Device and method for positioning a shadow mask

A device for positioning a shadow mask includes a mask application tool, the mask application tool comprising an inner body comprising, at an end surface of the inner body, one or more magnets. The mask application tool further comprises a hollow outer body for receiving the inner body, the outer body comprising, at an end surface of the outer body, a mask socket and one or more guide elements for positioning the mask application tool on a substrate tray.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims priority to European Patent Application No. 22165631.7, filed on Mar. 30, 2022, which is incorporated herein in its entirety by reference.

FIELD OF THE DISCLOSURE

The present disclosure relates a device and a method for positioning a shadow mask.

BACKGROUND OF THE INVENTION

Shadow masks are used for selectively covering portions of a substrate prior to coating the substrate with materials to be deposited on the substrate. Substrates are often disk-shaped and the masked area often lies completely within the substrate without protruding the disk sideways. As an example, disk shaped substrates may be coated such that the coated area describes a circle around the disks surface with a straight line through the center of the disk.

Currently, shadow masks are applied using a lithography process. As an example, in a lithography process, a photo-sensitive lacquer is applied to the substrate surface and then a mask is put on top. After exposing the substrate to a light source, thereby exposing uncovered portions of the lacquer. The un-exposed parts of the lacquer are washed away, whereas the exposed parts remain on the substrate to form a mask. The masked substrates may then be coated, e.g. after being sent to a coating provider and coated. After coating, the lacquer, i.e., the sacrificial layer, is washed away and the substrate remains with the coating where needed.

Due to exposure to environmental conditions (for example, temperature, humidity, and dust) after forming the lacquer mask, for example during transportation, issues may arise that lead to the coating not properly sticking to the substrate. Various tests showed that quality could be improved by drying, e.g., in an oven, of the substrates right before coating. However, using a lithography process, the drying temperature is limited by the lacquer. The drying temperatures compatible with lacquer often do not yield satisfactory results.

Accordingly, the lithography-based process has various challenges. It involves the use of various chemicals, like lacquer, which are often hazardous and require special handling (including, for example, protecting the lacquer from unwanted exposure to light). Moreover, drying times are necessary, thereby limiting throughput. In addition, lithography may result in unsatisfactory results due to the heating temperatures being limited and also due to inaccuracies in different steps in the lithography process, which may accumulate, particularly due to several manual steps involved, which are particularly prone to errors or inaccuracies. Moreover, the waste incurred, e.g., the lacquer layer that is completely discarded over the course of the lithography process, and the use of the chemicals may be an issue of concern from an ecological point of view.

BRIEF SUMMARY OF THE INVENTION

In one general aspect, the present disclosure describes a device and a method for positioning a shadow mask that overcome at least some of the above challenges.

The disclosure describes a device for positioning a shadow mask, particularly a magnetic shadow mask. The device comprises a mask application tool, the mask application tool comprising an inner body comprising, at an end surface of the inner body, one or more magnets. The mask application tool further comprises a hollow outer body for receiving the inner body, the outer body comprising, at an end surface of the outer body, a mask socket and one or more guide elements for positioning the mask application tool on a substrate tray.

An advantage of such a device is that a magnetic shadow mask can be securely held by magnetic force of the magnets, positioned accurately directly onto a substrate placed on the substrate tray by means of the guide pins, and then released by retracting the inner body from the outer body, thereby decreasing the distance between the magnets and the mask in a controlled manner. Accordingly, a device for precisely positioning a shadow mask is provided.

Allowing for a precise positioning of the shadow mask directly onto the substrate allows for omitting the steps of lithography entirely, i.e., all steps related to the lacquer mask are not required. Instead, the precisely positioned mask can be used directly for coating. Accordingly, the challenges described above in the context of the lithography process are overcome.

Specifically, the production process is sped up, the use of the chemicals that may be hazardous and difficult to handle is eliminated, waste is reduced, and reliability, quality, and accuracy is improved by reducing the number of steps and by eliminating the temperature limitation for heating brought about by the lacquer. Overall process costs are also improved due to reduced time, reduced number of steps, and reduced amount of chemicals and equipment required. Thus, the device of the present disclosure fulfils the above objective.

