Low-glue-spraying composite covering film
Through a unique layered structure design, the problems of uneven adhesive layer thickness, insufficient bonding strength, adhesive overflow, and moisture residue in composite cover films are solved, achieving high flatness, improved heat resistance and interlayer strength of the cover film, ensuring the reliability and service life of electronic products.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-24
- Publication Date
- 2026-04-10
AI Technical Summary
Existing composite cover films have problems such as uneven adhesive layer thickness, insufficient bonding strength, adhesive overflow, and moisture residue, which affect the reliability and service life of electronic products.
Employing a unique layered structure design, including a wavy interface and a honeycomb microporous transition layer, it enhances the bonding strength and stress distribution between adhesive layers through mechanical interlocking and pore size gradient changes, while reducing adhesive overflow and moisture residue.
It significantly improves the flatness, heat resistance, and interlayer bonding strength of the cover film, prevents interlayer peeling, reduces adhesive overflow, avoids copper foil oxidation, and improves the reliability and lifespan of electronic products.
Smart Images
Figure CN224103682U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a composite cover film, especially to a low glue spraying composite cover film, and belongs to the technical field of electronic materials. BACKGROUND
[0002] In the manufacturing process of electronic equipment, composite cover films are widely used for the protection and insulation treatment of components such as circuit boards. However, the existing composite cover films have some problems in actual use. For example, the cover films prepared by traditional processes are prone to uneven thickness of each adhesive layer due to differences in the flowability of the glue, affecting the flatness and performance stability of the cover film. During high-temperature pressing or bending, the bonding strength between different adhesive layers is insufficient, which can easily cause interlayer peeling, reducing the reliability of the product. In addition, the stress distribution between the release paper and the adhesive layer is uneven, which can cause glue overflow during pressing, affecting the service life of the electronic product. Therefore, it is necessary to develop a new type of low glue spraying composite cover film to solve the above problems in the prior art. SUMMARY
[0003] Therefore, the utility model provides a low glue spraying composite cover film, which improves the flatness, heat resistance stability, and interlayer bonding strength of the cover film through a unique structural design, and solves the problems of glue overflow and moisture residue.
[0004] The utility model discloses a low glue spraying composite cover film, which comprises a glue-coated film and a release paper.
[0005] The low glue spraying composite cover film comprises a glue-coated film and a release paper, the glue-coated film is formed by sequentially hot-pressing a film base material, a polyester resin adhesive layer, and an epoxy resin adhesive layer to form a laminated structure, a wave-shaped interface is arranged between the polyester resin adhesive layer and the epoxy resin adhesive layer, the wave crest and the wave trough of the wave-shaped interface are respectively embedded in the adjacent adhesive layers to form mechanical engagement, a honeycomb-shaped microporous transition layer is arranged between the epoxy resin adhesive layer and the release paper, and the micropore diameter gradually increases from the epoxy resin adhesive layer to the release paper.
[0006] The low glue spraying composite cover film has a unique structural design, which improves the flatness, heat resistance stability, and interlayer bonding strength of the cover film, and solves the problems of glue overflow and moisture residue. The laminated structure is hot-pressed to improve the flatness and heat resistance stability of the cover film, the wave-shaped interface is mechanically engaged to enhance the bonding strength between the polyester layer and the epoxy layer and prevent interlayer peeling, and the honeycomb-shaped microporous transition layer has a gradient change in the pore diameter to adjust the stress distribution, reduce glue overflow, and impart air permeability to avoid copper foil oxidation.
[0007] Specifically, the laminated structure is formed by hot pressing and compounding to ensure close adhesion between the adhesive layers, avoid uneven thickness caused by poor flowability of the adhesive in traditional processes, and significantly improve the overall flatness and heat resistance of the cover film; the wavy interface design forms a three-dimensional anchoring network through the mechanical biting action of the wave peaks and valleys, significantly enhances the bonding strength of the polyester layer and the epoxy layer, and effectively prevents interlayer peeling during high-temperature pressing or bending; the pore size gradient of the honeycomb-shaped microporous transition layer can dynamically adjust the stress distribution between the release paper and the epoxy adhesive layer during pressing, reducing the overflow phenomenon caused by local stress concentration, and the microporous structure gives the adhesive layer air permeability, avoiding the oxidation problem of copper foil caused by moisture residue.
[0008] Preferably, the surface of the thin film substrate is provided with periodically arranged inverted cone-shaped grooves, the groove depth direction is perpendicular to the adhesive layer coating direction, and the grooves are filled with polyester resin adhesive.
