KR100652860B1 - Noise suppressing film, noise-suppressed circuit substrate and method of manufacturing the same - Google Patents

Abstract

A noise suppressing film, a noise-suppressed circuit substrate, and a method of manufacturing the same are provided to guarantee a high electromagnetic wave suppressing effect in a wireless frequency band with a thickness under 100 micron by forming the noise suppressing film at a substrate or a film. In a noise suppressing film, a pattern layer(11) is formed by crossing a magnetic substance(11a) and a resistor(11b). A magnetic layer(12) is formed to be laminated on the pattern layer(11). The magnetic substance(11a) and the resistor(11b) are arranged in a thickness direction. The pattern layer(11) absorbs the electromagnetic wave. The magnetic layer(12) protects the pattern layer(11) and absorbs the remaining electromagnetic wave.

Description

Noise Reduction Film, Noise Reduction Circuit Board, and Manufacturing Method thereof {NOISE SUPPRESSING FILM, NOISE-SUPPRESSED CIRCUIT SUBSTRATE AND METHOD OF MANUFACTURING THE SAME}

1 is a perspective view showing a noise reduction film according to an embodiment of the present invention.

2 is a perspective view illustrating a noise attenuating circuit board according to another exemplary embodiment of the present invention.

3 is a perspective view illustrating a noise attenuating circuit board according to still another exemplary embodiment of the present invention.

4 is a perspective view illustrating a noise attenuating circuit board of the present invention or in another embodiment.

5 is a graph showing a result of a comparative experiment of the loss power characteristics of the noise reduction circuit board according to an embodiment of the present invention.

<Description of Drawing>

10: noise reduction film 11a, 21a, 31a, 41a: magnetic material

11b, 21b, 31b, and 41b: resistors 11, 21, 31, and 41: pattern layer

12,22,32,42: magnetic layer 20,30,40: noise reduction circuit board

23,33,43: Noise One 24,34,44: Board

The present invention relates to a noise reduction film, a noise reduction circuit board, and a manufacturing method thereof, and more particularly, to a noise reduction film, a noise reduction circuit board, and a method for manufacturing the same, which can shield electromagnetic waves from inside or outside. It is about.

Recently, digital electronic devices are accelerating the speed of processing of circuit signals of electronic devices, high frequency, high functionality, and miniaturization of product types. As a result, circuits are becoming more and more multi-layered and densified, resulting in increased line coupling, interference caused by radiation noise, and crosstalk, which often cause malfunction of the device, and in some cases, these noises affect external devices. Also

The countermeasures against noise and electromagnetic interference in the high speed, high functional, and high density electronic devices, particularly in the radio frequency (RF) band, include low pass filters and shielding. The countermeasures against noise by passive components are not suitable for urgent noise countermeasures for products with short product life because they require not only mounting space but also consideration from the design stage for miniaturization and thinning. Inductance components are still inadequate for use in the radio frequency band due to the low frequency characteristics of real permeability.

With the miniaturization of electronic devices, thinning is demanded for films and circuit boards for noise countermeasures used in the aforementioned radio frequency band. Conventional sheet-like radio wave absorber using ferrite and soft magnetic material uses noise attenuation effect due to magnetic loss. As the frequency increases, permeability is insufficient, and the thickness is limited. . Although components such as coils and filters can be used in the 10-100 MHz frequency band, there is no convenient noise countermeasure component in the aforementioned radio frequency band. Even if there are components corresponding to this, there is a problem that a huge cost is required to change the design of the substrate or the like.

Therefore, in order to solve such a problem, the invention of a thin film or a circuit board having an effective noise reduction ability than the conventional magnetic sheet is required. In addition, there is a need for a multilayer film or a circuit board for noise countermeasure, which is designed not only to have an effective noise attenuation efficiency by resistive loss and magnetic loss but also to be thinned.

Accordingly, the present invention has been made to solve the above-described problems, and includes a noise reduction film having a good bending characteristic and having a pattern layer in which a magnetic material and a resistor are formed in a predetermined pattern so as to reduce electromagnetic waves by absorption. An object of the present invention is to provide a noise reduction circuit board.