An additional advantage is that the mask, contrary to the lacquer mask, can be re-used ensuring a high reproducibility of coating results.

In the present disclosure, when arrangements of elements are described, unless otherwise specified, this will refer to the device in a configuration for intended use, particularly, where applicable, in an assembled state.

The end surface of the inner body having the magnets may, in an arrangement for intended use, be the end surface corresponding to the end surface of the outer body having the mask socket. For example, the end surface of the outer body may be a base surface of a hollow cylinder and the end surface of the inner body may be a base surface of a cylinder with a cylinder axis parallel to that of the hollow cylinder. The inner body may be inserted with the base surface first into the outer body in an arrangement for intended use.

The shadow mask to be used is of a magnetic material. The shape of the shadow mask may be such that the shadow mask does not protrude the substrate, and, accordingly the substrate socket, in a plane parallel to the surface of the substrate.

The device of the present disclosure may further comprise a substrate tray. The substrate tray may comprise one or more first positioning elements. The substrate tray may further comprise one or more substrate sockets having at least one substrate portion and having at least one positioning portion configured to engage with at least one of the guide elements of the outer body, in particular so as to receive at least one of one or more guide pins and/or protrude into at least one of one or more guide bores of the outer body, so as to position the outer body with respect to the substrate tray.

The device of the present disclosure may further comprise a base plate assembly. The base plate assembly may comprise one or more second positioning elements each configured to engage with one of the first positioning elements so as to position the substrate tray with respect to the base plate assembly. The base plate assembly may further comprise one or more magnets, in particular wherein the one or more magnets are associated with the one or more substrate sockets such that each substrate socket is associated with at least one of the one or more magnets of the base plate assembly.

In other words, a substrate tray may be configured for receiving a substrate in each of the substrate sockets, thereby defining a substrate position, and to allow for properly positioning the mask application tool with respect to the substrates may be provided. Accordingly, accurate positioning of the shadow mask is ensured.

A magnet being associated with a substrate socket may comprise a magnet being arranged at least partially inside of or directly below the substrate in an assembled state, i.e., in a state where the substrate tray is positioned on the base plate assembly.

Each substrate socket may be associated with at least one separate magnet. Alternatively substrate sockets may share a magnet.

The first positioning elements and the second positioning elements may comprise one or more holes and/or one or more pins. In one embodiment, the positioning elements can include a pair of first and second positioning elements embodied as a hole and a pin.

The base plate assembly may comprise one or more plates, wherein at least one of the plates is configured to define the position of the magnets relative to the substrate tray in an assembled state.

In an assembled state, the base plate assembly may be aligned with the substrate tray via the first and second positioning elements, such that one or more magnets are arranged in an area of each substrate socket. For example, the base plate assembly may have a plate with an array of holes, e.g., the magnet positioning holes mentioned below, each hole defining the position of at least one of the magnets.

The magnets may be configured to hold the mask positioned on top of a substrate placed in the substrate tray in place.

DETAILED DESCRIPTION OF THE INVENTION

FIGS.1aand1billustrate schematically an oblique view of a device1for positioning a shadow mask2. The device comprises a mask application tool3. The mask application tool comprises an inner body4and an outer body5for receiving the inner body. At the end surface4aof the inner body, two magnets4bare arranged. Specifically, the magnets4bare arranged at a cylinder base4c-1of a cylinder-shaped portion4cof the inner body4. The cylinder-shaped portion forms the inner end of the inner body4, i.e., the end that is inserted first into the hollow outer body5. The cylinder surface4c-2of the cylinder-shaped portion4chas two recesses4c-3. The recesses extend in the direction of a cylinder axis4c-4of the cylinder-shaped portion.

The hollow outer body5has, arranged at its end surface5a, a mask socket5band two guide elements5c, in this example guide pins5cprotruding from the end surface5a. The guide pins are configured for positioning the mask application tool on a substrate tray, e.g., by inserting them into corresponding holes or bores in a substrate tray.

