Planar capacitor terminals

Abstract

Electronic component, which includes: a layered busbar structure (212) comprising at least two busbar layers (212A-C) separated by an insulating layer; a transistor (214) connected to the layered busbar structure (212) on a first side thereof; and a capacitor (100) which is mounted on the first side of the layered busbar structure (212) and is positioned further away from the layered busbar structure (212) than the transistor (214), wherein the capacitor (100) has respective planar terminals (102, 104) which are parallel to each other and perpendicular to the layered busbar structure (212), wherein each of the planar terminals (102, 104) comprises a rectangular element, one side of which is connected to the capacitor (100) and the opposite end is connected to a corresponding busbar layer (212A-C), wherein each of the planar terminals (102, 104) has several feeder lines (108, 110) at the opposite end of the rectangular element, the feeder lines (108, 110) connecting the respective planar terminal (102, 104) to the corresponding busbar layer.

Description

BACKGROUND

[0001] Capacitors are used in a wide variety of electronic and other devices. One such application is in power converters, where a capacitor can be coupled to the switching elements to protect against transients and help maintain voltage on the DC bus. These capacitors are commonly referred to as DC link capacitors.

[0002] Furthermore, temperature management is an important aspect of many electronic devices, especially those involving high currents, which is often the case with power converters. One approach to protecting a component from thermal damage is to move the component further away from the main heat source. However, this can have undesirable consequences, such as reduced efficiency and / or an increase in the physical size of the device.

[0003] US 2012 / 0305283A1 discloses a busbar comprising: a first busbar layer consisting of a first busbar conductor having a first, generally uniform thickness; a first dielectric layer lying above an upper surface of the first busbar layer;and a second busbar layer comprising a second, generally uniform thickness, situated above an upper surface of the first dielectric layer and the upper surface of the first busbar layer, wherein: the first busbar layer comprises a first via for receiving a first electrical conductor of an electrical component and a second via for receiving a second electrical conductor of the electrical component, and wherein: the first dielectric layer and the second busbar layer each comprise a via aligned with the first via, wherein the first electrical conductor can pass from below the first busbar layer through the first dielectric layer and through the second busbar layer.

[0004] US 5,373,418 A discloses an electrical device for mounting electrical components comprising a one-piece die-cast aluminum base with recesses on its top surface for receiving the electrical components and cooling fins on its bottom surface for dissipating the heat generated by the components. The terminals of the electrical components housed in the recesses of the metal base are essentially at the same level, and the electrical connection between them is made via conductive traces on a printed circuit board. A highly thermally conductive resin material is located between the recesses and the components that generate a high amount of heat. Conversely, a heat-insulating resin material is located between the recess and the components that generate a low or negligible amount of heat.

[0005] US 2010 / 0091464A1 discloses a heat dissipation structure plate and a module with this heat dissipation structure for purposes requiring high reliability, such as a hybrid vehicle or an electric vehicle, as well as a method for manufacturing the heat dissipation structure.A resin structure is arranged on a connection frame forming a heat dissipation plate, and an irregularly shaped electronic component or the like is mounted on this connection frame or the like to cover the connection frame and the irregularly shaped electronic component or the like, and this resin structure is attached to a metal plate, a device housing or the like to form the heat dissipation structure plate as a whole, thereby increasing the fastening strengths for attaching the connection frame and the irregularly shaped electronic component or the like, as well as the bond strength at an interface between the connection frame and the heat transfer layer, etc. SUMMARY

[0006] The invention is based on the objective of providing an efficient and compact electronic component.

[0007] The problem is solved by an electronic component according to claim 1; exemplary further developments result from the dependent claims.

[0008] According to a first aspect, an electronic component comprises: a layered busbar structure comprising at least two busbar layers separated by an insulating layer; a transistor connected to the layered busbar structure on a first side thereof; and a capacitor attached to the first side of the layered busbar structure and positioned further away from the layered busbar structure than the transistor, wherein the capacitor has respective planar terminals parallel to each other and perpendicular to the layered busbar structure, each of the planar terminals comprising a rectangular element, one side of which is connected to the capacitor and an opposite end is connected to a corresponding busbar layer.The electronic component is an inverter comprising several transistors; the busbar layers comprise at least a first and a second DC busbar layer and an AC busbar layer; and the capacitor is a DC link capacitor for the inverter. Each of the planar terminals has several leads at the opposite end of the rectangular element, with the leads connecting the respective planar terminal to the corresponding busbar layer.

