RU2297988C1 - Method and the device for deposition of the multilayered coatings on the sheet glass - Google Patents

Abstract

FIELD: plasma engineering; methods and the devices for deposition of the multilayered coatings on the sheet glass.

SUBSTANCE: the invention is pertaining to the plasma engineering, in particular, to the method and the device for deposition of the multilayered modifying coatings made out of the metals, their oxides, nitrides and other compounds on the sheet glass and may be used for change and improvement of the optical properties of the sheet glass. The technical result of the invention is the increased productivity and efficiency of operation of all the assemblies of the device. The device contains the mounted in series first sluice chamber, the vacuum lock, the working chamber with the magnetron spray system, the second vacuum lock, the second sluice chamber, which are connected with the system of the vacuum-pumping and injection of the working gas. In the both sluice chambers there are cartridges with the plug-in accumulators for arrangement of the batch of the processed sheet glass. Transferring the sheets of the glass from one cartridge into another and vice versa with the minimum clearance between them conduct the sequential deposition of each layer of the coating onto each sheet of the whole batch of the sheet glass. The change of the gas medium of the working area is made once for the whole batch for each layer.

EFFECT: the invention ensures the increased productivity and efficiency of operation of all the assemblies of the device.

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Description

The invention relates to a plasma technique and can be used to change and improve the optical properties of sheet glass by applying multilayer thin coatings on it, in particular heat-reflecting coatings (TOP).

TOP is usually an oxide-metal-oxide film composition, each of which can consist of several layers (multilayer coatings can increase the coefficient of resistance to heat flux).

The coating is formed as a result of the interaction of the plasma with the cold surface of the glass. Its source is the magnetron sputtering system (MPC). If the medium contains a reactive gas, for example oxygen, nitrogen, then plasma-chemical reactions are possible, which lead to the formation of oxides, nitrides, and other compounds. In this way, it is possible to create multilayer coatings effective in terms of optical properties, which are very difficult to obtain by other methods.

The leading countries of the world in the field of plasma technologies (Germany, USA, etc.) have long and successfully developed and manufactured plants for applying modifying plasma coatings. These are mainly industrial automated lines for the production of flat glass with heat-reflecting coatings (TOP) with a productivity of 1 ÷ 10 million square meters per year and at a price of 10 ÷ 100 million US dollars (i.e. the unit cost of the equipment is 10 or more dollars per 1 m ^{2 of} annual output).

Similar in purpose, but more efficient, are VON ARDENNE installations (Germany, Dresden) of the GC 124 VC / CR models with a vertical position of the processed glass of size 2060 mm × 1240 mm and GC 321 N with a horizontal arrangement of the processed glass of 3210 mm × 6000 mm (VON ARDENNE. Aniagen technik. Www.ardenne-at.de). From the point of view of the technological process, they are close.

Their method of applying a multilayer coating consists in the fact that each layer is applied sequentially as the glass moves relative to the plasma sources and various gaseous media responsible for the deposition of a certain type of film. Moreover, the process is carried out in a single-pass mode, i.e. the glass moves in one direction and at the exit of the installation all coating layers are formed on it.

The main disadvantage of such single-pass devices is the very large longitudinal dimensions. So, the dimensions of the above installations, together with auxiliary equipment, are in the plan respectively 46 m × 11 m and 79 m × 12 m.

In addition, multilayer heat-reflecting coatings have a low hardness, which makes it difficult to transport coated glass due to the possibility of damage. Therefore, in close proximity it is necessary to have the production of double-glazed windows. In turn, the transportation of double-glazed windows, as well as other large-sized glass products, is also associated with difficulties.

In Russia, due to the need to transport processed glass over long distances, relatively small plants with a capacity of approximately 50–200 thousand m ² per year with a unit cost of equipment in the range of 4–5 US dollars per 1 m ^{2 of} annual output are more economically feasible. Such installations include the device according to patent RU 2138094, which is selected as a prototype.

The device according to patent RU 2138094 contains a sealed working chamber with two lock chambers at the inlet and outlet. The lock chambers are separated from the working chamber by vacuum locks. In the working chamber is placed MPC, which may consist of one or more magnetrons. The device also contains a cassette in which the processed glass sheet is fixed, and a mechanism for moving the cassette along the working chamber. The unit is connected to a vacuum and gas inlet system.

