Dimming assembly and dimming glass with high-reliability electrode connection

Abstract

The utility model provides a dimming assembly with high reliability and electrode connection and dimming glass. The dimming assembly comprises a dimming film and an electric connection part arranged on an edge half-cut electrode of the dimming film, and the electric connection part comprises a metal conductive layer coated on an electrode connection surface and a flexible lead-out wire attached to the surface of one side, opposite to the electrode connection surface, of the metal conductive layer. The flexible insulation layer is used for being connected with an external power source and covers the flexible outgoing line, and the flexible sealing part is formed in a hot press mode in the laminating process of the dimming film, wraps the electrode connecting face, the metal conductive layer, the flexible outgoing line and the flexible insulation layer and is tightly attached to the main surface of the dimming film to form a sealing structure. The permeation of the small-molecule plasticizer in the packaging adhesive film to the active layer of the dimming film is effectively blocked, and the industrial problem of edge dimming failure is fundamentally solved. And meanwhile, the stability and durability of electrode connection are ensured by the design of the integrated electric connection part.

Description

Technical Field

[0001] This utility model relates to the field of dimming devices, specifically to a dimming component and a dimming glass. Background Technology

[0002] Smart glass is an intelligent light-controlling device that actively adjusts light transmittance by sandwiching an electrically controlled dimming film between two layers of transparent glass. Its core functional layer—the dimming film—mainly includes various types such as polymer-dispersed liquid crystal (PDLC), suspended particle (SPD), and electrochromic (EC). When an electric field is applied, the active materials in the dimming film (such as liquid crystal molecules and suspended particles) undergo alignment or state changes, thereby switching the glass between a transparent state and a frosted (or dark) state. Due to this characteristic, smart glass shows broad application prospects in building curtain walls, smart doors and windows, automotive sunroofs, and high-end displays.

[0003] Currently, the mainstream manufacturing process for smart glass involves sandwiching a dimming film between two layers of encapsulating films such as polyvinyl butyral (PVB), and then laminating it with two sheets of encapsulated glass. To conduct electricity to the dimming film, electrodes are needed at its edges. A common electrode solution involves precision machining to partially remove the surface material at the edges of the dimming film, exposing the internal transparent conductive layer (such as ITO) as an electrical connection surface. Subsequently, an external conductive metal strip or flexible printed circuit board (FPC) is connected to the half-cut electrodes using a conductive adhesive, ultimately leading to an external power source.

[0004] However, the aforementioned traditional structure has significant technical drawbacks. First, after lamination, the encapsulating film (especially PVB) directly contacts the exposed edge of the half-cut electrode. Under thermal or wet aging conditions, the small-molecule plasticizers contained in the PVB film gradually penetrate and migrate into the active layer of the dimming film. This leads to contamination and denaturation of the dimming functional layer, specifically manifested as dimming failure, spots, or hazy defects in the edge area of ​​the dimming glass, severely affecting the product's optical uniformity, lifespan, and long-term reliability.

[0005] To address this issue, the industry has made some attempts. For example, Chinese patent application CN102067032A proposes using polymer membrane strips as seals at the edges of functional membranes and attempts to prevent migration by designing adhesive and non-adhesive areas. However, this solution still relies on adhesives for fixation, and the adhesives themselves may be at risk of performance degradation and failure under humid and hot aging environments. Furthermore, their chemical composition may still have a potential corrosive effect on the dimming active materials, failing to fundamentally solve the problem.

[0006] Furthermore, regarding the reliability of the electrode connection structure, simply using conductive adhesive to bond the FPC may lead to increased connection resistance, poor contact, or even detachment when dealing with thermal stress during the lamination process and environmental stress during long-term use, affecting the stability and efficiency of current transmission.

[0007] Therefore, there is an urgent need for a new type of electrode sealing structure that can effectively prevent the penetration of small molecules in the encapsulation film while ensuring the stability and service life of the dimming film, thereby promoting the further development and application of dimming glass technology. Utility Model Content

[0008] To improve the long-term stability of dimming films, this application provides a dimming assembly with highly reliable electrode connections, including a dimming film and an electrical connection portion. A half-cut electrode is provided at the edge of the dimming film. The half-cut electrode uses the surface of the conductive layer exposed by the transparent conductive substrate layer as the electrode connection surface to form an electrical connection with the electrical connection portion. The electrical connection portion includes: a metal conductive layer coated on the electrode connection surface; a flexible lead wire attached to the side of the metal conductive layer facing away from the electrode connection surface for connection to an external power source; a flexible insulating layer covering the flexible lead wire; and a flexible sealing portion formed by hot pressing during the lamination process of the dimming film, covering the electrode connection surface, the metal conductive layer, the flexible lead wire, and the flexible insulating layer, and tightly adhering to the main surface of the dimming film to form a sealed structure.

