Patent Description:
A power converter is widely used in the fields of servo motors, frequency converters, inverters, and the like, and is configured to implement functions such as alternating current-to-direct current conversion and direct current boost/buck. The power converter is formed by combining a power module and another electronic device based on specific functions. The power module usually has a defect of poor sealing performance. In addition, breakdown of the power module may occur due to insufficient heat dissipation, excessive transient current, or the like in a working process. An existing packaging material cannot shield an arc damage of the breakdown, and a large quantity of electronic devices in the power converter are easily damaged.

<CIT> provides a heat sink package in which a semiconductor package and a heat sink are bound to each other and a method of fabricating the same.

<CIT> provides relates to a semiconductor module comprising: a substrate; at least one semiconductor component applied to a first main surface of the substrate; a carrier with a pin or fin cooling structure, the substrate being arranged adjacent to the carrier with its second main surface facing away from the first main surface; with an encapsulation layer on the carrier covering the substrate and the at least one semiconductor component; with a plurality of electrically conductive supply lines for electrically conductive contacting of the at least one semiconductor component, which are arranged penetrating the encapsulation layer.

This application provides a power module, a method for manufacturing a power module, and a power converter including the power module. In addition to improving sealing performance of the power module, a breakdown arc direction of the power module can be further controlled, to reduce damage caused by a fault of the power module. This application specifically includes the following technical solutions.

According to a first aspect, this application provides a power module, including a housing, where the housing includes a main housing, a heat sink, and a fastening layer, the main housing is provided with a groove, a groove opening is located in on first outer surface, the fastening layer is disposed on a bottom surface of the groove, and the heat sink is located on a side away from an orientation of the groove opening; a circuit component, accommodated in a groove, where the circuit component includes a heat dissipation surface and a pin, the heat dissipation surface is fastened to the fastening layer through welding, the pin extends toward a direction away from the fastening layer, and a distal end of the pin extends out of a first outer surface; and a package, where the package is filled in the groove, and is configured to cover the circuit component, and to at least partially expose the distal end of the pin.

In the power module according to this application, the groove is disposed on the housing, so as to form an accommodating cavity with a bottom surface and a side wall made of a metal material. The circuit component is accommodated in the groove, so that protection strength of the circuit component can be improved. A structure of the fastening layer disposed on the bottom surface can achieve better welding and fastening effect on the circuit component, and improve heat conduction efficiency of the circuit component. The pin of the circuit component extends out of both the outer surface of the housing and the package, which also ensures connection reliability of the power module and an external device. When a breakdown accident occurs on the power module in this application, a structure of the groove can form reliable protection for the power module, and control an arc to propagate only toward the groove opening of the groove, thereby reducing fault damage of the power module.

In a possible implementation, the fastening layer is formed on the bottom surface of the groove through electroplating, or is formed on a bottom of the groove in an embedded manner.

In this implementation, the structure of the fastening layer may be formed on the bottom surface of the groove through electroplating or in an embedded manner, and connection reliability of the fastening layer at the bottom of the housing is ensured.

In a possible implementation, a main material of the fastening layer is copper, tin, nickel, or silver.

In a possible implementation, a connection layer is further disposed between the fastening layer and the heat dissipation surface, and a main material of the connection layer is tin, silver, copper, or resin.

In this implementation, tin, silver, copper, or resin is used as the connection layer to fasten the circuit component to the fastening layer, which can ensure heat conduction efficiency between the circuit component and the housing, and improve heat dissipation effect of the power module.

In a possible implementation, main materials of the main housing and the heat sink are metal with a thermal conductivity greater than or equal to <NUM> W/mK.

In a possible implementation, main materials of the main housing and the heat sink are aluminum.

In this embodiment, the aluminum has a relatively high thermal conductivity, light weight, and low costs, heat dissipation effect of the power module can be better improved, and the overall costs can be reduced.

In a possible implementation, the circuit component further includes a circuit board, a chip, and a bonding wire. One side surface of the circuit board forms the heat dissipation surface, the chip and the pin are attached to the other side surface of the circuit board, and the bonding wire is connected between the chip and the pin.

In this implementation, the circuit component implements a power conversion function by the chip carried on the circuit board, and implements an electrical connection between the circuit component and an external device by the pin.

In a possible implementation, a bonding wire is further connected between two chips.

In a possible implementation, the chip includes one or more of a metal-oxide-semiconductor field-effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), a diode, or a triode.

In a possible implementation, the circuit board includes a ceramic substrate, a first copper layer, and a second copper layer. The first copper layer and the second copper layer are respectively attached to two opposite sides of the ceramic substrate, and the heat dissipation surface is formed on the first copper layer.

In this implementation, the circuit board may be implemented by using a copper-clad ceramic piece. The first copper layer of the circuit board is configured to implement a reliable connection to the bottom surface of the groove, and the second copper layer is configured to implement an electrical connection function of the chip, the bonding wire, and the pin.

