Inkjet printing apparatus

Abstract

An inkjet printing apparatus according to an embodiment includes: a stage for supporting a substrate; and an inkjet head disposed above the stage and discharging the resin toward the stage. The stage includes: a first stage portion having a first thermal conductivity; and a second table portion disposed around the first table portion and surrounding at least a portion of the first table portion, where the second table portion has a second thermal conductivity greater than the first thermal conductivity.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0073450 filed in the Korean Intellectual Property Office on June 8, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to an inkjet printing apparatus, and more particularly, to an inkjet printing apparatus including a plurality of stages. Background Art

[0004] The display device is a device that displays an image, and includes various types such as a liquid crystal display device, a light emitting display device, a micro LED display device, and the like.

[0005] Such a display device can be formed by stacking a plurality of layers on a substrate, and an inkjet printing device can be used as one of various methods for forming each layer. For example, an organic thin film layer, a light-emitting layer, an adhesive layer, an insulating film, etc. of a display device can be formed using an inkjet printing device.

[0006] For example, in order to bond a display panel to a cover glass, an optically transparent resin (OCR) as a liquid adhesive may be applied to the display panel by an inkjet method. When the display panel and the cover glass are bonded, the profile of the resin at the outside may affect the dead zone of the product, and when the outer edge of the resin has a steep slope similar to a vertical side wall, it is beneficial to reduce the dead zone of the product. Therefore, a method for forming an effective edge profile when applying the resin to a substrate by an inkjet printing method is needed. Summary of the invention

[0007] The embodiment provides an inkjet printing apparatus capable of forming a desired profile during inkjet coating. In addition, the embodiment provides an inkjet printing apparatus capable of forming a profile closer to a vertical side wall at an edge of a resin while reducing the number of inkjet coating processes.

[0008] An inkjet printing apparatus according to an embodiment includes: a stage for supporting a substrate; and an inkjet head disposed above the stage and discharging a resin toward the stage. The stage includes: a first stage portion having a first thermal conductivity; and a second stage portion disposed around the first stage portion and surrounding at least a portion of the first stage portion, wherein the second stage portion has a second thermal conductivity. The second thermal conductivity is greater than the first thermal conductivity.

[0009] The substrate may cover all of the first stage portion and at least a portion of the second stage portion.

[0010] An edge of the substrate may extend beyond an edge of the first stage portion, and an edge of the second stage portion may extend beyond an edge of the substrate.

[0011] An upper surface of the first stage portion and an upper surface of the second stage portion may be coplanar.

[0012] The second stage portion may include a cooling unit.

[0013] The second stage portion may be provided at a corner portion of the first stage portion.

[0014] The second stage portion may be separable from the first stage portion by being movable in the vertical direction relative to the first stage portion while supporting the substrate.

[0015] The inkjet printing apparatus may further include a third stage portion disposed around the first stage portion and having a third thermal conductivity higher than the first thermal conductivity.

[0016] The second stage portion may be separable from the third stage portion, and at least one of the second stage portion and the third stage portion may be movable in the vertical direction while supporting the substrate.

[0017] At least one of the second stage portion and the third stage portion may include a cooling unit.

[0018] The first stage portion may include at least one of polyetheretherketone, polycarbonate, polyoxymethylene, and polypropylene.

[0019] The second stage portion may comprise metal.

[0020] The substrate may include a first region above the first land portion and a second region above the second land portion. The resin on the first region may be at a higher temperature than the resin on the second region.

[0021] The width of the second zone above the second land portion may be about 0.3 mm to about 3 mm.

[0022] The inkjet-printing apparatus may further include a third stage portion at least partially overlapping the first stage portion and having a higher thermal conductivity than the first stage portion.

[0023] An upper surface of the first stage portion and an upper surface of the third stage portion may be coplanar.

[0024] The first stage portion may include at least one of polyetheretherketone, polycarbonate, polyoxymethylene, and polypropylene.

[0025] The third stage portion may comprise metal.

[0026] The substrate may include a first region above the first land portion and a third region above the third land portion. The resin on the first region is in a higher temperature state than the resin on the third region.

[0027] The third stage portion may include a cooling unit.

[0028] According to an embodiment, an inkjet printing device capable of controlling the profile of an edge region can be provided. According to an embodiment, during the inkjet process, a desired profile of the resin (e.g., a nearly vertical profile at the edge) can be formed in the edge region without additional coating. In addition, the edge profile of the resin can be controlled with a small amount of application methods, and the dead zone of the product can be reduced while reducing the equipment investment cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a diagram schematically showing an inkjet printing apparatus according to an embodiment.

[0030] Figure 2 is a top plan view of a stage according to an embodiment.

[0031] Figure 3 is a top plan view in which a substrate is placed on a stage according to an embodiment.

