JPH02138467A - Differential pressure sealing method - Google Patents

Abstract

PURPOSE:To prevent the generation of flaws and stains on the treated surface of a strip, etc., by providing plural differential pressure vacuum chambers between a high-pressure vacuum treatment chamber and a low-pressure vacuum treatment chamber and controlling the pressures thereof to specific values at the time of subjecting the material, such as strip, to surface treatments in the two chambers of the different pressures. CONSTITUTION:The material to be treated, such as strip, is subjected to the surface treatment by a method, such as plasma CVD, in the high-pressure vacuum treatment chamber P1 and is then passed through slits S1 to S5 in the plural differential pressure chambers D1 to D4 and is subjected to the 2nd surface treatment by a method, such as sputtering, in the low- pressure vacuum treatment chamber P2. The pressure in the respective differential pressure chambers D1 to D4 are gradually lowered in this case; in addition, the pressure in the differential pressure chamber D1 adjacent to the high-pressure vacuum treatment chamber P1 is so controlled as to be higher than the pressure in the low-pressure vacuum treatment chamber P1. The pressure in the differential pressure D4 adjacent to the low-pressure vacuum treatment chamber P2 is so controlled as to be lower than pressure in the high-pressure vacuum treatment chamber P2, and the pressure differences between the respective differential pressure chambers are controlled to specified values. The intrusion of the treating gas and contaminants in the high-pressure vacuum treatment chamber P1 into the low-pressure vacuum treatment chamber P2 is prevented and, therefore, the surface-treated strip having the treated surface free from flaws and stains is obtd.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is applicable to a processing line in which a material in the form of a strip or web is continuously passed through two or more vacuum processing chambers with different pressures for coating, etc. , relates to a method of sealing differential pressure between vacuum processing chambers.

[Prior art] In order to impart decorative properties, corrosion resistance, abrasion resistance, etc. to strips and web-like materials, ion blasting, sputtering, plasma CVD (chemical vapor deposition), etc. are used in vacuum.
Coating techniques are being developed in which a ceramic or metal film is continuously formed on the surface of a material by performing vacuum evaporation or deposition. When carrying out two or more of these coating processes on one line, or when performing ion bombardment as surface treatment for coating, it is necessary to pass the material continuously through vacuum processing chambers with different pressures, and high-pressure vacuum processing is required. It is necessary to seal the differential pressure between the chamber and the low-pressure vacuum processing chamber, maintain the gas introduction amount ratio of each vacuum processing chamber constant, and maintain the atmosphere of each vacuum processing chamber.

As a conventional differential pressure sealing method in such a continuous vacuum processing line, a number of differential pressure vacuum chambers are provided between a high pressure vacuum processing chamber and a low pressure vacuum processing chamber, and a slit for material passage is provided between each vacuum chamber. the pressure in at least one specific differential pressure vacuum chamber is higher than the pressure in the high pressure vacuum processing chamber, or the specific differential pressure vacuum chamber and the high pressure A method for preventing contaminants from a high-pressure vacuum processing chamber from flowing into a low-pressure vacuum processing chamber by lowering the pressure of at least one differential pressure vacuum chamber between the vacuum processing chambers than the pressure of a specific differential pressure vacuum chamber. (Tokuko 1977
-6576), a method of ensuring differential pressure by arranging a pair of upper and lower seal rolls in a slit part and passing a strip material between the seal rolls (Japanese Patent Application Laid-Open No. 13572/1982)
etc. are known.

[Problems to be Solved by the Invention] Among conventional differential pressure sealing methods, the method disclosed in Japanese Patent Publication No. 44-6576 maintains a constant pressure difference between the differential pressure vacuum chamber adjacent to the high pressure vacuum processing chamber and the high pressure vacuum processing chamber. Because it is not controlled
When the pressure in the differential pressure vacuum chamber changes, the gas flow rate flowing through the slit between the differential pressure vacuum chamber and the high pressure vacuum processing chamber changes, affecting the gas introduction amount ratio, gas flow distribution, etc. in the high pressure vacuum processing chamber, and increasing the high pressure. A problem arises in the processing of the vacuum processing chamber.

For example, SiH4, N20. Ar
A mixed gas of s + o, I is introduced by plasma CvD.
When generating IQ, when the flow rate of gas (for example, Ar gas) flowing in from the slit changes, the gas flow mold ratio and the partial pressure of each gas introduced into the high-pressure vacuum processing chamber change, and the Si
n, changes the composition ratio of Si and 0 in the film, causing a decrease in corrosion resistance, which is a film quality. Further, due to a change in the gas flow rate flowing through the slit, the gas flow distribution within the high-pressure vacuum processing chamber is disturbed, leading to problems such as non-uniform film thickness distribution.

