Power module and power equipment

Abstract

The invention discloses a power module and power equipment, and aims to simplify the structure of the power module and improve the reliability of the power module. The power module comprises a chip, a first substrate and a packaging body, the first substrate comprises a first surface and a second surface which are opposite in position, the first surface of the first substrate is used for installing the chip and comprises a plurality of pins, one end of each pin is fixed to the first substrate, and the other end of each pin extends in the direction away from the first substrate; the packaging body is used for wrapping the chip, at least part of the first substrate and at least part of each pin, the other end of each pin is exposed out of the surface of one side of the packaging body, the surface of one side of the packaging body is flush with the other end of each pin, and the packaging body is in sealing fit with the contact part of each pin; the surface of the other side of the packaging body exposes the second surface of the first substrate.

Description

Technical Field

[0001] The present application relates to the field of electronic power, and in particular to a power module and a power device. Background Art

[0002] The power module is a functional module that combines power electrical devices according to certain functions and then encapsulates them into an integral whole. It is widely used in servo motors, frequency converters, inverters and other equipment. Housing packaging and molding packaging are the two most common packaging methods. Housing packaging is a process technology that uses a plastic shell and a substrate carrying electrical devices to form a cavity, and injects silicone gel into the cavity to protect each electrical device; molding packaging is a packaging method that places a substrate carrying electrical devices into a special injection mold, uses softened epoxy resin and other plastic packaging materials as packaging materials, and encapsulates and wraps the electrical devices under certain pressure and temperature conditions to protect the internal devices. Of these two packaging methods, housing packaging is easily limited by the material properties of silicone gel and is relatively weak in reliability. Molding packaging has high requirements for packaging process precision and is prone to the risk of overflow during the plastic packaging process. Summary of the invention

[0003] The present application provides a power module and a power device to simplify the structure of the power module and improve the reliability of the power module.

[0004] In the first aspect, the present application provides a power module, which may include a chip, a first substrate and a package. The first substrate includes a first surface and a second surface, and the first surface and the second surface are opposite to each other. The first surface of the first substrate can be used to install the chip, and the first surface includes a plurality of pins, one end of each pin is fixed to the first substrate, and the other end of each pin extends in a direction away from the first substrate. The package can be used to wrap the chip, at least part of the first substrate and at least part of each pin, and one side surface of the package can expose the other end of each pin, and the other side surface of the package exposes the second surface of the first substrate. In the present application, the contact part between the package and the pin can form a sealing fit, thereby effectively protecting the various components wrapped by the package. In addition, one side surface of the package is flush with the other end of the pin, and the side surface of the package facing away from the second substrate during the packaging process can be controlled by the molding surface of the injection mold, so there is no need to introduce a cover plate to control the surface position of the package, which can not only simplify the structure of the power module, but also avoid the risk of overflow caused by the introduction of the cover plate, thereby improving the reliability of the power module.

[0005] In some embodiments, the other end surface of the pin may be a plane. This design can facilitate the processing and manufacturing of the pin and improve the production yield of the pin.

[0006] In the above solution, the other end surface of the pin can be used as a welding surface to facilitate fixing with an external device by welding.

[0007] In some embodiments, the other end surface of the pin may have a blind hole, and the blind hole extends along the length direction of the pin. With this design, the other end of the pin can be fixedly connected to an external device through the blind hole.

[0008] Exemplarily, in one implementation, the blind hole at the other end of the pin can be fixedly connected to the external device by interference fit with the external device. In another implementation, the blind hole at the other end of the pin can be fixedly connected to the external device by threaded connection with the external device.

[0009] In some embodiments, the other end surface of the pin includes a first elastic member, which may be an annular structure, and the first elastic member is fixedly connected to the edge of the other end surface of the pin. The first elastic member can absorb the dimensional tolerance of the pin in the height direction, so that the other end surface of each pin can be kept at the same height during the packaging process, so as to ensure that the other end of each pin can be exposed on the surface of the package body, thereby improving the reliability of the power module.

[0010] In some embodiments, the pin may include a first conductive portion, a second elastic member, and a second conductive portion, the first conductive portion, the second elastic member, and the second conductive portion are arranged in sequence in a direction away from the first substrate, and the second elastic member is fixed to the first conductive portion and the second conductive portion, respectively. Similarly, the second elastic member may also play a role in absorbing the pin tolerance to ensure that the other end of each pin can be exposed on the surface of the package body, thereby improving the reliability of the power module.

