WO2019228592A1

WO2019228592A1 - Ventilation device and vacuum production plant

Info

Publication number: WO2019228592A1
Application number: PCT/DE2019/100467
Authority: WO
Inventors: Marco Fröhner; Alexander Böddicker
Original assignee: Meyer Burger (Germany) Gmbh
Priority date: 2018-05-29
Filing date: 2019-05-27
Publication date: 2019-12-05
Also published as: DE112019002724A5; CN110541154A; DE102018112853A1; CN210886214U

Abstract

The present invention relates to a ventilation device having at least one feed line for a ventilation gas from a ventilation gas source into the ventilation device, and at least one valve, wherein the valve is able to be opened for ventilation purposes, in order to allow the ventilation gas to flow into a lock chamber of a vacuum plant in an inflow direction. The invention also relates to a vacuum production plant having high throughput requirements and at least one lock chamber. Therefore, it is an object of the present ivnention to create a simple ventilation device with which rapid and low-disruption ventilation of a lock chamber of a vacuum production plant is possible. The object is achieved by a ventilation device that is distinguished by the fact that the ventilation device has a compressed-gas store upstream of the valve in the inflow direction and a buffer container downstream of the valve.

Description

Ventilation device and vacuum production plant

The present invention relates to a ventilation device having at least one inlet of a ventilation gas from a ventilation gas source in the ventilation device, and at least one valve, wherein the valve for venting is openable to flow the ventilation gas in a lock chamber of a vacuum system in an inflow direction. Furthermore, the invention relates to a vacuum production plant with high throughput requirements and at least one

Lock chamber.

Vacuum systems often have locks in order not to have to open the entire vacuum system for retraction and for extending objects in the vacuum system, but only a small part of the system, namely the lock chamber or more lock chambers. Depending on the concept of the plant, the lock or the lock chamber either serves to

Infeed as well as for discharging or it is used in a continuous system, a separate Einschleuskammer for introduction and a discharge chamber for discharging. Vacuum production plants have been used for various purposes for decades. In recent years, photovoltaic has enjoyed great economic success. Solar cell-based solar power plants have become the least expensive and cleanest electrical energy sources on Earth, thanks to the fast and cost-effective production of semiconductor-based solar cells. Further cost savings in the production of future solar cells will require vacuum production equipment with high throughputs of more than 4000 solar wafers per hour. With the increasing demands for throughput, i. to the

Processing speed and shorter cycle times, various components of the vacuum production plant must be improved. Improvements to the core areas of

Vacuum production systems, for example on the coating chambers, are not sufficient alone to meet the increasing demands. All other parts of the vacuum production plants must be improved in accordance with the growing demands. The removal of solar wafers must be done quickly. When aerating the discharge chamber more quickly, breakage of solar wafers should be avoided as much as possible.

In the prior art, various solutions are known for rapid venting of lock chambers. DE 10 2011011 279 A1 describes a lock chamber with arranged therein

Guiding plates for flow optimization of the ventilation gases within the lock chamber. DE 10 2015 117 753 Al proposes the extensive ventilation of lock chambers via shower heads or Showerheads in front. On the one hand, such solutions are expensive; on the other hand, fractures of solar wafers can occur in the case of rapid venting with increased aeration pre-pressure, despite the use of such flow-influencing arrangements. Control valves can also be used for rapid ventilation with an increased ventilation pressure. Disadvantages of control valves or proportional valves are high initial costs and high maintenance costs due to moving wear parts and complex calibration requirements in the establishment of such valves. Another possibility for ensuring high throughput speeds and correspondingly short cycle times is the series connection of at least two lock chambers in

Continuous flow systems, such as e.g. in DE 10 2016 107 830 Al, or corresponding arrangements of several lock chambers in one-end systems. The installation of additional lock chambers is expensive and leads over a larger footprint of the vacuum production plant to correspondingly high follow-up costs.

It is therefore an object of the present invention to provide a simple ventilation device with which a rapid venting of a lock chamber of a vacuum production plant is largely possible without substrate breaks.

The object is achieved by a ventilation device, which is characterized in that the ventilation device in the inflow direction in front of the valve has a compressed gas storage and after the valve has a buffer tank.

The ventilation device according to the invention is very simple, constructed from a few inexpensive standard components. The compressed gas storage can in the cyclic operation of

Provide the aeration chamber with a high pressure during a venting step. This is a good prerequisite for a quick ventilation. During the

subsequent evacuation step of the downstream lock chamber or the other ventilated chamber, the compressed gas storage for the next ventilation step can be filled up to the specified ventilation pre-pressure. The valve need not be a special proportional or control valve, often a simple on-off valve is sufficient. The buffer container is arranged in the inflow direction behind the valve and thus connected with the valve closed with the evacuated, downstream lock chamber. After opening the valve, the pressure in the buffer volume slowly rises. This avoids an initial pressure surge when opening the valve in the lock chamber. The buffer volume of the buffer container prevents an initially higher flow velocity due to the maximum pressure difference between the venting upstream pressure and the lock internal pressure when opening the valve, because the inflow velocity of the venting gas into the lock chamber initially as a function of lower differential pressure between the buffer tank and the lock chamber adjusts. With the filling of the buffer tank, the differential pressure to be ventilated chamber increases.