In addition, in the method of Japanese Patent Publication No. 44-6576, the pressure in the differential pressure vacuum chamber is always higher than the pressure in the low pressure vacuum processing chamber, and the scum for differential pressure sealing flows into the low pressure vacuum processing chamber. If a gas other than gas for differential pressure sealing is used in the chamber, problems may occur due to the effect on the ratio of the amount of gas introduced into the low-pressure vacuum processing chamber.

For example, when producing a TiN film by reactive sputtering using N2 gas as a reaction gas and a Ti target in a low-pressure vacuum processing chamber, a slit is inserted into the low-pressure vacuum processing chamber from a differential pressure vacuum chamber adjacent to the low-pressure vacuum processing chamber. When the amount of gas (for example, Ar gas) flowing through the chamber changes, the gas flow rate ratio and the partial pressure of each gas introduced into the low-pressure vacuum processing chamber change, the state of the plasma changes, and the Ti and This causes a change in the composition ratio of N, resulting in a decrease in film quality such as decoration, color tone, hardness, and abrasion resistance.

On the other hand, methods using seal rolls such as those disclosed in JP-A No. 62-13572 have excellent sealing effects due to their high airtightness, but the problem is that surface flaws and stains occur because the seal rolls come into contact with the treated surface of the material. There is.

The present invention reliably seals the differential pressure between the vacuum processing chambers in a processing line in which a material in the form of a strip or web is continuously passed through two or more vacuum processing chambers with different pressures for coating, etc. In addition, the purpose of the present invention is to provide a differential pressure sealing method that allows stable processing such as coating by preventing the atmospheres of each vacuum processing chamber from being influenced by each other, and which does not cause scratches or stains on the processing surface. do.

[Means for Solving the Problems 1 Effect] The differential pressure sealing method according to claim 1 of the present invention for achieving the above object provides two or more differential pressure vacuum chambers between a high pressure vacuum processing chamber and a low pressure vacuum processing chamber. are provided in series, each of the differential pressure vacuum chambers, the high pressure vacuum processing chamber, and the low pressure vacuum processing chamber are connected to each other via a slit, and the pressure of the differential pressure vacuum chamber adjacent to the high pressure vacuum processing chamber is controlled by the pressure of the differential pressure vacuum chamber adjacent to the high pressure vacuum processing chamber. It is characterized by being higher than the pressure in the high-pressure vacuum processing chamber and controlling the pressure difference to be constant.

Further, in the differential pressure sealing method according to claim 1, the pressure in the differential pressure vacuum chamber adjacent to the low pressure vacuum processing chamber is set to the pressure in the low pressure vacuum processing chamber. It is characterized by being lower than.

[Operation] The differential pressure sealing method of the present invention will be explained using a specific example shown in FIG.

Two or more (four in the figure) differential pressure vacuum chambers DI, D2. D3. D4
are installed in series, and each differential pressure vacuum chamber, , D2. D3. D4, the high-pressure vacuum processing chamber P1, and the low-pressure vacuum processing chamber P2 are connected to each other by slits St, S2. Connected via S*, S, , Ss,
The pressure in the differential pressure vacuum chamber D1 adjacent to the high pressure vacuum processing chamber P1 is controlled to be higher than the pressure in the high pressure vacuum processing chamber P1, and the pressure difference is kept constant. The pressure of the differential pressure vacuum chamber D4 adjacent to the low pressure vacuum processing chamber P2 is made lower than the pressure of the low pressure vacuum processing chamber P2.

High pressure vacuum processing chamber P2. Low pressure vacuum processing chamber P2 and differential pressure vacuum chambers DI, D2. D3. D4 is exhausted by the exhaust device 9, and gas is introduced into the high-pressure vacuum processing chamber P1 and the low-pressure vacuum processing chamber P2, and various treatments are performed on the material to be processed. Differential pressure vacuum chamber, D2. D3. If the pressure of D4 is simply lowered one after another, the gas in the high pressure vacuum processing chamber P will flow into the low pressure vacuum processing chamber P2, causing a problem in the processing in the low pressure vacuum processing chamber P2. In the method of the present invention according to claim 1, the differential pressure vacuum chamber D1 adjacent to the high pressure vacuum processing chamber P1
By making the pressure higher than the pressure in the high-pressure vacuum processing chamber PI, gas in the high-pressure vacuum processing chamber P1 is prevented from flowing into the low-pressure vacuum processing chamber P2. The gas flowing from the differential pressure vacuum chamber D1 into the high pressure vacuum processing chamber PI is controlled so that the difference between the pressure in the high pressure vacuum processing chamber P and the pressure in the differential pressure vacuum chamber D1 adjacent thereto is constant. The amount of -
- The pressure and gas introduction ratio of the high-pressure vacuum processing chamber Pl are maintained constant.

