Manufacturing method of tin material hole plugging circuit board and circuit board

Abstract

The invention discloses a method for manufacturing a circuit board with holes plugged by tin materials, which comprises the following steps of: manufacturing an inner-layer core board, taking prepregs and copper foils, and stacking and laminating to form a laminated board with a copper layer on the surface; drilling a through hole in the laminated plate to form a through hole plate; electroplating the through hole plate to form an electroplated plate; pasting a protective film on the electroplated plate to form a protective film plate; performing tin immersion processing on the protective film plate to form a tin immersion plate; tearing off the protective film on the surface of the tin immersion plate, and polishing to form a polished plate; a surface circuit pattern is manufactured on the polishing plate, a tin material hole plugging circuit board is formed through post-process machining, and a circuit board is provided and structurally comprises the tin material hole plugging circuit board; the processing plate is immersed in the tin material in the molten state, the through hole is filled with the tin material, the method that solid copper is electroplated or metal slurry is filled to form a conducting solid hole in the prior art is replaced, and the manufacturing method which can meet the signal transmission requirement quality and has the low processing cost is formed.

Description

Technical Field

[0001] The invention relates to the field of printed circuit board processing, and in particular to a method for manufacturing a tin-filled hole circuit board and a circuit board. Background Art

[0002] For circuit boards used in industrial control or communication fields, high requirements are placed on signal transmission performance and signal fidelity. Therefore, the through holes in the circuit boards are made into solid holes to provide a more convenient channel for signal transmission, avoiding detours that easily cause reflection and scattering, which in turn lead to signal disturbance and distortion.

[0003] Currently, there are two general methods for forming solid holes. One is the processing of electroplating solid holes, which mainly uses pulse electroplating to electroplate the hole with copper to form a solid copper through-hole.

[0004] Although the solid holes made by this method have high reliability and good application effect (can meet IPC3 standard), the pulse plating time is long, the consumption of plating solution is large, and there are problems of high processing cost, long time and great difficulty. It is generally suitable for the processing of ultra-high precision circuit boards.

[0005] Another method is to fill the via hole with metal paste (copper paste, silver paste, etc.) to form a solid hole. Although this method has a relatively convenient processing process, the material cost is high and more auxiliary tools are used, resulting in a more complicated processing process.

[0006] For common application fields, such as non-essential consumer electronic products, or electronic products with relatively simple functions (entry-level walkie-talkies, basic mobile phones, electronic remote-controlled toys, etc.), and general reliability requirements (for example, IPC level 1 or 2 standards are sufficient), the use of the above two methods will show the problem of relative excess material technology and excess manufacturing technology.

[0007] Therefore, based on the above background and problems, it is necessary to provide a method for manufacturing a solid hole circuit board that can meet certain requirements for circuit board signal transmission and has relatively low processing costs. Summary of the invention

[0008] The present invention aims at the problems of high processing cost, long processing time, high difficulty and cumbersomeness in the prior art of using pulse electroplating to form electroplated copper solid holes or using plug metal slurry to form plug slurry solid holes. A method for manufacturing a tin plug hole circuit board is provided, and the manufacturing method comprises the following steps: S10: making an inner core board, taking a prepreg and a copper foil, stacking and pressing them to form a pressed board with a copper layer on the surface; S20: drilling through holes in the pressed plate to form a through-hole plate; S30: electroplating the through-hole plate to form an electroplated plate; S40: attaching a protective film to the electroplated plate to form a protective film plate; S50: performing tin immersion processing on the protective film plate to form a tin immersion plate; S60: tearing off the protective film on the surface of the tin-immersion plate, and grinding it to form a grinding plate; S70: making a surface circuit pattern on the polished board, and performing post-processing to form the tin-filled via circuit board.

[0009] Furthermore, the manufacturing of the inner core board includes taking a copper-clad board and manufacturing an inner circuit pattern including a compensation circuit pattern; the compensation circuit pattern corresponds to the through-hole distribution, and a single side of all or part of the sides is larger than the diameter of the through-hole.

[0010] Furthermore, the ratio of the thickness of the through-hole plate to the diameter of the through-hole is 2:1 to 12:1.

