Surface-mounted resistor with raised tab

Abstract

A surface-mounted resistor (1) comprising an insulating, preferably plate-shaped, substrate (2) having a first and second main surface, wherein the first (3) and second (4) main surface of the substrate (2) are spaced apart from each other by a thickness (5) of the substrate, and lateral surfaces (6), wherein a resistive element (7), preferably a thick-film resistor, is arranged on the first (3) main surface, and wherein an electrical contact (8) is arranged at each of two ends of the resistive element (7), advantageously partially overlapping it, and wherein each electrical contact has an electrode, and wherein the electrodes (9) each comprise a contacting segment (10) and a connecting segment (11), wherein the contacting segment and the connecting segment are arranged in an L-shape relative to each other, and wherein a base element (12) is provided, on the surface of which two (4), spaced apart from each other,electrical connection sections (14) are arranged and wherein the base element (12) is spaced apart from the substrate (2) and wherein the contacting segment (10) is connected to each of the electrodes (9) with each of the electrical contacts (8) by means of a first electrically conductive connecting material (16), and wherein the connecting segment (11) is connected to each of the electrodes (9) with each of the connection sections (14) of the base element (12) by means of a second electrically conductive connecting material (17).

Description

[0001] A surface-mounted resistor comprising an insulating, preferably plate-shaped, substrate, having a first and second main surface, wherein the first and second main surfaces of the substrate are spaced apart from each other by a thickness of the substrate, and lateral surfaces, wherein a resistive element, preferably a thick-film resistor, is arranged on the first main surface, and wherein an electrical contact is arranged at each of two ends of the resistive element, preferably partially overlapping it, and wherein each electrical contact comprises an electrode, and wherein the electrodes each comprise a contacting segment and a connecting segment, the contacting segment and the connecting segment being arranged in an L-shape relative to each other, and wherein a base element is provided, on the surface of which two spaced-apartelectrical connection sections are arranged and wherein the base element is spaced away from the substrate and wherein the contacting segment of each of the electrodes is connected to each of the electrical contacts by means of a first electrically conductive connecting material, and wherein the connecting segment of each of the electrodes is connected to each of the connection sections of the base element by means of a second electrically conductive connecting material.

[0002] Various embodiments of surface-mounted resistors are known from the prior art. For example, WO1997022130A1 discloses a printed circuit board arrangement comprising: a printed circuit board, a power resistor mounted on the printed circuit board, wherein the power resistor has a body containing a resistive element on a substrate and generating significant heat when the resistor is mounted on the printed circuit board and a voltage is applied to the resistive element, wherein the power resistor has elongated leads or terminals having a thermal conductivity of less than about 65 W / m°K at 25°C in order to reduce the heat input into the printed circuit board.

[0003] US20110285498A1 discloses a surface-mounted resistor with a flat base element and a resistive element formed thereon, with a pair of external electrodes having first and second bend sections, wherein the position of the flat base element in the thickness direction is closer to the first bend section than to the second bend section, so that the stresses due to thermal expansion that arise in the surface-mounted substrate when the surface-mounted resistor is mounted on it will be reduced.

[0004] Reflow soldering, also known as re-soldering, is a standard process in electrical engineering for soft soldering surface-mount components or assemblies. In this process, components, solder, and any flux are pre-assembled in the desired position on a printed circuit board (PCB). The board is then heated above the solder's melting point, causing the solder to melt and form the desired solder joint.

[0005] The use of reflow soldering for surface-mounted components or assemblies can be complicated by the fact that other soft solder joints may already be necessary for the production of these components or assemblies. These existing joints could melt or be otherwise negatively affected by the necessary heating during reflow soldering. For example, an excessively high homologous temperature of the existing soft solder joint during reflow soldering can lead to undesirable thermal effects, such as diffusion-related effects, or thermomechanical effects.

[0006] This can be particularly problematic if the surface-mounted component or assembly is intended to be suitable for high operating temperatures and the solder used for the reflow soldering connection to the circuit board or other base element must have a correspondingly high melting point, which further increases the temperature stress during reflow soldering.

[0007] Selective soldering in connection with Through Hole Technology (THT) soldering processes is a possible alternative, but this involves higher process engineering effort.

[0008] The task for the expert in the field of technology is therefore to develop a surface-mounted resistor that is particularly suitable for reflow soldering.

