A multi-layer FPC folding and stacking design device
Patent Information
- Application Number
- CN202521495739.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-17
- Publication Date
- 2026-10-16
- Estimated Expiration
- 2035-07-17
AI Technical Summary
[0029] Compared with the prior art, the beneficial effects of this utility model are: through this folding method, multiple FPCs can be extended to the same length; through this stacking method, FPCs with thinner thickness can be arranged; through this design, the space occupied by multi-layer FPCs can be reduced, and the size of FPCs can be significantly extended under existing manufacturing processes, providing a solution for FPC packaging in small spaces.
Smart Images
Figure CN224863172U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of flexible printed circuit board (FPC) packaging technology, and in particular to a method for folding wiring in FPC within a small space. Background Technology
[0002] Flexible printed circuit boards (FPCs) are printed circuit boards made using flexible materials such as polyimide (PI) and polyester (PET) as substrates. They are characterized by their flexibility, foldability, and rollability, and can withstand dynamic bending (such as repeated folding) or static bending (such as fixed curved surface mounting). Utilizing the flexibility of FPCs, multilayer boards can be folded to reduce space occupation while maintaining circuit connectivity.
[0003] Suitable for scenarios requiring bending or three-dimensional wiring (such as mobile phone hinges, wearable devices, endoscope catheters, etc.), the core advantages of FPC are its flexibility, thinness and high reliability, making it particularly suitable for applications with dynamic bending, space constraints or high-frequency signal transmission.
[0004] The folding and stacking design of FPC multilayer boards is an important innovation in the field of electronic manufacturing. It provides an effective solution for the miniaturization and high performance of electronic devices. With the continuous advancement of technology and the continuous expansion of application fields, FPC multilayer board design will play an even more important role in future electronic manufacturing.
[0005] Based on this, this utility model designs a multi-layer FPC folding and stacking device to solve the problem. Utility Model Content
[0006] The purpose of this invention is to provide a multi-layer FPC folding and stacking design device, which makes it thinner and effectively extends the length of the FPC.
[0007] To achieve the above objectives, this utility model provides the following technical solution: a multi-layer FPC folding and stacking design device, wherein the entire flexible circuit includes multiple FPCs, and each FPC includes a first FPC segment, a second FPC segment, a third FPC segment, a fourth FPC segment, a fifth FPC segment, a first folding area, a second folding area, a third folding area, and a fourth folding area;
[0008] The first FPC segment, the second FPC segment, the third FPC segment, the fourth FPC segment, and the fifth FPC segment constitute the smallest cyclic unit of an FPC arrangement of equal length;
[0009] The first, second, third, and fourth folding areas each contain two creases. The first folding area includes a first crease and a second crease. The second folding area includes a third crease and a fourth crease. The third folding area includes a fifth crease and a sixth crease. The fourth folding area includes a seventh crease and an eighth crease. By folding inward and outward twice, the adjacent FPC parts can be arranged in parallel and overlapped vertically, effectively extending the length of the FPC. At the same time, the total thickness of the FPC at any position after folding does not exceed: (number of layers + 2) × thickness of a single FPC layer. Here, the number of layers refers to the number of FPC layers stacked outside the folding area.
[0010] Preferably, each FPC contains multiple circuit wires, each of which runs through the long end of the entire FPC to achieve electrical connection between the two ends of the FPC.
[0011] Preferably, the entire flexible circuit can contain multiple parallel FPC units, and the overall width can be reduced by folding into multiple layers, so that the total width is reduced to the width of a single-layer FPC. The total number of layers in the folded area is the number of parallel FPC units + 2, and the total number of layers outside the folded area is the number of FPC units.
[0012] Preferably, the FPC may include multiple FPC segments and folded areas; the more FPC segments included, the greater the length can be extended.
[0013] Preferably, the angle α in each folded region of the FPC ranges from 0 to 180°, and the relationship between the folding angle β and the angle α in the folded region is as follows:
[0014]
[0015] When this relationship is satisfied, the bent FPC can be folded along the creases to form a straight line, thereby extending its length. Through multiple folds at multiple corners, the bent FPC can be stretched out along a straight line, effectively extending the final length without increasing the processing difficulty.