Furthermore, it is an object of the present invention to provide a method for manufacturing a noise reduction film and a noise reduction circuit board which can be applied to a flexible substrate or a flexible device requiring flexibility to improve bending characteristics and reduce electromagnetic waves from inside or outside. .

In order to achieve this object, the noise reduction film according to an embodiment of the present invention includes a pattern layer formed by crossing a magnetic material and a resistor, and a magnetic layer formed by laminating the pattern layer. Oriented in the thickness direction, the pattern layer absorbs electromagnetic waves, the magnetic layer protects the pattern layer and absorbs residual electromagnetic waves.

According to another aspect of the present invention, there is provided a method of manufacturing a noise reduction film, including: generating a resistor slurry including a hexagonal plate-shaped resistor powder and a magnetic slurry including a hexagonal plate-shaped magnetic powder, and the resistor slurry and the magnetic slurry. Forming a pattern layer where the resistor and the magnetic body cross each other; forming a magnetic layer by laminating the pattern layer using the magnetic slurry; and hot compressing the pattern layer and the magnetic layer.

The noise reduction circuit board according to another embodiment of the present invention includes a wiring layer formed on the substrate and a noise reduction film formed on the wiring layer, wherein the noise reduction film includes a pattern layer formed by crossing a magnetic material and a resistor. And a magnetic layer laminated on the pattern layer, wherein the pattern layer shields the wiring layer from electromagnetic waves, and the magnetic layer protects the pattern layer and absorbs residual electromagnetic waves.

According to another aspect of the present invention, there is provided a method of manufacturing a noise reduction circuit board, the method including forming a wiring layer on a substrate, and generating a magnetic slurry including a resistive slurry including hexagonal plate-shaped resistive powder and a hexagonal plate-shaped magnetic powder. And forming a pattern layer in which the resistor and the magnetic body cross each other using the resistor slurry and the magnetic slurry on the wiring layer, and forming a magnetic layer on the pattern layer using the magnetic slurry. And hot compressing the pattern layer and the magnetic layer.

Preferably, the resistor powder and the magnetic powder are mixed and stirred with a polymer binder and a solvent in which the polymer binder is dissolved to generate a resistor slurry and a magnetic slurry, respectively. The polymer binder includes a thermosetting urethane, an epoxy resin, a thermoplastic acrylic resin, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, propylene, polyester, polyimide, silicone or ethylene-vinyl acetate resin, or the solvent Toluene. The magnetic body and the resistor are cross formed in a mosaic pattern or a stripe pattern. The magnetic material includes sandust, Fe-based amorphous alloys, or permalloy. The resistor includes crystalline carbon or graphite. And aligning the magnetic material and the resistor in the thickness direction.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 is a perspective view showing a noise reduction film according to an embodiment of the present invention.

Referring to FIG. 1, a magnetic layer 11a and a resistor 11b include a pattern layer 11 formed by crossing each other, and a magnetic layer 12 formed by being stacked on the pattern layer 11. Numeral 11b is oriented in the thickness direction, and the pattern layer 11 absorbs electromagnetic waves, and the magnetic layer 12 protects the pattern layer 11 and illustrates a noise reduction film 10 that absorbs residual electromagnetic waves.

On the other hand, the manufacturing method for manufacturing the noise reduction film 10 according to the embodiment of Figure 1 is as follows.

First, a resistor slurry containing hexagonal plate-shaped resistor powder and a magnetic slurry containing hexagonal plate-shaped magnetic powder are produced. Subsequently, a pattern layer in which the resistor 11b and the magnetic body 11a intersect is formed using the resistor slurry and the magnetic slurry. Subsequently, the magnetic layer 12 is formed by laminating the pattern layer 11 using the magnetic slurry. Thereafter, hot compressing the pattern layer 11 and the magnetic layer 12.

