Power circuit board, power converter, and manufacturing process for a power circuit board

Abstract

This invention belongs to the field of electronic chip packaging technology, providing a power circuit board, a power converter, and a manufacturing process for the power circuit board. The technical solution includes: a base plate, at least one chip, pins, an injection molded body, and a molding die; the upper surface of the base plate has designated chip location areas and designated pin location areas; the chip to be bonded is placed in the designated chip location area, and the chips are electrically connected to each other or to the base plate; the injection molded body, integrated with the pins, is fixed to the designated pin location area; the molding die includes an upper die and a lower die, the lower die is located at the bottom of the base plate, the upper die has a cavity and an upper die opening communicating with the cavity, the positions of the upper die openings correspond one-to-one with the pins, the cavity accommodates the base plate, the chip, and the injection molded body, and the upper die opening accommodates the pins. Compared to traditional potting protection, this method is more efficient and has a higher yield rate.

Description

Technical Field

[0001] This invention belongs to the field of electronic chip packaging technology, and particularly relates to power circuit boards, power converters, and the manufacturing process of power circuit boards. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Semiconductor components are one of the key factors determining the efficiency of power converters. Integrated power modules (IPMs) integrate multiple semiconductor components (such as power components, control components, and drive components) into a single component package, thereby improving the space utilization within the package. Power modules offer advantages such as ease of use and long mean time between failures (MTBF), and are used in many applications.

[0004] However, traditional power modules suffer from poor protection from soft silicone during integration, low efficiency of manual dispensing, and easy damage to internal components, resulting in low yield and making mass production and operation in humid or other complex and variable environments impossible.

[0005] To address the aforementioned issues, existing technologies propose a method where the first part is positioned within the lower mold groove to hold the encapsulation fixture, and the second part abuts against the substrate surface. After molding, the first and second parts are removed, and the second part creates a terminal mounting space within the encapsulation shell. This avoids direct compression of the terminals and the casing by the sealing material during the molding process, thus improving the yield of power modules. However, this method has the drawback that there are still clearance holes on the product surface, allowing moisture to easily penetrate the product, affecting its reliability and lifespan.

[0006] Another example is to use integral injection molding between the pins and the cover plate to ensure the spacing between the cover plate and the circuit board, thereby ensuring the injection molding quality of the molded part. However, the drawback is that the cover plate needs to be injection molded first, a sealing ring needs to be added to the board, and glue needs to be filled into the sealing ring. The process is complicated, and there may be delamination between the new injection molding material and the cover plate after the second injection molding. Summary of the Invention

[0007] In order to solve at least one of the technical problems existing in the background art, the first aspect of the present invention provides a power circuit board that uses an injection mold and epoxy resin filling method to realize the mass production of power modules and can work in more complex and variable environments.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A power circuit board includes a base plate, at least one chip, pin headers, an injection molded body, and a molding die.

[0010] The upper surface of the base plate is provided with a chip designated position area and a pin designated position area;

[0011] The chip to be bonded is placed in the designated area of ​​the chip, and electrical connections are made between chips or between chips and the copper ceramic substrate; the bottom of the injection molded body, which is integrated with the pins, is fixed to the designated area of ​​the pins.

[0012] The molding die includes an upper die and a lower die. The lower die is located at the bottom of the base plate. The upper die has a cavity and an upper die opening that connects the cavity. The position of the upper die opening corresponds one-to-one with the pins. The cavity contains the base plate, the chip and the injection molded body. The upper die opening contains the pins.

[0013] In one embodiment, a gap is provided between the top of the upper mold opening and the pin.

[0014] In one implementation, the pins are connected to form a single injection-molded body with a uniform height.

[0015] As one implementation, a sealing ring is provided between the injection molded body and the top of the cavity.

[0016] As one implementation method, epoxy resin is poured into the molding die.

[0017] In one implementation, chips are soldered together with each other or with a copper-ceramic substrate to form a path for conducting electrical signals.

[0018] In one implementation, the chip and the base plate are bonded together using vacuum reflow soldering.

