Apparatus and method for improving microinverter life

Abstract

An apparatus comprising: a first set of components on a first plate; a second group of components on the second plate, wherein the components of the first group of components are heat generating components configured to generate more heat than the components of the second group of components; and a plurality of connecting elements electrically coupled between the first component group and the second component group, where portions of the plurality of connecting elements are located in the thermal resistance medium, and the first component group and the second component group are separated by the thermal resistance medium.

Description

[0001] This application claims priority to U.S. Provisional Application No. 63 / 547,813, filed on November 8, 2023, entitled “DEVICES AND METHODS FOR IMPROVING MICROINVERTER LIFE,” which is hereby referenced and incorporated into this application. Technical Field

[0002] The present invention relates to a device and method for improving the life of a power conversion device, and in a specific embodiment, to a device and method for improving the life of a micro inverter by mounting heat-generating components and non-heat-generating components on different boards and separating the heat-generating components from the non-heat-generating components by a thermal resistance medium. Background Art

[0003] The renewable energy system includes multiple power sources and a power conversion system that generate direct current (DC) electricity. The multiple power sources can be multiple solar panels. The power conversion system converts the direct current into alternating current (AC) electricity. The AC electricity can be fed into the power grid. The power grid connected to the renewable energy system has an AC voltage of about 240 volts and 60 hertz.

[0004] In some solar applications, a single inverter can convert the DC output voltage of multiple solar panels into AC voltage. Multiple solar panels can be connected in series and then connected to a central inverter. The central inverter converts the DC voltage of the series solar panels into an AC voltage suitable for the grid. Another approach is to use a single microinverter on each solar panel. A microinverter is a system that converts the DC voltage of a single solar panel into AC voltage. The power from multiple microinverters is combined and fed into the grid.

[0005] The micro inverter includes an input filter, a DC / DC power converter, various bus capacitors, a PWM inverter, an output filter, a control unit, and various sensing and protection circuits. The DC / DC power converter can be implemented as an isolated interleaved boost converter. The DC / DC power converter includes various heat generating components, such as a power switch and an isolation transformer. The PWM DC / AC inverter also includes various heat generating components, such as a power switch. The input filter can include one electrolytic capacitor or multiple electrolytic capacitors connected in parallel. The micro inverter can be packaged in a module.

[0006] Figure 1A micro inverter module is shown. The micro inverter includes a plurality of components (e.g., a power switch, a transformer, an inductor, various capacitors, and a control circuit) mounted on a printed circuit board (e.g., a single-layer or multi-layer fiberglass printed circuit board, a single-layer or multi-layer ceramic printed circuit board, etc.). The printed circuit board is encapsulated in a housing. A sealant (e.g., a potting compound material) is filled in the housing. In particular, the sealant is formed around the plurality of components to substantially surround the plurality of components. The sealant may be a thermosetting epoxy molding compound. Once the sealant has filled the housing, a Figure 1 The brick-shaped power conversion module shown.

[0007] In existing microinverters, all electronic components are encapsulated with thermosetting epoxy molding compound. The temperature is transferred from the inside to the outside, so the internal temperature must be higher than the temperature of the housing of the microinverter module. For example, if the temperature of the housing of the brick-shaped power conversion module 100 is about 100 degrees, the internal temperature of the module may be about 120 degrees. The high temperature inside the brick-shaped power conversion module 100 may damage the life of some components that are prone to overheating, such as electrolytic capacitors or control circuits. Therefore, existing microinverters cannot easily meet the 25-year life requirement of existing solar applications.

[0008] The life of electronic components is directly related to temperature. Operating temperature has a significant impact on the performance, safety and service life of electronic components. Basically, for every ten degrees increase in temperature, the life of electronic components will be reduced by half. If the temperature of electronic components can be reduced, the life span will definitely be improved. The present disclosure addresses this need. Summary of the invention

[0009] These and other problems are generally solved or circumvented, and technical advantages are generally achieved, by the preferred embodiments of the present disclosure, which provide an apparatus and method for improving the life of a micro inverter by mounting heat-generating components and non-heat-generating components on different boards and separating the heat-generating components from the non-heat-generating components by a thermally resistive medium.

[0010] According to one embodiment, a device includes: a first component group on a first board; a second component group on a second board, wherein the components of the first component group are heat-generating components configured to generate more heat than the components of the second component group; and a plurality of connecting elements electrically connected between the first component group and the second component group, wherein portions of the plurality of connecting elements are located in a thermal resistance medium, and the first component group and the second component group are separated by the thermal resistance medium.

[0011] According to another embodiment, a microinverter includes power switches and magnetics on a first board, a control integrated circuit on a second board, and a plurality of connection elements electrically coupled between the first board and the second board, wherein portions of the plurality of connection elements are located in a thermally resistive medium.

[0012] According to another embodiment, a method includes providing a power conversion system including a first board, a first component group on the first board, a second board, a second component group on the second board, and a plurality of connecting elements between the first board and the second board, forming a first potting compound layer on the first board using a first liquid potting compound material, wherein the highest surface of the first component group is lower than a top surface of the first potting compound layer, hardening the first potting compound layer, forming a second potting compound layer on the first potting compound layer using a second liquid potting compound material, wherein the lowest surface of the second component group is higher than a top surface of the second potting compound layer, hardening the second potting compound layer, forming a third potting compound layer on the second potting compound layer using a third liquid potting compound material, wherein an upper surface of the third potting compound layer contacts the second board, and hardening the third potting compound layer.

