KR100582900B1 - Solution for forming black oxide layer on metal thin film, method for forming black oxide layer on metal thin film of electromagnetic interference filter and metal thin film of electromagnetic interference filter formed by the same method - Google Patents

Abstract

A solution for forming a black oxide layer on a metal thin film, a method of forming a black surface on a metal thin film of an electromagnetic shielding filter using the same, and a metal thin film of an electromagnetic shielding filter formed thereby are disclosed. When the black oxide layer is formed on the metal thin film by using a solution for forming the black oxide layer on the metal thin film, the black oxide layer is formed into a planar structure, and thus the characteristics of the hardness, the surface resistance value and the blackness of the black oxide layer are excellent. As a result, the efficiency of shielding the electromagnetic wave from the electromagnetic shielding filter is improved, and the contrast of the display provided with the electromagnetic shielding filter is improved.

Description

SOLUTION FOR FORMING BLACK OXIDE LAYER ON METAL THIN FILM, METHOD FOR Solution for forming black oxide layer on metal thin film, method of forming black oxide layer on metal thin film of electromagnetic wave shielding filter using the same FORMING BLACK OXIDE LAYER ON METAL THIN FILM OF ELECTROMAGNETIC INTERFERENCE FILTER AND METAL THIN FILM OF ELECTROMAGNETIC INTERFERENCE FILTER FORMED BY THE SAME METHOD}

1a and 1b is a view showing the surface structure and blackness of the black oxide layer formed by a conventional method.

2 is a diagram illustrating a schematic configuration of a PDP according to an embodiment of the present invention.

3 is a view showing the configuration of the electromagnetic shielding filter shown in FIG.

Figures 4a and 4b is a view showing the surface structure and blackness of the black oxide layer formed by the method according to an embodiment of the present invention.

5a and 5b is a view showing the surface structure and blackness of the black oxide layer formed by the method according to another embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

50: electromagnetic shielding filter 53: metal thin film

53a: mesh 54: black oxide layer

The present invention relates to a solution for forming a black oxide layer on a metal thin film, a method of forming a black surface on a metal thin film of an electromagnetic shielding filter using the same, and a metal thin film of an electromagnetic shielding filter formed thereby.

Display is a device that visually displays data in the form of characters or figures. Inside the display, a shielding filter that blocks electromagnetic waves harmful to the human body and a shielding film that blocks near infrared rays and prevents reflection are installed.

The electromagnetic shielding filter has a metal thin film made of Cu, which is a conductive metal. A mesh is formed on the metal thin film, and a black oxide layer is formed on one surface of the metal thin film on which the mesh is formed to prevent reflection.

In 1947, Meyer announced a method of depositing a thin metal film on a thin metal film by depositing a thin metal film in a solution containing a high concentration of sodium chlorite and a high concentration of sodium hydroxide.

The chlorites react with Cu to form Cu hydrate as shown in Scheme 1, and the Cu hydrate is formed in the form of copper oxide or copper nitrous oxide as shown in Scheme 2 by a dehydration reaction to form a black oxide layer on the surface of the metal thin film.

ClO ₂ ^- _{+ 2Cu + 2H 2 O -------->} 2Cu (OH) 2 + Cl -

2Cu (OH) ₂ --------> 2CuO or Cu ₂ O + H ₂ O

Sodium hydroxide forms a polymer complex salt, and Cu complex salt grows the tissue of the black oxide layer in the acicular or idol structure as in Scheme 3.

Cu (OH) ₂ + 2NaOH --------> Na (Cu (OH) ₄ )

However, the black oxide layer formed by Meyer's method as described above has a higher content ratio of copper oxide from the surface to the inside. That is, the surface of the black oxide layer has a high content ratio of copper oxide, which is a nonconductor, while the inside of contact with the metal thin film has a high content ratio of copper oxide, a conductor. Then, there is a disadvantage in that a surface resistance value of 0.1 Ω / □ (Square: omitted below) required by the electromagnetic shielding filter of the display cannot be obtained. If the surface resistance is low, it means electricity is well communicated. If electricity is well communicated, it means that the electromagnetic shielding filter shields electromagnetic waves well. In addition, when the black oxide layer is formed by Meyer's method as described above, the content ratio of copper oxide, which is a conductor, is increased so that the sheet resistance value of the black oxide layer can be obtained at 0.1 kW / □ or less, which is less than 30 required by the display. It is impossible to obtain blackness (L *). Blackness (L *) of 0 means full black, and blackness (L *) of 100 means white.

