Resistor assembly and method for determining temperature of resistor assembly

Abstract

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

Description

[0001] The invention relates to a resistor component having a coating for measuring the temperature of the resistor component and to a method for determining the temperature of a resistor component.

[0002] Current measurement in electronic circuits uses a measuring shunt connected in series with the component to be monitored. According to Ohm's law, the current intensity is determined by measuring the voltage drop across the shunt, which is described as a shunt resistor. A known resistance value is a prerequisite. Accurate and reliable measurement of current intensity is particularly important, for example, in battery management systems for electric or hybrid vehicles. A resistor assembly can be produced from a composite material with longitudinally welded seams. This resistor assembly includes a low-ohmic measuring shunt of this type with a nominal value of approximately 10 to 50 μΩ and connecting elements for connecting the resistor assembly to the circuit. This is known, for example, from the printed publication EP 0 605 800 A1. The composite material is produced from three metal strips, where the individual metal strips are welded together at the longitudinal seams using an electron beam or laser welding process. The central metal strip is composed of a material with a very low temperature coefficient of resistance. The actual resistor element of the measuring shunt is formed from this material. The two outer strips are typically composed of a material with high electrical conductivity, such as copper. This type of material generally exhibits a high temperature coefficient of resistance compared to the material of the resistor element. From the two outer strips a connecting element is formed, by means of which the measuring shunt can be connected to an electrical circuit.

[0003] Determining the current intensity from the voltage drop across the measuring shunt requires precise knowledge of the resistance value. The influence of temperature on the specific resistivity of the materials used plays a key role. Therefore, it is necessary to know the temperature of the resistor assembly, which can take values ​​between -40°C and +170°C during use, in order to be able to implement compensation for the temperature-dependent resistance behavior. The temperature of the resistor assembly can be measured with the help of a temperature sensor, and the resistance value can be corrected by reference to this information. This is known, for example, from the published documents DE 199 06 276 A1 and EP 2 793 034 B1. The determination of the temperature of the resistor assembly is usually implemented using a passive analog sensor (for example, an NTC thermistor, a PT100 temperature sensor, or a thermocouple) or an active sensor (IC) combined with a sensor data evaluation function and a communication interface. The temperature sensor is an additional component, which incurs costs and additional structural complexity. In addition, the temperature sensor responds to temperature changes with a time delay, which can have a negative impact on accuracy. This is particularly important in the context of capturing heating associated with short-term current spikes, which may occur, for example, under extreme acceleration conditions of electric vehicles.

[0004] The present invention aims to disclose a resistor assembly that overcomes the above-mentioned disadvantages. In particular, the temperature measurement function should respond quickly to temperature changes of the resistor assembly. Another object of the present invention is to disclose a method for measuring the temperature of a resistor assembly.

[0005] With regard to the resistor assembly, the invention is characterized by the features of claim 1, and with regard to the measuring method, the invention is characterized by the features of claim 17. The further dependent claims relate to advantageous embodiments and further developments of the invention.

[0006] The present invention relates to a resistor assembly comprising at least one connecting element for connecting the resistor assembly to an electrical power circuit, and at least one resistor element. The resistor element is connected to the connecting element in an electrically conductive manner at a contact surface. The extension of the resistor element in a direction perpendicular to the contact surface is described as the length. On the one hand, at least one resistor element and on the other hand, at least one connecting element are made of different electrically conductive materials, preferably metallic materials. The specific electrical resistance of the material of the resistor element may be at least 10 times greater than the specific electrical resistance of the material of the connecting element. Furthermore, the magnitude of the temperature coefficient of resistance of the material of the connecting element may be much greater than the magnitude of the temperature coefficient of resistance of the material of the resistor element, typically at least 80 times greater. In particular, the magnitude of the temperature coefficient of resistance of the material of the resistor element may be lower than 5.10 -5 1 / K, while the temperature coefficient of the material of the connecting element can be about 4·10 -3 1 / K. In particular, the resistor element may be composed of copper, preferably a low-alloy copper alloy, aluminum, or preferably a low-alloy aluminum alloy, or may include at least one of these materials. The resistor element may be composed of a copper alloy, which is commonly used as a resistor alloy. The at least one connecting element may include means for connecting the resistor assembly to an external power circuit (e.g., a via). The resistor assembly may preferably include two connecting elements, the resistor element being arranged between the two connecting elements.

