ARTICLE FOR POWER INVERTER AND POWER INVERTER

Abstract

An article for a power inverter, includes a multilayer printed circuit board having a first and second electrically conductive wiring layer and at least a first dielectric layer interposed between the first and second electrically conductive wiring layers. Each conductive wiring layer includes a common input and output line, the common input and output lines at least partially overlapping one another in a projection along a thickness of the multilayer printed circuit board. A set of input mounting pads is carried by the first common input line and a set of input mounting pads is carried by the second common input line, the input mounting pads of the second set of input mounting pads are interleaved with the input mounting pads of the first set of input mounting pads along a first axis. The article further includes a set output mounting pads carried by the common output line.

Claims

1. A multilayer printed circuit board, comprising: a dielectric material and at least two conductor layers; the conductor layers comprising: a plurality of individual mounting pads for high-side switches; a plurality of individual mounting pads for low-side switches alternatingly interleaved with the plurality of individual mounting pads for high-side switches; a first common input line for the high-side switches; and a second common input line for the low-side switches, wherein the first common input line and the second common input line at least partially overlap in a height direction of the printed circuit boards.

2. The printed circuit board of claim 1, wherein the multilayer printed circuit board comprises the dielectric material and at least four conductor layers.

3. The printed circuit board of claim 2, wherein the overlapping first and second common input lines are distributed on the at least four conductor layers.

4. The printed circuit board of claim 1, wherein the first common input line and the second common input line completely overlap in the height direction of the printed circuit boards.

5. An inverter comprising: a plurality of high-side switches; a plurality of low-side switches alternatingly arranged with the plurality of high-side switches; a multilayer printed circuit board comprising a dielectric material and at least two conductor layers; the conductor layers comprising: a respective mounting pad for each of the plurality of high-side switches; a respective mounting pad for each of the plurality of low-side switches alternatingly arranged with the respective mounting pads for each of the plurality of high-side switches; and a first common input line for the plurality of high-side switches; and a second common input line for the plurality of low-side switches, wherein the first common input line and the second common input line at least partially overlap in a height direction of the printed circuit boards.

6. The inverter of claim 5, wherein the multilayer printed circuit board comprises the dielectric material and at least four conductor layers.

7. The inverter of claim 6, wherein the overlapping first and second common input lines are distributed on the at least four conductor layers.

8. The inverter of claim 7, wherein the first common input line and the second common input line completely overlap in the height direction of the printed circuit boards.

9. The inverter of claim 7, wherein the first and the second common input lines at least partially overlap one another in a projection along a thickness of the multilayer printed circuit board.

10. The inverter of claim 5, wherein: the plurality of high-side switches comprise a first set of semiconductor switches, each of the semiconductor switches of the first set of semiconductor switches having a first node and a second node, the first node of the semiconductor switches of the first set electrically coupled to respective ones of one or more of input mounting pads of a first set of input mounting pads, and the second node of the semiconductor switches of the first set electrically coupled to respective ones of one or more of output mounting pads of a set of output mounting pads; and the plurality of low-side switches comprise a second set of semiconductor switches, each of the semiconductor switches of the second set of semiconductor switches having a first node and a second node, the first node of the semiconductor switches of the second set electrically coupled to respective ones of one or more of input mounting pads of a second set of input mounting pads, and the second node of the semiconductor switches of the second set electrically coupled to respective ones of one or more of output mounting pads of a set of output mounting pads.

11. The inverter of claim 10, wherein at least one of a first or a second electrically conductive wiring layer comprises a common output line, the common output line electrically isolated from the first and the second common input lines except via the semiconductor switches of the first and the second sets of semiconductor switches.

12. The inverter of claim 11, wherein the multilayer printed circuit board comprises at least a third electrically conductive wiring layer, and at least a second dielectric layer interposed between the third and the first electrically conductive wiring layer and at least one of the first or the second electrically conductive wiring layers, the third electrically conductive wiring layer comprising a common output line which is electrically isolated from the first and the second common input lines except via the semiconductor switches of the first and the second sets of semiconductor switches.