In addition, the Meyer method as described above has a weak strength because the black oxide layer is formed as a sharp needle-like or right upper tissue, and the black oxide layer is easily detached by an external impact. Thus, when the electromagnetic shielding filter and the near infrared shielding film are bonded to each other in a later process, the electromagnetic shielding filter and the near infrared shielding film may not be uniformly bonded to each other.

A solution for forming a black oxide layer applying the Meyer method as described above is disclosed in US Patent 4,512,818 (Inventor: Silvester Valayil). The solution disclosed in Silvester Valayil's patent was to add 60 g Alkali Metal Chlorite, 27 g Alkali Metal Hydroxide, 3 g Trialkali Metal Phosphate and 4 mg Vinol Polyvinyl Alcohol to 1 liter of water. After forming a black oxide layer on the metal thin film using the solution, the surface texture was photographed, and the surface resistance value and blackness were measured.

As shown in Figure 1a, the surface tissue was photographed at a magnification of 5,000 times with a scanning electron microscope (Scanning Electron Microscope), the tissue of the black oxide layer was a needle (狀) or idol (羽 () tissue. Because the structure of the black oxide layer was acicular or idol, its hardness (Hv: Vickers Hardness) was 9.34, which was worse than the hardness of 25.0. The surface resistance value was worse than the surface resistance value 0.1 Ω / □ to be obtained at 2.1 mA / □, and the blackness level L * was the black degree (L *) desired to be obtained at 14.07 as shown in Fig. 1B. ) Better than 30).

That is, when the black oxide layer is formed on the metal thin film with the solution disclosed in the Silvester Valayil patent, the texture, hardness, and surface resistance values have disadvantages that cannot be obtained.

 The present invention was created in order to solve the problems of the prior art as described above, an object of the present invention is to form the structure of the black oxide layer formed on the metal thin film in the shape of the structure, hardness, surface resistance value of the black oxide layer And a solution for forming a black oxide layer on a metal thin film capable of satisfying both blackness, a method of forming a black surface on a metal thin film of an electromagnetic shielding filter using the same, and a metal thin film of an electromagnetic shielding filter formed thereby.

The solution for forming the black oxide layer on the metal thin film according to the present invention for achieving the above object is 30 to 100 g of chlorite (Alkali Metal Chlorite), 10 to 30 g of sodium hydroxide (Sodium Hydroxide), sodium phosphate per 1 L of water. 0.1-10 g of Trialkali Metal Phosphate, 0.1-0.4 g of Ethlene Glycol, 0.01-10 g of Hydrochloric Acid, and 0.2-10 g of Amino Acids are mixed.
In addition, the solution for forming a black oxide layer on the thin metal film is 30 to 100 g of chlorite (Alkali Metal Chlorite), 10 to 30 g of sodium hydroxide (Trialkali Metal Phosphate) and 0.1 to 10 g of sodium hydroxide (Sodium Hydroxide) per 1 L of water. , 0.1 to 0.4 g of ethylene glycol (Ethlene Glycol), 0.01 to 10 g of hydrochloric acid, 0.2 to 10 g of amino acids and 0.1 to 10 g of pyrophosphate.

The method for forming a black surface on the metal thin film of the electromagnetic shielding filter according to the present invention for achieving the above object is to maintain the solution at 40 ~ 90 ℃, 30 seconds of a metal thin film made of Cu formed mesh The black oxide layer is formed on at least one of the upper and lower surfaces of the metal thin film and the side surface of the metal thin film forming the mesh by being deposited for ˜10 minutes.

Metal thin film of the electromagnetic shielding filter according to the present invention for achieving the above object is provided with a black oxide layer produced by the above method.

