Power circuit board, power converter and manufacturing process of power circuit board

Abstract

The invention belongs to the technical field of electronic chip packaging, and provides a power circuit board, a power converter and a manufacturing process of the power circuit board, and the technical scheme is that the power circuit board comprises a bottom plate, at least one chip, a pin contact pin, an injection molding body and a plastic packaging mold; the upper surface of the bottom plate is provided with a chip designated position area and a pin contact pin designated position area. Chips to be laminated are placed in the specified position areas of the chips, and the chips are electrically connected or the chips are electrically connected with the bottom plate; the bottom of the injection molding body connected with the pin contact pin into a whole is fixed to a specified position area of the pin contact pin; the plastic package mold comprises an upper mold and a lower mold, the lower mold is arranged at the bottom of the bottom plate, the upper mold is provided with a cavity and upper mold open holes communicated with the cavity, the positions of the upper mold open holes correspond to the pin contact pins one by one, the bottom plate, the chip and the injection molding body are accommodated in the cavity, and the pin contact pins are accommodated in the upper mold open holes. And compared with traditional glue pouring protection, the efficiency is higher, and the yield of finished products is higher.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic chip packaging, and particularly relates to a power circuit board, a power converter, and a manufacturing process of the power circuit board. Background Art

[0002] The statements in this part only provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] Semiconductor components are one of the important factors determining the efficiency of power converters. An integrated power module (IPM) integrates multiple semiconductor components (such as power components, control components, and drive components, etc.) in one component package, thereby improving the space utilization rate inside the package. The power module has advantages such as convenient use and a long mean time between failures, and is applied in many occasions.

[0004] However, when traditional power modules are integrated, there are problems such as poor protection effect of soft silicone and low efficiency of manual dispensing. At the same time, the internal components are easily damaged, resulting in a low yield rate, and it is impossible to achieve mass production and work in complex and changeable environments such as humidity.

[0005] To solve the above problems, the prior art proposes positioning the encapsulation jig by clamping the first part in the lower mold groove, and the second part abuts against the surface of the substrate. After plastic encapsulation, the first part and the second part are removed, and the second part separates a terminal installation space in the plastic encapsulation shell, avoiding the direct extrusion of the sealing material on the terminals and the cylinder during the plastic encapsulation process, and improving the yield rate of the power module. However, its defect is that there are still avoidance holes on the product surface, and water vapor is more likely to invade the product interior, affecting the product reliability and service life.

[0006] Another example is to integrally injection mold between the pins and the cover plate to ensure the spacing distance between the cover plate and the circuit board, thereby ensuring the injection quality of the plastic encapsulated parts. However, its defect is that the cover plate needs to be injection molded first, a sealing ring is added to the revised version, and glue is filled in the sealing ring. The process is complex, and there may be delamination between the new injection molding material and the cover plate after secondary injection molding. Summary of the Invention

[0007] To solve at least one of the above technical problems existing in the background art, the first aspect of the present invention provides a power circuit board, which realizes mass production of power modules by using an injection mold and epoxy resin filling, and can work in more complex and changeable environments.

[0008] To achieve the above object, the present invention adopts the following technical solutions: A power circuit board includes a bottom plate, at least one chip, pin inserts, an injection molded body, and a plastic encapsulation mold; The upper surface of the bottom plate is provided with a chip designated position area and a pin insertion designated position area; Place the chip to be bonded in the chip designated position area, and electrically connect between chips or between the chip and the copper ceramic substrate; and fix the bottom of the injection molded body integrally connected with the pin insertion to the pin insertion designated position area; The plastic encapsulation mold includes an upper mold and a lower mold. The lower mold is arranged at the bottom of the bottom plate. The upper mold is provided with a cavity and an upper mold opening communicating with the cavity. The positions of the upper mold openings correspond to the pin insertions one by one. The cavity accommodates the bottom plate, the chip and the injection molded body, and the upper mold openings accommodate the pin insertions.

[0009] As an implementation manner, a gap is provided between the top of the upper mold opening and the pin insertion.

[0010] As an implementation manner, the injection molded bodies integrally connected by the pin insertions have the same height after combination.

[0011] As an implementation manner, a sealing ring is provided between the injection molded body and the top of the cavity.