[0009] Furthermore, the conductive metal layer is a silver paste layer.

[0010] Furthermore, the flexible lead is a flexible circuit board, which is bonded to the metal conductive layer with conductive adhesive.

[0011] Furthermore, the flexible insulation layer is a polyimide tape.

[0012] Furthermore, the flexible sealing part is made of thermoplastic PET, PBT or PCT sheet, which does not have adhesive properties at room temperature and pressure.

[0013] This application also provides a dimming glass, including two encapsulation glasses, two encapsulation films disposed between the two encapsulation glasses, and a dimming component with a high-reliability electrode connection sandwiched between the two encapsulation films.

[0014] Furthermore, the active dimming layer of the dimming film in the dimming glass is one of the following: a polymer dispersed liquid crystal layer, a polymer dispersed dye liquid crystal layer, an electrochromic layer, or a suspended particle layer.

[0015] Furthermore, the encapsulating film material in the dimming glass is selected from one of the following: polyvinyl butyral, ethylene-vinyl acetate copolymer, polyolefin elastomer, polyurethane, or ionic interlayer film.

[0016] Compared with the prior art, the dimming component and dimming glass provided by this utility model have the following beneficial effects:

[0017] The conductive metal layer provides a low-resistance current path, and the FPC is reliably connected by conductive adhesive. Under the protection of the thermoplastic seal, the overall structure can resist lamination stress and thermal expansion and contraction during long-term use, maintaining the stability of the electrical connection.

[0018] This invention integrates electrode connections (metal conductive layer, FPC) and insulation protection (PI insulating layer) within a sealed structure, forming an integrated electrical connection. The electrode sealing part, made of thermoplastic materials (such as PET, PBT, PCT), softens and solidifies during the hot-pressing process of the dimming glass lamination, forming a dense physical barrier. This barrier effectively prevents the penetration and migration of small-molecule plasticizers from the encapsulation film (such as PVB) into the active layer of the dimming film.

[0019] The internal PI insulation layer and the external thermoplastic seal together provide double insulation protection, greatly reducing the risk of short circuits and improving safety. This fundamentally solves the industry problem in the prior art of edge dimming failure and spot / haze defects in smart glass during thermal and wet aging caused by small molecule infiltration. Attached Figure Description

[0020] Figure 1 Schematic diagram of dimming component structure

[0021] Figure 2 Schematic diagram of the cross-section of the dimming glass in the embodiment

[0022] 10 - Dimming film

[0023] 11—Transparent conductive substrate layer

[0024] 12—Active dimming layer

[0025] 13—Electrode connection surface

[0026] 20 - Electrical connection part

[0027] 21—Metallic conductive layer

[0028] 22—Flexible lead wire

[0029] 23—Flexible Insulation Layer

[0030] 24 - Flexible sealing part

[0031] 30 - Smart Glass

[0032] 31—Encapsulating film

[0033] 32 — Encapsulation glass. Detailed Implementation

[0034] To make the utility model's objectives, technical solutions, and beneficial effects clearer, the present invention will be described in detail below with reference to specific embodiments. It should be understood that the embodiments described in this specification are merely illustrative and not intended to limit the scope of the present invention.

[0035] For simplicity, this paper only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form an undefined range; and any lower limit can be combined with other lower limits to form an undefined range, just as any upper limit can be combined with any other upper limit to form an undefined range. Furthermore, although not explicitly stated, every point or individual value between the endpoints of a range is included within that range. Therefore, each point or individual value can serve as its own lower or upper limit and be combined with any other point or individual value, or with other lower or upper limits, to form an undefined range.

[0036] In this description, it should be noted that, unless otherwise stated, "above" and "below" include the stated number, and "multiple" in "one or more" means two or more.

