Power electronic component

Abstract

The invention relates to a power electronic component (10) comprising a circuit carrier (12) on which at least one semiconductor element (16) is arranged and electrically connected via a connecting element (18) at a connection point (20) to an electrical contact element (34). A base element (22) projecting beyond the connection point (20) in a bridge-like manner is arranged and configured with a recess (24) such that a contact surface (26) projecting beyond the connection point (20) is formed by the base element (22).

Description

The invention relates to a power electronic component in a motor vehicle, in particular an inverter and / or a power module. In particular, the invention relates to a power electronic component, in particular an inverter and / or a power module for a motor vehicle that is at least partially electrically powered. A power electronic component is understood to be, in particular, an element formed from a circuit carrier, especially a substrate, which has at least two load contacts, at least one semiconductor chip, and at least one contact element. The contact element can be a signal contact or a load contact. The at least one semiconductor chip is connected to the at least one signal contact via at least one electrically conductive connecting element. The circuit carrier has at least three layers, with a middle layer being an electrically insulating layer and the bottom and top layers each being formed by at least one electrically conductive metallic layer. Optionally, additional layers, in particular metallic layers, may be applied to one or more of these layers to fully or partially protect surfaces and / or to enable further joining processes. Silver, nickel, or gold layers are specifically mentioned in this regard. US patent 2013 / 0244490 A1 discloses a surface-mount electrical connection that forms an interface between solder balls on a BGA device (referred to as a "ball grid array") and a printed circuit board. No connection to power electronics is apparent, and nothing is disclosed regarding the design of connecting elements between a semiconductor element and a contact element. DE 10 2020 116 787 A1 discloses a semiconductor device and a semiconductor device manufacturing method. A section of one side of an external interconnect, which is located in an insertion hole in a cover plate, has an inclined surface inclined towards the external interconnect relative to the direction in which the external interconnect is inserted into the insertion hole. When this external interconnect is inserted into the insertion hole, it is guided perpendicular to the main plane of the ceramic printed circuit board through the inclined surface of a guide section, and the cover plate is secured. Consequently, the external interconnect, which protrudes from the cover plate of a casing, is secured in the correct position on a printed circuit board. German patent application DE 10 2015 210 603 A1 describes a method for manufacturing a semiconductor device. The ingress of resin into a cylindrical electrode can be prevented without excessively increasing the number of parts and without unnecessarily damaging components. For this purpose, a semiconductor chip and a cylindrical electrode are mounted on a main surface of the substrate. The substrate, the semiconductor chip, and the cylindrical electrode are sealed with resin material, such that the cylindrical electrode has one end mounted to the substrate and another opposite end that is at least partially exposed. After the sealing step, an opening is formed extending from the other end of the cylindrical electrode to a cavity within the electrode. Before this opening is formed, the other end of the cylindrical electrode is closed. The power semiconductor module of DE 10 2009 055 691 A1 comprises the following: a circuit substrate; power semiconductor elements connected to element mounting areas of the wiring pattern on the circuit substrate; at least one cylindrical connection area for the external connection, which is connected to the wiring pattern; circuit manufacturing devices for establishing an electrical connection between areas where an electrical connection is required; and spray resin for enclosing or encapsulating these components. The cylindrical connection area for the external connection is a metal cylinder and has a gel-filled opening. The power semiconductor device shown in DE 10 2009 042 399 A1 comprises a substrate having a circuit pattern on its upper surface. A semiconductor element is attached to the circuit pattern. A cylindrical electrode has an upper end at one end and is mounted upright on the substrate such that the other end of the electrode is attached to the circuit pattern. The cylindrical electrode has one section with a larger inner diameter than the other section. A resin coating covers the substrate, the semiconductor element, and the cylindrical electrode such that a rear surface of the substrate and one end of the cylindrical electrode are exposed to air. The locking element of US 2022 / 0108939A1 is used to connect electronic, micromechanical, and / or microelectromechanical components, particularly for controlling the drive system of an electric vehicle. The locking