Circuit board manufacturing method and circuit board
By setting up enhancement strips on the connection area of the finished product area of the core plate, the problem of large plate deformation when multiple core plates are pressed is solved, and the interlayer alignment and signal transmission quality of the circuit board are improved.
Patent Information
- Application Number
- CN202411411915.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2025-02-18
AI Technical Summary
When the core plates of multiple PTFE materials are pressed, the plate deformation is large, resulting in poor alignment between the circuit boards and distortion of signal transmission.
The first reinforcement bar is provided on the connection area of the finished product area of the core plate. By improving the rigidity and deformation resistance of the finished product area, the deformation of the board is reduced and the uniformity of the core plate is improved.
It improves the interlayer alignment of the circuit board and ensures high-speed and high-quality signal transmission.
Smart Images
Figure CN119485922A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of circuit board manufacturing, and in particular to a circuit board manufacturing method and a circuit board. Background Art
[0002] In electronic devices, circuit boards are indispensable components that connect and support electronic components. With the rapid development of the electronic information field, high-frequency and high-speed circuit board products are increasingly used in many fields, such as various communication equipment, radar systems, etc.
[0003] The transmission speed and quality of signals in the circuit board circuit require extremely high performance of the board material. For example, high-frequency circuit boards need to have good electrical properties, stable dielectric constants, and low losses to ensure high-speed, high-quality signal transmission. PTFE (Polytetrafluoroethylene) boards are known for their extremely low dielectric constants and loss tangents, and are widely used in high-frequency circuit boards. However, PTFE boards themselves also have problems such as poor rigidity and large thermal expansion coefficients, and are difficult to process. Especially when multiple core boards made of PTFE materials are pressed together, compared with conventional epoxy resin boards, the board deformation is larger and the expansion and contraction are inconsistent, resulting in poor inter-layer alignment of multi-layer circuit boards and distorted signal transmission. Summary of the invention
[0004] In view of this, the embodiments of the present application provide a circuit board manufacturing method and a circuit board to solve the problem of large board deformation when multiple core boards are pressed together.
[0005] The first aspect of the present application provides a circuit board manufacturing method, comprising:
[0006] Providing a plurality of core boards to be pressed together, wherein the core boards include a finished product area in the middle part and a process board edge area surrounding the finished product area, wherein the finished product area includes a plurality of units, and a connection area is provided between two adjacent units;
[0007] Disposing a first reinforcement strip in the connection area;
[0008] Multiple core boards are stacked and pressed together to form a multilayer board.
[0009] The beneficial effects of the circuit board manufacturing method provided in the embodiment of the present application are as follows: by setting a first reinforcement strip on the connection area of the finished product area to improve the rigidity of the finished product area and improve the deformation resistance, when multiple core boards are pressed together, the deformation of the board can be reduced, and the consistency of the expansion and contraction of the core board can be improved, thereby improving the inter-layer alignment of the circuit board to ensure high-speed and high-quality signal transmission.
[0010] In some embodiments, a plurality of the first reinforcement strips are provided, a portion of the first reinforcement strips extend along a first direction, and another portion of the first reinforcement strips extend along a second direction, and the first direction is perpendicular to the second direction.
[0011] The beneficial effect of adopting the above technical solution is that the core plate is subjected to more uniform forces in all directions during pressing, thereby further improving the deformation resistance.
[0012] In some embodiments, the width of the first reinforcement strip is adjusted according to the expansion and contraction value of the core panel.
[0013] The beneficial effects of adopting the above technical solution are as follows: due to the influence of external factors such as uneven distribution of lines, the expansion and contraction of the core board is nonlinear. In actual production, the expansion and contraction data of each area of the core board can be collected, and the width of the first reinforcement strip can be adjusted according to the expansion and contraction value of the core board to balance the overall expansion and contraction of the core board.
[0014] In some embodiments, the width of the first reinforcement strip gradually increases from the center to both ends thereof, and the maximum width of the first reinforcement strip is less than or equal to the width of the connection area.
[0015] Beneficial effects of adopting the above technical solution: Generally speaking, the stability of the core board decreases from the central area to the surrounding areas, and the width of the first reinforcement strip gradually increases from the center to both ends, which can further improve the consistency of the expansion and contraction of the core board.
