KR20010055796A - Manufacturing method of Al films having good adhesion - Google Patents

Abstract

PURPOSE: A method for manufacturing an aluminum film in which cohesion and deposition efficiency are improved is provided in which an aluminum film is formed by applying the ionization conditions to the ion plating after selecting a proper evaporation ratio as using an electronic beam evaporating source so as to find ionization conditions of aluminum generating a sufficient amount of ionization without using of a separate gas for ionization. CONSTITUTION: In manufacturing a film for extending the life cycle and improving the performance of a material by forming an aluminum film on the material in an ion plating method, the method for manufacturing an aluminum film in which cohesion and deposition efficiency are improved comprises the process of simultaneously evaporating aluminum (12) and ionizing the aluminum, thereby forming an aluminum film on the surface of a material without using a separate gas for ionization with a proper evaporation ratio for the ionization being 0.5 microns/min or more under the conditions that a voltage of an ionization electrode is 40 to 70 V, a current of the ionization electrode (3) is 8 to 30 A, and a current of a filament (4) is 40 to 50 A respectively.

Description

Manufacturing method of aluminum film with improved adhesion and deposition efficiency {Manufacturing method of Al films having good adhesion}

The present invention relates to a method for manufacturing an aluminum film used to improve the corrosion resistance and decoration by depositing an aluminum film on a material, in particular, by using an ion plating method using an electron beam evaporation method, by selecting an appropriate evaporation rate to separate ionization The present invention relates to a method for producing a fine aluminum film having improved adhesion, density and deposition efficiency by ionizing only an ionization electrode and a filament without using a gas.

In general, aluminum has a beautiful color and excellent corrosion resistance, and is widely used for decorative coatings such as cosmetic cases and accessories, as well as conductive films for semiconductors, protective films for magnetic materials, and steel sheets. In addition, aluminum has a wide variety of industrial applications due to its own properties (low density, excellent workability, corrosion resistance and thermal conductivity).

Recently, as the space development and the aviation industry are greatly developed, researches to improve the corrosion resistance and mechanical properties by actively coating aluminum on various materials have been actively conducted. McDonnell Douglas, for example, uses aluminum as a coating and abrasion resistant material for various parts used in airplanes.In Germany, vacuum deposition of aluminum on steel sheets is used for containers and home appliances. Is immeasurable.

Such aluminum has a low physical efficiency when coated with electroplating, so most of them use physical vapor deposition. Physical vapor deposition includes vacuum deposition, sputtering, and ion plating. For the purpose of improving corrosion resistance, ion plating is generally used. In particular, an aluminum coating known as AC coating in McDonnell Douglas Corporation or Sumitomo Special Metal is known. It produces and sells products.

Aluminum coatings generally contain many holes in the coating layer and also have a disadvantage of poor adhesion to the substrate. To solve this problem, the substrate must be heated to a high temperature in vacuum deposition, and applied to the substrate in ion plating. In order to increase the voltage or increase the ionization rate, it is necessary to introduce a larger amount of discharge gas. However, when the substrate is heated to a high temperature, not only the substrate is damaged but also the adhesion amount decreases as the substrate becomes a high temperature, thereby reducing economic efficiency, and a method of applying a high voltage to the substrate also damages the substrate. When the amount of discharge gas is increased to increase the ionization rate, the discharge gas is mixed into the film, which damages the film, and scattering occurs between the discharge gas and the evaporated aluminum, which also causes a decrease in adhesion amount.

In order to solve the above problems, various methods of vacuum deposition, sputtering, ion plating apparatus or method (Japanese Patent Publication 59-28569, Japanese Patent Publication 61-59861, British Patent Publication 2141442, Japanese Patent Publication Fire extinguishing 57-95749, British Patent 2162205, and Japanese Patent 7942676) have been developed, and are mainly technologies related to film uniformity and adhesion between film and substrate, stability of generated plasma, material and structure of evaporation source, high ionization rate and the like. The inventors of the present invention also filed a patent application to solve the problems described above "Method of forming a film with excellent adhesion and surface properties (Korean Patent No. 205117)" and "Method of manufacturing a high corrosion-resistant aluminum film for small sintered parts (Korean patent) Publication 99-52861), which also uses an inert gas, although at a high vacuum of 10 ^-4 Torr or less. In the case of an electron beam evaporation source, argon gas was generally used as a discharge gas for stable plasma.

