Patent Description:
A power module is a module obtained by combining and packaging electronic power devices based on specific functions. In the conventional technology, a power module is connected to a drive board, and a switch of a power chip packaged in the power module is controlled by using the drive board. However, in the conventional technology, a parasitic parameter between the drive board and the power chip in the power module is excessively large, affecting electrical performance of the power module.

<CIT> discloses a semiconductor device that includes a plurality of semiconductor units each including a laminated substrate formed by laminating an insulating board and a circuit board and a semiconductor element joined to the circuit board using a joining material which irreversibly makes a phase transition into a solid-phase state. In addition, the semiconductor device may include a base plate to which each of the plurality of semiconductor units is joined using solder and a connection unit which electrically connects the plurality of semiconductor units in parallel.

<CIT> describes challenges associated with different thermal expansion coefficients in a power semiconductor module. In particular, when post electrodes of the printed circuit board are joined to the semiconductor chip by an electrical bonding material such as solder, issues arise due to the different linear expansion coefficients. When the semiconductor chip generates heat during operation or the ambient temperature rises, this difference in coefficients leads to thermal stresses. Resultantly, the post electrodes are subjected to forces that pull them in an up-and-down motion. It is described that this can cause the semiconductor chip to become damaged or deformed under extreme conditions, threatening the module's reliability. To solve this problem, the document describes two main improvements. By reducing the length of the post electrodes, the force acting on the semiconductor chip due to the linear expansion coefficient difference is reduced. A higher bending rigidity in the printed circuit board has the benefit that the board will not deform significantly under the stress due to thermal expansion from solder or other bonding materials. This stiffness in the board helps to further suppress the force acting on the post electrodes that connect to the semiconductor chip and minimizes the risk of damage to the semiconductor chip.

The object of the present invention is to provide a power module, a converter, and an electronic device to reduce a parasitic parameter between a drive board and the power module, and improve electrical performance of the power module and the claimed invention is disclosed by the subject matter of present independent product claim <NUM> and its dependent claims <NUM>-<NUM>.

The following describes embodiments of this application with reference to accompanying drawings in embodiments of this application.

<FIG> is a schematic diagram of a structure of an electronic device <NUM>.

The electronic device <NUM> includes a converter <NUM> and a housing <NUM>. The converter <NUM> is accommodated in the housing <NUM>, and the converter <NUM> is configured to convert an electrical signal of the electronic device <NUM>. The electronic device <NUM> in this embodiment includes but is not limited to an electronic device <NUM> with the converter <NUM>, such as a wind turbine, a photovoltaic generator, an electric vehicle, and a major appliance. Integration and electrical performance of the electronic device <NUM> with the converter <NUM> provided in this application are effectively improved.

<FIG> is a schematic diagram of a partial structure of the converter <NUM> of the electronic device <NUM> shown in <FIG> according to the invention.

The converter <NUM> includes a power module <NUM> and a circuit board <NUM>. The power module <NUM> is mounted to the circuit board <NUM>, and the circuit board <NUM> is electrically connected to the power module <NUM> to control the power module <NUM>. The converter <NUM> in this embodiment includes but is not limited to a converter with the power module <NUM>, such as a direct current-to-alternating current converter and a direct current-to-direct current converter. Integration and electrical performance of the converter <NUM> with the power module <NUM> provided in this application are effectively improved.

<FIG> is a schematic diagram of a structure of a first embodiment of the power module <NUM> of the converter <NUM> shown in <FIG> according to the invention.

The power module <NUM> includes a power assembly <NUM> and a drive board <NUM>. The power assembly <NUM> includes a substrate <NUM>, a power chip <NUM>, and a package body <NUM>. The power chip <NUM> is disposed on a mounting surface <NUM> of the substrate <NUM>. The package body <NUM> packages the power chip <NUM> on the substrate <NUM>. The drive board <NUM> is disposed in the package body <NUM> and is located on a side, of the power chip <NUM>, that backs the mounting surface <NUM>, to form a packaged structure <NUM> with the power assembly <NUM>. The drive board <NUM> is electrically connected to the power chip <NUM>, to drive the power chip <NUM> to operate. It is understood that the package body <NUM> packages the drive board <NUM> and the power chip <NUM> on the substrate <NUM>, to form the packaged structure <NUM>.

In the power module <NUM> in this embodiment, the drive board <NUM> is disposed in the package body <NUM> of the power assembly <NUM>, and the drive board <NUM> is located on the side, of the power chip <NUM>, that backs the mounting surface <NUM>, to reduce a distance between the drive board <NUM> and the power chip <NUM>. Further, a connection line between the power chip <NUM> and the drive board <NUM> is shortened, thereby effectively reducing a parasitic parameter of the connection line between the power chip <NUM> and the drive board <NUM>, that is, reducing a parasitic parameter of the power module <NUM>, and improving electrical performance of the power module <NUM>. In addition, the drive board <NUM> is disposed in the package body <NUM> of the power assembly <NUM>, that is, the drive board <NUM> is disposed inside the power assembly <NUM>. Compared with disposing the drive board <NUM> and the power assembly <NUM> on a same plane, this can effectively reduce a planar area of the power module <NUM>. When the package body <NUM> is formed for the power assembly <NUM>, to ensure strength of the power assembly <NUM>, a thickness of the power assembly <NUM> is usually greater than <NUM>. This thickness is sufficient to allow the drive board <NUM> to be embedded in the package body <NUM> of the power assembly <NUM>, without increasing the thickness of the power assembly <NUM>. That is, disposing the drive board <NUM> in the package body <NUM> does not affect the thickness of the power assembly <NUM>, thereby effectively improving integration of the power module <NUM>, reducing a package size and reducing costs of the power module <NUM>.

It may be understood that there are mainly two parasitic parameters: a parasitic inductance and a parasitic resistance. A magnitude of the parasitic inductance is mainly affected by two factors: a length of the connection line, where a longer connection line results in a larger parasitic inductance; and an area surrounded by the connection line, where a larger area surrounded by the connection line results in a larger parasitic inductance. For the parasitic resistance, a longer connection line results in a larger parasitic resistance. Therefore, in this application, a shorter distance between the drive board <NUM> and the power chip <NUM> indicates a shorter connection line between the drive board <NUM> and the power chip <NUM>, and an area surrounded by the connection line is also reduced, thereby effectively reducing a parasitic inductance and a parasitic resistance of the power module <NUM>, and improving electrical performance of the power module <NUM>.

