Power converter device

Abstract

A power converter device (1) comprises: a first substrate (3) comprising a first circuit (31), wherein the first circuit (31) comprises at least one switching cell (33A-33H) arranged as semiconductor material in at least one integrated electronic device (331A-331H); and a second substrate (5) comprising a second circuit (51), wherein the first substrate (3) and the second substrate (5) are connected to each other by a connection between the integrated electronic device (331A-331H) and the second circuit (51).

Description

TECHNICAL AREA

[0001] This description refers to embodiments of a power converter device. BACKGROUND

[0002] Power converters are essential electronic circuits that play a crucial role in modern energy management systems. Their primary function is to convert the voltage of a power source from one level to another, ensuring a stable and efficient power supply for various electronic devices and systems. Power converters, such as DC-DC converters, are in high demand in rapidly growing industries like data centers, automotive, consumer electronics, and industrial machinery and vehicles, where DC-DC converters must meet extremely high standards.

[0003] The implementation of power converter devices typically faces several technical challenges in order to meet requirements regarding miniaturization and power density, performance improvement (such as reducing losses, reducing parasitic components and layout optimization), thermal management, integration complexity, cost, etc.

[0004] Several power converter designs are known in the prior art, such as:

[0005] A power converter device is implemented on a single substrate with surface-mount devices (SMDs) and reactive components mounted on the substrate, and can be manufactured using a simple and widely available process. However, mounting all components of the power converter device on a single substrate requires significant substrate space. Optimizing the thermal and electrical performance of such a single-substrate array can be challenging. Furthermore, the substrate stacking, such as the stacking of PCBs, is limited to conventional arrangements determined by the transformer's requirements.

[0006] Power converter devices where bare dies or pre-packaged transistors are embedded in a PCB substrate do not require much space, switching loop characteristics can be reduced, and thermal management can be improved. However, the manufacturing process can be complex, as the requirements for embedding semiconductors in a PCB substrate may conflict with the requirements for integrating magnetic components into the same PCB.

[0007] Power converter devices located on multiple substrates, such as printed circuit boards (PCBs), can overcome the design challenges mentioned above regarding the embedding of semiconductors in a single substrate. Specifically, the transformer and other reactive components can be placed on one substrate, while the semiconductors are placed on another. Both substrates are typically interconnected by mechanical components, such as copper blocks or half-hole edge contacts. However, the process of interconnecting the substrates using mechanical components can be complex, and the resulting power converter device may still have a relatively large form factor.

[0008] Therefore, there is a need for an improved power converter device that overcomes the problems mentioned above. SUMMARY

[0009] The subject matter of independent claim 1 is presented here. Features of further embodiments are defined in the dependent claims.

[0010] According to one embodiment, a power converter device comprises: a first substrate comprising a first circuit, wherein the first circuit comprises at least one switching cell arranged as semiconductor material in at least one integrated electronic device; and a second substrate comprising a second circuit, wherein the first substrate and the second substrate are connected to each other by a connection between the integrated electronic device and the second circuit.

[0011] In one example, the switching cell comprises a metal-oxide-semiconductor field-effect transistor, MOSFET.

[0012] In one example, the integrated electronic device is configured as a dissipative enclosure, in particular as a double-sided cooled enclosure, which encapsulates the semiconductor material in an insulating material.

[0013] In one example, a first side of the integrated electronic device includes at least one first access terminal of the first circuit, wherein the first access terminal is connected to the second circuit. In this example, a second side, opposite the first side, includes at least one second access terminal, in particular a source or drain terminal, wherein the second access terminal is connected to the first substrate, in particular to a tape conductor on the first substrate.

[0014] In one example, the second circuit includes a transformer, specifically a planar transformer.

[0015] In one example, the transformer includes at least two windings.

[0016] In one example, at least one access port of the second circuit is directly connected, in particular soldered, to the first access port on the first side of the integrated electronic device.

[0017] In one example, the power converter device comprises a conductive intermediate element, in particular a copper plate or column, which is arranged between the integrated electronic device and the second circuit.

[0018] In one example, the power converter comprises multiple switching cells and is configured as a full-bridge-to-full-bridge DC converter. In this example, a first full bridge can comprise a standard MOSFET full bridge, and a second full bridge can comprise four-quadrant devices. Alternatively, both the first and second full bridges can comprise standard MOSFET full bridges.

