Patent Description:
Processing of flexible substrates, such as plastic films or foils, is in high demand in the packaging industry, semiconductor industries and other industries. Processing may consist of coating a flexible substrate with a material, such as a metal, a semiconductor and a dielectric material, etching and other processing actions conducted on a substrate for the respective applications. Systems performing this task typically include a coating drum, e.g. a cylindrical roller, coupled to a processing system with a roller assembly for transporting the substrate, and on which at least a portion of the substrate is coated.

For example, a coating process such as a CVD process, a PVD process or an evaporation process can be utilized for depositing thin layers onto flexible substrates. Roll-to-roll deposition apparatuses are understood in that a flexible substrate of a considerable length, such as one kilometer or more, is uncoiled from a supply spool, coated with a stack of thin layers, and recoiled again on a wind-up spool. In particular, in the manufacture of thin film batteries, e.g. lithium batteries, the display industry and the photovoltaic (PV) industry, roll-to-roll deposition systems are of high interest. For example, the increasing demand for flexible touch panel elements, flexible displays, and flexible PV modules results in an increasing demand for depositing suitable layers in roll-to-roll -coaters.

There is a continuous demand for improved roll-to-roll processing systems, particularly with respect to processing quality, processing time, and processing efficiency. For example, one aspect affecting the processing efficiency is the time required for exchanging the substrate supply spool and the substrate wind-up spool. In conventional roll-to-roll processing systems, typically processing has to be stopped for exchanging the substrate spools. For instance, conventionally, the time for exchanging the substrate spools can take up to one hour. In particular, in vacuum processing systems according to the state of the art, the vacuum chambers with the substrate spools have to be vented for exchanging the substrate spools, which increases the downtime of the processing system.

Accordingly, in view of the above, there is a demand to provide solutions with which at least some of the disadvantages of the state of the art can be reduced or overcome.

In light of the above, a roll exchange chamber for exchanging a substrate roll, a roll-to-roll processing system, and a method of continuously providing a flexible substrate in a roll-to-roll processing system according to the independent claims are provided. Further aspects, advantages, and features are apparent from the dependent claims, the description, and the accompanying drawings.

According to an aspect of the present disclosure, a roll exchange chamber for exchanging a substrate roll is provided. The roll exchange chamber includes a rotatable base construction being rotatable around a central axis. The base construction includes a first roll holder for holding a first substrate roll, a second roll holder for holding a second substrate roll, and a wall for providing a first compartment and a second compartment in the roll exchange chamber. The wall is arranged between the first roll holder and the second roll holder.

According to a further aspect of the present disclosure, a roll-to-roll processing system for processing a flexible substrate is provided. The roll-to-roll processing system includes one or more vacuum chambers including at least one processing chamber. The at least one processing chamber includes a deposition unit for depositing material on the flexible substrate. Further, the roll-to-roll processing system includes a roll exchange chamber for exchanging a substrate roll. The roll exchange chamber includes a rotatable base construction being rotatable around a central axis. The base construction includes a first roll holder for holding a first substrate roll, a second roll holder for holding a second substrate roll, and a wall for providing a first compartment and a second compartment in the roll exchange chamber. The wall is arranged between the first roll holder and the second roll holder. In particular, the roll exchange chamber is a roll exchange chamber according to any of the embodiments described herein.

According to another aspect of the present disclosure, a method of continuously providing a flexible substrate in a roll-to-roll processing system is provided. The method includes exchanging an empty first substrate roll provided in a first compartment of a roll exchange chamber with a second substrate roll with a wound-up flexible substrate. Exchanging includes rotating a rotatable base construction around a central axis such that the first substrate roll coupled with a first roll holder of the base construction is transferred to a second compartment of the roll exchange chamber and the second substrate roll coupled with a second roll holder of the base construction is transferred to the first compartment. Further, the method includes connecting a trailing end of a flexible substrate unwound from the first substrate roll with a leading end of the flexible substrate provided on the second substrate roll.

Embodiments are also directed at apparatuses for carrying out the disclosed methods and include apparatus parts for performing each described method aspect. These method aspects may be performed by way of hardware components, a computer programmed by appropriate software, by any combination of the two or in any other manner. Furthermore, embodiments according to the disclosure are also directed at methods for operating the described apparatus. The methods for operating the described apparatus include method aspects for carrying out every function of the apparatus.

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the disclosure and are described in the following:.

