Manufacturing method of grounding performance metal-based circuit board for intelligent networked automobile

Abstract

The invention discloses a manufacturing method of a grounding performance metal-based circuit board for an intelligent networked automobile. The manufacturing method comprises the following steps: manufacturing a substrate according to design data, drilling for the first time, filling carbon oil, baking and curing for the first time, forming a filling hole, and forming a filling plate on the whole board; grinding is carried out, a grounding circuit pattern is manufactured on the surface copper layer, and the metal-based circuit board is formed on the whole board through post-process processing; through the manufacturing mode, the problems of hole wall cracking and separation caused by thermal expansion and cold contraction differences of multiple layers of materials of the substrate by adopting a method for forming a grounding circuit through an electroplating hole in the prior art are effectively avoided; meanwhile, complex procedures such as copper deposition and copper plating needed by electroplating are omitted, the processing flow is simplified, compared with silver paste and copper paste filling in the prior art, the carbon oil material is lower in cost and better in material matching performance with the circuit board body, electric connection between the grounding circuit and the metal base layer can be stably achieved, and good grounding performance is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of circuit board manufacturing, and in particular to a method for manufacturing a metal-based circuit board with grounding performance for intelligent connected vehicles. Background Art

[0002] In the field of intelligent connected vehicles, automotive control modules have strict requirements on the performance of circuit boards. On the one hand, since the module generates heat when working, a metal substrate (such as an aluminum substrate, a copper substrate, etc.) is used to ensure good heat dissipation performance; on the other hand, in order to prevent the module from being interfered with by static electricity or generating electromagnetic interference, a grounding circuit needs to be designed on the surface of the board.

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

[0004] (1) Make through holes or blind holes at the position of the circuit that needs to be grounded, and then electroplate to form metallized holes to achieve grounding; however, since the metal substrate is mainly composed of circuit copper, insulating dielectric layer (FR-4, etc.), insulating adhesive layer (epoxy resin layer, acrylic layer, etc.) and metal base layer, the structure is relatively complex, and the hole wall materials are diverse. It is difficult to ensure a balanced electroplating effect during electroplating, which can easily lead to problems such as poor quality of the hole wall copper layer. In addition, during long-term use, the thermal expansion and contraction of the metal substrate will further weaken the bonding force between the hole wall electroplating layer and the hole wall, and then the electroplating layer will split or detach, causing damage to the circuit board.

[0005] Furthermore, the blind hole is a non-through hole, which may cause the problem that the solution is difficult to exchange to the bottom of the blind hole, making it difficult to plate copper, resulting in no copper at the bottom of the blind hole and poor electrical connection. In addition, if the electroplated hole is required to be a solid hole, resin plugging processing is required after electroplating, and the materials used are more complex, and the processing process is long and the cost is high.

[0006] (2) Make through holes or blind holes at the locations of the circuits that need to be grounded, and then use silver paste or copper paste to fill the holes to achieve grounding; however, the material cost of silver paste and copper paste is relatively high, which will significantly increase the processing cost for grounding holes that only require ordinary grounding effects.

[0007] Therefore, in order to solve the above-mentioned problems, 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] The present invention aims to solve the complex processing methods of metal-based circuit boards in the prior art and the difficulty in ensuring processing quality. A method for manufacturing a metal-based circuit board with grounding performance for intelligent connected vehicles is proposed. The metal-based circuit board is manufactured according to design data, which includes a grounding hole and a grounding circuit pattern. The grounding hole is located within the range of the grounding circuit pattern. The manufacturing method includes the following steps:

[0009] S10: According to the design data, a substrate is manufactured, which is composed of a surface copper layer, an insulating dielectric layer, an insulating adhesive layer, and a metal base layer in sequence. A first drilling is performed to form a first blind hole. The first blind hole is then filled with carbon oil. After that, a first baking and curing is performed. The first blind hole becomes a filled hole, and the entire board becomes a filled board. The depth of the first drilling is from the surface copper layer to the metal base layer.

[0010] S20: polishing the filling plate, and then making a circuit pattern on the surface copper layer, the circuit pattern including the grounding circuit pattern, and then through post-processing, the filling hole forms the grounding hole, and the entire plate forms the metal-based circuit board.

[0011] Furthermore, forming the filling plate includes drilling a second hole corresponding to the center of the filling 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 than that of the first blind hole on one side; then filling the second blind hole with carbon oil, and then baking and curing it, the first blind hole and the second blind hole form a second filling hole, and the entire plate forms the filling plate.

