Electrical connection structure of flexible circuit board and flexible light control film

Abstract

This utility model discloses an electrical connection structure between a flexible circuit board and a flexible dimming film. The flexible circuit board includes a first insulating layer, a conductor layer, and a second insulating layer arranged sequentially. The flexible dimming film includes a first insulating layer, a first IOT conductive layer, a dimming composite material layer, a second IOT conductive layer, and a second insulating layer arranged sequentially. A first terminal area and a second terminal area adjacent to the first terminal area are provided between the flexible circuit board and the flexible dimming film. A third terminal area that is electrically connected to the outside is provided on the side of the flexible circuit board away from the flexible dimming film. The number of openings in the third terminal area is the sum of the number of openings in the first terminal area and the second terminal area. This invention directly uses a flexible circuit board with double-sided conductive adhesive to replace the conductive copper foil containing single-sided conductive adhesive, which can improve the stability of the product. At the same time, the flexible circuit board can be directly connected to an external circuit controller, replacing the process of soldering round wires to conductive copper foil with solder paste. This avoids the high temperature generated by solder paste soldering, which could damage the IOT indium tin oxide layer of the dimming film. It also reduces the number of solder bumps, making it easier to assemble the dimming film into the laminated glass.

Description

Technical Field

[0001] This utility model relates to the field of dimming film technology, and in particular to an electrical connection structure between a flexible circuit board and a flexible dimming film. Background Technology

[0002] The dimming glass can adjust the light transmittance of the glass by changing the current, so as to achieve the effect of arbitrarily changing the transparency of the glass. Its structure is a kind of laminated glass, with a liquid crystal film bonded between two pieces of glass. Each of the two pieces of glass and the bonding surface of the liquid crystal film is provided with a conductive film, and the power supply is connected through the conductive film. The liquid crystal film is a kind of polymer dispersion liquid crystal film, also called dimming film, which is a liquid crystal film based on the light valve characteristics of liquid crystal material.

[0003] The existing dimming film connection structure consists of an indium tin oxide (IOT) layer coated with silver paste, followed by a conductive copper foil containing single-sided conductive adhesive. A circular wire is then soldered to the surface of the conductive copper foil using solder paste. Solder paste soldering generates high temperatures, which can easily damage the IOT conductive layer of the dimming film, leading to electrical malfunction. Furthermore, the solder joint between the circular wire and the solder paste has a protrusion exceeding 1mm in thickness. This protrusion cannot be pressed into the laminated glass, hindering the complete assembly of the dimming film into the laminated glass. Chinese invention patent CN106773391A discloses a wiring structure for a dimming film that uses ACF thermosetting adhesive for connection. This requires high-temperature pressing technology and equipment for production, resulting in higher costs. Utility Model Content

[0004] To address the aforementioned technical problems, an electrical connection structure between a flexible circuit board and a flexible dimming film is provided. Utilizing the thin and light characteristics of the FPC, double-sided conductive adhesive is directly applied to the flexible circuit board, replacing the conductive copper foil containing single-sided conductive adhesive. The flexible circuit board has better tear resistance than the conductive copper foil, resulting in better product stability. Simultaneously, the flexible circuit board can be directly connected to an external circuit controller, replacing the process of soldering round wires to conductive copper foil with solder paste. This avoids the high temperatures generated during soldering that could damage the indium tin oxide (ITO) layer of the dimming film, while also reducing solder bumps, making it easier to assemble the dimming film into laminated glass.

[0005] To achieve the above objectives, this utility model discloses an electrical connection structure between a flexible circuit board and a flexible dimming film. The flexible circuit board includes a first insulating layer, a conductor layer, and a second insulating layer arranged sequentially. The flexible dimming film includes a first insulating layer, a first IOT conductive layer, a dimming composite material layer, a second IOT conductive layer, and a second insulating layer arranged sequentially. A first terminal area and a second terminal area adjacent to the first terminal area are provided between the flexible circuit board and the flexible dimming film. A third terminal area that is electrically connected to the outside is provided on the side of the flexible circuit board away from the flexible dimming film. The number of openings in the third terminal area is the sum of the number of openings in the first terminal area and the second terminal area.

[0006] Furthermore, the first terminal area is a single electrical conductive connection structure between the flexible circuit board and the flexible dimming film, including double-sided electrically conductive tape and conductive primer material stacked together.

[0007] Furthermore, the second terminal area is a single or multiple electrical conductive connection structure between the flexible circuit board and the flexible dimming film, including double-sided electrically conductive tape and conductive primer material stacked together.