Hereinafter, a solution for forming a black oxide layer on a metal thin film according to an embodiment of the present invention, a method of forming a black surface on a metal thin film of an electromagnetic shielding filter using the same, and an electromagnetic shielding filter formed thereby Will be described in detail.

A plasma display panel (hereinafter referred to as "PDP"), which is a kind of display, will be described with reference to FIG.

As shown in the drawing, the PDP 10 includes a front glass substrate 11 and a rear glass substrate 13 which form a discharge space by keeping minute intervals from each other. Discharge gas is enclosed in the discharge space between the front glass substrate 11 and the rear glass substrate 13, and the phosphor applied to the partition 13a of the rear glass substrate 13 by exciting the discharge space is excited. The light is displayed to display the screen. The drive controller 15 is installed on the rear surface of the rear glass substrate 13, and the optical film filter 17 is installed on the front surface of the front glass substrate 11. The optical film filter 17 has an antireflection film 17a, an electromagnetic wave shielding filter 50, and a color correction / near infrared shielding film 17b. Reference numeral 19 is a frame.

As shown in FIG. 3, the electromagnetic shielding filter 50 for shielding harmful electromagnetic waves emitted from an electronic component has a transparent substrate 51, a metal thin film 53, and a transparent resin 57. The transparent substrate 51 supports the metal thin film 53, and the metal thin film 53 is formed on the upper surface of the transparent substrate 11 to shield electromagnetic waves. The metal thin film 53 is made of a conductive metal such as Cu, and a mesh 53a is formed on the metal thin film 53. The transparent resin 57 is coated on the metal thin film 53 on which the mesh 53a is formed, and the transparent resin 57 improves light transmittance by flatly coating a portion of the mesh 53a of the metal foil 53. The black oxide layer 54 is formed on at least one of the upper, lower, and side surfaces of the metal thin film 53 on which the mesh 53a is formed. The black oxide layer 54 is formed before or after forming the metal thin film 53 on which the mesh 53a is formed on the upper surface of the transparent substrate 51. Reference numeral 59 is an adhesive layer.

The black oxide layer 54 formed on the metal thin film 53 according to the present embodiment has a planar structure. To this end, the solution for forming the black oxide layer on the metal thin film according to the present embodiment is 30 to 100 g of chlorite (Alkali Metal Chlorite), 10 to 30 g of sodium hydroxide (Sodium Hydroxide), and sodium phosphate (Trialkali Metal) to 1 l of water. In addition to 0.1 to 10 g of phosphate, 0.1 to 0.4 g of ethylene glycol (Ethlene Glycol), 0.01 to 10 g of hydrochloric acid, 0.2 to 10 g of amino acids and 0.1 to 10 g of pyrophosphoric acid (Popper Pyrophosphate) are added. Solution.

In detail, chlorites react with Cu to produce copper hydrate (Cu (OH) ₂ ), and sodium hydroxide reacts with copper hydrate to form copper complex salts (Na (Cu (OH) ₄ )). This is as described above. Sodium phosphate prevents the natural decomposition of sodium chlorite and refines the black oxide layer, and ethylene glycol reduces the tension of the Cu surface and refines the structure. In addition, hydrochloric acid reduces the sheet resistance value of the black oxide layer to 0.1 Ω / □ (Square: hereinafter omitted) by adjusting the formation rate of copper oxide and nitrous oxide described above, and amino acids modify the structure of the black oxide layer to planar tissue. At the same time, reduce the surface resistance to 0.1Ω / □ or less. Finally, the pyrophosphate system activates the black oxide layer forming solution to reduce the blackness (L *) of the black oxide layer to 30 or less.

Next, various embodiments of forming a black oxide layer on a metal thin film using a solution according to the present embodiment will be described.

Example 1

60 g of potassium chlorite, 27 g of sodium hydroxide, 3 g of H ₂ NaPO ₄ , soda phosphate, 1.3 g of hydrochloric acid, 2.7 g of amino acid, and 1.2 g of ethylene glycol were mixed and maintained at 40 to 90 ° C., followed by mesh formation. After immersing the thin film for 30 seconds to 10 minutes to form a black oxide layer, the surface texture, surface resistance value and blackness were respectively photographed and measured. At this time, the black oxide layer was formed on the upper surface of the metal thin film and the side surface of the metal thin film forming the mesh.

