Device and method for inspecting a sealing member

A sealing inspection device includes a scan unit through which a display device substrate including a top plate coupled to a bottom plate by a sealing member in the sealed area passes; and a photographing unit through which the display device substrate which has passed through the scan unit, further passes. The scan unit generates coordinate values of the sealed area of the display device substrate, detects a defective region in the sealed area of the display device substrate, and includes a plurality of scan cameras. The photographing unit generates an image of the sealed area of the display device substrate using the generated coordinate values, measures an effective sealing width of the sealed area using the generated image, and comprises a measuring camera.

This application claims priority to Korean Patent Application No. 10-2013-0085618 filed on Jul. 19, 2013, and all the benefits accruing therefrom under 35 U.S.C. §119, the entire contents of which are incorporated herein by reference.

BACKGROUND

The invention relates a sealing inspection device and a sealing inspection method. More particularly, the invention relates to a sealing inspection device and a sealing inspection method for inspecting a sealed state of a sealed area of a substrate formed by coupling a top plate and a bottom plate to each other by a sealing member.

(b) Description of the Related Art

As an information-oriented society has developed, the demand for various types of display devices has also increased. Accordingly, various kinds of display devices such as a liquid crystal display (“LCD”, a plasma display panel (“PDP”) and an organic light emitting diode (“OLED”) display have been researched and actively employed as display devices for a variety of equipment.

The OLED display among these kinds of display devices has a structure in which elements such as an organic layer including an emission layer is interposed between a pair of electrodes, e.g., first and second electrodes.

When moisture and/or oxygen are introduced into elements of the OLED display, the elements have various problems in that life span of the elements is reduced due to oxidation or exfoliation of an electrode material therein, light efficiency is deteriorated, and a light emitted color is deteriorated.

Therefore, encapsulation is typically performed to isolate the elements of the OLED display from the outside and prevent moisture from permeating thereto, in a manufacturing process of the OLED display.

To that end, the general OLED display generally includes a display substrate including an organic layer, and an encapsulation substrate disposed opposite to the display substrate and coupled to a sealing member (e.g., a sealant) to perform encapsulation of elements of the OLED display.

In a manufacturing process of the OLED display, the sealing member is coated on a sealed area of the OLED display and then cured such as by laser irradiation. In a curing operation or while a sealed state OLED display is transported, errors or defects are generated in the sealed state OLED display. Therefore, there remains a need for an improved manufacturing or inspection process for an OLED display which evaluates sealing effectiveness in a sealed state of the OLED display.

SUMMARY

One or more exemplary embodiment of the invention provides a sealing inspection device capable of measuring an effective sealing width of a sealed area.

One or more exemplary embodiment of the invention also provides a sealing inspection method capable of measuring an effective sealing width of a sealed area.

An exemplary embodiment of the invention provides a sealing inspection device for inspecting a state of a sealed area. The device includes: a scan unit through which a display device substrate including a top plate coupled to a bottom plate by a sealing member in the sealed area passes; and a photographing unit through which the display device substrate which has passed through the scan unit, further passes. The scan unit generates coordinate values of the sealed area of the display device substrate, detects a defective region in the sealed area of the display device substrate, and includes a plurality of scan cameras. The photographing unit generates an image of the sealed area of the display device substrate using the generated coordinate values, measures an effective sealing width of the sealed area using the generated image, and includes a measuring camera.

The measuring camera may include a dark-field illumination member.

The dark-field illumination member may be attachable to and detachable from the measuring camera.

The measuring camera may include an attachable microscope lens which is attachable to and detachable therefrom, and the dark-field illumination member may be in the microscope lens.

The dark-field illumination member may include a plurality of point light sources arranged annularly at an edge portion of the microscope lens.

The plurality of point light sources may respectively emit light obliquely with reference to a facing direction of the microscope lens.

The device may further include a stage upon which the display device substrate is mounted, and the stage may be configured to move the display device substrate from the scan unit toward the photographing unit.

The photographing unit, using the measuring camera, may generate an image of the defective region detected by the scan unit.