[0009] This technical problem is solved by the characterizing part of claim 1 or by the method according to claim 14.

[0010] One possible embodiment is a surface-mounted resistor comprising an insulating, preferably plate-shaped, substrate. The substrate has a first and a second main surface, the first and second main surfaces of the substrate being spaced apart from each other by the thickness of the substrate. The substrate also has lateral surfaces. A resistive element, preferably a thick-film resistor, is arranged on the first main surface of the substrate. An electrical contact is arranged at each of two ends of the resistive element, advantageously partially overlapping it, and each electrical contact has an electrode. The electrodes each comprise a contacting segment and a connecting segment, the contacting segment and the connecting segment being arranged in an L-shape relative to each other.Furthermore, a base element is present, on the surface of which two spaced-apart electrical connection sections are arranged. The base element is spaced away from the substrate. In particular, it can be provided that the base element is spaced away from the substrate in a thickness direction. Furthermore, the contacting segment of each electrode is connected to each of the electrical contacts by means of a first electrically conductive connecting material, and the connecting segment of each electrode is connected to each of the connection sections of the base element by means of a second electrically conductive connecting material. Moreover, the melting point of the first electrically conductive connecting material is at least 20 °C higher than the melting point of the second electrically conductive connecting material.

[0011] This design variant is particularly suitable for reflow soldering the surface-mount resistor onto the surface of a base element, as the first electrically conductive bonding material has a melting point at least 20 °C higher than the second electrically conductive bonding material, which in this case could be formed, for example, via reflow soldering. This prevents, for instance, the first electrically conductive bonding material from melting during the reflow soldering process. A melting point at least 20 °C higher is advantageous because it prevents the first electrically conductive bonding material from melting, even with typical fluctuations in the reflow soldering process. This also eliminates the need for the more technically complex selective soldering process.

[0012] Common reflow solders include tin-silver-copper ("SAC") solders, which have a melting point in the range of approximately 215–220°C. Soft solders with a melting point ≥ 245°C are, for example, those based on tin-antimony (Sn-Sb). In the case of silver sintering, the melting point of the first bonding material would be around 961°C.

[0013] It can also be stipulated that the second electrically conductive connecting material has a melting point of at least 210 °C. This makes the surface-mount resistor particularly suitable for use at high operating temperatures.

[0014] Methods or reference works for determining the melting point are known to experts.

[0015] Another possible embodiment of the surface-mounted resistor comprises a base element with two spaced-apart electrical connection sections arranged on its surface, and an insulating substrate having a first and second main surface, wherein the first main surface of the substrate faces the surface of the base element and the second main surface of the substrate faces away from the surface of the base element, and wherein the base element and substrate are spaced apart from each other, wherein a resistive element, advantageously a thick-film resistor, is arranged on one of the main surfaces, and wherein an electrical contact is arranged at each of the two ends of the resistive element, and wherein each electrical contact has an electrode, and wherein the electrodes each comprise a contacting segment and a connection segment, the contacting segment and the connection segment being arranged in an L-shape relative to each other.and wherein the contacting segment of each of the electrodes is connected to each of the electrical contacts by means of a first electrically conductive connecting material, and wherein the connecting segment of each of the electrodes is connected to each of the connecting sections of the base element by means of a second electrically conductive connecting material, characterized in that the melting point of the first electrically conductive connecting material is at least 20 °C higher than the melting point of the second electrically conductive connecting material.

[0016] All the embodiments mentioned below can also refer to this embodiment.

[0017] In one possible embodiment, a first resistive element, advantageously a thick-film resistor, is arranged on the first main surface of the substrate and a second resistive element on the second main surface of the substrate. It can be provided that an electrical contact is arranged at each of the two ends of the first and second resistive elements. Furthermore, it can be provided that each electrical contact has an electrode. It can also be provided that each electrode contacts one of the electrical contacts of the first and second resistive elements.

[0018] The substrate can be a technical ceramic, for example made of aluminum oxide or aluminum nitride. The resistive element is preferably a thick-film resistor applied and sintered over a paste comprising, for example, pure metal powder and glass powder or metal oxides. The nominal resistance value can be adjusted by the mixing ratio of the paste components and the geometric dimensions of the resistive element. However, the resistive element can also comprise other embodiments known to those skilled in the art.