[0007] A coating consisting of at least one layer is applied to at least a portion of the surface of the resistor element, or to at least a portion of the surface of the connecting element, through the substrate. The coating may comprise one or more layers. In this context, the term "layer" is understood to mean a spatial arrangement of homogeneous material, wherein the material extends in a spatial direction perpendicular to the substrate surface, i.e., the thickness of the layer is substantially smaller than the extension of the material in a spatial direction parallel to the substrate surface.

[0008] According to a first aspect of the invention, the coating is implemented so that at the boundary surface between the substrate and the coating, the metal and the semiconductor are in direct contact, so that a pn transition is formed at this boundary surface. Preferably, the material of the substrate forms a metal, and the coating that is in direct contact with the substrate is embodied as a semiconductor. On the one hand, a layer of the coating, and on the other hand, an uncoated portion of the surface of the substrate, that is, an uncoated portion of the resistor element or the connecting element can be contact-connected to capture a measurement signal for determining the temperature of the resistor assembly. If the coating is applied to the resistor element, on the one hand, at least one layer of the coating and on the other hand, an uncoated portion of the surface of the resistor element can be contact-connected to capture a measurement signal for determining the temperature of the resistor assembly. If the coating is applied to the connecting element, on the one hand, at least one layer of the coating and on the other hand, an uncoated portion of the surface of the connecting element can be contact-connected to capture a measurement signal for determining the temperature of the resistor assembly. Preferably, the layer of the coating that is in direct contact with the substrate can be contact-connected.

[0009] According to a second aspect of the invention, the coating is implemented such that at least at the boundary surface between the first layer of the coating and the second layer of the coating, the metal and the semiconductor are in direct contact with each other, or the first semiconductor and the second semiconductor are in direct contact with each other, so that a pn transition is formed at this boundary surface. On the one hand, the first layer of the coating and, on the other hand, at least one further layer of the coating, in particular the second layer of the coating that is in direct contact with the first layer, can be contact-connected, either directly or indirectly, in order to capture a measurement signal for determining the temperature of the resistor component.

[0010] The present invention is based on the following considerations, in which the temperature behavior of the current-voltage characteristic of the pn transition is used to directly determine the temperature. The current-voltage characteristic of the pn transition, in accordance with the diode characteristic, can be described by the Shockley equation. The Shockley equation includes temperature-dependent variables, namely the thermal voltage and the off-state current. Therefore, the current-voltage characteristic of the pn transition varies with temperature. If the current flowing through the pn transition and the voltage drop across the pn transition are known, then by reference to the known temperature dependence of the current-voltage characteristic, with the help of preconditions, the temperature prevailing at the pn transition can be determined. This type of metrological capture of the pn transition can be implemented, for example, with the help of discrete components (such as a constant current source and an operational amplifier or an analog-to-digital converter (ADC)) by means of a temperature sensor, or alternatively, it can be implemented in an integrated circuit (IC).

[0011] According to the present invention, this type of pn transition is implemented by a coating on the resistor component. Compared to the substrate, the coating is thin and exhibits only a low thermal mass. Instead, the thermal connection between the coating and the substrate is achieved over a large surface area. Therefore, the temperature at the pn transition is always identical to the substrate temperature with a high degree of accuracy. Even rapid temperature changes can be detected without significant time offsets. The coating can be applied to either the resistor element or the connecting element. Thus, the temperature of the resistor element or the connecting element can be determined.

[0012] The pn transition can be implemented directly at the boundary surface between the substrate and the coating. The conductive, preferably metallic, substrate, due to the presence of free electrons, functions as the n-side of the pn transition. The coating layer, which is bonded in direct contact with the substrate, must then be selected so that, in combination with the substrate, it functions as a semiconductor and, therefore, exhibits a lack of free electrons compared to the substrate. This forms the p-side of the pn transition. Resistor components including this type of pn transition can be manufactured by, for example, depositing or structuring a layer of a copper-based material, preferably an oxide, on the surface of the resistor component. This selected material pairing results in a pn transition exhibiting specific current-voltage characteristics.

[0013] Alternatively, the pn transition can be implemented at the boundary surface between the first and second layers of the coating, i.e., by a suitable layer structure of the coating, where either the metal and the semiconductor, or the first and second semiconductor, are joined in direct mutual contact.

