Mask cleaning liquid, method for manufacturing display device, and electronic apparatus

Abstract

The invention discloses a cleaning solution for a mask, a method for manufacturing a display device, and an electronic apparatus. A manufacturing method of a display device according to an embodiment of the present disclosure includes the steps of: forming a pixel circuit layer and forming a first electrode on the pixel circuit layer; cleaning the mask for the first time; arranging the mask in a chamber; and forming a light emitting portion on the first electrode within the chamber, in which the mask is not used in a deposition process before the first cleaning step is performed on the mask.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a cleaning solution for a mask, a method of manufacturing a display device, and an electronic apparatus. BACKGROUND

[0002] Recently, as the interest in information display increases, research and development of display devices are continuously ongoing. In particular, as the demand for high-quality display devices increases, discussions on display devices including light emitting elements having a micron level or a nanometer level are actively ongoing. The light emitting elements can include an anode electrode, a light emitting part, and a cathode electrode.

[0003] The light emitting part of the display device can be formed through a deposition process using a deposition mask. In the deposition process, impurities, for example, organic substances used for deposition, etc. can remain on the surface of the deposition mask due to the impurities, and thus it is required to clean the deposition mask. SUMMARY

[0004] An aspect of the present disclosure provides a cleaning solution for a mask and a cleaning method of a mask, which can reduce foreign substances present on the mask.

[0005] Another aspect of the present disclosure provides a method of manufacturing a display device, which can reduce a defective rate of the display device.

[0006] A method of manufacturing a display device according to an embodiment of the present disclosure can include the steps of forming a pixel circuit layer and a first electrode on the pixel circuit layer, cleaning a mask for a first time, arranging the mask in a chamber, and forming a light emitting part on the first electrode in the chamber, wherein the mask can not be used for a deposition process before the step of cleaning the mask for the first time.

[0007] According to an embodiment, the step of forming the light emitting part can include a step of depositing the light emitting part, and the step of cleaning the mask for the first time can be performed between a first time point at which the mask is manufactured and a second time point at which the mask is arranged in the chamber, and the mask can not be used for the deposition process of forming the light emitting part between the first time point and the second time point.

[0008] According to an embodiment, the step of cleaning the mask for the first time can include a step of cleaning the mask using at least one of a wet cleaning, a dry cleaning, a cleaning using a two-fluid, and a cleaning using a supercritical fluid.

[0009] According to the embodiment, the first cleaning of the mask includes a step of wet cleaning the mask with a cleaning liquid, and the cleaning liquid can include at least one of a first compound represented by the following [Chemical Formula 1], a second compound represented by the following [Chemical Formula 2], a third compound represented by the following [Chemical Formula 3], a fourth compound represented by the following [Chemical Formula 4], a fifth compound represented by the following [Chemical Formula 5], a sixth compound represented by the following [Chemical Formula 6], and a seventh compound, wherein the seventh compound is a lactam compound having 5 or less ring-forming atoms, and a nitrogen (N) as a ring-forming atom is bonded to a hydrogen (H) not forming a ring or an alkyl group having 1 carbon atom.

[0010] [Chemical Formula 1]

[0011] In the [Chemical Formula 1], R1 is a hydrogen (H), an alkyl group having 1 carbon atom, an alkyl group having 2 carbon atoms, an alkyl group having 3 carbon atoms, potassium (K), or sodium (Na).

[0012] [Chemical Formula 2]

[0013] In the [Chemical Formula 2], R2 is a hydrogen (H) or an alkyl group having 1 carbon atom.

[0014] [Chemical Formula 3]

[0015] In the [Chemical Formula 3], R3, R4, and R5 are each a hydrogen (H), an alkyl group having 1 carbon atom, an alkyl group having 2 carbon atoms, or an alkyl group having 3 carbon atoms.

[0016] [Chemical Formula 4]

[0017] In the [Chemical Formula 4], R6 and R7 are each a hydrogen (H), an alkyl group having 1 carbon atom, or an alkyl group having 2 carbon atoms.

[0018] [Chemical Formula 5]

[0019] In the [Chemical Formula 5], R8 and R9 are each a hydrogen (H), an alkyl group having 1 carbon atom, or an alkyl group having 2 carbon atoms.

[0020] [Chemical Formula 6]

[0021] In the [Chemical Formula 6], R 10 and R 11 each is hydrogen (H) or an alkyl group having 1 carbon atom.

[0022] According to an embodiment, the wet cleaning step can be performed more than twice.

[0023] According to an embodiment, the cleaning solution can include the third compound, and the content of the third compound can be 50 wt% or more, based on the total weight of the cleaning solution.

[0024] According to an embodiment, the cleaning solution can include the seventh compound, and the content of the seventh compound can be 50 wt% or more, based on the total weight of the cleaning solution.

[0025] According to an embodiment, the cleaning solution can include the third compound and the seventh compound, and the total content of the third compound and the seventh compound can be 50 wt% or more, based on the total weight of the cleaning solution.

[0026] According to an embodiment, the mask can include a plurality of opening portions, each of the plurality of opening portions can have a width of 10 µm or less, the mask can have a thickness of 5 µm or less, and the mask can include silicon (Si).

[0027] According to an embodiment, the forming the light emitting portion can include forming the light emitting portion by depositing an organic light emitting material.

[0028] According to an embodiment, the method of manufacturing the display device can further include moving the mask outside of the chamber, and performing a second cleaning of the mask, wherein the performing the second cleaning of the mask can be performed after the moving the mask outside of the chamber.

[0029] According to an embodiment, the performing the second cleaning of the mask includes cleaning the mask using at least one of a wet cleaning, a dry cleaning, a cleaning using a two-fluid, and a cleaning using a supercritical fluid, the wet cleaning can include a method of cleaning the mask using the cleaning solution, and the dry cleaning can include a method of cleaning the mask using at least one of an ion beam, a laser, a plasma, carbon dioxide (CO2), and ozone (O3).

[0030] A cleaning method for a mask used for depositing a light emitting part of a display device according to an embodiment of the disclosure can include a first cleaning of the mask and a second cleaning of the mask, wherein the first cleaning of the mask is performed between a first time point at which the mask is manufactured and a second time point at which the mask is arranged in a chamber in which the deposition of the light emitting part is performed, and the mask can not be used for a deposition process for forming the light emitting part between the first time point and the second time point.

