Combined protective film on circuit board and overlong FPC (Flexible Printed Circuit) film covering structure
By adopting a combined protective film and avoidance hole slot design on the ultra-long FPC, the adverse problems caused by splicing in the production of ultra-long FPC are solved, efficient coating and circuit conduction are achieved, and production costs are reduced.
Patent Information
- Application Number
- CN202422239630.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-12
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2034-09-12
AI Technical Summary
In the prior art, the production of ultra-long FPC requires segmented processing and splicing, resulting in unwanted phenomena such as bubbles and wrinkles at the joints, which affects the appearance and may lead to oxidation of the conductive layer of the circuit board.
A combined protective film is adopted, and the first protective film and the second protective film with flush ends are respectively bonded to the circuit board, and the other ends of the two are overlapped, and avoiding hole slots are provided to cover the circuit conduction part to avoid splicing and ensuring the quality of the adhesive.
Improve processing efficiency, avoid bad phenomena, ensure normal circuit conduction and circuit board function, and reduce production costs.
Smart Images
Figure CN223246765U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of FPC production, in particular to a combined protective film on a circuit board and a film covering structure of an ultra-long FPC. Background Art
[0002] An extra-long FPC refers to an FPC that is longer than 1.5 meters. Since at least one end face of the FPC's circuit board needs to be laminated with a protective film of equal length, and the maximum lamination length (width) of a conventional laminator is 1.5 meters, when the FPC's length exceeds 1.5 meters, it is generally produced in sections. However, the sectioned FPC needs to be spliced, and the joints may need to be laminated and laminated again, which is a cumbersome process. In addition, the joints are likely to be uneven due to accumulated errors, which can lead to bubbles, wrinkles, and other undesirable phenomena in the lamination at the seams. This not only affects the appearance, but can also seriously cause oxidation of the conductive metal layer on the circuit board. Utility Model Content
[0003] In response to the problems existing in the above-mentioned prior art, the utility model provides a combined protective film on a circuit board and a coating structure for an extra-long FPC. A first protective film and a second protective film that are flush with the two ends of the circuit board are adhered thereto, and the other ends of the two protective films are overlapped. The two protective films can be attached to the same circuit board and completely cover the area to be protected. The attachment quality of the protective films can be ensured, and there is no need for subsequent circuit board splicing processes, thereby improving processing efficiency.
[0004] In order to solve the above technical problems, a technical solution adopted by the present invention is as follows:
[0005] A combined protective film on a circuit board, wherein a protective film is attached to the upper end surface and / or the lower end surface of the circuit board, and each of the protective films is a combined protective film, including a first protective film and a second protective film, wherein:
[0006] The lengths of the first protective film and the second protective film are both shorter than the length of the circuit board, the circuit board is provided with one or more circuit conducting parts, and the first protective film and / or the second protective film are both provided with one or more first avoidance slots for avoiding the circuit conducting parts;
[0007] The length of the first protective film is less than or equal to 1.5 m, one end of the first protective film is flush with one end of the circuit board, and the other end extends to the end surface of the circuit board;
[0008] The length of the second protective film is less than or equal to 1.5m, one end portion thereof in the length direction is flush with the other end portion of the circuit board, and the other end portion thereof in the length direction overlaps with the upper end portion of the first protective film, and the projection of the overlapping portion on the circuit board falls on the outside of each of the circuit conductive portions.
[0009] As a further elaboration of the above technical solution:
[0010] In the above technical solution, the length of the overlapping portion is between 8 mm and 12 mm.
[0011] Another technical solution adopted in the present invention is as follows:
[0012] An extra-long FPC, on which two or more stacked circuit boards are arranged, including at least one main circuit board, each of which is greater than 1.5m in length, and its upper end surface and / or lower end surface are both affixed with the combined protective film described in the above technical solution.
[0013] As a further elaboration of the above technical solution:
[0014] In the above technical solution, the length of each of the first protective films is 1.5 m.
[0015] In the above technical solution, the length of each overlapping portion is 10 mm.
[0016] In the above technical solution, it also includes several small circuit boards, each of which is less than 1.5 meters in length and is stacked and fixed on the first protective film or the second protective film; a third protective film is provided on the upper and lower end surfaces of each small circuit board, and a second avoidance hole is provided on each third protective film and small circuit board directly above each first avoidance hole, and several third protective films are adhered and fixed on the first protective film or the second protective film.