[0016] Preferably, when the corner α is a right angle or an obtuse angle, a long FPC can be contracted into a smaller area through multiple corners, and the traces can be made to cover the entire printed FPC plane as much as possible, thus avoiding the increase in process difficulty caused by ultra-long FPC processing.
[0017] Preferably, when the corner α is an acute angle, multiple FPCs can be combined together in one production process to improve production efficiency and reduce costs.
[0018] Preferably, the corners α of the same FPC do not need to be consistent. Acute angles, obtuse angles, and right angles of extra-long FPCs can be mixed according to the actual situation to improve wiring efficiency and effectively increase the length of a single FPC. This folding method can achieve high wiring efficiency and obtain a very long FPC.
[0019] Preferably, the corner directions of the FPC can be inconsistent. With the corresponding reverse corners, a very long FPC can be obtained while ensuring good electromagnetic characteristics and high wiring efficiency, even if all corners α are obtuse angles.
[0020] Preferably, the outer corner of the FPC can be different from the inner corner in shape, that is, the sharp corner on the outside can be changed into a flat corner or a rounded arc, and the corresponding wire shape can also be treated with a flat corner or a rounded corner.
[0021] The first and second FPC segments are connected end-to-end through the first folding area; the second and third FPC segments are connected end-to-end through the second folding area; the third and fourth FPC segments are connected end-to-end through the third folding area; and the fourth and fifth FPC segments are connected end-to-end through the fourth folding area.
[0022] In the original state, the first FPC segment, the second FPC segment, the third FPC segment, the fourth FPC segment, the fifth FPC segment, the first folded area, the second folded area, the third folded area, and the fourth folded area are located on the same plane;
[0023] During the first fold, the first fold is performed along the first crease of the first folding area, so that the second FPC segment overlaps the first FPC segment vertically at a 90° angle. Then, the second fold is performed along the second crease of the first folding area, so that the second FPC segment overlaps the first FPC segment vertically in parallel. The first FPC segment and the second FPC segment are on a straight line, thus achieving the first extension of length.
[0024] During the second fold, a first fold is made along the second crease of the second folding area, so that the third FPC segment overlaps the second FPC segment vertically at a 90° angle. A second fold is made along the second crease of the second folding area, so that the third FPC segment overlaps the second FPC segment vertically in parallel. The second FPC segment and the third FPC segment are on a straight line, thus achieving a second extension of length.
[0025] During the third fold, a first fold is made along the first crease of the third folding area, so that the fourth FPC segment overlaps the third FPC segment vertically at a 90° angle. A second fold is made along the second crease of the third folding area, so that the fourth FPC segment overlaps the third FPC segment vertically in parallel. The third FPC segment and the fourth FPC segment are on a straight line, thus achieving the third extension of length.
[0026] During the fourth fold, a first fold is made along the first crease of the fourth folding area, so that the fifth FPC segment overlaps the fourth FPC segment vertically at a 90° angle. A second fold is made along the second crease of the fourth folding area, so that the fifth FPC segment overlaps the fourth FPC segment vertically in parallel. The fourth FPC segment and the fifth FPC segment are on a straight line, thus achieving the fourth extension of length.
[0027] In the folded state, the first, third, and fifth FPC segments are located on the same plane, and the second and fourth FPC segments are located on the same plane.
[0028] Preferably, the multiple FPCs and multiple folded regions can form a minimum loop region, thereby increasing the number of loops.
[0029] Compared with the prior art, the beneficial effects of this utility model are: through this folding method, multiple FPCs can be extended to the same length; through this stacking method, FPCs with thinner thickness can be arranged; through this design, the space occupied by multi-layer FPCs can be reduced, and the size of FPCs can be significantly extended under existing manufacturing processes, providing a solution for FPC packaging in small spaces.