[0031] According to an embodiment, the first cleaning of the mask and the second cleaning of the mask can each include a step of wet cleaning the mask using a cleaning solution including at least one of a first compound represented by [Chemical Formula 1], a second compound represented by [Chemical Formula 2], a third compound represented by [Chemical Formula 3], a fourth compound represented by [Chemical Formula 4], a fifth compound represented by [Chemical Formula 5], a sixth compound represented by [Chemical Formula 6], and a seventh compound.

[0032] According to an embodiment, the first cleaning of the mask and the second cleaning of the mask each include a step of cleaning the mask using at least one of wet cleaning, dry cleaning, cleaning using a two-fluid, and cleaning using a supercritical fluid, the mask can include a plurality of opening parts, each of the plurality of opening parts can have a width of 10 µm or less, the mask can have a thickness of 5 µm or less, and the mask can include silicon (Si).

[0033] According to an embodiment, the display device can include an organic light emitting element.

[0034] A cleaning solution for a mask according to an embodiment of the disclosure can include at least one of a first compound represented by [Chemical Formula 1], a second compound represented by [Chemical Formula 2], a third compound represented by [Chemical Formula 3], a fourth compound represented by [Chemical Formula 4], a fifth compound represented by [Chemical Formula 5], a sixth compound represented by [Chemical Formula 6], and a seventh compound.

[0035] According to an embodiment, the cleaning solution can include the third compound, and the content of the third compound can be 50 wt% or more, based on the total weight of the cleaning solution for a mask.

[0036] According to an embodiment, the cleaning solution can include the seventh compound, and the content of the seventh compound can be 50 wt% or more, based on the total weight of the cleaning solution for a mask.

[0037] According to an embodiment, the cleaning solution can include the third compound and the seventh compound, and the total content of the third compound and the seventh compound can be 50 wt% or more, based on the total weight of the cleaning solution for a mask.

[0038] An electronic device according to an embodiment of the disclosure can include a display device, which can be manufactured according to a manufacturing method of the display device.

[0039] According to an embodiment of the disclosure, a cleaning solution for a mask and a cleaning method of a mask, which can reduce foreign substances present on a mask, can be provided.

[0040] According to an embodiment of the disclosure, a manufacturing method of a display device, which can reduce a defective rate of the display device, can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 FIG. 1 is a schematic plan view illustrating a display device according to an embodiment.

[0042] Figures 2 to 4 FIG. 2 is a schematic plan view of a pixel illustrated in FIG. 1. Figure 1

[0043] Figure 5 FIG. 3 is a schematic cross-sectional view illustrating a display device according to an embodiment.

[0044] Figure 6 FIG. 4 is a schematic cross-sectional view illustrating a light emitting element according to an embodiment.

[0045] Figure 7 FIG. 5 is a schematic flowchart illustrating a manufacturing method of a display device according to an embodiment.

[0046] Figure 8 FIG. 6 is a schematic plan view of a mask according to an embodiment.

[0047] Figure 9 FIG. 7 is a schematic cross-sectional view at a process step of a manufacturing method of a display device according to an embodiment.

[0048] Figure 10 FIG. 8 is a TD-GC / MS analysis graph of a first experimental example and a first comparative example.

[0049] Figure 11 FIG. 9 is a TD-GC / MS analysis graph of a second experimental example and a second comparative example.

[0050] REFERENCE NUMERALS DETAILED DESCRIPTION

[0051] ​The present disclosure can be modified in a variety of ways and can have various forms, and specific embodiments will be illustrated in the drawings and described in detail herein. However, this is not intended to limit the present disclosure to a specific disclosed form, and it should be understood that all modifications, equivalents, and even alternatives included in the concept and technical scope of the present disclosure are included.

[0052] The terms "first", "second", and the like can be used to describe various constituent elements, but the constituent elements are not limited by the terms. The terms are used only for the purpose of distinguishing one constituent element from another constituent element. For example, a first constituent element can be named a second constituent element, and similarly, a second constituent element can be named a first constituent element, without departing from the scope of the present disclosure. The singular representation also includes the plural representation unless the context clearly dictates otherwise.

[0053] In the present disclosure, the terms "comprising" or "having" and the like are understood to specify the presence of a characteristic, number, step, operation, constituent element, component, or a combination thereof described in the specification, and do not preclude the presence or additional possibility of one or more other characteristics, numbers, steps, operations, constituent elements, components, or a combination thereof. Also, in the case where a portion of a layer, film, region, plate, or the like is positioned "on" another portion, this includes not only the case where it is positioned "immediately above" the other portion, but also the case where there is another portion therebetween. Furthermore, in the present specification, in the case where a portion of a layer, film, region, plate, or the like is formed "on" another portion, the formation direction is not limited to the upward direction, but also includes the case where it is formed in the lateral or downward direction. In contrast, in the case where a portion of a layer, film, region, plate, or the like is positioned "below" another portion, this includes not only the case where it is positioned "immediately below" the other portion, but also the case where there is another portion therebetween.

[0054] The present disclosure relates to a cleaning solution for a mask, a cleaning method of a mask, and a manufacturing method of a display device. Hereinafter, the cleaning solution for a mask, the cleaning method of a mask, and the manufacturing method of a display device according to an embodiment will be described with reference to the accompanying drawings. First, referring to Figures 1 to 6 A display device DD that can be manufactured according to the manufacturing method of a display device DD will be described.

[0055] Figure 1 FIG. 1 is a schematic plan view illustrating a display device according to an embodiment. Figures 2 to 4 FIG. 2 is a schematic plan view of a pixel illustrated in FIG. 1. Figure 1 FIG. 3 is a schematic plan view of a pixel illustrated in FIG. 1. Figure 5 FIG. 4 is a schematic cross-sectional view illustrating a display device according to an embodiment. Figure 6 FIG. 5 is a schematic cross-sectional view illustrating a light emitting element according to an embodiment.