[0032] Figures 4 to 6 It is along Figure 3 A cross-sectional view of an embodiment taken along line AA' in FIG.

[0033] Figure 7 is a top plan view of a stage according to an embodiment.

[0034] Figure 8 is a top plan view in which a substrate is placed on a stage according to an embodiment.

[0035] Fig. 9 It is along Figure 8 A cross-sectional view of an embodiment taken along line BB' in FIG.

[0036] Fig.10 is a cross-sectional view of a lifting operation of a table according to an embodiment.

[0037] Fig.11 is a top plan view of a stage according to an embodiment.

[0038] Fig.12 is a top plan view of a substrate mounted on a stage according to an embodiment.

[0039] Fig.13 It is along Fig.12 A cross-sectional view of an embodiment taken along line CC' in FIG.

[0040] Fig.14 is a top plan view in which a substrate is placed on a stage according to an embodiment.

[0041] Fig.15 It is along Fig.14 A cross-sectional view of an embodiment taken along line DD' in FIG.

[0042] Fig.16 is a cross-sectional view of a display device according to an embodiment. DETAILED DESCRIPTION

[0043] Hereinafter, various embodiments will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement. The inventive concept can be implemented in many different forms and is not limited to the embodiments set forth herein.

[0044] In order to clearly describe the present inventive concept, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar constituent elements throughout the specification.

[0045] Furthermore, since the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, the present inventive concept is not necessarily limited to the shown inventive concept.

[0046] In the drawings, the thickness is exaggerated to clearly show various layers and regions. In the drawings, the thickness of some layers and regions is exaggerated for convenience of explanation.

[0047] Furthermore, when a part such as a layer, film, region, or plate is referred to as being "over" or "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is an intervening part between the two parts. Conversely, when a part is referred to as being "directly on" another part, this means that there is no intervening part between the parts.

[0048] Furthermore, “above” or “on” a reference portion means being positioned above or below the reference portion, and does not necessarily mean being positioned “above” or “on” it in the opposite direction of gravity. Furthermore, throughout the specification, unless otherwise specified, when a component is referred to as “comprising”, it means that it may also include other components without excluding other components.

[0049] Furthermore, throughout the specification, a “planar image” is a view observed from a top plane, and a “cross-sectional image” is a view observed from a side surface of a target portion cut in a direction orthogonal to the top plane.

[0050] Furthermore, when two components "overlap," unless otherwise specified, it means that one of the components at least partially covers the other in a cross-sectional image.

[0051] Figure 1 is a diagram schematically showing an inkjet printing apparatus according to an embodiment.

[0052] refer to Figure 1 , the inkjet printing apparatus 10 may include a stage ST, an ink storage unit 200 , an inkjet head 300 , a nozzle unit 310 , and a control unit 400 .

[0053] The inkjet printing apparatus 10 can be used to manufacture a display device. A substrate SUB as a printing object can be placed on the stage ST. The substrate SUB can be an object among the constituent elements of the display device to be coated with a liquid adhesive resin (e.g., an optically transparent resin (OCR)) by the inkjet printing apparatus 10. The substrate SUB can be or include a display panel. The display panel can be a light-emitting display panel including an organic light-emitting device or an inorganic light-emitting device. For example, an adhesive layer can be formed on the surface of the display panel to bond the display panel to a cover glass; to this end, an inkjet method can be used to apply the resin to the surface of the substrate SUB (e.g., a display panel) placed on the stage ST. Reference will be made to Fig.16 Describe the structure of the display device.

[0054] The ink storage unit 200 may store ink used in the inkjet printing apparatus 10. The ink storage unit 200 may supply the stored ink to the inkjet head 300. The ink storage unit 200 may be provided separately from the inkjet head 300, or may be provided integrally with the inkjet head 300.

[0055] The inkjet head 300 is connected to the ink storage unit 200 , and it may eject ink supplied from the ink storage unit 200 at a certain rate through the nozzle unit 310 .

[0056] The nozzle unit 310 may be positioned at the bottom of the inkjet head 300. The nozzle unit 310 may include a plurality of nozzles. The nozzle unit 310 may extend from the inkjet head 300 toward the stage ST, or may be provided in the form of a hole or an opening on the lower surface of the inkjet head 300 positioned above the stage ST. Ink may drip onto the substrate SUB through the nozzle unit 310. The number, spacing, and size of the nozzle units 310 may vary.

[0057] The control unit 400 is connected to each component of the inkjet printing device 10, and can control the overall operation of the inkjet printing device 10. For example, the control unit 400 can be electrically connected to the inkjet head 300. The control unit 400 can control the inkjet head 300 to eject ink. The control unit 400 can control the movement of the inkjet head 300. The control unit 400 may include a plurality of modules providing a variety of functions, or may include a single module.

