Bonding structure and manufacturing method

Abstract

The invention discloses a bonding structure and a manufacturing method. The bonding structure comprises a first panel and a bonding agent. The first panel is provided with a first surface, and the first surface is suitable for being attached to a target object. The adhesive is coated on the first surface, and the first panel is suitable for being connected with a target object through the adhesive. Wherein the first surface is provided with a plurality of grooves, the plurality of grooves are uniformly distributed on the first surface at intervals, and at least part of the adhesive is located in the grooves. According to the invention, the bonding strength and stability can be improved.

Description

Technical Field

[0001] This invention relates to the field of structural bonding technology, and in particular to an adhesive structure and its manufacturing method. Background Technology

[0002] In modern consumer electronics, automotive electronics, smart homes, and industrial control, glass, composite plastics, or ceramic covers not only serve aesthetic and touch-screen functions but also need to maintain a strong bond with metal frames, bases, or heat sinks over long periods to withstand complex service environments such as drops, vibrations, humidity, and temperature cycling. As product thicknesses continue to decrease and bezels become increasingly narrow, traditional mechanical fasteners, screws, or riveting methods are no longer sufficient to meet the demands of narrow bezels, seamless designs, and lightweight construction. Therefore, adhesive technology has become a core process for structural connections. In everyday devices like mobile phones, watches, tablets, and even the central control screens of electric vehicles, the glass back covers and aluminum frames rely on high-performance adhesives for a durable connection. This invisible adhesive interface directly affects the overall strength, sealing life, and user experience.

[0003] However, existing technologies generally employ a method of directly coating acrylic, rubber, or epoxy adhesives onto smooth or simply polished metal surfaces for bonding. Due to the low surface energy of metals and the lack of effective mechanical anchors, the adhesive and metal are mainly bonded by weak intermolecular forces such as van der Waals forces. Under repeated high and low temperature impacts, the difference in thermal expansion can easily generate shear and peel stresses, leading to interface slippage, adhesive layer creep, and even delamination failure. Summary of the Invention

[0004] The main objective of this invention is to provide an adhesive structure and manufacturing method that can improve adhesive strength and stability.

[0005] To achieve the above objectives, some embodiments of the present invention provide an adhesive structure comprising: A first panel has a first surface, the first surface being adapted to fit a target object; An adhesive is applied to a first surface, and the first panel is adapted to bond a target object by means of the adhesive; The first surface has multiple grooves, which are evenly distributed at intervals on the first surface, and at least part of the adhesive is located in the grooves.

[0006] In some embodiments, the first surface includes a plurality of first ribs and second ribs, the plurality of first ribs being spaced apart along a first direction, the plurality of second ribs being spaced apart along a second direction, the first direction and the second direction intersecting, and the first ribs and second ribs cooperating to form a plurality of grooves.

[0007] In some embodiments, the distance between the plurality of first ribs ranges from 200µm to 400µm; and / or, The distance between the multiple second ribs ranges from 200µm to 400µm; and / or, Along a direction perpendicular to the first direction, the width of each first rib ranges from 30µm to 60µm; and / or, Along a direction perpendicular to the second direction, the width of each second rib ranges from 30µm to 60µm; and / or, Along the concave direction of the groove, the height of the first rib ranges from 50µm to 200µm; and / or, Along the concave direction of the groove, the height of the second rib ranges from 50µm to 200µm.

[0008] In some embodiments, the adhesive is a ternary blend system of silicone-polyurethane-acrylate, comprising polyurethane resin, silicone-modified acrylate resin, epoxy functionalized resin, and key functional modifiers. The polyurethane resin accounts for 60% to 70% of the mass fraction of the adhesive, the silicone-modified acrylate resin accounts for 20% to 30% of the mass fraction of the adhesive, and the epoxy functionalized resin accounts for 5% to 10% of the mass fraction of the adhesive. The cohesive strength of the cured adhesive is greater than the interfacial peel strength between it and the first panel.

[0009] In some embodiments, the key functional modifiers include silane coupling agents and nano-silica, wherein the silane coupling agent accounts for 1.0% to 2.0% of the adhesive by mass, and the nano-silica accounts for 1.5% to 2.5% of the adhesive by mass.

[0010] An embodiment of the second aspect of this application provides a manufacturing method for the adhesive structure described above, the manufacturing method comprising: S101: Provide a first panel and process a plurality of evenly spaced and regularly arranged grooves on the first surface to form a mechanically locking prestructure; S103: Apply adhesive to the first surface such that at least a portion of the adhesive fills the groove; S105: Attach the target object to the first surface and cure the adhesive to simultaneously form a mechanical interlock and a chemical bond between the first panel and the target object.

