TWI671339B - High-shielding colored ultra-thin cover film and the preparation method thereof - Google Patents

Abstract

A high-shielding colored ultra-thin cover film and a preparation method thereof. The high-shielding colored ultra-thin cover film includes a colored adhesive layer with a thickness of 3 to 25 microns, and at least one colored ink layer with a thickness of 1 to 10 microns. Is formed on the colored adhesive layer, wherein the transmittance of the cover film is 0.2 to 12.3%, the thickness of the colored adhesive layer and the colored ink layer is 4 to 35 microns, and the colored adhesive layer is Including pigments and resin materials, the pigments account for 2 to 50 weight percent of the total solids content of the colored adhesive layer, the resin materials account for 40 to 90 weight percent of the total solids content of the colored adhesive layer; the colored ink layer includes pigments and For resin materials, the pigment accounts for 2 to 50 weight percent of the total solids content of the colored ink layer.

Description

High-shielding colored ultra-thin cover film and preparation method

The invention relates to a cover film for a flexible printed circuit board (FPC) and a preparation method thereof, and more particularly, to a highly shielding colored ultra-thin cover film and a preparation method thereof.

In response to the development of thin and light electronic products in the market, in the production of flexible printed circuit multilayer boards, in order to reduce the thickness of flexible board materials, ultra-thin cover film products are designed according to demand. The common black cover film on the market uses black polyimide film. In the thin design, the bottleneck is that it is difficult to make a black polyimide film with a thickness of less than 5 microns, and the processing operability is not good; The use of epoxy-based adhesives has poor ionic purity, poor electrical properties, and high costs, which make it difficult to cope with the current trend of ultra-fine line and high-frequency and high-speed transmission.

In industrial design, for the requirements of circuit design not to be exposed, beautiful, visual protection, etc., for ultra-thin cover film (polyimide film thickness 7.5 micron) has demand, but the black polyimide manufacturers on the market are mainly casting process. In order to reduce the thickness of the film, when the thickness is designed to be 5 to 7.5 micron, the general technical indicators can not meet the requirements of industry specifications. For example, TW201132714 A1 discloses a low-gloss black polyfluorene imide film doped with ceramic powder, TW1481646 B discloses a low-gloss polyfluorene imine film doped with powder polyimide, and KR10-2012-0036253 discloses A black polyfluorene imide film doped with carbon black. However, in the above patents, it is not easy to achieve an ultra-thin polyimide film with a thickness of 5 to 7.5 microns.

Therefore, the industry urgently needs to develop a novel colored ultra-thin cover film to solve the aforementioned problems.

In order to meet the requirements of the current thin line design and meet the requirements of high shielding, and to meet the excellent ion mobility, extremely high ion purity, good adhesion, low rebound force, high flexibility, low temperature processing, high heat dissipation, The development direction of high flame retardancy, high hardness, and low cost, as well as functionally meeting the needs of high-density assembly and ultra-fine wiring, the present invention provides a highly shielding ultra-thin colored cover film.

The invention provides a colored ultra-thin cover film with high shielding property, which includes: a colored adhesive layer with a thickness of 3 to 25 microns, including a pigment and a resin material, and the pigment accounts for 2 to 2 of the total solid content of the colored adhesive layer. 50 weight percent, the resin material accounts for 40 to 90 weight percent of the total solids content of the colored adhesive layer; and at least one colored ink layer having a thickness of 1 to 10 microns is formed on the colored adhesive layer, and the The colored ink layer includes a pigment and a resin material, the pigment accounts for 2 to 50 weight percent of the total solids content of the colored ink layer; wherein the transmittance of the cover film is 0.2 to 12.3%; and the colored adhesive layer and the colored The thickness of the ink layer is 4 to 35 microns.

Preferably, the thickness of the colored adhesive layer is 3 to 10 micrometers. The thickness of the color ink layer is 1 to 3 microns.

In a specific embodiment, the dielectric constant (Dk value) of the colored adhesive layer is 2.4 to 10.0, the dielectric loss (Df value) is 0.002 to 0.080, the water absorption rate is 0.03 to 3%, and the line insulation The impedance is greater than 10 ¹¹ Ω (ohm), the surface resistance is greater than 10 ¹² Ω (ohm), and the volume resistance is greater than 10 ¹³ Ω˙cm (ohm˙cm).