In a possible implementation, a side that is of the package and that is away from the bottom surface is flush with the first outer surface or is lower than the first outer surface.

In this embodiment, the height of the package is limited, which can ensure that a distal end of the pin is reliably exposed relative to the first outer surface, and connection stability between the power module and the external device is ensured.

In a possible implementation, a material of the package is epoxy resin or silicon gel.

The groove includes a side wall. The side wall is connected between the first outer surface and the bottom surface, and a shape of any cross section that is of the side wall and that is perpendicular to the first outer surface is a stepped shape.

In this implementation, the cross-sectional shape of the side wall is set as the stepped shape, which can increase a contact area between the package and the side wall, and ensure sealing effect between the package and the side wall.

In a possible implementation, projection of the groove opening of the groove on the bottom surface is accommodated within the bottom surface.

In this implementation, an area of the groove opening of the groove is set to be less than that of the bottom surface of the groove, so that the groove can achieve better holding effect on the package, and structural stability of the power module can be improved.

According to a second aspect, this application provides a method for manufacturing a power module, including the following steps:.

In the manufacturing method for a power module in this application, after a structure of a circuit component is formed, the circuit component is attached to the bottom surface of the groove, and then the groove is packaged, so that this method may be used to manufacture the power module provided in the first aspect of this application. It may be understood that the power module manufactured by using the method in this application also has beneficial effect of high reliability, a strong heat dissipation capability, and relatively small fault damage in the case of breakdown of the foregoing power module.

In a possible implementation, the fastening the other side surface of the circuit board to a fastening layer of a housing through welding includes: fastening the other side surface of the circuit board to the fastening layer of the housing through welding by using tin soldering, silver sintering, copper sintering, silver paste, or prepreg.

In this implementation, because the fastening layer is disposed on the bottom surface of the groove, the fastening layer can be connected and fastened to the circuit component by using the foregoing process, and heat conduction efficiency between the circuit component and the groove can be improved.

According to a third aspect, this application provides a power converter, including a control module and the power module provided in the first aspect of this application. The control module is configured to control on or off of at least one power module, so as to implement power conversion.

According to a fourth aspect, this application provides a power supply device, including a power supply and the power converter provided in the third aspect of this application, where the power supply is electrically connected to the power converter, and outputs electrical energy through the power converter.

It may be understood that, because the power converter provided in the third aspect of this application uses the power module provided in the first aspect of this application, and the power supply device provided in the fourth aspect of this application also uses the power converter, beneficial effect of the two is roughly the same as those of the power module provided in the first aspect of this application.

The following describes the technical solutions in embodiments of this application with reference to the accompanying drawings in embodiments of this application. It is clear that the described embodiments are merely a part rather than all of embodiments of this application. All other embodiments obtained by a person of ordinary skill in the art based on embodiments of this application without creative efforts shall fall within the protection scope of this application.

The power supply device according to this application includes a power supply and a power converter. The power supply is configured to provide electrical energy. The power converter is electrically connected to the power supply, and is configured to perform power conversion on the electrical energy provided by the power supply, so as to achieve effect of providing the electrical energy to an electric device according to a preset specification and ensuring normal working of the electric device. A semiconductor circuit may be disposed in the power supply device. The power converter is applied to the semiconductor circuit, and may be specifically configured to implement power conversion functions such as alternating current-to-direct current conversion and direct current boost/buck. The power supply device in this application may be a device such as a servo motor, a frequency converter, or an inverter.

<FIG> is a schematic diagram of a circuit of a power converter in a semiconductor circuit <NUM> according to this application.

In the schematic diagram of <FIG>, the semiconductor circuit <NUM> is a boost circuit (BOOST). Specifically, the semiconductor circuit <NUM> includes an inductor <NUM>, a first power module <NUM>, a second power module <NUM>, a capacitor <NUM>, and a control module <NUM>. The first power module <NUM> and the second power module <NUM> may be power modules provided in <FIG> in this application. The control module <NUM> and the first power module <NUM> form a power converter according to this application.

In this embodiment, the semiconductor circuit <NUM> is configured to boost a first voltage of power received from an input end <NUM> to a second voltage, and the second voltage is output from an output end <NUM>, so that a power conversion function is implemented.

The inductor <NUM> is configured to implement energy storage and energy release of electrical energy of the power provided by the input end <NUM>.

The capacitor <NUM> is connected to the output end <NUM>, and is configured to obtain the second voltage after filtering the electrical energy of the power when the inductor <NUM> releases energy.

The second power module <NUM> is specifically a diode, and is connected between the inductor <NUM> and the capacitor <NUM> to implement unidirectional energy release of the inductor <NUM> to the output end <NUM>.