[0019] To address the aforementioned problems, a second aspect of the present invention provides a manufacturing process for a power circuit board that offers more reliable protection and higher efficiency compared to traditional potting protection. Furthermore, the yield of the finished product is higher due to the use of machinery throughout the process.

[0020] To achieve the above objectives, the present invention adopts the following technical solution:

[0021] A manufacturing process for a power circuit board includes the following steps:

[0022] Divide the wafer into multiple bare chips;

[0023] A predetermined shape is printed on a designated area of ​​the base chip, and the bare chip is attached to the printed solder paste surface.

[0024] Electrically connect chips to chips or chips to a baseboard;

[0025] An injection molded body is formed by injection molding at a specified position of the pin and the pin using an injection molding machine. The injection-molded pin and the pin are then soldered to the specified position of the pin and the pin.

[0026] A sealing ring is installed between the injection molded body and the top of the cavity;

[0027] The epoxy resin is melted and poured into the molding mold to cover the base plate, chip and injection body. After molding is completed, the molding mold is removed.

[0028] To address the aforementioned issues, a third aspect of this invention provides a manufacturing process for a power circuit board. Compared to traditional potting protection, this process utilizes injection molding and epoxy resin filling, enabling mass production of power modules and allowing them to operate in more complex and variable environments. This invention offers more reliable protection and higher efficiency, and because the entire process is carried out using machinery, the yield of finished products is also higher.

[0029] To achieve the above objectives, the present invention adopts the following technical solution:

[0030] A manufacturing process for a power circuit board includes the following steps:

[0031] Divide the wafer into multiple bare chips;

[0032] Place the solder pad at the designated position on the surface of the base plate, and then attach the bare chip to the solder pad;

[0033] Electrically connect chips to chips or chips to a baseboard;

[0034] An injection molded body is formed by injection molding at a specified position of the pin and the pin using an injection molding machine. The injection-molded pin and the pin are then soldered to the specified position of the pin and the pin.

[0035] A sealing ring is installed between the injection molded body and the top of the cavity;

[0036] The epoxy resin is melted and poured into the molding mold to cover the base plate, chip and injection body. After molding is completed, the molding mold is removed.

[0037] To address the aforementioned issues, a fourth aspect of the present invention provides a power converter that uses a mold for injection molding. Compared to manual dispensing, the process is more stable and controllable, enabling mass production. Furthermore, epoxy resin is used for encapsulation, which provides better protection for internal components compared to soft silicone protection, allowing the converter to operate in more complex and variable environments.

[0038] To achieve the above objectives, the present invention adopts the following technical solution:

[0039] A power converter includes a power circuit board as described in the first aspect;

[0040] A power input terminal is connected to the power circuit board; and

[0041] A power output terminal is 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 through the power output terminal.

[0042] Since the circuit board provided in the first aspect of this application is used, the effect is roughly the same, and will not be described in detail here.

[0043] The beneficial effects of this invention are:

[0044] 1. This invention uses injection molding and epoxy resin filling, resulting in a seamless, integrally sealed product surface without any gaps. This provides better protection against moisture intrusion, saves space, and allows for the arrangement of more pins on a single product, leading to greater module integration. Furthermore, the pre-sealing of the pins and subsequent re-sealing are done in a single step. The smaller amount of epoxy resin on the pins minimizes the contact area with the second sealing step, reducing the risk of delamination and saving costs. This enables mass production of power modules and allows them to operate in more complex and variable environments. It allows for rapid and efficient encapsulation of this type of module and enables mass production. Compared to traditional potting protection, this invention offers more reliable protection and higher efficiency. Because the entire process is performed using machinery, the yield rate of the finished product is also higher.

[0045] 2. In this invention, epoxy resin is heated and melted, then poured into the product using a mold to encapsulate the internal components and other structures. After cooling, it hardens. Epoxy resin is a thermosetting material, and once hardened, it will not melt or soften again. Epoxy resin has better adhesion to the substrate and other internal components, and once bonded, it is difficult to separate them. This solves the problem that traditional soft silicone is soft and cannot withstand external impacts, and that the adhesion between soft silicone and components is generally poor, making it easy to separate with ordinary tweezers.

