KR20230168650A - Expectation method of the examination quality and method of manufacturing display apparatus using the same - Google Patents

Abstract

The present invention provides an inspection quality prediction method that allows predicting defects in the early stages of the display device manufacturing process and a display device manufacturing method using the same, including a first step of acquiring first data through a lighting inspection of the display panel; , a second step of preparing a display module by attaching a printed circuit board and a driving chip to the display panel, a third step of acquiring second data through a lighting inspection of the display module, and first and second data. A fourth step of associating, a step of constructing a database by repeating the first to fourth steps, a step of obtaining first inspection data through a lighting inspection of the display panel to be inspected, and using the database A method for predicting inspection quality and a method for manufacturing a display device using the same are provided, including the step of obtaining predicted data by predicting second inspection data when a display panel to be inspected becomes a display module from first inspection data.

Description

{Expectation method of the examination quality and method of manufacturing display apparatus using the same}

Embodiments of the present invention relate to a method for predicting inspection quality and a method for manufacturing a display device using the same. More specifically, a method for predicting inspection quality that allows predicting defects in the early stages of the display device manufacturing process and manufacturing a display device using the same. It's about method.

Generally, a display device has a display area, and many pixels are located within the display area. If a defect occurs in the display area during the manufacturing process of such a display device, the quality of the image produced by the display device may deteriorate. Therefore, it is necessary to accurately determine whether defects occur in the display area during the manufacturing process.

However, in this conventional case, there was a problem in that it was sometimes difficult to accurately determine whether a defect occurred in the display area.

The present invention is intended to solve various problems including the problems described above. The purpose of the present invention is to provide an inspection quality prediction method that allows predicting defects at an early stage of the display device manufacturing process and a display device manufacturing method using the same. do. However, these tasks are illustrative and do not limit the scope of the present invention.

According to one aspect of the present invention, a first step of acquiring first data through a lighting inspection of the display panel, a second step of preparing a display module by attaching a printed circuit board and a driving chip to the display panel, and a display step. A third step of acquiring second data through a lighting inspection of the module, a fourth step of associating the first data with the second data, and a step of building a database by repeating the first to fourth steps. A step of acquiring first inspection data through a lighting inspection of the display panel to be inspected, and using a database to predict the second inspection data when the display panel to be inspected becomes a display module from the first inspection data. A method for predicting inspection quality is provided, including the step of acquiring data.

A step of preparing a display module to be inspected by attaching a printed circuit board and a driving chip to a display panel to be inspected; obtaining second inspection data through a lighting inspection of the display module to be inspected; predicting data and a second inspection; A step of comparing data may be further included.

Comparing the predicted data and the second inspection data may include determining that the display module inspection device is normal when the difference between the predicted data and the second inspection data is within a preset range.

The step of comparing the predicted data and the second inspection data may include determining that the display module inspection device is abnormal when the difference between the predicted data and the second inspection data is outside a preset range.

The prediction data and the second inspection data may be data about the same physical characteristics.

The predicted data and the second inspection data include any one of data on the average luminance of the display area, data on the difference between the maximum and minimum luminance of the display area, and data on the color coordinate that is most different from the normal color coordinate of the display area. It can be included.

The first inspection data and the first data may be data about the same physical characteristics.

The first inspection data and the first data are any one of data on the average luminance of the display area, data on the difference between the maximum luminance and minimum luminance of the display area, and data on the color coordinate that is most different from the normal color coordinate of the display area. may include.

The predicted data and the second data may be data about the same physical characteristics.

The predicted data and the second data include any one of data on the average luminance of the display area, data on the difference between the maximum and minimum luminance of the display area, and data on the color coordinate that is most different from the normal color coordinate of the display area. It can be included.

According to one aspect of the present invention, the step of determining whether the predicted data obtained according to the above-described method is data for a normal display module, and if the predicted data is data for a normal display module, installing a printed circuit on the display panel to be inspected. A display device manufacturing method is provided, including the step of attaching a substrate and a driving chip.

Other aspects, features and advantages other than those described above will become apparent from the detailed description, claims and drawings for carrying out the invention below.

According to an embodiment of the present invention made as described above, an inspection quality prediction method that allows predicting defects at an early stage of the display device manufacturing process and a display device manufacturing method using the same can be implemented. Of course, the scope of the present invention is not limited by this effect.

1 is a conceptual diagram schematically illustrating a manufacturing process of a display device that is the subject of quality prediction in the inspection quality prediction method according to an embodiment of the present invention.
FIG. 2 is a conceptual diagram schematically showing part A of FIG. 1.
FIG. 3 is a cross-sectional view schematically showing a cross-section taken along line III-III in FIG. 2.
FIG. 4 is a cross-sectional view schematically showing a cross-section taken along line IV-IV in FIG. 2.
FIG. 5 is a cross-sectional view schematically showing a portion of the display area of FIG. 1.
Figure 6 is a cross-sectional view schematically showing a portion of the manufacturing process of a display device that is the subject of quality prediction in the inspection quality prediction method according to an embodiment of the present invention.
Figure 7 is a flow chart schematically showing a method for predicting inspection quality according to an embodiment of the present invention.
Figure 8 is a flow chart schematically showing a method for predicting inspection quality according to an embodiment of the present invention.
Figure 9 is a flow chart schematically showing a method for predicting inspection quality according to an embodiment of the present invention.
Figure 10 is a cross-sectional view schematically showing a portion of the manufacturing process of a display device that is the subject of quality prediction in the inspection quality prediction method according to an embodiment of the present invention.

Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. The effects and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various forms.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When describing with reference to the drawings, identical or corresponding components will be assigned the same reference numerals and redundant description thereof will be omitted. .

In the following embodiments, when various components such as layers, films, regions, and plates are said to be “on” other components, this does not only mean that they are “directly on” the other components, but also when other components are interposed between them. Also includes cases where Additionally, for convenience of explanation, the sizes of components may be exaggerated or reduced in the drawings. For example, the size and thickness of each component shown in the drawings are shown arbitrarily for convenience of explanation, so the present invention is not necessarily limited to what is shown.

In the following embodiments, the x-axis, y-axis, and z-axis are not limited to the three axes in the Cartesian coordinate system, but can be interpreted in a broad sense including these. For example, the x-axis, y-axis, and z-axis may be orthogonal to each other, but may also refer to different directions that are not orthogonal to each other.

FIG. 1 is a conceptual diagram schematically showing one aspect of the manufacturing process of a display device that is the subject of quality prediction in the inspection quality prediction method according to an embodiment of the present invention, and FIG. 2 is a conceptual diagram schematically showing part A of FIG. 1. , FIG. 3 is a cross-sectional view schematically showing a cross-section taken along line III-III of FIG. 2, and FIG. 4 is a cross-sectional view schematically showing a cross-section taken along line IV-IV of FIG. 2.

In the inspection quality prediction method according to this embodiment, the display device that is the subject of quality prediction has a display area (DA) where a plurality of pixels are located, as shown in FIG. 1, and a peripheral area (PA) located outside the display area (DA). ) has. This may be understood as the substrate 100 having such a display area (DA) and a peripheral area (PA). The peripheral area (PA) includes the pad area (PADA), which is an area where various electronic devices or printed circuit boards are electrically attached.

Figure 1 may be understood as a plan view showing a substrate during the manufacturing process. That is, Figure 1 can be understood as a plan view showing a display panel in a state before a printed circuit board or driving chip is attached, rather than a final display device. The final display device is an electronic device such as a smartphone, mobile phone, navigation device, game console, TV, vehicle head unit, notebook computer, laptop computer, tablet computer, personal media player (PMP), or personal digital assistants (PDA). It can be. Additionally, these electronic devices may be flexible devices. Figure 1 shows a display panel when the final display device is an exemplary smartphone.

In the final display device, a portion of the substrate may be bent to minimize the area of the peripheral area (PA) perceived by the user. For example, the peripheral area (PA) may include a bending area, so that the bending area is located between the pad area (PADA) and the display area (DA). In this case, the substrate may be bent in the bending area so that at least a portion of the pad area (PADA) overlaps the display area (DA). Of course, in this case, the bending direction is set so that the pad area (PADA) does not cover the display area (DA), but rather the pad area (PADA) is located behind the display area (DA). Accordingly, the user perceives the display area (DA) as taking up most of the display device.

This substrate 100 may include various materials having flexible or bendable properties, such as polyethersulphone (PES), polyacrylate, polyetherimide (PEI), polyethylene or Phthalate (polyethylene naphthalate, PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyarylate (PAR), polyimide (PI), polycarbonate , PC) or cellulose acetate propionate (CAP). Of course, the substrate 100 has a multi-layer structure including two layers each containing such a polymer resin and a barrier layer containing an inorganic material (such as silicon oxide, silicon nitride, silicon oxynitride, etc.) sandwiched between the layers. Various modifications are possible, such as having . Furthermore, if the substrate 100 is not bent, the substrate 100 may be formed of glass or the like.

The edges of the display area DA may have an overall shape similar to a rectangle or square. However, as shown in FIG. 1, the display area DA may not have sharp edges. Specifically, the display area (DA) has a first edge (E1) and a second edge (E2) facing each other, and a third edge (E1) and a third edge (E2) facing each other but located between the first edge (E1) and the second edge (E2). It may include E3) and the fourth edge (E4). The pad area (PADA) is adjacent to the fourth edge (E4) of the first to fourth edges (E1) to (E4). At this time, the portion connecting the first edge (E1) and the fourth edge (E4) may have a round shape. Of course, the part connecting the second edge E2 and the fourth edge E4 of the display area DA may have a round shape, and other parts may also have a round shape.

As shown in FIG. 2, the display panel includes a plurality of test thin film transistors (TT) located in the peripheral area (PA), specifically, the pad area (PADA). These plurality of test thin film transistors (TT) are test thin film transistors to check whether the pixels of the display area (DA) operate normally during the manufacturing process.

As shown in FIGS. 2 to 4, each of the plurality of test thin film transistors (TT) has a semiconductor layer 120, a gate electrode 141, and a source electrode ( 161) and a drain electrode 162. In order to ensure insulation between the semiconductor layer 120 and the gate electrode 141, a gate insulating film 130 containing an inorganic material such as silicon oxide, silicon nitride, and/or silicon oxynitride is formed between the semiconductor layer 120 and the gate electrode 141. It may be interposed between the gate electrodes 141. In addition, an interlayer insulating film 150 containing an inorganic material such as silicon oxide, silicon nitride, and/or silicon oxynitride may be disposed on the top of the gate electrode 141, and the source electrode 161 and the drain electrode 162 may be disposed on such interlayer insulating film 150. In this way, an insulating film containing an inorganic material can be formed through CVD or ALD (atomic layer deposition). This also applies to the embodiments and modifications thereof described later.

