A manufacturing method of a ground performance metal-based circuit board for intelligent connected vehicles

Abstract

The application discloses a manufacturing method of a ground performance metal-based circuit board for an intelligent networked automobile. According to design data, a substrate is manufactured, first drilling is performed, and carbon oil is filled, then first baking and curing are performed, a filling hole is formed, and a filling plate is formed on the whole plate; then polishing is performed, a ground circuit pattern is manufactured on the surface copper layer, and a metal-based circuit board is formed on the whole plate through subsequent processing; through the manufacturing method, the problem of hole wall cracking and separation caused by the thermal expansion and cold shrinkage difference of multi-layer materials of the substrate is effectively avoided in the method for forming a ground circuit by adopting an electroplating hole in the prior art; meanwhile, the complex processes such as copper deposition and copper plating required in electroplating are omitted, the processing flow is simplified, the carbon oil material cost is lower than that of silver paste and copper paste in the prior art, the material matching of the carbon oil with the circuit board body is better, the electrical connection between the ground circuit and the metal-based layer can be stably realized, and good ground performance is ensured.

Description

Technical Field

[0001] This invention relates to the field of circuit board manufacturing, and more particularly to a method for manufacturing a grounding performance metal-based circuit board for intelligent connected vehicles. Background Technology

[0002] In the field of intelligent connected vehicles, vehicle control modules have stringent requirements for the performance of circuit boards. On the one hand, since the modules generate heat when they are working, metal substrates (such as aluminum substrates, copper substrates, etc.) are used to ensure good heat dissipation performance. On the other hand, in order to avoid the modules being subject to electrostatic interference or generating electromagnetic interference, grounding lines need to be designed on the surface of the board.

[0003] Currently, there are two main methods for fabricating the grounding circuit structure of this type of metal substrate:

[0004] (1) Make through holes or blind holes at the locations where grounding is required, and then electroplate to form metallized holes to achieve grounding; however, since the metal substrate is mainly composed of copper circuit, insulating dielectric layer (FR-4, etc.), insulating adhesive layer (epoxy resin adhesive layer, acrylic adhesive layer, etc.) and metal base layer, the structure is relatively complex and the hole wall materials are diverse. It is difficult to ensure the uniformity of electroplating effect during electroplating, which can easily lead to problems such as poor quality of copper layer on hole wall. In long-term use, the thermal expansion and contraction of the metal substrate will further weaken the bonding force between the electroplated layer on the hole wall and the hole wall, resulting in problems such as cracking and detachment of the electroplated layer, which will cause damage to the circuit board.

[0005] Furthermore, blind holes are non-through holes, which can easily lead to problems such as the inability of the plating solution to reach the bottom of the blind hole, resulting in the lack of copper at the bottom of the blind hole and poor electrical connection. In addition, if the electroplating hole is required to be a solid hole, resin plugging is required after electroplating, which involves more complex materials and a longer and more expensive process.

[0006] (2) Make through holes or blind holes at the locations where grounding is required, and then fill the holes with silver paste or copper paste to achieve grounding; however, the material cost of silver paste and copper paste is high, which will significantly increase the processing cost for grounding holes that only need ordinary grounding effect.

[0007] Therefore, in order to solve the problems mentioned above, it is necessary to provide a method for manufacturing a metal-based circuit board with grounding performance for intelligent connected vehicles. Summary of the Invention

[0008] This invention aims to solve the comprehensive problems of complex processing methods and difficulty in guaranteeing processing quality in existing metal-based circuit board manufacturing techniques. It proposes a method for manufacturing a grounding performance metal-based circuit board for intelligent connected vehicles. The metal-based circuit board is processed according to design data, which includes grounding holes and grounding line diagrams. The grounding holes are located within the range of the grounding line diagrams. The manufacturing method includes the following steps:

[0009] S10: According to the design data, a substrate consisting of a surface copper layer, an insulating dielectric layer, an insulating adhesive layer, and a metal base layer is fabricated. A first drilling is performed to form a first blind hole. The first blind hole is then filled with carbon oil, followed by a first baking and curing process. The first blind hole becomes a filled hole, and the entire board is formed into a filled board. The depth of the first drilling extends from the surface copper layer to the metal base layer.