Here, the polymer powder and the solvent for dissolving the polymer binder and the polymer binder are mixed and stirred in the resistor powder and the magnetic powder to produce a uniformly dispersed resistor slurry and a magnetic slurry, respectively. Polymeric binders include thermoset urethanes, epoxy resins, thermoplastic acrylic resins, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, propylene, polyesters, polyimides, silicones or ethylene-vinyl acetate resins, or the solvent is toluene Include. The slurry thus produced is used to form the noise attenuation film 10 by using a bar coater or a doctor blade. The polymer binder may be used without particular limitation as long as the polymer binder has excellent insulation and good dispersibility and miscibility with the functional plate particles, and has high moldability and processability.

The magnetic body 11a includes a sanddust, a Fe-based amorphous alloy, or a permalloy having a high shape ratio having a long axis length and a thickness ratio of 10 or more in the form of powder. Such magnetic powder is preferably high magnetic permeability, high magnetic loss and high frequency characteristics.

The resistor 11b includes crystalline carbon or graphite as plate-shaped particles having a size of 5 microns to 100 microns having anisotropy. Such resistor particles preferably have a high resistance loss.

Here, the method further includes the step of orienting the magnetic body 11a and the resistor 11b substantially in the thickness direction.

The magnetic layer 12 may be stacked on the pattern layer 11 as shown in (A) or may be stacked below the pattern layer 11 as in (B), and its electromagnetic wave absorption characteristics are substantially the same.

In addition, the magnetic body 11a and the resistor 11b are preferably cross-shaped in a mosaic pattern or a stripe pattern, but are not particularly limited thereto. This is because it has a wide range of absorption characteristics including the radio frequency band, and can reduce the transmission of radiation noise and secondary inductive coupling. As a result, it is possible to quickly counter the noise and to solve the obstacle caused by the miniaturization or high density of the circuit.

Meanwhile, in the present exemplary embodiment, the noise attenuating film 10 having the laminated structure of the pattern layer 11 and the magnetic layer 12 is illustrated, but is not limited thereto. The pattern layer 11 and the magnetic layer 12 may be repeatedly stacked. Of course, it may include a structure.

The noise attenuation film 10 is embedded by a noise source, for example, a silicon circuit board on which a transmission line or a wiring layer is formed, a flexible / hard circuit board, a silicon substrate or a top / bottom of a polyimide film or embedded therein. In addition, it can shield or absorb noise or electromagnetic wave by magnetic loss or resistance loss, and can make ultra thin.

2 is a perspective view illustrating a noise attenuating circuit board according to another exemplary embodiment of the present invention.

Referring to FIG. 2, a wiring layer 23 formed on the substrate 24 and a noise attenuating film formed on the wiring layer 23 are included. The noise attenuating film includes a magnetic body 21a and a resistor 21b intersecting each other. A pattern layer 21 to be formed, and a magnetic layer 22 stacked on the pattern layer 21. The pattern layer 21 shields the wiring layer 23 from electromagnetic waves, and the magnetic layer 22 is a pattern layer. A noise attenuating circuit board 20 that protects 21 and absorbs residual electromagnetic waves is illustrated.

Meanwhile, a manufacturing method of manufacturing the noise reduction circuit board 20 according to the embodiment of FIG. 2 is as follows.

First, the wiring layer 23 is formed on the substrate 24. Thereafter, a resistor slurry containing hexagonal plate-shaped resistor powder and a magnetic slurry containing hexagonal plate-shaped magnetic powder are produced. Subsequently, a pattern layer 21 in which the resistor 21b and the magnetic body 21a intersect is formed on the wiring layer 23 by using the resistor slurry and the magnetic slurry. Thereafter, the magnetic layer 22 is laminated on the pattern layer 21 by using the magnetic slurry. Thereafter, the pattern layer 21 and the magnetic layer 22 are hot compressed.

Here, the resistor powder and the magnetic powder are mixed and stirred with the solvent dissolving the polymer binder and the polymer binder, thereby producing a resistor slurry and a magnetic slurry, respectively. Polymeric binders include thermosetting urethanes, epoxy resins, thermoplastic acrylic resins, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, propylene, polyesters, polyimides, silicones or ethylene-vinyl acetate resins, or the solvent is toluene Include.