[0011] Furthermore, the electroplating is pulse electroplating, and after the pulse electroplating, the through hole forms an "hourglass-shaped" hole with thicker copper thickness in the center and thinner copper thickness at both ends.

[0012] Furthermore, forming the electroplating plate also includes laser ablation processing on the center of the "hourglass-shaped" hole.

[0013] Furthermore, the protective film affixing includes: taking high temperature resistant blue glue, making windows corresponding to the through holes, and then affixing it to the surface of the electroplating board in alignment.

[0014] Optionally, the applying of the protective film includes applying a high temperature resistant dry film to the surface of the electroplating board and making a high temperature resistant dry film pattern, wherein the high temperature resistant dry film pattern is a window pattern corresponding to the through hole.

[0015] Furthermore, the tin immersion process is to completely immerse the protective film plate into the molten tin material in the tin tank and then take it out; the protective film plate is immersed at an angle with the surface of the tin material.

[0016] Furthermore, the grinding is performed using a sanding belt.

[0017] The present invention also provides a circuit board, the structure of which includes the tin-filled hole circuit board produced as above; one side or both sides of the tin-filled hole circuit board are covered by other layers of the circuit board.

[0018] The technical solution of the present invention immerses the processing plate into molten tin and fills the tin into the through holes, replacing the existing method of electroplating solid copper or filling metal slurry to form a conductive solid hole, thereby forming a production method that can meet the quality requirements of signal transmission and has a lower processing cost.

[0019] Furthermore, a compensation circuit pattern is set on the inner core board, which can provide a copper layer foundation in the hole for subsequent pulse electroplating processing, make a through hole and use pulse electroplating to plate the through hole, forming an unclosed "semi-bridge" state, providing a good tin flow channel and exhaust channel for tin immersion and tin filling, and adopting a tin immersion method with a certain angle between the board body and the tin surface, which can improve the smoothness of the tin material flowing into the conductive hole and allow the gas to be discharged smoothly. After tin immersion, it is polished to form a flat board surface, which is conducive to the production of surface circuit patterns. After further processing, a tin-filled hole circuit board is formed. The production method has the advantages of shorter time and lower cost, and can meet the production requirements of basic conductive solid hole circuit boards.

[0020] In addition, a circuit board is also provided, in which the tin-filled via circuit board is regarded as an inner core board and is manufactured inside the circuit board, or a multi-layer circuit board is further stacked based on the tin-filled via circuit board, providing a variety of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0022] Figure 1 The main process flow chart included in this embodiment; Figure 2 is a cross-sectional schematic diagram of the stacked structure of this embodiment; Figure 3 is a schematic cross-sectional view of a pressed plate of this embodiment; Figure 4 is a schematic cross-sectional view of a through-hole plate of this embodiment; Figure 5 is a schematic cross-sectional view of an electroplating plate according to this embodiment; Figure 6 is a schematic cross-sectional view of a protective film plate of this embodiment; Figure 7 is a cross-sectional schematic diagram of a tin-immersion plate according to this embodiment; Figure 8 Schematic diagram of tin immersion processing in this embodiment; Fig. 9 is a schematic cross-sectional view of a grinding plate according to this embodiment; Fig.10 is a schematic cross-sectional view of a tin-filled via circuit board according to this embodiment; Fig.11 is a schematic cross-sectional view of a circuit board according to this embodiment; Fig.12 This is a (partial) physical picture of the board surface after tinning and removing the protective film in this embodiment; Fig.13 This is a real picture of the micro-section observation of the hole position of the tin-filled via circuit board of this embodiment; Fig.14 This is a micro-section (partial) observation of the hole position of the tin-filled via circuit board of this embodiment.

[0023] Explanation of the accompanying drawings: 10, stacked structure; 110, core board; 1110, inner layer circuit pattern; 1120, compensation circuit pattern; 120, prepreg; 130, copper foil; 130A, copper layer; 20, laminated board; 210, insulating dielectric layer; 30, through-hole board; 310, through-hole; 1120F, non-compensated circuit; 40, electroplated board; 410, via hole; 4110, hole copper; 4120, semi-bridged copper layer; 420, electroplated copper layer; 50, protective film board; 510, protective film; 60, tin-immersion board; 610, tin material; 60A, tin cylinder; 60B, molten tin material; 70, polished board; 80, tin-filled circuit board; 810, surface circuit pattern; 90, circuit board; 910, covering layer.

