A flexible electromagnetic shielding tape with broadband shielding effectiveness

Abstract

A flexible electromagnetic shielding tape with broadband shielding performance has an eight-layer structure, wherein a lower adhesive layer is coated on the lower surface of a substrate layer, an upper end of a lower protective film layer is bonded to the lower surface of the lower adhesive layer, a first metal layer is plated on the upper surface of the substrate layer, a second metal layer is plated on the upper surface of the first metal layer, a third metal layer is plated on the upper surface of the second metal layer, an upper adhesive layer is coated on the upper surface of the third metal layer, and a lower end of an upper protective film layer is bonded to the lower surface of the upper adhesive layer. The finished product is a flat strip structure as a whole. The present invention adopts a thin and flexible PTFE release film as a substrate, and three metal layers are plated on the surface of the PTFE release film. The material itself can play a shielding effect covering high-frequency and low-frequency electromagnetic radiation. The obtained finished product is thin, flexible, not easy to break and break, and can achieve good high-frequency and low-frequency electromagnetic shielding effects, ensuring the effective operation of electronic equipment. Based on the above, the present invention has good application prospects.

Description

Technical Field

[0001] The invention relates to the field of electromagnetic shielding materials, in particular to a flexible electromagnetic shielding tape with broadband shielding effectiveness. Background Art

[0002] With the rapid development of the electronic information industry, electronic components are becoming increasingly miniaturized and highly integrated, and electronic instruments are becoming increasingly lightweight, high-speed, digital, and with smaller signal levels. There is a problem that miniaturized electronic components and electronic instruments are more likely to be affected by external electromagnetic interference and thus their normal operation than large-scale electronic components and electronic instruments (hereinafter collectively referred to as electronic equipment). Due to external electromagnetic interference, electronic equipment is prone to errors in their work, which may lead to serious consequences. Especially in the field of military equipment, the consequences of errors in the work of electronic equipment are more serious; in addition, the electromagnetic radiation of electronic equipment itself can also cause electromagnetic information leakage, causing serious losses to the country's politics, economy and military. In order to make electronic equipment have the ability to resist electromagnetic interference and prevent information leakage, certain shielding measures must be taken, and it is particularly important to carry out the research and development and manufacture of electromagnetic shielding materials.

[0003] In order to make electronic equipment have the ability to resist electromagnetic interference and prevent information leakage, the existing technology mainly uses shielding tape with electromagnetic shielding function and adheres it to the electronic equipment components that need to be shielded, so as to achieve the shielding effect. Traditional shielding tape mainly achieves electromagnetic shielding by plating or bonding materials with good conductivity on the substrate (such as bonding copper foil layer), but the copper foil layer of existing shielding materials often only has a good shielding effect in the high frequency band, and the electromagnetic shielding performance in the low frequency band is very low or almost has no shielding function. For low-frequency magnetic fields, due to its low frequency, the skin effect is very small, the absorption loss is very small, and due to its low wave impedance, the reflection loss is also very small, so it is difficult to obtain the required low-frequency electromagnetic shielding effectiveness by simply relying on the absorption and reflection of existing materials.

[0004] Furthermore, the conductive substrate layer of the existing electromagnetic shielding tape is basically made of aluminum-plastic film. Since the aluminum-plastic film and copper foil layer have a certain thickness, the thickness of the finished product is relatively large, generally above 2 mm. This will lead to a problem that it is very inconvenient when installed as a component shield in a small electronic device with a narrow space (such as in a mobile phone, etc.). Another problem is that since the aluminum-plastic film and copper foil layer have a certain strength and low plasticity, when the shielding tape is applied to electronic components with large bending angles and irregular shapes (for example, shielding wrapping on the surface of transformers, etc.), it cannot achieve a good fit between the two, which will have a certain impact on the installation and electromagnetic shielding effect, and there are also problems such as the fragmentation and breakage of the aluminum-plastic film. High permeability materials (such as pure iron, silicon steel sheets, Permalloy, etc.), especially iron-nickel alloy (Permalloy), have high magnetic permeability and low coercivity in a weak magnetic field, and are a good low-frequency soft magnetic material. Therefore, using iron-nickel alloy as the material of the electromagnetic shielding tape will achieve a good low-frequency electromagnetic shielding effect. However, the existing electromagnetic shielding tape does not have the above materials, and therefore cannot achieve a good low-frequency electromagnetic shielding effect.

