KR102631679B1 - Fine patterning method - Google Patents

Abstract

The present invention relates to a fine patterning method, and more specifically, to form a fine pattern area for pixels of an OLED display without a FMM (Fine Metal Mask) by dividing the process in a non-vacuum state and the process in a vacuum state. It relates to a fine patterning method.
The micro-patterning method according to an embodiment of the present invention includes forming a plurality of first electrodes on a substrate, and forming a plurality of first electrodes on the substrate using expandable water using ultraviolet rays (UV) or/and heat to cover the plurality of first electrodes. A laminate manufacturing step of manufacturing a laminate by forming a ground layer and forming a release layer on the resin layer; And after placing the mask on the laminate in a vacuum, the ultraviolet rays and/or the heat are applied to remove the first electrode of the resin layer located between the first electrode of any one of the plurality of first electrodes and the opening area of the mask. It includes a vacuum patterning step of expanding one part and removing the expanded first part of the resin layer to form a first pattern area.

Description

Fine patterning method {FINE PATTERNING METHOD}

The present invention relates to a fine patterning method, and more specifically, to form a fine pattern area for pixels of an OLED display without a FMM (Fine Metal Mask) by dividing the process in a non-vacuum state and the process in a vacuum state. It relates to a fine patterning method.

Display devices using organic layers use organic photovoltaic cells (OPV), organic photodetectors (OPD), organic thin-film transistors (OTFT), and organic light-emitting diodes (OLED).

The conventional manufacturing method of a display device using an organic layer has many problems in patterning technology, especially patterning technology using FMM (Fine Metal Mask).

In general, in OLED displays, pixels are formed by applying heat to the OLED material in a vacuum deposition equipment to sublimate and vaporize it, and then selectively depositing it using a FMM (Fine Metal Mask).

However, the low material usage rate and the use of expensive equipment increased the production cost, and the shadow effect and FMM sagging that occur as gaseous organic matter passes through the FMM became an obstacle to implementing ultra-high resolution displays of 8K or higher in the future. .

The current display industry is focusing on producing premium ultra-high-resolution OLED (Organic Light-Emitting Diode) displays of 8K or higher. In order to improve the resolution of the display, the number of pixels mounted in the same area must be increased, and to do this, RGB sub The area occupied by pixels must be made small.

Currently, the FMM method is mainly used as a commercialized pixel patterning technology in OLED. This places a thin metal shadow mask under the substrate in a vacuum chamber, and allows the organic light emitting layer (EML) of the desired color to be deposited only on the open areas of the mask.

Therefore, in order to manufacture an ultra-high resolution display using the FMM method, there is a problem that the metal mask pattern must be manufactured extremely precisely. Additionally, in order to eliminate the shadow effect caused by the mask thickness, there is a problem that the thickness of the metal plate must be thinner than the size of the pixel. Furthermore, the thin mask thickness reduces its weight, which causes a mask sagging phenomenon in which the mask sags due to gravity.

Since manufacturing such a metal mask is not technically easy and there are cost issues, the ultra-high-resolution OLED manufacturing method using FMM still has limitations. Considering this, a new methodology is being proposed to overcome the limitations of the existing FMM method in order to pattern smaller pixels. One of them is the introduction of the semiconductor photolithography process. This is a method of solving the challenges of next-generation high-resolution displays by using fine patterning using photo resist, which has been mainly used in semiconductors.

Korean Patent Publication No. 10-2018-0021002 relates to a high-resolution patterning method of an organic layer and discloses a method of forming OLED pixels using photoresist. However, most materials used in OLED structures are very sensitive to various environmental factors such as air, moisture, and solvents, so their use is very limited depending on the manufacturing process.

For this reason, Republic of Korea Patent Publication No. 10-2018-0021002 forms a water-soluble shielding layer and a hydrophobic protective layer on the organic layer to block air and moisture, thereby blocking elements sensitive to organic materials. However, because the water-soluble shielding layer, hydrophobic protective layer, and photoresist layer formation processes are repeated to form the RGB OLED subpixel, each process repeats the fab line and vacuum line. As the process progresses, the production process becomes more complex, and the organic layer is exposed to air, moisture, and solvents, as well as lowering productivity.

Republic of Korea Patent Publication No. 10-2018-0021002

The present invention was conceived in consideration of the above-mentioned problems, and the purpose of the present invention is to divide the process in a non-vacuum state and the process in a vacuum state to form a fine pattern area for pixels of an OLED display without FMM. To provide a fine patterning method.

Furthermore, the purpose of the present invention is to provide an improved process that does not repeatedly go back and forth between the Fab. Line process in a non-vacuum state and the Vacuum Chamber line process in a vacuum state, and the fundamental elimination of FMM. The goal is to provide a fine patterning method that can achieve technical effects such as increasing efficiency, reducing manufacturing costs, and improving manufacturing yield.

In addition, the purpose of the present invention is to mask with a resin layer expandable by UV or/and heat with a thickness of 1 to 10 um when depositing an organic material in the light emitting layer (EML), thereby eliminating shadow effects, mask sagging, and alignment issues. The goal is to provide a fine patterning method that can improve product reliability by fundamentally blocking problematic phenomena.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned can be clearly understood by those skilled in the art from the description below. will be.