A buffer layer 110 containing an inorganic material such as silicon oxide, silicon nitride, and/or silicon oxynitride may be interposed between the test thin film transistor (TT) and the substrate 100. This buffer layer 110 serves to increase the smoothness of the upper surface of the substrate 100 or to prevent or minimize impurities from the substrate 100 from penetrating into the semiconductor layer 120 of the thin film transistor (TT) for testing. You can.

The gate electrodes 141 of the plurality of test thin film transistors (TT) may be electrically connected to each other. For example, as shown in FIG. 2, the gate electrodes 141 of a plurality of test thin film transistors (TT) may be integrated. In Figure 2, the integrated gate electrode 141 is shown as having a shape extending in one direction (x-axis direction). Of course, unlike this, the gate electrodes 141 of the plurality of test thin film transistors (TT) may be spaced apart from each other and electrically connected to each other by bridge wires. In this case, the gate electrodes 141 and bridge wires may be located on a virtual straight line extending along one direction (x-axis direction).

The gate electrode 141 is made of a metal such as molybdenum or aluminum, and may be formed by a method such as sputtering. The gate electrode 141 may have a single-layer structure or a multi-layer structure. For example, the gate electrode 141 may have a two-layer structure of Mo/Al.

The source electrode 161 and the drain electrode 162 may contain metal such as titanium or aluminum and may have a single-layer or multi-layer structure. For example, the source electrode 161 and the drain electrode 162 may have a three-layer structure of titanium/aluminum/titanium.

As shown in FIG. 1, a plurality of data lines DL cross the display area DA and extend into the peripheral area PA. Each of the plurality of test thin film transistors (TT) is electrically connected to a corresponding one of the plurality of data lines (DL). Accordingly, when an electrical signal is simultaneously applied to the gate electrodes 141 electrically connected to each other of a plurality of test thin film transistors (TT), a channel is simultaneously formed in the semiconductor layers 120 of the plurality of test thin film transistors (TT). do. When a plurality of test thin film transistors (TT) are simultaneously turned on, an electrical signal from the test signal line 168 is transmitted to the plurality of data lines DL. Accordingly, the pixels in the display area (DA) electrically connected to the plurality of data lines (DL) emit light, and it is possible to inspect whether the pixels in the display area (DA) are defective.

As described above, a plurality of data lines DL cross the display area DA and extend to the peripheral area PA. These plurality of data lines (DL) may contain the same material as the source electrode 161 and drain electrode 162 of the test thin film transistor (TT), for example, a metal such as titanium or aluminum, and may have a single-layer or multi-layer structure. You can have it. Furthermore, the plurality of data lines DL may be disposed on the same layer as the source electrode 161 and the drain electrode 162. Each of the plurality of test thin film transistors (TT) is electrically connected to the corresponding one of the plurality of data lines (DL), and this can be done by the connection wires 143. That is, the connection wires 143 connect a plurality of data lines (DL) and a plurality of test thin film transistors (TT).

These connection wires 143 may contain the same material as the gate electrodes 141, for example, a metal such as molybdenum or aluminum, and may have a single-layer or multi-layer structure. Furthermore, the connection wires 143 may be placed on the same layer as the gate electrodes 141. Of course, the end of the connection wire 143 in the data line (DL) direction is connected to the upper data line (DL) through a contact hole formed in the interlayer insulating film 150, and the test thin film transistor (TT) of the connection wire 143 The end in the ) direction is connected to the upper drain electrode 162 through a contact hole formed in the interlayer insulating film 150. Meanwhile, the source electrodes 161 of the test thin film transistors (TT) are connected to the test signal line 168 (extending in the x-axis direction). Specifically, the source electrodes 161 are integrated with the test signal line 168. It can be.

Meanwhile, as shown in FIGS. 2 and 3, the display device may further include a plurality of output pads 165. Each of the plurality of output pads 165 is located above a corresponding one of the connection wires 143, and can contact the corresponding one of the connection wires 143. Each of these plurality of output pads 165 may contain the same material as the source electrode 161 and drain electrode 162 of the test thin film transistor (TT), for example, a metal such as titanium or aluminum, and may be a single layer or a multilayer. It can have a structure. Alternatively, the output pads 165 may have a three-layer structure of titanium/aluminum/titanium. Furthermore, the plurality of output pads 165 may be disposed on the same layer as the source electrode 161 and the drain electrode 162. Accordingly, the plurality of output pads 165 may be connected to the lower connection wire 143 through the contact hole formed in the interlayer insulating film 150.

A plurality of input pads 166 may be located on the other side opposite to one side (+y direction) of the plurality of test thin film transistors (TT) where the plurality of output pads 165 are located. Each of these plurality of input pads 166 may contain the same material as the source electrode 161 and drain electrode 162 of the test thin film transistor (TT), for example, a metal such as titanium or aluminum, and may be a single layer or a multilayer. It can have a structure. Alternatively, the input pads 166 may have a three-layer structure of titanium/aluminum/titanium. Furthermore, the plurality of input pads 166 may be disposed on the same layer as the source electrode 161 and the drain electrode 162.