Reference will now be made in detail to the various embodiments of the disclosure, one or more examples of which are illustrated in the figures. Within the following description of the drawings, same reference numbers refer to same components. Only the differences with respect to individual embodiments are described. Each example is provided by way of explanation of the disclosure and is not meant as a limitation of the disclosure. Further, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the description includes such modifications and variations.

With exemplary reference to <FIG>, a roll exchange chamber <NUM> for exchanging a substrate roll <NUM> according to the present disclosure is described. According to embodiments, which can be combined with any other embodiments described herein, the roll exchange chamber <NUM> includes a rotatable base construction <NUM> being rotatable around a central axis <NUM>. Typically, the central axis <NUM> is a horizontal axis. As indicated by the double-sided arrow in <FIG>, the base construction <NUM> may be rotatable in a clockwise or anti-clockwise direction. The base construction <NUM> includes a first roll holder <NUM> and a second roll holder <NUM>. The first roll holder <NUM> is configured for holding a first substrate roll <NUM>. The second roll holder <NUM> is configured for holding a second substrate roll <NUM>. The first substrate roll <NUM> and the second substrate roll <NUM> are indicated in dotted lines. Further, the base construction <NUM> includes a wall <NUM> for providing a first compartment <NUM> and a second compartment <NUM> in the roll exchange chamber <NUM>. The wall <NUM> is arranged between the first roll holder <NUM> and the second roll holder <NUM>. As exemplarily shown in <FIG>, the base construction <NUM> may be point symmetrical with respect to the central axis <NUM>.

In particular, the wall <NUM> of the base construction <NUM> is configured such that the wall <NUM> may extend from an upper chamber wall <NUM> to a bottom chamber wall <NUM> for providing a first compartment <NUM> and a second compartment <NUM> within the roll exchange chamber <NUM>.

More specifically, the first compartment <NUM> and the second compartment <NUM> can be provided by the wall <NUM> of the base construction <NUM> when the wall <NUM> is in a vertical orientation. In other words, when the wall <NUM> is in the vertical orientation, the interior space of the roll exchange chamber <NUM> can be separated by the wall <NUM> into a first compartment <NUM> and a second compartment <NUM>. Typically, the first compartment <NUM> and the second compartment <NUM> can be separated by the wall <NUM> in an air-tight manner.

As exemplarily shown in <FIG>, the first roll holder <NUM> and the second roll holder <NUM> are typically connected to the wall <NUM>. For instance, the first roll holder <NUM> can be connected to the wall <NUM> via a first mechanical structure <NUM>. The second roll holder <NUM> can be connected to the wall <NUM> via a second mechanical structure <NUM>. Accordingly, it is to be understood that upon rotation of the base construction <NUM>, the wall <NUM>, first roll holder <NUM> and the second roll holder <NUM> are rotated.

<FIG> shows a schematic view of a roll exchange chamber <NUM> during rotation of the base construction <NUM> in a clockwise direction. <FIG> shows the roll exchange chamber <NUM> after rotation of the base construction by <NUM>° compared to the position of the base construction <NUM> shown in <FIG>. Further, <FIG> show an example in which the first substrate roll <NUM> is empty, i.e. the flexible substrate has been unwound from the first substrate roll <NUM>, and the second substrate roll <NUM> is full, i.e. the flexible substrate is wound on the second substrate roll <NUM>. The empty first substrate roll <NUM> is schematically illustrated by a smaller diameter compared to the full second substrate roll <NUM>.

Accordingly, from <FIG>, <FIG>, it is to be understood that the roll exchange chamber <NUM> is configured such that by rotating the rotatable base construction <NUM>, an empty first substrate roll <NUM> can be exchanged with a second substrate roll <NUM> with a wound-up flexible substrate.

Accordingly, compared to the state of the art, the roll exchange chamber <NUM> according to embodiments described herein beneficially provides for a significant reduction in roll exchange time, i.e. the time needed to replace an empty substrate roll with a new substrate roll with a wound-up substrate. Further, the roll exchange chamber as described herein has the advantage that the substrate roll exchanged can be automated and carried out under vacuum conditions.

Before various further embodiments of the present disclosure are described in more detail, some aspects with respect to some terms used herein are explained.