In a specific embodiment, the pigments of the colored adhesive layer and the colored ink layer independently include an inorganic pigment or an organic pigment; wherein the inorganic pigment is selected from the group consisting of cadmium red, cadmium lemon yellow, orange cadmium yellow, titanium dioxide, carbon At least one of the group consisting of black, black iron oxide, and black complex; and the organic pigment is selected from the group consisting of aniline black, perylene black, anthraquinone black, benzidine yellow pigment, phthalocyanine blue, and phthalocyanine green At least one of the group.

In a specific embodiment, the colored ink layer includes at least one of the group consisting of inorganic powder, organic powder, and flame retardant compound, wherein the inorganic powder system includes a member selected from calcium sulfate, dioxide At least one of the group consisting of silicon, zinc sulfide, zirconia, calcium carbonate, boron nitride, aluminum hydroxide, talc, aluminum nitride, glass powder, quartz powder, corundum and clay. The organic powder system is polymerized. Imine-based compounds, and the flame-retardant compounds include at least one selected from the group consisting of halogen-containing compounds, phosphorus-based compounds, nitrogen-based compounds, and boron-based compounds, wherein the silicon dioxide, talc The sum of the proportions of powder, calcium carbonate, glass powder, and quartz powder is 1 to 50 weight percent of the total solids content of the colored ink layer, and the proportion of the flame-retardant compound of the phosphorous compound is the total solids content of the colored ink layer. The content is 1 to 40 weight percent.

Preferably, when higher hardness is required, the powder in the colored ink layer is preferably selected from silicon dioxide. When higher flame resistance is considered, aluminum hydroxide, aluminum oxide, calcium carbonate, and phosphorous are preferably selected. At least one of the group consisting of flame retardant compounds of compounds, flame retardant compounds containing halogens, flame retardant compounds of nitrogen compounds, and flame retardant compounds of boron compounds, and generally, powder The higher the body content, the better the flame resistance.

In a specific embodiment, the colored adhesive layer includes at least one selected from the group consisting of inorganic powder, organic powder, and flame retardant compound, wherein the inorganic powder system includes one selected from calcium sulfate, two At least one of the group consisting of silicon oxide, zinc sulfide, zirconia, calcium carbonate, boron nitride, aluminum hydroxide, talc, aluminum nitride, glass powder, quartz powder, corundum and clay, the organic powder system A polyimide-based compound and the flame-retardant compound include at least one selected from the group consisting of a halogen-containing compound, a phosphorus-based compound, a nitrogen-based compound, and a boron-based compound, wherein the silicon dioxide, The sum of the proportions of talc, calcium carbonate, glass powder, and quartz powder is 1 to 50 weight percent of the total solids content of the colored ink layer, and the proportion of the flame-retardant compound of the phosphorous compound is the total of the colored ink layer. 1 to 50 weight percent solids.

In a specific embodiment, the method further includes another colored ink layer formed between the colored ink layer and the colored adhesive layer, and the thickness of the colored ink layer and the other colored ink layer is 2 to 3 microns.

In a specific embodiment, the colored ultra-thin cover film includes an auxiliary adhesive layer, which is formed between the colored ink layer and the colored adhesive layer, and the auxiliary adhesive layer has a thickness of 3 to 25 microns.

In a specific embodiment, the thickness sum of the colored ink layer and the colored adhesive layer is 4 to 7 microns.

In a specific embodiment, the release layer includes an upper release layer and a lower release layer. The upper release layer is a matting release film layer and is in contact with the colored ink layer. The surface roughness (Rz value) of the surface of the upper release layer is 0.1 to 10 microns.

In a specific embodiment, the upper release layer and the lower release layer may also be release paper.

In a specific embodiment, the surface hardness of the colored ink layer is 2H to 5H.

In a specific embodiment, the resin material is an epoxy resin, an acrylic resin, a urethane resin, a silicone rubber resin, a parylene resin, a bismaleimide resin, At least one of the group consisting of a polyimide resin and a polyimide.

In a specific embodiment, the resin material in the upper release layer and the lower release layer is at least one selected from the group consisting of polypropylene, biaxially oriented polypropylene, and polyethylene terephthalate.