The substrate 24 on which the wiring layer 23 is formed means a silicon circuit board, a flexible / hard circuit board, a silicon substrate, or a polyimide film, and is not particularly limited. The wiring layer 23 may also include a transmission line as a noise source.

The magnetic body 21a includes a sand dust, a Fe-based amorphous alloy, or permalloy having a high shape ratio having a long axis length and a thickness ratio of 10 or more in a plate shape in powder form. Such magnetic powder is preferably high magnetic permeability, high magnetic loss and high frequency characteristics.

The resistor 21b includes crystalline carbon or graphite as plate-shaped particles having anisotropy of 5 microns to 100 microns in size. Such resistor particles preferably have a high resistance loss.

Here, the method further includes the step of orienting the magnetic body 21a and the resistor 21b substantially in the thickness direction.

The magnetic layer 22 may be stacked on the pattern layer 21 as shown in (A) (Example 1) or may be stacked below the pattern layer 21 as in (B) (Example 2), and the electromagnetic wave thereof The absorption properties are substantially the same.

In addition, the magnetic body 21a and the resistor 21b are preferably cross-shaped in a mosaic pattern or a stripe pattern, but are not particularly limited thereto.

3 is a perspective view illustrating a noise attenuating circuit board according to still another exemplary embodiment of the present invention. Here, the description of the components and their manufacturing method substantially the same as the components of the embodiment of Figure 2 and its manufacturing method will be omitted.

Referring to FIG. 3, the pattern layer 31 including the magnetic material 31a and the resistor 31b is substantially formed in the longitudinal direction of the wiring layer 33.

The magnetic layer 32 may be stacked on the pattern layer 31 as shown in (A) (Example 3) or may be stacked below the pattern layer 31 as in (B) (Example 4), and the electromagnetic wave thereof The absorption properties are substantially the same.

4 is a perspective view illustrating a noise attenuating circuit board of the present invention or in another embodiment. Here, the description of the components and their manufacturing method substantially the same as the components of the embodiment of Figure 2 and its manufacturing method will be omitted.

Referring to FIG. 4, the pattern layer 31 including the magnetic material 31a and the resistor 31b is formed in a direction substantially perpendicular to the length direction of the wiring layer 33.

The magnetic layer 42 may be stacked above the pattern layer 41 as in (A) (Example 5) or may be stacked below the pattern layer 41 as in (B) (Example 6), and the electromagnetic wave thereof The absorption properties are substantially the same.

5 is a graph showing a result of a comparative experiment of the loss power characteristics of the noise reduction circuit board according to an embodiment of the present invention.

Referring to FIG. 5, a graph illustrating a result of experiments on a loss power / input power ratio according to the frequency of electromagnetic waves of a noise reduction circuit board according to the embodiments of FIGS. 2 to 4 is shown.

Noise reduction film according to an embodiment of the present invention (Examples 1 to 6) is 50 * 50 on the microstrip line formed on the dielectric substrate using a network analyzer (HP E8364A) The noise reduction film of mm was positioned to measure the transmission coefficient (S ₂₁ ) and the reflection coefficient (S ₁₁ ) between transmission lines.

The attenuation effect of the electromagnetic wave was evaluated by the loss power and input power ratio (P _loss / P _in ) according to Equation 1 below.

)로 평가하였으며, 이는 다음의 수학식 2에 의해 산출하였다.The final characteristics are the difference between the loss / input power ratio of the noise attenuating film including the pattern layer formed with the stripe or mosaic pattern of the magnetic material and the resistor, and the loss / input power ratio of the microstrip line itself without the noise attenuating film.

) Was calculated by the following equation (2).

As can be seen from the graphs A and B illustrated in this figure, it can be seen that a good noise attenuation effect is shown in a wide frequency band.

After that, the comparative example and the manufacturing method of the noise reduction circuit board according to each example (Examples 1 to 6) tested in the present comparative experiment will be described later.