[0056] The display device DD can be configured to emit light. The display device DD can include a light emitting element LD (see FIG. 10). Figure 5 According to an embodiment, the display device DD can be a device that displays a dynamic image or a still image. The display device DD can be used not only for a display screen of a portable electronic device such as a mobile phone, a smart phone, a tablet personal computer (PC), a smart watch, a watch phone, and the like, but also for a display screen of a product of various electronic devices such as a television, a notebook computer, a monitor, an advertisement board, an internet of things (IOT) device, and the like. However, the application field of the display device DD is not limited to a specific example. The electronic device can include the display device DD described above.

[0057] The display device DD can be formed as a plane having a rectangular shape with a short side in a first direction DR1 and a long side in a second direction DR2 intersecting the first direction DR1. A corner where the short side in the first direction DR1 meets the long side in the second direction DR2 can be smoothly formed with a predetermined curvature or formed as a right angle. The planar shape of the display device DD is not limited to a quadrangle, and can be formed as other polygons, a smoothly shaped shape such as a circle or an ellipse. The display device DD can be formed flat, but is not limited thereto. For example, the display device DD can include curved portions formed at left and right side ends with a predetermined curvature or with a varying curvature. In addition, the display device DD can be formed to be flexible so as to be bendable, foldable, rollable, foldable, or windable.

[0058] In the present disclosure, the first direction DR1 can be a "horizontal" direction that is a row direction of the pixels PXL. The second direction DR2 can be a column direction of the pixels PXL. The third direction DR3 can be a display direction of the display device DD or a normal direction of a plane on which the base layer BSL is disposed.

[0059] The display device DD can include a display area DA and a non-display area NDA. The non-display area NDA can indicate an area other than the display area DA. The non-display area NDA can surround at least a portion of the display area DA.

[0060] The base layer BSL can form a base component of the display device DD. To improve the integration of the sub-pixels SPX, the base layer BSL can be provided as a silicon substrate. The base layer BSL can include a silicon wafer substrate formed using a semiconductor process. The base layer BSL can include a semiconductor substance suitable for forming a circuit element. For example, the semiconductor substance can include silicon, germanium, and / or silicon-germanium. The base layer BSL can also be provided by a bulk wafer, an epitaxial layer, a Silicon On Insulator (SOI) layer, or a Semiconductor On Insulator (SeOI) layer, or the like.

[0061] The display region DA can represent a region in which the pixels PXL are arranged. The non-display region NDA can represent a region in which the pixels PXL are not provided. In the non-display region NDA, a drive circuit portion, a wiring, and a pad connected to the pixels PXL of the display region DA can be arranged.

[0062] According to an embodiment, the pixels PXL (or the sub-pixels SPX) can be arranged according to a stripe or a mosaic structure. However, the present disclosure is not necessarily limited thereto. Arrangement structures, etc. However, the present disclosure is not necessarily limited thereto.

[0063] According to an embodiment, the pixel PXL can include a light emitting element LD. The pixel PXL (or the sub-pixel SPX) can include a first sub-pixel SPX1, a second sub-pixel SPX2, and a third sub-pixel SPX3. At least one of the first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 can form one pixel unit PXU capable of emitting light of a plurality of colors.

[0064] The first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 of the display device DD according to an embodiment can have a width of a micrometer level or a nanometer level. For example, the first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 can have a width of 10 μm or less defined by the first direction DR1 or the second direction DR2, and the display device DD according to an embodiment can be a Micro Display. However, the present disclosure is not limited thereto.

[0065] In Figure 1 In the above-described embodiment, a case in which each of the pixels PXL includes three sub-pixels SPX1, SPX2, SPX3 is exemplified, but embodiments of the present specification are not limited thereto.

[0066] Referring to Figure 2The sub-pixel SPX can have a planar shape of a rectangle, a square, or a diamond. For example, each of the first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 can have a planar shape of a rectangle having a short side in a first direction DR1 and a long side in a second direction DR2 as shown in FIG. 10A. Alternatively, the sub-pixel SPX can have a planar shape of a square or a diamond including sides having the same length in the first direction DR1 and the second direction DR2. Figure 2

[0067] In an example, the areas of the first sub-pixel SPX1 to the third sub-pixel SPX3 can be substantially the same, but are not limited thereto. For example, at least one of the areas of the first sub-pixel SPX1 to the third sub-pixel SPX3 can be different from the other one. Alternatively, any two of the area of the first sub-pixel SPX1, the area of the second sub-pixel SPX2, and the area of the third sub-pixel SPX3 can be substantially the same, and the remaining one can be different from the two. Alternatively, the area of the first sub-pixel SPX1, the area of the second sub-pixel SPX2, and the area of the third sub-pixel SPX3 can be different from each other.

[0068] Referring to FIG. 10B, Figure 3 the first sub-pixel SPX1 can be arranged in the first direction DR1 with any one of the second sub-pixel SPX2 and the third sub-pixel SPX3, and in the second direction DR2 with the remaining one. For example, the first sub-pixel SPX1 can be arranged in the first direction DR1 with the second sub-pixel SPX2, and the first sub-pixel SPX1 can be arranged in the second direction DR2 with the third sub-pixel SPX3.

[0069] In an example, the third sub-pixel SPX3 can be disposed in the second direction DR2 of the first sub-pixel SPX1 and the second sub-pixel SPX2. In an example, the areas of the first sub-pixel SPX1 and the second sub-pixel SPX2 can be substantially the same, and the area of the third sub-pixel SPX3 can be different from the areas of the first sub-pixel SPX1 and the second sub-pixel SPX2. For example, the area of the third sub-pixel SPX3 can be greater than the areas of the first sub-pixel SPX1 and the second sub-pixel SPX2.

[0070] Referring to FIG. 10B, Figure 4 each of the first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 can have a planar shape of a hexagon or a regular hexagon. In an example, adjacent two of the six faces of each of the first sub-pixel SPX1 to the third sub-pixel SPX3 can face one face of an adjacent sub-pixel.

[0071] ​The first sub-pixel SPX1 can emit first light, the second sub-pixel SPX2 can emit second light, and the third sub-pixel SPX3 can emit third light. Here, the first light can be light of a red wavelength band, the second light can be light of a green wavelength band, and the third light can be light of a blue wavelength band.

[0072] Each of the first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 can include a light emitting element LD configured to be capable of emitting light.

[0073] The light emitting element LD according to the present disclosure can be an organic light emitting element (OLED). For example, the light emitting element LD according to an embodiment can be an organic light emitting element having a micron order or a nanometer order.