Each sheet of glass loaded into the installation undergoes a full cycle of coating processing, including evacuation of the lock chamber, opening the vacuum shutter, moving the workpiece from the first lock chamber through the working chamber to the second lock chamber and vice versa. In this case, the treated surface is cleaned (during the first pass) and individual layers of coating are applied.

After the operation to apply the next layer (or layers if the MPC contains more than one magnetron) is completed, the working gas atmosphere is replaced with each glass sheet and the sheet passes again through the working chamber. The process is repeated until all coating layers have been deposited. Then the vacuum shutter closes, depressurization of the lock chamber and replacement of the processed product (glass) with the following are performed. Thus, each sheet of glass is completely processed with all the auxiliary operations, and only after that the next sheet is processed. As a result of this, the duration of the technological cycle is increased by two to three times, which is not characteristic of single-pass devices, where the processing cycle is minimal.

One of the options for this installation allows you to get a multilayer coating in one pass of the sheet through the working chamber. For this, the working chamber is divided by diaphragms into separate compartments, each of which is equipped with its own gas inlet system, and the MPC consists of several magnetrons located in the compartments. With this installation, it works on the principle of analogues, and the disadvantages inherent in analogues are manifested: an increase in size, complication of installation, and hence an increase in the cost of processing glass.

From all of the above it follows (and the timing of the working cycle on a real installation confirms this) that the proportion of effective work of the MPC is less than half of the total resource of the working time of the installation.

The objective of the invention is the application of multilayer modifying coatings on sheet glass at the lowest cost.

The technical result of the invention is to increase the utilization rate of all units of the installation due to the new technological scheme for processing glass.

An additional technical result for a particular variant of the method is to reduce the dependence of the quality of the coating on the surface condition of the glass used.

To solve this problem, a new method has been developed for applying multilayer modifying coatings to sheet glass by plasma spraying, which, like the prototype, consists in feeding each sheet to the working chamber, applying individual layers of coating by passing glass through the working chamber with plasma sources with replacement if necessary working gas environment.

Unlike the prototype, at the initial stage of the process, the entire processed batch of sheets is loaded into the installation, each operation of applying separate layers is carried out sequentially on all sheets of the batch, moving them through the working chamber in a continuous stream with a minimum distance between them, then the gas medium and / or sources are replaced plasma and each subsequent operation of applying layers is also carried out on the entire processed batch of sheets.

Thus, the entire loaded batch of glass is evacuated from atmospheric pressure once. While the prototype after processing each sheet of glass is depressurized lock chamber, which is accompanied by the adsorption of air components on the internal structural elements and there is a need to remove them. With one setting of the gas medium, the entire batch of glass loaded into the device is subjected to the application of one layer (or layers) of coating. As a result, the replacement of the gas medium in the working chamber for applying a certain coating layer to the entire batch of glass is performed once, while in the prototype, the replacement of the gas medium for the corresponding coating layers is performed for each glass sheet. This helps to reduce the duration of the working cycle and reduce residual gases in the atmosphere of the working chamber, affecting the quality of the coating.

In addition, when applying each coating layer, the glass sheets move in a continuous stream. The gap between them does not exceed a few percent of the length of the sheet of glass, therefore, the magnetrons consume the material of their cathodes more rationally (losses do not exceed 10-15%, against 50-60% of the prototype).

To implement the proposed method, a device has been developed that, like the prototype, contains a working chamber with a magnetron spray system (MPC), a vacuum system and a working gas inlet, lock chambers at the inlet and outlet of the working chamber, separated from it by a vacuum shutter, as well as supply mechanisms sheet into the working chamber and moving it along the working chamber.

Unlike the prototype, each airlock is equipped with a magazine containing a removable drive for placing more than one sheet of glass in it and a drive stepping mechanism in the direction transverse to the longitudinal axis of the working chamber, synchronized with the mechanism for supplying the glass to the working chamber.

The removable drive is made in the form of a frame with slots for accommodating sheets of glass equipped with rollers for feeding sheets of glass into the working chamber. Removable drives allow loading and unloading of glass outside the unit during processing of another batch. When loading and unloading glass into the airlock, the entire batch of glass loaded into the drive is placed in the airlock.

Stores are used both to place glass inside the device and to reverse it during processing. There is no need to install separate reversing cameras.