The hollow outer body5has a cylinder-shaped opening5dfor receiving the inner body4. Specifically, the recess may be arranged at the end of the outer body opposite the end surface5a. The hollow outer body5in this example may be essentially shaped as a hollow cylinder. The cylinder surface5d-1of the cylinder-shaped opening5dhas two guide protrusions5d-2extending in the direction of a cylinder axis5d-3of the cylinder-shaped opening5d.

The guide protrusions5d-2of the outer body are each configured to engage with one of the recesses4c-3of the inner body so as to guide a sliding movement of the cylinder-shaped portion4cof the inner body along the cylinder axis5d-3.

In the example shown inFIG.1a, mask socket5bis configured as a recess-portion5b-1for receiving the shadow mask2. The end surface5aof the outer body5has two openings5a-1located in the recess-portion5b-1. These opening are configured to each receive one of the magnets4bof the inner body4. The mask application tool may optionally be configured such that an end surface4b-1of each magnet4bis aligned with the end surface5aof the outer body in the recess-portion5b-1.

Optionally, the recess-portion5b-1may comprise a sub-division5a-2, which is bar-shaped in this example, for mask-positioning. As can be understood from the semi-circular parts of the shadow mask2, when placed in the recess-portion, will be prevented from significantly shifting or rotating due to the sub-division5a-2.

The shadow mask2and the mask socket5b, in particular the recess-portion5b-1, are configured such that an outward-facing surface2aof the shadow mask aligns with a portion5b-2of the mask socket5boutside of, particularly adjacent to, the recess-portion5b-1when the shadow mask is placed in the recess-portion.

FIG.2shows a system13according to the present disclosure, which comprises a device1according to the present disclosure and a plurality of shadow masks2, which are not part of the device1.

A plurality of substrates14, which are not part of the system, are also shown inFIG.2for the sake of illustration.

The device1comprises a mask application tool3. The mask application tool is generally configured similarly to that ofFIG.1, except that the inner body and the opening of the hollow outer body and the guide elements5care differently shaped. Particularly, the inner body and the opening have an asymmetric shape to prevent rotation of the inner body in the outer body. The guide elements may have a base having a circular shape as shown inFIG.2or a base shaped as shown inFIG.1a. Alternatively, instead of the mask application tool shown inFIG.2, the device may comprise a mask application tool as described in the context ofFIGS.1aand1bor another mask application tool according to the present disclosure.

In addition, the device comprises a substrate tray6, also referred to as top tray, and a base plate assembly9. The base plate assembly9comprises a first plate9awith magnet positioning holes9band a second plate9c. The base plate assembly also comprises magnets11that are positioned in the magnet positioning holes9bin an assembled state. The second plate9csupports the magnets from below in an assembled state. Magnet mounting screws12may hold the magnets in place.

The base plate assembly also comprises second positioning elements10such as pins extending upwards from the first plate9a. The second positioning elements engage with corresponding first positioning elements7of the substrate tray6, which may be slotted holes, each slotted hole configured to receive one of the second positioning elements10, e.g., one of the pins.

The substrate tray also comprises substrate sockets8, each configured to receive one substrate. The substrate socket also has a positioning portion configured for receiving the guide pins5cof the mask application tool. An exemplary configuration of the substrate sockets8is explained in the context ofFIGS.3and4.

In the example shown inFIG.2, for each of the sockets8, two magnets11are provided. They are arranged, in an assembled state, directly below a substrate placed in the substrate socket.

FIG.3illustrates schematically parts of an exemplary device1for positioning a shadow mask according to the present disclosure, for example one of the above-described devices, in a disassembled state.FIG.3shows a first plate9aand a second plate9cof a base plate assembly9and a substrate tray6. Magnet mounting screws12are also shown.

FIG.3illustrates that the substrate tray having a plurality, in this example four, of first positioning elements7, here in the form of slotted holes. Moreover, the substrate tray is shown as having a plurality of substrate sockets8, each configured to receive one substrate, e.g., in a substrate portion8a, which is circular in this example. The substrate socket also has a positioning portion8bcomprising two positioning bores8b-1, each configured for receiving one of the guide pins5cof a mask application tool according to the present disclosure. Alternatively, the mask application tool may have guide bores as guide elements and the positioning portion may then have corresponding positioning pins to engage with the guide bores.