[0012] Furthermore, forming the filling plate includes partially filling the depth of the first blind hole with carbon oil, the portion not filled with carbon oil is the first half blind hole, and then performing the first baking and curing to form a half-filled hole; performing a third drilling corresponding to the center of the half-filled hole to form a second half blind hole; then filling the first half blind hole and the second half blind hole with carbon oil, and then baking and curing; forming the filling hole; and forming the filling plate on the entire plate.

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

[0014] Furthermore, the first drilling includes: extending the drilling toward 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, the number of the edge auxiliary holes is ≥2, and the plurality of edge auxiliary holes are unevenly distributed on the edge of the first blind hole.

[0017] Furthermore, a vacuum plugging machine is used to fill the carbon oil.

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

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

[0020] The technical solution of the present invention mainly has the following beneficial effects:

[0021] (1) By making a first blind hole and filling it with carbon oil, a grounding hole structure connecting the surface circuit and the metal base layer is formed, which effectively avoids the problem of hole wall cracking and detachment caused by the difference in thermal expansion and contraction of the multi-layer material of the substrate in the existing technology of using electroplated holes to form the grounding circuit; at the same time, it eliminates the complex processes such as copper deposition and copper plating required for electroplating, simplifying the processing flow; at the same time, compared with the silver paste and copper paste filling in the existing technology, carbon oil has lower cost and better matching with the material of the circuit board body, and can stably realize the electrical connection between the grounding circuit and the metal base layer, ensuring good grounding performance; further, the first blind hole is micro-etched to remove burrs and flashes on the hole wall, and form a uniform rough surface on the hole wall and the hole bottom, greatly improving the bonding strength between the carbon oil and the hole wall.

[0022] (2) By setting up a second blind hole, the originally flat bottom of the 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 between the thermal expansion and contraction of the two. On the other hand, it can make the contact surface of the carbon oil more dispersed and more irregular, preventing the carbon oil from splitting with the hole bottom due to stress concentration, and improving the long-term stability of the grounding hole.

[0023] (3) For the second blind hole setting, a part of the blind hole depth is filled with carbon oil and solidified to provide a solid "base" for drilling the second blind hole, avoiding damage to the hole wall caused by drilling directly into the empty blind hole. The second blind hole is then drilled and the remaining space is filled. This can not only greatly reduce the waste of carbon oil, but also complete the entire filling with the same set of plugging tools without the need to replace equipment, thereby reducing tool costs, shortening the processing process, 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 cross section of the circuit board body is increased, and the horizontal stress during the expansion and contraction of the carbon oil 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) Overall technical process The technical process is logically coherent and the previous and subsequent processes are closely related, forming a method for manufacturing metal-based circuit boards with grounding performance for intelligent connected vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0027] Figure 1 Schematic diagram of the process flow of an embodiment of the present invention;

[0028] Figure 2 Schematic cross-sectional view of a first blind hole plate according to an embodiment of the present invention;

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

[0030] Figure 4 Schematic cross-sectional view of a second blind hole plate according to an embodiment of the present invention;

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

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

[0033] Figure 7 Schematic cross-sectional view of the second half blind hole plate according to an embodiment of the present invention;

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

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

[0036] Figure 10 for Figure 9 A top view of

[0037] Figure 11 Schematic cross-sectional view of a metal base circuit board according to an embodiment of the present invention.

[0038] Explanation of the accompanying 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, filling plate; 2010, filling hole; 20A, half-filled plate; 2020, first half blind via; 2030, half-filled hole; 2040, edge auxiliary hole; 30, second blind via plate; 3010, second blind via; 30A, second half blind via plate; 3020, second half blind via; 40, second filling plate; 4010, second filling hole; 40A, third filling plate; 4020, third filling hole; 50, metal base circuit board; 5010, grounding line pattern; 5020, grounding hole.

[0039] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0041] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, inside, outside, etc.) are only used to explain the relative position relationship and movement status of the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0042] In addition, the terms "first," "second," and so on, used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referenced. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this disclosure, "plurality" means at least two, such as two or three, unless otherwise specifically defined.

[0043] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0044] See also Figure 1 , Figure 1 Schematic diagram of the process flow of an embodiment of the present invention.

[0045] The metal base circuit board of this embodiment is processed according to the design data. The design data 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 described in detail below.

[0046] See also Figure 2 and Figure 3 ; Figure 2 Schematic cross-sectional view of a first blind hole plate according to an embodiment of the present invention; Figure 3 Schematic cross-sectional view of a filling plate according to an embodiment of the present invention.