[0016] In some embodiments, a second reinforcement strip is disposed at the edge area of the process board, and the first reinforcement strip extends to and is connected to the second reinforcement strip.
[0017] The beneficial effects of adopting the above technical solution are as follows: since the first reinforcement strip is set in the finished product area and the second reinforcement strip is set in the edge area of the process board at the same time, and the first reinforcement strip in the finished product area and the second reinforcement strip in the edge area of the process board are connected, the rigidity of the core board during pressing can be enhanced and the deformation resistance can be improved.
[0018] In some embodiments, the core board includes a dielectric layer and a metal layer disposed on at least one side of the dielectric layer, and the circuit layer, the first reinforcement strip, and the second reinforcement strip on the core board are formed together by etching the metal layer.
[0019] The beneficial effect of adopting the above technical solution is that when processing the circuit layer on the core board, the first reinforcement strip and the second reinforcement strip are processed together, which can improve the processing efficiency.
[0020] In some embodiments, the metal layer is a copper layer, and the area of the reinforcement strip on the circuit layer with a low residual copper rate is greater than the area of the reinforcement strip on the circuit layer with a high residual copper rate.
[0021] The beneficial effects of adopting the above technical solution are: by adding a larger reinforcement strip to the circuit layer with low residual copper rate, the residual copper rate of the corresponding circuit layer is increased, thereby improving the rigidity of the core board. At the same time, it can also balance the residual copper rate between the circuit layers of the multilayer board, so that the expansion and contraction of each core board tends to be consistent during pressing, and there will be no warping problem due to too large a difference in residual copper rate.
[0022] In some embodiments, in the same circuit layer, the area of the reinforcement strip in the circuit-sparse region is larger than the area of the reinforcement strip in the circuit-dense region.
[0023] The beneficial effects of adopting the above technical solution are: it can ensure that the copper content of each area in the same circuit layer is relatively uniform, and under the condition of ensuring the rigidity of the core board, the expansion and contraction of each core board when pressed together tend to be consistent.
[0024] In some embodiments, in two adjacent circuit layers, two reinforcement strips arranged along the thickness direction of the core board are staggered.
[0025] The beneficial effects of adopting the above technical solution are: avoiding the stacking of reinforcement strips at the same position in the thickness direction of the core plate, reducing the height difference between two adjacent dielectric layers, and ensuring sufficient glue filling during pressing.
[0026] In some embodiments, a plurality of air guide grooves are respectively provided on the first reinforcement strip and the second reinforcement strip, and the air guide grooves on two adjacent reinforcement strips arranged in the first direction are staggered, and / or the air guide grooves on two adjacent reinforcement strips arranged in the second direction are staggered.
[0027] The beneficial effects of adopting the above technical solution are as follows: by adding air guide grooves, the gas between the core plates during pressing is easier to be discharged, and the glue flow is uniform; moreover, the staggered arrangement of the air guide grooves can improve the deformation resistance of the core plate.
[0028] In some embodiments, in two adjacent circuit layers, the air guide grooves on two reinforcement strips arranged along the thickness direction of the core board are staggered.
[0029] The beneficial effects of adopting the above technical solution are: avoiding multiple air guide grooves in the thickness direction of the core plate from being located at the same position, thereby improving the deformation resistance when multiple core plates are pressed together.
[0030] A second aspect of the present application provides a circuit board, which is manufactured by the circuit board manufacturing method described in the first aspect.
[0031] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or conventional technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0033] Figure 1 is a flow chart of a circuit board manufacturing method provided by some embodiments of the present application;
[0034] Figure 2 is a top view of a core plate provided in some embodiments of the present application;
[0035] Figure 3 is a top view of a core plate provided in some other embodiments of the present application;
[0036] Figure 4 is a top view of a core plate provided in some other embodiments of the present application;
[0037] Figure 5 yes Figure 2 Partial front view of the core board.
[0038] The meanings of the marks in the figure are:
[0039] 10. Core board;
[0040] 11. Finished product area; 111. Unit; 112. Connection area;
[0041] 12. Edge area of process board;
[0042] 13. The first reinforcement strip;
[0043] 14. Second reinforcement strip;
[0044] 15. Air guide groove;
[0045] 16. Dielectric layer. DETAILED DESCRIPTION
[0046] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.