The control module <NUM> and the first power module <NUM> are jointly used as a power converter of the semiconductor circuit <NUM>, that is, as a controllable switch. The controllable switch is connected to the inductor <NUM> and the input end <NUM>, to provide an energy storage path for the inductor <NUM>.

Specifically, the control module <NUM> is configured to control on or off of the first power module <NUM>. When the first power module <NUM> is in an on state, the inductor <NUM> is connected between two input ends <NUM>, and is in the energy storage path to store the electrical energy. When the first power module <NUM> is in an off state, the inductor <NUM> is connected to the output end <NUM> through the second power module <NUM> to form an energy release path, so that the electrical energy stored by the inductor <NUM> may be released, thereby achieving boost effect of the semiconductor circuit <NUM>.

<FIG> is a schematic diagram of a circuit of another power converter in a semiconductor circuit <NUM> according to this application.

In the schematic diagram of <FIG>, the semiconductor circuit <NUM> is an inverter circuit. Specifically, the semiconductor circuit <NUM> includes four power modules <NUM>, a control module <NUM>, and a capacitor <NUM>. The four power modules <NUM> are also the power modules provided in <FIG> in this application. The control module <NUM> is configured to control on or off of each power module <NUM>, and work together with each power module <NUM> to form a power converter according to this application.

The four power modules <NUM> are defined as switches Q1 to Q4 and form two bridge arms. Each bridge arm includes two power modules <NUM> connected in series to positive and negative electrodes of the semiconductor circuit <NUM>. The capacitor <NUM> is connected between a positive electrode and a negative electrode of an input end <NUM> to filter a voltage and a current in the input end <NUM> of the semiconductor circuit <NUM>.

In the semiconductor circuit <NUM> shown in <FIG>, under control of the control module <NUM>, the four power modules <NUM> are also used as controllable switches, and two different conductive paths are formed by controlling on and off states of the four power modules <NUM> in the two bridge arms.

Specifically, the control module <NUM> has four control ports A\B\C\D, which respectively control on and off of the four power modules <NUM> Q1\Q2\Q3\Q4. When the switches Q1 and Q4 are in an on state and the switches Q2 and Q3 are in an off state, the positive and negative electrodes of the semiconductor circuit <NUM> are in a positive phase transmission. When the switches Q2 and Q3 are in an on state and the switches Q1 and Q4 are in an off state, the positive and negative electrodes of the semiconductor circuit <NUM> are in a negative phase transmission. The positive and negative polarities of the voltages obtained by the output end <NUM> in the two states are reversed. Therefore, the semiconductor circuit <NUM> shown in <FIG> implements an inversion function. Direct current-to-alternating current conversion or alternating current-to-direct current conversion can be implemented to implement a power conversion function.

It may be learned from <FIG> that, in the semiconductor circuit <NUM> and the semiconductor circuit <NUM>, the power converter according to this application can implement a power conversion function in the semiconductor circuit through cooperation of the control module <NUM> (the control module <NUM> in <FIG>) and the power module (the first power module <NUM>, the second power module <NUM>, or the power module <NUM>) although specific working manners are different.

<FIG> shows a specific structure of a power module <NUM> according to this application. It may be understood that the specific structure of the power module <NUM> may also be used as a specific structure of the first power module <NUM> or the second power module <NUM> shown in <FIG>, or the power module <NUM> shown in <FIG>. The specific structure of the power module <NUM> may be applied to any power converter involved in this application and used as any one or more power modules in a semiconductor circuit. For understanding, refer to a decomposition diagram of the power module <NUM> shown in <FIG> and a schematic diagram of a cross section of the power module <NUM> shown in <FIG>.

The power module <NUM> includes a housing <NUM>, a circuit component <NUM>, and a package <NUM>. The housing <NUM> includes a main housing <NUM>. The main housing <NUM> has a first outer surface <NUM> and a second outer surface <NUM> that are opposite to each other. The housing <NUM> further includes a fastening layer <NUM> and heat sinks <NUM>. The heat sinks <NUM> are disposed in a protruding manner on the second outer surface <NUM>, and a groove <NUM> is formed in the first outer surface <NUM>. As shown in <FIG>, there are a plurality of heat sinks <NUM>. The plurality of heat sinks <NUM> are distributed on the second outer surface <NUM> at intervals in a same direction. A main material of the housing <NUM> is aluminum, and a main material of the fastening layer <NUM> is copper. That is, main materials of the main housing <NUM> and the heat sinks <NUM> are aluminum. An aluminum material has relatively light weight and relatively good thermal conductivity. A heat dissipation area of the housing <NUM> may be increased through the disposing of the plurality of heat sinks <NUM>, which is helpful to improve heat dissipation effect of the power module <NUM>.