[0009] Implementations may include some or all of the following features. The capacitor is enclosed in a housing, and the planar terminals extend outside the housing. Each rectangular element extends from one end of the housing to the other. The electronic component further includes a support structure for the rectangular elements, extending from the housing toward the layered busbar structure. The support structure holds the planar terminals at their edges, leaving the outward-facing faces of the rectangular elements free. A section of the support structure isolates the planar terminals from one another.The support structure and rectangular elements are designed to position a busbar positioning component relative to the electronic component, with the busbar positioning component being designed to accommodate the layered busbar structure. Each busbar layer has openings with corresponding tabs extending from its perimeter, and each tab is designed to align with and make contact with one of the multiple leads. The leads of the respective planar terminals are paired and positioned adjacent to one of the multiple transistors. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 shows an example of a capacitor with planar terminals. Fig. Figure 2 is a section of an electronic component that has a capacitor with planar terminals. Fig. 3 is another cut of the electronic component of Fig. 2. DETAILED DESCRIPTION

[0010] This document describes examples of capacitors connected to the rest of an electronic device via one or more terminals with a relatively large planar form. This terminal structure can provide a capacitor that is thermally isolated from the electronics but electrically close to them. In this way, for example, a capacitor with low inductance and improved temperature management can be provided.

[0011] Fig. Figure 1 shows an example of a capacitor 100 with planar terminals 102 and 104. The electrical conductors of the capacitor are contained in a housing 106. Most of terminal 102 is visible outside the housing, while terminal 104 is hidden here, except for its leads, which extend along the top of the capacitor 100.

[0012] Any form of capacitor conductor can be used, including films or foils (e.g., folded or rolled into a compact structure that fits inside the housing 106). For example, the housing can provide two or more compartments, each accommodating a corresponding section of the capacitor. The housing can be made of any material that provides sufficient insulation and structural strength to the capacitor (e.g., a polymer).

[0013] Each of the planar terminals 102 and 104 comprises a rectangular element, one side of which is connected to the capacitor leads inside the housing 106. The proportions of the terminal section outside the housing can be chosen depending on the system's characteristics. In some implementations, the rectangular element may have a width-to-height ratio of approximately 3:1 or 4:1. For example, the terminal may be more than three times as wide as it is long. As another example, the width-to-height-to-thickness ratio may be between approximately 50:1 and 200:1. Here, the sections of terminals 102 and 104 outside the housing extend essentially from one end of the housing 106 to the other, although other widths may also be used. The planar terminals are made of a conductive material (e.g., copper).

[0014] Each of the planar terminals can have leads formed on one or more of its sides. Here, terminal 102 has 108 leads, and terminal 104 has 110 leads. In some implementations, the two terminals have the same number of leads, with the respective leads arranged in pairs along the upper edges of the terminals. For example, in devices using multiple transistors, the leads of each planar terminal can be positioned adjacent to one of the multiple transistors.

[0015] The capacitor 100 has a support structure 112. For example, the support structure can be configured to hold the planar terminals 102 and 104 at their edges, leaving their outward-facing surfaces free. The support structure can also serve to electrically isolate the terminals from one another. As another example, the support structure can be configured to help position a busbar positioning component (not shown), which in turn is used to hold other components of an electronic device. The support structure can be made of the same material as the housing, to give just one example.

[0016] Fig. Figure 2 is a section of an electronic component 200, which includes a capacitor 202 with a housing 203 and planar terminals 204 and 206. The electronic component has a printed circuit board 208 with one or more components 210 on it and a layered busbar structure 212, which here comprises busbars 212A-C separated by respective insulating layers. The busbar layers are made of a conductive material such as copper.

[0017] Transistors 214 are mounted on the circuit board and the busbars. Any of several different types of active switching devices can be used (e.g., IGBTs). For example, the collector and emitter leads of the transistor can be connected to two of the busbar layers 212A-C, and one gate lead can be connected to the circuit board. In some implementations, the transistors are mounted on a heat sink 216. For example, the heat sink can have an internal cavity to ensure circulation of coolant that is in thermal contact with the transistor(s). This allows, for example, the transistors to be positioned on one side of the circuit board and arranged essentially perpendicular to it for improved temperature management.In some implementations, the transistors 214 are arranged in pairs on opposite sides of the heatsink, with several pairs positioned along the length of the heatsink. Furthermore, terminals 204 and 206 allow the capacitor 202 to be mounted on the same side of the layered busbar structure as the transistors and positioned further away from the layered busbar structure than the transistors.