[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.
[0048] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.
[0049] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0050] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.
[0051] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).
[0052] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.
[0053] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.
[0054] The transmission speed and quality of signals in the circuit board circuit require extremely high performance of the board material. For example, high-frequency circuit boards need to have good electrical properties, stable dielectric constants, and low losses to ensure high-speed, high-quality signal transmission. PTFE boards are known for their extremely low dielectric constants and loss tangents, and are widely used in high-frequency circuit boards. However, PTFE boards themselves also have problems such as poor rigidity and large thermal expansion coefficients, and are difficult to process. Especially when multiple core boards made of PTFE materials are pressed together, compared with conventional epoxy resin boards, the board deformation is larger and the expansion and contraction are inconsistent, resulting in poor inter-layer alignment of multi-layer circuit boards and distorted signal transmission.
[0055] In order to solve the problem of large board deformation when multiple core boards are pressed together, the inventor has designed a circuit board manufacturing method and a circuit board after in-depth research.
[0056] The circuit board manufacturing method arranges a first reinforcement strip on the connection area of the finished product area to improve the rigidity of the finished product area and the anti-deformation ability. When multiple core boards are pressed together, the deformation of the board can be reduced, the consistency of the expansion and contraction of the core board can be improved, and the problem of large deformation of the board when multiple core boards are pressed together can be solved. The circuit board is manufactured by the circuit board manufacturing method, which improves the inter-layer alignment of the circuit board and ensures high-speed and high-quality signal transmission.
[0057] The first embodiment of the present application provides a method for manufacturing a circuit board. Figure 1 and Figure 2 , the circuit board manufacturing method includes:
[0058] S1. Provide a plurality of core boards 10 to be pressed together. The core boards 10 include a finished product area 11 in the middle and a process board edge area 12 surrounding the finished product area 11. The finished product area 11 includes a plurality of units 111. A connection area 112 is provided between two adjacent units 111.
[0059] It can be understood that the number of the plurality of core plates 10 can be two, three, four or more.
[0060] Among them, finished product area 11 is Figure 2In the area enclosed by the middle dotted line, the process board edge area 12 is arranged around the finished product area 11, that is, the process board edge area 12 is a U-shaped structure.
[0061] Optionally, the multiple units 111 in the finished product area 11 are arranged in an array, for example, the number of units 111 may be two, four or six, etc. When there are four or more units 111, a portion of the connection area 112 extends along the first direction X, and another portion of the connection area 112 extends along the second direction Y.
[0062] S2. Arrange a first reinforcement strip 13 in the connection area 112.
[0063] Optionally, the first reinforcement bar 13 is a metal bar, for example, a copper bar. It is understood that the first reinforcement bar 13 can be a sheet-shaped copper bar or a mesh copper bar. The sheet-shaped copper bar refers to a copper bar with no grooves on its surface.
[0064] The length and width of the first reinforcement strip 13 can be set as required.
[0065] S3, stacking and pressing a plurality of core boards 10 to form a multilayer board.
[0066] When stacking the boards, a semi-cured sheet is provided between two adjacent core boards 10. Under high temperature and high pressure conditions, the semi-cured sheet melts and flows to fill between the adjacent core boards 10, and after a polymerization reaction and hardening, the multiple core boards 10 are bonded together to form a multilayer board.
[0067] Among them, the multilayer board undergoes post-processing to obtain a finished circuit board.
[0068] The post-process at least includes plate forming, which is milling a large-sized multi-layer board into units 111, and each unit 111 includes at least one finished circuit board. Of course, the post-process may also include at least one of the processes of drilling, outer layer circuit, solder mask, character printing, surface treatment, and quality inspection of each process.
[0069] It should be noted that, when the gong plate is formed, the first reinforcement strip 13 is separated from the unit 111, that is, the first reinforcement strip 13 will not remain on the finished circuit board.