[0008] Furthermore, the flexible circuit boards in the first terminal area and the second terminal area are disposed on the same side or opposite side of the flexible dimming film. The surface of the first IOT conductive layer or the second IOT conductive layer of the flexible dimming film is coated with a conductive primer material. The surface of the conductive primer material is connected to the conductor layer of the flexible circuit board by double-sided electrical conductive tape. The solid content of the conductive primer material is >60 wt%, and the resistance value is ≤0.01Ω·cm.

[0009] Furthermore, the main components of the double-sided electrically conductive tape are conductive acrylic acid and conductive cloth, the contact resistance in the Z direction is 0.05Ω, the thickness of the double-sided electrically conductive tape is 10μm~100μm, and the peel force is 5N / cm~50N / cm.

[0010] Furthermore, the flexible dimming film has a single-zone or multi-zone structure, the thickness of the first IOT conductive layer and the second IOT conductive layer is 100nm to 1000nm, and the thickness of the first insulating layer and the second insulating layer of the dimming film is 50μm to 200μm.

[0011] Furthermore, the thickness of the first insulating layer and the second insulating layer of the circuit board is 10μm to 100μm, and the thickness of the conductor layer of the circuit board is 6μm to 300μm.

[0012] Furthermore, the openings on the flexible circuit board and the flexible dimming film surface in the first terminal area and the second terminal area are 0.5mm wide recessed insulating openings, and the exposed conductors are square, grid-like, or fine line-like in shape, wherein the wire diameter of the grid-like and fine line-like conductors is 0.1mm to 2mm. The overall dimensions of the exposed conductor area are 2mm to 100mm in length and 2mm to 20mm in width.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model discloses an electrical connection structure between a flexible circuit board and a flexible dimming film. Utilizing the thin and light characteristics of FPC, double-sided conductive adhesive is directly applied to the flexible circuit board to replace the conductive copper foil containing single-sided conductive adhesive. The flexible circuit board has better tear resistance than the conductive copper foil, which can make the product more stable. At the same time, the flexible circuit board can be directly connected to the external circuit controller, replacing the process of soldering round wires to conductive copper foil with solder paste. This avoids the high temperature generated by solder paste soldering, which would damage the IOT indium tin oxide layer of the dimming film. At the same time, it reduces the number of solder bumps, making it easier to assemble the dimming film into the laminated glass. Attached Figure Description

[0014] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0015] Figure 1 This is a schematic diagram of the connection structure of this utility model.

[0016] Figure 2 This is a schematic diagram of the connection of the first terminal area in Embodiment 1 of this utility model.

[0017] Figure 3 This is a schematic diagram of the connection of the second terminal area in Embodiment 1 of this utility model.

[0018] In the diagram: 1 is the flexible circuit board; 11 is the first insulating layer of the circuit board; 12 is the conductor layer of the circuit board; 13 is the second insulating layer of the circuit board; 2 is the flexible dimming film; 21 is the first insulating layer of the dimming film; 22 is the first IOT conductive layer; 23 is the dimming composite material layer; 24 is the second IOT conductive layer; 25 is the second insulating layer of the dimming film; 3 is the first terminal area; 4 is the second terminal area; 5 is the third terminal area; 6 is the double-sided electrical conductive tape; 7 is the conductive primer material. Detailed Implementation

[0019] 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 of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] The flexible circuit board 1 includes a first insulating layer 11, a conductor layer 12, and a second insulating layer 13 arranged sequentially. The flexible dimming film 2 includes a first insulating layer 21, a first IOT conductive layer 22, a dimming composite material layer 23, a second IOT conductive layer 24, and a second insulating layer 25 arranged sequentially. A first terminal region 3 and a second terminal region 4 adjacent to the first terminal region 3 are provided between the flexible circuit board 1 and the flexible dimming film 2. A third terminal region 5 electrically connected to the outside is provided on the side of the flexible circuit board 1 away from the flexible dimming film 2. The number of openings in the third terminal region 5 is equal to the number of openings in the first terminal region 3 and the second terminal region 4. The sum of the number of openings in the two-terminal area 4, the surface of the conductive primer 7 is connected to the conductor layer 12 of the flexible circuit board through double-sided electrically conductive tape 6. Taking advantage of the thinness of the FPC, the double-sided electrically conductive adhesive is directly applied to the flexible circuit board to replace the conductive copper foil containing single-sided conductive adhesive. The flexible circuit board has better tear resistance than the conductive copper foil, which can make the product more stable. At the same time, the flexible circuit board can be directly connected to the external circuit controller, replacing the process of soldering round wires to conductive copper foil with solder paste. This avoids the high temperature generated by solder paste soldering, which would damage the IOT indium tin oxide layer of the dimming film. At the same time, it reduces the solder bumps, which makes it easier to assemble the dimming film into the laminated glass.