[0011] In some embodiments, step S101 includes: Grooves are created by laser engraving. The laser power used in laser engraving ranges from 20W to 80W, the scanning speed ranges from 500mm / s to 2000mm / s, the frequency ranges from 20kHz to 100kHz, the groove depth ranges from 50µm to 200µm, the groove width ranges from 30µm to 60µm, and the center-to-center distance between adjacent grooves ranges from 200µm to 400µm.

[0012] In some embodiments, after step S101, the manufacturing method includes: The first surface is subjected to plasma cleaning or ultrasonic degreasing for 30s to 300s to make the surface water contact angle less than or equal to 10°, so as to remove contaminants and activate surface functional groups.

[0013] In some embodiments, step S103 includes: The adhesive is applied to the first surface by means of slit coating, scraping, or screen printing, and the dry film thickness is controlled within the range of 50µm to 100µm.

[0014] In some embodiments, step S105 includes: Initial curing at room temperature for 2-4 hours; After curing at 60℃~80℃ for 1h~2h, the crosslinking density of the adhesive after curing is ≥90%.

[0015] According to the above embodiments, the beneficial effects of the present invention are: The adhesive structure of this application includes a first panel and an adhesive. The first panel has a first surface adapted to adhere to a target object. The adhesive is applied to the first surface, and the first panel is adapted to connect the target object by the adhesive. The first surface has a plurality of grooves evenly distributed at intervals on the first surface, and at least a portion of the adhesive is located within the grooves.

[0016] By pre-setting uniformly distributed grooves on the panel bonding surface and ensuring the adhesive fully penetrates these grooves before curing, the bonding structure of this application forms a continuous three-dimensional anchoring effect at the interface. When the target object and the panel experience thermal expansion and contraction or external mechanical loads, the sidewalls of the grooves exert multi-directional constraints on the adhesive, dispersing shear and peel stresses and preventing crack initiation and propagation along the interface. Simultaneously, the contact area between the adhesive and the groove walls is significantly increased, upgrading the weak connection that originally relied on planar van der Waals forces to a three-dimensional interlocking, effectively overcoming the insufficient adhesion problem caused by low surface energy and lack of mechanical anchor points on smooth metal surfaces. With this physical locking mechanism, the bonding structure can maintain interface integrity even under repeated temperature shocks or long-term vibration conditions, avoiding common failures such as delamination, slippage, or separation in traditional solutions, thereby extending product lifespan and improving overall reliability.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is a three-dimensional structural diagram of an adhesive structure in the prior art; Figure 2 This is a three-dimensional structural diagram of the adhesive structure in one embodiment of this application; Figure 3 This is a flowchart of a manufacturing method in one embodiment of this application.

[0020] Explanation of icon numbers: First panel 100; first surface 110; groove 111.

[0021] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0024] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or," "and / or," or "and / or" throughout the text implies three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0025] In related technologies, the product experiences large and frequent temperature cycles, ranging from the frigid outdoors in winter to the scorching heat inside a car in summer. The difference in thermal expansion and contraction of the materials generates significant periodic internal stress at the bonding interface. (Refer to...) Figure 1 Traditional solutions using smooth surfaces and conventional adhesives lack effective mechanical anchors and rely solely on weak intermolecular forces. This makes it difficult to maintain interface stability under repeated high and low temperature shocks, and it is prone to fatigue delamination, delamination, or warping failure, directly threatening the reliability, durability, and safety of the entire machine.

[0026] The following is for reference. Figure 2 and Figure 3 This describes the adhesive structure and manufacturing method according to embodiments of the present invention. (Refer to...) Figure 2 The adhesive structure of this application includes a first panel 100 and an adhesive. The first panel 100 has a first surface 110, which is adapted to adhere to a target object. The adhesive is applied to the first surface 110, and the first panel 100 is adapted to connect the target object by the adhesive. The first surface 110 has a plurality of grooves 111, which are evenly distributed at intervals on the first surface 110, and at least a portion of the adhesive is located within the grooves 111.

[0027] By pre-setting uniformly distributed grooves 111 on the panel bonding surface and ensuring the adhesive fully penetrates these grooves 111 before curing, this adhesive structure forms a continuous three-dimensional anchoring effect at the interface. When the target object and the panel experience thermal expansion and contraction or external mechanical loads, the sidewalls of the grooves 111 exert multi-directional constraints on the adhesive, dispersing shear and peel stresses and preventing crack initiation and propagation along the interface. Simultaneously, the contact area between the adhesive and the groove walls 111 is significantly increased, upgrading the weak connection that originally relied on planar van der Waals forces to a three-dimensional interlocking, effectively overcoming the insufficient adhesion problem caused by low surface energy and lack of mechanical anchor points on smooth metal surfaces. With this physical locking mechanism, the adhesive structure can maintain interface integrity even under repeated temperature shocks or long-term vibration conditions, avoiding common failures such as delamination, slippage, or separation in traditional solutions, thereby extending product lifespan and improving overall reliability.