[0011] In some embodiments, the pins include cylindrical pins or prismatic pins, and both end faces of the pins can be planes, so as to reduce the difficulty of processing the pins and improve the production yield of the pins.

[0012] In some embodiments, the package includes a plurality of bolt holes, defining the arrangement direction of the first surface and the second surface of the first substrate as a first direction, the projection of the plurality of bolt holes in the first direction does not overlap with the projection of the first substrate in the first direction, and the power module can be fixed to the heat sink by means of the plurality of bolt holes and the plurality of bolts.

[0013] In some embodiments, a boss is provided on one side surface of the package, the projection of the boss in the first direction can cover the projection of each pin in the first direction, and the edge of the boss and the side surface of the package facing away from the second substrate can form a step structure. The step structure can increase the creepage distance between the pin and the bolt, thereby reducing the influence of the bolt on the signal transmitted in the pin, and improving the reliability of the power module.

[0014] In some embodiments, a side surface of the package body may include a plurality of retaining walls, each retaining wall may extend along a first direction, and a projection of each retaining wall in the first direction may be located between a projection of a bolt hole in the first direction and a projection of a boss in the first direction. The design of the retaining wall may also increase the creepage distance between the pin and the bolt, thereby further improving the reliability of the power module.

[0015] In some embodiments, the power module may further include a second substrate, which may be used to support the first substrate, the second substrate being stacked on a side of the first substrate facing away from the chip, and the second substrate being in contact with a second surface of the first substrate facing away from the chip. The heat generated when the chip is working may be transferred to the second substrate through the first substrate, and dissipated to the outside through the second substrate, thereby achieving heat dissipation of the chip. The package may wrap at least a portion of the second substrate to increase the connection strength between the second substrate and the package. In addition, the package may also expose a side surface of the second substrate facing away from the first substrate, so that heat can be dissipated to the outside through the side surface of the second substrate.

[0016] In the second aspect, the present application also provides a power device, which includes a circuit board and a power module in any implementation scheme of the first aspect, and the other end of the pin is electrically connected to the circuit board, so that the circuit board is used to provide current or voltage input and output and power supply and other functions for the power module. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of a photovoltaic system provided in an embodiment of the present application;

[0018] Figure 2 A schematic diagram of the structure of a power device provided in an embodiment of the present application;

[0019] Figure 3 A side view of a power module provided in an embodiment of the present application;

[0020] Figure 4 for Figure 3 A side view of the partial structure of the power module shown in FIG.

[0021] Figure 5 A schematic diagram of the structure of a power module provided in an embodiment of the present application;

[0022] Figure 6a A schematic diagram of the structure of a pin provided in an embodiment of the present application;

[0023] Figure 6b for Figure 6a Schematic diagram of the connection between the pins and external devices shown in;

[0024] Figure 7a A schematic diagram of the structure of another pin provided in an embodiment of the present application;

[0025] Figure 7b for Figure 7a Schematic diagram of the connection between the pins and external devices shown in;

[0026] Figure 8a A schematic diagram of the structure of another pin provided in an embodiment of the present application;

[0027] Figure 8b for Figure 8a Schematic diagram of the connection between the pins and external devices shown in;

[0028] Fig. 9 Another structural schematic diagram provided for an embodiment of the present application;

[0029] Fig.10 Another structural schematic diagram provided for an embodiment of the present application.

[0030] 1000-power equipment;

[0031] 100-housing;

[0032] 200-circuit board; 210-connection terminal; 210a-other end surface of the connection terminal; 211-extension column;

[0033] 300 - power module; 310 - first substrate; 310a - first surface; 310b - second surface; 311 - ceramic substrate; 312 - first metal layer;

[0034] 313 - second metal layer; 320 - chip; 330 - package body; 331 - bolt hole; 332 - boss; 333 - step structure; 334 - retaining wall;

[0035] 340 - second substrate; 341 - extension portion; 342 - avoidance hole; 350 - pin; 350a - one end surface of the pin; 350b - the other end surface of the pin;

[0036] 351 - blind hole; 352 - first elastic member; 353 - first conductive part; 354 ​​- second elastic member; 355 - second conductive part. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the present application clearer, the embodiments of the present application will be further described in detail below in conjunction with the accompanying drawings. However, the example implementation can be implemented in various forms and should not be construed as being limited to the implementations set forth herein. The same reference numerals in the figures represent the same or similar structures, and thus their repeated description will be omitted. The words expressing position and direction described in the embodiments of the present application are all illustrated by taking the accompanying drawings as examples, but changes may be made as needed, and the changes made are all included in the scope of protection of the present application. The drawings of the embodiments of the present application are only used to illustrate the relative position relationship and do not represent the true proportion.

