Electrical connection structure for a single- or multi-segment intelligent dimming film

Abstract

Electrical connection structure for a single- or multi-segment intelligent dimming film, characterized in that it comprises the following: a dimming foil body with a control area and several dimming areas, wherein each of the dimming areas is provided with a dimming foil and metal wires, the metal wires being brought out and brought together in the said control area; a flexible printed circuit board comprising, from bottom to top, a first insulating layer, several independent conductor tracks and a second insulating layer, wherein the part of the first insulating layer of the flexible printed circuit board that is laminated onto the control area has been removed, and the exposed independent conductors are attached to the metal wires by means of a conductive adhesive layer in order to establish a conductive connection with the metal wires in the control area. a control unit that controls the dimming film via the flexible circuit board; wherein the connecting part between the dimming foil body and the flexible circuit board is an electrically conductive structure; The conductive adhesive layer has vent holes that are arranged between the independent conductors and the metal wires; U-shaped longitudinal slots are provided between the independent conductors of the flexible printed circuit board.

Description

Technical field

[0001] The present utility model relates to dimming films, in particular an electrical connection structure for a single- or multi-segment intelligent dimming film. Background of the invention

[0002] Existing dimming films use a simple ACF lamination process. Due to the random distribution of conductive particles in the ACF, this process poses a risk of short circuits and interruptions at the connection point between the external control unit and the dimming film. Summary of the invention

[0003] To overcome the aforementioned disadvantages of the prior art, the present utility model provides an electrical connection structure for a single- or multi-segment intelligent dimming film. The design of the electrically conductive structural component of this single- or multi-segment dimming film achieves an interference-free connection between the dimming film body and the control unit.

[0004] To achieve the aforementioned objective, the present utility model provides the following technical solution: An electrical connection structure for a single- or multi-segment intelligent dimming film, characterized in that it comprises the following: a dimming foil body with a control area and several dimming areas, each of the dimming areas being provided with a dimming foil and metal wires, the metal wires being brought out and brought together in the control area; a flexible printed circuit board comprising, from bottom to top, a first insulating layer, several independent conductor tracks and a second insulating layer, wherein the part of the first insulating layer of the flexible printed circuit board that is laminated onto the control area has been removed, and the exposed independent conductors are attached to the metal wires by means of a conductive adhesive layer in order to establish a conductive connection with the metal wires in the control area. a control unit that controls the dimming film via the flexible printed circuit board; wherein the connecting part between the dimming film body and the flexible printed circuit board is an electrically conductive structure; The conductive adhesive layer has vent holes that are arranged between the independent conductors and the metal wires; U-shaped longitudinal slots are provided between the independent conductors of the flexible printed circuit board.

[0005] In particular, the dimming film mentioned is a PDLC film.

[0006] In particular, the metal wires are located at the conductive contacts of the top layer of the dimming film or at the conductive contacts of the bottom layer of the dimming film.

[0007] In particular, a cover layer is provided on the side of the second insulating layer of the control area, wherein the material of the cover layer is epoxy resin adhesive or a polyimide film, which serves to increase the tensile strength of the flexible printed circuit board.

[0008] In particular, the length of the U-shaped longitudinal slots on the flexible circuit board is 5 mm to 8 mm and the width is 1 mm to 2 mm.

[0009] In particular, the vent holes provided in the conductive adhesive layer are round vent holes with a diameter of 1 mm to 2 mm.

[0010] In particular, the thickness of the conductive adhesive layer is 20 µm to 30 µm.

[0011] In particular, the thickness ratio between the insulating layer, the conductive copper layer and the conductive adhesive layer of the flexible printed circuit board is approximately 3:2:2.

[0012] In particular, the width of the aforementioned metal wires and the center-to-center distance are 2-3 mm.

