WO2025256741A1

WO2025256741A1 - Power supply assembly

Info

Publication number: WO2025256741A1
Application number: PCT/EP2024/066340
Authority: WO
Inventors: Lasse Petteri PALM; Pedro André MARTINS BEZERRA; Chengfeng JIANG
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2024-06-13
Filing date: 2024-06-13
Publication date: 2025-12-18
Anticipated expiration: 2026-12-13

Abstract

The disclosure relates to a power supply assembly (100), comprising: a first PCB (110) carrying one or more power dies; a second PCB (120) carrying at least one electrical component (122) which is arranged within an electrical distance to the one or more power dies; and a carrier board (130). The first PCB and the second PCB are mounted on opposite sides of the carrier board to enable a double-side cooling. The one or more power dies together with the at least one electrical component are configured to receive electrical power along a current path which is traversing the first and the second PCB and the carrier board. The first and the second PCB are mounted at least partially overlapping on the opposite sides of the carrier board such that a part of the current path is arranged vertically between the top side and the bottom side of the carrier board, in order to reduce the electrical distance between the one or more power dies on the first PCB and the at least one electrical component on the second PCB and to enable double sided cooling.

Description

POWER SUPPLY ASSEMBLY

TECHNICAL FIELD

The disclosure relates to the field of power devices and particularly to a power supply assembly. The disclosure further relates to a Split Power Supply for Board Mounted Power (BMP).

BACKGROUND

SUMMARY

This disclosure provides a solution for increasing the electrical and thermal performance of the board mounted power (BMP) assembly and for reducing the required surface area on the system board.

The foregoing and other objects are achieved by the features of the independent claims. Further implementation forms are apparent from the dependent claims, the description and the figures.

Embodiments of the disclosure present techniques for increasing the performance and power density by dividing the BMP module at least in two sub modules which areas are mounted on the opposite sides of the system board. Both parts can use 3D ECP (embedding) technologies, for example, to minimize the parasitic and size and maximize the electrical and thermal performance.

Embodiments of the disclosure present techniques for dividing the power supply assembly at least in two separate parts that are mounted on different sides of the system board. The system board can be used also for routing and connecting the different power supply parts together. Additional passives components that are needed but not required in closed distance with the power dies can also be mounted on the system board. When the power module is divided in two separate sub modules that are mounted on opposite sides of the system board the cooling of the module can be done very effectively from both top and bottom side. Distance between the components on top and bottom die can be minimized and the necessary components accurately mounted on top of each other on the other side of the assembly and connected together with direct vias through the system board.

In order to describe the disclosure in detail, the following terms and notations will be used. PCB Printed Circuit Board

CE Chip Embedding

ECP Embedded Chip (or Component) Package

DSC Double Side(d) Cooling

BMP Board Mounted Power

SMA Surface Mount Assembly

SMD Surface Mount Device

In this disclosure, Chip embedding (CE) and embedded component packaging (ECP) is described. CE or ECP is an advanced packaging technology where bare dies typically with Cu metallization are embedded inside PCB material and connected to the Cu routing on the package with plated jivias. This packaging technology uses PCB manufacturing processes for the embedding or encapsulation of semiconductor dies. The result can either be an SMT package or module which can be soldered onto standard PCBs, or a PCB board which has semiconductor dies or components integrated inside. Chip embedding is a panel level packaging process technology.

In this disclosure, PCBs with FR4 material are described. FR4 is a composite material that is widely used in PCB industry as a substrate material. It consists of epoxy’ resin with or without additional ceramic particles and it is reinforced with woven glass fiber.

In this disclosure, Board Mounted Power (BMP) and BMP modules are described. BMP is a definition for board level DC power conversion module that are used for example in telecom related applications. According to a definition a board mount power supply converts electrical power from a source into a format suitable for powering a desired load, such as DC to DC converters.

In this disclosure, double side cooling (DSC) of power modules is described. DSC is a new and effective approach, method and structure that is used in advanced power modules to enhance the heat dissipation. In double sided cooled modules, the heat sink can be attached on both sides of the module allowing more effective heat flow from the power devices to the surrounding cooling structures.

According to a first aspect, the disclosure relates to a power supply assembly, comprising: a first printed circuit board carrying one or more power dies; a second printed circuit board carrying at least one electrical component, the at least one electrical component being arranged within an electrical distance to the one or more power dies; and a carrier board having a top side and a bottom side opposite to the top side, wherein the first printed circuit board and the second printed circuit board are mounted on opposite sides of the carrier board to enable a double-side cooling of the power supply assembly; wherein the one or more power dies together with the at least one electrical component are configured to receive electrical power along a current path from a source to a load, wherein the current path is traversing the first printed circuit board, the second printed circuit board and the carrier board; wherein the first printed circuit board and the second printed circuit board are mounted at least partially overlapping on the opposite sides of the carrier board such that a part of the current path is arranged vertically between the top side and the bottom side of the carrier board, in order to reduce the electrical distance between the one or more power dies on the first printed circuit board and the at least one electrical component on the second printed circuit board and to enable double sided cooling.

