Manufacturing method of multi-task parallel high-current-carrying power supply control module circuit board

Abstract

According to the circuit board manufacturing technology provided by the invention, the circuit board comprises a copper embedding area and a non-copper embedding area, and the circuit board manufacturing technology comprises the following steps: manufacturing a blue glue layer of a first window covering the junction position of the copper embedding area and the non-copper embedding area on a first surface of a copper foil, manufacturing a tin layer for the first window, manufacturing a second window falling into the range of the first window for the copper foil, taking a first prepreg, and taking a second prepreg; a release film with the size equal to that of the second window is pasted, the release film faces the copper foil and is pressed, then the blue glue layer in the tin layer range is removed, the first prepreg corresponding to the release film is removed, a surface layer auxiliary structure is formed, a stepped copper block and a second prepreg with a third window are taken, a thick copper block area is embedded into the third window, and the surface layer auxiliary structure is formed. The second window and the two surface layer auxiliary structures are stacked and laminated, tin stripping is carried out, the copper foil in the second window is removed, the blue glue layer is removed, and the circuit board is formed through post-process processing; the stepped copper block is used for participating in current management, polishing is not needed in the machining process, and the reliability of the embedded copper block is improved.

Description

Technical Field

[0001] This invention relates to the field of circuit board design and fabrication, and in particular to a method for fabricating a circuit board for a multi-task parallel high current-carrying power supply control module. Background Technology

[0002] As the technology of battery modules for intelligent connected vehicles becomes more mature and intelligent, the requirements for the refined and intelligent management of battery systems are becoming increasingly stringent. This has led to the emergence of a type of power control module designed for multi-task parallel operation during high-power charging, enabling efficient and safe management of the charging process. For a type of battery management system application used in intelligent connected vehicles, high heat dissipation and high current carrying capacity are required. Existing technologies generally use thick copper lines to achieve high current carrying capacity and use embedded copper blocks to meet high heat dissipation requirements. By embedding the copper blocks into the board, heat dissipation and current control are achieved.

[0003] However, in application, simply embedding copper blocks generally only meets the requirements of high heat dissipation. For increasingly complex battery management systems, it is difficult to meet the requirements of current adjustment and distribution, and it is difficult to achieve the combined effect of thick copper lines and embedded copper blocks.

[0004] Furthermore, if there is a conductive relationship between the embedded copper block and the electroplated copper layer, cracks may easily occur at the longitudinal junction of the copper block and the electroplated copper layer due to current impact or external vibration during high current and high voltage applications, affecting the reliability and lifespan of the circuit board.

[0005] During the process of embedding copper blocks into circuit boards, problems such as excessive glue overflow around the copper blocks can easily occur. The excess glue is usually removed by sanding with a sanding belt or using a ceramic grinding plate. However, sanding will cause significant vibration and pulling on the embedded copper blocks, affecting their firmness and reliability. In severe cases, it may even cause cracks between the copper blocks and the board.

[0006] Based on the above problems, there is a need to provide a circuit board manufacturing method for an automotive battery management system that embeds a stepped copper block with high heat dissipation, achieves effective interconnection between the copper block and the circuit, forms an effective current adjustment and distribution function, and forms a reliable processing process. Summary of the Invention

[0007] This invention addresses the problems of existing high-heat-dissipation, high-current-carrying circuit boards with embedded copper blocks, which struggle to achieve the current adjustment and distribution functions of the embedded copper blocks, are prone to cracking during circuit board application, and are susceptible to cracking between the embedded copper blocks and the board body during processing, particularly through grinding. The invention provides a method for manufacturing a multi-tasking parallel high-current-carrying power supply control module circuit board. The circuit board features embedded copper blocks, which are stepped copper blocks. The planar area of ​​the circuit board includes both embedded and non-embedded copper areas. The manufacturing method includes the following steps:

[0008] S10: Take copper foil, and form a blue adhesive layer with a first window on the first side of the copper foil to form a blue adhesive copper-clad layer; the first window covers the boundary between the copper-embedded area and the non-copper-embedded area; then form a tin layer on the first window; then form a second window on the copper foil, the range of the second window falling within the range of the first window; the whole is formed into a tin-patterned copper foil board;

[0009] S20: Take the first prepreg and attach a release film to its first surface. The size range of the release film is equal to the size range of the inner edge of the second window. Place the release film toward the copper foil and perform the first pressing. Then remove the blue adhesive layer within the inner edge range of the tin layer and remove the first prepreg corresponding to the release film. The surface layer auxiliary structure is formed as a whole.

