DE102012013726B4 - Device for cooling strip-shaped substrates - Google Patents

Abstract

Device for cooling a strip-shaped substrate in a vacuum comprising a) at least one convex cooling surface (2) as the outer boundary of a cooling body (1); b) means for guiding at least one strip-shaped substrate in such a way that the substrate at least partially integrates the convex cooling surface (2) C) a plurality of openings (4) which are arranged distributed over the contact area of the cooling surface (2) and which extend through the cooling surface (2) into the cooling body (1), whereby) a first subset extends the openings (4i) extends into at least one first channel (5i) which runs inside the cooling body (1) and opens into at least one end face (3) of the cooling body (1), e) a second subset of the openings (4h) extends into at least one second channel (5h) running inside the heat sink (1) extends into it and opens at at least one end face (3) of the heat sink (1), f) a third subset of the openings extends (4j) extends into at least one third channel (5j) which runs inside the heat sink (1) and opens out at at least one end face (3) of the heat sink, g) the second subset of the openings (4h) as viewed in the direction of movement of the substrate the first subset of the openings (4i) is arranged and the third subset of the openings (4j) is arranged in front of the first subset of the openings (4i); h) first means for providing a fluid such that the fluid through the first channel (5i ) flows into the heat sink; i) second means for sucking off the fluid from the second channel (5h) and third channel (5j).

Description

The invention relates to a device for cooling strip-shaped substrates in a vacuum. The device can be used in vacuum systems wherever strip-shaped substrates are exposed to thermal stress. Examples of this are various forms of vacuum coating, surface modifications or forms of targeted thermal treatment of surfaces in a vacuum.

State of the art

For technological reasons, the substrates to be treated often need to be cooled if damage to the substrate due to overheating is to be expected without cooling due to thermal stress or if a substrate temperature would set in which would counteract the desired effect without cooling. Examples of the latter can also be found in the field of vacuum coating. Often a certain layer is to be deposited on a substrate, which has special structural properties. The layer structure often shows a strong dependence on the temperature of the substrate.

Since cooling through convection in a vacuum at low pressures plays a minor role and effective heat radiation only takes place at temperatures that are either to be avoided in many coating processes or cannot be set due to other technological boundary conditions, the focus of substrate cooling in vacuum processes is on dissipation the energy introduced by heat conduction from the location of the energy input, i.e. the substrate surface, into and through the substrate to a heat sink. The effectiveness of such cooling essentially depends on how effectively the heat transfer from the substrate to the heat sink can take place.

It is known to cool strip-shaped substrates by guiding them over a convex cooling surface, usually part of the outer surface of a largely cylindrical cooling roller. The effectiveness of the cooling is influenced, among other things, by the temperature of the cooling roller. For this purpose, coolants are passed through the inside of the cooling roller, also known as the cooling drum ( U.S. 4,343,834 A ; U.S. 3,381,660 A ; DE 1 741 856 U ). The surface of the chill roll is effectively cooled by providing liquid cooling inside the chill roll. This results in an effective heat transfer from the surface of the cooling roller to its interior.

The cooling of the roller affects the temperature of the substrate. A cooled roller only leads to effective cooling of the substrate if the cooling surface and the substrate are in close thermal contact.

It is known that the thermal contact between the substrate and the cooling surface can be improved by adding a film to facilitate this contact ( DE 37 40 483 A1 ; DE 28 45 131 A1 ), whereby it is also known to precool this film, whereby the heat capacity of the film itself is used to cool the substrate. Otherwise, the film primarily serves to compensate for unevenness in the contacting surfaces. Overall, however, the heat transfer through foils is insufficient for many applications.

It is also known to expose the back of the strip-shaped substrates to a cooling gas flow before the substrate comes into contact with the cooling surface ( DE 198 53 418 A1 ; U.S. 5,076,203 A ; U.S. 5,743,966 A ). The cooling gas is often supplied in the form of so-called gas lances. As a result, a thin gas cushion should remain in the contact area between the cooling surface and the substrate, which can provide thermal contact. However, when the gas is supplied outside the contact area between the substrate and the cooling surface, a large part of the introduced gas flows into the process space and is therefore not available for the gas cushion between the substrate and the cooling surface, but often puts an unacceptable load on the process vacuum.

It is known to intensify the thermal contact via a gas cushion using electrical fields and plasmas ( GB 2 326 647 A ). However, the effect of such methods is slight and can only be implemented with selected substrates such as plastic film.