The first plate9aof the base plate assembly is shown as comprising a plurality of magnet positioning holes9b, particularly, two magnet positioning holes for each of the substrate sockets. In an assembled state, this means that two magnets will be arranged directly below each substrate socket.

The first plate9ais also shown as having a plurality of, in this example four, second positioning elements10. The second positioning elements10are each configured as pins. The pins extend upwards and, in an assembled state, are each received by one of the slotted holes.

In this example, in an assembled state, an end surface11aof the one or more magnets11, the end surface facing the second plate9c, is aligned with a surface9a-1of the first plate9afacing the second plate9c.

FIG.4illustrates schematically parts of a device for positioning a shadow mask according to the present disclosure. The device is shown in a state wherein the substrate tray6is positioned on the base plate assembly9. Here, for the sake of illustration, magnets11and magnet mounting screws12are only shown for some of the substrate sockets8to better illustrate the overall arrangement. In intended use, magnets11may be provided for each of the substrate sockets8, in particular, two magnets for each substrate socket.

Since the same reference signs are used inFIG.4as inFIGS.2and3and the elements may be the same or similar as described inFIGS.2and3, reference is made to the description of these features presented above in the context ofFIGS.2and3.

The device1according to the present disclosure may comprise the substrate tray6and base plate assembly9as shown inFIG.2,3, or4, and any type of mask application tool3, particularly the mask application tool as shown inFIG.1orFIG.2.

It is noted that the device1for positioning a shadow mask according to the present disclosure may be used for/with other types of shadow masks than the ones shown in the Figures. Specifically, the Figures show a mask that is made of two pieces, i.e., two separate, in this example, essentially semicircular parts. Alternatively, a one-piece mask or a mask having more than two pieces may be applied with the claimed device. When the mask is a single-piece mask, it may be held by only one magnet of the mask application tool and only one magnet by the base plate assembly, or by two or more magnets, respectively. When the mask has more than two pieces, there may be one magnet for each of the pieces comprise in the mask application tool and one magnet for each of the pieces comprised in the base plate assembly.

In the following, an exemplary method for positioning a shadow mask according to the present disclosure, for example using a device or system as described in the context ofFIGS.1to4, is described. Moreover, optional steps preceding and following the positioning are also described below.

In step S1the base plate assembly9is assembled, e.g., by placing magnets11in magnet positioning holes9bof the first plate9a, with the second plate9barranged below the first plate and the magnets. The magnets may be fixed by means of magnet mounting screws12. The base plate assembly may then be kept as it is.

In step S2, substrates14are placed in the substrate sockets8of the substrate tray6.

In step S3, the top tray with the substrates is heated in an oven, e.g., for drying.

In step S4, the substrate tray including the substrates is placed on top of the base plate assembly, specifically the first plate thereof, and positioned, e.g. by guide pins10of the base plate assembly and slotted holes7of the substrate tray.

In step S5, the mask is inserted in the outer body of the mask application tool3and held by the magnets4bof the inner body4of the mask application tool.

In step S6, the application tool is positioned on the substrate tray using its guide pins5cof the mask application tool, such that the mask is placed on one of the substrates.

In step S7, the inner body4is removed from the outer body5of the mask application tool, thereby moving the magnets4bof the inner body away from the mask.

In step S8, the mask is being held in place by the magnets11of the base plate assembly underneath the substrate.

In step S9, the outer body5of the mask application tool is lifted from the substrate tray.

Steps S5to S9may be repeated for all substrates. Alternatively, they may be performed concurrently for a plurality, in particular all, of substrates using a plurality of mask application tools3or by using a modified mask application tool scaled to position a plurality of masks at the same time.

In step S10, with the masks positioned in the substrate sockets8and held in place by the magnets11, a coating step is performed, wherein the substrate and masks are coated.

In step S11, the substrate tray including the substrates and masks is lifted from the base plate assembly. The masks are now no longer held in place by the magnets11of the base plate.

In step S12, the masks and substrates are removed from the substrate tray.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered exemplary and not restrictive. The invention is not limited to the disclosed embodiments. In view of the foregoing description and drawings it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention, as defined by the claims.

