TWI631889B - Electromagnetic wave shielding composite film - Google Patents

Abstract

The electromagnetic wave shielding composite film of the present invention is characterized by a multi-layered absorption structure (Multi-Layered Absorbing Stack Structure), which at least includes: a reflective layer, a absorbing layer, and an incident layer, wherein the resistance of the absorbing layer is adopted. The value is higher than the resistance value of the reflective layer, which can guide the electromagnetic wave to escape back and forth between the absorbing layer and the reflective layer, promote the attenuation of the incident electromagnetic wave energy in the space, and reduce or eliminate the reflected electromagnetic wave. According to this, the electromagnetic wave shielding composite film of the present invention has a multilayer wave absorbing structure, which can prevent electromagnetic waves from interfering with adjacent circuits and components. In addition, the thickness of the multilayer wave absorbing structure is thin, which can meet the requirements of light circuit board, light weight Thin, flexible requirements.

Description

Electromagnetic wave shielding composite film

The invention relates to an electromagnetic wave shielding composite film, in particular to an electromagnetic wave shielding composite film having a multi-layered absorbing structure.

In order to meet the market demand for multifunctional electronic and communication products, the IC structure of circuit substrates needs to be lighter, thinner, shorter, and smaller; in terms of functions, it needs powerful and high-speed signal transmission. Therefore, the density of the number of I / O pins is bound to increase, and the number of IC pins must also increase. The distance between the IC carrier board lines is getting closer and closer, and the operating frequency is toward high-bandwidth, which makes the electromagnetic interference (EMI) situation between ICs more and more serious. Therefore, how to effectively manage electromagnetic compatibility ( Electromagnetic Compatibility (EMC), maintaining normal signal transmission of electronic products and improving reliability will become important issues.

In the market, the electromagnetic wave shielding composite film for flexible boards can be roughly divided into two types: conductive conductive paste (Conductive Paste) and conductive adhesive film (Conductive Adhesive Film) according to the construction method. In general, conventional printed circuit boards (hard boards) for electromagnetic wave interference protection measures mostly use conductive powders (such as silver, copper, nickel and other metals) to be added to polymer materials to form printed conductive pastes. Silver paste has excellent storage stability, and the electromagnetic wave shielding effect is the best among conductive metal materials, but the disadvantage is that the material cost is too high. Copper paste has good conductivity, and its electromagnetic wave shielding ability is second only to silver paste. However, the disadvantage is that the oxidation resistance is poor, and the surface of copper powder is very easy in the air. This produces copper oxide with poor conductivity. Compared with silver and copper paste, the electromagnetic shielding ability of nickel paste is much weaker, especially at frequencies lower than 30MHz, but its oxidation resistance is better than that of copper metal. The price of powder materials is also much cheaper than silver and copper metal. Therefore, it still has its product use; the current electromagnetic shielding materials used in flexible boards, because of the nickel paste compared to silver and copper paste to achieve good electromagnetic shielding characteristics need a thicker coating, so flexible board electromagnetic shielding materials Most still use silver and copper conductive paste. In the manufacturing process, printed conductive paste has the advantages of convenient processing, no conductive adhesive is required, and relatively low investment cost of equipment, but it still has many disadvantages that need to be improved, such as: flatness of conductive paste coating and film Thickness uniformity is not easy to control, and the output efficiency is low. In order to achieve better electromagnetic wave shielding benefits, a conductive paste of a certain thickness needs to be coated, resulting in sacrificing resistance to bending. In addition, suspicions of printed conductive layers with pores or delamination are limited to electromagnetic wave shielding in areas such as flexible board products or hard boards that do not require significant bending, that is, high-end flexible board related products are not suitable for use.

The second method of electromagnetic wave shielding composite film is vacuum sputtering or evaporation, which deposits a single layer of silver conductive metal film on the conductive adhesive film, thereby improving the conductive adhesive film to electromagnetic waves. Interference shielding capability. Considering the flexibility of the metal thin film material, material cost, and electromagnetic wave shielding ability, the thickness of the silver thin film is about 0.1 μm. The conductive adhesive film of the electromagnetic wave shielding film is mainly composed of conductive powder particles and a polymer material having a certain degree of curing cross-linking reaction B-stage. Generally used polymer materials are epoxy resin (Epoxy Resin), polyimide resin (Polyimide Resin), silicone resin (Silicon Resin) and so on. Considering material cost and manufacturing process, the polymer materials used in traditional conductive adhesive films are mostly composed of thermosetting epoxy materials. The resin material itself must have good adhesive strength, high temperature dimensional stability, and protect the flexible board from external chemicals and moisture. In addition to the basic functional characteristics of the film, such as the effects of solvents and environmental influences, in order to meet the processability of flexible board assembly and flexible board product characteristics, the reaction mechanism design of the resin material formula requires rapid low temperature curing (~ 150 ° C) and appropriate flow. Denaturation and excellent flexibility.

