Circuit breaker unit

Abstract

The present invention relates to a power switch unit comprising a power switch element, a printed circuit board unit, wherein a sink of the power switch element is arranged on the printed circuit board unit by means of a solder joint array in an energy and / or signal-conducting manner in order to conduct both electrical energy and thermal energy from the power switch element (12) to the printed circuit board unit, wherein the power switch unit is configured to measure a resistance of two solder joints of the solder joint array by means of a two-wire measurement in order to determine a state of the two solder joints during operation of the power switch element.

Description

State of the art

[0001] The present invention relates to a circuit breaker unit and a vehicle.

[0002] Currently, a wide variety of solutions exist for the design of circuit breaker units in the automotive sector. Due to the increasing number of circuit breaker units in vehicles driven by electromobility and the heightened performance and quality requirements, the demand for innovative and robust circuit breaker units is constantly rising.

[0003] The continuous reduction of weight in the vehicle sector to reduce fuel consumption, as well as increasing competition, is causing cost pressure, leading to a greater demand for cheaper and more efficient vehicle components.

[0004] Switch units are known from WO 2024 094430 A1 and DE 10 2009 019 774 B4. Disclosure of the invention

[0005] The circuit breaker unit according to the invention, with the features of claim 1, has the advantage over known units that it enables condition monitoring of power elements during active operation, such as circuit breaker elements, and thus allows the condition of a circuit breaker unit to be determined. In particular, two-wire measurement allows cracks in drain solder joints of the solder joint array to be detected despite current flow in the circuit breaker element, especially a MOSFET, thereby enabling condition monitoring and thus health monitoring. As a consequence of this monitoring, potential failures of electronic systems can be sustainably avoided through timely repair or replacement of the components in question.

[0006] This is achieved according to the invention by the fact that the power switch unit comprises a power switch element and a printed circuit board unit, wherein a sink of the power switch element is arranged on the printed circuit board unit by means of a solder joint array in an energy and / or signal-conducting manner in order to conduct both electrical energy and thermal energy from the power switch element to the printed circuit board unit, wherein the power switch unit is configured to measure a resistance of two solder joints of the solder joint array by means of a two-wire measurement in order to determine a state of the two solder joints during operation of the power switch element.

[0007] In other words, the condition of the solder joints can be determined by measuring their resistance and observing changes in this resistance. The resistance can preferably be measured using an electrically inactive but thermally active BGA structure to detect cracks. For example, defective solder joints can be identified by an increase in resistance, particularly when the heat input to other solder joints increases significantly. Thus, the resistance of two solder joints changes when two other solder joints no longer conduct signals and / or energy, and consequently, the thermal input from the power switching element into the printed circuit board assembly increases.

[0008] The dependent claims describe preferred embodiments of the invention.

[0009] Preferably, the two solder joints form a chain, and the power switch unit is configured to measure the chain using two-wire measurement to determine the resistance of the two solder joints. An advantage of this embodiment is that the detection accuracy can be improved by designing a chain, loop, or similar configuration.

[0010] Preferably, the circuit breaker unit is configured to determine the resistance curve of the two solder joints, and is configured to emit a signal indicating a failure of the two solder joints when the curve reaches a predetermined limit. An advantage of this embodiment is that the signal output can indicate to other systems that the condition of the circuit breaker unit may have deteriorated. For example, the resistance curve can be recorded over the number of switching cycles of the circuit breaker element, and the resistance for each pair of solder joints can be determined.

[0011] Preferably, the circuit breaker unit is configured to measure two additional solder joints using a further two-wire measurement in order to determine the condition of the two solder joints and the two additional solder joints during operation of the circuit breaker element. An advantage of this embodiment is that the increased monitoring density allows for a more precise determination of the circuit breaker unit's condition.

[0012] Preferably, the two solder joints and the two additional solder joints are configured to share a ground connection. An advantage of this embodiment is that the component density is increased, thus providing more space for additional components on the printed circuit board layer.