[0010] S30: Take two stepped copper blocks, the thicker area of ​​the stepped copper blocks is called the thick copper block area, and the thinner area is called the thin copper block area; take a second semi-cured sheet, and make two third windows on the second semi-cured sheet, the size of the two third windows corresponding to the size of the thick copper block area; embed the thick copper block areas of the two stepped copper blocks into the two third windows respectively; the two stepped copper blocks are stacked in a centrally symmetrical structure, and the two thin copper block areas are arranged opposite each other to form a pre-pressed embedding structure; take two surface layer auxiliary structures, stack the two first semi-cured sheets opposite each other, and place the pre-pressed embedding structure between the two surface layer auxiliary structures; form a stacked structure as a whole, press it together, and form a press plate as a whole.

[0011] S40: Remove the tin from the laminated board, then remove the copper foil within the inner edge range of the second window, and then remove the remaining blue adhesive layer to form a copper-embedded core board; perform whole-board electroplating on the copper-embedded core board and fabricate surface circuits, and then process it in subsequent processes to form the power control module circuit board.

[0012] Optionally, the apex of the thin copper block area is a chamfered structure or an arc-shaped structure; the interior angle of the step formed by the thin copper block area and the thick copper block area is an arc-shaped structure angle.

[0013] Optionally, forming the blue adhesive copper-clad layer includes taking blue adhesive tape, attaching it to the first side of the copper foil, laser-cutting the blue adhesive tape corresponding to the edge of the first window, and then removing the blue adhesive tape within the range of the first window to form the blue adhesive copper-clad layer as a whole.

[0014] Optionally, forming the blue adhesive copper-clad layer includes: taking liquid blue adhesive and making a screen printing stencil with blocking points, the positions of which correspond to the positions of the first openings; using the screen printing stencil to screen print the liquid blue adhesive onto the first side of the copper foil, and then baking and curing it; and forming the blue adhesive copper-clad layer as a whole.

[0015] Optionally, the tin layer is formed by printing solder paste onto the first window and then reflowing the blue glue copper layer to form the tin layer.

[0016] The tin layer is formed by applying a second high-temperature resistant blue adhesive to the second side of the copper foil of the blue adhesive copper-clad layer to form a double-sided blue adhesive copper layer; performing hot air leveling on the double-sided blue adhesive copper layer, and then removing the second high-temperature resistant blue adhesive; the tin layer is formed in the area of ​​the first window.

[0017] Optionally, the sum of the thicknesses of the copper foil, the first prepreg, and the second prepreg in the laminating plate is equal to the thickness of the thick copper block region.

[0018] Optionally, the second prepreg is a multilayer core board with a prepreg surface.

[0019] Optionally, forming the pre-pressed embedded structure includes extending the two thin copper block regions into each other's coverage area, and having an area less than or equal to that of each thin copper block region.

[0020] Optionally, forming the copper-embedded core board includes: removing the tin from the laminate, then forming a wet film layer on the board surface, and sequentially exposing and developing it, retaining the wet film layer in the non-copper-embedded area to form a wet film pattern board; then sequentially etching and removing the film from the wet film pattern board, and then removing the remaining blue adhesive layer to form the copper-embedded core board.

[0021] The beneficial effects of the technical solution of this invention mainly include:

[0022] (1) Embedding stepped copper blocks provides a more feasible and reliable way to design, process and apply power control module circuit boards. The embedded stepped copper blocks form a direct matching relationship with the circuit and become part of the circuit board circuit, thereby forming an effective circuit interconnection and heat distribution process and effect, providing a more flexible and reliable foundation for the management system. At the same time, the present invention provides a structure and processing method for embedding multiple stepped copper blocks, realizing the connection of multiple stepped copper blocks with surface circuits to support the board function of multi-task parallelism, greatly improving the density of the circuit board, reducing the size of the circuit board, and improving the working efficiency and heat dissipation efficiency of the circuit board.