The invention is illustrated by graphic materials, which schematically show:

Figure 1 is a General view of the proposed device in section, top view;

Figure 2 - the lock chamber of the device in a section along aa;

Figure 3 is the same, a section along BB.

The device (Fig. 1) consists of a lock chamber 1, which is connected through a vacuum shutter 2 to the working chamber 3. In the working chamber 3 are ion sources 4 and MPC, made in the form of turrets 5, which include two or more each magnetron 6. On the other side of the working chamber 3 there is a second lock chamber 7, separated from the working chamber by a second vacuum shutter 8. To reduce the cost, the chamber 7 can be connected directly to the working chamber 3 without a vacuum shutter, but this reduces the functionality of the devices and, since the second lock chamber 7 will only perform the functions of reversing and accumulating the processed products. Both lock chambers have doors 9 for loading processed products. In the case of the second lock chamber 7 without a vacuum shutter 8, its door 9 serves to repair and service the elements located inside the chamber.

The lock chambers 1 and 7 and the working chamber 3 are connected to a vacuum and gas inlet system (not shown).

To move the glass from the lock chamber 1 through the vacuum lock 2 into the working chamber 3 in the lower part of the lock chamber 1 is a glass feed mechanism 10 (Fig. 2,). A similar mechanism is located in the second lock chamber 7.

Shops 11 are located in each of the lock chambers 1 and 7. Shop 11 contains a removable drive 12 for accommodating a batch of sheet glass 13. The replaceable drive 12 (Fig. 2) is equipped with a device for its stepwise movement across the longitudinal axis of the working chamber 3. In this particular of construction, this mechanism is a trolley 14, which has the ability to move along the guides 15 (Fig.3) located in the upper part of both lock chambers 1 and 7. A removable drive 12 is attached to the lower part of the trolley 14. The stepwise movement of the trolley 14 provides Chiva driving mechanism comprising lead screw 16 and nut 17, and the stepping motor 18 (with gear, if necessary). Rotation from the stepper motor 18 to the sealed chamber is transmitted through the vacuum inlet 19. To synchronize the drive mechanism with the glass feed mechanism 13, a displacement sensor 20 is provided in the working chamber 3.

The removable drive 12 is a frame with guides 21 equipped with rollers on which sheet glass 13 is placed and moved during processing. Glass sheets are arranged with an inclination of 5 ° ... 9 ° from the vertical parallel to the direction of their working movement.

The loading and unloading of glass in the removable drive 12 is carried out outside the lock chamber. Therefore, for normal operation, at least one additional drive 12 is required.

Ion sources 4 in the working chamber 3 are located on both sides of the glass sheet 13. Two-sided treatment with accelerated ions makes the process less dependent on the quality of the glass surface, since accelerated ions reliably remove contaminants, adsorbed gases and moisture.

MPC in this device design is represented by three turret heads 5. Each turret 5 is a block of extended magnetrons 6 located and fixed parallel to each other around a common longitudinal axis. There is a device that allows you to rotate the magnetron block around its axis (not shown) to bring each magnetron to its working position. Through the longitudinal axis, power and coolant are supplied to the magnetrons. The use of turrets 5 can reduce the length of the working chamber 3 in two to three times, while the idle magnetrons are protected from unwanted spraying working.

The working chamber 3 consists of one or several modules, each of which contains one turret 5 or an ion source 4. Between the modules of the working chamber, if necessary, pumping modules are installed, which are chambers connected to a pumping vacuum system.

The use of prefabricated modular working chambers is preferable, since it allows changing the installation parameters without high costs.

The operation of the device is as follows.

Initial position (figure 1): the sheets of glass 13 are washed, dried and placed in the accumulator 12, and to accelerate the desorption of gases and water vapor, the glass can be heated to a temperature of at least 90 ° C. (Above 300 ° C, the glass is not heated during processing.) The number of sheets can be from two to several tens. The most optimal is the amount of glass processed in one shift or half. The working chamber 3 and the lock chamber 7 are evacuated. Magnetron turrets 5 and ion sources 4 are brought into working condition.

The loading device through the door 9 feeds the drive 12 with the glass 13 into the lock chamber 1, where it fixes it in the trolley 14 of the store 11.

The door 9 of the lock chamber 1 is closed. Vacuuming is performed. At this time, the drive 12 is brought into a position in which the first glass rises to its working position.