It should be proposed that, the main material of the housing <NUM> may also be another metal with a thermal conductivity greater than or equal to <NUM> W/mK (W/mK) in addition to aluminum. The thermal conductivity is the heat transferred per unit temperature gradient (the temperature decreases by <NUM> within a length of <NUM>) and per unit time by a unit heat conducting surface. In the conventional technology, metal such as copper, silver, or gold also has a thermal conductivity greater than or equal to <NUM> W/mK, and the foregoing metal may also be used as a main material of the housing <NUM> of the power module <NUM> in this application. It may be understood that when the main material of the housing <NUM> is aluminum, the weight of the housing <NUM> is relatively light, and costs are relatively low. Therefore, subsequent embodiments of this application are described based on that the main material of the housing <NUM> is aluminum.

On the other side, the main material of the fastening layer <NUM> may also be metal such as tin, nickel, or silver in addition to copper. Connections and fastenings between these materials and internal devices of the power module <NUM> are relatively stable, so that overall structural stability of the power module <NUM> can be improved. Subsequent embodiments of this application are described based on that the main material of the fastening layer <NUM> is copper. In embodiments of this application, a main material of "A" is "B", and it should be understood that a material of "A" is "B", or a material of "A" is a "B"-containing alloy.

On a side of the first outer surface <NUM> shown in <FIG>, the groove <NUM> is formed in the first outer surface <NUM>, and has a groove opening <NUM> close to the first outer surface <NUM>, a bottom surface <NUM> located between the second outer surface <NUM> and the first outer surface <NUM>, and a side wall <NUM> connected between the bottom surface <NUM> and the first outer surface <NUM>. The side wall <NUM> surrounds a periphery of the bottom surface <NUM>, and encloses to form a structure of accommodating space with the bottom surface <NUM>.

For the power module <NUM> in this application, the fastening layer <NUM> is disposed on the bottom surface <NUM> of the groove <NUM>. Specifically, in an embodiment, the fastening layer <NUM> may be formed on the bottom surface <NUM> through electroplating. That is, electroplating is performed on the main housing <NUM> made of the aluminum material to attach copper to the bottom of the groove <NUM>, so that the bottom surface <NUM> forms a structure of the fastening layer <NUM>. The structure of the fastening layer <NUM> formed through electroplating may form a relatively good adhesion force with the aluminum material of the main housing <NUM>, and does not easily fall off from the main housing <NUM>.

However, in another embodiment, a copper block may also be further embedded into the bottom of the groove <NUM>. The copper block may be embedded into the bottom of the groove <NUM> by extruding, and form interference fit with the groove <NUM>. By controlling the interference between the copper block and the groove <NUM>, a reliable connection between the copper block and the main housing <NUM> can also be ensured, so that the copper block does not easily fall off from the main housing <NUM>. Thus, an outer surface, facing the groove opening <NUM>, of a side of the copper block forms the bottom surface <NUM> of the groove <NUM>, and the bottom surface <NUM> of the groove <NUM> also forms the structure of the fastening layer <NUM>.

It may be understood that when the main material of the fastening layer <NUM> is another material, the fastening layer <NUM> may also be formed on the bottom surface <NUM> of the groove <NUM> through electroplating, or formed on the bottom surface of the groove <NUM> in an embedded manner.

The circuit component <NUM> is accommodated in the groove <NUM>, and the structure of the fastening layer <NUM> on the bottom surface <NUM> is configured to be fastened to the circuit component <NUM> through welding and to implement reliable holding of the circuit component <NUM>. For details, refer to schematic diagrams of a structure of the circuit component <NUM> shown in <FIG> and <FIG>. <FIG> is a schematic diagram of a structure of the circuit component <NUM>, and <FIG> is a decomposition diagram of the circuit component <NUM>.

The circuit component <NUM> of the power module <NUM> in this application includes a circuit board <NUM>, a chip <NUM>, a pin <NUM>, and a bonding wire <NUM>. The circuit board <NUM> includes two opposite side surfaces, where one side surface is defined as a heat dissipation surface <NUM>, and the other side surface is defined as a connection surface <NUM>. Further, refer to a decomposition diagram of the circuit board <NUM> shown in <FIG>. The circuit board <NUM> in this application includes a first copper layer <NUM>, a ceramic substrate <NUM>, and a second copper layer <NUM> that are sequentially stacked. The ceramic substrate <NUM> is located between the first copper layer <NUM> and the second copper layer <NUM>, and the first copper layer <NUM> and the second copper layer <NUM> are respectively attached to two opposite side surfaces of the ceramic substrate <NUM>. The circuit board <NUM> in this application may be implemented by using a copper-clad ceramic piece.