The invention further provides a method for preparing a high-shielding colored ultra-thin cover film, which comprises: coating a colored ink raw material on the surface of the upper release layer, and curing the colored ink raw material at 50 to 180 ° C. to form a colored ink. A colored adhesive layer is formed on the surface of the colored ink layer by a coating method or a transfer method; and a lower release layer is adhered on the surface of the colored adhesive layer.

In a specific embodiment, the highly shielding colored ultra-thin cover film The preparation method includes forming another colored ink layer on the surface of the colored ink layer before forming the colored adhesive layer.

In a specific embodiment, the method for preparing the highly-shielding colored ultra-thin cover film includes forming an auxiliary adhesion layer on the surface of the colored ink layer after forming the colored ink layer.

According to the present invention, the system has at least the following advantages:

1. In the present invention, a colored ink layer is matched with a colored adhesive layer, and the pigment added in the colored adhesive layer occupies 2 to 50% by weight of the total solid content of the colored adhesive layer, so as to adjust the light transmittance of the cover film and make the cover The light transmittance of the film reaches 0.2 to 12.3%, and the light transmittance is extremely low, that is, the covering property is excellent. Therefore, the covering film of the present invention has better shielding property; and the colored haze colored ultra-thin high-frequency covering is also known. The film has good electrical properties, but after the colored ink layer is dyed, the color uniformity is poor and it is easy to transmit light, that is, its shielding property is not ideal, and its manufacturing process is difficult, the reject rate is high, and it is not easy to mass-produce. The addition of colored pigments in the colored ink layer completely overcomes the problem of poor color uniformity of the colored ink layer. It is not easy to transmit light, has high shielding properties, and has an easy manufacturing process, high yield, and easy mass production.

2. Both the colored ink layer and the colored adhesive layer of the present invention may contain at least one of inorganic powder, organic powder and flame retardant compound, and silicon dioxide, talc, calcium carbonate, glass powder and The sum of the proportion of the quartz powder is 1 to 50% by weight of the total solids content of the colored ink layer, and the ratio of the flame retardant compound of the phosphorus-based compound is 1 to 40% by weight of the total solids content of the colored ink layer. Silicon dioxide, talc The sum of the proportions of powder, calcium carbonate, glass powder and quartz powder is 1 to 50 weight of the total solids content of the colored adhesive layer. Percentage, the proportion of flame-retardant compounds of phosphorus-based compounds is 1 to 50 weight percent of the total solids content of the colored adhesive layer, and the formula is reasonable to make it meet excellent ion mobility, extremely high ion purity, good adhesion, Low rebound force, high flexibility, low temperature processability, high heat dissipation, and high flame retardancy.

3. The sum of the thicknesses of the colored ink layer and the colored adhesive layer of the present invention can reach a minimum of 4 to 7 micrometers, and the thickness of the cover film is ultra-thin, which can meet the current design requirements for thinned lines of flexible printed circuit boards and adapt to the fourth Requirements for modern electronic products.

4. If higher hardness, mechanical strength and indirect stress are required, the present invention can add an auxiliary adhesive layer between the colored ink layer and the colored adhesive layer. The thickness of the auxiliary adhesive layer is 3 to 25 microns. Effectively increase the adhesion between the colored ink layer and the colored adhesive layer, and improve the overall hardness and mechanical strength of the product.

5. The present invention can adopt a two-layer ink method, that is, the colored ink layer includes a colored ink layer and another colored ink layer. A plurality of ink layers can solve the problem of micropores in the coating process and improve the yield rate of the process.

6. The powder is added to the colored ink layer of the present invention, and the hardness is 2H to 5H. Therefore, the cover film of the present invention not only has a matte property, but also has high hardness, which can prevent surface scratches, and is not easily affected by chemistry in the downstream process. The reagent is corrosive and has good weather resistance. In addition, the pigment in the colored adhesive layer is sufficient to ensure the covering property of the cover film. Therefore, the powder content in the colored ink layer can be adjusted by adjusting the high shielding property of the cover film. To obtain the required haze.

7. The surface of the colored ink layer of the present invention uses a matting release film layer, which The surface Rz (roughness) is 0.1 to 10 microns. Through this form, the colored ink layer and the release layer of the cover film are easily separated, thereby greatly improving the operability of the downstream terminal, and the extinction release film layer makes the cover film After the rapid compression molding, the release film layer is peeled off, which helps the surface morphology of the colored ink layer to be matte.