In the present disclosure, a "roll exchange chamber" can be understood as a chamber configured for exchanging a roll, particularly a substrate roll. A "substrate roll" can be understood as a roll configured for carrying a flexible substrate wound on the roll. A "flexible substrate" can be understood as a bendable substrate. The term "flexible substrate" or "substrate" may be synonymously used with the term "foil" or the term "web". In particular, it is to be understood that embodiments of the roll exchange chamber and of the roll-to-roll processing system described herein can be utilized for any kind of flexible substrate. For example, a flexible substrate as described herein may include materials like PET, HC-PET, PE, PI, PU, TaC, OPP, CPP, one or more metals (e.g. copper or aluminium), paper, combinations thereof, and already coated substrates like Hard Coated PET (e.g. HC-PET, HC-TaC) or metal coated polymeric substrates (e.g. copper coated PET) and the like. According to an example, the substrate may be a metal foil, e.g. a foil consisting of copper or other metals. For example, the substrate thickness can be <NUM> or more and <NUM> or less. The substrate can be transparent or non-transparent.

In the present disclosure, a "rotatable base construction" can be understood as a rigid mechanical structure or assembly which is rotatably mounted on one or more bearings. In particular, the base construction is rotatably mounted on one or more bearings such that the base construction can be rotated around a central axis, particularly a horizontal central axis.

In the present disclosure, a "roll holder for holding a substrate roll" can be understood as a holding device configured for holding a substrate roll as described herein. For instance, the roll holder may include a bolt or a shaft on which the substrate roll can be mounted. Further, the roll holder may include a coupling device, particularly an automated coupling device, for coupling the substrate roll with the roll holder. Typically, the roll holder is rotatably mounted, particularly around a central axis of the roll holder. Accordingly, it is to be understood that by rotating the roll holder, the flexible substrate wound on the substrate roll can be unwound.

In the present disclosure, a "substrate roll" can be understood as a roll configured for carrying a flexible substrate. Accordingly, an "empty" substrate roll can be understood as a substrate roll without a flexible substrate and a "full" substrate roll can be understood as a substrate roll with a wound-up flexible substrate.

In the present disclosure, a "wall for providing a first compartment and a second compartment in the roll exchange chamber" can be understood as a wall which is configured such that the roll exchange chamber can be divided into a first compartment and a second compartment. In other words, the wall may separate the first compartment from the second compartment, particularly in an air-tight manner.

With exemplary reference to <FIG> and <FIG>, further embodiments of the roll exchange chamber <NUM> are described.

<FIG> shows a schematic view of a section of the rotatable base construction <NUM> according to embodiments described herein. According to embodiments, which can be combined with any other embodiments described herein, the rotatable base construction <NUM> is mounted on a central bearing unit <NUM> having a feedthrough <NUM> for supply lines. For example, the feedthrough <NUM> may be provided in a bolt <NUM> mounted to the wall <NUM>. As exemplarily shown in <FIG>, the central bearing unit <NUM> may include a ball bearing <NUM>. Typically, the ball bearing <NUM> is mounted on the bolt <NUM>. However, it is to be understood that alternatively other bearings, e.g. a slide bearing may be implemented. Further, it is to be understood that the central bearing unit <NUM> provides for the possibility to rotate the base construction <NUM>.

As exemplarily shown in <FIG>, according to embodiments which can be combined with any other embodiments described herein, the wall <NUM> has an interior hollow space <NUM>. The interior hollow space <NUM> may be provided with one or more ribs <NUM>. The one or more ribs <NUM> may include one or more openings <NUM> for supply lines. The supply lines may include one or more of power cables, data cables and tubes for media supply. The supply lines can for example be used to supply the motors, actuators, rollers, measurement devices etc. provided in the roll exchange chamber <NUM>.

Providing a central bearing unit <NUM> with a feedthrough <NUM> and one or more ribs with one or more openings <NUM> for supply lines as described herein, provides for an improved supply line connection to motors, actuators, rollers, measurement devices etc. mounted to the rotatable base construction <NUM>.

Further, it is to be noted that providing a wall <NUM> with an interior hollow space <NUM> has the advantage that a vacuum may be provided inside the wall, which can be beneficial for reducing particle contamination within the roll exchange chamber <NUM>. For example, for providing a vacuum in the interior hollow space <NUM> of the wall <NUM>, a vacuum pump connection may be provided above and/or below the wall <NUM>, i.e. in the upper chamber wall <NUM> and/or the bottom chamber wall <NUM>.

According to embodiments, which can be combined with any other embodiments described herein, the roll exchange chamber <NUM> further includes a locking mechanism <NUM> for engaging with the wall <NUM>. The locking mechanism <NUM> is configured for locking a position of the rotatable base construction <NUM>. In particular, the locking mechanism <NUM> may include a locking bolt <NUM> configured for engaging with a corresponding reception provided in the wall <NUM>. As exemplarily indicated by the double sided arrow in <FIG>, the locking bolt <NUM> may be connected to a linear actuator for translating the locking bolt <NUM> for locking and unlocking.

