POWER MODULE

Abstract

A power module comprises at least one semiconductor chip, at least one substrate supporting the at least one semiconductor chip, and a first lead. The first lead comprises: (i) an extended portion having a first end connected to the at least one substrate and a second end projecting outwardly from the at least one substrate, and (ii) a resistive portion disposed between the first end and the second end of the extended portion.

Description

TECHNICAL FIELDThe present disclosure relates to a power module having a current sensor structure integrated with the output terminal.PRIOR ARTWith the increasing interest in the environment, there is a trend toward more eco-friendly vehicles equipped with electric motors as drive sources. Eco-friendly vehicles, also known as electrified vehicles, include electric vehicles (EVs) and hybrid electric vehicles (HEVs).In electrified vehicles, an inverter is typically equipped to convert DC current to AC current for motor operation, and the inverter is typically comprised of one or more power modules with semiconductor chips that perform switching functions.In order to control the power conversion system of a vehicle having a power module, the current of the power module needs to be detected, which can be achieved either by providing an external current sensor or by incorporating resistance elements such as shunt resistors inside the power module.SUMMARY OF THE INVENTIONIt is an object of the present disclosure to provide a power module capable of securing space for current measurement, reducing cost, and improving accuracy of current measurement by allowing a current sensor implemented by the output terminal to measure the current of the power module.The objects of the present disclosure are not limited to the foregoing, and other objects not described herein will be clearly understood by those skilled in the art from the following descriptions.In order to achieve the above objects, a power module includes at least one semiconductor chip, at least one substrate on which the at least one semiconductor chip is mounted, and a first lead having an extended portion connected at one end to the at least one substrate and extending at the other end to protrude from the at least one substrate, and a resistor portion disposed between the one end and the other end.For example, the first line may electrically connect the substrate to an external terminal by connecting the other end of the extended portion to the external terminal.For example, the first line may form a current flow path from the substrate to the external terminal.For example, the first line may form a current flow path in the direction from one end of the extended portion to the other end of the extended portion via the resistor portion.For example, the resistor portion may extend in a direction crossing the direction in which the extended portion extends.For example, the one end and the other end of the extended portion may be connected via the resistor portion.For example, the one end and the other end of the extended portion may be connected to opposite ends of the resistor portion in the direction in which the extended portion extends.For example, a power module may further include a connector connected to the resistor portion to output a voltage across both ends of the resistor portion.For example, the connector may be connected to the resistor portion extending along the direction from one end to the other end of the extended portion, the resistor portion being disposed between one end and the other end of the connector.For example, the connector may include terminals and a cover that covers the terminals in predetermined directions, the terminals including a plurality of first terminals each outputting a voltage at both ends of the resistor portion.For example, the terminals may be connected to an external control board.For example, the terminals may include a second terminal connected to the external control board.For example, the power module may further include a plurality of second lines connected to the at least one substrate and separated from the first line.For example, the first line may receive the current flow from at least one of the plurality of second lines through the substrate and an end of the extended portion.For example, the power module may further include a molded element enclosing the at least one semiconductor chip and an end of the extended portion.For example, the at least one substrate may include a first substrate and a second substrate spaced apart from each other with the semiconductor chip interposed therebetween, and an end of the first lead may be disposed between the first and second substrates.As described above, in various embodiments of the present disclosure, the power module is advantageous in terms of reducing the internal space required for current measurement by implementing a current sensor structure at its output terminal.With the reduction in the space required for the detection, it becomes possible to secure the space for the arrangement of the components within the power module, which enables enlargement of the individual components, resulting in improvement in the performance of the power module.In addition, by ensuring space for current detection, it becomes possible to detect the current without relying on an external current sensor, thereby eliminating the cost associated with the placement of external current sensors.Moreover, it is possible to improve the performance of current detection by detecting the current immediately before the output of the current from the power module.The advantages of the present disclosure are not limited to the above, and other advantages not described herein can be clearly understood by those skilled in the art from the following descriptions.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a diagram showing an example of a power module. FIG. 2 is a diagram showing an example of a first line. FIG. 3 is a diagram showing an example of a connector.DETAILED DESCRIPTIONHereinafter, the implementations disclosed in the present specification will be described with reference to the accompanying drawings, in which the same reference numerals are assigned to refer to the same or similar components, and redundant description thereof will be omitted.In some implementations, it is proposed that a power module have a current sensor structure integrated into the output terminal, thereby ensuring the space for the current sensor and improving the sensing performance.For example, a power module having a structure capable of performing current detection while reducing the space required for placing the current sensor inside the power module, compared to the case where the current sensor is mounted inside the power module, is proposed. In some examples, the current sensor may be placed on the power module board.In some implementations, a power module having a structure capable of reducing the size and the cost compared to the case where a separate external current sensor is mounted outside the power module is proposed.Hereinafter, the power module according to one or more embodiments of the present disclosure will be described in detail with reference to FIGS. 1 to 3.FIG. 1 is a diagram illustrating an example of a power module, FIG. 2 is a diagram illustrating an example of a first line, and FIG. 3 is a diagram illustrating an example of a connector.In some embodiments, referring to FIG. 1, the power module 10 may include at least one semiconductor chip 100, at least one substrate 200, a first lead 310, a plurality of second leads 320, and a molded element 400. It should be noted, however, that FIG. 1 only shows the components essential for describing an implementation of the present disclosure, and that the actual power module may be implemented with more or fewer components. Hereinafter, the individual components of the power module according to the implementations of the present disclosure will be explained in detail.In some embodiments, the at least one semiconductor chip 100 may be mounted on at least one substrate 200 and electrically connected to the at least one substrate 200. More specifically, the semiconductor chip 100 may be bonded to the substrate 200 by soldering or sintering, and a separate member such as a spacer may be used for the bonding to the substrate 200.In some examples, the semiconductor chip 100 may be turned on and off based on switching signals, and the connection between the upper and lower sides of the semiconductor chip 100 may be determined based on its on and off state.For example, the semiconductor chips 100 may be implemented as switching devices such as insulated gate bipolar transistors (IGBT) or metal oxide