Double-sided heat dissipation power circuit board and preparation method thereof

Abstract

The invention discloses a double-sided heat dissipation power circuit board and a preparation method thereof, and belongs to the field of circuit board packaging design, and the power circuit board comprises a copper-free substrate which is provided with a plurality of through holes; the coating layers are arranged on the upper surface and the lower surface of the copper-free substrate and the inner walls of the through holes, and the coating layers are etched to form full-etching insulating circuits, half-etching steps and non-etching areas; the chip is arranged on the half etching step; the copper conducting layer is arranged on the outer sides of the coating layer and the chip; the metal conducting layer is arranged on the outer side of the copper conducting layer; the radiator is correspondingly arranged on the outer side of the metal conducting layer; the layers of the circuit board are connected through copper paste welding spots; and insulating resin layers are filled among the layers of the circuit board. According to the invention, the yield loss of laser drilling and copper plating processes is reduced, the time cost is saved, the connection mode is more convenient and efficient, and the advantages of high power conversion rate, system integration and double-sided heat dissipation are achieved.

Description

Technical Field

[0001] The present invention belongs to the field of circuit board packaging design, and particularly relates to a power circuit board with double-sided heat dissipation and a preparation method thereof. Background Art

[0002] With the wide application of new energy vehicles, the power modules in inverters are also constantly developing and innovating. Their design schemes and process technologies are still in the iterative innovation process. Better performance and higher integration are important development trends. Among them, the power module in the form of an embedded circuit board has attracted extensive research due to its optimal parasitic parameters, excellent integration and flexibility, and good heat dissipation coefficient.

[0003] In the currently commonly used power circuit board preparation schemes, traditional laser drilling and metal copper plating processes of the circuit board are required. The manufacturing method is relatively complex, and it is necessary to strictly control the process window to avoid damage to the chips, making the manufacturing threshold of the embedded power circuit board high and it is difficult to guarantee the mass production yield. At the same time, the current power circuit board design scheme is still in the form of single-layer chips with single-sided heat dissipation, and the heat dissipation efficiency is low. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a power circuit board with double-sided heat dissipation and a preparation method thereof, so as to overcome the problems that the preparation of the power circuit board in the prior art adopts a single-layer structure, and the use of traditional laser drilling and metal copper plating processes results in low yield and output, and low heat dissipation efficiency.

[0005] To achieve the above purpose, the present invention is implemented by adopting the following technical solutions:

[0006] First aspect

[0007] A preparation method of a power circuit board with double-sided heat dissipation includes:

[0008] Step 1: Set a plurality of through holes on a copper-free substrate;

[0009] Step 2: Coat a coating layer on the upper and lower surfaces of the copper-free substrate and the inner wall of the through holes, etch full-etching insulating lines, semi-etching steps and unetched areas with different depths on the coating layer, and fill the through holes with resin materials;

[0010] Step 3: Connect the chips to the semi-etching steps, and arrange the upper and lower layers of chips in a cross pattern;

[0011] Step 4: Reserve positions for a plurality of circuit connection points on the surfaces of the chips and the coating layer, print copper paste materials respectively, and obtain conical copper solder joints through pre-drying and curing;

[0012] Step 5: Add a first insulating resin layer outside the coating layer and the chip, and the tip of the conical copper solder joint penetrates the first insulating resin layer;

[0013] Step 6: Set a copper conductive layer outside the first insulating resin layer;

[0014] Step 7: Using the methods of Steps 4 to 6 above, print the copper paste material at the reserved positions of multiple circuit connection points outside the copper conductive layer respectively, and sequentially stack a second insulating resin layer and a metal conductive layer outside the copper conductive layer;

[0015] Step 8: Set a metal heat sink outside the metal conductive layer, and the area of the metal heat sink is larger than the sum of the areas of the upper chip and the lower chip.

[0016] The coating layer in the through hole is used to realize the connection between the upper and lower layer circuits of the power circuit board. The output circuit of the upper chip serves as the input circuit of the lower chip. The upper chip, the lower chip, the copper-free substrate, and the coating layer form a half-bridge topology, and the upper chip and the lower chip are the two bridge arm switches of the half-bridge topology.

[0017] An output electrode is provided at the through hole, and the output electrode is the output end of the half-bridge topology.