[0014] Suitable material combinations, where the aforementioned semiconductor properties are known and copper is used as the primary material, include, for example, Cu / Cu(I)O, p-Cu2O / n-ZnO, SnF2:SnO2 / CuAlO2, or p-Cu2O / n-Cu2O. The oxides specified by way of example exhibit semiconductor properties. They can be described as "oxide semiconductors." In oxides of this type, the energy difference (band gap) between the valence band and the conduction band is of the same order of magnitude as that associated with semiconductors, i.e., in the region of a few electron volts (eV). Electrons can jump from the valence band into the conduction band via thermal excitation. Consequently, the electrical conductivity of the oxide increases with temperature. The aforementioned material pairings form material transitions exhibiting current-voltage characteristics, which, as in the case of semiconductor diodes, can be described by the Shockley equation. Based on the above examples, further material pairings exhibiting similar properties can be identified. In material pairs of this type, the oxides act as semiconductors and, therefore, can be included within the term "semiconductor" within the context of the present invention.

[0015] A particular advantage of the present invention is that the temperature sensor formed by the coating is not applied point by point, but rather over the entire surface of the resistor assembly. This provides effective thermal coupling between the sensor and the object whose temperature is to be measured. Furthermore, the coating has only a very low specific heat capacity, which enables the temperature sensor to respond very quickly to changes in substrate temperature. In other words, due to its very low thermal mass, the coating exhibits very low thermal inertia and can therefore detect changes in substrate temperature in a particularly flexible manner.

[0016] In the context of one embodiment of the present invention, the coating can include at least one layer formed from or including a doped semiconductor. Doping allows for targeted adjustment of semiconductor properties. In particular, doping can influence the current-voltage characteristic of the pn transition. This can, for example, improve the accuracy of temperature measurements. Thus, for example, in the case of p-Cu2O / n-Cu2O, p-doping and n-doping of the same substrate material are conceivable. Doping can be performed during the coating process.

[0017] In the context of another embodiment of the present invention, the coating can include at least two layers selected so that the pn transition is an element of the npn transition or the pnp transition. In this way, a bipolar layer sequence is achieved. The third material in the layer sequence can be the third layer of the coating or the substrate, that is, one of the conductive materials of the resistor component. Since the npn transition or the pnp transition exhibits significantly higher temperature stability than the pn transition, this type of component can significantly improve measurement accuracy. In a particularly preferred arrangement of this embodiment, all three materials of the bipolar layer sequence, in particular all three layers of the bipolar layer sequence, can be contact-connected to capture a measurement signal for determining the temperature of the resistor component. This provides an embodiment option corresponding to a circuit with a diode-connected bipolar transistor.

[0018] In the context of further embodiments of the invention, the coating may be applied only to a portion of the surface of the resistor element. In this way, it is possible to determine the temperature at critical points on the resistor element, for example at points of particularly high temperature.

[0019] In particular, in this embodiment, the resistor element may have a length perpendicular to the contact surface between the resistor element and the connecting element, and the coating may be arranged centrally on the surface of the resistor element relative to the length of the resistor element. Consequently, the coating is positioned in the region of the resistor element furthest from the contact surface with the connecting element. The highest temperature occurs in this region, and the average temperature of the resistor assembly can be derived from this highest temperature.

[0020] Preferably, the extension of the coating in a direction perpendicular to the contact surface can be measured to be at least 1 mm, particularly preferably at least 1.5 mm, and a maximum of 4 mm, particularly preferably a maximum of 2.5 mm. By selecting the dimensions of the coating within this range, the electrical variable to be measured can be set within a favorable range.

[0021] Furthermore, in the context of the specific configuration of the above-described embodiment of the present invention, the coating can be applied over the entire width of the resistor element. The width of the resistor element is understood to be its longitudinal extension relative to the contact surface, i.e., transverse to the direction of current flow. In a specific configuration of the present invention, the temperature is measured and averaged over the entire width of the resistor element.

[0022] In the context of another specific configuration of the above-described embodiment of the present invention, the first measuring tap can be in contact with the coating, i.e., one layer of the coating, and the second measuring tap can be in contact with, and thus mounted to, an uncoated portion of the surface of the resistor element. This arrangement of the measuring taps captures the voltage drop occurring across the Pn transition at the boundary surface between the resistor element (via the substrate) and the coating.