[0047] Step S10:

[0048] According to the design data, a substrate is manufactured, which consists of a surface copper layer 1010, an insulating dielectric layer 1020, an insulating adhesive layer 1030 and a metal base layer 1040 in sequence. A 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. After a first baking and curing, the first blind hole 1050 becomes a filled hole 2010, and the entire plate forms a filled 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 the subsequent production of circuit patterns. The insulating dielectric layer 1020 and the insulating adhesive layer 1030 play the role of insulation and adhesion respectively, and the metal base layer 1040 assumes the functions of heat dissipation and grounding.

[0050] The substrate is drilled for the first time, and the depth of the first blind hole 1050 formed 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. Carbon oil is then filled into the first blind hole 1050. Carbon oil has good electrical conductivity. After post-processing, electrical connection between the surface copper layer 1010 and the metal base layer 1040 is achieved. In addition, the cost of carbon oil is much lower than that of materials such as silver paste and copper paste.

[0051] See also Figure 4 and Figure 5 , Figure 4 Schematic cross-sectional view of a second blind hole plate according to an embodiment of the present invention; Figure 5 Schematic cross-sectional view of a second filling plate according to an embodiment of the present invention.

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

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

[0054] At the same time, 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 due to stress concentration, and ensuring the structural stability and conductive reliability of the grounding hole 5020.

[0055] See also Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 and Figure 10 , Figure 6 is a schematic cross-sectional view of a half-filled plate according to an embodiment of the present invention; Figure 7 Schematic cross-sectional view of the second half blind hole plate according to an embodiment of the present invention; Figure 8 Schematic cross-sectional view of a third filling plate according to an embodiment of the present invention.

[0056] Optionally, carbon oil is partially filled into the depth of the first blind hole 1050, and the portion not filled with carbon oil is the first half blind hole 2020, which is then baked and cured for the first time to form a half-filled hole 2030; a half-filled plate 20A is formed, and a third hole is drilled corresponding to the center of the half-filled hole 2030 to form a second half blind hole 3020; a second half blind hole plate 30A is formed, and the first half blind hole 2020 and the second half blind hole 3020 are filled with carbon oil, and then baked and cured; a third filling hole 4020 is formed; and the entire plate forms a third filling plate 40A.

[0057] By first filling part of the carbon oil and solidifying it, the originally hollow first blind hole 1050 forms a "semi-solid" structure, providing a stable support foundation for the subsequent drilling of the second half blind hole 3020, ensuring the accuracy of the third drilling and the integrity of the hole wall. If drilling is directly performed in an empty blind hole that is not filled with carbon oil, deformation, burrs and other problems may easily occur due to lack of support of the hole wall.

[0058] On the one hand, filling part of the carbon oil first and then drilling, 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 one time; on the other hand, the entire filling process does not require changing the plugging tool, and the processing can be completed with the same set of equipment, saving the time of changing tools and the purchase cost of additional tools, thereby shortening the processing process 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 into the hole smoothly during the filling process due to the hole diameter being too small, which may easily lead to problems such as incomplete filling and residual bubbles, affecting the filling quality.

[0061] If the hole diameter exceeds 1.2mm, on the one hand, it is difficult for the carbon oil to completely fill the entire hole cavity during filling, especially voids are likely to appear at the edges and corners of the hole, which can easily lead to discontinuous grounding paths; on the other hand, during subsequent baking and curing and long-term use, the large hole diameter means that more carbon oil is filled into the hole, and the carbon oil will expand more when heated and contract more when cooled, which may lead to the carbon oil and the hole wall splitting, thereby destroying the structural integrity and conductive stability of the grounding hole 5020.

[0062] Therefore, controlling the diameter of the first blind hole 1050 within the range of 0.25 mm to 1.2 mm can not only ensure smooth filling of carbon oil and avoid material waste, but also avoid splitting problems caused by excessive expansion and contraction, laying the foundation for the reliability of the grounding hole 5020.

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

[0064] Optionally, the first drilling includes: extending the drilling toward the edge of the first blind hole 1050 to form an edge auxiliary blind hole; and filling the hole through a post-process to form an edge auxiliary hole 2040 , wherein the hole 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 the traditional first blind holes 1050 are mostly regular circles, their hole walls are smooth arc-shaped in the horizontal direction. This regular structure will cause the contact surface between the filled carbon oil and the hole wall to be relatively regular. When the carbon oil expands and contracts due to temperature changes during baking and curing, the stress is easily released in a fixed direction, causing the carbon oil and the side wall of the blind hole to split.