The micro-patterning method according to an embodiment of the present invention includes forming a plurality of first electrodes on a substrate, and forming a plurality of first electrodes on the substrate using expandable water using ultraviolet rays (UV) or/and heat to cover the plurality of first electrodes. A laminate manufacturing step of manufacturing a laminate by forming a ground layer and forming a release layer on the resin layer; And after placing the mask on the laminate in a vacuum, the ultraviolet rays and/or the heat are applied to remove the first electrode of the resin layer located between the first electrode of any one of the plurality of first electrodes and the opening area of the mask. It includes a vacuum patterning step of expanding one part and removing the expanded first part of the resin layer to form a first pattern area.

Here, the vacuum patterning step sequentially forms a first organic layer stack and a second electrode on the laminate on which the first pattern region is formed, and the first pattern region is formed among the first organic layer stack and the second electrode. The excess first organic layer stack and second electrode disposed outside can be removed.

Here, in the vacuum patterning step, a release layer is formed on the laminate from which the excess first organic layer stack and the second electrode are removed, the mask is placed on the laminate, and then the ultraviolet rays and/and the Heat is applied to expand the second portion of the resin layer located between the first electrode of another one of the plurality of first electrodes and the opening area of the mask, and the expanded second portion of the resin layer is removed to form a second portion. After forming a pattern region and sequentially forming a second organic layer stack and the second electrode on the laminate on which the second pattern region is formed, the first and second electrodes are formed among the second organic layer stack and the second electrode. 2 The excess second organic layer stack and second electrode disposed outside the pattern area can be removed.

Here, in the vacuum patterning step, a release layer is formed on the laminate from which the excess second organic layer stack and the second electrode are removed, the mask is placed on the laminate, and then the ultraviolet rays and/and the Heat is applied to expand the third portion of the resin layer located between another first electrode among the plurality of first electrodes and the opening area of the mask, and the expanded third portion of the resin layer is removed to form a third portion. After forming three pattern regions and sequentially forming a third organic layer stack and the second electrode on the laminate on which the third pattern region is formed, the first to the first to the second electrodes among the third organic layer stack and the second electrode 3 The excess third organic layer stack and second electrode disposed outside the pattern area can be removed.

Here, the vacuum patterning step removes the release layer on the first subpixel, the release layer on the second subpixel, the release layer formed in the laminate manufacturing step, and the resin layer remaining on the substrate to form the first to A third subpixel may be formed.

Here, the release layer and the resin layer can be removed using a liftoff or dry etching method.

Here, the laminate manufacturing step may be performed in a non-vacuum state.

Here, the patterning step may be performed in a vacuum chamber.

Here, the resin layer may be a resin mixed with a base resin, an organic solvent, and a photoactivator.

Here, the resin layer may be dry patterning resin.

The pixel structure according to another embodiment of the present invention is a pixel structure of an OLED display manufactured by the fine patterning method described above.

According to the fine patterning method according to the present invention, it is possible to form a fine pattern area for pixels of an OLED display without FMM by dividing the process in a non-vacuum state and the process in a vacuum state. Then, a fine pattern area can be formed using the photoactivity and expandability of the expandable resin layer, and each RGB OLED pixel can be formed in the formed fine pattern area.

In addition, according to the fine patterning method according to the present invention, an improved process and FMM that do not repeatedly go back and forth between the Fab. Line process in a non-vacuum state and the Vacuum Chamber line process in a vacuum state It has technical effects such as increasing process efficiency, reducing manufacturing costs, and improving manufacturing yield by fundamentally eliminating .

Furthermore, when depositing an organic material on the light emitting layer (EML), it is masked with an expandable resin layer with a thickness of 1 to 10 μm, thereby fundamentally blocking phenomena such as shadow effect, mask sagging, and alignment issue, thereby improving product reliability.

The effects of the present invention are not limited to the effects described above, and may be expanded in various ways without departing from the spirit of the present invention.

Figure 1 is a schematic diagram showing the expansion of a resin layer and the formation of a fine pattern area by UV irradiation and heating to explain the concept of the present invention.
FIG. 2 is a graph of the expansion ratio according to the photoactive agent content in the expandable resin layer shown in FIG. 1 and a graph of the expansion ratio due to heat.
Figure 3 is a schematic diagram of a micro-patterning system according to the present invention.
Figure 4 is a flow chart showing the first line process of the fine patterning method according to the present invention.
Figure 5 is a flow chart showing the second line process of the fine patterning method according to the present invention.
6 to 10 are schematic diagrams for explaining the fine patterning method according to the present invention.
Figure 11 is a photograph of the expansion of an expandable resin layer formed by the micro-patterning method according to the present invention.
Figure 12 is a patterning photograph of an expandable resin layer formed by the micro-patterning method according to the present invention.

In the description of the present invention, in the case where each component is described as being formed "on top or bottom", the top or bottom means that the two components are directly connected to each other. This includes anything formed by contact or by placing one or more other components between two components.

In addition, when expressed as "top (above) or bottom (bottom)", it may include not only the upward direction but also the downward direction based on one component.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Additionally, the size of each component does not entirely reflect the actual size.