In addition to the electromagnetic wave shielding composite film produced by the conductive adhesive film method, in addition to continuous and rapid production, its biggest feature is that when it is used with a flexible board, it has excellent flexibility, superior mechanical adhesion and high reliability. Adhesive film is widely used in the industry in recent years. The conductive adhesive film can be appropriately cut according to the size of the electromagnetic wave shielding area, and then under rapid thermal compression conditions (150 ~ 170 ° C, 3 ~ 10min), the conductive particles in the conductive adhesive film are heat-pressed by the resin material. Deformation flow occurs, and then a conductive path is formed by contact with the ground trace on the flexible board. After a period of time, the resin is completely cross-linked and cured to maintain good electrical and physical properties and reduce the impedance of the ground trace on the flexible board. Value while reducing electromagnetic interference. Because the thickness of the metal thin film is between 0.1 and 1um, it can meet the flexural characteristics required for flexible boards, and meet the requirements of material cost and electromagnetic wave shielding benefits. It has superior bendability, mechanical properties, and reliability. However, this conductive adhesive film method has the disadvantages of relatively high R & D and equipment investment costs and inability to effectively shield low-frequency electromagnetic waves.

In view of the above-mentioned shortcomings, it is still urgent to develop an electromagnetic wave shielding composite film that can exhibit excellent full-band electromagnetic wave shielding effects, is suitable for thin design, and can reduce costs, in order to meet its needs when applied to flexible circuit boards.

The purpose of the present invention is to provide an electromagnetic wave shielding composite film, which uses a multi-layered wave absorbing structure to improve the full-wave electromagnetic wave shielding effect, and at the same time can reduce the cost of manufacturing an electromagnetic wave shielding film by a conductive adhesive film. Thickness, 俾 can be simplified with Soft circuit board integration process.

To achieve the above object, the present invention provides an electromagnetic wave shielding composite film including: an incident layer including a conductive filling material; a wave absorbing layer disposed on one side of the incident layer; and a reflective layer, It is arranged on the wave absorbing layer to sandwich the wave absorbing layer between the incident layer and the reflection layer, wherein the resistance value of the wave absorption layer is higher than the resistance value of the reflection layer.

According to this, the present invention sequentially stacks the absorbing layer and the reflective layer on the incident layer. The resistance value of the absorbing layer is higher than the resistance value of the reflecting layer, so the electromagnetic waves are guided back and forth to escape from the absorbing layer. Between the wave layer and the reflective layer, the energy of electromagnetic waves incident in space is attenuated, and the reflected electromagnetic waves are reduced or eliminated, thereby achieving a better full-wave electromagnetic shielding effect. In this way, the electromagnetic wave shielding composite film with the multilayer wave absorbing structure of the present invention is advantageous for thin design, so as to exhibit the flexural characteristics required for a flexible board.

In the present invention, the conductive filling material in the incident layer may be a graphene, wherein the graphene may be at least one single-layer graphene, at least one multi-layer graphene, or a mixture thereof, and the graphene is preferably a It is prepared by a chemical vapor deposition method (Chemical Vapor Deposition; CVD) or a mechanical exfoliation method (Mechanical Exfoliation), and the average thickness thereof may range from about 0.2 nm to 300 nm.

The shielding effect of carbon-based materials mainly depends on the surface reflection, and the structure of the graphene is more conducive to increasing the multiple reflection loss. In particular, the graphene is a layer-by-layer structure closely arranged in parallel, which passes through the layer-to-layer contact The conductive path is realized. Because of its large contact surface and low resistance, it has strong conductive ability, and can achieve excellent electromagnetic wave shielding effect. In addition, the area resistance value of the incident layer can be adjusted by changing the content ratio of the conductive filling material in the incident layer. For example, based on the total weight of the incident layer, the incident layer may include 0.5 to 80 Weight hundred The conductive filling material is proportioned to guide the electromagnetic wave incident into the electromagnetic wave shielding composite film as a whole to ensure that the electromagnetic wave can be introduced into the wave absorbing layer and the reflection layer from the grounded copper thin pad on the flexible circuit board. Here, the thickness of the incident layer may be 5 μm to 25 μm.

