Circuit board structure, electronic equipment and manufacturing method
By setting a bend area on the flexible circuit board and setting copper layers on both sides, using the difference in hardness to form stress points, the problems of poor bending accuracy and low efficiency of the flexible circuit board are solved, and more efficient bending and reducing fractures are achieved.
Patent Information
- Application Number
- CN202510399550.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-31
- Publication Date
- 2025-06-20
AI Technical Summary
In the process of bending with special shapes and large angles of flexible circuit boards, the prior art has problems such as poor bending accuracy, low efficiency and easy to cause fractures.
By setting a bent area on the flexible circuit board and setting a copper laying layer on both sides of the bent area, the hardness difference between the copper laying layer and the non-copper laying layer is used to form stress points for bending, improving bending efficiency and reducing bruises.
It improves the bending efficiency of the flexible circuit board and the probability of bending in one go, reduces the risk of repeated operations and fractures, and saves the cost of silk-printed white oil lines.
Smart Images
Figure CN120186876A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of flexible printed circuit boards, and particularly to a circuit board structure, an electronic device, and a manufacturing method thereof. Background Art
[0002] During the assembly process, when the FPC (flexible printed circuit board) needs to be bent at a large angle in a special shape, a silk-screen line is usually added at the bending center position of the FPC as a bending reference positioning line. To facilitate the bending of the FPC, the copper plating is removed on one side of the bending position of the FPC, and the width dimension of the area where the copper plating is removed is not controlled. When the FPC is bent in a special shape, manual positioning needs to be carried out according to the bending white oil line, and the white oil line itself has a tolerance of ±0.3 mm, resulting in a bending accuracy of the overall FPC > 0.5 mm, poor bending accuracy, and low efficiency. In addition, in the existing bending scheme, when the bending is not in place at one time, multiple bending reworks are required, which is likely to cause damage to the FPC. Summary of the Invention
[0003] This application aims to solve at least one of the technical problems existing in the prior art. For this reason, this application provides a circuit board structure and an electronic device, which can improve the bending operation efficiency of the flexible printed circuit board, reduce repeated operations, and avoid damage to the flexible printed circuit board at the same time.
[0004] An embodiment of the first aspect of this application provides a circuit board structure, including:
[0005] A flexible printed circuit board having a bending area;
[0006] A copper plating layer is laid on at least one surface of the flexible printed circuit board, and the copper plating layer is laid on both sides of the bending area on the same surface of the flexible printed circuit board.
[0007] Further, the bending area is arranged at an angle of 45 degrees obliquely with respect to the edge of the flexible printed circuit board.
[0008] Further, it further includes an adhesive layer, and the adhesive layer is arranged on the copper plating layer on one side of the bending area. After the flexible printed circuit board is bent, the adhesive layer is used to connect with the copper plating layer on the other side of the bending area.
[0009] Further, the contour of one side of each copper plating layer close to the bending area is a wavy contour.
[0010] Further, the position where the center line of the bending area is located is the bending center, and the distance between the bending center and the edge of the copper plating layer inside the bending area is a, where a > 0.
[0011] Further, the distance between the bending center and the edge of the copper plating layer outside the bending area is b, and b > a.
[0012] Furthermore, the distance between the peaks and valleys of the wavy contour is c, where c > 0.
[0013] An embodiment of the second aspect of the present application provides an electronic device, including the circuit board structure as described above.
[0014] An embodiment of the third aspect of the present application provides a method for manufacturing a circuit board structure, including the following steps:
[0015] Provide a flexible circuit board, expand outward by a first distance from a preset bending center line on both sides to define a bending area, and perform softening treatment on the bending area.
[0016] Perform copper plating on the flexible circuit board on both sides of the bending area.
[0017] Provide an adhesive layer, and set the adhesive layer in the copper-plated area. The adhesive layer is used to connect the flexible circuit board after bending.
[0018] Furthermore, the bending area is a copper-plating prohibited area, and the contour of the copper-plating prohibited area presents a wavy shape.
[0019] Furthermore, the width of the bending area outside the bending area is greater than the width of the bending area inside the bending area.