A surface that is of the first copper layer <NUM> and that is away from the ceramic substrate <NUM> is the heat dissipation surface <NUM> of the circuit board <NUM>. The heat dissipation surface <NUM> further forms the heat dissipation surface <NUM> of the circuit component <NUM>. The first copper layer <NUM> is configured to be fastened to the bottom surface <NUM> (that is, the fastening layer <NUM>) of the groove <NUM> through welding. A surface that is of the second copper layer <NUM> and that is away from the ceramic substrate <NUM> is the connection surface <NUM> of the circuit board <NUM>. The chip <NUM>, the pin <NUM>, and the bonding wire <NUM> are fastened to the second copper layer <NUM>. There may be one or more chips <NUM>, and each chip <NUM> is attached to the connection surface <NUM> of the second copper layer <NUM>. In some embodiments, there may also be a plurality of circuit boards <NUM>. The plurality of circuit boards <NUM> are arranged in parallel, and are separately stacked and fastened to the bottom surface <NUM> of the groove <NUM>. Chips <NUM> and pins <NUM> are respectively carried on the plurality of circuit boards <NUM>, which may be configured to jointly implement a function of the power module <NUM>, or may be separately configured to implement different functions of the power module <NUM>. This is not particularly limited in this application.

There may be a plurality of pins <NUM>. Each pin <NUM> is approximately in a long strip shape, and includes a fixed end <NUM> and a connection end <NUM> opposite to each other in a length direction of the pin <NUM>. The fixed end <NUM> of each pin <NUM> is fastened to the connection surface <NUM>, and the connection end <NUM> of the pin <NUM> extends toward a direction away from the circuit board <NUM>. Further, the connection end <NUM> of the pin <NUM> further extends out of the groove <NUM>, and is exposed outside the first outer surface <NUM>. That is, a length size of the pin <NUM> is greater than a depth size of the groove <NUM>, so that the connection end <NUM> of the pin <NUM> can extend out of the housing <NUM>, thereby facilitating connection between the pin <NUM> and external devices.

Further, the second copper layer <NUM> may also be patterned to match with a structure of the bonding wire <NUM> so as to implement an electrical connection between two chips <NUM> and/or between the chip <NUM> and the pin <NUM>. Specifically, one end of the bonding wire <NUM> is connected to the chip <NUM>, and the other end is connected to the pin <NUM> or another chip <NUM>, that is, the bonding wire <NUM> is electrically connected between the chip <NUM> and the pin <NUM>, or the bonding wire <NUM> is electrically connected between the two chips <NUM>. The circuit component <NUM> in the power module <NUM> in this application may implement a preset power change function through cooperation of the chip <NUM>, and implement connection to an external device through the connection end <NUM> of the pin <NUM>.

It should be proposed that an identifier of the bonding wire <NUM> in <FIG> and <FIG> is only used to show a possibility of a connection manner of the bonding wire <NUM>, and is not used to limit a specific connection relationship of the bonding wire <NUM> in the power module <NUM>. In addition, a patterned structure of the second copper layer <NUM> shown in <FIG> is only used to show a possibility of patterning the second copper layer <NUM>, and does not limit a specific patterned shape of the second copper layer <NUM>. In an actual using process, based on a specific usage scenario of the power module <NUM> and a functional characteristic of the power module <NUM>, a position and a connection relationship of the bonding wire <NUM> may be freely matched, and a patterned shape of the second copper layer <NUM> may be freely matched.

In some embodiments, the chip <NUM> may include one or more of an insulated gate bipolar transistor (IGBT), a metal-oxide-semiconductor field-effect transistor (MOSFET), a diode, or a triode.

On one side of the first copper layer <NUM>, the heat dissipation surface <NUM> is configured to be fastened to the bottom surface <NUM> (that is, the fastening layer <NUM>) of the groove <NUM> through soldering. Specifically, as shown in <FIG>, a connection layer <NUM> may be further disposed between the fastening layer <NUM> and the heat dissipation surface <NUM>. It is also described as that the circuit component <NUM> is fastened to the bottom surface <NUM> of the groove <NUM> through the connection layer <NUM> through soldering. The connection layer <NUM> may be understood as a solder, and a main material of the connection layer <NUM> may be tin, silver, copper, or resin. Two opposite surfaces of the connection layer <NUM> are respectively attached to the bottom surface <NUM> and the heat dissipation surface <NUM>, so as to fasten the circuit component <NUM> to the interior of the groove <NUM> through soldering.

When the main material of the connection layer <NUM> is tin, the heat dissipation surface <NUM> may be fastened to the bottom surface <NUM> through welding by using tin soldering. When the main material of the connection layer <NUM> is silver, the heat dissipation surface <NUM> may be fastened to the bottom surface <NUM> using silver sintering or silver paste. When the main material of the connection layer <NUM> is copper, the heat dissipation surface <NUM> may be fastened to the bottom surface <NUM> through welding by using copper sintering. When the main material of the connection layer <NUM> is resin, the heat dissipation surface <NUM> may be fastened to the bottom surface <NUM> through welding by using a prepreg. Because the bottom surface <NUM> of the groove <NUM> is the fastening layer <NUM>, and the main material of the fastening layer <NUM> is copper, it is convenient to form a structure of the connection layer <NUM> in the foregoing manners, heat conduction efficiency between the circuit component <NUM> and the main housing <NUM> is ensured, and the heat dissipation performance of the power module <NUM> is improved.