[0038] It should be noted that specific details are described in the following description to facilitate understanding of the present application. However, the embodiments of the present application can be implemented in a variety of other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the embodiments of the present application. Therefore, the present application is not limited to the specific implementation methods disclosed below.

[0039] Power devices are widely used in photovoltaic systems, energy storage systems, or powertrain systems of new energy vehicles to convert current or voltage in the application system. Power devices can include inverters and micro inverters in photovoltaic systems, converters in energy storage systems, or motor controllers in powertrains of new energy vehicles.

[0040] Taking photovoltaic system as an example, Figure 1 A schematic diagram of the structure of a photovoltaic system provided in an embodiment of the present application, the photovoltaic system includes one or more photovoltaic strings, an inverter and a transformer. The photovoltaic string may include a plurality of photovoltaic modules connected in series, and the photovoltaic module is a DC power supply composed of solar cells packaged in series or in parallel, which is used to convert light energy into electrical energy; the inverter is a DC-AC power device, which can be used to convert the DC power output by the photovoltaic string into AC power output to the transformer; the transformer is used to transform the AC power output by the inverter and then merge it into the AC power grid, thereby realizing the grid connection of the photovoltaic system.

[0041] Figure 2 This is a schematic diagram of the structure of the power device 1000 provided in an embodiment of the present application. Figure 2As shown, the power device 1000 may include a housing 100, a circuit board 200 and a power module 300 contained in the housing 100, and the power module 300 is electrically connected to the circuit board 200. The circuit board 200 may be a printed circuit board (PCB), a flexible printed circuit (FPC), or a soft-hard combination circuit board. The power module 300 is a core component of the power device 1000 for realizing the power conversion function. The power module 300 may include multiple ports, such as input positive and negative ports, output positive and negative ports, power supply positive and negative ports, etc. These ports are electrically connected to the circuit board 200 through pins, so that the circuit board 200 is used to provide the power module 300 with current or voltage input and output and power supply functions.

[0042] The power module may include various electrical components such as power devices, inductors, capacitors, etc. These electrical components are connected according to certain functional combinations and then packaged as a whole through a packaging process. Common power module packaging processes include housing packaging, molding packaging, etc. Housing packaging is a process technology that uses a plastic shell and a carrier substrate carrying the above-mentioned electrical components to form a housing cavity, and injects silicone gel into the cavity to protect the electrical components. This packaging method is easily limited by the material properties of silicone gel and is relatively weak in reliability performance; molding packaging is to place the carrier substrate carrying the electrical components into the cavity of a special injection mold, and use softened epoxy resin and other plastic packaging materials as packaging materials. Under certain pressure and temperature conditions, the electrical components are packaged and wrapped to protect the internal components. Molding packaging often requires setting a cover plate on the back of the electrical device to the upper side of the carrier substrate, and setting holes in the cover plate at the positions of the pins of the power module, so that the pins extend outward through the holes in the cover plate, and then plastic sealing is performed. In this packaging method, the cover plate itself has disadvantages such as low hole position accuracy and overly complex structure, and there is a risk of overflow during the plastic sealing process.

[0043] In view of this, the embodiment of the present application provides a power module and a power device using the power module. The power module is not only simple in structure, but also has a relatively low risk of flashing during the packaging process and high reliability, thereby improving the production cost of the power device using the power module. The power module and the power device provided in the embodiment of the present application are described in detail below in conjunction with the accompanying drawings.

[0044] For reference Figure 3 and Figure 4 As shown, Figure 3 A side view of a power module 300 provided in an embodiment of the present application. Figure 4 for Figure 33 is a side view of a partial structure of a power module 300 shown in FIG. In an embodiment of the present application, the power module 300 may include a first substrate 310, a chip 320, and a package 330. The first substrate 310 includes a first surface 310a and a second surface 310b, and the first surface 310a and the second surface 310b of the first substrate 310 are arranged opposite to each other along a first direction, and the first direction may be understood as the thickness direction of the first substrate 310. The chip 320 is mounted on the first surface 310a of the first substrate 310, and the package 330 may be used to include the chip 320 and at least a portion of the first substrate 310, and the package 330 exposes the second surface of the first substrate 310.