[0010] S20: The filler board is polished, and then a circuit pattern is made on the surface copper layer. The circuit pattern includes the grounding circuit pattern. After subsequent processing, the filler hole forms the grounding hole, and the whole board forms the metal base circuit board.

[0011] Furthermore, forming the filler plate includes drilling a second hole corresponding to the center of the filler hole to form a second blind hole. The depth of the second blind hole is greater than that of the first blind hole, and the diameter of the second blind hole is smaller on one side than that of the first blind hole. Then, carbon oil is filled into the second blind hole, followed by baking and curing. The first blind hole and the second blind hole form a second filler hole, and the entire plate forms the filler plate.

[0012] Furthermore, forming the filler plate includes: filling a portion of the first blind hole with carbon oil, the portion not filled with carbon oil being a first semi-blind hole; then performing the first baking and curing to form a semi-filled hole; drilling a third hole corresponding to the center of the semi-filled hole to form a second semi-blind hole; then filling the first semi-blind hole and the second semi-blind hole with carbon oil, followed by baking and curing to form the filler hole; and finally forming the filler plate from the whole plate.

[0013] Furthermore, forming the filler plate includes performing a micro-etching process after the first drilling.

[0014] Furthermore, the first drilling includes: extending the drilling towards the edge of the first blind hole to form an edge auxiliary hole; the diameter of the edge auxiliary hole is less than or equal to 1 / 2 of the diameter of the first blind hole.

[0015] Furthermore, the center of the edge auxiliary hole falls within the range of the first blind hole.

[0016] Furthermore, there are ≥2 edge auxiliary holes, and several edge auxiliary holes are non-uniformly distributed on the edge of the first blind hole.

[0017] Furthermore, the carbon oil is filled using a vacuum plugging machine.

[0018] Furthermore, the first baking and curing process involves baking at a temperature of 75°C to 90°C for 40 to 60 minutes.

[0019] Furthermore, the baking and curing process involves: first baking at a temperature of 75°C to 90°C for 40 to 60 minutes; then baking at a temperature of 100°C to 110°C for 40 to 60 minutes; and finally baking at a temperature of 120°C to 150°C for 60 to 120 minutes.

[0020] The technical solution of this invention has the following main advantages:

[0021] (1) By creating the first blind hole and filling it with carbon oil, a grounding hole structure connecting the surface line and the metal substrate is formed, which effectively avoids the problem of hole wall cracking and detachment caused by the thermal expansion and contraction difference of the multilayer material of the substrate when using electroplated holes to form grounding lines in the existing technology. At the same time, it eliminates the complex processes such as copper plating and copper immersion required by electroplating, simplifying the processing flow. Compared with the silver paste and copper paste filling of the existing technology, carbon oil has a lower cost and better material matching with the circuit board body, which can stably realize the electrical connection between the grounding line and the metal substrate and ensure good grounding performance. Furthermore, micro-etching treatment of the first blind hole can remove burrs and flashes on the hole wall and make the hole wall and bottom form a uniform rough surface, which greatly improves the bonding force between carbon oil and hole wall.

[0022] (2) By setting a second blind hole, the bottom of the originally flat blind hole is transformed into an irregular structure, which disperses the expansion and contraction stress of the carbon oil in the vertical direction. On the one hand, it can reduce the area of ​​the "large flat surface" between the carbon oil and the bottom of the first blind hole, and reduce the stress caused by the mismatch of thermal expansion and contraction between the two. On the other hand, it makes the contact surface of the carbon oil more dispersed and more irregular, preventing the carbon oil from splitting with the bottom of the hole due to stress concentration, and improving the long-term stability of the grounding hole.

[0023] (3) For the second blind hole setting, by first filling a portion of the blind hole depth with carbon oil and solidifying it, a solid "base" is provided for drilling the second blind hole, avoiding damage to the hole wall caused by drilling directly in the empty blind hole. Then, the second blind hole is drilled and the remaining space is filled. This can greatly reduce carbon oil waste and complete the filling with the same set of plugging tools without changing equipment, thereby reducing tool costs, shortening the processing flow, and improving overall processing efficiency.