The measuring camera may be movable in at least one axis direction.

The display device substrate may an organic light emitting element.

Another exemplary embodiment of the invention provides a sealing inspection method for inspecting a state of a sealed area. The method includes: detecting a defective region of the sealed area of a display device substrate including a top plate coupled to a bottom plate by a sealing member in the sealed area, in a scanning unit of a sealing inspection device; photographing the detected defective region to generate an image of the defective region, in a photographing unit of the sealing inspection device; and measuring an effective sealing width of the sealed area.

The detecting may include: generating coordinate values of the sealed area; and detecting the coordinate values of the defective region of the sealed area by using a plurality of scan cameras of the scanning unit.

The photographing may include: positioning a measuring camera of the photographing unit at the defective region of the sealed area by using the detected coordinate values of the defective region; and generating the image of the defective region by using the measuring camera positioned at the defective region.

The measuring may include measuring the effective sealing width of the sealed area may include using a measuring camera of the photographing unit, the measuring camera including a dark-field illumination member.

The measuring camera may include a microscope lens which is attachable thereto and detachable therefrom, and the dark-field illumination member is in the microscope lens.

The dark-field illumination member may include a plurality of point light sources arranged annularly at an edge portion of the microscope lens.

The plurality of point light sources may respectively emit light obliquely with reference to a facing direction of the microscope lens.

In accordance with one or more exemplary embodiment of the invention, a sealed area may be efficiently inspected by photographing the sealed area and generating an image thereof.

In accordance with one or more exemplary embodiment of the invention, an effective sealing width of the sealed area may be measured by using a camera equipped with a dark-field illumination member.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the invention will be described in detail with reference to the attached drawings such that the invention can be easily put into practice by those skilled in the art. As those skilled in the art would realize, the described exemplary embodiments may be modified in various different ways, all without departing from the spirit or scope of the invention.

In the drawings and this specification, parts or elements that are not related to the description hereof are omitted in order to clearly describe the invention, and the same or like constituent elements are designated by the same reference numerals throughout the specification. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for better understanding and ease of description, but the invention is not limited thereto.

Further, throughout this specification, when a first part of a layer, a film, a plate, or the like is described as being arranged “on” or “over” a second part, this indicates that the first part is arranged on or over the second part directly or with a third part therebetween.

Hereinafter, the invention will be described in detail with reference to the accompanying drawings.

FIG. 1is a plan view of an exemplary embodiment of a substrate, andFIG. 2is a cross-sectional view taken along line II-II′ ofFIG. 1.

First, an exemplary embodiment of a substrate10serving as a target object to be inspected will be described before describing a sealing inspection device, in accordance with the invention.

One or more exemplary embodiment of a sealing inspection device in accordance with the invention serves as a device for inspecting a sealed area S of the substrate10to determine whether or not the substrate10is defective by detecting whether or not the sealed area S of the substrate10is defective.

Referring toFIG. 1andFIG. 2, the substrate10has a structure in which a top plate12and a bottom plate14are coupled or adhered to each other by a sealing member16. In the illustrated exemplary embodiment, the substrate10may be a substrate for a display device, but the invention is not limited thereto.

In one exemplary embodiment, for example, the substrate10may be a substrate for an organic light emitting diode (“OLED”) display including an organic light emitting element.

Where the substrate10is a substrate for an OLED display, the bottom plate14may be a display substrate on which an emission layer15including an organic light emitting element is disposed, and the top plate12may be an encapsulation substrate which encapsulates the display substrate and the elements thereon.

Accordingly, the exemplary embodiment of the substrate10serving as a target object to be inspected by one or more exemplary embodiment of a sealing inspection device may be an adhering substrate having a structure encapsulated by the encapsulation structure.

In accordance with the illustrated exemplary embodiment, the substrate10may include a plurality of cells as shown inFIG. 1. Referring toFIG. 2as an exemplary embodiment of a cell shown inFIG. 1, each of the cells of the substrate10may include the emission layer15and may be sealed by the sealing member16.