[0045] In some embodiments, the chip 320 may include an insulated gate bipolar transistor (IGBT), a metal-oxide-semiconductor field-effect transistor (MOSFET), or a power transistor.

[0046] In the embodiment of the present application, the power module 300 may include one or more first substrates 310, for example Figure 2 , an example in which the power module 300 includes two first substrates 310 is shown. In the case where there are multiple first substrates 310, each first substrate 310 is spaced apart from each other. The first substrate 310 may be a ceramic substrate, and the first substrate 310 includes a ceramic substrate 311 and two metal layers, and the two metal layers are respectively fixed to the two side surfaces of the ceramic substrate 311 at opposite positions. For ease of explanation, in this embodiment, the metal layers fixed to the two side surfaces of the ceramic substrate 311 are respectively referred to as the first metal layer 312 and the second metal layer 313, wherein the side surface of the first metal layer 312 facing away from the ceramic substrate 311 can be formed as the first surface 310a of the first substrate 310, and the side surface of the second metal layer 313 facing away from the ceramic substrate 311 can be formed as the second surface 310b of the first substrate 310. The first surface 310 a of the first substrate 310 is used to mount not only the chip 320 but also electrical devices such as inductors and capacitors. The chip 320 is electrically connected to these electrical devices through the circuit formed by the first metal layer 312 to form a functional circuit of the power module 300 .

[0047] In one embodiment, the material of the ceramic substrate 311 includes aluminum oxide or aluminum nitride, etc., the first metal layer 312 and the second metal layer 313 can be copper layers respectively, and the first substrate 310 is a copper-clad ceramic substrate (direct bonding copper, DBC). In some other embodiments, the first metal layer 312 and the second metal layer 313 can also be aluminum layers respectively, and the first substrate 310 is an aluminum-clad ceramic substrate (direct bonded aluminum, DBA).

[0048] Continue to refer Figure 3 and Figure 4 In the embodiment of the present application, the power module 300 may further include a second substrate 340, which may be used to carry the first substrate 310, and the second substrate 340 is stacked on the side of the first substrate 310 facing away from the chip 320, and the second substrate 340 is in contact with the second surface 310b of the first substrate 310 facing away from the chip 320. The heat generated by the chip 320 during operation may be transferred to the second substrate 340 through the first substrate 310, and dissipated to the outside through the second substrate 340, thereby achieving heat dissipation of the chip 320. In addition, the edge of the second substrate 340 may exceed the edge of the first substrate 310, or it may be understood that the projection of the second substrate 340 in the first direction covers the projection of the first substrate 310 in the first direction, so as to improve the heat dissipation performance of the power module 300 by increasing the volume of the second substrate 340. The second substrate 340 may be made of a metal material with good thermal conductivity, for example, the second substrate 340 may be a copper substrate or an aluminum substrate.

[0049] In the case where the power module 300 includes the second substrate 340, the package body 330 may further wrap at least a portion of the second substrate 340 to improve the connection strength between the second substrate 340 and the package body 330, thereby helping to improve the overall structural strength of the power module 300. In addition, the package body 330 may expose a side surface of the second substrate 340 that is away from the first substrate 310, so that heat can be dissipated to the outside through the side surface of the second substrate 340.

[0050] In some embodiments, the power device may further include a heat sink, which contacts the surface of the second substrate 340 on one side facing away from the first substrate 310, and the contact may be direct contact or indirect contact through other media. The heat transferred from the first substrate 310 to the second substrate 340 may be further transferred to the heat sink through the second substrate 340, so that the heat sink dissipates heat for the power module 300. Exemplarily, the heat sink may be a liquid-cooled heat sink or an air-cooled heat sink.

[0051] Of course, in some other embodiments, the power module 300 may not include the second substrate 340 . In this case, the heat sink of the power device can directly dissipate heat for the power module 300 by contacting the second surface 310 b of the first substrate 310 .