[0018] The input end and the output end of the power circuit board with double-sided heat dissipation are respectively arranged on both sides of the power circuit board.

[0019] A drive circuit and a signal circuit are provided on the metal conductive layer, so that the circuit board has logical functions.

[0020] The coating layer, the chip and the adjacent copper conductive layer are electrically connected through conical copper solder joints; the copper conductive layer and the adjacent metal conductive layer are electrically connected through conical copper solder joints.

[0021] Second aspect

[0022] A power circuit board with double-sided heat dissipation includes a copper-free substrate on which a plurality of through holes are provided; a coating layer which is arranged on the upper and lower surfaces of the copper-free substrate and the inner wall of the through hole, and the coating layer is etched to form a fully etched insulating circuit, a semi-etched step and an unetched area; a chip which is arranged on the semi-etched step; a copper conductive layer which is arranged outside the coating layer and the chip; a metal conductive layer which is arranged outside the copper conductive layer; a heat sink which is correspondingly arranged outside the metal conductive layer; a plurality of circuit connection point reserved positions are provided on the chip, the coating layer, the copper conductive layer and the metal conductive layer, and copper paste solder joints are printed on each circuit connection point reserved position.

[0023] A first insulating resin layer is provided between the coating layer and the copper conductive layer, and the copper paste solder joints on the coating layer penetrate through the first insulating resin layer to achieve electrical connection between the coating layer and the copper conductive layer; a second insulating resin layer is provided between the copper conductive layer and the metal conductive layer, and the copper paste solder joints on the copper conductive layer penetrate through the second insulating resin layer to achieve electrical connection between the copper conductive layer and the metal conductive layer.

[0024] The through-hole is filled with a resin material.

[0025] The area of the heat sink is larger than the sum of the areas of the upper chip and the lower chip.

[0026] The coating layer in the through-hole is used to connect the upper and lower layer circuits of the power circuit board. The output circuit of the upper chip serves as the input circuit of the lower chip. The upper chip, the lower chip, the copper-free substrate, and the coating layer form a half-bridge topology, and the upper chip and the lower chip are the two bridge arm switches of the half-bridge topology.

[0027] The present invention discloses a power circuit board with double-sided heat dissipation. Power chips are welded inside the circuit board, and electrical connection is achieved through copper paste materials, eliminating the need for laser drilling and then coating conductive materials to achieve chip connection and in-board interconnection. The back of the power chip is combined with the substrate by welding or sintering and the electrodes are led out. After printing copper paste on the front and pre-drying, conical copper solder joints are obtained to achieve connection with the upper conductive material layer. Except for the through-connection of the upper and lower layers of the substrate by mechanical drilling and then coating conductive materials, other connection methods are the same as the connection of the front electrodes of the chips. The insulating layers between the layers of the circuit board play roles of mechanical support, electrical insulation, void filling, and connection bonding. The solution of the present invention reduces the yield loss and time cost of laser drilling and copper plating processes, and the connection method is more convenient and efficient. Finally, the power circuit board of the present invention has advantages such as high power conversion rate, system integration, and double-sided heat dissipation, and can be applied in the electronic fields with high power level, high power density, high heat dissipation efficiency, and low loss requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the first step in the preparation of the power circuit board according to Embodiment 1 of the present invention;

[0029] Figure 2 Schematic diagram of the second step in the preparation of the power circuit board according to Embodiment 1 of the present invention;

[0030] Figure 3 Schematic diagram of the third step in the preparation of the power circuit board according to Embodiment 1 of the present invention;

[0031] Figure 4 Schematic diagram of the fourth step in the preparation of the power circuit board according to Embodiment 1 of the present invention;

[0032] Figure 5 Schematic diagram of step five in the preparation of the power circuit board according to Embodiment 1 of the present invention;

[0033] Figure 6 Schematic diagram of step six in the preparation of the power circuit board according to Embodiment 1 of the present invention;

[0034] Figure 7 Schematic diagram of step seven in the preparation of the power circuit board according to Embodiment 1 of the present invention;

[0035] Figure 8 Schematic diagram of step eight in the preparation of the power circuit board according to Embodiment 1 of the present invention;