The substrate <NUM> includes a bearing plate a1, a line layer a2, and a metal layer a3. The line layer a2 and the metal layer a3 are respectively formed on two opposite surfaces of the bearing plate a1, and the line layer a2 and the metal layer a3 are respectively located on two sides of the bearing plate a1, to ensure flatness of the bearing plate a1 and prevent warpage of the bearing plate a1. A surface, of the line layer a2, that backs the bearing plate a1 is the mounting surface <NUM>, that is, the power chip <NUM> is disposed on the surface, of the line layer a2, that backs the bearing plate a1. A surface, of the substrate <NUM>, that backs the power chip <NUM> is a rear surface <NUM>, that is, a surface, of the metal layer a3, that backs the bearing plate a1 is the rear surface <NUM>, and the rear surface <NUM> is exposed from the package body <NUM>. The line layer a2 may be configured to implement an electrical connection between the power chip <NUM> and another device, or may be configured to implement an electrical connection between power chips <NUM>. Because the rear surface <NUM> of the metal layer a3 is exposed from the package body <NUM>, the metal layer a3 can effectively transmit heat of the power chip <NUM> to the outside, thereby improving heat dissipation efficiency of the power chip <NUM>. In addition, the metal layer a3 can further effectively enhance strength of the substrate <NUM>.

In this embodiment, the bearing plate a1 may be made of an insulation and heat dissipation material such as ceramic. The ceramic may be, for example, a ceramic material such as aluminum oxide, silicon nitride, or aluminum nitride. The ceramic material has good heat dissipation effect, and can quickly dissipate heat for the power chip <NUM>. The line layer a2 and the metal layer a3 are made of a metal material, for example, a copper, nickel, or aluminum material, and can quickly dissipate heat for the power chip <NUM>. The line layer a2 and the metal layer a3 may be made of a same material or different materials. In addition, the line layer a2 is further configured to implement an electrical connection between the power chip <NUM> and another line. Certainly, in another embodiment, the bearing plate a1 may be alternatively made of another insulation material.

In this embodiment, the line layer a2 includes a first line a21 and a second line a22. Second lines a22 are located on two sides of the first line a21. Surfaces, of the first line a21 and the second line a22, that back the bearing plate a1 jointly constitute the mounting surface <NUM>. The power chip <NUM> is disposed on the first line a21, and the power chip <NUM> is connected to the second line a22 through a lead. Certainly, the power chip <NUM> may be alternatively connected to the second line a22 by using another conducting structure, and the second line a22 is connected to another element. That is, the second line a22 is configured to implement a connection between the power chip <NUM> and the another element. Certainly, in another embodiment, a structure of the line layer a2 is not limited to the foregoing descriptions, and a specific structure of the line layer a2 may be arranged according to a connection requirement of the power chip <NUM>.

In this embodiment, there are one or more power chips <NUM>. In <FIG>, for example, there are two power chips <NUM>. The two power chips <NUM> are disposed on the first line a21 at a spacing, and the two power chips <NUM> are electrically connected through a lead. A lead connection process is mature and simple, and has low costs. The power chip <NUM> may be an insulated gate bipolar transistor (IGBT), a metal-oxide semiconductor field-effect transistor (MOSFET), and/or a diode. The power chip <NUM> may be fastened to the first line a21 through welding, bonding, or the like. For example, when the power chip <NUM> needs to be electrically connected to the first line a21, the power chip <NUM> may be fastened to the first line a21 through welding. When the power chip <NUM> does not need to be electrically connected to the first line a21, the power chip <NUM> may be fastened to the first line a21 in another manner such as bonding. Certainly, in another embodiment, the two power chips <NUM> may be alternatively connected by using a connection structure such as a lead frame.

The package body <NUM> according to the invention is formed by using a plastic packaging process. The package body <NUM> is made of a plastic material such as epoxy resin or silicone. The package body <NUM> formed by using the plastic packaging process has good sealing performance, so that moisture resistance and reliability of the packaged structure <NUM> can be improved. Specifically, the package body <NUM> is packaged in a region from the rear surface <NUM> of the substrate <NUM> to a side, of the drive board <NUM>, that backs the power chip <NUM>, and no package body <NUM> is disposed at an edge of the side, of the drive board <NUM>, that backs the power chip <NUM>, thereby facilitating fitting between the power chip <NUM> and a related structure. In another embodiment, the package body <NUM> may be alternatively formed by using another process such as a housing packaging process. It should be noted that whenever in this disclosure there is a reference that a package body is not using plastic packaging, this packaging body does not fall within the scope of the claimed invention.

The power assembly <NUM> further includes a pin <NUM>. The pin <NUM> penetrates the drive board <NUM> and a part of the package body <NUM>. One end of the pin <NUM> is disposed on the mounting surface <NUM> and is electrically connected to the power chip <NUM>, and the other end of the pin <NUM> is exposed from the package body <NUM>. Specifically, the pin <NUM> is disposed on a second line a22 corresponding to the pin <NUM>, so that the pin <NUM> is electrically connected, through the second line a22, to a power chip <NUM> corresponding to the pin <NUM>. The pin <NUM> is configured to implement an electrical connection between the power chip <NUM> and the circuit board <NUM> (<FIG>). Certainly, in another embodiment, the pin <NUM> of the power chip <NUM> may be alternatively configured to implement an electrical connection between the power chip <NUM> and the drive board <NUM>. Alternatively, the pin <NUM> may not penetrate the drive board <NUM>. Alternatively, the power chip <NUM> may be connected to the circuit board <NUM> by using a structure other than the pin <NUM>.

In a direction perpendicular to the mounting surface <NUM>, a distance between the drive board <NUM> and the power chip <NUM> is less than a distance between the drive board <NUM> and a surface, of the package body <NUM>, that backs the mounting surface <NUM>. In this embodiment, the distance between the drive board <NUM> and the power chip <NUM> is required to be less than the distance between the drive board <NUM> and the surface, of the package body <NUM>, that backs the mounting surface <NUM>, to ensure that the distance between the drive board <NUM> and the power chip <NUM> is sufficiently short, thereby ensuring that the parasitic parameter of the connection line between the drive board <NUM> and the power chip <NUM> is sufficiently small, and effectively improving electrical performance of the power module <NUM>.

In this embodiment, there are two pins <NUM>, and the two pins <NUM> are respectively disposed on second lines a22 on two sides of the two power chips <NUM>. In other words, the two power chips <NUM> are disposed between the two pins <NUM>. The pin <NUM> may be welded to a second line a22 corresponding to the pin <NUM> by using solder paste, or may be fastened to a second line a22 corresponding to the pin <NUM> through ultrasonic welding, silver sintering, or the like. A shape of the pin <NUM> may be a cylindrical shape, an elliptic cylindrical shape, a cuboid shape, a polygonal shape, or the like. Shapes of the two pins <NUM> may be the same or different. A material of the pin <NUM> may be a metal or an alloy with good conductivity, for example, Cu, Ag, or Al. Certainly, in another embodiment, an arrangement manner of the power chip <NUM> and the pin <NUM> and a quantity of pins <NUM> may be alternatively arranged according to an actual requirement.