[0019] The electrical contacts are, for example, silver or silver-palladium (Ag-Pd) contacts; these can be applied, for example, via a screen printing process and subsequent heat treatment.

[0020] The base element can, for example, be a printed circuit board, and the connecting sections formed on the surface of the base element can be copper traces on the circuit board. These copper traces can, for example, be silver-plated or gold-plated, or have protective layers against environmental influences. Other embodiments familiar to those skilled in the art are also conceivable.

[0021] The plate-shaped substrate can be rectangular and preferably has a length between 10 and 70 mm, a width between 5 mm and 50 mm, and a thickness between 0.5 and 2.5 mm. Furthermore, the width of the electrodes can be at least 50% of the width of the substrate.

[0022] The spacing between the base element and the substrate, particularly in the thickness direction of the substrate, refers to the distance between the surface of the base element and the main surface of the substrate closest to the base element. This spacing is preferably between 2 mm and 10 mm. A smaller spacing is critical with regard to heat input into the base element at high operating temperatures of the surface-mounted resistor. A larger spacing is critical with regard to the mechanical stability of the surface-mounted resistor, for example, with regard to vibration-induced loads.

[0023] To protect against environmental influences, additional protective layers may be provided on the resistive element or on other features of the surface-mounted resistor; these may be, for example, glass- or epoxy-based protective layers.

[0024] In another possible embodiment of the surface-mount resistor, the first electrically conductive interconnect is formed by soft soldering with a solder having a melting point ≥ 245 °C, hard soldering, press sintering, silver sintering, or diffusion soldering. The second electrically conductive interconnect is formed via a reflow soldering process. In particular, it can also be provided that the second electrically conductive interconnect has a melting point ≥ 210 °C.

[0025] This design variant is particularly suitable for reflow soldering the surface-mount resistor to the surface of a base element, as the first electrically conductive bonding material is formed in such a way that it has a significantly higher melting point than typical reflow solders, which in this case form the second electrically conductive bonding material. Common reflow solders are, for example, tin-silver-copper ("SAC") solders, which have a melting point in the range of approximately 215–220°C. Soft solders with a melting point ≥ 245°C are, for example, those based on tin-antimony (Sn-Sb). In the case of silver sintering, the melting point of the first electrically conductive bonding material would be around 961°C. One advantage of silver sintering is that it is technically inexpensive to implement.

[0026] Another advantage of this design variant is that it is particularly suitable for the use of high-melting-point soft solders to form the second electrically conductive connecting material.

[0027] In another possible embodiment of the surface-mount resistor, the first electrically conductive interconnect is formed by compression molding or silver sintering, and the electrodes are multilayered. The electrodes comprise an electrically conductive core layer, a diffusion barrier layer (advantageously made of nickel) attached to the electrically conductive core layer, and a silver layer attached to the diffusion barrier layer. The silver layer can be formed only in the contact area with the first electrically conductive interconnect or it can extend over larger areas of the electrode.

[0028] One advantage of the silver layer is its particularly good compatibility with silver sintering. A gold layer can also be used as an alternative to the silver layer.

[0029] Regardless of whether press sintering or silver sintering is used, applying a diffusion barrier layer or a protective layer against environmental influences to the core layer of the electrode can be advantageous. The electrically conductive core layer of the electrode can also be made of various metals or metal alloys, for example, copper and copper alloys, aluminum and aluminum alloys, or silver and silver alloys. Other electrically conductive materials known to those skilled in the art are also conceivable.

[0030] In another possible embodiment of the surface-mounted resistor, the melting point, measured in °C, of ​​the first electrically conductive connecting material is at least twice as high, and in particular advantageously three or four times as high, as the melting point of the second electrically conductive connecting material.

[0031] Such a large difference in the melting points of the first and second electrically conductive joining materials can be advantageous with regard to the reflow soldering of the second electrically conductive joining material, as temperature-related effects, such as softening or even melting of the first electrically conductive joining material, or diffusion-related phenomena are reduced or prevented.

[0032] The use of reflow soldering for surface-mounted components or assemblies can be made more difficult by the fact that other soft solder joints may already be necessary for the production of the components or assemblies, which may melt or be negatively affected by the necessary heating during reflow soldering, for example by an excessively high homologous temperature during reflow soldering and the associated undesirable effects, such as diffusion-related effects.