According to the present disclosure, the substrate tray may be mounted on the base plate assembly, in particular, so as to be arranged between the base plate assembly and the mask application tool. This arrangement refers to an assembled state with the mask application tool positioned, by means of the guide elements, on the substrate tray. Thus, the one or more magnets of the mask application tool will hold the shadow mask from the top and one or more magnets of the base plate assembly will hold the shadow mask from below, particularly, when a substrate is placed in the substrate tray, from below the substrate. This allows for a smooth transition from the mask being held by the mask application tool and the mask being held in place on the substrate, as will be explained in more detail below.

As outlined above, at the time of positioning the mask, the substrate tray may be arranged between the base plate assembly and the mask application tool, thereby, all elements are properly aligned and held in place. It is noted that at the mask will be held by the magnet of the mask application tool and the magnet of the base plate assembly while being positioned on the substrate. The mask is then released onto the substrate by sliding the inner body including the magnet of the mask application tool away from the mask, thereby decreasing the hold of said magnet on the mask.

The substrate tray may be mounted removably on the base plate assembly. Accordingly, the substrate tray may be separately used for any processing steps of the substrates, e.g., heating prior to coating. Moreover, by lifting the substrate tray from the base plate assembly, the hold of the magnets on the mask is decreased, thereby allowing for easy removal of the substrate and mask, which are then no longer held in place by the magnets.

As can be seen from the above, the mask may be held in place with one or more magnets from below the substrate to prevent movement during the coating process. After coating the masks can be removed easily by lifting the substrates away from the magnets by lifting the substrate tray from the base plate assembly.

The device may be configured such that the substrate tray and the base plate assembly can be taken apart without tooling.

It is noted that the magnets of the mask application tool and/or the magnets of the base plate assembly may be permanent magnets. Alternatively, the magnets, particularly the magnets of the base plate assembly, may be electromagnets.

According to the present disclosure, the substrate tray may be heat-resistant. This allows for heating of substrates placed on the substrate tray.

According to the present disclosure, the outer body may have a cylinder-shaped opening for receiving the inner body. Alternatively or in addition, the inner body may have a cylinder-shaped portion, the one or more magnets arranged at a cylinder base of the cylinder-shaped portion.

In particular, a cylinder surface of the cylinder-shaped portion may have one or more recesses extending in the direction of a cylinder axis of the cylinder-shaped portion and a cylinder surface of the cylinder-shaped opening may have one or more guide protrusions extending in the direction of a cylinder axis of the cylinder-shaped opening. The one or more guide protrusions may each be configured to engage with one of the recesses so as to guide a sliding movement of the cylinder-shaped portion along the cylinder axis of the cylinder-shaped opening.

Alternatively or in addition, one or more recesses extending in the direction of the cylinder axis of the cylinder-shaped opening may be provided in the cylinder surface of the cylinder-shaped opening and the cylinder surface of the cylinder-shaped portion may have one or more guide protrusions extending in the direction of the cylinder axis of the cylinder-shaped portion and the guide protrusions may each be configured to engage with one of the recesses so as to guide a sliding movement of the cylinder-shaped portion along the cylinder axis of the cylinder-shaped opening.

Thus, the movement of the inner body in the outer body can be controlled, allowing for more easily inserting the inner body, particularly in such a manner, that the magnets will be located in proper positions when the inner body is inserted. For example, if there are one or more openings configured to receive the magnets, as described below as an example, the inner body may be guided so as to easily insert the magnets into the openings.

Cylinder-shaped, in the present application, is not limited to a circular right cylinder. The cylinder shape may, for example, comprise a right cylinder having any base shape, including but not limited to a circular shape, a polygon-shape or an elliptical shape.

The cylinder-shaped portion may be fitted to be received by the outer body.

According to the present disclosure, the mask socket may be configured as a recess-portion for receiving the shadow mask and the end surface of the outer body may have one or more openings located in the recess-portion. The one or more openings may be configured to receive the one or more magnets of the inner body, in particular, such that an end surface of each magnet is aligned with or recessed with respect to the end surface of the outer body in the recess-portion. In an example, the openings may extend all the way from the recess-portion to the inside of the hollow outer body. As such, they may be through-holes through a wall of the outer body.