[0013] The above is a fairly broad overview of the features and technical advantages of the present disclosure so that the subsequent detailed description of the present disclosure can be better understood. Additional features and advantages of the present disclosure will be described below, which form the subject matter of the claims of the present disclosure. It should be understood by those skilled in the art that the disclosed concepts and specific embodiments can be easily used as a basis for modifying or designing other structures or processes to achieve the same purpose as the present disclosure. It should also be recognized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the present disclosure set forth in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:

[0015] Figure 1 A microinverter module is shown;

[0016] Figure 2 shows a block diagram of a power conversion module according to various embodiments of the present disclosure;

[0017] Figure 3 Various embodiments according to the present disclosure are shown. Figure 2 A first embodiment of the power conversion module is shown;

[0018] Figure 4 Various embodiments according to the present disclosure are shown. Figure 3 The embodiments of the first component group and the second component group shown;

[0019] Figure 5 Various embodiments according to the present disclosure are shown. Figure 2 A second embodiment of the power conversion module shown;

[0020] Figure 6 Various embodiments according to the present disclosure are shown. Figure 2 A third embodiment of the power conversion module is shown;

[0021] Figure 7 and Figure 8 Various embodiments according to the present disclosure are shown. Figure 2 A fourth embodiment of the power conversion module shown; and

[0022] Fig. 9 Shows Figure 6 Flow chart of a method for manufacturing a power conversion module shown in .

[0023] Corresponding numerals and symbols in the different figures generally refer to corresponding components unless otherwise indicated.The figures are drawn to clearly illustrate the relevant aspects of the various embodiments and are not necessarily drawn to scale. DETAILED DESCRIPTION

[0024] The implementation and use of the currently preferred embodiments are discussed in detail below. However, it should be understood that the present disclosure provides many applicable inventive concepts that can be embodied in a variety of specific environments. The specific embodiments discussed are only to illustrate the specific ways to implement and use the present disclosure, and do not limit the scope of the present disclosure.

[0025] The present disclosure will be described in conjunction with a preferred embodiment in a specific context, namely, an apparatus and method for improving the life of a micro inverter by mounting a heat generating component and a non-heat generating component on different boards and separating the heat generating component from the non-heat generating component through a thermal resistance medium. However, the present disclosure can also be applied to various power conversion systems, such as outdoor uninterruptible power supply (UPS) systems, on-board chargers for electric vehicle (EV) applications, outdoor communication power supplies, communication base station power supplies, solar energy optimizers, high-power motor drive inverters, etc. In the following, various embodiments will be explained in detail with reference to the accompanying drawings.

[0026] Figure 2A block diagram of a power conversion device according to various embodiments of the present disclosure is shown. In some embodiments, the power conversion device is a micro inverter. The micro inverter includes a first component group 101, a second component group 102, and a plurality of connecting elements 103. In some embodiments, the first component group 101 is located on a first board. The second component group 102 is located on a second board. The components of the first component group 101 are heating elements that are configured to generate more heat than the components of the second component group 102. In a micro inverter, power switches and magnetic devices (such as transformers and / or inductors) are considered to be heating elements of the micro inverter. The remaining components are considered to be non-heating elements. Depending on different applications and design requirements, some capacitors can be considered as heating elements. For example, the resonant capacitor of an inductor-inductor-capacitor (LLC) resonant converter can be considered as a heating element because a large amount of current flows through the resonant capacitor.

[0027] The plurality of connection elements 103 are electrically connected between the first component group 101 and the second component group 102. Parts of the plurality of connection elements 103 are located in the thermal resistance medium. The first component group 101 and the second component group 102 are separated by the thermal resistance medium.

[0028] In some embodiments, multiple connecting elements can be implemented as multiple cables, which are configured to conduct multiple signals and / or power between the first board and the second board. In an alternative embodiment, at least some of the thermally conductive signal cables are replaced by one or more wireless communication channels, and some control signals flow between the first board and the second board through these channels. In addition, at least some of the thermally conductive power cables are replaced by one or more wireless transmission channels. For example, bias power can be transferred from the second board to the first board. The bias power can be transmitted through a wireless power transmission channel, which includes a transmitting circuit, a transmitting coil, a receiving coil magnetically coupled to the transmitting coil, and a receiving circuit.

[0029] In some embodiments, the heat-resistance medium is air. In an alternative embodiment, the heat-resistance medium may be a suitable heat-resistance material filled between the first component group 101 and the second component group 102 .

[0030] In some embodiments, the first plate is a fast heat conduction plate. The second plate is a printed circuit board. In some embodiments, the fast heat conduction plate is a thermally conductive and electrically isolated ceramic printed circuit board. In an optional embodiment, the fast heat conduction plate is a thermally conductive and electrically isolated metal plate, which has a metal support plate, a dielectric layer above the metal support plate, and a circuit layer above the dielectric layer. The metal support plate is made of aluminum. The circuit layer is made of copper.

[0031] In some embodiments, the components of the first component group 101 include heat generating components, such as a power switch. The components of the second component group include a plurality of integrated circuits and at least one electrolytic capacitor. The first component group is located in a first module.

[0032] In a first embodiment of a microinverter, the microinverter includes an input filter coupled to a photovoltaic panel, a single-stage DC / AC inverter without galvanic isolation, and an output filter. The input filter includes at least one electrolytic capacitor. The single-stage DC / AC inverter can be implemented as a full-bridge DC / AC inverter including four power switches. The electrolytic capacitor is coupled to a photovoltaic bus. The electrolytic capacitor is used to control voltage ripple on the photovoltaic bus.

[0033] In the first embodiment of the microinverter, the components of the first component group 101 may include the power switch of the single-stage DC / AC inverter and the inductor of the output filter. For ease of layout and compactness, the gate driver of the power switch and the output capacitor of the output filter may also be included in the first component group 101. The electrolytic capacitor, the integrated circuit for controlling the single-stage DC / AC inverter, and the passive components associated with the integrated circuit are included in the second component group 102.

