Patent Application
20210057680
The present invention relates to a manufacturing method of a display device.
PTL 1 discloses covering, with an organic buffer layer, a foreign matter adhered to an arrangement region for a light-emitting element in a display device or the like to flatten the arrangement region before the light-emitting element is finally sealed with an inorganic sealing layer. Additionally, PTL 2 discloses covering a foreign matter with a lower inorganic sealing layer, polishing and flattening the entire surface of the lower inorganic sealing layer, and then forming an upper inorganic sealing layer on the lower inorganic sealing layer.
PTL 1: Japanese Patent Application Publication No. 2015-56335 A (published on Mar. 23, 2015)
PTL 2: Japanese Patent Application Publication No. 2014-093195 A (published on May 19, 2014)
However, PTL 1 does not take into consideration any foreign matter having a height equal to or greater than the thickness of the organic buffer layer. In a case where a foreign matter having a height equal to or greater than the thickness of the organic buffer layer is present, the coverage of the inorganic sealing layer formed on the organic buffer layer is negatively affected, leading to poor sealing. Since the light-emitting element is susceptible to moisture, oxygen, and the like, in a case where the light-emitting element comes into contact with a trace amount of moisture or oxygen, properties of the light-emitting element deteriorate, leading to problems such as reduced reliability of an apparatus finally obtained.
In addition, in the method of PTL 2, the entire lower inorganic sealing layer is polished and flattened, and thus there is a problem in that defects such as cracks may occur in the lower inorganic sealing layer or a surface of a structure beneath the lower inorganic sealing layer may be polished. In addition, in a case that the foreign matter is completely removed by polishing, the layer beneath the foreign matter may be damaged.
To solve the above problem, a manufacturing method of a display device according to an aspect of this application is a manufacturing method of a display device including a light-emitting element layer including a plurality of light-emitting elements and a sealing film covering the light-emitting element layer, the sealing film including a first flattened layer and a first inorganic sealing layer provided on the first flattened layer, the manufacturing method including a light-emitting element layer forming step of forming the light-emitting element layer, an inspection step of inspecting, after the light-emitting element layer forming step, a position and a height of a protrusion present in a formation region of the first flattened layer, including at least a foreign matter, and protruding upward from a plane at a periphery of the foreign matter, a selection step of selecting the protrusion having a height equal to or greater than a threshold value, a polishing step of polishing a portion of the protrusion having a height equal to or greater than the threshold value to make the height of the protrusion less than a thickness of the first flattened layer, a first flattened layer forming step of forming the first flattened layer to cover the protrusion polished in the polishing step, and a first inorganic sealing layer forming step of forming the first inorganic sealing layer on the first flattened layer.
According to one aspect of the present invention, the foreign matter having a height equal to or greater than the threshold value is selected, only a part of the protrusion including at least the foreign matter is polished to a height at which the part can be covered with the first flattened layer, and not the entire protrusion is polished. In other words, according to an aspect of the present invention, not the entire surface of the sealing film is polished and not all of the foreign matter is polished or removed. Thus, a manufacturing method of a display device can be provided that can suppress poor sealing before forming the first inorganic sealing layer and that can manufacture a highly reliable display device.
Hereinafter, a manufacturing method of a display device according to an embodiment of the present invention will be described in detail with reference to
Configuration and manufacturing method of display device
In a case that a flexible display device is manufactured, as illustrated in
Then, the support substrate is peeled from the resin layer 12 by irradiation with laser light or the like (S7). Then, a lower face film 10 is bonded to the lower face of the resin layer 12 (S8). Then, a layered body including the lower face film 10, the resin layer 12, the barrier layer 3, the TFT layer 4, the light-emitting element layer 5, and the sealing film 6 is partitioned into a plurality of individual pieces (S9). Then, an upper face film 39 is bonded to the obtained individual pieces (S10). Then, an electronic circuit board (for example, an IC chip and an FPC) is mounted to a portion (terminal portion TM, see
Examples of a material for the resin layer 12 include polyimide. The portion of the resin layer 12 can be replaced with a bilayer resin film (for example, a polyimide film) and an inorganic insulating film sandwiched therebetween.
The barrier layer 3 is a layer that prevents a foreign matter such as water and oxygen from entering the TFT layer 4 or the light-emitting element layer 5, and can be formed of a silicon oxide film, a silicon nitride film, or a silicon oxynitride film, or by a layered film of these films, formed by chemical vapor deposition (CVD).