These input pads 166 and output pads 165 may later be connected to a display module or a driving chip 180 (see FIG. 6) included in the display device. This will be described later. In addition, information about the image to be implemented in the display area (DA) may be input to the driving chip 180. To this end, the plurality of input pads 166 extend in a direction away from the plurality of test thin film transistors (TT), and the portion of the plurality of input pads 166 in the direction away from the plurality of test thin film transistors (TT) ( 167) may be electrically connected to the output terminals of the printed circuit board 190 (see FIG. 6) provided in the display module or display device. This will be described later.

In this way, the input terminals of the driving chip 180, which will be later attached to the display panel, are connected to the input pads 166, and the output terminals of the driving chip 180 are connected to the output pads 165. At this time, in order to ensure that the driving chip 180 is positioned stably, the height h1 from the bottom of the substrate 100 to the top of the output pads 165, and the height h1 from the bottom of the substrate 100 to the top of the input pads 166 It is necessary to ensure that the height (h2) is the same.

For this purpose, since the connection wires 143 are located at the bottom of the output pads 165, a step adjustment unit 145 is provided at the bottom of the portion in the direction of the plurality of test thin film transistors (TT) of each of the input pads 166. It can be positioned. This step adjustment unit 145 may contain the same material as the connection wires 143, that is, the same material as the gate electrodes 141, for example, a metal such as molybdenum or aluminum, and may have a single-layer or multi-layer structure. . Of course, unlike what is shown in FIGS. 2 and 3, the portion 167 in the direction away from the plurality of test thin film transistors (TT) of each of the input pads 166, that is, the output terminal of the printed circuit board 190 ( A step adjustment portion may also be located below the portion 167 connected to 191).

FIG. 5 is a cross-sectional view schematically showing a portion of the display area DA of FIG. 1. As shown in FIG. 5, a display element 310 and a thin film transistor 210 to which the display element 310 is electrically connected may be located in the display area DA of the substrate 100. FIG. 5 shows that an organic light emitting element as the display element 310 is located in the display area DA. The fact that such an organic light emitting device is electrically connected to the thin film transistor 210 can be understood as the pixel electrode 311 being electrically connected to the thin film transistor 210.

The semiconductor layer 211, gate electrode 213, source electrode 215a, and drain electrode 215b of the thin film transistor 210 in the display area (DA) are thin films for testing in the peripheral area (PA) as described above. It includes the same material as the semiconductor layer 120, gate electrode 141, source electrode 161, and drain electrode 162 of the transistor (TT) and may be located on the same layer. However, in Figure 5, the thin film transistor 210 is shown as including a source electrode 215a and a drain electrode 215b, but the present invention is not limited thereto. For example, the source electrode 215a and/or the drain electrode 215b may be part of the wiring. Alternatively, the thin film transistor 210 may not have a source electrode 215a and/or a drain electrode 215b, and the source region of the semiconductor layer 211 may serve as a source electrode or the drain region may serve as a drain electrode. For example, the source region of the semiconductor layer 211 of the thin film transistor 210 may be integrated with the drain region of another thin film transistor, in which case the drain electrode of the other thin film transistor is connected to the source electrode of the thin film transistor 210. It can be understood as being electrically connected.

A planarization layer 170 may be disposed on the thin film transistor 210. For example, when an organic light emitting device is disposed on the thin film transistor 210 as shown in FIG. 5, the planarization layer 170 may serve to substantially planarize the upper part of the thin film transistor 210. This planarization layer 170 may be formed of an organic material such as acrylic, benzocyclobutene (BCB), or hexamethyldisiloxane (HMDSO). In FIG. 5, the planarization layer 170 is shown as a single layer, but various modifications are possible, such as a multi-layer structure.

In the display area DA of the substrate 100, the display element 310 may be located on the planarization layer 170. The display device 310 may be, for example, an organic light emitting device having a pixel electrode 311, a counter electrode 315, and an intermediate layer 313 interposed between them and including a light emitting layer.

The pixel electrode 311 is electrically connected to the thin film transistor 210 by contacting either the source electrode 215a or the drain electrode 215b through an opening formed in the planarization layer 170, etc., as shown in FIG. 5. . The pixel electrode 311 may include a translucent conductive layer formed of a translucent conductive oxide such as ITO, In ₂ O ₃ or IZO, and a reflective layer formed of a metal such as Al or Ag. For example, the pixel electrode 311 may have a three-layer structure of ITO/Ag/ITO.

A pixel defining layer 175 may be disposed on the planarization layer 170. This pixel definition film 175 serves to define a pixel by having an opening corresponding to each subpixel, that is, an opening that exposes at least the central portion of the pixel electrode 311. In addition, in the case shown in FIG. 5, the pixel defining film 175 increases the distance between the edge of the pixel electrode 311 and the counter electrode 315 on the top of the pixel electrode 311, thereby ) plays a role in preventing arcs from occurring at the edges. The pixel defining layer 175 may be formed of an organic material such as polyimide or hexamethyldisiloxane (HMDSO).