In addition, the inventors of the present invention as a patent application using a number of filaments while using a resistance heating evaporation source "a method for producing an aluminum film by arc discharge induction ion plating (Korean Patent No. 66523)" Although the method does not use gas, it does not have problems such as the limit of evaporation rate due to resistance heating source, increase of temperature of substrate by using multiple filaments and fluctuation of vapor distribution.

The present invention has been invented to solve the problems of the conventional aluminum film manufacturing method in view of the above situation, by selecting an appropriate evaporation rate using an electron beam evaporation source, a sufficient amount of ionization occurs without using a separate ionization gas. It is an object of the present invention to provide a method for manufacturing an aluminum film having improved adhesion and deposition efficiency for forming an aluminum film by finding an ionization condition of aluminum to be applied to ion plating.

1 is a block diagram of an ion plating apparatus for producing an aluminum film employed in the present invention

to be.

<Explanation of symbols for main parts of drawing>

1: vacuum chamber 2: evaporation source

3: ionization electrode 4: filament

5: shutter 6: thickness monitor

7: heating device 8: specimen holder

9: vacuum gauge 10: gas inlet

11 Psalm 12 Evaporate (Aluminum)

In order to achieve the above object, the present invention provides a method for producing an aluminum film having improved adhesion and deposition efficiency by coating aluminum on a material by an ion plating method to produce a film for extending the life or improving the performance of the material. The required evaporation rate is 0.5 µm / min or more, and no ionization gas is used, the voltage of the ionization electrode is 40-70 V, the current is 8-30 A, and the filament current is 40-50 A. Simultaneously ionizing while evaporating aluminum to form an aluminum film on the material surface.

Hereinafter, a method of manufacturing an aluminum film having improved adhesion and deposition efficiency will be described in detail.

The present invention is to prepare an aluminum film by installing an ionization electrode and a filament in a conventional ion plating apparatus. FIG. 1 is a configuration diagram of an ion plating apparatus for producing an aluminum film employed in the present invention, wherein an ionization electrode 3 and a filament 4 are first installed in a vacuum chamber 1 to ionize vapor. In addition to the inside of the vacuum chamber 1, an evaporation source 2, a shutter 5, a thickness monitor 6, a heating device 7, a specimen holder 8, a vacuum gauge 9 capable of measuring the degree of vacuum and a gas are injected. The gas introduction port 10 etc. which are mentioned are provided.

As the evaporation source 2, an electron gun evaporation source was used, but an alumina crucible (not shown) was used as a liner. The reason for using the alumina crucible is that the evaporation rate is limited in the water-cooled crucible due to the characteristics of aluminum. The specimen 11 should be pretreated before and after loading in the container. In the present invention, sandblasting was used as a pretreatment method before loading in the container.

The pretreatment method of the specimen 11 should be different depending on the characteristics of the specimen 11 to be treated, the contaminants to be removed, and the like. In the laboratory, ultrasonic cleaning using a cleaning agent or a solvent after a mild polishing is appropriate, but industrially, sand blasting and chemical cleaning are used. Contaminants typically present in components such as fixtures, tools and bearings include lubricants, cutting oils, oxides and fingerprints. In the present invention, an excellent commercial applicability, economic and environmentally friendly sand blast was used as a pretreatment. Charge the pre-treated specimen 11 into the barrel specimen holder 8, fill the evaporation source 2 with aluminum 12, close the vessel and evacuate to the desired vacuum using a vacuum pump (not shown). do.