[0046] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0047] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0048] Figure 1 This is a schematic diagram of the overall structure of the power circuit board provided in an embodiment of the present invention;

[0049] Figure 2 This is a detailed structural diagram of the molding process of the power circuit board provided in the embodiment of the present invention;

[0050] Figure 3 This is a schematic diagram of the mounting result provided in an embodiment of the present invention;

[0051] Figure 4 This is a schematic diagram of the bonding results provided in an embodiment of the present invention;

[0052] Figure 5 This is a schematic diagram of pin injection molding provided in an embodiment of the present invention;

[0053] Figure 6 This is a schematic diagram of pin soldering provided in an embodiment of the present invention;

[0054] Figure 7 This is a schematic diagram of the molding result provided in an embodiment of the present invention;

[0055] Figure 8 This is a schematic diagram of the power converter structure provided in an embodiment of the present invention;

[0056] Explanation of reference numerals in the attached diagram: 1. Base plate, 2. Chip, 3. Pin, 4. Injection body, 5. Molding mold, 501. Upper mold, 502. Lower mold, 6. Upper mold opening, 7. Sealing ring, 8. Welding line, 9. Epoxy resin. Detailed Implementation

[0057] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0058] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0059] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0060] In this invention, terms such as "upper," "lower," "top," and "bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are merely relational terms determined for the convenience of describing the structural relationship of the various components or elements of this invention, and do not specifically refer to any component or element in this invention, nor should they be construed as limiting this invention.

[0061] In this invention, terms such as "connected" and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can determine the specific meaning of these terms in this invention based on the specific circumstances, and they should not be construed as limitations on the invention.

[0062] To address the issues mentioned in the background of this invention regarding the poor protection provided by soft silicone during integration of traditional power modules, the inefficiency of manual dispensing, and the vulnerability of internal components to damage, resulting in low yield rates and hindering mass production and operation in humid and variable environments, existing technologies suffer from the following problems: unobstructed holes remain on the product surface, allowing moisture to easily penetrate and affecting reliability and lifespan. Current power modules require first injection molding a cover plate, then adding a sealing ring, and finally filling the sealing ring with adhesive; this process is complex, and delamination may occur between the new injection molded material and the cover plate after the second injection molding.

[0063] This invention employs an injection molding process with epoxy resin filling. The product surface has no gaps or voids, resulting in a fully encapsulated design. This provides better protection against moisture intrusion, saves space, and allows for more pins to be arranged on a single piece, leading to greater module integration. Furthermore, the pre-encapsulation of the pins and subsequent encapsulation in a single step, combined with the smaller epoxy resin area on the pins and the smaller contact area with the second encapsulation step, reduces the risk of delamination and saves costs. This enables mass production of power modules and allows them to operate in more complex and variable environments. The workflow is more stable and controllable. Compared to soft silicone, epoxy resin provides better protection for internal components, allowing for operation in more complex and variable environments.

[0064] Example 1

[0065] like Figure 1 and Figure 2 As shown, this embodiment provides a power circuit board, including a base plate 1, at least one chip 2, pins 3, an injection molded body 4, and a molding die 5;

[0066] The base plate 1 can be made of materials such as copper frame, PCB board, ceramic substrate, or BT substrate that can support chips and connect circuits. In this embodiment, the base plate 1 is a copper-clad ceramic substrate (DBC).

[0067] Chip 2 is the core component of the power circuit board;

[0068] Chip fixing materials include solder paste, solder pads, adhesive, DAF, etc., which are used to fix the chip.

[0069] The welding wire 8 includes alloy wires, copper wires, copper strips, aluminum wires, aluminum strips, gold wires, etc., which can connect the chip and the baseboard to enable signal communication.

[0070] Epoxy resin is used to encapsulate chip 2, circuitry, etc., to protect the internal components.

[0071] Pin 3 is used to connect to the outside world to transmit signals.

