A manufacturing method of a long board circuit board, the long board circuit board and an electronic product

Abstract

The present invention discloses a manufacturing method of a long-board circuit board, a long-board circuit board and an electronic product. The long-board circuit board is formed by overlapping m short circuit boards end to end. The short circuit board is a double-layer circuit board or a multi-layer circuit board, and includes a front circuit layer, a back circuit layer and an intermediate insulating layer therebetween. A plurality of vias are provided on the short circuit board. Adjacent short circuit boards are joined together at the overlapping position, and there are at least two copper layers sandwiched in the middle at the overlapping position, including a first copper layer on one of the short circuit boards and a second copper layer on the adjacent short circuit board; or, adjacent short circuit boards are joined together at the overlapping position, and there is only one copper layer sandwiched in the middle at the overlapping position, and this copper layer is located on one of the short circuit boards, and adjacent short circuit boards are joined to this copper layer through the intermediate insulating layer at the overlapping position; or, there is no copper layer sandwiched in the middle at the overlapping position, and the two intermediate insulating layers at the overlapping position are joined together.

Description

Technical Field

[0001] The present invention relates to the field of circuit boards, and more specifically, to a method for manufacturing a long circuit board, a long circuit board, and an electronic product. Background Art

[0002] For double-sided or multi-layer (referring to 3 layers or more) flexible circuit boards, the circuit design can be more complex and variable, thus having a wider range of uses. In order to achieve the interconnection and conduction between the upper and lower layers or multiple layers of circuits, the currently common method is to drill holes and then fabricate conductive materials on the hole walls and electroplate copper, so that an electroplated copper layer is formed on the hole walls, and the electroplated copper layer on the hole walls is used to achieve the interconnection and conduction between the upper and lower layers or multiple layers of circuits. Taking a double-sided circuit board as an example, the current process for manufacturing a double-sided circuit board is as follows:

[0003] ①. Single-piece production method: A double-sided flexible copper clad laminate with a length of more than 100 meters produced in a whole roll is cut into short copper clad laminates with a length of less than 1 meter (including 1 meter), and then more than 20 pieces are stacked together and drilled simultaneously. Then, conductive materials and electroplated copper are fabricated on the hole walls, and through processes such as circuit etching, a flexible circuit board with a length of 1 meter and 1 meter or less is produced. Due to the short length of the flexible circuit board, long-board assembly line production (whole-roll production) cannot be achieved during the production process of the circuit board and when attaching electronic components. Compared with short-board production, long-board production has a higher degree of automation, higher efficiency, and requires fewer workers. For the same output, the number of workers in whole-roll production is only half of that in short-board production. For whole-roll production, long boards are not prone to wrinkling and jamming, while during short-board production, the corners of the boards are prone to warping, resulting in problems such as board jamming and wrinkling when passing through the assembly line. Moreover, since many products must use long boards, for example, LED light strips on the market with a length of 5 meters and above account for 90% of the industry share, and long flexible circuit boards must be used, the short boards obtained by the single-piece production method cannot meet the usage requirements.

[0004] ②. Whole-roll long-board production method: The whole-roll long copper clad laminate is drilled with a laser drilling machine. Currently, it is all single-layer drilling, drilled section by section, with very low efficiency. Moreover, the laser drilling machine for drilling copper clad laminates is very expensive. Generally speaking, the price of a two-axis laser drilling machine and a two-axis ordinary needle-type drilling machine (mechanical drilling) differs by more than twice. The former is about 700,000 yuan per unit, and the latter is about 300,000 yuan per unit; from the perspective of the working principle, the laser drilling machine can only drill a single copper clad laminate (limited by the laser penetration ability, unable to drill multiple sheets simultaneously), while the ordinary needle-type drilling machine can stack at least 20 flexible copper clad laminates, resulting in a 20-fold difference in working efficiency and a 40-fold difference in return on investment between the ordinary needle-type drilling machine and the laser drilling machine. For the whole-roll production of long flexible double-sided circuit boards, since a laser drilling machine must be used, the investment is too large, and the input-output ratio is very low, resulting in too high costs and making it difficult to popularize and promote.

[0005] To this end, the inventor has developed a method for manufacturing a long-board circuit board (patent application number: 202211246353.0). By bonding a short copper-clad laminate (single-layer copper) with via holes to a bare circuit board (or bare copper foil), a double-layer circuit board is obtained (the short copper-clad laminate serves as the front copper layer, and the bare circuit board or bare copper foil serves as the back copper layer). However, as shown in Figure 7 As shown, through actual production, it is found that since the short copper-clad laminate needs to be press-bonded to the bare circuit board, during the pressing process, the adhesive is not cured and has a certain fluidity. Under the action of the pressing force, the adhesive will be extruded (referred to as overflow adhesive a) and fill the back copper layer in the via holes, resulting in the back copper layer (bottom copper) in the via holes being partially or completely covered by the adhesive. If the overflow adhesive completely covers the bottom copper, it will bring the defect that the upper and lower layers of the circuit cannot be conducted at the via hole position; if the overflow adhesive partially covers the bottom copper, the surface of the overflow adhesive is uneven, making the copper plating layer b bonded at the overflow adhesive place not firm during subsequent conductive material treatment and copper plating of the hole wall, forming voids and gaps. When performing SMT soldering on the circuit board, since it needs to pass through a reflow soldering furnace above 200 °C, the copper bonded to the surface of the overflow adhesive will delaminate and separate during the furnace passing, resulting in a low yield rate during mass production.

[0006] To this end, it is necessary to further improve and optimize the existing manufacturing method, structure, etc. of the long-board circuit board. Summary of the Invention

[0007] The present invention aims to solve at least one of the problems in the prior art. To this end, the present invention provides a method for manufacturing a long-board circuit board, a long-board circuit board, and an electronic product, in which there is no overflow adhesive phenomenon in the via holes, and the copper plating layer at the via hole position is firmly bonded.

[0008] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0009] In a first aspect, an embodiment of the present invention provides a method for manufacturing a long-board circuit board, including:

[0010] Material preparation: Prepare a long copper-clad laminate, the long copper-clad laminate includes a front copper layer and a back copper layer respectively located on its upper and lower surfaces, and there is an intermediate insulating layer between the front copper layer and the back copper layer;

[0011] Adhesive application: Apply adhesive at intervals on the long copper-clad laminate, so that a plurality of adhesive positions arranged at intervals are formed in the length direction of the long copper-clad laminate;

[0012] Board cutting: Cut the long copper-clad laminate into multiple short copper-clad laminates. The short copper-clad laminate includes an A board with adhesive at both ends; or the short copper-clad laminate includes an A board with adhesive at both ends and a B board without adhesive at both ends; or the short copper-clad laminate includes a C board with adhesive at one end;

[0013] Hole making: Stack multiple short copper clad laminates and then drill holes so that via holes are formed in the short copper clad laminates, and the via holes penetrate the front copper layer, the back copper layer, and the intermediate insulating layer;

[0014] Board connection: Stack the m short copper clad laminates with holes made, end to end, and bond the overlapping positions together with adhesive at the ends;

[0015] Electroplating the via holes;

[0016] Circuit production.