[0024] (4) By making edge auxiliary holes, the "regular shape structure" of the original first blind hole is broken, the fine contact area between the carbon oil and the circuit board body is increased, the horizontal stress when the carbon oil expands and contracts is dispersed, so that the stress after the carbon oil plugs the hole will not be too concentrated and released in the same direction, thereby preventing the carbon oil from splitting with the side wall of the blind hole, and further ensuring the structural integrity of the grounding hole.

[0025] (5) The overall technical process is logically coherent and closely related to the preceding and following processes, forming a method for manufacturing grounding performance metal-based circuit boards for intelligent connected vehicles. 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 schematic diagram of the process flow of an embodiment of the present invention;

[0028] Figure 2 This is a cross-sectional schematic diagram of the first blind hole plate according to an embodiment of the present invention;

[0029] Figure 3 This is a cross-sectional schematic diagram of the filling plate according to an embodiment of the present invention;

[0030] Figure 4 This is a cross-sectional schematic diagram of the second blind hole plate according to an embodiment of the present invention;

[0031] Figure 5 This is a cross-sectional schematic diagram of the second filling plate according to an embodiment of the present invention;

[0032] Figure 6 This is a cross-sectional schematic diagram of a semi-filled plate according to an embodiment of the present invention;

[0033] Figure 7 This is a cross-sectional schematic diagram of the second semi-blind hole plate according to an embodiment of the present invention;

[0034] Figure 8 This is a cross-sectional schematic diagram of the third filling plate according to an embodiment of the present invention;

[0035] Figure 9 This is a cross-sectional schematic diagram of a filling plate with edge auxiliary holes according to an embodiment of the present invention;

[0036] Figure 10 for Figure 9 Top view;

[0037] Figure 11 This is a cross-sectional schematic diagram of a metal-based circuit board according to an embodiment of the present invention.

[0038] Explanation of reference numerals: 10, First blind via plate; 1010, Surface copper layer; 1020, Insulating dielectric layer; 1030, Insulating adhesive layer; 1040, Metal base layer; 1050, First blind via; 20, Filler plate; 2010, Filler hole; 20A, Semi-filler plate; 2020, First semi-blind via; 2030, Semi-filler hole; 2040, Edge auxiliary hole; 30, Second blind via plate; 3010, Second blind via; 30A, Second semi-blind via plate; 3020, Second semi-blind via; 40, Second filler plate; 4010, Second filler hole; 40A, Third filler plate; 4020, Third filler hole; 50, Metal base circuit board; 5010, Grounding line diagram; 5020, Grounding hole.

[0039] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0040] 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.

[0041] It should be noted that all directional indications (such as up, down, left, right, front, back, inside, outside, 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.

[0042] 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.

[0043] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0044] Please see Figure 1 , Figure 1 This is a schematic diagram of the process flow according to an embodiment of the present invention.

[0045] The metal-based circuit board in this embodiment is manufactured according to design data, which includes a grounding hole 5020 and a grounding line pattern 5010. The grounding hole 5020 is located within the grounding line pattern 5010. The manufacturing method includes... Figure 1 The steps are explained in detail below.

[0046] Please see Figure 2 and Figure 3 ; Figure 2 This is a cross-sectional schematic diagram of the first blind hole plate according to an embodiment of the present invention; Figure 3 This is a cross-sectional schematic diagram of the filling plate according to an embodiment of the present invention.

[0047] Step S10:

[0048] According to the design data, a substrate is made consisting of a surface copper layer 1010, an insulating dielectric layer 1020, an insulating adhesive layer 1030, and a metal base layer 1040 in sequence. The first drilling is performed to form a first blind hole 1050, forming a first blind hole plate 10. The first blind hole 1050 is then filled with carbon oil, followed by a first baking and curing process. The first blind hole 1050 forms a filling hole 2010, and the entire board forms a filling plate 20. The depth of the first drilling is from the surface copper layer 1010 to the metal base layer 1040.

[0049] The surface copper layer 1010 is the basis for subsequent circuit pattern fabrication. The insulating dielectric layer 1020 and the insulating adhesive layer 1030 serve the functions of insulation and adhesion, respectively, while the metal base layer 1040 is responsible for heat dissipation and grounding.

[0050] The substrate is drilled for the first time, and the depth of the first blind hole 1050 is controlled to extend from the surface copper layer 1010 to the metal base layer 1040, forming a connection channel between the surface copper layer 1010 and the metal base layer 1040. Then, carbon oil is filled into the first blind hole 1050. Utilizing the good conductivity of carbon oil, after subsequent processing, the electrical connection between the surface copper layer 1010 and the metal base layer 1040 is achieved. Moreover, the cost of carbon oil is much lower than that of materials such as silver paste and copper paste.