element consists of a perforated body with a first and a second end, and an axial recess for the precise insertion of a connecting pin. A first flange projects transversely from the perforated body at the first end, and a second flange at the second end. The first flange has a larger surface area than the second and is designed for ultrasonic soldering to a conductive carrier plate to form a power module. A challenge in the design and manufacturing of power electronic components is often the high degree of integration and the resulting limited installation space. Additionally, substrate area is often—after the semiconductors—one of the most significant material cost factors, creating a need to design the power electronic component in the most space-saving way possible. This approach is particularly challenged by the requirement to maintain distances between electrical connections and nearby semiconductor elements, for example, to allow tool access. Therefore, the following designs for semiconductor elements are particularly common in practice. Firstly, it is possible to maintain the necessary distances between the substrate surfaces through appropriate design and planning. However, the disadvantage of this is that the substrate surface area increases substantially, resulting in additional costs for the substrate, optional encapsulation with a potting compound, and cooling. Furthermore, it is known from practical experience to provide an additional substrate layer in the power electronic component, thus generating additional space. The disadvantage of this solution is that, on the one hand, it is highly complex to manufacture, and on the other hand, the additional layer also needs to be cooled, resulting in increased costs. Furthermore, it is conceivable to reduce the thickness of the contact elements used, especially wire thicknesses, so that less area is required for contacting. This, and especially the use of thinner wires, also reduces the current-carrying capacity, meaning that only lower currents can be transmitted. This limits the range of applications for such components. The invention is based on the objective of providing a power electronic component according to the preamble of claim 1 that requires as little installation space as possible on a circuit carrier. The problem is solved according to the invention by the features of the independent claims. Further practical embodiments and advantages of the invention are described in connection with the dependent claims. The power electronic component according to the invention, in particular an inverter and / or a power module, comprises a circuit carrier. The circuit carrier is, in particular, a substrate. At least one semiconductor element is arranged on the circuit carrier. The semiconductor element can be, for example, transistors, in particular MOSFETs, and / or power diodes and / or temperature sensors. The semiconductor device is electrically connected to an electrical contact element at a connection point via a connecting element. The connecting element can be, for example, a bond wire or ribbon, but this is not limited to this. Preferably, the contact element is a signal or load contact. Load contacts are typically used to transmit high electrical currents and voltages within the power electronic component and to connect to other (external power) components. Signal contacts, on the other hand, typically transmit control, monitoring, and measurement signals that are necessary for the safe and efficient operation of the power electronic component. A base element projecting over the connection point in a bridge-like manner is arranged and configured with a recess above the connection surface such that a contact surface projecting over the connection point is formed by the base element. In this context, the term "bridge-like projecting base element" can be understood to mean that the base element has a gap on its underside due to the recess, in which the connection point is located and where – in the assembled state of the base element – ​​the electrical connection between the semiconductor element and the electrical contact element takes place. For example, the base element can be joined to the substrate, in particular by ultrasonic welding, sintering, or soldering. Furthermore, the base element preferably comprises an electrically conductive material, for example, copper or aluminum. The aforementioned arrangement advantageously enables a configuration on the power electronic component in which the connecting element overlaps the outgoing interface (the base element) on one side. This allows for more efficient use of the space required for the connection point of the connecting element compared to the prior art, resulting in a reduced space requirement. According to one practical embodiment, the base element comprises at least two sub-elements. In a state where the base element is arranged on the circuit carrier, one sub-element, located directly at the connection point, is solid, and another sub-element, arranged on top of this sub-element, has a recess. Due to their spatial arrangement, the solid sub-element is subsequently referred to as the lower sub-element, and the sub-element arranged on top of it as the upper sub-element. Preferably, the