POWER MODULE

Introduced is a power module including a first substrate and a second substrate, a semiconductor chip, and a via spacer electrically connecting the first substrate and the second substrate, wherein the via spacer includes a first portion electrically connected to the first substrate, a second portion electrically connected to the second substrate, and a resistor portion including a resistance value greater than resistance values of the first portion and the second portion and arranged between the first portion and the second portion.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application Nos. 10-2023-0078085, filed Jun. 19, 2023, and 10-2023-0137726, filed Oct. 16, 2023, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND OF THE PRESENT DISCLOSURE

Field of the Present Disclosure

The present disclosure relates to a power module equipped with via spacers for internal current conduction and sensing.

Description of Related Art

With the growing interest in the environment, there is a trend of increasing eco-friendly vehicles equipped with electric motors as power 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 direct current power to alternating current power for motor operation, and the inverter is usually composed of one or multiple power modules incorporating semiconductor chips that perform switching functions.

To control the power conversion system of a vehicle incorporating power modules, it is necessary to detect the current of the power modules, which may be achieved by equipping external current sensors or integrating resistive elements such as shunt resistors internally within the power modules.

If resistive elements such as shunt resistors are integrated inside the power modules, it is necessary to appropriately manage the heat generation of these resistive elements and the formation of current loops within the power module caused by the flow of high currents.

BRIEF SUMMARY

Various aspects of the present disclosure are directed to providing a power module which is configured for establishing electrical connection between a plurality of substrates through via spacers with a resistive element, while simultaneously allowing for current sensing within the module.

The objects of the present disclosure are not limited to the aforesaid, and other objects not described herein will be clearly understood by those skilled in the art from the descriptions below.

In order In various aspects of the present disclosure, a power module according to an exemplary embodiment of the present disclosure includes a first substrate and a second substrate including each an insulating layer and a metal layer disposed on one surface of the insulating layer and arranged, spaced from each other, for the metal layers to face each other, a semiconductor chip disposed between the first substrate and the second substrate, and a via spacer extending in a first direction, electrically connecting the first substrate and the second substrate, between the first substrate and the second substrate and separated from the semiconductor chip with a predetermined distance in a second direction crossing the first direction, wherein the via spacer includes a first portion electrically connected to the first substrate, a second portion electrically connected to the second substrate, and a resistor portion including a resistance value greater than resistance values of the first portion and the second portion and arranged along the first direction between the first portion and the second portion.

For example, the first portion and the second portion may extend in the same length in the first direction, and the resistor portion may be disposed at the center portion of the via spacer.

For example, the resistor portion may extend in the same length as the first portion and the second portion in the second direction.

For example, the potentials of the first portion and the second portion may be transferred to at least one of the first substrate and the second substrate.

For example, at least one of the first substrate and the second substrate may include a plurality of patterns individually formed to receive the potentials.

For example, the first portion and the second portion may each be connected to the plurality of patterns through a wire.

For example, the plurality of patterns may be connected to a signal lead transferring the received potentials to the outside thereof.

For example, the via spacer may receive first current passed through the semiconductor chip through one of the first substrate and the second substrate and transfer the received first current to the other substrate.

For example, the resistor portion may receive second current separate for sensing the first current, separately from the first current.

For example, the second current may include a current value less than that of the first current.

Through various embodiments of the present disclosure as described above, it becomes possible to implement a current sensor within the power module through via spacers, improving sensing performance by reducing sensing errors compared to the case where the current sensor is located outside the power module.

Furthermore, compared to the case where the current sensor is located outside the power module, the arrangement of additional components for connecting the resistive element may be omitted, resulting in a reduction in the overall volume and cost of the components required for current sensing.

Furthermore, the heat generated during the current sensing may be transferred to the two substrates, allowing for current sensing to be performed at relatively lower temperatures, which leads to the improvement of linearity between temperature and resistance values, enhancing the accuracy of sensing.

Furthermore, it becomes possible to accommodate larger currents with the same size, allowing for further reduction in the volume of components required for current sensing.

Furthermore, by integrating the current sensor and via spacers, which serve separate functions, into a single configuration, it becomes possible to simplify the internal structure of the power module.

DETAILED DESCRIPTION

The specific structural or functional descriptions of the exemplary embodiments of the present disclosure included in the present specification or patent application are illustrative examples intended to describe embodiments of the present disclosure, and the exemplary embodiments of the present disclosure may be implemented in various forms and should not be construed as being limited to those described in the present specification or the application.