[0030] This invention designs solutions for various angle scenarios (right angle, acute angle, and obtuse angle) α, demonstrating that in all three cases, the FPC can be effectively extended by folding twice at each corner without increasing its width. When angle α is a right angle, the FPC can be arranged back and forth at two corners, which is beneficial for achieving a long FPC length within a limited printing area. When angle α is an obtuse angle, the corner folding causes less electromagnetic interference, making it suitable for higher frequency applications. When angle α is an acute angle, the printed FPC can be arranged back and forth at a single corner, achieving high wiring density and effectively reducing manufacturing costs. However, due to the presence of a loop in the cable after folding, the parasitic inductance is slightly larger, making it suitable for lower frequency circuits.
[0031] This utility model demonstrates that various different corner αs can be used interchangeably. Through appropriate combinations, long FPC wires can be obtained by folding while maintaining high-density FPC and good electromagnetic properties.
[0032] This utility model demonstrates that the corners and folding directions can be repeatedly changed. Through appropriate combinations, long FPC wires can be obtained by folding while maintaining high-density FPC and good electromagnetic properties. Attached Figure Description
[0033] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0034] Figure 1 A schematic diagram of the original state structure of the FPC provided in the embodiments of this application;
[0035] Figure 2 This is a schematic diagram of the FPC structure after its first fold, provided in an embodiment of this application.
[0036] Figure 3 This is a schematic diagram of the FPC structure after its second fold, provided in an embodiment of this application.
[0037] Figure 4 This is a schematic diagram of the FPC structure after the third fold, provided in an embodiment of this application.
[0038] Figure 5 This is a schematic diagram of the FPC structure after the fourth fold, provided in an embodiment of this application.
[0039] Figure 6 This is a schematic diagram of the structure of the FPC after the fifth fold, provided in an embodiment of this application.
[0040] Figure 7 This is a schematic diagram of the structure of the FPC after the sixth fold, provided in an embodiment of this application.
[0041] Figure 8 This is a schematic diagram of the structure of the FPC after the seventh fold, provided in an embodiment of this application.
[0042] Figure 9 This is a schematic diagram of the FPC structure after the eighth fold, provided in an embodiment of this application.
[0043] Figure 10 This is a schematic diagram of an FPC with an obtuse corner provided in an embodiment of this application;
[0044] Figure 11 Schematic diagrams of FPC corners with acute angles and non-sharp angles provided in the embodiments of this application;
[0045] Figure 12 This is a schematic diagram of the structure of multiple FPC circuits printed simultaneously according to an embodiment of this application;
[0046] Figure 13 This application provides a schematic diagram of an FPC structure with a combination of obtuse and acute angles at the corners, achieving an ultra-long FPC.
[0047] Figure 14 This is a schematic diagram of the structure of an FPC with obtuse corners but some corners in the opposite direction, provided in an embodiment of this application, to achieve an ultra-long FPC.
[0048] The attached diagram lists the components represented by each number as follows:
[0049] 1. First FPC segment; 2. Second FPC segment; 3. Third FPC segment; 4. Fourth FPC segment; 5. Fifth FPC segment; 6. First fold area; 7. Second fold area; 8. Third fold area; 9. Fourth fold area; 10. First crease; 11. Second crease; 12. Third crease; 13. Fourth crease; 14. Fifth crease; 15. Sixth crease; 16. Seventh crease; 17. Eighth crease; 18. Circuit wire; 19. Width of FPC; 20. Corner α is obtuse; 21. Corner α is acute; 22. Corresponding folding angle β; 23. FPC corner tip is flat; 24. FPC corner tip is rounded; 25. Multiple FPCs manufactured simultaneously; 26. Acute angle of extra-long FPC; 27. Obtuse angle of extra-long FPC; 28. Reverse corner when only obtuse angle is used. Detailed Implementation
[0050] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.