[0023] (2) Using stepped copper blocks, the thick copper block area and the thin copper block area are an integral structure rather than an electroplated connection structure, forming a larger bonding area with the surface electroplated copper layer, and together with the electroplated copper layer, they form the surface circuit processing, improving the reliability of the copper block connection circuit, while supporting the large current carrying capacity of the thick copper circuit, and can alleviate the problem of cracks at the interface between the copper block and the electroplated copper caused by vibration and other factors during the application process.

[0024] (3) In terms of processing, the overall process relies on the differences in structure and performance of different materials to form a process flow. The method of not needing to grind effectively improves the firmness and reliability of the copper-embedded blocks. By making a surface copper layer auxiliary structure, a surface copper base is provided for overall pressing, while also providing a structural base for preventing pressing glue overflow and a structural base for pressing uniformity. This effectively ensures the uniformity, integrity and completeness of the board during pressing, and prevents the pressing performance of the copper-embedded blocks and non-copper-embedded blocks from being mismatched, or from producing problems such as excessive glue overflow and unevenness.

[0025] (4) There is a correlation between each process. In the early stage of the process of forming the surface copper layer auxiliary structure, the tin layer, the thickness of the first prepreg, the opening of the prepreg and the opening of the copper foil provide the corresponding preconditions for the subsequent whole board lamination. The whole board lamination forms the overall structure. Then, based on the preconditions, the processes of tin removal, wet film printing, etching, film removal and blue glue removal are formed, forming an effective front-to-back matching processing process, thereby improving the feasibility of processing and the reliability of the product. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0027] Figure 1 This is a process flow diagram of the circuit board manufacturing method according to this embodiment;

[0028] Figure 2 This is a schematic cross-sectional view of the stacked structure of the tin pattern copper foil and the functional prepreg in this embodiment.

[0029] Figure 3 This is a cross-sectional schematic diagram of the surface layer auxiliary structure in this embodiment;

[0030] Figure 4 for Figure 3 A top-down view of the planar structure;

[0031] Figure 5 for Figure 3 A schematic diagram of the planar structure from an upward-looking perspective;

[0032] Figure 6 This is a cross-sectional schematic diagram of the stacked structure in this embodiment;

[0033] Figure 7 This is a three-dimensional structural diagram of the two stepped copper blocks in this embodiment;

[0034] Figure 8 This is a cross-sectional schematic diagram of another stacked structure in this embodiment;

[0035] Figure 9 This is a cross-sectional schematic diagram of the pressing plate in this embodiment;

[0036] Figure 10 This is a cross-sectional schematic diagram of the wet film graphic plate of this embodiment;

[0037] Figure 11 This is a cross-sectional schematic diagram of the copper-embedded core board of this embodiment;

[0038] Figure 12 This is a plan view of the copper-embedded core board of this embodiment;

[0039] Figure 13 This is a cross-sectional schematic diagram of the circuit board according to this embodiment.

[0040] Explanation of icon numbers:

[0041] 100. Copper-embedded area; 200. Non-copper-embedded area; 10. Tin-patterned copper foil board; 110. Copper foil; 1110. First window; 1120. Second window; 120. Blue adhesive layer; 130. Tin layer; 20. Functional prepreg; 210. First prepreg; 220. Release film; 30. Surface auxiliary structure; 30F. Top view; 30Y. Bottom view; 40. Stacked structure; 410. Second prepreg; 4110. Third window. ; 4210, First-step copper block; 4220, Second-step copper block; 430, Pre-pressed embedded structure; 40A, Another stacked structure; 4210H, First thick copper block area; 4210B, First thin copper block area; 4220H, Second thick copper block area; 4220B, Second thin copper block area; 50, Press plate; 60, Wet film pattern board; 610, Wet film pattern; 70, Copper-embedded core board; 80, Power control module circuit board; 810, Surface wiring.

[0042] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0044] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0045] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0046] Please see Figure 1 , Figure 1 This is a flowchart of the circuit board manufacturing method according to this embodiment.

[0047] Figure 2 This is a schematic cross-sectional view of the stacked structure of the tin pattern copper foil and the functional prepreg in this embodiment.