[0028] Furthermore, this application ingeniously transforms macroscopic assembly into microscopic anchoring. When faced with the problem of adhesion failure between smooth metals and non-metals, the conventional approach for technicians is to replace the adhesive, apply a primer, or roughen the overall surface. This application, by arranging evenly spaced micron-level grooves 111 on the back of the first panel 100, allows ordinary adhesives to achieve the mechanical locking force of a rivet array. Taking a mobile phone glass back cover as an example, a laser engraves a grid pattern on the inner surface, almost invisible to the naked eye, yet this causes the adhesive layer to form hundreds of micro-barbs after curing. The shear stress generated by the thermal expansion difference during thermal shock is dispersed to each micro-area, reducing the interface slip by an order of magnitude. This preserves the thin and aesthetically pleasing glass while eliminating the need for expensive primers and baking processes, achieving a concealed enhancement that is compact and improves reliability.

[0029] In some embodiments, this application is applicable to the bonding of non-metallic cover plates to metal frames. Specifically, the first panel 100 can be a glass cover plate, a composite decorative panel, or an engineering plastic shell, and the first surface 110 corresponds to the back side to be bonded, such as a grid area formed by laser engraving on the inner side of a mobile phone glass back cover, a micro-groove surface on the edge of an automotive interior composite panel, or a rib-shaped recess obtained through precision machining on a plastic shell of outdoor equipment. The groove 111 design of this application allows the first panel 100 to provide a three-dimensional anchoring space for the adhesive without increasing thickness or changing appearance, thus achieving a reliable connection.

[0030] In some embodiments, the adhesive can be a silicone-polyurethane-acrylate ternary blend, a one-component moisture-curing polyurethane, a two-component epoxy structural adhesive, or a modified silane sealant, or even a high-temperature resistant tape layer containing a rubber elastomer. After curing, the adhesive forms a mechanical bond with the wall of the panel groove 111 and a chemical bond with the surface of the target object, thereby maintaining the interface without peeling or delamination under conditions such as alternating hot and cold temperatures, vibration, and impact, meeting the high-reliability bonding requirements of consumer electronics, automobiles, or outdoor equipment.

[0031] In some embodiments, the groove 111 can be orthogonal straight grooves, honeycomb hexagonal recesses, concentric rings, or spirals; it can also be a discrete lattice of cylindrical blind holes, inverted trapezoidal dovetail grooves, or continuous wavy patterns. The grooves 111 can be arranged in an equidistant matrix to cover the entire bonding area, or they can be denser at the edges and sparser in the center according to stress distribution, or they can be oriented and inclined along the main force direction to form a herringbone pattern. The opening of the groove 111 can be uniform, or it can be etched with a wide outer and narrow inner flared opening and slightly undercut sidewalls using laser gradient power, so that the adhesive forms a hook-like locking mechanism after curing, balancing adhesive storage capacity and pull-out resistance to meet the reliable anchoring requirements of different materials and different thermal expansion differences.

[0032] Reference Figure 2 In some embodiments, the first surface 110 includes a plurality of first ribs and second ribs. The plurality of first ribs are spaced apart along a first direction, and the plurality of second ribs are spaced apart along a second direction. The first and second directions intersect, and the first and second ribs cooperate to form a plurality of grooves 111. By constructing a cross-rib grid on the first surface 110, the grooves 111 are naturally divided into continuous, closed, and regularly arranged microcavities. After the adhesive is injected, the ribs in both the longitudinal and transverse directions simultaneously provide lateral support and multi-directional restraint for the colloid, allowing the interfacial stress to be rapidly dispersed over a larger area, reducing local stress concentration, and avoiding shear slippage that is prone to occur under lateral loads in traditional unidirectional grooves. It can be understood that the cross nodes of the ribs constitute rivet seats, and the cured colloid forms reinforcing pillars at the nodes, further improving the peel resistance and pry resistance. At the same time, the regular grid makes the adhesive layer thickness uniform, eliminating voids or weak interfaces caused by uneven adhesive amount. Even under repeated thermal expansion and contraction or mechanical vibration, the overall bonding stability can be maintained, effectively extending the product's service life and improving reliability.

[0033] In some embodiments, the first and second ribs can be micron-level straight ridges, V-shaped ridges, or trapezoidal ridges left on the metal surface by laser engraving, or they can be trapezoidal ribs or semi-circular ribs directly transferred to the plastic frame during injection molding, or even wavy ridges and rectangular ridges obtained by rolling or etching. The first and second ribs intersect to form a grid in the same plane, and the ridges naturally form continuous grooves 111, which act as both guide walls for the flow of the colloid and mechanical locking keys after curing, so that the originally smooth bonding surface instantly has three-dimensional interlocking ability, which can be widely used in scenarios requiring high-reliability bonding, such as glass back covers, composite decorative panels, or automotive metal frames.