[0051] Please see Figures 1 to 14 This utility model provides a technical solution: a multi-layer FPC folding and stacking design device, wherein the FPC includes: a first FPC1, a second FPC2, a third FPC3, a fourth FPC4, a fifth FPC5, a first folding area 6, a second folding area 7, a third folding area 8, and a fourth folding area 9; the first FPC1 and the second FPC2 are connected end to end through the first folding area 6, the second FPC2 and the third FPC3 are connected end to end through the second folding area 7, the third FPC3 and the fourth FPC4 are connected end to end through the third folding area 8, and the fourth FPC4 and the fifth FPC5 are connected end to end through the fourth folding area 9.
[0052] In the original state, the first FPC1, the second FPC2, the third FPC3, the fourth FPC4, the fifth FPC5, the first folded area 6, the second folded area 7, the third folded area 8, and the fourth folded area 9 are located on the same plane; and the first FPC1, the third FPC3, and the fifth FPC5 are parallel to each other, the second FPC2 and the fourth FPC4 are parallel to each other, and the first FPC1, the third FPC3, and the fifth FPC5 are perpendicular to the second FPC2 and the fourth FPC4.
[0053] In the folded state, the first FPC1, the second FPC2, the third FPC3, the fourth FPC4, and the fifth FPC5 extend in the same direction and are arranged in a straight line.
[0054] For example, the first folding area 6 has a first crease 10 and a second crease 11, the first fold is folded along the first crease 10, and the second fold is folded along the second crease 11.
[0055] For example, the second folded area 7 has a third crease 12 and a fourth crease 13, the third fold is folded along the third crease 12, and the fourth fold is folded along the fourth crease 13.
[0056] For example, the third fold area 8 has a fifth crease 14 and a sixth crease 15, the fifth fold is folded along the fifth crease 14, and the sixth fold is folded along the sixth crease 15.
[0057] For example, the fourth fold area 9 has a seventh fold 16 and an eighth fold 17, the seventh fold is folded along the seventh fold 16, and the eighth fold is folded along the eighth fold 17.
[0058] For example, the FPC body can be a single-sided FPC or a double-sided FPC.
[0059] The first segment FPC1, the second segment FPC2, the third segment FPC3, the fourth segment FPC4, the fifth segment FPC5, the first folded area 6, the second folded area 7, the third folded area 8, and the fourth folded area 9 of the FPC constitute the minimum cycle period. Each FPC in the cycle can be arranged in an equal length after being folded.
[0060] For example, to obtain a longer final FPC size, a new minimum cycle can be connected to the end of the fifth FPC5 segment, and so on.
[0061] The folding method of this application is as follows:
[0062] Step 1: As Figure 2 Fold along the first crease 10 so that the first segment FPC1 and the second segment FPC2 are arranged in parallel.
[0063] Step 2: As Figure 3 Fold along the second crease 11 so that the first FPC1 and the second FPC2 overlap vertically.
[0064] Step 3: As Figure 4 Fold along the third crease 12 to make the second FPC2 and the third FPC3 parallel;
[0065] Step 4: As Figure 5 Fold along the fourth crease 13 so that the second FPC2 and the third FPC3 overlap vertically.
[0066] Step 5: As Figure 6 Fold along the fifth crease 14 to make the third segment FPC3 and the fourth segment FPC4 parallel;
[0067] Step 6: As Figure 7 Fold along the sixth fold 15, so that the third FPC3 and the fourth FPC4 overlap vertically.
[0068] Step 7: As Figure 8 Fold along the seventh fold 16 to make the fourth segment FPC4 and the fifth segment FPC5 parallel;
[0069] Step 8: As Figure 9 Fold along the eighth fold 17, so that the fourth FPC5 and the fifth FPC5 overlap vertically.
[0070] The accompanying drawings in this application are for illustrative purposes only. The dimensions and shapes of the components shown are not actual limitations but are merely schematic representations. In actual implementation, the components can be reasonably configured and adjusted according to specific needs and actual conditions.
[0071] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0072] The preferred embodiments of this utility model disclosed above are merely illustrative of the present utility model. These preferred embodiments do not exhaustively describe all details, nor do they limit the utility model to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents.