The TFT layer 4 includes a semiconductor film 15, an inorganic insulating film 16 (gate insulating film) in an upper layer overlying the semiconductor film 15, gate electrodes GE and gate wiring lines GH in an upper layer overlying the inorganic insulating film 16, an inorganic insulating film 18 in an upper layer overlying the gate electrodes GE and the gate wiring lines GH, a capacitance electrode CE in an upper layer overlying the inorganic insulating film 18, an inorganic insulating film 20 in an upper layer than the capacitance wiring line CE, a source wiring line SH in an upper layer overlying the inorganic insulating film 20, and an interlayer insulating film 21 in an upper layer overlying the source wiring line SH.
The semiconductor film 15 is formed of, for example, low-temperature polysilicon (LTPS) or an oxide semiconductor (for example, an In—Ga—Zn—O-based semiconductor), and a transistor (TFT) is formed of the semiconductor film 15 and the gate electrode GE.
The gate electrodes GE, the gate wiring line GH, the capacitance electrode CE, and the source wiring line SH each is formed of a metal single layer film or a layered film of metal including at least one of, for example, aluminum (Al), tungsten (W), molybdenum (Mo), tantalum (Ta), chromium (Cr), titanium (Ti), and copper (Cu). The TFT layer 4 in
Each of the inorganic insulating films 16, 18, and 20 can be formed of, for example, a silicon oxide (SiOx) film or a silicon nitride (SiNx) film, or a layered film of these, formed using CVD. The interlayer insulating film 21 can be formed of, for example, a coatable photosensitive organic material, such as a polyimide, an acrylic, or the like.
The light-emitting element layer 5 includes an anode 22 in an upper layer overlying the interlayer insulating film 21, an anode cover film 23 having insulating properties and covering an edge of the anode 22, an electroluminescence (EL) layer 24 in an upper layer overlying the anode cover film 23, and a cathode 25 in an upper layer overlying the EL layer 24. The light-emitting element layer 5 may include a capping layer such as an organic capping layer or an inorganic capping layer in an upper layer overlying the cathode 25. The anode cover film 23 is formed by applying an organic material such as a polyimide or an acrylic resin and then by patterning the organic material by photolithography, for example.
For each subpixel, a light-emitting element ES including the anode 22 shaped like an island, the EL layer 24, and the cathode 25 (for example, an OLED: organic light emitting diode, QLED: quantum dot diode) is formed in the light-emitting element layer 5, and a subpixel circuit controlling the light-emitting element ES is formed in the TFT layer 4.
For example, the EL layers 24 are formed by layering a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer in this order, from the lower layer side. The light-emitting layer is formed into an island shape at an opening (for each subpixel) in the anode cover film 23 by vapor deposition or an ink-jet method. Other layers are formed in an island shape or a solid-like shape (common layer). A configuration is also possible in which one or more layers are not formed, out of the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer.
In a case that the light-emitting layer of the OLED is formed by vapor deposition, a fine metal mask (FMM) is used. The FMM is a sheet including a large number of openings (and made of, for example, an invar material), and an island shaped light-emitting layer (corresponding to one subpixel) is formed by an organic material passing through one opening.
For the light-emitting layer of a QLED, an island shaped light-emitting layer (corresponding to one subpixel) can be formed by ink-jet coating a solvent with quantum dots diffused into the solvent.
The anode (anode electrode) 22 is formed by layering of Indium Tin Oxide (ITO) and silver (Ag) or alloy containing Ag, for example, and have light reflectivity. The cathode (cathode electrode) 25 can be formed of a transparent conductive material such as a MgAg alloy (extremely thin film), ITO, or IZO (Indium zinc Oxide).
In a case that the light-emitting element layer ES is an OLED, a drive current between the anode 22 and the cathode 25 recombines positive holes and electrons inside the light-emitting layer to generate excitons. During transition of the excitons into a ground state, light is emitted. Since the cathode 25 is transparent and the anode 22 has light reflectivity, the light emitted from the EL layer 24 travels upward and becomes top-emitting.
In a case that the light-emitting element ES is a QLED, a drive current between the anode 22 and the cathode 25 recombines positive holes and electrons inside the light-emitting layer to generate excitons. During transition of the excitons from a conduction band of the quantum dots to a valence band of the quantum dots, light (fluorescence) is emitted.