The sealing member16may include a frit, but the invention is not limited thereto.

In an exemplary embodiment of forming the substrate10and/or a cell, sealing material of the sealing member16is coated on an edge of each cell, and a laser or the like is irradiated to portions thereof coated with the sealing material of the sealing member16, to cure the sealing material and form the sealing member16.

In the aforementioned curing operation of the sealing member16, a cross-section of the sealing member16may have a non-uniform width taken in a direction parallel to the top and/or bottom plates14and15. An upper width and a lower width of the formed sealing member16may not be uniform.

For example, as shown inFIG. 2, the cured sealing member16may be have a trapezoidal shape, e.g., a form in which a lower width is smaller than an upper width thereof, in a cross-section thereof.

Where the cured sealing member16has the trapezoidal shape described above, an effective width substantially used for encapsulation may be smaller than an entire width coated with the sealing member16.

Accordingly, it is possible to detect whether a sealed state is poor by measuring a substantially effective width of the coated sealing member16.

In the illustrated exemplary embodiment, as shown inFIG. 2, a smaller width, e.g., the lower width of the sealing member16, is defined as an effective sealing width ES, and a larger width, e.g., the upper width thereof, is defined as the entire sealing width TS.

Further, in exemplary embodiments of the invention, a portion of the substrate10coated with the sealing member16is defined as the sealed area S.

Hereinafter, a sealing inspection device for inspecting the sealed area S of the substrate10will be described with reference toFIG. 3toFIG. 7.

FIG. 3is a front cross-sectional view of an exemplary embodiment of a sealing inspection device in accordance with the invention.FIG. 4is a plan view of the sealing inspection device ofFIG. 3in accordance with the invention.FIG. 5shows an exemplary embodiment of a microscope lens in a sealing inspection device in accordance with the invention.FIG. 6is a cross-sectional view of the microscope lens ofFIG. 5in accordance with the invention.FIG. 7is a photograph of a sealed state of a sealed area measured by an exemplary embodiment of a sealing inspection device in accordance with the invention.

Referring toFIG. 3andFIG. 4, an exemplary embodiment of a sealing inspection device100of the invention serving to inspect a state of the sealed area S in the substrate10for a display device may include a frame110, a column180, a stage160, a scan unit120and a photographing unit140.

The frame110and the column180constitute a body of the sealing inspection device100. In the illustrated exemplary embodiment, the column180may be installed to intersect the frame110, and a scan camera and a measuring camera to be described later may be installed therein.

The substrate10serving as a target object to be inspected, may be mounted on the stage160. The stage160may be substantially flat.

Further, the stage160may be equipped with a fixing member for fixing the substrate10thereto, e.g., an absorber or a clamper.

In exemplary embodiments, the stage160may be movable in at least one axis direction in accordance with the invention.

For example, the stage160may be movable in an X-axis direction as shown inFIG. 3andFIG. 4.

Accordingly, when the substrate10serving as a target object to be inspected is mounted on the stage160, the stage160can move the substrate10mounted thereon in the axis direction.

Further, in accordance with an exemplary embodiment, the stage160can help to perform the sealing inspecting operation efficiently while moving the substrate10from the scan unit120to the photographing unit140to be described later.

The exemplary embodiment of the sealing inspection device100may be divided into two parts with respect to the column180, one of which serves as the scan unit120and the other of which serves as the photographing unit140. The scan unit120and the photographing unit140will now be described in detail.

The scan unit120serves to detect a defective region of the sealed area S of the substrate10, and may be provided at one side of the sealing inspection device100.

In accordance with the illustrated exemplary embodiment, the scan unit120may include a plurality of scan cameras122serving as an imaging member.

As illustrated inFIG. 4, the plurality of scan cameras122may be installed and disposed in a line and side-by-side with respect to the column180. The scan cameras122may be attached to the column180, but are exposed from the column180in the scan unit120of the sealing inspection device100.

The installation and disposition of the scan cameras122are not limited thereto, and the scan cameras122may be installed and disposed at different positions in various ways.