[0020] It can be seen from the above technical solutions that the embodiments of the present application at least have the following beneficial effects:
[0021] In the circuit board structure, electronic device and its manufacturing method provided by the embodiments of the present application, by setting a bending area on the flexible circuit board and arranging copper-plated layers on both sides of the bending area, stress points are formed around the center position of the bending area by using the hardness difference between the copper-plated layer and the non-copper-plated layer, so as to facilitate the bending of the flexible circuit board, improve the bending efficiency, and increase the probability of bending in place at one time. At the same time, in the embodiments of the present application, there is no need to rely on the silk-screened white oil line for bending positioning. If the silk-screened line is separately arranged on one side of the flexible circuit board, the cost of one silk-screened white oil line can be saved. Description of the Drawings
[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0023] Figure 1 It is a schematic diagram of the state before bending of a flexible circuit board;
[0024] Figure 2 Schematic diagram of the state of a flexible circuit board after bending;
[0025] Figure 3 Schematic diagram of the structure of a circuit board according to an embodiment of the present application;
[0026] Figure 4 Schematic diagram of the structure of a circuit board according to an embodiment of the present application, wherein the schematic diagram shows the structure inside the flexible circuit board;
[0027] Figure 5 It is Figure 4 Enlarged schematic diagram of part A in
[0028] Figure 6 Schematic diagram of the structure of a circuit board according to an embodiment of the present application, wherein the schematic diagram shows the structure outside the flexible circuit board;
[0029] Figure 7 It is Figure 6 Partially enlarged schematic diagram of part B in
[0030] Figure 8 Schematic diagram of the structure of a circuit board according to an embodiment of the present application.
[0031] Reference numerals in the drawings:
[0032] 1. Bending reference positioning line;
[0033] 100. Flexible circuit board; 110. Bending area;
[0034] 200. Copper plating layer;
[0035] 300. Adhesive layer;
[0036] 400. GND trace. Detailed implementation manners
[0037] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.
[0038] Refer to Figure 1 and Figure 2, during the assembly process, when the FPC (i.e., flexible printed circuit board) needs to be bent at a large angle with a special shape, usually a silk screen line is added at the bending center position of the FPC as the bending reference positioning line 1. To facilitate the bending of the FPC, the copper plating is removed on one side of the bending position of the FPC, and the width dimension of the copper plating removal area is not controlled. When the FPC is bent with a special shape, manual positioning needs to be carried out according to the bending white oil line, and the white oil line itself has a tolerance of ±0.3 mm, resulting in the bending accuracy of the overall FPC > 0.5 mm, with poor bending accuracy and low efficiency. At the same time, in the existing bending scheme, when the bending is not in place at one time, multiple bending reworks are required, which easily causes damage to the FPC.
[0039] In view of this, the embodiments of the present application propose a circuit board structure, an electronic device and a manufacturing method to effectively solve the foregoing problems.
[0040] See Figure 1 As shown, the embodiments of the first aspect of the present application disclose a circuit board structure, including a flexible printed circuit board 100 and a copper plating layer 200.
[0041] Specifically, the flexible printed circuit board 100 has a bending area 110; the copper plating layer 200 is laid on at least one surface of the flexible printed circuit board 100, and the copper plating layer 200 is laid on both sides of the bending area 110 on the same surface of the flexible printed circuit board 100.
[0042] Furthermore, the bending area 110 is softened to facilitate the bending of the flexible printed circuit board 100.
[0043] In this embodiment, the copper plating layer 200 is laid on both surfaces of the flexible printed circuit board 100, and on the same surface of the flexible printed circuit board 100, the copper plating layer 200 is laid on both sides of the bending area 110.
[0044] It should be understood that the contour of the copper plating layer 200 provided on both sides of the bending area 110 is the contour of the bending area 110.
[0045] In the circuit board structure provided by the embodiments of the present application, by setting the bending area 110 on the flexible printed circuit board 100 and setting the copper plating layer 200 on both sides of the bending area 110, and the bending area 110 is a non - copper - plated layer, using the hardness difference between the copper plating layer 200 and the non - copper - plated layer, stress points are formed around the center position of the bending area 110, which can facilitate the bending of the flexible printed circuit board 100, improve the bending efficiency, and increase the probability of one - time bending in place. At the same time, in the embodiments of the present application, it is not necessary to use the silk - printed white oil line for bending positioning. If the silk - printed line is on a single side, one silk - printing cost can be saved.