[0072] The upper surface of the base plate 1 is provided with a chip designated position area and a pin designated position area;

[0073] Chip 2 to be bonded is placed in the designated chip location area, and chips 2 are electrically connected to each other or to the base plate 1; the bottom of the injection molded body 4, which is connected to the pins 3, is fixed to the designated pin location area.

[0074] The molding die 5 includes an upper die 501 and a lower die 502. The lower die 502 is located at the bottom of the base plate 1. The upper die 501 has a cavity and an upper die opening 6 that communicates with the cavity. The positions of the upper die opening 6 correspond one-to-one with the pins 3. The cavity accommodates the base plate 1, the chip 2, and the injection molded body 4. The upper die opening 6 accommodates the pins 3. After the molding die 5 is closed, epoxy resin 9 is poured into the cavity. After molding is completed, the molding die is removed.

[0075] In a specific implementation, a gap is provided between the top of the upper mold opening 6 and the pin 3.

[0076] A sealing ring 7 is provided between the injection body 4 and the top of the cavity to prevent mold overflow. The sealing ring can also act as a buffer to prevent the mold from crushing the product.

[0077] The pins 3 are connected to form an integral injection molded body 4, and the height of the assembly is consistent.

[0078] Among them, chips 2 are welded to each other or to the base plate 1 through welding wires 8 to form a path for conducting electrical signals.

[0079] In this embodiment, the chip 2 and the base plate 1 are bonded by vacuum reflow soldering.

[0080] It is understood that in this embodiment, the pin 3 is made of copper, but in other embodiments, it can be selected according to the actual situation.

[0081] The above solution enables mass production of power modules, which can operate in more complex and variable environments. It can quickly and efficiently complete the packaging of this type of product and achieve mass production. Compared with traditional potting protection, this invention provides more reliable protection and is more efficient. Since the entire process is carried out using machinery and equipment, the yield of finished products is also higher.

[0082] Example 2

[0083] This embodiment provides a method for manufacturing a power circuit board, including the following steps:

[0084] Step 1: Dicing, using a dicing machine to dic the wafer into individual bare chips 2;

[0085] Step 2: Component Mounting: Using solder paste for mounting, first, the predetermined shape is printed on the location where the component needs to be mounted on the base plate 1. Then, a pick-and-place machine is used to fix the individual bare chips onto the printed solder paste surface. The semi-finished product is placed in a vacuum oven for reflow soldering to firmly fix the chips onto the base plate 1. Afterwards, cleaning and testing are performed. Figure 3 As shown;

[0086] Step 3: Bonding: Using bonding equipment, wires are soldered between chips or between chips and substrate 1 to make the circuit conductive and allow signals to be transmitted between them; for example... Figure 4 As shown.

[0087] Step 4: Pin injection molding: To prevent overflow of glue from the mold during subsequent overall injection molding, use injection molding equipment and mold to inject a ring of epoxy resin at the designated position of the pin to obtain injection molded body 4, and add a sealing ring on top of the epoxy resin during injection molding.

[0088] Step 5: Pin Soldering: Use soldering equipment to solder the injection-molded pins to the designated positions on the substrate, such as... Figure 5 and Figure 6 As shown.

[0089] Step 6: First, clean the semi-finished product using a plasma cleaner to remove surface dirt, improving the bonding between the epoxy resin and the semi-finished product. Then, use injection molding equipment and molds to melt the epoxy resin 9 and pour it into the mold. After it cures, remove it and place it in an oven for a post-curing process to eliminate internal stress and make it more stable and reliable. Figure 7 As shown.

[0090] Because this step involves welding the pins first and then encapsulating them, in order to prevent the mold from damaging the pins during mold closing, it is necessary to make an opening in the upper mold to avoid these pins. Therefore, there will be some gaps between the mold and the pins. These gaps will cause glue overflow during pouring. So, a ring of epoxy resin needs to be injected at the designated position of the pins, and then a sealing ring is added on top of the epoxy resin to prevent glue overflow from the mold. The sealing ring can also play a buffering role to prevent the mold from damaging the product.