In accordance with an exemplary embodiment, the scan unit120is configured to determine coordinate values of the sealed area S of the substrate10which passes therethrough by using the scan cameras122.

Specifically, the substrate10may be mounted on the stage160to move together with the stage160in an axis direction, e.g., in an x-axis direction as shown inFIG. 3andFIG. 4.

Where the substrate10moves together with the stage160in the axis direction, in accordance with an exemplary embodiment, the substrate10may be moved from the scan unit120toward the photographing unit140to be described later, so as to pass by the scan cameras122installed at one side of the scan unit120.

Herein, the scan cameras122may be disposed to correspond to the sealed area S of the passing substrate10so as to photograph the sealed area S.

Accordingly, the scan cameras122can photograph the sealed area S of the substrate10, and thus the scan unit120can determine the coordinate values of the sealed area S.

The sealing inspection device100may further include a controller (not shown) additionally provided in the scan unit120to calculate the coordinate values of the sealed area S photographed by the scan cameras122.

Further, since the stage160on which the substrate10is mounted is movable, it is possible to effectively photograph the sealed area S of the substrate10even though the location of the scan cameras122is fixed.

However, exemplary embodiments of the invention are not limited to fixing the location of the scan cameras122, and the scan cameras122may be configured to move in several directions.

In an exemplary embodiment, the scan unit120can detect a defective region of the sealed area S of the substrate10.

As described above, the scan cameras122included in the scan unit120are configured to photograph the sealed area S of the substrate10passing through the scan unit120and detect a defective region of the photographed sealed area S.

The scan unit120can determine the coordinate values of the sealed area S of the substrate10passing through the scan unit120and detect the coordinate values of the defective region of the sealed area S photographed by the scan cameras122.

Herein, a calculation operation of the coordinate values of the defective region may be performed by a controller (not shown) additionally provided in the scan unit120

Accordingly, in accordance with the illustrated exemplary embodiment, as the substrate10passes through the scan unit120, the scan unit120can detect the coordinate values of the defective region of the sealed area S while determining the coordinate values of the sealed area S of the substrate10.

As described above, the substrate10passing through the scan unit120may be moved to the photographing unit140.

Herein, in the sealing inspection device100of the illustrated exemplary embodiment, the photographing unit140may be disposed continuously with the scan unit120, and thus the stage160on which the substrate10is mounted may be continuously moved from the scan unit120to the photographing unit140. In one exemplary embodiment, for example, the frame110and/or the column180as the body of the sealing inspection device100may provide the structure such that the stage160on which the substrate10is mounted may continuously move from the scan unit120to the photographing unit140.

The photographing unit140serving to generate an image of the sealed area S of the substrate10passing through the scan unit120may be provided at the other side of the sealing inspection device100.

The sealing inspection device100may be divided into two parts with respect to the column180, one side of which is allotted to the scan unit120and the other side of which is allotted to the photographing unit140, but is not limited thereto.

In the illustrated exemplary embodiment, the photographing unit140may include a measuring camera150.

The measuring camera150serves to photograph a specific region of the sealed area S of the substrate10and generate a detailed image of the specific region. The measuring camera150may include a microscope lens152.

In the illustrated exemplary embodiment, the microscope lens152may be attachably provided in the measuring camera150. In one exemplary embodiment, the microscope lens152is attachably and detachably disposed with the measuring camera150.

Specifically, the microscope lens152may include a plurality of lenses having different magnifications, and one lens may be replaced with an appropriate lens for photographing as necessary.

The measuring camera150may be installed in the column180of the sealing inspection device100and may be movable in at least one axis direction. The measuring camera150may be attached to the column180, but is exposed from the column180in the photographing unit140of the sealing inspection device100.

In the illustrated exemplary embodiment, the measuring camera150can be moved in a vertical direction with respect to the moving direction of the stage160upon which the substrate10is mounted, e.g., in a y-axis direction, as shown inFIG. 4.

However, the moving direction of the measuring camera150is not limited to the y-axis direction. The measuring camera150may be configured to move in several axis directions as necessary.