[0023] In the context of an alternative embodiment of the present invention, the coating can be applied only to a portion of the surface of the connecting element, immediately adjacent to the contact surface of the connecting element with the resistor element. In this arrangement of the coating, the temperature of the connecting element is measured immediately adjacent to the resistor element. From this measured temperature, the temperature of the resistor element can be determined with sufficient accuracy. Depending on the preferred material, applying the coating to the connecting element can be simpler than applying it to the resistor element.

[0024] In the context of the specific configuration of this embodiment of the present invention, the first measuring tap can be in contact with the coating, i.e., one layer of the coating, and the second measuring tap can be in contact with and thus mounted on an uncoated portion of the surface of the connecting element. This arrangement of the measuring taps captures the voltage drop occurring across the pn transition at the boundary surface between the resistor element (via the substrate) and the coating.

[0025] In the context of a further embodiment of the invention, the coating can include a layer which is in direct contact with the substrate and which comprises an oxide of the material of the substrate or is formed by an oxide of the material of the substrate. Due to the material affinity between the substrate and the material of the coating which is in direct contact with the substrate, particularly favorable prerequisites for the formation of a pn transition are provided. For example, in the case where the coating is applied to a connecting element of a copper structure, the layer which is in direct contact with the connecting element can consist of Cu(I)O or can contain Cu(I)O. In a similar manner, in the case where the coating is applied to a resistor element of a copper-manganese alloy, the layer which is in direct contact with the resistor element can consist of CuMnO2 or can contain CuMnO2.

[0026] In the context of an alternative embodiment of the present invention, a barrier layer can be arranged between the substrate and the coating. A first measuring tap contacts a first coating layer, and a second measuring tap contacts another coating layer. The barrier layer provides a material separation between the substrate and the coating, but not a thermal separation. Therefore, the substrate has no material influence on the processes in the coating. Consequently, the coating can be selected from a wide range of materials, independent of the substrate material. Consequently, the coating can be optimized for its function as a temperature sensor. For example, the barrier layer can be made of nickel.

[0027] In the context of a further embodiment of the present invention, the coating may further comprise a layer for passivating the coating and for electrical contact-connection of the non-metallic layer of the coating. The passivating layer is preferably a metallic layer. This type of layer may be the layer of the coating that is at the greatest distance from the substrate.

[0028] In the context of further embodiments of the present invention, the coating can include at least one layer having a thickness of at least 50 nm, preferably at least 70 nm, and a maximum of 100 μm, preferably a maximum of 10 μm. In particular, each layer of the coating can have a thickness within the above-specified ranges, and in particular within preferred subranges thereof. Coatings comprising one or more layers within the specified ranges are particularly suitable for embodiments of temperature sensors based on pn transitions.

[0029] In the context of another embodiment of the present invention, the coating can be applied by a CVD method or by a PVD method. CVD methods and PVD methods are suitable for applying coatings of the above-mentioned type. In particular, these methods enable doping of the semiconductor layer applied by means of these methods.

[0030] In the context of another embodiment of the present invention, the coating can be applied to recessed portions of the substrate surface or to areas raised above the substrate surface. In some applications, it may be advantageous to apply the coating to recessed portions of the substrate surface to protect it from environmental influences, such as corrosive mechanical impacts. Conversely, in some applications, it may be advantageous to apply the coating to areas raised above the substrate surface. This can facilitate contact connection with a measuring tap, for example.

[0031] In the context of another embodiment of the present invention, the resistor assembly can be contact-connected to capture the measurement signal by means of a plug, a printed circuit board, or a cable. These components enable simple and cost-effective tapping of the measurement signal, which is required for temperature determination.

[0032] With regard to further technical features and advantages of the resistor assembly according to the invention, explicit reference may be made to the explanations, figures, figure legends and exemplary embodiments provided with reference to the method according to the invention for determining the temperature of a resistor assembly.

[0033] Another aspect of the present invention relates to a method for determining the temperature of a resistor assembly. The resistor assembly includes a coating of the type described above. The coating is selected so that a pn transition is formed at the contact surface between the substrate and the coating, or at the contact surface between two layers of the coating. According to the present invention, the current flowing through the pn transition and the voltage drop across the pn transition are determined. From these two measured variables, the temperature of the resistor assembly is determined by utilizing the temperature-dependent current-voltage characteristic of the pn transition. According to another aspect of the present invention, the coating described above is used to determine the temperature of the resistor assembly.