[0046] In some embodiments of the present application, see Figure 3, the bending region 110 is arranged at an oblique 45 degrees with respect to the edge of the flexible circuit board 100. When the flexible circuit board 100 is bent at the bending region 110, the bent flexible circuit board 100 is arranged at 90 degrees with respect to the unbent flexible circuit board 100. Setting the bending region 110 at an inclined 45 degrees can avoid the situation that one side of the bending region 110 fails to bend due to too small a bending area or damage occurs at the edge of the flexible circuit board 100.
[0047] It should be noted that the inclination angle between the bending region 110 and the edge of the flexible circuit board 100 is related to the bending direction of the flexible circuit board 100. In practical applications, the inclination angle of the bending region 110 can be set according to the bending direction of the flexible circuit board 100.
[0048] When the flexible circuit board 100 is bent, stress concentration is likely to occur at the edge of the copper plating layer 200 near the bending region 110, making the flexible circuit board 100 prone to breakage after bending.
[0049] Based on this, in some embodiments of the present application, see Figures 4 to 7 , the contour of one side of each copper plating layer 200 close to the bending region 110 is a wavy contour. By setting the edge of the copper plating layer 200 close to the bending region 110 to be wavy, the pre-bending stress points are at the bending center near the bending region 110, which can reduce the stress concentration at the edge of the copper plating layer 200 and also improve the accuracy of bending alignment.
[0050] In a possible implementation manner, see Figures 3 to 7 , among the copper plating layers 200 on both sides of the bending region 110, the wave crests in one copper plating layer 200 are opposite to the wave crests in the other copper plating layer 200, and the wave troughs in one copper plating layer 200 are opposite to the wave troughs in the other copper plating layer 200. In this way, the pre-bending stress points can be at the bending center near the bending region 110, which is beneficial to improving the bending accuracy.
[0051] In some embodiments of the present application, see Figure 5 , the position where the center line of the bending region 110 is located is the bending center, and the distance between the bending center and the edge of the copper plating layer 200 inside the bending region 110 is a, where a > 0.
[0052] In a possible implementation manner, a is equal to 0.4 mm. That is to say, inside the bending region 110, the minimum interval between the bending center and the edge of the copper plating layer 200 is about 0.4 mm.
[0053] In other embodiments, the specific value of a can also be adjusted accordingly according to the thickness, material, etc. of the flexible circuit board 100.
[0054] In some embodiments of the present application, see Figure 6 and Figure 7 , the distance between the bending center and the edge of the copper-clad layer 200 outside the bending area 110 is b, b>a. Specifically, on the outside of the bending area 110, the bending radius of the flexible circuit board 100 is larger than that on the inside. Based on this, the distance b between the edge of the copper-clad layer 200 on the outside and the bending center is set to be greater than the distance a between the edge of the copper-clad layer 200 on the inside and the bending center, which can reduce the bending difficulty of the flexible circuit board 100.
[0055] It should be pointed out that Figure 5 and Figure 7 As shown, the dotted line F is the bending center line or bending center.
[0056] In the above embodiment, b is greater than a, that is, the inner copper layer 200 is closer to the bending center than the outer copper layer 200, so it is beneficial to form a pre-bending position at the center line of the bending center, to achieve one-time bending, and to improve the accuracy of bending alignment. In addition, it can also reduce the stress concentration at the edge of the copper layer 200.
[0057] In this embodiment, the area of a is 0.4mm, and the value of b is 0.7mm, that is, the copper plating on the two surfaces of the flexible circuit board 100 is avoided by 0.3mm, avoiding stress concentration at the edge of the copper plating layer 200, ensuring that the pre-bending stress point is close to the bending center, and improving the accuracy of the bending alignment, which can be controlled within ±0.3mm.
[0058] In some embodiments of the present application, see Figure 5 or Figure 7 , the distance between the crest and trough of the wavy profile is c, c>0.
[0059] In a possible implementation manner, the distance c between the wave crest and the wave trough of the profile of the copper plating layer 200 is specifically 0.5 mm.