[0034] like Figure 2 As shown, the first component group 101 and the second component group 102 are separated by a heat-resistance medium (e.g., air). Therefore, the heat-generating components (e.g., power switches) and the non-heat-generating components (e.g., integrated circuits) are separated by the heat-resistance medium. Therefore, the heat-generating components will not cause a significant increase in the temperature of the non-heat-generating components that are prone to overheating.

[0035] In a second embodiment of the microinverter, the microinverter includes an input filter coupled to a photovoltaic panel, a single-stage DC / AC inverter without galvanic isolation, and an output filter. The input filter does not include an electrolytic capacitor. Other suitable capacitors (e.g., tantalum capacitors, ceramic capacitors, etc.) are used instead of electrolytic capacitors. The single-stage DC / AC inverter can be implemented as a full-bridge inverter including four power switches.

[0036] In a second embodiment of the micro-inverter, the components of the first component group 101 may include a power switch of a single-stage DC / AC inverter and an inductor of an output filter. For ease of layout and compactness, capacitors in the input filter, gate drivers of the power switch, and output capacitors of the output filter may also be included in the first component group 101. Integrated circuits for controlling the single-stage DC / AC inverter and passive components associated with the integrated circuit are included in the second component group 102. Similar to the first embodiment, heat-generating components (e.g., power switches) and non-heat-generating components (e.g., integrated circuits) are separated by a thermally resistive medium. Therefore, the heat-generating components do not cause a significant increase in the temperature of non-heat-generating components that are susceptible to overheating.

[0037] In a third embodiment of the microinverter, the microinverter includes an input filter coupled to a photovoltaic panel, a single-stage DC / DC converter without galvanic isolation, a DC link, a DC / AC inverter without galvanic isolation, and an output filter. The input filter includes at least one electrolytic capacitor. The single-stage DC / DC converter can be implemented as a boost converter. The DC / AC inverter can be implemented as a full-bridge DC / AC inverter. The electrolytic capacitor is coupled to a photovoltaic bus.

[0038] In a third embodiment of the microinverter, the components of the first component group 101 may include a power switch and an inductor of a single-stage DC / DC converter, a power switch of a DC / AC inverter, and an inductor of an output filter. For ease of layout and compactness, the gate driver of the power switch, the capacitor of the DC link, and the output capacitor of the output filter may also be included in the first component group 101. Electrolytic capacitors, integrated circuits for controlling the single-stage DC / AC converter and the DC / AC inverter, and passive components associated with the integrated circuits are included in the second component group 102. Similar to the first embodiment, heat-generating components (such as power switches) and non-heat-generating components (such as integrated circuits) are separated by a thermally resistive medium. Therefore, the heat-generating components do not cause a significant increase in the temperature of non-heat-generating components that are susceptible to overheating.

[0039] In a fourth embodiment of the microinverter, the microinverter includes an input filter coupled to a photovoltaic panel, a single-stage DC / DC converter without electrical isolation, a DC link, a DC / AC inverter without current isolation, and an output filter. The input filter does not include an electrolytic capacitor. Other suitable capacitors (e.g., tantalum capacitors, ceramic capacitors, etc.) are used instead of electrolytic capacitors. The single-stage DC / DC converter can be implemented as a boost converter. The DC / AC inverter can be implemented as a full-bridge inverter.

[0040] In a fourth embodiment of the micro-inverter, the components of the first component group 101 may include a power switch and an inductor of a single-stage DC / DC converter, a power switch of a DC / AC inverter, and an inductor of an output filter. For ease of layout and compactness, an input capacitor of an input filter, a gate driver of a power switch, a DC link capacitor, and an output capacitor of an output filter may also be included in the first component group 101. Integrated circuits for controlling a single-stage DC / DC converter and a DC / AC inverter, and passive components associated with the integrated circuits are included in the second component group 102. Similar to the first embodiment, heat generating components (e.g., power switches) and non-heat generating components (e.g., integrated circuits) are separated by a thermally resistive medium. Therefore, the heat generating components do not cause a significant increase in the temperature of non-heat generating components that are susceptible to overheating.

[0041] In a fifth embodiment of the microinverter, the microinverter comprises an input filter coupled to a photovoltaic panel, a single-stage DC / AC inverter with galvanic isolation, and an output filter. The input filter comprises at least one electrolytic capacitor. The single-stage DC / AC inverter can be implemented as a full-bridge inverter including a transformer.

[0042] In a fifth embodiment of the microinverter, the components of the first component group 101 may include a power switch of a single-stage DC / AC inverter, a transformer of a single-stage DC / AC inverter, and an inductor of an output filter. For ease of layout and compactness, the gate driver of the power switch and the output capacitor of the output filter may also be included in the first component group 101. The electrolytic capacitor, the integrated circuit for controlling the single-stage DC / AC inverter, and the passive components associated with the integrated circuit are included in the second component group 102. Similar to the first embodiment, the heat-generating component (e.g., the power switch) and the non-heat-generating component (e.g., the integrated circuit) are separated by a thermally resistive medium. Therefore, the heat-generating component does not cause a significant increase in the temperature of the non-heat-generating component that is susceptible to overheating.

[0043] In a sixth embodiment of the microinverter, the microinverter includes an input filter coupled to a photovoltaic panel, a single-stage DC / AC inverter without electrical isolation, and an output filter. The input filter does not include an electrolytic capacitor. Other suitable capacitors (such as tantalum capacitors, ceramic capacitors, etc.) are used instead of electrolytic capacitors. The single-stage DC / AC inverter can be implemented as a full-bridge inverter including a transformer.