[0017] Optionally, in the shearing process, cut at the glue position to obtain board A with glue at both ends; or, in the shearing process, cut outside the glue position to obtain board A with glue at both ends and board B without glue at both ends; or, in the shearing process, cut simultaneously at the glue position and on the long copper clad laminate between adjacent glue positions to obtain board C with glue at one end.

[0018] Optionally, it further includes a copper removal process, such that the interlayer copper at the overlapping position is partially removed to form a toothed end, and the end-to-end overlapping positions are bonded together with the glue at the toothed end; or it further includes a copper removal process, such that the interlayer copper at the overlapping position is completely removed, and the end-to-end overlapping positions bond the two intermediate insulating layers together with glue; or, it further includes a copper removal process, such that the interlayer copper at the overlapping position is partially removed, and there is only one copper layer sandwiched in the overlapping position.

[0019] Optionally, before applying glue, perform the copper removal process on the long copper clad laminate; or perform the copper removal process after applying glue and before shearing; or perform the copper removal process at one or both ends of the short copper clad laminate after shearing and before hole making; or perform the copper removal process at one or both ends of the short copper clad laminate after hole making and before board connection; or perform the copper removal process on the overlapping position after board connection.

[0020] Optionally, the length of the long copper clad laminate > 3 meters, and the length of the short copper clad laminate ≤ 3 meters.

[0021] In a first aspect, an embodiment of the present invention further provides another method for manufacturing a long board circuit board, including:

[0022] Material preparation: Prepare m short copper clad laminates, and the short copper clad laminates include a front copper layer and a back copper layer located on their upper and lower surfaces respectively, and there is an intermediate insulating layer between the front copper layer and the back copper layer;

[0023] Hole making: Stack multiple short copper clad laminates and then drill holes so that via holes are formed in the short copper clad laminates, and the via holes penetrate the front copper layer, the back copper layer, and the intermediate insulating layer;

[0024] Gluing: Glue is applied to both ends of all short copper clad laminates to obtain Plate A; alternatively, Plate A is obtained by applying glue to both ends of a part of the short copper clad laminates, and the short copper clad laminates without glue applied to both ends form Plate B; or, glue is applied to one end of the short copper clad laminate to obtain Plate C;

[0025] Board connection: m short copper clad laminates with holes made are overlapped end to end, and the overlapping positions are bonded together by the glue at the ends;

[0026] Electroplating through holes;

[0027] Circuit production.

[0028] Optionally, it further includes a copper removal process, such that the interlayer copper at the overlapping position is partially removed to form a toothed end, and the overlapping positions at the head and tail are bonded together by the glue at the toothed end; or it further includes a copper removal process, such that the interlayer copper at the overlapping position is completely removed, and the overlapping positions at the head and tail are bonded together by the glue to bond the two intermediate insulating layers; or, it further includes a copper removal process, such that the interlayer copper at the overlapping position is partially removed, and there is only one copper layer sandwiched in the middle at the overlapping position.

[0029] Optionally, before hole making, a copper removal process is performed at one or both ends of the short copper clad laminate; or after hole making and before gluing, a copper removal process is performed at one or both ends of the short copper clad laminate; or after gluing, a copper removal process is performed at one or both ends of the short copper clad laminate; or, after board connection, a copper removal process is performed at the overlapping position.

[0030] Optionally, the copper removal process is as follows: using a mold or a milling cutter, simultaneously cutting off the copper layer and the intermediate insulating layer at the tooth groove position to obtain a fully hollowed tooth groove; or, using a milling cutter or a laser, removing the unnecessary copper on the front copper layer or / and the back copper layer of the copper clad laminate, and retaining the intermediate insulating layer at the tooth groove position to obtain a semi-hollowed tooth groove; or, applying an anti-etching material on the copper clad laminate, exposing the positions of the copper clad laminate where the copper layer needs to be removed, and then putting the copper clad laminate coated with the anti-etching material into an etching solution for etching, etching away the front copper layer or / and the back copper layer of the copper clad laminate not covered by the anti-etching material, and retaining the intermediate insulating layer at the tooth groove position to obtain a semi-hollowed tooth groove; or removing the copper at the ends of the front copper layer or / and the back copper layer, such that the ends of the front or / and the back are copper-free.

[0031] Optionally, the gluing is printing glue, or pasting glue, or dispensing glue.

[0032] Optionally, the circuit production includes photoresist, exposure, development, and etching the circuit.

[0033] Optionally, the copper clad laminate is a double-layer board; or the copper clad laminate is a multi-layer board, and an inner layer circuit layer is sandwiched between the intermediate insulating layers, and the inner layer circuit layer has been made before drilling.

[0034] Optionally, after the circuit production, a solder mask layer is further produced.

[0035] One of the beneficial effects of the first aspect of the present invention is at least as follows: By selecting a copper clad laminate with a front copper layer and a back copper layer, applying glue and shearing the long copper clad laminate to obtain short copper clad laminates or directly applying glue to the short copper clad laminates, and then splicing the boards, in the board splicing process, the adjacent short copper clad laminates overlap at the head and tail, and the overlapping positions are bonded together by the glue at the ends. Only the head and tail ends of the adjacent short copper clad laminates overlap. The via holes can be arranged to avoid the overlapping positions, and the uncured glue at the overlapping positions will not enter the via holes to form glue overflow; and since the copper clad laminate has a front copper layer and a back copper layer, the adhesive between the front copper layer and the back copper layer is already in a cured state, and during board splicing, the adhesive between the front copper layer and the back copper layer will not be pressed into the via holes at non-overlapping positions to form glue overflow. That is, the embodiment of the present invention will not form a glue overflow phenomenon in the via holes, abandoning the previous method of making long boards by bonding short copper clad laminates (single-layer copper) to a bare circuit board or copper foil to obtain a double-layer circuit board, completely overcoming the glue overflow defect brought by the previous long board production method. Thus, the long board circuit board obtained has a firmly bonded copper plating layer at the via hole position and is not easy to loosen, and the front copper layer and the back copper layer can form a good and reliable conduction at the via hole position; the embodiment of the present invention drills holes after stacking multiple short copper clad laminates, improving the production efficiency of via holes, splicing the drilled short copper clad laminates into a long board, realizing the production of a whole roll of long boards in subsequent processes, improving the production efficiency of the circuit board, and achieving the balance between cost and efficiency.

[0036] In a second aspect, an embodiment of the present invention provides a long board circuit board, which is characterized in that it includes: the long board circuit board is formed by overlapping and splicing m short circuit boards at the head and tail. The short circuit board includes a front circuit layer, a back circuit layer, and an intermediate insulating layer therebetween. A plurality of via holes are provided on the short circuit board, and the via holes penetrate through the front circuit layer, the back circuit layer, and the intermediate insulating layer. The short circuit board is a double-layer circuit board or a multi-layer circuit board. The adjacent short circuit boards are combined together at the overlapping positions, and there are at least two copper layers sandwiched in the middle at the overlapping positions, including a first copper layer on one of the short circuit boards and a second copper layer on the adjacent short circuit board; or, the adjacent short circuit boards are combined together at the overlapping positions, and there is only one copper layer sandwiched in the middle at the overlapping positions, and this copper layer is located on one of the short circuit boards, and the adjacent short circuit boards are combined with this copper layer through the intermediate insulating layer at the overlapping positions; or, there is no copper layer sandwiched in the middle at the overlapping positions, and the two intermediate insulating layers at the overlapping positions are combined together.