[0052] Please continue to refer to Figure 3 and Figure 4 In the embodiment of the present application, the first surface 310a of the first substrate 310 includes a plurality of pins 350, and the plurality of pins 350 are respectively arranged along the first direction, one end of each pin 350 is fixed to the first substrate 310, and the other end of each pin 350 extends in a direction away from the first substrate 310. In one implementation, the first surface 310a of the first substrate 310 includes a plurality of pads, and one end of each pin 350 is respectively welded to a corresponding pad, so that each pin 350 is fixed to the first surface 310a of the first substrate 310 and realizes electrical connection with the first substrate 310.

[0053] Based on the relative positional relationship between the package body 330 and the first substrate 310, the package body 330 can wrap at least part of each pin 350 while wrapping the first substrate 310 and the chip 320, and the other end of each pin 350 can be exposed on the surface of the package body 330 facing away from the second substrate 340, so that each pin 350 can be electrically connected to an external device, thereby realizing electrical connection between the power module 300 and the external device. Here, the external device can be a circuit board of a power device used by the power module 300.

[0054] In this embodiment, the surface of the package body 330 facing away from the second substrate 340 is substantially flush with the other end of each pin 350. During the packaging process, the surface of the package body 330 facing away from the second substrate 340 can be controlled by the molding surface of the injection mold. Therefore, there is no need to introduce a cover plate to control the surface position of the package body 330. This not only simplifies the structure of the power module 300, but also avoids the risk of overflow caused by the introduction of the cover plate, thereby improving the reliability of the power module 300 and helping to shorten the development cycle of the power module 300.

[0055] In addition, by Figure 3 and Figure 4It can be seen that the surface of the package body 330 facing away from the second substrate 340 is the top surface of the power module 300. Therefore, in this embodiment, each pin 350 is exposed on the top surface of the power module 300, so that the power module 300 can be interconnected with the outside on the top surface. Since the top surface area of ​​the power module 300 is relatively large, sufficient layout space can be provided for the pins 350, and it is also feasible to set more pins 350 for the power module 300, which helps to improve the flow capacity of the power module 300.

[0056] In the packaging process of the power module 300, the assembled first substrate 310, the second substrate 340, the chip 320, the pins 350 and various electrical components are first placed in the cavity of the injection mold, and the other end surface of each pin 350 is protected by the injection mold to reduce the risk of the packaging material completely wrapping the pin 350 in the subsequent process. Then, the packaging material is injected into the cavity to wrap the first substrate 310, the chip 320, the electrical components, at least part of the second substrate 340 and at least part of each pin 350. After the packaging material is cured, the packaging body 330 is formed. Among them, the packaging material used to form the packaging body 330 can be an epoxy molding compound.

[0057] It is easy to understand that during the process of injecting the packaging material, the packaging material fits tightly against the peripheral surface of each pin 350, so that after the packaging material is solidified into the packaging body 330, the contact parts between the packaging body 330 and the pins 350 can naturally form a sealed fit, thereby effectively protecting the various components wrapped by the packaging body 330.

[0058] Figure 5 This is a schematic diagram of the structure of the power module 300 provided in the embodiment of the present application. Figure 3 and Figure 5 As shown, in the embodiment of the present application, the package body 330 may include a plurality of bolt holes 331, and the plurality of bolt holes 331 respectively penetrate the package body 330 along the first direction, and the projection of the plurality of bolt holes 331 in the first direction does not overlap with the projection of the first substrate 310 in the first direction. Exemplarily, the plurality of bolt holes 331 may be arranged near the edge of the package body 330. As mentioned above, the power device may include a heat sink for dissipating heat from the power module 300. In the embodiment, the power module 300 may be fixed to the heat sink by the plurality of bolt holes 331 and a plurality of bolts.

[0059] In one embodiment, the package body 330 may include four bolt holes 331, and the four bolt holes 331 are spaced apart along the edge of the package body 330 to improve the force uniformity of the package body 330. For example, the four bolt holes 331 may be distributed at the four corners of the package body 330.

[0060] In addition, in the example where the power module 300 includes the second substrate 340, the second substrate 340 includes two extensions 341, and the two extensions 341 are respectively distributed on both sides of the second substrate 340 along the length direction of the second substrate 340. The package body 330 wraps the two extensions 341, and includes two bolt holes 331 in the areas corresponding to the two extensions 341. Accordingly, avoidance holes 342 can be respectively provided at the positions of the two extensions 341 corresponding to the bolt holes 331, so that the bolts can pass through the package body 330 and the extensions 341 of the second substrate 340 in sequence and then be fixed to the heat sink, thereby improving the connection reliability between the power module 300 and the heat sink.