[0012] As an implementation manner, epoxy resin is poured into the plastic encapsulation mold.

[0013] As an implementation manner, between chips or between the chip and the copper ceramic substrate are welded by welding wires to form a path for transmitting electrical signals.

[0014] As an implementation manner, the chip and the bottom plate are combined by vacuum reflow soldering.

[0015] To solve the above problems, the second aspect of the present invention provides a manufacturing process of a power circuit board. Compared with the traditional potting protection, the protection effect of this invention is more reliable and the efficiency is also higher. Since the whole process uses machine equipment for operation, the yield of the finished product is also higher.

[0016] To achieve the above object, the present invention adopts the following technical solutions: A manufacturing process of a power circuit board includes the following steps: Divide the wafer into multiple bare chips; Print a predetermined shape on the chip designated position area of the bottom plate, and attach the bare chip to the surface of the printed solder paste; Electrically connect between chips or between the chip and the bottom plate; Use injection molding equipment to inject at the pin insertion designated position to obtain an injection molded body integrally connected with the pin insertion, and weld the injection molded pin insertions to the pin insertion designated position; Set a sealing ring between the injection molded body and the top of the cavity; Use a plastic encapsulation mold to melt the epoxy resin and pour it into the interior of the plastic encapsulation mold to encapsulate the base plate, chip, and injection molded body. After the plastic encapsulation is completed, remove the plastic encapsulation mold.

[0017] To solve the above problems, the third aspect of the present invention provides a manufacturing process for a power circuit board. Compared with traditional potting protection, the method of using an injection mold and filling with epoxy resin realizes the mass production of power modules and can work in more complex and variable environments. The protection effect of this invention is more reliable and the efficiency is also higher. Since the whole process uses machinery and equipment for operation, the yield rate of the finished product is also higher.

[0018] To achieve the above object, the present invention adopts the following technical solutions: A manufacturing process for a power circuit board, comprising the following steps: Divide the wafer into multiple bare chips; Place the solder pads at designated positions on the surface of the base plate, and attach the bare chips to the solder pads; Electrically connect between the chips or between the chip and the base plate; Use an injection molding device to perform injection molding at the designated positions of the pin inserts to obtain an injection molded body integrally connected to the pin inserts, and weld the injection molded pin inserts to the designated positions of the pin inserts; Set a sealing ring between the injection molded body and the top of the cavity; Use a plastic encapsulation mold to melt the epoxy resin and pour it into the interior of the plastic encapsulation mold to encapsulate the base plate, chip, and injection molded body. After the plastic encapsulation is completed, remove the plastic encapsulation mold.

[0019] To solve the above problems, the fourth aspect of the present invention provides a power converter, which uses a mold for injection molding. Compared with manual dispensing, the operation process is more stable and controllable, and mass production can be carried out. At the same time, epoxy resin is used for plastic encapsulation. Compared with using soft silicone rubber for protection, epoxy resin can better protect the internal components, so it can work in more complex and variable environments.

[0020] To achieve the above object, the present invention adopts the following technical solutions: A power converter, comprising a power circuit board as described in the first aspect; A power input terminal connected to the power circuit board; and A power output terminal connected to the power circuit board; wherein the power input terminal receives an input voltage, which is converted into an output voltage by the power circuit board and output via the power output terminal.

[0021] Because the circuit board provided in the first aspect of the present application is adopted, the effects are roughly the same and will not be elaborated here.

[0022] The beneficial effects of the present invention are: 1. The present invention adopts the method of injection molding die plus epoxy resin filling. There are no avoiding holes on the product surface, and it is integrally encapsulated, which can better protect the product from water vapor intrusion. At the same time, it saves space, and more pins can be arranged on the same piece of product, making the module more integrated. Meanwhile, after pre-encapsulation on the pins, it is formed in one step during the second encapsulation. Moreover, the epoxy resin on the pins is small, and the contact area with the second encapsulation is small, making it not easy to delaminate and saving costs. It realizes the mass production of power modules and can work in more complex and changeable environments. It can complete the encapsulation of this type of module product quickly and efficiently and can achieve mass production. Compared with the traditional potting protection, the protection effect of this invention is more reliable and the efficiency is also higher. Since the whole process uses machine equipment for operation, the yield of the finished product is also higher.