[0074] Referring to Figure 5 and Figure 6 , the display device DD can include a pixel circuit layer PCL and a light emitting element layer LEL.

[0075] The pixel circuit layer PCL can be a layer including a pixel circuit for driving the light emitting element LD. The pixel circuit layer PCL can include a base layer BSL, a conductive layer for forming the pixel circuit, and an insulating layer disposed between the conductive layer.

[0076] The pixel circuit PXC can include a transistor and can be electrically connected with the light emitting element LD to provide an electrical signal for the light emitting element LD to emit light.

[0077] The light emitting element layer LEL can be disposed on the pixel circuit layer PCL. According to an embodiment, the light emitting element layer LEL can include the light emitting element LD, a pixel defining film PDL, and a sealing layer TFE.

[0078] The light emitting element LD can be disposed on the pixel circuit layer PCL. According to an embodiment, the light emitting element LD can include a first electrode ELT1, a light emitting part EL, and a second electrode ELT2.

[0079] According to an embodiment, the light emitting part EL can be disposed in a region defined by the pixel defining film PDL. According to an embodiment, a width in a first direction DR1 or a second direction DR2 of the region defined by the pixel defining film PDL can be 10 µm or less. One surface of the light emitting part EL can be electrically connected with the first electrode ELT1, and the other surface of the light emitting part EL can be electrically connected with the second electrode ELT2.

[0080] The first electrode ELT1 can be an anode electrode ANO for the light emitting portion EL, and the second electrode ELT2 can be a cathode electrode CAT for the light emitting portion EL. According to an embodiment, the first electrode ELT1 and the second electrode ELT2 can include an electrically conductive substance. For example, the first electrode ELT1 can include an electrically conductive substance having a reflective property, and the second electrode ELT2 can include a transparent electrically conductive substance, but the present disclosure is not necessarily limited thereto. The first electrode ELT1 can be a cathode electrode CAT for the light emitting portion EL, and the second electrode ELT2 can also be an anode electrode ANO for the light emitting portion EL.

[0081] The light emitting portion EL can have a multi-layer thin film structure including a light generation layer (e.g., a light emitting layer EML). The light emitting portion EL can be equipped with a hole injection layer HIL that injects holes, a hole transport layer HTP that is excellent in the transport property of holes and serves to increase the recombination opportunity of holes and electrons by suppressing the movement of electrons that fail to combine in the light emitting layer EML, a light emitting layer EML that emits light by the recombination of injected electrons and holes, an electron transport layer ETL for smoothly transporting electrons to the light emitting layer, and an electron injection layer EIL that injects electrons. The light emitting portion EL can emit light based on an electric signal supplied from the anode electrode ANO (e.g., the first electrode ELT1) and the cathode electrode CAT (e.g., the second electrode ELT2).

[0082] In Figure 6 , a case where the light emitting element LD has one light emitting portion EL is shown, but the present disclosure is not limited thereto. According to an embodiment, the light emitting portion EL can be formed in a plurality, and the plurality of light emitting portions EL can be stacked along the third direction DR3 with the charge generation layer interposed therebetween, and according to an embodiment, the light emitting element LD can have a tandem structure.

[0083] The pixel definition film PDL can be arranged on the pixel circuit layer PCL to define the position at which the light emitting portion EL is arranged. At least a portion of the pixel definition film PDL can be arranged on the first electrode ELT1. The pixel definition film PDL can be arranged on the pixel circuit layer PCL to expose at least a portion of the first electrode ELT1. The pixel definition film PDL can include an inorganic material. For example, the pixel definition film PDL can include silicon oxide (SiO x ) and silicon nitride (SiN xAt least one of the following. However, this disclosure is not limited thereto. The pixel-defining film (PDL) may also include organic materials. According to embodiments, the pixel-defining film (PDL) may include one or more of the group consisting of acrylic resin, epoxy resin, phenolic resin, polyamide resin, and polyimide resin. However, this disclosure is not limited thereto.

[0084] The encapsulation layer TFE can be disposed on the light-emitting element LD (e.g., the second electrode ELT2). The encapsulation layer TFE can compensate for the step difference generated by the light-emitting element LD and the pixel defining film PDL. The encapsulation layer TFE may include multiple insulating films covering the light-emitting element LD. According to an embodiment, the encapsulation layer TFE may also have a structure in which inorganic and organic films are stacked alternately.

[0085] Apart from Figure 5 In addition to the stacking structure shown, the display device DD may also have various stacking structures, and the stacking structure of the display device DD disclosed herein is not limited to... Figure 5 The example shown.

[0086] The following is for reference Figures 7 to 9 A method for manufacturing a display device DD according to an embodiment and a mask cleaning solution will be described. Figure 7 This is a schematic flowchart illustrating a method for manufacturing a display device according to an embodiment. Figure 8 This is a schematic plan view of the mask according to an embodiment. Figure 9 This is a schematic cross-sectional view illustrating the process steps of a method for manufacturing a display device according to an embodiment.

[0087] Reference Figure 7 The manufacturing method of the display device DD may include the following steps: performing a first cleaning of the mask (S100); placing the mask in the cavity (S200); forming the light-emitting part (S300); moving the mask to the outside of the cavity (S400); and performing a second cleaning of the mask (S500).

[0088] The mask is used for depositing the light-emitting portion (EL) of a display device (DD), as shown in the reference. Figure 8 The mask MSK may include multiple openings OPN. In step S300 of forming the light-emitting part, the deposit material for forming the light-emitting part EL can be deposited through the multiple openings OPN, thereby forming the light-emitting part EL.

[0089] Each of the opening portions OPN can have an opening portion width OPN_W. The opening portion width OPN_W can be defined along the first direction DR1 or the second direction DR2. According to an embodiment, the opening portion width OPN_W can be 10 pm or less. In a case where the opening portion width OPN_W is excessively large (e.g., in a case where it exceeds 10 pm), it can be difficult to deposit the light emitting portion EL of the micro display. According to an embodiment, in a case where the opening portion width OPN_W of the mask MSK is formed to be 10 pm or less, the mask MSK can be suitable for depositing the light emitting portion EL of the micro display.