According to the invention, the drive board <NUM> includes a center region <NUM> and an edge region <NUM> surrounding the center region <NUM>. The center region <NUM> is arranged opposite to the power assembly <NUM>. Electronic elements such as a drive chip <NUM>, a resistor <NUM>, a capacitor, and an optocoupler are disposed in the center region <NUM> to form a drive circuit. The power chip <NUM> of the power assembly <NUM> is electrically connected to the drive chip <NUM>. The packaged structure <NUM> includes a mounting hole <NUM>. The mounting hole <NUM> is located in the edge region <NUM>, and penetrates the drive board <NUM> and the package body <NUM> in a direction from the drive board <NUM> to the power chip <NUM>. A related component is connected to the packaged structure <NUM> through the mounting hole. The edge region <NUM> and the package body <NUM> located in the edge region <NUM> may be understood as a mounting part of the packaged structure <NUM>, so that the packaged structure <NUM> is fastened to another component by using the mounting part.

Certainly, in an implementation scenario of another embodiment which does not fall within the scope of the claimed invention, a related component may be alternatively fastened to the packaged structure <NUM> by using a screw or in another fastening manner. In another implementation scenario of another embodiment which does not fall within the scope of the claimed invention, the packaged structure <NUM> may be alternatively fastened to a related component in another connection manner such as bonding or clamping. In still another implementation scenario of another embodiment which does not fall within the scope of the claimed invention, small electronic elements such as the resistor <NUM>, the capacitor, and the optocoupler may be alternatively partially disposed in the edge region <NUM>. In yet another implementation scenario of another embodiment which does not fall within the scope of the claimed invention, when the drive board <NUM> does not need to be fastened to a related component, the drive board <NUM> may alternatively include only the center region <NUM>, that is, the drive board <NUM> may not include the edge region <NUM>.

According to the invention, a surface, of the edge region <NUM>, that backs the power chip <NUM> is exposed from the package body <NUM>, that is, no package body <NUM> is disposed on the surface, of the edge region <NUM>, that backs the power chip <NUM>, so that a screw <NUM> is fastened through the surface, of the edge region <NUM>, that backs the power chip <NUM>. In addition, the package body <NUM> is made of a brittle material, and the package body <NUM> is prone to breakage under large stress. Because no package body <NUM> is disposed in the edge region <NUM>, the screw <NUM> directly transmits a locking force to the drive board <NUM>, thereby reducing the stress applied to the package body <NUM>, and avoiding a risk that the package body <NUM> cracks because the screw <NUM> directly transmits the locking force to the package body <NUM>.

The drive board <NUM> further includes a through hole <NUM>. The through hole <NUM> is configured to allow a pin <NUM> corresponding to the drive board <NUM> to pass through, so that the pin <NUM> penetrates the drive board <NUM> and is connected to a related external element. In this embodiment, the pin <NUM> passes through the through hole <NUM> and is not electrically connected to the through hole <NUM>. Certainly, in another embodiment, the pin <NUM> may be alternatively electrically connected to the drive board <NUM> through the through hole <NUM>, to implement an electrical connection between the drive board <NUM> and the power chip <NUM>.

The power module <NUM> further includes a heat sink <NUM>, and the heat sink <NUM> is fastened to the packaged structure <NUM> and is in contact with the rear surface <NUM>. Specifically, the screw <NUM> is connected to the heat sink <NUM> through the mounting hole <NUM>, to fasten the heat sink <NUM> to the packaged structure <NUM>. The rear surface <NUM> of the substrate <NUM> is in direct contact with the heat sink <NUM>, so that heat of the power chip <NUM> can be quickly transmitted to the heat sink <NUM> and then transmitted by the heat sink <NUM> to the outside, thereby effectively improving heat dissipation efficiency of the power chip <NUM>.

The power module <NUM> further includes a conductor <NUM>. The conductor <NUM> is located between the power chip <NUM> and the drive board <NUM>. The power chip <NUM> is connected to the drive board <NUM> through the conductor <NUM>. Specifically, the drive chip <NUM> on the drive board <NUM> is connected to the power chip <NUM> of the power assembly <NUM> through the conductor <NUM>. Because the drive board <NUM> is disposed in the package body <NUM> of the power assembly <NUM>, the distance between the drive board <NUM> and the power chip <NUM> is reduced. Further, the connection line (the conductor <NUM>) connected between the drive board <NUM> and the power chip <NUM> is shortened, thereby effectively reducing the parasitic parameter of the connection line of the power module <NUM>, and improving electrical performance of the power module <NUM>.

The conductor <NUM> in this embodiment may be implemented in a plurality of manners. Details are described below.

In an implementation, as shown in <FIG>, the conductor is a copper rod <NUM>, and two ends of the copper rod <NUM> are respectively electrically connected to the power chip <NUM> and the drive board <NUM>. Specifically, the two ends of the copper rod <NUM> are electrically connected to the power chip <NUM> and the drive chip <NUM> on the drive board <NUM>. A quantity of copper rods <NUM> corresponds to a quantity of power chips <NUM>, and one copper rod <NUM> corresponds to one power chip <NUM>. A length of the copper rod <NUM> is equal to the distance between the drive board <NUM> and the power chip <NUM>. It may be understood that a length direction of the copper rod <NUM> is a flow direction of a current in the copper rod <NUM>, so that the length of the copper rod <NUM> is the shortest, thereby effectively reducing the parasitic parameter of the connection line of the power module <NUM>, and improving electrical performance of the power module <NUM>. Certainly, in another embodiment, the power chip <NUM> may be alternatively connected to the drive board <NUM> by using another conducting structure such as a lead.

<FIG> is a schematic diagram according to the invention of a structure of another implementation of the power module <NUM> shown in <FIG> according to the invention.

In another not claimed implementation, the conductor is a lead frame (Lead Frame, LF) <NUM>. The lead frame <NUM> includes a first terminal <NUM> and a second terminal <NUM> that are connected to each other. The first terminal <NUM> is electrically connected to the power chip <NUM>. The second terminal <NUM> is electrically connected to the drive board <NUM>. Specifically, the second terminal <NUM> is electrically connected to the drive chip <NUM> on the drive board <NUM>. A quantity of lead frames <NUM> corresponds to a quantity of power chips <NUM>. In this implementation, the lead frame <NUM> has a quite good through-current capability, thereby effectively reducing the parasitic parameter of the power module <NUM>, and effectively improving a heat dissipation capability of the power chip <NUM>. In addition, two power chips <NUM> may also be electrically connected through the lead frame, thereby effectively reducing manufacturing steps of the power module <NUM>, and improving production efficiency of the power module <NUM>.

The lead frame <NUM> further includes a not claimed third terminal <NUM> electrically connected to the first terminal <NUM>, and the third terminal <NUM> is electrically connected to the pin <NUM>. Specifically, the third terminal <NUM> is electrically connected to the second line a22, so as to be electrically connected to the pin <NUM>. That is, the lead frame <NUM> in this implementation can also implement an electrical connection between the pin <NUM> and the power chip <NUM>, so that no additional lead needs to be introduced to connect the power chip <NUM> and the pin <NUM>. Therefore, a structure of the power module <NUM> is simpler, and manufacturing steps of the power module <NUM> are reduced, thereby improving production efficiency of the power module <NUM>. In addition, compared with a lead, the lead frame <NUM> has a stronger through-current capability and a smaller parasitic parameter, so that heat dissipation effect of the power chip <NUM> can be further improved.