[0058] Figure 2 is a top plan view of a table according to an embodiment, and Figure 3 Is installed in Figure 2 A top plan view of a substrate on a stage.

[0059] refer to Figure 2 and Figure 3 , the inkjet printing apparatus according to the embodiment may include a stage ST on which a substrate SUB is placed when performing an inkjet printing process.

[0060] The stage ST according to the embodiment may include a first stage portion ST1 and a second stage portion ST2 positioned around the first stage portion ST1. On a plane, the first stage portion ST1 includes a central portion of the stage ST, and the second stage portion ST2 may surround at least a portion of the first stage portion ST1 and be arranged along the edge of the first stage portion ST1 like a frame. The first stage portion ST1 and the second stage portion ST2 may meet each other at a cross-sectional boundary, and the upper surface of the first stage portion ST1 and the upper surface of the second stage portion ST2 may be coplanar. In an embodiment, the first stage portion ST1 and the second stage portion ST2 are integrated into a single stage ST, and may be different regions in the stage ST. The first stage portion ST1 and the second stage portion ST2 may be provided as separate components.

[0061] The first stage part ST1 and the second stage part ST2 can have different thermal conductivities. The first stage part ST1 including the central part of the stage ST can include a material with a first thermal conductivity. The second stage part ST2 positioned around the periphery of the first stage part ST1 and including the edge of the stage ST can include a material with a second thermal conductivity. The first thermal conductivity is lower than the second thermal conductivity. For example, the first stage part ST1 can include a plastic or resin such as polyetheretherketone, polycarbonate, polyoxymethylene or polypropylene, and the second stage part ST2 can include a metal such as aluminum (Al), copper (Cu) or iron (Fe). The listed materials are examples where the second thermal conductivity is higher than the first thermal conductivity, and are not meant to be exhaustive.

[0062] Figure 3 A top view of a substrate SUB placed on a stage ST is depicted. As shown, the substrate SUB is mounted on the stage ST so that an edge of the substrate SUB is between an edge of the first stage portion ST1 and an edge of the second stage portion ST2 in a plan view. In a case where the first stage portion ST1, the second stage portion ST2, and the substrate SUB are concentrically arranged in a plan view, the edge of the substrate SUB may be farther from the center than the edge of the first stage portion ST1, but not as far from the center as the edge of the second stage portion ST2. The area surrounded by the edge of the first stage portion ST1 in a plan view may be smaller than the area surrounded by the edge of the substrate SUB, and the area surrounded by the edge of the second stage portion ST2 may be larger than the area surrounded by the edge of the substrate SUB. The flat substrate SUB may overlap with the front of the first stage portion ST1, and may overlap with at least a portion of the second stage portion ST2. Although Figure 2 and Figure 3 The substrate SUB is shown to be arranged concentrically with the stage ST, but this is not a limitation of the present disclosure.

[0063] Furthermore, although the stage ST is depicted as a rectangle, the shape of the stage ST may vary according to the implementation and may be circular, oval, polygonal, or irregular, and the shapes of the first stage portion ST1 and the second stage portion ST2 may also be modified.

[0064] Figure 4 It is along Figure 3 A cross-sectional view of an embodiment taken along line AA' in FIG.

[0065] refer to Figure 4 , the substrate SUB is positioned on the stage ST. The resin may be applied on the substrate SUB by an inkjet printing method. Figure 4 Also shown are cross-sectional profiles P0 and P1 of the resin applied on the substrate SUB.

[0066] The top surfaces of the first stage portion ST1 and the second stage portion ST2 may be on the same plane (ie, coplanar), and a substrate SUB may be mounted on the top surface of the stage ST. The substrate SUB may include a first region R1 covering the first stage portion ST1 and a second region R2 covering the second stage portion ST2.

[0067] As described above, the substrate SUB may cover the front of the first stage portion ST1 and may at least partially cover the second stage portion ST2. The substrate SUB may be arranged to cover the edge region of the second stage portion ST2, and the width of the second region R2 overlapping the second stage portion ST2 and the substrate SUB may be approximately 0.3 mm to 3 mm. On a plane, the width of the second region R2 may be the same as the distance between the edge of the first stage portion ST1 and the edge of the substrate SUB.

[0068] The first stage portion ST1 includes a central portion of the stage ST, and may include a material having a first thermal conductivity. The second stage portion ST2 is located adjacent to an edge of the first stage portion ST1, and may include a material having a second thermal conductivity higher than the first thermal conductivity.