Furthermore, in the method of the present invention according to claim 2, the pressure of the differential pressure vacuum chamber 04 adjacent to the low pressure vacuum processing chamber P2 is lowered than the pressure of the low pressure vacuum processing chamber P2. Gas in the differential pressure vacuum chamber D4 does not flow in. Since both compartments are at low pressure, the amount of gas flowing out from the low-pressure vacuum processing chamber P2 to the differential pressure vacuum chamber D4 is small, so even if the pressure difference between the compartments is not controlled constant, the pressure difference between the low-pressure vacuum processing chamber P2 and the The pressure and the gas introduction ratio are kept constant.

In the example in Figure 1, the material to be treated such as a strip;
SO, St, S2, 53. S4. It is generally fed to the left and right through Si, 56. In this way, since the material to be processed is conveyed through the slit S, at least one side of the material to be processed H can be processed without contact. Therefore, no scratches or stains will occur on the processing surface [Example] A plasma CVD apparatus is designated as a high-pressure vacuum processing chamber P, a sputtering apparatus is designated as a low-pressure vacuum processing chamber P2, and a differential pressure vacuum chamber is installed as shown in FIG. A stainless steel strip was conveyed from right to left in FIG. 1 in four chambers, and the lower surface of the strip was coated. When exhausting each room, use the exhaust shutoff valve 8.
Leave it open.

This is done by adjusting the exhaust speed control valve 6.

The pressure in the differential pressure vacuum chamber D1 is made higher than the pressure in the high pressure vacuum processing chamber P and the pressure difference is controlled to be constant as follows. The gas introduction shutoff valve 7a is opened, and the opening degree of the gas introduction amount adjustment valve 5a is adjusted to introduce a gas having a predetermined composition into the high pressure vacuum processing chamber panel. The pressure setting value of the high-pressure vacuum processing chamber P1 is manually entered into the exhaust pressure control device 1a, and compared with the pressure signal of the vacuum gauge 48 provided in the high-pressure vacuum processing chamber P1, the evacuation is performed so that the difference becomes; The opening degree of the speed control valve 6a is automatically adjusted to exhaust the air. In addition, the pressure difference set value between the high pressure vacuum processing chamber P1 and the differential pressure vacuum chamber D1 is manually entered into the calculation device 3, and the pressure value based on the pressure signal of the vacuum gauge 48 is added thereto to obtain the gas introduction pressure. The control device 2 is manually operated to compare the pressure signal from the vacuum gauge 41) provided in the differential pressure vacuum chamber D1, and automatically adjust the opening degree of the gas introduction amount control valve 5b so that the difference becomes zero. Gas is introduced into the pressure vacuum chamber 0. The predetermined gas composition of the high pressure vacuum processing chamber P1 is
When the gas is a mixture of a reaction gas and a diluent gas, the gas introduced into the differential pressure vacuum chamber is used as the diluent gas.

The pressure in the differential pressure vacuum chamber D4 is made lower than the pressure in the low pressure vacuum processing chamber P2 in the following manner. Open the gas introduction shutoff valve 7C, set the opening degree of the gas introduction counterfeit control valve 5c for one week, and supply the gas of a predetermined composition to the low-pressure vacuum processing chamber P.
Introduced in 2. Input the pressure setting value of the low-pressure vacuum processing chamber P2 into the exhaust pressure control device l)), and compare it with the pressure signal of the vacuum gauge 4d provided in the low-pressure vacuum processing chamber P2, until the difference in value becomes zero. The opening degree of the exhaust speed control valve 6d is automatically adjusted as shown in FIG. In addition, the opening degree of the exhaust speed control valve 6C is set so that the pressure signal of the vacuum gauge 40 of the differential pressure vacuum chamber D4 is always lower than the pressure signal of 4d.
Exhaust 4. Note that the opening degree of the exhaust speed control valve 6C may be automatically adjusted based on the pressure signals from the vacuum gauges 40 and 4d.