<FIG> is a schematic diagram according to the invention of a structure of a second embodiment of the power module <NUM> shown in <FIG> according to the invention.

The structure of the power module <NUM> in this embodiment is approximately the same as that in the first embodiment. A difference lies in that, in this embodiment, the power chip <NUM> is electrically connected to the drive board <NUM> through the pin <NUM>, and the pin <NUM> is electrically connected to the drive board <NUM>, so that the drive board <NUM> is electrically connected to the power chip <NUM>. Specifically, the pin <NUM> is electrically connected to a hole wall of the through hole <NUM> when penetrating the drive board <NUM> through the through hole <NUM>, and the hole wall of the through hole <NUM> is electrically connected to the drive chip <NUM> on the drive board <NUM>. An end, of the pin <NUM>, that is away from the mounting surface <NUM> is further connected to the circuit board <NUM> (<FIG>). That is, the pin <NUM> can implement an electrical connection between the power chip <NUM> and the drive chip <NUM> on the drive board <NUM>, and can also implement an electrical connection between the power chip <NUM> and the external circuit board <NUM>, thereby simplifying a structure of the power module <NUM>. Certainly, in another embodiment, the pin <NUM> may be alternatively configured to implement only an electrical connection between the power chip <NUM> and the drive chip <NUM> on the drive board <NUM>.

<FIG> is a schematic diagram of a structure of a third embodiment, which does not fall within the scope of the claimed invention, of the power module <NUM> shown in <FIG>.

The structure of the power module <NUM> in this embodiment is approximately the same as that in the first embodiment. A difference lies in that, in this embodiment, the power module <NUM> further includes a not claimed package housing <NUM>. The power assembly <NUM> and the drive board <NUM> are accommodated in the package housing <NUM>. An end, of the pin <NUM>, that backs the power chip <NUM> extends out of the package housing <NUM>. The package body <NUM> is injected into a gap in the package housing <NUM> by using a housing packaging process. Specifically, a packaging material such as silicon gel or epoxy resin is injected into the package housing <NUM> to form the package body <NUM>. In this application, the package body <NUM> is formed by using the housing packaging process. The process is simple, thereby effectively improving production efficiency of the power module <NUM>.

The package housing <NUM> includes a base plate <NUM> and a cover <NUM>. The cover <NUM> covers the base plate <NUM>, and forms a space for accommodating the power assembly <NUM> and the drive board <NUM> with the base plate <NUM>. Specifically, the metal layer a3 of the substrate <NUM> is fastened to the base plate <NUM> through welding, and an end, of the pin <NUM>, that backs the power chip <NUM> extends out of the cover <NUM>. In this embodiment, the metal layer a3 is fastened to the base plate <NUM> through welding. While ensuring strength of the connection between the substrate <NUM> and the base plate <NUM>, this helps quickly transmit, to the base plate <NUM>, heat transmitted from the power chip <NUM> to the substrate <NUM>, so that the heat is transmitted to the outside through the base plate <NUM>, thereby effectively improving heat dissipation efficiency of the power module <NUM>. Certainly, the metal layer a3 of the substrate <NUM> may be alternatively fastened to the base plate <NUM> in another connection manner such as bonding or clamping.

In this embodiment, a lead is used to connect the two power chips <NUM> and connect the power chip <NUM> to the pin <NUM>, and the power chip <NUM> is connected to the drive board <NUM> through the copper rod <NUM>. Certainly, the power chip <NUM> may be alternatively connected to the drive board <NUM> through the lead. In addition, a lead frame <NUM> may be used to connect the two power chips <NUM>, connect the power chip <NUM> to the pin <NUM>, and connect the power chip <NUM> to the drive board <NUM>.

The drive board <NUM> in this embodiment includes only a center region <NUM>. Electronic elements such as a drive chip <NUM>, a resistor <NUM>, a capacitor, and an optocoupler are disposed in the center region <NUM> to form a drive circuit. The power chip <NUM> of the power assembly <NUM> is electrically connected to the drive chip <NUM>.

The heat sink <NUM> is fastened to the base plate <NUM>, and is in contact with a surface, of the base plate <NUM>, that backs the substrate <NUM>, so that the base plate <NUM> quickly transmits heat of the power chip <NUM> to the outside through the heat sink <NUM>, thereby improving heat dissipation efficiency of the power chip <NUM>, and further improving electrical performance of the power module <NUM>. Specifically, the heat sink <NUM> may be fastened to the base plate <NUM> in one of connection manners such as screwing, clamping, and bonding. Certainly, in another embodiment, the power module in this embodiment may be alternatively not provided with a heat sink.

<FIG> is a schematic diagram of a structure of a fourth embodiment, which does not fall within the scope of the claimed invention, of the power module <NUM> shown in <FIG>.

The structure of the power module <NUM> in this embodiment is approximately the same as that in the first embodiment. A difference lies in that there are two power assemblies <NUM> in this embodiment. Mounting surfaces <NUM> of the two power assemblies <NUM> are arranged opposite to each other and are electrically connected to each other. Package bodies <NUM> of the two power assemblies <NUM> are connected. The drive board <NUM> is disposed between the two power assemblies <NUM> and is electrically connected to at least one power assembly <NUM>. It may be understood that the drive board <NUM> may be embedded in a package body <NUM> of any one of the power assemblies <NUM>; or the drive board <NUM> may be embedded between the package bodies <NUM> of the two power assemblies <NUM>, to be specific, a part of the drive board <NUM> is embedded in a package body <NUM> of one power assembly <NUM>, and the other part is embedded in a package body <NUM> of the other power assembly <NUM>.

In this embodiment, the drive board <NUM> is embedded between the two power assemblies <NUM>, to shorten distances between the drive board <NUM> and power chips <NUM> of the two power assemblies <NUM>, and further shorten connection lines between the drive board <NUM> and the power chips <NUM> of the two power assemblies <NUM>, thereby effectively reducing parasitic parameters of the connection lines, and improving electrical performance of the power module <NUM>. In addition, surfaces, of metal layers a3 of the two power assemblies <NUM>, that back the drive board <NUM> are both exposed from the package body <NUM>, to dissipate heat for the power chips <NUM> corresponding to the two power assemblies <NUM>, thereby improving heat dissipation efficiency of the power chips <NUM>, and effectively improving electrical performance of the power module <NUM>.