A light-emitting element (such as an inorganic light emitting diode) other than the OLED or QLED may be formed in the light-emitting element layer 5.
The sealing film 6 is transparent, and includes an inorganic layer 26 covering the cathode 25, an organic layer 27 (an organic sealing layer) in an upper layer overlying the inorganic layer 26, and an inorganic film 28 in an upper layer overlying the organic layer 27 (see
The inorganic layer 26 and the inorganic layer 28 can be formed of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a layered film of these films, formed by CVD, for example. The organic layer 27 is a transparent organic layer having a flattening effect and can be formed of an organic material such as an acrylic resin or PI.
The organic layer 27 can be formed by, for example, ink-jet coating.
As illustrated in
The bank 41 holds back the ink used to form the organic layer 27, defining an edge of the organic layer 27. The bank 42 holds back ink that flows over the bank 41 in a case that the bank 41 fails to hold back the ink.
The inside of the bank 41 is covered with the organic layer 27, and the edge of the organic layer 27 overlaps with the bank 41. Thus, the region surrounded by the bank 41 is used as a formation region of the organic layer 27.
The bank 41 may be formed using the same material as that of the anode cover film 23 simultaneously with formation of the anode cover film 23. Additionally, the bank 42 has a two-layer structure with a lower layer and an upper layer, for example. The lower layer can be formed using the same material as that of the interlayer insulating film 21 simultaneously with formation of the interlayer insulating film 21. The upper layer may be formed using the same material as that of the anode cover film 23 simultaneously with formation of the anode cover film 23.
The lower face film 10 is a film bonded on a lower face of the resin layer 12 after the support substrate is peeled off, to provide a display device with excellent flexibility, and is, for example, a PET film. The upper face film 39 has at least one of, for example, an optical compensation function, a touch sensor function, and a protection function.
The flexible display device has been described. However, in a case that a non-flexible display device is manufactured, generally, formation of a resin layer or replacement of a base material and the like are unnecessary, and thus, for example, layering steps from S2 to S5 are performed on the glass substrate, and the process proceeds to step S9.
As illustrated in
In the lower inorganic layer forming step (S21), as illustrated in (a) of
To be provided to the inspection step (S22), the substrate on which the inorganic layer 26 is formed in the lower inorganic layer forming step (S21) is suitably transported, under an atmosphere of inert gas such as nitrogen, out from a film formation chamber used to form the inorganic layer 26. The inspection step (S22), the selection step (S23), and the polishing step (S24) are all performed under an atmosphere of inert gas such as nitrogen, and movement of the substrate between these steps and movement of the substrate after the polishing step (S24) are also performed under an atmosphere of inert gas such as nitrogen. Note that in the present embodiment, the inorganic layer 26 is formed on the surface of the substrate, and thus transport of the substrate from the film formation chamber, and the inspection step (S22) and the selection step (S23) need not necessarily be performed under an atmosphere of inert gas. However, a portion of the inorganic layer 26 is polished in the polishing step (S24), and thus the polishing step (S24) and transport of the substrate after the polishing step (S24) need to be performed under an atmosphere of inert gas such as nitrogen.
In the inspection step (S22), after the lower inorganic layer forming step (S21), the positions and heights of protrusions 62 present in a formation region of the organic layer 27 are checked, each of the protrusions including at least a foreign matter 63 and protruding upward from a plane at the periphery of the foreign matter 63. Here, inspection refers to acquiring position information and height information regarding the protrusion 62.
In the present embodiment, as described above, the foreign matter 63 is covered by the inorganic layer 26. Thus, in the present embodiment, the plane at the periphery of the foreign matter 63 means the surface of a portion of the inorganic layer 26 in which no foreign matter is present at the periphery of the foreign matter 63 (that is, the plane formed of the inorganic layer 26). In addition, in the present embodiment, the protrusion 62 refers to a portion in which the foreign matter 63 and the inorganic layer 26 covering the foreign matter protrude from the plane formed of the inorganic layer 26 at the periphery of the foreign matter 63, as illustrated in the frame box in (a) of
In the present embodiment, the protrusion 62 includes the foreign matter 63 and the inorganic layer 26 covering the foreign matter 63. As illustrated in (b) of
In the inspection step (S22), a method for inspecting the position and height d1 of the protrusion 62 is not particularly limited. Examples of the methods include a method for inspection using an automated optical inspection (AOI) device including a charge coupled device (CCD) camera.