In the present invention, the incident layer further includes a polymer material, and the conductive filling material is coated on or mixed with the polymer material, and the polymer material is not particularly limited as long as it is It is sufficient to have the basic functional characteristics of the adhesive film without affecting the electromagnetic wave shielding effect. It is preferably a low-viscosity polymer material. Examples include thermoplastic plastic, thermosetting plastic, thermosetting rubber, thermoplastic viscoelastic body, or conductive polymer. More specifically, the polymer material can be selected from polyimide (PI), polyethylene (PE), epoxy resin (Epoxy), polyethylene terephthalate (PET), and polycarbonate (PC ), Polypropylene (PP), bismaleimide (BMI), and acrylic polymers, but not limited thereto. For example, specific embodiments of the present invention use epoxy resin, and specific examples include: bisphenol A epoxy resin, phenol novolac epoxy resin, glycidyl ether epoxy resin, and cresol novolac epoxy resin. Resins, glycidyl ester epoxy resin, glycidylamine epoxy resin, linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, various polyfunctional epoxy resins and halogenated epoxy resins Things, but not limited to this. The above epoxy resins can be used alone or in combination. Polyamide is used as the hardener in the epoxy resin system. Specific examples include: aromatic polyamines, dicyandiamide, acid anhydrides, and various novolac resins. , But not limited to this.

In the present invention, the incident layer may be optionally added with an appropriate amount of dispersant, which may be an alcohol dispersant, such as polyvinyl alcohol (Polyvinyl Alcohol; PVA), and polyethylene glycol (Polyethylene Glycol) with different molecular weights. PEG, MW = 200 ~ 10,000), Ethyl Alcohol, Ethylene Glycol, Propylene Glycol, Butylene Glycol, Butylene Glycol, Isopropyl Alcohol; IPA) or its derivative or mixture; anion dispersing agent, such as sodium oleate (C ₁₇ H ₃₃ COONa), carboxylate, sulfate (RO-SO ₃ Na), sulfonate (R-SO ₃ Na), sodium lauryl sulfate (SDS), or a derivative or mixture thereof, but is not limited thereto. In addition, the incident layer may further include a defoamer, and specific examples thereof include: organosiloxane, polyether, silicon and ether grafting, amines, imines, and amidines, etc., but is not limited to this.

In the present invention, the incident layer may be optionally added with an appropriate amount of an organic solvent (Organic Solution), such as acetone, methyl ethyl ketone, toluene, xylene, methyl isobutyl ketone, ethyl acetate, ethyl Glycol monomethyl ether, N, N-dimethylformamide, N, N-dimethylacetamide, methanol or ethanol, but it is not limited thereto, and the above organic solvents can be used alone or in combination.

In the present invention, the materials of the absorbing layer and the reflecting layer are preferably different metal materials, which can be independently selected from the group consisting of gold, silver, copper, iron, tin, lead, cobalt, chromium, aluminum, nickel, and alloys thereof. In at least one of the groups, the resistance values of the wave absorbing layer and the reflection layer can be adjusted by material selection and thickness control. For example, the wave absorbing layer can be adjusted to have a sheet resistance of 10 to 100 Ω / □, and the reflection layer has a sheet resistance of 0.2 Ω / □ or less, whereby the resistance value of the wave absorbing layer is higher than that of the reflection layer, thereby guiding The electromagnetic waves are scattered back and forth between the wave absorbing layer and the reflection layer, and the energy of electromagnetic waves incident in space is attenuated, and the reflected electromagnetic waves are reduced or eliminated, thereby achieving a better full-wave electromagnetic shielding effect. In addition, the formation method of the wave absorbing layer and the reflection layer is not particularly limited, and may be sequentially formed on the surface of the incident layer (for example, the wave absorbing layer) by, for example, chemical deposition, evaporation, sputtering, or other methods. The two opposite surfaces are respectively in contact with the incident layer and the reflective layer), and the thicknesses thereof may be 0.02 μm to 0.3 μm, respectively. As a result, since the reflective layer and the wave absorbing layer are very thin, the full-band electromagnetic wave from the electronic component can be quickly absorbed, so as to exhibit a better full-band electromagnetic wave. Shielding effect.