In this embodiment, as shown in <FIG>, for ease of differentiation, the two power assemblies <NUM> are a power assembly 11a and a power assembly 11b, and the power assembly 11a is electrically connected to the drive board <NUM>. Specifically, a power chip <NUM> of the power assembly 11a is connected to the drive chip <NUM> on the drive board <NUM> through the lead frame <NUM>. Certainly, the power chip <NUM> of the power assembly 11a may be alternatively connected to the drive chip <NUM> on the drive board <NUM> by using a conducting structure such as a lead or a metal rod. In another embodiment, the drive board <NUM> may be alternatively electrically connected to the power chips <NUM> of the two power assemblies <NUM>. In addition, the drive board <NUM> may be connected to the power assembly 11a and the power assembly 11b in a same manner or different manners.

The power module <NUM> includes a conducting rod <NUM> and a pin <NUM>. Two ends of the conducting rod <NUM> are respectively connected to a mounting surface <NUM> of the power assembly 11a corresponding to the conducting rod <NUM> and a mounting surface <NUM> of the power assembly 11b corresponding to the conducting rod <NUM>. Specifically, the two ends of the conducting rod <NUM> are respectively connected to a second line a22 of the power assembly 11a corresponding to the conducting rod <NUM> and a second line a22 of the power assembly 11b corresponding to the conducting rod <NUM>, and are respectively electrically connected to the power chip <NUM> of the power assembly 11a and the power chip <NUM> of the power assembly 11b. One end of the pin <NUM> is fastened to the conducting rod <NUM> of the second line a22 of the power assembly 11a, and the other end of the pin <NUM> extends out of a side of a package body <NUM> of the power assembly 11a and/or a package body <NUM> of the power assembly 11b, to connect to a related external device, for example, a circuit board. As shown in <FIG>, there are two conducting rods <NUM> and two pins <NUM>, the two conducting rods <NUM> are respectively located on two sides of the two power chips <NUM>, and the two pins <NUM> respectively extend out of the package body <NUM> from two sides of the package body <NUM>. In this application, the conducting rod <NUM> is configured to implement an electrical connection between the power assembly 11a and the power assembly 11b, and the pin <NUM> is configured to connect the power assembly 11a and the power assembly 11b to an external device. Certainly, in another embodiment, quantities and specific structures of pins <NUM> and conducting rods <NUM> are not limited to the foregoing descriptions.

In this embodiment, the lead frame <NUM> is used to connect two power chips <NUM> of the power assembly 11a, and connect the power chips <NUM> to the conducting rods <NUM>. A lead is used to connect two power chips <NUM> of the power assembly 11b, and connect the power chips <NUM> to the conducting rods <NUM>. Certainly, a lead or another conducting structure may be alternatively used to connect the two power chips <NUM> of the power assembly 11a, and connect the power chips <NUM> to the conducting rods <NUM>. The lead frame <NUM> or another conducting structure may be alternatively used to connect the two power chips <NUM> of the power assembly 11b, and connect the power chips <NUM> to the conducting rods <NUM>.

The package body <NUM> of the power assembly 11a and the package body <NUM> of the power assembly 11b are integrated, so that connection strength of the packaged structure <NUM> including the power assembly 11a, the power assembly 11b, and the drive board <NUM> is higher. Specifically, the package body <NUM> of the power assembly 11a and the package body <NUM> of the power assembly 11b form an integrally molded package body <NUM> by using a plastic packaging process. Certainly, the package body <NUM> of the power assembly 11a and the package body <NUM> of the power assembly 11b may be alternatively formed by using a housing packaging process.

The protection scope of this application is not limited to the first embodiment to the fourth embodiment, and any combination of the first embodiment to the fourth embodiment also falls within the protection scope of this application. That is, the foregoing plurality of embodiments may be alternatively combined according to an actual requirement.

<FIG> is a schematic flowchart of a manufacturing method, which does not fall within the scope of the claimed invention, for the power module shown in <FIG>. As shown in <FIG>, the manufacturing method for the power module includes S110 to S130.

S110: Provide a first power board, where the first power board includes a substrate <NUM> and a power chip <NUM> disposed on a mounting surface <NUM> of the substrate <NUM>.

Specifically, as shown in <FIG>, all of which are not falling within the scope of the claimed invention, specific steps of providing the first power board 11c are as follows: First, as shown in <FIG>, the substrate <NUM> is provided. The substrate <NUM> includes a bearing plate a1, a line layer a2, and a metal layer a3. The line layer a2 and the metal layer a3 are respectively formed on two opposite surfaces of the bearing plate a1, and the line layer a2 and the metal layer a3 are respectively located on two sides of the bearing plate a1, to ensure flatness of the bearing plate a1 and prevent warpage of the bearing plate a1. A surface, of the line layer a2, that backs the bearing plate a1 is the mounting surface <NUM>, that is, the power chip is disposed on the surface, of the line layer a2, that backs the bearing plate a1. A surface, of the substrate <NUM>, that backs the power chip is a rear surface <NUM>, that is, a surface, of the metal layer a3, that backs the bearing plate a1 is the rear surface <NUM>. The line layer a2 includes a first line a21 and a second line a22. Second lines a22 are located on two sides of the first line a21. Surfaces, of the first line a21 and the second line a22, that back the bearing plate a1 jointly constitute the mounting surface <NUM>. Certainly, in another embodiment, a structure of the line layer a2 is not limited to the foregoing structure, and a specific structure of the line layer a2 may be arranged according to a connection requirement of the power chip.

In this embodiment, the bearing plate a1 may be made of an insulation and heat dissipation material such as ceramic. The ceramic may be, for example, a ceramic material such as aluminum oxide, silicon nitride, or aluminum nitride. The ceramic material has good heat dissipation effect, and can quickly dissipate heat for the power chip disposed on the substrate <NUM> in a subsequent process. The line layer a2 and the metal layer a3 are made of a metal material, for example, a copper, nickel, or aluminum material, can quickly dissipate heat for the power chip disposed on the substrate <NUM> in the subsequent process, and can further effectively enhance strength of the substrate <NUM>. The line layer a2 and the metal layer a3 may be made of a same material or different materials. In addition, the line layer a2 is further configured to implement an electrical connection between the power chip disposed on the substrate <NUM> in the subsequent process and another line. Certainly, in another embodiment, the bearing plate a1 may be alternatively made of another insulation material.

Then, as shown in <FIG>, the power chip <NUM> is provided. The power chip <NUM> may be an insulated gate bipolar transistor (IGBT), a metal-oxide semiconductor field-effect transistor (MOSFET), and/or a diode. Certainly, in another embodiment, the power chip <NUM> may be provided before the substrate <NUM> Alternatively, the substrate <NUM> and the power chip <NUM> may be provided simultaneously.

Then the power chip <NUM> is disposed on the mounting surface <NUM> of the substrate <NUM>. Specifically, soldering tin is printed on the first line a21, and then the power chip <NUM> is welded to the first line a21. In this embodiment, there are two power chips <NUM>. The two power chips <NUM> are disposed on the first line a21 at a spacing. Certainly, in another embodiment, one or more power chips <NUM> may be alternatively welded to the first line a21. Alternatively, the power chip <NUM> may be fastened to the first line a21 through welding, bonding, or the like based on different conditions. For example, when the power chip <NUM> needs to be electrically connected to the first line a21, the power chip <NUM> may be fastened to the first line a21 through welding. When the power chip <NUM> does not need to be electrically connected to the first line a21, the power chip <NUM> may be fastened to the first line a21 in another manner such as bonding.