[0034] With regard to further technical features and advantages of the method for determining the temperature of a resistor assembly according to the invention, and with regard to the use of a coating for determining the temperature of a resistor assembly according to the invention, explicit reference may be made to the explanations, drawings, illustrations of the drawings, and exemplary embodiments provided in conjunction with the resistor assembly according to the invention.

[0035] Exemplary embodiments of the present invention are described in more detail below with reference to schematic diagrams which are not true to scale. In the drawings:

[0036] Figure 1 A resistor assembly having a coating on the resistor element is shown;

[0037] Figure 2 A resistor assembly having a coating in a recess of the resistor element is shown;

[0038] Figure 3A resistor assembly is shown having a coating on raised areas of the resistor element;

[0039] Figure 4 A resistor assembly having a coating on a connecting element is shown;

[0040] Figure 5 A resistor element having a coating with a first layer structure is shown;

[0041] Figure 6 A resistor element is shown having a coating with a second layer structure; and

[0042] Figure 7 A resistor element is shown having a coating with a third layer structure.

[0043] In all the figures, mutually corresponding parts are identified by the same reference numerals.

[0044] Figure 1 A resistor assembly 2 is shown having two connecting elements 3, 3' and a resistor element 4 arranged between the two connecting elements 3, 3'. The resistor element 4 is connected to the two connecting elements 3, 3' in an electrically conductive manner at contact surfaces 34, 34'. The extension of the resistor element 4 between the two contact surfaces 34, 34' is indicated as length L. In the exemplary embodiment represented, for the sake of simplicity, the resistor element 4 is shown so that its width B in the longitudinal direction of the contact surfaces 34, 34' is of equal size to the extension of the connecting elements 3, 3' in this direction. Typically, the extension of the resistor element 4 in the longitudinal direction of the contact surfaces 34, 34' is slightly smaller than the extension of the connecting elements 3, 3' in this direction. For the sake of simplicity, means for connecting the resistor assembly 2 to an external power circuit, such as holes in the connecting elements 3, 3', are not shown.

[0045] The resistor element 4 includes a freely accessible surface 41. A coating 5 is applied in a narrow strip to a portion 411 of the surface 41 of the resistor element 4. The coating 5 is applied centrally between the two contact surfaces 34, 34', so that in each case, an uncoated portion 412, 412' of the surface 41 providing the resistor element 4 is located between the coating 5 and one of the connection elements 3, 3', respectively. The coating extends over the entire width B of the resistor element 4. Alternatively, it is also possible for the coating 5 to extend only over a portion of the width B of the resistor element 4. A pn ​​transition (not shown in detail) is provided at the boundary surface 61 between the coating 5 and the resistor element 4.

[0046] The first measuring tap 71 is mounted such that it is directly contact-connected to the coating 5. The second measuring tap 72 is mounted such that it is contact-connected to the uncoated portion 412 of the surface 41 of the resistor element 4. With the aid of these two measuring taps 71, 72, the voltage drop across the pn transition can be determined.

[0047] exist Figure 1 In a case not shown in FIG, in which the coating 5 extends only over a portion of the width B of the resistor element 4, the uncoated portion 412, 412' of the surface 41 of the resistor element 4 also includes a region arranged at a spacing equal to the spacing between the connecting elements 3, 3' and the corresponding spacing of the coating 5. Therefore, when a current flows through the resistor element 4, this region assumes the same electrical potential as the coating 5. In this case, the second measuring tap 72 can advantageously be mounted on this region of the uncoated portion 412, 412' of the surface 41 of the resistor element 4. It is particularly preferred that the second measuring tap 72 be positioned so that it is at an equal distance from the two connecting elements 3, 3', just like the first measuring tap 71 that contacts and connects the coating 5. Errors in the measured values ​​are accordingly reduced.

[0048] Figure 2 A preferred embodiment of the resistor assembly 2 is shown. Figure 2 The embodiment shown in Figure 1 The embodiment shown in FIG. 4 differs in that the coating 5 is located in a recess 8 of the resistor element 4 . Figure 2 All other features of the resistor assembly 2 shown in correspond to Figure 1 Those features of the resistor assembly 2 shown in FIG. Figure 1 As described, it is further possible that the coating 5 and the recess 8 extend only over a portion of the width B of the resistor element 4, or that only the coating 5 extends only over a portion 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 connected as in combination with Figure 1 Positioning is performed as described.

