Conductive joint structure for enhancing adhesion and conductivity

Abstract

The utility model relates to a kind of conductive joint structure of enhancing adhesion and conductivity, including substrate assembly, positive electrode assembly and negative electrode assembly, in positive electrode assembly and negative electrode assembly, at least one includes foil and conductive glue, foil is connected with the surface of substrate assembly in one surface in thickness direction, and foil is provided with through hole along its thickness direction, and conductive glue includes surface layer colloid part and inlay colloid part, surface layer colloid part is bonded to the surface of foil away from substrate assembly, and inlay colloid part passes through through hole and connects substrate assembly.In the utility model, foil is provided with through hole, and conductive glue includes surface layer colloid part and inlay colloid part, inlay colloid part is bonded in through hole and inlay colloid part bonding connects surface layer colloid part and substrate assembly, significantly reduce the risk that conductive glue peels off foil caused by thermal stress, ensure that conductive glue and foil can still maintain stable connection relationship under temperature change or external force impact.

Description

Technical Field

[0001] This utility model relates to the field of conductive bonding technology, and in particular to a conductive bonding structure that enhances adhesion and conductivity. Background Technology

[0002] Electrochromic lenses, as intelligent optical devices, can dynamically adjust their optical properties by applying an electric field, and are widely used in automotive rearview mirrors, building curtain walls, and other fields. Traditional electrochromic lenses use foil and conductive silver paste for external electrical connection. The foil is connected to the lens body and connected to an external power source, while the conductive silver paste connects the foil and the lens body. This structure faces severe reliability challenges in practical applications. Due to the significant difference in the coefficients of thermal expansion between the foil and the conductive silver paste, significant thermal stress is generated during temperature cycling, leading to microcracks at the interface. Simultaneously, the mechanical bonding strength between the conductive paste and the foil is insufficient, making the interface between the conductive silver paste and the foil highly susceptible to peeling under external impact or manual repair. More seriously, the conductive path between the conductive silver paste and the foil in traditional structures relies solely on planar contact; when localized delamination occurs, it causes a sharp decline in conductivity or even complete failure. These problems severely restrict the lifespan and reliability of electrochromic lenses. Although the industry has attempted to improve adhesion by increasing the thickness of the conductive silver paste layer or by refining the adhesive formulation, the fundamental problem of insufficient interfacial bonding between the conductive silver paste and the foil has remained unresolved. Therefore, existing technologies urgently need improvement to address these issues. Utility Model Content

[0003] Therefore, this utility model provides a conductive bonding structure that enhances adhesion and conductivity, thereby improving the bonding force between conductive silver paste and foil.

[0004] To address the aforementioned technical problems, this utility model provides a conductive bonding structure that enhances adhesion and conductivity, comprising a substrate assembly, a positive electrode assembly, and a negative electrode assembly. At least one of the positive electrode assembly and the negative electrode assembly includes a foil and a conductive adhesive. One surface of the foil in the thickness direction is bonded to the surface of the substrate assembly, and the foil has a through hole extending along its thickness direction. The conductive adhesive includes a surface adhesive portion and an embedded adhesive portion. The surface adhesive portion is bonded to the surface of the foil opposite to the substrate assembly, and the embedded adhesive portion passes through the through hole and connects to the substrate assembly.

[0005] Furthermore, the through hole can be a full hole or a half hole.

[0006] Furthermore, the distance between the opposite sidewalls of the through hole is 100-300 micrometers.

[0007] Furthermore, the foil has an adhesive backing layer on its surface facing the substrate assembly, and the through hole penetrates the foil and the adhesive backing layer.

[0008] Furthermore, the area where the foil is connected to the conductive adhesive is a roughened surface.

[0009] Furthermore, the area where the foil is connected to the conductive adhesive is provided with an electroplated layer.

[0010] Furthermore, the electroplated layer is an electroplated nickel layer, an electroplated tin layer, or an electroplated silver layer.

[0011] Furthermore, the foil of the positive electrode assembly is aluminum foil, the foil of the negative electrode assembly is copper foil, and the conductive adhesive is conductive silver paste.