[0024] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] 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...) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0027] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0028] 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 the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0029] See also Figure 1 ; Figure 1 This is a main process flow chart included in this embodiment.

[0030] On the one hand, a method for manufacturing a tin-filled via circuit board according to an embodiment of the present invention comprises: Figure 1 The main production process is described in detail step by step as follows.

[0031] See also Figure 2 , Figure 3 ; Figure 2 is a cross-sectional schematic diagram of the stacked structure of this embodiment; Figure 3 It is a schematic cross-sectional view of the pressed plate of this embodiment.

[0032] Step S10: An inner core board 110 is manufactured, and a prepreg 120 and a copper foil 130 are taken and stacked to form a stacked structure 10, which is then pressed to form a pressed board 20 with a copper layer 130A on the surface.

[0033] This embodiment takes the production of a multi-layer circuit board as an example, and adopts the lamination of a core board and a surface copper foil to form a multi-layer circuit board structure. The multi-layer circuit structure includes an insulating dielectric layer 210 .

[0034] See also Figure 4 ; Figure 4 Schematic cross-sectional view of the through-hole plate of this embodiment.

[0035] Step S20: The through hole 310 is drilled in the press plate 20 to form the through hole plate 30 .

[0036] Furthermore, making the inner core board 110 includes taking a copper clad board and making an inner circuit pattern 1110 including a compensation circuit pattern 1120 ; the compensation circuit pattern 1120 is distributed corresponding to the through hole 310 , and a single side of all or part of the sides is larger than the diameter of the through hole 310 .

[0037] The through hole 310 formed in this embodiment is subsequently processed by deep hole electroplating using pulse plating. In order to provide conditions for the pulse plating to make it easier for copper to be electroplated in the hole, a compensation circuit pattern 1120 is set, especially at a position where a through hole 310 needs to be made but no inner layer circuit pattern 1110 is distributed. After the drilled through hole 310 is made, the compensation circuit pattern 1120 forms an inner hole ring of the through hole 310, which can provide favorable metal layer conditions for the subsequent pulse electroplating to form copper growth in the hole. A complete hole ring is set, and the single side of all sides of the compensation circuit pattern 1120 is larger than the diameter of the through hole 310.

[0038] However, if the inner layer circuit pattern 1110 is densely distributed and the spacing between the through hole 310 and the adjacent circuit is small, resulting in the compensation circuit pattern 1120 not having a large area to be set, it is not necessary to set it, or half of the hole ring can be set, that is, a single side of some sides of the compensation circuit pattern 1120 is larger than the diameter of the through hole 310.

[0039] Preferably, the thickness of the inner layer circuit pattern 1110 is ≤105 μm. In this embodiment, tin material 610 is used to plug the holes. If the inner layer copper is too thick, excessive heat conduction may cause the temperature in the hole to be too high and it is difficult to fill with tin.

[0040] Preferably, all or part of the edges of the compensation circuit pattern 1120 are larger than the diameter of the through hole 310 by 20 μm to 0.1 mm. If the space is large, the hole ring of the inner layer circuit can be appropriately designed to be larger. If the space is small, the hole ring of the inner layer circuit can be appropriately designed to be smaller.

[0041] It can be seen that if the through hole 310 is close to the adjacent inner layer circuit pattern 1110, the compensation circuit pattern 1120 cannot be set at this position, and it is chosen to be left blank, that is, a non-compensation circuit 1120F is formed.

[0042] Further, the ratio of the thickness of the through-hole plate 30 to the diameter of the through-hole 310 is 2:1 to 12:1.

[0043] In the latter step of the present embodiment, the conductive hole 410 is filled with tin material 610. If the ratio of the thickness of the through-hole plate 30 to the diameter of the through-hole 310 is too large (i.e., the thickness-to-diameter ratio is too large), the tin material 610 will not easily enter the hole, resulting in tin-filled voids in the hole and separation from the hole wall. If the ratio is too large, the tin material 610 will easily enter the hole but leak out, resulting in the problem that the tin filling is difficult to remain in the hole.