semiconductor field effect transistors (MOSFET), and may be made of silicon or silicon carbide.In some examples, the at least one substrate 200 may be manufactured by stacking a plurality of layers including an insulation layer and metal layers.For example, the substrate 200 may be formed by stacking an insulating layer and a metal layer disposed on the surface facing the inside of the power module 10. In this case, the insulation layer may electrically insulate the inside and outside of the power module, while the metal layer facing the inside of the power module may form electrical connections inside the power module.For improving cooling efficiency, a metal layer may also be disposed on the surface of the insulation layer facing the outside of the power module, and these metal layers may facilitate heat dissipation from the inside of the power module, particularly from the semiconductor chips 100, by heat transfer with the outside, and thus cool the power module.The insulating layer may be made of materials such as ceramic, while the metal layer may be made of materials such as copper. In this case, the at least one substrate 200 may be realized by methods such as active metal brazing (AMB) or direct bonded copper (DBC).In some examples, the power module may have a structure in which the semiconductor chip 100 is mounted on a single substrate 200. In some examples, the power module may have a structure in which the semiconductor chip 100 is mounted between a plurality of substrates 200. In the former case, the heat generated in the semiconductor chip 100 can be dissipated in one direction through a single substrate 200 using a single-side cooling method, while in the latter case, the heat generated in the semiconductor chip 100 can be dissipated in both directions through two substrates 200 using a two-side cooling method.In the case where the power module 10 is implemented with a two-side cooling method in which the semiconductor chip 100 is mounted between a plurality of substrates 200 as mentioned above, the plurality of substrates 200 spaced apart from each other and arranged around the semiconductor chip 100 may be referred to as the first substrate and the second substrate, respectively, and in this case, the first lead 310 may include an extended portion 311 of which one end is arranged between the first substrate and the second substrate.In some examples related to FIGS. 1 and 2, the first lead 310 may include the extended portion 311 connected at one end to the at least one substrate 200 and extending at the other end to protrude from the at least one substrate 200, and a resistor portion disposed between the one end and the other end of the extended portion 311.The other end of the extended portion 311 of the first lead 310 may be connected to an external terminal, thereby electrically connecting the substrate 200 to an external terminal, and specifically forming a current path from the substrate 200 to the external terminal.More specifically, the first line 310 may form a current path in the direction from one end of the extended portion 311, through the resistor portion 312, and to the other end of the extended portion 311.Through this current path, the current flows from the inside of the power module 10 to the external terminal through the resistor portion 312, and the voltage is applied to both ends of the resistor portion 312. The voltage may be used to detect the output current of the power module 10, for example.To achieve this, the resistor portion 312 may extend in a direction crossing the direction in which the extended portion 311 extends. That is, the resistor portion 312 may be formed in a direction crossing the extended portion 311.In this case, the one end and the other end of the extended portion 311 may be connected to each other through the resistor portion 312. For example, the first line 310 may include three parts connected in the order of the one end of the extended portion 311, the resistance portion 312, and the other end of the extended portion 311.The extended portion 311 and the resistor portion 312 may have the same width and thickness, whereby all current flowing through the cross section of the one end of the extended portion 311 may flow through the cross section of the resistor portion 312 and then be output along the cross section of the other end of the extended portion 311.In some examples, referring to FIGS. 1 and 3, a connector 313 may be connected to the resistor portion 312 to output the voltage across both ends of the resistor portion 312, and the ends of the resistor portion 312 may be distinguished as one end side of the extended portion 311 and the other end side of the extended portion 311.In this case, the connector 313 may be connected to the resistor portion 312 extending along the direction from one end to the other end of the extended portion 311, so that the resistor portion 312 is disposed between one end and the other end of the connector 313. That is, one end of the connector 313 may be disposed on the one end side of the extended portion 311, and the other end of the connector 313 may be disposed on the other end side of the extended portion 311, with the resistor portion 312 connected therebetween.In some examples, the connector 313 may include terminals T and a cover C covering the terminals T in predetermined directions. Specifically, the terminals T may include a plurality of first terminals T 1 each outputting the voltage at both ends of the resistor portion 312, and the cover C covers the terminals T to prevent errors due to noise and other disturbances in current detection from occurring. The cover C may be formed to surround the sides of the terminals T and have one or both ends thereof left open so that the first lead 310 and the terminals T are exposed to the outside.The terminals T may be connected to an external control board, which may include a processor, such as a microcontroller or microcomputer, capable of determining the current based on the voltage difference across both ends of the resistor portion 312.In addition to the first terminals T 1, the terminals T may include a second terminal T 2 connected to the external control board.In some examples, in addition to the first line 310, a plurality of second lines 320 connected to the at least one substrate 200 and spaced apart from the first line 310 may be further present.In this case, the first line 310 may receive the current inflow from at least one of the plurality of second lines 320 through the substrate 200 and an end of the extended portion 311.For example, the first line 310 may correspond to an output terminal, while the plurality of second lines 320 may correspond to terminals N and P.The first line 310 and the second lines 320 may be aligned side by side on one side of the power module 10, or as shown in FIG. 1, may be aligned on different sides of the power module 20.The molded member 400 may enclose the at least one semiconductor chip 100 and an end of the extended portion 311 of the first lead 310 among the components constituting the power module 10. Moreover, the mold member 400 may surround a portion of the substrate 200 and provide protection for the components constituting the power module 10 while ensuring electrical insulation between the inside and the outside of the power module 10.For example, the molding member 400 may be made of materials such as epoxy molding compound (EMC) to protect the components of the power module 10 from moisture, heat, shocks, etc.As described above, in various implementations of the present disclosure, the power module is advantageous in terms of reducing the internal space required for the detection of the current detection by the implementation of the current sensor structure at its output terminal.By reducing the space required for detection, it becomes possible to secure the space for arranging the components inside the power module, which enables enlargement of the individual components, leading to improvement in performance of the power module.In addition, by securing the space for current detection, it is possible to detect the current without relying on an external current sensor, thereby eliminating the cost associated with the placement of external current sensors.Moreover, it is possible to improve the performance of the current detection by detecting the current immediately before the output of the current by the power module.Although the present disclosure has been illustrated and described in connection with specific implementations, it will be apparent to those skilled in the art that various modifications and changes may be made thereto without departing from the scope of the present disclosure, which is defined by the appended claims.

