (L) in the direction perpendicular to the contact surface (34, 34') and that the coating (5) is applied centrally on the surface (41) of the resistance element (4) with respect to the length (L) of the resistance element (4).

6. Resistor arrangement (2) according to claim 4 or 5, characterized in that the resistance element (4) has a width (B) in the direction longitudinal to the contact surface (34, 34') and the coating (5) is applied over the entire width (B) of the resistance element (4).

7. Resistor arrangement (2) according to one of claims 4 to 6, characterized in that a first measuring tap (71) contacts the coating (5) and that a second measuring tap (72) contacts the uncoated part (412, 412') of the surface (41) of the resistance element (4).

8. Resistor arrangement (2) according to one of claims 1 to 3, characterized in that the coating (5) is applied to a part (311) of the surface (31) of the connecting element (3, 3') and directly adjacent to the contact surface (34, 34') to the resistance element (4).

9. Resistor arrangement (2) according to claim 8, characterized in that a first measuring tap (71) contacts the coating (5) and that a second measuring tap (72) contacts the uncoated part (312) of the surface (31) of the connecting element (3, 3').

10. Resistor arrangement (2) according to one of claims 1 to 9, characterized in that the coating (5) has a layer (50) which is in direct contact with the substrate and which comprises or is an oxide of the material of the substrate.

11. Resistor arrangement (2) according to one of claims 1 to 6 or 8, characterized in that a barrier layer (58) is present between the substrate and the coating (5), that a first measuring tap (71) contacts a first layer (51) of the coating (5) and that a second measuring tap (72) contacts a further layer (52, 53) of the coating (5).

12. Resistor arrangement (2) according to one of claims 1 to 11, characterized in that the coating (5) has a layer (59) which serves to passivate the coating (5) and to electrically contact a non-metallic layer (50, 51, 52, 53) of the coating (5).

13. Resistor arrangement (2) according to one of claims 1 to 12, characterized in that the coating (5) has at least one layer (50, 51, 52, 53) whose thickness is at least 50 nm and at most 100 pm.

14. Resistor arrangement (2) according to one of claims 1 to 13, characterized in that the coating (5) is applied by means of a CVD process or by means of a PVD process.

15. Resistor arrangement (2) according to one of claims 1 to 14, characterized in that the coating (5) is applied in a recess (8) of the surface (31, 41) of the substrate or on a region (9) raised above the surface (31, 41) of the substrate.

16. Resistor arrangement (2) according to one of claims 1 to 15, characterized in that for detecting the measuring signals, the resistor arrangement (2) is contacted by means of a plug, a printed circuit board or a cable.

17. Method for determining the temperature of a resistor arrangement (2) according to one of the preceding claims, characterized in that the electrical current flowing through the pn junction and the electrical voltage dropping across the pn junction are determined and the temperature of the resistor arrangement (2) is determined therefrom.

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