[0048] This embodiment provides a method for manufacturing a multi-task parallel high-current power control module circuit board 80. The power control module circuit board 80 has embedded copper blocks, wherein the copper blocks are stepped copper blocks, and the planar range of the power control module circuit board 80 includes a copper-embedded area 100 and a non-copper-embedded area 200. The manufacturing method includes... Figure 1 The process flow is explained in detail below.

[0049] Step S10:

[0050] Take copper foil 110, and form a blue adhesive layer 120 with a first window 1110 on the first side of the copper foil 110 to form a blue adhesive copper-clad layer; the first window 1110 covers the boundary between the copper-embedded area 100 and the non-copper-embedded area 200; then form a tin layer 130 on the first window 1110; then form a second window 1120 on the copper foil 110, the area of ​​the second window 1120 falling within the area of ​​the first window 1110, that is, the second window 1120 falling within the area of ​​the tin layer 130; the whole is formed into a tin pattern copper foil board 10.

[0051] In this embodiment, the copper foil 110 is essentially the base copper layer of the non-copper-embedded area 200 of the laminating plate 50, and the surface copper layer that protects the copper-embedded area 100 during the lamination process. The base copper layer and the surface copper layer need to be independent so that the base copper layer can effectively bond with other layers during lamination. At the same time, the surface copper layer will not affect the bonding effect of the base copper layer and can be effectively removed after lamination.

[0052] Therefore, a blue adhesive layer 120 is first formed on the surface of the copper foil 110 to provide support for the copper foil 110 and to provide a workable basis for the formation of the first window 1110 and the tin layer 130. After the tin layer 130 is formed, a second window 1120 is formed on the copper foil 110, which cuts off the copper-embedded area 100 and the non-copper-embedded area 200. At the same time, the tin layer 130 spans the area of ​​the copper-embedded area 100 and the non-copper-embedded area 200, thus connecting the copper-embedded area 100 and the non-copper-embedded area 200. This forms an effective structure in which the copper-embedded area 100 and the non-copper-embedded area 200 are disconnected but connected by the tin layer 130. This structure provides a partitioned copper foil 110 base for the effective bonding of the base copper to other layers and the effective removal of the surface copper layer after lamination.

[0053] Instead of using tape or film to form a connection, the tin layer 130 forms a tighter bond with the copper foil 110 surface. This prevents the flow of adhesive from overflowing from the second window 1120 during subsequent lamination. The copper foil 110 is treated with alkaline etching during the fabrication of the second window 1120, which does not affect the tin layer 130. The subsequent desoldering process uses desoldering solution, which does not affect the copper foil 110. By utilizing the differences between the materials, a pattern transfer and processing assistance process is formed, avoiding the problem of adhesive flow adhering to tape or film after lamination, which is difficult to remove.

[0054] Optionally, forming a blue adhesive copper cladding layer includes taking a blue adhesive tape, attaching it to the first side of the copper foil 110, laser-cutting the blue adhesive tape corresponding to the edge of the first window 1110, and then removing the blue adhesive tape within the range of the first window 1110 to form a blue adhesive copper cladding layer.

[0055] After applying blue tape, laser cutting is performed to form the first window 1110, a high-precision processing process suitable for processing high-precision circuit boards and circuit boards with dense circuits.

[0056] Alternatively, the blue tape can be applied using a film applicator.

[0057] Optionally, forming the blue adhesive copper-clad layer includes taking liquid blue adhesive and making a dot screen, with the position of the dot corresponding to the position of the first window 1110; using the dot screen to screen print the liquid blue adhesive onto the first side of the copper foil 110, and then baking and curing; and forming the overall blue adhesive copper-clad layer.

[0058] Using screen printing with blue glue creates a more efficient and lower-cost processing method, suitable for mass production of circuit boards with relatively low precision.

[0059] Optionally, the blue adhesive layer 120 is a high-temperature resistant blue adhesive layer 120; it withstands high temperatures during the fabrication of the tin layer 130 and subsequent lamination.

[0060] Optionally, the tin layer 130 is made by printing solder paste onto the first window 1110, and then reflowing the blue glue copper layer to form the tin layer 130.