[0009] The inverted cone-shaped groove design forms directional anchoring points through periodic arrangement, and the filled polyester resin adhesive and the substrate form a "barb" type mechanical lock, significantly enhancing the adhesion of the adhesive layer and the substrate, especially in high and low temperature alternating environment, which can inhibit the interface separation caused by shrinkage of the adhesive layer; the perpendicular arrangement of the groove depth direction and the coating direction can disperse the internal stress generated during the curing of the adhesive layer, and avoid warping or cracking of the substrate edge caused by stress concentration; the polyester resin adhesive filled in the groove forms a continuous transition interface with the substrate, reducing micro-cracks caused by the difference in thermal expansion coefficient of the materials, and improving the durability of the cover film under repeated bending conditions.
[0010] Preferably, the wave peak of the wavy interface is provided with a columnar protrusion penetrating the polyester resin adhesive layer, and the top of the columnar protrusion extends into the epoxy resin adhesive layer to form an anchoring structure.
[0011] The columnar protrusion anchoring structure connects the polyester layer and the epoxy layer as a whole through physical penetration, forming a three-dimensional support network that can resist shear force and peeling force in both directions, especially suitable for the deformation resistance requirements of small pad areas in high-density circuit boards; the design of the protrusion top extending into the epoxy layer increases the contact area between the adhesive layers, and simultaneously disperses external loads by utilizing the high rigidity characteristics of the epoxy resin, avoiding adhesive layer fracture caused by local stress concentration; this structure naturally forms through heat deformation in the pressing process, without the need for additional processing steps, balancing production efficiency and structural reliability.
[0012] Preferably, the pore wall surface of the honeycomb-shaped microporous transition layer is coated with a hydrophobic nano coating, and the micropores are filled with elastic silica gel particles.
[0013] The hydrophobic nano-coating can effectively prevent moisture from penetrating into the adhesive layer through the micropores, prevent the copper foil from oxidizing and discoloring, and reduce the water absorption of the adhesive layer to ensure the insulation performance of the cover film in a humid environment. The elastic silica gel particles fill the elastic deformation of the micropores to absorb the expansion stress generated during the hot pressing process, reducing the risk of glue overflow or cracking caused by thermal expansion and contraction of the adhesive layer. The synergistic effect of silica gel particles and honeycomb-shaped micropores can provide buffer protection when the release paper is peeled off, avoiding damage to the adhesive layer due to instantaneous tension and improving the yield.
[0014] Preferably, the adhesive surface of the release paper is provided with an array of hemispherical protrusions matching the honeycomb-shaped microporous transition layer.
[0015] The array of hemispherical protrusions is designed by geometric matching to uniformly distribute pressure to the honeycomb-shaped microporous transition layer during pressing, avoiding the crushing of the adhesive layer or the collapse of the micropores caused by excessive local pressure of traditional flat release paper. The ratio of protrusion height to micropore diameter is set to ensure that only the weakly bonded interface between the transition layer and the release paper is broken when the release paper is peeled off, while the integrity of the main structure of the adhesive layer is preserved, reducing the risk of residual glue. The regular arrangement of the protrusion array can guide the directional flow of the adhesive layer during pressing, further optimizing the uniformity of glue overflow distribution to meet the stringent requirements of precision circuits for the flatness of the cover film edges.
[0016] Preferably, the bottom of the inverted conical groove is provided with an array of blind holes extending into the substrate, and the blind holes are filled with epoxy adhesive.
[0017] The blind hole array extends into the substrate to form a "barb" type three-dimensional anchor point, and the filled epoxy adhesive forms a cross-layer mechanical lock with the polyester layer, significantly improving the peel resistance of the substrate and the adhesive layer. The blind hole design can disperse the thermal stress at the interface between the adhesive layer and the substrate, alleviating the problem of interface separation caused by the difference in thermal expansion coefficient. The curing of epoxy resin in the blind hole forms a rigid support structure, enhancing the dimensional stability of the cover film during high-temperature pressing.
[0018] Preferably, the pore wall of the honeycomb-shaped microporous transition layer is a double-layer composite structure, the inner layer of the pore wall is a hydrophobic material, and the outer layer of the pore wall is an elastic resin coating layer.