In the selection step (S23), the protrusion 62 is selected having the height d1 of the protrusion 62, inspected in the inspection step (S22) and illustrated in (b) of
The threshold value is set to a value that is equal to or less than the thickness of the organic sealing layer (first flattened layer) resulting from the polishing step (S24).
Thus, in the present embodiment, a value equal to or less than the thickness of the organic layer 27 is set as the threshold value. In this case, the protrusion 62 whose height d1 is equal to or greater than the thickness of the organic layer 27 is selected as an object to be polished in the polishing step (S24) described below.
By setting the threshold value to a value equal to or less than the thickness of the organic layer 27, the height d1 of the protrusion 62 can be reliably set less than the thickness of the organic layer 27.
In the polishing step (S24), as illustrated in (c) and (d) of
In the present step, as illustrated in (c) of
In addition, at polishing and after polishing, a step such as air blowing or suction may be performed in order to remove debris (not illustrated) generated from the foreign matter 63 by polishing.
The amount of polishing may be an amount at which the height d1 of the protrusion 62 is less than the thickness of the organic layer 27, but the height d1 of the protrusion 62 after polishing is preferably set to be no greater than half the thickness of the organic layer 27. By setting the amount of polishing in this manner, in a case that the foreign matter 63 is present in the display region DA illustrated in
In the organic layer forming step (S25), as illustrated in (e) of
As described above, the organic layer 27 is formed, for example, by applying, by ink-jet coating or the like, ink into a region enclosed by a bank 41, and curing the ink by UV curing or the like. The ink can be made of a coatable organic material such as an acrylic resin.
In the upper inorganic layer forming step (S26), as illustrated in (f) of
The inorganic layer 26 and the inorganic layer 28 have a moisture-proof function to prevent penetration of moisture, and function as barrier layers to prevent degradation of the light-emitting element ES caused by moisture or oxygen. The organic layer 27 relieves stress on the inorganic layers 26 and 28 having high film stress, covers steps and the foreign matter 63 on the surface of the light-emitting element layer 5 for flattening, fills up pinholes, or suppresses occurrence of cracks or film peeling at the time of layering the inorganic layer 28.
The thickness of each of the inorganic layers 26 and 28 is, for example, 500 to 1500 nm. The thickness of the organic layer 27 is, for example, 5 μm or more and 15 μm or less.
According to the present embodiment, as described above, after the inorganic layer 26 is formed to cover the foreign matters 63 present in the formation region of the organic layer 27, the positions and heights of the foreign matters 63 covered by the inorganic layer 26 (in other words, the protrusions 62 including the foreign matters 63) are inspected, and the protrusion 62 having a height at which the protrusion fails to be covered by the organic layer 27 is selected and polished. At this time, in the present embodiment, only a portion of the protrusion 62 is polished down to a height at which the protrusion can be covered by the organic layer 27, and not the entire protrusion 62 is polished. Accordingly, poor sealing can be suppressed before the inorganic layer 28 is formed, and an increase in the number of foreign matters 63 and possible defects such as cracks in the inorganic layer 26 are prevented. Thus, the display device 2 having high reliability can be manufactured.
The display device 2 according to the present embodiment and a manufacturing method of the display device 2 according to the present embodiment will be described in detail with reference to
As illustrated in
As illustrated in
In the present embodiment, as illustrated in
In the present embodiment, after the lower organic layer forming step (S31), the inspection step (S22), the selection step (S23), and the polishing step (S24) are performed. Thus, in the inspection step (S22), after the lower organic layer forming step (S31), the positions and heights of the protrusions 62 present in the formation region of the organic layer 27 are inspected, each of the protrusions 62 including at least the foreign matter 63 and protruding upward from the plane at the periphery of the foreign matter 63.