When the vacuum is less than 10 ^-5 Torr, argon gas is injected to clean the specimen and a negative voltage is applied to the specimen to clean the specimen. Cleaning the specimen is a very important step and includes removing not only impurities such as organic matter present in the specimen, but also naturally occurring oxide films. If these impurities are not removed sufficiently, it will affect the adhesion and should be sufficiently cleaned. Specimen cleaning is usually performed by inducing a glow discharge by applying a negative voltage of 400 to 1,000 V to the specimen in an argon gas atmosphere of approximately 10 ^-2 Torr. In this way, argon ions present in the discharge region collide with the specimen to remove impurities present in the specimen. After the specimen is cleaned, the vacuum level is maintained at 10 ^-5 Torr or lower, and the coating is performed in earnest. After the film production is completed in vacuum, the specimen 11 is taken out, and then the surface roughness is removed and polished again using sandblasting to make a metallic shiny surface, and all the processes of aluminum film production are completed.

Next, a method of manufacturing an aluminum film having improved adhesion and deposition efficiency according to the present invention will be described in more detail.

Inventive Example 1 manufactures an aluminum film to improve the corrosion resistance of the nidium permanent magnet. Specimen 11 used in Inventive Example 1 was coated with 150 pieces of a plate-shaped niobium permanent magnet with a hole having an outer diameter of 24 mm, an inner diameter of 18 mm, and a thickness of 1.2 mm. The specimen 11 was subjected to sandblasting using alumina beads of # 200 mesh from the outside, and then loaded into the barrel specimen holder 8. Next, aluminum 12, which is an evaporate, was placed in the electron beam evaporation source 2, an ionization electrode 3 and a filament 4 were installed, and the vacuum chamber 1 was closed and exhausted using a vacuum pump.

When the vacuum degree was 10 ⁻⁵ Torr or less, 1.2 × 10 ⁻² Torr of argon gas was injected through the gas inlet 10 to clean the specimen 11 to perform secondary cleaning of the specimen by glow discharge. At this time, the voltage applied to the barrel was 500 V, and the current was 400 to 800 mA, and cleaning was performed for 20 minutes while rotating the barrel. After the cleaning of the specimen was finished and the vacuum degree again to 10 ^-5 Torr or less to prepare an aluminum film.

First, an electron gun power source was applied to the electron beam evaporation source 2, and aluminum was evaporated while power was applied to the ionization electrode 3 and the filament 4 to generate a stable plasma. Alumina crucibles were used to improve evaporation rate during evaporation of aluminum by electron beam, and the power of electron beam was adjusted to 10 kV, 150-400 mA. When the evaporation of aluminum is stabilized by the electron beam, the power is applied to the filament 4 so that a current of 50 A flows, and a voltage of 50 V is applied to the ionization electrode 3 to adjust the ionization current to 16 A. The voltage of the ionization electrode 3 is preferably in the range of 40 to 70 V. The reason is as follows.

When the voltage of the ionizing electrode 3 is 40 V or less, the ionization does not occur sufficiently, resulting in poor adhesion and density, and when the voltage of the ionizing electrode 3 is 70 V or more, the film may be damaged due to abnormal discharge or the like. Because of the size.

The current of the filament (4) is suitable for 40 ~ 60 A. The reason is that if the current of the filament (4) is 40 A or less, the ionization is not enough, and if the temperature is 60 A or more, the substrate temperature rises due to overheating of the filament (4). This is because abnormal phenomena such as or arc discharge are likely to occur, and the filament 4 itself is easily damaged by thermal deformation.

The current of the ionization electrode 3 is suitably in the range of 8 to 20 A because it is similar to the voltage of the ionization electrode 3 described above. When the plasma was stabilized, a voltage of 100 V was applied to the substrate, and the shutter 5 was opened while rotating the specimen holder 8, which is a barrel, and deposited for 2 hours. The thickness of the aluminum film coated on the specimen 11 was measured by using the thickness monitor 6, and the average thickness of 10 µm was deposited.