In the present invention, the electromagnetic wave shielding composite film may further include an insulating layer disposed on the reflective layer (that is, the reflective layer is located between the insulating layer and the wave absorbing layer), wherein the thickness of the insulating layer is It can be 1 micron to 5 micron, and the material of the insulating layer can be selected from polyimide (PI), polyethylene (PE), epoxy resin (Epoxy), polyethylene terephthalate (PET), and polyethylene. At least one of the group consisting of carbonate (PC), polypropylene (PP), bismaleimide (BMI), and acrylic polymers, but is not limited thereto. In addition, the electromagnetic wave shielding composite film may further include a release film and a transfer film, wherein the release film is disposed on the other side of the incident layer, and the transfer film is disposed on the insulating layer ( That is, the incident layer is located between the release film and the wave absorbing layer, and the insulating layer is located between the transfer film and the reflection layer) to protect the incident layer, the wave absorbing layer and the reflection layer from being affected. External environmental pollution (such as hydrolysis, dust, etc.), and the release film and the transfer film can be torn off when the electromagnetic wave shielding composite film is used. Here, the materials of the release film and the transfer film can be separated respectively. Independently selected from the group consisting of polyethylenimine, epoxy resin, polyethylene, polyethylene terephthalate, polycarbonate, polypropylene, bismaleimide, and acrylic polymers At least one of them can have a thickness of 30 to 150 microns.

In summary, in the present invention, the wave absorbing layer and the reflection layer having different resistance values are sequentially formed on the incident layer, so as to improve the shielding effect of electromagnetic waves in a full band, wherein the thickness of the wave absorbing layer and the reflection layer Below about 300 nanometers respectively (that is, the combined thickness of the absorbing layer and the reflective layer can be reduced to about 600 nanometers), the desired full-wave electromagnetic shielding effect can be achieved, which can greatly reduce costs and Conducive to thin design, can meet the requirements of light circuit board light weight, thin material, good flexibility, and can save the thickness of the protective film (Coverlay) when applied to the flexible circuit board, even without the protective film (Coverlay ) Case, use this electromagnetic shielding Composite film is helpful for simplifying the integration process with flexible circuit boards.

100‧‧‧electromagnetic wave shielding composite film

102‧‧‧ transfer film

104‧‧‧Insulation

106‧‧‧Reflective layer

108‧‧‧ Absorber

110‧‧‧ incident layer

112‧‧‧ release film

FIG. 1 is a sectional view of an electromagnetic wave shielding composite film according to a specific embodiment of the present invention.

FIG. 2 is a test result chart of the electromagnetic wave shielding composite film of Example 1 of the present invention.

FIG. 3 is a test result chart of the electromagnetic wave shielding composite film of Example 2 of the present invention.

FIG. 4 is a test result chart of the electromagnetic wave shielding composite film of Example 3 of the present invention.

FIG. 5 is a test result chart of the electromagnetic wave shielding composite film of Comparative Example 1 of the present invention.

FIG. 6 is a test result chart of the electromagnetic wave shielding composite film of Comparative Example 2 of the present invention.

The following is a description of specific embodiments of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the spirit of the present invention.

Please refer to FIG. 1, which is a sectional view of an electromagnetic wave shielding composite film in a specific embodiment of the present invention. As shown in FIG. 1, the electromagnetic wave shielding composite film 100 of the present invention includes a transfer film 102, an insulating layer 104, a reflective layer 106, a wave absorbing layer 108, an incident layer 110, and a release film 112 in this order from top to bottom. The method for preparing the electromagnetic wave shielding composite film of the present invention will be described in detail in Examples 1 to 3 below, and its electromagnetic wave shielding effect will be tested, and the test results will be compared with the electromagnetic wave shielding composite films of Comparative Examples 1 to 2.