8. The invention has a lower rebound force and is suitable for downstream high-density assembly processes.

100‧‧‧ upper release layer

200‧‧‧ colored ink layer

201‧‧‧ colored ink layer

202‧‧‧Another colored ink layer

300‧‧‧ colored adhesive layer

400‧‧‧ lower release layer

500‧‧‧ auxiliary bonding layer

The embodiments of the present invention will be described by way of example with reference to the accompanying drawings: FIG. 1 is a schematic diagram of the structure of a highly shielding colored ultra-thin cover film with a colored ink layer of the present invention; and FIG. 2 is a two-layer colored with the present invention The schematic diagram of the structure of the highly-shielding colored ultra-thin cover film of the ink layer; and FIG. 3 is a schematic diagram of the structure of the highly-shielding colored ultra-thin cover film with an auxiliary adhesive layer of the present invention.

The following is a description of specific embodiments of the present invention. Those skilled in the art can easily understand the advantages and effects of the present invention from the content disclosed in this specification.

It should be noted that the structures, proportions, sizes, etc. shown in the drawings in this specification are only used to match the content disclosed in the specification for the understanding and reading of those skilled in the art, and are not intended to limit the implementation of the present invention. The qualifications are not technically meaningful. Any modification of the structure, the change of the proportional relationship, or the adjustment of the size will not affect the functions that can be produced by the present invention. Under the effect and the purpose that can be achieved, it should still fall within the scope of the technical content disclosed in the present invention. At the same time, the references such as “一”, “下” and “上” in this specification are for clarity only, and are not intended to limit the scope of the present invention. Substantially changing the technical content should also be regarded as the scope in which the present invention can be implemented. In addition, all ranges and values herein are inclusive and combinable. Any value or point that falls within the range described herein, for example, any integer can be used as the minimum or maximum value to derive the lower range, etc.

In order to solve the above-mentioned bottleneck of thinning thin film produced by black polyimide manufacturers, the colored polyimide cover film was replaced with a colored ultra-thin cover film composed of a colored ink layer and a colored adhesive. Among them, the colored ink layer can be obtained by changing the resin or doped powder and other methods, and through the powder content ratio improvement, particle size design, etc., to obtain high flame retardancy, high ionic purity, high hardness and other advantages of the ink layer. Among them, colored adhesives can also be used to improve the resin type, add powder, and other methods, and also through the powder content ratio, powder type, particle size design and other differences, to obtain high flame retardant, high ionic purity and other advantages of the adhesive . The prepared colored ultra-thin cover film has excellent ion mobility, excellent adhesion, low rebound force, high flexibility, low temperature processing, high heat dissipation, high hardness, excellent heat resistance, dimensional stability, and excellent electrical properties. The invention uses the composition of a colored ultra-thin ink layer and a colored adhesive to achieve a high shielding effect, and is particularly suitable for use in high-density assembled ultra-fine lined circuits with line width and line spacing below 35/35 microns. . In addition, in mobile phones and computers, heat dissipation performance is a major indicator, such as in the field of wireless charging, and the ultra-thin cover film design of the present invention also has excellent heat dissipation.

As shown in FIG. 1, it shows a specific embodiment of the highly shielding colored ultra-thin cover film of the present invention, which includes: a colored adhesive layer 300 having a thickness of 3 to 25 microns; and at least one layer having a thickness of 1 to A 10 micron colored ink layer 200 is formed on the colored adhesive layer 300; wherein the transmittance of the cover film is 0.2 to 12.3%; the sum of the thicknesses of the colored adhesive layer and the colored ink layer 4 to 35 microns; the colored adhesive layer includes a pigment and a resin material, the pigment accounts for 2 to 50% by weight of the total solids content of the colored adhesive layer, and the resin material accounts for 40 to 50% of the total solids content of the colored adhesive layer 90% by weight; and the colored ink layer includes a pigment and a resin material, and the pigment accounts for 2 to 50% by weight of the total solids content of the colored ink layer.

In this embodiment, the colored ink layer 200 is a single layer, and the sum of the thicknesses of the colored adhesive layer 300 and the colored ink layer 200 is 4 to 35 microns.

In a specific embodiment, the surface hardness of the colored ink layer 200 is 2H to 5H.

Preferably, the sum of the thicknesses of the colored ink layer 200 and the colored adhesive layer 300 is 4 to 7 microns.