The exemplary embodiments of the present disclosure may be subject to various modifications and can take on different forms, so specific embodiments are illustrated in the drawings and described in detail in the present specification or the application. However, this should not be construed as limiting the exemplary embodiments of the present disclosure to specific disclosed form, but rather should be understood to encompass all modifications, equivalents, or substitutes that fall within the scope of the concept and technological scope of the present disclosure.

Unless otherwise defined, all terms used herein, including technical or scientific terminology, include the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs. It will be further understood that terms, including those defined in commonly used dictionaries, should be interpreted in a manner consistent with their meaning in the context of the relevant field and should not be interpreted in an idealized or overly formal sense unless explicitly defined in the present specification.

Hereinafter, descriptions include the exemplary embodiments disclosed in the present specification with reference to the accompanying drawings in which the same reference numbers are assigned to refer to the same or like components and redundant description thereof is omitted.

As used in the following description, the suffix “module” and “unit” are granted or used interchangeably in consideration of easiness of description but, by itself, including no distinct meaning or role.

Furthermore, detailed descriptions of well-known technologies related to the exemplary embodiments included in the present specification may be omitted to avoid obscuring the subject matter of the exemplary embodiments included in the present specification. Furthermore, the accompanying drawings are only for easy understanding of the exemplary embodiments included in the present specification and do not limit the technical spirit included herein, and it should be understood that the exemplary embodiments include all changes, equivalents, and substitutes within the spirit and scope of the present disclosure.

As used herein, terms including an ordinal number such as “first” and “second” may be used to describe various components without limiting the components. The terms are used only for distinguishing one component from another component.

It will be understood that when a component is referred to as being “connected to” or “coupled to” another component, it may be directly connected or coupled to the other component or intervening component may be present. In contrast, when a component is referred to as being “directly connected to” or “directly coupled to” another component, there are no intervening component present.

It will be further understood that the terms “comprises” or “has,” when used in the present specification, specify the presence of a stated feature, number, step, operation, component, element, or a combination thereof, but they do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, elements, or combinations thereof.

For example, each controller may include a communication device communicating with another controller or sensor to control a function in charge, a memory that stores operating system or logic instructions and input/output information, and one or more processors for determination, operation, and decision-making necessary for functions in charge.

The power module according to an exemplary embodiment of the present disclosure is provided with via spacers that not only connect a plurality of substrates but also perform the role of current sensing, improving the sensing performance and efficiency of the internal current within the power module and simplifying the internal structure of the power module.

Hereinafter, a description first includes the overall configuration of the power module according to an exemplary embodiment of the present disclosure with reference toFIG.1.

FIG.1is a cross-sectional view exemplarily illustrating the overall configuration of the power module according to an exemplary embodiment of the present disclosure.

With reference toFIG.1, the power module according to an exemplary embodiment of the present disclosure includes a first substrate110, a second substrate120, a semiconductor chip200, and a via spacer300. However, it should be noted thatFIG.1illustrates only the components related to an exemplary embodiment of the present disclosure, and the actual power module may include more or fewer components than shown. Each component will be described in detail hereinafter.

First, the first substrate110including an insulating layer111and a metal layer112disposed on one side of the insulating layer111and the second substrate120including an insulating layer121and a metal layer122disposed on one side of the insulating layer121are arranged to be spaced from each other so that the metal layers112and122face each other.

The first substrate110and the second substrate120may be referred to as the lower substrate or the upper substrate, depending on their vertical arrangement, and in the following description, the first substrate110is assumed to be the lower substrate while the second substrate120is assumed to be the upper substrate. However, this is for the convenience of explanation, and the arrangement between the first substrate110and the second substrate120is not limited to the present configuration, and the exemplary embodiments of the present disclosure may be applicable even when the first substrate110and the second substrate120are arranged in the opposite manner.

The insulating layers111and121are provided for electrical insulation between the inside and the outside of the power module, and the metal layers112and122are arranged to face the inside of the power module, allowing for conduction within the power module and forming patterns to establish electrical connections within the power module.

The dual-sided structure of the first substrate110and the second substrate120allows the heat generated inside the power module to be transferred up and down and cooled, resulting in a dual-sided cooling with high cooling efficiency compared to single-sided cooling. As the cooling efficiency increases, the operating temperature of the power module may decrease, improving operational stability.