[0069] In an embodiment, the resin can be discharged at a temperature higher than room temperature. The first stage portion ST1 contains a material having a first (low) thermal conductivity, so the resin discharged in the first region R1 of the substrate SUB can maintain a relatively high temperature without losing heat to the lower first stage portion ST1. In contrast, the second stage portion ST2 contains a material having a second (high) thermal conductivity, so the resin discharged in the second region R2 of the substrate SUB can reach a relatively low temperature due to heat transfer to the second stage portion ST2. When such a relative temperature gradient is formed, the viscous resin may move from the first region R1 of high temperature to the second region R2 of low temperature due to the Marangoni effect, and therefore, the cross-sectional profile of the resin may change from the initial coating state profile P0 to the deformed profile P1 due to the temperature difference.

[0070] The Marangoni effect refers to the flow of fluids due to differences in surface tension. Since liquids with high surface tension pull on surrounding liquids more strongly than liquids with low surface tension, a gradient in surface tension naturally causes liquids to flow from areas of low surface tension to areas of high surface tension. This surface tension gradient can be caused by a temperature gradient. In the case of a fluid, since the surface tension in a high temperature area is relatively low and the surface tension in a low temperature area is relatively high, the fluid can move from a high temperature area with low surface tension to a low temperature area with high surface tension.

[0071] refer to Figure 4 The profile P0 is a profile in the initial application state of the resin, and the profile P1 is a profile deformed according to the temperature difference of the region of the substrate SUB. As depicted, in one embodiment, the resin may move from the first region R1 of relatively high temperature to the second region R2 of relatively low temperature after the initial application, and therefore, the center of the resin protrusion (the thickest part of the resin application) may move from the center toward the edge of the substrate SUB, and the cross-sectional profile P1 of the resin may have a steeper slope at the edge of the substrate SUB than the profile P0 at the time of initial application.

[0072] In this way, the stage ST of the inkjet printing device according to the embodiment includes a first stage portion ST1 and a second stage portion ST2 having different thermal conductivities, causing a temperature distribution of the resin applied on the substrate SUB mounted on the stage ST, thereby inducing the resin to move toward the edge of the substrate SUB, and allowing a desired profile to be formed at the edge portion. Therefore, sufficient protrusions can be formed in the edge region without an additional process. Since the protrusions migrate toward the edge, a steeper, almost vertical profile is formed in the edge region, so that the boundary of the contact portion of the product is not visually recognized, and the dead zone can be reduced.

[0073] Figure 5 and Figure 4The embodiment differs in that the second stage portion ST2 includes the first stage portion ST1, and Figure 6 and Figure 5 The difference of the embodiment is that the second stage part ST2 further includes a cooling unit 500. Figure 4 The redundant description of the components of the embodiment of the present invention is omitted. The configuration follows Figure 4 implementation method.

[0074] refer to Figure 5 , the second stage portion ST2 and the first stage portion ST1 may at least partially overlap, and the second stage portion ST2 may also be formed to accommodate the first stage portion ST1. The top surface of the first stage portion ST1 and the top surface of the second stage portion ST2 may be on the same plane. The lower surface of the first stage portion ST1 and the lower surface of the second stage portion ST2 may be on the same plane or on different planes.

[0075] The first stage portion ST1 and the second stage portion ST2 include materials having different thermal conductivities, and the thermal conductivity of the second stage portion ST2 may be higher than that of the first stage portion ST1. Therefore, when the substrate SUB is mounted on the stage ST, the temperature of the resin applied to the second region R2 covering the second stage portion ST2 may be lower than the temperature of the resin applied to the first region R1 covering the first stage portion ST1. According to this temperature distribution, the resin may migrate from the first region R1 of high temperature to the second region R2 of low temperature, allowing a protrusion to be formed on the edge of the substrate SUB without additional coating.

[0076] In addition, if Figure 6 As shown in , the second stage part ST2 may further include a cooling unit 500 to more quickly reduce the temperature of the resin applied in the second region R2. In an embodiment, the cooling unit 500 may include a pipe that reduces the temperature of the second stage part ST2 by circulating cooling water. For example, the cooling unit 500 may include a water jacket, a water pump, a thermostat, a transmission belt, etc., and it may be a coolant circulation device that circulates a coolant to reduce the temperature of the second stage part ST2.

[0077] Figure 7 is a plan view of a table according to an embodiment, and Figure 8 Is installed according to Figure 7 A plan view of a substrate on a stage of an embodiment of the present invention. Fig. 9 It is along Figure 8 A cross-sectional view of the embodiment taken along line BB' in FIG. Fig.10 is based on Fig. 9 A cross-sectional view of a lifting operation of a table according to an embodiment of the present invention.

[0078] Figures 7 to 10 The implementation method and Figure 2 The embodiment of FIG. 4 is different in that the second stage portion ST2 is positioned only at the corners of the first stage portion ST1.

[0079] In an embodiment, the first stage portion ST1 includes a central portion of the stage ST, and the second stage portion ST2 may be disposed adjacent to each corner portion of the first stage portion ST1. The top surfaces of the first stage portion ST1 and the second stage portion ST2 are flush, thus forming a plane, and the substrate SUB may be placed on the top surface of the stage ST. The substrate SUB may include a first region R1 overlapping the first stage portion ST1 and a second region R2 overlapping the second stage portion ST2.