13. The inverter of claim 10, further comprising: a controller communicatively coupled to provide control signals to the semiconductor switches of the first and the second sets of semiconductor switches, the controller which provides control signals to places the semiconductor switches of the second set of semiconductor switches in an opposite state from the semiconductor switches of the first set of semiconductor switches.

14. The inverter of claim 10, wherein the semiconductor switches of the first and the second sets of semiconductor switches are integrated gate bipolar transistors (IGBTs) or metal oxide semiconductor field effect transistors (MOSFETs).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In the drawings, identical reference numbers identify similar elements or acts. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not necessarily drawn to scale, and some of these elements may be arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn, are not necessarily intended to convey any information regarding the actual shape of the particular elements, and may have been solely selected for ease of recognition in the drawings.

[0049] FIG. 1 is a schematic diagram of at least a portion of an inverter circuit in the form of a half bridge illustrated in a first state with a high-side switch in an ON state and a low-side switched in an OFF state.

[0050] FIG. 2 is a schematic diagram of at least a portion of the inverter circuit of FIG. 1, illustrated in a second state with a high-side switch in an OFF and a low-side switched in an ON state.

[0051] FIG. 3A is a top plan view of at least a portion of a printed circuit board with a plurality of high-side switches electrically coupled in parallel and a plurality of low-side switches electrically coupled in parallel which can implement a half bridge of an inverter, with arrows illustrating a flow of current in a first state with the plurality of high-side switches in an ON state and the plurality of low-side switches in an OFF state.

[0052] FIG. 3B is a top plan view of at least the portion of the printed circuit board of FIG. 3A, with arrows illustrating a flow of current in a second state with the plurality of high-side switches in an OFF state and the plurality of low-side switches in an ON state.

[0053] FIG. 4A is a top plan view of at least a portion of a printed circuit board according to at least one illustrated implementation, with at least partially overlapping high-side low-side input lines, and a plurality of high-side switches electrically coupled in parallel and a plurality of low-side switches electrically coupled in parallel and interleaved with the high-side switches, which can implement a half bridge of an inverter, with arrows illustrating a flow of current in a first state with the plurality of high-side switches in an ON state and the plurality of low-side switches in an OFF state.

[0054] FIG. 4B is a top plan view of at least the portion of the printed circuit board of FIG. 4A, with arrows illustrating a flow of current in a second state with the plurality of high-side switches in an OFF state and the plurality of low-side switches in an ON state.

[0055] FIG. 5 is top plan view of a printed circuit board for a power module, according to at least one illustrated implementation.

DETAILED DESCRIPTION

[0056] In the following description, certain specific details are set forth in order to provide a thorough understanding of various disclosed embodiments. However, one skilled in the relevant art will recognize that embodiments may be practiced without one or more of these specific details, or with other methods, components, materials, etc.

[0057] Unless the context requires otherwise, throughout the specification and claims which follow, the word comprise and variations thereof, such as, comprises and comprising are to be construed in an open, inclusive sense, that is, as including, but not limited to.

[0058] Reference throughout this specification to one implementation or an implementation or to one embodiment or an embodiment means that a particular feature, structure or characteristic described in connection with the implementation or embodiment is included in at least one implementation or embodiment. Thus, the appearances of the phrases in one implementation or in an implementation or in one embodiment or in an embodiment in various places throughout this specification are not necessarily all referring to the same implementation or embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more implementations or one or more embodiments.

[0059] As used in this specification and the appended claims, the singular forms a, an, and the include plural referents unless the content clearly dictates otherwise. It should also be noted that the term or is generally employed in its sense including and/or unless the content clearly dictates otherwise.

[0060] The terms input traces, input lines, input buses, or input rails are used interchangeably herein. The term high-side generally refers to the relatively higher electrical potential, for example a side or component electrically coupled to a positive node or pole of a voltage source, while the term low-side generally refers to the relatively lower electrical potential, for example a side or component electrically coupled to a negative node or pole of a voltage source.