[0005] In summary, it is particularly necessary to provide an adhesive tape which has good flexibility, low thickness, and not only good high-frequency electromagnetic shielding effect, but also good low-frequency electromagnetic shielding effect. Summary of the invention

[0006] In order to overcome the disadvantages of the existing electromagnetic shielding tapes, such as high thickness, poor flexibility and poor low-frequency electromagnetic shielding effect due to structural limitations, the present invention provides a PET release film with thin thickness and good flexibility as a substrate, and three metal layers are plated on the surface of the PTFE release film through existing mature magnetron sputtering and electroplating processes, wherein the first layer is a single metal layer of metal copper, nickel, iron, silver, etc., the second layer is a single metal or alloy layer of metal copper, nickel, iron, silver, etc., and the third layer is an iron-nickel alloy layer. The three metal layers are stacked layer by layer, have a thin thickness, and can better cover the substrate without dead angles. The material itself can play a shielding effect covering high-frequency and low-frequency electromagnetic radiation. The finished product is thin in thickness (not exceeding 0.6mm), has high flexibility, is not easy to break and break, can be conveniently used in small electronic devices with narrow installation space, and can better fit the surface of irregularly shaped electronic components, so as to achieve good high-frequency and low-frequency electromagnetic shielding effects, and ensure the effective operation of electronic equipment. A flexible electromagnetic shielding tape with broadband shielding efficiency.

[0007] The technical solution adopted by the present invention to solve its technical problem is:

[0008] A flexible electromagnetic shielding tape with broadband shielding performance, characterized by having an eight-layer structure, from top to bottom, respectively, an upper protective film, an upper adhesive layer, a third metal layer, a second metal layer, a first metal layer, a substrate layer, a lower adhesive layer, and a lower protective film layer; the first metal layer, the second metal layer, and the third metal layer are respectively used as a conductive metal layer, a high-frequency shielding layer, and a low-frequency shielding layer, and the substrate layer is a PTFE release film; the lower adhesive layer is coated on the lower surface of the substrate layer, and the upper end of the lower protective film layer is bonded to the lower surface of the lower adhesive layer; the first metal layer is plated On the upper surface of the substrate layer, the second metal layer is plated on the upper surface of the first metal layer, and the third metal layer is plated on the upper surface of the second metal layer; the upper adhesive layer is coated on the upper surface of the third metal layer, and the lower end of the upper protective film layer is bonded to the lower surface of the upper adhesive layer; after the upper protective film, upper adhesive layer, third metal layer, second metal layer, first metal layer, substrate layer, lower adhesive layer, and lower protective film layer are combined and formed in layers, the finished product as a whole is a flat strip structure, the finished product is wound into a ring shape, the upper and lower ends of the finished product are both in a flat and horizontal state, and the thickness is less than 0.6mm.

[0009] Furthermore, the substrate layer can also be made of one of PET release film, PE release film and OPP release film.

[0010] Furthermore, the upper adhesive layer and the lower adhesive layer are hot melt adhesives, and pressure sensitive adhesives can also be used.

[0011] Furthermore, the upper protective film and the lower protective film layer are self-adhesive paper protective paper films.

[0012] Furthermore, the conductive metal layer is a copper-plated layer.

[0013] Furthermore, the high-frequency shielding layer is a nickel-plated layer.

[0014] Furthermore, the low-frequency shielding layer is made of an iron-nickel alloy layer.

[0015] Furthermore, the conductive metal layer can also be made of one of the single metals such as nickel, iron, silver, etc., and the high-frequency shielding layer can also be made of one of the single metals such as copper, iron, silver, etc. or an alloy.

[0016] Furthermore, the low-frequency shielding layer plating solution comprises 20-240 g / L nickel sulfate, 10-60 g / L nickel chloride, 20-150 g / L ferrous sulfate, 10-100 g / L complexing agent, 10-60 g / L boric acid, 0.5-5 g / L saccharin, and 0.1-0.5 g / L sodium benzenesulfinate. The plating solution operating temperature is 30-80°C, and the pH value is 2-5.

