FPC press-fit structure and PDLC dimming film
By splitting the copper foil in the FPC compressed structure into multiple pieces and optimizing the direction of the window opening line, the connection intensity between the FPC and the PDLC dimming film is enhanced, and the problem of insufficient connection intensity in the prior art is solved, and a higher pulling force and lower defect rate are achieved.
Patent Information
- Application Number
- CN202422548030.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-21
- Publication Date
- 2025-08-01
- Estimated Expiration
- 2034-10-21
AI Technical Summary
The FPC and diaphragm connection strength of the existing PDLC dimming film is low and it is easy to fall off during production, handling, packaging and assembly, resulting in high product defect rate and increased scrap cost.
Using the FPC press-bonding structure, the entire piece of copper foil is split into multiple pieces of copper foil and wrapped with ACF glue to form a PI film-ACF glue-electrode structure, increasing the adhesion and stress-bearing sections, and optimizing the direction of the window opening line to disperse stress.
The horizontal and vertical pulling force of FPC and PDLC dimming films is significantly improved, the product defect rate and scrap rate are reduced, the FPC is stable and the FPC is not easy to fall off, and the product yield is improved.
Smart Images
Figure CN223180522U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of dimming films, in particular to an FPC pressing structure and a PDLC dimming film. Background Art
[0002] PDLC dimming films are widely used in automotive dimming sunroofs. FPC, Flexible Printed Circuit, is a key component for connecting PDLC dimming films to in-vehicle power supply devices. Therefore, ensuring the connection strength between the FPC and the film is crucial. The connection strength between the FPC and the film can usually be reflected by measuring the horizontal pulling force and the vertical pulling force.
[0003] When testing the horizontal pulling force of the existing structure, the film with the FPC is fixed on the tabletop, and the end of the FPC is fixed on the pulling force testing instrument. The whole is kept on the same horizontal line. Then, the testing instrument is pulled in the horizontal direction until the FPC and the film are separated. The horizontal pulling force data obtained from the instrument is 10 - 30 N.
[0004] When testing the vertical pulling force of the existing structure, the FPC is divided into two parts, the film is placed vertically, the bottom end of the film is fixed to the fixture under the vertical pulling force testing instrument, and the end of the FPC is fixed to the fixture above the instrument. After the testing instrument is started, the fixture above rises until the FPC and the film are separated. The instrument shows that the vertical pulling force data is 1 - 2 N.
[0005] From the measurement results, it can be seen that the horizontal pulling force and the vertical pulling force values of the existing structure are small, and the connection strength between the FPC and the film is low. Although the existing structure can meet the basic requirements, during the production, handling, packaging, and assembly of PDLC dimming films, it is inevitable that there may be contact, collision, or even pulling with people or objects. The low connection strength between the FPC and the film may still cause the FPC to fall off from the film, and occasional falling-off events will cause huge waste. Therefore, it is necessary to improve the connection strength between the FPC and the film so that the FPC will not easily fall off from the PDLC dimming film, improve the product yield rate, and reduce the scrap cost. Summary of the Utility Model
[0006] The purpose of the utility model is to provide an FPC pressing structure and a PDLC dimming film to alleviate the problem of low connection strength between the FPC and the film in the existing structure.
[0007] To solve the above technical problems, the technical solution provided by the utility model is as follows:
[0008] In a first aspect, the present utility model provides an FPC lamination structure, comprising: an FPC, an ACF adhesive, and an electrode. The FPC includes a PI film and multiple copper foils. The ACF adhesive wraps multiple copper foils therein, and the PI film is hot-pressed to form the FPC lamination structure of PI film - ACF adhesive - electrode from top to bottom.
[0009] Furthermore, multiple copper foils are arranged at intervals in a single row.
[0010] Furthermore, the width range of each copper foil is 0.8 - 2.5 mm.
[0011] Furthermore, multiple copper foils are arranged oppositely in two rows, and two opposite copper foils are both arranged vertically to form a fishbone structure.
[0012] Furthermore, multiple copper foils are arranged oppositely in two rows, and two opposite copper foils are both arranged at an angle to the vertical direction to form a cross structure.
[0013] Furthermore, the FPC lamination structure has a lamination area, and the length dimension and width dimension of the ACF adhesive are both larger than the corresponding dimensions of the lamination area.
[0014] Furthermore, the PI film includes an upper PI film and a lower PI film, and the upper PI film is provided with a window structure.
[0015] Furthermore, the window structure exposes the lower PI film and multiple copper foils, and the lower PI film and the copper foils are arranged alternately.
[0016] Furthermore, the window structure has a window line, and the window line is arranged in a straight line along the horizontal direction.
[0017] In a second aspect, the present utility model provides a PDLC dimming film, comprising the FPC lamination structure described in the first aspect.