Preferably, the thickness of the colored adhesive layer 300 is 3 to 10 microns, and the thickness of the colored ink layer 200 is 1 to 3 microns.

The colored adhesive layer 300 has a dielectric constant (Dk value) of 2.4 to 10.0, a dielectric loss (Df value) of 0.002 to 0.080, a water absorption rate of 0.03 to 3%, and an insulation resistance between the wires is greater than 10 ¹¹ Ω (ohm ), The surface resistance is greater than 10 ¹² Ω (ohm), and the volume resistance is greater than 10 ¹³ Ω˙cm (ohm˙cm).

The pigments of the colored adhesive layer and the colored ink layer independently include an inorganic pigment or an organic pigment; wherein the inorganic pigment is selected from the group consisting of cadmium red, cadmium lemon yellow, orange cadmium yellow, titanium dioxide, carbon black, black iron oxide, and black tint. And at least one organic pigment selected from the group consisting of aniline black, perylene black, anthraquinone black, benzidine yellow pigment, phthalocyanine blue, and phthalocyanine green.

In a specific embodiment, preferred pigments are black pigments (carbon black, black iron oxide, black complex, nigrosine, perylene black, or anthraquinone black) and white pigments (titanium dioxide), but are not limited thereto. Pigments of other colors are also possible.

In a specific embodiment, the colored ink layer 200 includes at least one selected from the group consisting of inorganic powder, organic powder, and flame retardant compound; wherein the inorganic powder system includes one selected from calcium sulfate, two At least one of the group consisting of silicon oxide, zinc sulfide, zirconia, calcium carbonate, boron nitride, aluminum hydroxide, talc, aluminum nitride, glass powder, quartz powder, silicon carbide, and clay; the organic powder system A polyimide-based compound; and the flame-retardant compound includes at least one selected from the group consisting of a halogen-containing compound, a phosphorus-based compound, a nitrogen-based compound, and a boron-based compound; wherein the silicon dioxide, The sum of the proportions of talc, calcium carbonate, glass powder, and quartz powder is 1 to 50 weight percent of the total solids content of the colored ink layer, and the proportion of the flame-retardant compound of the phosphorus-based compound is the total of the colored ink layer. 1 to 40 weight percent solids.

Preferably, when higher hardness is required, the powder in the colored ink layer 200 is preferably selected from silicon dioxide. When higher flame resistance is considered, hydrogen is preferably selected. Alumina, alumina, calcium carbonate, phosphorus-based compounds, flame-retardant compounds, halogen-containing flame-retardant compounds, nitrogen-based compounds, flame-retardant compounds, and boron-based compounds At least one of the groups, and generally, the higher the powder content, the better the flame resistance.

In a specific embodiment, the colored adhesive layer includes at least one of the group consisting of inorganic powder, organic powder, and flame retardant compound; wherein the inorganic powder system includes a member selected from the group consisting of calcium sulfate and carbon. At least one of the group consisting of black, silicon dioxide, zinc sulfide, zirconia, calcium carbonate, boron nitride, aluminum hydroxide, talc, aluminum nitride, glass powder, quartz powder, corundum and clay; the An organic powder system polyimide-based compound; and the flame-retardant compound system includes at least one selected from the group consisting of a halogen-containing compound, a phosphorus-based compound, a nitrogen-based compound, and a boron-based compound; wherein the two The sum of the proportions of silica, talc, calcium carbonate, glass powder, and quartz powder is 1 to 50 weight percent of the total solids content of the colored ink layer, and the proportion of the flame-retardant compound of the phosphorus-based compound is the colored 1 to 50 weight percent of the total solids content of the ink layer.

In addition, the highly shielding colored ultra-thin cover film includes a release layer, which includes an upper release layer 100 and a lower release layer 400, and the upper release layer 100 is a matting release film layer, and The surface roughness (Rz value) of the surface of the upper release layer 100 that the colored ink layer 200 contacts is 0.1 to 10 microns.

In a specific embodiment, the upper release layer 100 and the lower release layer 400 may also be release paper.

The resin material is an epoxy resin, an acrylic resin, a urethane resin, a silicone rubber resin, a parylene resin, At least one of the group consisting of maleimide resin, polyimide resin, and polyimide.

As for the resin material in the upper release layer 100 and the lower release layer 400, it is at least one selected from the group consisting of polypropylene, biaxially oriented polypropylene, and polyethylene terephthalate.