[0044] In a sixth embodiment of the microinverter, the components of the first component group 101 may include a power switch, a transformer, and an inductor of an output filter of a single-stage DC / AC inverter. For ease of layout and compactness, a capacitor of an input filter, a gate driver of a power switch, and an output capacitor of an output filter may also be included in the first component group 101. Integrated circuits for controlling a single-stage DC / AC inverter and passive components associated with the integrated circuit are included in the second component group 102. Similar to the first embodiment, heat generating components (e.g., a power switch) and non-heat generating components (e.g., an integrated circuit) are separated by a thermally resistive medium. Therefore, the heat generating components do not cause a significant increase in the temperature of non-heat generating components that are susceptible to overheating.

[0045] In a seventh embodiment of the microinverter, the microinverter includes an input filter coupled to a photovoltaic panel, a live single-stage DC / DC converter, a DC link, a DC / AC inverter without electrical isolation, and an output filter. The input filter includes at least one electrolytic capacitor. The single-stage DC / DC converter can be implemented as any isolated DC / DC converter, such as a flyback converter, an LLC resonant converter, and any combination thereof. The DC / AC inverter can be implemented as a full-bridge inverter.

[0046] In a seventh embodiment of the microinverter, the components of the first component group 101 may include a transformer in a power switch and a single-stage DC / DC converter, a power switch of a DC / DC inverter, and an inductor of an output filter. For ease of layout and compactness, the gate driver of the power switch, the capacitor of the DC link, and the output capacitor of the output filter may also be included in the first component group 101. Electrolytic capacitors, integrated circuits for controlling single-stage DC / DC converters and DC / AC inverters, and passive components associated with the integrated circuits are included in the second component group 102. Similar to the first embodiment, heat-generating components (e.g., power switches) and non-heat-generating components (e.g., integrated circuits) are separated by a thermally resistive medium. Therefore, the heat-generating components do not cause a significant increase in the temperature of non-heat-generating components that are susceptible to overheating.

[0047] In an eighth embodiment of the microinverter, the microinverter includes an input filter coupled to a photovoltaic panel, a single-stage DC / DC converter without current isolation, a DC link, a DC / AC inverter without current isolation, and an output filter. The input filter does not include an electrolytic capacitor. Other suitable capacitors (such as tantalum capacitors, ceramic capacitors, etc.) are used to replace the electrolytic capacitors. The single-stage DC / DC converter can be implemented as any isolated DC / DC converter, such as a flyback converter, an LLC resonant converter, and any combination thereof. The DC / AC inverter can be implemented as a full-bridge inverter.

[0048] In an eighth embodiment of the micro-inverter, the components of the first component group 101 may include a power switch and a transformer of a single-stage DC / DC converter, a power switch of a DC / AC inverter, and an inductor of an output filter. For ease of layout and compactness, the first component group 101 may include an input capacitor of an input filter, a gate driver of a power switch, a capacitor of a DC link, and an output capacitor of an output filter. The second component group 102 may include an integrated circuit for controlling a single-stage DC / DC converter and a DC / AC inverter, and passive components associated with the integrated circuit. Similar to the first embodiment, a heat generating component (e.g., a power switch) and a non-heat generating component (e.g., an integrated circuit) are separated by a thermally resistive medium. Therefore, the heat generating component does not cause a significant increase in the temperature of a non-heat generating component that is susceptible to overheating.

[0049] In some embodiments, the components of the first component group 101 are surrounded by a first potting compound material. The first component group 101 is located in a first module. The components of the second group 102 are surrounded by a second potting compound material. The second component group 102 is located in a second module.

[0050] Each of the plurality of connection elements 103 includes three parts. The first part of the plurality of connection elements 103 is located in the first module and is surrounded by the first encapsulation compound material. The middle part of the plurality of connection elements 103 is surrounded by a thermal resistance medium (e.g., air). The second part of the plurality of connection elements 103 is located in the second module and is surrounded by the second encapsulation compound material.

[0051] In some embodiments, the micro inverter is implemented on two open frame packages. The first component group 101 is located on the first open frame package. The second component group 102 is located on the second open frame package. A plurality of connecting elements are connected between the first open frame package and the second open frame package.

[0052] The first open frame package includes a first thermally conductive and electrically isolating metal plate. The components of the first component group 101 are mounted on the first thermally conductive and electrically isolating metal plate. The second open frame package includes a second thermally conductive and electrically isolating metal plate. The components of the second component group 102 are mounted on the second thermally conductive and electrically isolating metal plate.

[0053] In the first embodiment of the micro inverter based on the open frame package, the first potting compound material partially covers the components of the first component group 101. The second potting compound material partially covers the components of the second component group 102.

[0054] In a second embodiment of the micro inverter based on the open frame package, the first metal housing covers a portion of the components of the first component group, and the second metal housing covers a portion of the components of the second component group.

[0055] In a third embodiment of the micro inverter based on the open frame package, the first metal mesh covers a portion of the components of the first component group, and the second metal mesh covers a portion of the components of the second component group.

[0056] In some embodiments, the metal housing and the metal mesh cover are used for local EMI isolation. In some embodiments, the potting compound material, the metal housing and the metal mesh cover are used for local heat dissipation. In some embodiments, the potting compound material, the metal housing and the metal mesh cover are used to partially protect components in harsh environments.

[0057] In some embodiments, the electrolytic capacitor is electrically coupled to the second component group 102. The electrolytic capacitor and the second component group 102 are located in two different modules. The two different modules are separated by a thermally resistive medium.

[0058] In some embodiments, the electrolytic capacitor is electrically coupled to the second component group 102. The electrolytic capacitor, the first component group 101, and the second component group 102 are located in three different modules. The three different modules are separated by a thermal resistance medium.