As shown in FIG. 4A, the surface structure of the black oxide layer 54 was formed in a planar structure, and the hardness thereof was superior to the characteristic value 25.0 required to be 36.02. And the surface resistance value obtained the same characteristic as the characteristic value calculated | required at 0.10 kPa / square, and blackness (L *) was superior to the characteristic value 30 requested at 25.43, as shown in FIG. 4B.

Example 2

To 1 liter of water, 60 g of potassium chlorite, 27 g of sodium hydroxide, 3 g of H ₂ NaPO ₄ , sodium phosphate, 1.3 g of hydrochloric acid, 2.7 g of amino acid, 1.2 g of ethylene glycol, and 0.5 g of Cu ₂ P ₂ O _{7 of} pyrophosphoric acid were mixed. After maintaining at 40 to 90 ° C., the metal thin film was immersed for 30 seconds to 10 minutes to form a black oxide layer, and surface texture, surface resistance value, and blackness were respectively photographed and measured. At this time, the black oxide layer was formed on the upper surface of the metal thin film and the side surface of the metal thin film forming the mesh.

As shown in Fig. 5A, the surface structure of the black oxide layer 54 was formed in a planar structure, and thus the hardness was 27.68, which was superior to the required characteristic value 25.0. The sheet resistance value was better than the characteristic value 0.1 mW / square required at 0.09 kV / square, and the blackness level L * was superior to the characteristic value 30 required at 16.62, as shown in Fig. 5B.

That is, an appropriate amount of sodium phosphate, ethylene glycol, hydrochloric acid, amino acids and pyrophosphoric acid is added to the solution for forming the black oxide layer on the metal thin film according to the present embodiment. Due to the additive, the black oxide layer 54 formed on the metal thin film 53 is formed in a planar structure. As a result, the black oxide layer 54 has the characteristics of hardness of 25 or less, blackness (L *) of 30 or less, and sheet resistance of 0.1 kΩ / square or less, which are required by the electromagnetic wave shielding filter for PDP during display.

As described above, when the black oxide layer is formed on the metal thin film by using the solution for forming the black oxide layer on the metal thin film according to the present invention, the black oxide layer is formed into a planar structure. The characteristic of the figure becomes excellent. As a result, the efficiency of shielding the electromagnetic wave from the electromagnetic shielding filter is improved, and the contrast of the display provided with the electromagnetic shielding filter is improved.

In the above, the present invention has been described in accordance with one embodiment of the present invention, but those skilled in the art to which the present invention belongs and also changes and modifications within the scope without departing from the spirit of the present invention Of course.

Claims (6)

30 to 100 g of Alkali Metal Chlorite, 10 to 30 g of Sodium Hydroxide, 0.1 to 10 g of Trialkali Metal Phosphate, 0.1 to 0.4 g of Ethlene Glycol, per liter of water A solution for forming a black oxide layer on a metal thin film, comprising 0.01 to 10 g of hydrochloric acid and 0.2 to 10 g of amino acids. 30 to 100 g of Alkali Metal Chlorite, 10 to 30 g of Sodium Hydroxide, 0.1 to 10 g of Trialkali Metal Phosphate, 0.1 to 0.4 g of Ethlene Glycol, per liter of water A solution for forming a black oxide layer on a metal thin film, comprising 0.01 to 10 g of hydrochloric acid, 0.2 to 10 g of amino acids, and 0.1 to 10 g of copper pyrophosphate. delete After maintaining the solution according to claim 1 or 2 at 40 to 90 ° C., a metal thin film made of Cu formed with a mesh is deposited in the solution for 30 seconds to 10 minutes, and the upper and lower surfaces of the metal thin film and the mesh Forming a black oxide layer on the metal thin film of the electromagnetic shielding filter, characterized in that to form a black oxide layer on at least one side of the side of the metal thin film to form a. A metal thin film of an electromagnetic shielding filter, comprising a black oxide layer prepared by the method according to claim 4. delete

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