[0049] Figure 3 Another preferred embodiment of a resistor assembly 2 is shown, in which the coating 5 is applied to the raised areas 9 of the resistor element 4 . Figure 3 All other features of the resistor assembly 2 represented in correspond to Figure 1 Those features of the resistor assembly 2 represented in FIG. Figure 1As described, it is further possible that the coating 5 and the raised area 9 extend only over a portion of the width B of the resistor element 4, or that only the coating 5 extends over a portion of the width B of the resistor element 4 and the raised area 9 extends over the entire width B of the resistor element 4. In these cases, the second measuring tap 72 can advantageously be connected as in combination with Figure 1 Positioning is performed as described.

[0050] Figure 4 An alternative embodiment of a resistor assembly 2 is shown. The basic layout of this resistor assembly 2 with respect to the connection elements 3, 3' and the resistor element 4 corresponds to Figure 1 The embodiment shown. Connecting element 3 includes a freely accessible surface 31. A coating 5 in the form of a narrow strip is applied directly to a portion 311 of surface 31 of connecting element 3 at the transition to resistor element 4. Surface 31 of connecting element 3 thus includes an uncoated portion 312. The coating is applied over the entire extension of connecting element 3 in the longitudinal direction of contact surfaces 34, 34'. Alternatively, the coating may be applied over only a portion of the extension of connecting element 3 in the longitudinal direction of contact surfaces 34, 34'. A pn ​​transition is provided at boundary surface 61 between coating 5 and connecting element 3, not shown in greater detail. A first measuring tap 71 is mounted so that it directly contacts and connects to coating 5. A second measuring tap 72 is mounted so that it contacts and connects to uncoated portion 312 of surface 31 of connecting element. These two measuring taps 71, 72 allow the voltage drop across the pn transition to be determined.

[0051] exist Figure 4 In the case not shown in FIG, in which the coating 5 extends only over a portion of the width B of the connecting element 3, the uncoated portion 312 of the surface 31 of the connecting element 3 also includes a region that is equidistant from the resistor element 4 as the coating 5. When a current flows through the resistor assembly 2, this region therefore assumes 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 portion 312 of the surface 31 of the connecting element 3. It is particularly preferred that the second measuring tap 72 be positioned so that it is at the same distance from the resistor element 4 as the first measuring tap 71 of the contact-connecting coating 5.

[0052] exist Figure 4The embodiment of the resistor assembly 2 shown in FIG can be modified in that, on the two connecting elements 3, 3', a coating 5 in the form of a narrow strip is applied directly to the respective transition of the resistor element 4. Thus, the respective temperatures of the two connecting elements 3, 3' can be measured in the immediate vicinity of the respective contact surfaces 34, 34'. By reference to these temperatures, the resulting thermal voltage at the respective transition between the resistor element 4 and the connecting elements 3, 3' can be estimated.

[0053] Figure 5 A coating 5 with a resistor element 4 is shown with a first layer structure. The resistor element 4 shown may be a Figures 1 to 3 Part of a resistor assembly 2. For simplicity, the connecting elements 3, 3' that contact and connect the resistor element 4 on both sides are not shown. The coating 5 consists of a first layer 50, which directly contacts and connects the resistor element 4, and a further layer 59, which serves to passivate the coating 5 and electrically contact and connect the first layer 50. The first layer 50 can preferably be formed from an oxide of the material of the resistor element 4, or can include such an oxide. The further layer 59 is composed of a metal and represents the uppermost layer 59 of the coating 5, i.e., the layer furthest from the substrate. A pn ​​transition (not shown) is provided at the boundary surface 61 between the first layer 50 of the coating 5 and the resistor element 4. A first measuring tap 71 contacts and connects the coating 5, where it contacts and connects the uppermost layer 59 of the coating 5. In this way, the first layer 50 of the coating 5 is electrically contacted. A second measuring tap 72 contacts and connects the resistor element 4 in the uncoated area 412 of its surface 41. With the aid of the two measuring taps 71 , 72 , the voltage drop across the pn transition can be determined.