With exemplary reference to <FIG>, according to embodiments, which can be combined with any other embodiments described herein, one or more inflatable seals <NUM> may be provided for providing an airtight sealing between the wall <NUM> of the base construction <NUM> and the roll exchange chamber. In particular, the one or more inflatable seals <NUM> are arranged and configured for providing an airtight sealing between the outer surface of the wall <NUM> and the opposite interior surface of the roll exchange chamber <NUM>. According to an example as shown in <FIG>, a first inflatable seal 147A may be provided at a first compartment side and a second inflatable seal 147B may be provided at a second compartment side. In particular, it is to be understood that the first inflatable seal 147A and the second inflatable seal 147B can be arranged and configured for providing a sealing of the interior hollow space <NUM> of the wall <NUM> (as exemplarily described with reference to <FIG>) from the first compartment <NUM> and the second compartment <NUM>, respectively. Accordingly, different pressure conditions can be provided in the first compartment <NUM>, the interior hollow space <NUM> of the wall <NUM>, and the second compartment <NUM>. It is to be understood that typically for rotating the rotatable base construction <NUM> the one or more inflatable seals <NUM> are deflated.

According to embodiments, which can be combined with any other embodiments described herein, the roll exchange chamber further includes one or more first vacuum pumps <NUM> for providing vacuum conditions in the first compartment <NUM>. Additionally, the roll exchange chamber can include one or more second vacuum pumps <NUM> for providing vacuum conditions in the second compartment <NUM>. The term "vacuum", as used herein, can be understood in the sense of a technical vacuum having a vacuum pressure of less than, for example, <NUM> mbar. Typically, the pressure in a vacuum chamber as described herein may be between <NUM>-<NUM> mbar and about <NUM>-<NUM> mbar, more typically between <NUM>-<NUM> mbar and <NUM>-<NUM> mbar, and even more typically between about <NUM>-<NUM> mbar and about <NUM>-<NUM> mbar.

According to embodiments, which can be combined with any other embodiments described herein, the roll exchange chamber <NUM> includes a substrate connecting device <NUM> for connecting a first end of a first flexible substrate <NUM> with a second end of a second flexible substrate <NUM>. In particular, the substrate connecting device <NUM> can be a splice unit. For example, the substrate connecting device <NUM> may include a roller <NUM> with a splice tape. The roller <NUM> of the substrate connecting device <NUM> may also be referred to as a splice roller. Typically, the roller <NUM> of the substrate connecting device <NUM> is connected to a linear actuator <NUM> for pushing the roller <NUM> with the splice tape onto the first substrate being in contact with a counter roller <NUM>. Further, the substrate connecting device <NUM> may include a cutting device for cutting the splice tape after substrate connection. <FIG> shows an example in which a trailing end portion of the first flexible substrate <NUM> is connected with a leading end portion of the second flexible substrate <NUM> by using the substrate connecting device <NUM>.

According to embodiments, which can be combined with any other embodiments described herein, the roll exchange chamber <NUM> includes a tension measuring roller <NUM> for measuring a substrate tension, particularly the tension measuring roller <NUM> being arranged upstream from the substrate connecting device <NUM>. The tension measuring roller <NUM> is configured for measuring a tension of the flexible substrate during substrate transportation. In particular, providing a tension measuring roller <NUM> can be beneficial for identifying a situation when the substrate roll has to be exchanged. In this regard, it is to be noted that the substrate tension decreases when the substrate is almost completely unwound from the substrate roll. According to embodiments, which can be combined with any other embodiments described herein, one or more of the guide rollers <NUM>, as exemplarily shown in <FIG>, may be tension measuring rollers.

The terms "upstream from" and "downstream from" as used herein may refer to the position of the respective component with respect to another component along the substrate transportation path in the substrate transportation direction. For better understanding, the substrate transportation direction <NUM> is exemplarily indicated in <FIG>. For instance, in <FIG> the second flexible substrate <NUM> is guided from the second substrate roll <NUM> to a guide roller <NUM>, from the guide roller <NUM> to the tension measuring roller <NUM>, from the tension measuring roller <NUM> to a further guide roller <NUM>, from the further guide roller <NUM> to the counter roller <NUM>, and so forth. Accordingly, the guide roller <NUM> is arranged downstream from the second substrate roll <NUM>, the tension measuring roller <NUM> is arranged downstream from the guide roller <NUM>, and the counter roller <NUM> is arranged downstream from the tension measuring roller <NUM> and the further guide roller <NUM>. Accordingly, the second substrate roll <NUM> is arranged upstream from the guide roller <NUM>, the guide roller <NUM> is arranged upstream from the tension measuring roller <NUM>, and the tension measuring roller <NUM> is arranged upstream from the further guide roller <NUM> and the counter roller <NUM>.

