1. Field
Example embodiments relate to an apparatus for depositing and inspecting an organic light emitting display panel, and a method of depositing and inspecting an organic light emitting display panel by using the apparatus.
2. Description of the Related Art
Thin, e.g., portable, flat panel display apparatuses, e.g., light emitting display apparatuses that are emissive display apparatuses, have recently received attention as display apparatuses with good characteristics, e.g., wide viewing angle, high contrast ratio, and short response times. Also, organic light emitting display apparatuses, i.e., in which a light emitting layer is formed of an organic material, are superior to inorganic light emitting display apparatuses, i.e., in which a light emitting layer is formed of an inorganic material, in terms of brightness, driving voltage, response time characteristics, and multi-color display.
An organic light emitting display apparatus includes a thin film transistor (TFT) and an organic light emitting device driven by the TFT. The organic light emitting device may include an anode layer, an organic film layer, and a cathode layer that are sequentially stacked. Thus, when a voltage is applied between the anode layer and the cathode layer of the organic light emitting device by driving the TFT, an energy difference is formed in the organic film layer, and accordingly, an emissive layer included in the organic film layer generates light. Each of the layers of the organic light emitting device may be formed by a deposition method.
Embodiments are directed to an apparatus for depositing and inspecting an organic light emitting display panel and a method of using the same, which substantially overcome one or more of the problems due to the limitations and disadvantages of the related art.
It is therefore a feature of an embodiment to provide an apparatus for depositing and inspecting an organic light emitting display panel by determining correctness of a layer deposition thickness during a deposition process.
It is therefore another feature of an embodiment to provide a method of depositing and inspecting a thickness of a thin film layer during a deposition process by using the apparatus.
At least one of the above and other features and advantages may be realized by providing an apparatus for depositing and inspecting an organic light emitting display panel, the apparatus including a depositor part configured to deposit thin film layers on a panel, the thin film layers including an anode layer, an organic film layer, and a cathode layer, and an inspector part configured to measure spectra of light reflected from the thin film layers, compare the measured spectra to reference spectra, and determine thickness correctness of individual thin film layers.
The inspector part may include a reflectometer for radiating light onto the thin film layers and receiving reflection light reflected by the thin film layers, a computer for determining whether the thickness of each of the thin film layers is correct or not by analyzing spectrums of the reflection light received by the reflectometer, and a controller for controlling the deposition process in response to the analysis result of the computer.
The computer may compare a measured spectrum of reflection light received by the reflectometer to a reference spectrum that is set in the computer, and determines whether the deposition thickness is correct or not by inspecting one of the change of location of the peak wavelength, the change of magnitude of the minimum refractive index, and the change of a full width at half maximum.
The controller may remove a panel that is determined as a defective by the computer from the deposition process and gives a warning notice to the operator.
The depositor part may include a plurality of process chambers in which the deposition of the thin film layers is performed, a plurality of carrying chambers each having a carrying device for conveying the panel to the process chambers, and a buffer chamber for connecting the adjacent carrying chambers, wherein the inspector part is installed in one of the above chambers.
The inspector part may be configured to operate after deposition of each of the organic film layer and the cathode layer.
The inspector part may be configured to operate multiple times during a deposition process of a single panel, the inspector part being configured to operate after deposition of each of the organic film layer and the cathode layer on the single panel.
The inspector may be configured to operate before deposition completion of all of the thin film layers.
The inspector part may be configured to determine a thickness of each layer in the organic film layer and the cathode layer separately.
At least one of the above and other features and advantages may also be realized by providing a method of depositing and inspecting an organic light emitting display panel, the method including depositing on a panel thin film layers including an anode layer, an organic film layer, and a cathode layer, measuring spectra of a reflection light by irradiating light onto the thin film layers, and determining whether the thickness of each of the thin film layers is correct or not by comparing the measured spectra of reflection light to reference spectra.
The determining whether the thickness of each of the thin film layers is correct or not may include one of determining the change of location of the peak wavelength, determining the change of magnitude of the minimum refractive index, and determining the change of a full width at half maximum.
The method may further include controlling the depositing according to the determination result in the determining process.
The controlling the deposition may include removing a panel determined to be defective from the deposition process and providing a warning notice to the operator.
In the depositing, the anode layer, the organic film layer, and the cathode layer may be sequentially deposited in that order, and the measuring, determining, and controlling may be performed whenever each of the thin film layers is deposited after the organic film layer is deposited.
The depositing of the thin film layers may further include depositing a protective capping layer on the cathode layer.
In the measuring of a spectrum of a reflection light, light may be irradiated onto the thin film layers in a direction from the cathode layer to the anode layer.