After a pressure equalization between the compressed gas storage and the buffer tank or a dynamic pressure equilibrium has been established, the high pre-admission pressure causes a rapid venting. The time gained in venting outweighs any small delays that may occur in evacuating the buffer volume and associated chamber in some cases. When using additional valves and corresponding piping, the buffer tank can be used temporarily as a vacuum buffer tank for faster evacuation. The aeration gas may be air, dried or purified air, nitrogen, oxygen, water vapor, or another venturi gas or gas mixture.

Between the buffer tank and the lock chamber, the ventilation device may have a ventilation piping. Through the pipes of the ventilation piping, the ventilation gas can be cheaply brought to the required locations. In other variants of the

Ventilation device according to the invention can channels, for example within a

Showerheads in the lock chamber, used for gas distribution. It may also be a buffer tank attached directly to a ventilation inlet or at several

Ventilation entrances can be mounted in each case a small buffer tank.

Between the compressed gas storage and the buffer tank, a pressure equalization line can be installed, which, when opened, has a larger passage cross-section than the

Ventilation piping. The pressure equalization line can be used to quickly equalize the pressure between the compressed gas storage tank and the buffer tank so that the goal of quickly aerating the lock is achieved. The compressed gas storage, the valve and the buffer tank can alternatively be mounted directly to each other.

The ventilation piping may have at least one branch. The venting of the lock should be done quickly, but strong currents in the lock are undesirable because they can lead to damage of substrates or to the stirring up of particles. By distributing the aeration gas flow to two or more than two ventilation inlets, the aeration flows can be reduced by a divider 2 or greater, and overall, beneficial flows in the airlock can be adjusted. In this case, some simple openings can be used as a gas inlet within the ventilated chamber. If it is expedient, a distribution of the venting gas can also be realized within the lock via branched pipes or otherwise. The ventilation piping may terminate at least two flanges, the

Connecting flanges can be connected to ventilation entrances of a lock chamber. Flanges can be easily and quickly opened during maintenance. If maintenance is not or only rarely required, the ventilation piping can also be permanently, without

intermediate flanges, be installed on the lock chamber.

The buffer tank may be smaller than the accumulator. For example, the lock may have a volume of 401. The compressed gas storage can have a volume of 101 and the

Buffer tank has a volume of 21. A small buffer tank delays the venting and evacuation little. However, the buffer tank must be large enough to achieve the desired buffering effect after valve opening, i. the damage of

Avoid substrates due to excessive flow during venting. The optimum size of the buffer container will depend on a number of factors and may be determined by one skilled in the art to an individual case. The size of the buffer tank may be approximately 1/5 the size of the accumulator.

The aeration gas can be available in the compressed gas storage at a high pressure, in particular at a pressure above 5 bar. For venting the compressed gas storage, for example, a template pressure of 5.8 bar can be set so that more gas is stored in the compressed gas storage than is required for aeration. The flea of the template pressure depends on which aeration gas is used, for example, whether air from a compressor must be compressed, or whether the compressed gas is already available in compressed form from a flop pressure bottle. At a higher form a smaller accumulator is sufficient and at a lower form a larger pressure accumulator is needed. The available space is therefore also a criterion for determinations of the form and the size of the compressed gas storage. When defining the form, legal regulations to be observed for pressure vessels and different costs in different pressure classes may also be taken into account.

The buffer tank is in variants of the ventilation device according to the invention an integral part of the airlock chamber to be ventilated. For example, if a lock chamber is made by milling from a solid aluminum block, walls of the later buffer tank can be left standing during milling. The buffer container can then be completed by inflating a lid. Such an integrated buffer container can be provided material and space economically. The valve can be a flood valve. A flood valve is a valve that quickly releases a large flood cross section. The flood valve is simple, correspondingly inexpensive and durable. As a valve different types of inline valves, angle valves,

Sliding valves or control valves may be used, depending on the concrete to be met

Conditions.

The object of the invention is achieved in one aspect by a vacuum production plant with high throughput requirements and at least one lock chamber, which has at least one ventilation device according to the invention on at least one chamber.

Vacuum production systems have different structures. For example, single-end configurations are used in which the substrates to be processed at one end of the plant, i. in a lock, both retracted and

be extended. In this case, the lock is an in- and outfeed chamber. Other vacuum production plants are conceived as so - called in - line or continuous plants, in which the substrates are retracted in one direction into a Einschleuskammer and from a

Extracted discharge chamber at the other end of the inline system. All

Lock chambers must be periodically ventilated and evacuated. The gentle and rapid venting with the ventilation device according to the invention is particularly needed in simple Ausschleuskammern and combined infeed and Ausschleuskammern because in the venting the damage of sensitive substrates, such as solar wafers, is to be avoided. In rare cases, ventilation may also be required on a chamber other than a lock chamber and may be realized by at least one ventilation device according to the invention. Two or more than two ventilation devices according to the invention may also be installed on a lock chamber of the vacuum production system according to the invention in order to provide the ventilation gas in the lock chamber as needed.