The chip, RGB OLED pixel, and RGB OLED subpixel used in the following description of the present invention may be defined as follows.

Chips are a concept that includes RGB chips, R chips, G chips, B chips, Mini OLED chips, and Micro OLED chips.

RGB OLED pixel refers to one OLED pixel defined as Red OLED, Green OLED, and Blue OLED as one pixel unit.

RGB OLED subpixel refers to one OLED subpixel defined as one subpixel unit for each of Red OLED, Green OLED, and Blue OLED.

1 is a schematic diagram showing the expansion of an expandable resin layer and the formation of a fine pattern by UV irradiation or/and heating to explain the concept of the present invention.

The present invention utilizes the deterioration characteristics and expandability of an expandable resin layer. The expandable resin layer is a mixture of base resin, organic solvent, and photoactivator. A photoreaction occurs and acid is generated by UV irradiation, and only the UV irradiated area expands. It can be defined as:

When the base resin is irradiated with UV light, a photo reaction occurs in the internal Novolak Resin and the photoactivator, generating acid. This acid is in a liquid state and is exposed to UV when the wafer is placed on a hot plate and temperature is applied. Expansion occurs only in the irradiated area. In other words, expansion occurs when the volume of liquid acid trapped inside the expandable resin layer rapidly increases due to heat. The expansion of the base resin enables fine patterning to form OLED subpixels.

The expandable resin layer of the present invention can be made of a transfer resin mixed with a base resin, an organic solvent, and a photoactivator.

The base resin may be one of phenol resin, epoxy resin, UV resin, polyester resin, polyurethane resin, or acrylic resin, or a mixture of two or more resins. Among phenol resins, novolak resin may be preferably used.

The organic solvent (solvent) may be selected from one or more of alcohols, petroleum-based substances, aromatic solvents, ketones, glycol ethers, acetates, or DMCs, and preferably acetate, acetone, or PGMEA.

Photoactivator refers to a substance in a comprehensive sense that refers to any one of a photo acid generator (PAG), a photo active compound (PAC), a photoinitiator, a photosensitive compound, or a photoactive compound. The photoactivator may be an Oxime-ester, s-Triazine, or Phosphineoxide-based photoinitiator, and a PAC material composed of one or more of these may be used, preferably 2-diazo-1 among the ester-based materials. Ester compounds of -naphthone-5-sulfonic acid chloride can be applied.

The expandable resin layer may be dry patterning resin (DPR).

Referring to (A) of FIG. 1, a first electrode 103 is formed on a substrate 101, an expandable resin layer 105 is applied to cover the first electrode 103, and the expandable resin layer is A release layer (107) is formed on the upper surface of (105). Afterwards, the mask 109 is placed and UV is irradiated. The substrate 101 may be a TFT (Thin Film Transistor) substrate, but is not limited thereto. The release layer 107 may also be called an Easy Peeling Layer (EPL).

Next, referring to (B) of FIG. 1, some areas of the expandable resin layer 105 that are irradiated with UV expand, and other areas of the expandable resin layer 105 that are not irradiated with UV do not expand. .

That is, the UV irradiation area varies depending on the pattern of the mask 109, and some areas of the expandable resin layer 105 irradiated with UV expand upward.

Next, referring to (C) of FIG. 1, some expanded areas of the expandable resin layer 105 are removed, and the removed areas become pattern areas 125 in which RGB OLED (sub) pixels are to be formed. Specifically, some expanded areas of the expandable resin layer 105 may be removed using a lift-off method.

Lift-off is a nickname for the photoresist pattern used as an etch mask to form a specific pattern. Instead of removing the photoresist pattern, it forms a material layer on the entire surface including the photoresist pattern and then removes the photoresist pattern from the substrate. This refers to a method in which the material layer formed on the photoresist pattern is removed together to form a predetermined pattern. In the present invention, the expandable resin layer pattern can be formed in the same manner by applying the expandable resin layer pattern as a photoresist pattern.

Meanwhile, in relation to the expansion of the expandable resin layer 105, various methods of applying heat, such as a hot plate, an infrared lamp, or a laser, can be used.

FIG. 2 is a graph of the expansion ratio according to the photoactive agent content in the expandable resin layer 105 shown in FIG. 1 and a graph of the expansion ratio due to heat. Specifically, Figure 2 (A) is a graph showing the results of experimentally verifying the photoactive agent content and expansion ratio in the expandable resin layer, and Figure 2 (B) is a graph showing the results of experimentally verifying the photoactive agent content and expansion ratio in the expandable resin layer. This is a graph showing the expansion ratio.

First, referring to (A) of Figure 2, when the PAC content is 4 to 6 wt%, it can be seen that the slope value is steep, and it has an expansion power of the maximum efficiency according to the PAC content within that range. You can. As a result, it can be confirmed that when the PAC content is 4 to 6 wt%, the expansion ratio of the expandable resin layer is 1.8 to 5.6 times.

When the PAC content is 10wt% or more, the expansion ratio appears to converge to 6.0 times. Looking at the expansion ratio alone, there is no significant difference in the expansion ratio above 6wt%, but if the PAC content is increased to 6wt% or more, for example, 12.7wt%, the defect rate increases as a result. can result in a significant reduction. This reduction in defect rate is because the higher the PAC content, the greater the density (or density) of the expandable resin layer, and this can be confirmed through repeated experiments.