connecting element is arranged on the lower sub-element and electrically connects it to the semiconductor device. As already mentioned, the upper sub-element extends beyond the connecting element in a bridge-like fashion through the recess. The advantage of this embodiment lies in the fact that attaching the connecting element to the sub-element located directly at the connection point allows for a higher position of the connecting element, thus enabling the reliable spanning of additional components of the power electronic component. Furthermore, this increases the insulation distance, allowing the electronic component components to be installed closer together, thereby saving space. In addition, the upper sub-element of the base element can be adapted to a wide variety of outgoing interfaces with minimal effort. In a practical embodiment, the at least two sub-elements differ in their material. Specifically, this means that the first sub-element comprises a first material and the second sub-element a second material, with the first and second materials being different. For example, the lower sub-element may be made of or comprise aluminum, while the upper sub-element may be made of or comprise copper. Using different materials for the two sub-elements allows for adaptation to various application scenarios and also offers advantages with regard to costs and / or manufacturing requirements. For example, the lower sub-element can be glued to the connection point, while the upper sub-element is attached by friction welding or laser welding. Furthermore, it can be advantageous if, according to a practical embodiment, the base element has an alignment element for correctly aligning the connecting element at the connection point. Correctly aligning the connecting element has the advantage of establishing a precise connection with the semiconductor elements. In particular, this avoids mechanical stresses, which increases the service life of the electrical connection. According to an alternative practical embodiment, the base element is monolithic. Preferably, the monolithic base element also has the aforementioned recess. For the purposes of the invention, "monolithic" means that the base element is manufactured in one piece, i.e., "as a single casting." This embodiment has the advantage that only one base element needs to be positioned at the connection point. This results in a simpler and more cost-effective solution. According to a practical embodiment, the base element has several base sections, each with a recess, arranged one above the other in a vertical orientation of the base element. To form the multiple base sections, either several sub-elements of the type already mentioned above can be arranged one above the other, or the monolithic base element mentioned above can have several recesses. This embodiment allows several connecting elements to be attached to a single base element and thus enables the parallel control of two or more semiconductor elements, thereby saving further installation space. In another practical embodiment, the base element has a coating and / or undergoes a processing procedure. For the purposes of this invention, "processing procedure" can be understood as the application of specific manufacturing or processing methods that modify the component's material to achieve the desired mechanical, thermal, or electrical properties in order to fulfill its function in the final product and thus ensure higher performance, reliability, and durability of the components. For example, the aluminum base element can be further processed, e.g., nickel-plated or coated, in order to be subsequently bonded to other components, and in particular to or at the connection point and / or to the other base element. It can also be advantageous if the recess is designed as a blind hole. In this case, the recess is not a through hole, but rather a contoured opening. This allows for a larger contact area during force-intensive joining processes. Furthermore, the blind hole design enables higher strength due to less material removal and therefore offers advantages with regard to mechanical stress, vibrations, and subsequent processes. To simplify the electrical contact between the socket element and the semiconductor element, the connecting element is designed as a contact tab and pre-mounted on the socket element. In other words, the connecting element, designed as a contact tab, is already attached to the socket element before it is mounted on the connection point, i.e., on the power electronic component. Thus, only one-sided contact, namely with the semiconductor element, is required, which simplifies the contacting process. Furthermore, the socket element with the contact tab can also be manufactured monolithically. A socket-side connection of the connecting element is therefore unnecessary. Alternatively, the connecting element can also be designed as a pre-assembled contact strip. To ensure, in particular, mechanical protection of the power electronic component and preferably the electrical contacts, at least the connection point is potted with a potting compound. Preferably, the entire power electronic component is potted with a potting compound that serves as an encapsulation. For