[0012] Furthermore, the conductive bonding structure is an electrochromic lens; The substrate assembly includes a first glass substrate, a transparent conductive layer, an electrochromic layer, a reflective electrode layer, and a second glass substrate, which are sequentially stacked along the thickness direction of the electrochromic lens. The surface of the transparent conductive layer facing the electrochromic layer has an edge region that is not covered by the electrochromic layer, the reflective electrode layer, and the second glass substrate. The electrochromic layer has sealant on both sides in the width direction. The reflective electrode layer and the second glass substrate have an insulating layer on one side in the width direction and a conductive layer on the other side in the width direction. The foil of the positive electrode assembly is bonded to the insulating layer and the surface of the second glass substrate facing away from the reflective electrode layer; The foil of the negative electrode assembly is bonded to the conductive layer and the surface of the second glass substrate facing away from the reflective electrode layer; The conductive adhesive extends along the length of the electrochromic lens, and the conductive adhesive further includes a gel portion C; The embedded colloid portion of the positive electrode assembly is connected to the insulating layer, and the surface colloid portion of the positive electrode assembly is also bonded to the surface of the insulating layer not covered by the foil and the edge region of the transparent conductive layer. The embedded colloid portion of the negative electrode assembly is connected to the conductive layer, and the surface colloid portion of the negative electrode assembly is also bonded to the surface of the conductive layer that is not covered by the foil.

[0013] Furthermore, the insulating layer is an etched layer, and the conductive layer is a metal plating layer.

[0014] Compared with the prior art, the above-mentioned technical solution of this utility model has the following advantages: The conductive bonding structure of this utility model with enhanced adhesion and conductivity has through holes in the foil material, and the conductive adhesive includes a surface adhesive part and an embedded adhesive part. The embedded adhesive part is bonded to the through hole and bonds the surface adhesive part and the substrate assembly, which significantly reduces the risk of conductive adhesive peeling off the foil material due to thermal stress and ensures that the conductive adhesive and the foil material can maintain a stable connection relationship under temperature changes or external impact. Attached Figure Description

[0015] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0016] Figure 1 This is a front view of the electrochromic lens in Embodiment 1 of this utility model; Figure 2 This is a cross-sectional schematic diagram of point AA in Embodiment 1 of this utility model; Figure 3 for Figure 2 Enlarged section view at point B; Figure 4 for Figure 2 Enlarged sectional view at point C; Explanation of reference numerals in the instruction manual: 1. Substrate assembly; 11. First glass substrate; 12. Transparent conductive layer; 121. Edge region; 13. Electrochromic layer; 14. Reflective electrode layer; 15. Second glass substrate; 16. Sealant; 17. Insulating layer; 18. Conductive layer; 2. Positive electrode assembly; 21. First foil; 211. First through hole; 212. First backing adhesive layer; 22. First conductive adhesive; 221. First surface adhesive portion; 222. First embedded adhesive portion; 3. Negative electrode assembly; 31. Second foil; 311. Second through hole; 312. Second backing adhesive layer; 32. Second conductive adhesive; 321. Second surface adhesive portion; 322. Second embedded adhesive portion. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0018] Example 1: See Figures 1 to 4 As shown, this utility model provides an embodiment of an electrochromic lens.

[0019] Electrochromic lenses include: The substrate assembly 1 includes a first glass substrate 11, a transparent conductive layer 12, an electrochromic layer 13, a reflective electrode layer 14, and a second glass substrate 15, which are sequentially stacked along the thickness direction of the electrochromic lens. The transparent conductive layer 12 has an edge region 121 on the surface facing the electrochromic layer 13 that is not covered by the electrochromic layer 13, the reflective electrode layer 14, and the second glass substrate 15. The electrochromic layer 13 has sealant 16 on both sides in the width direction. The reflective electrode layer 14 and the second glass substrate 15 have an insulating layer 17 on one side in the width direction. The reflective electrode layer 14 and the second glass substrate 15 have a conductive layer 18 on the other side in the width direction. The positive electrode assembly 2 includes a first foil 21 and a first conductive adhesive 22. The first foil 21 is bonded to one of its surfaces in the thickness direction, which is the surface of the insulating layer 17 and the second glass substrate 15 away from the surface of the reflective electrode layer 14. The first foil 21 is provided with a first through hole 211 extending along its thickness direction. The first conductive adhesive 22 extends along the length direction of the electrochromic lens and includes a first surface adhesive portion 221 and a first embedded adhesive portion 222. The first surface adhesive portion 221 is bonded to the surface of the first foil 21 away from the insulating layer 17, the area of ​​the insulating layer 17 not covered by the first foil 21, and the edge area 121 of the transparent conductive layer 12. The first embedded adhesive portion 222 passes through the first through hole 211 and connects to the insulating layer 17. The negative electrode assembly 3 includes a second foil 31 and a second conductive adhesive 32. One surface of the second foil 31 in the thickness direction is bonded to the conductive layer 18 and the surface of the second glass substrate 15 away from the reflective electrode layer 14. The second foil 31 is provided with a second through hole 311 extending along its thickness direction. The second conductive adhesive 32 includes a second surface adhesive portion 321 and a second embedded adhesive portion 322. The second surface adhesive portion 321 is bonded to the surface of the second foil 31 away from the conductive layer 18 and the area of ​​the conductive layer 18 not covered by the second foil 31. The second embedded adhesive portion 322 passes through the second through hole 311 and connects to the conductive layer 18.