In the measuring a spectrum of a reflection light, light may be irradiated onto the thin film layers in a direction from the anode layer to the cathode layer.
The above and other features and advantages will become more apparent to those of ordinary skill in the art by describing in detail exemplary embodiments with reference to the attached drawings, in which:
Korean Patent Application No. 10-2010-0015803, filed on Feb. 22, 2010, in the Korean Intellectual Property Office, and entitled: “Apparatus for Depositing and Inspecting Organic Light Emitting Display Panel and Method of Depositing and Inspecting Organic Light Emitting Display Panel by Using the Apparatus,” is incorporated by reference herein in its entirety.
Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
In the drawing figures, the dimensions of layers and regions may be exaggerated for clarity of illustration. It will also be understood that when a layer (or element) is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. In addition, it will also be understood that when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present. Like reference numerals refer to like elements throughout.
Referring to
Although not shown in detail, the organic film layer 12 may include a hole injection layer (HIL), a hole transport layer (HTL), an emission material layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL). Light emission is realized through a process of combining the holes and electrons in the EML. The EML may include one of a red EML, a green EML, and a blue EML according to the color of light emitted from the EML, so a color image is realized by combining lights emitted from adjacently disposed organic light emitting display panels respectively having the EMLs of the three colors.
The cathode layer 13 may be a semi-transparent layer formed of an alloy of Mg and Ag, and may transmit light emitted from the organic film layer 12. The capping layer 14 formed on the cathode layer 13 may be a transparent layer and may transmit light. The top emission type organic light emitting display panel 10 may also include an encapsulation layer 15.
Although not shown, a TFT for driving the top emission type organic light emitting display panel 10 may be disposed under the anode layer 11. Accordingly, when voltage is applied between the anode layer 11 and the cathode layer 13 by the TFT, light is emitted from the organic film layer 12 and proceeds toward the capping layer 14.
Referring to
The organic film layer 22, like the organic film layer 12, may also include an HIL, an HTL, an EML, an ETL, and an EIL, and light emission may be realized through a process of combining the holes and electrons in the EML. The EML may include one of a red EML, a green EML, and a blue EML according to the color of light emitted from the EML, and a color image is realized by combining lights emitted from adjacently disposed organic light emitting display panels respectively having the EMLs of the three colors.
The cathode layer 23 may be a reflection layer formed of Al and may reflect light generated from the organic film layer 22 toward the anode layer 21. The bottom emission type organic light emitting display panel 20 may also include an encapsulation layer 25, and a TFT for driving the bottom emission type organic light emitting display panel 20 may be formed under the anode layer 21. Accordingly, when voltage is applied between the anode layer 21 and the cathode layer 23 by the TFT, light is generated from the organic film layer 22 and proceeds toward the anode layer 21.
Conventionally, a quality of either of the top or bottom emission type organic light emitting display panels 10 or 20 is inspected through a light emission test after all of the deposition processes, i.e., all of the layers, are completed and encapsulation layers 15 and 25 for sealing the organic light emitting devices are formed. That is, a voltage is applied between the anode layers 11 and 21 and the respective cathode layers 13 and 23 after the fabrication processes of the organic light emitting display panels 10 and 20 are completed, so light emitted from the organic light emitting display panels 10 and 20 may be examined. It is noted that poor product quality refers to characteristics of emitted light that deviate from a desired range, e.g., due to inaccurate film thickness deposition of one or more of the layers stacked in the organic light emitting display panel, thereby exhibiting inaccurate color image.
However, as the product quality is conventionally inspected after process completion, poor product quality, e.g., product defects, may be detected and confirmed only when fabrication of the organic light emitting display panel is complete. Therefore, when a product failure is confirmed, there may be a high possibility that all of the completed and intermediate products that have already undergone the deposition process are defective products.
Therefore, according to example embodiments, a deposition and inspection apparatus 100 configured to inspect products, e.g., in terms of thickness accuracy, in each stacking process during deposition, i.e., before product completion, will be described hereinafter with reference to
Referring to
Referring to
In detail, the apparatus 100 may have a structure in which two carrying chambers, i.e., first and second carrying chambers 111 and 121, may be connected to each other via a buffer chamber 130. Hereinafter, a combination of the first carrying chamber 111 with the process chambers 112, 113, 114, and 115 attached to and surrounding the first carrying chamber 111 will be referred to as a first cluster 110. Similarly, a combination of the second carrying chamber 121 with the process chamber 122 attached thereto will be referred to as a second cluster 120. The first cluster 110 may be positioned on a left side of the buffer chamber 130, and the second cluster 120 may be positioned on a right side of the buffer chamber 130. When the deposition processes in the first cluster 110 are completed, the panel 30 may be conveyed to the second cluster 120 through the buffer chamber 130, and a subsequent deposition process may be performed in the second cluster 120. It is noted that even though only two clusters, i.e., the first and second clusters 110 and 120, are described in the present embodiment, the number of clusters may be increased according to the deposition processes. The first and second clusters 110 and 120 with the buffer chamber 130 may define the depositor part 170.