[0051] Please see Figure 4 and Figure 5 , Figure 4 This is a cross-sectional schematic diagram of the second blind hole plate according to an embodiment of the present invention; Figure 5 This is a cross-sectional schematic diagram of the second filling plate according to an embodiment of the present invention.

[0052] Optionally, a second hole is drilled at the center of the filling hole 2010 to form a second blind hole 3010, forming a second blind hole plate 30. The depth of the second blind hole 3010 is greater than that of the first blind hole 1050, and the diameter of the second blind hole 3010 is smaller on one side than that of the first blind hole 1050. The second blind hole 3010 is then filled with carbon oil and then baked and cured. The first blind hole 1050 and the second blind hole 3010 form a second filling hole 4010, and the entire plate forms the second filling plate 40.

[0053] The setting of the second blind hole 3010 can change the bottom shape of the first blind hole 1050 in the vertical direction, making it change from the original flat state to an "irregular" structure. This structure can provide a smaller buffer space for the thermal expansion and contraction of carbon oil, effectively dispersing the expansion and contraction stress of carbon oil in the vertical direction, thereby alleviating the problem of expansion and contraction mismatch between carbon oil and metal base layer 1040 due to large-area contact.

[0054] Meanwhile, the second blind hole 3010 can also reduce the contact area of ​​the "large flat surface" between the carbon oil and the bottom of the first blind hole 1050, making the contact surface of the carbon oil more irregular and more dispersed, thereby avoiding problems such as carbon oil splitting caused by stress concentration, and ensuring the structural stability and conductivity reliability of the grounding hole 5020.

[0055] Please see Figure 6 , Figure 7 , Figure 8 , Figure 9 and Figure 10 , Figure 6 This is a cross-sectional schematic diagram of a semi-filled plate according to an embodiment of the present invention; Figure 7 This is a cross-sectional schematic diagram of the second semi-blind hole plate according to an embodiment of the present invention; Figure 8 This is a cross-sectional schematic diagram of the third filling plate according to an embodiment of the present invention.

[0056] Optionally, a portion of the depth of the first blind hole 1050 is filled with carbon oil, and the portion not filled with carbon oil is the first semi-blind hole 2020. After a first baking and curing, a semi-filled hole 2030 is formed; a semi-filled plate 20A is formed, and a third drilling is performed corresponding to the center of the semi-filled hole 2030 to form a second semi-blind hole 3020; a second semi-blind hole plate 30A is formed, and the first semi-blind hole 2020 and the second semi-blind hole 3020 are filled with carbon oil, and then baked and cured; a third filled hole 4020 is formed; the entire plate forms the third filled plate 40A.

[0057] By first filling and curing a portion of the carbon oil, the originally hollow first blind hole 1050 is transformed into a "semi-solid" structure, providing a stable support base for drilling the second semi-blind hole 3020, ensuring the accuracy and integrity of the hole wall during the third drilling. If drilling is performed directly in an empty blind hole without carbon oil filling, problems such as deformation and burrs are likely to occur due to the lack of support for the hole wall.

[0058] On the one hand, filling part of the carbon oil first and then drilling the hole, and finally filling the remaining space, can reduce the amount of carbon oil used and avoid material waste compared to filling the entire first blind hole 1050 at once. On the other hand, the entire filling process does not require changing the plugging tool, and the same set of equipment can be used to complete the processing, saving the time of changing tools and the cost of purchasing additional tools, thereby shortening the processing flow and effectively improving processing efficiency.

[0059] It is worth noting that the diameter of the first blind hole 1050 is greater than or equal to 0.25 mm to 1.2 mm.

[0060] If the hole diameter is less than 0.25mm, the carbon oil will have difficulty flowing smoothly into the hole during the filling process due to the small hole size, which may lead to problems such as incomplete filling and residual air bubbles, thus affecting the filling quality.