When the power chip <NUM> is disposed on the mounting surface <NUM> of the substrate <NUM>, a pin <NUM> is fastened to the mounting surface <NUM>. First, soldering tin is printed on both the first line a21 and the second line a22. Then the power chip <NUM> is welded to the first line a21, and the pin <NUM> is welded to the second line a22 at the same time. Specifically, there are two pins <NUM>, and the two pins <NUM> are respectively welded to second lines a22 on two sides of the two power chips <NUM>. In this embodiment, the pin <NUM> is perpendicular to the mounting surface <NUM>. Alternatively, the pin <NUM> may be fastened to a second line a22 corresponding to the pin <NUM> through welding by using solder paste, ultrasonic welding, silver sintering, or the like. A shape of the pin <NUM> may be a cylindrical shape, an elliptic cylindrical shape, a cuboid shape, a polygonal shape, or the like. Shapes of the two pins <NUM> may be the same or different. A material of the pin <NUM> may be a metal or an alloy with good conductivity, for example, Cu, Ag, or Al. Certainly, a quantity and an arrangement manner of pins <NUM> may be alternatively arranged according to an actual requirement. Alternatively, the pin <NUM> may not be perpendicular to the mounting surface <NUM>.

In this embodiment, the power chip <NUM> and the pin <NUM> are simultaneously mounted to the mounting surface <NUM>. This helps reduce manufacturing steps of the power module, reduce production costs, and improve production efficiency of the power module. In another embodiment, alternatively, the power chip <NUM> may be mounted to the mounting surface <NUM> before the pin <NUM>, or the pin <NUM> may be mounted to the mounting surface <NUM> before the power chip <NUM>.

Then, as shown in <FIG>, a conductor <NUM> electrically connected to the power chip <NUM> is formed on a surface, of the power chip <NUM>, that backs the mounting surface <NUM>, and the conductor <NUM> is configured to electrically connect the power chip <NUM> to a related element mounted in a subsequent process. Specifically, steps of forming the conductor <NUM> may be implemented in a plurality of manners. Details are described as follows.

In an implementation, as shown in <FIG>, when the conductor is a copper rod <NUM>, before the conductor <NUM> is formed on the surface, of the power chip <NUM>, that backs the mounting surface <NUM>, first, the two power chips <NUM> are electrically connected, and the power chip <NUM> is electrically connected to a pin <NUM> corresponding to the power chip <NUM>. The two power chips <NUM> are connected through a lead, and the power chip <NUM> is indirectly electrically connected to the pin <NUM> corresponding to the power chip <NUM>. Specifically, the lead is connected between the second line a22 and the power chip <NUM>, so that the power chip <NUM> is indirectly electrically connected to the pin <NUM> corresponding to the power chip <NUM>. A lead connection process is mature and simple, and has low costs. Certainly, in another embodiment, a connection structure such as a lead frame may be alternatively used to connect the two power chips <NUM>, and connect the power chip <NUM> to the pin <NUM> corresponding to the power chip <NUM>. Then one end of the copper rod <NUM> is fastened to the surface, of the power chip <NUM>, that backs the mounting surface <NUM>, and is electrically connected to the power chip <NUM>. A quantity of copper rods <NUM> corresponds to a quantity of power chips <NUM>, and one copper rod <NUM> corresponds to one power chip <NUM>. Certainly, in another embodiment, the conductor <NUM> may be alternatively connected by using another conducting structure such as a lead.

In another implementation, as shown in <FIG>, when the conductor is a lead frame <NUM>, the lead frame <NUM> is provided. The lead frame <NUM> includes a first terminal <NUM>, a second terminal <NUM>, and a third terminal <NUM> that are connected to each other, and the first terminal <NUM> is electrically connected to the second terminal <NUM> and the third terminal <NUM>. In this embodiment, there are two lead frames <NUM>. The first terminal <NUM> of the lead frame <NUM> is electrically connected to a power chip <NUM> corresponding to the lead frame <NUM>, and the third terminal <NUM> is connected to a second line a22 corresponding to the lead frame <NUM>, so that the lead frame <NUM> is connected to a pin <NUM> corresponding to the lead frame <NUM> through the second line a22. The second terminal <NUM> is configured to connect to a related element in a subsequent process. In addition, the two power chips <NUM> can be further electrically connected through the lead frame <NUM>.

When the conductor is the lead frame <NUM>, the lead frame <NUM> implements both an electrical connection between the pin <NUM> and the power chip <NUM> and an electrical connection between the two power chips <NUM>, so that no additional lead needs to be introduced to connect the power chip <NUM> and the pin <NUM> and connect the two power chips <NUM>. Therefore, a structure of the power module is simpler, and manufacturing steps of the power module are reduced, thereby improving production efficiency of the power module. In addition, compared with a lead, the lead frame <NUM> has a stronger through-current capability and a smaller parasitic parameter, so that heat dissipation effect of the power chip <NUM> can be further improved.

Certainly, in another embodiment, as shown in <FIG>, which does not fall within the scope of the claimed invention, no conductor needs to be formed on the surface, of the power chip <NUM>, that backs the mounting surface <NUM>, and a lead is used to directly connect the power chip <NUM> to the pin <NUM>, and connect the two power chips <NUM>. Alternatively, another conducting structure is used to directly connect the power chip <NUM> to the pin <NUM>, and connect the two power chips <NUM>.

S120: Provide a drive board <NUM>, dispose the drive board <NUM> on a side, of the power chip <NUM>, that backs the mounting surface <NUM>, and electrically connect the drive board <NUM> to the power chip <NUM>, to form a to-be-packaged structure 13a.

Specifically, as shown in <FIG>, all of which do not fall within the scope of the claimed invention, first, the drive board <NUM> is provided. In this embodiment, as shown in <FIG>, the drive board <NUM> includes a center region <NUM> and an edge region <NUM> surrounding the center region <NUM>. Electronic elements such as a drive chip <NUM>, a resistor <NUM>, a capacitor, and an optocoupler are disposed in the center region <NUM> to form a drive circuit. The drive board <NUM> further includes a through hole <NUM> and a via <NUM>. The through hole <NUM> is located in the center region <NUM>, and the via <NUM> is located in the edge region <NUM>. Certainly, in another embodiment, small electronic elements such as the resistor <NUM>, the capacitor, and the optocoupler may be alternatively partially disposed in the edge region <NUM>. Alternatively, the drive board <NUM> may include only the center region <NUM>, that is, the drive board <NUM> may not include the edge region <NUM>.