[0037] Optionally, two adjacent short circuit boards are electrically connected to each other, and are electrically connected through sidewall copper connection, or / and through solder connection.

[0038] Optionally, when the first copper layer and / or the second copper layer are / is present at the overlapping position, the first copper layer and / or the second copper layer have a toothed end portion, the toothed end portion includes tooth protrusions and tooth grooves, the tooth protrusions form tooth protrusion circuits, and part or all of the tooth protrusion circuits are connected to the circuits at the non-overlapping position, and part or all of the tooth grooves disconnect the adjacent circuits; or, at the overlapping position, the first copper layer and the second copper layer do not have a toothed shape.

[0039] Optionally, at the position of the tooth groove, the first copper layer and / or the second copper layer form a toothed shape, and the intermediate insulating layer at the position of the tooth groove is retained; or the first copper layer and the second copper layer form a toothed shape, and at the position of the tooth groove, only one intermediate insulating layer is retained; or at the position of the tooth groove, the intermediate insulating layer and all copper layers form tooth grooves.

[0040] Optionally, at the overlapping position, the length of the overlapping position is less than the length of the tooth protrusions.

[0041] Optionally, a solder mask layer is further included, and the solder mask layer covers the tooth grooves; or the solder mask layer does not cover the tooth grooves.

[0042] Optionally, when the first copper layer and the second copper layer are present at the overlapping position, the first copper layer and the second copper layer are not connected to the circuits at the non-overlapping position, or at least one line extends out and is connected to the circuits at the non-overlapping position.

[0043] Optionally, there are at least two circuits connected between adjacent short circuit boards.

[0044] One of the beneficial effects of the embodiments of the second aspect of the present invention is at least as follows: The long circuit board is formed by overlapping and butting a plurality of short circuit boards end to end. The short circuit board includes a front circuit layer, a back circuit layer, and an intermediate insulating layer therebetween. Adjacent short circuit boards are bonded and fixed at the overlapping position through an adhesive layer. The vias can be arranged to avoid the overlapping position, and the uncured adhesive at the overlapping position will not enter the vias to form overflow glue, because the glue in the copper clad laminate for making the short circuit board has formed a stable cured state, so that in subsequent processes such as drilling and board connection, the cured glue (without fluidity) around the vias will not be squeezed into the vias to form overflow glue. Abandoning the previous method of making a long board by bonding a short copper clad laminate (single-layer copper) to a bare circuit board or copper foil to obtain a double-layer circuit board, it completely overcomes the overflow glue defect brought by the previous long board making method. At the via position of the long circuit board, the copper plating layer is firmly bonded and not easy to loosen, and the front circuit layer and the back circuit layer can form good and reliable conduction at the via position.

[0045] In a third aspect, an embodiment of the present invention provides an electronic product, including the long circuit board according to any one of the embodiments of the second aspect, and electronic components are soldered on the long circuit board.

[0046] Optionally, the electronic product is an automobile, a robot or an LED light strip. Description of the Drawings

[0047] Figure 1.1 is a schematic plan view of the long copper clad laminate after sizing in an embodiment of the present invention;

[0048] Figure 1.2 is Figure 1.1 a schematic plan view of the short copper clad laminate (A plate) obtained after cutting;

[0049] Figure 1.3 is another schematic plan view of the long copper clad laminate after sizing in an embodiment of the present invention;

[0050] Figure 1.4 is Figure 1.3 a schematic plan view of the short copper clad laminate (A plate + B plate) obtained after cutting;

[0051] Figure 1.5 is another schematic plan view of the long copper clad laminate after sizing in an embodiment of the present invention;

[0052] Figure 1.6 is Figure 1.5 a schematic plan view of the short copper clad laminate (C plate) obtained after cutting;

[0053] Figure 1.7 is another schematic plan view of the long copper clad laminate after sizing in an embodiment of the present invention;

[0054] Figure 1.8 is Figure 1.7 a schematic plan view of the short copper clad laminate (C plate) obtained after cutting;

[0055] Figure 1.9 is Figure 1.8 a schematic cross-sectional view thereof (the short copper clad laminate is schematically drawn as one layer, but actually includes a front copper layer, a back copper layer and an intermediate insulating layer);

[0056] Figure 2.0 is Figure 1.4 a schematic plan view after hole making;

[0057] Figure 2.1 is Figure 2.0 a schematic plan view when the short copper clad laminates are overlapped end to end to form a long plate;

[0058] Figure 2.2 is Figure 2.1 a schematic plan view after etching;

[0059] Figure 2.3 is Figure 2.2 a schematic plan view after making a solder mask;

[0060] Figure 2.4 is a schematic plan view (without applying glue) of the short copper clad laminate after hole making in an embodiment of the present invention;

[0061] Figure 3.1 is to select Figure 2.1 a three-dimensional structure schematic diagram of two adjacent short copper clad laminates at position A in (without toothed ends, via holes not drawn) when not overlapped;

[0062] Figure 3.2 is Figure 3.1 a schematic cross-sectional structure diagram of the short copper clad laminate in;

[0063] Figure 3.3 is Figure 3.1 a three-dimensional structure schematic diagram of the two short copper clad laminates shown when overlapped end to end;

[0064] Figure 3.4 is Figure 3.3 a front projection schematic diagram of the two short copper clad laminates shown when overlapped end to end;

[0065] Figure 3.5 is Figure 3.4 a schematic cross-sectional structure diagram at the overlapping position;

[0066] Figure 3.6 is Figure 3.3 a three-dimensional structure schematic diagram after electroplating (copper electroplating adhered to the surface);

[0067] Figure 3.7 is Figure 3.6 a schematic cross-sectional structure diagram at the overlapping position;

[0068] Figure 3.8 is Figure 3.6 a three-dimensional structure schematic diagram after etching;

[0069] Figure 3.9 is Figure 3.8 a schematic cross-sectional structure diagram at the overlapping position;

[0070] Figure 4.1 is to select Figure 2.1 a three-dimensional structure schematic diagram of two adjacent short copper clad laminates at position A in (one of the short copper clad laminates has toothed ends, via holes not drawn) when not overlapped;

[0071] Figure 4.2 is Figure 4.1 a three-dimensional structure schematic diagram of the two short copper clad laminates shown when overlapped end to end;

[0072] Figure 4.3 is Figure 4.2 a schematic cross-sectional structure diagram at the overlapping position;

[0073] Figure 4.4 isFigure 4.2 Schematic diagram of the three-dimensional structure after electroplating (copper electroplating is attached to the surface);

[0074] Figure 4.5 is Figure 4.4 Schematic diagram of the cross-sectional structure at the overlapping position;

[0075] Figure 4.6 is Figure 4.4 Schematic diagram of the three-dimensional structure after etching;