[0034] Reference Figure 2In some embodiments, the distance between the plurality of first ribs ranges from 200µm to 400µm, for example, 200µm, 300µm, and 400µm. In some embodiments, the distance between the plurality of second ribs ranges from 200µm to 400µm, for example, 200µm, 300µm, and 400µm. By controlling the rib spacing, width, and height within a micrometer-level and mutually matching range, the opening size and depth of the grid groove 111 form a balanced ratio for adhesive storage, locking, and proportion, where the spacing is neither too narrow to hinder sufficient adhesive flow nor too wide to result in sparse anchor points.

[0035] In some embodiments, the width of each first rib ranges from 30µm to 60µm along a direction perpendicular to the first direction, for example, 30µm, 40µm, 50µm, and 60µm. In some embodiments, the width of each second rib ranges from 30µm to 60µm along a direction perpendicular to the second direction, for example, 30µm, 40µm, 50µm, and 60µm. The rib width ensures the strength of the boss itself, making it less prone to breakage during curing shrinkage or thermal expansion and contraction; the height provides sufficient sidewall area for the groove 111, allowing the colloid to form a continuous, three-dimensional interlocking wall after curing.

[0036] In some embodiments, the height of the first rib along the recessed direction of the groove 111 ranges from 50µm to 200µm, for example, 50µm, 100µm, 150µm, and 200µm. In some embodiments, the height of the second rib along the recessed direction of the groove 111 ranges from 50µm to 200µm, for example, 50µm, 100µm, 150µm, and 200µm. By limiting the depth of the groove 111 to a moderate range within the micrometer level, the depth and the amount of adhesive filling form an optimal anchor and buffer balance. The depth is sufficient to allow the adhesive to form continuous columnar rivets after curing, producing a three-dimensional locking effect to resist peeling and shearing, while the depth is not too deep, thereby avoiding wasted adhesive or weakening of the panel body, and avoiding insufficient adhesive at the bottom and stress concentration. This depth range allows the sidewalls of the groove 111 to provide sufficient interlocking area. During thermal expansion and contraction and impact vibration, the adhesive columns can flexibly deform to absorb energy, preventing crack initiation and propagation, and achieving a highly reliable and long-life adhesive interface.

[0037] In summary, this combination of geometric parameters allows the stress at the adhesive interface to be progressively dispersed by numerous tiny anchor points when subjected to peeling, shearing, or impact loads, avoiding localized stress peaks caused by the random dimensions of traditional coarsened structures. Simultaneously, the regular, repetitive microstructure ensures process consistency, guaranteeing that each panel achieves the same high adhesive reliability in mass production, reducing the risk of failure due to geometric deviations, thereby extending the overall lifespan and improving quality stability.

[0038] In some embodiments, the adhesive is a ternary blend system of silicone-polyurethane-acrylate, comprising polyurethane resin, silicone-modified acrylate resin, epoxy functionalized resin, and key functional modifiers. The polyurethane resin accounts for 60%–70% of the adhesive by mass, for example, 60%, 65%, or 70%. The silicone-modified acrylate resin accounts for 20%–30% of the adhesive by mass, for example, 20%, 25%, or 30%. The epoxy functionalized resin accounts for 5%–10% of the adhesive by mass, for example, 5%, 6%, 7%, 8%, 9%, or 10%. The cohesive strength of the cured adhesive is greater than its interfacial peel strength with the first panel 100. Using a silicone-polyurethane-acrylate ternary blend system as the adhesive allows for the integration of flexibility, toughness, and rigidity within the same adhesive layer. The long polyurethane chains impart excellent low-temperature flexibility and resilience to the colloid, buffering stress and preventing brittleness during cold shrinkage. The silicone segments enhance heat and weather resistance, reduce the risk of high-temperature softening, and maintain the cohesive stability of the adhesive surface. The epoxy functional groups form a highly cross-linked network after curing, enhancing overall rigidity and inhibiting creep. The synergistic optimization of the three components ensures that the adhesive layer's strength consistently exceeds the interfacial peel stress, transforming the failure mode from traditional delamination to cohesive failure within the adhesive, fundamentally eliminating the risk of failure due to adhesive performance degradation. Simultaneously, this system exhibits excellent wetting and chemical bonding tendencies with metal oxides and various non-metallic cap plates, achieving strong adhesion without the need for a primer. This simplifies the process, reduces VOC emissions, and improves mass production consistency, providing a long-term reliable bonding solution for consumer electronics, automotive, and outdoor equipment under harsh conditions such as wide temperature ranges, high humidity, and strong vibration.