[0033] Even at high operating temperatures of the surface-mount resistor, such a large difference in melting points can be advantageous, since the first electrically conductive interconnect material, due to its connection and general proximity to the resistive element, is exposed to significantly higher temperature loads than the second electrically conductive interconnect material. Therefore, a high melting point of the first electrically conductive interconnect material compared to the second can also be very beneficial, as the homologous temperature of the first electrically conductive interconnect material is considerably lower during operation or reflow soldering. For clarity, however, it should be noted that the homologous temperature is calculated in Kelvin and not in °C.This can be particularly important with regard to additional mechanical stresses, such as vibration loads, during operation. A low homologous temperature can reduce the influence of thermal, diffusion-related, or thermomechanical effects, such as creep.

[0034] In another possible embodiment of the surface-mounted resistor, the end of the electrode's connecting segment and the connecting section are in blunt contact with each other.

[0035] For example, the connecting segment or its end and the surface of the base element can also be arranged at right angles to each other. Right angles here are defined as angles between 85° and 95°.

[0036] The advantage of a butt joint or butt solder joint is that visual inspection of the forming solder joint or solder meniscus is easily possible. Simple quality control can be essential for the use of surface-mount resistors at high operating temperatures and / or high mechanical loads, in order to reduce the probability of failure during operation.

[0037] In another possible embodiment of the surface-mounted resistor, the electrical contacts each also include a lateral contact section that is electrically connected to the respective electrical contact. The respective lateral contact sections are arranged on opposite lateral surfaces of the substrate. It is provided that the contact segment of the respective electrode and the respective lateral contact section run exclusively parallel and are connected by means of the first electrically conductive connecting material.

[0038] In this embodiment, the connecting segment of the electrode could run parallel to the surface of the base element or to the connecting sections, and a large contact area would be available, which can be advantageous, for example, under high mechanical loads during operation.

[0039] In another possible embodiment of the surface-mount resistor, the electrical contacts each also include a second contact section, which is arranged opposite the electrical contact on the second main surface of the substrate and is connected to it via a through-hole. The contact segments of the electrodes are connected to each of the second contact sections by means of a first electrically conductive connecting material.

[0040] In another possible embodiment of the surface-mounted resistor, a support material is arranged between the substrate and the base element. It is thus located in the area of ​​the gap between the substrate and the base element. In particular, it can be provided that this support material is arranged between one of the main surfaces of the substrate and the electrodes, or between one of the main surfaces of the substrate and the base element.

[0041] The introduction of such a support material can be advantageous in the case of particularly high mechanical loads during operation.

[0042] In another possible embodiment of the surface-mounted resistor, the resistance element has a nominal resistance of 0.1 ohms to 1,000,000 ohms, in particular of 10 ohms to 10,000 ohms.

[0043] In another possible embodiment of the surface-mounted resistor, the resistive element has a nominal voltage of 3 volts to 2500 volts, in particular of 10 volts to 2000 volts, and comprises a nominal power of at least 3 watts, in particular of at least 8 watts.

[0044] In another possible embodiment of the surface-mounted resistor, the surface-mounted resistor is suitable for a maximum operating temperature of the resistance element of 400 °C.

[0045] It should be noted that this is the maximum operating temperature of the resistive element itself. Other components and features of the surface-mount resistor therefore exhibit correspondingly lower temperatures, depending on their thermal conductivity and the ambient conditions, even at the resistive element's maximum operating temperature of 400°C. Nevertheless, this also places specific demands on the other components and features. For example, it is advantageous if the first electrically conductive connecting material in this case has a high melting point, such as that produced by silver sintering, where the connecting material has a melting point of approximately 961°C.

[0046] In another possible embodiment of the surface-mounted resistor, the resistor is also suitable for a vibration load of 80 G and a maximum operating temperature of 400 °C. These operating conditions place corresponding demands on the temperature resistance and thermal stability of all features of the surface-mounted resistor.

[0047] In another possible embodiment of the surface-mounted resistor, the first electrically conductive connecting material has a shear strength of at least 10 N / mm² at a temperature of 260°C, advantageously at least 20 N / mm².

[0048] The shear strength ("Die shear strength") is determined according to ÖVE / ÖNORM EN 60749-19.

[0049] This can be particularly advantageous in the case of high thermomechanical stresses, for example when high operating temperatures occur together with mechanical stress.