[0059] In some embodiments, the first component group 101 is located in a first module. The first board is a fast thermal conductive board, and the first potting compound material partially covers the components of the first component group 101. The second component group 102 is located in a second module. The second board is a printed circuit board, and the second potting compound material partially covers the components of the second component group 102.

[0060] In some embodiments, the first component group 101 is located in a first module. The first board is a fast heat conduction board, and the first metal shielding shell covers the components of the first component group 101. The second component group is located in a second module. The second board is a printed circuit board, and the second metal shielding shell covers the components of the second component group 102.

[0061] In some embodiments, the first component group 101 is located in a first module. The first board is a fast heat conduction board, and the first metal mesh covers the components of the first component group 101. The second component group 102 is located in a second module. The second board is a printed circuit board, and the second metal mesh covers the components of the second component group 102.

[0062] The components of microinverters can be divided into two groups. The first group (e.g. Figure 2 The first component group 101 shown in FIG. 1 includes about 30% of the total components of the microinverter. 30% of the total components are heat generating components, such as power switches and magnetic components. The second group (e.g., Figure 2 The second component group 102 shown in FIG. 1 includes about 70% of the total components of the microinverter. 70% of the total components generate no heat or very little heat. The second group includes various control and signal processing circuits, such as a controller configured to control the operation of the microinverter.

[0063] exist Figure 1 In the package of the conventional micro inverter shown, since the heat is radiated from the inside to the outside, the temperature inside is necessarily higher than the outside, and the temperature difference is usually about 20 degrees.

[0064] During operation, assuming that the temperature of the chassis on the first component group (heat-generating components) is 100 degrees, the temperature of the components in the second component group that are isolated from the heat will be much lower than the temperature of the chassis on the hot end (the first component group), such as 70 degrees. In this case, Figure 2 The temperature difference between the microinverter shown and a conventional microinverter (all components in one package) is about 30 degrees (100 degrees - 70 degrees) plus 20 degrees (the internal temperature is about 20 degrees higher than the chassis), which is 50 degrees. 70% of the components will be below Figure 1 The temperature of the brick package shown. The temperature is reduced by 50 degrees. It is understood that for every 10 degrees of temperature reduction, the life span can be extended by 50%. Then, the life span of 70% of the components will be extended by 32 times. This is a significant improvement in life.

[0065] A lot of data shows that the failure of micro inverters is caused by 70% of the components (non-heat generating components). Figure 2 With the packaging method shown, the life of the micro inverter will be greatly improved.

[0066] Electrolytic capacitors are the most important components in the life of micro inverters. Theoretically, electrolytic capacitors are the components with the shortest life in micro inverter design. Figure 1 The prior art method shown in FIG. 1 encapsulates the electrolytic capacitor in the micro inverter. If the outside temperature is 100 degrees, the temperature of the electrolytic capacitor will be in the range of about 110 degrees to about 120 degrees. Figure 2 As shown, the electrolytic capacitors are located in the second component group 102. The electrolytic capacitors are separated from the heat generating elements.

[0067] During operation, the temperature of the first component group (heat generating component) is 100 degrees. At the same time, the temperature of the second group is in the range of about 70 degrees to about 80 degrees. The highest temperature of the electrolytic capacitor is 80 degrees. Figure 1 Compared with the original one shown, the temperature of the electrolytic capacitor is reduced by 40 degrees from 120 degrees to 80 degrees, which is equivalent to a 16-fold increase in the life of the electrolytic capacitor.

[0068] Figure 3 Various embodiments according to the present disclosure are shown. Figure 2 The first embodiment of the power conversion device shown in FIG. 1 is a first embodiment of the power conversion device shown in FIG. 1 . The components of the micro inverter are divided into two groups. The first component group includes thermal components. In other words, the components of the first component group are heat generating components. The group corresponds to Figure 2 The first component group 101 is shown. The second component group includes cold components. In other words, the components of the second component group generate no heat or very little heat. This group corresponds to Figure 2 A second component group 102 is shown.

[0069] In some embodiments, the components of the second component group (non-heat generating components) are encapsulated in the bottom module 302. In some embodiments, the bottom module 302 can be formed by applying a potting compound material on a board on which the non-heat generating components are installed. The components of the first component group (heat generating components) are encapsulated in the top module 306. In some embodiments, the top module 306 can be formed by applying a potting compound material on a board on which the heat generating components are installed. The two modules are connected by various cables 304. The non-heat generating components and the heat generating components are separated by a thermal resistance medium such as air. Since the non-heat generating components are separated from the heat generating components by air, the temperature of the cold components (non-heat generating components) will be much lower than that of the hot components (heat generating components). In some embodiments, the temperature difference is about 30 degrees. This temperature difference helps to increase the service life of the non-heat generating components, thereby increasing the life of the micro inverter.

[0070] Figure 4 Various embodiments according to the present disclosure are shown. Figure 3 The first component group and the second component group are shown in the embodiment of the bottom module 302 (such as Figure 3 ) includes a bottom plate 402 and a plurality of non-heat generating components 403 mounted on the bottom plate 402. The top module 306 (as shown in Figure 3 As shown) includes a top plate 406 and a plurality of heat-generating components 405 mounted on the top plate 406.

[0071] In some embodiments, the top plate 406 is implemented as a fast thermal conductive substrate, such as an aluminum substrate, and the bottom circuit board is implemented as a printed circuit board, such as a FR4 printed circuit board (PCB).

[0072] Figure 5 Various embodiments according to the present disclosure are shown. Figure 2 The second embodiment of the power conversion device shown in the figure has all thermal components placed on a fast thermal conductive substrate 502. All thermal components are exposed to the air, which is beneficial to heat dissipation.