[0019] The inner layer of the hydrophobic material blocks moisture penetration through physical structure, avoiding reliance on chemical coating modification to ensure the stability of long-term moisture resistance; the outer layer of the elastic resin coating layer is flexible with the epoxy adhesive layer and the release paper, absorbing stress fluctuations during pressing and peeling through elastic deformation to reduce damage to the adhesive layer; the double-layer composite structure separates the hydrophobic and elastic functions, avoiding the functional limitations of a single material, while simplifying the production process.
[0020] Preferably, the sidewall of the columnar protrusion is provided with a circumferentially distributed annular indentation, and the indentation depth gradually changes along the extension direction of the protrusion.
[0021] The annular indentation forms a gradient friction interface, and improves the pull-out resistance of the anchoring structure and the epoxy layer.
[0022] Compared with the prior art, the utility model has the beneficial effects that:
[0023] The low-spraying adhesive composite mulching film has the advantages that: the unique structure design improves the flatness, heat-resistant stability and bonding strength between adhesive layers of the mulching film, and solves the problems of glue overflow and moisture residue; the heat-pressing composite of the laminated structure improves the flatness and heat-resistant stability of the mulching film; the mechanical interlocking of the wave-shaped interface enhances the bonding strength between the polyester layer and the epoxy layer and prevents interlayer peeling; the pore size gradient change of the honeycomb-shaped microporous transition layer dynamically adjusts the stress distribution between the release paper and the epoxy adhesive layer during pressing, reduces the glue overflow caused by local stress concentration, and the microporous structure gives the adhesive layer air permeability, thereby avoiding the copper foil oxidation caused by moisture residue. BRIEF DESCRIPTION OF DRAWINGS
[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation to the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor.
[0025] Figure 1 FIG. 1 is a structural diagram of a low-spraying adhesive composite mulching film according to an embodiment of the present application.
[0026] Figure 2 For Figure 1 FIG. 2 is an enlarged view of region A in FIG. 1.
[0027] LABEL EXPLANATION
[0028] The adhesive film (1), the release paper (2), the film substrate (11), the polyester resin adhesive layer (12), the epoxy resin adhesive layer (13), the wave-shaped interface (14), the honeycomb-shaped microporous transition layer (15), the inverted conical groove (111), the columnar protrusion (141), the hemispherical protrusion array (21), the blind hole array (112), the inner layer of the hole wall (151), the outer layer of the hole wall (152), and the annular indentation (142). DETAILED DESCRIPTION
[0029] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations.
[0030] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.
[0031] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In the description of the embodiments of the present application, it needs to be understood that the terms "upper", "lower", "left", "right", "vertical", "horizontal" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the product of the application is used, or the orientation or positional relationship commonly understood by those skilled in the art, which is only for the convenience of describing the present application and simplifying the description, and is not intended to indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.
[0032] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In the description of the embodiments of the present application, it needs to be understood that the terms "upper", "lower", "left", "right", "vertical", "horizontal" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the product of the application is used, or the orientation or positional relationship commonly understood by those skilled in the art, which is only for the convenience of describing the present application and simplifying the description, and is not intended to indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.
[0033] The technical solutions in the present application will be described below with reference to the accompanying drawings.
[0034] The present embodiment provides a low-spray adhesive composite mulch film, which comprises a glue-coated film 1 and a release paper 2. The glue-coated film 1 is formed by sequentially hot-pressing a film substrate 11, a polyester resin adhesive layer 12 and an epoxy resin adhesive layer 13 to form a laminated structure. A wave-shaped interface 14 is arranged between the polyester resin adhesive layer 12 and the epoxy resin adhesive layer 13. The wave crests and wave troughs of the wave-shaped interface 14 are respectively embedded in the adjacent adhesive layers to form mechanical interlocking. A honeycomb-shaped microporous transition layer 15 is arranged between the epoxy resin adhesive layer 13 and the release paper 2. The pore size gradually increases from the epoxy resin adhesive layer 13 to the release paper 2.
[0035] The low spray adhesive composite mulch film improves the flatness, heat resistance stability, and bonding strength between adhesive layers through unique structural design, and solves problems such as overflow and moisture residue. The flatness and heat resistance stability of the mulch film are improved through thermal compression of the laminated structure, the bonding strength between the polyester layer and the epoxy layer is enhanced through mechanical interlocking of the wave-shaped interface 14 to prevent interlayer peeling, and the stress distribution is adjusted through the gradient change of the pore size of the honeycomb-shaped microporous transition layer 15 to reduce overflow and give the film air permeability to avoid copper foil oxidation.