[0044] See also Figure 5 ; Figure 5 It is a schematic cross-sectional view of the electroplating plate of this embodiment.

[0045] Step S30: The through-hole board 30 is electroplated to form the electroplated board 40 ; before the electroplating, a pre-treatment is required to clean the board body and perform copper deposition processing.

[0046] Furthermore, the electroplating is pulse electroplating, and after the through hole 310 is subjected to pulse electroplating, an "hourglass-shaped" hole is formed with thicker copper thickness in the center and thinner copper thickness at both ends; the diameter of the minimum channel position of the "hourglass-shaped" hole is ≥0.2mm.

[0047] Pulse plating can be applied to situations where strict requirements are placed on the copper thickness of the inner wall of the hole and the copper plating rate. Pulse plating can be used to form solid holes (solid holes are filled with plated copper). The process is "pulse plating → bridging → filling with copper" for the through hole 410. The "bridging" is the growth of copper in the center of the hole (copper at both ends of the intersecting holes) first. After the growth is completely closed, a "bridge" body is formed from micro-section observation.

[0048] In the present embodiment, when the thickness-to-diameter ratio of the circuit board is relatively small, pulse plating is used, and only a half-bridge copper layer 4120 is formed inside the conductive hole 410. Even if the thickness of the half-bridge copper layer 4120 grows to a certain extent at the center of the hole, it is not completely closed, and there is still a relatively small hole in the middle, which provides a flow channel for the molten tin material 60B to enter the hole during subsequent tinning. The reason why pulse plating is used to process the half-bridge copper layer 4120 for the circuit board with a relatively small thickness-to-diameter ratio is that the tin material 610 in the hole with a relatively small thickness-to-diameter ratio (as described above) is easy to enter the hole but easy to leak out, and the state of the half-bridge copper layer 4120 can increase the thickness-to-diameter ratio to a certain extent, and the copper grown in the hole can provide more favorable adhesion conditions for the tin material 610.

[0049] Optionally, the main processing parameters of pulse plating are: forward current is 2.0A·dm -2 Up to 7.0A·dm -2 , reverse current is 10.0A·dm -2 Up to 25.0A·dm -2 , the pulse time ratio (forward: reverse) is 80:2 to 80:10, and the jet frequency is 30Hz to 60Hz.

[0050] After electroplating, the surface of the copper layer 130A is also electroplated with a certain thickness of electroplated copper layer 420, which can be used for subsequent surface circuit processing.

[0051] It has been verified that the minimum diameter of the "hourglass-shaped" hole formed should not be too small, that is, the channel of the hole remaining after the half-bridge copper layer 4120 should not be too small, otherwise it will cause problems such as tin filling blockage and voids.

[0052] It is worth noting that compared with the solid copper holes formed by direct pulse electroplating, this embodiment combines the feature of pulse electroplating that can make the copper growth rate in the center of the hole faster than that at both ends of the hole, and subsequently uses tin filling to replace the direct copper plating filling process, which effectively reduces the processing cost and greatly improves the processing efficiency.

[0053] It is worth noting that compared with the processing method of using ordinary electroplating to directly thicken the overall hole copper 4110, the use of pulse electroplating can avoid excessive thickening of the surface copper thickness and prevent the increase of difficulty in subsequent processing steps. On the other hand, the cost of thickening the overall hole copper 4110 is higher.

[0054] Furthermore, forming the electroplating plate 40 also includes performing laser ablation processing on the center of the “hourglass-shaped” hole.

[0055] In order to effectively ensure that the central channel of the half-bridge copper layer 4120 of the "hourglass-shaped" hole is unobstructed and to prevent problems such as copper thorns at the edge of the half-bridge copper layer 4120 formed by pulse electroplating, laser ablation can be used for trimming to make the channel unobstructed.

[0056] See also Figure 6 ; Figure 6 is a schematic cross-sectional view of a protective film plate of this embodiment; Step S40: The protective film 510 is attached to the plated plate 40 to form the protective film plate 50 .