It is also known to build up the recipient from several areas that are partially decoupled in terms of vacuum technology ( EP 0 311 302 A1 ). The gas inlet takes place outside the process space. However, complete decoupling cannot be achieved in this way, or only with great technical effort.

Furthermore, the heat transfer can be improved by increasing the contact pressure between the heat sink and the substrate to be cooled. In the case of strip-shaped substrates, this is usually done by increasing the tension of the strip. However, this method is also subject to physical limits, since the effective contact surface is only slightly enlarged even with a strong increase in the contact pressure, which can essentially be explained by microgeometric conditions.

It is known to introduce gas below the substrate to be cooled through openings that can be closed by valves ( U.S. 3,414,048 A ). However, the large number of valves increases the mechanical susceptibility of such a plant system.

It is also known to implement a gas supply through the cooling surface by forming part of the cooling surface as a porous molded body ( U.S. 5,076,203 A ). A similar cooling principle is in US 2010/0291308 A1 disclosed. It is proposed here to make openings in the cooling surface of a cylindrical cooling body, which openings extend through the cooling surface into the cooling body and through which a cooling medium is introduced into the contact area between the cooling body and a substrate to be cooled. A disadvantage of this method is the large amount of cooling gas flowing out into the recipient after the substrate has been cooled, and this puts a strain on the process vacuum.

It is also known to let cooling gas under a hood through holes in the annular gap of a cooling drum ( WO 02/070778 A1 ). As a result, a certain gas pressure can be applied under the substrate. It is also mentioned to laterally seal the contact area between the cooling roller and the substrate and to use further inlet options. However, this technical embodiment also does not have an effective way of keeping the cooling gas, once introduced, away from the process vacuum as effectively as possible after the cooling surface and the substrate to be cooled are no longer in contact.

In summary, it can be noted in relation to the prior art cited so far that the focus of efforts to cool strip-shaped substrates is evidently placed on mediating the thermal contact between substrate and heat sink through a remaining gap with a defined gas filling. The problem, however, is that the minimum gas pressure required for this in the case of moving strip-shaped substrates requires a constant supply of a considerable amount of gas, which at least partially loads the process vacuum after it has escaped from the cooling zone. For many vacuum applications - e.g. For example, all applications in which an electron beam is used - this is a problem that is limiting in many ways.

DE 10 2004 050 821 A1 also suggests making openings in the cooling surface of a cylindrical cooling body and guiding a cooling medium through these openings into a first contact area between the cooling surface and a strip-shaped substrate to be cooled. In addition, it is proposed to suck the cooling medium through the cooling surface from adjacent contact areas which, viewed in the direction of movement of the substrate, are arranged before and after the first contact area. In this way, the load on the vacuum with additionally introduced coolant within a process chamber is reduced. A disadvantage of this solution is that both the supply and the pumping of the cooling medium take place from the interior of a cylindrical cooling body, which means that sliding sealing elements have to be implemented on curved surfaces, which require a high level of technical effort. In addition, there is often no wear resistance here.

Task

The invention is therefore based on the technical problem of creating a device by means of which the disadvantages from the prior art are overcome and which allows an improved substrate cooling of moving strip-shaped substrates compared to the prior art. In particular, the device according to the invention is intended to largely avoid additional loading of the vacuum within a process chamber with a cooling medium. The device should also be distinguished by a simple structure.

The solution to the technical problem results from the subjects with the features of patent claim 1. Further advantageous embodiments of the invention emerge from the dependent claims.

The invention is based on the assumption that it is expedient to use a fluid, which is in direct contact with the rear side of the substrate and the surface of the heat sink, to establish the thermal contact between a substrate to be cooled and a cooling body. Gap geometry, substrate material, surface geometry of a substrate, fluid type and fluid pressure are the determining parameters. A fluid used can be both a gas and a liquid. The heat transfer from the substrate to the heat sink takes place more effectively, the smaller the distance between the substrate and the heat sink and the higher the pressure of the fluid providing the thermal contact.

A high fluid pressure causes a high mechanical load on the substrate, since the substrate forms an interface between fluid and vacuum and has to absorb forces resulting from the pressure difference. These forces are absorbed by the tape tension on the substrate, which generates restoring forces counteracting the forces caused by the pressure difference.