[0013] Compared to the prior art, the advantages of this utility model are as follows: By using a flexible FPC circuit board for connection to the dimming film, the control of several areas of the dimming film is achieved and complex, multiple wiring is avoided; the design of U-shaped longitudinal slots between the independent conductors of the flexible FPC circuit board increases the non-pressurized area, interrupts the electrical connection of the anisotropic conductive adhesive layer (ACF conductive adhesive) between two independent conductors and thus avoids the risk of a short circuit between adjacent independent conductors.The design of round vent holes in the ACF conductive adhesive allows for venting during lamination, improves the flatness of the ACF lamination, prevents air inclusions from interfering with the contact of the conductive particles, and avoids a poor electrical connection between the flexible FPC circuit board and the smart dimming film, which would pose a risk of an open circuit. Applying a topcoat (the topcoat material can be epoxy adhesive or a polyimide film) to the non-adhesive, exposed side of the flexible FPC circuit board increases the tensile strength of the bond. Brief description of the drawings

[0014] To clarify the technical solutions in the embodiments of the present application, the drawings used in these embodiments are briefly presented below. It is evident that the drawings in the following description represent only some embodiments of the present application. A person skilled in the art can derive further drawings from these without incurring any creative effort. Fig. Figure 1 is a schematic representation of the state of the completed connection between the flexible printed circuit board and the dimming foil body in an embodiment of the present utility model; Fig. Figure 2 is a schematic cross-sectional view of the state of the completed connection between the flexible printed circuit board and the dimming foil body in an embodiment of the present utility model; Fig. Figure 3 is a schematic representation of the flexible printed circuit board in an embodiment of the present utility model; Fig. Figure 4 is a schematic representation of the conductive adhesive layer in an embodiment of the present utility model; Fig. Figure 5 is a schematic representation of the top layer (the material of the top layer can be epoxy resin adhesive or a polyimide film) in an embodiment of the present utility model. Detailed description

[0015] The exemplary embodiments of the present application are described in detail below with reference to the attached drawings.

[0016] The embodiments of the present application are explained below with reference to specific examples. A person skilled in the art in this field can easily understand the further advantages and effects of the present application from the content disclosed in this description. Obviously, the described embodiments are only a part of the embodiments of the present application and not all embodiments. The present application can also be implemented or applied by other different specific embodiments, and the various details in this description can be modified or amended differently based on different considerations and applications without departing from the spirit of the present application. It should be noted that the following embodiments and the features in the embodiments can be combined with one another, provided there is no contradiction.All other embodiments which a person skilled in the art obtains on the basis of the embodiments in the present application without any creative work shall fall within the scope of protection of the present application.

[0017] It should be noted that various aspects of the embodiments described in the appended claims are described below. It should be obvious that the aspects described herein can be embodied in a multitude of forms and that each specific structure and / or function described herein is merely exemplary. Based on the present application, a person skilled in the art should understand that any aspect described herein can be implemented independently of any other aspects and that two or more of these aspects can be combined in various ways. For example, a device can be implemented and / or a method can be practiced using any number of the aspects set forth herein.Furthermore, such a device may be implemented using other structures and / or functionalities in addition to or instead of one or more of the aspects set out herein, and / or such a procedure may be practiced.

[0018] It should also be noted that the illustrations provided in the following exemplary embodiments merely schematically depict the basic concept of the present application. The drawings show only the components relevant to the present application and are not drawn according to the number, shape, and size of the components in the actual implementation. In the actual implementation, the type, number, and proportions of the individual components can be arbitrarily changed, and the arrangement of the components can also be more complex.

[0019] Furthermore, specific details are given in the following description to facilitate a thorough understanding of the examples. However, a person skilled in the art will understand that the aspects mentioned can also be practiced without these specific details.

[0020] The present utility model provides an electrical connection structure for a single- or multi-segment intelligent dimming film. As shown in Fig. As shown in Figure 1, the interconnect structure comprises: a dimming foil body (1), a flexible printed circuit board (2) and a control unit (3).

[0021] The connecting part between the dimming foil body and the flexible circuit board is an electrically conductive structure.

[0022] The dimming foil body (1) comprises: a control area (10) and several dimming areas (11). The dimming areas (11) are provided with a dimming foil (110) and metal wires (111). The metal wires (111) extend from the respective dimming foils (110), converge in the control area (10) of the dimming foil body (1), and are arranged in the control area (10).