Compared with a solution in the conventional technology, in which a circuit board is attached to a radiator by using thermally conductive silicone grease, the connection layer <NUM> in the power module <NUM> in this application has higher heat conduction efficiency and more stable structure, a phenomenon that the thermally conductive silicone grease curls or falls off after a relatively long working time does not occur, and a service life of the power module <NUM> may be prolonged. In addition, a heat sink <NUM> is disposed on the main housing <NUM> of the power module <NUM> in this application, and heat generated when the circuit component <NUM> works may be directly dissipated through the housing <NUM>. Compared with the power module in the conventional technology, a structure of a heat conducting plate is omitted, the heat conduction efficiency of the power module is higher, and better heat dissipation effect is also achieved.

The package <NUM> is filled in the groove <NUM>. An outer surface of the package <NUM> is attached to both the bottom surface <NUM> and the side wall <NUM> of the groove <NUM>, covers most structures of the circuit component <NUM>, and only exposes the connection end <NUM> of the pin <NUM>. A material of the package <NUM> may be epoxy resin (EMC) or silicon gel. The package <NUM> covers the circuit board <NUM>, the chip <NUM>, the fixed end <NUM> of the pin <NUM>, and the bonding wire <NUM>, which can form sealing protection on these devices, and prevent external water vapor from intruding into the circuit component <NUM> to cause damage to the circuit component <NUM>. In addition, the attachment of the package <NUM> to the bottom surface <NUM> and the side wall <NUM> further prevents a risk that external water vapor intrudes into the groove <NUM>.

As shown in <FIG>, the package <NUM> includes a first surface <NUM>. The first surface <NUM> is a surface that is of a side of the package <NUM> and that is away from the bottom surface <NUM> of the groove <NUM>. In the schematic diagram of <FIG>, the first surface <NUM> is flush with the first outer surface <NUM> of the main housing <NUM>. In this case, the groove <NUM> is fully filled with the package <NUM>. A fitting area between the package <NUM> and the side wall <NUM> of the groove <NUM> is relatively large, which may increase a holding force between the package <NUM> and the side wall <NUM>, and improve connection stability of the package <NUM> in the groove <NUM>. In addition, the first surface <NUM> is flush with the first outer surface <NUM>, so that a volume of covering the circuit component <NUM> by the package <NUM> is also relatively large, and better protection effect may be achieved.

However, in some other embodiments, the first surface <NUM> of the package <NUM> may also be lower than the first outer surface <NUM>. That is, a distance between the first surface <NUM> of the package <NUM> and the bottom surface <NUM> is less than a depth of the groove <NUM>. In this case, the package <NUM> is integrally accommodated in the groove <NUM>. Good sealing effect may also be achieved by covering the circuit component <NUM> by the package <NUM>.

Because of the limitation that the connection end <NUM> of the pin <NUM> is located outside the first outer surface <NUM>, and the first surface <NUM> of the package <NUM> is flush with the first outer surface <NUM> or is lower than the first outer surface <NUM>, it can be ensured that the connection end <NUM> of the pin <NUM> is exposed outside the package <NUM>. The package <NUM> is made of an insulation material. When an external device is connected to the pin <NUM>, a material of the package <NUM> cannot be formed at the connection end <NUM>, which can ensure reliable conduction between the pin <NUM> and the external device.

In this way, the external device may be electrically connected to the power module <NUM> through the pin <NUM>. An electrical signal enters the chip <NUM> through the bonding wire <NUM> after entering the power module <NUM> in this application through the pin <NUM> (there may be a plurality of pins <NUM>) on one side, and may be transmitted through the bonding wire <NUM> to the pin <NUM> (there may be a plurality of pins <NUM>) on the other side for outputting after power conversion is completed, so as to achieve power conversion effect of the power module <NUM> in this application.

For a power module in the conventional technology, a circuit component of the power module is generally only covered through a package. When a breakdown phenomenon occurs, a structure similar to the package is insufficient to shield an arc generated by breakdown, and devices around the power module in the conventional technology will be damaged accordingly. However, the circuit component <NUM> of the power module <NUM> in this application is accommodated in the groove <NUM>, and both the bottom surface <NUM> and the side wall <NUM> of the groove <NUM> are metal structures. When a breakdown phenomenon occurs in a working process of the power module <NUM> due to insufficient heat dissipation, an excessively large transient current, or the like, the bottom surface <NUM> and the side wall <NUM> of the metal structure can limit the arc to spread outward, so as to achieve protection effect on the devices around the power module <NUM>. An arc damage caused by breakdown is emitted only from the groove opening <NUM> of the groove <NUM>, so that an arc direction of the power module <NUM> in this application is controllable when the breakdown occurs, thereby reducing a damage range.