[0013] Preferably, the two solder points and the two additional solder points are arranged on one side of the circuit board assembly facing away from the power switch element and are connected to the power switch element by means of at least three vias through the circuit board assembly. An advantage of this embodiment is that the contact point is arranged on the side facing away from the power switch element and the signals from the power switch element can be tapped via vias.

[0014] Preferably, the two solder joints and the two additional solder joints are connected to the at least three vias by means of conductive traces. An advantage of this embodiment is that thermal changes, which can lead to a change in resistance, can be specifically taken into account in the two-wire measurement by means of the conductive traces and their layout.

[0015] Preferably, the conductor tracks are arranged according to a predetermined pattern. An advantage of this embodiment is that the conductor tracks can be designed according to the predetermined pattern in such a way that very good monitoring of the thermal changes on the circuit board unit can be achieved, thus further refining the determination of the condition of the power switch unit.

[0016] Preferably, the two-wire measurement using the two solder joints is essentially free of energy- and / or signal-carrying signals. An advantage of this embodiment is that the resistance of the two-wire measurement changes based on the temperature. If one solder joint fails, the temperature input increases due to the reduced transmission capacity, leading to a change in resistance. Thus, the condition of the printed circuit board assembly can be determined, particularly without signal tapping or similar methods. "Essentially free of energy- and / or signal-carrying signals" in this context means, in particular, that only the resistance that changes based on a thermal change is measured.

[0017] Another aspect of the invention relates to a vehicle which has a power switch unit as described above and below. Brief description of the drawings

[0018] Exemplary embodiments of the invention are described in detail below with reference to the accompanying drawings. The drawing shows: Fig. 1 to 5 a circuit breaker unit according to one embodiment, Fig. 6 a diagram illustrating the operation of the circuit breaker unit according to one embodiment, Fig. 7 a circuit diagram to illustrate the operation of the circuit breaker unit according to one embodiment, Fig. 8 a diagram illustrating the operation of the circuit breaker unit according to one embodiment, Fig. 9 a vehicle according to an embodiment, and Fig. 10 A diagram illustrating the operation of the circuit breaker unit according to one embodiment. Embodiments of the invention

[0019] Preferably, all identical elements, units and / or steps in all figures are labelled with the same reference symbols.

[0020] Fig. Figure 1 shows a circuit breaker unit 10 according to one embodiment. The circuit breaker unit 10 comprises a circuit breaker element 12 and a printed circuit board unit 14, wherein a recess of the circuit breaker element 12 is arranged on the printed circuit board unit 14 by means of a solder joint array 16 in an energy- and / or signal-conducting manner in order to conduct both electrical energy and thermal energy from the circuit breaker element 12 to the printed circuit board unit 14, wherein the circuit breaker unit 10 is configured to measure a resistance of two solder joints 18 of the solder joint array 16 by means of a two-wire measurement in order to determine the state of the two solder joints 18 during operation of the circuit breaker element 12.

[0021] Fig. Figure 2 shows a circuit breaker unit 10 according to one embodiment. In the Fig. Figure 2 shows a perspective view of the power switch unit 10, which shows a power switch element 12, such as a MOSFET, on the printed circuit board unit 14. Preferably, the printed circuit board unit 14 is arranged on a cooling element 202. Preferably, the power switch element 12 is connected to the printed circuit board unit 14 by means of a solder joint array 16.

[0022] Fig. Figure 3 shows a power switch unit 10 according to one embodiment. The power switch element 12 is arranged on the printed circuit board unit 14 by means of a solder joint array 16. A plurality of solder joints, comprising at least two solder joints 18, are formed between the solder joint array 16 and the printed circuit board unit 14. The power switch unit 10 is configured to measure the resistance of two solder joints 18 of the solder joint array 16 by means of a two-wire measurement in order to determine the state of the two solder joints 18 during operation of the power switch element 12. Preferably, the state of the power switch unit 10 can be determined by the failure and / or thermal change in the printed circuit board unit 14. Preferably, the printed circuit board unit 14 can be arranged on a cooling element 202 by means of a thermally conductive layer 204.