[0061] If the hole diameter exceeds 1.2mm, on the one hand, the carbon oil will be difficult to completely fill the entire cavity during filling, especially the edges and corners of the hole, which are prone to voids and can easily lead to discontinuity in the grounding path; on the other hand, during subsequent baking and curing and long-term use, a large hole diameter means that more carbon oil is filled into the hole, and the carbon oil will expand when heated and contract when cooled, which may lead to the carbon oil splitting from the hole wall, damaging the structural integrity and conductivity stability of the grounding hole 5020.

[0062] Therefore, controlling the diameter of the first blind hole 1050 within the range of 0.25mm to 1.2mm can ensure smooth filling of carbon oil and avoid material waste, while also avoiding splitting problems caused by excessive expansion and contraction, thus laying the foundation for the reliability of the grounding hole 5020.

[0063] Figure 9 This is a cross-sectional schematic diagram of a filling plate with edge auxiliary holes according to an embodiment of the present invention; Figure 10 for Figure 9 Top view.

[0064] Optionally, the first drilling includes: extending the drilling to the edge of the first blind hole 1050 to form an edge auxiliary blind hole; and filling it in a subsequent process to form an edge auxiliary hole 2040, wherein the diameter of the edge auxiliary hole 2040 is less than or equal to 1 / 2 of the diameter of the first blind hole 1050.

[0065] Since traditional first blind holes 1050 are mostly regular circles with smooth arc-shaped walls in the horizontal direction, this regular structure leads to a relatively regular contact surface between the filled carbon oil and the hole wall. When the carbon oil expands and contracts due to temperature changes during baking and curing, the stress is easily concentrated and released in a fixed direction, causing the carbon oil to split from the blind hole sidewall.

[0066] Therefore, by setting an edge auxiliary hole 2040, this regular circular structure is broken, and an edge auxiliary blind hole is formed at the edge of the first blind hole 1050. This increases the contact area between the carbon oil and the circuit board in the horizontal cross section, making the carbon oil bond with the hole wall tighter. At the same time, the stress generated by expansion and contraction is dispersed to multiple directions, avoiding concentration in one place that could lead to splitting.

[0067] Furthermore, the diameter of the edge auxiliary hole 2040 should not be too large. On the one hand, if the diameter of the edge auxiliary hole 2040 is too large, it will occupy more substrate space and affect the overall wiring layout. On the other hand, an excessively large hole diameter will increase the difficulty of carbon oil filling and may result in incomplete filling. After baking and curing, it may crack or void due to uneven internal stress, which will affect the stability of the grounding hole 5020.

[0068] Furthermore, the center of the edge auxiliary hole 2040 falls within the range of the first blind hole 1050.

[0069] When the arc of the edge auxiliary hole 2040 is less than 180°, the intersection area of ​​the first blind hole 1050 and the edge auxiliary hole 2040 will not form a closed "dead corner". The carbon oil can flow smoothly into every corner along the natural transition of the hole wall, ensuring the reliability of the filling.

[0070] Conversely, if the center of the edge auxiliary hole 2040 falls outside the range of the first blind hole 1050, the arc formed by the intersection of the edge auxiliary blind hole and the first blind hole 1050 will be greater than 180°. At this time, a concave dead angle will appear at the intersection of the two holes. Since carbon oil has a certain viscosity, it is difficult to completely enter this closed dead angle area during filling, and air is easily left behind or unfilled voids are formed, affecting the conductivity continuity and structural stability of the grounding hole 5020.

[0071] Furthermore, there are ≥2 edge auxiliary holes 2040, and several edge auxiliary holes 2040 are non-uniformly distributed on the edge of the first blind hole 1050.

[0072] Setting multiple edge auxiliary holes 2040 can create more irregular protrusions and depressions on the horizontal cross-section of the first blind hole 1050, which is equivalent to adding more "dispersion points" on the contact surface between the carbon oil and the hole wall. When the carbon oil generates expansion and contraction stress due to temperature changes, these dispersion points can guide the stress to different directions and avoid stress concentration in one place.

[0073] Furthermore, the non-uniform distribution method can break the symmetry of the hole structure. If the edge auxiliary holes 2040 are evenly distributed (for example, symmetrically arranged on an axis), the horizontal cross-section of the entire first blind hole 1050 and the edge auxiliary holes 2040 may still show a symmetrical shape. The expansion and contraction stress may be concentrated and released along the axis of symmetry, causing the carbon oil to split from the hole wall.

