JPH0674863B2 - Automatic evacuation device for vacuum container - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vacuum container in which an exhaust port of a vacuum container is sealed with a seal flange having a permanent magnet attracted by a magnetic material attached to the exhaust port. Automatic exhaust device.

[Prior Art] For example, for storing and transporting semiconductor chips, a vacuum container and an automatic exhaust device for exhausting the inside of the vacuum container are used to maintain a clean state.

In the conventional automatic exhaust device, the valve operation and the like are performed manually, and no one with sufficient performance is found, and it lacks the ability to withstand high vacuum and maintain high cleanliness.

Generally, various kinds of magnetically operated vacuum break valves and sluice valves are known, for example, Japanese Utility Model Laid-Open No. 1-100965 and Japanese Utility Model Laid-Open No. 53-120321.
It is disclosed in Japanese Patent Publication No. However, such a known technique cannot be applied to the case where an article is inserted into and removed from a vacuum container.

[Problem to be Solved by the Invention] Therefore, an object of the present invention is to provide an automatic exhaust device for a vacuum container, which can maintain the vacuum container at a high degree of cleanliness and which can be easily attached to and detached from the vacuum container.

[Means for Solving the Problems] According to the present invention, in an automatic exhaust device for a vacuum container, the exhaust port of the vacuum container is sealed by a seal flange provided with a permanent magnet attracted by a magnetic material attached to the exhaust port. An enclosure (10) for enclosing the seal flange (6),
Sealing means (12, 13) between the enclosure (10) and the vacuum container (A), a purge mechanism (15, L3) for purging the sealing surface of the enclosure (10) with clean gas, and an enclosure Or, an exhaust mechanism (L to evacuate the enclosure and the vacuum container (A))
1, 31), an electromagnet (18, 19) for adsorbing, gripping and opening the seal flange (6), and a pressing mechanism (35) for pressing or disconnecting the enclosure (10) against the vacuum container (A). It has.

Furthermore, according to the present invention, the disclosure of the seal flange (6) is provided with measuring means (L2, 32) such as a vacuum gauge for measuring vacuum pressure.

And according to the present invention, the exhaust port (1) of the vacuum container (A)
A permanent magnet degaussing coil (17) is attached to the magnetic body (4) attached to the exhaust port (1).

Further, according to the present invention, there is provided a control means (30) for judging whether to draw a vacuum or to close the seal flange by comparing the value measured by the measuring means with a specified value and giving an operation instruction.

[Operation] In the automatic evacuation device configured as described above, when the enclosure is attached to the vacuum container, the control means opens the valve as necessary to inject clean air or noble gas to the tight sealing surface to purge. .

The control means presses the enclosure against the vacuum container or separates it with a pressing mechanism that presses the enclosure into close contact with the vacuum container, operates the vacuum pump to evacuate, and defines the pipeline to the seal flange. Reduce to pressure.

Next, the electromagnetic coil on the permanent magnet side of the seal flange is excited to reduce the magnetic force of the permanent magnet, and the electromagnetic coil on the magnetic body side of the enclosure is excited to attract and open the seal flange.

In this state, based on the detection signal from the vacuum gauge, if the pressure inside the vacuum container is higher than the specified value, continue evacuation, and when the specified value is reached, demagnetize both electromagnetic coils and insert the seal flange via the permanent magnet. Is adsorbed on the magnetic material on the container side, the exhaust port is closed and sealed.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

This automatic evacuation device is provided with an enclosure 10 closely attached to the vacuum container A.
A vacuum pump 31 connected to the enclosure 10 via an exhaust pipe L1, a pressure extraction pipe L2 connected to the enclosure 10 and a measuring means comprising a vacuum gauge 32 connected to the extraction pipe L2; Supply pipe L3 connected to the enclosure 10 and provided with a valve 34 and the supply pipe
Tank of clean air or noble gas such as N ₂ connected to L3
The vacuum pump comprises a purging mechanism consisting of 33, a pressing mechanism 35 for bringing the enclosure 10 into close contact with the vacuum container A, and a control means 30 connected to an opening / closing means described later of the enclosure 10 via an electric wire l. 31, vacuum type 32, valve 34 and pressing mechanism 35
Is connected to the control means 30.

The exhaust pipe L1 and the vacuum container pump 31 form an exhaust mechanism.

2 and 3, an annular protrusion 2 is formed at a portion of the vacuum container A where the exhaust port 1 is opened, and an O-ring 3 is provided on an end surface of the protrusion 2. An annular first magnetic body 4 having an L-shaped cross section and an inner end surface slightly lower than that of the protrusion 2 is provided surrounding the protrusion 2, and is fixed to the vacuum container A by a bolt 5. A seal flange 6 that fits inside the magnetic body 4 is provided, and the seal flange 6 includes
A plurality of (eight in the illustrated example) cylindrical second magnetic bodies 7 are provided upright on the circumference of the circle, and permanent magnets 8 are embedded in the ends thereof. Therefore, when the permanent magnets 8 are attracted to the magnetic body 4, the seal flange 6 seals the end face of the protrusion 2 through the O-ring 3 to seal the end face. A disk-shaped third magnetic body 9 is embedded in the end surface of the seal flange 6.

The enclosure 10 is provided with recesses 11 for accommodating the first magnetic body 4 with gaps C1 and C2, and O-rings 12 and 13 constituting sealing means are provided on the contact surface with the vacuum container A. There is.

An exhaust passage 14 that opens into the gap C1 is provided in the enclosure 10, and an exhaust pipe L1 is connected to the exhaust passage 14.
An injection passage 15 that opens between the O-rings 12 and 13 is provided, and a supply pipe L3 is connected to the injection passage 15. Further, a pressure extraction passage 16 opening to the gap C1 is provided, and a pressure extraction pipe L2 is connected to the pressure extraction passage 16.