[0017] The beneficial effect of the present invention is that in the application of the present invention, the electromagnetic shielding tape roll is cut into a certain length as required, and then the lower protective film is torn off and then bonded to the surface of the electronic equipment component to be shielded through the back adhesive layer. The present invention adopts a thin and flexible PTFE release film as a substrate. Compared with the existing aluminum-plastic film substrate, the PTFE release film has better flexibility and thinner thickness. The surface of the PTFE release film is coated with three metal layers by existing mature magnetron sputtering and electroplating industrial technology. The first layer is one of metals such as copper, nickel, iron, silver, etc. The second layer is one of metals such as copper, nickel, iron, silver, etc. or alloys. The third layer is an iron-nickel alloy layer (permalloy). The three metal layers are stacked layer by layer, thin in thickness, and can better cover the substrate without dead angles. The material itself can play a good role in shielding high-frequency and low-frequency electromagnetic radiation. The finished product is thin in thickness (not more than 0.6mm), flexible, not easy to break and break, and can be conveniently used in small electronic devices with narrow installation space, and can better fit the surface of irregularly shaped electronic components, achieving better high-frequency and low-frequency electromagnetic shielding effects, and ensuring the effective operation of electronic equipment. Based on the above, the present invention has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0019] Figure 1 It is a schematic diagram of a cross-sectional structure of the present invention. DETAILED DESCRIPTION

[0020] Figure 1 As shown in the figure, a flexible electromagnetic shielding tape with broadband shielding performance has an eight-layer structure, which includes, from top to bottom, an upper protective film 1, an upper adhesive layer 2, a third metal layer 3, a second metal layer 4, a first metal layer 5, a substrate layer 6, a lower adhesive layer 7, and a lower protective film layer 8; the first metal layer 5, the second metal layer 4, and the third metal layer 3 are respectively used as a conductive metal layer, a high-frequency shielding layer, and a low-frequency shielding layer, and the substrate layer 6 is a PTFE release film; the lower adhesive layer 7 is coated on the lower surface of the substrate layer 6, and the upper end of the lower protective film layer 8 is bonded to the lower surface of the lower adhesive layer 7; the first metal layer 5 is plated on The second metal layer 4 is plated on the upper surface of the first metal layer 5, and the third metal layer 3 is plated on the upper surface of the second metal layer 4; the upper adhesive layer 2 is coated on the upper surface of the third metal layer 3, and the lower end of the upper protective film layer 1 is bonded to the lower surface of the upper adhesive layer 2; after the upper protective film 1, the upper adhesive layer 2, the third metal layer 3, the second metal layer 4, the first metal layer 5, the substrate layer 6, the lower adhesive layer 7, and the lower protective film layer 8 are combined and formed in layers, the finished product as a whole is a flat strip structure, the finished product is wound into a ring shape, the upper and lower ends of the finished product are both in a flat and horizontal state, and the thickness is less than 0.6mm.

[0021] Figure 1 As shown in the figure, the thickness of the PTFE release film layer 6 is 0.05mm, and one of the PET release film, PE release film, and OPP release film can also be used. The upper adhesive layer 2 and the lower adhesive layer 7 are hot melt adhesives, and pressure sensitive adhesives can also be used. The thermosensitive adhesive is heated at room temperature and coated using the gluing process in the industrial field. The upper protective film 1 and the lower protective film layer 8 are self-adhesive paper protective paper films. The conductive metal layer 5 adopts the magnetron sputtering or vacuum evaporation process in the industrial field to coat copper on the upper surface of the substrate layer. The impedance of the copper-plated layer is less than 1.5Ω / □, the thickness is 600Å, and the current density is 400A / dm 2 The high-frequency shielding layer 4 is electroplated with nickel on the upper surface of the first metal layer 5 using an industrial electroplating process. The nickel-plated layer has an impedance of less than 2Ω / □, a thickness of 500Å, and a current density of 260A / dm 2 The low-frequency shielding layer 3 is electroplated on the upper surface of the second metal layer 4 with an iron-nickel alloy (Permalloy) using an industrial electroplating process. The impedance of the iron-nickel alloy layer 3 is less than 2.5Ω / □, the thickness is 500Å, and the current density is 300A / dm 2 . The conductive metal layer 5 can also be made of one of the single metals such as nickel, iron, silver, etc., and the high-frequency shielding layer 4 can also be made of one of the single metals such as copper, iron, silver, etc. or an alloy. The plating solution components of the low-frequency shielding layer 3 are nickel sulfate 20~240g / L, nickel chloride 10~60g / L, ferrous sulfate 20~150 g / L, complexing agent 10~100 g / L, boric acid 10~60 g / L, saccharin 0.5~5 g / L, sodium benzenesulfinate 0.1~0.5 g / L, the plating solution operating temperature is 30-80℃, and the pH value is 2~5.