[0019] In one example, the first substrate and the second substrate are each configured as a printed circuit board (PCB).

[0020] The invention also relates to the use of a dissipative housing, in particular a double-sided cooled housing, in a power converter device according to one of the preceding claims.

[0021] According to some embodiments described here, a design is proposed which includes a compact size, improved switching performance, reduced line and connection losses, and improved cost efficiency.

[0022] Experts will recognize additional features and advantages upon reading the following detailed description and examining the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The parts in the figures are not necessarily to scale; instead, the emphasis is on illustrating the principles of the invention. Furthermore, identical reference numerals in the figures denote corresponding parts. The drawings show: Fig. 1(A) schematically a top view of an arrangement of a power converter device of the prior art; Fig. 1(B) schematically a bottom view of the in Fig. 1(A) shown arrangement of the prior art power converter device; Fig. 2(A) schematically and by way of example a substitute circuit of a power converter device according to a first embodiment; Fig. 2(B) schematically and by way of example a switching cell arranged in an integrated electronic device; Fig. 2(C) schematically and by way of example a switching cell according to a first configuration; Fig. 2(D) schematically and exemplarily a switching cell according to a second configuration; Fig. 2(E) schematically and by way of example a top view of the first substrate of the power converter device according to the first embodiment; Fig. 2(F) schematically and by way of example a bottom view of the second substrate of the power converter device according to the first embodiment; Fig. 2(G) a sectional view through electronic devices arranged on the first substrate and connected to respective electrical contact surfaces of the second substrate; Fig. 2(H) schematically and by way of example a side view of the power converter device according to the first embodiment; Fig. 2(i) schematically and by way of example a perspective of the power converter device according to the first embodiment; Fig. 3(A) schematically and by way of example a substitute circuit of a power converter device according to a second embodiment; Fig. 3(B) schematically and by way of example a top view of the first substrate of the power converter device according to the second embodiment; Fig. 3(C) schematically and by way of example a bottom view of the second substrate of the power converter device according to the second embodiment; Fig. 3(D) schematic and exemplary side view of the power converter device according to the second embodiment; Fig. 4. Schematic and exemplary perspective of the power converter device according to a third embodiment; Fig. 5 schematically and exemplarily a perspective of the power converter device according to a fourth embodiment; DETAILED DESCRIPTION

[0024] The following detailed description refers to the accompanying drawings, which form a part thereof and in which certain embodiments in which the invention can be exercised are shown as illustrations.

[0025] In this respect, directional terminology such as "above," "below," "below," "in front of," "behind," "backward," "leading," "following," "above," "horizontal," "vertical," etc., may be used with reference to the orientation of the described figures. Since parts of embodiments can be positioned in a number of different orientations, the directional terminology is used for illustrative purposes and is in no way limiting. It is understood that other embodiments may be used and structural or logical modifications may be made without derogating from the scope of protection of the present invention. The following detailed description should therefore not be understood in a limiting sense, and the scope of protection of the present invention is defined by the appended claims.

[0026] Various embodiments will now be discussed in detail, one or more examples of which are illustrated in the figures. Each example is provided as an explanation and is not intended to limit the invention. Features illustrated or described as part of an embodiment can, for example, be used in or in combination with other embodiments to obtain yet another embodiment. The present invention is intended to include such modifications and variations. The examples are described using specific language that is not intended to limit the scope of the accompanying claims. The drawings are not to scale and are for illustrative purposes only.For clarity, the same elements in the various drawings have been marked with the same reference symbols, unless otherwise stated.

[0027] In this description, the term "substrate" can be generally understood as a layer of insulating material on which components of the power converter device are mounted. The components can be interconnected on the substrate by interconnection elements, such as conductive traces. In one example, the first substrate and the second substrate are each configured as a printed circuit board (PCB).

[0028] The term "switching cell", as used here, can be used to refer to an electronic switch, such as a diode or transistor, configured for aperiodic or periodic switching.

[0029] The term "gate driver," as used in this description, refers to a power amplifier circuit that receives a low-power input, for example from a controller, and generates a high-current drive input for switching cells, such as the gate of a MOSFET transistor, which may be implemented as a switching cell. The gate driver can be considered the interface between control signals (from a digital or analog controller) and the switching cell. These control signals can be periodic signals originating from a microcontroller.