[0076] Figure 4.7 is Figure 4.6 Schematic diagram of the cross-sectional structure at the overlapping position;

[0077] Figure 5.1 is to select Figure 2.1 Schematic diagram of the three-dimensional structure of two adjacent short copper clad laminates at position A when not overlapped (both short copper clad laminates have toothed ends, and the via holes are not drawn);

[0078] Figure 5.2 is Figure 5.1 Schematic diagram of the three-dimensional structure when the two short copper clad laminates shown overlap end to end;

[0079] Figure 5.3 is Figure 5.2 Schematic diagram of the cross-sectional structure at the overlapping position;

[0080] Figure 5.4 is Figure 5.2 Schematic diagram of the three-dimensional structure after electroplating (copper electroplating is attached to the surface);

[0081] Figure 5.5 is Figure 5.4 Schematic diagram of the cross-sectional structure at the overlapping position;

[0082] Figure 5.6 is Figure 5.4 Schematic diagram of the three-dimensional structure after etching;

[0083] Figure 5.7 is Figure 5.6 Schematic diagram of the cross-sectional structure at the overlapping position;

[0084] Figure 5.8 is Figure 5.6 Schematic diagram of the cross-sectional structure at the non-overlapping position;

[0085] Figure 6.1 Cross-sectional view of the short copper clad laminate at the via hole position;

[0086] Figure 6.2 is Figure 6.1 Cross-sectional view after electroplating;

[0087] Figure 6.3 Schematic diagram of the structure after connecting multiple short copper clad laminates;

[0088] Figure 6.4 It is another schematic structural view after multiple short copper clad laminates are joined together;

[0089] Figure 7 It is a schematic cross-sectional structure view of the prior art when there is glue overflow on a double-sided circuit board (the copper plating layer cannot be firmly bonded to the bottom copper at the glue overflow position);

[0090] Explanation of the reference numerals in the drawings: 1 - long copper clad laminate, 11 - front copper layer, 12 - back copper layer, 13 - intermediate insulating layer, 131 - insulating film, 132 - adhesive layer, 2 - glue position, 3 - short copper clad laminate, 4 - via hole, 5 - toothed end, 51 - tooth convex, 52 - tooth groove, 6 - short circuit board, 61 - front circuit layer, 62 - back circuit layer, 63 - first copper layer, 64 - second copper layer, 65 - sidewall copper, 7 - solder mask layer, a - glue overflow, b - copper plating layer. Detailed implementation manners

[0091] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, without conflict, the embodiments described below and the features in the embodiments can be combined arbitrarily with each other.

[0092] Many different implementation manners or examples are provided below to implement the methods and structures of the present invention.

[0093] See Figures 1.1 - 5.8 , an embodiment of the first aspect of the present invention provides a method for manufacturing a long board circuit board.

[0094] Embodiment 1:

[0095] Prepare materials: Prepare a long copper clad laminate 1. The so-called long copper clad laminate refers to a copper clad laminate with a length > 3 meters. In this embodiment, the length of the long copper clad laminate is selected as 30 meters. The long copper clad laminate includes a front copper layer 11 and a back copper layer 12 respectively located on its upper and lower surfaces, and there is an intermediate insulating layer 13 between the front copper layer 11 and the back copper layer 12; the long copper clad laminate 1 can be a double-sided copper clad laminate, that is, the copper layer only has a front copper layer and a back copper layer, or the long board copper clad laminate can be a multi-layer copper clad laminate. In the industry, multi-layer means 3 layers or more layers. Taking 3 layers as an example, they are a front copper layer, a back copper layer, and a sandwiched wire copper layer. The sandwiched wire copper layer has been made into a circuit to form an inner circuit layer. The long copper clad laminate is a mature technology in the art and will not be elaborated further.

[0096] Gluing: Glue is applied at intervals on the long copper clad laminate 1 so as to form a plurality of glue positions 2 arranged at intervals in the length direction of the long copper clad laminate 1; The gluing method can be screen printing, such as by pad printing; It can also be carried out by pasting glue, that is, pasting the glue strip on the long copper clad laminate, or it can be carried out by dispensing glue using a glue dispenser; Refer to Figure 1.1 , Figure 1.3 , Figure 1.5 and Figure 1.7 shown, which is a schematic plan view of the long copper clad laminate after gluing at intervals;

[0097] Plate cutting: Use a cutting machine to cut the long copper clad laminate into multiple short copper clad laminates 3. The so-called short copper clad laminate refers to a copper clad laminate with a length ≤ 3 meters. In this embodiment, the number of short copper clad laminates obtained by cutting is 20. Depending on the cutting position, the obtained short copper clad laminates are different. The short copper clad laminates 3 obtained by cutting can be A plates with glue at both ends (such as Figure 1.2 shown), or a part of A plates with glue at both ends and another part of B plates without glue at both ends (such as Figure 1.4 shown); It can also be C plates with glue at one end (such as Figure 1.6 , Figure 1.8 shown); Specifically, refer to Figure 1.1 and Figure 1.2 shown. In the plate cutting process, cut at the glue positions of the Figure 1.1 shown long copper clad laminate with glue to obtain the Figure 1.2 shown A plates with glue at both ends; Or, refer to Figure 1.3 and Figure 1.4 shown. In the plate cutting process, cut outside the glue positions. After cutting, there are two types of short copper clad laminates obtained. One is A plates with glue at both ends, and the other is B plates without glue at both ends; Or, refer to Figure 1.7 and Figure 1.8 shown. In the plate cutting process, cut both at the glue positions and on the long copper clad laminate between adjacent glue positions to obtain C plates with glue at one end; It can also be as Figure 1.5 and Figure 1.6 shown. Cut on one side of the glue position to obtain C plates with glue at one end.

[0098] Hole making: After stacking multiple short copper clad laminates, use a needle drill to drill holes so that via holes 4 are formed on the short copper clad laminates. Compared with the traditional single-hole drilling of long copper clad laminates, in this embodiment, multiple short copper clad laminates are stacked and then drilled, enabling hole making to be completed simultaneously on multiple short copper clad laminates in one drilling operation, with high hole-making efficiency. The obtained via holes penetrate the front copper layer, the back copper layer, and the intermediate insulating layer; when stacking multiple short copper clad laminates, in order to prevent the glue on the short copper clad laminate from bonding to the short copper clad laminate stacked on it, a release paper can be set on the glue. For example, for the glue application method of pasting glue strips, the pasted glue strips already come with a release paper. For the glue application methods of printing glue or dispensing glue, a release paper can be made on the glue after glue application; regarding the via holes, refer to Figure 2.1 and Figures 6.1 - 6.2 . In this embodiment, the obtained via holes 4 penetrate the front copper layer 11, the back copper layer 12, and the intermediate insulating layer 13, where the intermediate insulating layer 13 includes an insulating film 131 and adhesive layers 132 on the upper and lower surfaces of the insulating film 131. The adhesive layers 132 are used to bond the front copper layer 11 and the back copper layer 12.