[0039] In some embodiments, the key functional modifiers include silane coupling agents and nano-silica. The silane coupling agent accounts for 1.0% to 2.0% of the adhesive's mass fraction, for example, 1.0%, 1.5%, or 2.0%. The nano-silica accounts for 1.5% to 2.5% of the adhesive's mass fraction, for example, 1.5%, 2.0%, or 2.5%. Introducing silane coupling agents and nano-silica into ternary blend resins can simultaneously construct a dual-reinforcing network of chemical bridges and nano-reinforcing bars within the colloid. The siloxane group at one end of the coupling agent condenses with the hydroxyl groups on the metal surface, while the active group at the other end crosslinks with the resin, upgrading the originally physically adsorbed interface to a covalent bond connection, significantly improving resistance to damp heat and peeling resistance. Nano-silica, with its high specific surface area and uniform dispersion, forms numerous micro-reinforcing points in the adhesive layer, inhibiting crack initiation and hindering crack propagation, enabling the colloid to maintain high toughness and low creep under thermal shock. With the synergistic effect of both, the bonding interface and the adhesive layer are strengthened at the same time, and the failure mode is always cohesive failure, which completely eliminates the risk of debonding caused by interface weakening or adhesive softening, thereby ensuring the long-term stable operation of the bonded structure in harsh environments such as wide temperature range, high humidity, and strong vibration.

[0040] Reference Figure 3 The second aspect of this application provides a manufacturing method for the adhesive structure of any of the above embodiments, the manufacturing method comprising: S101: Provide a first panel 100, and process a plurality of evenly spaced and regularly arranged grooves 111 on the first surface 110 to form a mechanically locking prestructure; S103: Apply adhesive to the first surface 110 such that at least a portion of the adhesive fills the groove 111; S105: The target object is attached to the first surface 110 and the adhesive is cured to simultaneously form a mechanical interlock and a chemical bond between the first panel 100 and the target object.

[0041] The manufacturing method of this application introduces micro-mechanical locking and chemical bonding into the bonding interface in one step through three consecutive operations, fundamentally improving the reliability of the connection. Specifically, in S101, uniformly spaced and regularly arranged grooves 111 are first processed on the first surface 110, transforming the originally smooth plane into a three-dimensional prestructure with sidewalls, bottom, and edges, providing anchor holes for the subsequent adhesive and avoiding stress concentration caused by the randomness of traditional roughening; this step also increases the effective contact area, so that the interfacial shear force generated by thermal expansion and contraction is shared by many micro-regions. In S103, the adhesive is coated on the surface of the pre-made grooves 111, and the adhesive actively penetrates into each micro-cavity under capillary action, ensuring that there are no air bubbles or voids inside the grooves 111, forming a continuous and full adhesive column prototype; this process does not require high-pressure injection, simplifying equipment and processes, but allows the adhesive to achieve three-dimensional integration with the panel before curing. S105 transforms liquid adhesive columns into solid rivets through bonding and curing. Mechanical interlocking occurs between the adhesive and the sidewall of groove 111, while chemical cross-linking occurs between the adhesive layer and the surface of the target object. Mechanical interlocking prevents peeling and slippage, and chemical bonding resists damp heat erosion. The synergistic effect of these two factors changes the failure mode from interfacial debonding to cohesive failure within the adhesive. Because groove 111 is regular and the amount of adhesive is controllable, curing shrinkage stress is released evenly, avoiding local cracking. This ensures high consistency and high yield in mass production and extends the service life of finished products under wide temperature range, high humidity, and strong vibration conditions.

[0042] In some embodiments, step S101 includes: processing a groove 111 by laser engraving, wherein the laser power used for laser engraving is in the range of 20W to 80W (e.g., 20W, 40W, 60W, 80W), the scanning speed is in the range of 500mm / s to 2000mm / s (e.g., 500mm / s, 1000mm / s, 1500mm / s, 2000mm / s), and the frequency is in the range of 20kHz to 100kHz (e.g., 20kHz). The groove 111 has a depth range of 50µm to 200µm (e.g., 50µm, 100µm, 150µm, 200µm), a groove width range of 30µm to 60µm (e.g., 30µm, 40µm, 50µm, 60µm), and a center-to-center distance range of 200µm to 400µm (e.g., 200µm, 300µm, 400µm).