Comparative Example 1

70% by weight of the plate-like sand dust powder and 30% by weight of chlorinated polyethylene resin, which are soft magnetic particles, are dissolved in toluene, which is a solvent, stirred using a mixer to form a powder slurry, and coated onto a film using a doctor blade to orient the plate particles. After drying, a magnetic film having a thickness of 75 microns was prepared.

Example 1

70% by weight of the plate-like carbon powder and 30% by weight of chlorinated polyethylene resin are dissolved in toluene as a solvent, stirred using a mixer to form a powder slurry, coated with a film using a doctor blade, dried, and then plate-shaped particles 50 A micron resistor film was obtained. The film in which the plate-shaped sandust was oriented was also manufactured by the same method, and the sandust magnetic film was obtained. These films are first placed on a polymer film or a substrate with a transmission line by placing a mosaic layer in which a magnetic body and a resistor are arranged in a mosaic form, and then sand sand magnetic layers are sequentially stacked thereon, followed by heat compression at 70 degrees Celsius to reduce noise at a 75 micron thickness. Microstrip circuit boards to films were formed. It is a noise reduction circuit board substantially the same as A of FIG.

Example 2

In the same manner as in Example 1, a resistor film and a magnetic film were prepared, respectively, and a magnetic layer, a mosaic layer composed of a resistor and a magnetic material were sequentially stacked on a polymer film or a substrate having a transmission line, and heat-compressed at 70 degrees Celsius to 75 microns in thickness. Microstrip circuit boards or films in which the noise reduction film was formed were fabricated. It is a noise reduction circuit board substantially the same as B of FIG.

Example 3

In the same manner as in Example 1, a resistor film and a magnetic film were manufactured, respectively, and a stripe layer composed of a resistor and a magnetic body was placed horizontally on the transmission line on a polymer film having a transmission line or a substrate, and the magnetic layers were sequentially stacked thereon to 70 degrees Celsius. Microstrip circuit boards or films were prepared by heating and compressing them to form a 75 micron-thick noise reduction film. It is a noise reduction circuit board substantially the same as A of FIG.

Example 4

In the same manner as in Example 1, a resistor film and a magnetic film were manufactured, and a magnetic layer was placed on a polymer film or a substrate having a transmission line, and a stripe layer composed of a resistor and a magnetic body was placed horizontally on a transmission path, and then laminated to a degree Celsius. Microstrip circuit boards or films were prepared by heating and compressing at 70 degrees to form a 75 micron-thick noise reduction film. It is a noise reduction circuit board substantially the same as B of FIG.

Example 5

In the same manner as in Example 1, a resistor film and a magnetic film were manufactured, respectively, and a stripe layer composed of a resistor and a magnetic material was placed perpendicular to the transmission line on a polymer film having a transmission line or a substrate, and the magnetic layers were sequentially stacked thereon in degrees Celsius. Microstrip circuit boards or films were prepared by heating and compressing at 70 degrees to form a 75 micron-thick noise reduction film. It is a noise reduction circuit board substantially the same as A of FIG.

Example 6

In the same manner as in Example 1, a resistor film and a magnetic film were prepared, and a magnetic layer was placed on a polymer film or a substrate having a transmission line, and a stripe layer composed of the resistor and the magnetic body was disposed perpendicular to the transmission path, and then laminated to the Celsius degree. Microstrip circuit boards or films were prepared by heating and compressing at 70 degrees to form a 75 micron-thick noise reduction film. It is a noise reduction circuit board substantially the same as B of FIG.

The present invention is not limited to the above embodiments, and many variations are possible by those skilled in the art within the spirit of the present invention.

According to the present invention, a noise attenuating film having a stripe or mosaic pattern layer composed of a magnetic material and a resistor is formed on a substrate or a film having a transmission line, so that the electromagnetic wave attenuation effect is high in the radio frequency band even at a thickness of 100 microns or less. There is an effect that can produce a film to a circuit board.

In addition, the multi-layered microstrip circuit board having the stripe pattern layer disposed close to the transmission line has an effect of more effectively attenuating electromagnetic waves in the frequency band of 10 MHz to 1 GHz.