[0099] Board connection: Stack the m short copper clad laminates 3 with holes made, end to end, and bond the overlapping positions together with the glue at the ends. In the shearing process, there are various situations for the obtained short copper clad laminates. When the obtained is the A board with glue at both ends as shown in Figure 1.2 , stack the A boards end to end and use a press to press them so that the glue at the overlapping positions bonds adjacent short copper clad laminates together; when the cut is the A board + B board as shown in Figure 1.4 , for two adjacent short copper clad laminates, one is selected as the A board and the other is selected as the B board; when the cut is the C board as shown in Figure 1.6 or Figure 1.8 , both adjacent short copper clad laminates are selected as C boards, and the end with glue and the end without glue are overlapped and combined; depending on the board connection method, after connecting multiple adjacent short copper clad laminates 3, refer to Figure 6.3 and Figure 6.4 as shown.

[0100] Electroplated via holes, a conductive material layer is fabricated on the hole wall of the via holes and the side walls of the overlapping positions. The fabrication of the conductive material can be completed on the black hole line, the polymer conductive adhesive line, or the electroless copper plating line. The conductive materials are graphite, polymer conductive adhesive, or copper (all of which are prior arts). Then, electroplating is performed to form a copper plating layer on the hole wall of the via holes and the side walls of the overlapping positions. The copper plating layer in the via holes connects the front copper layer and the back copper layer, and the copper plating layer on the side walls (side wall copper) connects the short copper clad laminates on both sides of the overlapping position. Since when fabricating the via holes, the glue on the intermediate insulating layer that combines the front copper layer and the back copper layer has been cured, there will be no overflow of glue on the hole wall of the via holes, and the hole wall of the via holes is very straight, making the copper plating layer firmly bonded in the via holes and no voids will be formed; the thickness of the conductive material is very thin, only about 1 μm. After electroplating, the copper plating layer and the conductive material are integrated. The function of the conductive material is to make the hole wall and the side walls conductive and connect the copper layers at the hole wall and the side walls. However, this layer of conductive material is too thin and the conductivity is insufficient, and copper must be electroplated again to achieve sufficient conductivity. During electroplating, the hole wall and the side walls need to be electrically connected to form a current path so that a layer of copper can be plated on the hole wall and the side walls to form a copper plating layer.

[0101] Circuit fabrication, the circuit fabrication method is a well-known technology in the art. Specifically, the etching method can be used to fabricate the circuit, including hole photoresist, exposure, development, and circuit etching.

[0102] In some embodiments of the present invention, a copper removal process is further included, so that the interlayer copper at the overlapping position is partially removed to form a toothed end 5, and the head and tail overlapping positions are bonded together by the glue of the toothed end 5. Specifically, refer to Figures 4.1 - 5.7 As shown, the toothed end can be provided on one of the adjacent short copper clad laminates, such as Figure 4.1 As shown, toothed ends can also be formed on both of the two adjacent short copper clad laminates, such as Figure 5.1 As shown; in some other embodiments of the present invention, a copper removal process is further included, so that the interlayer copper at the overlapping position is completely removed, and the head and tail overlapping positions are bonded together by the glue to bond the two intermediate insulating layers together, that is, there is no interlayer copper at the overlapping position (this interlayer copper does not include the inner circuit layer already sandwiched in the multilayer board itself). Specifically, for the glue that bonds the overlapping position together, the intermediate insulating layers are bonded to its upper surface and lower surface, rather than the copper layers; in some other embodiments of the present invention, a copper removal process is further included, so that the interlayer copper at the overlapping position is partially removed, and there is only one layer of copper sandwiched in the overlapping position, that is, for two adjacent short copper clad laminates, one of the short copper clad laminates has a layer of copper removed at the overlapping end to expose the intermediate insulating layer, and the copper at the overlapping end of the other short copper clad laminate is not removed.

[0103] Regarding the copper removal process, it can be implemented at different stages. Specifically, in some embodiments, the copper removal process is implemented on the long copper clad laminate before sizing. After preparing the long copper clad laminate, copper can be removed at the sizing position by a mold or a milling cutter, and then sizing is performed after copper removal; in some embodiments of the present invention, the copper removal process is implemented after sizing and before shearing the board, that is, after sizing, the unnecessary copper at the sizing position and the adhesive corresponding to the unnecessary copper are removed together by a mold or a milling cutter. It can be understood that this method is applicable to the case of forming a toothed end; in some embodiments of the present invention, the copper removal process is implemented at one or both ends of the short copper clad laminate after shearing and before hole making, and a toothed end can also be formed; in other embodiments, the copper removal process can also be implemented at one or both ends of the short copper clad laminate after hole making and before board connection; in other embodiments, the copper removal process can be implemented at the overlapping position after board connection, and this method is applicable to the case of forming a toothed end, and the unnecessary copper, the adhesive at the groove position, and the intermediate insulating layer are removed together.

[0104] The above embodiments are realized by applying adhesive on the long copper clad laminate and then shearing the board. However, this is not the only way. Therefore, the first aspect embodiment of the present invention also provides another method for manufacturing a long board circuit board.

[0105] Embodiment 2:

[0106] Material preparation: Prepare m short copper clad laminates 3. The short copper clad laminate includes a front copper layer 11 and a back copper layer 12 respectively located on its upper and lower surfaces. There is an intermediate insulating layer 13 between the front copper layer 11 and the back copper layer 12, and the length of the short copper clad laminate ≤ 3 meters;

[0107] Hole making: Drill holes after stacking multiple short copper clad laminates 3, so that via holes 4 are formed on the short copper clad laminates. Drilling holes once to form via holes on multiple short copper clad laminates to improve the hole making efficiency. Refer to Figure 2.4 As shown, the via holes penetrate through the front copper layer, the back copper layer, and the intermediate insulating layer;

[0108] Sizing: Apply adhesive to both ends of all short copper clad laminates 3 to obtain board A; or, apply adhesive to both ends of some short copper clad laminates 3 to obtain board A, and do not apply adhesive to both ends of the other part of short copper clad laminates 3 to form board B; or, apply adhesive to one end of the short copper clad laminate 3 to obtain board C. It can be understood that in this embodiment, hole making can be performed before sizing, or sizing can be performed before hole making; it can be understood that the sizing method is not limited to the above three.

[0109] Board connection: Overlap the m short copper clad laminates 3 with holes made at the head and tail, and bond the overlapping positions together with the adhesive at the ends;

[0110] Electroplating the via holes, which is the same as in Embodiment 1;

[0111] The circuit manufacturing process is the same as that in the above-mentioned Embodiment 1 and will not be elaborated here.

[0112] In Embodiment 2, the copper removal process can also be carried out. As a result, the interlayer copper at the overlapping position is partially removed to form a toothed end, and the head and tail overlapping positions are bonded together by the glue at the toothed end; or the copper removal process is carried out so that the interlayer copper at the overlapping position is completely removed, and the head and tail overlapping positions are bonded together by the glue to bond the two intermediate insulating layers; or, it further includes a copper removal process, so that the interlayer copper at the overlapping position is partially removed, and there is only one copper layer sandwiched in the overlapping position.