Such a power supply assembly allows to increase the electrical and thermal performance of the board mounted power (BMP) assembly and to reduce the required surface area on the system board. By dividing the BMP module at least in two sub modules which areas are mounted on the opposite sides of the system board, the performance and power density can be improved. By using 3D ECP (embedding) technologies, for example, the parasitic and size can be minimized and the electrical and thermal performance can be maximized.

Mounting the components that are generating most heat (typically power dies and inductor) to opposite sides of the assembly allows more effective cooling.

In an exemplary implementation of the power supply assembly, the carrier board comprises a through-via configured to vertically route the part of the current path through the carrier board.

By such through- via, the shortest electrical path between the power die(s) of the first PCB and the electrical component of the second PCB can be used, thereby reducing parasitics and improving performance.

In an exemplary implementation of the power supply assembly, the one or more power dies are embedded in the first printed circuit board.

This allows mechanical robust implementation and at the same time reduced electrical distance.

In an implementation, the back side of at least one of the power dies is facing towards the heat sink. The back side of a power die can be the side on which the drain connection is mounted.

This enables efficient cooling.

In an exemplary implementation of the power supply assembly, the first printed circuit board comprises a top side that is facing opposite to the top side of the carrier board; and the first printed circuit board comprises a thermally conductive electrically isolating layer that is embedded inside the first printed circuit board between the one or more power dies and the top side of the first printed circuit board, the thermally conductive electrically isolating layer being configured to transfer heat of the one or more power dies to a heat sink mountable at the top side of the first printed circuit board.

Thermal conductivity limits for thermal enhanced material such as the thermally conductive electrically isolating layer may be defined as follows: Minimum 1,2 W/mK, preferably more than 2W/mK or even more than 3W/mK. With more than 3W/mK better thermal conductivity and thus better heat transfer can be obtained.

Such thermally conductive electrically isolating layer improves heat transfer.

In an exemplary implementation of the power supply assembly, the first printed circuit comprises a thermal interface material layer disposed at the top side of the first printed circuit board, the thermal interface material layer being configured to mechanically and thermally connect the first printed circuit board to the heat sink; wherein the thermal interface material layer is electrically conductive or is at least composed of electrically conductive parts to improve the heat transfer.

An electrically non-isolating material layer can improve the heat transfer, since electrically conductive material has usually a higher thermal conductivity than electrically isolating material. In an exemplary implementation of the power supply assembly, the thermal interface material layer is soldered or laminated to the first printed circuit board, or in mechanical connection with the first printed circuit board by pressure and/or screws.

Different design options for the thermal interface material layer can be used.

In an exemplary implementation of the power supply assembly, the first printed circuit board comprises a top side that is facing opposite to the top side of the carrier board; wherein the first printed circuit comprises a thermal interface material layer disposed at the top side of the first printed circuit board, the thermal interface material layer being configured to mechanically and thermally connect the first printed circuit board to the heat sink; wherein the thermal interface material layer is electrically insulating.

Such design with thermal interface material layer allows efficient cooling.

In an exemplary implementation of the power supply assembly, the first printed circuit board comprises a top side that is facing opposite to the top side of the carrier board; wherein the one or more power dies are surface mounted with or without an exposed Copper clip at the top side of the first printed circuit board.

Surface mounting with Cu clip is preferred. The clip that is connecting the source to the lead frame is exposer (grinded open).

In an exemplary implementation of the power supply assembly, the first printed circuit comprises a thermal interface material layer disposed at the top side of the first printed circuit board, the thermal interface material layer being configured to mechanically and thermally connect the first printed circuit board to a heat sink; wherein the thermal interface material layer is electrically insulating; wherein the one or more power dies are embedded in the thermal interface material layer.

When embedding the one or more power dies in the thermal interface material layer, heat transfer can be increased.

In an exemplary implementation of the power supply assembly, the first printed circuit board comprises one or more surface mount assembly, SMA, components which are surface-mounted at a bottom side of the first printed circuit board that is facing towards the top side of the carrier board; and wherein the power supply assembly comprises one or more spacers electrically connecting the first printed circuit board to the carrier board, wherein a thickness of the one or more spacers is greater than a thickness of the one or more SMA components.

Such design allows to place additional SMA components on the first PCB.

In an exemplary implementation of the power supply assembly, the one or more spacers are configured to vertically route part of the current path from the first printed circuit board to the carrier board and vice versa, in order to reduce a distance of the current path between the first printed circuit board and the carrier board.

Such design allows short and effective vertical current flow instead of lateral current flow.