The expandable resin layer of the present invention may further include a solvent (acetone), including 30 to 35% by weight of the base resin, 45 to 50% by weight of the organic solvent, 5 to 10% by weight of the solvent, and 10 to 10% by weight of the photoactivator. It can be prepared by mixing 15% by weight.

The expandable resin layer of the present invention may further include a filler that can increase the rigidity of the resin, and may further include ultrapure water (DI Water) that plays an auxiliary role in improving foaming performance.

At this time, the filler may be selected from the SiOF series, SiOF2 series, SiOF3 series, etc. In a preferred embodiment, a SiOF3 series filler with a size of 3㎛ can be used.

Additionally, the expandable resin layer may include 0.1 wt% to 10 wt% of filler and 0.1 wt% to 10 wt% of ultrapure water.

Referring to (B) of FIG. 2, the expandable resin layer expands above a predetermined temperature, and the expansion rate of the expandable resin layer has a maximum value at a specific heating temperature. After expansion of the expandable resin layer, the expansion rate does not increase even if a higher temperature is applied.

In other words, it can be confirmed that expansion of the expandable resin layer occurs above a predetermined temperature, has a maximum expansion ratio at a specific temperature, and does not re-expand even if a higher temperature is applied beyond the specific temperature.

The inventor of the present invention confirmed the predetermined temperature value for causing expansion of at least a portion of the expandable resin layer and the specific temperature value at which maximum expansion was achieved through repeated experiments. However, since the present invention uses only the expansion properties of the expandable resin layer, the specific temperature value obtained through repeated experiments is not disclosed.

Figure 3 is a schematic diagram of a micro-patterning system according to the present invention. As shown in Figure 3, the fine patterning system according to the present invention includes a first line and a second line.

The first line L1 corresponds to a fab line (Fab. (Fabrication) Line) and may include one or more devices (depositor, etcher, etc.) for performing processes such as deposition and etching. The second line (L2) is a vacuum chamber line, which includes one or more devices (depositor, etcher, etc.) for performing processes such as deposition and etching, and a vacuum chamber that accommodates them and maintains a vacuum state. More may be included.

The first line L1 forms a first electrode on the substrate 501, forms an expandable resin layer 505 on the substrate 501 on which the first electrode is formed, and then forms the expandable resin layer 505. A release layer 507 is formed on it. The specific materials of the expandable resin layer 505 and the release layer 507 are as described above. Here, the first electrode may be an anode electrode.

The first line (L1) performs a single resin layer coating on the substrate 501. At this time, single resin layer coating means coating the resin layer on the substrate 501 only once, and the present invention forms a plurality of RGB OLED subpixels (900R, 900G, 900B) on the substrate 501. Therefore, only one resin layer coating is required.

The release layer 507 in the first line L1 may be formed by either coating or deposition (wet or dry), but coating may be preferably used.

The stack of the substrate 501, the expandable resin layer 505, and the release layer 507 manufactured through the first line (L1) enters the second line (L2). The second line L2 performs a process of selectively removing one or more partial regions of the expandable resin layer 505 coated on the substrate 501. This is a process to form a space where RGB OLED subpixels will be formed.

Specifically, in the second line L2, a mask corresponding to one or more regions of the substrate 501 is disposed and UV or/and heat is applied to expand one or more regions of the expandable resin layer 505. Thereafter, a portion of the expanded area of the expandable resin layer 505 is removed to form a pattern area in which one of the RGB OLED subpixels will be disposed. This is the same as described with reference to FIG. 1.

The second line L2 stacks an organic layer stack on the substrate 501 on which the expandable resin layer 505, the release layer 507, and the pattern area are formed, and forms a second electrode on the organic layer stack. At this time, the organic layer stack and the second electrode may be stacked only in the pattern area, but may also be stacked in areas outside the pattern area. Accordingly, the second line L2 removes the excess organic layer stack and second electrode present in the remaining area except for the organic layer stack and second electrode present in the pattern area. In other words, the remaining organic layer stack material and second electrode material are removed. Thereby, the first OLED subpixel is formed. Here, the second electrode may be a cathode electrode.

Again, to form the second OLED subpixel, the second line L2 deposits the release layer 507 again on the first OLED subpixel, that is, on the second electrode in the pattern area, and then deposits the release layer 507 on the substrate ( Place the corresponding mask in another area of 501). At this time, deposition of the release layer 507 may be performed on the entire substrate including the expandable resin layer 505, the release layer 507, and the organic layer stack. The other area corresponds to the area where the second OLED subpixel will be formed. Then, a second OLED subpixel is formed in the corresponding pattern area through the same process as described above. At this time, the release layer 507 can be deposited by dry deposition because the second line L2 is a vacuum chamber line.

After the above-described process of the second line L2 is repeated to form a plurality of RGB OLED subpixel arrays, the remaining expandable resin layer 505 is finally removed to form RGB OLED subpixels 900R, 900G, and 900B. It can be formed on this substrate 501.

The above-described patterning method utilizes the expandability of the expandable resin layer 505, making it easy to form fine patterns, and the second line L2 maintains a vacuum state, so organic compounds sensitive to air, moisture, and solvents (organic layer) ) can be easily formed.