[0113] In Embodiment 2, the copper removal process can be implemented at different stages. Specifically, before hole making, the copper removal process is implemented at one or both ends of the short copper clad laminate; or after hole making and before glue application, the copper removal process is implemented at one or both ends of the short copper clad laminate; or after glue application, the copper removal process is implemented at one or both ends of the short copper clad laminate; or, after board connection, the copper removal process is implemented at the overlapping position.

[0114] In Embodiment 1 and Embodiment 2, regarding the copper removal process, there can be different choices as to whether the intermediate insulating layer between the front copper layer and the back copper layer is removed together when removing copper, whether all the copper is removed when removing copper, and what method is used for copper removal. Specifically, in some embodiments, the copper removal process is as follows: using a mold or a milling cutter, the copper layer and the intermediate insulating layer at the tooth groove position are simultaneously cut off to obtain a fully hollowed tooth groove, as specifically shown in Figure 4.1 and Figure 5.1 ; in some other embodiments, a milling cutter or a laser is used to remove the unnecessary copper on the front copper layer or / and the back copper layer of the copper clad laminate, and the intermediate insulating layer at the tooth groove position is retained to obtain a semi-hollowed tooth groove; in some other embodiments, the copper etching method can also be used for copper removal. Specifically, an anti-etching material (well-known material) is coated on the copper clad laminate to expose the positions of the copper clad laminate where the copper layer needs to be removed, and then the copper clad laminate coated with the anti-etching material is put into the etching solution for etching, and the front copper layer or / and the back copper layer of the copper clad laminate not covered by the anti-etching material is etched away, and the intermediate insulating layer at the tooth groove position is retained to obtain a semi-hollowed tooth groove; or the copper at the ends of the front copper layer or / and the back copper layer is removed so that the ends of the front or / and the back are copper-free. At this time, the interlayer copper at the overlapping position is completely removed, and the head and tail overlapping positions are bonded together by the glue to bond the two intermediate insulating layers.

[0115] In Embodiment 1 and Embodiment 2, after the circuit manufacturing, a solder mask is also manufactured, and the obtained long board circuit board is a complete circuit board. The manufacturing of the solder mask includes the manufacturing of the front solder mask and the back solder mask. The solder mask can be a solder mask film, such as a PET film, or it can also be a solder mask ink.

[0116] In Embodiment 1 and Embodiment 2, by using a copper-clad laminate with a front copper layer and a back copper layer (the short copper-clad laminate with a single layer of copper used in the prior art was bonded to a bare circuit board or copper foil), the long copper-clad laminate was glued and sheared to obtain a short copper-clad laminate or directly glued on the short copper-clad laminate, and then the boards were joined. In the board joining process, the adjacent short copper-clad laminates overlapped head to tail, and the overlapping positions were bonded together by the glue at the ends. Only the head and tail ends of the adjacent short copper-clad laminates overlapped. The vias could be arranged to avoid the overlapping positions (in the prior art, the short copper-clad laminate with a single layer of copper was entirely bonded and overlapped on the bare circuit board or copper foil, so that the vias on the short copper-clad laminate with a single layer of copper could not avoid the overlapping positions, and when bonded and overlapped, the glue between the short copper-clad laminate and the bare circuit board (or copper foil) was in an uncured state, and the uncured glue would enter the vias to form glue overflow). In this embodiment, since the copper-clad laminate has a front copper layer and a back copper layer, the adhesive between the front copper layer and the back copper layer has been in a cured state. When joining the boards, the glue at the via positions has been cured and shaped, and will not be extruded by the pressing force during board joining and flow out to the wall of the vias. That is, in the embodiment of the present invention, no glue overflow phenomenon will occur in the vias, abandoning the long board manufacturing method of bonding the previous short copper-clad laminate (single layer of copper) to the bare circuit board or copper foil, overcoming the glue overflow defect brought by the previous long board manufacturing method. The long board circuit board thus obtained has a firmly bonded copper plating layer at the via positions and is not prone to loosening. The front copper layer and the back copper layer can form a good and reliable conduction at the via positions; in the embodiment of the present invention, by stacking multiple short copper-clad laminates and then drilling holes, the efficiency of via manufacturing is improved. After drilling, the short copper-clad laminates are joined into a long board, realizing the production of a whole roll of long boards in subsequent processes, improving the production efficiency of the circuit board, and achieving the balance between cost and efficiency.

[0117] According to the methods of the above Embodiment 1 and Embodiment 2, the embodiments of the second aspect of the present invention can be obtained: Refer to Figure 3.8 、 Figure 3.9 、 Figure 4.6 、 Figure 4.7 、 Figure 5.6 、 Figure 5.7As shown, a long board circuit board includes: the long board circuit board is formed by overlapping and connecting m short circuit boards 6 end to end. The short circuit board 6 includes a front circuit layer 61, a back circuit layer 62, and an intermediate insulating layer 13 therebetween. A plurality of vias 4 are provided on the short circuit board 6, and the vias 4 penetrate through the front circuit layer 61, the back circuit layer 62, and the intermediate insulating layer 13. The short circuit board is a double-layer circuit board or a multi-layer circuit board. Adjacent short circuit boards 6 are joined together at the overlapping position, and there are at least two copper layers sandwiched in the overlapping position, including a first copper layer 63 on one of the short circuit boards and a second copper layer 64 on the adjacent short circuit board. That is, for two adjacent short circuit boards, one on top is called the upper circuit board and one below is called the lower circuit board. At the overlapping position, the back circuit layer of the upper circuit board is not removed or not completely removed, and the front circuit layer of the lower circuit board is not removed or not completely removed; or, adjacent short circuit boards 6 are joined together at the overlapping position, and there is only one copper layer sandwiched in the overlapping position, and this copper layer is located on one of the short circuit boards. The adjacent short circuit boards are joined to this copper layer through the intermediate insulating layer at the overlapping position. That is, the back circuit layer of the upper circuit board is not removed or not completely removed, and the front circuit layer of the lower circuit board is completely removed to expose the intermediate insulating layer; it is also possible to retain the front circuit layer of the lower circuit board and remove the back circuit layer of the upper circuit board to expose the intermediate insulating layer; or, there is no copper layer sandwiched in the overlapping position, and the two intermediate insulating layers at the overlapping position are joined together. That is, at the overlapping position, the metals of the back circuit layer of the upper circuit board and the front circuit layer of the lower circuit board are completely removed to expose their respective intermediate insulating layers, and the two intermediate insulating layers are joined together. It can be understood that in this embodiment, the joining is achieved by means of glue.

[0118] In some embodiments of the present invention, referring to Figure 3.8 , Figure 3.9 , Figure 4.6 , Figure 4.7 , Figure 5.6 , Figure 5.7 As shown, two adjacent short circuit boards are electrically connected to each other. Specifically, the electrical connection can be achieved through sidewall copper 65, and the sidewall copper 65 is a copper plating layer formed in the electroplating process; in other embodiments of the present invention, the two adjacent short circuit boards can also be electrically connected through soldering, and the soldering can be carried out simultaneously when soldering electronic components. Thus, the long board circuit board can be directly used as a long board after soldering electronic components.