[0061] The headings and Abstract of the Disclosure provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.

[0062] FIG. 1 shows an inverter circuit 100 in a first state. FIG. 2 shows the inverter circuit 100 in a second state. The inverter circuit 100 is illustrated as a half bridge topology with a first or high-side switch S101 electrically coupled between a high-side or positive node of a voltage source V1 and an output or AC node 102, and a second or low-side switch S102 electrically coupled between a low-side or negative node of the voltage source V1 and the output or AC node 102. The inverter circuit 100 can be combined with other Half bridge circuits to form a full H-bridge topology or 3-phase bridge or other imagined circuits comprising of multiple half bridges. The high-side switch S101 and low-side switch S102 can take the form of semiconductor switches, for example bipolar transistors, insulated gate bipolar transistors (IGBTs), field effect transistors (FETs), or metal oxide semiconductor field effect transistors (MOSFETs) including GAN and SiC technologies. While illustrated as single switches S101, S102, in some implementations the high-side switch S101 can take the form of two or more parallel or serial switches and the low-side switch S101 can take the form of two or more parallel or serial switches. While high-side and low-side switches S101, S102 can be switched (i.e., turned ON and OFF) independently from one another, in typical operation control signals are provide such that the high-side switch S101 and the low-side switch S102 are in opposite states from one another. Further, when multiple switches are used in parallel, the timing for each switch can be varied so the turn on or turn off times can be offset from one another. Generally, when the high-side switch S101 is in an ON state and the low-side switch S102 is in an OFF state, current I01 flows through a loop of the inverter circuit 100 along a first path in a first direction (e.g., clockwise) to a load (e.g., inductance 104) via the output or AC node 102. Conversely, when the low-side switch S102 is in an ON state and the high-side switch S101 is in an OFF state, the reverse happens, current I102 flows through the loop of the inverter circuit 100 along a second path in a second direction (e.g., counter clockwise) to the load, the second direction a reverse direction with respect to the first direction. The inverter circuit 100 provides at least one of rectification and/or regulation of the current.

[0063] The inverter circuit rectifies a negative voltage (e.g., negative grid voltage) to a positive voltage. For this application, a switching frequency for the high-side and low-side switches S101, S102 is preferably twice a grid frequency, resulting in substantially reduced switching loss, which are otherwise substantial in a regular switching mode inverter.

[0064] FIGS. 3A and 3B show at least a portion of a printed circuit board 300 with a plurality of high-side switches S301a, S301b, S301c (three shown, collective S301) electrically coupled in parallel with one another and a plurality of low-side switches S302a, S302b, S302c (three shown, collective S302) electrically coupled in parallel with one another, which can implement a power module in the form of a half bridge of an inverter. In particular, FIG. 3A shows a current flow I301 in a first state with the plurality of high-side switches S301 in an ON state and the plurality of low-side switches S302 in an OFF state. In particular, FIG. 3B shows a current flow I302 in a second state with the plurality of low-side switches S302 in an ON state and the plurality of high-side switches S301 in an OFF state.

[0065] The printed circuit board 300 includes a high-side input bus 306 and a low-side input bus 308, which may be formed in or by an electrically conductive wiring layer of the printed circuit board 300. Notably, the high-side input bus 306 and a low-side input bus 308 are arranged in tandem across a width or length of the printed circuit board 300, electrically isolated from one another and spaced from one another sufficiently to prevent electromagnetic coupling therebetween. The printed circuit board 300 also includes an output or AC bus 310, which may be formed in or by an electrically conductive wiring layer of the printed circuit board 300. The high-side switches S301a, S301b, S301c electrically couple the high-side input bus 306 to the output or AC bus 310 when in an ON state. The low-side switches S302a, S302b, S302c electrically couple the low-side input bus 308 to the output or AC bus 310 when in an ON state.