In an exemplary implementation of the power supply assembly, the one or more power dies are embedded in the first printed circuit board; wherein the first printed circuit board comprises a top side that is facing opposite to the top side of the carrier board; wherein the first printed circuit board comprises one or more spacers that are mounted at the top side of the first printed circuit board above the one or more power dies; wherein the power supply assembly comprises a thermal interface material layer disposed at the top side of the first printed circuit board, the thermal interface material layer being configured to mechanically and thermally connect the first printed circuit board to a heat sink; wherein the thermal interface material layer is electrically insulating; wherein the thermal interface material layer is contacting the one or more spacers for transferring heat of the one or more power dies to the heat sink.

Such design allows for an effective double-sided cooling. A double sided assembly on system board reduces the required area on the system board and the overall thickness of the complete system.

In an exemplary implementation of the power supply assembly, the one or more spacers are embedded in a mold layer at the top side of the first printed circuit board; wherein additional electrical components are mounted at the top side of the first printed circuit board which are embedded in the mold layer.

Such design allows for better protecting the electrical components by the mold layer.

In an exemplary implementation of the power supply assembly, the one or more power dies are electrically connected to form a half-bridge configuration.

Such power supply assembly can thus be applied in typical switching applications using half-bridge configuration.

In an exemplary implementation of the power supply assembly, the at least one electrical component comprises at least one inductor and optionally passive electrical components, capacitors and/or drivers.

These components can be mounted on top of the substrate with SMA or some of the components can also be embedded inside the substrate.

In an exemplary implementation of the power supply assembly, the at least one electrical component is surface-mounted at a top side of the second printed circuit board or embedded inside the second printed circuit board.

This allows flexibility in design options.

The top side of the second printed circuit board is facing opposite to the bottom side of the carrier board.

In an exemplary implementation of the power supply assembly, one or more passive electrical components which are electrically connected to the one or more power dies and/or the at least one electrical component are mounted on the top side and/or the bottom side of the carrier board.

This design allows integration of passive electrical components.

According to a second aspect, the disclosure relates to a method for producing a power supply assembly, the method comprising: arranging one or more power dies on a first printed circuit board; arranging at least one electrical component on a second printed circuit board, wherein the at least one electrical component is arranged within an electrical distance to the one or more power dies; and mounting the first printed circuit board and the second printed circuit board on opposite sides of a carrier board having a top side and a bottom side opposite to the top side to enable a double-side cooling of the power supply assembly; wherein the one or more power dies together with the at least one electrical component are configured to receive electrical power along a current path from a source to a load, wherein the current path is traversing the first printed circuit board, the second printed circuit board and the carrier board; wherein the first printed circuit board and the second printed circuit board are mounted at least partially overlapping on the opposite sides of the carrier board such that a part of the current path is arranged vertically between the top side and the bottom side of the carrier board, in order to reduce the electrical distance between the one or more power dies on the first printed circuit board and the at least one electrical component on the second printed circuit board and to enable double sided cooling.

Such method allows to manufacture a robust and reliable power supply assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

Further embodiments of the disclosure will be described with respect to the following figures, in which:

Figure 1 shows a cross section of a power supply assembly 100 according to the disclosure;

Figure 2 shows cross sections of two power supply assemblies 200a, 200b according to embodiments with fully overlapping 200a and partially overlapping 200b submodules (first and second PCBs);

Figure 3 shows a cross section of a power supply assembly 300 according to a first embodiment;

Figure 4 shows a cross section of a power supply assembly 400 according to a second embodiment;

Figure 5 shows a cross section of a power supply assembly 500 according to a third embodiment; and

Figure 6 shows a cross section of a power supply assembly 600 according to a fourth embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

In the following detailed description, reference is made to the accompanying drawings, which form a part thereof, and in which is shown by way of illustration specific aspects in which the disclosure may be practiced. It is understood that other aspects may be utilized and structural or logical changes may be made without departing from the scope of the disclosure. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the disclosure is defined by the appended claims.

It is understood that comments made in connection with a described method may also hold true for a corresponding device or system configured to perform the method and vice versa. For example, if a specific method step is described, a corresponding device may include a unit to perform the described method step, even if such unit is not explicitly described or illustrated in the figures. Further, it is understood that the features of the various exemplary aspects described herein may be combined with each other, unless specifically noted otherwise.

Figure 1 shows a cross section of a power supply assembly 100 according to the disclosure. The power supply assembly 100 comprises: a first printed circuit board 110 carrying one or more power dies 310, 311 (not shown in Figure 1, see for example Figure 3).

The power supply assembly 100 comprises: a second printed circuit board 120 carrying at least one electrical component 122 (not shown in Figure 1, see for example Figure 3). This at least one electrical component 122 is arranged within an electrical distance to the one or more power dies 310, 311.

The power supply assembly 100 comprises: a carrier board 130 having a top side 130a and a bottom side 130b opposite to the top side 130a, wherein the first printed circuit board 110 and the second printed circuit board 120 are mounted on opposite sides 130a, 130b of the carrier board 130 to enable a double-side cooling 111, 121 of the power supply assembly 100.