With exemplary reference to <FIG>, it is to be understood that typically the base construction <NUM> is configured to be point symmetrical with respect to the central axis <NUM>. Accordingly, the first mechanical structure <NUM> and the second mechanical structure <NUM> can be point symmetrical with respect to the central axis <NUM>. Further, it is to be understood that the first roll holder <NUM> and the second roll holder <NUM> can be point symmetrical with respect to the central axis <NUM>. The respective guide rollers <NUM> of the first mechanical structure <NUM> and the second mechanical structure <NUM> can be point symmetrical with respect to the central axis <NUM>. The respective tension measuring roller <NUM> of the first mechanical structure <NUM> and the second mechanical structure <NUM> can be point symmetrical with respect to the central axis <NUM>. The respective substrate connecting device <NUM> of the first mechanical structure <NUM> and the second mechanical structure <NUM> can be point symmetrical with respect to the central axis <NUM>. The respective interleaf holder <NUM> of the first mechanical structure <NUM> and the second mechanical structure <NUM> can be point symmetrical with respect to the central axis <NUM>.

According to embodiments, which can be combined with any other embodiments described herein, the roll exchange chamber <NUM> includes a door <NUM> for providing access to the second compartment <NUM> from an atmospheric maintenance space <NUM>.

According to embodiments, which can be combined with any other embodiments described herein, the roll exchange chamber <NUM> includes a substrate feedthrough opening <NUM> for providing a substrate from the first compartment to an adjacent chamber of a substrate processing system. The substrate feedthrough opening <NUM> may be provided with a sealing device, e.g. a gap sluice. The sealing device may also be referred to as a load lock or a load lock valve.

With exemplary reference to <FIG>, according to embodiments which can be combined with any other embodiments described herein, an interleaf module including an interleaf holder <NUM> for holding an interleaf roll <NUM> may be provided. Typically, the interleaf holder <NUM> is connected to the base construction <NUM>. For instance, one or both of the first mechanical structure <NUM> and the second mechanical structure <NUM> may be provided with an interleaf holder <NUM>. Providing an interleaf module has the advantage that an interleaf <NUM> can be provided between adjacent layers of the flexible substrate such that direct contact of one layer of the flexible substrate with an adjacent layer of the flexible substrate on the substrate roll can be avoided. Upon unwinding the flexible substrate with the interleaf from the substrate roll, the interleaf <NUM> can be wound on the interleaf roll <NUM>. Accordingly, it is to be understood that, while winding the flexible substrate onto the substrate roll, an interleaf can be provided between adjacent layers of the flexible substrate wound on the substrate roll.

With exemplary reference to <FIG>, according to embodiments which can be combined with any other embodiments described herein, the first compartment <NUM> of the roll exchange chamber may be equipped with a cold trap <NUM>. The cold trap <NUM> can beneficial for reducing humidity inside the first compartment <NUM>, which can be beneficial for improving the processing quality.

With exemplary reference to <FIG>, a roll-to-roll processing system <NUM> for processing a flexible substrate according to the present disclosure is described. More specifically, the roll-to-roll processing system can be a vacuum processing system having at least one vacuum deposition chamber. For instance, the roll-to-roll processing system may be configured for a substrate length of <NUM> or more, <NUM> or more, or several kilometers. The substrate width can be <NUM> or more, particularly <NUM> or more, more particularly <NUM> or more. Further, the substrate width can be <NUM> or less, particularly <NUM> or less.

According to embodiments, which can be combined with any other embodiments described herein, the roll-to-roll processing system <NUM> includes one or more vacuum chambers including at least one processing chamber <NUM> having one or more deposition units <NUM> for depositing material on the flexible substrate. Typically, the roll-to-roll processing system <NUM> includes a coating drum <NUM> configured for guiding the flexible substrate past the one or more deposition units <NUM>.