[0066] As is illustrated, the positive or high-side components (i.e., high-side input bus 306, high-side switches S301a, S301b, S301c) are grouped together and the negative or low-side components (i.e., low-side input bus 308, low-side switches S302a, S302b, S302c) are grouped together. In FIG. 3A the positive or high-side switches S301a, S301b, S301c are ON and the negative or low-side switches S302a, S302b, S302c are OFF. As shown in FIG. 3A, the current I301 flows through the positive or high-side input bus 306 and high-side switches S301a, S301b, S301c in a first direction (e.g., clockwise). As shown in FIG. 3B, the current I302 flows through the negative or low-side input bus 308 and low-side switches S302a, S302b, S302c in a second direction (e.g., counterclockwise).

[0067] In operation, assume that initially the high-side switches S301a, S301b, S301c are in an ON state and the low-side switches S302a, S302b, S302c are in an OFF state. Thus, current I301 flows out of the high-side switches S301a, S301b, S301c and out of the half-bridge. Then, the high-side switches S301a, S301b, S301c are turned OFF and the low-side switches S302a, S302b, S302c are turned ON. The current in the high-side is turned off and the current in the low-side is turned on. These conducting currents I301, I302 generate magnetic fields. The stored energy in the magnetic fields is a significant problem with fast switching of inverters because the energy stored due to the generated magnetic field has to be dissipated. The magnetic field is specified or set by the physical layout of the components. The mechanical structures and physical layouts for the devices of FIGS. 3A and 3B are designed to reduce loop inductances in the two or more voltages generator devices being switched.

[0068] Instead of only minimizing loop inductance, circuit performance can be improved if the magnetic field is not formed or if a magnitude of the magnetic field that is generated is kept to a minimum. Minimizing the magnetic field also reduces switch cost.

[0069] As illustrated in FIGS. 4A and 4B, instead of designing and manufacturing an article where the circuit traces are spaced from each other to minimize electromagnetic coupling, the circuit traces, particularly the input traces, input lines or input buses, are spaced sufficiently near each other so that those input traces, input lines or input buses are electromagnetically coupled during operation and the high-side and low-side switched are interleaved. According to at least one implementation, at least the input traces or input or input buses at least partially overlap one another in a projection of the boundaries of those input traces or input buses along an axis that defines a thickness of a printed circuit board. The electromagnetic coupling or mutual inductance, which does not occur if the electrical conductors are too far apart, improves switching characteristics.

[0070] FIGS. 4A and 4B show at least a portion of a printed circuit board 400 with a plurality of high-side switches S401a, S401b, S401c (three shown, collective S401) electrically coupled in parallel with one another and a plurality of low-side switches S402a, S402b, S402c (three shown, collective S402) are alternatingly arranged and electrically coupled in parallel with one another, which can implement a power module in the form of a half bridge of an inverter. In particular, FIG. 4A shows a current flow I401 in a first state with the plurality of high-side switches S401 in an ON state and the plurality of low-side switches S402 in an OFF state. In particular, FIG. 4B shows a current flow I402 in a second state with the plurality of low-side switches S402 in an ON state and the plurality of high-side switches S401 in an OFF state.

[0071] The printed circuit board 400 includes a high-side input bus 406 and a low-side input bus 408, which may be formed in or by an electrically conductive wiring layer of the printed circuit board 400. As shown, the high-side input bus 406 and the low-side input bus 408 are different conductive layers of the printed circuit board 400. Notably, the high-side input bus 406 and the low-side input bus 408 are arranged across a width or length of the printed circuit board 400, electrically isolated from one another and spaced from one another. The printed circuit board 400 also includes an output or AC bus 410, which may be formed in or by an electrically conductive wiring layer of the printed circuit board 400. The high-side switches S401a, S401b, S401c electrically couple the high-side input bus 406 to the output or AC bus 410 when in an ON state. The low-side switches S402a, S402b, S402c electrically couple the low-side input bus 408 to the output or AC bus 410 when in an ON state.