[0070] The beneficial effects of the circuit board manufacturing method provided in the embodiment of the present application are as follows: by setting a first reinforcement strip 13 on the connection area 112 of the finished product area 11 to improve the rigidity of the finished product area 11 and improve the deformation resistance, when multiple core boards 10 are pressed together, the deformation of the board can be reduced, and the consistency of the expansion and contraction of the core board 10 can be improved, thereby improving the inter-layer alignment of the circuit board to ensure high-speed and high-quality signal transmission.
[0071] Optionally, the plate material used for the core plate 10 is a PTFE plate material. Of course, the core plate 10 can also be other plates with a larger deformation amount during pressing.
[0072] Please refer to Figure 2 In some embodiments, a plurality of first reinforcement strips 13 are provided, a portion of the first reinforcement strips 13 extend along a first direction X, and another portion of the first reinforcement strips 13 extend along a second direction Y, and the first direction X is perpendicular to the second direction Y.
[0073] By adopting the above technical solution, the core plate 10 is subjected to more uniform forces in all directions during pressing, thereby further improving the deformation resistance of the core plate 10 .
[0074] In other embodiments, the first reinforcement strip 13 only extends along the first direction X, or the first reinforcement strip 13 only extends along the second direction Y.
[0075] In some embodiments, the width of the first reinforcement strip 13 gradually increases from the center to both ends thereof, and the maximum width of the first reinforcement strip 13 is less than or equal to the width of the connection area 112 .
[0076] Generally speaking, the stability of the core plate 10 decreases from the central area to the surrounding areas, and the width of the first reinforcement strip 13 gradually increases from the center to both ends, which can further improve the consistency of the expansion and contraction of the core plate 10.
[0077] Of course, in other embodiments, affected by external factors such as uneven distribution of lines, the expansion and contraction of the core board 10 is nonlinear. In actual production, the expansion and contraction data of each area of the core board 10 can be collected, and the width of the first reinforcement strip 13 in the corresponding area can be adjusted according to the expansion and contraction values of each area to balance the overall expansion and contraction of the core board 10.
[0078] In other embodiments, the width of the first reinforcement strip 13 is equal from the center to both ends thereof, and the width of the first reinforcement strip 13 is less than or equal to the width of the connection area 112 .
[0079] In some embodiments, in some products, the circuit board in unit 111 is also provided with a broken edge, which is used for clamping the device when mounting the circuit board and plays a supporting role. For products with this design, a third reinforcement strip can be laid on the broken edge to further improve the structural strength of the core board 10.
[0080] Please refer to Figure 2 In some embodiments, a second reinforcement strip 14 is disposed at the edge region 12 of the process board, and the first reinforcement strip 13 extends to and is connected to the second reinforcement strip 14 .
[0081] Optionally, four second reinforcement strips 14 are provided, two of which extend along the first direction X, and the other two extend along the second direction Y. The two ends of the first reinforcement strip 13 extending along the first direction X are respectively connected to the two second reinforcement strips 14 extending along the second direction Y; the two ends of the first reinforcement strip 13 extending along the second direction Y are respectively connected to the two second reinforcement strips 14 extending along the first direction X.
[0082] Of course, one, two or three second reinforcement strips 14 may be provided. When two second reinforcement strips 14 are provided, both of them may extend along the first direction X; or both of them may extend along the second direction Y; or one of the second reinforcement strips 14 may extend along the first direction X, and the other second reinforcement strip 14 may extend along the second direction Y.
[0083] It should be noted that when the gong plate is formed, the process plate edge area 12 is separated from the finished product area 11, that is, the second reinforcement strip 14 will not remain on the finished circuit board.
[0084] By adopting the above technical solution, since the first reinforcement strip 13 is set in the finished product area 11 and the second reinforcement strip 14 is set in the process board edge area 12, and the first reinforcement strip 13 in the finished product area 11 and the second reinforcement strip 14 in the process board edge area 12 are connected, the rigidity of the core board 10 during pressing can be enhanced and the deformation resistance can be improved.
[0085] In other embodiments, when the second reinforcement strip 14 is provided in the process board edge region 12 , the first reinforcement strip 13 may not be connected to the second reinforcement strip 14 .
[0086] In other embodiments, when the anti-deformation capability is satisfied, the first reinforcement strip 13 may be provided only in the finished product area 11 , and the second reinforcement strip 14 may not be provided in the process board edge area 12 .
