Peelable composite copper foil and separation method thereof
By combining ultraviolet light-induced adhesion reduction materials and thermal adhesion reduction materials, the separation of peelable composite copper foil was achieved, solving the problem that the carrier copper foil could no longer be used, improving material utilization and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-06
- Publication Date
- 2026-04-14
AI Technical Summary
In existing technologies, the carrier copper foil cannot be reused after the ultrathin copper foil is peeled off, resulting in low material utilization and high costs.
By combining ultraviolet light-induced adhesion reduction material and thermal adhesion reduction material, and through ultraviolet light irradiation and heating at a preset temperature, the peelable composite copper foil is separated into two copper foils, namely the first copper foil and the second copper foil, each used for circuit board processing.
This improved material utilization and reduced the cost of circuit board production.
Smart Images
Figure CN121848764A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of circuit board technology, and in particular to a peelable composite copper foil and a method for separating the peelable composite copper foil. Background Technology
[0002] In the field of circuit board (PCB) technology, separable copper foil is typically used to enable the reseparation of circuit boards or substrates.
[0003] In related technologies, refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a separable copper foil in related technologies. A nanoscale ultrathin peelable layer is deposited on one side of a carrier copper foil, and then an ultrathin copper foil is formed on the peelable layer. The ultrathin copper foil can constitute the conductive layer of a circuit board. The peelable layer between the carrier copper foil and the ultrathin copper foil is a nanoscale ultrathin peelable layer, enabling the separation of the ultrathin copper foil from the carrier copper foil.
[0004] However, the carrier copper foil is only used as a support carrier. After the ultra-thin copper foil is peeled off, the carrier copper foil cannot be used anymore, resulting in low material utilization and high cost. Summary of the Invention
[0005] This application provides a peelable composite copper foil and a method for separating the peelable composite copper foil. The peelable composite copper foil can be separated into two copper foils, namely a first copper foil and a second copper foil. Both of the separated copper foils can be used for circuit board processing, thus improving material utilization and reducing costs.
[0006] This application provides a peelable composite copper foil, comprising a first copper foil, a first adhesive layer, a support layer, a second adhesive layer, and a second copper foil stacked sequentially. The first adhesive layer includes an ultraviolet light-reducing adhesive material, and the first adhesive layer can be separated from the first copper foil after being irradiated with ultraviolet light; The second adhesive layer includes a heat-resistant adhesive material, and the second adhesive layer can be separated from the second copper foil after being heated at a preset temperature.
[0007] In some embodiments, the first adhesive layer includes a first resin, a first curing agent, and a photoinitiator, wherein the photoinitiator reduces the adhesiveness of the first adhesive layer after being irradiated with ultraviolet light.
[0008] In some embodiments, the photoinitiator includes at least one of azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, acetophenone, benzophenone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methylphenylacetone, trimethylbenzoyl-diphenylphosphine oxide, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, triarylthionyl salt, benzoyl peroxide, dodecyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, dicumyl peroxide, ditert-tert-butyl peroxide, tert-butyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyvalerate, diethylhexyl peroxide, diisopropyl peroxide, dicyclohexyl peroxide, sodium persulfate, and ammonium persulfate.
[0009] In some embodiments, the first resin includes one or any blend of epoxy resin, acrylate resin, polyurethane and its modifiers, and the first curing agent includes one or more of isocyanate curing agents, metal salt curing agents, and epoxy curing agents.
[0010] In some embodiments, the second adhesive layer includes a second resin, a second curing agent, and thermosensitive expansion microspheres, which expand upon heating at a preset temperature, causing a decrease in the adhesiveness of the second adhesive layer.
[0011] In some embodiments, the thermosensitive expansion microspheres are polyamides, and the initial expansion temperature of the thermosensitive expansion microspheres is 180~190 degrees, the maximum expansion temperature is 190~210 degrees, and the expansion ratio is 30~50 times.
[0012] In some embodiments, the second resin includes one or any blend of epoxy resin, acrylate resin, polyurethane and its modifiers, and the second curing agent includes one or more of isocyanate curing agents, metal salt curing agents, and epoxy curing agents.
[0013] In some embodiments, the first copper foil has a smooth surface and a rough surface, the smooth surface of the first copper foil facing the first adhesive layer, and the rough surface of the first copper foil facing away from the first adhesive layer.