The intermediate layer 313 of the organic light emitting device may include a low molecule or high molecule material. When the middle layer 313 includes a low molecular material, the middle layer 313 includes a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), and an electron transport layer (ETL). : Electron Transport Layer), Electron Injection Layer (EIL), etc. may have a single or complex laminated structure and may be formed by vacuum deposition. When the middle layer 313 includes a polymer material, the middle layer 313 may have a structure including a hole transport layer (HTL) and an emission layer (EML). At this time, the hole transport layer may include PEDOT, and the light-emitting layer may include a polymer material such as poly-phenylenevinylene (PPV)-based or polyfluorene-based. This intermediate layer 313 can be formed by screen printing, inkjet printing, laser induced thermal imaging (LITI), or the like.

Of course, the middle layer 313 is not necessarily limited to this and may have various structures. In addition, the layers other than the light emitting layer of the middle layer 313 may be integrated across the plurality of pixel electrodes 311. The light emitting layer may be formed to correspond to each of the plurality of pixel electrodes 311.

The counter electrode 315 is disposed on top of the display area (DA) and may be arranged to cover the display area (DA). That is, the counter electrode 315 is formed integrally with the plurality of organic light emitting elements and can correspond to the plurality of pixel electrodes 311. The counter electrode 315 may include a transmissive conductive layer made of ITO, In ₂ O ₃ or IZO, and may also include a semi-transmissive film containing a metal such as Al or Ag. For example, the counter electrode 315 may include a semi-permeable membrane containing MgAg.

Since these organic light emitting devices can be easily damaged by moisture or oxygen from the outside, an encapsulation layer (not shown) can cover these organic light emitting devices to protect them. The encapsulation layer covers the display area (DA) and may extend to at least a portion of the peripheral area (PA). This encapsulation layer may include a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer.

After preparing such a display panel, first data is obtained through a lighting inspection of the display panel. Specifically, an electrical signal is applied to the common gate electrode 141 of a plurality of thin film transistors (TT) located in the peripheral area (PA) to simultaneously apply a channel to the semiconductor layers 120 of a plurality of test thin film transistors (TT). By forming this, a plurality of test thin film transistors (TT) are turned on at the same time. Accordingly, the electrical signal from the test signal line 168 is transmitted through a plurality of test thin film transistors (TT) to a plurality of data lines (DL) electrically connected to the test thin film transistors (TT). As a result, the pixels in the display area (DA) electrically connected to the plurality of data lines (DL) emit light, and it is possible to inspect whether the pixels in the display area (DA) are defective. In particular, since the same electrical signal from the test signal line 168 is transmitted to the pixels of the display area (DA) electrically connected to the plurality of data lines (DL) through a plurality of test thin film transistors (TT), different The presence of pixels that emit light can be confirmed by luminance.

Of course, a plurality of test thin film transistors (TT) having a common gate electrode 141 can be connected only to data lines (DL) connected to pixels that emit red light. The common gate electrode of the plurality of test thin film transistors connected to the data lines connected to the pixels emitting green light may be different from the common gate electrode 141 shown in FIG. 2. In this case, only pixels that emit red light may be inspected for defects, or only pixels that emit green light may be inspected for defects. This can also be applied to pixels that emit blue light.

Meanwhile, the pixels emitting red light, the pixels emitting green light, and the pixels emitting blue light all emit simultaneously, and the color coordinates are confirmed with the display area DA displaying a white image, thereby determining the color coordinates of the ideal white light. You can also check how much of a difference there is. Of course, you can check the color coordinates of ideal red light by checking the color coordinates with only the pixels emitting red light, and you can check the color coordinates of the ideal green light by checking the color coordinates with only the pixels emitting green light. You can check to what extent there is a difference, and by checking the color coordinates with only the pixels that emit blue light emitting light, you can also check to what extent there is a difference from the color coordinates of ideal blue light.

In this way, the first data obtained through the lighting inspection of the display panel may be data about the average luminance of the display area (DA) or data about the difference between the maximum luminance and minimum luminance of the display area (DA). , It may be data for the color coordinates that are most different from the normal color coordinates of the display area (DA). Of course, the first data may include these different types of data. For reference, data about the difference between the maximum luminance and minimum luminance of the display area (DA) may mean data about the difference between the luminance of the brightest part and the darkest part of the display area (DA).

After acquiring the first data on the display panel in this way, it is shown in Figure 6, which is a cross-sectional view schematically showing a part of the manufacturing process of the display device that is the subject of quality prediction in the inspection quality prediction method according to an embodiment of the present invention. As described above, a display module is prepared by attaching the printed circuit board 190 and the driving chip 180 to the display panel. FIG. 6 can be understood as a cross-section taken along line III-III of FIG. 2 of a display module in which a printed circuit board 190 and a driving chip 180 are attached to a display panel.

The driving chip 180 includes a body 183 and output terminals 181 and input terminals 182 located on both sides of the body 183. In Figure 6, because it is a cross-sectional view, only one output terminal 181 and one input terminal 182 of the driving chip 180 are shown. However, the driving chip 180 has a plurality of output terminals (arranged along the x-axis direction). (181) and a plurality of input terminals (182) may be provided. This driving chip 180 may be, for example, an IC chip.

Input terminals 182 of the driving chip 180 are connected to input pads 166 of the display panel, and output terminals 181 of the driving chip 180 are connected to output pads 165 of the display panel. Accordingly, when driving a display module or display device, an electrical signal from the driving chip 180 is transmitted from the output terminals 181 of the driving chip 180 through the output pads 165 and connection wires 143. It can be transmitted through lines DL, and as a result, it can be transmitted to a plurality of pixels in the display area DA.