[0043] The laser engraving process upgrades the processing of grooves 111 from traditional rough grinding to controllable micro-nano molding, laying a precise and repeatable mechanical bonding foundation for subsequent bonding. First, the coordinated adjustment of laser power, scanning speed, and frequency allows the material to melt and vaporize instantly before cooling, forming grooves 111 with clear edges and flat bottoms. This avoids excessive heat-affected zones or recast layers, ensuring sufficient roughness and activity on the sidewalls to facilitate adhesive wetting and chemical bonding. Simultaneously, non-contact processing eliminates tool wear, resulting in near-zero dimensional deviations between batches. Second, the depth, groove width, and center-to-center spacing are limited to a narrow micrometer range. Specifically, the depth is sufficient to provide the three-dimensional anchoring length without excessively weakening the rigidity of the panel itself; the groove width ensures rapid filling of the adhesive through capillary action, preventing air bubbles from accumulating due to excessive narrowness, and avoiding sparse anchor points due to excessive width; the center-to-center spacing maintains continuous ribs between adjacent grooves 111, forming a mesh-like reinforcing skeleton to disperse peel stress. Through digital programming, the laser head can scan at high speed in any direction within a plane, easily creating quadrilateral, hexagonal, or herringbone-shaped meshes to meet the anisotropic mechanical requirements of different products. The processing involves no chemical reagent emissions, making it environmentally friendly, and it can be integrated online with automated production lines, significantly improving efficiency and yield. Finally, the regular and high-precision 111 array of grooves creates a micro-rivet array after the colloid cures, suppressing interface slippage caused by thermal expansion and contraction, and providing stable and reliable mechanical interlocking for subsequent bonding, curing, and long-term use.

[0044] In some embodiments, after step S101, the manufacturing method includes: The first surface 110 is subjected to plasma cleaning or ultrasonic degreasing for a treatment time of 30s to 300s (e.g., 30s, 50s, 100s, 150s, 200s, 250s, 300s) to make the surface water contact angle less than or equal to 10° (e.g., 10°, 9°, 8°, 7°, 6°) in order to remove contaminants and activate surface functional groups.

[0045] Plasma cleaning or ultrasonic degreasing, as an immediate joining step after the processing of groove 111, has the core value of dual functions: decontamination and activation. First, micro-debris, coolant film, and fingerprint grease adhering during handling, leftover from laser engraving, are instantly removed by high-energy ion bombardment or cavitation bubbles, preventing these micron-sized contaminants from occupying the direct contact sites between the adhesive and metal, thus eliminating the potential for future interfacial slippage. Second, active particles in the plasma break down the inert oxide layer on the metal surface, re-exposing fresh metal ions and generating polar functional groups such as hydroxyl and carboxyl groups. Ultrasonic waves, under the impact of liquid microjets, simultaneously increase the surface free energy, transforming the originally hydrophobic sidewalls of groove 111 into a hydrophilic state, reducing the water contact angle to below 10°, ensuring excellent spreading and capillary penetration of the adhesive. The processing time is limited to tens of seconds to several minutes, ensuring sufficient reaction while avoiding excessive etching that could lead to microstructure collapse or oxide thickening. This step requires no acid or alkali reagents, conforming to green manufacturing principles, and can be integrated with the laser processing cavity to achieve integrated online engraving and cleaning operations, shortening the cycle time. The cleaned and activated surface of groove 111 provides sufficient active sites for the formation of stable chemical bonds between the colloid and the metal, enabling mechanical interlocking and chemical bridging to work synergistically. Ultimately, this gives the adhesive structure a highly reliable performance that does not peel off or delaminate under humid heat, thermal shock, and long-term load.

[0046] In some embodiments, step S103 includes: The adhesive is applied to the first surface 110 by means of slit coating, scraping or screen printing, and the dry film thickness is controlled to be in the range of 50µm to 100µm (e.g. 50µm, 60µm, 70µm, 80µm, 90µm, 100µm).

[0047] Specifically, step S103 employs three methods—slot coating, blade coating, or screen printing—to precisely spread the adhesive onto the first surface 110 of the pre-fabricated groove 111. By controlling the dry film thickness, the amount of adhesive is optimally matched with the microstructure. Slot coating relies on the gap between a precision die and the substrate to output a uniform tape in one pass, suitable for high-speed roll materials or large glass cover plates. The lateral thickness difference of the adhesive layer is minimal, avoiding localized adhesive shortages that could lead to anchoring failure. Blade coating utilizes adjustable blade and platform speeds to quickly apply adhesive to small batches of irregularly shaped panels, with simple equipment and rapid changeover. Screen printing quantitatively transfers the adhesive to the bonding area through the screen opening pattern, resulting in clear edge contours, suitable for complex shapes requiring localized thickening or pre-reserved venting channels. All three processes are low-shear coating methods, allowing the adhesive to maintain complete fluidity without disrupting the dispersion of the filler in the ternary blend system. This spontaneously generates capillary filling within the groove 111, completely expelling air and forming a continuous, pore-free adhesive column. The dry film thickness is limited to the middle range in the micrometer range. On the one hand, it is thick enough to ensure that the groove 111 is fully filled and a certain amount of planar adhesive layer is retained, so that it still has sufficient deformation capacity after being bonded to the target object, which can buffer the difference in thermal expansion and contraction. On the other hand, the dry film is not too thick, which would cause overflow, sagging, or stress concentration due to curing shrinkage. Through online thickness measurement and closed-loop feedback, the coating parameters can be finely adjusted in real time to ensure that the adhesive weight of each panel is consistent. This provides a highly repeatable basis for subsequent curing and reliability testing, thereby continuously outputting adhesive pre-coated layers with full interfaces, no bubbles, and uniform thickness in mass production, improving the yield of finished products and long-term weather resistance.