[0014] In some embodiments, the second copper foil has a smooth surface and a rough surface, with the smooth surface of the second copper foil facing the second adhesive layer and the rough surface of the second copper foil facing away from the second adhesive layer.
[0015] This application also provides a method for separating peelable composite copper foil, including: A peelable composite copper foil is provided, wherein the peelable composite copper foil is any of the peelable composite copper foils described above. The peelable composite copper foil is subjected to ultraviolet light irradiation to separate the first copper foil from the first adhesive layer. The peelable composite copper foil is heated at a preset temperature to separate the second copper foil from the second adhesive layer.
[0016] The peelable composite copper foil of this application embodiment can be separated into two copper foils, namely a separate first copper foil and a separate second copper foil, by ultraviolet irradiation and heating at a preset temperature. Both separated copper foils can be used for circuit board processing, such as for forming circuit patterns, thus improving material utilization and reducing costs. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the structure of separable copper foil in related technologies.
[0019] Figure 2 This is a schematic diagram of the structure of the peelable composite copper foil according to an embodiment of this application.
[0020] Figure 3 This is a schematic flowchart of the separation method for peelable composite copper foil according to an embodiment of this application. Detailed Implementation
[0021] The technical solutions of the embodiments of this application 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 this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0022] It should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this application to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals denote the same elements throughout.
[0023] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or portion discussed below may be referred to as the second element, component, area, layer, or portion.
[0024] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below” or “under” the other element or feature will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.
[0025] It should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0026] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.
[0027] This application provides a peelable composite copper foil, which can be separated into two copper foils, namely a first copper foil and a second copper foil. Both separated copper foils can be used for circuit board processing.
[0028] refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of a peelable composite copper foil according to an embodiment of this application. The peelable composite copper foil includes a first copper foil, a first adhesive layer, a support layer, a second adhesive layer, and a second copper foil stacked sequentially.
[0029] The first and second copper foils are ultra-thin copper foils with a thickness ranging from 1µm to 50µm, preferably from 3µm to 12µm. The thicknesses of the first and second copper foils can be the same or different. In some embodiments, the thicknesses of the first and second copper foils are preferably the same. Both the first and second copper foils can constitute the conductive layer of a circuit board (PCB), on which circuit patterns can be formed, for example, through processes such as lamination, exposure, development, and etching.
[0030] The support layer serves to support the first and second copper foils. The support layer can be made of materials such as PI (polyimide), PET (polyethylene terephthalate), or PP (polypropylene). The thickness of the support layer ranges from 5µm to 100µm, preferably from 10µm to 50µm, and even more preferably from 20µm to 30µm.
[0031] The thickness of the first adhesive layer and the second adhesive layer ranges from 1µm to 50µm, preferably from 2µm to 30µm, and more preferably from 5µm to 20µm. The thickness of the first adhesive layer and the second adhesive layer may be the same or different. In some embodiments, the thickness of the first adhesive layer and the second adhesive layer is preferably the same.
[0032] The first adhesive layer includes an ultraviolet (UV) anti-adhesion material. After being irradiated with ultraviolet light, the first adhesive layer can be separated from the first copper foil, and after separation, the first adhesive layer remains on the support layer. The second adhesive layer includes a thermal anti-adhesion material.
[0033] The second adhesive layer can be separated from the second copper foil after heating at a preset temperature, leaving the second adhesive layer on the support layer. The preset temperature can be determined experimentally or empirically. The preset temperature is determined by the material composition of the second adhesive layer.
[0034] In practical applications, when the peelable composite copper foil needs to be peeled off, it can be irradiated with ultraviolet light to rapidly reduce the adhesion of the first adhesive layer, thus achieving reduced adhesion or even non-adhesion. The first copper foil and the first adhesive layer become weakly bonded, allowing the first copper foil to separate from the first adhesive layer, resulting in a separate first copper foil. Furthermore, the peelable composite copper foil can be heated at a preset temperature to rapidly reduce the adhesion of the second adhesive layer, thus achieving reduced adhesion or even non-adhesion. The second copper foil and the second adhesive layer become weakly bonded, allowing the second copper foil to separate from the second adhesive layer, resulting in a separate second copper foil.