[0072] As is illustrated, the positive or high-side components (e.g., high-side switches S401a, S401b, S401c) are interleaved or alternative successively arranged with the negative or low-side components (e.g., low-side switches S402a, S402b, S402c). In FIG. 4A the positive or high-side switches S401a, S401b, S401c are ON and the negative or low-side switches S402a, S402b, S402c are OFF. As shown in FIG. 4A, the current I401 flows through the positive or high-side input bus 406 and high-side switches S401a, S401b, S401c. In FIG. 4B the positive or high-side switches S401a, S401b, S401c are OFF and the negative or low-side switches S402a, S402b, S402c are ON. As shown in FIG. 4B, the current I402 flows through the negative or low-side input bus 408 and low-side switches S402a, S402b, S402c.

[0073] In operation, assume that initially the high-side switches S401a, S401b, S401c are in an ON state and the low-side switches S402a, S402b, S402c are in an OFF state. Thus, current I401 flows out of the high-side switches S401a, S401b, S401c and out of the half-bridge. Then, the high-side switches S401a, S401b, S401c are turned OFF and the low-side switches S402a, S402b, S402c are turned ON. The current in the high-side is turned OFF and the current in the low-side is turned ON. These conducting currents I401, I402 generate magnetic fields. Circuit performance can be improved if the magnetic field formed when the high-side is active (ON) is offset when the low-side is activated (turned ON).

[0074] FIGS. 4A and 4B show a layout of interleaved devices. As shown in FIGS. 4A and 4B, instead of grouping high-side and low-side components as shown in FIGS. 3A and 3B, the high-side switches S401a, S401b, S401c and low-side switches S402a, S402b, S402c are interleaved sharing a common output 410 or an overlapping output. The interleaving establishes a mutual inductance in the common output 410 so that the current flowing I401, I402 in each of the high-side switches S401a, S401b, S401c and low-side switches S402a, S402b, S402c is equal in magnitude.

[0075] The interleaving of the high-side switches S401a, S401b, S401c and low-side switches S402a, S402b, S402c minimizes leakage inductance. For example, when the conductors are spread far apart as is the case in the grouped device example of FIGS. 3A, 3B, there is a relative large amount of leakage inductance. As the mutual inductance is increased with the interleaved design, a high frequency transformer is formed.

[0076] Additionally, the interleaved design provides for conductors being near one another. A substantial amount of capacitance is present between the overlapping conductors. This capacitance provides high frequency decoupling. The interleaved and overlapped conductors function as a distributed capacitor.

[0077] While illustrated with a high-side comprising three parallel high-side switches S401a, S401b, S401c and the low-side comprising three parallel low-side switches S402a, S402b, S402c, other numbers of parallel switches can be employed.

[0078] The high-side switches S401a, S401b, S401c and low-side switches S402a, S402b, S402c are interleaved as shown in FIGS. 4A, 4B. The high-side conductors and low-side conductors are on stacked layers, each of the high-side and the low-side being on a respective layer. For a two-layer printed circuit board (i.e., two conductor layers and one dielectric layer), one conductor layer is provided for the high-side and one conductor layer is provided for the low-side, although more layers can be used. For example, instead of the B+/B layers, where B+ represents the high side and B represents the low-side, in a two-layer implementation, a four layer implementation would be B+/B/B+/B. The more layers that are used, the better the coupling will be between the layers.

[0079] The multilayer layout with interleaved high-side and low-side switches maintains the currents I410/I402 generally on top of each other because the conductor traces of the multilayer printed circuit board overlap. This layout minimizes an amount of the magnetic field that has to change when switching from the low-side to the high-side and vice versa. The interleaving and the minimization of the field dramatically reduces the net energy released during a switching event, thereby reducing over voltage and allowing faster switching speeds.

[0080] While FIGS. 4A and 4B show the high-side switches S401a, S401b, S401c and low-side switches S402a, S402b, S402c on a first face of the printed circuit board 400, the high-side switches S401a, S401b, S401c and low-side switches S402a, S402b, S402c can be arranged on opposite faces of the printed circuit board 400. It should be note that even when arranged on opposite faces of the printed circuit board 400 the high-side switches S401a, S401b, S401c and low-side switches S402a, S402b, S402c are interleaved.