[0030] The term "power converter device," as used in this description, is intended to describe a device that converts one voltage level from a power source to another. In examples, the device is a direct current (DC)-DC converter. In alternative examples, the device may be a DC-AC, AC-DC, or AC-AC converter. The device may be a semiconductor device and may be configured to convert a voltage of 48 V to 12 V or 48 V to 1 V.

[0031] In the Fig. 1A and Fig. Figure 1B shows a prior art power converter device 100 located on two substrates, wherein in the Fig. 1A and Fig. Figure 1B shows opposite sides of the power converter device 100. In the prior art example shown, a first substrate 300, comprising a first circuit 310, and a second substrate 500, comprising a second circuit 510, are interconnected by mechanical parts 601, 603, shown as copper blocks. The substrates 300, 500 in the prior art example are implemented as PCB boards, and the first circuit 310 comprises two full bridges of a full-bridge-to-full-bridge DC-DC power converter. The second circuit 510 comprises a planar transformer. The prior art approach shown, in which the substrates 310, 510 are mechanically and / or electronically interconnected with the mechanical parts 601, 603, as in Figure 1B, is a significant improvement. Fig. 1A and Fig. As shown in 1B, however, it requires a rather sophisticated, multi-stage manufacturing process.

[0032] First, with reference to the Fig. Sections 2A - 2I describe a first embodiment of the power converter device 1, which is configured as a DC-DC power converter:

[0033] Fig. Figure 2A shows an equivalent circuit of the power converter device 1. The power converter device 1 comprises, for example, on a first substrate 3 (first dashed bounding box), a first circuit 31, which includes eight switching cells 33A - 33H, each arranged as semiconductor material in at least one integrated electronic device. In the embodiment shown, each switching cell 33A - 33H comprises a MOSFET transistor.

[0034] In the Fig. In the power converter device 1 shown in Figure 2A, the switching cells 33A - 33H are arranged as two full bridges on the first substrate 3. The first substrate 3 further comprises four gate driver circuits 35A - 35D, which are connected to the gates of the MOSFET transistors in the switching cells 33A - 33H. The gate driver circuits 35A - 35D can be provided either in the package of the integrated electronic devices or as a discrete module mounted on the first substrate 3.

[0035] The power converter device 1 further comprises a second substrate 5 (second dashed bounding box) of the same type as the first substrate 3 in the illustrated embodiment, i.e., both substrates 3 and 5 are PCB substrates. In alternative embodiments, the first substrate 3 and the second substrate 5 may be of different types. A second circuit 51 is mounted on the second substrate 5 and, in the illustrated embodiment, comprises a transformer 511. The transformer 511 may be a planar transformer, enabling voltage transformation and providing galvanic isolation between the input and output sides of the power converter device 1. In the illustrated embodiment, the transformer 511 comprises two windings. In alternative embodiments, the transformer 511 may comprise more than two windings, such as three windings.Furthermore, the second circuit 51 can alternatively or additionally include components such as capacitors, C, inductors, L, and / or LC circuits. For example, the transformer 511 in the second circuit 51 can include a so-called resonant tank on the primary side, comprising a capacitor and inductors, and center-tapped windings on the secondary side. Alternatively, the second circuit 51 could include a transformer with a resonant tank on the primary side and a single winding on the secondary side, or a transformer with two resonant tanks on the secondary side. Also in . Fig. Tabs 2A are shown for the input voltage, V. IN , the tabs for the output voltage, V OUT , as well as the respective ground tabs, GND1, GND2 of the power converter device 1.

[0036] Fig. Figure 2B shows opposing surfaces 333, 335 of a switching cell 33, which is arranged in an integrated electronic device 331 comprising a first surface 333 and an opposing second surface 335. The switching cell 33 shown, which is arranged in the integrated electronic device 331, is, in the first embodiment, as shown in Figure 2B, arranged in the first embodiment according to the illustration in Figure 2B. Fig. 2E is used. The integrated electronic device 331 is configured as a dissipative package, a so-called double-sided cooled package, which encapsulates the semiconductor material in an insulating material. The side-cooled package can, for example, be a so-called OptiMOS. TM--housing. The integrated electronic device 331 comprises a first access port 337A on the first surface 333 and three second access ports 337B, 338, 339 on the second surface 335. One of the second access ports 337B is shown with the same reference number, i.e., reference number 337, as the first access port 337A, since both access ports 337A, 337B are electrically connected to each other.