Of course, information about the image to be implemented in the display area DA can be input to the driving chip 180 through the input terminals 182 of the driving chip 180. For this purpose, the display module may be provided with a printed circuit board 190 including a plate 192 and output terminals 191. The plurality of input pads 166 of the display panel extend in a direction away from the plurality of test thin film transistors (TT), and the portion of the plurality of input pads 166 in the direction away from the plurality of test thin film transistors (TT) The output terminals 191 of the printed circuit board 190 may be electrically connected to (167).

Meanwhile, as the input terminals 182 of the driving chip 180 are connected to the input pads 166 and the output terminals 181 of the driving chip 180 are connected to the output pads 165, as shown in FIG. As shown, the driving chip 180 is located on top of the thin film transistors (TT) for testing. At this time, in order to ensure that the driving chip 180 is positioned stably, the height h1 from the bottom of the substrate 100 to the top of the output pads 165, and the height h1 from the bottom of the substrate 100 to the top of the input pads 166 It is necessary to ensure that the height (h2) is the same.

To this end, as described above, the step adjustment unit 145 may be located at the lower part of each of the input pads 166 in the direction of the plurality of test thin film transistors (TT). Of course, unlike what is shown in FIG. 6, the portion 167 in the direction away from the plurality of test thin film transistors (TT) of each of the input pads 166, that is, the output terminal 191 of the printed circuit board 190 and A step adjustment portion may also be located at the bottom of the connected portion 167.

Meanwhile, in FIG. 6, the input terminals 182 of the driving chip 180 are shown as directly contacting the input pads 166, but the present invention is not limited thereto. For example, an anisotropic conductive film, etc. may be interposed between the input terminals 182 and the input pads 166 of the driving chip 180. This can also be applied between the output terminals 181 and the output pads 165 of the driving chip 180, and the portion 167 in the direction away from the test thin film transistors (TT) of the input pads 166 and the printed circuit. It can also be applied between the output terminals 191 of the substrate 190. This also applies to the embodiments and modifications thereof described later.

After preparing the display module in this way, second data is obtained through a lighting inspection of the display module. In the process of acquiring the second data, unlike acquiring the first data, a plurality of test thin film transistors (TT) are not used, but a test signal is applied to the driving chip 180 through the printed circuit board 190. And, the signal from the driving chip 180 is transmitted to the data lines DL through the output pads 165. As a result, the pixels in the display area (DA) electrically connected to the plurality of data lines (DL) emit light, and it is possible to inspect whether the pixels in the display area (DA) are defective. The signal transmitted to the data lines DL through the driving chip 180 may be a signal that has undergone gamma correction, etc. in the driving chip 180.

For reference, when performing a lighting test for obtaining second data, a plurality of test thin film transistors (TT) are maintained in a turned off state. Specifically, when the plurality of test thin film transistors (TT) are PMOS thin film transistors that turn on when a low signal is applied to the gate electrode 141, no signal is applied to the gate electrode 141. By applying a high signal, a plurality of test thin film transistors (TT) can be maintained in a turned off state.

When acquiring the second data in this way, it can be confirmed whether there are pixels in the display area DA that emit light at a different luminance than the intended luminance. And in the display area (DA), only pixels that emit red light can be inspected for defects, only pixels that emit green light can be inspected for defects, and only pixels that emit blue light can be inspected for defects.

Meanwhile, when acquiring the second data, the pixels emitting red light, the pixels emitting green light, and the pixels emitting blue light all emit simultaneously, so that the display area DA displays a white image, and the color coordinates By checking , you can also check how much it differs from the color coordinates of ideal white light. Of course, you can check the color coordinates of ideal red light by checking the color coordinates with only the pixels emitting red light, and you can check the color coordinates of the ideal green light by checking the color coordinates with only the pixels emitting green light. You can check to what extent there is a difference, and by checking the color coordinates with only the pixels that emit blue light emitting light, you can also check to what extent there is a difference from the color coordinates of ideal blue light.

In this way, the second data obtained through the lighting inspection of the display module may be data about the average luminance of the display area (DA) or data about the difference between the maximum luminance and minimum luminance of the display area (DA). , It may be data for the color coordinates that are most different from the normal color coordinates of the display area (DA). Of course, the second data may include these different types of data. For reference, data about the difference between the maximum luminance and minimum luminance of the display area (DA) may mean data about the difference between the luminance of the brightest part and the darkest part of the display area (DA).

After acquiring the second data in this way, the second data can be associated with the previously acquired first data. Associating second data with previously acquired first data means storing the pair of first data and second data in the database. For each of the plurality of display panels, first data is obtained through a lighting inspection of the display panel, a printed circuit board and a driving chip are attached to the display panel to create a display module, and the display module thus made is turned on. The second data is obtained through inspection, and the first data and the second data are related. By repeating these steps, a database in which the first data and the second data are linked and stored can be built.

Figure 7 is a flow chart schematically showing the process of building a database in this way. As described above, first data is obtained through a lighting inspection of the display panel (S110), a display module is prepared by attaching a printed circuit board and a driving chip to the display panel (S120), and then a lighting inspection of the display module is performed. Through this process, second data can be acquired (S130), the first data and second data can be associated (S140), and a database can be built for a plurality of display panels through this process (S150).