[0073] like Figure 5 As shown in FIG. 5 , all heat generating components are placed on a fast heat conducting substrate 502. Assuming the chassis is 100 degrees, all heat generating components are Figure 1 The temperature of the original package shown (eg, 120 degrees) is 20 degrees lower.

[0074] Figure 5The packaging technology shown can also be summarized as an open frame packaging technology, that is, all thermal components are placed on a layer of fast thermal conduction substrate, such as an aluminum substrate or a ceramic substrate. The heat generating components are mounted on the fast thermal conduction substrate. Other components that do not generate heat are placed on the FR4 board. The FR4 board is electrically connected to the fast thermal conduction substrate through a plurality of connection elements such as PCB through-hole pins, and the heat conduction between the fast thermal conduction substrate and the FR4 board is blocked. The thermal resistance medium can be air or other non-thermal conductive materials.

[0075] In this case, most of the non-heat-generating components are on this FR4 board, so its temperature will be much lower than on a fast thermal conductive substrate because both use insulating materials (such as air) to isolate the heat.

[0076] Figure 6 Various embodiments according to the present disclosure are shown. Figure 2 A third embodiment of a power conversion device is shown. Figure 6 The power conversion device shown is a micro inverter. The components of the power conversion device are divided into two groups. The first component group 603 includes a power switch and a magnetic device. The second component group 605 includes the remaining components including at least one integrated circuit. The components of the first component group 603 are heat generating elements configured to generate more heat than the components of the second component group 605.

[0077] The components of the first component group 603 are mounted on the first substrate 602. In some embodiments, the first board 602 is a fast heat conduction board. The fast heat conduction board can be implemented as an aluminum substrate, a ceramic substrate, etc. The components of the second component group 605 are mounted on the second substrate 606. In some embodiments, the second substrate 606 is a printed circuit board. A plurality of connecting elements 604 are connected between the first board 602 and the second board 606. In some embodiments, the plurality of connecting elements 604 are implemented as Figure 6 The connection pins are shown in .

[0078] Figure 6 Further illustrated are three potting compound layers formed between the first plate 602 and the second plate 606. During the process of forming the three potting compound layers, the four sidewalls may be temporarily placed between the first plate 602 and the second plate 606. A first potting compound layer 612 is formed on the first plate 602 using a first liquid potting compound material such as an epoxy potting compound. In some embodiments, the topmost surface of the first component group 603 is lower than the top surface of the first potting compound layer 612. A suitable hardening process such as a curing process is applied to the first potting compound layer 612. Once the hardening process is completed, a second potting compound layer 614 is formed on the first potting compound layer 612 using a second liquid potting compound material. The bottommost surface of the second component group 605 is higher than the top surface of the second potting compound layer 614.

[0079] In some embodiments, the second liquid potting compound material is a compound material having a low thermal conductivity. Materials such as certain epoxy formulations, silicone rubber, or polyurethane compounds may be selected for their insulating properties.

[0080] A suitable hardening process, such as a curing process, is applied to the second potting compound layer 614. Once the hardening process is complete, a third potting compound layer 616 is formed over the second potting compound layer 614 using a third liquid potting compound material. The topmost surface of the third potting compound layer 616 is in contact with the second plate 606. In some embodiments, the third liquid potting compound material is similar to the first liquid potting compound material. A suitable hardening process, such as a curing process, is applied to the third potting compound layer 616.

[0081] Figure 7 and Figure 8 Various embodiments according to the present disclosure are shown. Figure 2 A fourth embodiment of the power conversion device is shown. Figure 7 As shown, electrolytic capacitor 702 is embedded in a module. In some embodiments, the module is separated from the module where the heat generating components are located. Figure 8 A microinverter comprising at least one electrolytic capacitor is shown.

[0082] like Figure 8 As shown, the components of the micro inverter are divided into two groups. The first component group 802 includes heat generating components (e.g., power switches). The second component group 806 includes electrolytic capacitors 702 and components that generate no or little heat (e.g., integrated circuits).

[0083] like Figure 8 As shown, the heat generating component is encapsulated in the bottom module. The heat generating component is mounted on a substrate in the bottom module. The remaining components, especially the electrolytic capacitor 702, are encapsulated in the top module. The formation process of the bottom module and the top module is similar to the above-mentioned Figure 3 The two modules are connected by various connecting elements 804. In some embodiments, the terminal leads of the electrolytic capacitor 702 are part of the connecting elements 804. For each electrolytic capacitor, the body of the electrolytic capacitor is in the top module. The terminal leads of the electrolytic capacitor serve as connecting elements. The bottommost surface of the terminal leads of the electrolytic capacitor is connected to the board of the bottom module. In addition, the connection area between the terminal leads and the body is covered with a suitable sealing material, such as epoxy resin. The sealing material can form a trapezoidal area around the terminal leads. In some embodiments, the bottommost surface of the trapezoidal area is flush with the surface of the bottom module.

[0084] The heat generating components and the non-heat generating components are separated by a heat resistive medium such as air. Since the non-heat generating components are separated from the heat generating components by air, the temperature of the cold components (non-heat generating components) will be much lower than the hot components (heat generating components). In some embodiments, the temperature difference is about 30 degrees. This temperature difference helps to increase the life of the electrolytic capacitor, thereby increasing the life of the micro inverter.

[0085] Fig. 9 The manufacturing method according to various embodiments of the present disclosure is shown. Figure 6 Flow chart of the method of the power conversion device shown in . Fig. 9 The flowcharts shown are examples only and should not unduly limit the scope of the claims. A person of ordinary skill will recognize many variations, alternatives, and modifications. For example, Fig. 9 The various steps shown in can be added, deleted, replaced, rearranged and repeated.