[0060] It is worth to understand that in some other embodiments, the specific value of the distance c can be appropriately adjusted according to the distance between the bending center and the edge of the copper-plated layer 200 .
[0061] In some embodiments of the present application, see Figure 3 The circuit board structure further includes an adhesive layer 300, which is disposed on the copper-clad layer 200 on one side of the bending region 110. After the flexible circuit board 100 is bent, the adhesive layer 300 is used to connect with the copper-clad layer 200 on the other side of the bending region 110. The adhesive layer 300 can fix the two parts of the flexible circuit board 100 after bending, and can prevent the flexible circuit board 100 from rebounding.
[0062] In a possible implementation, the bonding layer 300 is specifically a double-sided adhesive, which is disposed on the copper-clad layer 200 inside the flexible circuit board 100. At this time, the double-sided adhesive is located on one side of the bending area 110. When the flexible circuit board 100 is bent from the bending area 110, the flexible circuit board 100 on the other side of the bending area 110 abuts against the double-sided adhesive. Thus, the flexible circuit boards 100 on both sides of the bending area 110 can be connected and fixed by the double-sided adhesive.
[0063] It should be understood that the bonding layer 300 can also be other adhesives or other bonding materials that do not react with the flexible circuit board 100 or the copper-clad layer 200, and are not limited herein.
[0064] In this embodiment, the circuit board structure includes GND traces 400. Specifically, two GND traces 400 are provided at positions close to the board edge on both sides of the bending area 110 to connect the copper-clad layers 200 on the left and right sides to ensure the integrity of the copper-clad layer 200. Among them, GND traces 400 need to be added to both the inner and outer copper-clad layers, as Figure 8 shown.
[0065] An embodiment of the second aspect of the present application discloses an electronic device, including the circuit board structure as described above, having all the technical effects of the foregoing circuit board structure, which will not be elaborated herein.
[0066] An embodiment of the third aspect of the present application discloses a method for manufacturing a circuit board structure, including the following steps:
[0067] Provide a flexible circuit board 100, expand a first distance outward from a preset bending center line on both sides to define a bending area 110, and perform a softening treatment on the bending area 110;
[0068] Lay a copper-clad layer 200 on the flexible circuit board 100 on both sides of the bending area 110;
[0069] Provide a bonding layer 300, and set the bonding layer 300 on the copper-clad layer 200. The bonding layer 300 is used to connect the bent flexible circuit board 100.
[0070] Among them, the bonding layer 300 can specifically be selected as a double-sided adhesive, which is used to fix the bent flexible circuit board 100 to prevent the flexible circuit board 100 from rebounding and bulging.
[0071] In the above embodiment, by optimizing the design of the copper cladding, using the hardness difference between the copper-clad area and the non-copper-clad area, stress points are formed around the position of the bending center, improving the bending efficiency of the production line and ensuring that the bending can be completed in one step.
[0072] It is worth understanding that the softening treatment of the flexible circuit board 100 is a process of improving the bending performance and flexibility of the circuit board through a series of chemical or physical methods. This treatment is intended to maintain excellent electrical and mechanical properties and meet the needs of modern electronic products for lightness, thinness and high performance.
[0073] In this embodiment, the softening process for the flexible circuit board 100 refers to removing the copper plating at the bending area 110 .
[0074] In some embodiments of the present application, the white silk screen line at the center of the bend is removed when the bend area 110 is softened. Specifically, this embodiment does not require the use of silk screen white silk screen lines for bend positioning. If the silk screen line is on a single side, the cost of a silk screen printing can be saved.
[0075] In some embodiments of the present application, the bending area 110 is a copper-free area, and the contour of the copper-free area is wavy. The wavy copper-free contour avoids stress concentration at the edge of the copper-free area, ensures that the pre-bending stress point is close to the center of the bend, and improves the accuracy of the bend alignment.
[0076] In some embodiments of the present application, the width of the bending region 110 outside the bending region 110 is greater than the width of the bending region 110 inside the bending region 110. In this way, the flexible circuit board 100 can be bent conveniently.