[0017] Compared with the prior art, the beneficial effects of the present invention are: by attaching the first protective film and the second protective film whose two ends are respectively flush with the circuit board, and overlapping the other ends of the two protective films, the two protective films can be attached to the same circuit board and completely cover the area to be protected, and the attachment quality of the protective films can be ensured, without the need for subsequent circuit board splicing processes, thereby improving processing efficiency; by respectively arranging avoidance holes and grooves on the two protective films, and arranging the overlapping parts of the two protective films on the outside of the circuit conductive part of the circuit board, it is convenient to brush the solder paste into the circuit board during the subsequent solder paste brushing operation, thereby ensuring that the circuit board is conductive with the external circuit and ensuring that the circuit board functions normally. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a structural diagram of embodiment 1;
[0019] Figure 2 It is a structural diagram of Example 2.
[0020] In the figure: 10, main circuit board; 20, small circuit board; 1, first protective film; 2, second protective film; 3, circuit conduction part; 4, first avoidance hole groove; 5, overlapping part; 6, third protective film; 7, second avoidance hole groove. DETAILED DESCRIPTION
[0021] The present invention will be further described in detail below with reference to the accompanying drawings.
[0022] The embodiments described with reference to the accompanying drawings are illustrative and intended to explain the present application, and should not be construed as limiting the present application. In the description of this application, it should be understood that terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise" indicate positions or locations based on the positions or locations shown in the accompanying drawings. These terms are intended solely to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed to indicate or imply relative importance or to implicitly specify the number of the technical features referred to. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this application, "several" and "a plurality" mean two or more, unless otherwise specifically defined. In this application, unless otherwise specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they can refer to fixed, removable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; or internal communication between two components. A person skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances. In this application, unless otherwise specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or the first and second features being in contact through another feature between them. Furthermore, "above," "above," and "above" a first feature may include the first feature being directly above or diagonally above the second feature, or simply indicate that the first feature is at a higher level than the second feature. "Below," "below," and "below" a first feature may include the first feature being directly below or diagonally below the second feature, or simply indicate that the first feature is at a lower level than the second feature.
[0023] like Figure 1 As shown, a combined protective film is attached to the upper end surface and / or the lower end surface of the circuit board. Each protective film is a combined protective film, including a first protective film 1 and a second protective film 2, wherein:
[0024] The lengths of the first protective film 1 and the second protective film 2 are both shorter than the length of the circuit board. The circuit board is provided with one or more circuit conducting portions 3. The first protective film 1 and / or the second protective film 2 are both provided with one or more first avoidance slots 4 for avoiding the circuit conducting portions 3.
[0025] The length of the first protective film 1 is less than or equal to 1.5 m, one end of the first protective film 1 is flush with one end of the circuit board, and the other end extends to the end surface of the circuit board;
[0026] The length of the second protective film 2 is less than or equal to 1.5m, one end of the length direction is flush with the other end of the circuit board, and the other end of the length direction overlaps with the upper end of the first protective film 1, and the projection of the overlapping part 5 on the circuit board falls on the outside of each circuit conductive part 3.
[0027] During operation, first align and fit the first protective film 1 to one end of the circuit board, ensure that the avoidance hole groove 4 is aligned with the circuit conductive part 3, and use a laminator to perform the first lamination. Then, align and fit the second protective film 2 of appropriate length to the other end of the circuit board, ensure that the avoidance hole groove 4 is aligned with the circuit conductive part 3, and ensure that the overlapping part 5 avoids the circuit conductive part 3. Finally, use a laminator to perform the second lamination.
[0028] The utility model attaches the first protective film 1 and the second protective film 2, whose two ends are respectively flush with the circuit board, and overlaps the other ends of the two protective films, so that the two protective films can be attached to the same circuit board and completely cover the area to be protected, and the attachment quality of the protective films can be ensured, and no subsequent circuit board splicing process is required, thereby improving processing efficiency; by respectively arranging avoidance holes 4 on the two protective films and arranging the overlapping part of the two protective films on the outside of the circuit conductive part 3 of the circuit board, it is convenient to brush the solder paste into the circuit board during the subsequent solder paste brushing operation, thereby ensuring that the circuit board is conductive with the external circuit and ensuring that the circuit board functions normally.
[0029] In order to ensure that the two protective films can be completely pressed together and that bubbles, wrinkles and other defects can be completely pushed to the overlapping part, ensure that the second protective film 2 attached to the circuit board has no wrinkles and there are no bubbles between the circuit board and the second protective film 2, and at the same time reduce the area of the overlapping part 5 on the second protective film 2, the length of the overlapping part 5 is set between 8mm and 12mm.