[0061] By using the printed solder paste reflow soldering method, less mechanical impact is applied to the copper foil 110 and the blue adhesive layer 120, resulting in higher precision of the solder layer 130.

[0062] Optionally, the tin layer 130 is formed by creating a second high-temperature resistant blue adhesive (not shown in the figure) on the second side of the copper foil 110 of the blue adhesive copper layer to form a double-sided blue adhesive copper layer; performing hot air leveling on the double-sided blue adhesive copper layer, and then removing the second high-temperature resistant blue adhesive; and forming the tin layer 130 in the area of ​​the first window 1110.

[0063] Hot air leveling, commonly known as tin spraying, uses a tin spraying process to create a 130mm tin layer. This process is more efficient and suitable for mass production.

[0064] Please continue reading. Figure 2 Please see Figures 3 to 5 ; Figure 3 This is a cross-sectional schematic diagram of the surface layer auxiliary structure in this embodiment; Figure 4 for Figure 3 A top-down view of the planar structure; Figure 5 for Figure 3 A schematic diagram of the planar structure from an upward-looking perspective.

[0065] Step S20:

[0066] Take the first prepreg 210 and attach a release film 220 to its first surface. The size range of the release film 220 is equal to the size range of the inner edge of the second window 1120 to form a functional prepreg 20. Place the release film 220 toward the copper foil 110 and perform the first pressing. Then remove the blue adhesive layer 120 within the inner edge range of the tin layer 130 and remove the first prepreg 210 corresponding to the release film 220. The surface layer auxiliary structure 30 is formed as a whole.

[0067] Figure 3 The floor plan corresponding to the mid-view view of the 30th floor Figure 4 The plan view corresponding to the upward visual perspective at 30Y Figure 5 .

[0068] The copper foil 110 is divided into a base copper layer in the non-copper-embedded area 200 and a surface copper layer in the copper-embedded area 100. The base copper layer needs to be bonded to other layers during the lamination process through the first prepreg 210, while the surface copper layer does not need to be bonded to other layers. Therefore, it is necessary to make a partitioned structure of the first prepreg 210. If the first prepreg 210 is first opened and then laminated, it is easy to produce uneven lamination due to uneven surface. In severe cases, it may cause the surface copper layer to sink or fall off. Therefore, a release film 220 is used as a way to transfer the structure, providing a flat surface base for the lamination process, so that the overall structure after lamination is flat, and the first prepreg 210 corresponding to the release film 220 is easy to remove, forming a high-precision processing process.

[0069] Optionally, the first pressing uses a pre-pressing method, that is, pressing until the two adhere to each other without needing to press with high pressure; this ensures the adhesion between the layers while retaining the fluidity of the first semi-cured sheet 210, providing a better foundation for subsequent full-board pressing and preventing excessive glue flow caused by over-pressing in the first pressing.

[0070] Optionally, the release film 220 can be a PTFE film, PP film, or PI film, which can achieve a good release effect.

[0071] Please see Figures 6 to 9 ; Figure 6 This is a cross-sectional schematic diagram of the stacked structure in this embodiment; Figure 7 This is a three-dimensional structural diagram of the two stepped copper blocks in this embodiment; Figure 8 This is a cross-sectional schematic diagram of another stacked structure in this embodiment; Figure 9 This is a cross-sectional schematic diagram of the pressing plate in this embodiment.

[0072] Step S30:

[0073] Take two stepped copper blocks, namely the first stepped copper block 4210 and the second stepped copper block 4220. The thicker areas of the stepped copper blocks are called thick copper block areas, namely the first thick copper block area 4210H of the first stepped copper block 4210 and the second thick copper block area 4220H of the second stepped copper block 4220. The thinner areas are called thin copper block areas, namely the first thin copper block area 4210B of the first stepped copper block 4210 and the second thin copper block area 4220B of the second stepped copper block 4220. Take the second semi-cured sheet 410 and fabricate two third... The dimensions of the two third windows 4110 correspond to the dimensions of the thick copper block area. The thick copper block areas of the two stepped copper blocks are respectively embedded into the two third windows 4110. The two stepped copper blocks are stacked in a centrally symmetrical structure, and the two thin copper block areas are set opposite each other to form a pre-pressed embedding structure 430. Two surface layer auxiliary structures 30 are taken, and the two first semi-cured sheets 210 are stacked opposite each other. The pre-pressed embedding structure 430 is placed between the two surface layer auxiliary structures 30. The whole stacked structure 40 is formed and pressed together to form a press plate 50.