[0061] Continue to refer Figure 5 In the embodiment of the present application, the surface of the package body 330 on one side facing away from the second substrate 340 has a boss 332, the projection of the boss 332 in the first direction can cover the projection of each pin 350 in the first direction, and the edge of the boss 332 and the surface of the package body 330 on one side facing away from the second substrate 340 can form a step structure 333. The step structure 333 can increase the creepage distance between the pin 350 and the bolt hole 331, that is, increase the creepage distance between the pin 350 and the bolt, so this design can reduce the influence of the bolt on the signal transmitted in the pin 350, which helps to improve the reliability of the power module 300.

[0062] In one embodiment, the surface of the package body 330 facing away from the second substrate 340 may include a plurality of retaining walls 334, each retaining wall 334 may extend along the first direction, and each retaining wall 334 is spaced from the boss 332, so that the projection of each retaining wall 334 in the first direction may be located between the projection of a bolt hole in the first direction and the projection of the boss 332 in the first direction. Similar to the function of the boss 332, the design of the retaining wall 334 can effectively increase the creepage distance between the pin 350 and the bolt, thereby further improving the reliability of the power module 300.

[0063] Please continue to refer to Figure 5 In the embodiment of the present application, the other end surface of the pin 350 exposed to the surface of the package body 330 can be a plane, and this design can facilitate the processing and manufacturing of the pin 350 and improve the production yield of the pin 350. In addition, the heights of the pins 350 along the first direction can be roughly equal, which facilitates the design that the other end surface of each pin 350 is flush with the surface of the package body 330.

[0064] Figure 6a This is a schematic diagram of the structure of a pin 350 provided in an embodiment of the present application. Figure 6aAs shown, in this embodiment, the pin 350 can be roughly a cylindrical structure, and both end surfaces of the pin 350 can be used as welding surfaces. One end surface 350a of the pin 350 is welded and fixed to the pad on the first surface of the first substrate, and the other end surface 350b of the pin 350 can also be fixed to the external device by welding.

[0065] For reference Figure 6b , Figure 6b for Figure 6a Schematic diagram of the connection method between the pin 350 and the external device shown in . Taking the circuit board of the power device as an example, the circuit board includes a connection terminal 210, one end of the connection terminal 210 is electrically connected to the circuit board, such as by welding; the other end face 210a of the connection terminal 210 is a welding surface, so as to facilitate welding and fixing with the other end face 350b of the pin 350 exposed to the surface of the package body 330, thereby realizing the electrical connection between the power module and the circuit board. Exemplarily, the shape of the end face of the connection terminal 210 used for connecting with the pin 350 can be circular, and the size of the end face of the connection terminal 210 can be greater than or equal to the size of the other end face 350b of the pin 350, so as to increase the contact area between the connection terminal and the pin 210 and improve the connection reliability between the two.

[0066] Figure 7a This is a schematic diagram of another structure of a pin 350 provided in an embodiment of the present application. Figure 7a As shown, in this embodiment, the pin 350 may be a substantially prismatic structure, and the cross-sectional shape of the pin 350 perpendicular to the first direction includes a triangle, a rectangle, or any regular or irregular polygon. Similar to the previous embodiment, both end surfaces of the pin 350 can be used as welding surfaces, and one end surface 350a of the pin 350 is welded and fixed to the pad on the first surface of the first substrate, and the other end surface 350b of the pin 350 can also be welded and fixed to the external device.

[0067] For reference Figure 7b As shown, Figure 7b for Figure 7a Schematic diagram of the connection between the pin 350 and the external device shown in . Also, taking the circuit board of the power device as an example, the circuit board includes a connection terminal 210, one end of the connection terminal 210 is electrically connected to the circuit board, and the other end face 210a of the connection terminal 210 is a welding surface, so as to facilitate welding and fixing with the other end face 350b of the pin 350 exposed on the surface of the package body 330. Exemplarily, the shape of the end face of the connection terminal 210 used for connecting with the pin can be the same as the shape of the other end face 350b of the pin 350, so as to increase the contact surface between the connection terminal 210 and the pin 350, thereby improving the connection reliability between the connection terminal 210 and the pin 350.