[0090] According to an embodiment, the mask MSK can have a thickness of 5 pm or less. The thickness of the mask MSK can be defined along the third direction DR3. In a case where the thickness of the mask MSK is excessively large (e.g., in a case where it exceeds 5 pm), it can be difficult to reduce the opening portion width OPN_W. According to an embodiment, the mask MSK can have a thickness of 5 pm or less, and can be suitable for depositing the light emitting portion EL of the micro display.

[0091] The mask MSK can include silicon (Si). As the mask MSK according to the present disclosure includes silicon (Si), it can have substantially the same coefficient of thermal expansion as the base layer BSL. The base layer BSL of the micro display can include a silicon substrate, and according to an embodiment, the mask MSK also includes silicon (Si), so that the mask MSK and the base layer BSL can have substantially the same coefficient of thermal expansion.

[0092] The manufacturing method of the display device DD according to the present disclosure includes a cleaning method of the mask MSK. The cleaning method of the mask MSK can include the steps of: first cleaning the mask (S100); and second cleaning the mask (S500).

[0093] The step S100 of first cleaning the mask can be performed before the step S200 of arranging the mask in the chamber. The step S100 of first cleaning the mask can be performed between a point in time at which the mask MSK is manufactured (hereinafter, a first point in time) and a point in time at which the mask MSK is arranged in the chamber CB (refer to Figure 9 ).

[0094] The chamber CB according to the present disclosure can be a chamber for deposition that performs the step 300 of forming the light emitting portion. The mask MSK cleaned in the step S100 of cleaning the mask for the first time refers to a mask MSK that has never been used in a deposition process performed between the first time point and the second time point. For example, the mask MSK can be a mask MSK that has not been used in a deposition process of forming the light emitting portion EL before the step S100 of cleaning the mask for the first time. For example, the mask MSK cleaned in the step S100 of cleaning the mask for the first time can correspond to an initial mask MSK that has never been used in a deposition process after the mask MSK is manufactured.

[0095] There can be foreign matter formed when the mask MSK is manufactured and foreign matter flowing in from the external environment after the mask MSK is manufactured, etc. on the initial mask MSK. In the related art, since the initial mask MSK is not cleaned but directly used, there can be a risk that the foreign matter is mixed when the light emitting portion EL is deposited.

[0096] The manufacturing method of the display device DD according to the present disclosure includes the step S100 of cleaning the mask for the first time, by which the foreign matter present on the surface of the initial mask MSK can be removed before the light emitting portion EL is deposited, and the foreign matter present on the surface of the mask MSK can be reduced. Thereby, the risk that the foreign matter is mixed when the light emitting portion EL is deposited can be reduced.

[0097] The step S500 of cleaning the mask for the second time can be performed after the step S300 of forming the light emitting portion. For example, the step S500 of cleaning the mask for the second time can be performed after the second time point. The step S500 of cleaning the mask for the second time can be performed after the step S400 of moving the mask to the outside of the chamber after the second time point.

[0098] The mask MSK cleaned in the step S500 of cleaning the mask for the second time refers to a mask MSK that has been used at least once in a deposition process for forming the light emitting portion EL. The manufacturing method of the display device DD according to the present disclosure includes the step S500 of cleaning the mask for the second time, by which the foreign matter present on the surface of the mask MSK can be removed after the light emitting portion EL is deposited, and the foreign matter present on the surface of the mask MSK can be reduced. Thereby, in the case where the mask MSK is repeatedly used, the risk that the foreign matter is mixed when the light emitting portion EL is deposited can be reduced.

[0099] The first cleaning of the mask step S100 and the second cleaning of the mask step S500 can each include a step of cleaning the mask MSK using at least one of a wet cleaning, a dry cleaning, a cleaning using a two-fluid, and a cleaning using a supercritical fluid. The first cleaning of the mask step S100 and the second cleaning of the mask step S500 can each use one of a wet cleaning, a dry cleaning, a cleaning using a two-fluid, and a cleaning using a supercritical fluid, or can use two or more of them, according to an embodiment.

[0100] The wet cleaning, which is a method of cleaning the mask MSK using a cleaning solution, can include at least one of a dipping, a nozzle spray, an ultrasonic, a spin, and a brush.

[0101] The cleaning method using the dipping is a method of cleaning the mask MSK by dipping the mask MSK in a bath or the like filled with the cleaning solution. The cleaning method using the nozzle spray is a method of cleaning the mask MSK by spraying the cleaning solution to the mask MSK using a nozzle spray. The cleaning method using the ultrasonic is a method of cleaning the mask MSK using the cleaning solution and an ultrasonic. The cleaning method using the spin is a method of cleaning the mask MSK by spraying the cleaning solution while rotating the mask MSK, or cleaning the mask MSK in the rotating cleaning solution. The cleaning method using the brush is a method of cleaning the mask MSK by using the cleaning solution and a brush. However, the disclosure is not limited thereto, and the wet cleaning can include various kinds of wet cleaning methods known in the art, according to an embodiment.

[0102] According to an embodiment, in a case where the first cleaning of the mask step S100 and the second cleaning of the mask step S500 each include a step of wet cleaning, the step of wet cleaning can include a step of wet cleaning the mask MSK using the cleaning solution two or more times. For example, the step of wet cleaning can be performed two or more times. In a case where the mask MSK is wet cleaned two or more times, foreign substances present in the mask MSK can be more effectively removed, and the foreign substances can be further reduced.

[0103] According to an embodiment, the cleaning solution can include at least one of a compound (a first compound) represented by the following [Chemical Formula 1], a compound (a second compound) represented by the following [Chemical Formula 2], a compound (a third compound) represented by the following [Chemical Formula 3], a compound (a fourth compound) represented by the following [Chemical Formula 4], a compound (a fifth compound) represented by the following [Chemical Formula 5], a compound (a sixth compound) represented by the following [Chemical Formula 6], and a lactam compound (a seventh compound) in which the number of ring-forming atoms is 5 or less, in which the lactam compound can be a compound in which a nitrogen (N) as a ring-forming atom is combined with a hydrogen (H) or an alkyl group having 1 carbon atom that does not form a ring. Here, the number of ring-forming atoms being 5 or less means a cyclic compound having a pentagon or less. In the lactam compound, the hydrogen (H) or the alkyl group having 1 carbon atom combined with the nitrogen (N) as a ring-forming atom can be a side chain of the lactam compound, and the side chain can not form a ring.