[0081] A controller 425 is communicatively coupled to the high-side switches S401a, S401b, S401c and low-side switches S402a, S402b, S402c to provide control signals to the high-side switches S401a, S401b, S401c and low-side switches S402a, S402b, S402c. The control signals turn the respective switches on and off with a same or different timing. The controller is a microprocessor with memory or the like, or a microcontroller or the like.

[0082] FIG. 5 is an exemplary printed circuit board 530 for a power module. As shown, the mounting pads for high-side switches 550 (HS) and the mounting pads for the low-side switches 540 (LS) are interleaved and staggered side-to-side with respect to common output lines 515, 525. This layout achieves a power switching stage capable of 500a turn OFF in 60 nS with about 6 volts of overshoot.

[0083] The printed circuit board 530 is typically made from an FR4 epoxy laminate and prepreg, polyimide laminates and prepreg, Teflon laminates and bonding plies, ceramics, and the like. Prepreg is a thin glass fabric that is coated with resin and dried. Typically, a multilayer printed circuit board is utilized. Copper cladding is used for the conductive traces.

[0084] According to one aspect of the invention, the printed circuit board 530 can be manufactured using direct bonded copper (DBC), active metal braze (AMB), or Insulated metal substrate (IMS) technology. DBC and AMB substrates for printed circuit board 530 use ceramic substrates, typically made from a material in the aluminum oxide family, aluminum nitride, or beryllium oxide. DBC and AMB substrates are typically produced without joint layer that might increase thermal resistance. DBC substrates are used in power modules because of their thermal conductivity.

[0085] DBC substrates are composed of a ceramic substrate, commonly alumina, with one or more sheet of copper bonded to one or both sides by a high-temperature oxidation process. The copper layers can be preformed prior to firing or chemically etched using printed circuit board technology to form an electrical circuit.

[0086] IMS substrates comprise a metal baseplate, commonly aluminum, covered by a thin layer of dielectric, usually an epoxy-based layer, and a layer of copper. For the present application, multiple dielectric and copper layers are preferred for coupling between the conductors.

[0087] As shown, the printed circuit board 530 has mounting pads 550 for five high-side switches HS and mounting pads 540 for five low-side switches LS. The printed circuit board 530 has three mounting pads for high-side switches HS and three low-side switches LS arranged on either side of imaginary line 510. Each of these mounting pads are arranged so that an output of the respective high-side or low-side switch HS, LS is fed to common output line 515. While a single common output line 515 is shown, there are overlapping output conductors, one for the high-side switches HS and one for the low-side switches LS. The printed circuit board 530 also has two mounting pads 550 for high-side switches HS and mounting pads 540 for two low-side switches LS arranged on either side of imaginary line 520. Each of these mounting pads is arranged so that an output of the respective high-side switch HS or low-side switch LS is fed to common output line 525. Again, the common output line 525 comprises overlapping conductors and the mounting pads for the high-side and low-side switches are interleaved. The common output lines 515, 525 generally correspond to the conductor 410 in FIGS. 4A, 4B. Further, according to one aspect of the invention, the high-side and low-side switches alternate or are interleaved along a length of the common output lines 515, 525.

[0088] In the above description, certain specific details are set forth in order to provide a thorough understanding of various disclosed implementations. However, one skilled in the relevant art will recognize that implementations may be practiced without one or more of these specific details, or with other methods, components, materials, etc. In other instances, well-known structures associated with power systems, power converters, power modules, and power supplies have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the implementations.

[0089] The various embodiments described above can be combined to provide further embodiments. Aspects of the implementations can be modified, if necessary, to employ systems, circuits and concepts of the various patents, applications and publications identified herein to provide yet further implementations.

[0090] Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method acts that perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method acts shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.