[0036] In the figure: 1 - copper-free substrate; 2 - through hole; 3 - coating layer; 4 - resin material; 5 - chip; 6 - conical copper solder joint; 7 - insulating layer; 8 - copper conductive layer; 9 - heat sink; 10 - metal conductive layer. Detailed implementation manners

[0037] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0038] Embodiment 1

[0039] Refer to Figure 1-8 As shown, a method for preparing a power circuit board with double-sided heat dissipation includes the following steps:

[0040] Step 1: Set a plurality of through holes 2 on the copper-free substrate 1;

[0041] The copper-free substrate 1 can be used to directly make the through holes 2 by mechanical drilling, which is simple and efficient, and is convenient to make conductive layers with different height differences and etched circuits on its surface; the positions and numbers of the through holes 2 need to be set according to the actual circuit conduction relationship.

[0042] Step 2: Coat a layer of conductive material on the upper and lower surfaces of the perforated copper-free substrate 1 made in Step 1 and the inner wall of the through holes 2 to form a coating layer 3. The coating layers 3 on the upper and lower sides of the copper-free substrate 1 will be etched into fully etched insulating circuits, semi-etched steps and unetched areas with different depths according to different circuit design requirements, and the areas on the inner wall of the through holes 2 where the conductive material is not coated are filled with the resin material 4;

[0043] The coating layer 3 in the through holes 2 is used to realize the connection of the circuits on the upper and lower sides of the copper-free substrate 1, and the remaining parts in the through holes 2 are filled with the resin material 4, which can prevent the existence of gas or water-absorbing areas in the circuit board.

[0044] Step 3: Connect the chips 5 to the semi-etched steps of the coating layer 3, and the upper and lower layers of chips 5 are arranged in a cross pattern;

[0045] The back electrode of chip 5 is connected in series with the circuit on the copper-free substrate 1 by welding or sintering; at this time, the coating layer 3 connected to the back of chip 5 can be regarded as the back electrode of the chip and used as part of the power circuit. After connection, the surfaces of the upper and lower chips 5 are at the same height as the unetched parts of the upper and lower coating layers 3. The cross-arrangement of the upper and lower chips 5 is beneficial to improving the heat dissipation efficiency.

[0046] Step 4: Print copper paste materials at the reserved positions of multiple circuit connection points on chip 5 and coating layer 3 respectively, and perform pre-drying and curing to form conical copper solder joints 6.

[0047] Step 5: Add a first insulating resin layer outside coating layer 3 and chip 5, and preset the temperature and pressure to make the tip of conical copper solder joint 6 penetrate the first insulating resin layer.

[0048] The first insulating resin layer can insulate and fill the spaces between conical copper solder joint 6, chip 5, coating layer 3 and other voids.

[0049] Step 6: Cover a copper conductive layer 8 outside the first insulating resin layer. Through the process of heating and pressurizing, make the tip of conical copper solder joint 6 melt and deform to achieve reliable connection with copper conductive layer 8.

[0050] During this period, the penetrated first insulating resin layer will also soften and flow, bonding coating layer 3 and copper conductive layer 8, and filling the interlayer gaps and voids.

[0051] In this embodiment, the fabricated circuit board already has the function of a power module and is regarded as a basic power module. Its structure is a double-layer power circuit board with a half-bridge topology. The input and output terminals are at both ends of the circuit board. The conductive circuits of the upper and lower layers are opposite, which can effectively reduce parasitic parameters. The coating layer in the through hole is used to connect the upper and lower layer circuits of the power circuit board. The output circuit of the upper-layer chip serves as the input circuit of the lower-layer chip. The upper-layer chip, lower-layer chip, copper-free substrate, and coating layer form a half-bridge topology. The upper-layer chip and lower-layer chip are the two bridge arm switches of the half-bridge topology.

[0052] Step 7: Repeat the methods of steps 4 to 6. Print copper paste materials at the reserved positions of multiple circuit connection points outside copper conductive layer 8 respectively, and sequentially stack a second insulating resin layer and a metal conductive layer 10 outside it.

[0053] The circuit connection between copper conductive layer 8 and metal conductive layer 10 is realized through conical copper solder joint 6 formed by copper paste material. A second insulating resin layer is filled between copper conductive layer 8 and metal conductive layer 10.