In the present disclosure, a "coating drum" can be understood as a drum or a roller having a substrate support surface for contacting the flexible substrate. In particular, the coating drum can be rotatable about a rotation axis and may include a substrate guiding region. Typically, the substrate guiding region is a curved substrate support surface, e.g. a cylindrically symmetric surface, of the coating drum. The curved substrate support surface of the coating drum may be adapted to be (at least partly) in contact with the flexible substrate during operation of the processing system.

In the present disclosure, a "deposition unit" can be understood as a unit or device configured for depositing material on a substrate. For example, the deposition unit may be a sputter deposition unit, a CVD deposition unit, an evaporation deposition unit, a PVD or PECVD deposition unit, or another suitable deposition unit.

Further, as exemplarily shown in <FIG>, the roll-to-roll processing system <NUM> includes a roll exchange chamber <NUM> for exchanging a substrate roll <NUM>. The roll exchange chamber <NUM> includes a rotatable base construction <NUM> being rotatable around a central axis <NUM>. The base construction <NUM> includes a first roll holder <NUM> and a second roll holder <NUM>. The first roll holder <NUM> is configured for holding a first substrate roll <NUM>. The second roll holder <NUM> is configured for holding a second substrate roll <NUM>. Further, the base construction <NUM> includes a wall <NUM> for providing a first compartment <NUM> and a second compartment <NUM> in the roll exchange chamber <NUM>. The wall <NUM> is arranged between the first roll holder <NUM> and the second roll holder <NUM>. It is to be noted that the roll exchange chamber <NUM> can be a roll exchange chamber <NUM> according to any embodiments described herein.

As exemplarily shown in <FIG>, the roll exchange chamber <NUM> as described herein can be employed as a substrate supply chamber <NUM> and as a substrate take-up chamber <NUM>. Accordingly, from the exemplary embodiment of <FIG>, it is to be understood that the second substrate roll <NUM> of the substrate supply chamber <NUM> can be a substrate supply roll and the first substrate roll <NUM> of the substrate take-up chamber <NUM> can be a substrate take-up roll.

With exemplarily reference to the block diagram of <FIG>, a method <NUM> of continuously providing a flexible substrate in a roll-to-roll processing system is described. According to embodiments, which can be combined with any other embodiments described herein, the method includes exchanging (represented by block <NUM> in <FIG>) an empty first substrate roll <NUM> provided in a first compartment <NUM> of a roll exchange chamber <NUM> with a second substrate roll <NUM> with a wound-up flexible substrate.

Exchanging the empty first substrate roll <NUM> with the second substrate roll <NUM> includes rotating (represented by block <NUM> in <FIG>) a rotatable base construction <NUM> around a central axis <NUM> such that the first substrate roll <NUM> coupled with a first roll holder <NUM> of the base construction <NUM> is transferred to a second compartment <NUM> of the roll exchange chamber <NUM>. Additionally, the second substrate roll <NUM> coupled with a second roll holder <NUM> of the base construction <NUM> is transferred to the first compartment <NUM> by rotating the rotatable base construction <NUM> around the central axis <NUM>.

Further, the method includes connecting (represented by block <NUM> in <FIG>) a trailing end of the flexible substrate unwound from the first substrate roll <NUM> with a leading end of the flexible substrate provided on the second substrate roll <NUM>.

According to embodiments, which can be combined with any other embodiments described herein, connecting (represented by block <NUM> in <FIG>) the trailing end of the flexible substrate unwound from the first substrate roll <NUM> with the leading end of the flexible substrate provided on the second substrate roll <NUM> involves using (represented by block <NUM> in <FIG>) a substrate connecting device <NUM>. In particular, the substrate connecting device <NUM> is a splice unit including a roller <NUM> with a splice tape. Further, the substrate connecting device <NUM> may include a cutting device cutting the splice tape.

It is to be understood that according to embodiments, which can be combined with any other embodiments described herein, the method is typically carried out by using a roll exchange chamber according any embodiments described herein.

Claim 1:
A roll exchange chamber (<NUM>) for exchanging a substrate roll (<NUM>), characterized by comprising:
- a rotatable base construction (<NUM>) being rotatable around a central axis (<NUM>), the base construction (<NUM>) comprising:
- a first roll holder (<NUM>) for holding a first substrate roll (<NUM>);
- a second roll holder (<NUM>) for holding a second substrate roll (<NUM>); and
- a wall (<NUM>) for providing a first compartment (<NUM>) and a second compartment (<NUM>) in the roll exchange chamber (<NUM>), the wall (<NUM>) being arranged between the first roll holder (<NUM>) and the second roll holder (<NUM>).