For example, when the top emission type organic light emitting display panel 10 of
As further illustrated in
The inspector part 150 is configured to inspect an object by measuring a spectrum of light reflected from the object after irradiating light onto the object. That is, a predetermined spectrum of reflected light is emitted from each deposition layer. Therefore, a change in deposition thickness modifies the spectrum of the reflected light, so the inspector part 150 may determine whether the deposition thickness is correct, e.g., accurate, or not by measuring a spectrum of reflected light.
In detail, referring to
The computer 152 may store, e.g., include a database with, reference spectra for comparing with the measured spectra of the reflected light received by the reflectometer 151. That is, a spectrum of reflected light that is emitted from each layer with an accurate thickness, i.e., a layer with a thickness within a desired range, may be stored as a reference spectrum in the computer 152. Then, an actually measured spectrum may be compared to the reference spectrum to determine whether the actually measured spectrum is within the reference range or not.
In order to measure a spectrum of reflected light of the organic film layer 12, after the organic film layer 12 having a green light emitting layer is deposited in the process chamber 114 of
It is noted that
Similarly, in order to measure the spectrum of reflected light of the cathode layer 13, after the cathode layer 13 is deposited in the process chamber 115 of
Similarly, in order to measure the spectrum of the reflected light of the capping layer 14, after the capping layer 14 is deposited in the process chamber 122 of
As described above, if the product in each deposition process is inspected by analyzing the reflected light, a product failure may be detected in advance, i.e., during the deposition process and before completion thereon. Thus, an appropriate action may be rapidly taken, thereby reducing the failure rate of products.
A method of depositing and inspecting an organic light emitting display device by using the apparatus 100 for depositing and inspecting an organic light emitting display panel will now be described.
Referring to
Similarly, after the cathode layer 13 is deposited, the spectrum of light reflected from the panel 30 may be measured in the carrying chamber 111 by using the inspector part 150, and if the panel 30 is determined as not defective, the corresponding panel 30 is moved to the process chamber 122 of the second cluster 120 so as to deposit the capping layer 14. In the same manner, after the capping layer 14 is deposited, the product is inspected in the carrying chamber 121 by measuring the spectrum of the reflection light with the inspector part 150, and if no failure is detected, the corresponding panel 30 is moved to a process of covering the panel 30 with an encapsulation layer 15. After the panel 30 is covered by the sealing substrate 15, the spectrum of the reflection light may further be measured to inspect the panel 30 in terms of whether the panel 30 is correctly sealed or not in the sealing process.
In this way, since the products, i.e., thin film layers, are continuously inspected after each operation of the deposition processes, presence of a defective product may be detected early. Therefore, the defective product may be immediately removed from the process and a warning notice may be generated, thereby reducing the failure rate of products.
In the current embodiment, the top emission type organic light emitting display panel 10 shown in
Also, as described above, the inspector part 150 may be directly installed in the process chambers 112, 113, 114, 115, or 122, besides the carrying chambers 111 and 121, or may be installed in the buffer chamber 130. That is, the inspector part 150 may be installed at any location where the panel 30 passes.
Also, it is noted that while the deposition apparatus 100 is described as having a cluster structure in which the process chambers 112, 113, 114, 115, and 122 surround the carrying chambers 111 and 121, other configurations are included within the example embodiments. For example, the deposition apparatus 100 may have an inline structure in which the process chambers 112, 113, 114, 115, and 122 are disposed in a row, the inspector part 150 may be installed on any location where the panel 30 passes, and the inspection of products may be performed by analyzing the spectrum of reflection light.
Therefore, an apparatus for depositing and inspecting an organic light emitting display panel according to example embodiments may perform inspection of products by analyzing the spectrum of reflection light during the process of deposition, regardless of the shape of the deposition apparatus or the kind of organic light emitting display panel. According to the inspection results, an appropriate action may be taken, thereby reducing the failure rate of products. That is, since a product may be inspected in advance in the course of depositing thin film layers, an appropriate action may be rapidly taken with respect to the deposition process, thereby reducing the failure rate of products and reducing manufacturing costs.
Exemplary embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. Accordingly, it will be understood by those of ordinary skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.
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