[0023] Fig. Figure 4 shows a circuit breaker unit 10 according to one embodiment. Fig. Figure 4 shows a sectional view of the circuit breaker unit 10. Here, the circuit breaker element 12 is preferably attached to the printed circuit board unit 14 by means of the solder joint array 16. Two solder joints 18 are provided between the solder joint array 16 and the printed circuit board unit 14. Preferably, the solder joints 18 can be routed to different layers of the printed circuit board unit 14 by means of vias 24. Preferably, the two-wire measurement of the two solder joints 18 and / or of two further solder joints 20 can be carried out on a side 22 facing away from the circuit breaker element 12.

[0024] Fig. Figure 5 shows a circuit breaker unit 10 according to one embodiment. Fig. Figure 5 shows a detailed view of the contacting of the solder point array 16 on the printed circuit board unit 14 by means of two solder points 18 as well as two further solder points 20.

[0025] Fig. Figure 6 shows a diagram 210 illustrating the operation of the circuit breaker unit 10 according to one embodiment. Diagram 210 has a first axis 212, which represents the thermal resistance. Furthermore, diagram 210 has a second axis 214, which represents the number of switching cycles of the circuit breaker element 12. Diagram 210 shows a first curve 216 of a first solder joint pair, a second curve 218 of a second solder joint pair, a third curve 220 of a third solder joint pair, a fourth curve 222 of a fourth solder joint pair, and a fifth curve 224 of a fifth solder joint pair. As can be seen in diagram 210, the respective curves exceed a limit value, suggesting a selection process, particularly at points 226, 228, 230, and 232. Only curve 224 does not exceed the limit value.

[0026] Fig. Figure 7 shows a circuit diagram 300 according to one embodiment. The circuit diagram 300 has two upper layers 302 and 304, which represent a continuous assembly of the printed circuit board unit 14. A lower layer 306 is also encompassed by the printed circuit board unit 14. In the lower layer 306, there is space for the vias 24 to the solder pads 18, as well as the further solder pads 20, which are connected to the vias 24 by means of conductor tracks 26.

[0027] Fig. Figure 8 shows a diagram 400 illustrating the operation of the circuit breaker unit 10. The circuit breaker unit 10 is switched on, causing an increase in the internal temperature of the circuit breaker element 12. Two-wire measurement can be performed, particularly when the temperature is high. The diagram 400 has a first axis 402, which represents the temperature of the circuit breaker element 12 over time on the second axis 404. Two-wire measurement, or multiple two-wire measurements, can be performed, especially during time intervals 408 where the temperature is high.

[0028] Fig. Figure 9 shows a vehicle 100 according to one embodiment. The vehicle 100 preferably has a circuit breaker unit 10, as described above and below.

[0029] Fig.Figure 10 shows a diagram 500 illustrating the operation of the circuit breaker unit 10 according to one embodiment. The diagram 500 has a first axis 502 and a second axis 504. The first axis 502 shows, in particular, a DC resistance, and the second axis 504 shows the number of switching cycles of the circuit breaker element 12. Furthermore, a first curve 506, a second curve 508, and a third curve 510 are shown. As can be seen in the diagram, the curve 506, which shows the resistance at two solder joints, can exhibit an increased value from point 512 onwards, indicating a failure. A similar phenomenon is shown in the second curve 508, which shows the resistance across two further solder joints, and in the curve 510, which shows a third resistance at a third pair of solder joints.The second and third courses also show points 514 and 516, where the resistance increases sharply and thus indicates a failure. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2024 094430 A1

[0004] DE 10 2009 019 774 B4

[0004]

Images