[0037] In a first configuration of the switching cell 33, which includes a MOSFET transistor, the first access terminal 337A and the first second access terminal 337B are the drain access terminals of the MOSFET transistor, the second second access terminal 338 is the gate access terminal of the MOSFET transistor, and the third second access terminal 339 is the source access terminal of the MOSFET transistor. In a second configuration of the switching cell 33, the first access terminal 337A and the first second access terminal 337B are a source access terminal of the MOSFET transistor, the second second access terminal 338 is a gate access terminal of the MOSFET transistor, and the third second access terminal 339 is a drain access terminal of the MOSFET transistor.

[0038] Two configurations of a switching cell, which is not contained in an integrated electronic device according to the first and second configurations, are described in the Fig. 2C and Fig. Shown in 2D.

[0039] The in Fig. The first configuration shown in 2C can also be called the source-down configuration, where the first access terminal 337A and the first second access terminal 337B are the drain access terminals of the MOSFET transistor, the second second access terminal 338 is the gate access terminal of the MOSFET transistor, and the third second access terminal 339 is the source access terminal of the MOSFET transistor.

[0040] The in Fig. The second configuration shown in 2D can also be called a drain-down configuration, where the first access terminal 337A and the first second access terminal 337B are the source access terminals of the MOSFET transistor, the second second access terminal 338 is the gate access terminal of the MOSFET transistor, and the third second access terminal 339 is the drain access terminal of the MOSFET transistor.

[0041] In the above in the Fig. 2C and Fig. In the 2D configurations shown, the second access terminals 337B, 338, 339 can be located on a conductor frame, allowing the MOSFET transistor to be mounted on the substrate. The first access terminal 337A can also be referred to as a clip and can be implemented as a copper clip, enabling vertical current flow through the MOSFET transistor. Furthermore, the clip allows for cooling from both sides of the MOSFET transistor, thus improving its thermal performance.

[0042] Fig. Figure 2E shows a top view of the first substrate 3 of the power converter device 1 according to the first embodiment. The switching cells 33A, 33B, 33E, 33F are configured in a drain-down configuration, and the switching cells 33C, 33D, 33G, 33H are configured in a source-down configuration and are arranged in integrated electronic devices 331A - 331F, as shown in Figure 2E. Fig. Figure 2B shows the switching cells 33A, 33B, 33E, 33F, which are configured in a drain-down configuration, and the switching cells 33C, 33D, 33G, 33H, which are configured in a source-down configuration, are arranged in the same type of electronic device 331. Fig. 2E only indicates the second access connections, which are used to connect the elements according to the equivalent circuit of Fig. 2A are connected to conductor tracks on substrate 3. In Fig. The second access ports are designated Source, S, Drain, D, and Gate G. Accordingly, the first access ports of switching cells 33A, 33B, 33E, and 33F are accessible as Source access ports on the top side of switching cells 33A, 33B, 33E, and 33F. Consequently, the first access ports of switching cells 33C, 33D, 33G, and 33H are accessible as Drain access ports on the top side of switching cells 33C, 33D, 33G, and 33H.

[0043] Furthermore, in Fig. 2E shows the four gate driver circuits 35A - 35D, which are connected to the gate access terminals G of the MOSFET transistors in the switching cells 33A - 33H arranged in the integrated electronic devices 331A - 331F.

[0044] Fig. Figure 2F shows a bottom view of the second substrate 5 of the power converter device 1 according to the first embodiment. The transformer is arranged on the opposite side of the second substrate 5 and is in Fig. 2F is not visible. In other examples, the transformer could also be located inside the second substrate 5 or arranged around the second substrate 5. The ends of the two transformer coils are led through vias, i.e., holes in a material of the second substrate 5, to the underside of the second substrate 5, where they are each electrically connected to the contact surfaces 53A–53D. The contact surfaces 53A–53D comprise conductive material, such as copper, for electrically connecting the transformer coils via the contact surfaces 53A–53D.