[0035] Therefore, the peelable composite copper foil of this application embodiment can be separated into two copper foils, namely a separate first copper foil and a separate second copper foil, by ultraviolet irradiation and heating at a preset temperature. Both separated copper foils can be used for circuit board processing, such as for forming circuit patterns, thus improving material utilization and reducing costs.
[0036] In some embodiments, such as Figure 2 As shown, the first copper foil has a smooth surface (which can be called a glossy surface) and a rough surface (which can be called a rough surface). The smooth surface of the first copper foil faces the first adhesive layer, while the rough surface faces away from the first adhesive layer. It can be understood that having the smooth surface of the first copper foil facing the first adhesive layer allows for a rapid decrease in the adhesive force between the first copper foil and the first adhesive layer when the first adhesive layer is irradiated with ultraviolet light, making it easier to separate the copper foil into individual pieces. Conversely, having the rough surface of the first copper foil facing away from the first adhesive layer enhances the adhesion of the first copper foil during the formation of the circuit pattern, resulting in a stronger bond between the film and the first copper foil, preventing poor adhesion of the film and thus avoiding defects in the formed circuit pattern.
[0037] In some embodiments, such as Figure 2As shown, the second copper foil has a smooth surface (which can be called a glossy surface) and a rough surface (which can be called a rough surface). The smooth surface of the second copper foil faces the second adhesive layer, while the rough surface faces away from the second adhesive layer. It is understood that having the smooth surface of the second copper foil facing the second adhesive layer allows for a rapid reduction in the adhesive force between the second copper foil and the second adhesive layer when the second adhesive layer is heated at a preset temperature, making it easier to separate the second copper foil into individual pieces. Conversely, having the rough surface of the second copper foil facing away from the second adhesive layer enhances the adhesion of the second copper foil during the circuit pattern formation process, resulting in a stronger bond between the film and the second copper foil, preventing poor film adhesion that could lead to defective circuit patterns.
[0038] In some embodiments, the first adhesive layer includes a first resin, a first curing agent, and a photoinitiator. The photoinitiator, after being irradiated with ultraviolet light, reduces the tackiness of the first adhesive layer, thereby achieving reduced tack or even non-tack.
[0039] In some embodiments, the first resin includes one or a blend of any of the following: epoxy resin, acrylate resin, polyurethane, and modified polyurethane. The first curing agent includes one or more of the following: isocyanate curing agents, metal salt curing agents, and epoxy curing agents.
[0040] In some embodiments, the photoinitiator includes at least one of azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, acetophenone, benzophenone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methylphenylacetone, trimethylbenzoyl-diphenylphosphine oxide, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, triarylthionyl salt, benzoyl peroxide, dodecyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, dicumyl peroxide, ditert-tert-butyl peroxide, tert-butyl peroxide, tert-butyl peroxybenzoate, diethylhexyl peroxide, diisopropyl peroxide, dicyclohexyl peroxide, sodium persulfate, and ammonium persulfate.
[0041] In some embodiments, the second adhesive layer includes a second resin, a second curing agent, and thermosensitive expandable microspheres. The thermosensitive expandable microspheres expand upon heating at a preset temperature, causing a decrease in the adhesiveness of the second adhesive layer, thereby achieving reduced adhesion or even non-adhesiveness.
[0042] In some embodiments, the second resin comprises one or any blend of epoxy resin, acrylate resin, polyurethane, and modified forms thereof. The second curing agent comprises one or more of isocyanate curing agents, metal salt curing agents, and epoxy curing agents.
[0043] In some embodiments, the thermosensitive expandable microspheres are polyamides. Polyamides are a class of polymers containing amide segments (-CONH-). The initial expansion temperature of the thermosensitive expandable microspheres is 180~190 degrees Celsius, the maximum expansion temperature is 190~210 degrees Celsius, and the expansion ratio is 30~50 times. Therefore, the preset temperature can be 180~210 degrees Celsius.
[0044] This application also provides a method for separating peelable composite copper foil, applicable to the peelable composite copper foil of any of the above embodiments. (Reference) Figure 3 , Figure 3 This is a schematic flowchart illustrating the separation method for peelable composite copper foil according to an embodiment of this application. The separation method includes the following steps: 110, providing peelable composite copper foil; 120. The peelable composite copper foil is irradiated with ultraviolet light to separate the first copper foil from the first adhesive layer. 130. The peelable composite copper foil is heated at a preset temperature to separate the second copper foil from the second adhesive layer.