[0057] Furthermore, attaching the protective film 510 includes: taking high temperature resistant blue glue, making windows corresponding to the through holes 310, and then aligning and attaching it to the surface of the electroplating board 40.

[0058] In the post-process tin immersion processing, tin is only filled into the via hole 410, so the protective film 510 is used to cover the area that does not need to be filled with tin, and a window needs to be made to expose the via hole 410. Optionally, the single side of the window is 20μm to 50μm larger than the single side of the via hole 410, providing an error tolerance range for alignment; the temperature of the tin tank is generally 250℃ to 288℃, and the high-temperature resistant blue glue needs to withstand the temperature shock.

[0059] Furthermore, applying the protective film 510 includes applying a high temperature resistant dry film to the surface of the electroplating board 40 and making a high temperature resistant dry film pattern, wherein the high temperature resistant dry film pattern is a window pattern corresponding to the through hole 310 .

[0060] The use of high temperature resistant dry film for window opening has higher precision and is more conducive to high precision processing of circuit boards.

[0061] See also Figure 7 , Figure 8 ; Figure 7is a cross-sectional schematic diagram of a tin-immersion plate according to this embodiment; Figure 8 Schematic diagram of tin immersion processing in this embodiment.

[0062] Step S50: The protective film plate 50 is subjected to tin immersion processing to form a tin immersion plate 60; Furthermore, the tin immersion process is to completely immerse the protective film 50 into the molten tin material 60B in the tin tank 60A, and then take it out; the protective film 50 is immersed at an angle with the surface of the molten tin material 60B.

[0063] Optionally, the present embodiment may use the existing tin spraying process (hot air leveling process) of the tin cylinder 60A for processing, while not turning on the hot air blowing function; optionally, the time for the protective film plate 50 to be immersed in and removed from the tin cylinder 60A is 1s to 5s.

[0064] Immersing at an angle (rather than immersing perpendicularly to the tin surface) can make the via 410 form an angle with the tin surface, so that when the molten tin 60B flows into the via 410, it is less likely to cause congestion and blockage, and it is more conducive to exhaust and prevents problems such as tin plugging and voids. Optionally, the angle between the protective film 50 and the tin surface is 3° to 10°.

[0065] Optionally, after the tinning process, the tinning plate 60 is left to cool naturally, or cooled by blowing natural wind.

[0066] See also Fig. 9 , Fig. 9 is a schematic cross-sectional view of a grinding plate according to this embodiment; Step S60: The protective film 510 on the surface of the tin-immersion plate 60 is torn off and polished to form a polished plate 70 .

[0067] Further, the grinding is grinding with a sanding belt grinding plate; optionally, the grinding parameters that can be used for the sanding belt grinding plate are: 800 mesh sanding belt grinding once and then 1200 mesh sanding belt grinding once, or 1000 mesh sanding belt grinding twice and then 1200 mesh sanding belt grinding once, or 800 mesh sanding belt grinding once and then 1000 mesh sanding belt grinding once and then 1200 mesh sanding belt grinding once.

[0068] Since the hardness of the tin material 610 is lower than that of the electroplated copper, the belt grinding can select appropriate grinding parameters according to the height and size of the tin material 610 protruding from the board surface to avoid excessive grinding of the copper surface.

[0069] It is worth mentioning that after polishing, if it is necessary to cover the tin surface with copper, the surface copper layer can be further thickened by electroplating.

[0070] See also Fig.10 , Fig.10It is a cross-sectional schematic diagram of the tin-filled via circuit board of this embodiment.

[0071] Step S70: The surface circuit pattern 810 is made on the polished board 70, and after post-processing, a tin-filled via circuit board 80 is formed.

[0072] See also Fig.11 , Fig.11 Schematic diagram of the cross section of the circuit board of this embodiment.

[0073] On the other hand, a circuit board 90 is provided, the structure of which includes the tin-filled hole circuit board 80 formed as described above; one side or both sides of the tin-filled hole circuit board 80 are covered by other layers of the circuit board 90 (i.e. Fig.11 The covering layer 910 in FIG.

[0074] The tin-plugged circuit board 80 produced in this embodiment can be selected as a finished board, or it can be made into an internal layer of the circuit board 90 to play the role of the core board 110 according to the application, structure, and processing requirements, or other layers can be further pressed based on the tin-plugged circuit board 80 to form other circuit board products.