As shown in FIG. 2, it shows a highly shielding colored ultra-thin cover film formed with two colored ink layers. The two colored ink layers are a colored ink layer 201 and another colored ink layer 202, respectively. The other colored ink layer 202 is formed between the one colored ink layer 201 and the colored adhesive layer 300, and the thickness of the one colored ink layer 201 and the other colored ink layer 202 is 2 to 3 microns.

In this embodiment, the composition and ratio of the one colored ink layer 201 and the other colored ink layer 202 can refer to the composition and ratio of the aforementioned single colored ink layer.

In order to obtain the highly-shielding colored ultra-thin cover film of this embodiment, the manufacturing process can refer to the aforementioned manufacturing method. The difference is that after forming one colored ink layer 201, the other colored ink layer 202 is formed.

As shown in FIG. 3, the highly shielding colored ultra-thin covering film including the auxiliary adhesive layer 500 is shown. The difference from the highly shielding colored ultra-thin covering film shown in FIG. 1 is that the highly shielding colored ultra-thin covering film The thin cover film includes an auxiliary adhesive layer 500 formed between the colored ink layer 200 and the colored adhesive layer 300, and the auxiliary adhesive layer 500 has a thickness of 3 to 25 microns.

In order to obtain the highly shielding colored ultra-thin cover film of this specific implementation mode, the manufacturing process can refer to the specific implementation mode shown in Fig. 1. The difference lies in this A specific embodiment includes forming an auxiliary adhesive layer 500 on the surface of the colored ink layer 200 after forming the colored ink layer 200, and then forming a colored adhesive layer 300.

The auxiliary adhesive layer system includes epoxy resin (TC-K901 resin of Wanqian Chemical Co., Ltd.), curing agent (phthalic anhydride of Zhenggao Chemical Co., Ltd.), and filler powder (Dongguan Zhongtai Chemical Import & Export Co., Ltd. Co., Ltd.'s titanium dioxide), rubber (Nitrile butadiene rubber of Japan JSR Co., Ltd.), and solvents, wherein the amount of the curing agent added is 0.1 to 0.3% by weight of the solid content of the epoxy resin main agent, and the filler powder is added The amount is 5 to 10 weight percent of the total solids content, the rubber added amount is 10 to 15 weight percent of the total solids content, and the solvent is added to the 5 to 10 weight percent of the total solids content.

The invention further provides a method for preparing a high-shielding colored ultra-thin cover film, which comprises: coating a colored ink raw material on the surface of the upper release layer, and curing the colored ink raw material at 50 to 180 ° C. to form a colored ink. A colored adhesive layer is formed on the surface of the colored ink layer by a coating method or a transfer method; and a lower release layer is adhered on the surface of the colored adhesive layer.

In a specific embodiment, the method for preparing the highly-shielding colored ultra-thin cover film includes forming another colored ink layer on the surface of the colored ink layer before forming the colored adhesive layer.

In a specific embodiment, the method for preparing the highly-shielding colored ultra-thin cover film includes forming an auxiliary adhesion layer on the surface of the colored ink layer after forming the colored ink layer.

Table 1 shows the specific stacking structure and basic properties of the colored adhesive layer and the colored ink layer of Examples A1 to A8. The results are as follows.

Thermal conductivity coefficient of the present invention 0.05W / (m. ℃), heat resistance value 1.5 ℃ * cm ² / W, breakdown voltage resistance 0.5KV and the insulation resistance between the wires is> 10 ⁸ Ω / KV.

In Table 1, the colored ink layer system includes a polyimide compound, a curing agent (phthalic anhydride of Zhenggao Chemical Co., Ltd.), carbon black, and silicon dioxide, wherein the amount of the curing agent added is polymerized. 0.1% by weight of the main imine, the added amount of the carbon black is 7.83% by weight of the total solid content, and the added amount of silicon dioxide is 6.34% by weight of the total solid content; the other colored ink layer and the first The composition of the colored ink layer is the same.

The colored adhesive layer system includes a polyimide compound, a curing agent, an epoxy resin, and a filler powder, wherein the addition amount of the curing agent is 0.1% by weight of the main polyimide agent, and the amount of the epoxy resin. The added amount is 2.4% by weight of the total solid content, and the added amount of the filler powder is 6.3% by weight of the total solid content; the curing agent is phthalic anhydride purchased from Zhenggao Chemical Co., Ltd .; the epoxy resin is TC-K901 type resin purchased from Wanqian Chemical Co., Ltd .; and the filler powder system was purchased from Dongguan China Titanium Chemical Import and Export Co., Ltd. titanium dioxide (TiO ₂ ).