[0080] refer to Figure 8 and Fig. 9 , when the substrate SUB is mounted on the stage ST, the edge of the first stage portion ST1 may be positioned close to the center of the stage ST. In a plan view, the edge of the substrate SUB may be between the edge of the first stage portion ST1 and the edge of the second stage portion ST2. In a plane, the area surrounded by the edge of the first stage portion ST1 may be smaller than the area surrounded by the edge of the substrate SUB. The substrate SUB may overlap with the front of the first stage portion ST1.

[0081] The second stage portion ST2 may be positioned at each corner of the first stage portion ST1. As used herein, a "corner" is an area where two straight edges meet to form an angle. When the substrate SUB is placed on the stage ST, the second stage portion ST2 may be at least partially covered by the corner of the substrate SUB.

[0082] The first stage portion ST1 and the second stage portion ST2 include materials having different thermal conductivities, and the thermal conductivity of the second stage portion ST2 may be higher than that of the first stage portion ST1. For example, the first stage portion ST1 may include plastic or resin having low thermal conductivity such as polyetheretherketone, polycarbonate, polyoxymethylene, polypropylene, etc. The second stage portion ST2 may include metal having high thermal conductivity such as aluminum (Al), copper (Cu), iron (Fe), and is not limited thereto.

[0083] Therefore, the temperature of the resin applied to the second region R2 of the substrate SUB covering the second stage portion ST2 may be lower than the temperature of the resin applied to the first region R1 of the substrate SUB covering the first stage portion ST1. According to an embodiment, the second stage portion ST2 may further include a cooling unit to more quickly reduce the temperature of the resin applied to the second region R2. Due to the difference in thermal conductivity between the first stage portion ST1 and the second stage portion ST2, the resin coated on the substrate SUB will have a temperature gradient. Therefore, the resin can migrate from the first region R1 of relatively high temperature to the second region R2 of relatively low temperature, allowing sufficient resin to be coated on the corner portion of the substrate SUB without additional coating materials or processes. The inventive concept requires that the resin be uniformly deposited on the substrate SUB by forming a thermal conductivity difference between different portions of the stage ST, and then the resin is deposited on the region with the lowest thermal conductivity so that the resin migrates to the target region with higher thermal conductivity.

[0084] In addition, reference Fig.10 In an embodiment, the second stage part ST2 may be detachable from the first stage part ST1, for example, by vertical movement as indicated by an arrow. The second stage part ST2 is connected to a driving unit (not shown) and may move in a vertical direction; therefore, the second stage part ST2 may accommodate a substrate SUB and allow it to rest on the first stage part ST1, or it may lift the substrate SUB resting on the first stage part ST1. The second stage part ST2 may vertically lift the substrate SUB by supporting a corner portion of the substrate SUB.

[0085] Fig.11 is a top plan view of a table according to an embodiment, and Fig.12 Is installed according to Fig.11 A top plan view of a substrate on a stage of an embodiment. Fig.13 It is along Fig.12 A cross-sectional view of an embodiment taken along line CC' in FIG.

[0086] In the following, reference will be made to Figures 11 to 13 A stage of an inkjet printing apparatus according to an embodiment is described.

[0087] and Figure 7 Compared with the implementation method, Fig.11 , Fig.12 and Fig.13 The embodiments of FIG. 5 are different in that they include a third stage portion ST3 positioned between adjacent second stage portions ST2 positioned at corners of the first stage portion ST1.

[0088] In an embodiment, the stage ST may include a first stage portion ST1 including a central portion of the stage ST, a second stage portion ST2 arranged at each corner of the first stage portion ST1, and a third stage portion ST3 arranged between adjacent second stage portions ST2 and adjacent to each side of the first stage portion ST1.

[0089] The second stage portion ST2 and the third stage portion ST3 may be arranged to surround at least a portion of the first stage portion ST1. Top surfaces of the first stage portion ST1, the second stage portion ST2, and the third stage portion ST3 may be coplanar, and a substrate SUB may be mounted on the top surface of the stage ST. The substrate SUB may include a first region R1 overlapping the first stage portion ST1, a second region R2 overlapping the second stage portion ST2, and a third region R3 overlapping the third stage portion ST3.

[0090] refer to Fig.12 and Fig.13 The substrate SUB is placed on the stage ST so that an edge of the substrate SUB extends beyond an edge of the first stage portion ST1. On a plane, an area surrounded by an edge of the first stage portion ST1 may be smaller than an area surrounded by an edge of the substrate SUB. The substrate SUB may cover a front surface of the first stage portion ST1.