<< Example 1 >>

The electromagnetic wave shielding composite film of this embodiment is completed by the following process steps: graphene is prepared by mechanical exfoliation, and its average thickness can range from about 0.2 nm to 300 nm, and then graphene (25 Weight percent), low viscosity polymer binder (40 weight percent epoxy resin), hardener (15 weight percent polyamide hardener), dispersant (0.5 weight percent anionic dispersant), organic solvent (19 Weight percent of methyl ethyl ketone, toluene and ethyl acetate mixed solvent) and auxiliary agent (0.5 weight percent of defoaming agent) are fully and uniformly mixed, and coated and dispersed on the surface of the PET release film 112 to form The conductive incident layer 110 has a thickness of about 15 micrometers. Then, a 50 nm-thick nickel-chromium alloy absorbing layer 108 and a 300 nm-thick copper metal reflective layer are sequentially formed on the surface of the incident layer 110 by sputtering. 106. In addition, a 5 micron-thick epoxy resin was coated on the PET transfer film 102, and the solvent was removed by baking at 80 ° C to form an insulating layer 104 and a transfer film 102. Finally, the insulating layer 104 and the transfer film 102 and the reflective layer 106 are adhered to each other, thereby manufacturing the electromagnetic wave shielding composite film 100 of this embodiment.

<< Example 2 >>

The electromagnetic wave shielding composite film of this embodiment is completed by the following process steps: graphene is prepared by mechanical exfoliation, and its average thickness can range from about 0.2 nm to 300 nm, and then graphene (25 Weight percent) with low viscosity polymer binder (40 weight percent epoxy resin), hardener (15 weight percent polyamide hardener), dispersant (0.5 weight percent anionic dispersant), organic solvent (19 Weight percent of methyl ethyl ketone, toluene and ethyl acetate mixed solvent) and auxiliary agent (0.5 weight percent of defoaming agent) are fully and uniformly mixed, and coated and dispersed on the surface of the PET release film 112 to form The conductive incident incident layer 110 has a thickness of about 15 micrometers. Then, a 50 nm-thick nickel-chromium alloy absorbing layer 108 and a 200 nm-thick silver metal layer are sequentially formed on the surface of the incident layer 110 by sputtering. 106. In addition, coating A 5 micron-thick epoxy resin was deposited on the PET transfer film 102, and the solvent was baked at 80 ° C to form an insulating layer 104 and the transfer film 102. Finally, the insulating layer 104 and the transfer film 102 and the reflective layer 106 were formed. By bonding to each other, the electromagnetic wave shielding composite film 100 containing graphene in this embodiment is manufactured.

"Example 3"

The electromagnetic wave shielding composite film of this embodiment is completed by the following process steps: graphene is prepared by mechanical exfoliation, and its average thickness can range from about 0.2 nm to 300 nm, and then graphene (25 Weight percent) with low viscosity polymer binder (40 weight percent epoxy resin), hardener (15 weight percent polyamide hardener), dispersant (0.5 weight percent anionic dispersant), organic solvent (19 Weight percent of mixed solvent of methyl ethyl ketone, toluene and ethyl acetate) and auxiliaries (0.5 weight percent of defoamer) are fully and uniformly mixed and coated on the surface of the PET release film 112 to form a highly conductive The incident layer 110 has a thickness of about 15 micrometers; then, a 50 nm-thick nickel-chromium alloy absorbing layer 108 and a 300 nm-thick aluminum metal reflective layer 106 are sequentially formed on the surface of the incident layer 110 by sputtering. In addition, a 5 micron-thick epoxy resin was coated on the PET transfer film 102, and the solvent was baked at 80 ° C to form an insulating layer 104 and a transfer film 102. Finally, the insulating layer 104 and the transfer film 102 and The reflective layers 106 are adhered to each other, thereby manufacturing the electromagnetic wave shielding composite film 100 containing graphene in this embodiment.

Comparative Example 1

The electromagnetic wave shielding composite film of this comparative example is substantially the same as that described in Example 1, except that the difference is only that no absorbing layer 108 is formed between the incident layer 110 and the reflective layer 106 of this comparative example, that is, this comparative example is directly A reflective layer 106 of copper metal having a thickness of 300 nm is formed on the surface of the incident layer 110.

Comparative Example 2

The electromagnetic wave shielding composite film of this comparative example is substantially the same as that described in Example 3, except that the difference is only that no absorbing layer 108 is formed between the incident layer 110 and the reflective layer 106 in this comparative example, that is, this comparative example is directly A reflective layer 106 of aluminum metal having a thickness of 300 nm is formed on the surface of the incident layer 110.

"Test case"

This test example uses the HP8722 Vector Network Analyzer, with a coaxial fixture, and in accordance with ASTM D4935-99 standard specifications, in the electromagnetic wave frequency range of 30 megahertz (MHz) to 3 gigahertz (GHz) The electromagnetic shielding effectiveness of the electromagnetic shielding composite films made in Examples 1 to 3 and Comparative Examples 1 to 2 was tested.