Accordingly, the present invention can solve the problems caused by the existing FMM (Fine Metal Mask) method, and when using a PR mask, there is no need to form a special layer to block air, moisture, solvents, etc., and the OLED pixel is processed through a simple process. Manufacturing is possible. In addition, since only one resin layer coating (single resin layer coating) is used, Fab. There is no need to go back and forth between the Line and Vacuum Chamber Line. Therefore, Fab. By repeating the Line and Vacuum Chamber Line, the defective rate of organic layer formation due to exposure to air, moisture, and solvents can be minimized.

4 and 5 are flow charts showing the fine patterning method according to the present invention. Specifically, Figure 4 is a flow chart showing the first line process of the fine patterning method according to the present invention, and Figure 5 is a flow chart showing the second line process of the fine patterning method according to the present invention.

First, each step of the first line process is Fab. It is performed on Line. Referring to the first line process shown in FIG. 4, first, a substrate is provided (S220). Afterwards, a first electrode is formed on the substrate (S230), and an expandable resin layer is coated on the substrate on which the first electrode is formed (S240). Afterwards, a release layer is formed on the expandable resin layer by coating or deposition (S250). At this time, the resin layer coating on the substrate is Fab. It only happens once in Line.

Thereafter, referring to the second line process shown in FIG. 5, when the laminate (or laminate) of the substrate, the expandable resin layer, and the release layer enters the second line process, which is a vacuum chamber line, any one of the substrates After placing the mask corresponding to the area (S310), UV or/and heat is applied to expand the expandable resin layer present in the area (S320). The expandable resin layer is a mixture of base resin, organic solvent, and photoactivator and has deterioration characteristics and expansion properties. In other words, a photoreaction occurs and acid is generated by UV irradiation, and only the UV irradiated area has the characteristic of expanding.

Thereafter, a portion of the expanded area of the expandable resin layer is removed (S330) to form a pattern area in which one of the RGB OLED subpixels will be placed (S340). Removal of the partially expanded area may be performed by lift-off or dry etching, but is not limited thereto.

Some areas removed from the expandable resin layer are spaces where organic layer stacks for pixels or subpixels of the OLED display are laminated, so the size, shape, and volume of the removed area depend on the size, shape, and volume of the pixels or subpixels. can be decided.

Afterwards, an organic layer stack is stacked on the pattern area (S350), and a second electrode is formed on it (S360).

Each subpixel consists of a second electrode for injecting electrons, a first electrode for injecting holes, and an organic layer formed between the two electrodes. The organic layer includes a hole injection layer (HIL), a hole transport layer (HTL), an electron injection layer (EIL), an electron transport layer (ETL), and an emitting layer (EML). ) may include. Here, the light emitting layer (EML) may include a red light emitting layer (Red EML) that generates red light, a green light emitting layer (Green EML) that generates green light, and a blue light emitting layer (Blue EML) that generates blue light.

In the second line process, the mask may be arranged so that the opening area (or open area) overlaps the first electrode on the substrate. Accordingly, when a portion of the expandable resin layer is removed, the first electrode is exposed, an organic layer stack is laminated on the first electrode, and then a second electrode is formed thereon. By this process, the organic layer stack can be positioned between the second electrode and the first electrode.

Meanwhile, each material forming the organic layer stack and the second electrode can be deposited only in the pattern area. In another embodiment, considering that it is not easy to achieve deposition only in a specific area of the microstructure, the organic layer stack and the second electrode forming material are deposited over an area larger than the pattern area, and then the excess organic layer and the second electrode forming material present outside the pattern area are deposited. The excess second electrode is removed (S370).

Afterwards, since the expansion and removal process of the expandable resin layer must be performed again through mask placement, the release layer is reformed in the pattern area (S380). By depositing the release layer over the entire structure on the substrate, the release layer can be formed up to the pattern area. At this time, since the second line process is performed in a vacuum chamber, reformation of the release layer is performed by dry deposition.

When the release layer is reformed, steps S310 to S370 are repeated again. At this time, in step S350, the organic layer stack for the R OLED subpixel, the organic layer stack for the G OLED subpixel, and the organic layer stack for the B OLED subpixel may be formed alternately.

When the desired number of RGB OLED subpixel arrays is finally formed, the remaining expandable resin layer is removed.

6 to 10 are schematic diagrams for explaining the fine patterning method according to the present invention. First, Figure 6 is a schematic diagram for explaining the basic process (pre-process) of the fine patterning method according to the present invention. Referring to Figure 6, the basic process (pre-process) is Fab. It is performed on Line.

First, a plurality of first electrodes 503 to form RGB OLED subpixels are formed on the substrate 501 (A1).

The substrate 501 may be a TFT (Thin Film Transistor) substrate, and depending on the type of channel (type of active layer), any of a-si TFT, Oxide TFT, and LTPS TFT may be used, and further any substrate known to those skilled in the art may be used. It may be any other suitable substrate.

The organic layer of each subpixel may include a second electrode (cathode electrode) that injects electrons, a first electrode (anode electrode) that injects holes, and an organic layer formed between the two electrodes.