Since high fluid pressures should also be aimed for for effective cooling, At the same time, however, as little fluid as possible may escape into the process vacuum, there are further requirements that must be met by the solution of the object according to the invention.

Accordingly, in a device according to the invention, the restoring forces required for absorbing forces applied to the substrate due to a high fluid pressure are generated by elastic pretensioning of the substrate, which is guided around a convex cooling surface. The pretension is set by means of a belt tension in such a way that the forces applied to the substrate by the fluid pressure do not cause the substrate to lift off the convex cooling surface. By guiding the strip-shaped substrate under a belt tension around a convex cooling surface, a certain contact pressure results with which the substrate is pressed against the region of the cooling surface around which it is wrapped. Even with very smooth cooling surfaces, a gap remains between the back of the substrate and the cooling surface, which gap is sufficient for a fluid filling according to the invention. The existence of a fillable gap area between the back of the substrate and the cooling surface can in principle be assumed based on microgeometric surface conditions.

A device according to the invention for cooling a strip-shaped substrate in a vacuum comprises at least one convex cooling surface as the outer boundary of a cooling body. The cooling body also has at least one end face, which preferably runs perpendicular to the convex cooling surface. For example, the cooling body can be designed as a fixed form shoulder, as a cylindrical cooling drum or as a cylindrical cooling roller. The device according to the invention also includes means for guiding the strip-shaped substrate in such a way that the substrate wraps around the convex cooling surface at least partially in a contact area, so that a flat contact is created between the substrate and a contact area of the convex cooling surface. The convex cooling surface has a multiplicity of openings which are arranged at least distributed over the contact area of the cooling surface and which extend through the cooling surface into the cooling body. If the heat sink is cylindrical and rotates around its cylinder axis, the openings are distributed over the entire convex lateral surface of the cylinder. The openings preferably extend perpendicularly from the cooling surface into the interior of the cooling body, because such a configuration of the openings is easiest to produce, for example by means of drilling. Alternatively, however, the openings can also extend from the cooling surface into the interior of the cooling body at an angle other than 90 °.

A first subset of the openings extends into the interior of the cooling body and ends there in at least one first channel which extends across the width of the strip-shaped substrate to be cooled through the cooling body and which opens at the at least one end face of the cooling body. The opening of the at least one first channel on the end face of the cooling body is connected to a reservoir of a cooling fluid, so that the fluid flows from the reservoir into the first channel, from where it flows through the first subset of openings into a gap area between the convex cooling surface and to cooling substrate. In this way, the substrate can be effectively cooled with the fluid.

Because the inflowing fluid should not, if possible, load the vacuum inside a recipient, in a device according to the invention this is also sucked out of the gap area between the convex cooling surface and the substrate to be cooled.

This is done by a second subset and a third subset of openings in the convex cooling surface, of which a subset, viewed in the direction of movement of the substrate, is arranged in front of the first subset of openings and the other subset after the first subset of openings. The second subset of openings extends from the cooling surface into the interior of the cooling body and ends there in at least one second channel, which extends across the width of the strip-shaped substrate to be cooled through the cooling body and which opens at the at least one end face of the cooling body. The third subset of openings extends from the cooling surface into the interior of the cooling body and ends there in at least one third channel, which extends across the width of the strip-shaped substrate to be cooled through the cooling body and which opens at the at least one end face of the cooling body. The front openings of the second and third channels are connected to at least one pump device, by means of which the fluid is sucked through the second and third channels and through the second and third subset of openings from the gap area between the cooling surface and the substrate to be cooled. Thus, the fluid is sucked off both before and after the area into which the fluid is let in between the cooling surface and the substrate.

Letting in and sucking off the fluid through channel openings in a flat end face of the cooling body that runs perpendicular to the cooling surface is particularly advantageous if the cooling body is designed as a rotating roller or drum. A sliding element then required, which a sliding and sealing contact between the openings of the first to third channels and the associated connecting elements to the fluid reservoir and for the pump is technically easier to implement on a flat surface than on a curved surface in the interior of the heat sink, as shown, for example, in FIG DE 10 2004 050 821 A1 is shown.

Embodiments

• 1a, 1b eine schematische Darstellung einer erfindungsgemäßen Vorrichtung mit einer Kühlwalze,
• 2 eine schematische perspektivische Darstellung einer alternativen erfindungsgemäßen Vorrichtung mit einer Kühltrommel,
• 3 eine schematische perspektivische Darstellung einer weiteren alternativen Vorrichtung mit einer Kühlwalze.