The recess portion may ensure a proper positioning of the mask on the mask application tool. The openings for receiving the magnets may allow for a strong hold of the magnets on the shadow mask that is not impeded by a wall separating the magnets from the shadow mask. However, the holes are not necessary, as long as the magnetic force is not shielded to such an extent that the magnet(s) cannot hold the mask.

According to the present disclosure, the recess-portion may comprise one or more sub-divisions for mask-positioning, particularly limiting rotational and/or translational movement of the shadow mask, particularly, rotational and/or translational movements in a direction or plane parallel to the end surface of the outer body. A subdivision may be a portion that protrudes relative to the recess-portion.

According to the present disclosure, the one or more guide elements of the outer body may comprise at least two guide pins and/or at least two guide bores and/or at least one guide pin and at least one guide bore. The at least one positioning portion of the substrate tray may comprise at least two positioning bores and/or at least two positioning pins and/or at least one positioning bore and at least one positioning pin, each configured to engage with one of the guide elements of the outer body, in particular, to receive one of the guide pins of the outer body and/or protrude into one of the guide bores of the outer body.

According to the present disclosure a/each positioning bore and/or a/each positioning pin of the at least one positioning portion of the substrate tray may be configured to engage with one of the guide elements, in particular to receive one of the guide pins and/or protrude into one of the guide bores, of the outer body of the mask positioning tool such that a rotational and/or translational movement of the guide element is limited.

That is, a movement of the outer body with respect to the substrate tray may be limited by at least two guide elements of the outer body, each engaging with a corresponding element of the substrate tray. A guide element may be a guide pin and the corresponding element may be a positioning bore configured to receive the guide pin. A guide element may be a guide bore and the corresponding element may be a positioning pin configured to be received by the guide bore. Using at least two pairs of corresponding elements is easy for use, as it allows for at least two orientations for positioning the mask positioning tool.

The translational movement in this case may refer to translations in a direction parallel to the surface of the substrate tray facing the substrates. The rotational movement in this case may refer to a rotation in a plane parallel to the surface of the substrate tray facing the substrates.

According to the present disclosure, the mask application tool may be configured to apply a plurality of shadow masks concurrently, in particular, may comprise a plurality of mask sockets. For example, the mask application tool may have at least one magnet associated with each mask socket. It may have a plurality of inner bodies, in particular some or all of which may be movable independently of each other. Alternatively, it may have exactly one inner body. The mask application tool may be configured to apply one or more rows of masks concurrently. Concurrent application is advantageous in view of speed.

According to the present disclosure, the first positioning elements may comprise one or more holes and/or one or more pins and the second positioning elements may comprise one or more holes and/or one or more pins, in particular, a, in particular each, pair of first positioning elements and second positioning elements may comprise a hole and a pin.

According to the present disclosure, at least one of the one or more first positioning elements of the substrate tray may be configured as a hole, particularly as a slotted hole, configured to receive one of the second positioning elements of the base plate assembly, in particular one of the pins of the base plate assembly. Alternatively or in addition, at least one of the one or more second positioning elements of the base plate assembly may be configured as a hole, particularly as a slotted hole, configured to receive one of the first positioning elements of the substrate tray, in particular one of the pins of the substrate tray.

The first positioning elements and second positioning elements may comprise slotted holes and the pins, wherein the slotted holes may each be configured to receive one of the pins and to compensate heat expansion of the substrate tray in a direction perpendicular to an insertion direction of the pin into the slotted hole.

According to the present disclosure, the base plate assembly comprises at least a first plate comprising a/the one or more second positioning elements, particularly the one or more pins, and comprising one or more magnet positioning holes, each configured to position one of the one or more magnets of the base plate assembly in such a position as to be associated with one of the one or more substrate sockets.

Positioning of the magnets may here refer to shifting in a direction parallel to the substrate-facing surface of the base plate assembly, and optionally but not necessarily vertical movements. For example, the magnet positioning holes may be configured to be essentially form fitting with a respective magnet.