[0068] Figure 8a This is a schematic diagram of another structure of a pin 350 provided in an embodiment of the present application. Figure 8a As shown, in this embodiment, the other end face 350b of the pin 350 exposed to the surface of the package body has a blind hole 351, and the blind hole 351 extends along the length direction of the pin 350, that is, extends along the first direction. One end face 350a of the pin 350 can be a welding surface, so as to facilitate welding and fixing of the pad on the first surface of the first substrate, and the other end face 350b of the pin 350 is fixedly connected to the external device through the blind hole. In addition, in this embodiment, the pin 350 can be either a cylindrical pin or a prismatic pin.

[0069] For reference Figure 8b As shown, Figure 8b for Figure 8a Schematic diagram of the connection between the pin 350 and the external device shown in . Also, taking the circuit board of the power device as an example, the circuit board includes a connection terminal 210, one end of the connection terminal 210 is electrically connected to the circuit board, and the other end surface 210a of the connection terminal 210 includes an extension column 211, which is fixed in the blind hole 351 of the pin 350 to achieve the fixation and electrical connection between the connection terminal 210 and the pin 350. The length of the extension column 211 is substantially the same as the depth of the blind hole 351, so as to increase the matching area between the two, thereby improving the connection reliability between the connection terminal 210 and the pin 350.

[0070] In one implementation, the cross-sectional shape of the blind hole 351 is the same as the cross-sectional shape of the extension column. The inner wall of the blind hole 351 is a relatively smooth surface, and accordingly, the outer wall of the extension column 211 is also a relatively smooth surface. The extension column 211 is interference-fitted in the blind hole 351, thereby achieving a fixed connection between the connection terminal 210 and the pin 350.

[0071] In one implementation, the inner wall of the blind hole 351 has an internal thread, and correspondingly, the outer wall of the extension column 211 has an external thread, and the extension column 211 is screwed into the blind hole 351, thereby achieving relative fixation of the connection terminal 210 and the pin 350 by threaded connection.

[0072] refer to Fig. 9 As shown, Fig. 9 A schematic diagram of another structure of a pin 350 provided in an embodiment of the present application. In this embodiment, the other end surface 350b of the pin 350 exposed to the surface of the package body includes a first elastic member 352, and the first elastic member 352 can be deformed along the length direction of the pin 350. The pin 350 can be a cylindrical pin or a prismatic pin.

[0073] It is easy to understand that the pins 350 will inevitably have certain processing errors during the manufacturing process, which makes it difficult for the other end faces 350b of the multiple pins 350 of the power module to remain in the same plane. In the packaging process, since the other end faces 350b of each pin 350 need to be protected by a mold, the other end faces 350b of the pins 350 with a shorter length are prone to inadequate protection. By setting the first elastic member 352, even if the heights of the pins 350 are different, the deformation characteristics of the first elastic member 352 of each pin 350 can be used to compensate for the respective differences during the packaging process, so that the mold can achieve reliable protection for each pin 350, further reducing the risk of the other end faces 350b of each pin 350 being wrapped, and improving the reliability of the power module.

[0074] In one implementation, the first elastic member 352 can be made of rubber or plastic. The first elastic member 352 can be an annular structure, and the first elastic member 352 is fixedly connected to the edge of the other end face 350b of the pin 350, thereby exposing the central area of ​​the other end face 350b of the pin 350, so that the pin 350 can be electrically connected to an external device by welding or designing a blind hole. Exemplarily, the first elastic member 352 can be fixedly connected to the end face of the pin 350 by bonding. In addition, the first elastic member 352 can adopt an existing structure such as a sealing ring to simplify the manufacturing process of the pin 350.

[0075] In one implementation, the first elastic member 352 may also be a spring. In this implementation, the first elastic member 352 may also be fixedly connected to the edge of the other end surface 350b of the pin 350. Exemplarily, the first elastic member 352 is fixed to the end surface of the pin 350 by welding.

