KR102518437B1 - A faraday cage manufactured using metal micro-patterning - Google Patents

Abstract

The Faraday cage of the present invention includes a transparent substrate and a metal layer formed by depositing a conductive metal on one surface of the substrate, wherein the metal layer includes a region formed of a pattern composed of a plurality of closed shapes, and the pattern consists of continuous lines with a width of 1 to 100 μm.

Description

Faraday cage using metal micro-patterning {A faraday cage manufactured using metal micro-patterning}

The present invention relates to a Faraday cage, and more particularly, to a Faraday cage having electro-optical characteristics by including a conductive metal layer in which a pattern of fine holes is processed on a transparent substrate.

A Faraday cage refers to a box or enclosure made to prevent transmission of electric force or electromagnetic waves. It is usually made by processing a metal plate, but since this structure cannot transmit light, there is a problem that it cannot be applied to an optical device.

There is a method of laminating a metal mesh structure formed by an etching process on a transparent substrate to secure light transmittance. However, for excellent electro-optical properties, the mesh should be fine and dense, but it is difficult to implement this.

A traditional method of etching a thin metal film is wet etching. Because it uses a chemical reaction, not only does it generate toxic substances that are harmful to the human body and pollute the environment, but also the holes formed by processing are isotropic. Since it has a profile of , dispersion occurs according to the depth of the hole, so it is not suitable for fine hole processing (usually, 40 μm or less is not possible), and the yield is low (about 17%).

In the case of general wet etching, it is possible to process anisotropic uniform holes, but the productivity is low, and there are limitations applicable only to the processing of volatile materials, and CMP (Chemical- Mechanical Polishing) In the case of going through the process, various problems are caused as in wet etching.

The problem to be solved by the present invention is, firstly, by processing high-density fine holes in a metal layer formed on a transparent substrate to secure sufficient electromagnetic shielding power and to provide an optically excellent Faraday cage panel and a Faraday cage to which it is applied will be.

Second, even when the metal layer is made of a non-volatile metal, it is to provide a panel for a Faraday cage in which fine holes are processed and a Faraday cage to which the same is applied.

Third, to provide a panel for a Faraday cage in which a pattern defining holes formed in the metal layer is formed of lines having a fine width, and a Faraday cage to which the same is applied.

The Faraday cage of the present invention includes a transparent substrate and a metal layer formed by depositing a conductive metal on one surface of the substrate, wherein the metal layer includes a region formed of a pattern composed of a plurality of closed shapes, and the pattern consists of continuous lines with a width of 1 to 100 μm.

The closed figure may include a polygon. The closed figure may include a regular hexagon.

The pattern may include partially overlapping polygons. The maximum length of the region surrounded by the closed figure may be 10 μm to 10,000 μm.

The thickness of the metal layer may be 1 μm or less.

The metal may include one or more elements selected from Ti, Cu, Au, Ag, Cr, Ni, Pd, and Pt.

The pattern may be processed by a dry etching method.

The metal may be non-volatile.

A panel for a Faraday cage of the present invention includes a transparent substrate and a metal layer formed by depositing a conductive metal on one surface of the substrate, wherein the metal layer includes a region composed of a pattern composed of a plurality of closed shapes, The pattern consists of continuous lines with a thickness of 1 to 100 μm.

First, the Faraday cage of the present invention implements a pattern composed of a very narrow width on a metal layer of a thin film formed by deposition on a transparent substrate, so that it has optical transparency as a whole despite the light shielding characteristics of the metal constituting the metal layer.

Second, a Faraday cage can be implemented regardless of the material of the metal layer, especially when it is made of a non-volatile metal.

Third, since the width and thickness of the lines constituting the pattern are formed very finely using a dry etching device, the electro-optical properties are excellent.