This allows for an easy to assemble and configure way of arranging the magnets in the proper position corresponding to the substrate sockets. High flexibility can be provided, as magnets can be added or removed in positions as needed depending on the substrate tray and/or type of substrate or mask for a given application.

According to the present disclosure, the one or more magnets of the base plate assembly may be attached to the first plate, in particular, wherein the one or more magnet positioning holes may be threaded holes and each of the one or more magnets of the base plate assembly may be screwed into one of the one or more magnet positioning holes.

Alternatively or in addition, the one or more magnets of the base plate assembly may each be screwed to a magnet mounting screw arranged between the first plate and the mask application tool.

Thus, the magnets can be held in place, particularly are not removed from the magnet positioning, while the above-mentioned flexibility is still maintained.

According to the present disclosure, the base plate assembly may comprise a second plate, wherein the first plate is arranged between the second plate and the substrate tray. In particular, the second plate may be configured to support the one or more magnets of the base plate assembly, i.e., the magnets may be supported by the second plate from the bottom.

According to the present disclosure, the first plate may, in particular, be mounted on top of the second plate, in particular mounted on top and in contact with second plate.

According to the present disclosure, an end surface of the one or more magnets of the base plate assembly facing the second plate may be aligned with a surface of the first plate facing the second plate.

Thus, the base plate assembly, in an assembled state, may properly hold the magnets in position, particularly, avoid that they fall from the first plate.

The present disclosure also provides a system for positioning a shadow mask. The system comprises the device of the present disclosure, e.g., a device as described above and/or claimed, and a magnetic shadow mask. The shadow mask and/or the mask socket, in particular the recess-portion for receiving the shadow mask, is/are configured such that an outward-facing surface of the shadow mask aligns with or protrudes over a portion of the mask socket outside of, particularly adjacent to, the recess-portion when the shadow mask is placed in the recess-portion. In particular, the shadow mask may align with or protrude over the entire end surface of the outer body.

The outward-facing surface of the shadow mask is the surface that will be placed onto the substrate. Accordingly, the mask aligning with or protruding over the surface may allow for making contact between mask and substrate without making contact between the outer body and the substrate. The shadow mask may be a, particularly re-usable, metal mask.

The present disclosure also provides method for positioning a shadow mask, particularly a magnetic shadow mask, using a device or system for positioning a shadow mask, in particular a device or system according to the present disclosure, e.g., as described above and/or claimed. The device comprises a mask application tool comprising an inner body comprising, at an end surface of the inner body, one or more magnets, and a hollow outer body for receiving the inner body, the outer body comprising, at an end surface of the outer body, a mask socket and one or more guide elements for positioning the mask application tool on a substrate tray.

The method of the present disclosure comprises placing the shadow mask into the mask socket. The method further comprises inserting, prior to or after placing the shadow mask into the mask socket, the inner body into the outer body so as to hold the shadow mask in the mask socket by means of the one or more magnets. The method further comprises positioning the mask application tool on a substrate tray using the one or more guide elements so as to position the shadow mask on a substrate arranged on the substrate tray, while holding the shadow mask in the mask socket by means of the one or more magnets. The method further comprises, after positioning the shadow mask on the substrate, partially or completely drawing the inner body from the outer body so as to release the shadow mask from the mask socket and, optionally, lifting the outer body from the substrate tray after releasing the shadow mask.

Inserting the inner body into the outer body so as to hold the shadow mask may entail inserting the inner body into the outer body until the magnets of the inner body are close to the shadow mask, for example, until the magnets are located in the openings in the recess-portion of the outer body. In this position, they will be close enough to properly hold the mask in place.

As an example, the shadow mask may be positioned in the mask tray while the mask tray is facing essentially upwards and after inserting the inner body so as to hold the shadow mask, the mask application tool may be turned such that the shadow mask faces downwards, e.g., facing towards the substrate tray with substrates facing upwards. In this orientation, the mask application tool may be positioned on the substrate tray.