In the present embodiment, the foreign matter 63 is covered by the inorganic layer 26 and the lower organic layer 27a. Thus, in the present embodiment, as illustrated in (b) of
Then, in the selection step (S23), the protrusion 62 is selected having the height d2, illustrated in (b) of
In this case, as the threshold value, a value is set that is equal to or less than the thickness of the organic sealing layer (first flattened layer) resulting from the polishing step (S24). Accordingly, in the present embodiment, the organic sealing layer is the upper organic layer 27b, and as the threshold value, a value is set that is equal to or less than the thickness of the upper organic layer 27b. Thus, in the present embodiment, the protrusion 62 the height d2 of which is equal to or greater than the thickness of the upper organic layer 27b is selected to be polished in the polishing step (S24). By setting the threshold value to a value equal to or less than the thickness of the upper organic layer 27b, the height d2 of the protrusion 62 can be reliably set less than the thickness of the upper organic layer 27b.
In the polishing step (S24), as illustrated in (c) and (d) of
In the upper organic layer forming step (S32), as illustrated in (e) of
As described above in the polishing step (S24), the height of the polished protrusion 62 is less than the thickness of the upper organic layer 27b. Thus, even in a case that, in the present step, the upper organic layer 27b is formed on the protrusion 62 remaining in the formation regions of the lower organic layer 27a and the upper organic layer 27b, the upper organic layer 27b can be formed to prevent the protrusion 62 including the foreign matter 63 from protruding from the surface of the upper organic layer 27b.
In the upper inorganic layer forming step (S26), as illustrated in (f) of
According to the present embodiment, as described above, after the inorganic layer 26 and the lower organic layer 27a are formed to cover the foreign matters 63 present in the formation region of the organic layer 27 (that is, the formation regions of the lower organic layer 27a and the upper organic layer 27b), the positions and heights of foreign matters 63 covered by the inorganic layer 26 and the lower organic layer 27a (in other words, the protrusions 62 including the foreign matters 63) are inspected, and the protrusion 62 having a height at which the protrusion fails to be covered by the upper organic layer 27b is selected, and the selected protrusion 62 is polished. At this time, in the present embodiment, only a portion of the protrusion 62 is polished down to a height at which the protrusion can be covered by the upper organic layer 27b, and not the entire protrusion 62 is polished. Accordingly, poor sealing can be suppressed before the inorganic layer 28 is formed, and an increase in the number of foreign matters 63 and possible defects such as cracks in the inorganic layer 26 are prevented. Thus, the display device 2 having high reliability can be manufactured.
A method of manufacturing the display device 2 according to the present embodiment will be described in detail below with reference to
As illustrated in
In the present embodiment, as illustrated in
Then, as illustrated in (b) of
Examples of the organic material (resin material) contained in the ink La include polyimide, acrylate, polyurea, parylene, and polyamide. Here, each droplet of the ink La contains approximately 10 pL, and the viscosity of the ink La is approximately 0.01 Pa-s. The ejection frequency of the ink La is from approximately several kHz to approximately several tens of kHz, for example. The ejection voltage of the ink La is from approximately 7 V to approximately 15 V, for example. The ejection velocity of the ink La is approximately from 8 m/s to approximately 10 m/s. Note that before the ink La is ejected, meniscus of the ink La inside the nozzle may be vibrated to facilitate ejection of the first shot. Additionally, the viscosity of the ink La (e.g., 0.02 Pa-s) may be set higher than the viscosity of ink Lb described below (e.g., 0.01 Pa-s) to reliably place the ink La on the foreign matter 63. In addition, the ejection velocity of the ink La (e.g., 10 m/s) may be set higher than the ejection velocity of the ink Lb described below (e.g., 8 m/s) to reliably place the ink La on the foreign matter 63. The ink La and the ink Lb are made of the same organic material (a resin material, but the inks La and Lb may have different viscosities as described above), but may be made of different organic materials (different resin materials).
Subsequently, the second inspection step (S43) is performed similarly to the first inspection step (S41) using, for example, AOI or the like. In the second inspection step (S43), the foreign matter 63 is covered by the inorganic layer 26 and the spot coating layer 27c. In the second inspection step (S43), after the spot coating layer forming step (S42), the positions and heights of protrusions 62′ present in the formation region of the organic layer 27 are inspected, each of the protrusions 62′ including at least the foreign matter 63 and protruding upward from the plane at the periphery of the foreign matter 63. Here, as illustrated in (c) of
Then, in the selection step (S23), the protrusions 62′ is selected having the height d3 inspected in the second inspection step (S23) and illustrated in (b) of
In a polishing step (S24), as illustrated in (d) of
In the organic layer forming step (S25), as illustrated in (e) of
As described in the polishing step (S24) described above, the height of the polished protrusion 62′ is less than the thickness of the organic layer 27. Thus, even in a case that, in the present step, the organic layer 27 is formed on the protrusion 62′ remaining in the formation region of the organic layer 27, the organic layer 27 can be formed to prevent the protrusion 62′ from protruding from the plane of the organic layer 27.