[0045] The peelable composite copper foil can be any of the peelable composite copper foils described in the above embodiments. It should be noted that the specific implementation methods of each step in the above separation method can be found in the descriptions of the various embodiments of the peelable composite copper foil, and will not be repeated here.
[0046] In the separation method of the peelable composite copper foil in this application embodiment, the peelable composite copper foil can be separated into two copper foils by irradiating it with ultraviolet light and heating it at a preset temperature. These two copper foils are a first copper foil and a second copper foil. Both copper foils can be used for circuit board processing, such as for forming circuit patterns. Therefore, the utilization rate of materials can be improved and the cost can be reduced.
[0047] In the description of this application, it should be understood that terms such as “first” and “second” are used only to distinguish similar objects and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.
[0048] The peelable composite copper foil and the method for separating the peelable composite copper foil provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application, and the descriptions of the embodiments above are only for the purpose of helping to understand this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A peelable composite copper foil, characterized in that, It includes a first copper foil, a first adhesive layer, a support layer, a second adhesive layer, and a second copper foil stacked in sequence; The first adhesive layer includes an ultraviolet light-reducing adhesive material, and the first adhesive layer can be separated from the first copper foil after being irradiated with ultraviolet light; The second adhesive layer includes a heat-resistant adhesive material, and the second adhesive layer can be separated from the second copper foil after being heated at a preset temperature.
2. The peelable composite copper foil according to claim 1, characterized in that, The first adhesive layer includes a first resin, a first curing agent, and a photoinitiator. The photoinitiator reduces the adhesiveness of the first adhesive layer after being irradiated with ultraviolet light.
3. The peelable composite copper foil according to claim 2, characterized in that, The photoinitiator includes at least one of the following: azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, acetophenone, benzophenone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methylphenylacetone, trimethylbenzoyl-diphenylphosphine oxide, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, triarylthionyl salt, benzoyl peroxide, dodecyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, dicumyl peroxide, ditert-tert-butyl peroxide, tert-butyl peroxide, tert-butyl peroxybenzoate, diethylhexyl percarbonate, diisopropyl peroxide, dicyclohexyl peroxide, sodium persulfate, and ammonium persulfate.
4. The peelable composite copper foil according to claim 2, characterized in that, The first resin includes one or any blend of epoxy resin, acrylate resin, polyurethane and its modifiers, and the first curing agent includes one or more of isocyanate curing agents, metal salt curing agents and epoxy curing agents.
5. The peelable composite copper foil according to claim 1, characterized in that, The second adhesive layer includes a second resin, a second curing agent, and thermosensitive expansion microspheres. The thermosensitive expansion microspheres expand when heated at a preset temperature, causing the adhesiveness of the second adhesive layer to decrease.
6. The peelable composite copper foil according to claim 5, characterized in that, The thermosensitive expansion microspheres are polyamides, with an initial expansion temperature of 180-190 degrees Celsius, a maximum expansion temperature of 190-210 degrees Celsius, and an expansion ratio of 30-50 times.
7. The peelable composite copper foil according to claim 5, characterized in that, The second resin includes one or any blend of epoxy resin, acrylate resin, polyurethane and its modifiers, and the second curing agent includes one or more of isocyanate curing agents, metal salt curing agents and epoxy curing agents.
8. The peelable composite copper foil according to any one of claims 1 to 7, characterized in that, The first copper foil has a smooth surface and a rough surface, with the smooth surface of the first copper foil facing the first adhesive layer and the rough surface of the first copper foil facing away from the first adhesive layer.
9. The peelable composite copper foil according to any one of claims 1 to 7, characterized in that, The second copper foil has a smooth surface and a rough surface, with the smooth surface of the second copper foil facing the second adhesive layer and the rough surface of the second copper foil facing away from the second adhesive layer.
10. A method for separating peelable composite copper foil, characterized in that, include: A peelable composite copper foil is provided, wherein the peelable composite copper foil is the peelable composite copper foil according to any one of claims 1 to 9; The peelable composite copper foil is subjected to ultraviolet light irradiation to separate the first copper foil from the first adhesive layer. The peelable composite copper foil is heated at a preset temperature to separate the second copper foil from the second adhesive layer.