[0087] Please refer to Figure 2 and Figure 5 In some embodiments, the core board 10 includes a dielectric layer 16 and a metal layer disposed on at least one side of the dielectric layer 16, and the circuit layer, the first reinforcement strip 13 and the second reinforcement strip 14 on the core board 10 are formed together by etching the metal layer.
[0088] A metal layer is provided on at least one side of the dielectric layer 16. It can be understood that the metal layer is provided on the upper side or the lower side of the dielectric layer 16, or the metal layer is provided on both the upper and lower sides of the dielectric layer 16. Optionally, the metal layer is a copper layer.
[0089] The unit 111 of the finished product area 11 is provided with a circuit pattern, which is formed by etching the metal layer of the core board 10. Specifically, through the steps of laminating, exposing, developing, and etching, the metal layer is protected by the dry film after exposure, the unexposed dry film is removed by a developing solution, and then the metal layer not protected by the dry film is removed by an etching solution, and then the preset circuit pattern is transferred to the surface of the core board 10 to form a corresponding circuit layer. When laminating and exposing the metal layer of the core board 10, the area covered with the dry film also includes the position corresponding to the first reinforcement strip 13 on the connection area 112, and the position corresponding to the second reinforcement strip 14 on the process board edge area 12, that is, the first reinforcement strip 13, the second reinforcement strip 14 and the circuit layer on the surface of the core board 10 are etched together.
[0090] In this embodiment, the first reinforcement strip 13 and the second reinforcement strip 14 are processed together when processing the circuit layer on the core board 10, so that the processing efficiency can be improved.
[0091] In other embodiments, the circuit layer and the first reinforcement strip 13 and the second reinforcement strip 14 may be processed separately.
[0092] In some embodiments, the metal layer is a copper layer, and the area of the reinforcement strip on the circuit layer with a low residual copper rate is greater than the area of the reinforcement strip on the circuit layer with a high residual copper rate.
[0093] The residual copper rate refers to the ratio of the copper area on the board to the area of the entire board after the copper layer is etched to form the circuit pattern. The lower the residual copper rate, the less copper layer remains on the board.
[0094] By adding a larger reinforcement strip (which may include only the first reinforcement strip 13 or both the first reinforcement strip 13 and the second reinforcement strip 14) to the circuit layer with a low residual copper rate, the residual copper rate of the corresponding circuit layer is increased, thereby increasing the rigidity of the core board 10. At the same time, the residual copper rates between the circuit layers of the multilayer board can be balanced, so that the expansion and contraction trends of the core boards 10 during pressing are consistent, and warping problems will not occur due to large differences in residual copper rates.
[0095] Different areas of reinforcing strips can be set for circuit layers with different residual copper rates by changing the size of the reinforcing strips. For example, if the length of the reinforcing strips is the same, the width of the reinforcing strips can be increased for layers with low residual copper rates. The copper content of the reinforcing strips can also be changed. For example, for layers with low residual copper rates, the reinforcing strips are sheet-shaped copper strips, and for layers with high residual copper rates, the reinforcing strips are mesh copper strips. Figure 3 shown.
[0096] It is understandable that in other embodiments, in actual products, the situation may be encountered that the residual copper rate of the two circuit layers is the same, but the circuit distribution is uneven. For example, the residual copper rate of circuit layer A and circuit layer B is 50%, but the circuits of circuit layer A are evenly distributed on the board surface, but the circuits of circuit layer B are densely distributed on one side of the board surface. At this time, the reinforcement strips of circuit layer A and circuit layer B can also be set with different patterns; for example, circuit layer A can use grid copper strips or sheet copper strips to make the copper layer distribution still uniform, circuit layer B can use sheet copper strips, and the width of the reinforcement strips set on the side with sparse lines is greater than the width of the reinforcement strips on the side with dense lines.
[0097] In some embodiments, in the same circuit layer, the area of the reinforcement strips in the sparse circuit area is greater than the area of the reinforcement strips in the dense circuit area. For example, in the first direction X of the same circuit layer, there are mainly sparse circuits, and in the second direction Y, there are mainly dense circuits. If the width of the reinforcement strips is the same, the reinforcement strips in the first direction X can be set as sheet copper strips, and the reinforcement strips in the second direction Y can be set as mesh copper strips.