The opening / closing means of the seal flange 6 includes a first electromagnetic coil 17 that covers the second magnetic body 7, a third magnetic body 9, and a fourth cylindrical body that faces the third magnetic body 9 and slightly projects into the gap C1. Magnetic body 18
And a second electromagnetic coil 19 surrounding the magnetic body 18,
Both electromagnetic coils 17 and 19 are connected to a lead wire 20 and a terminal 23 of a feedthrough 22 attached via an O-ring 21 of the enclosure 10.
Is connected to the electric wire l via.

Next, the operation will be described.

A semiconductor wafer is placed in a carrier in the vacuum container A in advance and closed with a cover. When the enclosure 10 is attached to the vacuum container A, the control means 30 controls the vacuum container A.
Open the valve 34 as necessary, such as when is in the atmosphere,
Clean air or noble gas is injected from the injection passage 15 to purge the contact surface of the vacuum container A.

Next, the control means 30 brings the enclosure 10 into close contact with the vacuum container A by the pressing mechanism 35. Then, operate the vacuum pump 31,
After evacuating the pipelines up to the gaps C1 and C2 to the specified pressure,
The first magnetic coil 17 is excited to reduce the magnetic force of the second magnetic body 7 and the permanent magnet 8, and the second magnetic coil 19 is excited to attract the third magnetic body 9 to the fourth magnetic body 18 to seal the flange. Open 6

In this state, if the vacuum pressure is higher than the specified value based on the signal from the vacuum gauge, the vacuum evacuation is continued. After reaching the specified value, the electromagnetic coils 17 and 19 are demagnetized, the seal flange 6 is attracted to the first magnetic body 4 by the attractive force of the permanent magnet 8, and the exhaust port 1 is closed and sealed.

4 and 5 show another embodiment of the present invention, in which the second magnetic body 7A is formed in an annular body surrounding the outer circumference of the seal flange 6, and the permanent magnet 8A and the first electromagnetic coil 17A are respectively formed in the second shape.
This is an example in which a ring-shaped body corresponding to the magnetic body 7A is formed, and the others are configured substantially the same as in FIG. Also in this embodiment, the same operational effects as those in FIG. 2 are obtained.

[Effects of the Invention] As described above, the present invention has the following excellent effects.

(I) The enclosure can be securely attached to the vacuum container, and the vacuum container can be easily exhausted.

(Ii) Since the seal flange is suction-held and opened / closed by the electromagnet, automation is possible and the work is reliable.

(Iii) If a measuring means for measuring the vacuum pressure is provided, it is sufficient to exhaust the gas until it reaches a specified value, which facilitates automation.

(Iv) If the demagnetizing coil for permanent magnets is attached, the enclosure can be easily separated from the exhaust port after demagnetization, and the enclosure can be opened and closed even when the magnetic force becomes large, thus increasing the size of the device. it can.

(V) If the control means instructs the operation based on the data from the measuring means, even if the degree of vacuum in the vacuum container decreases with time, it is possible to evacuate before the degree of vacuum falls below a certain degree. It is possible to reduce the vacuuming work time and prevent abnormal vacuum pressure rise.

[Brief description of drawings]

FIG. 1 is a schematic view showing the overall structure of the present invention, FIG. 2 is a side sectional view showing the essential parts of a first embodiment of the present invention, FIG. 3 is a front view of a seal flange, and FIGS. The drawings correspond to FIGS. 2 and 3 showing a second embodiment of the present invention. A ... vacuum container, 1 ... exhaust port, 4 ... first magnetic body, 6
...... Seal flange, 7, 7A ...... Second magnetic body, 8,8A ...
… Permanent magnet, 9 …… Third magnetic body, 10, 10A …… Enclosure, 1
4 …… Exhaust passage, 16 …… Pressure extraction passage, 17, 17A …… First
Electromagnetic coil, 18 ... Fourth magnetic body, 19 ... Second electromagnetic coil, 30 ... Control means, 31 ... Vacuum pump, 32 ... Vacuum gauge, 33 ... Tank, 35 ... Pressing mechanism

Claims (4)

[Claims] 1. An automatic exhaust device for a vacuum container, wherein the exhaust port of the vacuum container (A) is sealed by a seal flange (6) equipped with a permanent magnet that is attracted to a magnetic material attached to the exhaust port. The enclosure (10) for enclosing the seal flange (6), the sealing means (12, 13) between the enclosure (10) and the vacuum container (A), and the sealing surface of the enclosure (10). A purge mechanism (15, L3) for purging with clean gas, an exhaust mechanism (L1, 31) for evacuating the inside of the enclosure or the inside of the enclosure and the vacuum container (A), and the gripping and opening / closing of the seal flange (6). An automatic evacuation device for a vacuum container, comprising: electromagnets (18, 19) and a pressing mechanism (35) for pressing or disconnecting the enclosure (10) from the vacuum container (A). 2. The automatic vacuum container according to claim 1, further comprising measuring means (L2, 32) such as a vacuum gauge for measuring a vacuum pressure when the seal flange (6) is opened. Exhaust system. 3. A seal flange (6) which is sucked by a magnetic body (4) attached to an exhaust port (1) of a vacuum container (A).
An automatic exhaust device for a vacuum container according to claim 1 or 2, wherein a demagnetizing coil (17) for permanent magnets for demagnetizing a permanent magnet (8) attached to the is attached. . 4. A control means (30) for instructing an operation by judging whether a vacuum drawing or a seal flange is closed by comparing a value measured by the measuring means (L2, 32) with a specified value. An automatic evacuation device for a vacuum container according to any one of claims 1 to 3.