[0074] The non-uniform distribution causes the positions of each edge auxiliary hole 2040 to be staggered, and the contact area between the carbon oil and the hole wall is more randomly distributed. This randomness allows the stress of the carbon oil during expansion and contraction to be more thoroughly dispersed in all directions, further reducing the risk of carbon oil splitting with the hole wall due to stress concentration.

[0075] Optionally, forming the filler plate 20 includes performing a micro-etching process after the first drilling.

[0076] During the drilling process, the friction between the drill bit and the substrate material causes irregular rough surfaces to appear on the bottom and wall of the first blind hole 1050, resulting in irregular bonding surfaces between the carbon oil and the bottom of the first blind hole 1050, which affects the overall bonding effect between the carbon oil and the first blind hole 1050.

[0077] Therefore, micro-etching is used to slightly corrode the inner wall and bottom of the blind hole to form a uniform rough surface, which can significantly improve the bonding between carbon oil and the hole wall. At the same time, micro-etching can also accurately remove the burrs and flashes generated by drilling at the opening of the first blind hole 1050, ensuring that the edge of the opening is smooth and providing a guarantee for the integrity and stability of subsequent carbon oil filling.

[0078] Optionally, a vacuum plugging machine can be used to fill the carbon oil.

[0079] Filling with carbon oil in a vacuum environment allows the carbon oil to adhere tightly to the hole wall, laying the foundation for a firm bond between the carbon oil and the hole wall after subsequent baking and curing, thereby ensuring the conductivity stability and structural integrity of the grounding hole 5020.

[0080] Furthermore, the first baking and curing process involves baking at a temperature of 75°C to 90°C for 40 to 60 minutes.

[0081] The first baking and curing process brings the carbon oil to a semi-cured state. On the one hand, the semi-cured carbon oil can form a solid base, providing reliable processing conditions for drilling the second blind hole 3010. On the other hand, the semi-cured state also reserves bonding space for the subsequent second filling of carbon oil. Since the carbon oil is not completely cured at this time, the newly filled carbon oil can bond tightly with it, effectively avoiding the occurrence of delamination.

[0082] Furthermore, the baking and curing process involves: first baking at 75°C to 90°C for 40 to 60 minutes; then baking at 100°C to 110°C for 40 to 60 minutes; and finally baking at 120°C to 150°C for 60 to 120 minutes.

[0083] If high-temperature baking is used directly, the resin on the surface will quickly solidify to form a hard shell, while the solvent and unreacted components inside will have difficulty evaporating or continuing to react, resulting in insufficient curing with a "hard outside and soft inside" appearance.

[0084] Segmented heating avoids this problem. By curing in stages, the carbon oil is cured evenly from the inside out, stabilizing the overall structure of the carbon oil and ensuring the long-term reliability of the grounding hole 5020. This effectively avoids the problem of insufficiently cured parts inside expanding and contracting due to temperature changes during subsequent use, which could lead to splitting with the wall of the blind hole.

[0085] Please see Figure 11 , Figure 11 This is a cross-sectional schematic diagram of a metal-based circuit board according to an embodiment of the present invention.

[0086] Step S20:

[0087] The filler board 20 is polished, and then the surface copper layer 1010 is made into a circuit pattern, including a grounding circuit pattern 5010. After subsequent processing, the filler hole 2010 is formed into a grounding hole 5020, and the whole board is formed into a metal base circuit board 50.

[0088] By polishing the protruding carbon oil on the surface of the filling hole 2010, the surface of the carbon oil is made flush with the surface copper layer 1010 of the substrate in the horizontal direction. This avoids problems such as uneven etching of the circuit pattern caused by the protrusion of the carbon oil during subsequent circuit pattern fabrication. Finally, after subsequent processing, the filling hole 2010 forms a grounding hole 5020. At this time, the carbon oil in the grounding hole 5020 uses its own conductivity to complete the electrical connection between the grounding circuit pattern 5010 and the metal base layer 1040, and the whole board forms a metal base circuit board 50.