1 shows a Faraday cage according to an embodiment of the present invention.
FIG. 2 shows light passing through the panel shown in FIG. 1 .
FIG. 3 shows a pattern formed on the metal layer shown in FIG. 2 .
4 is another embodiment of a pattern formed on a metal layer.
5 shows a dry etching apparatus applied to process a pattern on a metal layer.
6 shows steps in which a pattern is processed by a dry etching device.
7 is a graph showing a change in the waveform of the bidirectional voltage power supply voltage formed between the cathode and the anode when the bidirectional voltage power supply shows an alternating current waveform and direct current power is applied to the anode part.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

1 shows a Faraday cage according to an embodiment of the present invention. FIG. 2 shows light passing through the panel shown in FIG. 1 . FIG. 3 shows a pattern formed on the metal layer shown in FIG. 2 . 4 is another embodiment of a pattern formed on a metal layer.

Referring to FIG. 1, a Faraday cage 1 according to an embodiment of the present invention includes a transparent substrate 11 and a metal layer 12 formed by depositing a conductive metal on one surface of the substrate 11. (10) is included. The Faraday cage 1 has a predetermined space inside to accommodate electrical or optical devices, and the space may be defined by at least one panel 10 .

1 shows that each surface is composed of the panel 10 in the form of a square box, but it is not necessarily limited to this, and it is sufficient if at least one surface of the plurality of surfaces constituting the cage is composed of the panel 10. In addition, depending on the embodiment, the shape of the panel 10 may also be curved, and the curved surface does not necessarily have to be rigid and regular, but may be formed by deformation of a flexible or soft sheet.

Also, in the embodiment, the metal layer 12 is formed on the outer surface of each panel 10, but may be formed on the inner surface of the panel 10 or on both sides.

The substrate 11 is transparent and may be glass or spinel, and the material may include one or more elements selected from SiO2 and Al2O3. In addition, the substrate 11 is not limited to a hard material, and may be a flexible material capable of being deformed such as bending or folding.

The metal layer 12 includes a region 12a formed of a pattern composed of a plurality of closed shapes. Here, the pattern is made of continuous lines having a width W of 1 to 100 μm, preferably 1 to 10 μm.

The periphery of the region formed of the pattern may be connected to each other, and in the embodiments, a rectangular region 12b is provided along the circumference of the pattern 12a composed of a plurality of closed shapes, so that all lines forming the pattern are connected to each other. has been

Here, a closed shape is a figure that defines a closed area where the start and end points of a line meet, and there is no limit to the type of polygons such as triangles, squares, pentagons, hexagons, and octagons, or curved shapes such as circles and ellipses. However, an equilateral triangle, square, or regular hexagon is suitable to easily fill a predetermined area around one dot with a repeating pattern, and a prototile of a shape other than these basic figures is also possible.

Depending on the embodiment, the pattern formed on the metal layer 12 may consist of partially overlapping polygons. (See Figure 4.)

The metal layer 12 may be formed by depositing a metal on the surface of the substrate 11 . Alternatively, the metal layer 12 may be formed by laminating a metal plate on the substrate 11 . The metal may be at least one element selected from Ti, Cu, Au, Ag, Cr, Ni, Pd, and Pt, and is preferably Au.

The metal may be non-volatile. In particular, in the case of non-volatile metals, it is impossible to process a pattern with a normal dry etching method, but when using the dry etching apparatus 100, which will be described later, invented by the applicant, it is preferable to process a pattern made of thin lines as described above. possible.

The maximum length (L) of the region (A) surrounded by one closed figure may be 10 to 10,000 μm. Here, the maximum length (L) is defined as the maximum length of a straight line that can be drawn in the area (A) surrounded by the closed figure, and the applicant has demonstrated sufficient electromagnetic wave blocking performance when the maximum length (L) is 10 to 10,000 μm through several experiments. I found out that this is secured.

The thickness of the metal layer 12 may be 1 μm or less. Even a thin film of 1 μm or less has sufficient electrical characteristics as well as excellent optical characteristics when the maximum length (L) is appropriately determined to form a pattern consisting of a plurality of fine holes.

In particular, since metal is basically a material that does not transmit light, even if it is a thin film of 1 μm or less, it can be said that it has non-transmissive properties in the line section where the pattern is formed. Since it is very thin and the pattern is densely formed, the panel 10 has excellent optical characteristics as a whole and can be used for accommodating an optical sensor or radar.

Hereinafter, a process of manufacturing a panel for a Faraday cage according to embodiments of the present invention will be described.