[0091] The second stage portion ST2 may be positioned at each corner of the first stage portion ST 1. In a state in which the substrate SUB is seated on the stage ST, the second stage portion ST2 may overlap at least a portion of the corner of the substrate SUB.

[0092] The third stage portion ST3 may be positioned adjacent to each side of the first stage portion ST1. In an embodiment where the first stage portion ST1 is rectangular, the third stage portion ST3 may have four segments, each along each side of the first stage portion ST1. The third stage portion ST3 may be positioned between the second stage portions ST2 located in the corner portion, and the second stage portion ST2 and the third stage portion ST3 may at least partially overlap the substrate SUB.

[0093] The first stage portion ST1 may include plastic or resin having low thermal conductivity such as polyetheretherketone, polycarbonate, polyoxymethylene, and polypropylene, but is not limited thereto.

[0094] The second stage portion ST2 and the third stage portion ST3 may include a material having a higher thermal conductivity than the first stage portion ST1. For example, the second stage portion ST2 and the third stage portion ST3 may include a metal having a high thermal conductivity such as aluminum (Al), copper (Cu), and iron (Fe), but are not limited thereto. The second stage portion ST2 may include the same or different material as the third stage portion ST3, and according to an embodiment, they may be separated from each other.

[0095] Therefore, the temperature of the resin applied to the second region R2 and the third region R3 on the second stage portion ST2 and the third stage portion ST3 of the substrate SUB may be lower than the temperature of the resin applied to the first region R1 on the first stage portion ST1 of the substrate SUB. According to another embodiment, the second stage portion ST2 and / or the third stage portion ST3 may further include a cooling unit to more quickly reduce the temperature of the resin applied in the second region R2 and / or the third region R3.

[0096] In this way, the resin coated on the substrate SUB has a temperature gradient due to the difference in thermal conductivity between the first stage portion ST1 and the second and third stage portions ST2 and ST3. Therefore, the resin moves from the first region R1 of high temperature to the second and third regions R2 and R3 of low temperature, so that sufficient resin can be coated on the edge (including the corner) of the substrate SUB without the need for additional coating materials or processes.

[0097] In an embodiment, the second stage portion ST2 and / or the third stage portion ST3 can be separated from the first stage portion ST1 by moving in the vertical direction relative to the first stage portion ST1. The second stage portion ST2 and / or the third stage portion ST3 can be connected to a driving portion (not shown) and can move in the up and down direction. When moving up and down, the substrate SUB can be supported to be mounted on the stage ST, or the substrate SUB mounted on the stage ST can be lifted. For example, the third stage portion ST3 adjacent to the first stage portion ST1 is fixed, and the second stage portion ST2 positioned at the corner of the first stage portion ST1 can be separated from the first stage portion ST1 and the third stage portion ST3, and move in the vertical direction to move the substrate SUB.

[0098] According to an embodiment, the second stage portion ST2 positioned at the corner of the first stage portion ST1 is fixed, and the third stage portion ST3 positioned on each side of the first stage portion ST1 can be separated from the first and second stage portions ST1 and ST2 by moving in the vertical direction. The third stage portion ST3 can carry the substrate SUB in the vertical direction.

[0099] In the embodiment, the stage ST is depicted as a square, but the shape of the stage ST may vary according to the embodiment and may be circular, oval, polygonal or irregular, and the shapes of the first stage portion ST1, the second stage portion ST2 and the third stage portion ST3 may also be variously modified.

[0100] Fig.14 is a plan view of a substrate mounted on a stage according to an embodiment, and Fig.15 It is along Fig.14 A cross-sectional view of an embodiment taken along line DD' in FIG.

[0101] Fig.14 The difference from the previous embodiment is that the substrate SUB includes an opening OP. According to some embodiments, in order to add various functions to the display device, the substrate may include an opening therethrough. For a substrate including a small hole, contour control may be required at the boundary of the small hole.

[0102] refer to Fig.14 and Fig.15 The stage ST may include a first stage portion ST1 including a central portion of the stage ST, a second stage portion ST2 arranged at each corner portion of the first stage portion ST1, and a third stage portion ST3 at least partially aligned with the opening OP of the substrate SUB.

[0103] Top surfaces of the first, second, and third mesa portions ST1, ST2, and ST3 are coplanar, and a substrate SUB may be seated on the top surface of the mesa ST. The substrate SUB may include a first region R1 covering the first mesa portion ST1 and a third region R3 covering the third mesa portion ST3.

[0104] When the substrate SUB is placed on the stage ST, an edge of the substrate SUB may extend beyond an edge of the first stage portion ST1. As viewed from the top, an area of ​​the first stage portion ST1 may be smaller than an area of ​​the substrate SUB. The substrate SUB may cover a front portion of the first stage portion ST1.