[0076] refer to Fig.10 As shown, Fig.10 A schematic diagram of the structure of another pin 350 provided for an embodiment of the present application. In this embodiment, the pin 350 may include a first conductive portion 353, a second elastic member 354, and a second conductive portion 355, the first conductive portion 353, the second elastic member 354, and the second conductive portion 355 are arranged in sequence in a direction away from the first substrate, and the second elastic member 354 is fixed to the first conductive portion 353 and the second conductive portion 355, respectively. The second elastic member 354 in this embodiment can play the same role as the first elastic member in the aforementioned embodiment, that is, it is used to absorb the tolerance of the pin 350, and the specific details are not repeated here. In addition, the first conductive portion 353 and the second conductive portion 355 can be either a cylindrical structure or a prismatic structure. The first conductive portion 353 can be electrically connected to the first substrate by welding, and the second conductive portion 355 can be electrically connected to an external device by welding or by designing a blind hole.

[0077] In a specific implementation, the second elastic member 354 can be a spring, and the second elastic member 354 and the first conductive part 353 can be welded and fixed, and the second elastic member 354 and the second conductive part 355 can also be welded and fixed, so that the second elastic member 354 is respectively fixed and electrically connected to the first conductive part 353 and the second conductive part 355.

[0078] To sum up, the power module in the embodiment of the present application is designed to have the surface of the package body and the external connection ends of each pin be flush with each other, and there is no need to introduce a cover plate to control the surface position of the package body during the packaging process. This not only simplifies the structure of the power module, but also avoids the risk of overflow caused by the introduction of the cover plate, thereby improving the reliability of the power module and helping to shorten the development cycle of the power module.

[0079] It should be understood that the packaging form provided in the embodiments of the present application is not only applicable to the above-mentioned power modules, but can also be applied to module structures such as ICT modules, plastic-encapsulated chip power modules, and embedded chip packaging (encapsulation chip package, ECP) ​​structures that require external electrical interconnection through pins.

[0080] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A power module, characterized in that: The invention comprises a chip, a first substrate and a package body, wherein: The first substrate comprises a first surface and a second surface opposite to each other, the first surface of the first substrate is used to mount the chip, and the first surface comprises a plurality of pins, one end of each of the pins is fixed to the first substrate, and the other end of each of the pins extends in a direction away from the first substrate; The package body is used to wrap the chip, at least part of the first substrate and at least part of each pin, one side surface of the package body exposes the other end of the pin, and one side surface of the package body is flush with the other end of the pin, the contact part between the package body and the pin is sealed, and the other side surface of the package body exposes the second surface of the first substrate.

2. The power module according to claim 1, characterized in that: The other end surface of the pin is a plane.

3. The power module according to claim 1 or 2, characterized in that: The other end surface of the pin has a blind hole, and the blind hole extends along the length direction of the pin.

4. The power module according to any one of claims 1 to 3, characterized in that: The other end surface of the pin includes a first elastic member, the first elastic member is an annular structure, and the first elastic member is fixedly connected to the edge of the other end surface of the pin.

5. The power module according to any one of claims 1 to 4, characterized in that: The pin includes a first conductive part, a second conductive part and a second elastic member, the first conductive part, the second elastic member and the second conductive part are arranged in sequence in a direction away from the first substrate, and the second elastic member is fixed to the first conductive part and the second conductive part respectively.

6. The power module according to any one of claims 1 to 5, characterized in that: The pins include cylindrical pins or prismatic pins.

7. The power module according to any one of claims 1 to 6, characterized in that: The package body comprises a plurality of bolt holes, and projections of the plurality of bolt holes in a first direction do not overlap with a projection of the first substrate in the first direction; The first direction is an arrangement direction of the first surface and the second surface.

8. The power module according to claim 7, characterized in that: A boss is disposed on one side surface of the package body, the projection of the boss in the first direction covers the projections of the plurality of pins in the first direction, and an edge of the boss forms a step structure with the one side surface of the package body.

9. The power module according to claim 8, characterized in that: One side surface of the package body includes a plurality of retaining walls, each of which extends along the first direction, and a projection of each of the retaining walls in the first direction is located between a projection of a bolt hole in the first direction and a projection of the boss in the first direction.

10. The power module according to any one of claims 1 to 9, characterized in that: The power module further includes a second substrate, the second substrate is used to support the first substrate, and the second substrate is in contact with a second surface of the first substrate; The packaging body is also used to wrap at least a portion of the second substrate, and the other side surface of the packaging body exposes a side surface of the second substrate facing away from the first substrate.

11. A power device, characterized in that: It comprises a circuit board and a power module as described in any one of claims 1 to 10, wherein the other end of the pin is electrically connected to the circuit board.

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