It may be understood that the power converter according to this application also has characteristics such as high reliability, a strong heat dissipation capability, and relatively small damage in the case of fault due to application of the foregoing power module <NUM>. However, the power supply device in this application achieves similar beneficial effect because of using the power converter.

Refer now to <FIG>. On any cross section perpendicular to the first outer surface <NUM>, a shape of a side wall <NUM> of the <NUM> is further constructed as a stepped shape. Because the package <NUM> is formed in the groove <NUM> by using a filling process, a surface, in contact with the side wall <NUM>, of the package <NUM> is also formed into a stepped shape with the shape of the side wall <NUM>. The step-shaped side wall <NUM> may form a larger contact area with the step-shaped package <NUM>, so as to form a larger holding force for the package <NUM>, and ensure structural stability of the package <NUM> in the groove <NUM>. It may be understood that, in some other embodiments, a shape of a cross section of the side wall <NUM> may also be another shape such as an arc, a trapezoid, or a wave shape, and correspondingly, a surface of the package <NUM> is also formed into a structure matched with the side wall <NUM>, so that effect of increasing a contact area between the package <NUM> and the side wall <NUM> may also be achieved.

In the schematic diagram of <FIG>, the width of the groove opening <NUM> of a step structure of the side wall <NUM> is greater than the width of the bottom surface <NUM>. That is, the step structure of the side wall <NUM> is in a state of being large above and small below. The structure facilitates filling of the package <NUM>, and avoids generating bubbles inside the package <NUM> to affect sealing effect of the package <NUM>.

<FIG> shows a flowchart of a method for manufacturing a power module according to this application. In this embodiment, the manufacturing method for a power module <NUM> includes the following steps:.

Specifically, the manufacturing method for a power module of this embodiment is used for implementing the structure of the foregoing power module <NUM>. For details, refer to schematic diagrams of a structure in <FIG>.

In S110, a circuit board <NUM> is first provided. The circuit board <NUM> may be a copper-clad ceramic substrate. The circuit board <NUM> includes a heat dissipation surface <NUM> and a connection surface <NUM> that are opposite to each other. Then, as shown in <FIG>, a solder layer <NUM> is laid on the connection surface <NUM> of the circuit board <NUM>. A position of the solder layer <NUM> is disposed corresponding to a position at which the chip <NUM> is carried subsequently. In the schematic diagram of <FIG>, the chip <NUM> is attached to a position at which the solder layer <NUM> is disposed on the connection surface <NUM>. The chip <NUM> may be attached by using solder reflow, silver sintering, or copper sintering. However, in the schematic diagram of <FIG>, a bonding wire <NUM> is disposed on the chip <NUM>. The bonding wire <NUM> may be connected between two chips <NUM>, or may be connected between the chip <NUM> and the connection surface <NUM>. It may be understood that, when the bonding wire <NUM> is disposed between the chip <NUM> and the connection surface <NUM>, one end that is of the bonding wire <NUM> and that is away from the chip <NUM> is configured to communicate with a pin <NUM> subsequently carried.

In S120, as shown in <FIG>, a fixed end <NUM> of the pin <NUM> is welded to the connection surface <NUM> of the circuit board <NUM>. In addition, the pin <NUM> is connected to one end that is of the bonding wire <NUM> and that is away from the chip <NUM>. The connection end <NUM> of the pin <NUM> extends toward a direction away from the circuit board <NUM>. In this way, a structure of the circuit component <NUM> in the power module <NUM> in this application may be formed. Then, as shown in <FIG>, the heat dissipation surface <NUM> of the circuit board <NUM> is fastened to the fastening layer <NUM> of the housing <NUM> through welding. Specifically, the fastening layer <NUM> is located at the bottom surface <NUM> of the groove <NUM> formed in the main housing <NUM>. The heat dissipation surface <NUM> may be fastened to the fastening layer <NUM> through welding by disposing a connection layer <NUM> between the bottom surface <NUM> and the heat dissipation surface <NUM>. After this step is completed, the height of the connection end <NUM> of the pin <NUM> is higher than the depth of the groove <NUM>, that is, the connection end <NUM> of the pin <NUM> extends out of the groove <NUM>.