In the upper inorganic layer forming step (S26), as illustrated in (g) of
According to the present embodiment, the same effects as those of the first embodiment can be produced, and as described above, before the polishing step (S24), the ink La is locally applied to cover the protrusion 62 and form the spot coating layer 27c. This allows mitigation of damage (stress relief) to the underlayer of the polished protrusion 62′ in the polishing step (S24).
Note that in the organic material coating step, the surfaces of all of the protrusions 62 may be covered by the ink La regardless of the height d1 of each of the protrusions 62 inspected in the first inspection step S27 and that, after the first inspection step (S27), a selection step similar to the selection step (S23) may be performed, and the surface of the protrusion 62 having a height equal to or greater than the threshold value (second threshold) may be covered by the ink La. Here, the second threshold value may be a value less than the first threshold value or may be the same value as the first threshold.
In addition, in the case described above in the present embodiment as an example, the selection step (S23) is performed after the second inspection step (S43). However, in a case that the selection step is performed after the first inspection step (S27), then in the polishing step (S24), for example, the protrusion 62′ is polished in consideration of the height of the spot coating layer 27c resulting from the selection step, thus allowing omission of the second inspection step (S43) and the selection step following the second inspection step (S43). Thus, the selection step (S23) may be performed after the first inspection step (S41) and before the spot coating layer forming step (S42).
In addition, in the case described above in the present embodiment as an example, as illustrated in
The manufacturing method of the display device 2 according to the present embodiment will be described in detail below with reference to
In the present embodiment, as illustrated in
In the present embodiment, before the sealing film 6 is formed, the substrate on which the light-emitting element layer 5 is formed is transported out from the film forming chamber in order to be subjected to the inspection step (S22). Thus, with a capping layer (not illustrated) formed in an upper layer overlying the cathode 25, the substrate is transported out from a film formation chamber used to form the inorganic layer 26 under an atmosphere of inert gas such as nitrogen. In addition, the inspection step (S22), the selection step (S23), and the polishing step (S24) are all performed in an inert gas atmosphere such as nitrogen, and the movement of the substrate between the steps and the movement of the substrate after the polishing step (S24) is also performed under an inert gas atmosphere such as nitrogen.
In the present embodiment, after the light-emitting element layer forming step (S4), the inspection step (S22), the selection step (S23), and the polishing step (S24) are performed. Thus, in the inspection step (S22), after the light-emitting element layer forming step (S4), the positions and heights of the protrusions 62 present in the formation region of the organic layer 27 are inspected, each of the protrusions 62 including at least the foreign matter 63 and protruding upward from the plane at the periphery of the foreign matter 63.
Accordingly, in the present embodiment, as illustrated in (a) of
Note that, in (a) of
In a case that a portion of the foreign matter 63 is buried in the capping layer, the plane formed of the light-emitting element layer 5 at the periphery of the foreign matter 63 is formed of the capping layer, and the protrusion 62 is a portion protruding upward from the capping layer.
The following describes a case as an example in which, as illustrated in (a) of
Then, in the selection step (S23), the foreign matter 63 is selected having the height d4 of the foreign matter 63, illustrated in (b) of
In the polishing step (S24), as illustrated in (c) of
In the present embodiment, after the polishing step (S24), the sealing film forming step (S5) is performed. Thus, in the present embodiment, after the polishing step (S24), the inorganic layer 26, the organic layer 27, and the inorganic layer 28 are formed in this order as is the case with the first embodiment, as illustrated in (d) to (f) of
According to the present embodiment, as described above, for example, the positions and heights d4 of the foreign matters 63 present in the formation region of the organic layer 27 are inspected as the positions and heights of the protrusions 62, and the foreign matter 63 having a height at which the foreign matter 63 fails to be covered by the organic layer 27 is selected and polished. At this time, in the present embodiment, only a portion of the foreign matter 63 is polished down to a height at which the foreign matter 63 can be covered by the organic layer 27, and not the entire foreign matter 63 is polished. Accordingly, poor sealing can be suppressed before the inorganic layer 28 is formed, and an increase in the number of foreign matters 63 and possible defects such as cracks in the inorganic layer 26 are prevented. Thus, the display device 2 having high reliability can be manufactured.