[0050] Inverter intermediate circuit of a vehicle, in particular an electric motor vehicle, comprising a surface-mounted resistor according to one of claims 1 to 12, or according to one of the embodiments, as a discharge or pre-charge resistor.

[0051] One possible method variant for manufacturing a surface-mounted resistor according to one of claims 1 to 13 or one of the embodiments comprises the following method steps. a. Providing an insulating substrate, wherein a resistive element is arranged on the first main surface and an electrical contact is arranged at each of the two ends of the resistive element, and wherein each electrical contact has an electrode. b. Arranging a contacting segment of the electrode to the electrical contacts and forming the connection by the first electrically conductive connecting material. c. Providing a base element on whose surface two spaced-apart electrical connection sections are arranged. d. Arranging a connecting segment of the electrodes to the connecting sections of the base element such that the surface-mounted resistor and the base element are spaced apart from each other, and forming the connection by the second electrically conductive connecting material.

[0052] One possible method variant for manufacturing a surface-mounted resistor according to one of claims 1 to 13 or one of the embodiments comprises the following method steps: a. Providing an insulating, preferably plate-shaped, substrate comprising a first and second main surface, wherein the first and second main surfaces of the substrate are spaced apart by a thickness of the substrate, as well as lateral surfaces. b. Arranging the electrical contacts on the first main surface of the substrate by applying a paste, preferably by screen printing, and subsequent heat treatment. c. Arranging the resistive element on the first main surface of the substrate such that it abuts or overlaps the electrical contacts, preferably by printing a paste and subsequent heat treatment. d. Arranging the contacting segments of the electrode against the electrical contacts and forming the connection by the first electrically conductive connecting material. e.Providing a base element on whose surface two spaced-apart electrical connection sections are arranged. Arranging the connection segments of the electrodes to the connection sections of the base element such that the surface-mounted resistor and the base element are spaced apart, and forming the connection by means of the second electrically conductive connecting material.

[0053] The heat treatment of the paste for arranging the electrical contacts or for arranging the resistance element can, in particular, involve sintering.

[0054] One possible design variant for the production of a surface-mounted resistor further includes the formation of the connection through the first electrically conductive connecting material via press or silver sintering and the formation of the connection through the second electrically conductive connecting material via reflow soldering.

[0055] For optimal results in press or silver sintering, it is advantageous if the sintering temperature is above 230°C, particularly above 250°C, and the sintering pressure is greater than 10 MPa, particularly greater than 15 MPa, and the sintering process takes more than 2 minutes, particularly more than 5 minutes. The production of an electrically conductive bonding material with less than 25% residual porosity and a Young's modulus of more than 30 GPa at 25°C is advantageous. Pressureless sintering processes are also conceivable. This combination is particularly advantageous for applications with high mechanical loads.

[0056] The invention is explained below by way of example with reference to schematic drawings in various possible, non-limiting embodiments. The drawings show: Fig. 1 a schematic view of a possible embodiment of a surface-mounted resistor according to the invention. Fig. 2another schematic view of a possible embodiment of a surface-mounted resistor according to the invention. Fig. 3 another schematic view of a possible embodiment of a surface-mounted resistor according to the invention. Fig. 4 another schematic view of a possible embodiment of a surface-mounted resistor according to the invention. Fig. 5 another schematic view of a possible embodiment of a surface-mounted resistor according to the invention.

[0057] The disclosure of publication EP4374395A1 is hereby fully incorporated into the disclosure of the present application, in particular with regard to details concerning the resistance, especially parameters, manufacturing variants, materials used and area of ​​application or purpose.