[0037] The above description of this utility model is not intended to describe every disclosed embodiment or implementation of this utility model. The following description provides more specific examples of exemplary embodiments. Throughout the application, guidance is provided through a series of embodiments that can be used in various combinations. In each embodiment, the examples are listed only as representative groups and should not be construed as exhaustive.

[0038] Terminology Explanation

[0039] The term "dimming film" as used in this application refers to an electronically controlled dimming film, which is composed of a first transparent conductive substrate layer, a dimming active layer, and a second transparent conductive substrate layer stacked sequentially.

[0040] The term "dimming active layer" used in this application refers to the functional layer in a dimming film that enables electro-optical changes, such as a polymer-dispersed liquid crystal layer, a polymer-stabilized liquid crystal layer, a dye liquid crystal layer, or a suspended particle layer.

[0041] The term "main surface of dimming film" as used in this application refers to the two largest outer surfaces of dimming film 10 perpendicular to the thickness direction, which serve as the incident or exit surface of light.

[0042] The term "edge of dimming film" as used in this application refers to an annular strip-shaped area ≤30mm from the edge of the dimming film, the boundary of which is defined by equidistant contour lines parallel to the edge of the film.

[0043] The term "half-cut" as used in this application refers to the processing technology of the edge of the dimming film: the cutting line starts from the main surface of the dimming film, passes through the transparent conductive substrate layer and the dimming active layer on one side of the cutting surface in sequence, and ends at the interface between the dimming active layer and the transparent conductive substrate layer on the side opposite to the cutting surface; after removing the material between the edge of the dimming film and the cutting line or between two cutting lines, a stepped or recessed conductive structure with the exposed transparent conductive substrate layer as the main body is formed, which is called "half-cut electrode".

[0044] The term "thermoplastic material" as used in this application refers to a polymer that can be softened and reshaped within a specific temperature range, does not undergo cross-linking reaction when softened, and has no chemical adhesiveness after cooling.

[0045] Example

[0046] like Figure 1 As shown, the dimming assembly provided in this application includes a dimming film 10 and an electrical connection portion 20. The dimming film 10 is composed of a transparent conductive substrate layer 11 and an active dimming layer 12. At the edge of the dimming film 10, a half-cut electrode is formed by a half-cutting process, and the exposed ITO surface of the half-cut electrode serves as the electrode connection surface 13.

[0047] In some embodiments, the transparent conductive substrate layer 11 is preferably a polyethylene terephthalate film with an indium tin oxide coating on its surface, and the thickness ranges from 50 μm to 300 μm.

[0048] In some embodiments, the active dimming layer 12 is a polymer dispersed dye liquid crystal layer with a thickness of 10 μm to 50 μm.

[0049] In some embodiments, the metallic conductive layer 21 is a silver paste layer coated on the electrode connection surface, formed by a screen printing process, with a thickness of approximately 10 μm to 30 μm. After low-temperature curing (e.g., 80-120°C), the silver paste layer forms an ohmic contact with the ITO layer, significantly reducing the contact resistance. In some embodiments, the thickness of the metallic conductive layer is approximately 10 μm to 30 μm.

[0050] In some implementations, the flexible lead is a 22-inch flexible printed circuit board (FPC): it is coated and electrically connected to a silver paste layer with conductive adhesive, such as anisotropic conductive film. A reliable connection is achieved through thermoforming, used to introduce external power. The flexible printed circuit board used in this application is a common commercially available product with a thickness of approximately 30μm-70μm.

[0051] The flexible insulating layer 23 is a polyimide (PI) tape covering the FPC. This PI tape has pressure-sensitive adhesion at room temperature, can be firmly attached to the FPC surface, and provides excellent electrical insulation protection. The PI tape used in this application is a common commercially available product with a thickness of approximately 10μm-70μm.

[0052] The flexible sealing part 24 is made of thermoplastic sheet, which does not have adhesive properties at room temperature and pressure. During the subsequent assembly of the dimming glass, this sealing part is thermoformed and tightly bonded to the main surface of the dimming film 10, ultimately forming an integrated sealing structure. The thermoplastic sheet used in this application is a common commercially available product with a thickness of approximately 20μm-100μm.

[0053] like Figure 2 As shown, in some application embodiments, the dimming glass 30 includes two encapsulated glass 32, two encapsulating films 31 disposed between the two encapsulated glass, and a dimming assembly sandwiched between the two encapsulating films, the dimming assembly including a flexible sealing part 24.