[0045] To assemble the power converter 1, the first access terminals of the switching cells 33A - 33H are electrically and mechanically connected to the contact surfaces 53A - 53D on the second substrate 5 according to the diagram. Fig. The equivalent circuit shown in 2A is connected. The electrical and mechanical connection can be made by directly soldering the first access terminals to the respective contact surfaces 53A - 53D.

[0046] Fig. Figure 2G shows a sectional view in a vertical direction through the integrated electronic devices 331A - 331D located on the first substrate 3, as shown in Fig. 2E are shown, arranged, and with the respective electrical contact surfaces 53A, 53B of the second substrate 5, as shown in Fig. 2F shown, connected are

[0047] In Fig. In Figure 2G, the second access terminals 337B, 338, 339 of the electronic devices 331A - 331D of the MOSFET transistors are shown side by side to facilitate understanding of this invention. In examples of the invention, the second access terminals 337B, 338, 339 can be distributed on the second surface 335 of the electronic devices 331A - 331D, as shown in Figure 2G. Fig. 2B shown. Fig. 2G are the access ports numbered 337A, 337B, 338, 339 and identified by specifying the access ports as Source, S, Drain, D and Gate G to facilitate understanding of the invention. Fig. In the embodiment shown in Figure 2E, the second access terminals 337B, 338, 339 are connected to the substrate 3, i.e., to conductor tracks on the substrate 3, while the first access terminals 337A of the electronic devices 331A - 331D shown, which are located on a respective first surface 333 of the electronic devices 331A - 331D, are connected to the electrical contact surfaces 53A, 53B of the second substrate 5, as shown in Figure 2E. Fig. 2G shown, according to the equivalent circuit of Fig. 2A are connected.

[0048] In Fig. Figure 2H shows a side view of the assembled power converter device 1 according to the first embodiment, and Fig. Figure 2I shows a perspective view of the power converter device 1 according to the first embodiment, wherein the first substrate 3 and the second substrate 5 are connected to each other by a direct connection of the integrated electronic devices 331A - 331F and the second circuit 51. Here, the first substrate 3 and the second substrate 5 are bridged across their top surfaces, i.e., the first access terminals of the integrated electronic devices 331A - 331F. This configuration allows for a reduced footprint corresponding to the lateral layouts known in the prior art. Due to the vertical current flow through the MOSFET transistors, the heat distribution in the power converter device 1 can be improved, and conduction losses and loop inductances from the access terminals of the MOSFET transistors used within the integrated electronic devices 331A to 331F can be reduced / eliminated.Furthermore, the configuration described here can be manufactured using standard PCB manufacturing processes.

[0049] Fig. Figure 3A shows an equivalent circuit of a power converter device 1 according to a second embodiment. The in Fig. The equivalent circuit shown in 3A differs from the equivalent circuit shown in Fig. The first embodiment shown in Figure 2A differs in that only one of the two full bridges comprises the switching cells 33A - 33D, which contain MOSFET transistors. The second full bridge in the second embodiment comprises the switching cells 33E - 33H, which contain four-quadrant devices.

[0050] Fig. Figure 3B shows a top view of the first substrate 3 of the power converter device 1 according to the second embodiment. The switching cells 33A - 33H are on the first substrate 3 as shown in Figure 3B. Fig. The equivalent circuit shown in 3A is arranged. The second access terminals, located on the second side of switching cells 33A - 33H in the integrated electronic devices 331A - 331F, are in Fig. 3B is designated as Source, S, Drain, D, and Gate, G.

[0051] As shown, the inventive concept of the present invention is adaptable and can also be applied to topologies that differ from the topology described in the first embodiment.

[0052] Fig. Figure 3C shows a bottom view of the second substrate 5 of the power converter device 1 according to the second embodiment. The second substrate 5 is similar to the second substrate 5 of the first embodiment; only the geometry of the contact surfaces 53A - 53D and the distance between the contact surfaces 53A - 53D can vary in order to electrically and mechanically contact the switching cells 33A - 33H of the second embodiment, which are arranged on the respective first substrate 3.

[0053] Fig. 3D shows a side view of the power converter device 1 according to the second embodiment.