The one or more power dies together with the at least one electrical component are configured to receive electrical power along a current path 101 from a source to a load, wherein the current path 101 is traversing the first printed circuit board 110, the second printed circuit board 120 and the carrier board 130.

The first printed circuit board 110 and the second printed circuit board 120 are mounted at least partially overlapping on the opposite sides 130a, 130b of the carrier board 130 such that a part of the current path 101 is arranged vertically between the top side 130a and the bottom side 130b of the carrier board 130, in order to reduce the electrical distance between the one or more power dies on the first printed circuit board 110 and the at least one electrical component on the second printed circuit board 120 and to enable double sided cooling.

The electrical distance is here the physical distance of between both electrical components which corresponds to the length of an electrical path between the two electrical components.

An idea of this implementation is to mount the components that are generating most heat to opposite sides of the assembly to allow more effective cooling (typically power dies and inductor).

The carrier board 130 may comprise a through- via 301, as shown in Figure 3, for example, which may be configured to vertically route the part of the current path 101 through the carrier board 130.

The one or more power dies 310, 311 may be electrically connected to form a half-bridge configuration, for example.

The at least one electrical component 122 may comprise at least one inductor and optionally passive electrical components, capacitors and/or drivers.

The at least one electrical component 122 can be surface-mounted at a top side of the second printed circuit board 120 or embedded inside the second printed circuit board 120.

The top side of the second printed circuit board 120 is facing opposite to the bottom side 130b of the carrier board 130. One or more passive electrical components 131, 132, 133, 134, 135, 136, 137 which may be electrically connected to the one or more power dies 310, 311 and/or the at least one electrical component 122 may be mounted on the top side 130a and/or the bottom side 130b of the carrier board 130 as shown in Figure 1.

As can be seen from Figure 1, the power supply system, i.e., the power supply assembly 100 is divided into three parts which are the two sub modules (first PCB 110 and second PCB 120) and the system board (carrier board 130).

The power sub module part 1, i.e., the first PCB 110 contains at least the power components and components that need to be in very close distance of the power dies. Power components can be embedded inside the module 110. Inside the module 110 the power components are facing toward the system board 130 (PMIC prefered from thermal point of view) or different direction (high side, HS and low side, LS to optimize the electrical performance). The component is moved close to the cooling structure, the die backside to the outside of the module 110 and heat sink. Cooling is implemented to the bottom (or top side, depending on the assembly direction). Integrated isolation can be provided between the power dies and outside. This design allows to use integrated isolation. Thus, no additional isolation between the module and heatsink is required; and the modules can be connected directly to the heat sink/cooling structures.

The power sub module part 2, i.e., the second PCB 120 may include at least inductor(s) and optionally e.g. passives, capacitors, driver, etc. The module 120 can contain several components (or in the simplest format one single component). The output capacitors can be emebdded inside the module 120. The inductor can be embedded or mounted on top of the embedded module. Cooling of the inductor (and other components that generate heat) can be from the side that is facing away from the system board/carrier board 130.

The system board, i.e., the carrier board 130 is used to connect power module 1 and 2 together. The system board 130 can include additional components that do not need to be in close distance to the power dies or components that should be in the output/input line (e.g output capacitors). If needed the top side components can be shielded from bottom side components by using metal stuctures inside the system board 130.

By splitting the Power supply module, i.e., power supply assembly 100, in at least two parts/sub modules, the following design options can be implemented:

The sub modules 110, 120 can be mounted above each other (typically but not a must is at least partially overlapping each other) on opposite sides of the system board.

The system board 130 can be used for routing and connecting the sub modules 110, 120 to each other.

At least the power switches can be embedded (or in some cases SMA mounted) inside the first power supply part 110 and heat sink or cooling structure can be attached on one side of the first part 110 (embedding allows minimized distance from the embedded components to the cooling structure).

The power supply part 2, 120 may include embedded inductors and/or capacitors and/or other embedded components.

Isolation can be integrated at least inside the first part 110 that allows to connect the module 110 directly and electrically to the heats sink or cooling structure. The current path between the components is short and optimized due to real 3D stacking, where components are in multiple layers in ideal location compared to each other.

Such a power supply assembly 100 allows enhanced cooling of the power devices due to short and close distance to the heat sink that allows effective heat flow and cooling. Enhanced electrical performance can be achieved due to reduced parasitic (embedding and 3D stacking). Reduced surface area can be implemented due to 3D stacking. Minimized and optimized current flow can be achieved. Short and effective vertical current flow can be implemented instead of lateral current flow. An effective double-sided cooling can be implemented. The double-sided assembly on system board 130 reduces the required area on the system board 130 and the overall thickness of the complete system 100.

Figure 2 shows cross sections of two power supply assemblies 200a, 200b according to embodiments with fully overlapping 200a and partially overlapping 200b submodules (first and second PCBs).

The design of the two power supply assemblies 200a, 200b corresponds to the design described above with respect to Figure 1.