[0054] Test methods

[0055] High temperature and humidity aging test: The dimming glass sample in the corresponding test case was tested according to the method specified in GB 15763.3-2009.

[0056] Resistance test: The dimming components shall be tested in accordance with the method specified in GB 15763.3-2009.

[0057] Example 1

[0058] This embodiment provides a dimming component with a high-reliability electrode connection, the specific structural parameters of which are as follows:

[0059] Metal conductive layer 21: silver paste is applied to the semi-cut electrode connection surface of the dimming film by screen printing process, with a thickness of about 20 micrometers.

[0060] Flexible lead 22: It adopts a flexible circuit board (FPC) with a thickness of 50 micrometers and is thermo-bonded to the silver paste layer by anisotropic conductive adhesive (ACF).

[0061] Flexible insulating layer 23: A 20-micron thick polyimide (PI) tape is applied to the FPC surface.

[0062] Flexible sealing part 24: It is made of thermoplastic polyethylene terephthalate (PET) sheet with a thickness of 50 micrometers, which is hot-pressed in the subsequent lamination process.

[0063] Example 2

[0064] This embodiment provides another dimming component with high-reliability electrode connections, the specific structural parameters of which are as follows:

[0065] Metal conductive layer 21: made of silver paste, with a thickness of approximately 50 micrometers.

[0066] Flexible lead 22: Utilizes a flexible printed circuit board (FPC) with a thickness of 100 micrometers.

[0067] Flexible insulation layer 23: made of polyimide (PI) tape with a thickness of 50 micrometers.

[0068] Flexible sealing part 24: made of thermoplastic polycyclohexanediol terephthalate (PCT) sheet with a thickness of 100 micrometers.

[0069] Similarly, the sample from this application example was aged for 1000 hours under the same harsh conditions (85°C, 85% RH). After testing, the sample appeared intact and showed no abnormalities. The resistance measurement at the electrode connection was as low as 8 ohms, indicating lower conductivity loss and extremely high connection reliability.

[0070] Application Example 1:

[0071] The dimming glass comprising the dimming component prepared in Example 1 was prepared using the following steps:

[0072] S1: Lay the electrical connection part 20 on the main surface of the dimming film as described in the implementation scheme;

[0073] S2: Position the electrical connection part 20 using positioning tape or positioning adhesive;

[0074] S3: Test the resistance value of the dimming component;

[0075] S4: Sequentially stack the encapsulation glass 32, encapsulation film 31, dimming component, lower encapsulation film 31, and encapsulation glass 32. Use a vacuum ring to assemble the stacked components at 120°C. The resulting dimming glass cross-section is shown below. Figure 2 As shown.

[0076] S5: Test the aging performance of the dimming glass;

[0077] The test results for Application Example 1 are as follows:

[0078] 1. The resistance at the electrode connection point is 14 ohms.

[0079] 2. The dimming glass sample was subjected to accelerated aging testing for 1000 hours at an environment of 85℃ and 85% relative humidity. After the test, the sample showed no abnormalities in appearance, and no problems such as edge dimming failure, fogging, or spots were observed.

[0080] Application Example 2

[0081] The difference between Application Example 2 and Application Example 1 is that the dimming component in Example 2 is used to prepare the dimming glass. The test results are as follows:

[0082] 1. The resistance at the electrode connection point is 8 ohms.

[0083] 2. The dimming glass sample was subjected to accelerated aging testing for 1000 hours at an environment of 85℃ and 85% relative humidity. After the test, the sample showed no abnormalities in appearance, and no problems such as edge dimming failure, fogging, or spots were observed.

[0084] Application Comparative Example 1

[0085] In Comparative Example 1, the electrical connection 20 of the dimming assembly lacks the flexible insulating layer 23 (PI tape), while the other structures are similar to those in Application Example 1. After aging at the same 85°C / 85% RH for 1000 hours, the metallic conductive layer 21 (silver paste) in the sample showed significant oxidation and blackening, with the resistance rising to 45 ohms. This indicates that the lack of insulating protection makes the electrodes susceptible to corrosion in humid and hot environments, resulting in significant deterioration of electrical performance.