The present invention is explained in more detail below on the basis of exemplary embodiments. The figures show:

• 1a , 1b a schematic representation of a device according to the invention with a cooling roller,
• 2 a schematic perspective illustration of an alternative device according to the invention with a cooling drum,
• 3 a schematic perspective illustration of a further alternative device with a cooling roller.

In 1a is the heat sink 1 a device according to the invention shown schematically. Here is the heat sink 1 designed as a cylindrical cooling roller with a convex cooling surface 2 and two flat end faces, one of which is the end face 3 in 1a is shown. Over the entire cooling surface 2 openings are distributed 4th arranged, which extends through the cooling surface in the direction of the cylinder axis of the heat sink 1 extend. From the front 3 of the heat sink 1 several channels extend 5 inside the heat sink 1 .

The channels 5 , their openings in the front 3 are arranged radially symmetrically around the cylinder axis, run parallel to the cooling surface 2 and all end immediately in front of the opposite end face. The channels 5 thus do not pierce the face 3 opposite face. Furthermore, all channels are 5 with an equal dimension from an adjacent channel 5 spaced.

From the openings 4th that stand out from the cooling surface 2 inside the heat sink 1 extend, a subset of openings opens 4a in the canal 5a , a subset of openings 4b in the canal 5b . This continues clockwise up to a subset of openings 4p that in the canal 5p flows out.

In 1b is the heat sink 1 out 1a shown schematically in a different perspective. In addition, in 1 b a sliding element 6th at the front 3 of the heat sink 1 arranged which the openings of the channels 5h , 5i , 5y covered. While the heat sink 1 rotates around its cylinder axis in the operating state, the sliding element remains 6th fixed in place. The sliding element 6th thus has a sliding contact with the end face in the operating state 3 of the heat sink 1 on, so that the assignment of the mouths of the three channels 5 , which by means of the sliding element 6th are covered, changes continuously.

In the area of the mouth of the canal 5i has the sliding element 6th one through the sliding element 6th completely through opening, which in a connection element 7th flows out. The connection element is in the operating state 7th connected to the reservoir of a cooling fluid, so that the fluid through the connection element 7th in the canal 5i flows in and from there through the openings 4i in a gap area between the cooling surface 2 and one on the cooling surface 2 adjacent strip-shaped substrate to be cooled arrives.

In the operating state, a strip-shaped substrate to be cooled is to be arranged in such a way that the substrate is in flat contact with the cooling surface 2 forms and at least in the angular range of the cooling surface 2 of the heat sink 1 , over which the sliding element 6th at the front 3 extends. This applies to all devices according to the invention with a rotating cylindrical heat sink. For this purpose, deflection rollers can be used, for example, which ensure that a strip-shaped substrate to be cooled wraps around the cooling surface at least in the aforementioned angular range. However, all other means known from the prior art for this purpose can also be used.

In addition to the opening extending through the sliding element, the opening in the connecting element 7th opens, there are two more openings through the sliding element 6th . One of them is in the area of the mouth of the canal 5h . At this opening in the sliding element 6th is the connection element 8th attached. The third opening that extends through the sliding element 6th extends therethrough, is located in the region of the mouth of the channel 5y . The connection element is at this third opening 9 attached.

If the device according to the invention is in operation, then the connection elements are 8th and 9 with at least one in 1b not shown connected pumping device. By means of this pumping device, the fluid which flows through the openings 4i in the gap area between the cooling surface 2 and the substrate to be cooled flows in again with suction, initially through the openings 4 h and 4y , then through the one with the openings 4h and 4y connected channels 5h and 5y and finally through the connection elements 8th and 9 towards the pumping device.

By means of a device according to the invention, a fluid for cooling the substrate is thus admitted and in a first contact area between a heat sink and a substrate to be cooled The fluid is sucked off again from two further contact areas, one of the two further contact areas being arranged in front of the first contact area and the other after the first contact area when viewed in the direction of movement of the substrate. In this way, the vacuum conditions in a recipient are changed less by the cooling fluid.

It is advantageous if between a sliding element - such as a sliding element 6th - and the face of the heat sink - such as the face 3 - A sealing element is arranged so that from this side as well, as far as possible, no fluid that flows through the connection elements 7th , 8th and 9 flows, can get into the process vacuum. Such a sealing element is preferably firmly connected to the sliding element on one side and has a sliding contact with the end face of the heat sink on the other side. Plastic materials, for example, are suitable for such a sealing element.