[0075] See also Fig.12 , Fig.13 and Fig.14 ; Fig.12 This is a (partial) physical picture of the board surface after tinning and removing the protective film in this embodiment; Fig.13 This is a real picture of the micro-section observation of the hole position of the tin-filled via circuit board of this embodiment; Fig.14 This is a micro-section (partial) observation of the hole position of the tin-filled via circuit board of this embodiment.

[0076] It can be seen that the tin filling effect of the via hole 410 after tin immersion is good. The microsection shows that the hole is fully filled with tin without voids, poor bonding and other problems. After testing, all performances meet the requirements of relevant IPC standards.

[0077] It is worth noting that due to the actual design and processing of circuit boards, the actual structure diagram and the thickness of each layer, line width and other dimensions are all in the micron level. For example, the thickness of each layer is generally 5μm to 50μm. If the drawings in the specification are made according to the actual proportion, there will be a problem of unclear drawings. Therefore, in order to more clearly show the implementation process of the manufacturing method, the drawings of this embodiment are all schematic diagrams that enlarge the technical features, which do not represent the size of the actual structure diagram, nor do they represent enlarged views of the actual structure diagram in proportion.

[0078] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for manufacturing a tin-filled via circuit board, characterized in that: The production method comprises the following steps: S10: making an inner core board, taking a prepreg and a copper foil, stacking and pressing them to form a pressed board with a copper layer on the surface; S20: drilling through holes in the pressed plate to form a through-hole plate; S30: electroplating the through-hole plate to form an electroplated plate; S40: attaching a protective film to the electroplated plate to form a protective film plate; S50: performing tin immersion processing on the protective film plate to form a tin immersion plate; S60: tearing off the protective film on the surface of the tin-immersion plate, and grinding it to form a grinding plate; S70: making a surface circuit pattern on the polished board, and performing post-processing to form the tin-filled via circuit board.

2. The method for manufacturing a tin-filled via circuit board according to claim 1, characterized in that: The manufacturing of the inner core board includes taking a copper-clad board and manufacturing an inner circuit pattern including a compensation circuit pattern; the compensation circuit pattern corresponds to the through hole distribution, and a single side of all or part of the sides is larger than the diameter of the through hole.

3. The method for manufacturing a tin-filled via circuit board according to claim 1, characterized in that: The ratio of the thickness of the through-hole plate to the diameter of the through-hole is 2:1 to 12:

1.

4. The method for manufacturing a tin-filled via circuit board according to claim 1, characterized in that: The electroplating is pulse electroplating, and after the through hole is subjected to the pulse electroplating, an "hourglass-shaped" hole is formed with thicker copper thickness in the center and thinner copper thickness at both ends.

5. The method for manufacturing a tin-filled via circuit board according to claim 4, characterized in that: Forming the electroplating plate also includes laser ablation processing on the center of the "hourglass-shaped" hole.

6. The method for manufacturing a tin-filled via circuit board according to claim 5, characterized in that: The protective film affixing process comprises: taking high temperature resistant blue glue, making windows corresponding to the through holes, and then affixing the protective film to the surface of the electroplating board in an aligned manner.

7. The method for manufacturing a tin-filled via circuit board according to claim 5, characterized in that: The step of attaching the protective film includes attaching a high temperature resistant dry film to the surface of the electroplating board and making a high temperature resistant dry film pattern, wherein the high temperature resistant dry film pattern is a window pattern corresponding to the through hole.

8. The method for manufacturing a tin-filled via circuit board according to claim 1, 6 or 7, characterized in that: The tin immersion process is to completely immerse the protective film plate into the molten tin material in the tin tank and then take it out; the protective film plate is immersed at an angle with the surface of the tin material.

9. The method for manufacturing a tin-filled via circuit board according to claim 1, characterized in that: The grinding is performed by using a sanding belt and a sanding plate.

10. A circuit board, characterized in that: The structure of the circuit board comprises the tin-filled via circuit board as claimed in any one of claims 1 to 9; one side or both sides of the tin-filled via circuit board are covered by other layers of the circuit board.

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