[0066] Therefore, by setting the 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, which increases the contact area between the carbon oil and the circuit board in the horizontal section, makes the carbon oil and the hole wall more tightly bonded, and at the same time disperses the stress generated by expansion and contraction in multiple directions to avoid concentration in a certain place and causing splitting.

[0067] In addition, the hole 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 filling with carbon oil, and it is easy to cause incomplete filling. After baking and curing, it may cause splitting or voids 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", and the carbon oil can flow smoothly into every corner along the natural transition of the hole wall, ensuring the reliability of filling.

[0070] On the contrary, 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 retained or unfilled voids are formed, affecting the conductive continuity and structural stability of the grounding hole 5020.

[0071] Furthermore, the number of the edge auxiliary holes 2040 is ≥2, and the plurality of edge auxiliary holes 2040 are unevenly distributed on the edge of the first blind hole 1050 .

[0072] The provision of multiple edge auxiliary holes 2040 can form 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 to avoid stress concentration in one place.

[0073] Furthermore, the use of non-uniform distribution 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 present a symmetrical shape, and the expansion and contraction stresses may be concentratedly released along the axis of symmetry, resulting in the splitting of the carbon oil and the hole wall.

[0074] The non-uniform distribution makes the positions of each edge auxiliary hole 2040 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 splitting of the carbon oil and the hole wall due to stress concentration.

[0075] Optionally, forming the filling 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 will cause irregular rough surfaces on the bottom and wall of the first blind hole 1050, resulting in irregular bonding between the carbon oil and the bottom of the first blind hole 1050, affecting 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 uniformly rough surface, which can significantly improve the bonding between the carbon oil and the hole wall. At the same time, micro-etching can also accurately remove the burrs and burrs generated by drilling at the opening of the first blind hole 1050, ensuring a smooth edge of the hole, thus providing protection for the integrity and stability of the subsequent carbon oil filling.

[0078] Optionally, use a vacuum plugging machine to fill with carbon oil.

[0079] Filling carbon oil in a vacuum environment allows the carbon oil to fit tightly against 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 conductive stability and structural integrity of the grounding hole 5020.

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

[0081] The carbon oil is semi-solidified through the first baking and curing. On the one hand, the semi-solidified carbon oil can form a solid base, providing reliable processing conditions for the subsequent drilling of the second blind hole 3010; on the other hand, the semi-solidified state also reserves bonding space for the subsequent second filling of carbon oil. Since the carbon oil is not completely solidified at this time, the new carbon oil filled subsequently can be tightly combined with it, effectively avoiding the occurrence of stratification.

[0082] Furthermore, the baking and curing is as follows: first baking at a temperature of 75°C to 90°C for 40 minutes to 60 minutes; then baking at a temperature of 100°C to 110°C for 40 minutes to 60 minutes; and finally baking at a temperature of 120°C to 150°C for 60 minutes 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 be difficult to evaporate or continue to react, resulting in insufficient curing of "hard outside and soft inside".

[0084] The staged heating method can avoid this problem. Through staged curing, the carbon oil can be evenly cured from the inside to the outside, making the overall structure of the carbon oil stable and ensuring the long-term reliability of the grounding hole 5020. It effectively avoids the internal part that is not fully cured from causing additional expansion and contraction due to temperature changes during subsequent use, which may cause problems such as splitting with the blind hole wall.

[0085] See also Figure 11 , Figure 11 Schematic cross-sectional view of a metal base circuit board according to an embodiment of the present invention.

[0086] Step S20:

[0087] The filling plate 20 is polished, and then a circuit pattern is made on the surface copper layer 1010, and the circuit pattern includes a grounding circuit pattern 5010. After further processing, the filling holes 2010 are formed into grounding holes 5020, and the entire plate is formed into a metal-based circuit board 50.

[0088] By grinding and smoothing the protruding carbon oil on the surface of the filling hole 2010, the carbon oil surface is made flush with the surface copper layer 1010 of the substrate in the horizontal direction, thereby avoiding the problem of uneven etching of the circuit pattern due to the protrusion of carbon oil when the circuit pattern is subsequently produced. Finally, after post-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 entire board forms a metal-based circuit board 50.