In the fully overlapping power supply assembly 200a, the first PCB 110 is mounted above the second PCB 120 without a lateral offset as shown on the left-hand side of Figure 2. Both PCBs 110, 120 can have the same size in terms of area or they can have a different size (not shown here) and they can be mounted above each other.

In the partially overlapping power supply assembly 200b, the first PCB 110 is mounted with a lateral offset above the second PCB 120 as shown on the right-hand side of Figure 2. Both PCBs 110, 120 can have the same size in terms of area or they can have a different side (not shown here).

The current flow 101 can be in the same direction as shown in the fully overlapping power supply assembly 200a or it can be to a different direction as shown in the partially overlapping power supply assembly 200b on the right-hand side of Figure 2. The current path 101 can be selected (for both overlapping configurations 200a, 200b) based on the application requirements.

Figure 3 shows a cross section of a power supply assembly 300 according to a first embodiment.

The design of the power supply assembly 300 corresponds to the design described above with respect to Figure 1. However, following additional features can be implemented:

The one or more power dies 310, 311 may be embedded in the first printed circuit board 110.

In an implementation, the back side of at least one of the power dies 310, 311 may be facing towards the heat sink 302. The back side of a power die can be the side on which the drain connection is mounted.

The first printed circuit board 110 comprises a top side 110a that is facing opposite to the top side 130a of the carrier board 130.

The first printed circuit board 110 may comprise a thermally conductive electrically isolating layer 304 that is embedded inside the first printed circuit board 110 between the one or more power dies 310, 311 and the top side 110a of the first printed circuit board 110. The thermally conductive electrically isolating layer 304 may be configured to transfer heat of the one or more power dies 310, 311 to a heat sink 302 mountable at the top side 110a of the first printed circuit board 110.

The first printed circuit 110 may comprise a thermal interface material layer 303 disposed at the top side 110a of the first printed circuit board 110. The thermal interface material layer 303 may be configured to mechanically and thermally connect the first printed circuit board 110 to the heat sink 302. The thermal interface material layer 303 may be electrically conductive or may be at least composed of electrically conductive parts to improve the heat transfer.

An electrically non-isolating material layer can improve the heat transfer, since electrically conductive material has usually a higher thermal conductivity than electrically isolating material.

The thermal interface material layer 303 may be soldered or laminated to the first printed circuit board 110, or may be in mechanical connection with the first printed circuit board 110 by pressure and/or screws, for example.

Basic design considerations for this first embodiment can be described as follows:

The power components are embedded inside the Power Supply part 1 by using normal ECP process. The embedded power components (in half bridge configuration) can be mounted facing same or opposite directions (picture from orientation presented later). Power dies (310, 311) can be bare dies or prepackaged dies.

The routing layer where the embedded dies are connected can be isolated from the outer most layer with thermally enhanced prepreg (no plated vias between this layer and outermost Cu layer). This layer is an optional layer that can be also skipped if isolation and additional routing layer of other side is not needed.

The additional components that are not embedded inside the module can be SMA mounted on the side of the Power Supply part 1 that is facing toward the system board (between the Power Supply 1 and system board). This allows to connect the top side of the module directly to the heat sink (TIM, thermal grease or even with soldering or sintering in case the top side metal layer is isolated from the devices.

The embedded power dies are located closed to the heat sink and can be effectively cooled though the thermally enhanced isolation layer.

The module is connected to the system board with Cu spacers that are thicker than the SMA components.

The Power Supply part 1 is mounted on opposite side of the system board and it at least partially overlap the power module part 2.

The Power Supply part 2 typically includes at least one or several embedded or SMA mounted components e.g. inductor, capacitors, resistors or logic die. In the simplest case it can be e.g. module with embedded inductor that is soldered on the system board.

The system board can include also additional SMA components e.g., input and output capacitors and other components that do not need to be located in a very close distance to the power dies. The second heat sink, cooling structure or case (optional) can be bonded direct on top of the Power Supply part 2 e.g. with TIM, thermal grease or even with soldering or sintering incase the top side metal layer is isolated from the devices.

The cooling structure is mounted and connected one or both sides of the Split Power Supply assembly and the isolation between the power module (part 1 and part 2) and heat sink is done with integrated isolation (inside the module). The cooling structure at least in part 1 can be connected electrically (soldering, sintering, conductive TIM) because the isolation is done inside the module with integrated isolation (back side of the module is not connected to the inner layers, the used isolation material can be e.g. normal PCB material or thermally enhanced PCB material - preferred option).

Figure 4 shows a cross section of a power supply assembly 400 according to a second embodiment.

The design of the power supply assembly 400 corresponds to the design described above with respect to Figure 1. However, following additional features can be implemented:

The first printed circuit 110 may comprise a thermal interface material layer 403 disposed at the top side 110a of the first printed circuit board 110. This thermal interface material layer 403 is configured to mechanically and thermally connect the first printed circuit board 110 to the heat sink 302 as can be seen from Figure 4. The thermal interface material layer 403 is electrically insulating.