example, the potting compound may be an epoxy resin and / or a silicone resin and / or a thermoplastic potting compound. Furthermore, a method for electrically connecting a semiconductor component to an electrical contact element is described, the method comprising the following steps: a) providing a power electronic component comprising a circuit carrier on which at least one semiconductor element is arranged; b) electrically contacting a connecting element at a connection point of the circuit carrier and optionally electrically contacting the connecting element with the semiconductor element; c) arranging a socket element on the circuit carrier such that a recess of the socket element projects over the connection point in a bridge-like manner. Furthermore, an alternative method for electrically connecting a semiconductor component to an electrical contact element is to be described, the method comprising the following steps: a) providing a power electronic component comprising a circuit carrier on which at least one semiconductor element is arranged; b) arranging a sub-element of a socket element on the circuit carrier; c) electrically contacting a connecting element at a connection point of the sub-element and optionally electrically contacting the connecting element with the semiconductor element; d) arranging another sub-element of the socket element on the sub-element such that a recess of the further sub-element projects over the connection point in a bridge-like manner. Further practical embodiments of the invention are described below in connection with the drawings. The drawings show: Fig. 1 a schematic perspective view of a power electronic component according to the invention on which a semiconductor element is arranged and electrically connected to an electrical contact element via a connecting element at a connection point and a socket element; Figs. 2a-d a schematic view of the steps for arranging and electrically connecting the socket element on the power electronic component; Fig. 3 a schematic perspective view of the power electronic component according to Fig. 1, which is potted with a potting compound; and Fig. 4 a schematic perspective view of a section of the power electronic component according to Fig. 1 on which an alternative socket element is arranged. In the figures, identical or equivalent components are always represented with the same reference symbols. Figure 1 shows a schematic and perspective view of a power electronic component 10 according to the invention. The power electronic component 10 comprises a circuit carrier 12, which is preferably a substrate. Furthermore, the power electronic component 10 has an electrically conductive substrate layer 14 arranged on the circuit carrier 12. A semiconductor element 16 is arranged on the circuit carrier 12, and in particular on the electrically conductive substrate layer 14. In the illustrated embodiment, the circuit carrier 12 has four semiconductor elements 16. The semiconductor elements 16 can be, for example, transistors or temperature sensors, but this is not a limitation. Furthermore, each semiconductor element 16 is electrically connected to an electrical contact element 34 at a connection point 20 (see Fig. 2c) via a respective connecting element 18. In the present embodiment, the connecting element 18 is a bond wire. Additionally, the power electronic component 10 has electrical load contacts 28, which, however, will not be discussed further below due to their lack of relevance to the invention. Furthermore, the power electronic component 10 has a base element 22 with a recess 24 that projects beyond the connection point 20 in a bridge-like manner. The base element 22 is arranged and configured on the circuit carrier 12 such that a contact surface 26 projecting beyond the connection point 20 is formed by the base element 22. The base element 22 has two sub-elements 30a and 30b, a lower sub-element 30a and an upper sub-element 30b, each viewed in a vertical orientation V. In the illustrated embodiment, the recess 24 is formed in the upper sub-element 30b. The bridge-like design of the base element 22, in particular the upper sub-element 30b, enables a space-saving construction and contacting of the semiconductor element 16 via the base element 22. The bridge-like design of at least the upper sub-element 30b allows the connection point 20 to be reliably bridged and a contact surface 26 to be realized on the upper side of the base element 22, for example for external connections. A contact next to the base element 22, as known from the prior art, can be avoided. At the same time, however, specified and / or required insulation distances are maintained. Figures 2a-2d show the basic arrangement process of the base element 22 described in Figure 1. Figure 2a shows the unoccupied space of the electrically conductive substrate layer 14 on the circuit carrier 12. The base element 22, in particular the lower part 30a of the base element 22, is then arranged on this, as shown in Fig. 2b. This can be done, for example, by ultrasonic welding, sintering or brazing. Subsequently, as shown in Fig. 2c, the connecting element 18 is electrically bonded to the connection point 20 on the upper side of the lower sub-element 