[0020] In the above description, the first glass substrate 11 and the second glass substrate 15 serve as the supporting framework for the entire lens, providing mechanical strength and a basis for light transmission (the glass material ensures high light transmittance), while protecting the internal functional layers from external abrasion. The transparent conductive layer 12 is a transparent conductive material, serving as the "positive conductive path" for the electrochromic layer. Its uncovered edge region 121 is the connection point for the external positive electrode, ensuring that current can be uniformly introduced into the electrochromic layer 13. The electrochromic layer 13 is the core functional layer, composed of electrochromic material, which undergoes an oxidation-reduction reaction under the action of an electric field, resulting in changes in optical properties (light transmittance, reflectance) (such as changing from transparent to colored). The reflective electrode layer 14 serves as the "negative conductive path" for the electrochromic layer, while also having a reflective function (adjusting the reflectance of the lens). It forms an electric field loop with the transparent conductive layer 12, driving the reaction of the electrochromic layer 13. Sealant 16: Located on both sides of the electrochromic layer's width direction (i.e., the "left and right edge direction" of the lens), its function is to seal the electrochromic layer, preventing moisture, oxygen, etc., from intruding and causing material aging, while also fixing the relative positions of each layer. Insulating layer 17 and conductive layer 18 are located on both sides of the width direction of the reflective electrode layer 14 and the second glass substrate 15, respectively. Insulating layer 17 isolates the reflective electrode layer 14 from the positive electrode assembly (preventing short circuits); conductive layer 18 acts as a "conductive bridge" between the reflective electrode layer 14 and the negative electrode assembly, ensuring stable transmission of the negative electrode current. The positive electrode assembly 2 is responsible for guiding the external positive electrode current into the transparent conductive layer 12. The first foil 21 serves as the "lead-out end" of the external positive electrode, attached to the insulating layer 17 and the back side of the second glass substrate 15 (the side facing away from the reflective electrode layer), serving both fixing and conductive functions. The first conductive adhesive 22 is a key material that combines conductivity and adhesion. Through a "surface layer + embedded layer" design, it achieves multi-dimensional connectivity. The first surface adhesive portion 221 simultaneously adheres to the back of the first foil 21, the uncovered area of ​​the insulating layer 17, and the edge area 121 of the transparent conductive layer 12, conducting current from the first foil 21 to the transparent conductive layer 12. The first embedded adhesive portion 222 passes through the first through-hole 211 and connects to the insulating layer 17, further strengthening the contact between the first conductive adhesive 22 and the first foil 21, while also assisting in the stability of current conduction. The negative electrode assembly 3 is responsible for guiding the external negative electrode current into the reflective electrode layer 14. The second foil 31 serves as the "lead-out end" of the external negative electrode, adhering to the conductive layer 18 and the back of the second glass substrate 15, forming the basic conductive path of the negative electrode. The second conductive adhesive 32 also achieves connection through a "surface layer + embedded" design. The second surface adhesive portion 321 adheres to the back of the second foil 31 and the uncovered area of ​​the conductive layer 18, conducting current from the second foil 31 to the conductive layer 18, and then through the conductive layer 18 to the reflective electrode layer 14. The second embedded adhesive portion 322 passes through the second through hole 311 and connects to the conductive layer 18, enhancing the reliability of mechanical fixation and current conduction.

[0021] Positive circuit of electrochromic lens: external power supply positive terminal → first foil 21 → first conductive adhesive 22 → transparent conductive layer 12 → electrochromic layer 13; The negative electrode circuit of the electrochromic lens: electrochromic layer 13 → reflective electrode layer 14 → conductive layer 18 → second conductive adhesive 32 → second foil 31 → external power supply negative electrode.

[0022] Through the above technical solution, the foil is provided with through holes, and the conductive adhesive includes a surface adhesive part and an embedded adhesive part. The embedded adhesive part is bonded to the through holes and bonds the surface adhesive part and the substrate assembly, which significantly reduces the risk of conductive adhesive peeling off the foil due to thermal stress and ensures that the conductive adhesive and the foil can maintain a stable connection under temperature changes or external impacts.

[0023] In this embodiment, the first through hole 211 is a full hole or a half hole, and the second through hole 311 is a full hole or a half hole.