Then the drive board <NUM> is disposed on the side, of the power chip <NUM>, that backs the mounting surface <NUM>, and the drive board <NUM> is electrically connected to the power chip <NUM>, to form the to-be-packaged structure 13a. Specifically, the drive board <NUM> is disposed between two ends of the pin <NUM>, and is close to an end, of the pin <NUM>, that is electrically connected to the power chip <NUM>. The drive board <NUM> is required to be disposed close to the end, of the pin <NUM>, that is electrically connected to the power chip <NUM>, to ensure that a distance between the drive board <NUM> and the power chip <NUM> is sufficiently short, thereby ensuring that a parasitic parameter of a connection line between the drive board <NUM> and the power chip <NUM> is sufficiently small, and effectively improving electrical performance of the power module.

Specifically, this step may be implemented in a plurality of manners. In an implementation, in a scenario in which the copper rod <NUM> or the lead frame <NUM> is disposed on the surface, of the power chip <NUM>, that backs the mounting surface <NUM>, as shown in <FIG> and <FIG>, first, the drive board <NUM> is disposed at an end, of the copper rod <NUM>, that backs the power chip <NUM> or is disposed at the second terminal <NUM> of the lead frame <NUM>, the center region <NUM> is arranged opposite to the first power board 11c, and the pin <NUM> passes through the through hole <NUM> on the drive board <NUM> and is connected to the drive board <NUM> in an insulated manner. Then the end, of the copper rod <NUM>, that backs the power chip <NUM> or the second terminal <NUM> of the lead frame <NUM> is welded to the drive board <NUM>, so that the drive chip <NUM> on the drive board <NUM> is electrically connected to the power chip <NUM> through the conductor <NUM>, to form the to-be-packaged structure 13a.

In this implementation, a length of the copper rod <NUM> is equal to the distance between the drive board <NUM> and the power chip <NUM>. It may be understood that a length direction of the copper rod <NUM> is a flow direction of a current in the copper rod <NUM>, so that the length of the copper rod <NUM> is the shortest, that is, the connection line between the drive board <NUM> and the power chip <NUM> is the shortest, thereby effectively reducing the parasitic parameter of the connection line of the power module, and improving electrical performance of the power module.

In another implementation, in a scenario in which no copper rod <NUM> or lead frame <NUM> is disposed on the surface, of the power chip <NUM>, that backs the mounting surface <NUM>, as shown in <FIG>, first, the drive board <NUM> is disposed on a side, of the power chip <NUM>, that backs the mounting surface <NUM>, the center region <NUM> is arranged opposite to the first power board 11c, and the pin <NUM> passes through the through hole <NUM> on the drive board <NUM>. Then a hole wall of the through hole <NUM> is electrically connected to the pin <NUM>, so that the drive chip <NUM> on the drive board <NUM> is electrically connected to the power chip <NUM> through the pin <NUM>, to form the to-be-packaged structure 13a.

In another embodiment, the drive board <NUM> includes only the center region <NUM>, a copper rod or a lead frame is disposed on the surface, of the power chip <NUM>, that backs the mounting surface <NUM>, and the pin <NUM> is not perpendicular to the mounting surface <NUM>. In this scenario, as shown in <FIG>, which does not fall within the scope of the claimed invention, an example in which the lead frame <NUM> is disposed on the surface, of the power chip <NUM>, that backs the mounting surface <NUM> is used for description in <FIG>. First, the drive board <NUM> is disposed at the second terminal <NUM> of the lead frame <NUM>, and the center region <NUM> is arranged opposite to the first power board 11c and is located between two pins <NUM>. Then the second terminal <NUM> of the lead frame <NUM> is welded to the drive board <NUM>, so that the drive chip <NUM> on the drive board <NUM> is electrically connected to the power chip <NUM> through the lead frame <NUM>. Finally, a second power board 11d is provided. Structures of the second power board 11d and the first power board 11c are basically the same. The second power board 11d is disposed on a side, of the drive board <NUM>, that backs the first power board 11c, and is electrically connected to the first power board 11c, to form the to-be-packaged structure 13a. Specifically, a mounting surface <NUM> of the second power board 11d is arranged opposite to the mounting surface <NUM> of the first power board 11c. That is, the first power board 11c and the second power board 11d are symmetrically disposed on two sides of the drive board <NUM>. Certainly, an arrangement manner of the pin <NUM>, the drive board <NUM>, the first power board, and the second power board is not limited to the foregoing descriptions. Alternatively, the power chip <NUM> may be connected to a circuit board by using a structure other than the pin <NUM>.

S130: Package the to-be-packaged structure 13a by using a package body <NUM>, to form a power module.

Specifically, as shown in <FIG> which does not fall within the scope of the claimed invention but is useful for understanding the invention and <FIG> which falls within the scope of the claimed invention, the to-be-packaged structure 13a is packaged by using a plastic packaging process. The to-be-packaged structure 13a may be the to-be-packaged structure 13a shown in <FIG>, <FIG>. An example in which the to-be-packaged structure 13a is the to-be-packaged structure 13a shown in <FIG> is used below for description. Specifically, first, the to-be-packaged structure 13a is placed in a package mold. An end, of the pin <NUM>, that is away from the power chip <NUM> extends out of the package mold. An avoidance structure is disposed in the package mold, and the avoidance structure is located on a surface, of the edge region <NUM> of the drive board <NUM>, that backs the power chip <NUM>, and extends, through the via in the edge region <NUM>, toward a plane on which the rear surface <NUM> of the substrate <NUM> is located. Then the package mold is filled with the package body <NUM>. The package body <NUM> is made of a plastic material such as epoxy resin. After being cured, the package body <NUM> forms the packaged structure <NUM> with the to-be-packaged structure 13a, so as to form the power module <NUM>. Finally, the package mold is removed. In this embodiment, the power module <NUM> formed by using the plastic packaging process has good sealing performance, so that moisture resistance and reliability of the power module <NUM> can be improved.

In this embodiment, the package body <NUM> is packaged in a region from the rear surface <NUM> of the substrate <NUM> to the side, of the drive board <NUM>, that backs the power chip <NUM>, and the end, of the pin <NUM>, that is away from the power chip <NUM> is exposed from the package body <NUM>, to be electrically connected to a related external device. According to the invention, the rear surface <NUM> of the substrate <NUM> is exposed from the package body <NUM>. Because the rear surface <NUM> of the metal layer a3 is exposed from the package body <NUM>, the metal layer a3 can effectively transmit heat of the power chip <NUM> to the outside, thereby improving heat dissipation efficiency of the power chip <NUM>. In addition, the formed packaged structure <NUM> includes the via <NUM> formed by the avoidance structure avoiding the package body <NUM> and a mounting hole <NUM> of the package body <NUM>, and a related component is connected to the packaged structure <NUM> through the mounting hole <NUM>. A surface, of the edge region <NUM>, that backs the power chip <NUM> is exposed from the package body <NUM>, thereby facilitating fitting between the power chip <NUM> and a related structure.