[0048] In some embodiments, step S105 includes: Initial curing at room temperature for 2 to 4 hours (e.g., 2 hours, 3 hours, 4 hours); After curing at 60℃~80℃ (e.g., 60℃, 70℃, 80℃) for 1h~2h (e.g., 1h, 1.5h, 2h), the crosslinking density of the adhesive after curing is ≥90% (e.g., 90%, 92%, 96%, 98%).

[0049] Specifically, step S105 employs a two-stage process of room temperature initial curing and medium-temperature post-curing, allowing the adhesive to smoothly transition from a fluid state to a highly cross-linked solid state, balancing ease of operation and final performance. During the room temperature initial curing stage, the adhesive layer gels without an external heat source, and the molecular chains first form a preliminary three-dimensional network. At this stage, the colloid still retains a certain degree of flexibility, which can fully relax the internal stress generated during coating and bonding, preventing microcracks due to sudden volume changes during subsequent heating. Simultaneously, initial curing allows the adhesive pillars to be positioned within the groove 111, preventing slippage during handling or clamping and ensuring the integrity of the micro-mechanical interlocking. In the medium-temperature post-curing stage, heat accelerates the reaction of residual functional groups, rapidly increasing the cross-linking density to the target level. The glass transition temperature and cohesive strength of the adhesive layer increase, thereby enhancing its heat resistance, moisture resistance, and creep resistance. The controlled, mild temperature shortens the curing cycle without causing thermal deformation or oxidation to heat-sensitive cover plates or metal substrates, making it suitable for various materials such as glass, composite decorative panels, and coated metals. The two temperature and time windows are connected to each other, allowing the curing shrinkage stress to be released in stages, ultimately forming a dense and defect-free adhesive interface. This ensures that the bonded structure maintains the cohesive failure mode under subsequent high and low temperature cycles, humid heat aging, and mechanical loads, thereby achieving long-term reliable sealing and high-strength connection.

[0050] The adhesive structure and manufacturing method of this application are described below with reference to a specific embodiment. Figure 2 and Figure 3 This application achieves highly reliable adhesion between a cover plate and a metal target object over a wide temperature range by constructing a micron-level regular groove array 111 on the first surface 110 of a non-metallic first panel 100 and cooperating with a silicone-polyurethane-acrylate ternary blend adhesive. The grooves 111 are formed in one step by laser engraving, forming a quadrilateral or hexagonal grid with intersecting ribs. The rib spacing, rib width, and recess depth are all controlled within a narrow micron-level range, forming a continuous, closed cavity with micro-overlapping sidewalls. The adhesive completely fills the cavity under capillary action and forms an array of micro-rivets after curing, providing multi-directional mechanical locking, dispersing peeling and shear stress, preventing crack initiation and propagation, and changing the failure mode from interfacial debonding to cohesive failure of the adhesive. This solves the problems of debonding and slippage that occur on traditional smooth metal surfaces due to low surface energy and lack of anchor points.

[0051] The adhesive employs a ternary blend system of silicone, polyurethane, and acrylate. The long-chain segments of polyurethane impart low-temperature toughness and resilience, while the silicone segments enhance heat and weather resistance. The epoxy functional groups form a highly cross-linked network after curing, increasing rigidity and inhibiting creep. The proportions of these three components are synergistically optimized to ensure that the cohesive strength of the adhesive layer consistently exceeds the interfacial peel stress. The key functional modifier consists of a silane coupling agent and nano-silica. One end of the coupling agent condenses with the hydroxyl groups on the metal surface, while the other end cross-links with the resin matrix, building a covalent bridge between the inorganic and organic interfaces. The uniformly dispersed nano-silica acts as a reinforcing nano-reinforcement, improving the modulus, hardness, and creep resistance of the adhesive layer, ensuring the bonded structure maintains interfacial integrity under humid heat, thermal shock, and long-term mechanical loads.