It is also advantageous if a device according to the invention has at least one mechanical spring element with which a sliding element - such as a sliding element, for example 6th - is pressed against the face of a heat sink in order to achieve a high degree of sealing between the heat sink and the sliding element so that as little fluid as possible can escape into the process space between the heat sink and sliding element.

For the sake of completeness, it should also be mentioned that during operation of the device 1b due to the rotating heat sink 1 constantly reassigning channels 5 takes place in which the fluid passes through the connection element 7th flows in or out of which the fluid flows through the connection elements 8th and 9 is sucked off.

A device according to the invention can be used for cooling all strip-shaped substrate materials (such as, for example, metallic strips, strips made of a plastic or also a thin glass) which can be guided over a convex surface and are to be subjected to a cooling process. This can be the case, for example, when the substrate is coated (for example by vapor deposition or sputtering) or is etched by means of ions. It should be understood that the back of the substrate, that is to say the side that is not subjected to any machining process during the cooling process, is passed over the heat sink of a device according to the invention. Alternatively, a device according to the invention can also be used only for cooling a strip-shaped substrate without a surface treatment being carried out on the substrate at the same time in order to prepare the substrate for a subsequent processing step, for example.

An alternative device according to the invention is shown in FIG 2 shown schematically. A heat sink 21 is designed in this embodiment as a cylindrical cooling drum rotating about the cylinder axis, which has a cooling surface 22nd , an end face 23 and an opposite not in 2 Has shown end face. Over the entire cooling surface 22nd openings are distributed 24 introduced, which is through the cooling surface 22nd inside the heat sink 21 extend. The openings run 24 perpendicular to the cooling surface 22nd and extend into channels 25th , which are arranged in a ring around the cylinder axis and run parallel to the cylinder axis. Unlike the heat sink 1a and 1b run the canals 25th through the entire heat sink 21 and thus point both on the front side 23 as well as mouth openings on the opposite end face.

At the front 23 the heat sink 21 again a sliding element that does not rotate with the heat sink 26th with connection elements through which a fluid in channels 25th let in or out of channels 25th is sucked off. So shows the sliding element 26th a connection element 27 on, through which a fluid enters channels 25th can flow in. To the connection element 27 an area extends around it 27a . The sliding element has in this area 26th on the the heat sink 21 facing side has a recess that extends over the mouth openings of three channels 25th extends. In this way, the connection element can do this 27 flowing fluid simultaneously in three channels 25th as a result, the fluid is admitted through more openings 24 in a gap area between the cooling surface 22nd and a strip-shaped substrate to be cooled 20th flow and thus a larger substrate area can be cooled. With a device according to the invention, there is no limit to the number of channels into which a fluid for cooling a substrate is admitted at the same time. The area 27a could thus also have any other number of mouth openings of channels 25th extend.

The connection elements 28a , 28b , 29a , 29b in turn serve to suck out the fluid from associated channels 25th and thus via the associated openings 24 from corresponding gap areas between the heat sink 21 and substrate to be cooled 20th . In the exemplary embodiment, the connection elements are 28a , 28b , 29a , 29b designed in such a way that through this only from a respectively assigned channel 25th Fluid is sucked off. Alternatively, each of the connection elements could 28a , 28b , 29a , 29b an area similar to area 27a have, in which the back of the sliding element is recessed in the area of the corresponding connection element and which extends over several mouth openings of channels 25th extends.

During the operation of the device off 2 are the connection elements 28a and 29a connected to at least one first pump device which operates at a first pressure. The connection elements 28b and 29b are connected to at least one second pump device that operates at a second pressure. As a result, the fluid is pumped out of the gap area between the cooling surface and the substrate to be cooled in two pressure stages, which further increases the degree of the fluid being pumped out. In the same way, however, the fluid could also be sucked off in alternative exemplary embodiments with more than just two pressure stages.

As the channels 25th through the entire heat sink 21 extend, is at the rear, in 2 non-visible end face a second sliding element arranged, which with the sliding element 26th is identical. The second sliding element also always covers the same channels 25th who have favourited the sliding element 26th covered. This means that the same channels are always entered from both ends 25th the fluid let in or from both sides always from the same channels 25th the fluid is pumped out. In this way, the width of the strip-shaped substrate to be cooled 20th seen a more uniform supply of the fluid or a more uniform pumping of the fluid and also a greater pumping speed realized.