In the illustrated exemplary embodiment, the photographing unit140can photograph the defective region of the sealed area S of the substrate10and generate an image of the defective region, by using the measuring camera150.

In the illustrated exemplary embodiment, as described above, the scan unit120can detect the coordinate values of the defective region of the sealed area S. The coordinate values of the defective region detected by the scan unit120may be transferred to the measuring camera150of the photographing unit140, such as by a processor and/or a controller.

Accordingly, the measuring camera150can be moved to be located at the defective region of the sealed area S by using the transferred coordinate values of the defective region.

The measuring camera150is movable, and the substrate10is also movable by the movement of the stage160.

In accordance with the illustrated exemplary embodiment, for example, the measuring camera150can be efficiently located at the defective region since the substrate10is movable in the x-axis direction and the measuring camera150is movable in the y-axis direction.

In other words, it is possible to locate the measuring camera150at a specific region by using only the measuring camera150which is movable in a one-axis direction.

Accordingly, a detailed image of the defective region of the sealed area S of the substrate can be photographed and generated by using the measuring camera150.

In an exemplary embodiment, the photographing unit140can measure the effective sealing width ES (seeFIG. 2) of the sealed area S by using the measuring camera150.

Accordingly, it is possible to detect whether or not the sealed state of the sealed area S is defective and detect whether or not the sealing by the sealing member16is defective.

The effective sealing widths ES of all sealed areas S may be measured by using the measuring camera150. However, alternatively, the effective sealing widths ES of specific regions of the sealed areas S of several cells a sample (and not all sealed areas) may be measured to determine whether or not the sealed state is defective.

In addition, it is possible to more precisely inspect the sealed states of the defective regions of the sealed areas S detected by the scan unit120by measuring the effective sealing widths ES of the defective regions of the sealed areas detected by the scan unit120.

In an exemplary embodiment, the measuring camera150may use dark-field illumination to measure the effective sealing width of the sealed area S.

The dark-field illumination is an illumination member for effectively observing particles that are smaller than a lens resolution and/or an object included in a transparent sample.

Specifically, in general illumination, light is vertically emitted to a target object and the target object is observed by using thus-reflected light, while in the dark-field illumination, light is obliquely emitted to a target object and the target object is observed by using only light scattered by the target object.

The exemplary embodiment of the sealing inspection device100of the invention can photograph not only the entire sealing width TS of the sealed area S, but also the effective sealing width ES as shown inFIG. 2by using the measuring camera150including the dark-field illumination member.

A sealed state of a sealed area S measured by the sealing inspection device, e.g., the measuring camera150including the dark-field illumination member is shown inFIG. 7. Referring toFIG. 7, when the sealed area S is photographed by using the measuring camera150including the dark-field illumination member, both of the entire sealing width TS and the effective sealing width ES are shown. As a result, the sealed state can be inspected in more detail.

A ratio of the effective sealing width ES to the entire sealing width TS may be calculated. The ratio may be used to obtain an effective sealing effect and may be set up as a reference value in order to determine whether or not the sealed state is poor by using measurements of the effective sealing width ES.

In the illustrated exemplary embodiment, the dark-field illumination member may be attachably installed in the measuring camera150. In one exemplary embodiment, the dark-field illumination member may be attachable to and detachable from the measuring camera150.

As described above, the measuring camera150may include the microscope lens152which includes a plurality of lenses and is configured to be attachable and detachable from the measuring camera150. The dark-field illumination member may be installed in at least one of the microscope lens152and the lenses of the microscope lens152.

Accordingly, in a case that the sealed area S is photographed by using the measuring camera150, when the dark-field illumination is required to measure the effective sealing width ES, the microscope lens152including the dark-field illumination member may be attached to the measuring camera150. In one exemplary embodiment, the dark-field illumination member may be attachable to and detachable from the measuring camera150, via the microscope lens152.

In accordance with the illustrated exemplary embodiment, the dark-field illumination member may be installed in an annular form at an edge portion of the microscope lens152.

The dark-field illumination member may be installed obliquely with respect to a facing direction of the microscope lens152in order to obliquely emit light to the substrate10.