[0022] Figure 1As shown in, in the application of the present invention, the electromagnetic shielding tape roll is cut to a certain length as needed, and then the lower protective film 8 is torn off and bonded to the surface of the electronic equipment component that needs to be shielded through the lower adhesive layer 7. The present invention adopts a thin and flexible PTFE release film 6 as a substrate. Compared with the existing aluminum-plastic film substrate, the PTFE release film 6 has better flexibility and thinner thickness; the present invention uses the existing mature magnetron sputtering and electroplating industrial technology to plate three layers of conductive metal layer 5, high-frequency shielding layer 4, and low-frequency shielding layer 3 on the substrate layer 6. The three metal layers are stacked layer by layer, with thin thickness, and can better cover the substrate layer 6 without dead angles. The finished product has a thin overall thickness (not exceeding 0.6mm), high flexibility, not easy to break and break, and greater bending. It can be conveniently used in small electronic equipment with narrow installation space, and can better fit the surface of irregularly shaped electronic components. The first metal layer 5 of the present invention is one of the single metals such as copper, nickel, iron, and silver. The copper of the first metal layer 5 makes the conductive direction of the first metal layer 5 not in a disordered state, and the conductive performance is stable. It can effectively shield the external electromagnetic wave interference signal and the electromagnetic signal generated by itself, ensuring the normal operation of the electronic equipment. The second metal layer 4 is one of the single metals such as copper, nickel, iron, and silver or an alloy. The above materials can play a good electromagnetic interference shielding effect in the high frequency band, ensuring that the electronic equipment can still work normally under the condition of electromagnetic interference in the high frequency band, and can prevent the high frequency electromagnetic signal generated by itself from affecting the operation of other electronic equipment. The third metal layer 3 is an iron-nickel alloy layer (permalloy), and the iron-nickel alloy layer can play a good electromagnetic interference shielding effect in the low frequency band, ensuring that the electronic equipment can still work normally under the condition of electromagnetic interference in the low frequency band, and can prevent the low frequency electromagnetic signal generated by itself from affecting the operation of other electronic equipment. The present invention uses the joint action of multiple metal layers to ensure that the electronic equipment using the present invention can achieve good high and low frequency electromagnetic interference shielding effects, and the thickness is thin, the flexibility is good, and the application area is wider.

[0023] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0024] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in the embodiments may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A flexible electromagnetic shielding tape with broadband shielding effectiveness, characterized in that It has an eight-layer structure, which are, from top to bottom, an upper protective film, an upper adhesive layer, a third metal layer, a second metal layer, a first metal layer, a substrate layer, a lower adhesive layer, and a lower protective film layer; the first metal layer, the second metal layer, and the third metal layer are respectively used as a conductive metal layer, a high-frequency shielding layer, and a low-frequency shielding layer, and the substrate layer is a PTFE release film; the lower adhesive layer is coated on the lower surface of the substrate layer, and the upper end of the lower protective film layer is bonded to the lower surface of the lower adhesive layer; the first metal layer is plated on the upper surface of the substrate layer, the second metal layer is plated on the upper surface of the first metal layer, and the third metal layer is plated on the upper surface of the second metal layer; the upper adhesive layer is coated on the upper surface of the third metal layer, and the lower end of the upper protective film layer is bonded to the lower surface of the upper adhesive layer; the upper protective film, the upper adhesive layer, the third metal layer, the second metal layer, After the first metal layer, the substrate layer, the lower adhesive layer and the lower protective film layer are combined and formed in layers, the finished product as a whole is a flat strip structure, the finished product is wound into a ring shape, the upper and lower ends of the finished product are both flat and horizontal, and the thickness is less than 0.6mm; the substrate layer can also use one of PET release film, PE release film, and OPP release film; the upper adhesive layer and the lower adhesive layer are hot melt adhesive, and can also use pressure sensitive adhesive; the upper protective film and the lower protective film layer are self-adhesive paper protective paper film; the conductive metal layer uses a copper-plated layer; the high-frequency shielding layer uses a nickel-plated layer; the low-frequency shielding layer uses an iron-nickel alloy layer; the conductive metal layer can also use one of the metal nickel, iron, and silver single metals, and the high-frequency shielding layer can also use one of the metal copper, iron, and silver single metals or alloys; the low-frequency shielding layer plating solution composition is nickel sulfate 20~240g / L, nickel chloride 10~60 g / L, ferrous sulfate 20~150 g / L, chelating agent 10~100 g / L, boric acid 10~60 g / L, saccharin 0.5~5 g / L, sodium benzenesulfinate 0.1~0.5 g / L, the plating solution operating temperature is 30-80℃, and the pH value is 2~5.

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