[0098] Based on the above solution, the copper content of each area in the same circuit layer can be ensured to be relatively uniform, and under the condition of ensuring the rigidity of the core board 10, the expansion and contraction of each core board 10 when pressed together tends to be consistent.
[0099] Of course, it is also possible to not set the reinforcement strip in the circuit layer with a residual copper rate ≥ 70%, and set the reinforcement strip in the circuit layer with a residual copper rate < 70%, and after setting the reinforcement strip, the difference in residual copper rate between each circuit layer is ≤ 15%.
[0100] In some embodiments, in two adjacent circuit layers, two reinforcement strips arranged along the thickness direction of the core board 10 are staggered.
[0101] For example, Figure 5 As shown, the core board 10 is provided with first reinforcement strips 13 on both sides in the thickness direction thereof, and the two first reinforcement strips 13 are staggered, that is, the projections of the two first reinforcement strips 13 on the dielectric layer 16 do not overlap; wherein the two first reinforcement strips 13 can both extend along the first direction X, and can also both extend along the second direction Y.
[0102] Of course, the core board 10 is provided with second reinforcement strips 14 on both sides in the thickness direction thereof, and the two second reinforcement strips 14 are staggered, that is, the projections of the two second reinforcement strips 14 on the dielectric layer 16 do not overlap.
[0103] Based on the above solution, the stacking of the reinforcement strips at the same position in the thickness direction of the core board 10 is avoided, and the height difference between two adjacent dielectric layers 16 is reduced to ensure sufficient glue filling during pressing.
[0104] Please refer to Figure 4In some embodiments, a plurality of air guide grooves 15 are respectively provided on the first reinforcement strip 13 and the second reinforcement strip 14. The air guide grooves 15 on two adjacent reinforcement strips arranged in the first direction X are staggered, and the air guide grooves 15 on two adjacent reinforcement strips arranged in the second direction Y are staggered.
[0105] The air guide grooves 15 on the adjacent first reinforcement strips 13 and the second reinforcement strips 14 arranged in the first direction X are staggered, and the air guide grooves 15 on the two adjacent first reinforcement strips 13 arranged in the first direction X are staggered. The air guide grooves 15 on the adjacent first reinforcement strips 13 and the second reinforcement strips 14 arranged in the second direction Y are staggered, and the air guide grooves 15 on the two adjacent first reinforcement strips 13 arranged in the second direction Y are staggered.
[0106] Of course, the air guide grooves 15 on all the reinforcement strips arranged in the first direction X are staggered, that is, the air guide grooves 15 on all the reinforcement strips arranged in the first direction X are not on the same straight line; the air guide grooves 15 on all the reinforcement strips arranged in the second direction Y are staggered, that is, the air guide grooves 15 on all the reinforcement strips arranged in the second direction Y are not on the same straight line.
[0107] By adding the air guide grooves 15, the gas between the core plates 10 during pressing can be more easily discharged, and the glue flow is uniform; moreover, the staggered arrangement of the air guide grooves 15 can improve the deformation resistance of the core plate 10 in the same direction.
[0108] In some embodiments, in two adjacent circuit layers, the air guide grooves 15 on the two reinforcement strips arranged along the thickness direction of the core board 10 are staggered, that is, the projections of at least two air guide grooves 15 on the dielectric layer 16 do not overlap.
[0109] Avoid multiple air guide grooves 15 in the thickness direction of the core plate 10 being located at the same position, thereby improving the deformation resistance when multiple core plates 10 are pressed together.
[0110] Taking a 10-layer board as an example, five double-sided copper-clad core boards 10 are pressed together, and a semi-cured sheet is arranged between the core boards 10. Under high temperature and high pressure conditions, the semi-cured sheet melts and flows to fill the gaps between the circuits, and after a polymerization reaction and hardening, the multiple core boards 10 are bonded together.
[0111] Assume that each layer is numbered L1-L10, where L1 and L2 are the copper layers on both sides of a core board 10, and so on. L1 and L10 are the outermost layers after lamination, and L2-L8 are the inner layers after lamination. Optionally, the reinforcement strip is arranged in the inner layer, i.e., L2-L8 layer.