[0054] Figure 6 A resistor element 4 is shown with a coating 5 having a second layer structure. The resistor element 4 shown may be a Figures 1 to 4Part of a resistor assembly 2. For simplicity, the connecting elements 3, 3' that are contact-connected to the resistor element 4 on both sides are not shown. The coating 5 consists of a barrier layer 58 applied directly to the resistor element 4, an uppermost layer 59 for passivation and contact-connection of the coating 5, and two further layers 51, 52 arranged between the barrier layer 58 and the uppermost layer 59. The first of these two layers, layer 51, is applied to the barrier layer 58. The second of these two layers, layer 52, directly contacts and joins the uppermost layer 59. The first layer 51 can be a p-type doped semiconductor. In this case, the second layer 52 is an n-type doped semiconductor. However, it is also possible for the first layer 51 to be an n-type doped semiconductor and the second layer 52 to be a p-type doped semiconductor. In both cases, a pn transition (not shown) is provided at the boundary surface 62 between the first and second layers 51, 52 of the other two layers. The first measuring tap 71 is contact-connected to the first layer 51 of the other two layers. The second measuring tap 72 is contact-connected to the coating 5, wherein it contacts and engages 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 contact-connected. The voltage drop across the pn transition can be determined using these two measuring taps 71, 72.

[0055] Figure 7 The resistor element 4 is shown with a coating 5 having a third layer structure. The resistor element 4 shown may be a Figures 1 to 4Part of a resistor assembly 2. For simplicity, the connecting elements 3, 3' that are contact-connected to the resistor element 4 on both sides are not shown. The coating 5 consists of a barrier layer 58 applied directly to the resistor element 4, an uppermost layer 59 for passivation and contact-connection of the coating 5, and three other layers 51, 52, and 53 arranged between the barrier layer 58 and the uppermost layer 59. The first layer 51 of these three layers is applied to the barrier layer 58. The third layer 53 of these three layers is directly in contact with and bonded to the uppermost layer 59. The second layer 52 of these three layers is arranged between the first layer 51 and the third layer 53. The first layer 51 can be a p-type doped semiconductor. In this case, the second layer is an n-type doped semiconductor, and the third layer 53 can be a p-type doped semiconductor. However, the first layer 51 can also be an n-type doped semiconductor, the second layer 52 a p-type doped semiconductor, and the third layer 53 an n-type doped semiconductor. A pn ​​transition (not shown) is provided at the boundary surface 62 between the first layer 51 and the second layer 52 of the other three layers. A pn transition (not shown) is also provided at the boundary surface 62' between the second layer 52 and the third layer 53 of the other three layers, so that the other three layers 51, 52, and 53 represent an npn or pnp bipolar layer sequence. A first measuring tap 71 is contact-connected to the first layer 51 of the other three layers. A second measuring tap 72 is contact-connected to the coating 5, where it contacts and engages the uppermost layer 59 of the coating 5. This electrically contacts the third layer 53 of the other three layers of the coating 5. The optional third measuring tap 73 is also contact-connected to the second layer 52. The combination of the three measuring taps 71, 72, and 73 forms a circuit in which two pn transitions can be used to capture temperature. This circuit corresponds to a diode-connected bipolar transistor.

[0056] Figure 5 、 Figure 6 and Figure 7 The coating 5 shown in FIG can be applied not only to the resistor element 4 but also in a similar manner to the resistor element 4. Figure 4 The connecting element 3 shown, or applied to two connecting elements 3, 3', such as combined Figure 4 Just as described.