Claims

A power module comprising: at least one semiconductor chip; at least one substrate holding the at least one semiconductor chip; and a first lead comprising: an extended portion having (i) a first end connected to the at least one substrate and (ii) a second end protruding outward away from the at least one substrate, and a resistor portion disposed between the first end and the second end of the extended portion.The power module of claim 1, wherein the first lead is configured to electrically connect the at least one substrate to an external terminal based on the second end of the extended portion connected to the external terminal.The power module of claim 2, wherein the first line is configured to define a current flow path from the at least one substrate to the external terminal.The power module of claim 3, wherein the first line is configured to define the current flow path in a direction from the first end of the extended portion to the second end of the extended portion via the resistor portion.The power module of claim 1, wherein the extended portion extends in a first direction and the resistor portion extends in a second direction intersecting the first direction.The power module according to claim 5, wherein the first end and the second end of the extended portion are connected via the resistor portion.The power module according to claim 6, wherein the first end and the second end of the extended portion are connected to opposite ends of the resistor portion in the first direction, respectively.The power module of claim 1, further comprising a connector connected to the resistor portion and configured to output a voltage between the ends of the resistor portion.The power module of claim 8, wherein the connector is connected to the resistor portion and has a first end and a second end spaced apart from each other in a first direction, wherein the connector extends along the first direction from the first end of the connector toward the second end of the extended portion, and wherein the resistor portion is disposed between the first end of the connector and the second end of the connector.The power module according to claim 8, wherein the connector includes: a plurality of terminals, the plurality of terminals including a plurality of first terminals configured to output voltages between the portions of the resistor portion, respectively; and a cover covering the plurality of terminals in predetermined directions.The power module of claim 10, wherein the plurality of terminals are connected to an external control board.The power module of claim 11, wherein the plurality of terminals further comprises a second terminal connected to a ground of the external control board.The power module of claim 1, further comprising a plurality of second leads connected to the at least one substrate, the plurality of second leads being separate from the first lead, the first lead configured to receive current inflow from at least one of the plurality of second leads through the at least one substrate and the first end of the extended portion.The power module of claim 1, further comprising a molding that covers the at least one semiconductor chip and the first end of the extended portion.

Images