In 3 a further alternative device according to the invention is shown schematically. A heat sink 31 is again designed in this device as a cylindrical cooling roller rotating about its cylinder axis, which has a cooling surface 32 and has two flat end faces, one of which is the end face 33 in 3 is shown. Over the entire cooling surface 32 openings are distributed 34 introduced, which is through the cooling surface 32 inside the heat sink 31 extend. The openings run 34 perpendicular to the cooling surface 32 and extend into channels 35 , which are arranged in a ring around the cylinder axis and which run parallel to the cylinder axis. In this embodiment too, the channels run 35 through the entire heat sink 31 and thus point both on the front side 33 as well as mouth openings on the opposite end face.

On both edges of the cylindrical cooling surface 32 there are further openings around the circumference of the cylinder 40a and 40b into the cooling surface 32 incorporated, which is also like the openings 34 inside the heat sink 31 extend. However, the openings end 40a not in the channels 35 but in channels 41 that also like the channels 35 from the front 33 in the heat sink 31 lead in. Here are the channels 41 also arranged in a ring around the cylinder axis, each with the same distance from an adjacent channel 41 . The channels 41 are only worked into the heat sink to such an extent that it only connects to the openings 40a stay in contact. Same configuration as the openings 40a and the associated channels 41 is available on the concealed face of the heat sink 31 . There, too, further short channels lead into the concealed face and only have a connection with associated openings 40b on.

At the front 33 is a sliding element 36 arranged, which first of all has elements from the sliding element 26th out 2 are known. So can through a connection element 37 a cooling fluid in three channels at the same time 35 be let in, as that of the front side 33 facing side of the sliding element 36 in the area 37a has a recess that extends over the mouths of three channels 35 extends. Through the connection elements 38a , 38b , 39a , 39b can the fluid through assigned channels 35 and associated openings 34 can be pumped out in two pressure stages, as it has to be 2 has been described.

The sliding element 36 a connection element 42 on. In one area 42a that is around the connector 42 extends around, has the sliding element on the end face 33 facing side another recess, which extends over the mouths of a total of seven of the channels 41 extends. Extending this area over the mouths of seven canals 41 is selected only as an example and can also have any other number of channels in other exemplary embodiments 41 affect. At the connection element 42 a further pumping device is connected during operation, by means of which through the connection element 42 , the associated seven channels 41 and associated openings 40a the fluid can be pumped out. In this way it is ensured that the fluid that is used for cooling in a gap area between the cooling surface 32 and a substrate to be cooled is admitted, also does not get into the process vacuum at the side edges of the strip-shaped substrate, but that it also passes through the openings there 40a and on the other side through the openings 40 b is sucked off. As with the device 2 is known, so is also with the device in 3 a too sliding element 36 identical sliding element on the non-visible face of the heat sink 31 arranged.

Between the front 33 and the sliding element 36 there is an in 3 Sealing element, not shown, made of a plastic, which on one side is fixed to the sliding element 36 is connected and on the other side a sliding and sealing mechanical contact with the end face 33 manufactures.

In order to prevent a fluid from escaping to the side, sealing elements surrounding a cylindrical heat sink could alternatively be used. For example, a circumferential groove could be machined into the cooling surface shortly before both end faces of a cylindrical heat sink, into each of which a circumferential rubber band is inserted. This could also reduce the lateral escape of a fluid. However, sealing elements of this type are often only temperature-resistant up to a certain degree and are therefore not suitable for every application. For this reason, the sealing element encircling the groove can alternatively also consist of a different material, such as a metal.

In the exemplary embodiment from 3 are the openings 34 , 40a and 40b in rows on the cooling surface 32 of the cylindrical heat sink 31 arranged, with each row extending along the cylindrical extent in height. I. E. in each row of openings 34 there is an opening at one end 40a and an opening at the other end 40b . The mouth of a canal is located accordingly 41 on a circular angle of the circular face 33 on which there is also the mouth of a canal 35 located, with the mouths of the channels 41 form an outer ring and the mouths of the channels 35 an inner ring. The openings protrude accordingly 34 deeper into the heat sink 1 in than the openings 40a and 40b .