[0054] At this time, on the basis of power, the drive circuit and the signal circuit are added to the metal conductive layer 10, and the circuit board can take into account the logical functions. Moreover, by expanding the area of the circuit board, more functional circuits can be added to achieve a multi-functional systematic integration.

[0055] Step 8: A metal heat sink 9 with an area slightly larger than the area of the power chip is arranged outside the metal conductive layer 10.

[0056] In this embodiment, the heat sink 9 is connected to the outside of the metal conductive layer 10 by welding or sintering. The area of the heat sink 9 is slightly larger than the area corresponding to the cross-arrangement of the upper and lower chips 5, which can better realize the double-sided heat dissipation function of the power circuit board.

[0057] In summary, the coating layer 3, the chip 5 and the adjacent copper conductive layer 8 are electrically connected through the conical copper solder joints 6; the copper conductive layer 8 and the adjacent metal conductive layer 10 are electrically connected through the conical copper solder joints 6.

[0058] The repeatedly added insulating resin layers will form an integral insulating layer 7 after being heated during the production process of the circuit board, filling the holes and gaps between the layers of the circuit board, and enhancing its mechanical structure and safety. The insulating layer 7 selects a high thermal conductivity insulating material to achieve internal insulation of the power module; the chip 5 is connected to the heat sink 9 after passing through the insulating layer 7, the copper conductive layer 8 and the metal conductive layer 10, and the heat conduction path is extremely short, effectively reducing the thermal resistance.

[0059] The preparation method of the present invention can greatly improve the performance and heat dissipation of the embedded power module while increasing the production rate and yield, and the area of the power circuit board is only half of the previous area, and the power density is doubled.

[0060] Embodiment 2

[0061] Reference Figure 8 As shown, a power circuit board with double-sided heat dissipation includes: a copper-free substrate 1, the upper and lower surfaces of which are coated with a conductive coating layer 3. At least one chip 5 is installed on each of the upper and lower sides of the coating layer 3. The outside of the upper and lower coating layers 3 and the chips 5 are sequentially provided with a first insulating resin layer, a copper conductive layer 8, a second insulating resin layer, a metal conductive layer 10, and a heat sink 9. The two insulating resin layers are respectively added and finally connected into an integral insulating layer 7. The coating layer 3, the chip 5, the copper conductive layer 8, and the metal conductive layer 10 are connected through copper paste solder joints.

[0062] More specifically, the copper-free substrate 1, as the connection substrate and the central support structure of the chip 5, is provided with a plurality of through holes 2; using a copper-free material for the substrate is easy to make the through holes 2, facilitating the coating of conductive materials on its surface and realizing the etching of circuits with different height differences.

[0063] A coating layer 3 is provided on the upper and lower surfaces of the copper-free substrate 1 and the inner wall of the through hole 2. The coating layer 3 is etched to form a fully etched insulating circuit, a semi-etched step, and an unetched area. The coating layer at the inner wall of the through hole 2 is used to connect the upper and lower layers of circuits, so that the output circuit of the upper chip serves as the input circuit of the lower chip. The through hole 2 is filled with a resin material 4 to prevent the presence of gas or absorbent water vapor areas in the circuit board. The material used for the coating layer 3 can be a conductive material such as copper.

[0064] In this embodiment, the upper and lower chips 5 are respectively disposed on the upper and lower semi-etched steps by means of welding, sintering, etc. The height after connection is the same as the height of the unetched area of the coating layer. The chips 5 on the upper and lower layers of the circuit board are arranged in a staggered manner, which is beneficial to heat dissipation. At this time, the back surface of the chip 5 connected to the semi-etched step coating layer can be regarded as the back electrode of the chip and serves as a part of the power circuit.

[0065] A plurality of circuit connection point reserved positions are provided on the upper and lower coating layers 3 and the chips 5. A copper paste material is printed on each circuit connection point reserved position, and after pre-drying and curing, a conical copper solder joint 6 is obtained.

[0066] A first insulating resin layer is provided on the outside of the upper and lower coating layers and the chips. The first insulating resin layer fills the gaps between the conical copper solder joints 6, the chips 5, and the coating layer 3. The conical copper solder joints 6 penetrate the first insulating resin layer.