[0074] This embodiment utilizes a first stepped copper block 4210 and a second stepped copper block 4220 to form a centrally symmetrical stacked structure 40, corresponding to the copper embedding area 100. A third window 4110 is made of the second prepreg 410, matching the first thick copper block area 4210H and the second thick copper block area 4220H, providing a fixed foundation for the stepped copper blocks and forming a filling effect during the pressing process. After pressing, the first thick copper block area 4210H and the second thick copper block area 4220H are longitudinally fixed in the board body, and are adhered and surrounded by the first prepreg 210 and the second prepreg 410 through adhesive flow. Meanwhile, the first thin copper block area 4210B and the second thin copper block area 4220B form adhesion and filling with the adhesive flow of the second prepreg 410 in the planar direction, thereby forming an effective adhesion and bonding of the stepped copper blocks.

[0075] The integration of the first thin copper block area 4210B and the second thin copper block area 4220B with the overall board surface improves the bonding force between the embedded copper block and the board body, and provides a good bonding foundation and pattern processing foundation for subsequent whole board electroplating to form a surface copper plating layer and to make surface circuit 810. It effectively avoids problems such as cracks at the interface between the copper block and the electroplated copper caused by vibration and other factors during application.

[0076] During lamination, the tin layer 130 effectively restricts the flow of adhesive on the second prepreg 410, making it difficult for the adhesive to overflow the board surface, especially the transition area between the copper-embedded area 100 and the non-copper-embedded area 200. This provides an effective board surface foundation for lamination and also provides a board surface foundation for subsequent processing methods that do not require "grinding".

[0077] Optionally, forming the pre-pressed embedded structure 430 includes extending two thin copper block areas into each other's coverage area, and the area of ​​each thin copper block area is less than or equal to the area of ​​each thin copper block area (i.e., the area of ​​the intersecting areas is less than or equal to the area of ​​each thin copper block area).

[0078] It allows for vertically staggered alignment of stepped copper blocks, improving the wiring density and heat dissipation efficiency of the circuit board, and providing a more flexible circuit foundation for battery management.

[0079] Optionally, the second prepreg 410 is a multilayer core board 410D with a prepreg surface, which is stacked to form another stacking structure 40A.

[0080] This implementation method can also be applied to the processing of multilayer circuit boards to create a high-density wiring effect with multiple inner circuit layers.

[0081] Optionally, the first prepreg 210 is another multilayer core board with a prepreg surface.

[0082] Embedded copper blocks can also be configured to be buried in copper blocks to achieve the effect of high-density vertical wiring on the circuit board.

[0083] Optionally, the sum of the thicknesses of the copper foil 110, the first prepreg 210, and the second prepreg 410 of the laminating plate 50 is equal to the thickness of the thick copper block region.

[0084] After lamination, a good interlayer bonding effect is formed, realizing a high-precision machining process and effect for embedding stepped copper blocks, improving the bonding force between the embedded stepped copper blocks and the board, and achieving a smooth surface effect. Based on this, a suitable prepreg is required before lamination as an interlayer bonding and insulating layer, so as to form a matching relationship between the thicknesses of each layer after lamination.

[0085] Optionally, the apex of the thin copper block area is a chamfered structure or an arc-shaped structure; the interior angle of the stepped position formed by the thin copper block area and the thick copper block area is an arc-shaped structure angle.

[0086] Chamfering or rounding the edges effectively avoids problems such as poor or uneven filling of adhesive at corners during lamination. Similarly, setting the inner corners to a rounded structure also improves the filling effect of the prepreg during the lamination process.

[0087] Please see Figures 10 to 13 ; Figure 10 This is a cross-sectional schematic diagram of the wet film graphic plate of this embodiment; Figure 11 This is a cross-sectional schematic diagram of the copper-embedded core board of this embodiment; Figure 12 This is a plan view of the copper-embedded core board of this embodiment; Figure 13 This is a cross-sectional schematic diagram of the circuit board according to this embodiment.