The first electrode 503 may be formed of a transparent conductive material such as indium tin oxide (ITO), and the second electrode to be formed in a later process may be formed of a conductive metal material that reflects light.

After step A1, an expandable resin layer 505 is applied to cover the substrate 501 and the plurality of first electrodes 503 (B1).

The expandable resin layer 505 can be spin coated and then subjected to a soft baking step.

After step B1, a release layer 507 is formed on the expandable resin layer 505 (C1).

In the process of forming the RGB OLED subpixel (and pixel) of the release layer 507, the organic layers remaining on the top of the release layer 507 can be removed through a lift-off process or dry etching.

According to this basic process (pre-process), the patterning and formation process of RGB OLED sub-pixels (or RGB OLED pixels) can be prepared, and all processing processes in the pre-process are performed before the organic layer is formed, so it is possible to prepare a typical Fab. It can be done on Line.

Figure 7 shows the pattern and formation process diagram of the R OLED subpixel on the middle pixel process (post-process) in the fine patterning method according to the present invention.

Referring to Figure 7, the pixel process (post process) is Fab of Figure 6. After the basic process (pre-process) is performed on the line, it can be performed in the vacuum chamber line.

First, at a predetermined location on the upper part of the laminate including the substrate 501, a plurality of first electrodes 503, the expandable resin layer 505, and the release layer 507 formed in the basic process (pre-process) of FIG. Position the mask 509, irradiate UV, and apply heat (A2). Here, the opening area of the mask 509 may overlap with at least one first electrode among the plurality of first electrodes 503.

At this time, the exposed area of the resin layer 505 exposed by UV expands to form the exposed/expanded area 601. Since there is no expansion in the unexposed area, the expandable resin layer 505 maintains its original state.

The unexposed area of the expandable resin layer 505 is then used as is when forming the pattern of the G and B OLED subpixels, and is used to form the pattern of the RGB OLED subpixel by forming the resin layer 505 once in the first line. This can be performed sequentially.

Here, the expandable resin layer 505 only undergoes a UV exposure process and a heat expansion process, and no development process is performed. In this respect, it is fundamentally different from the use of photosensitive resin in semiconductor processes such as pattern formation.

Next, when the exposure/expansion area 601 is removed through a lift-off or dry etching process, an R pattern area 603 in which an R OLED subpixel is to be formed is formed (B2). At this time, as the exposure/expansion area 601 is removed, a portion of the release layer 507 formed on the area is also removed.

After step B2, a red organic layer stack (605) is deposited on the entire area, and a second electrode 607 is formed on the red organic layer stack (605) (C2). A red organic layer stack is provided between the first electrode 503 and the second electrode 607 and contacts the first electrode 503 and the second electrode 607, respectively. And, the red organic layer stack may include HIL, HTL, EIL, ETL, Red EML, etc.

As shown in step C2, within the R pattern area 603, the red organic layer stack 605 is formed by contacting the second electrode 607 on the upper side and the first electrode 503 on the lower side.

And, in areas other than the R pattern area 603, a red organic layer stack 605 and a second electrode 607 are sequentially formed on the release layer 507 that was not removed in step B2.

Afterwards, the red organic layer stack 605 and the second electrode 607 formed in the C2 step, excluding the R pattern area 603, are Lift-Off or Dry. It is removed by etching (D2).

During the Lift-Off or Dry Etching process in step D2, the red organic layer stack 605a and the second electrode 607a remain in the R pattern area 603 without the release layer 507, and other areas remain with the release layer. Since 507 is present, the red organic layer stack 605 and the second electrode 607 can be removed.

By completing step D2, R OLED subpixels of the substrate 501, the first electrode 503, the red organic layer stack 605a, and the second electrode 607a can be finally formed.

Figure 8 shows the pattern and formation process diagram of the G OLED subpixel on the pixel process (post-process) of the fine patterning method according to the present invention.

The process diagram of FIG. 8 is a pattern formation process for the G OLED subpixel, and is not an independent process, but a process performed continuously following the basic process (pre-process) of FIG. 6 and the R OLED subpixel process of FIG. 7.

First, in a vacuum chamber line, a release layer 507a is deposited on the entire upper surface of the laminate formed in the process of FIGS. 6 and 7 (A3), masks 509 spaced at predetermined positions are placed, and UV is irradiated. Apply heat (B3). Here, the opening area of the mask 509 may overlap with at least one other first electrode among the plurality of first electrodes 503.

At this time, the exposed area of the resin layer 505 exposed by UV is expanded by heat to form the exposed/expanded area 701. Since there is no expansion in the unexposed area, the expandable resin layer 505 maintains its original coating state.

The unexposed area of the expandable resin layer 505 is later used as is when forming the pattern of the B OLED subpixel. That is, the pattern formation of the RGB OLED subpixel can be used as is by forming the resin layer 505 once in the first line.

Next, when the exposure/expansion area 701 is removed through a lift-off or dry etching process, a G pattern area 703 in which a G OLED subpixel is to be formed is formed (C3). At this time, as the exposure/expansion area 701 is removed, a portion of the release layer 507 formed on the area is also removed.

After step C3, a green organic layer stack (705) is deposited on the entire area, and a second electrode (707) is formed on the green organic layer stack (705) (D3).