Claims (22)

A pattern layer formed by crossing a magnetic material and a resistor, It includes a magnetic layer laminated on the pattern layer, The magnetic material and the resistor are oriented in the thickness direction, the pattern layer absorbs electromagnetic waves, the magnetic layer protects the pattern layer and absorbs residual electromagnetic waves. The method of claim 1, The magnetic material and the resistor is a noise reduction film that is cross-formed in a mosaic pattern or a stripe pattern. The method of claim 2, The magnetic material is a noise reduction film comprising a sand dust, Fe-based amorphous alloy, or permalloy (permalloy). The method of claim 2, The resistor is a noise damping film containing crystalline carbon or graphite. Generating a resistor slurry comprising a hexagonal plate-shaped resistor powder and a magnetic slurry comprising a hexagonal plate-shaped magnetic powder, Using the resistor slurry and the magnetic slurry to form a pattern layer where the resistor and the magnetic body cross each other; Forming a magnetic layer by laminating the pattern layer using the magnetic slurry; The method of manufacturing a noise reduction film comprising the step of hot compressing the pattern layer and the magnetic layer. The method of claim 5, And a polymer binder and a solvent in which the polymer binder is dissolved in the resistor powder and the magnetic powder are mixed and stirred to produce a resistor slurry and a magnetic slurry, respectively. The method of claim 6, The polymer binder includes a thermosetting urethane, an epoxy resin, a thermoplastic acrylic resin, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, propylene, polyester, polyimide, silicone or ethylene-vinyl acetate resin, or the solvent A method for producing a noise reduction film containing toluene. The method of claim 5, The magnetic material and the resistor is a method of manufacturing a noise reduction film that is cross-formed in a mosaic pattern or a stripe pattern. The method of claim 8, The magnetic material is a method for producing a noise reduction film comprising a sand dust, Fe-based amorphous alloy, or permalloy (permalloy). The method of claim 8, The resistor is a method for producing a noise reduction film containing crystalline carbon or graphite. The method of claim 8, And aligning the magnetic material and the resistor in the thickness direction. A wiring layer formed on the substrate, It includes a noise reduction film formed on the wiring layer, The noise reduction film, A pattern layer formed by crossing a magnetic material and a resistor, It includes a magnetic layer laminated on the pattern layer, And the pattern layer shields the wiring layer from electromagnetic waves, and the magnetic layer protects the pattern layer and absorbs residual electromagnetic waves. The method of claim 12, And the magnetic material and the resistor cross each other in a mosaic pattern or a stripe pattern. The method of claim 13, The magnetic material is a noise reduction circuit board containing a sand dust, Fe-based amorphous alloy, or permalloy. The method of claim 13, The resistor is a noise reduction circuit board containing crystalline carbon or graphite. Forming a wiring layer on the substrate, Generating a resistor slurry comprising a hexagonal plate-shaped resistor powder and a magnetic slurry comprising a hexagonal plate-shaped magnetic powder, Using the resistor slurry and the magnetic slurry to form a pattern layer in which the resistor and the magnetic body cross each other on the wiring layer; Forming a magnetic layer on the pattern layer by using the magnetic slurry; And hot compressing the pattern layer and the magnetic layer. The method of claim 16, And a polymer binder and a solvent in which the polymer binder is dissolved in the resistor powder and the magnetic powder to stir to produce a resistor slurry and a magnetic slurry, respectively. The method of claim 17, The polymer binder includes a thermosetting urethane, an epoxy resin, a thermoplastic acrylic resin, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, propylene, polyester, polyimide, silicone or ethylene-vinyl acetate resin, or the solvent A method of manufacturing a noise reduction circuit board containing toluene. The method of claim 16, And the magnetic material and the resistor are cross-formed in a mosaic pattern or a stripe pattern. The method of claim 19, The magnetic material is a method for manufacturing a noise reduction circuit board comprising a sand dust, Fe-based amorphous alloy, or permalloy. The method of claim 19, The resistor is a method of manufacturing a noise reduction circuit board containing crystalline carbon or graphite. The method of claim 19, And aligning the magnetic material and the resistor in the thickness direction.

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