[0024] In the above text, a complete hole refers to a hole whose sidewalls form a complete, continuous closed profile along the circumference, without any gaps or breaks. For example, a common circular through-hole has a sidewall that is a closed ring; a square through-hole has a sidewall that is a closed quadrilateral border. A half-hole refers to a hole whose sidewalls have at least one obvious break or gap along the circumference, making it impossible to form a closed profile. For example, in groove-like structures such as "C-shaped" or "U-shaped" structures, the opening is the break point of the sidewall, making the hole's profile incomplete in the circumferential direction.

[0025] The above technical solution can achieve the requirement of embedding the first conductive adhesive 22 and the second conductive adhesive 32.

[0026] In this embodiment, the distance between the opposite sidewalls of the first through hole 211 is 100-300 micrometers, and the distance between the opposite sidewalls of the second through hole 311 is 100-300 micrometers.

[0027] In the above text, the size of the first through hole 211 and the size of the second through hole 311 are set within a certain range, and the distance between the opposite sidewalls of the first through hole 211 and the second through hole 311 is, for example, 100 micrometers, 150 micrometers, 200 micrometers, 250 micrometers or 300 micrometers.

[0028] With the above technical solution, the distance between the opposite sidewalls of the first through hole 211 and the second through hole 311 is between 100 and 300 micrometers. The colloid can fully fill the first through hole 211 and the second through hole 311, while avoiding local weakening of the first foil 21 and the second foil 31 caused by excessive size.

[0029] In this embodiment, the surface of the first foil 21 facing the substrate assembly 1 is provided with a first adhesive layer 212, and the first through hole 211 penetrates the first foil 21 and the first adhesive layer 212. The surface of the second foil 31 facing the substrate assembly 1 is provided with a second adhesive layer 312, and the second through hole 311 penetrates the second foil 31 and the second adhesive layer 312.

[0030] In the above text, the first adhesive layer 212 and the second adhesive layer 312 use their own adhesiveness to tightly bond the first foil 21 and the second foil 31 to the corresponding areas of the substrate assembly (insulating layer 17, back side of the second glass substrate 15, and conductive layer 18).

[0031] Through the above technical solution, the first foil 21 and the second foil 31 can be firmly fixed to the substrate assembly 1. The first foil 21 and the second foil 31 are not easily detached from the substrate assembly 1. Therefore, the first conductive adhesive 22 and the second conductive adhesive 32 are not easily detached from the first foil 21 and the second foil 31.

[0032] In this embodiment, the area where the first foil 21 and the first conductive adhesive 22 are connected is a roughened surface, and the area where the second foil 31 and the second conductive adhesive 32 are connected is a roughened surface.

[0033] In the above text, roughened surface refers to the uneven texture formed by processes such as sandblasting, etching, and electrolysis, which can significantly increase the actual contact area between the first foil 21 and the first conductive adhesive 22, and between the second foil 31 and the second conductive adhesive 32.

[0034] Through the above technical solution, the concave-convex structure allows the first conductive adhesive 22 and the second conductive adhesive 32 to be embedded in the texture gaps of the first foil 21 and the second foil 31 during the curing process, forming an anchoring effect similar to "mechanical interlocking", which greatly improves the bonding strength between the first conductive adhesive 22 and the first foil 21, and between the second conductive adhesive 32 and the second foil 31.

[0035] In this embodiment, the first foil 21 is aluminum foil, the second foil 31 is copper foil, and the first conductive adhesive 22 and the second conductive adhesive 32 are both conductive silver paste.

[0036] As described above, aluminum foil, as the carrier of the positive electrode component, offers advantages such as lightweight design, controllable cost, and ease of processing. Copper foil, as the carrier of the negative electrode component, offers the advantage of high conductivity. Conductive silver paste offers advantages such as high conductivity, excellent adhesion, and good chemical stability.

[0037] Through the above technical solution, aluminum foil undertakes the tasks of lightweighting and basic conductivity, while copper foil ensures low loss in the core conductive path. The two form an efficient current loop through the high conductivity of silver paste, ensuring the uniformity of the electric field of the electrochromic layer.

[0038] In this embodiment, the insulating layer 17 is an etched layer, and the conductive layer 18 is a metal plating layer.

[0039] In the above description, the insulating layer 17 is an etched layer, which bonds tightly to the substrate material and eliminates the risk of interface peeling. The etching process allows for precise control of the thickness and extent of the insulating layer 17, ensuring a continuous, non-porous insulating barrier between the reflective electrode layer 14 and the positive electrode assembly, effectively blocking current leakage. The conductive layer 18 is a metal plating layer, offering advantages such as high conductivity and continuity, compact structure, and stable adhesion.