[0030] like Figure 1 As shown, in an application embodiment of the above embodiment, an extra-long FPC is involved, on which two or more stacked circuit boards are provided, including at least one main circuit board 10, each main circuit board 10 has a length greater than 1.5m, and its upper end surface and / or lower end surface are both affixed with a combined protective film as in the above embodiment.
[0031] In order to effectively utilize the laminating machine and improve its laminating efficiency, the length of each first protective film 1 is 1.5 m, which is the maximum laminating length of a conventional laminating machine.
[0032] In this embodiment, the length of each overlapping portion 5 is 10 mm. It has been verified in production that during the second lamination process, the laminating machine can completely push the wrinkles, bubbles and other defects at the overlapping parts of the second protective film 2 into the area of this length (width), thereby achieving a better balance between ensuring the lamination quality within the coverage range of the second protective film 2 on the main circuit board 10 and reducing the loss of the second protective film 2.
[0033] Currently, FPCs typically have a double-sided structure, with two main circuit boards (10) overlapped and glued together. Each main circuit board (10) is affixed with a protective film to protect the circuitry, and the circuits of the two main circuit boards (10) are connected using a solder paste process. This structure is common knowledge among those skilled in the art, and its detailed structure will not be elaborated on here.
[0034] like Figure 2 As shown, in another application embodiment of the above embodiment, it also includes a plurality of small circuit boards 20, each of which is less than 1.5 meters in length and is stacked and fixed on the first protective film 1 or the second protective film 2; a third protective film 6 is provided on the upper and lower end faces of each of the small circuit boards 20, and a second avoidance hole groove 7 is provided on each of the third protective films 6 and the small circuit board 20 directly above each of the first avoidance hole grooves 4, and a plurality of third protective films 6 are glued and fixed on the first protective film 1 or the second protective film 2.
[0035] In this embodiment, several small circuit boards 20 are used to replace an extra-long main circuit board, which can further reduce the processing and lamination costs of the extra-long circuit board. By setting a second avoidance hole groove 7 on it, it is convenient to brush solder paste into it in subsequent operations to conduct the small circuit boards 20 and the main circuit board 10, thereby ensuring the normal function of the FPC itself.
[0036] The above does not limit the technical scope of the present invention. Any modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.
Claims
1. A combined protective film on a circuit board, wherein the protective film is attached to the upper end surface and / or the lower end surface of the circuit board, characterized in that: Each of the protective films is a combined protective film, comprising a first protective film and a second protective film, wherein: The lengths of the first protective film and the second protective film are both shorter than the length of the circuit board, the circuit board is provided with one or more circuit conducting parts, and the first protective film and / or the second protective film are both provided with one or more first avoidance slots for avoiding the circuit conducting parts; The length of the first protective film is less than or equal to 1.5 m, one end of the first protective film is flush with one end of the circuit board, and the other end extends to the end surface of the circuit board; The length of the second protective film is less than or equal to 1.5m, one end portion thereof in the length direction is flush with the other end portion of the circuit board, and the other end portion thereof in the length direction overlaps with the upper end portion of the first protective film, and the projection of the overlapping portion on the circuit board falls on the outside of each of the circuit conductive portions.
2. The combined protective film on the circuit board according to claim 1, characterized in that: The length of the overlapping portion is between 8 mm and 12 mm.
3. A super-long FPC covering structure, wherein two or more circuit boards are stacked on the FPC, characterized in that: It comprises at least one main circuit board, each of which has a length greater than 1.5 m, and has an upper end surface and / or a lower end surface thereof affixed with the combined protective film according to any one of claims 1 to 2.
4. The super-long FPC coating structure according to claim 3, characterized in that: The length of each of the first protective films is 1.5 m.
5. The super-long FPC coating structure according to claim 3, characterized in that: The length of each overlapping portion is 10 mm.
6. The super-long FPC coating structure according to claim 3, characterized in that: It also includes several small circuit boards, each of which is less than 1.5 meters in length and is stacked and fixed on the first protective film or the second protective film; a third protective film is provided on the upper and lower end surfaces of each small circuit board, and each of the third protective films and small circuit boards is provided with a second avoidance hole groove directly above each of the first avoidance hole grooves, and several of the third protective films are pasted and fixed on the first protective film or the second protective film.