[0023] 2. After the epoxy resin is heated and melted, the present invention uses a mold to pour it into the product to wrap the internal components and other structures, and it hardens after cooling. Epoxy resin belongs to thermosetting material and will not be melted or softened again after hardening. The epoxy resin has a better bonding property with the substrate and other internal components. Once the two are combined, it is very difficult to separate them; it solves the problems that the traditional soft silicone has a soft texture and cannot withstand external force impact, and the bonding property between the soft silicone and the components is average, and it can be easily separated with ordinary tweezers.

[0024] Advantages of additional aspects of the present invention will be partially given in the following description, partially will become obvious from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0026] Figure 1 It is a schematic diagram of the overall structure of the power circuit board provided by the embodiment of the present invention; Figure 2 It is a detailed structural diagram of the encapsulation process of the power circuit board provided by the embodiment of the present invention; Figure 3 It is a schematic diagram of the chip mounting result provided by the embodiment of the present invention; Figure 4 It is a schematic diagram of the bonding result provided by the embodiment of the present invention; Figure 5 It is a schematic diagram of the pin insertion injection molding of the present invention; Figure 6 It is a schematic diagram of the pin insertion welding of the present invention; Figure 7 It is a schematic diagram of the encapsulation result provided by the embodiment of the present invention; Figure 8 It is a schematic structural diagram of a power converter provided by an embodiment of the present invention; Explanation of reference numerals: 1, bottom plate; 2, chip; 3, pin; 4, injection molded body; 5, plastic sealing mold, 501, upper mold, 502, lower mold; 6, upper mold opening; 7, sealing ring; 8, welding wire; 9, epoxy resin. Specific embodiments

[0027] The present invention will be further described below in conjunction with the drawings and embodiments.

[0028] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0029] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments of the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0030] In the present invention, terms such as "upper", "lower", "top", "bottom", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only relational terms determined for the convenience of describing the structural relationship of each component or element of the present invention and do not specifically refer to any component or element of the present invention and should not be construed as a limitation of the present invention.

[0031] In the present invention, terms such as "connected" and "coupled" should be understood in a broad sense, which may mean a fixed connection, an integral connection or a detachable connection; it may be directly connected or indirectly connected through an intermediate medium. For those skilled in relevant scientific research or technology in the field, the specific meanings of the above terms in the present invention can be determined according to specific circumstances and should not be construed as a limitation of the present invention.

[0032] In order to solve the problems mentioned in the background art of the present invention, that is, when traditional power modules are integrated, the soft silicone protection effect is poor, the manual dispensing efficiency is low, and the internal components are easily damaged, resulting in a low yield rate, inability to achieve mass production, and inability to work in complex and changeable environments such as humidity. The prior art has the following technical problems: there are still avoidance holes on the product surface, and water vapor is more likely to invade the product interior, affecting the product reliability and lifespan. The existing power modules need to first injection mold a cover plate, add a sealing ring to the cover plate, and fill the sealing ring with glue. The process is complex, and there may be delamination between the new injection molded material and the cover plate after secondary injection molding.

[0033] The present invention adopts the method of using an injection mold and filling with epoxy resin. There are no avoidance holes on the product surface, and it is integrally encapsulated, which can better protect the product from water vapor intrusion, save space at the same time, and more pins can be arranged on the same product, making the module more integrated. At the same time, after pre-encapsulation on the pins, it is formed in one step during the second encapsulation. Moreover, the epoxy resin on the pins is small, and the contact area with the second encapsulation is small, making it not easy to delaminate and saving costs. It realizes the mass production of power modules and can work in a more complex and changeable environment. The operation process is more stable and controllable, enabling the mass production of power modules and working in a more complex and changeable environment. At the same time, using epoxy resin for encapsulation can better protect the internal components compared with using soft silicone for protection, so it can work in a more complex and changeable environment.