[0057] Reference numerals

[0058] 2 resistor components

[0059] 3. 3' connecting element

[0060] 31 Surface

[0061] 311 coating part

[0062] 312 Uncoated part

[0063] 34, 34' contact surface

[0064] 4 Resistor elements

[0065] 41 Surface

[0066] 411 Coated Parts

[0067] 412, 412' uncoated portion

[0068] 5 coatings

[0069] 50th, 51st, 52nd, and 53rd floors

[0070] 58 barrier layer

[0071] 59th floor

[0072] 61, 62, 62' boundary surface

[0073] 71, 72, 73 measurement taps

[0074] 8 recess

[0075] 9 Raised area

[0076] L length

[0077] B width

Claims

1. A resistor assembly (2) comprising at least one connecting element (3, 3') for connecting the resistor assembly (2) to a power circuit and at least one resistor element (4), wherein The resistor element (4) is connected to the connecting element (3, 3') in an electrically conductive manner at a contact surface (34, 34'), wherein, on the one hand, at least one resistor element (4) and, on the other hand, at least one connecting element (3, 3') consist of different electrically conductive materials, and wherein, by means of a substrate, on at least a portion (411) of the surface (41) of the resistor element (4) or by means of a substrate, on at least a portion (311) of the surface (31) of the connecting element (3, 3'), a coating (50, 51, 52, 53) consisting of at least one layer (50) is applied, characterized in that The coating (5) is implemented so that at the boundary surface (61) between the substrate and the coating (5), the metal and the semiconductor are in direct contact, so that a pn transition is formed at this boundary surface (61), and / or is characterized in that at least at the boundary surface (62, 62') between the first layer (50, 51) of the coating (5) and the second layer (52) of the coating (5), the metal and the semiconductor are in direct contact and joined, or the first semiconductor and the second semiconductor are in direct contact and joined, so that a pn transition is formed at the boundary surface (62, 62'). Transition, wherein both, on the one hand, at least one layer (50, 51, 52, 53) of a coating (5) and, on the other hand, an uncoated portion (412, 412') of a surface (41) of a resistor element (4) or an uncoated portion (312) of a surface (31) of a connecting element (3, 3'), or both, on the one hand, a first layer (50, 51) of a coating (5) and, on the other hand, at least one further layer (52, 53), can be contact-connected in order to capture a measurement signal for determining the temperature of a resistor component (2).

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

3. The resistor assembly (2) according to claim 1 or 2, characterized in that The coating (5) comprises at least two layers (50, 51, 52, 53) which are selected such that the pn transition is an element of an np-n transition or a pnp transition.

4. The resistor assembly (2) according to any one of claims 1 to 3, characterized in that The coating (5) is applied only to a portion (411) of the surface (41) of the resistor element (4).

5. The resistor assembly (2) according to claim 4, characterized in that The resistor element (4) has a length (L) in a direction perpendicular to the contact surface (34, 34'), and the coating (5) is arranged on the surface (41) of the resistor element (4) centrally relative to the length (L) of the resistor element (4).

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

7. The resistor assembly (2) according to any one of claims 4 to 6, characterized in that The first measuring tap (71) is contact-connected to the coating (5), and the second measuring tap (72) is contact-connected to an uncoated portion (412, 412') of the surface (41) of the resistor element (4).

8. The resistor assembly (2) according to any one of claims 1 to 3, characterized in that The coating (5) is applied to a portion (311) of the surface (31) of the connection element (3, 3') adjacent to the contact surface (34, 34') of the connection element (3, 3') with the resistor element (4).

9. The resistor assembly (2) according to claim 8, characterized in that The first measuring tap (71) is in contact with the coating (5), and the second measuring tap (72) is in contact with an uncoated portion (312) of the surface (31) of the connecting element (3, 3').

10. The resistor assembly (2) according to any one of claims 1 to 9, characterized in that The coating (5) comprises a layer (50) bonded to the substrate in direct contact and comprising or formed from an oxide of the material of the substrate.

11. The resistor assembly (2) according to any one of claims 1 to 6 or 8, characterized in that A barrier layer (58) is arranged between the substrate and the coating (5), characterized in that a first measuring tap (71) is in contact with a first layer (51) of the coating (5) and a second measuring tap (72) is in contact with another layer (52, 53) of the coating (5).

12. The resistor assembly (2) according to any one of claims 1 to 11, characterized in that The coating (5) comprises a layer (59) for passivating the coating (5) and for electrical contact-connection of the non-metallic layers (50, 51, 52, 53) of the coating (5).

13. The resistor assembly (2) according to any one of claims 1 to 12, characterized in that The coating (5) comprises at least one layer (50, 51, 52, 53) having a thickness of at least 50 nm and a maximum of 100 μm.

14. The resistor assembly (2) according to any one of claims 1 to 13, characterized in that The coating (5) is applied by a CVD method or by a PVD method.

15. The resistor assembly (2) according to any one of claims 1 to 14, characterized in that The coating (5) is applied to recesses (8) in the surface (31, 41) of a substrate or to raised areas (9) above the surface (31, 41) of a substrate (9).

16. The resistor assembly (2) according to any one of claims 1 to 15, characterized in that In order to capture the measurement signal, the resistor assembly (2) is contact-connected via a plug, a printed circuit board or a cable.

17. A method for determining the temperature of a resistor assembly (2) according to any one of the preceding claims, characterized in that The current flowing through the pn transition and the voltage drop across the pn transition are determined, and from this the temperature of the resistor assembly (2) is determined.

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