[0077] It should be noted that the outer side of the bending area 110 refers to one side of the outer surface of the flexible circuit board 100 after the flexible circuit board 100 is bent; the inner side of the bending area 110 is the other side of the flexible circuit board 100 .
[0078] The following is a detailed description of the method for manufacturing a circuit board according to an embodiment of the present application using a specific embodiment. It should be noted that the following embodiment is only an exemplary description and should not be construed as limiting the embodiment of the present application.
[0079] See also Figures 1 to 8 As shown, the method for manufacturing the circuit board structure of this embodiment includes the following steps:
[0080] 1. The bending area 110 of the flexible circuit board 100 is made to be inclined at 45 degrees according to the bending direction, and the white oil silk screen line at the center of the bending is removed;
[0081] 2. The inner side of the bending area 110 is expanded 0.4mm from the bending center to both sides to form a copper-free area. The copper-free area is made into a wave shape to disperse part of the force and prevent the formation of a pre-folded position at the edge of the copper. The distance between the crest and the trough is about 0.5mm;
[0082] 3. On the outer side of the bending area 110, a copper-free area is expanded 0.7 mm to both sides from the bending center, and it is also made into a wavy shape to further disperse the stress at the copper-clad edge area, so as to better form bending stress points around the bending center line;
[0083] 4. After the flexible circuit board 100 is bent, it is fixed with 0.03 mm double-sided tape to prevent the FPC from rebounding and bulging;
[0084] 5. Two GND traces are added at positions near the board edge on both sides of the bending area 110 to connect the copper-clad layers 200 on the left and right sides to ensure the integrity of the copper-clad layer 200. Among them, GND traces 400 need to be added to the copper-clad layers 200 on both the inner and outer sides of the flexible circuit board 100, as Figure 8 shown.
[0085] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.
[0086] The terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise stated, the meaning of "a plurality" is two or more.
[0087] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.
[0088] In the description of this specification, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.
[0089] It should be understood that although the steps in the flowchart of the accompanying drawings are shown sequentially according to the indication of the arrows, these steps are not necessarily executed sequentially in the order indicated by the arrows. Unless there is a clear indication in this document, there is no strict order restriction for the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed and completed at the same moment, but can be executed at different moments, and their execution order is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or sub-steps or stages of other steps.
Claims
1. A circuit board structure, characterized in that: include: A flexible circuit board having a bending area; The copper-clad layer is laid on at least one surface of the flexible circuit board, and the copper-clad layer is laid on both sides of the bending area on the same surface of the flexible circuit board.
2. The circuit board structure according to claim 1, characterized in that: The bending area is arranged obliquely compared to the edge of the flexible circuit board.
3. The circuit board structure according to claim 1, characterized in that: The profile of one side of each copper-clad layer close to the bending area is a wavy profile.
4. The circuit board structure according to claim 3, characterized in that: The position where the center line of the bending area is located is the bending center, and the distance between the bending center and the edge of the copper plating layer inside the bending area is a, where a>0.
5. The circuit board structure according to claim 4, characterized in that: The copper layer is laid on both surfaces of the flexible circuit board, and the distance between the bending center and the edge of the copper layer outside the bending area is b, b>a.
6. The circuit board structure according to claim 1, characterized in that: It also includes an adhesive layer, which is arranged on the copper-clad layer on one side of the bending area. After the flexible circuit board is bent, the adhesive layer is used to connect with the copper-clad layer on the other side of the bending area.
7. An electronic device, characterized in that: Comprising the circuit board structure as claimed in any one of claims 1 to 6.
8. A method for manufacturing a circuit board structure, characterized in that: The steps include: A flexible circuit board is provided, with a preset bending center line extending outwardly to both sides by a first distance to define a bending area, and the bending area is softened; Laying a copper layer on the flexible circuit board at both sides of the bending area; An adhesive layer is provided, and the adhesive layer is arranged in the area of the copper-plated layer, and the adhesive layer is used to connect the flexible circuit board after bending.
9. The manufacturing method according to claim 8, characterized in that: The bending area is a copper-free area, and the outline of the copper-free area is wavy.
10. The manufacturing method according to claim 9, characterized in that: The width of the outer side of the bending area is greater than the width of the inner side of the bending area.