In the case of a database constructed in this way, first data of a normal display panel and second data of a normal display module prepared using the display panel, first data of a normal display panel and an abnormal display module prepared using the display panel second data of an abnormal display panel, first data of an abnormal display panel, and second data of a normal display module prepared using the display panel, first data of an abnormal display panel, and an abnormal display module prepared using the display panel. It may include secondary data, etc.

After constructing the database in this way, it is possible to use it to obtain predicted data for the lighting inspection of the display module even if the lighting inspection is not performed on the display module. Specifically, as shown in FIG. 8, which is a flowchart schematically showing the inspection quality prediction method according to an embodiment of the present invention, after building the database (S100), the above-mentioned data with reference to FIGS. 1 to 4 A display panel to be inspected similar to the above can be prepared. Then, first inspection data can be obtained through a lighting inspection of the display panel to be inspected (S200). The first inspection data may be data about the same physical characteristics as the first data stored in the database. That is, the first inspection data may be data about the average luminance of the display area (DA) of the display panel to be inspected, or may be data about the difference between the maximum and minimum luminance of the display area (DA), and the display area (DA) It may be data for the color coordinate that is most different from the normal color coordinate of DA). Of course, the first inspection data may include these different types of data.

Afterwards, using the constructed database, prediction data can be obtained by predicting the second inspection data when the display panel to be inspected becomes a display module from the first inspection data (S300). If the predicted data is for a normal display module, the display device manufacturing process continues using this display panel. If the predicted data is for an abnormal display module, the display panel is treated as defective and the manufacturing process continues. You may not proceed any further.

For reference, the prediction data may be prediction data about the average luminance of the display area (DA) of the display module to be inspected using the display panel to be inspected, or the difference between the maximum and minimum luminance of the display area (DA). It may be prediction data, or it may be prediction data for the color coordinates that are most different from the normal color coordinates of the display area (DA). Of course, prediction data may include these different types of data. That is, the predicted data may be data about the same physical characteristics as the above-described second data.

In the case of the inspection quality prediction method according to this embodiment, the quality of the display module is predicted before the printed circuit board and driving chip are actually attached to the display panel, and inspection is performed after unnecessary processes, saving time and parts, etc. Waste can be effectively prevented.

Meanwhile, as shown in FIG. 9, which is a flowchart schematically showing the inspection quality prediction method according to an embodiment of the present invention, after obtaining the prediction data (S300), the inspection as described above with reference to FIG. 6 is performed. The target display panel can be prepared (S400). In other words, a display module to be inspected can be prepared by attaching a printed circuit board and a driving chip to the display panel to be inspected (S400). Afterwards, the second inspection data can be obtained through a lighting inspection of the display module to be inspected (S500).

The second inspection data may be data on the same physical characteristics as the prediction data obtained using a database. That is, the second inspection data may be data about the average luminance of the display area (DA) of the display module to be inspected, or may be data about the difference between the maximum and minimum luminance of the display area (DA), and the display area (DA) It may be data for the color coordinate that is most different from the normal color coordinate of DA). Of course, the second inspection data may include these different types of data. That is, the second inspection data may be data about the same physical characteristics as the prediction data.

Afterwards, the predicted data and the second inspection data can be compared (S600). Comparing the predicted data and the second inspection data is to determine whether the display module inspection device is normal. That is, if the difference between the predicted data and the second inspection data is within the preset range, the display module inspection device is judged to be normal, and if the difference between the predicted data and the second inspection data is outside the preset range, the display module inspection device is abnormal. It can be judged that it is.

For example, if the predicted data and the second inspection data are each data about the average luminance of the display area (DA), and the difference between the predicted data and the second inspection data is within 10% of the predicted data, the display module inspection device is normal. In other cases, it can be determined that the display module inspection device is abnormal. If each of the predicted data and the second inspection data is data about the difference between the maximum and minimum luminance of the display area (DA), the difference between the predicted data and the second inspection data is within 10% of the predicted data and the difference in the predicted data is If the difference between the maximum brightness and the maximum brightness in the second inspection data is within 10% of the maximum brightness in the predicted data, the display module inspection device is judged to be normal, and in other cases, the display module inspection device is judged to be abnormal. can do. If each of the predicted data and the second inspection data is data for a color coordinate that is most different from the normal color coordinate of the display area (DA), the difference between the color coordinate value of the predicted data and the color coordinate value of the second inspection data is the color coordinate value of the predicted data. If it is within 10%, the display module inspection device can be judged to be normal, and in other cases, the display module inspection device can be judged to be abnormal.

Through this process, if the display module inspection device is determined to be abnormal, the display module inspection device can be inspected or replaced with a normal display module inspection device. In this way, by automatically determining whether the display module inspection device is normal or abnormal during the manufacturing process of the display device, the manufacturing efficiency of high-quality display devices can be dramatically increased.

Figure 10 is a cross-sectional view schematically showing a portion of the manufacturing process of a display device that is the subject of quality prediction in the inspection quality prediction method according to an embodiment of the present invention. As described above with reference to FIG. 5 , the planarization layer 170 may be located within the display area DA. In this case, the planarization layer 170 may also be located in the peripheral area (PA). FIG. 10 is a cross-sectional view schematically showing a portion of the peripheral area (PA) of the display module in this case, and can be said to be a modified example of the display module shown in FIG. 6.