[0018] The present utility model at least brings the following beneficial effects:
[0019] Since the present utility model provides an FPC lamination structure, comprising: an FPC, an ACF adhesive, and an electrode. The FPC includes a PI film and multiple copper foils. The ACF adhesive wraps multiple copper foils therein, and the PI film is hot-pressed to form the FPC lamination structure of PI film - ACF adhesive - electrode from top to bottom.
[0020] The FPC lamination structure splits an existing whole piece of copper foil into multiple pieces of copper foil, increasing the contact area between the PI film and the ACF adhesive. After hot pressing the PI film, the bonding force between the formed PI film-ACF adhesive-electrode structure is much greater than the bonding force between the existing copper foil-ACF adhesive-electrode structure, and the horizontal pulling force is significantly increased. At the same time, the ACF adhesive wraps multiple pieces of copper foil inside, and the high bonding force on both sides of each piece of copper foil ensures the bonding strength between the copper foil and the ACF adhesive, further improving the horizontal pulling force between the FPC and the PDLC dimming film.
[0021] In the vertical direction, a whole piece of copper foil in the existing structure can only provide one stress section. Once there is a pull in the vertical direction, the FPC will easily fall off completely. However, the FPC lamination structure of this application increases the stress sections in the vertical direction through the design of multiple pieces of copper foil, and can withstand multiple unexpected situations. Even if there is an occasional pull, only one or two pieces of copper foil of the FPC will be peeled off, and the remaining multiple pieces of copper foil still maintain stable connection, and the FPC can still supply power normally, and the function of the PDLC dimming film will not be affected at all. The FPC lamination structure improves the connection strength between the FPC and the film in both the horizontal and vertical directions, making the FPC not easily fall off from the PDLC dimming film, greatly reducing the defect rate and scrap rate of the product.
[0022] In order to make the above-mentioned objects, features and advantages of the present utility model more obvious and understandable, the following specifically gives preferred embodiments and, in conjunction with the accompanying drawings, detailed descriptions are as follows. Description of the Drawings
[0023] In order to more clearly illustrate the specific embodiments of the present utility model or the technical solutions in the related art, the following will briefly introduce the drawings required to be used in the description of the specific embodiments or the related art. Obviously, the following drawings are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0024] Figure 1 Schematic diagram of the FPC lamination area of the prior art;
[0025] Figure 2 Schematic diagram of the FPC lamination structure of the prior art;
[0026] Figure 3 Schematic diagram of the prior art window line;
[0027] Figure 4 Schematic diagram of the FPC lamination structure provided by the embodiment of the present utility model;
[0028] Figure 5 Schematic of the FPC lamination structure provided by the embodiment of the present utility modelFigure 1 ;
[0029] Figure 6 Schematic diagram of the FPC pressing structure provided by the embodiment of the present utility model Figure 2 ;
[0030] Figure 7 Schematic diagram of the FPC pressing structure provided by the embodiment of the present utility model Figure 3 ;
[0031] Figure 8 Schematic diagram of the windowing line provided by the embodiment of the present utility model.
[0032] Icon:
[0033] 001 - Upper electrode FPC pressing area of PDLC film; 002 - Lower electrode FPC pressing area of PDLC film; 003 - Stress concentration point; 100 - PI film; 110 - Upper PI film; 120 - Lower PI film; 200 - Copper foil; 300 - ACF adhesive; 400 - Electrode; 500 - Windowing line. Detailed implementation manners
[0034] Next, the technical solutions of the present utility model will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.
[0035] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.
[0036] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "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 utility model 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 of the present utility model. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. Physical quantities in formulas, unless otherwise separately marked, should be understood as the basic quantities of the International System of Units or derived quantities derived from the basic quantities through mathematical operations such as multiplication, division, differentiation, or integration.
[0037] Furthermore, terms such as "horizontal," "vertical," and "overhanging" do not necessarily imply that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.
[0038] It should also be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.
[0039] The following embodiments of the present invention are described in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.
[0040] In the following embodiments, PI film, Poly imi deFi lm, is a polyimide film; ACF glue, An isotropic conductive Fi lm, is anisotropic conductive glue; PDLC dimming film, polymer dispersed liquid crystal dimming film, is polymer dispersed liquid crystal dimming film.
[0041] Example 1
[0042] During the production, handling, packaging, and assembly processes of PDLC dimming films, contact, collision, and even pulling with people or objects is unavoidable. Low connection strength between the FPC and the film can cause the FPC to detach from the film, and these occasional detachments can result in significant waste. Therefore, it is necessary to improve the connection strength between the FPC and the film to prevent the FPC from easily detaching from the PDLC dimming film, thereby improving product yield and reducing scrap costs.