5 shows a dry etching apparatus applied to process a pattern on a metal layer. 6 shows steps in which a pattern is processed by a dry etching device.

5 and 6, the applicant expands the sheath region of the plasma so that the high-energy ion source has higher kinetic energy and collides with the metal layer to be etched, and high voltage and 1 MHz or less bi-directional A method to improve the density of plasma using a voltage power source was studied.

In addition, an insulator 116 is applied to prevent current from being applied to the work object for temperature control of the work object, and a temperature control function is added to the cathode unit 110.

The dry etching apparatus 100 was developed in consideration of the above, and includes a cathode part 110, an anode part 120, a holding part 140, a bi-directional voltage power supply part 130 and a flat part 180. can include

A cathode unit 110 generating ions is disposed above the anode unit 120, and bidirectional voltage power is applied through the bidirectional voltage power supply unit 130. The bidirectional voltage power source may be defined as a power source in which the polarity of current alternately changes between positive and negative over time.

A frequency of the power supply of the bi-directional voltage may be 1 MHz or less. The high-frequency power source can contribute to the expansion of the sheath area by increasing the charge accumulation time, and can secure the time for ions to accelerate toward the workpiece side, so that the workpiece W provided on the flat portion 180 can be moved with higher energy. may collide with surfaces. The work object W may be the metal layer 12 of the panel 10 .

The work object W may be fixed to the lower surface of the flat portion 180 by the adhesive layer 184 . The adhesive layer 184 may be an adhesive film, adhesive, or the like. Not limited to this, it is also possible to fix the workpiece W to the lower surface of the flat portion 180 using static electricity.

Since atoms etched away from the surface of the work object W fall toward the anode unit 120 by gravity, redeposition on the surface of the work object W is prevented.

The flat portion 180 may include a flat plate 182 and a photoresist film 186 . As shown in FIG. 6, the work object W is attached to the flat plate 182, and as shown in FIG. W) is placed.

A photoresist film 186 may be laminated on the outside of the flat plate 182 to which the workpiece W is attached. A pattern may be formed by exposing the photoresist film 186 to light. (See (e) of FIG. 6.) Etching is performed by colliding ions on a region corresponding to the exposed pattern on the surface of the workpiece W.

A mounting portion 140 capable of adjusting the height of the flat portion 180 may be provided. A spacing adjusting unit 150 for adjusting the distance between the cathode unit 110 and the anode unit 120 may be provided.

The charge amount (Q) is proportional to the applied voltage (V), permittivity (ε) and the area (A) of the workpiece, and is inversely proportional to the distance (d) between the cathode part 110 and the anode part 120. (Q = εVA / d) By adjusting the distance between the cathode unit 110 and the anode unit 120 through the spacing control unit 150, it is possible to control the optimal amount of charge even if the working area (A) is changed .

On the other hand, the aforementioned redeposition is a phenomenon in which the fallen atoms separated from the object by etching meet and collide with ions or gases advancing to the surface of the work object W, and are deposited on the surface of the work object W again. . Therefore, in order to prevent redeposition, the workpiece W needs to reduce the ion hitting time and increase the electron hitting time. To this end, (+) or (- ) is provided with a DC voltage power application unit 160 for applying a DC current voltage power source.

The voltage waveform supplied to the cathode 110 by the bidirectional voltage power supply 130 is a form in which the polarity of the voltage changes over time, and may be a general AC sine waveform or a trapezoidal bipolar waveform. there is. This voltage waveform includes a boosting section in which the magnitude of the voltage increases and a lowering section converging to 0V. In the case of a bipolar waveform, there may be a holding period in which a voltage is maintained constant after passing through a boosting period.

7 is a graph showing a change in the waveform of the bidirectional voltage power supply voltage formed between the cathode and the anode when the bidirectional voltage power supply shows an alternating current waveform and direct current power is applied to the anode part. Referring to FIG. 7 , when the (-) side of DC is applied to the anode unit 120 by the DC voltage power supply unit 160, the bidirectional voltage power supply formed between the cathode unit 110 and the anode unit 120 The waveform of is shifted upward, and the shifted waveform is indicated by a dotted line in FIG. 7 .