Additionally, besides the metal layers112and122, additional metal layers113and123may be arranged on the opposite sides of the insulating layers111and121, facing the outside of the power module to further improve the cooling efficiency. These additional metal layers113and123play a role in dissipating the heat generated inside the power module to the external environment through heat exchange with the outside thereof.

Furthermore, to achieve even better cooling efficiency, cooling channels, through which a coolant flows, may be connected to the external side of the additional metal layers113and123. Thermal interface material (TIM) or the like may be applied between the additional metal layers113and123and the cooling channels to facilitate heat transfer from the substrates110and120to the cooling channels, or a portion of the substrates110and120including the additional metal layers113and123may be inserted into the cooling channels to facilitate heat transfer from the substrates110and120to the cooling channels.

The insulating layers111and121may be made of ceramic, while the metal layers112,122,113, and123may be made of copper (Cu). In the instant case, the first substrate110and the second substrate120may be implemented using active metal brazed (AMB) or direct bonded copper (DBC) techniques.

Meanwhile, the semiconductor chip200is disposed between the first substrate110and the second substrate120.

The semiconductor chip200may be attached to one of the first substrate and the second substrate110and120through an adhesive C and then connected to the other substrate via a chip spacer210.FIG.1shows the semiconductor chip200attached to the first substrate110, but the placement of the semiconductor chip200is not limited to the present arrangement, and semiconductor chip200may also be placed on the second substrate120.

Here, the semiconductor chip200may be turned on or off based on a switching signal, and the conductivity between the upper and lower sides of the semiconductor chip200may be determined by the ON/OFF state.

The semiconductor chip200may be implemented as a switching device such as an insulated gate bipolar transistor (IGBT) or a metal-oxide-semiconductor field-effect transistor (MOSFET).

The via spacer300extends in the first direction1between the first substrate110and the second substrate120and is connected to the first substrate110and the second substrate120by adhesive C, electrically connecting the first substrate and the second substrate110and120, while being positioned away from the semiconductor chip200in the second direction2crossing the first direction1thereof.

The via spacer300is described in more detail with reference toFIG.2hereinafter.

FIG.2is a diagram illustrating the via spacer of the power module according to an exemplary embodiment of the present disclosure.

With reference toFIG.2, the via spacer300may be divided into a first portion310, a second portion320, and a resistor portion330.

In detail, the first portion310is electrically connected to the first substrate110, while the second portion320is electrically connected to the second substrate120. The resistor portion330may have a higher resistance compared to the first portion and the second portion310and320and is positioned between the first portion and the second portion310and320in the first direction.

The first portion and the second portion310and320may extend in the same length in the first direction, and the resistor portion330may be positioned at the center portion of the via spacer300between the equal lengths of the first portion and the second portion310and320.

Additionally, the resistor portion330may extend in the second direction to the same length as the first portion and the second portion310and320, resulting in a consistent cross-sectional shape of the via spacer300in the second direction.

By incorporating the resistor portion330in the via spacer300, the current flowing into the via spacer300may pass through the resistor, and the current passing through the resistor may be transferred back to the first substrate110or the second substrate120.

The via spacer300is configured to electrically connect the first substrate110and the second substrate120within the power module and is distinguished from the chip spacer210in that the via spacer300connects the first substrate and the second substrate110and120in the state of being separated from the semiconductor chip200in the second direction rather than connecting the semiconductor chip200to the first substrate and the second substrate110and120.

Furthermore, the via spacer300may also serve as a sensor configured for sensing the current within the power module. Sensing the current within the power module may be achieved by utilizing the potential difference between the two end portions of the resistor portion330connected to the first portion and the second portion310and320, as well as the resistance value of the resistor portion330.

For example, when the current flown into the first portion310of the power module passes through the resistor portion330and then exits through the second portion320, a voltage drop occurs due to the resistance in the resistor portion330, leading to the generation of a potential difference between the first portion310and the second portion320.

In the instant case, the resistance value of the resistor element400may be determined based on the temperature of the power module.

By utilizing the potential difference and resistance value of the resistor portion330, the current value inside the power module may be known, and the controller connected to the power module may perform control of a motor driven by the power module based on such sensing results.

For the present purpose, the potentials of the first portion and the second portion310and320may be transmitted to at least one of the first substrate and the second substrate110and120.

For example, the potential of the first portion310may be transmitted to the first substrate110while the potential of the second portion may be transmitted to the second substrate120, or both the potentials of the first portion and the second portion310and320may be transmitted to either the first substrate110or the second substrate120.