The following Examples and Table 1 are divided into the invention examples and comparative examples to explain the effects of the present invention and then compared the characteristics of the adhesion and the density, deposition efficiency and the like coated on the specimen.

Adhesion is divided into three stages by measuring with a tape test and a scratch tester, and the case of excellent adhesion is indicated by ●, and the case of dropping by tape as △ in the middle is indicated by ×.

The density of the film was expressed by the wet method after the amount of aluminum per unit area for the specimens of the same thickness was compared, and the amounts were shown as upper, middle and lower.

Deposition efficiency is a comparison of the time taken to form a certain thickness to increase productivity. When the deposition time up to 10 µm is within 30 minutes, it is in the range between 30 and 60 minutes. Marked with x. The calculation of the thickness of the deposited layer in this case means the average thickness on the fixed plate.

Inventive Example 2 is the same as that of Inventive Example 1 except that the film is prepared with an evaporation rate of 1.0 μm / min, a filament current of 45 A, an ionization current of 20 A, and a substrate voltage of 50 V.

Inventive Example 3 is the same as that of Inventive Example 1 except that a film is prepared with an evaporation rate of 0.8 µm / min and an ionization current of 16 A.

Inventive Example 4 is the same as that of Inventive Example 1 except that the film is prepared with an evaporation rate of 1.0 μm / min, a filament current of 55 A, an ionization current of 24 A, and a substrate voltage of 50 V.

Inventive Example 5 is the same as that of Inventive Example 1 except that the film is prepared with an evaporation rate of 1.2 μm / min, a filament current of 40 A, an ionization current of 20 A, and a substrate voltage of 50 V.

Comparative Example 1 is a case of comparing the characteristics by depositing aluminum on the nidium magnet by the vacuum deposition method in order to compare with the invention example.

Comparative Example 2 is the same as Inventive Example 1, but using water-cooled copper as a crucible, 3x10 ^-4 Torr of argon gas was injected, the evaporation rate is 0.15 ㎛ / min, the filament current 50 A and the ionization current 16 A and the substrate This is the case where a film is manufactured with a voltage of 200V.

Comparative Example 3 is the same as that of Inventive Example 1 except that the film is prepared with an evaporation rate of 0.3 μm / min, a filament current of 50 A, and an ionization current of 2 A.

Comparative Example 4 was the same as that of Inventive Example 1 except that the film was prepared in a state in which the ionization current hardly flows with the filament current as 30 A.

Example No. Evaporation rate (㎛ / min) Filament Current (A) Ionizing Electrode Current (A) Substrate Voltage (V) Adhesion Density Deposition Efficiency Inventive Example 1 0.5 50 12 100 ● Prize ● Inventive Example 2 1.0 45 20 50 ● Prize ● Inventive Example 3 0.8 50 16 100 ● Prize ● Inventive Example 4 1.0 55 24 50 ● Prize ● Inventive Example 5 1.2 40 20 50 ● Prize ● Comparative Example 1 0.2 - - - × Ha △ Comparative Example 2 0.15 50 16 200 △ medium × Comparative Example 3 0.3 50 2 100 △ medium △ Comparative Example 4 0.5 30 - 100 △ Ha ●

As described above, when the aluminum film is manufactured by the method of the present invention, it is possible to lower the substrate voltage as compared to the existing method, and it is possible to economically manufacture the aluminum film with high deposition efficiency, excellent adhesion, and improved density. have.

Claims (1)

In the production of a film for extending the life or improving the performance of the material by coating aluminum on the material by ion plating method, the appropriate evaporation rate required for ionization is 0.5 μm / min or more, without using a separate ionization gas, Adhesion, characterized in that to form an aluminum film on the surface of the material by simultaneously ionizing while evaporating aluminum with a voltage of 40 to 70 V, an electric current of 8 to 30 A and a current of filament of 40 to 50 A Manufacturing method of aluminum film with improved deposition efficiency.