[0112] Specifically, in the engineering data design stage, in addition to the preset graphic circuits of each layer, the reinforcement strips (including the first reinforcement strip 13 and the second reinforcement strip 14) are also arranged on the board surface. After each core board 10 is cut and cleaned, the preset graphic circuits and reinforcement strips are transferred to the surface of the core board 10 through film lamination, exposure, development, and etching processes.
[0113] The core board 10 with the inner layer circuit and the reinforcement strips is laminated with the prepreg laminate according to the preset laminate structure to form a multilayer board. Because the core board 10 is provided with reinforcement strips, the core board 10 has good anti-deformation ability and expands and contracts uniformly during lamination.
[0114] The laminated multilayer board also includes processes such as drilling, outer layer circuits, solder mask, character printing, surface treatment, plate forming, and quality inspection of each process to form the final finished circuit board.
[0115] The second aspect of the present application proposes a circuit board. The circuit board is made by the circuit board manufacturing method described in the first aspect. When the circuit board is manufactured, a first reinforcement strip 13 is set on the connection area 112 to improve the rigidity of the finished product area 11 and improve the anti-deformation ability. When multiple core boards 10 are pressed together, the deformation of the board can be reduced, the consistency of the expansion and contraction of the core board 10 can be improved, and the interlayer alignment of the circuit board can be improved to ensure high-speed and high-quality signal transmission.
[0116] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.
Claims
1. A method for manufacturing a circuit board, characterized in that: include: Providing a plurality of core boards to be pressed together, wherein the core boards include a finished product area in the middle part and a process board edge area surrounding the finished product area, wherein the finished product area includes a plurality of units, and a connection area is provided between two adjacent units; Disposing a first reinforcement strip in the connection area; Multiple core boards are stacked and pressed together to form a multilayer board.
2. The method for manufacturing a circuit board according to claim 1, wherein: There are a plurality of first reinforcement strips, a portion of which extend along a first direction, and another portion of which extend along a second direction, wherein the first direction is perpendicular to the second direction.
3. The method for manufacturing a circuit board according to claim 1, wherein: The width of the first reinforcement strip is adjusted according to the expansion and contraction value of the core plate.
4. The method for manufacturing a circuit board according to claim 3, wherein: The width of the first reinforcement strip gradually increases from the center to both ends thereof, and the maximum width of the first reinforcement strip is less than or equal to the width of the connection area.
5. The method for manufacturing a circuit board according to claim 1, wherein: A second reinforcement strip is arranged at the edge area of the process board, and the first reinforcement strip extends to and is connected to the second reinforcement strip.
6. The method for manufacturing a circuit board according to claim 5, wherein: The core board includes a dielectric layer and a metal layer disposed on at least one side of the dielectric layer. The circuit layer, the first reinforcement strip and the second reinforcement strip on the core board are formed together by etching the metal layer.
7. The method for manufacturing a circuit board according to claim 6, wherein: The metal layer is a copper layer, and the area of the reinforcement strips on the circuit layer with a low residual copper rate is greater than the area of the reinforcement strips on the circuit layer with a high residual copper rate.
8. The method for manufacturing a circuit board according to claim 6, wherein: In the same circuit layer, the area of the reinforcement strip in the circuit-sparse region is larger than that in the circuit-dense region.
9. The method for manufacturing a circuit board according to claim 6, wherein: In two adjacent circuit layers, two reinforcement strips arranged along the thickness direction of the core board are staggered.
10. The method for manufacturing a circuit board according to claim 6, wherein: The first reinforcement strip and the second reinforcement strip are respectively provided with a plurality of air guide grooves, and the air guide grooves on two adjacent reinforcement strips arranged in the first direction are staggered, and / or the air guide grooves on two adjacent reinforcement strips arranged in the second direction are staggered.
11. The method for manufacturing a circuit board according to claim 10, wherein: In two adjacent circuit layers, the air guide grooves on the two reinforcement strips arranged along the thickness direction of the core board are staggered.
12. A circuit board, characterized in that: The circuit board is manufactured by the circuit board manufacturing method according to any one of claims 1-11.