[0088] Step S40:

[0089] The tin is removed from the lamination board 50, then the copper foil 110 within the inner edge range of the second window 1120 is removed, and the remaining blue adhesive layer 120 is removed to form the copper-embedded core board 70; the copper-embedded core board 70 is electroplated as a whole board, and surface circuits 810 are made. After subsequent processing, the power control module circuit board 80 is formed.

[0090] The tin layer 130 is removed by desoldering, followed by the removal of the copper foil 110 in the copper embedding area 100 and the removal of the blue adhesive layer 120, forming a copper-embedded core board 70 with embedded stepped copper blocks. This serves as the basic structure for further processing. The entire board is electroplated to form an effective conductive foundation, and surface circuits 810 are fabricated to realize the circuit layout and interconnection on the board surface.

[0091] Optionally, the copper foil 110 within the inner edge range of the second window 1120 can be removed by etching. Since there is adhesive flow and bonding of the second semi-cured sheet 410 under the copper foil 110 at this position during lamination, if the bonding area is large, directly tearing off the copper foil 110 may easily damage the copper-embedded core board 70. Therefore, etching is used to remove the copper foil 110 at this position to ensure the reliability and quality of the copper-embedded core board 70.

[0092] It is worth noting that if the lines in the non-copper embedded area 200 are independent lines (e.g., the first pad), and if the lines in the stepped copper block of the copper embedded area 100 are independent lines (e.g., the second pad), then it is not necessary to perform full-board electroplating. The surface circuit 810 can be directly fabricated, and the functional connection between the first pad and the second pad can be achieved by soldering components.

[0093] Optionally, forming the copper-embedded core board 70 includes: removing the tin from the lamination board 50, then forming a wet film layer on the board surface, and sequentially exposing and developing it, retaining the wet film layer of the non-copper-embedded area 200 to form a wet film pattern 610, and forming a wet film pattern board 60 as a whole; then sequentially etching and removing the film from the wet film pattern board 60, and then removing the remaining blue adhesive layer 120 to form the copper-embedded core board 70.

[0094] Since the tin layer 130 spans the copper-embedded area 100 and the non-copper-embedded area 200, after removing the tin layer 130 by stripping, part of the copper foil 110 in the non-copper-embedded area 200 will be exposed. If the copper foil 110 at this location is not pre-processed, or if it is difficult to pre-process due to the high density of the circuit distribution, then if the copper foil 110 within the inner edge range of the second window 1120 is directly removed by etching, the exposed part of the copper foil 110 will also be etched away. Therefore, a wet film is coated or printed, and a wet film pattern 610 is made to protect the copper foil 110 at this location. Then, the copper foil 110 within the inner edge range of the second window 1120 is removed by etching, and then the film is stripped to achieve a high-precision processing process, effectively protecting the copper foil 110 from damage.

[0095] Optionally, the tinning process is performed using a tinning solution; the tinning is performed using a tinning solution from the existing "positive wafer" process, resulting in a selective effect of tinning without copper removal.

[0096] Removing the tin layer 130, copper foil 110, and blue adhesive layer 120 does not require "polishing," effectively avoiding problems such as the embedded copper block being pulled, and effectively improving the firmness and reliability of the embedded copper block.