[0089] It is worth noting that the second blind via 3010 in this embodiment is formed to disperse the vertical expansion and contraction stress of the carbon oil at the bottom of the hole after plugging; the edge auxiliary blind via is formed to disperse the horizontal expansion and contraction stress of the carbon oil along the hole wall after plugging; and the method of partially plugging the first blind via 1050 and then plugging it a second time is to ensure more reliable carbon oil filling and better baking and curing effects after filling. Therefore, the characteristics of these three manufacturing methods can be selected according to the desired grounding effect according to actual application needs. Alternatively, a method can be selected to partially fill the first blind via 1050 with carbon oil, then form the second half blind via 3020, and then fill the first half blind via 2020 and the second half blind via 3020 with carbon oil (without forming the edge auxiliary blind via), thus achieving a complete process and grounding effect; or a method can be selected to partially fill the first blind via 1050 with carbon oil, then form the edge auxiliary blind via, and then fill the first half blind via 2020 and the edge auxiliary blind via with carbon oil, thus achieving a complete process and grounding effect.

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

Claims

1. A method for manufacturing a metal-based circuit board with grounding performance for an intelligent connected vehicle, wherein the metal-based circuit board is processed according to design data, wherein the design data includes a grounding hole and a grounding circuit pattern, wherein the grounding hole is located within the range of the grounding circuit pattern, and wherein: The production method comprises the following steps: S10: According to the design data, a substrate is manufactured, which is composed of a surface copper layer, an insulating dielectric layer, an insulating adhesive layer, and a metal base layer in sequence. A first drilling is performed to form a first blind hole. The first blind hole is then filled with carbon oil. After that, a first baking and curing is performed. The first blind hole becomes a filled hole, and the entire board becomes a filled board. The depth of the first drilling is from the surface copper layer to the metal base layer. S20: polishing the filling plate, and then making a circuit pattern on the surface copper layer, the circuit pattern including the grounding circuit pattern, and then through post-processing, the filling hole forms the grounding hole, and the entire plate forms the metal-based circuit board.

2. The method for manufacturing a metal-based circuit board with good grounding performance for an intelligent connected vehicle according to claim 1, wherein: Forming the filling plate includes drilling a second hole corresponding to the center of the filling 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 than that of the first blind hole on one side; filling the second blind hole with carbon oil, and then baking and curing it. The first blind hole and the second blind hole form a second filling hole, and the entire plate forms the filling plate.

3. The method for manufacturing a metal-based circuit board with good grounding performance for an intelligent connected vehicle according to claim 1, wherein: Forming the filling plate includes partially filling the first blind hole with carbon oil, the portion not filled with carbon oil is the first half blind hole, and then performing the first baking and curing to form a half-filled hole; performing a third drilling corresponding to the center of the half-filled hole to form a second half blind hole; then filling the first half blind hole and the second half blind hole with carbon oil, and then baking and curing to form the filling hole; and forming the filling plate on the entire plate.

4. The method for manufacturing a metal-based circuit board with good grounding performance for an intelligent connected vehicle according to claim 1, wherein: Forming the filler plate includes performing a micro-etching process after the first drilling.

5. The method for manufacturing a metal-based circuit board with good grounding performance for an intelligent connected vehicle according to claim 1 or 2, wherein: The first drilling includes: extending the drilling toward 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.

6. The method for manufacturing a metal-based circuit board with good grounding performance for an intelligent connected vehicle according to claim 5, wherein: The center of the edge auxiliary hole falls within the range of the first blind hole.

7. The method for manufacturing a metal-based circuit board with good grounding performance for an intelligent connected vehicle according to claim 5, wherein: The number of the edge auxiliary holes is ≥2, and the plurality of edge auxiliary holes are unevenly distributed on the edge of the first blind hole.

8. The method for manufacturing a metal-based circuit board with good grounding performance for an intelligent connected vehicle according to claim 1 or 2, wherein: The carbon oil was filled using a vacuum plugging machine.

9. The method for manufacturing a metal-based circuit board with good grounding performance for an intelligent connected vehicle according to claim 1, 2 or 3, wherein: The first baking and curing is: baking at a temperature of 75° C. to 90° C. for 40 minutes to 60 minutes.

10. The method for manufacturing a metal-based circuit board with good grounding performance for an intelligent connected vehicle according to claim 2 or 3, wherein: The baking and curing is as follows: First bake at 75℃ to 90℃ for 40 minutes to 60 minutes; Then bake at 100°C to 110°C for 40 to 60 minutes; Finally, bake at 120℃ to 150℃ for 60 minutes to 120 minutes.

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