[0034] Embodiment 1 As Figure 1 and Figure 2 shown, this embodiment provides a power circuit board, which includes a bottom plate 1, at least one chip 2, pin inserts 3, an injection molded body 4, and an encapsulation mold 5; Among them, the bottom plate 1 can adopt materials such as copper frames, PCB boards, ceramic substrates, BT substrates, etc. that can carry chips and connect circuits. In this embodiment, the bottom plate 1 adopts a copper-clad ceramic substrate (DBC); The chip 2 is the core device of the power circuit board; The chip fixing materials include solder paste, solder pads, glue, DAF, etc. for fixing the chip 2.

[0035] The bonding wire 8 includes wire materials such as alloy wires, copper wires, copper strips, aluminum wires, aluminum strips, gold wires, etc. that can connect the chip and the bottom plate to make their signals connected.

[0036] Epoxy resin is used to wrap the chip 2, circuits, etc., and its function is to protect the internal devices.

[0037] The pin inserts 3 are used to connect to the outside to achieve signal transmission.

[0038] The upper surface of the bottom plate 1 is provided with a chip designated position area and a pin insert designated position area; The to-be-bonded chip 2 is placed in the chip designated position area, and the chips 2 are electrically connected to each other or the chip 2 is electrically connected to the bottom plate 1; the bottom of the injection molded body 4 connected to the pin inserts 3 is fixed to the pin insert designated position area; The plastic encapsulation mold 5 includes an upper mold 501 and a lower mold 502. The lower mold 502 is disposed at the bottom of the bottom plate 1. The upper mold 501 is provided with a cavity and an upper mold opening 6 communicating with the cavity. The position of the upper mold opening 6 corresponds to the pin insert 3 one by one. The cavity accommodates the bottom plate 1, the chip 2, and the injection molded body 4, and the upper mold opening 6 accommodates the pin insert 3. After the plastic encapsulation mold 5 is closed, epoxy resin 9 is poured into the cavity. After the plastic encapsulation is completed, the plastic encapsulation mold is taken out.

[0039] As a specific implementation manner, a gap is provided between the top of the upper mold opening 6 and the pin insert 3.

[0040] A sealing ring 7 is provided between the injection molded body 4 and the top of the cavity to prevent the mold from overflowing with glue. The sealing ring can also play a buffering role to prevent the mold from damaging the product.

[0041] The combined height of the pin inserts 3 and the injection molded body 4 connected together is the same.

[0042] Among them, the chips 2 are welded to each other or the chips 2 are welded to the bottom plate 1 through welding wires 8 to form a circuit for transmitting electrical signals.

[0043] In this embodiment, the chips 2 and the bottom plate 1 are combined by vacuum reflow soldering.

[0044] It can be understood that in this embodiment, the pin inserts 3 are made of copper pins, and in other embodiments, they can also be selected according to actual situations.

[0045] Through the above solution, mass production of the power module is achieved, and it can work in a more complex and changeable environment. The encapsulation of this type of module product can be completed quickly and efficiently, and mass production can be realized. Compared with traditional potting protection, the protection effect of this invention is more reliable and the efficiency is also higher. Since the whole process uses machine equipment for operation, the yield of the finished product is also higher.

[0046] Embodiment 2 This embodiment provides a manufacturing method for a power circuit board, including the following steps: Step 1: Dicing, using a dicing machine to dice the wafer into single bare chips 2; Step 2: Chip mounting: Use solder paste for chip mounting. First, print a predetermined shape at the position on the bottom plate 1 where the chip needs to be mounted, and then use a chip mounter to fix the single bare chip on the surface of the printed solder paste. Place the semi-finished product in a vacuum furnace for reflow soldering to firmly fix the chip on the bottom plate 1, and then perform cleaning, detection, etc.; as Figure 3 shown; Step 3: Bonding: Use bonding equipment to weld wires between the chips or between the chips and the bottom plate 1 to make the circuit conductive and the signals can be transmitted to each other; as Figure 4 shown.

[0047] Step 4: Pin Insertion and Injection Molding: To prevent mold flashing during subsequent overall injection molding, use injection molding equipment and molds to inject a ring of epoxy resin at the designated position of the pins to obtain the injection molded body 4. During injection molding, add a sealing ring above the epoxy resin.

[0048] Step 5: Pin Insertion and Soldering: Use soldering equipment to solder the injection molded pin inserts to the designated positions on the substrate, as Figure 5 and Figure 6 shown.