In S130, as shown in <FIG>, injection molding is performed in the groove <NUM> by using a packaging material, so as to manufacture a structure of the package <NUM>. A material of the package <NUM> may be epoxy resin or silicon gel. The package <NUM> is in contact with both the bottom surface <NUM> and the side wall <NUM> of the groove <NUM>, and is configured to cover the circuit board <NUM>, the chip <NUM>, the bonding wire <NUM>, and the pin <NUM> located in the groove <NUM>, so as to form sealing protection for the circuit component <NUM> in the power module <NUM>. The injection molding height of the package <NUM> is less than or equal to the depth of the groove <NUM> of the main housing <NUM>, so that the package <NUM> does not penetrate out of the groove <NUM>, and the package <NUM> is prevented from covering a part of the pin <NUM> exposed in the groove <NUM>, thereby ensuring connection reliability of the power module <NUM> and an external device.

Therefore, the power module <NUM> according to this application may be obtained by the foregoing manufacturing method for a power module. It may be understood that the power module <NUM> manufactured by the method in this application also has characteristics, brought by the foregoing power module <NUM>, such as high reliability, a strong heat dissipation capability, and relatively small damage in the case of fault. Details are not further described in this embodiment.

It should be proposed that, in S120 of the method in this application, the "fasten the other side surface of the circuit board <NUM> to a fastening layer <NUM> of a housing <NUM> through welding" may use tin soldering, silver sintering, copper sintering, silver paste, or a prepreg. Because the bottom surface <NUM> of the groove <NUM> is disposed as a fastening layer, after the groove <NUM> is fastened and connected to the circuit component <NUM> by using the foregoing process, heat conduction efficiency between the circuit component <NUM> and the groove <NUM> may be improved.

On the other side, in S120, an assembly sequence of the pin <NUM> and the heat dissipation surface <NUM> is not strictly limited. Based on different solders used by the welding pin <NUM> and the heat dissipation surface <NUM>, the assembly sequence of the pin <NUM> and the heat dissipation surface <NUM> in S120 may be matched and set according to melting points of different solders.

For example, in decomposition steps shown in <FIG>, the pin <NUM> is first fastened to the circuit board <NUM> to form a complete circuit component <NUM>, and then the circuit component <NUM> is fastened in the groove <NUM> (that is, fastening and connection between the heat dissipation surface <NUM> and the bottom surface <NUM> are completed). The manufacturing sequence is applicable to a case in which a melting point of a solder for the pin <NUM> is higher than that of a solder for the heat dissipation surface <NUM>.

Specifically, in the embodiment shown in <FIG> in which the pin <NUM> is fastened to the circuit board <NUM>, solder paste printing, solder pad attachment, silver paste printing, or the like may be used for implementation. For example, when the solder paste printing is used, solder paste (solder) with a model of SAC305 may be used, and a melting point of the solder paste is about <NUM>. When the heat dissipation surface <NUM> is fastened to the bottom surface <NUM> as shown in <FIG> through welding, a low-temperature lead-free welding manner may be used for implementation. For example, when low-temperature tin soldering is used, the solder may be a tin-bismuth solder (SnBi), and a melting point of the solder is about <NUM>, which is lower than a melting point of the solder for the pin <NUM>. Therefore, after the pin <NUM> is fastened to the circuit board <NUM>, in the process of welding and fastening the heat dissipation surface <NUM> to the bottom surface <NUM>, the soldering temperature does not cause remelting of the solder for the pin <NUM>, and connection stability between the pin <NUM> and the circuit board <NUM> is ensured.

However, in decomposition steps shown in <FIG>, in S120, the heat dissipation surface <NUM> may also be first fastened to the bottom surface <NUM> through welding, and then the pin <NUM> is fastened to the connection surface <NUM> of the circuit board <NUM>. The manufacturing sequence is applicable to a case in which the melting point of the solder for the pin <NUM> is lower than that of the solder for the heat dissipation surface <NUM>.

Claim 1:
A power module (<NUM>), comprising:
a housing (<NUM>), comprising a main housing (<NUM>), a heat sink (<NUM>), and a fastening layer (<NUM>), wherein the main housing is provided with a groove (<NUM>), a groove opening (<NUM>) is located on a first outer surface (<NUM>), the fastening layer is disposed on a bottom surface (<NUM>) of the groove, and the heat sink is located on a side away from an orientation of the groove opening;
a circuit component (<NUM>), accommodated in the groove, wherein the circuit component comprises a heat dissipation surface (<NUM>) and a pin (<NUM>), the heat dissipation surface is fastened to the fastening layer (<NUM>) through welding, the pin extends toward a direction away from the fastening layer, and a distal end of the pin extends out of the first outer surface; and
a package (<NUM>), wherein the package is filled in the groove, and is configured to cover the circuit component, and to at least partially expose the distal end of the pin;
characterised in that the groove comprises a side wall (<NUM>), the side wall is connected between the first outer surface and the bottom surface, and a shape of any cross section that is of the side wall and that is perpendicular to the first outer surface is a stepped shape;
wherein the width of the groove opening is greater than the width of the bottom surface.