[0023] In one embodiment, the dimming film is a PDLC film, and the metal wires are located at the conductive contacts of the top layer of the dimming film or at the conductive contacts of the bottom layer of the dimming film. The flexible printed circuit board (2) is connected to the dimming film body (1) in the control area (10) via a conductive adhesive layer (4). A complete flexible printed circuit board (2) comprises, from bottom to top, a first insulating layer, several independent conductors, and a second insulating layer. When the flexible printed circuit board (2) is connected to the dimming film body (1), a portion of the first insulating layer of the flexible printed circuit board (2) in the control area (10) is removed, while the several independent conductors (21) and the second insulating layer (20) remain.The exposed multiple independent conductors (21) are attached to the metal wires via the conductive adhesive layer (4) in a one-to-one corresponding manner, thereby connecting the multiple independent conductors (21) and the metal wires (111) in the control area (10) in a conductive manner.

[0024] In one embodiment, the conductive adhesive layer is an anisotropically conductive adhesive (ACF). An ACF is a thin film formed by incorporating a specific quantity of conductive particles into a polymer matrix. Before bonding, the conductive particles in the anisotropically conductive adhesive layer are generally distributed approximately uniformly, do not touch each other, and are protected by an insulating layer. Therefore, the ACF film itself is non-conductive. When pressure and heat are applied to the ACF film, it softens and enters a colloidal state. This allows the conductive particles to flow and distribute themselves evenly, ensuring that a defined number of particles are available for each individual conductor track, thus guaranteeing a stable electrical resistance. Under the influence of bonding pressure, the insulating layer of the conductive particles breaks down.Several conductive particles, deformed under pressure, are clamped between the contact bumps on the wafer and the corresponding metallic conductor tracks on the substrate of the dimming film. These deformed conductive particles establish the electrical connection between the upper and lower contact bumps. The particles in the other areas, which are not subjected to pressure, remain separated from each other. In this way, an anisotropic electrical connection is achieved.

[0025] In one embodiment, as in Fig. As shown in Figure 3, U-shaped longitudinal slots (22) are made between the several independent conductor tracks (21) of the control area (10), and the second insulating layer (20) between these independent conductor tracks (21) is removed. When the now exposed, independent conductor tracks (21) are fixed one-to-one to the metallic conductor tracks (111) using the conductive adhesive layer (4), the conductive adhesive layer (4) has three positional states.The area of ​​the conductive adhesive layer (40) located between the independent conductors (21) and the metallic conductors (111) is pressurized and fully conductive; the area of ​​the conductive adhesive layer (41) located in the angle between the second insulating layer (20) and the independent conductor (21) is partially pressurized, which poses a risk of unintended conductivity; and the area of ​​the conductive adhesive layer (42) located in the U-shaped longitudinal slots (22) is non-pressurized and completely non-conductive. The arrangement of the U-shaped longitudinal slots (22) increases the non-pressurized area of ​​the conductive adhesive layer. This ensures that the area (42) of the conductive adhesive layer in the U-shaped longitudinal slots (22) is completely non-conductive.This interrupts the electrical connection of the conductive adhesive layer (4) between two independent conductor tracks (21) and thus avoids the risk of a short circuit between two adjacent independent conductor tracks (21).

[0026] In one embodiment, the length of the U-shaped longitudinal slots (22) on the flexible circuit board (2) is 5 mm to 8 mm and the width is 1 mm to 2 mm.

[0027] In one embodiment, a cover layer (5) is provided on the side of the second insulating layer (20) of the control area (10) (the material of the cover layer can be an epoxy resin adhesive or a polyimide film) to increase the tensile strength of the flexible printed circuit board (2).

[0028] In one embodiment, the thickness of the conductive adhesive layer (4) is 20 µm to 30 µm.

[0029] In one embodiment, as in Fig. As shown in Figure 4, vent holes (43) are provided on the conductive adhesive layer (4). The vent holes (43) are arranged between the independent conductive traces (21) and the metallic conductive traces (111). They serve to allow venting during the lamination of the conductive adhesive layer (4) and the flexible printed circuit board (PCB) to prevent bubble formation. This improves the flatness of the laminated conductive adhesive layer (4), reduces insufficient contact of the conductive particles, and avoids the risk of poor electrical conductivity between the independent conductive trace (21) and the metallic conductive trace (111), which could lead to an open circuit.