[0049] Step 6: First, clean the semi-finished product using a plasma cleaner to remove surface dirt, making the bonding between the epoxy resin and the semi-finished product better. Then, use injection molding equipment and molds to melt the epoxy resin 9 and pour it into the mold cavity. After it cures, take it out and then put it into an oven for a post-curing process to eliminate internal stress and make it more stable and reliable. As Figure 7 shown.

[0050] In this step, since the pins are soldered first and then encapsulated, to avoid the mold pressing and damaging the pins during mold closing, it is necessary to open holes on the upper mold to avoid these pins. Therefore, there will be some gaps between the mold and the pins. These gaps will cause flashing during pouring. So, inject a ring of epoxy resin at the designated position of the pin inserts, and then add a sealing ring above the epoxy resin to prevent mold flashing. The sealing ring can also play a buffering role to prevent the mold from pressing and damaging the product.

[0051] Through the above solution, the present invention can quickly and efficiently complete the encapsulation of this type of module product and can achieve mass production. Compared with traditional potting protection, the protection effect of this invention is more reliable and the efficiency is higher. Since the whole process uses machine equipment for operation, the yield of the finished product is also higher.

[0052] Example 3 This embodiment provides a manufacturing method for a power circuit board, including the following steps: Step 1: Dicing, use a dicing machine to dice the wafer into single bare chips 2; Step 2: Chip Mounting: Use solder pads for mounting. First, place the solder pads at the designated positions on the upper surface of the substrate, then attach the chips to the solder pads, and finally place the semi-finished product in a vacuum furnace for reflow soldering to firmly fix the chips. Finally, perform cleaning and inspection processes; as Figure 3 shown.

[0053] Step 3: Bonding: Use bonding equipment to solder wires between the chips or between the chips and the base plate 1 to make the circuits conductive and the signals can be transmitted to each other; as Figure 4 shown.

[0054] Step 4: Pin Insertion and Injection Molding: To prevent mold flashing during subsequent overall injection molding, use injection molding equipment and molds to inject a ring of epoxy resin at the designated positions of the pins to obtain the injection molded body 4. During injection molding, add a sealing ring above the epoxy resin.

[0055] Step 5: Pin Insertion and Soldering: Use soldering equipment to solder the injection molded pins to the designated positions on the substrate. As Figure 5 and Figure 6 shown.

[0056] Step 6: First, use a plasma cleaner to clean the semi-finished product to remove surface dirt, making the bonding between the epoxy resin and the semi-finished product better. Then, use injection molding equipment and molds to melt the epoxy resin and pour it into the mold cavity. After it cures, take it out and then put it into an oven for a post-curing process to eliminate internal stress and make it more stable and reliable. As Figure 7 shown.

[0057] In this step, since the pins are soldered first and then encapsulated, in order to avoid the mold pressing and damaging the pins during mold closing, it is necessary to open holes on the upper mold to avoid these pins. Therefore, there will be some gaps between the mold and the pins. These gaps will cause flashing during pouring. So, inject a ring of epoxy resin at the designated positions of the pin insertions, and then add a sealing ring above the epoxy resin to prevent mold flashing. The sealing ring can also play a buffering role to prevent the mold from pressing and damaging the product.

[0058] Through the above solution, the present invention can quickly and efficiently complete the encapsulation of this type of module product and can achieve mass production. Compared with traditional potting protection, the protection effect of this invention is more reliable and the efficiency is also higher. Since the whole process uses machine equipment for operation, the yield of the finished product is also higher.

[0059] Embodiment 4 Please refer to Figure 8 , Figure 8 which is a schematic diagram of a power converter shown according to an embodiment of the present invention.

[0060] As Figure 8 shown, the power converter includes a power circuit board, a power input terminal VI, and a power output terminal VO as described in Embodiment 1; and the power input terminal VI and the power output terminal VO are respectively connected to the power module.

[0061] Furthermore, the power converter receives an input voltage through a power input terminal VI, converts it into an output voltage via a power module, and outputs the aforementioned output voltage through a power output terminal VO, achieving the effect of converting electrical energy. Classified according to the method of converting electrical energy, the power converter can be any one of a non-isolated AC / DC power converter, a non-isolated DC / DC power converter, an isolated DC / DC converter, and an isolated AC / DC power converter. Accordingly, the power converter in the embodiments of the present invention can convert the set power module according to its method, achieving the effect of converting its electrical energy according to its method.