The auxiliary adhesive layer includes epoxy resin, curing agent, filler powder, rubber, and solvent. The amount of the curing agent added is 0.21 weight percent of the solid content of the epoxy resin main agent, and the amount of the filler powder is added. 6.3% by weight of the total solids content and 12.4% by weight of the total solids content; the epoxy resin is a TC-K901 resin purchased from Wanqian Chemical Co., Ltd .; the curing agent is purchased from Zhenggao Phthalic anhydride of Chemical Co., Ltd .; the rubber is a nitrile rubber purchased from Japan JSR Corporation; and the filler powder system is titanium dioxide (TiO ₂ ) purchased from Dongguan China Titanium Chemical Import & Export Co., Ltd.

Table 2 shows the pigment addition and performance indicators of Examples B1 to B23 and Comparative Examples of the present invention. In each of the Examples and Comparative Examples, a single colored ink layer is included, and the thickness of the colored ink layer is Both are 5 microns, and the thickness of the colored adhesive layer is 10 microns.

Note: 1. Titanium dioxide in Table 2 is a white pigment.

2. The black pigment in Table 2 is one or more of black iron oxide or black complex, aniline black, perylene black, and anthraquinone black.

In a specific embodiment, the black pigment system includes black iron oxide, black complex, aniline black, and titanium black. In Table 1, the addition amount of the black iron oxide is 50% by weight of the total solid content of the black pigment, the addition amount of the black complex is 15% by weight of the total solid content of the black pigment, and the addition amount of the aniline black is The total solid content of the black pigment is 25% by weight, and the added amount of the titanium black is 10% by weight of the total solid content of the black pigment.

It can be seen from Table 2 that the colored adhesive layer of the example contains a colored pigment, and the colored adhesive layer of the comparative example does not contain a colored pigment. The transmittance of the embodiment is significantly lower than that of the comparative example, that is, it contains The maskability of the cover film of the colored adhesive layer is significantly better than that of the cover film of the ordinary adhesive layer (which does not contain a color pigment).

As can be seen from Tables 1 and 2, the colored ultra-thin cover film provided by the present invention is composed of a colored ink layer and a colored adhesive layer, and the upper and lower release layers can be attached to the upper and lower layers, respectively. Stack thickness, high heat dissipation, high flame retardancy, surface gloss adjustment, high shielding, especially suitable for use in ultra-fine line, the application of black colored ink layer and black colored adhesive layer is particularly applicable It protects the shielding property of the circuit, which can replace the black polyfluorene imide film which is costly and has technical problems.

The above-mentioned embodiments are merely illustrative and not intended to limit the present invention. Anyone skilled in the art can modify and change the above embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the rights of the present invention is defined by the scope of the patent application attached to the present invention, as long as it does not affect the effect and implementation purpose of the present invention, it should be covered in this disclosed technical content.

Claims (12)