[0104] [Chemical Formula 1]

[0105] According to an embodiment, in [Chemical Formula 1], R1 can be a hydrogen (H), an alkyl group having 1 carbon atom, an alkyl group having 2 carbon atoms, an alkyl group having 3 carbon atoms, potassium (K), or sodium (Na). For example, the first compound can include ethanol, isopropyl alcohol, and potassium hydroxide (KOH).

[0106] [Chemical Formula 2]

[0107] According to an embodiment, in [Chemical Formula 2], R2 can be a hydrogen (H) or an alkyl group having 1 carbon atom. For example, the second compound can include formic acid and acetic acid.

[0108] [Chemical Formula 3]

[0109] According to an embodiment, in [Chemical Formula 3], R3, R4, and R5 can each be a hydrogen (H), an alkyl group having 1 carbon atom, an alkyl group having 2 carbon atoms, or an alkyl group having 3 carbon atoms. For example, the third compound can include formamide, N,N-dimethyl formamide, and N,N-diethyl formamide.

[0110] [Chemical Formula 4]

[0111] According to an embodiment, in [Chemical Formula 4], R6and R7may each be hydrogen (H), an alkyl group having 1 carbon atom, or an alkyl group having 2 carbon atoms. For example, the fourth compound can include acetone and methylethyl ketone.

[0112] [Chemical Formula 5]

[0113] According to an embodiment, in [Chemical Formula 5], R8and R9may each be hydrogen (H), an alkyl group having 1 carbon atom, or an alkyl group having 2 carbon atoms. For example, the fifth compound can include dimethyl sulfoxide.

[0114] [Chemical Formula 6]

[0115] According to an embodiment, in [Chemical Formula 6], R 10 and R 11 may each be hydrogen (H) or an alkyl group having 1 carbon atom. For example, the sixth compound can include hydrogen peroxide.

[0116] For example, the seventh compound can include 2-pyrrolidone and N-Methyl-2-pyrrolidone.

[0117] According to an embodiment, the content of at least one of the first to seventh compounds can be 50 wt% or more and 100 wt% or less, based on the total weight of the cleaning solution. According to an embodiment, the cleaning solution can include the third compound, and the content of the third compound can be 50 wt% or more and 100 wt% or less, based on the total weight of the cleaning solution. According to an embodiment, the cleaning solution can include the seventh compound, and the content of the seventh compound can be 50 wt% or more and 100 wt% or less, based on the total weight of the cleaning solution.

[0118] According to an embodiment, the cleaning solution can include at least two of the first to seventh compounds. For example, according to an embodiment, the third and seventh compounds can be included, and the total content of the third and seventh compounds can be 50 wt% or more and 100 wt% or less, based on the total weight of the cleaning solution.

[0119] R1to R 11In the case where R1 to R7 are alkyl groups, if the number of carbon atoms is excessively increased, the cleaning effect of the cleaning solution can be reduced. For example, it can not be possible to effectively remove foreign matter on the mask MSK. Since R1 to R7 in the cleaning solution according to the present disclosure have the number of carbon atoms in the aforementioned numerical range, the cleaning effect of the cleaning solution is not reduced. 11 In the case where R1 to R7 are alkyl groups, if the number of carbon atoms is excessively increased, the cleaning effect of the cleaning solution can be reduced. For example, it can not be possible to effectively remove foreign matter on the mask MSK. Since R1 to R7 in the cleaning solution according to the present disclosure have the number of carbon atoms in the aforementioned numerical range, the cleaning effect of the cleaning solution is not reduced.

[0120] In the case where the cleaning solution includes the seventh compound, if the number of carbon atoms of the side chain bonded to nitrogen (N) is excessively increased, the cleaning effect of the cleaning solution can be reduced. In the seventh compound, nitrogen (N) is bonded to hydrogen (H) or an alkyl group having a number of carbon atoms of 1 as a side chain, and accordingly, the cleaning effect is not reduced even if the cleaning solution includes the seventh compound.

[0121] The cleaning solution according to the present disclosure, which is a cleaning solution for a mask MSK, includes at least one of the first to seventh compounds, and accordingly, it is possible to effectively remove foreign matter present on the mask MSK and to reduce foreign matter present on the mask MSK.

[0122] Dry cleaning can include a method of cleaning the mask MSK using at least one of an ion beam, a laser, plasma, carbon dioxide (CO2), and ozone (O3). However, the present disclosure is not limited thereto, and according to an embodiment, the dry cleaning can include various dry cleaning methods known in the art.

[0123] Cleaning using a two-fluid is a method of cleaning using a two-fluid in which two or more fluids are mixed. According to an embodiment, the two or more fluids can be a liquid and a gas, and the gas can exist in the form of bubbles in the liquid. Cleaning using a supercritical fluid can include, for example, carbon dioxide (CO2).

[0124] Referring to FIG. 1, Figure 9 The step S200 of arranging the mask in the chamber can include a step of arranging the mask MSK in such a manner that the opening portion OPN corresponds to the position at which the light emitting portion EL is arranged. The position at which the light emitting portion EL defined by the pixel defining film PDL is arranged and the opening portion OPN of the mask MSK can overlap when viewed from a planar surface.

[0125] After the step S200 of arranging the mask in the chamber, the step S300 of forming the light emitting portion can be performed. Before the step S300 of forming the light emitting portion, the pixel circuit layer PCL and the first electrode ELT1 can be formed. The method of manufacturing the display device DD can further include a step of forming the pixel circuit layer PCL and a step of forming the first electrode ELT1 on the pixel circuit layer PCL.

[0126] The step S300 of forming the light emitting portion can include a step of forming the light emitting portion EL by depositing a material (e.g., an organic light emitting material) forming the light emitting portion EL. The step S300 of forming the light emitting portion can be performed inside the chamber CB. The material forming the light emitting portion EL can pass through the opening portion OPN of the mask MSK, and can be deposited at a position defined by the pixel defining film PDL through the opening portion OPN.

[0127] In combination Figure 5 After the step S300 of forming the light emitting portion, a step of forming the second electrode ELT2 and a step of forming the encapsulation layer TFE can also be performed, and a display device DD according to the embodiment can be manufactured.