[0105] The second stage portion ST2 may be located at each corner of the first stage portion ST 1. When the substrate SUB is mounted on the stage ST, the second stage portion ST2 may overlap at least a portion of the corner of the substrate SUB.

[0106] The third stage portion ST3 is placed in a position corresponding to the opening OP of the substrate SUB, so that the third stage portion ST3 forms a base of the opening OP. In some embodiments, the third stage portion ST3 may have the same shape as the opening OP of the substrate SUB. In some embodiments, as Fig.15 As depicted in FIG. 1 , the third stage portion ST3 may be wider than the opening OP and covered by a third region R3 of the substrate SUB defining the opening OP. The width W of the third region R3 may be approximately 0.3 mm to 3 mm. On a plane, the width W of the third region R3 may be the same as the distance between the edge of the first stage portion ST1 and the boundary of the opening OP.

[0107] The first stage portion ST1 may be disposed around the third stage portion ST3, and it may cover at least a portion of the third stage portion ST3. The first stage portion ST1 may include plastic or resin having low thermal conductivity such as polyetheretherketone, polycarbonate, polyoxymethylene, polypropylene, etc., but is not limited thereto.

[0108] The third stage portion ST3 may include a material having higher thermal conductivity than the first stage portion ST 1. For example, the third stage portion ST3 may include a material having high thermal conductivity such as aluminum (Al), copper (Cu), and iron (Fe), and is not limited thereto.

[0109] In an embodiment, the resin may be discharged at a temperature higher than room temperature. The first stage portion ST1 includes a material having a first thermal conductivity, so the resin discharged in the first region R1 of the substrate SUB may maintain a relatively high temperature state without transferring heat to the lower first stage portion ST1. In contrast, the third stage portion ST3 includes a material having a second thermal conductivity higher than the first thermal conductivity, so the resin discharged in the third region R3 of the substrate SUB may be cooled faster by faster heat loss to the lower third stage portion ST3. Therefore, the temperature of the resin applied to the third region R3 of the substrate SUB above the third stage portion ST3 may be lower than the temperature of the resin applied to the first region R1 of the substrate SUB covering the first stage portion ST1. According to an embodiment, the third stage portion ST3 may further include a cooling unit to more quickly reduce the temperature of the resin applied in the third region R3.

[0110] In this way, the resin coated on the substrate SUB has a temperature gradient due to the difference in thermal conductivity between the first terrace portion ST1 and the third terrace portion ST3. Therefore, the resin moves from the first region R1 of high temperature to the third region R3 of low temperature. By generating a temperature gradient, sufficient resin can be coated at the boundary of the opening OP of the substrate SUB without additional coating material, and a desired coating profile P1 with a steep slope can be formed at the edge.

[0111] Specific reference Fig.15 , the resin profile around the opening OP of the substrate SUB can be checked. Profile P0 is the profile of the resin thickness when the resin is initially applied, and profile P1 is the profile after the resin moves due to the temperature difference. In other words, in an embodiment, the resin may move from a relatively high temperature first region R1 to a relatively low temperature third region R3 after the initial application, and therefore, the center of the resin protrusion (the thickest coated portion of the resin) may move toward the edge of the opening OP. The cross-sectional profile P1 of the resin may be formed with a higher protrusion near the edge of the opening OP, resulting in a profile having a steeper slope at the edge than the initially coated profile P0.

[0112] As described above, since the inkjet printing device according to the embodiment includes a plurality of stage portions with different thermal conductivities, a temperature gradient of the resin applied to the substrate placed on the stage is generated, thereby generating a temperature gradient on the substrate. The temperature gradient causes the resin to move, so that there is no need to apply more resin near the edge. In addition, the movement of the resin to the edge produces a steep slope profile at the edge, which is a desired profile. In addition, when the substrate includes an opening, the desired profile can be formed by inducing the movement of the resin around the opening. Therefore, a bulge can be formed without an additional process, and the dead zone around the opening of the substrate including the opening can be reduced by forming a profile with a steeper slope.

[0113] Fig.16 is a cross-sectional view of a display device according to an embodiment.

[0114] refer to Fig.16 , the display device 1000 may include a cover window WU, a display panel DP, and a housing member HM. The polarizing layer POL may be positioned between the cover window WU and the display panel DP, and the polarizing layer POL may be attached to the display panel DP by an adhesive, or it may be formed on top of the display panel DP. The polarizing layer POL may be a part of the display panel DP. The display device 1000 may further include an electronic module such as a camera or a sensor.

[0115] The cover window WU is placed on the display panel DP to protect the front of the display panel DP. The cover window WU may include a transparent area corresponding to the display area DA and a blocking area corresponding to the non-display area PA. The transmission area may be an optically transparent area and may transmit incident light. The blocking area may be an area having a relatively low light transmittance compared to the transmission area. The blocking area defines the shape of the transmission area, and the blocking area may surround the transmission area. The blocking area may represent a predetermined color. The blocking area may overlap with the non-display area PA of the display panel DP to prevent the non-display area PA from being recognized from the outside.