30a. Since the connecting element 18 is preferably designed as a bonding wire, this step can be carried out, for example, using a bonding tool. In the embodiment shown in Figs. 2a-2d, the lower sub-element 30a is the electrical contact element 34. After the electrical connection of the connecting element 18, an upper sub-element 30b of the base element 22 is positioned on the upper side of the lower sub-element 30a of the base element 22. The upper sub-element 30b has the recess 24, which extends like a bridge over the connection point 20. The upper side of the upper sub-element 30b serves as a contact surface 26 for an external connection. Figure 3 shows a perspective view of the power electronic component 10 shown in Figure 1. In Figure 3, however, the power electronic component 10 is completely encased in a potting compound 32 to protect the electrical and / or electronic components of the circuit carrier 12. To allow for external connection, only the load contacts 28 and the contact surfaces 26 of the socket elements 22 protrude from or are free of the potting compound 32. An alternative embodiment of the base element 22 is shown in a schematic perspective view in Fig. 4. The embodiment of the power electronic component 10 shown here essentially corresponds to the embodiment shown in Fig. 1, so that with regard to the other components, reference is made to the descriptions in Fig. 1. The essential difference of the base element 22 is that it has a monolithic structure. This means that the base element 22 does not have two sub-elements 30a, 30b as shown in the embodiment in Fig. 1. Rather, the base element 22 is formed in one piece according to Fig. 4. This alternative embodiment has proven advantageous with regard to simpler manufacturing of the base element 22 as well as simplified assembly or arrangement of the base element 22 on the electrically conductive substrate layer 14. In the embodiment shown in Fig. 4, the electrical contact element 34 is formed by the electrically conductive substrate layer 14, since the connecting element 18 is directly electrically connected to the electrically conductive substrate layer 14. The features of the invention disclosed in the present description, the drawings, and the claims can be essential for realizing the invention in its various embodiments, both individually and in any combination. The invention can be varied within the scope of the claims and taking into account the knowledge of the person skilled in the art. Reference symbol list 10 Power electronic component 12 Circuit carrier 14 Electrically conductive substrate layer 16 Semiconductor elements 18 Connecting element 20 Connection point 22 Base element 24 Recess 26 Contact surface 28 Load contacts 30a Lower sub-element 30b Upper sub-element 32 Potting compound 34 Electrical contact element V Vertical alignment

Claims

Power electronic component (10) comprising a circuit carrier (12) on which at least one semiconductor element (16) is arranged, which is electrically connected via a connecting element (18) at a connection point (20) to an electrical contact element (34), characterized in that a base element (22) projecting over the connection point (20) in a bridge-like manner with a recess (24) is arranged and designed such that a contact surface (26) projecting over the connection point (20) is formed by the base element (22). Power electronic component (10) according to the preceding claim, characterized in that the base element (22) has at least two sub-elements (30a, 30b), in particular wherein in a state of the base element (22) arranged on the circuit carrier (12) a sub-element (30a) arranged directly on the connection point (20) is solid and a further sub-element (30b) arranged thereon is formed with the recess (24). Power electronic component (10) according to the preceding claim, characterized in that the at least two sub-elements (30a, 30b) differ in their material. Power electronic component (10) according to claim 1 or 2, characterized in that the base element (22) has an alignment element for angularly aligning the connecting element (18) at the connection point (20). Power electronic component (10) according to claim 1, characterized in that the base element (22) is monolithic. Power electronic component (10) according to one of the preceding claims, characterized in that the base element (22) has several base sections, each with a recess (24), wherein the base sections are arranged one above the other in a vertical orientation (V) of the base element (22). Power electronic component (10) according to one of the preceding claims, characterized in that the base element (22) has a coating and / or a process engineering treatment. Power electronic component (10) according to one of the preceding claims, characterized in that the recess (24) is designed as a blind hole. Power electronic component (10) according to one of the preceding claims, characterized in that the connecting element (18) is designed as a contact tab and is pre-assembled on the base element (22). Power electronic component (10) according to one of the preceding claims, characterized in that at least the connection point (20) is potted with a potting compound (32).

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