A colored, ultra-thin covering film with high shielding properties, comprising: a colored adhesive layer having a thickness of 3 to 25 microns, including a pigment and a resin material, the pigment accounting for 2 to 50% by weight of the total solid content of the colored adhesive layer, The resin material accounts for 40 to 90 weight percent of the total solids content of the colored adhesive layer; and at least one colored ink layer having a thickness of 1 to 10 microns is formed on the colored adhesive layer, and the colored ink layer includes Pigments and resin materials, the pigments accounting for 2 to 50 weight percent of the total solids content of the colored ink layer; wherein the transmittance of the cover film is 0.2 to 12.3%; and the thickness of the colored adhesive layer and the colored ink layer Sum is 4 to 35 microns. The high-shielding colored ultra-thin cover film according to item 1 of the scope of the patent application, wherein the dielectric constant (Dk value) of the colored adhesive layer at a measurement frequency of 10 GHz is 2.4 to 10.0, and the dielectric loss (Df Value) is 0.002 to 0.080, water absorption is 0.03 to 3%, insulation resistance between wires is greater than 10 ¹¹ Ω (ohms), surface resistance is greater than 10 ¹² Ω (ohms), and volume resistance is greater than 10 ¹³ Ω˙cm (ohms˙ Cm). The highly-shielding colored ultra-thin cover film according to item 1 of the scope of patent application, wherein the pigments of the colored adhesive layer and the colored ink layer independently include an inorganic pigment or an organic pigment, wherein the inorganic pigment is selected from cadmium At least one of the group consisting of red, cadmium lemon yellow, orange cadmium yellow, titanium dioxide, carbon black, black iron oxide, and black complex, and the organic pigment is selected from the group consisting of aniline black, perylene black, anthraquinone black, and At least one of the group consisting of aniline yellow pigment, phthalocyanine blue and phthalocyanine green. The highly-shielding colored ultra-thin cover film according to item 1 of the scope of patent application, wherein the colored ink layer comprises at least one of the group consisting of inorganic powder, organic powder, and flame-retardant compound, wherein The inorganic powder system includes calcium sulfate, silicon dioxide, zinc sulfide, zirconia, calcium carbonate, boron nitride, aluminum hydroxide, talc, aluminum nitride, glass powder, quartz powder, corundum and clay. At least one of the group consisting, the organic powder system polyimide-based compound, and the flame-retardant compound system include a group selected from halogen-containing compounds, phosphorus-based compounds, nitrogen-based compounds, and boron-based compounds At least one of the group, wherein the sum of the proportions of the silicon dioxide, talc, calcium carbonate, glass powder, and quartz powder is 1 to 50 weight percent of the total solids content of the colored ink layer, and The proportion is 1 to 40 weight percent of the total solids content of the colored ink layer. The highly shielding colored ultra-thin cover film according to item 1 of the scope of the patent application, wherein the colored adhesive layer comprises at least one of the group consisting of inorganic powder, organic powder, and flame-retardant compound, The inorganic powder system includes calcium sulfate, silicon dioxide, zinc sulfide, zirconia, calcium carbonate, boron nitride, aluminum hydroxide, talc, aluminum nitride, glass powder, quartz powder, silicon carbide, and At least one of the group consisting of clay, the organic powder system polyimide-based compound, and the flame-retardant compound system are selected from the group consisting of halogen-containing compounds, phosphorus-based compounds, nitrogen-based compounds, and boron-based compounds. At least one of the group, wherein the sum of the proportions of silicon dioxide, talc, calcium carbonate, glass powder, and quartz powder is 1 to 50 weight percent of the total solids content of the colored ink layer, and the phosphorus compound The proportion is 1 to 50 weight percent of the total solids content of the colored ink layer. The high-shielding colored ultra-thin cover film as described in item 1 of the patent application scope, further comprising another colored ink layer, formed between the colored ink layer and the colored adhesive layer, and the colored ink layer and the The other colored ink layer has a thickness of 2 to 3 microns. The high-shielding colored ultra-thin cover film as described in item 1 of the scope of patent application, which includes an auxiliary adhesive layer, is formed between the colored ink layer and the colored adhesive layer, and the thickness of the auxiliary adhesive layer is 3 Up to 25 microns. The highly-shielding colored ultra-thin cover film according to item 1 of the scope of the patent application, wherein the thickness of the colored ink layer and the colored adhesive layer is 4 to 7 microns. The high-shielding colored ultra-thin cover film according to item 1 of the scope of the patent application, which includes a release layer formed on the surface of the colored ink layer and a release layer formed on the surface of the colored adhesive layer. The surface roughness (Rz value) of the surface of the upper release layer in contact with the colored ink layer is 0.1 to 10 micrometers. A method for preparing a high-shielding colored ultra-thin cover film according to item 1 of the scope of patent application, which comprises: coating a colored ink raw material on the surface of the upper release layer, and curing the colored ink at 50 to 180 ° C. Raw materials to form a colored ink layer; a colored adhesive layer is formed on the surface of the colored ink layer by a coating method or a transfer method; and a lower release layer is pasted on the surface of the colored adhesive layer. According to the method for preparing a highly-shielding colored ultra-thin cover film described in item 10 of the scope of the patent application, the method further includes forming another colored ink layer on the surface of the colored ink layer before forming the colored adhesive layer. According to the method for preparing a highly-shielding colored ultra-thin cover film according to item 10 of the scope of the patent application, the method further comprises forming an auxiliary adhesive layer on the surface of the colored ink layer after forming the colored ink layer.