[0119] In some embodiments of the present invention, when the first copper layer 63 and / or the second copper layer 64 are present at the overlapping position, the first copper layer 63 and / or the second copper layer 64 have a toothed end 5, and the toothed end 5 includes tooth protrusions 51 and tooth grooves 52. The tooth protrusions 51 form tooth protrusion circuits. According to the requirements of circuit design, the tooth protrusion circuits used as circuits can be all connected to the circuits at non-overlapping positions, or partially connected to the circuits at non-overlapping positions; the tooth grooves 52 can completely disconnect or partially disconnect the adjacent circuits (adjacent in the width direction of the circuit board). In other embodiments of the present invention, at the overlapping position, the first copper layer 63 and the second copper layer 64 do not have teeth. If the presence of the first copper layer and / or the second copper layer causes a short circuit, the long circuit board can be sheared at the overlapping position to form a short circuit board. Specifically, in some embodiments, when making an LED light strip in a whole roll of the long circuit board, after the LED light strip is made, the LED light strip can be cut at the overlapping position for use, or cut into section circuit boards before welding electronic components for use.

[0120] Regarding the position of the tooth groove, there are multiple situations. Specifically, at the position of the tooth groove, the first copper layer and / or the second copper layer form teeth, and the intermediate insulating layer at the tooth groove position is retained; or, the first copper layer and the second copper layer form teeth, and at the position of the tooth groove, only one intermediate insulating layer is retained, that is, the intermediate insulating layer of the short circuit board where the first copper layer (or the second copper layer) is located at the tooth groove position is retained, and the intermediate insulating layer of the short circuit board where the second copper layer (or the first copper layer) is located at the tooth groove position is removed; or, at the position of the tooth groove, the intermediate insulating layer and all copper layers form tooth grooves, that is, the intermediate insulating layer can be retained at the tooth groove position, or there can be no intermediate insulating layer. This is brought about by the formation method of the toothed end, and the formation method of the toothed end has been described in detail above.

[0121] The setting of the toothed end can divide the interlayer copper sandwiched at the overlapping position into multiple circuits when the tooth groove disconnects the adjacent circuits, so that the circuit board will not short-circuit at the overlapping position, and the circuit board can be directly used as a long board after welding electronic components.

[0122] In some embodiments of the present invention, at the overlapping position, the length of the overlapping position is less than the length of the tooth protrusion, so that the tooth groove can separate the copper layers at the overlapping position and avoid short circuit formation.

[0123] In some embodiments of the present invention, it further includes a solder mask layer 7, and the solder mask layer covers the tooth groove 52; or the solder mask layer does not cover the tooth groove 52.

[0124] When there is a first copper layer and a second copper layer at the overlapping position, the first copper layer and the second copper layer may not be connected to the circuits at the non-overlapping positions. After the long board circuit board is welded with electronic components, it is cut at the overlapping position to obtain a short LED light strip; alternatively, at least one line extends to be connected to the circuit at the non-overlapping position. Thus, the LED light strip made from the long board circuit board can be used as a long light strip.

[0125] In some embodiments of the present invention, there are at least two circuits connected between adjacent short circuit boards 6, generally two main lines of positive and negative are connected, so that the long board circuit board can be used as a long board. The specific connection can be achieved through the above-mentioned toothed end portions and sidewall copper.

[0126] As can be analyzed above, the long board circuit board of the embodiment of the present invention is formed by overlapping and lapping a plurality of short circuit boards end to end. The short circuit board includes a front circuit layer, a back circuit layer and an intermediate insulating layer therebetween. Adjacent short circuit boards are bonded and fixed at the overlapping position through an adhesive layer. The via holes can be arranged to avoid the overlapping position, and the uncured adhesive at the overlapping position will not enter the via holes to form overflow glue; because the glue in the copper clad laminate for making the short circuit board has formed a stable cured state, it will not squeeze the cured glue (without fluidity) around the via holes into the via holes to form overflow glue during subsequent processes such as drilling and board connection. Abandoning the previous long board manufacturing method of bonding short copper clad laminates (single-layer copper) on bare circuit boards or copper foils, it completely overcomes the overflow glue defect brought by the previous long board manufacturing method. At the via hole position of the long board circuit board, the copper plating layer is firmly combined and not easy to loosen, and the front circuit layer and the back circuit layer can form good and reliable conduction at the via hole position. See Figure 6.1 and Figure 6.2 As shown, at the via hole 4 position, no overflow glue will be generated, and the copper plating layer b can be well combined on the hole wall of the via hole 4, so as to conduct the front copper layer 11 and the back copper layer 12 well; see Figure 7 As shown, for the long board circuit board manufactured by the prior art, there is obvious overflow glue a in the via hole. The surface of the overflow glue a is uneven, so that when electroplating copper subsequently, the copper plating layer b combined at the overflow glue place is not firm, forming a cavity gap, and finally affecting the reliable conduction between the front copper layer and the back copper layer.

[0127] An embodiment of the third aspect of the present invention provides an electronic product, including the long board circuit board described in any one of the above embodiments. Electronic components are welded on the long board circuit board, and the electronic product is an automobile, a robot or an LED light strip.

[0128] The above has described the embodiments of the present invention in detail with reference to the drawings. However, the present invention is not limited to the above embodiments. Within the knowledge scope of those of ordinary skill in the art to which the present invention pertains, various changes can be made without departing from the purpose of the present invention.

Claims

1. A manufacturing method of a long board circuit board, characterized in that , including: Stock preparation: Prepare a long copper clad laminate, which includes a front copper layer and a back copper layer located on its upper and lower surfaces respectively, and an intermediate insulating layer is provided between the front copper layer and the back copper layer; Glue application: Apply glue at intervals on the long copper clad laminate, so as to form a plurality of glue positions arranged at intervals in the length direction of the long copper clad laminate; Plate cutting: Cut the long copper clad laminate into multiple short copper clad laminates. The short copper clad laminate includes a type-A plate with glue at both ends; or the short copper clad laminate includes a type-A plate with glue at both ends and a type-B plate without glue at both ends; or the short copper clad laminate includes a type-C plate with glue at one end; Hole making: Stack multiple short copper clad laminates and then drill holes, so that via holes are formed on the short copper clad laminates, and the via holes penetrate through the front copper layer, the back copper layer and the intermediate insulating layer; Plate connection: Overlap the m short copper clad laminates with holes made, and the overlapping positions are bonded together by the glue at the ends; Electroplate the via holes; Circuit production.

2. The manufacturing method of a long board circuit board according to claim 1, characterized in that : In the plate cutting process, cut at the glue positions to obtain a type-A plate with glue at both ends; or, in the plate cutting process, cut outside the glue positions to obtain a type-A plate with glue at both ends and a type-B plate without glue at both ends; or, in the plate cutting process, cut both at the glue positions and on the long copper clad laminate between adjacent glue positions to obtain a type-C plate with glue at one end.

3. The manufacturing method of a long board circuit board according to claim 1, characterized in that : It also includes a copper removal process, so that the interlayer copper at the overlapping positions is partially removed to form a toothed end, and the head and tail overlapping positions are bonded together by the glue at the toothed ends; or it also includes a copper removal process, so that the interlayer copper at the overlapping positions is completely removed, and the head and tail overlapping positions bond the two intermediate insulating layers together by glue; or, it also includes a copper removal process, so that the interlayer copper at the overlapping positions is partially removed, and there is only one copper layer sandwiched in the overlapping position.