[0021] The conductive primer material 7 has a solid content >60 wt% and a resistance value ≤0.01Ω·cm. In order to improve the adhesion and conductivity uniformity, a layer of conductive material is coated on the surface of the current collector such as copper foil or aluminum foil. We call this process the primer coating process. Generally speaking, the composition of the conductive coating is mainly conductive agent materials such as conductive graphite, carbon black, carbon nanotubes and graphene paste, supplemented by some binders and additives. After dispersion, it is uniformly coated on the surface of the current collector with a thickness of about 1μm to 5μm. After the primer coating process is improved, the adhesion and conductivity uniformity of the electrode sheet will be improved to a certain extent. In this application, the conductive primer material is preferably conductive silver paste, conductive graphite or conductive adhesive.

[0022] The main components of the double-sided electrically conductive tape 6 are conductive acrylic and conductive cloth. The contact resistance in the Z direction is 0.05Ω. The thickness of the double-sided electrically conductive tape 6 is 10μm to 100μm, and the peel force is 5N / cm to 50N / cm. The double-sided electrically conductive tape of this application uses low-temperature pressure-sensitive adhesive, which does not require high-temperature pressing process and can be directly bonded and installed.

[0023] The thickness of the first IOT conductive layer 22 and the second IOT conductive layer 24 is 100nm to 1000nm, and the thickness of the first insulating layer 21 and the second insulating layer 25 of the dimming film is 50μm to 200μm.

[0024] The thickness of the first insulating layer 11 and the second insulating layer 13 of the circuit board is 10μm to 100μm, and the thickness of the conductor layer 12 of the circuit board is 6μm to 300μm.

[0025] The openings on the surfaces of the flexible circuit board 1 and the flexible dimming film 2 in the first terminal area 3 and the second terminal area 4 are 0.5mm wide recessed insulating openings. The exposed conductors are square, grid-like, or fine line-like in shape, with the wire diameter of the grid-like and fine line-like conductors being 0.1mm to 2mm. The overall dimensions of the exposed conductor area are 2mm to 100mm in length and 2mm to 20mm in width to ensure connection stability.

[0026] Embodiment 1 of this application is a preferred embodiment, such as... Figure 1 As shown, the flexible dimming film in the second terminal area adopts a four-zone structure and is connected to the flexible circuit board. The circuit board conductor layer under the five openings in the third terminal area is respectively connected to the circuit board conductor layers under the first and second terminal areas, as shown below. Figure 2 As shown, the second insulating layer of the circuit board in the first terminal area has a single insulating layer opening. The first insulating layer of the dimming film, the first IOT conductive layer, and the dimming composite material layer all have openings, exposing the second IOT conductive layer. The opening direction of the flexible circuit board matches the front opening of the flexible dimming film. The surface of the second IOT conductive layer is coated with a conductive primer and electrically connected to the conductor layer of the circuit board via double-sided electrically conductive tape. Figure 3 As shown, the circuit board in the second terminal area has four openings in the first insulating layer, the second insulating layer of the dimming film, the second IOT conductive layer, and the dimming composite material layer, exposing the first IOT conductive layer. The opening direction of the flexible circuit board matches the back opening of the flexible dimming film. The surface of the first IOT conductive layer is coated with a conductive primer and electrically connected to the conductor layer of the circuit board through double-sided electrical conductive tape. The first terminal area and the second terminal area of ​​the flexible circuit board are respectively located on the front and back sides of the flexible dimming film to reduce interference and facilitate stable connection.

[0027] The difference between Embodiment 2 and Embodiment 1 is that the flexible circuit board in the first terminal area is located on the back of the flexible dimming film, while the flexible circuit board in the second terminal area is located on the front of the flexible dimming film. A suitable connection structure is selected according to different installation environments.

[0028] The difference between Embodiment 3 and Embodiment 1 is that the flexible circuit boards of the first terminal area and the second terminal area are both located on the front side of the flexible dimming film. The terminal areas set on the same side can be bonded in one step. With the matching opening processing parameters of the flexible dimming film, there is no need to flip the product.