The differential pressure vacuum chambers , D, , D are evacuated by an exhaust device 9b. Since gas is introduced into the O3 chamber, O2, O3
The pressure decreases in this order, and an appropriate pressure gradient is achieved by adjusting the opening degree of the exhaust speed control valve 6b and the opening degree of the gas introduction amount control valve 5b described above.

The above explanation is an example in which four differential pressure vacuum chambers are provided.
When the pressure difference between the high-pressure vacuum processing chamber P1 and the low-pressure vacuum processing chamber P2 is small, the number of differential pressure vacuum chambers may be small, and when the pressure difference is large, it is better to increase the number.

(Example 1) Ar gas was introduced into the low-pressure vacuum processing chamber P2, and a TiN target was sputtered to form a TiN film on the stainless steel strip. SiH and N20 are used in the high pressure vacuum processing chambers P and I.
A mixed gas of SiO and Ar is introduced onto the TiN film.
A film of □ was formed. Ar gas for differential pressure sealing was introduced into the differential pressure vacuum chamber Pl to make the pressure higher than that of the high pressure vacuum processing chamber Pl. The pressure in each chamber was as shown in FIG. 2, with the differential pressure vacuum chamber P2 being the highest pressure and the low pressure vacuum processing chamber P2 being the lowest pressure.

(Example 2) N2 gas was introduced as a reaction gas into the low-pressure vacuum processing chamber P, and a Ti target was sputtered to deposit T on the stainless steel strip.
A film of iN was formed. High pressure vacuum processing chamber P.

A mixed gas of 5il14, N20, and Ar was introduced into the T
A SiO□ film was formed on the iN film. Ar gas for differential pressure sealing was introduced into the differential pressure vacuum chamber O1 to make the pressure higher than that in the high pressure vacuum processing chamber P1. The pressure in each chamber was as shown in FIG. 3, with the differential pressure vacuum chamber D4 being the highest pressure and the differential pressure vacuum chamber D4 being the lowest pressure.

In both Examples 1 and 2, the pressure in each chamber was kept constant during the treatment, and the gas introduction amount ratio in the high-pressure vacuum treatment chamber P and low-pressure vacuum treatment chamber P2 remained unchanged, and a uniform film was formed over the entire length of the stainless steel strip. It was done.

The S i H4 introduced into the high pressure vacuum processing chamber P is a harmful gas, but since the pressure in the differential pressure vacuum chamber D1 is higher, the entire amount was exhausted by the exhaust device 9a.
It was only necessary to treat the exhaust gas.

Since the lower surface of the stainless steel strip was conveyed under tension so as not to come into contact with the slit S, a beautiful coating film without scratches or stains was obtained.

[Effects of the Invention] According to the method of the present invention as described above, in a processing line in which a strip or web-shaped material is continuously passed through two or more vacuum processing chambers with different pressures for coating, etc., each vacuum processing chamber is The differential pressure between the chambers is reliably sealed, and the ratio of gas introduced into each vacuum processing chamber does not fluctuate, making it possible to perform coatings and other processes stably.Furthermore, the processing surface is free from scratches and stains, making it beautiful. A treated surface is obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a specific example of an apparatus for carrying out the method of the present invention, FIG. 2 is a diagram showing pressure distribution in an embodiment of the present invention (Claim 1), and FIG. 3 is a diagram showing another embodiment of the present invention. It is a figure which shows the pressure distribution of (Claim 2). DESCRIPTION OF SYMBOLS 1... Pressure control device for exhaust, 2... Pressure control device for gas introduction, 3... Arithmetic device, 4... Vacuum gauge, 5...
・Gas introduction amount adjustment valve, 6... Exhaust speed steel jm valve, 7... Gas introduction shutoff valve, 8... Exhaust shutoff valve, 9... Exhaust device, D... Differential pressure vacuum Chamber, Pl...High pressure vacuum processing chamber, P2...Low pressure vacuum processing chamber, S...Slit.

Claims (1)

[Claims] 1. Two or more differential pressure vacuum chambers are provided in series between a high pressure vacuum processing chamber and a low pressure vacuum processing chamber, and each differential pressure vacuum chamber, the high pressure vacuum processing chamber, and the low pressure vacuum processing The chambers are connected to each other via a slit, and the pressure in the differential pressure vacuum chamber adjacent to the high pressure vacuum processing chamber is controlled to be higher than the pressure in the high pressure vacuum processing chamber, and the pressure difference is controlled to be constant. Differential pressure sealing method. 2. The differential pressure sealing method according to claim 1, wherein the pressure in a differential pressure vacuum chamber adjacent to the low pressure vacuum processing chamber is lower than the pressure in the low pressure vacuum processing chamber.