[0043] In view of this, an embodiment of the present invention provides an FPC pressing structure, including: FPC, ACF glue 300 and electrode 400, the FPC includes a PI film 100 and multiple copper foils 200, the ACF glue 300 wraps the multiple copper foils 200 inside, and the PI film 100 is hot-pressed to form an FPC pressing structure of PI film-ACF glue-electrode from top to bottom.
[0044] In the existing technology of laminating FPC and PDLC dimming film, ACF glue 300 is used to firmly bind the two together through heat pressing. The structure is copper foil-ACF glue-electrode.Figure 1 and Figure 2 。 Figure 1 The upper electrode FPC pressing area 001 of the PDLC film, the lower electrode FPC pressing area 002 of the PDLC film, and the copper foil 200 in the FPC are shown in Figure 2 The existing large piece of copper foil 200 forms a copper foil - ACF adhesive - electrode structure after pressing. The area of the existing whole copper foil 200 is relatively large, and the length and width of the ACF adhesive 300 are both smaller than the corresponding dimensions of the pressing area, resulting in the ACF adhesive 300 being wrapped by the copper foil 200.
[0045] The FPC pressing structure of this embodiment splits the existing whole copper foil 200 into multiple pieces of copper foil 200, increasing the contact area between the PI film 100 and the ACF adhesive 300. Please refer to Figure 4 After the PI film 100 is hot - pressed, the bonding force between the formed PI film - ACF adhesive - electrode structures is much greater than the bonding force between the existing copper foil - ACF adhesive - electrode structures, and the horizontal pulling force is significantly increased. At the same time, the ACF adhesive 300 wraps multiple pieces of copper foil 200 inside, and the high bonding force on both sides of each piece of copper foil 200 ensures the bonding strength between the copper foil 200 and the ACF adhesive 300, further improving the horizontal pulling force between the FPC and the PDLC dimming film.
[0046] In the vertical direction, the existing whole copper foil 200 can only provide one stress section. Once there is a pull in the vertical direction, the FPC will easily fall off completely. However, the FPC pressing structure of this application increases the stress sections in the vertical direction through the design of multiple pieces of copper foil 200, and can withstand multiple accidental situations. Even if there is an occasional pull, only one or two pieces of copper foil 200 of the FPC will be peeled off, and the remaining multiple pieces of copper foil 200 still maintain stable connection, and the FPC can still supply power normally, and the function of the PDLC dimming film will not be affected at all. The FPC pressing structure improves the connection strength between the FPC and the film in both the horizontal and vertical directions, making the FPC not easily fall off from the PDLC dimming film, and greatly reducing the defective rate and scrap rate of the product.
[0047] In an optional manner of this embodiment, the FPC pressing structure has a pressing area, and the length dimension and width dimension of the ACF adhesive 300 are both larger than the corresponding dimensions of the pressing area.
[0048] The resistance value from the FPC to the ACF adhesive 300 is a hard index for the power - on performance of the PDLC dimming film. If the resistance value is too large, it will affect the normal performance of the PDLC dimming film. This embodiment can reduce this resistance value by reducing the area of the copper foil 200 in the pressing area, so as to achieve the effect of improving conductivity.
[0049] As an alternative, multiple copper foils 200 are arranged at single-row intervals, and the width range of each copper foil 200 is 0.8 - 2.5 mm.
[0050] Specifically, please refer to Figure 5 , six copper foils 200 are arranged at single-row intervals, and the width of each copper foil 200 can be any value such as 0.8 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, etc. An existing whole-piece complete copper foil 200 can only provide one stress-bearing section, while six small copper foils 200 not only improve the vertical pulling force, but also even if there is a pull, only one or two copper foils 200 will be peeled off, and the remaining four or five copper foils 200 still maintain a stable bond. Moreover, the structure of multiple small copper foils 200 enables the ACF adhesive 300 to completely cover the copper foils 200, and the high adhesive force on both sides of each copper foil 200 further ensures the bonding strength between the copper foil 200 and the ACF adhesive 300.
[0051] As another alternative, multiple copper foils 200 are arranged in a double-row and opposite manner, and the two opposite copper foils 200 are both arranged vertically to form a fishbone structure.
[0052] Specifically, please refer to Figure 6 , a whole-piece complete copper foil 200 can be divided into several fishbone structures with a width of 0.2 mm and a length of 1.4 mm. By further dividing the copper foil 200, the ACF adhesive 300 can cover more small copper foils 200, and the strong bonding force between the ACF adhesive 300 and the PI film 100 after hot pressing makes the bonding between the copper foil 200 and the electrode 400 more firm, further improving the load that the FPC can bear.