[0058] Figure 1Figure 1 shows a surface-mounted resistor (1) according to the invention. The surface-mounted resistor (1) comprises a rectangular substrate (2) with a first (3) and a second (4) main surface, which are spaced apart from each other by a thickness (5) of the substrate (2), as well as lateral surfaces (6). A resistive element (7), advantageously a thick-film resistor, is arranged on the first main surface (3) of the substrate. An electrical contact (8) is arranged at each of two ends of the resistive element (7) and partially overlapping it. In addition, a pair of electrodes (9) is provided, each comprising a contacting segment (10) and a connecting segment (11), which are arranged in an L-shape relative to each other. It should be noted that the term L-shape in the context of this disclosure does not necessarily mean a 90° angle between the contacting segment (10) and the connecting segment (11).Instead, L-shaped can also refer to other acute or obtuse angles, particularly between 45° and 130°. Furthermore, a base element (12) is included, on whose surface (13) two spaced-apart electrical connection sections (14) are arranged. The base element (12), or rather the surface of the base element (13), is spaced away from the substrate (2) in a thickness direction of the substrate (2). This spacing is defined in . Figure 1 as indicated by (15). Furthermore, the contacting segment (10) of each of the electrodes (9) is connected to each of the electrical contacts (8) by means of a first electrically conductive connecting material (16), and the connecting segment (11) of each of the electrodes (9) is connected to each of the connecting sections (14) of the base element (12) by means of a second electrically conductive connecting material (17). In the case of Fig. 1The connecting segment (11) and the connecting section (14) are in butt contact with each other. The second electrically conductive connecting material (17) can be formed, for example, by reflow soldering. This has the advantage that the resulting connection is easily accessible for optical inspection and the contact surface is well defined. The melting point of the first electrically conductive connecting material is at least 20 °C higher than the melting point of the second electrically conductive connecting material. Furthermore, a protective layer (18) can be provided on the resistive element and / or on other features of the surface-oriented resistor.

[0059] Furthermore, it can be advantageous to have a gap (20) between the lateral surfaces (6) of the substrate (2) and the nearest lateral surface of the electrode (9). This can be particularly important with regard to vibration loads on the surface-mounted resistor. The lateral distance or gap (20) between the lateral surfaces (6) of the substrate (2) and the nearest lateral surface of the electrode (9) can, for example, be in the range of 0.2 mm to 1 mm.

[0060] In the case of Figure 1 The first principal surface (3) of the surface-mounted resistor (1) is the principal surface of the substrate (2) facing away from the surface (13) of the base element (12). However, arrangements are also conceivable in which the first principal surface (2) is the principal surface of the substrate (2) facing the surface (13) of the base element (12), see [reference]. Figure 2 .

[0061] Figure 3Figure 1 shows a variant embodiment of the surface-mounted resistor (1) in which the electrical contacts (8) each also include lateral contact sections (19). The respective lateral contact sections (19) are arranged on opposite lateral surfaces (6) of the substrate (2). Figure 3 The contacting segments (10) of the respective electrodes (9) and the respective lateral contact sections (19) run exclusively parallel to each other and are connected by means of the first electrically conductive connecting material (16). In the Figure 3In the illustrated embodiment, the connecting segment (11) of the electrode runs parallel to the surface (13) of the base element (12) or to the connecting sections (14). This allows, for example, a large contact area to be provided, which can be advantageous under high mechanical loads. However, it is also possible for the connecting segment (11) of the electrode to run at an acute angle to the surface (13) of the base element (12) or to the connecting sections (14); this is, for example, Figure 4 shown. This variant has the advantage of a large contact area and higher mechanical stability of the electrode.

[0062] Figure 5Figure 1 shows an embodiment of the surface-mounted resistor (1) in which the electrical contacts (8) each also include a second contact section (21) which is arranged opposite the respective electrical contact (8) on the second main surface (4) of the substrate (2) and is connected to it via a through-hole (22), and wherein the contacting segments (10) of the electrodes (9) are connected to each of the second contact sections (21) by means of a first electrically conductive connecting material (16).

Claims

1. A surface-mounted resistor comprising an insulating, preferably plate-shaped, substrate, having a first and second main surface, wherein the first and second main surfaces of the substrate are spaced apart from each other by a thickness of the substrate, and lateral surfaces, wherein a resistive element, preferably a thick-film resistor, is arranged on the first main surface, and wherein an electrical contact is arranged at each of two ends of the resistive element, preferably partially overlapping it, and wherein each electrical contact comprises an electrode, and wherein the electrodes each comprise a contacting segment and a connecting segment, the contacting segment and the connecting segment being arranged in an L-shape relative to each other, and wherein a base element is provided, on the surface of which two spaced-apartelectrical connection sections are arranged and wherein the base element is spaced away from the substrate and wherein the contacting segment of each of the electrodes is connected to each of the electrical contacts by means of a first electrically conductive connecting material, and wherein the connecting segment of each of the electrodes is connected to each of the connection sections of the base element by means of a second electrically conductive connecting material, , characterized by the fact that the melting point of the first electrically conductive compound material is at least 20 °C higher than the melting point of the second electrically conductive compound material.