Basic design considerations for this second embodiment can be described as follows:

The power components are embedded inside the Power Supply part 1 (110) by using normal ECP process. The embedded power components (in half bridge configuration, for example) can face same or opposite directions.

The additional components that are not embedded inside the module can be SMA mounted on the side of the Power Supply part 1 (110) that is facing toward the system board 130 (between the Power Supply 1 (110) and system board 130).

The top side of the module 110 can be connected to the heat sink 302 with isolating TIM, thermal grease or other isolating and thermally conductive material.

The embedded power dies 310, 311 are located close to the heat sink 302 and can be effectively cooled through the TIM layer 403.

The module 110 is connected to the system board 130 with Cu spacers that are thicker than the SMA components.

The Power Supply part 1 (110) is mounted on opposite side of the system board 130 and it at least partially overlaps the power module part 2 (120). The Power Supply part 2 (120) includes at least one or several embedded or SMA mounted components, e.g. inductor, capacitors, resistors or logic die. In the simplest case it can be e.g., module with embedded inductor that is soldered on the system board 130.

The system board 130 can include also additional SMA components, e.g. input and output capacitors and other components that do not need to locate that is very close distance e.g. to the power dies.

The second heat sink, cooling structure or case (optional) can be bonded directly on top of the Power Supply part 2 (120) e.g. with TIM, thermal grease or even with soldering or sintering incase the top side metal layer is isolated from the devices.

Figure 5 shows a cross section of a power supply assembly 500 according to a third embodiment.

The design of the power supply assembly 500 corresponds to the design described above with respect to Figure 1. However, following additional features can be implemented:

The first printed circuit board 110 comprises a top side 110a that is facing opposite to the top side 130a of the carrier board 130. The one or more power dies 310, 311 may be surface mounted with or without an exposed Copper clip at the top side 110a of the first printed circuit board 110.

Surface mounting with exposed Cu clip may be preferred. The clip that is connecting the source to the lead frame is exposer (grinded open).

The first printed circuit board 110 may comprises a thermal interface material layer 503 disposed at the top side 110a of the first printed circuit board 110. The thermal interface material layer 503 may be configured to mechanically and thermally connect the first printed circuit board 110 to a heat sink 302. The thermal interface material layer 503 may be electrically insulating. The one or more power dies 310, 311 may be embedded in the thermal interface material layer 503 as shown in Figure 5.

The first printed circuit board 110 may comprise one or more surface mount assembly, SMA, components 320 which can be surface-mounted at a bottom side 110b of the first printed circuit board 110 that is facing towards the top side 130a of the carrier board 130.

The power supply assembly 600 may comprise one or more spacers 305 electrically connecting the first printed circuit board 110 to the carrier board 130, wherein a thickness of the one or more spacers 305 is greater than a thickness of the one or more SMA components 320.

The one or more spacers 305 may be configured to vertically route part of the current path 101 from the first printed circuit board 110 to the carrier board 130 and vice versa, in order to reduce a distance of the current path 101 between the first printed circuit board 110 and the carrier board 130.

Basic design considerations for this third embodiment can be described as follows: The power components 310, 311 can be surface mounted on top of the Power Supply part 1 board 110 (between the substrate and heatsink). This allows the minimized distance between the power component top side and the heatsink that can be mounted on top of the SMA power components.

The power components can have exposed Cu clip to improve the heat dissipation (required better isolation between the components and heatsink).

The additional components can be embedded inside the module or SMA mounted on the side of the Power Supply part 1 (110) that is facing toward the system board 130 (between the Power Supply 1 and system board). Components that are thinner than the power components 310, 311 can also be mounted on the same side as the power components 310, 311 (not shown in Figure 5).

The module 110 may be connected to the system board 130 with soldering, for example.

The Power Supply part 1 can be mounted on opposite side of the system board 130 and it at least partially overlaps the power module part 2.

The Power Supply part 2 may include at least one or several embedded or SMA mounted components e.g., inductor, capacitors, resistors or logic die. In the simplest case it can be e.g., a module with embedded inductor that is soldered on the system board.

The system board 130 can include also additional SMA components, e.g. input and output capacitors and other components that do not need to be located in very close distance e.g. to the power dies 310, 311.

The second heat sink, cooling structure or case (optional) can be bonded directly on top of the Power Supply part 2, e.g. with TIM, thermal grease or even with soldering or sintering in case the top side metal layer is isolated from the devices.

The design of the power supply assembly 600 corresponds to the design described above with respect to Figure 1. However, following additional features can be implemented:

The one or more power dies 310, 311 may be embedded in the first printed circuit board 110. The first printed circuit board 110 comprises a top side 110a that is facing opposite to the top side 130a of the carrier board 130.

The first printed circuit board 110 may comprise one or more spacers 605 that are mounted at the top side 110a of the first printed circuit board 110 above the one or more power dies 310, 311.