However, even when the potentials of the first portion and the second portion310and320are both transmitted to one of the first substrate and the second substrate110and120, the potentials of the first and second portions310and320are transmitted in a separated state.

Furthermore, at least one of the first substrate and the second substrate110and120may include a plurality of patterns individually formed to receive the potentials of the first portion and the second portion310and320. In the instant case, the plurality of patterns may be electrically isolated from other portions of the substrate for current sensing.

These patterns may be connected by wires, and the first portion and the second portion310and320may be electrically connected to the plurality of patterns through the wires.

Furthermore, signal leads for transmitting the received potentials to the outside may be connected to the plurality of patterns formed in at least one of the first substrate and the second substrate110and120.

By performing current sensing through the via spacer300inside the power module, it is possible to eliminate the need to arrange additional components for current sensing compared to the case where a separate current sensor is provided outside the power module.

This allows for advantages in terms of the volume and cost of components required for current sensing. Furthermore, the performance of current sensing may also be improved compared to using an external current sensor.

Meanwhile, as the resistor portion330is connected to the first portion and the second portion310and320, the heat generated by the current flowing through the resistor portion330may be transferred to both sides of the substrates110and120. This provides an advantage in heat dissipation during the current sensing process compared to the case where the resistor element400is connected to only one side of the substrate110or120, allowing heat to be dissipated in a single direction.

Considering that the linearity between temperature and resistance value decreases as the temperature of the resistor portion330increases, heat dissipation in both directions facilitates reducing the temperature of the resistor portion330, improving the linearity between temperature and resistance value and enhancing the accuracy of current sensing.

Meanwhile, the current flowing through the semiconductor chip200and transmitted to the via spacer300is referred to as the first current in the following description, and the via spacer300may receive the first current through one of the first substrate and the second substrate110and120and transmit the first current to the other substrate. Here, the first current may be understood as the current which is the target of sensing.

For example, the path of the first current may be of ‘first substrate110—semiconductor chip200—chip spacer210—second substrate120—second portion320—resistor portion330—first portion310—first substrate110.’

Meanwhile, a second current, which is separate from the first current, may be applied to the resistor portion330to detect the first current. That is, the Kelvin contact (or 4-terminal sensing) method may be applied to the current sensing of the power module according to an exemplary embodiment of the present disclosure.

This allows for improved sensing accuracy even with a low resistance value of the resistor element400and a high internal current (i.e., the first current) in the power module.

The second current may include a smaller magnitude compared to the first current, and as the ratio of the second current to the first current decreases, the sensing accuracy may be further enhanced.

Meanwhile, in the case where the via spacer300according to various exemplary embodiments of the present disclosure is not applied, a spacer is placed between the first substrate110and the second substrate120for electrical connection, and a shunt resistor for current sensing may be disposed on the first substrate110separately from the spacer.

In the instant case, the shunt resistor is connected to the first substrate110but not to the second substrate120and thus the heat generated from the shunt resistor is transmitted only to the first substrate110.

Meanwhile, in the power module with the via spacer300according to various exemplary embodiments of the present disclosure, the via spacer300including the resistor portion330doubles as the electrical connection and current sensing between the first substrate110and the second substrate120, simplifying the internal arrangement of the substrate compared to the comparative example.

Furthermore, because the resistor portion330is connected to the first substrate and the second substrate110and120through the first portion and the second portion310and320, the heat generated from the resistor portion330may be transferred in both directions, to the first substrate and the second substrate110and120during the current sensing process, facilitating heat dissipation and allowing current sensing to be performed at relatively low temperatures compared to the comparative example.

Through various embodiments of the present disclosure as described above, it becomes possible to implement a current sensor within the power module through a via spacer, improving sensing performance by reducing sensing errors compared to the case where the current sensor is located outside the power module.

Furthermore, compared to the case where the current sensor is located outside the power module, the arrangement of additional components for connecting the resistive element may be omitted, resulting in a reduction in the overall volume and cost of the components required for current sensing.

Furthermore, the heat generated during the current sensing may be transferred to the two substrates, allowing for current sensing to be performed at relatively lower temperatures, which leads to the improvement of linearity between temperature and resistance values, enhancing the accuracy of sensing.

Furthermore, it becomes possible to accommodate larger currents with the same size, allowing for further reduction in the volume of components required for current sensing.

Furthermore, by integrating the current sensor and via spacers, which serve separate functions, into a single configuration, it becomes possible to simplify the internal structure of the power module.