[0128] After the step S300 of forming the light emitting portion, a step S400 of moving the mask outside the chamber can be performed. The mask MSK can be moved outside the chamber CB after forming the light emitting portion EL. After the step S400 of moving the mask outside the chamber, a step S500 of performing secondary cleaning of the mask can be performed.

[0129] Hereinafter, the foreign matter residual rate on the mask MSK according to the cleaning method of the mask MSK of the present disclosure is described with reference to experimental results.

[0130] <Experimental example of performing the step S100 of performing first cleaning of the mask> First, with reference to Figure 10 and Figure 11 , the foreign matter residual rate on the mask MSK in the case where the step S100 of performing first cleaning of the mask is performed and in the case where the step S100 of performing first cleaning of the mask is not performed is described. Figure 10 is a TD-GC / MS analysis graph of the first experimental example and the first comparative example. Figure 11 is a TD-GC / MS analysis graph of the second experimental example and the second comparative example. The mask MSK of the first experimental example and the second experimental example refers to a mask MSK cleaned before use in a deposition process. In contrast, the mask MSK of the first comparative example and the second comparative example refers to a mask MSK not cleaned before use in a deposition process. The mask MSK of the first experimental example, the second experimental example, the first comparative example, and the second comparative example are all initial mask MSKs that have never been used in a deposition process.

[0131] The method of cleaning the mask MSK of the first experimental example and the second experimental example used a wet cleaning method using immersion. The mask MSK of the first experimental example was immersed in a first cleaning solution including N-Methyl-2-pyrrolidone, a second cleaning solution including ethanol, and a third cleaning solution including acetone, for 10 minutes each, in this order, and the same cleaning process was repeated three times. The mask MSK of the second experimental example was immersed in a first cleaning solution including N,N-dimethyl formamide and N,N-diethyl formamide, a second cleaning solution including ethanol, and a third cleaning solution including acetone, for 10 minutes each, in this order, and the same cleaning process was repeated three times.

[0132] In Figure 10 and Figure 11 , the Y-axis indicates the amount of gas captured by burning the substances present on the mask MSK, and the X-axis indicates the time at which the analysis was performed. Referring to the thermal desorption gas chromatograph-mass spectrometer (TD-GC / MS) analysis graph of Figure 10 , it can be confirmed that the amount of gas observed in the TD-GC / MS analysis graph 2000 of the first experimental example is less than that of the TD-GC / MS analysis graph 1000 of the first comparative example. Referring to the TD-GC / MS analysis graph of Figure 11 , it can be confirmed that the amount of gas observed in the TD-GC / MS graph 4000 of the second experimental example is less than that of the TD-GC / MS analysis graph 3000 of the second comparative example. The small amount of gas means that there are fewer foreign substances present on the mask MSK, which means that the foreign substances on the mask MSK are further removed compared to the initial situation in which no cleaning is performed.

[0133] According to the cleaning method of the mask MSK and the manufacturing method of the display device DD according to the present disclosure, the mask MSK not used in the deposition process is cleaned in advance before the deposition of the light emitting part EL, so that the foreign substances can be prevented from being mixed into the display device DD when the light emitting part EL is deposited, and the yield of the display device DD can be reduced.

[0134] <Experimental example of performing the second cleaning of the mask> The third and fourth experimental examples were used to measure the foreign matter remaining rate on the mask MSK when the step S500 of performing the second cleaning of the mask was performed. The mask MSK of the third and fourth experimental examples refers to the mask MSK that is cleaned after being used in the deposition process. In contrast, the mask MSK of the third and fourth comparative examples refers to the mask MSK that is not cleaned after being used in the deposition process.

[0135] The method of cleaning the mask MSK of the third experimental example used a wet cleaning method using immersion. The mask MSK of the third experimental example was immersed in a first cleaning solution including N-methyl-2-pyrrolidone, a second cleaning solution including distilled water and potassium hydroxide, and distilled water, respectively, for 10 minutes each, in this order, and the same cleaning process was repeated three times. The method of cleaning the mask MSK of the fourth experimental example used a dry cleaning method. ECOLITE 3000 (PSK Holding Co. model) was used as a device for dry cleaning, and the use conditions of the ECOLITE 3000 were set to a temperature of 25°C, a pressure of 450 mTorr, M / W 1500W, RF Bias 300W, a gap of 50mm, O22000sccm, and N2200sccm.

[0136] In order to measure the foreign matter remaining rate on the mask MSK of each of the third experimental example and the third comparative example, liquid chromatography / mass spectrometry (LC / MS) was used. It was confirmed that a smaller number of types of chemicals and a smaller amount of chemicals were detected in the mask MSK of the third experimental example than in the mask MSK of the third comparative example. This means that there is less foreign matter in the mask MSK of the third experimental example than in the mask MSK of the third comparative example, and that the foreign matter in the mask MSK of the third experimental example is further removed than in the mask MSK of the third comparative example, which is not cleaned of foreign matter on the mask MSK.

[0137] In order to measure the foreign matter remaining rate on the mask MSK of each of the fourth experimental example and the fourth comparative example, an inductively coupled plasma mass spectrometer (ICP / MS: Inductively Coupled Plasma-Mass Spectrometry) was used. It was confirmed that a smaller number of kinds of chemical substances and a smaller amount of chemical substances were detected in the mask MSK of the fourth experimental example than in the mask MSK of the fourth comparative example. This means that there are fewer foreign matters in the mask MSK of the fourth experimental example than in the mask MSK of the fourth comparative example, and means that the foreign matters in the mask of the fourth experimental example are further removed than in the mask MSK of the fourth comparative example in which the foreign matters on the mask MSK are not cleaned.

[0138] The cleaning method of a mask and the manufacturing method of a display device according to the present disclosure can prevent foreign matters from being mixed into the display device DD and can reduce the yield of the display device DD by cleaning the mask MSK used in the deposition process, thereby reusing the mask MSK when the light emitting part EL is deposited thereafter.

[0139] As described above, although the description has been made with reference to the preferred embodiments of the present disclosure, it is understood by those skilled in the art or those having ordinary knowledge in the art that various modifications and changes can be made to the present disclosure within the scope of the concept and technical field of the present disclosure recited in the claims, without departing from the scope of the present disclosure.