The power supply assembly 100 may comprise a thermal interface material layer 603 disposed at the top side 110a of the first printed circuit board 110. This thermal interface material layer 603 may be configured to mechanically and thermally connect the first printed circuit board 110 to a heat sink 302. The thermal interface material layer 603 is electrically insulating. The thermal interface material layer 603 may be contacting the one or more spacers 605 for transferring heat of the one or more power dies 310, 311 to the heat sink 302.

The one or more spacers 605 may be embedded in a mold layer 606 at the top side 110a of the first printed circuit board 110. Additional electrical components 610 can be mounted at the top side 110a of the first printed circuit board 110 which are embedded in the mold layer 606.

Basic design considerations for this fourth embodiment can be described as follows:

The power components can be embedded inside the Power Supply part 1 board. A Cu spacer can be soldered on top of the embedded power dies.

The additional SMA components can be mounted on the top side of the Power Supply part 1 board (between the Power Supply 1 and heat sink).

The side where the additional components and Cu spacers are soldered can be protected with molding.

The Cu spacers may be exposed with grinding.

The module may be connected to the system board with soldering.

The heat sink may be connected to the exposed Cu spacers on the molded side of the Power Supply part 1 with isolated TIM, thermal grease or with other isolating and thermally conductive material.

The Power Supply part 2 may include at least one or several embedded or SMA mounted components, for example, e.g. inductor, capacitors, resistors or logic die. In the simplest case it can be e.g. a module with embedded inductor that is soldered on the system board.

The system board can include also additional SMA components e.g. input and output capacitors and other components that do not need to be located in very close distance e.g. to the power dies.

The second heat sink, cooling structure or case (optional) can be bonded directly on top of the Power Supply part 2, e.g., with TIM, thermal grease or even with soldering or sintering in case the top side metal layer is isolated from the devices.

While a particular feature or aspect of the disclosure may have been disclosed with respect to only one of several implementations, such feature or aspect may be combined with one or more other features or aspects of the other implementations as may be desired and advantageous for any given or particular application. Furthermore, to the extent that the terms "include", "have", "with", or other variants thereof are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term "comprise". Also, the terms "exemplary", "for example" and "e.g." are merely meant as an example, rather than the best or optimal. The terms “coupled” and “connected”, along with derivatives may have been used. It should be understood that these terms may have been used to indicate that two elements cooperate or interact with each other regardless whether they are in direct physical or electrical contact, or they are not in direct contact with each other. Although specific aspects have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific aspects shown and described without departing from the scope of the disclosure. This application is intended to cover any adaptations or variations of the specific aspects discussed herein.

Although the elements in the following claims are recited in a particular sequence with corresponding labeling, unless the claim recitations otherwise imply a particular sequence for implementing some or all of those elements, those elements are not necessarily intended to be limited to being implemented in that particular sequence. Many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the above teachings. Of course, those skilled in the art readily recognize that there are numerous applications of the disclosure beyond those described herein. While the disclosure has been described with reference to one or more particular embodiments, those skilled in the art recognize that many changes may be made thereto without departing from the scope of the disclosure. It is therefore to be understood that within the scope of the appended claims and their equivalents, the disclosure may be practiced otherwise than as specifically described herein.

Claims

CLAIMS i. A power supply assembly (100), comprising: a first printed circuit board (110) carrying one or more power dies (310, 311); a second printed circuit board (120) carrying at least one electrical component (122), the at least one electrical component (122) being arranged within an electrical distance to the one or more power dies (310, 311); and a carrier board (130) having a top side (130a) and a bottom side (130b) opposite to the top side (130a), wherein the first printed circuit board (110) and the second printed circuit board (120) are mounted on opposite sides (130a, 130b) of the carrier board (130) to enable a double-side cooling (111, 121) of the power supply assembly (100); wherein the one or more power dies together with the at least one electrical component are configured to receive electrical power along a current path (101) from a source to a load, wherein the current path (101) is traversing the first printed circuit board (110), the second printed circuit board (120) and the carrier board (130); wherein the first printed circuit board (110) and the second printed circuit board (120) are mounted at least partially overlapping on the opposite sides (130a, 130b) of the carrier board (130) such that a part of the current path (101) is arranged vertically between the top side (130a) and the bottom side (130b) of the carrier board (130), in order to reduce the electrical distance between the one or more power dies on the first printed circuit board (110) and the at least one electrical component on the second printed circuit board (120) and to enable double sided cooling.

2. The power supply assembly (100) of claim 1, wherein the carrier board (130) comprises a through- via (301) configured to vertically route the part of the current path (101) through the carrier board (130).

3. The power supply assembly (100) of claim 1 or 2, wherein the one or more power dies (310, 311) are embedded in the first printed circuit board (110).