[0062] The power converter further includes a heat sink, which can be arranged adjacent to a heat dissipation substrate (not shown in Figure 8 ) in the power module to provide better heat dissipation performance for the power converter.

[0063] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A power circuit board, characterized in that, It includes a base plate (1), at least one chip (2), pin inserts (3), an injection molded body (4), and a plastic encapsulation mold (5); The upper surface of the base plate (1) is provided with a chip designated position area and a pin insert designated position area; Place the chips (2) to be bonded in the chip designated position area, and make electrical connections between the chips or between the chips and the base plate (1); and fix the bottom of the injection molded body (4) integrated with the pin inserts (3) to the pin insert designated position area; The plastic encapsulation mold (5) includes an upper mold (501) and a lower mold (502). The lower mold (502) is arranged at the bottom of the base plate (1). The upper mold (501) is provided with a cavity and an upper mold opening (6) communicating with the cavity. The position of the upper mold opening (6) corresponds to the pin inserts (3) one by one. The cavity accommodates the base plate (1), the chips (2), and the injection molded body (4), and the upper mold opening (6) accommodates the pin inserts (3).

2. The power circuit board according to claim 1, characterized in that, A gap is provided between the top of the upper mold opening (6) and the pin inserts (3).

3. A power circuit board as claimed in claim 1, wherein The injection molded bodies (4) integrated with the pin inserts (3) have the same height after combination.

4. A power circuit board according to claim 1, characterized in that, A sealing ring (7) is provided between the injection molded body (4) and the top of the cavity.

5. A power circuit board according to claim 1, characterized in that, Epoxy resin is poured into the plastic encapsulation mold (5).

6. A power circuit board according to claim 1, characterized in that, The chips (2) are welded to each other or to the base plate (1) through bonding wires to form a path for transmitting electrical signals.

7. A power circuit board according to claim 1, characterized in that, The chips (2) and the base plate (1) are combined by vacuum reflow soldering.

8. A manufacturing process of the power circuit board according to any one of claims 1-7, characterized in that, It includes the following steps: Divide the wafer into multiple bare chips (2); Print a predetermined shape on the chip designated position area of the base plate (1), and attach the bare chips to the surface of the printed solder paste; Make electrical connections between the chips (2) or between the chips (2) and the base plate (1); Use an injection molding device to inject at the pin insert designated position to obtain an injection molded body (4) integrated with the pin inserts (3), and weld the injection molded pin inserts (3) to the pin insert designated position; Set a sealing ring (7) between the injection molded body (4) and the top of the cavity; Use the plastic encapsulation mold (5) to melt the epoxy resin (5) and pour it into the interior of the plastic encapsulation mold (5) to cover the base plate (1), the chips (2), and the injection molded body (4). After plastic encapsulation is completed, take out the plastic encapsulation mold (5).

9. A manufacturing process of the power circuit board according to any one of claims 1-7, characterized in that, It includes the following steps: Divide the wafer into multiple bare chips (2); Place the solder pads at the designated positions on the surface of the base plate (1), and attach the bare chips (2) to the solder pads; Make electrical connections between the chips (2) or between the chips (2) and the base plate (1); Use an injection molding device to inject at the pin insert designated position to obtain an injection molded body (4) integrated with the pin inserts (3), and weld the injection molded pin inserts (3) to the pin insert designated position; Set a sealing ring (7) between the injection molded body (4) and the top of the cavity; Use the plastic encapsulation mold (5) to melt the epoxy resin (5) and pour it into the interior of the plastic encapsulation mold (5) to cover the base plate (1), the chips (2), and the injection molded body (4). After plastic encapsulation is completed, take out the plastic encapsulation mold (5).

10. A power converter, characterized in that, It includes a power circuit board as described in any one of claims 1-7; A power input terminal, connected to the power circuit board; and A power output terminal, connected to the power circuit board; wherein the power input terminal receives an input voltage, which is converted into an output voltage by the power circuit board and output via the power output terminal.

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