Alternatively, the openings 40a and 40b also deviating from the rows of openings 34 be arranged, ie one or more of the openings 40a and 40b can each between the rows of openings 34 be arranged. In such a case, the mouths of the canals would also be 41 on other circle angles of the face 33 be arranged as the mouths of the channels 35 . In such an embodiment, the openings 40a and 40b shorter, just as deep or even deeper in the direction of the cylinder axis in a heat sink than the openings 34 , because with such a configuration there is no risk of the openings 40a and 40b on the canals 35 to meet.

The device according to the invention has been described in that a fluid is let into a first contact area of substrate and cooling surface and is sucked out of two adjacent contact areas, one being arranged in front of the first contact area and the other after the first contact area when viewed in the direction of movement of the substrate. Alternatively, however, it is also conceivable that it is sufficient, especially at high belt speeds, if the fluid is only sucked out of a contact area which, viewed in the direction of movement of the substrate, is arranged after the first contact area.

The subject matter of the invention was further described only to the effect that it can be used for cooling a strip-shaped substrate. Depending on the temperature of a fluid used, a device according to the invention can also be used to keep the temperature of a strip-shaped substrate constant or else to heat a strip-shaped substrate. In addition, a device according to the invention can be combined with all devices known from the prior art which are used for cooling a heat sink itself. For example, the cooling body of a device according to the invention can be traversed by channels through which a cooling medium flows in order to cool the cooling body itself.

Claims (10)

Device for cooling a strip-shaped substrate in a vacuum, comprising a) at least one convex cooling surface (2) as the outer boundary of a cooling body (1); b) means for guiding at least one strip-shaped substrate in such a way that the substrate wraps around the convex cooling surface (2) at least partially in a contact area; c) a plurality of openings (4) which are arranged distributed over the contact area of the cooling surface (2) and which extend through the cooling surface (2) into the cooling body (1), wherein d) a first subset of the openings extends (4i) extends into at least one first channel (5i) which runs inside the heat sink (1) and opens out on at least one end face (3) of the heat sink (1), e) a second subset of the openings (4h) extends into at least one inside the cooling body (1) extending a second channel (5h) which opens at at least one end face (3) of the cooling body (1), f) a third subset of the openings (4j) into at least one inside the cooling body (1) extending third channel (5j) extends into at least one end face (3) of the heat sink, g) the second subset of openings (4h) being arranged after the first subset of openings (4i) viewed in the direction of movement of the substrate and the third subset of openings (4j) is arranged in front of the first subset of openings (4i); h) first means for providing a fluid in such a way that the fluid flows through the first channel (5i) into the cooling body; i) second means for sucking off the fluid from the second channel (5h) and third channel (5j). Device according to Claim 1 , characterized in that the convex cooling surface is part of a fixed form shoulder. Device according to Claim 1 , characterized in that the cooling body is designed as a cylindrical cooling roller (1) or as a cylindrical cooling drum (21). Device according to Claim 3 , characterized by at least one stationary sliding element (6) which is arranged on an end face (3) of the cylindrical cooling body (1) rotating about the cylinder axis and which connection means (7) for feeding the fluid into the first channel (5i) and connection means ( 8; 9) for pumping out the fluid from the second channel (5h) and third channel (5j). Device according to Claim 4 , characterized in that the sliding element comprises at least one sealing element which is firmly connected to the sliding element on one side and which has a sliding mechanical contact with the end face of the rotating heat sink on the other side. Device according to Claim 5 , characterized in that the sealing element consists of a plastic. Device according to one of the Claims 4 to 6th , characterized by at least one mechanical spring element which presses the sliding element against the end face of the rotating heat sink. Device according to one of the Claims 4 to 7th , characterized in that the first, second and third channel (25) extend from one end face (23) of the cylindrical heat sink (21) through the heat sink (21) to the opposite end face of the heat sink (21) and that on both end faces of the heat sink (21) each at least one sliding element (26) is arranged. Device according to Claim 8 , characterized in that the first, second and third channels (25) run parallel to the cylinder axis of the cooling body (21). Device according to one of the Claims 4 to 9 , characterized in that openings (40a) are machined into the cooling body (31) at least at one edge of the cooling surface (32) circumferentially around the cylinder circumference, each opening (40a) of which extends into an associated channel (41) connected to the end face (33) of the cooling body (31) opens and that the sliding element (36) has at least one connection element (42) through which the fluid can be pumped out of at least one channel (41).

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