[0067] A copper conductive layer 8 is covered on the outside of the upper and lower first insulating resin layers. Through the process of heating and pressing, the tip of the conical copper solder joint 6 is melted and deformed to achieve reliable connection with the copper conductive layer 8. During this period, the penetrated first insulating resin layer will also soften and flow, bonding the upper and lower coating layers 3 and the copper conductive layer 8, and filling the interlayer gaps and voids.

[0068] At this time, the circuit board structure can be regarded as a power module of a double-layer power circuit board with a half-bridge topology. The input and output ends of the power module are provided at both ends of the circuit board. The upper and lower conductive circuits are opposite, effectively reducing parasitic parameters. The chips 5 on the upper and lower layers of the circuit board are connected to serve as the upper and lower bridge arm switches of the half-bridge topology respectively.

[0069] A metal conductive layer 10 is disposed outside the copper conductive layer 8. A second insulating resin layer is provided between the copper conductive layer 8 and the metal conductive layer 10. A plurality of circuit connection point reserved positions are provided on both the copper conductive layer 8 and the metal conductive layer 10. Copper paste solder joints are printed on each circuit connection point reserved position. After pre-drying and curing, a conical copper solder joint 6 is obtained. The conical copper solder joint 6 on the copper conductive layer 8 penetrates through the second insulating resin layer to achieve electrical connection between the copper conductive layer 8 and the metal conductive layer 10. A driving circuit and a signal circuit are added on the upper layer of the metal conductive layer 10, and logical functions can be realized thereon.

[0070] Based on the power circuit board, the area of the circuit board can be enlarged, and more functional circuits can be designed thereon to achieve multi-functional systematic integration.

[0071] A heat sink 9 is disposed outside the metal conductive layer 10 by welding or sintering; the area of the heat sink 9 is slightly larger than the area of the regions where the upper and lower layer chips 5 are located, and the double-sided heat dissipation function of the power circuit board can be realized. The chip 5 is connected to the heat sink 9 through the copper conductive layer 8, the insulating resin layer, and the metal conductive layer 10, and the heat conduction path is extremely short, effectively reducing the thermal resistance.

[0072] The first insulating resin layer and the second insulating resin layer are filled between the respective circuit layers of the circuit board, and finally form an integral insulating layer 7 to achieve mechanical support, electrical insulation, hole filling, and bonding and fixing between the various layers of the power circuit board.

[0073] The present invention discloses a power circuit board with double-sided heat dissipation. Power chips are welded inside the circuit board, and electrical connection is achieved through copper paste materials, without the need to realize chip connection and in-board interconnection by means of laser drilling and then coating conductive materials. The back surface of the power chip is combined with the substrate by welding or sintering and the electrodes are led out. After printing copper paste on the front surface and pre-drying, a conical copper solder joint is obtained to achieve connection with the upper conductive material layer. Except for the upper and lower layers of the substrate being connected through mechanical drilling and then coating conductive materials, other connection methods are the same as the connection of the front electrodes of the chip. The insulating resin layers between the various layers of the circuit board play roles of mechanical support, electrical insulation, cavity filling, and connection and bonding. The solution of the present invention reduces the yield loss and time cost of the laser drilling and copper plating processes, and the connection method is more convenient and efficient. Finally, the power circuit board of the present invention has advantages such as high power conversion rate, system integration, and double-sided heat dissipation, and can be applied in the electronic fields with high power levels, high power densities, high heat dissipation efficiencies, and low loss requirements.

[0074] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with

[0075] "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0076] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific circumstances.

[0077] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit and scope protected by the claims of the present invention. All of these are within the protection scope of the present invention.