[0030] In one embodiment, as in Fig. 4 shown, the vent holes (43) are circular and have a diameter of 1 mm to 2 mm.

[0031] In one embodiment, the thickness ratio between the insulating layer (20) and the conductor layer (21) of the flexible circuit board (2), the conductive adhesive layer (4), and the metallic conductor tracks (111) is approximately 3:2:2. The control unit (3) is connected to the dimming film (1) via the flexible circuit board (2) in order to control it.

[0032] In one embodiment, where space on the dimming foil is limited and the short metallic conductor tracks cannot be brought together at an adjacent position, the end of the flexible circuit board is extended where the second insulating layer is removed and the U-shaped longitudinal slots are provided between the independent conductor tracks. This end of the flexible circuit board is then guided up to the metallic conductor tracks, allowing the exposed independent conductor tracks to be fixed one-to-one with the metallic conductor tracks using the conductive adhesive layer, thus electrically connecting each of the short metallic conductor tracks. For this purpose, vent holes are provided on the conductive adhesive layer, positioned between the independent conductor tracks and the metallic conductor tracks.These serve to vent during the lamination of the conductive adhesive film layer and the FPC end to prevent bubble formation, improve the flatness of the laminated adhesive film layer, reduce insufficient contact of the conductive particles, and avoid the risk of poor conductivity between the independent conductor tracks and the metallic conductor tracks leading to an open circuit.

Claims

[1] Electrical interconnect structure for a single- or multi-segment smart dimming film, characterized by that it includes the following: a dimming foil body with a control area and several dimming areas, wherein each of the dimming areas is provided with a dimming foil and metal wires, the metal wires being brought out and brought together in the said control area; a flexible printed circuit board comprising, from bottom to top, a first insulating layer, several independent conductor tracks and a second insulating layer, wherein the part of the first insulating layer of the flexible printed circuit board that is laminated onto the control area has been removed, and the exposed independent conductors are attached to the metal wires by means of a conductive adhesive layer in order to establish a conductive connection with the metal wires in the control area. a control unit that controls the dimming film via the flexible circuit board; wherein the connecting part between the dimming foil body and the flexible circuit board is an electrically conductive structure; The conductive adhesive layer has vent holes that are arranged between the independent conductors and the metal wires; U-shaped longitudinal slots are provided between the independent conductors of the flexible printed circuit board. [2] Electrical connection structure for a single- or multi-segment intelligent dimming film according to claim 1, characterized by that the dimming film is a PDLC film. [3] Electrical connection structure for a single- or multi-segment intelligent dimming film according to claim 1, characterized by that the metal wires are located on the conductive contacts of the top layer of the dimming film or on the conductive contacts of the bottom layer of the dimming film. [4] Electrical connection structure for a single- or multi-segment intelligent dimming film according to claim 1, characterized by , that a cover layer is provided on the side of the second insulating layer of the control area, wherein the material of the cover layer is epoxy resin adhesive or a polyimide film, which serves to increase the tensile strength of the flexible printed circuit board. [5] Electrical connection structure for a single- or multi-segment intelligent dimming film according to claim 1, characterized by , that the length of the U-shaped longitudinal slots on the flexible circuit board is 5 mm to 8 mm and the width is 1 mm to 2 mm. [6] Electrical connection structure for a single- or multi-segment intelligent dimming film according to claim 1, characterized by that the vent holes provided in the conductive adhesive layer are round vent holes with a diameter of 1 mm to 2 mm. [7] Electrical connection structure for a single- or multi-segment intelligent dimming film according to claim 1, characterized by , that the thickness of the aforementioned conductive adhesive layer is 20 µm to 30 µm. [8] Electrical connection structure for a single- or multi-segment intelligent dimming film according to claim 1, characterized by , that the thickness ratio between the insulating layer, the conductive copper layer and the conductive adhesive layer of the flexible printed circuit board is approximately 3:2:

2. [9] Electrical connection structure for a single- or multi-segment intelligent dimming film according to claim 1, characterized by that the width of the aforementioned metal wires and the center-to-center distance is 2-3 mm.

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