The vacuum production plant according to the invention may be a plant for the production of solar wafers with a throughput of more than 4000 solar wafers per hour. The production volumes of solar cells are currently increasing at an annual rate of approximately 30%, based on 100 GW of solar cell output produced annually in 2017 worldwide. At the same time sink

Production costs per solar cell continue from. In this environment can only

Maintaining vacuum production systems on the market, which satisfy the growing demands of solar cell manufacturers through high throughputs of, for example, 4000 or 6000 solar wafers per hour and which are economical with sufficiently low unit costs per manufactured solar cell. Optimized ventilation times can contribute to the cost reduction associated with the large annual production of photovoltaic solar power on the order of 100 GW.

The presented options and embodiments of the present invention may be combined with one another by a person skilled in the art according to their own discretion, even if the concrete combination is not specifically embodied here. Designs for one option of the ventilation device also apply to the corresponding option of

Vacuum production plant. Randomly described options or features of the invention may not be misinterpreted as a compelling combination of features.

The present invention will be explained below with reference to the figure Fig. 1, wherein

Fig. 1 shows two ventilation devices according to the invention.

FIG. 1 shows two ventilation devices 1 according to the invention in a perspective view

Representation in an arrangement for mounting on a lock chamber of a vacuum production plant according to the invention. Each ventilation device 1 has a valve 2 between a

Pressure gas storage 3 and a buffer tank 4, wherein the valve 2 in the illustrated

Embodiment is integrated into a pressure equalization line 8. In other embodiments, not shown, the valve 2 is mounted directly at the outlet of the compressed gas reservoir 3 or at the inlet of the buffer tank 4.

From the outlet of the buffer tank 4, the ventilation gas is passed from a ventilation piping 5 to the connection flanges 7, which are detachably connected to the lock chamber, not shown. In the ventilation piping 5 3 branches 6a, 6b, 6c are involved in the illustrated embodiment, so that from the one outlet of the buffer tank 4, the ventilation gas is distributed to four flanges. However, the connected discharge chamber has not only four but eight inputs for the ventilation gas. In the illustrated embodiment, a second to the other four inputs for the ventilation gas to the discharge chamber

Ventilation device 1 connected, which is largely the same as the first ventilation device 1, but mirrored constructed. The two ventilation devices 1 are each supplied via a ventilation gas inlet 9 via a ventilation gas supply, not shown, with the ventilation gas. reference numeral

1 ventilation device

2 valve

3 compressed gas storage

4 buffer tanks

5 ventilation piping

6a, 6b, 6c branching of the ventilation piping

7 connection flange

8 pressure compensation line

9 compressed gas inlet

Claims

claims

A ventilation device (1) having at least one supply line of a ventilation gas from a ventilation gas source into the ventilation device (1), and at least one valve (2), wherein the venting valve (2) is openable to vent the ventilation gas into a chamber of a vacuum system to flow in an inflow direction, characterized in that the

Ventilation device (1) in the inflow direction in front of the valve (2) has a compressed gas reservoir (3) and after the valve (2) has a buffer tank (4).

2. Ventilation device (1) according to claim 1, characterized in that the

Ventilation device (1) between the buffer tank (4) and the lock chamber a ventilation piping (5).

3. Ventilation device according to claim 2, characterized in that an open pressure equalization line (8) between the compressed gas storage and the buffer tank has a larger passage cross-section than the ventilation piping (5).

4. Ventilation device (1) according to claim 2 or 3, characterized in that

Ventilation piping (5) has at least one branch (6a, 6b, 6c).

5. Ventilation device (1) according to claim 4, characterized in that the

Ventilation piping (5) ends at at least two connecting flanges (7), wherein the

Connection flanges (7) can be connected to ventilation entrances of a lock chamber.

6. Ventilation device (1) according to at least one of the preceding claims, characterized in that the buffer container (4) is smaller than the compressed gas storage (3).

7. Ventilation device (1) according to claim 6, characterized in that the

Compressed gas storage (3) has a volume of 101 and the buffer tank (4) has a volume of 21.

8. Ventilation device (1) according to at least one of the preceding claims, characterized in that the venting gas in the pressure accumulator (3) is ready at a high pressure, in particular at a pressure above 5 bar.

9. Ventilation device (1) according to claim 1, characterized in that the

Buffer tank (4) is an integral part of the ventilated chamber.

10. Ventilation device (1) according to at least one of the preceding claims, characterized in that the valve (2) is a flood valve.

11. Vacuum production plant with high throughput requirements and at least one lock chamber, characterized in that the vacuum production plant has at least one ventilation device (1) according to at least one of claims 1 to 9 at least one chamber.

12. Vacuum production plant according to claim 11, characterized in that the

Vacuum production plant is a plant for the production of solar wafers with a throughput of more than 4000 solar wafers per hour.