As shown, the planarization layer 170 may cover the input pads 166 and output pads 165. Accordingly, additional input pads 172 and additional output pads 171 may be positioned on the planarization layer 170 to correspond to the input pads 166 and output pads 165. Of course, the additional input pads 172 and the additional output pads 171 are connected to the lower input pads 166 and output pads 165 through contact holes formed in the planarization layer 170. Additionally, the additional input pads 172 are connected to the input terminals 182 of the driving chip 180, and the additional output pads 171 are connected to the output terminals 181 of the driving chip 180. These additional input pads 172 and additional output pads 171 are made of the same material as the pixel electrode 311 of the display element 310 in the display area DA, such as ITO, IZO, and/or In ₂ O ₃ . It can be included.

Of course, since the planarization layer 170 covers the input pads 166, the planarization layer 170 also covers the portions 167 of the input pads 166 in a direction away from the test thin film transistor (TT). Accordingly, additional signal pads 173 may be positioned on the planarization layer 170 to correspond to portions 167 of the input pads 166 facing away from the test thin film transistor TT. Of course, the additional signal pads 173 are connected to the portions 167 of the lower input pads 166 through contact holes formed in the planarization layer 170. And the additional signal pads 173 are connected to the output terminals 191 of the printed circuit board 190. These additional signal pads 173 may also include the same material as the pixel electrode 311 of the display element 310 in the display area DA, such as ITO, IZO, and/or In ₂ O ₃ .

Of course, the present invention is not limited to this, and the display panel, display module, and/or display device may have a different layer structure from that shown in FIG. 10. For example, an additional insulating layer may be disposed below the pixel electrode 311, and an additional wiring layer may be interposed between the insulating layers.

So far, the explanation has been focused on the inspection quality prediction method, but the display device manufacturing method using this inspection quality prediction method is also within the scope of the present invention. For example, using the database constructed as described above with reference to FIG. 8, predicted data is obtained by predicting the second inspection data when the display panel to be inspected becomes a display module from the first inspection data, and this predicted data If the predicted data is data for a normal display module, the display device manufacturing process continues using this display panel. If the predicted data is data for an abnormal display module, this display panel is treated as defective and the manufacturing process continues. You may not.

As such, the present invention has been described with reference to the embodiments shown in the drawings, but these are merely illustrative, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. . Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the attached claims.

100: substrate 110: buffer layer
120: semiconductor layer 130: gate insulating film
141: Gate electrode 143: Connection wiring
145: Step adjustment unit 150: Interlayer insulating film
161: source electrode 162: drain electrode
165: output pad 166: input pad
168: Test signal line 170: Flattening layer
171: Additional output pad 172: Additional input pad
173: Additional signal pad 175: Pixel definition film
180: Driving chip 190: Printed circuit board

Claims (11)

A first step of acquiring first data through a lighting inspection of the display panel;
A second step of preparing a display module by attaching a printed circuit board and a driving chip to the display panel;
A third step of acquiring second data through a lighting inspection of the display module;
A fourth step of associating first data and second data;
Building a database by repeating the first to fourth steps;
Obtaining first inspection data through a lighting inspection of a display panel to be inspected; and
Obtaining predicted data by predicting second inspection data when the display panel to be inspected becomes a display module from the first inspection data using a database;
Including, inspection quality prediction method. According to paragraph 1,
Preparing a display module to be inspected by attaching a printed circuit board and a driving chip to the display panel to be inspected;
Obtaining second inspection data through a lighting inspection of a display module to be inspected; and
Comparing predicted data and second inspection data;
A method for predicting inspection quality, further comprising: According to paragraph 2,
The step of comparing the predicted data and the second inspection data includes determining that the display module inspection device is normal when the difference between the predicted data and the second inspection data is within a preset range. According to paragraph 2,
The step of comparing the predicted data and the second inspection data includes determining that the display module inspection device is abnormal when the difference between the predicted data and the second inspection data is outside a preset range. According to any one of claims 2 to 4,
An inspection quality prediction method in which the predicted data and the second inspection data are data about the same physical characteristics. According to any one of claims 2 to 4,
The predicted data and the second inspection data include any one of data on the average luminance of the display area, data on the difference between the maximum and minimum luminance of the display area, and data on the color coordinate that is most different from the normal color coordinate of the display area. Including, inspection quality prediction method. According to any one of claims 1 to 4,
An inspection quality prediction method in which the first inspection data and the first data are data about the same physical characteristics. According to any one of claims 1 to 4,
The first inspection data and the first data are any one of data on the average luminance of the display area, data on the difference between the maximum luminance and minimum luminance of the display area, and data on the color coordinate that is most different from the normal color coordinate of the display area. Including, inspection quality prediction method. According to any one of claims 1 to 4,
A method for predicting inspection quality, wherein the predicted data and the second data are data about the same physical characteristics. According to any one of claims 1 to 4,
The predicted data and the second data include any one of data on the average luminance of the display area, data on the difference between the maximum and minimum luminance of the display area, and data on the color coordinate that is most different from the normal color coordinate of the display area. Including, inspection quality prediction method. Determining whether the predicted data obtained according to the method of claim 1 is data for a normal display module; and
If the predicted data is for a normal display module, attaching a printed circuit board and a driving chip to the display panel to be inspected;
A method of manufacturing a display device, including.

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