[0040] Through the above technical solution, both the insulating layer 17 and the conductive layer 18 achieve their functions through "surface modification" rather than "additional stacking", which simplifies the layered structure of the lens and ensures the electrical safety and conductivity efficiency of the edge area.

[0041] Example 2: The rest is the same as Example 1, except that the area where the first foil is connected to the first conductive adhesive is provided with an electroplated layer, and the area where the second foil is connected to the second conductive adhesive is provided with an electroplated layer.

[0042] In the above text, electroplating refers to a metal or alloy coating formed through an electrochemical deposition process.

[0043] By using the above technical solution, an electroplating layer is formed on the foil, thereby improving the mechanical connection strength between the first foil and the first conductive adhesive, and between the second foil and the second conductive adhesive.

[0044] In this embodiment, the electroplated layer is an electroplated nickel layer, an electroplated tin layer, or an electroplated silver layer.

[0045] In the above text, the electroplated nickel layer refers to a metallic nickel coating layer formed on the surface of a thin foil through an electrochemical deposition process, and the electroplated tin layer refers to a metallic tin coating layer formed on the surface of a thin foil through an electrochemical deposition process. The electroplated silver layer refers to a metallic silver coating layer formed on the surface of a thin foil through an electrochemical deposition process.

[0046] The above solutions can all improve the mechanical connection strength between the first foil and the first conductive adhesive, and between the second foil and the second conductive adhesive.

[0047] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A conductive bonding structure that enhances adhesion and conductivity, characterized in that, The device includes a substrate assembly, a positive electrode assembly, and a negative electrode assembly. At least one of the positive electrode assembly and the negative electrode assembly includes a foil and a conductive adhesive. One surface of the foil in the thickness direction is bonded to the surface of the substrate assembly, and the foil has a through hole extending along its thickness direction. The conductive adhesive includes a surface adhesive portion and an embedded adhesive portion. The surface adhesive portion is bonded to the surface of the foil opposite to the substrate assembly, and the embedded adhesive portion passes through the through hole and connects to the substrate assembly. The conductive adhesive is conductive silver paste.

2. The conductive bonding structure according to claim 1, characterized in that, The through hole can be a full hole or a half hole.

3. The conductive bonding structure according to claim 1, characterized in that, The distance between the opposite sidewalls of the through hole is 100-300 micrometers.

4. The conductive bonding structure according to claim 1, characterized in that, The foil has an adhesive backing layer on its surface facing the substrate assembly, and the through hole penetrates the foil and the adhesive backing layer.

5. The conductive bonding structure according to claim 1, characterized in that, The area where the foil is connected to the conductive adhesive is a roughened surface.

6. The conductive bonding structure according to claim 1, characterized in that, The area where the foil is connected to the conductive adhesive is provided with an electroplated layer.

7. The conductive bonding structure according to claim 6, characterized in that, The electroplated layer is an electroplated nickel layer, an electroplated tin layer, or an electroplated silver layer.

8. The conductive bonding structure according to claim 1, characterized in that, The foil of the positive electrode assembly is aluminum foil, and the foil of the negative electrode assembly is copper foil.

9. The conductive bonding structure according to any one of claims 1 to 8, characterized in that, The conductive bonding structure is an electrochromic lens; The substrate assembly includes a first glass substrate, a transparent conductive layer, an electrochromic layer, a reflective electrode layer, and a second glass substrate, which are sequentially stacked along the thickness direction of the electrochromic lens. The surface of the transparent conductive layer facing the electrochromic layer has an edge region that is not covered by the electrochromic layer, the reflective electrode layer, and the second glass substrate. The electrochromic layer has sealant on both sides in the width direction. The reflective electrode layer and the second glass substrate have an insulating layer on one side in the width direction and a conductive layer on the other side in the width direction. The foil of the positive electrode assembly is bonded to the insulating layer and the surface of the second glass substrate facing away from the reflective electrode layer; The foil of the negative electrode assembly is bonded to the conductive layer and the surface of the second glass substrate facing away from the reflective electrode layer; The conductive adhesive extends along the length of the electrochromic lens, the embedded adhesive portion of the positive electrode assembly is connected to the insulating layer, and the surface adhesive portion of the positive electrode assembly is also bonded to the surface of the insulating layer not covered by the foil and the edge region of the transparent conductive layer. The embedded colloid portion of the negative electrode assembly is connected to the conductive layer, and the surface colloid portion of the negative electrode assembly is also bonded to the surface of the conductive layer that is not covered by the foil.

10. The conductive bonding structure according to claim 9, characterized in that, The insulating layer is an etched layer, and the conductive layer is a metal plating layer.

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