When the AC waveform falls to the lower side (-side) of 0 Voltage, ions collide with the work object (W), and when the AC waveform rises to the upper side (+ side) of 0 Voltage, electrons collide with the work object (W). crash Therefore, as shown in FIG. 7, when the waveform is moved upward, the time for ions to collide with the work object W is shortened, and the time for electrons to hit the work object W is shortened. time) is longer.

Furthermore, the ion hitting time and the electron hitting time can be adjusted by controlling the power applied to the anode part 120 by the DC voltage power applying part 160 . Such control may be performed by the controller 190 . In addition, the controller 190 may also be in charge of controlling other components of the device 100.

Such an etching apparatus 100 has the advantage of being able to process elaborate patterns with little redeposition because atoms separated from the workpiece W fall by its own weight, and to process non-volatile materials as well. Furthermore, since the ion collision time and the electron collision time can be adjusted through the control of the DC voltage power supply unit 160, the occurrence of redeposition can be more reliably prevented.

Meanwhile, the etching apparatus 100 may further include a temperature control unit 170 for adjusting the temperature of the cathode unit 110 . The temperature controller 170 may include a cooling channel 172 , a refrigerant circulation unit 174 and a temperature measurement unit 176 .

The cooling channel 172 has a tubular shape extending from the surface of the first conductor 112 to the inside of the second conductor 114, and cooling water can be circulated therein. The refrigerant circulation unit 174 may transfer cooling water along the cooling channel 172 . Here, the first conductor 112 is made of a conductor such as a grounded metal, and the second conductor 114 is disposed below the first conductor 112 to provide low-frequency AC power from the bidirectional voltage power supply unit 130. is applied, and may be formed of a conductive metal such as Al.

The control unit 190 may drive the refrigerant circulation unit 174 so that the temperature measured by the temperature measuring unit 176 does not exceed a set temperature range. Specifically, when the measured temperature rises, the refrigerant circulation amount increases. The circulation unit 174 may be controlled.

Since the temperature can be controlled through the temperature controller 170, overheating of the workpiece W can be prevented. Even in the case of this weak material, the metal layer 12 on the substrate 11 can be processed.

Claims (10)

comprising at least one panel;
the panel,
transparent substrate; and
A metal layer formed by depositing a conductive metal on one surface of the substrate,
The metal layer,
a first region 12a including a repeating pattern of a plurality of closed shapes made of continuous lines; and
a second region 12b extending along the circumference of the first region 12a and integrally formed with the first region 12b and electrically connected to all lines constituting the pattern;
The pattern is
a first pattern in which a plurality of closed shapes consisting of continuous lines having a width of 1 to 100 μm are repeated; and
A second pattern having the same shape and function as the first pattern and partially overlapping the first pattern in a state where the first pattern is shifted and inverted; is integrally formed,
A Faraday cage in which all lines constituting the first pattern and the second pattern are electrically connected. According to claim 1,
The closed figure is a Faraday cage including a polygon. According to claim 2,
The closed figure is a Faraday cage including a regular hexagon. delete According to claim 1,
A Faraday cage wherein the maximum length of the region surrounded by the closed figure is 10 to 10,000 μm. According to claim 1,
A Faraday cage in which the thickness of the metal layer is 1 μm or less. According to claim 1,
the metal,
A Faraday cage containing at least one element selected from Ti, Cu, Au, Ag, Cr, Ni, Pd, and Pt. According to claim 1,
The pattern is a Faraday cage processed by a dry etching method. According to claim 1,
The metal is a non-volatile Faraday cage. transparent substrate; and
A metal layer formed by depositing a conductive metal on one surface of the substrate,
The metal layer,
a first region 12a including a repeating pattern of a plurality of closed shapes made of continuous lines; and
a second region 12b extending along the circumference of the first region 12a and integrally formed with the first region 12b and electrically connected to all lines constituting the pattern;
The pattern is
a first pattern in which a plurality of closed shapes consisting of continuous lines having a width of 1 to 100 μm are repeated; and
A second pattern having the same shape and function as the first pattern and partially overlapping the first pattern in a state where the first pattern is shifted and inverted; is integrally formed,
A panel for a Faraday cage in which all lines constituting the first pattern and the second pattern are electrically connected.

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