4. The power supply assembly (100) of claim 3, wherein the first printed circuit board (110) comprises a top side (110a) that is facing opposite to the top side (130a) of the carrier board (130); wherein the first printed circuit board (110) comprises a thermally conductive electrically isolating layer (304) that is embedded inside the first printed circuit board (110) between the one or more power dies (310, 311) and the top side (110a) of the first printed circuit board (110), the thermally conductive electrically isolating layer (304) being configured to transfer heat of the one or more power dies (310, 311) to a heat sink (302) mountable at the top side (110a) of the first printed circuit board (110).

5. The power supply assembly (100) of claim 4, wherein the first printed circuit (110) comprises a thermal interface material layer (303) disposed at the top side (110a) of the first printed circuit board (110), the thermal interface material layer (303) being configured to mechanically and thermally connect the first printed circuit board (110) to the heat sink (302); wherein the thermal interface material layer (303) is electrically conductive or is at least composed of electrically conductive parts to improve the heat transfer.

6. The power supply assembly (100) of claim 5, wherein the thermal interface material layer (303) is soldered or laminated to the first printed circuit board (110), or in mechanical connection with the first printed circuit board (110) by pressure and/or screws.

7. The power supply assembly (100) of claim 3, wherein the first printed circuit board (110) comprises a top side (110a) that is facing opposite to the top side (130a) of the carrier board (130); wherein the first printed circuit (110) comprises a thermal interface material layer (403) disposed at the top side (110a) of the first printed circuit board (110), the thermal interface material layer (403) being configured to mechanically and thermally connect the first printed circuit board (110) to the heat sink (302); wherein the thermal interface material layer (403) is electrically insulating.

8. The power supply assembly (100) of claim 1 or 2, wherein the first printed circuit board (110) comprises a top side (110a) that is facing opposite to the top side (130a) of the carrier board (130); wherein the one or more power dies (310, 311 ) are surface mounted with or without an exposed Copper clip at the top side (110a) of the first printed circuit board (110).

9. The power supply assembly (100) of claim 8, wherein the first printed circuit (110) comprises a thermal interface material layer (503) disposed at the top side (110a) of the first printed circuit board (110), the thermal interface material layer (503) being configured to mechanically and thermally connect the first printed circuit board (110) to a heat sink (302); wherein the thermal interface material layer (503) is electrically insulating; wherein the one or more power dies (310, 311 ) are embedded in the thermal interface material layer (503).

10. The power supply assembly (100) of any of claims 3 to 9, wherein the first printed circuit board (110) comprises one or more surface mount assembly, SMA, components (320) which are surface-mounted at a bottom side (110b) of the first printed circuit board (110) that is facing towards the top side (130a) of the carrier board (130); and wherein the power supply assembly (100) comprises one or more spacers (305) electrically connecting the first printed circuit board (110) to the carrier board (130), wherein a thickness of the one or more spacers (305) is greater than a thickness of the one or more SMA components (320).

11. The power supply assembly (100) of claim 10, wherein the one or more spacers (305) are configured to vertically route part of the current path (101) from the first printed circuit board (110) to the carrier board (130) and vice versa, in order to reduce a distance of the current path (101) between the first printed circuit board (110) and the carrier board (130).

12. The power supply assembly (100) of claim 1 or 2, wherein the one or more power dies (310, 311 ) are embedded in the first printed circuit board (110); wherein the first printed circuit board (110) comprises a top side (110a) that is facing opposite to the top side (130a) of the carrier board (130); wherein the first printed circuit board (110) comprises one or more spacers (605) that are mounted at the top side (110a) of the first printed circuit board (110) above the one or more power dies (310, 311); wherein the power supply assembly (100) comprises a thermal interface material layer (603) disposed at the top side (110a) of the first printed circuit board (110), the thermal interface material layer (603) being configured to mechanically and thermally connect the first printed circuit board (110) to a heat sink (302); wherein the thermal interface material layer (603) is electrically insulating; wherein the thermal interface material layer (603) is contacting the one or more spacers (605) for transferring heat of the one or more power dies (310, 311) to the heat sink (302).

13. The power supply assembly (100) of claim 12, wherein the one or more spacers (605) are embedded in a mold layer (606) at the top side (110a) of the first printed circuit board (110); wherein additional electrical components (610) are mounted at the top side (110a) of the first printed circuit board (110) which are embedded in the mold layer (606).

14. The power supply assembly (100) of any of the preceding claims, wherein the one or more power dies (310, 311) are electrically connected to form a half-bridge configuration.

15. The power supply assembly (100) of any of the preceding claims, wherein the at least one electrical component (122) comprises at least one inductor and optionally passive electrical components, capacitors and/or drivers.

16. The power supply assembly (100) of any of the preceding claims, wherein the at least one electrical component (122) is surface-mounted at a top side of the second printed circuit board (120) or embedded inside the second printed circuit board (120).

17. The power supply assembly (100) of any of the preceding claims, wherein one or more passive electrical components (131, 132, 133, 134, 135, 136, 137) which are electrically connected to the one or more power dies (310, 311) and/or the at least one electrical component (122) are mounted on the top side (130a) and/or the bottom side (130b) of the carrier board (130).