[0054] Fig. Figure 4 shows a perspective view of the power converter device 1 according to a third embodiment. The power converter device 1 of the third embodiment differs from the power converter devices of the first and second embodiments in that the first substrate 3 and the second substrate 5 are not connected to each other by a direct connection between the integrated electronic devices and the second circuit 51. Instead, the power converter device 1 comprises conductive intermediate elements 7A-7D, which are implemented as flat copper plates and are arranged between the access terminals on the integrated electronic devices 331A-331F and the contact surfaces of the second circuit 51.The first access connections can be soldered to one side of the respective conductive intermediate elements 7A - 7D, and the contact surfaces of the second circuit 51 can be soldered to the opposite side of the respective conductive intermediate elements 7A - 7D.

[0055] The conductive intermediate elements 7A–7D can be adjusted in height to accommodate larger components to be placed between the first substrate 3 and the second substrate 5. Furthermore, the copper-containing conductive intermediate elements 7A–7D can act as heat spreaders, providing additional thermal improvements. In addition, the intermediate elements 7A–7D can contribute to the mechanical stability of the assembly and can be used to mitigate reliability issues such as those caused by thermal cycling.

[0056] Fig. Figure 5 shows a perspective of the power converter device 1 according to a fourth embodiment, which uses conductive intermediate elements 7A - 7D. In the embodiment of Fig. The conductive intermediate elements 7A-7D are implemented as U-shaped copper elements and are arranged between the integrated electronic devices and the contact surfaces of the second circuit 51. The U-shaped copper elements can increase mechanical stability, reduce thermomechanical stresses at the access terminals, and facilitate mechanical assembly.

[0057] As described above, the conductive intermediate elements 7A - 7D of embodiments 3 and 4 can be used with the power converter devices 1 according to embodiments 1 and 2.

Claims

[1] Power converter device (1) comprising: a first substrate (3) comprising a first circuit (31), wherein the first circuit (31) comprises at least one switching cell (33A-33H) arranged as semiconductor material in at least one integrated electronic device (331A-331H); and a second substrate (5) comprising a second circuit (51), characterized by , that the first substrate (3) and the second substrate (5) are connected to each other by a connection between the integrated electronic device (331A-331H) and the second circuit (51). [2] Power converter device (1) according to claim 1, characterized by , that the switching cell (33A-33H) includes a metal-oxide-semiconductor field-effect transistor, MOSFET. [3] Power converter device (1) according to claim 1 or 2, characterized by, that the integrated electronic device (331A-331H) is configured as a dissipative enclosure, in particular as a double-sided cooled enclosure, which encapsulates the semiconductor material in an insulating material. [4] Power converter device (1) according to any one of the preceding claims, characterized by , that a first side (333) of the integrated electronic device (331A-331H) includes at least one first access port (337A) of the first circuit (31), wherein the first access port (337A) is connected to the second circuit (51). [5] Power converter device (1) according to claim 4, characterized by, that a second side (335) opposite the first side (333) includes at least a second access port (337B, 338, 339), in particular a source or drain port, wherein the second access port (337B, 338, 339) is connected to the first substrate (3), in particular to a tape conductor on the first substrate (3). [6] Power converter device (1) according to any one of the preceding claims, characterized by , that the second circuit (51) comprises a transformer (511), in particular a planar transformer. [7] Power converter device (1) according to claim 6, characterized by , that the transformer (511) comprises at least two windings. [8] Power converter device (1) according to any one of claims 4 to 7, characterized by, that at least one access port (53A-53D) of the second circuit (51) is directly connected, in particular soldered, to the first access port (337A) on the first side (333) of the integrated electronic device (331A-331H). [9] Power converter device (1) according to any one of claims 4 to 7, characterized by a conductive intermediate element (7A-7D), in particular a copper plate or column, arranged between the integrated electronic device (331A-331H) and the second circuit (51). [10] Power converter device (1) according to any one of the preceding claims, characterized by , that the power converter device (1) comprises a plurality of switching cells (33a - 33H) and is configured as a full-bridge-to-full-bridge DC converter [11] Power converter device (1) according to claim 10, characterized by, that a first full bridge comprises a standard MOSFET full bridge and a second full bridge comprises four-quadrant devices. [12] Power converter device (1) according to any one of the preceding claims, characterized by , that the first substrate (3) and the second substrate (5) are each configured as a printed circuit board, PCB boards. [13] Use of a dissipative housing, in particular a double-sided cooled housing, in a power converter device (1) according to one of the preceding claims.

Images