[0053] As another alternative, multiple copper foils 200 are arranged in a double-row and opposite manner, and the two opposite copper foils 200 are both arranged at an angle to the vertical direction to form a cross structure.
[0054] Specifically, please refer to Figure 7 , while further dividing the copper foil 200, the direction of the copper foil 200 is changed, not just a single vertical direction, but an oblique orientation to form a cross structure. The anisotropy of the cross structure enables the FPC to disperse the concentrated force when subjected to a horizontal pulling force, so it can bear a greater load.
[0055] In the alternative of this embodiment, the PI film 100 includes an upper PI film 110 and a lower PI film 120, and the upper PI film 110 is provided with a window structure. The window structure exposes the lower PI film 120 and multiple copper foils 200, and the lower PI film 120 and the copper foils 200 are alternately arranged.
[0056] Specifically, please refer to Figure 5, after windowing the upper PI film 110, multiple internal copper foils 200 and the lower PI film 120 are exposed. After the exposed lower PI film 120 is hot-pressed, an FPC lamination structure of PI film-ACF adhesive-electrode can be formed.
[0057] Furthermore, the windowing structure has a windowing line 500, and the windowing line 500 is arranged in a straight line along the horizontal direction.
[0058] The PI film 100 is more likely to undergo stress tearing when subjected to shear force, while it can withstand a higher load when subjected to tensile force. In the prior art, the windowing line 500 adopts an L-shaped scheme, please refer to Figure 3 . When the FPC is subjected to a horizontal pulling force, a stress concentration point 003 will appear in the lower right corner, which will cause the windowing line 500 to be subjected to shear force and is very likely to undergo stress tearing, and the force it can withstand is small. In this embodiment, the direction of the windowing line 500 is changed to a straight line, as Figure 8 shown, which can avoid the appearance of stress concentration points. When the FPC is subjected to a horizontal pulling force, the windowing line 500 is perpendicular to the direction of the force, and the windowing line 500 is subjected to tensile force, so it can withstand a greater load. At the same time, the structure of multiple copper foils 200 in this embodiment makes the force at the windowing line 500 more uniform, further improving the load that the FPC can withstand.
[0059] This embodiment optimizes the FPC lamination structure, splitting the existing large copper foil 200 in the lamination area into multiple small copper foils 200, increasing the coverage of the ACF adhesive 300 on the copper foil 200, increasing the contact area between the PI film 100 and the ACF adhesive 300 in the lamination area, and significantly improving the horizontal pulling force of the FPC. At the same time, the multiple small copper foils 200 also increase the force-bearing section in the vertical direction, increasing from the existing one-time force shedding to multiple times of force bearing, making the lamination of the FPC and the PDLC dimming film more firm in both the horizontal and vertical directions.
[0060] Embodiment 2
[0061] The embodiment of the present utility model provides a PDLC dimming film, including the FPC lamination structure of Embodiment 1. Since the PDLC dimming film includes all the structures of the FPC lamination structure, it has all the beneficial effects of Embodiment 1, which will not be elaborated here.
[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. An FPC pressing structure, characterized in that Comprising: An FPC, an ACF adhesive, and an electrode. The FPC includes a PI film and multiple copper foils. The ACF adhesive wraps multiple copper foils inside. The PI film is hot-pressed to form the FPC lamination structure of PI film - ACF adhesive - electrode from top to bottom.
2. The FPC lamination structure according to claim 1, wherein: Multiple copper foils are arranged at intervals in a single row.
3. The FPC lamination structure according to claim 2, wherein: The width range of each copper foil is 0.8 - 2.5 mm.
4. The FPC lamination structure according to claim 1, wherein: Multiple copper foils are arranged opposite to each other in two rows, and the two opposite copper foils are both arranged in the vertical direction, forming a fishbone structure.
5. The FPC lamination structure according to claim 1, wherein: Multiple copper foils are arranged opposite to each other in two rows, and the two opposite copper foils are both arranged at an angle to the vertical direction, forming a cross structure.
6. The FPC lamination structure according to claim 1, wherein: The FPC lamination structure has a lamination area, and the length dimension and width dimension of the ACF adhesive are both larger than the corresponding dimensions of the lamination area.
7. The FPC lamination structure according to any one of claims 1 - 6, wherein: The PI film includes an upper PI film and a lower PI film, and the upper PI film is provided with a window structure.
8. The FPC lamination structure according to claim 7, wherein: The window structure exposes the lower PI film and multiple copper foils, and the lower PI film and the copper foils are arranged alternately.
9. The FPC lamination structure according to claim 8, wherein: The window structure has a window line, and the window line is arranged in a straight line along the horizontal direction.
10. A PDLC dimming film, characterized in that, Comprising the FPC lamination structure according to any one of claims 1 - 9.