[0091] Through the above solution, the present invention can quickly and efficiently complete the packaging of the module-type product and achieve mass production. Compared with traditional potting protection, the protection effect of this invention is more reliable and more efficient. Since the entire process is carried out by machine equipment, the yield of finished products is also higher.

[0092] Example 3

[0093] This embodiment provides a method for manufacturing a power circuit board, including the following steps:

[0094] Step 1: Dicing, using a dicing machine to dic the wafer into individual bare chips 2;

[0095] Step 2: Die Mounting: Using solder pads for mounting, first place the solder pads at the designated positions on the upper surface of the substrate, then attach the chips onto the solder pads, and finally place the semi-finished product in a vacuum oven for reflow soldering to firmly fix the chips. Finally, perform cleaning and inspection processes. Figure 3 As shown.

[0096] Step 3: Bonding: Using bonding equipment, wires are soldered between chips or between chips and substrate 1 to make the circuit conductive and allow signals to be transmitted between them; for example... Figure 4 As shown.

[0097] Step 4: Pin injection molding: To prevent overflow of glue from the mold during subsequent overall injection molding, use injection molding equipment and mold to inject a ring of epoxy resin at the designated position of the pin to obtain injection molded body 4, and add a sealing ring on top of the epoxy resin during injection molding.

[0098] Step 5: Pin Soldering: Use soldering equipment to solder the injection-molded pins to the designated locations on the substrate. For example... Figure 5 and Figure 6 As shown.

[0099] Step 6: First, clean the semi-finished product using a plasma cleaner to remove surface dirt, improving the bonding between the epoxy resin and the semi-finished product. Then, use injection molding equipment and molds to melt the epoxy resin and pour it into the mold. After it cures, remove it and place it in an oven for a post-curing process to eliminate internal stress and make it more stable and reliable. Figure 7 As shown.

[0100] Because this step involves welding the pins first and then encapsulating them, in order to prevent the mold from damaging the pins during mold closing, it is necessary to make an opening in the upper mold to avoid these pins. Therefore, there will be some gaps between the mold and the pins. These gaps will cause glue overflow during pouring. So, a ring of epoxy resin needs to be injected at the designated position of the pins, and then a sealing ring is added on top of the epoxy resin to prevent glue overflow from the mold. The sealing ring can also play a buffering role to prevent the mold from damaging the product.

[0101] Through the above solution, the present invention can quickly and efficiently complete the packaging of the module-type product and achieve mass production. Compared with traditional potting protection, the protection effect of this invention is more reliable and more efficient. Since the entire process is carried out by machine equipment, the yield of finished products is also higher.

[0102] Example 4

[0103] Please refer to Figure 8 , Figure 8 This is a schematic diagram of a power converter according to an embodiment of the present invention.

[0104] like Figure 8 As 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; the power input terminal VI and the power output terminal VO are respectively connected to the power module.

[0105] Furthermore, the power converter receives the input voltage through the power input terminal VI, converts it into an output voltage via the power module, and then outputs the aforementioned output voltage through the power output terminal VO, thus achieving the function of converting electrical energy. Based on the method of converting electrical energy, the power converter can be any of the following: a non-isolated AC / DC power converter, a non-isolated DC / DC power converter, an isolated DC / DC converter, or an isolated AC / DC power converter. Accordingly, the power converter in this embodiment of the invention can change the power module configuration according to its method to achieve the function of converting electrical energy in that manner.

[0106] The power converter also includes a heat sink, which may be disposed adjacent to a heat dissipation substrate (not shown) in the power module. Figure 8 (This has provided better heat dissipation performance for the power converter.)