[0018] The electronic component includes a busbar positioning component 218, which serves to position busbars, transistors, heat sinks, etc., relative to one another. A mounting space element 218A forms a mounting space in which the transistors 214 and the heat sink 216 are positioned. A busbar slot 218B of the busbar positioning component is used to position one or more busbars within the electronic component, for example, to create connections with the layered busbar structure 212.

[0019] Terminals 204 and 206 are separated here by a support structure 200. The support structure extends from the housing 203 and serves to hold the terminals and electrically isolate them from each other. The support structure can help to position the busbar positioning component. For example, the busbar positioning component and the capacitor can be attached to each other in an initial stage of assembly, and the transistors 214, the heat sink 216, the layered busbar structure 212, and the printed circuit board 208 can then be assembled on the busbar positioning component and thereby positioned relative to each other.

[0020] The electronic component 200 can be used in several different systems. In some implementations, the electronic component forms an inverter, which uses the transistors 214 to convert direct current to alternating current. In some implementations, the capacitor 202 can be a DC link capacitor for the inverter. For example, the busbar layers 212 can then comprise at least a first and a second DC busbar layer and an AC busbar layer.

[0021] Fig. 3 is another cut of the electronic component 200 of Fig.2. This is a view from the opposite direction. Here it is shown that terminal 204 has respective supply leads 300 at its distal end (i.e., the end opposite the one where the terminal is connected to the capacitor leads). Similarly, terminal 206 has respective supply leads at its distal end. The supply leads allow the terminals to be connected to corresponding busbar layers 212A-C. For example, each of the busbar layers 212A-C may have openings with corresponding tabs extending from their circumferences, and each of the tabs may be configured to align with and make contact with a corresponding supply lead 300 or 302. The supply lead and the tab can therefore be joined, for example, by welding.In some implementations, each of the leads 300 and 302 can be paired and positioned adjacent to one of the transistors 214.

Claims

[1] Electronic component which includes: a layered busbar structure (212) comprising at least two busbar layers (212A-C) separated by an insulating layer; a transistor (214) connected to the layered busbar structure (212) on a first side thereof; and a capacitor (100) which is mounted on the first side of the layered busbar structure (212) and is positioned further away from the layered busbar structure (212) than the transistor (214), wherein the capacitor (100) has respective planar terminals (102, 104) which are parallel to each other and perpendicular to the layered busbar structure (212), wherein each of the planar terminals (102, 104) comprises a rectangular element, one side of which is connected to the capacitor (100) and the opposite end is connected to a corresponding busbar layer (212A-C), wherein each of the planar terminals (102, 104) has several feeder lines (108, 110) at the opposite end of the rectangular element, the feeder lines (108, 110) connecting the respective planar terminal (102, 104) to the corresponding busbar layer. [2] Electronic component according to claim 1, wherein the capacitor (100) is enclosed by a housing (106) and wherein the planar terminals (102, 104) extend outside the housing (106). [3] Electronic component according to claim 2, wherein each rectangular element extends from one end of the housing (106) to the other. [4] Electronic component according to claim 2 or 3, which further comprises a support structure (112) for the rectangular elements extending from the housing (106) in the direction of the layered busbar structure (212). [5] Electronic component according to claim 4, wherein the support structure (112) holds the planar connectors (102, 104) at their edges, leaving outwardly facing surfaces of the rectangular elements free. [6] Electronic component according to claim 4 or 5, wherein a section of the support structure (112) isolates the planar connections (102, 104) from each other. [7] Electronic component according to claim 4, 5 or 6, wherein the support structure (112) and the rectangular elements are configured to position a busbar positioning component (218) relative to the electronic component, wherein the busbar positioning component (218) is configured to allow the layered busbar structure (212) to be attached to it. [8] Electronic component according to one of the preceding claims, wherein the electronic component is an inverter comprising several transistors, the busbar layers comprising at least a first and a second DC busbar layer and an AC busbar layer, and the capacitor is a DC intermediate circuit capacitor for the converter. [9] Electronic component according to one of the preceding claims, wherein each of the busbar layers (212A-C) has openings with corresponding tabs extending from the circumference thereof, and wherein each of the tabs is designed to align with and come into contact with a corresponding feed line. [10] Electronic component according to one of the preceding claims, wherein the leads (108, 110) of the respective planar terminals (102, 104) are paired and positioned adjacent to a respective transistor.

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