[0036] Specifically, the laminated structure is formed through thermal compression, ensuring that the adhesive layers are tightly bonded, avoiding uneven thickness caused by poor flowability of the adhesive in traditional processes, and significantly improving the overall flatness and heat resistance stability of the mulch film. The wave-shaped interface 14 is designed to form a three-dimensional anchoring network through the mechanical interlocking action of the peaks and valleys, significantly enhancing the bonding strength between the polyester layer and the epoxy layer and effectively preventing interlayer peeling during high-temperature compression or bending. The gradient change in the pore size of the honeycomb-shaped microporous transition layer 15 can dynamically adjust the stress distribution between the release paper 2 and the epoxy adhesive layer during compression, reducing the overflow phenomenon caused by local stress concentration, and the microporous structure gives the adhesive layer air permeability, avoiding the problem of copper foil oxidation caused by moisture residue.
[0037] In this embodiment, the surface of the film substrate 11 is provided with periodically arranged inverted conical grooves 111, the groove depth direction is perpendicular to the adhesive coating direction, and the grooves are filled with polyester resin adhesive.
[0038] The inverted conical grooves 111 are designed to form directional anchoring points through periodic arrangement, and the filled polyester resin adhesive forms a "barb" type mechanical lock with the substrate, significantly enhancing the adhesion between the adhesive layer and the substrate, especially in high-low temperature alternating environments, which can inhibit interface separation caused by adhesive shrinkage. The perpendicular arrangement of the groove depth direction and the coating direction can disperse the internal stress generated during the curing of the adhesive layer, avoiding warping or cracking of the substrate edge due to stress concentration; the polyester resin adhesive filled in the grooves forms a continuous transition interface with the substrate, reducing microcracks caused by differences in the thermal expansion coefficient of the materials, and improving the durability of the mulch film under repeated bending conditions.
[0039] In this embodiment, the wave-shaped interface 14 is provided with a columnar protrusion 141 penetrating the polyester resin adhesive layer 12 at the peak of the wave-shaped interface 14, and the columnar protrusion 141 extends to the inside of the epoxy resin adhesive layer 13 to form an anchoring structure.
[0040] The columnar protrusion 141 anchoring structure connects the polyester layer and the epoxy layer into a whole by physical penetration, forms a three-dimensional support network, can resist the bidirectional action of shear force and peeling force, and is especially suitable for the anti-deformation requirement of a small pad area in a high-density circuit board; the design that the top of the protrusion extends to the inside of the epoxy layer increases the contact area between the glue layers, and disperses external load by using the high rigidity characteristics of the epoxy resin to avoid the glue layer fracture caused by local stress concentration; the structure is naturally formed by heat melting deformation in the pressing process, and no additional processing steps are required, so that the production efficiency and the structural reliability are considered.
[0041] In the embodiment, the hole wall surface of the honeycomb microporous transition layer 15 is coated with a hydrophobic nano coating, and the micropores are filled with elastic silica gel particles.
[0042] The hydrophobic nano coating can effectively block the penetration of moisture through the micropores into the glue layer, prevent the oxidation and discoloration of the copper foil, reduce the water absorption of the glue layer, and ensure the insulation performance of the cover film in a humid environment; the elastic deformation of the elastic silica gel particles filled in the micropores absorbs the expansion stress generated in the hot pressing process, reduces the risk of glue overflow or cracking caused by thermal expansion and cold contraction of the glue layer; the synergistic effect of the silica gel particles and the honeycomb microporous structure can provide buffer protection when the release paper 2 is peeled off, avoid damage to the glue layer caused by instantaneous tension, and improve the yield.
[0043] In the embodiment, the bonding surface of the release paper 2 is provided with a hemispherical protrusion array 21 matched with the honeycomb microporous transition layer 15.
[0044] The hemispherical protrusion array 21 is designed by geometric matching to uniformly disperse the pressure to the honeycomb microporous transition layer 15 during the pressing process, avoiding the glue layer crushing or micropore collapse caused by excessive local pressure of the traditional plane release paper; the ratio of the protrusion height to the micropore diameter is set to ensure that only the weak bonding interface between the transition layer and the release paper 2 is damaged when the release paper 2 is peeled off, while the integrity of the main structure of the glue layer is preserved, reducing the risk of residual glue; the regular arrangement of the protrusion array can guide the directional flow of the glue layer during pressing, further optimizing the uniformity of glue overflow distribution, and meeting the stringent requirements of precise lines on the flatness of the cover film edge.