[0140] Therefore, the technical scope of the present disclosure is not limited to the contents recited in the detailed description of the specification, but should be determined by the claims.

Claims

1. A method for manufacturing a display device, comprising the following steps: A pixel circuit layer is formed and a first electrode is formed on the pixel circuit layer; Perform the first cleaning of the mask; The mask is arranged within the cavity; and A light-emitting portion is formed on the first electrode within the cavity. in, The mask was not used in the deposition process prior to the first cleaning step.

2. The method for manufacturing the display device as claimed in claim 1, wherein, The step of forming the light-emitting portion includes the step of depositing the light-emitting portion. The first cleaning step of the mask is performed between the first time point of manufacturing the mask and the second time point of placing the mask in the cavity. Between the first time point and the second time point, the mask was not used in the deposition process for forming the light-emitting portion.

3. The method for manufacturing the display device as claimed in claim 1, wherein, The first cleaning of the mask includes the following steps: cleaning the mask using at least one of the following methods: wet cleaning, dry cleaning, two-fluid cleaning, and supercritical fluid cleaning.

4. The method for manufacturing the display device as claimed in claim 1, wherein, The first cleaning step of the mask includes a wet cleaning step of the mask using a cleaning solution. The cleaning solution comprises at least one of the following compounds: a first compound represented by [Chemical Formula 1], a second compound represented by [Chemical Formula 2], a third compound represented by [Chemical Formula 3], a fourth compound represented by [Chemical Formula 4], a fifth compound represented by [Chemical Formula 5], a sixth compound represented by [Chemical Formula 6], and a seventh compound, wherein the seventh compound is a lactam compound having five or fewer cyclic atoms, wherein in the lactam compound, the nitrogen atom, as a cyclic atom, is combined with a non-cyclic hydrogen atom or an alkyl group having one carbon atom: [Chemical Formula 1] ， In the [Chemical Formula 1], R1 is hydrogen, an alkyl group with 1 carbon atom, an alkyl group with 2 carbon atom, an alkyl group with 3 carbon atom, potassium, or sodium; [Chemical Formula 2] ， In the above [Chemical Formula 2], R2 is a hydrogen atom or an alkyl group having one carbon atom; [Chemical Formula 3] ， In the above [Chemical Formula 3], R3, R4 and R5 are each hydrogen, an alkyl group with 1 carbon atom, an alkyl group with 2 carbon atoms, or an alkyl group with 3 carbon atoms; [Chemical Formula 4] ， In the above [Chemical Formula 4], R6 and R7 are each hydrogen, an alkyl group having one carbon atom, or an alkyl group having two carbon atoms; [Chemical Formula 5] ， In the aforementioned [Chemical Formula 5], R8 and R9 are each hydrogen, an alkyl group having one carbon atom, or an alkyl group having two carbon atoms; [Chemical Formula 6] ， In the aforementioned [Chemical Formula 6], R 10 and R 11 Each is either a hydrogen atom or an alkyl group having one carbon atom. The method for manufacturing the display device further includes the following steps: Moving the mask outside the chamber; and The mask is then cleaned a second time. The step of performing a second cleaning of the mask is performed after the step of removing the mask outside the chamber. The second cleaning step of the mask includes the following steps: cleaning the mask using at least one of the following methods: wet cleaning, dry cleaning, two-fluid cleaning, and supercritical fluid cleaning. The wet cleaning includes a method of cleaning the mask using the cleaning solution. The dry cleaning includes a method of cleaning the mask using at least one of ion beams, lasers, plasma, carbon dioxide, and ozone.

5. The method for manufacturing a display device as claimed in claim 4, wherein, The cleaning solution includes the third compound. Based on the total weight of the cleaning solution, the content of the third compound is 50 wt% or more.

6. The method of manufacturing the display device as claimed in claim 4, wherein, The cleaning solution includes the seventh compound. Based on the total weight of the cleaning solution, the content of the seventh compound is 50 wt% or more.

7. The method of manufacturing the display device as claimed in claim 4, wherein, The cleaning solution includes the third compound and the seventh compound. Based on the total weight of the cleaning solution, the total content of the third compound and the seventh compound is 50 wt% or more.

8. The method of manufacturing the display device as claimed in claim 1, wherein, The mask includes multiple openings. The width of each of the plurality of openings is less than 10 μm. The thickness of the mask is less than 5 μm. The mask comprises silicon. The step of forming the light-emitting part includes the step of forming the light-emitting part by depositing an organic light-emitting material.

9. A mask cleaning fluid comprising at least one of the following compounds: a first compound represented by [Chemical Formula 1], a second compound represented by [Chemical Formula 2], a third compound represented by [Chemical Formula 3], a fourth compound represented by [Chemical Formula 4], a fifth compound represented by [Chemical Formula 5], a sixth compound represented by [Chemical Formula 6], and a seventh compound, wherein, The seventh compound is a lactam compound with five or fewer cyclic atoms. In the lactam compound, the nitrogen atom, which is a cyclic atom, is combined with a non-cyclic hydrogen atom or an alkyl group having one carbon atom. [Chemical Formula 1] ， In the [Chemical Formula 1], R1 is hydrogen, an alkyl group with 1 carbon atom, an alkyl group with 2 carbon atom, an alkyl group with 3 carbon atom, potassium, or sodium; [Chemical Formula 2] ， In the above [Chemical Formula 2], R2 is a hydrogen atom or an alkyl group having one carbon atom; [Chemical Formula 3] ， In the above [Chemical Formula 3], R3, R4 and R5 are each hydrogen, an alkyl group with 1 carbon atom, an alkyl group with 2 carbon atoms, or an alkyl group with 3 carbon atoms; [Chemical Formula 4] ， In the above [Chemical Formula 4], R6 and R7 are each hydrogen, an alkyl group having one carbon atom, or an alkyl group having two carbon atoms; [Chemical Formula 5] ， In the aforementioned [Chemical Formula 5], R8 and R9 are each hydrogen, an alkyl group having one carbon atom, or an alkyl group having two carbon atoms; [Chemical Formula 6] ， In the aforementioned [Chemical Formula 6], R 10 and R 11 Each is either a hydrogen atom or an alkyl group having one carbon atom.

10. An electronic device comprising a display device manufactured according to the method of manufacturing the display device according to claim 1.

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