Claims

1. A method for preparing a double-sided heat dissipation power circuit board, characterized in that: include, Step 1: Setting a plurality of through holes on the copper-free substrate; Step 2: coating a coating layer on the upper and lower surfaces of the copper-free substrate and the inner wall of the through hole, etching fully etched insulating lines, half-etched steps and unetched areas of different depths on the coating layer, and filling the through hole with a resin material; Step 3: Connect the chip to the half-etched step, and arrange the upper and lower layers of chips crosswise; Step 4: Printing copper paste materials at reserved positions of multiple circuit connection points on the surface of the chip and the coating layer, respectively, and pre-drying and solidifying the shapes to obtain conical copper soldering points; Step 5: adding a first insulating resin layer on the outer sides of the coating layer and the chip, wherein the tip of the conical copper solder joint penetrates the first insulating resin layer; Step 6: Disposing a copper conductive layer outside the first insulating resin layer; Step 7: Using the method of the above steps 4 to 6, the copper paste material is printed on the reserved positions of the multiple circuit connection points outside the copper conductive layer, and a second insulating resin layer and a metal conductive layer are sequentially stacked on the outside of the copper conductive layer; Step 8: Dispose a metal heat sink on the outer side of the metal conductive layer, the metal heat sink having an area larger than the sum of the areas of the upper chip and the lower chip.

2. The method for preparing a double-sided heat dissipation power circuit board according to claim 1, characterized in that: The coating layer in the through hole is used to realize the connection between the upper and lower circuits of the power circuit board. The output circuit of the upper chip serves as the input circuit of the lower chip. The upper chip, the lower chip, the copper-free substrate, and the coating layer constitute a half-bridge topology. The upper chip and the lower chip are the two bridge arm switches of the half-bridge topology.

3. The method for preparing a double-sided heat dissipation power circuit board according to claim 2, characterized in that: An output electrode is arranged at the through hole, and the output electrode is the output end of the half-bridge topology.

4. The method for preparing a double-sided heat dissipation power circuit board according to claim 1, characterized in that: The input end and the output end of the double-sided heat dissipation power circuit board are respectively arranged on two sides of the power circuit board.

5. The method for preparing a double-sided heat dissipation power circuit board according to claim 1, characterized in that: A driving circuit and a signal circuit are arranged on the metal conductive layer, so that the circuit board has a logic function.

6. The method for preparing a double-sided heat dissipation power circuit board according to claim 1, characterized in that: The coating layer, the chip and the adjacent copper conductive layer are electrically connected via conical copper soldering points; the copper conductive layer and the adjacent metal conductive layer are electrically connected via conical copper soldering points.

7. A double-sided heat dissipation power circuit board, characterized in that: include, A copper-free substrate having a plurality of through holes disposed thereon; A coating layer, which is arranged on the upper and lower surfaces of the copper-free substrate and the inner wall of the through hole, and the coating layer is etched to form a fully etched insulating line, a half-etched step and an unetched area; A chip, which is arranged on the half-etched steps of the upper and lower layers; A copper conductive layer, which is disposed on the coating layers of the upper and lower layers and the outer side of the chip; A metal conductive layer, which is arranged on the outer sides of the copper conductive layers of the upper and lower layers; A heat sink is disposed on the outer sides of the metal conductive layers of the upper and lower layers; A plurality of reserved positions for circuit connection points are arranged on the chip, the coating layer, the copper conductive layer and the metal conductive layer, and a copper paste soldering point is printed on each of the reserved positions for circuit connection points; A first insulating resin layer is arranged between the coating layer and the copper conductive layer, and the copper paste solder joints on the coating layer are pre-dried and solidified to obtain conical copper solder joints that penetrate the first insulating resin layer, thereby realizing the connection between the coating layer and the copper conductive layer; a second insulating resin layer is arranged between the copper conductive layer and the metal conductive layer, and the copper paste solder joints on the copper conductive layer are pre-dried and solidified to obtain conical copper solder joints that penetrate the second insulating resin layer, thereby realizing the connection between the copper conductive layer and the metal conductive layer.

8. A double-sided heat dissipation power circuit board according to claim 7, characterized in that: The through hole is filled with resin material.

9. The double-sided heat dissipation power circuit board according to claim 7, characterized in that: The area of ​​the heat sink is larger than the sum of the area of ​​the upper chip and the area of ​​the lower chip.

10. The double-sided heat dissipation power circuit board according to claim 7, characterized in that: The coating layer in the through hole is used to realize the connection between the upper and lower circuits of the power circuit board. The output circuit of the upper chip serves as the input circuit of the lower chip. The upper chip, the lower chip, the copper-free substrate and the coating layer constitute a half-bridge topology. The upper chip and the lower chip are the two bridge arm switches of the half-bridge topology.

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