Accordingly, the test results of Examples 1 to 3 and Comparative Examples 1 to 2 are shown in FIGS. 2 to 6. The results show that Examples 1 to 3 can exhibit excellent electromagnetic shielding effects in each band (see FIGS. 2 to 2). 4), however, Comparative Examples 1 to 2 have almost no electromagnetic wave shielding effect at low frequencies (see Figs. 5 to 6). From this, it can be confirmed that the wave absorbing layer 108 provided between the incident layer 110 and the reflective layer 106 in the present invention with a resistance value greater than that of the reflective layer 106 can indeed greatly improve the electromagnetic wave shielding effect to exhibit an unexpectedly excellent effect. Therefore, the electromagnetic wave shielding composite film 100 of the present invention having a multilayer wave absorbing structure is particularly suitable for electromagnetic wave shielding on electronic devices, wires, and components, such as the electromagnetic shielding structure of a printed circuit board, and is particularly suitable as a structure for a flexible circuit board to resist electromagnetic interference.

The above embodiments are merely examples for the convenience of description. The scope of the claimed rights of the present invention should be based on the scope of the patent application, rather than being limited to the above embodiments.

Claims (13)

An electromagnetic wave shielding composite film includes: an incident layer including a conductive filling material; and a wave absorbing layer disposed on one side of the incident layer. The wave absorbing layer is a metal layer. The material is at least one selected from the group consisting of gold, silver, copper, iron, tin, lead, cobalt, chromium, aluminum, nickel, and alloys thereof; and a reflective layer disposed on the absorbing layer To sandwich the wave absorbing layer between the incident layer and the reflection layer, wherein the surface resistance value of the wave absorption layer is higher than the surface resistance of the reflection layer Wherein, the thickness of the absorbing layer is 0.02 μm to 0.3 μm; wherein the absorbing layer has a sheet resistance of 10 to 100Ω / □, and the reflective layer has a sheet resistance of 0.2Ω / □ or less. The electromagnetic wave shielding composite film according to item 1 of the scope of patent application, wherein the material of the reflective layer is selected from the group consisting of gold, silver, copper, iron, tin, lead, cobalt, chromium, aluminum, nickel, and alloys thereof. At least one of them. The electromagnetic wave shielding composite film according to item 1 of the scope of patent application, wherein the thickness of the reflective layer is 0.02 μm to 0.3 μm. The electromagnetic wave shielding composite film according to item 1 of the patent application scope, wherein the conductive filling material is a graphene. The electromagnetic wave shielding composite film according to item 4 of the scope of patent application, wherein the graphene is at least one single-layer graphene, at least one multi-layer graphene, or a mixture thereof. The electromagnetic wave shielding composite film according to item 4 of the scope of patent application, wherein the average thickness of the graphene is 0.2 nm to 300 nm. The electromagnetic wave shielding composite film according to item 1 of the scope of patent application, wherein the content of the conductive filling material is 0.5 to 80 weight percent of the total weight of the incident layer. The electromagnetic wave shielding composite film according to item 1 of the patent application scope, wherein the incident layer further comprises a polymer material, and the conductive filling material is coated on the polymer material or mixed in the polymer material. The electromagnetic wave shielding composite film according to item 8 of the scope of patent application, wherein the polymer material is selected from polyimide (PI), polyethylene (PE), epoxy resin (Epoxy), and polyethylene terephthalate. At least one of the group consisting of diester (PET), polycarbonate (PC), polypropylene (PP), bismaleimide (BMI), and acrylic polymers. The electromagnetic wave shielding composite film according to item 1 of the scope of the patent application, wherein the thickness of the incident layer is 5 μm to 25 μm. The electromagnetic wave shielding composite film according to item 1 of the scope of patent application, further comprising: a release film, which is disposed on the other side of the incident layer, and the incident layer is located on the release film and the absorbing layer between. The electromagnetic wave shielding composite film according to item 1 of the scope of the patent application, further comprising: an insulating layer disposed on the reflective layer, and the reflective layer is located between the insulating layer and the wave absorbing layer. The electromagnetic wave shielding composite film according to item 12 of the patent application scope further comprises: a transfer film, which is disposed on the insulating layer, and the insulating layer is located between the transfer film and the reflective layer.