Claims
1. A multi-layer FPC folding and stacking design device, characterized in that: The entire flexible circuit consists of multiple FPCs, each of which includes a first FPC (1), a second FPC (2), a third FPC (3), a fourth FPC (4), a fifth FPC (5), a first folding area (6), a second folding area (7), a third folding area (8), and a fourth folding area (9). The first FPC segment (1), the second FPC segment (2), the third FPC segment (3), the fourth FPC segment (4), and the fifth FPC segment (5) constitute the smallest cyclic unit of an equal-length FPC arrangement; The first folding area (6), the second folding area (7), the third folding area (8), and the fourth folding area (9) each contain two creases. The first folding area (6) includes a first crease (10) and a second crease (11). The second folding area (7) includes a third crease (12) and a fourth crease (13). The third folding area (8) includes a fifth crease (14) and a sixth crease (15). The fourth folding area (9) includes a seventh crease (16) and an eighth crease (17). By folding inward and outward twice, the FPCs of two adjacent parts can be arranged in parallel and overlapped, effectively extending the length of the FPC. At the same time, the total thickness of the FPC at any position after folding does not exceed: (number of layers + 2) × thickness of a single FPC layer. Here, the number of layers refers to the number of FPC layers stacked outside the folding area.
2. The multi-layer FPC folding and stacking design device according to claim 1, characterized in that: Each FPC contains multiple circuit wires (18), and each circuit wire (18) runs through the long end of the entire FPC to realize the electrical connection between the two ends of the FPC.
3. The multi-layer FPC folding and stacking design device according to claim 1, characterized in that: The entire flexible circuit can contain multiple parallel FPC units, and the overall width can be reduced by folding into multiple layers, so that the total width is reduced to the width of a single-layer FPC (19). The total number of layers in the folded area is the number of parallel FPC units + 2, and the total number of layers outside the folded area is the number of FPC units.
4. The multi-layer FPC folding and stacking design device according to claim 1, characterized in that: The FPC can contain multiple FPC segments and folded areas. The more FPC segments it contains, the greater the length can be extended.
5. The multi-layer FPC folding and stacking design device according to claim 1, characterized in that: The angle α(21) in each folded region of the FPC ranges from 0 to 180°. The relationship between the folding angle β(22) and the angle α(21) in the folded region is as follows: When this relationship is satisfied, the bent FPC can be folded along the crease to form a straight line, thereby extending its length. Through multiple folds at multiple corners, the bent FPC can be stretched out along a straight line, effectively extending the final length without increasing the processing difficulty.
6. The multi-layer FPC folding and stacking design device according to claim 1, characterized in that: When the corner α is a right angle or an obtuse angle (20), a long FPC can be condensed into a small area through multiple corners, and the traces can be spread as much as possible across the entire printed FPC plane, thus avoiding the increase in process difficulty caused by ultra-long FPC processing.
7. The multi-layer FPC folding and stacking design device according to claim 1, characterized in that: When the corner α (21) is an acute angle, multiple FPCs can be combined together in one production process (25) to improve production efficiency and reduce costs.
8. The multi-layer FPC folding and stacking design device according to claim 1, characterized in that: The corners α of the same FPC do not need to be consistent. Acute angles (26), obtuse angles (27) of extra-long FPCs, and right angles can be mixed according to the actual situation to improve wiring efficiency and effectively increase the length of a single FPC. This folding method can achieve high wiring efficiency and obtain a very long FPC.
9. The multi-layer FPC folding and stacking design device according to claim 1, characterized in that: The corner directions of the FPC can be inconsistent. With the corresponding reverse corner (28), a very long FPC can be obtained under the premise that all corners α (20) are obtuse angles, ensuring good electromagnetic characteristics and high wiring efficiency.
10. The multi-layer FPC folding and stacking design device according to claim 1, characterized in that: The outer corner of the FPC can be different from the inner corner. That is, the sharp corner on the outside can be changed into a flat corner (23) or a rounded corner (24). The corresponding wire shape can also be made into a flat corner or a rounded corner.