A manufacturing method of the display device 2 according to the present embodiment will be described in detail below with reference to
The display device 2 does not necessarily require the inorganic layer 26. Thus, as illustrated in
In the present embodiment, as illustrated in
Steps illustrated in (a) to (c) of
Accordingly, also in the present embodiment, for example, only a portion of the foreign matter 63 is polished down to a height at which the foreign matter 63 can be covered by the organic layer 27, and not the entire foreign matter 63 is polished, as in the fourth embodiment. Accordingly, poor sealing can be suppressed before the inorganic layer 28 is formed, and an increase in the number of foreign matters 63 and possible defects such as cracks in the inorganic layer 26 are prevented. Thus, the display device 2 having high reliability can be manufactured.
Note that, in the present embodiment, a description has been given of the differences between the present embodiment and the fourth embodiment in the production of the display device 2 illustrated in
A manufacturing method of a display device according to an aspect of the present invention is a manufacturing method of a display device including a light-emitting element layer including a plurality of light-emitting elements and a sealing film covering the light-emitting element layer, the sealing film including a first flattened layer and a first inorganic sealing layer provided on the first flattened layer, the manufacturing method including a light-emitting element layer forming step of forming the light-emitting element layer, an inspection step of inspecting, after the light-emitting element layer forming step, a position and a height of a protrusion present in a formation region of the first flattened layer, including at least a foreign matter, and protruding upward from a plane at a periphery of the foreign matter, a selection step of selecting the protrusion having a height equal to or greater than a threshold value, a polishing step of polishing a portion of the protrusion having a height equal to or greater than the threshold value to make the height of the protrusion less than a thickness of the first flattened layer, a first flattened layer forming step of forming the first flattened layer to cover the protrusion polished in the polishing step, and a first inorganic sealing layer forming step of forming the first inorganic sealing layer on the first flattened layer.
According to this method, only a portion of the protrusion is polished down to a height at which the protrusion can be covered by the first flattened layer, and not the entire protrusion is polished. Thus, a manufacturing method of a display device can be provided that can suppress poor sealing before forming the first inorganic sealing layer and that can manufacture a highly reliable display device.
In the manufacturing method of a display device described above, the threshold value may be a value equal to or less than the thickness of the first flattened layer.
According to the method described above, the height of the protrusion can be reliably set less than the thickness of the first flattened layer.
In the manufacturing method of a display device, the sealing film may further include a sealing layer provided in a lower layer than the first flattened layer and having a thickness that is less than a height of the foreign matter, the protrusion may be a portion protruding upward from the sealing layer, the manufacturing method may further include a sealing layer forming step of forming the sealing layer before the inspection step, and in the polishing step, a portion of the protrusion protruding upward from the sealing layer may be polished.
According to the method described above, a display device including three layers of a sealing layer, a first flattened layer, and a first inorganic sealing layer can be manufactured without causing defects on the inorganic sealing film.
In the manufacturing method of a display device, the sealing layer may be a second inorganic sealing layer.
In the manufacturing method of a display device, the sealing layer may be a second flattened layer.
In the manufacturing method of a display device, the sealing film may further include a second inorganic sealing layer provided in a lower layer than the first flattened layer and having a thickness less than the height of the foreign matter, the manufacturing method may further include, between the polishing step and the first flattened layer forming step, a second inorganic sealing layer forming step of forming the second inorganic sealing layer to cover the protrusion polished in the polishing step, and in the first flattened layer forming step, the first flattened layer may be formed to cover the protrusion polished in the polishing step and the second inorganic sealing layer formed on the protrusion.
The manufacturing method of a display device may further include an organic material applying step of locally applying, before the polishing step, an organic material to cover the protrusion.
In the manufacturing method of a display device, the organic material may include polyimide.
The present invention is not limited to each of the embodiments described above, and various modifications may be made within the scope of the claims. Embodiments obtained by appropriately combining technical approaches disclosed in each of the different embodiments also fall within the technical scope of the present invention. Moreover, novel technical features can be formed by combining the technical approaches disclosed in the embodiments.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2018/013829 | 3/30/2018 | WO | 00 |