In the illustrated exemplary embodiment, as shown inFIG. 5, the dark-field illumination member may include a plurality of point light sources such as a plurality of light emitting diode (“LED”) bulbs154in an annular arrangement. The LED bulbs154emit light obliquely with respect to the facing direction of the microscope lens152, as illustrated inFIG. 6. Referring toFIG. 1andFIG. 6, a distal surface of the microscope lens152may face and be substantially parallel to the x-y plane, such that the light generated by the LED bulbs154is emitted obliquely with respect to the x-y plane.

Accordingly, the light emitted by the LED bulbs154travels obliquely with respect to the substrate10.

As such, the exemplary embodiment of the sealing inspection device100of the invention includes the scan unit120and the photographing unit140to inspect the sealed area S of a substrate20more efficiently. The photographing unit140can not only photograph and generate the image of the defective region of the sealed area S, but can also more efficiently measure the effective sealing width ES of the sealed area S in order to determine whether or not the sealed state of the substrate10is defective.

Hereinafter, an exemplary embodiment of a sealing inspection method using the sealing inspection device100in accordance with the invention will be described.

FIG. 8is a flowchart which shows a sealing inspection method in accordance with the invention.

Referring toFIG. 8, the exemplary embodiment of the sealing inspection method includes operations of detecting the defective region in the sealed area S of the substrate (S100); photographing the image of the defective region (S200); and measuring the effective sealing width ES of the sealed area S (S300).

The detecting operation (S100) may be performed by the scan unit120of the sealing inspection device100, and may include generating the coordinate values of the sealed area S, and detecting the coordinate values of the defective region of the sealed area S.

In one exemplary embodiment, a generating operation of the coordinate values of the sealed area S and a detecting operation of the detective region may both be performed by the scan cameras122of the scan unit120. The generating and detecting operations may be performed substantially simultaneously but the invention is not limited thereto.

The photographing operation (S200) and the measuring operation (S300) may both be sequentially performed by the photographing unit140and by using the measuring camera150.

In one exemplary embodiment, the photographing operation (S200) performed by the photographing unit140may include: locating the measuring camera150at the defective region by using the coordinate values of the defective region detected in the detecting operation; and photographing the defective region to generate an image thereof, by using the measuring camera150located at the coordinate values of the defective region.

In the illustrated exemplary embodiment, the measuring camera150may be configured to move in at least one axis direction.

The measuring camera150is configured to move in a direction perpendicular to the moving direction of the stage160upon which the substrate10is mounted so as to be efficiently located at the defective region and to generate the image thereof.

The measuring operation (S300) performed by the photographing unit140serves to measure the effective sealing width ES of the sealed area S. The measuring operation can measure not only the effective sealing width ES of the defective region imaged in the photographing operation but also that of a specific region of the sealed area S or the entire sealed area S.

In one exemplary embodiment, the effective sealing width ES of the sealed area S can be photographed by using the measuring camera150equipped with the dark-field illumination member.

Further, in accordance with an exemplary embodiment, the dark-field illumination member is included in the microscope lens152which is attachably and detachably installed with respect to the measuring camera150so that the measuring camera150used in the photographing operation can also be used in the measuring operation.

Accordingly, both of the photographing operation (S200) and the measuring operation (S300) can be sequentially or simultaneously performed by the photographing unit140of the sealing inspection device100.

As such, in an exemplary embodiment, the coordinate values of the sealed area S of the substrate10and the defective region of the sealed area S can be generated and detected by the scan unit120. Accordingly, the photographing unit140can efficiently photograph the defective region of the sealed area S and generate an image of the defective region.

Further, the photographing unit140can measure the effective sealing width ES of the sealed area S by using the dark-field illumination. Accordingly, the sealed state of the sealed area S of the substrate10is more effectively inspected.

Resultantly, determining the existence of the sealed state of the substrate10can be achieved more efficiently by using one or more exemplary embodiment of the sealing inspection method of the invention to thereby improve quality of the substrate10.