2. Surface-mounted resistor according to claim 1, characterized by the fact thatThe first electrically conductive joining material is formed by soft soldering with a solder having a melting point ≥ 245 °C, hard soldering, press or silver sintering, or diffusion soldering, and the second electrically conductive joining material is formed via a reflow soldering process.

3. Surface-mounted resistor according to claim 1 or 2, characterized by the fact that the first electrically conductive connecting material is formed by means of press or silver sintering and the electrodes are multilayered and comprise an electrically conductive core layer, a diffusion barrier layer arranged on the electrically conductive core layer, and a silver layer arranged on the diffusion barrier layer in the contact area with the first electrically conductive connecting material.

4. Surface-mounted resistor according to any one of the preceding claims, characterized by the fact thatThe melting point, measured in °C, of ​​the first electrically conductive compound material is at least twice as high, and in particular advantageously three or four times as high, as the melting point of the second electrically conductive compound material.

5. Surface-mounted resistor according to any one of the preceding claims, characterized by the fact that the end of the electrode's connecting segment and the connecting section are in blunt contact with each other.

6. Surface-mounted resistor according to any one of claims 1 to 4, characterized by the fact thatThe electrical contacts each also include a lateral contact section which is in electrical communication with the electrical contact, and wherein the respective lateral contact sections are arranged on opposite lateral surfaces of the substrate, wherein the contacting segment of the respective electrode and the respective lateral contact section run exclusively parallel and are connected by means of the first electrically conductive connecting material.

7. Surface-mounted resistor according to any one of claims 1 to 5, characterized by the fact thatthe electrical contacts each also comprise a second contact section which is arranged opposite the electrical contact on the second main surface of the substrate and is connected to it via a through-hole, and wherein the contacting segments of the electrodes are connected to each of the second contact sections by means of a first electrically conductive connecting material.

8. Surface-mounted resistor according to any one of the preceding claims, characterized by the fact that a support material is arranged between the substrate and the base element, wherein this is arranged in particular between one of the main surfaces of the substrate and the electrodes or between one of the main surfaces of the substrate and the base element.

9. Surface-mounted resistor according to any one of the preceding claims, characterized by the fact thatThe resistance element has a nominal resistance of 0.1 ohms to 1,000,000 ohms, in particular of 10 ohms to 10,000 ohms.

10. Surface-mounted resistor according to any one of the preceding claims, characterized by the fact that the resistive element has a nominal voltage of 3 volts to 2500 volts, in particular of 10 volts to 2000 volts, and comprises a nominal power of at least 3 watts, in particular of at least 8 watts.

11. Surface-mounted resistor according to any one of the preceding claims, characterized by the fact that The surface-mounted resistor is suitable for a maximum operating temperature of the resistance element of 400 °C.

12. Surface-mounted resistor according to any one of the preceding claims, characterized by the fact that the first electrically conductive bonding material to achieve a shear strength of at least 10 N / mm at a temperature of 260°C 2 , preferably of at least 20 N / mm 2 exhibits.

13. Inverter intermediate circuit of a vehicle, in particular an electric motor vehicle, comprising a surface-mounted resistor according to one of claims 1 to 12 as a discharge or pre-charge resistor.

14. Method for manufacturing a surface-mounted resistor according to any one of claims 1 to 13, characterized by the fact thatThe method comprises the following steps: a. Providing an insulating substrate, wherein a resistive element is arranged on the first main surface and wherein an electrical contact is arranged at each of two ends of the resistive element, and wherein an electrode is provided at each electrical contact. b. Arranging a contacting segment of the electrode to the electrical contacts and forming the connection by means of the first electrically conductive connecting material. c. Providing a base element on whose surface two spaced-apart electrical connection sections are arranged. d. Arranging a connecting segment of the electrodes to the connecting sections of the base element such that the surface-mounted resistor and the base element are spaced apart from each other, and forming the connection by means of the second electrically conductive connecting material.

15. Method for manufacturing a surface-mounted resistor according to claims 3 and 14, characterized by the fact that The formation of the connection is achieved through the first electrically conductive joining material via press or silver sintering, and the formation of the connection through the second electrically conductive joining material is achieved via reflow soldering.

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