[0097] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A method for manufacturing a circuit board for a multi-task parallel high-current power supply control module, wherein the circuit board has embedded copper blocks, the copper blocks being stepped copper blocks, and the planar range of the circuit board includes copper-embedded areas and non-copper-embedded areas, characterized in that, The manufacturing method includes the following steps: S10: Take copper foil, and form a blue adhesive layer with a first window on the first side of the copper foil to form a blue adhesive copper-clad layer; the first window covers the boundary between the copper-embedded area and the non-copper-embedded area; then form a tin layer on the first window; then form a second window on the copper foil, the range of the second window falling within the range of the first window; the whole is formed into a tin-patterned copper foil board; S20: Take the first prepreg and attach a release film to its first surface. The size range of the release film is equal to the size range of the inner edge of the second window. Place the release film toward the copper foil and perform the first pressing. Then remove the blue adhesive layer within the inner edge range of the tin layer and remove the first prepreg corresponding to the release film. The surface layer auxiliary structure is formed as a whole. S30: Take two stepped copper blocks, the thicker area of ​​the stepped copper blocks is called the thick copper block area, and the thinner area is called the thin copper block area; take a second semi-cured sheet, and make two third windows on the second semi-cured sheet, the size of the two third windows corresponding to the size of the thick copper block area; embed the thick copper block areas of the two stepped copper blocks into the two third windows respectively; the two stepped copper blocks are stacked in a centrally symmetrical structure, and the two thin copper block areas are arranged opposite each other to form a pre-pressed embedding structure; take two surface layer auxiliary structures, stack the two first semi-cured sheets opposite each other, and place the pre-pressed embedding structure between the two surface layer auxiliary structures; form a stacked structure as a whole, press it together, and form a press plate as a whole. S40: Remove the tin from the laminated board, then remove the copper foil within the inner edge range of the second window, and then remove the remaining blue adhesive layer to form a copper-embedded core board; perform whole-board electroplating on the copper-embedded core board and fabricate surface circuits, and then process it in subsequent processes to form the power control module circuit board.

2. The method for manufacturing the multi-task parallel high-current power supply control module circuit board according to claim 1, characterized in that, The apex of the thin copper block area is a chamfered or arc-shaped structure; the interior angle of the stepped position formed by the thin copper block area and the thick copper block area is an arc-shaped structure angle.

3. The method for manufacturing the multi-task parallel high-current power supply control module circuit board according to claim 1, characterized in that, The process of forming the blue adhesive copper cladding layer includes taking blue adhesive tape, attaching it to the first side of the copper foil, laser cutting the blue adhesive tape corresponding to the edge of the first window, and then removing the blue adhesive tape within the range of the first window to form the blue adhesive copper cladding layer as a whole.

4. The method for manufacturing the multi-task parallel high-current power supply control module circuit board according to claim 1, characterized in that, The process of forming the blue adhesive copper-clad layer includes taking liquid blue adhesive and making a dotted screen, wherein the position of the dotted point corresponds to the position of the first window. The liquid blue adhesive is screen-printed onto the first side of the copper foil using the dotted screen printing plate, followed by baking and curing. The blue adhesive copper-clad layer is formed as a whole.

5. The method for manufacturing the multi-task parallel high-current power supply control module circuit board according to claim 1, characterized in that, The tin layer is formed by printing solder paste onto the first window, followed by reflow soldering the blue glue copper layer, and the solder paste forms the tin layer.

6. The method for manufacturing the multi-task parallel high-current power supply control module circuit board according to claim 1, characterized in that, The tin layer is formed by applying a second high-temperature resistant blue adhesive to the second side of the copper foil of the blue adhesive copper-clad layer to form a double-sided blue adhesive copper layer; performing hot air leveling on the double-sided blue adhesive copper layer, and then removing the second high-temperature resistant blue adhesive; the tin layer is formed in the area of ​​the first window.

7. The method for manufacturing the multi-task parallel high-current power supply control module circuit board according to claim 1, characterized in that, The sum of the thicknesses of the copper foil, the first prepreg, and the second prepreg in the laminating plate is equal to the thickness of the thick copper block region.

8. The method for manufacturing a multi-task parallel high-current power supply control module circuit board according to claim 1 or 7, characterized in that, The second semi-cured sheet is a multilayer core board with a semi-cured sheet surface.

9. The method for manufacturing the multi-task parallel high-current power supply control module circuit board according to claim 1, characterized in that, Forming the pre-pressed embedded structure includes extending the two thin copper block regions into each other's coverage area, and the area of ​​each thin copper block region is less than or equal to that of the other thin copper block region.

10. The method for manufacturing the multi-task parallel high-current power supply control module circuit board according to claim 1, characterized in that, The process of forming the copper-embedded core board includes: removing the tin from the lamination board, then forming a wet film layer on the board surface, and sequentially exposing and developing it, retaining the wet film layer in the non-copper-embedded area to form a wet film pattern board; then sequentially etching and removing the film from the wet film pattern board, and finally removing the remaining blue adhesive layer to form the copper-embedded core board.

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