Finally, as shown in <FIG>, an embodiment falling within the scope of the claimed invention, a heat sink <NUM> is fastened to the packaged structure <NUM>, and the heat sink <NUM> is in contact with the rear surface <NUM> of the substrate <NUM>, to improve heat dissipation efficiency of the power chip <NUM>. A specific step of fastening the heat sink <NUM> to the packaged structure <NUM> is as follows: A screw <NUM> passes through the mounting hole <NUM> from the surface, of the edge region <NUM>, that backs the power chip <NUM>, and is tightened to the heat sink <NUM>. No package body <NUM> is disposed on the surface, of the edge region <NUM>, that backs the power chip <NUM>, so that the screw <NUM> is fastened through the surface, of the edge region <NUM>, that backs the power chip <NUM>. In addition, the package body <NUM> is made of a brittle material, and the package body <NUM> is prone to breakage under large stress. Because no package body is disposed in the edge region <NUM>, the screw <NUM> directly transmits a locking force to the drive board <NUM>, thereby reducing the stress applied to the package body <NUM>, and avoiding a risk that the package body <NUM> cracks because the screw <NUM> directly transmits the locking force to the package body <NUM>. Certainly, in another embodiment, the heat sink <NUM> may be alternatively fastened to the packaged structure <NUM> by using a screw or in another fastening manner, but these would not fall within the scope of the present claimed invention.

As shown in <FIG>, an embodiment which does not fall within the scope of the claimed invention, in which the to-be-packaged structure 13a (<FIG>) includes a first power board 11c, a drive board <NUM>, and a second power board 11d, after the to-be-packaged structure 13a is packaged by using the package body <NUM>, rear surfaces <NUM> of substrates <NUM> of the first power board 11c and the second power board 11d are both exposed from the package body <NUM>, so that the substrates <NUM> of the first power board 11c and the second power board 11d are respectively connected to heat sinks corresponding to the rear surfaces <NUM> of the substrates <NUM> of the first power board 11c and the second power board 11d, so as to implement good heat dissipation for the power module <NUM>.

In another embodiment which does not fall within the scope of the claimed invention, as shown in <FIG>, a specific method for packaging the to-be-packaged structure 13a by using the package body <NUM> may be alternatively as follows: First, a package housing <NUM> is provided, the to-be-packaged structure 13a is fastened in the package housing <NUM>, and an end, of the pin <NUM>, that is away from the mounting surface <NUM> is exposed from the package housing <NUM>. The to-be-packaged structure 13a may include a first power board 11c and a drive board <NUM> (as shown in <FIG>), or may include a first power board 11c, a drive board <NUM>, and a second power board. Then adhesive is injected into the package housing <NUM> to fill a gap in the package housing <NUM>, so as to form the package body <NUM>. The package body <NUM>, the to-be-packaged structure 13a, and the package housing <NUM> jointly constitute the packaged structure <NUM>, to form the power module <NUM>. Specifically, silicon gel is injected into the package housing <NUM> to form the package body <NUM>. In this embodiment, the package body <NUM> is formed by using a housing packaging process. The process is simple, thereby effectively improving production efficiency of the power module <NUM>. In a scenario of this embodiment, the drive board <NUM> in the to-be-packaged structure 13a includes only a center region <NUM>. The heat sink <NUM> is disposed on the package housing <NUM> to dissipate heat for the power module <NUM>.

In the manufacturing method for the power module <NUM> in this disclosure, which does not fall within the scope of this claimed invention, the drive board <NUM> is disposed on the side, of the power chip <NUM>, that backs the mounting surface <NUM>, the drive board <NUM> is electrically connected to the power chip <NUM> to form the to-be-packaged structure 13a, and then the to-be-packaged structure 13a is packaged to form the packaged structure <NUM>. To be specific, the drive board <NUM> and the power chip <NUM> are packaged together, so that a distance between the drive board <NUM> and the power chip <NUM> can be shortened. Further, a connection line between the power chip <NUM> and the drive board <NUM> is shortened, thereby effectively reducing a parasitic parameter of the connection line between the power chip <NUM> and the drive board <NUM>, that is, reducing a parasitic parameter of the power module <NUM>, and improving electrical performance of the power module <NUM>. In addition, the drive board <NUM> and the first power board 11c are packaged together. Compared with disposing the drive board <NUM> and the first power board 11c on a same plane, this can effectively reduce a planar area of the power module <NUM>. During packaging of the first power board 11c, to ensure strength of the first power board 11c after packaging, a thickness of the first power board 11c after packaging is usually greater than <NUM>. This thickness is sufficient to allow the drive board <NUM> and the first power board 11c to be packaged together without increasing the thickness of the first power board 11c. That is, packaging the drive board <NUM> and the first power board 11c together does not affect the thickness obtained after packaging, thereby effectively improving integration of the power module <NUM>, reducing a package size, and reducing costs of the power module <NUM>.

Claim 1:
A power module (<NUM>), wherein the power module (<NUM>) comprises a power assembly (<NUM>, 11a, 11b) and a drive board (<NUM>), the power assembly (<NUM>, 11a, 11b) comprises a substrate (<NUM>), a power chip (<NUM>), and a package body (<NUM>, <NUM>), the package body (<NUM>, <NUM>) is made of a plastic material, the power chip (<NUM>) is disposed on a mounting surface (<NUM>) of the substrate (<NUM>), the package body (<NUM>, <NUM>) packages the power chip (<NUM>) on the substrate (<NUM>), the drive board (<NUM>) is disposed in the package body (<NUM>, <NUM>) and is located on a side, of the power chip (<NUM>), that backs the mounting surface (<NUM>), and the drive board (<NUM>) is electrically connected to the power chip (<NUM>);
wherein the drive board (<NUM>) and the power assembly (<NUM>, 11a, 11b) constitute a packaged structure, a surface, of the substrate (<NUM>), that backs the power chip (<NUM>) is a rear surface (<NUM>), the rear surface (<NUM>) is exposed from the package body (<NUM>, <NUM>), the power module (<NUM>) further comprises a heat sink (<NUM>), and the heat sink (<NUM>) is fastened to the packaged structure and is in contact with the rear surface (<NUM>); and
wherein the drive board (<NUM>) comprises a center region (<NUM>) and an edge region (<NUM>) surrounding the center region (<NUM>), the center region (<NUM>) is arranged opposite to the power assembly (<NUM>, 11a, 11b), the packaged structure comprises a mounting hole (<NUM>), the mounting hole (<NUM>) is located in the edge region (<NUM>), and penetrates the drive board (<NUM>) and the package body (<NUM>, <NUM>) in a direction from the drive board (<NUM>) to the power chip (<NUM>), and the heat sink (<NUM>) is connected to the packaged structure through the mounting hole (<NUM>); and
wherein a surface, of the edge region (<NUM>), that backs the power chip (<NUM>) is exposed from the package body (<NUM>, <NUM>), so that a screw (<NUM>) is fastened through the surface, of the edge region (<NUM>), that backs the power chip (<NUM>).