[0086] In step 902, a power conversion system is provided. The power conversion system includes a first board (e.g., first board 602), a first component group on the first board (e.g., first component group 603), a second board (e.g., second board 606), a second component group on the second board (e.g., second component group 605), and a plurality of connecting elements (e.g., connecting elements 604) between the first board and the second board.

[0087] At step 904, a first potting compound layer (eg, first potting compound layer 612) is formed on the first board using a first liquid potting compound material. The topmost surface of the first component group is lower than the top surface of the first potting compound layer.

[0088] At step 906 , the first potting compound layer is hardened by a suitable hardening process.

[0089] At step 908, a second potting compound layer (eg, second potting compound layer 614) is formed on the first potting compound layer using a second liquid potting compound material. The bottommost surface of the second component group is higher than the top surface of the second potting compound layer.

[0090] At step 910 , the second potting compound layer is hardened by a suitable hardening process.

[0091] At step 912 , a third potting compound layer (eg, third potting compound layer 616 ) is formed on the second potting compound layer using a third liquid potting compound material, wherein a topmost surface of the third potting compound layer is in contact with the second plate.

[0092] At step 914 , the third potting compound layer is hardened by a suitable hardening process.

[0093] The power conversion system is a micro inverter. The first component group includes a power switch and a magnetic device. The second component group includes an integrated circuit.

[0094] The components of the first component group are heat generating components configured to generate more heat than the components of the second component group. The first board is a fast heat conducting board. The second board is a printed circuit board.

[0095] The components of the first component group are embedded in a first potting compound layer. At least one component of the second component group is embedded in a third potting compound layer. The middle part of the plurality of connection elements is surrounded by a second potting compound layer comprising a thermal resistance medium.

[0096] The above embodiments are also applicable to the powertrain of an electric vehicle (EV). An EV car may include an on-board charger (OBC), a DC / DC converter, and a motor drive system.

[0097] The components of the on-board charger of an EV vehicle can be divided into two groups, namely a first component group (heat generating component group) and a second component group (non-heat generating component group). The first component group and the second component group can be packaged into at least two different modules. The first component group and the second component group are separated by a thermal resistance medium.

[0098] The components of the DC / DC converter of the EV car can be divided into two groups, namely the first component group (heat generating component group) and the second component group (non-heat generating component group). The first component group and the second component group can be packaged into at least two different modules. The first component group and the second component group are separated by a thermal resistance medium.

[0099] The components of the motor drive system of an EV vehicle can be divided into two groups, namely a first component group (heat generating component group) and a second component group (non-heat generating component group). The first component group and the second component group can be packaged into at least two different modules. The first component group and the second component group are separated by a thermal resistance medium.

[0100] The above embodiments are also applicable to base stations of advanced communication systems (e.g., 5G wireless communication systems). The base station may include an AC / DC converter, a plurality of DC / DC converters, and a battery charger. The components of each power converter in the base station may be divided into two groups, namely a first component group (heat generating component group) and a second component group (non-heat generating component group). The first component group and the second component group may be packaged into at least two different modules. The first component group and the second component group are separated by a thermal resistance medium. In addition, the first component group of a plurality of power converters may be packaged in a first module. The second component group of a plurality of power converters may be packaged in a second module. The first module and the second module are separated by a thermal resistance medium. In addition, the first component group of all power converters (AC / DC converters, a plurality of DC / DC converters, and a battery charger) may be packaged in a first module. The second component group of the corresponding power converter may be packaged in a second module. The first module and the second module are separated by a thermal resistance medium.

[0101] The above embodiments are also applicable to power supplies of Wi-Fi transmitting and receiving stations and other outdoor power supplies. The components of these power supplies can be divided into two groups, namely a first component group (heat-generating component group) and a second component group (non-heat-generating component group). The first component group and the second component group can be packaged into at least two different modules. The first component group and the second component group are separated by a thermal resistance medium.

[0102] Although the embodiments of the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims.

[0103] In addition, the scope of the present application is not intended to be limited to the specific embodiments of the processes, machines, manufactures, material compositions, devices, methods, and steps described in the specification. It will be readily understood by those skilled in the art from the disclosure of the present disclosure that processes, machines, manufactures, material compositions, devices, methods, or steps that currently exist or will be developed in the future and perform substantially the same functions or achieve substantially the same results as the corresponding embodiments described herein can be utilized according to the present invention. Therefore, the appended claims are intended to include such processes, machines, manufactures, material compositions, devices, methods, or steps within their scope.

Claims

1. A device, comprising: a first component group on a first plate; a second component group on a second board, wherein the components of the first component group are heat generating components configured to generate more heat than the components of the second component group; as well as A plurality of connection elements are electrically coupled between the first component group and the second component group, wherein portions of the plurality of connection elements are located in a thermal resistance medium, and the first component group and the second component group are separated by the thermal resistance medium.

2. The method according to claim 1, wherein: The thermal resistance medium is air; The first plate is a fast heat conduction plate; and The second board is a printed circuit board.

3. The device according to claim 2, wherein: The rapid heat conduction plate is a thermally conductive and electrically isolated ceramic printed circuit board.

4. The device according to claim 2, wherein: The rapid heat conduction plate is a heat-conducting and electrically isolated metal plate, and the metal plate comprises a metal support plate, a dielectric layer above the metal support plate, and a circuit layer above the dielectric layer; in The metal support plate is made of aluminum; and The circuit layer is made of copper.

5. The device according to claim 1, wherein: The components of the first component group include a power switch and a magnetic device; and The components of the second component group include at least one electrolytic capacitor.