[0107] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A manufacturing process for a power circuit board, characterized in that, Includes the following steps: Divide the wafer into multiple bare chips (2); A predetermined shape is printed on the designated location area of ​​the chip on the base plate (1), and the bare chip is attached to the printed solder paste surface to form a semi-finished product; Connect chip (2) to chip (2) or chip (2) to base plate (1) electrically; The upper surface of the base plate (1) is provided with a chip designated position area and a pin designated position area; An injection molding machine is used to inject a ring of epoxy resin at a specified position of the pin to obtain an injection molded body (4) that is integrated with the pin (3). During injection molding, a sealing ring is added above the epoxy resin. Solder the injection-molded pin (3) to the designated position of the pin; The molding die (5) includes an upper die (501) and a lower die (502). The lower die (502) is located at the bottom of the base plate (1). The upper die (501) has a cavity and an upper die opening (6) that connects the cavity. The position of the upper die opening (6) corresponds one-to-one with the pins (3). The cavity contains the base plate (1), the chip (2) and the injection body (4). The upper die opening (6) contains the pins (3). A gap is provided between the top of the upper die opening (6) and the pins (3). A sealing ring (7) is provided between the injection molded body (4) and the top of the cavity; First, the semi-finished product is cleaned using a plasma cleaner to remove surface dirt, so that the epoxy resin and the semi-finished product have better bonding. Then, the epoxy resin is melted and poured into the encapsulation mold (5) using injection molding equipment and mold to cover the base plate (1), chip (2) and injection body (4). After encapsulation is completed, the encapsulation mold (5) is taken out and then placed in an oven for post-curing.

2. A manufacturing process for a power circuit board, characterized in that, Includes the following steps: Divide the wafer into multiple bare chips (2); Place the solder pad at the designated position on the surface of the base plate (1), and attach the bare chip (2) to the solder pad to form a semi-finished product; Connect chip (2) to chip (2) or chip (2) to base plate (1) electrically; The upper surface of the base plate (1) is provided with a chip designated position area and a pin designated position area; An injection molding machine is used to inject a ring of epoxy resin at a specified position of the pin to obtain an injection molded body (4) that is integrated with the pin (3). During injection molding, a sealing ring is added above the epoxy resin. Solder the injection-molded pin (3) to the designated position of the pin; The molding die (5) includes an upper die (501) and a lower die (502). The lower die (502) is located at the bottom of the base plate (1). The upper die (501) has a cavity and an upper die opening (6) that connects the cavity. The position of the upper die opening (6) corresponds one-to-one with the pins (3). The cavity contains the base plate (1), the chip (2) and the injection body (4). The upper die opening (6) contains the pins (3). A gap is provided between the top of the upper die opening (6) and the pins (3). A sealing ring (7) is provided between the injection molded body (4) and the top of the cavity; First, the semi-finished product is cleaned using a plasma cleaner to remove surface dirt, so that the epoxy resin and the semi-finished product have better bonding. Then, the epoxy resin is melted and poured into the encapsulation mold (5) using injection molding equipment and mold to cover the base plate (1), chip (2) and injection body (4). After encapsulation is completed, the encapsulation mold (5) is taken out and then placed in an oven for post-curing.

3. A power circuit board, manufactured using the power circuit board manufacturing process described in claim 1 or 2, characterized in that, It includes a base plate (1), at least one chip (2), pin headers (3), an injection molded body (4), and a molding die (5); The chip (2) to be bonded is placed in the designated area of ​​the chip, and the chips are electrically connected to each other or to the base plate (1); the bottom of the injection molded body (4) which is connected to the pins (3) is fixed to the designated area of ​​the pins; the injection molded body is obtained by injection molding a ring of epoxy resin on the designated position of the pins using injection molding equipment.

4. A power circuit board as described in claim 3, characterized in that, The pins (3) are connected to form an integral injection molded body (4) with a consistent height.

5. A power circuit board as described in claim 3, characterized in that, Epoxy resin is poured into the molding die (5).

6. A power circuit board as described in claim 3, characterized in that, Chips (2) are welded together with each other or between chips (2) and the base plate (1) to form a circuit for conducting electrical signals.

7. A power circuit board as described in claim 3, characterized in that, The chip (2) and the base plate (1) are bonded together by vacuum reflow soldering.

8. A power converter, characterized in that, Includes a power circuit board as described in any one of claims 3-7; A power input terminal is connected to the power circuit board; and A power output terminal is 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 through the power output terminal.

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