After reaching the set pressure, the vacuum shutter 2 opens. The glass feed mechanism 10 of the lock chamber 1 is turned on, which is connected to the glass moving mechanism 22 of the working chamber 3, and the glass enters the working chamber 3, where its surface is cleaned with a beam of accelerated ions of source 4 and applied the first coating layer with magnetrons 6. Glass sheets at the entrance to the working chamber can be heated to a temperature of not more than 300 ° C.

As soon as the trailing edge of the previous glass, leaving the magazine 11 in the working chamber 3, makes room for the magazine 11 to be moved with the glass, the transverse feed sensor sends a signal to the control unit of the stepper motor 18, and it moves the magazine 11 by one position. After that, the glass feed mechanism 10 of the lock chamber 1 will work and the next glass will begin to move into the working chamber 3. This cycle is repeated until the magazine 11 of the lock chamber 1 is completely empty.

After passing through the working chamber 3, the glass enters the corresponding slot in the magazine 11 of the second lock chamber 7. After the sensor 20 is activated, it signals that the glass has reached its normal position, the magazine 11 moves one position. Gradually, all the glass from the store 11 of the first lock chamber will move to the store 11 of the second lock chamber 7. After that, they change their functions, now the entire batch of glass moves in the opposite direction, and the next coating layer is applied.

After the next operation in the device, the gas medium is replaced, the turrets with magnetrons are switched to the cathodes corresponding to the next coating layer. Then, in the same order, the following operation is performed.

The application of this processing principle can reduce idle time losses, changes in the composition of the gas medium and downtime of unused magnetrons. Glasses move with an interval determined by the ratio of the speeds of the store, glass in the store and in the working chamber.

For example, in the manufacture of glass with TOP based on silver: T102 [32 nm] - Ni alloy (80%) - Cr (20%) [1 nm] - Ag [10 nm] - Ni-Cr alloy [1 nm] - TiO ₂ [36 nm], three turrets are enough, each of which will contain at least two magnetrons. Considering that the wear of the cathode for deposition of oxide coatings is higher, two cathodes - sources of oxide can be installed in each of the turrets, and in some cases in three magnetrons. Thus, when applying the oxide layer, all three turrets work as sources of oxides.

After the deposition of the oxide layer on the entire batch of glass loaded in the device, the turrets are switched in the following order. The first magnetron applies a barrier layer - Ni-Cr, the second - a reflective layer - silver, the third - the second barrier layer - Ni-Cr. These three layers are superimposed in one pass and, which is very important for the quality of such coatings, the time interval between their application is minimal. If this condition is not satisfied, the adsorption of atoms (molecules) of residual oxygen from the gas medium of the working chamber to the surface of the first barrier layer or oxidation of silver. This is a rejection mark.

After this operation is completed, as well as after the previous one, the gas environment of the working zone changes, and all three turrets switch to applying a second oxide layer.

Claims (4)

1. The method of applying multilayer modifying coatings on sheet glass by plasma spraying, which consists in the step-by-step application of individual coating layers with multiple passage of glass through the working chamber with plasma sources, characterized in that the entire batch of glass sheets to be processed and each coating operation are loaded into the installation carried out sequentially over all sheets of the party, moving them through the working chamber in a continuous stream with a minimum distance between them, then replace the gas medium and / or plasma sources and each successive step of applying the layers is also carried out on the entire batch of processed sheets. 2. Device for applying multilayer modifying coatings on sheet glass by plasma spraying, containing a working chamber with a magnetron spray system, a vacuum system and a working gas inlet, lock chambers at the inlet and outlet of the working chamber, separated from it by vacuum gates, a glass sheet feeding mechanism the working chamber and moving it along the working chamber, characterized in that each airlock is equipped with a magazine containing a removable removable drive to accommodate more than one sheet of glass and indexing drive mechanism transversely relative to the longitudinal axis direction of the working chamber, synchronized with the feeding mechanism of the glass in the working chamber. 3. The device according to claim 2, characterized in that the removable drive is made in the form of a frame with sockets for placing sheets of glass, equipped with rollers for moving sheets of glass into the working chamber and vice versa. 4. The device according to claim 2, characterized in that at the entrance to the working chamber there are two ion sources with a band-type beam, one on each side of the glass.

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