6. The device according to claim 1, wherein: The first component group is located in a first module, and wherein the components of the first component group are surrounded by a first potting compound material; and The second component group is located in a second module, and wherein the components of the second component group are surrounded by a second potting compound material, and wherein: A first portion of the plurality of connection elements is located in the first module and is surrounded by the first potting compound material. The middle parts of the plurality of connecting elements are surrounded by the heat-resistance medium; and A second portion of the plurality of connection elements is located in the second module and is surrounded by the second potting compound material.

7. The device according to claim 1, wherein: The first component group is located on a first open frame package; and The second component group is located on a second open frame package, and wherein the plurality of connecting elements are connected between the first open frame package and the second open frame package.

8. The device according to claim 7, wherein: The first open frame package includes: a first thermally conductive and electrically isolating metal plate and components of the first component group mounted on the first thermally conductive and electrically isolating metal plate; and The second open frame package includes a second thermally conductive and electrically isolating metal plate and components of the second component group mounted on the second thermally conductive and electrically isolating metal plate.

9. The device according to claim 8, wherein: A first potting compound material partially covers components of the first component group; and A second potting compound material partially covers the components of the second component group.

10. The device according to claim 8, wherein: A first metal housing covers a portion of a component of the first component group; and The second metal housing covers a portion of the components of the second component group.

11. The device according to claim 8, wherein: A first metal mesh covers a portion of the components of the first component group; and The second metal mesh covers a portion of the components of the second component group.

12. The device according to claim 1, further comprising: at least one electrolytic capacitor electrically coupled to the first component group, wherein the at least one electrolytic capacitor and the first component group are located in two different modules, and wherein, The terminal leads of the at least one electrolytic capacitor are part of the plurality of connection elements; and The two different modules are separated by the heat-resistance medium.

13. The device according to claim 1, wherein: The first component group is located in a first module, wherein the first plate is a fast heat transfer plate, and a first potting compound material partially covers the components of the first component group; and The second component group is located in a second module, wherein the second board is a printed circuit board, and a second potting compound material partially covers the components of the second component group.

14. The device according to claim 1, wherein: The first component group is located in a first module, wherein the first plate is a fast heat conduction plate, and a first metal shielding shell covers the components of the first component group; and The second component group is a second module, wherein the second board is a printed circuit board, and the second metal shielding shell covers the components of the second component group.

15. The device according to claim 1, wherein: The first component group is located in a first module, wherein the first plate is a fast heat conduction plate, and a first metal mesh cover covers the components of the first component group; and The second component group is located in a second module, wherein the second board is a printed circuit board, and a second metal mesh cover covers the components of the second component group.

16. The device according to claim 1, wherein: The components of the first component group are located on a first side of the first plate; At least one component of the second component group is located on the first side of the second plate; At least one component of the second assembly group is located on a second side of the second plate; The plurality of connection elements are electrically coupled between a first side of the first board and a first side of the second board.

17. A micro inverter, comprising: a power switch and a magnetic device located on the first board; a control integrated circuit located on the second board; as well as A plurality of signal and power paths are coupled between the first board and the second board, wherein the power and the plurality of signals flow through a thermally resistive medium disposed between the first board and the second board.

18. The micro inverter according to claim 17, further comprising: a first potting compound layer in contact with the first plate; a third potting compound layer in contact with the second plate; as well as The second potting compound layer is located between the first potting compound layer and the third potting compound layer, wherein the second potting compound layer includes the thermal resistance medium.

19. The microinverter of claim 18, wherein the plurality of signal and power channels are implemented as a plurality of cables, and wherein: The power switch and the magnetic device are embedded in the first potting compound layer; A control integrated circuit is embedded in the third potting compound layer; An intermediate portion of the plurality of cables is surrounded by a second potting compound layer.

20. The micro-inverter according to claim 17, further comprising: An electrolytic capacitor is located on the second plate, wherein terminal leads of the electrolytic capacitor are part of the plurality of signal and power channels, and a bottommost surface of the terminal leads of the electrolytic capacitor directly contacts the first plate.

21. The microinverter of claim 17, wherein the plurality of signal and power channels include a plurality of cables and wireless power transmission channels, wherein: The power switch and the magnetic device are embedded in a first potting compound layer in contact with the first board; The control integrated circuit is embedded in a third potting compound layer in contact with the second plate; a middle portion of the plurality of cables is surrounded by a second potting compound layer, the second potting compound layer being formed between the first potting compound layer and the third potting compound layer; and The wireless power transfer channel is configured to provide bias power to a power switch on the first board.

22. A method comprising: A power conversion system is provided, the power conversion system comprising a first board, a first component group on the first board, a second component group on a second board, and a plurality of connecting elements between the second board; forming a first potting compound layer on the first board using a first liquid potting compound material, wherein the uppermost surface of the first component group is lower than a top surface of the first potting compound layer; hardening the first potting compound layer; forming a second potting compound layer on the first potting compound layer using a second liquid potting compound material, wherein a bottommost surface of the second component group is higher than a top surface of the second potting compound layer; hardening the second potting compound layer; forming a third potting compound layer on the second potting compound layer using a third liquid potting compound material, wherein an uppermost surface of the third potting compound layer is in contact with the second plate; and hardening the third potting compound layer.

23. The method of claim 22, wherein: The power conversion system is a microinverter; The first component group includes a power switch and a magnetic device; The second component group includes integrated circuits.

24. The method according to claim 22, wherein: The components of the first component group are heat generating elements configured to generate more heat than the components of the second component group; The first plate is a fast heat conduction plate; The second board is a printed circuit board.

25. The method according to claim 22, wherein: The components of the first component group are embedded in the first potting compound layer; At least one component of the second component group is embedded in the third potting compound layer; The middle portions of the plurality of connection elements are surrounded by a second potting compound layer containing a heat-resistance medium.

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