Drawing the inner body away from the shadow mask, particularly drawing it partly or completely from the outer body, will release the shadow mask from the mask tray, as the hold of the magnets decreases. The mask application tool may then be lifted from the substrate tray, while the shadow mask remains on the substrate. Gravity and potentially magnets below the substrates may hold the shadow mask in place during this process.

The method of the present disclosure may comprise, prior to positioning the mask application tool on the substrate tray, placing one or more substrates including the substrate on the substrate tray, in particular into a substrate socket of the substrate tray, and subsequently positioning the substrate tray on top of a base plate assembly by means of first positioning elements of the substrate tray and second positioning elements of the base plate assembly, such that at least one of one or more magnets of the base plate assembly is arranged underneath the substrate.

As seen above, such magnets allow for holding the shadow mask in place, particularly while lifting the mask application tool and also during subsequent processing steps.

The one or more magnets being arranged underneath the substrate may comprise that the magnets are arranged directly below the substrate, for example.

The method of the present disclosure may comprise, while drawing the inner body from the outer body so as to release the shadow mask from the mask socket and, optionally, while lifting the outer body from the substrate tray after releasing the shadow mask, keeping the substrate tray positioned on top of the base plate assembly so as to hold the shadow mask in place by the at least one magnet of the base plate assembly.

The method of the present disclosure may comprise, after placing one or more substrates on the substrate tray and prior to positioning the substrate tray on top of a base plate assembly, performing a heating step, wherein the one or more substrates placed on the substrate tray are heated, for example in an oven.

For example, to dry the substrates, the top tray without magnets can be placed in an oven. Heating may be performed at temperatures up to 400° C. Thus moisture and residues may be removed from the substrates to a sufficient level.

Alternatively or in addition, the method of the present disclosure may comprise, after placing the positioning the shadow mask on the substrate on the substrate tray and particularly after performing a/the heating step, a coating step, while keeping the substrate tray positioned on top of the base plate assembly so as to hold the shadow mask in place by the at least one magnet of the base plate assembly.

Thus, it is possible to perform a heating step with any temperatures that are necessary for high quality, yet it is also possible to use more heat sensitive materials, e.g., the magnets, to hold the shadow masks in place. The relative positioning of the magnets can easily be achieved by the configuration of the substrate tray and base plate assembly.

The coating step may entail placing the base plate assembly with the substrate tray mounted thereon, the substrate(s) placed on the substrate tray, and the mask(s) positioned on the substrate(s) into a machine configured for coating substrates, e.g., by utilizing physical processes like sputtering. During the coating process the base plate assembly, substrate tray, the substrate(s), and the mask(s) may be exposed to temperatures above room temperature. During the coating, one or more layers of various thicknesses and materials may be applied.

Alternatively or in addition, the method of the present disclosure may comprise, after performing a/the coating step, lifting the substrate tray from the base plate assembly so as to release the shadow mask from the at least one magnet of the base plate assembly, and in particular, after lifting the substrate tray from the base plate assembly, removing the substrates from the substrate tray.

By lifting the substrate tray from the base plate assembly, the distance between the magnet and the shadow mask is decreased and the hold of the magnet on the shadow mask will decrease. Thus, the substrate and mask may then be taken from the tray easily.

The device of the present disclosure may comprise a mask removal tool configured to remove one or more masks. The mask removal tool may comprise one or more magnets, particularly one or more magnets configured to remove multiple masks at the same time, particularly in such a manner that translation movement of the mask or masks parallel to the substrate surface is avoided. The method of the present disclosure may comprise positioning each of a plurality of shadow masks on one of a plurality of substrates placed on the substrate tray sequentially, e.g., using the same mask application tool for each shadow mask. Alternatively, the present disclosure may comprise positioning each of a plurality of shadow masks on one of a plurality of substrates placed on the substrate tray concurrently by means of a plurality of the mask application tools or by means of a mask application tool configured to apply a plurality of shadow masks concurrently. Mask application tools that allow for applying a plurality of shadow masks concurrently have been described above.

The features and advantages outlined above in the context of the device for positioning a shadow mask similarly apply to the methods for positioning a shadow mask described herein.

Further features, examples, and advantages will become apparent from the detailed description making reference to the accompanying drawings.