[0086] Application Comparative Example 2

[0087] In this comparative example, the electrical connection portion of the dimming assembly lacks the flexible sealing portion 24 (thermoplastic sheet), while the other structures are similar to those in Application Example 1. After aging testing, the edge area of ​​the dimming glass became transparent, indicating dimming failure. The resistance was 14 ohms. Although the electrical connection was not severely affected at the moment, this demonstrated that the small molecule plasticizer in the encapsulating film (such as PVB) had penetrated and damaged the active layer of the dimming film, leading to the failure of the core optical function.

[0088] Application Comparative Example 3

[0089] In this comparative example, the electrical connection portion of the dimming assembly lacks both the flexible insulating layer 23 and the flexible sealing portion 24. After aging testing, the dual problems of edge transparency and oxidation of the metal conductive layer were observed, resulting in a significant deterioration in resistance to 66 ohms. This result combines the deficiencies of Comparative Examples 1 and 2, demonstrating the indispensability of the synergistic effect of the insulating layer and the sealing portion in ensuring long-term reliability in this invention.

[0090] Application Comparative Example 4

[0091] In this comparative example, the electrical connection of the dimming component lacks a metal conductive layer 21. An attempt was made to directly connect the FPC to the half-cut electrode of the dimming film using conductive adhesive. Although there were no visible abnormalities after aging, the initial connection resistance was very high, reaching 96 ohms. This indicates that the lack of a metal conductive layer (such as silver paste) as a transition prevents the formation of a low-resistance, reliable ohmic contact between the transparent conductive layer of the dimming film and the FPC, resulting in increased power consumption and low driving efficiency.

[0092] The comparative test data from the above application examples and comparison examples demonstrate that the integrated electrical connection structure provided by this invention, which combines a metallic conductive layer, a flexible insulating layer, and a thermoplastic flexible sealing part, is crucial for ensuring that the dimming glass maintains excellent optical performance and stable electrical performance over a long period under high temperature and high humidity environments. The absence of any one of these components will result in a serious deficiency in product reliability.

Claims

1. A high-reliability electrode-connected dimming assembly comprising a dimming film (10) and an electrical connection portion (20), the dimming film (10) being provided with a half-cut electrode at an edge portion, the half-cut electrode being electrically connected to the electrical connection portion (20) with an electrode connection surface (13) of a conductive layer exposed with a transparent conductive substrate layer (11), characterized in that, The electric connection part (20) comprises: a metal conductive layer (21) coated on the electrode connection surface (13); a flexible lead wire (22) attached to the back surface of the metal conductive layer (21) away from the electrode connection surface (13) for connecting with an external power supply; a flexible insulation layer (23) covering the flexible lead wire (22); a flexible sealing part (24) formed by hot pressing during the lamination of the light control film, covering the electrode connection surface (13), the metal conductive layer (21), the flexible lead wire (22) and the flexible insulation layer (23), and tightly adhering to the main surface of the light control film to form a sealed structure.

2. The high-reliability electrode-connected dimming assembly of claim 1, wherein, The metal conductive layer (21) is a silver paste layer.

3. The high-reliability electrode-connected dimming assembly of claim 1, wherein, The flexible lead wire (22) is a flexible circuit board, which is bonded to the metal conductive layer by conductive adhesive.

4. The high-reliability electrode-connected dimming assembly of claim 1, wherein, The flexible insulation layer (23) is a polyimide tape.

5. The high-reliability electrode-connected dimming assembly of claim 1, wherein, The flexible sealing part (24) is made of thermoplastic PET, PBT or PCT sheet, which has no adhesion at normal temperature and pressure.

6. A light-adjustable glass (30) comprising two pieces of encapsulating glass (32), two pieces of encapsulating film (31) arranged between the two pieces of encapsulating glass, and a light-adjustable component sandwiched between the two pieces of encapsulating film, characterized in that, The light control assembly is a high-reliability electrode connection light control assembly as claimed in any one of claims 1 to 5.

7. The switchable glass (30) of claim 6, wherein, The active light control layer (12) of the light control film is one of a polymer dispersed liquid crystal layer, a polymer dispersed dye liquid crystal layer, an electrochromic layer or a suspended particle layer.

8. The switchable glass (30) of claim 6, wherein, The material of the encapsulation adhesive film (31) is selected from one of polyvinyl butyral, ethylene-vinyl acetate copolymer, polyolefin elastomer, polyurethane or ionic intermediate film.

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