The green organic layer stack 705 is provided between the first electrode 503 and the second electrode 707 and contacts the first electrode 503 and the second electrode 707, respectively. The green organic layer stack 705 may include HIL, HTL, EIL, ETL, Green EML, etc.

As shown in step D3, within the G pattern area 703, the green organic layer stack 705 is formed by contacting the second electrode 707 on the upper side and the first electrode 503 on the lower side. Additionally, a green organic layer stack 705 and a second electrode 707 are sequentially formed on top of the release layers 507 and 507a in areas other than the G pattern area 703.

Afterwards, the green organic layer stack 705 and the second electrode 707 formed in step D3, excluding the G pattern area 703, are Lift-Off or Dry. It is removed by etching (E3).

In the R pattern area 603 and G pattern area 703, the expandable resin layer has a thickness of several ㎛, and the organic layer and electrode metal are less than 0.5 ㎛, so the green organic layer stack 705 and the inside are in the form of a well. The second electrode 707 remains as is.

Therefore, at this time, during the Lift-Off or Dry Etching process, the green organic layer stack 705a and the second electrode 707a remain in the R pattern area 603 and G pattern area 703, and the other areas remain as a release layer ( Since 507 and 507a) are present and at the top of the well, the green organic layer stack 705 and the second electrode 707 can be removed.

In step E3, the R OLED subpixels of the substrate 501, the first electrode 503, the red organic layer stack 605a, and the second electrode 607a (green organic layer stack 705a and the second electrode 707a) are finally formed. It can be seen that the remaining state) and G OLED subpixels of the substrate 501, the first electrode 503, the green organic layer stack 705a, and the second electrode 707a are formed.

Figure 9 shows the pattern and formation process diagram of the B OLED subpixel on the pixel process (post-process) of the fine patterning method according to the present invention.

The process diagram of FIG. 9 is a pattern formation process of the B OLED subpixel, and is not an independent process, but follows the basic process (pre-process) of FIG. 6, the R OLED subpixel process of FIG. 7, and the G OLED subpixel process of FIG. 8. It is a process that is carried out continuously.

First, a release layer 507b is deposited on the entire upper surface of the laminate formed in the process of FIGS. 6 to 8 (A4), a mask 509 is placed in a predetermined area, UV is irradiated, and heat is applied (B4). ). All or part of the opening area of the mask 509 may overlap another first electrode 503 in a vertical direction (stacking direction of each configuration).

At this time, the exposed area of the resin layer 505 exposed by UV is expanded by heat to form the exposed/expanded area 801. Conversely, since the unexposed area is not expanded, the unexposed area of the expandable resin layer 505 maintains its original coating state.

Next, when the exposure/expansion area 801 is removed through a lift-off or dry etching process, the B pattern area 803 in which the B OLED subpixel is to be formed is formed (C4).

At this time, as the exposure/expansion area 801 is removed, the release layer 507 formed on the area is also removed.

After step C4, a blue organic layer stack (805) is deposited on the entire area, and a second electrode (807) is formed on the blue organic layer stack (805) (D4).

A blue organic layer stack 805 is provided between the first electrode 503 and the second electrode 807, and is in contact with each of the first electrode 503 and the second electrode 807, and the blue organic layer stack 805 is May include HIL, HTL, EIL, ETL, Blue EML, etc.

As shown in step D4, within the B pattern region 803, the blue organic layer stack 805 is formed by contacting the second electrode 807 on the upper side and the first electrode 503 on the lower side.

Additionally, a blue organic layer stack 805 and a second electrode 807 are sequentially formed on top of the release layers 507, 507a, and 507b in areas other than the B pattern area 803.

Afterwards, the blue organic layer stack 805 and the second electrode 807 formed in step D4, excluding the B pattern area 803, are Lift-Off or Dry. It is removed by etching (E4).

The thickness of the expandable resin layer in the R pattern area 603, G pattern area 703, and B pattern area 803 is about several ㎛, and the organic layer and electrode metal are less than 0.5 ㎛, so they are in the form of a well and have a blue color inside. The organic layer stack 805 and the second electrode 807 remain as is.

Therefore, at this time, during the lift-off or dry etching process, the blue organic layer stack 805a and the second electrode 807a remain in the R pattern region 603, G pattern region 703, and B pattern region 803, and , Since the release layers 507, 507a, and 507b are present in other areas and at the top of the well, the blue organic layer stack 805 and the second electrode 807 can be removed.

In step E4, finally, the R OLED subpixels of the substrate 501, the first electrode 503, the red organic layer stack 605a, and the second electrode 607a (the green organic layer stack 705a and the second electrode 707a) and the blue organic layer stack 805a and the second electrode 807a remaining), and the G OLED sub of the substrate 501, the first electrode 503, the green organic layer stack 705a, and the second electrode 707a. B OLED of a pixel (with the blue organic layer stack 805a and the second electrode 807a remaining), the substrate 501, the first electrode 503, the blue organic layer stack 805a, and the second electrode 807a. It can be seen that subpixels are formed.

Figure 10 shows an RGB OLED pixel formed by a fine patterning method according to the present invention.