[0052] The manufacturing method used to create the aforementioned adhesive structure includes the following steps: laser engraving, surface cleaning, precision coating, and two-stage curing. The laser engraving step uses a fiber optic or ultraviolet laser to scan a grid pattern in one pass using a CNC program. Power, scanning speed, and frequency are set collaboratively to ensure clear edges and a flat bottom for the grooves 111, avoiding heat-affected zones or recast residue. Immediately after processing, plasma cleaning or ultrasonic degreasing is performed for tens of seconds to several minutes to remove micro-debris and organic contaminants, while simultaneously activating surface functional groups to reduce the contact angle to below 10°, ensuring effective wetting and capillary penetration of the adhesive. In the coating stage, slot coating, scraping, or screen printing are used, flexibly switching according to product form and production capacity requirements. Online thickness measurement and closed-loop control ensure the dry film thickness remains stable in the micron range, filling the grooves 111 while preventing adhesive overflow. The curing process employs a two-stage process: room temperature initial curing and medium-temperature post-curing. In the initial curing stage, no external heat is required. The adhesive layer solidifies and releases internal stress, ensuring that the micro-rivets are positioned without slippage. In the post-curing stage, the temperature is gently increased to accelerate the cross-linking reaction to the target density, ultimately forming a dense, defect-free three-dimensional network. This ensures that the bonded structure maintains the cohesive failure mode under subsequent wide-temperature cycling, humid heat aging, and strong vibration conditions, achieving long-term reliable sealing and high-strength connection.

[0053] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. An adhesive structure, characterized in that, include: A first panel has a first surface, the first surface being adapted to adhere to a target object; An adhesive is applied to the first surface, and the first panel is adapted to connect the target object by the adhesive; The first surface has a plurality of grooves, which are evenly distributed at intervals on the first surface, and at least a portion of the adhesive is located within the grooves.

2. The adhesive structure according to claim 1, characterized in that, The first surface includes a plurality of first ribs and second ribs, the plurality of first ribs being spaced apart along the first direction, the plurality of second ribs being spaced apart along the second direction, the first direction and the second direction intersecting, and the first ribs and the second ribs cooperating to form a plurality of grooves.

3. The adhesive structure according to claim 2, characterized in that, The distance between the plurality of first ribs ranges from 200µm to 400µm; and / or, The distance between the plurality of second ribs ranges from 200µm to 400µm; And / or, Along a direction perpendicular to the first direction, the width of each of the first protruding ribs ranges from 30µm to 60µm; and / or, Along a direction perpendicular to the second direction, the width of each of the second protruding ribs ranges from 30µm to 60µm; and / or, Along the concave direction of the groove, the height of the first rib ranges from 50µm to 200µm; and / or, Along the concave direction of the groove, the height of the second rib ranges from 50µm to 200µm.

4. The adhesive structure according to claim 1, characterized in that, The adhesive is a ternary blend system of silicone-polyurethane-acrylate, comprising polyurethane resin, silicone-modified acrylate resin, epoxy functionalized resin, and key functional modifiers. The polyurethane resin accounts for 60% to 70% of the mass fraction of the adhesive, the silicone-modified acrylate resin accounts for 20% to 30% of the mass fraction of the adhesive, and the epoxy functionalized resin accounts for 5% to 10% of the mass fraction of the adhesive. The cohesive strength of the cured adhesive is greater than the interfacial peel strength between it and the first panel.

5. The adhesive structure according to claim 4, characterized in that, The key functional modifier includes a silane coupling agent and nano-silica, wherein the silane coupling agent accounts for 1.0% to 2.0% of the mass fraction of the adhesive, and the nano-silica accounts for 1.5% to 2.5% of the mass fraction of the adhesive.

6. A manufacturing method, characterized in that, The manufacturing method for the adhesive structure according to any one of claims 1 to 5 includes: S101: Provide the first panel and process a plurality of evenly spaced and regularly arranged grooves on the first surface to form a mechanically locking prestructure; S103: Apply the adhesive to the first surface such that at least a portion of the adhesive fills the groove; S105: The target object is attached to the first surface and the adhesive is cured to simultaneously form a mechanical interlock and a chemical bond between the first panel and the target object.

7. The manufacturing method according to claim 6, characterized in that, Step S101 includes: The grooves are created by laser engraving, wherein the laser power used in the laser engraving ranges from 20W to 80W, the scanning speed ranges from 500mm / s to 2000mm / s, the frequency ranges from 20kHz to 100kHz, the depth of the grooves ranges from 50µm to 200µm, the groove width ranges from 30µm to 60µm, and the distance between the centers of adjacent grooves ranges from 200µm to 400µm.

8. The manufacturing method according to claim 6, characterized in that, After step S101, the manufacturing method includes: The first surface is subjected to plasma cleaning or ultrasonic degreasing for 30s to 300s to make the surface water contact angle less than or equal to 10°, so as to remove contaminants and activate surface functional groups.

9. The manufacturing method according to claim 6, characterized in that, Step S103 includes: The adhesive is applied to the first surface by means of slit coating, scraping, or screen printing, and the dry film thickness is controlled to be in the range of 50µm to 100µm.

10. The manufacturing method according to claim 6, characterized in that, Step S105 includes: Initial curing at room temperature for 2-4 hours; After curing at 60℃~80℃ for 1h~2h, the crosslinking density of the adhesive after curing is ≥90%.

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