[0045] In the embodiment, the bottom of the inverted conical groove 111 is provided with a blind hole array 112 extending into the substrate, and the blind holes are filled with epoxy resin adhesive.
[0046] The blind hole array 112 extends into the substrate to form a “barb” type three-dimensional anchor point, and the filled epoxy resin adhesive forms a cross-layer mechanical lock with the polyester layer, significantly improving the anti-peeling performance of the substrate and the glue layer; the blind hole design can disperse the thermal stress at the interface between the glue layer and the substrate, and relieve the interface separation problem caused by the difference in thermal expansion coefficient; the curing of the epoxy resin in the blind hole forms a rigid support structure, enhancing the dimensional stability of the cover film during high-temperature pressing.
[0047] In the embodiment, the hole wall of the honeycomb microporous transition layer 15 is a double-layer composite structure, the inner layer 151 of the hole wall is a hydrophobic material, and the outer layer 152 of the hole wall is an elastic resin coating layer.
[0048] The hydrophobic material of the inner layer 151 blocks moisture penetration through physical structure, avoids relying on chemical coating modification, and ensures the stability of long-term moisture-proof performance; the elastic resin coating layer of the outer layer 152 is flexibly attached with the epoxy layer and the release paper 2, absorbs stress fluctuation in the pressing and peeling process through elastic deformation, and reduces damage to the glue layer; the double-layer composite structure separates the hydrophobic and elastic functions, avoids the functional limitations of a single material, and simplifies the production process.
[0049] In the embodiment, the side wall of the columnar protrusion 141 is provided with annular indentations 142 distributed around, and the indentation depth gradually changes along the extension direction of the protrusion.
[0050] The annular indentations 142 form a gradient friction interface, which improves the pull-off resistance of the anchoring structure and the epoxy layer.
[0051] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the utility model, and the scope of the utility model is defined by the appended claims and their equivalents.
Claims
1. A low-spraying adhesive composite mulch film comprising an adhesive-coated film (1) and a release paper (2), characterized in that, The glue film (1) is formed by a film substrate (11), a polyester resin adhesive layer (12) and an epoxy resin adhesive layer (13) through hot pressing and compounding in sequence. The polyester resin adhesive layer (12) and the epoxy resin adhesive layer (13) are provided with a wave-shaped interface (14), and the wave crest and the wave trough of the wave-shaped interface (14) are embedded in the adjacent adhesive layers to form mechanical interlocking. The epoxy resin adhesive layer (13) and the release paper (2) are provided with a honeycomb-shaped microporous transition layer (15), and the micropore diameter gradually increases from the epoxy resin adhesive layer to the release paper.
2. The low-spray-tape composite coverlay of claim 1, wherein, The film substrate (11) is provided with a periodic arrangement of inverted conical grooves (111), the groove depth direction is perpendicular to the adhesive coating direction, and the grooves are filled with polyester resin adhesive.
3. The low spray-tape composite mulch film according to claim 1, wherein, The wave crest of the wave-shaped interface (14) is provided with a columnar protrusion (141) penetrating through the polyester resin adhesive layer (12), and the top of the columnar protrusion extends into the epoxy resin adhesive layer (13) to form an anchoring structure.
4. The low spray-tie composite mulch film according to claim 1, wherein, The hole wall surface of the honeycomb-shaped microporous transition layer (15) is coated with a hydrophobic nano coating, and the micropores are filled with elastic silica gel particles.
5. The low spray-tie composite mulch film according to claim 1, wherein, The bonding surface of the release paper (2) is provided with a hemispherical protrusion array (21) matched with the honeycomb-shaped microporous transition layer (15).
6. The low spray adhesive composite mulch film of claim 2, wherein, The groove bottom of the inverted conical groove (111) is provided with a blind hole array (112) extending into the substrate, and the blind holes are filled with epoxy resin adhesive.
7. The low spray-tape composite mulch film of claim 1, wherein, The hole wall of the honeycomb-shaped microporous transition layer (15) is a double-layer composite structure, the inner layer (151) of the hole wall is a hydrophobic material, and the outer layer (152) of the hole wall is an elastic resin coating layer.
8. The low spray-tie composite mulch film according to claim 3, wherein, The sidewall of the columnar protrusion (141) is provided with a circumferentially distributed annular indentation (142), and the indentation depth gradually changes along the protrusion extension direction.