[0089] It is worth noting that the second blind hole 3010 in this embodiment is made to disperse the expansion and contraction stress of the carbon oil at the bottom of the hole in the vertical direction after plugging; while the edge auxiliary blind hole is made to disperse the expansion and contraction stress of the carbon oil in the horizontal direction of the hole wall after plugging; and the method of partially plugging the first blind hole 1050 first and then plugging it a second time is to make the carbon oil filling more reliable and the baking and curing effect after filling better. Therefore, the features of these three manufacturing methods can be selected according to the grounding effect required and the actual application needs. Alternatively, one can choose to fill the first blind hole 1050 with carbon oil to a partial depth, then make the second half-blind hole 3020, and then fill the first half-blind hole 2020 and the second half-blind hole 3020 with carbon oil (without making the edge auxiliary blind hole) to form a processing process and grounding effect; or one can choose to fill the first blind hole 1050 with carbon oil to a partial depth, then make the edge auxiliary blind hole, and then fill the first half-blind hole 2020 and the edge auxiliary blind hole with carbon oil to form a processing process and grounding effect.

[0090] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for manufacturing a grounding performance metal-based circuit board for intelligent connected vehicles, wherein the metal-based circuit board is processed according to design data, the design data including grounding holes and grounding line patterns, the grounding holes being located within the range of the grounding line patterns, characterized in that, The manufacturing method includes the following steps: S10: According to the design data, a substrate consisting of a surface copper layer, an insulating dielectric layer, an insulating adhesive layer, and a metal base layer is fabricated. A first drilling is performed to form a first blind hole. The first blind hole is then filled with carbon oil, followed by a first baking and curing process. The first blind hole becomes a filled hole, and the entire board is formed into a filled board. The depth of the first drilling extends from the surface copper layer to the metal base layer. The process of forming the filler plate includes drilling a second hole corresponding to the center of the filler hole to form a second blind hole; the depth of the second blind hole is greater than that of the first blind hole, and the diameter of the second blind hole is smaller on one side than that of the first blind hole; then filling the second blind hole with carbon oil, followed by baking and curing, the first blind hole and the second blind hole form the second filler hole, and the whole plate forms the filler plate; or, The process of forming the filler plate includes filling a portion of the first blind hole with carbon oil, leaving the unfilled portion as a first semi-blind hole, followed by the first baking and curing to form a semi-filled hole; drilling a third hole corresponding to the center of the semi-filled hole to form a second semi-blind hole; filling the first and second semi-blind holes with carbon oil, followed by baking and curing to form the filler hole; and finally forming the filler plate from the entire plate. S20: The filler board is polished, and then a circuit pattern is made on the surface copper layer. The circuit pattern includes the grounding circuit pattern. After subsequent processing, the filler hole forms the grounding hole, and the whole board forms the metal base circuit board.

2. The method for manufacturing a grounding performance metal-based circuit board for intelligent connected vehicles as described in claim 1, characterized in that, Forming the filler plate includes performing a micro-etching process after the first drilling.

3. The method for manufacturing a grounding performance metal-based circuit board for intelligent connected vehicles as described in claim 1, characterized in that, The first drilling includes: extending the drilling towards the edge of the first blind hole to form an edge auxiliary hole; the diameter of the edge auxiliary hole is less than or equal to 1 / 2 of the diameter of the first blind hole.

4. The method for manufacturing a grounding performance metal-based circuit board for intelligent connected vehicles as described in claim 3, characterized in that, The center of the edge auxiliary hole falls within the range of the first blind hole.

5. The method for manufacturing a grounding performance metal-based circuit board for intelligent connected vehicles as described in claim 3, characterized in that, There are ≥2 edge auxiliary holes, and several edge auxiliary holes are non-uniformly distributed on the edge of the first blind hole.

6. The method for manufacturing a grounding performance metal-based circuit board for intelligent connected vehicles as described in claim 1, characterized in that, The carbon oil was filled using a vacuum plugging machine.

7. The method for manufacturing a grounding performance metal-based circuit board for intelligent connected vehicles as described in claim 1, characterized in that, The first baking and curing process involves baking at a temperature of 75°C to 90°C for 40 to 60 minutes.

8. The method for manufacturing a grounding performance metal-based circuit board for intelligent connected vehicles as described in claim 1, characterized in that, The baking and curing process is as follows: Bake at 75°C to 90°C for 40 to 60 minutes. Then bake at 100°C to 110°C for 40 to 60 minutes; Finally, bake at 120°C to 150°C for 60 to 120 minutes.

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