[0029] The difference between Embodiment 4 and Embodiment 3 is that the flexible circuit boards of both the first terminal area and the second terminal area are located on the back side of the flexible dimming film.

[0030] The difference between Embodiment 5 and Embodiment 1 is that the flexible dimming film in the second terminal region has an opening in the IOT conductive layer, which can be a single-zone, double-zone, triple-zone, or multi-zone structure, and the number of openings in the third terminal region varies accordingly.

[0031] Several points need to be clarified: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly, and can refer to mechanical or electrical connections, or internal connections between two components, or direct connections. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships, and the relative positional relationships may change when the absolute position of the described objects changes. Second, in this document, relational terms such as "first" and "second" are only used to distinguish one entity from another entity, and do not necessarily require or imply any such actual relationship or order between these entities.

[0032] The above examples are merely illustrative of this utility model and do not constitute a limitation on the scope of protection of this utility model. All designs that are the same as or similar to this utility model are within the scope of protection of this utility model.

Claims

1. An electrical connection structure between a flexible circuit board and a flexible dimming film, characterized in that, The flexible circuit board (1) includes a first insulating layer (11), a conductor layer (12), and a second insulating layer (13) arranged sequentially. The flexible dimming film (2) includes a first insulating layer (21), a first IOT conductive layer (22), a dimming composite material layer (23), a second IOT conductive layer (24), and a second insulating layer (25) arranged sequentially. A first terminal area (3) and a second terminal area (4) adjacent to the first terminal area (3) are provided between the flexible circuit board (1) and the flexible dimming film (2). The side of the flexible circuit board (1) away from the flexible dimming film (2) is provided with a first terminal area (3) and a second terminal area (4). A third terminal area (5) is provided for electrical connection with the outside world. The number of openings in the third terminal area (5) is the sum of the number of openings in the first terminal area (3) and the second terminal area (4). The first terminal area (3) is a single electrical connection structure between the flexible circuit board (1) and the flexible dimming film (2), including double-sided electrically conductive tape (6) and conductive primer material (7) stacked together. The second terminal area (4) is a single or multiple electrical connection structure between the flexible circuit board (1) and the flexible dimming film (2), including double-sided electrically conductive tape (6) and conductive primer material (7) stacked together.

2. The electrical connection structure between a flexible circuit board and a flexible dimming film according to claim 1, characterized in that, The flexible circuit board (1) in the first terminal area (3) and the second terminal area (4) is disposed on the same side or opposite side of the flexible dimming film (2). The surface of the first IOT conductive layer (22) or the second IOT conductive layer (24) of the flexible dimming film (2) is coated with a conductive primer material (7). The surface of the conductive primer material (7) is connected to the conductor layer (12) of the flexible circuit board through a double-sided electrical conductive tape (6). The solid content of the conductive primer material (7) is >60 wt%, and the resistance value is ≤0.01Ω·cm.

3. The electrical connection structure between a flexible circuit board and a flexible dimming film according to claim 1, characterized in that, The main components of the double-sided electrically conductive tape (6) are conductive acrylic acid and conductive cloth. The contact resistance in the Z direction is 0.05Ω. The thickness of the double-sided electrically conductive tape (6) is 10μm to 100μm and the peel force is 5N / cm to 50N / cm.

4. The electrical connection structure between a flexible circuit board and a flexible dimming film according to claim 1, characterized in that, The flexible dimming film (2) has a single-zone or multi-zone structure. The thickness of the first IOT conductive layer (22) and the second IOT conductive layer (24) is 100nm to 1000nm, and the thickness of the first insulating layer (21) and the second insulating layer (25) of the dimming film is 50μm to 200μm.

5. The electrical connection structure between a flexible circuit board and a flexible dimming film according to claim 1, characterized in that, The thickness of the first insulating layer (11) and the second insulating layer (13) of the circuit board is 10μm to 100μm, and the thickness of the conductor layer (12) of the circuit board is 6μm to 300μm.

6. The electrical connection structure between a flexible circuit board and a flexible dimming film according to claim 1, characterized in that, The openings on the surfaces of the flexible circuit board (1) and the flexible dimming film (2) in the first terminal area (3) and the second terminal area (4) are 0.5mm wide recessed insulating openings. The exposed conductors are square, grid-like, or fine line-like, with the wire diameter of the grid-like and fine line-like conductors being 0.1mm to 2mm. The overall dimensions of the exposed conductor area are 2mm to 100mm in length and 2mm to 20mm in width.

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