As shown in FIG. 10, after step E4 of FIG. 9, the remaining expandable resin layer 505 and release layers 507, 507a, and 507b are removed through Lift-Off and Full Dry Etching processes. Accordingly, as shown in FIG. 10, R OLED subpixel 900R, G OLED subpixel 900G, and B OLED subpixel 900B may be formed on the substrate.

Figure 11 is a photograph of the expansion of the expandable resin layer formed by the fine patterning method according to the present invention, and Figure 12 is a photograph of the patterning of the expandable resin layer formed by the fine patterning method according to the present invention.

Figure 11 (A) is an optical microscope photograph after expansion of the expandable resin layer, and (B) is an SEM cross-sectional photograph of the V-V cross section of (A) after expansion of the expandable resin layer. Figures 10 (A) and (B) show that the expandable resin layer formed on the substrate is expanded in the pattern area where RGB OLED subpixels will be formed by applying UV irradiation and heat.

Figure 12 (A) is an optical microscope photograph after patterning of the expandable resin layer, and (B) is an SEM cross-sectional photograph of the V-V cross section of (A) after patterning of the expandable resin layer. Figures 12 (A) and (B) show that after the expandable resin layer formed on the substrate is expanded as shown in Figure 10, the pattern area where RGB OLED subpixels will be formed is patterned by the Lift-Off or Dry Etching process. .

The features, structures, effects, etc. described in the embodiments above are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified and implemented in other embodiments by a person with ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the present invention.

In addition, although the above description focuses on the embodiment, this is only an example and does not limit the present invention, and those skilled in the art will be able to understand the above without departing from the essential characteristics of the present embodiment. You will see that various modifications and applications not illustrated are possible. For example, each component specifically shown in the embodiments can be modified and implemented. And these variations and differences in application should be construed as being included in the scope of the present invention as defined in the appended claims.

L1: first line
L2: 2nd line
101, 501: substrate
103, 503: first electrode
105, 505: expandable resin layer
107, 507, 507a, 507b: release layer
109, 509: Mask
601, 701, 801: exposure/expansion area
603: R pattern area
605, 605a: red organic layer stack
607, 707, 807, 607a, 707a, 807a: second electrode
703: G pattern area
705, 705a: green organic layer stack
803: B pattern area
805, 805a: blue organic layer stack
900R:R OLED Subpixel
900G:G OLED subpixel
900B:B OLED Subpixel

Claims (11)

A plurality of first electrodes are formed on a substrate, a resin layer expandable by ultraviolet rays (UV) and/or heat is formed on the substrate to cover the plurality of first electrodes, and a release layer is formed on the resin layer. A laminate manufacturing step of forming a laminate; and
In a vacuum state, after placing a mask on the laminate, the ultraviolet rays and/or the heat are applied to remove the first electrode of the resin layer located between the first electrode of any one of the plurality of first electrodes and the opening area of the mask. A vacuum patterning step of expanding one part and removing the first part of the expanded resin layer to form a first pattern area,
The vacuum patterning step is,
A first organic layer stack and a second electrode are sequentially formed on the laminate on which the first pattern area is formed, and a surplus first organic layer is disposed outside the first pattern area among the first organic layer stack and the second electrode. Remove the stack and second electrode,
A release layer is formed on the laminate from which the excess first organic layer stack and the second electrode have been removed, the mask is placed on the laminate, and then the ultraviolet rays and/or the heat are applied to form the plurality of first organic layer stacks. expanding a second portion of the resin layer located between the first electrode of the other one of the electrodes and the open area of the mask;
forming a second pattern area by removing the second portion of the expanded resin layer;
After sequentially forming a second organic layer stack and the second electrode on the laminate on which the second pattern region is formed, among the second organic layer stack and the second electrode, disposed outside the first and second pattern regions removing excess second organic layer stack and second electrode,
Fine patterning method.
delete delete The method of claim 1, wherein the vacuum patterning step includes:
A release layer is formed on the laminate from which the excess second organic layer stack and the second electrode have been removed, the mask is placed on the laminate, and then the ultraviolet rays and/or the heat are applied to form the plurality of first expanding a third portion of the resin layer located between the first electrode of another one of the electrodes and the open area of the mask;
forming a third pattern area by removing the third portion of the expanded resin layer;
After sequentially forming the third organic layer stack and the second electrode on the laminate on which the third pattern region is formed, a surplus disposed outside the first to third pattern regions among the third organic layer stack and the second electrode A fine patterning method for removing the third organic layer stack and the second electrode.
The method of claim 4, wherein the vacuum patterning step includes:
Forming first to third subpixels by removing the release layer in the first pattern area, the release layer in the second pattern area, the release layer formed in the laminate manufacturing step, and the resin layer remaining on the substrate, Fine patterning method.
According to claim 5,
A fine patterning method of removing the release layer and the resin layer using a liftoff or dry etching method.
According to claim 1,
The fine patterning method wherein the laminate manufacturing step is performed in a non-vacuum state.
According to claim 1,
The patterning step is performed in a vacuum chamber.
According to claim 1,
The resin layer is a resin mixed with a base resin, an organic solvent, and a photoactivator.
According to claim 1,
A fine patterning method wherein the resin layer is dry patterning resin.
A pixel structure of an OLED display manufactured by the fine patterning method of any one of claims 1, 4 to 10.

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