4. The manufacturing method of a long board circuit board according to claim 3, characterized in that : Before glue application, perform a copper removal process on the long copper clad laminate; or after glue application and before plate cutting, perform a copper removal process; or after plate cutting and before hole making, perform a copper removal process at one or both ends of the short copper clad laminate; or after hole making and before plate connection, perform a copper removal process at one or both ends of the short copper clad laminate; or after plate connection, perform a copper removal process on the overlapping positions.

5. The manufacturing method of a long board circuit board according to claim 1, characterized in that , including: The long copper clad laminate > 3 meters, and the short copper clad laminate ≤ 3 meters.

6. A manufacturing method of a long board circuit board, characterized in that , including: Stock preparation: Prepare m short copper clad laminates, which include a front copper layer and a back copper layer located on its upper and lower surfaces respectively, and an intermediate insulating layer is provided between the front copper layer and the back copper layer; Hole making: Stack multiple short copper clad laminates and then drill holes, so that via holes are formed on the short copper clad laminates, and the via holes penetrate through the front copper layer, the back copper layer and the intermediate insulating layer; Glue application: Apply glue at both ends of all short copper clad laminates to obtain type-A plates; or, apply glue at both ends of some short copper clad laminates to obtain type-A plates, and the other short copper clad laminates without glue at both ends form type-B plates; or, apply glue at one end of the short copper clad laminate to obtain type-C plates; Plate connection: Overlap the m short copper clad laminates with holes made, and the overlapping positions are bonded together by the glue at the ends; Electroplate the via holes; Circuit production.

7. The manufacturing method of a long-board circuit board according to claim 6, characterized in that : It also includes a copper removal process, such that the interlayer copper at the overlapping position is partially removed to form a toothed end, and the head and tail overlapping positions are bonded together by the glue at the toothed end; or it also includes a copper removal process, such that the interlayer copper at the overlapping position is completely removed, and the head and tail overlapping positions are bonded together by the glue between the two intermediate insulating layers; or, it also includes a copper removal process, such that the interlayer copper at the overlapping position is partially removed, and there is only one copper layer sandwiched in the overlapping position.

8. The manufacturing method of a long board circuit board according to claim 7, characterized in that : Before hole making, the copper removal process is implemented at one or both ends of the short copper clad laminate; or after hole making and before glue application, the copper removal process is implemented at one or both ends of the short copper clad laminate; or after glue application, the copper removal process is implemented at one or both ends of the short copper clad laminate; or, after board connection, the copper removal process is implemented at the overlapping position.

9. The manufacturing method of a long-board circuit board according to claim 4 or 8, characterized in that : The copper removal process is as follows: using a mold or a milling cutter to simultaneously cut off the copper layer and the intermediate insulating layer at the tooth groove position to obtain a fully hollowed tooth groove; or, using a milling cutter or a laser to remove the unnecessary copper on the front copper layer or / and the back copper layer of the copper clad laminate, and retaining the intermediate insulating layer at the tooth groove position to obtain a semi-hollowed tooth groove; or, applying an anti-etching material on the copper clad laminate to expose the positions of the copper layers that need to be removed on the copper clad laminate, and then putting the copper clad laminate coated with the anti-etching material into an etching solution for etching to etch away the front copper layer or / and the back copper layer that is not covered by the anti-etching material, and retaining the intermediate insulating layer at the tooth groove position to obtain a semi-hollowed tooth groove; or removing the copper at the ends of the front copper layer or / and the back copper layer so that the ends of the front or / and the back are copper-free.

10. The manufacturing method of a long board circuit board according to any one of claims 1-8, characterized in that : The glue application is screen printing glue, or sticking glue, or dispensing glue.

11. A method for manufacturing a long board circuit board according to any one of claims 1-8, characterized in that : The circuit production includes photoresist, exposure, development, and circuit etching.

12. A manufacturing method of a long board circuit board according to any one of claims 1-8, characterized in that : The copper clad laminate is a double-layer board; or the copper clad laminate is a multi-layer board, and an inner circuit layer is sandwiched between the intermediate insulating layers, and the inner circuit layer has been produced before drilling.

13. A manufacturing method of a long board circuit board according to any one of claims 1-8, characterized in that : After circuit production, it also includes the production of a solder mask layer.

14. A long board circuit board, characterized in that : It includes: the long board circuit board is formed by overlapping and lapping m short circuit boards end to end. The short circuit board includes a front circuit layer, a back circuit layer, and an intermediate insulating layer therebetween. A plurality of via holes are provided on the short circuit board, and the via holes penetrate through the front circuit layer, the back circuit layer, and the intermediate insulating layer. The short circuit board is a double-layer circuit board or a multi-layer circuit board. Adjacent short circuit boards are combined together at the overlapping position, and there are at least two copper layers sandwiched in the overlapping position, including a first copper layer on one of the short circuit boards and a second copper layer on the adjacent short circuit board; or, adjacent short circuit boards are combined together at the overlapping position, and there is only one copper layer sandwiched in the overlapping position, and this copper layer is located on one of the short circuit boards, and adjacent short circuit boards are combined with this copper layer through the intermediate insulating layer at the overlapping position; when there is a first copper layer and / or a second copper layer at the overlapping position, the first copper layer and / or the second copper layer has a toothed end, and the toothed end includes tooth protrusions and tooth grooves. The tooth protrusions form tooth protrusion circuits, and part or all of the tooth protrusion circuits are connected to the circuits at non-overlapping positions, and part or all of the tooth grooves disconnect the adjacent circuits; at the overlapping position, the length of the overlapping position is less than the length of the tooth protrusions.

15. A long-board circuit board according to claim 14, wherein : Adjacent two short circuit boards are electrically connected to each other, either through the sidewall copper connection or / and through the solder connection.

16. A long board circuit board according to claim 14, characterized in that : At the tooth groove position, the first copper layer and / or the second copper layer form teeth, and the intermediate insulating layer at the tooth groove position is retained; or, the first copper layer and the second copper layer form teeth, and at the tooth groove position, only one intermediate insulating layer is retained; or, at the tooth groove position, the intermediate insulating layer and all copper layers form tooth grooves.

17. A long board circuit board according to any one of claims 14-16, characterized in that : It further includes a solder mask layer, and the solder mask layer covers the tooth groove; or the solder mask layer does not cover the tooth groove.

18. A long board circuit board according to claim 14, characterized in that : When there are a first copper layer and a second copper layer at the overlapping position, the first copper layer and the second copper layer are not connected to the circuit at the non-overlapping position, or at least one line extends out and is connected to the circuit at the non-overlapping position.

19. A long board circuit board according to claim 14, characterized in that : There are at least two circuits connected between adjacent short circuit boards.

20. An electronic product, characterized in that : It includes the long board circuit board described in any one of claims 14-19, and electronic components are soldered on the long board circuit board.

21. An electronic product according to claim 20, characterized in that : The electronic product is a mobile phone, an automobile, a computer, a robot or an LED light strip.

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