[0116] The display panel DP may be a rigid display panel or a flexible display panel. The display panel according to an embodiment is a light-emitting display panel. For example, the display panel may be an organic light-emitting display panel or a quantum dot light-emitting display panel. The middle layer of the organic light-emitting display panel may include a functional layer and a light-emitting layer, and the light-emitting layer may include an organic light-emitting material. The middle layer of the quantum dot light-emitting display panel may include quantum dots and quantum rods. According to an embodiment, it may be an inorganic light-emitting display pattern including an inorganic light-emitting diode. Hereinafter, the display panel DP will be described using an organic light-emitting display panel.

[0117] The display panel DP displays an image on the front side. The front of the display panel DP includes a display area DA and a non-display area PA. An image is displayed in the display area DA. The non-display area PA may surround the display area DA.

[0118] The display panel DP may include a plurality of pixels positioned in the display area DA. The pixel may emit light in response to an electrical signal. The light emitted by the pixel may be gathered to realize an image. A single pixel includes a pixel circuit portion including a plurality of transistors and a light emitting diode that receives current from the pixel circuit portion and emits light. The pixel circuit portion may include more capacitors. The number of transistors and capacitors included in a pixel and their connection relationship may vary in a variety of ways.

[0119] The polarizing layer POL may be located on the upper surface of the display panel DP. The polarizing layer POL may be formed to prevent light originating from the outside from being reflected from the display panel DP and recognized by the user. Here, the polarizing layer POL may be attached to the display panel DP by an adhesive layer, and in this case, the adhesive layer may be formed using the previously described inkjet printing device. The organic layer formed on the display panel DP may be formed using the previously described inkjet printing device.

[0120] In an implementation, the display panel DP may include a penetration opening area or a transparent area, and on the back of this portion, an electronic module such as a camera or a sensor may be located.

[0121] The display panel DP includes a non-display area PA extending from the display area DA, where a plurality of signal lines and pads are positioned. In the non-display area PA, a data driving unit may be positioned, and a pad portion of the non-display area PA may be electrically connected to a printed circuit board including a driving chip. An adhesive layer AD may be positioned between the polarization layer POL and the cover window WU. The adhesive layer AD may be formed using the above-mentioned inkjet printing device.

[0122] Meanwhile, the display panel DP may further include a touch sensor capable of detecting a user's touch. The touch sensor may be positioned in the front of the display panel DP and may include at least one touch electrode.

[0123] The shell member HM is placed at the bottom of the display panel DP. The shell member HM is combined with the cover window WU to form the appearance of the display device 1000. The shell member HM may include a material with relatively high rigidity. For example, the shell member HM may include a plurality of frames and / or plates made of glass, plastic, or metal. The shell member HM provides a predetermined accommodation space. The display panel DP can be accommodated in the accommodation space and protected from external impacts.

[0124] Although the embodiments have been described in detail above, the scope of the present disclosure is not limited thereto and various modifications and improvements made by those skilled in the art using the basic concept of the present disclosure defined in the appended claims are also included in the scope.

Claims

1. Inkjet printing equipment, include: a stage for supporting a substrate; as well as an inkjet head disposed above the stage and discharging a resin toward the stage, Wherein, the platform comprises: A first stage portion having a first thermal conductivity; and a second stage portion disposed around the first stage portion and surrounding at least a portion of the first stage portion, the second stage portion having a second thermal conductivity, and The second thermal conductivity is greater than the first thermal conductivity.

2. The inkjet printing device according to claim 1, in: The substrate covers all of the first stage portion and at least a portion of the second stage portion.

3. The inkjet printing device according to claim 1, in: An upper surface of the first stage portion and an upper surface of the second stage portion are coplanar.

4. The inkjet printing device according to claim 1, in: The second stage portion includes a cooling unit.

5. The inkjet printing device according to claim 1, in: The second stage portion is disposed at a corner of the first stage portion.

6. The inkjet printing device according to claim 1, in: The second stage portion is separable from the first stage portion by being movable in a vertical direction relative to the first stage portion while supporting the substrate.

7. The inkjet printing device according to claim 6, further comprising: include: The third stage portion is disposed around the first stage portion and has a third thermal conductivity higher than the first thermal conductivity.

8. The inkjet printing device according to claim 1, in: The first stage portion includes at least one of polyetheretherketone, polycarbonate, polyoxymethylene, and polypropylene.

9. The inkjet printing device according to claim 1, in: The second stage portion includes metal.

10. The inkjet printing device according to claim 1, further comprising: include: The third land portion at least partially overlaps the first land portion and has a higher thermal conductivity than the first land portion.

Images