KR100711895B1 - Laser sealing apparatus and method for fabricating flat panel display device using the same - Google Patents

Abstract

A laser irradiation apparatus according to an embodiment of the present invention comprises a first and second substrates and a mask on a substrate stage, and the laser irradiation apparatus for melting a frit pattern formed in a predetermined region of the second substrate, wherein the frit pattern At least two laser heads provided adjacent to each other so that the laser is irradiated along at least two paths of the image; A laser head guide supporting the laser head, the laser head moving the frit pattern region; At least one first alignment unit attached to one region of the laser head guide, the first CCD configured to measure positions of the substrate and the mask, and for aligning the substrate and the mask; And a second CCD attached to an area of the laser head and measuring a position of the substrate and the laser head, and a second alignment part for aligning the substrate and the laser head.

Description

Laser irradiation apparatus and method for manufacturing flat panel display using the same {Laser sealing apparatus and method for fabricating flat panel display device using the same}

1 is a schematic perspective view of a laser irradiation apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a flat panel display manufactured by the laser irradiation apparatus shown in FIG. 1. FIG.

3a and 3b are diagrams showing the energy waveform of the laser irradiated upon melting the frit pattern.

4A to 4D are cross-sectional views illustrating a manufacturing process of a flat panel display device according to an exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

14 frit pattern 16 laser head

100: flat panel display 110: substrate

112: light emitting unit 120: sealing member

130: frit pattern

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser irradiation apparatus and a method for manufacturing a flat panel display using the same. The present invention relates to a laser irradiation apparatus and a method for manufacturing a flat panel display using the same.

Recently, various flat panel displays have been developed to reduce weight and volume, which are disadvantages of cathode ray tubes. The flat panel display includes a liquid crystal display, a field emission display, a plasma display panel, and an organic light emitting display.

Such flat panel display devices are ultra-thin and flexible in view of their driving characteristics, and thus many studies have been conducted.

Among these, the organic electroluminescent display device has a property deteriorated by the penetration of moisture, and thus requires a sealing member to prevent the penetration of moisture.

Conventionally, metal cans or glass substrates are processed into caps so as to have grooves to form a sealing member, and a desiccant for absorbing moisture is mounted in the form of a powder or in the form of a film. After manufacturing and adhering with a double-sided tape, a method of joining the sealing member to a substrate on which an element was formed using a UV curing sealant or a thermosetting sealant was used.

That is, in the related art, the substrate on which the element is formed and the sealing member are bonded by using a UV curing sealant or a heat curing sealant. However, in the case of the sealant of the material, there is a limit to preventing penetration of oxygen or moisture. There is.

As such, when oxygen or moisture penetrates into the device, external moisture may be degraded due to internal factors such as deterioration of the light emitting layer due to oxygen from the first electrode ITO and deterioration due to the reaction between the light emitting layer and the interface. , Deterioration due to external factors such as oxygen, ultraviolet rays and fabrication conditions of the device easily occurs. That is, external moisture or the like penetrates into the display unit, causing separation between the light emitting layer and the electrode and generating defective pixels.

In order to overcome this problem, a desiccant for absorbing moisture is mounted inside the sealing member. The method of mounting such a desiccant has a complicated process, thereby increasing materials and process cost, and increasing the overall thickness of the substrate. There is a disadvantage that the substrate used for encapsulation is not transparent or cannot be used for front emission or double-sided emission due to the portion on which the desiccant is mounted.

In addition, in the case of the sealant for bonding the sealing member and the substrate, the pressure resistance characteristics are not good, and as the time passes, the moisture permeability is significantly lowered, thereby reducing the sealing effect.

In the organic light emitting device, when moisture or oxygen flows into the device from the surrounding environment, the life of the device is shortened due to oxidation and peeling of the electrode material, and the luminous efficiency is lowered and the color of light emission is deteriorated. do.

In order to solve the above problems, a method of encapsulating a capsule has been devised to improve adhesion between a device substrate and a cap by using a frit as a material for bonding the substrate and the sealing member.

According to US Patent Publication No. 20040207314, which discloses a structure in which a frit is applied to a glass substrate to seal an organic electroluminescent display device, a frit is used and a laser is melted so that the device substrate and the cap are completely separated. Since the sealing is more effective to protect the organic light emitting device.

However, in irradiating the frit pattern with a laser, the energy region of the laser capable of melting the frit pattern including the point where the laser is irradiated is smaller than the width of the frit pattern.

Therefore, when curing the frit pattern by using a laser irradiation apparatus having a single head, when the laser head is irradiated along the center portion of the frit pattern, the energy of the laser does not reach the edge region of the frit pattern due to incomplete melting. Some incomplete hardening may occur, and when incomplete hardening occurs, oxygen or moisture penetrates, causing separation between the light emitting layer and the electrode provided in the light emitting unit, and causing a problem such as generating a bad pixel. have.

The present invention melts the frit pattern formed on the sealing member with the substrate and the sealing member on which the element is formed, so that the laser can be irradiated along at least two paths so that the frit pattern is formed. An object of the present invention is to provide a laser irradiation apparatus for preventing incomplete melting and curing and a method of manufacturing a flat panel display using the same.

In order to achieve the above object, a laser irradiation apparatus according to an embodiment of the present invention includes a first substrate, a second substrate, and a mask on a substrate stage, and a laser irradiation apparatus for melting a frit pattern formed in a predetermined region of the second substrate. A laser head comprising: at least two laser heads disposed adjacent to each other to irradiate a laser along at least two paths on the frit pattern; A laser head guide supporting the laser head, the laser head moving the frit pattern region; At least one first alignment unit attached to one region of the laser head guide, the first CCD configured to measure positions of the substrate and the mask, and for aligning the substrate and the mask; And a second CCD attached to an area of the laser head and measuring a position of the substrate and the laser head, and a second alignment part for aligning the substrate and the laser head.

Here, the laser heads are provided in pairs, and the pair of laser heads are positioned on the same line or spaced apart from each other by a predetermined interval.

The first substrate may be a substrate on which a plurality of light emitting parts are formed, the second substrate may be a sealing member facing one surface of the substrate on which the light emitting parts are formed, and the light emitting part may be an organic electroluminescent part including an organic electroluminescent element. The organic electroluminescent device is characterized by comprising a pair of electrodes facing each other and an organic layer disposed between the electrodes and including at least an organic light emitting layer.

In addition, the frit pattern melted by the laser irradiation is characterized in that it has at least one or more inflection point in the region bonded to the first substrate.

In addition, a method of manufacturing a flat panel display device according to an embodiment of the present invention includes the steps of forming a plurality of light emitting elements on one surface of a substrate; Preparing a sealing member to face one surface of the substrate; Applying a frit pattern to one surface of the sealing member facing the substrate, and bonding the frit pattern to the substrate; The frit pattern is melted by irradiating a laser simultaneously or at predetermined time intervals along each path along at least two paths to the frit pattern, and the substrate and the sealing member are bonded by curing the melted frit pattern. Characterized in that the step is included.

Here, the light emitting device is an organic electroluminescent device, and when the laser is irradiated with the laser along two paths of the frit pattern, the laser is irradiated along one quarter and three quarters of the frit pattern. When the laser is irradiated along two paths, a pair of laser heads located on the same line is driven to melt the frit pattern, or when the laser is irradiated along the two paths, a pair of laser heads spaced apart by a predetermined interval The laser is irradiated along the first path by the first laser head to melt the first region of the frit pattern first, and after a predetermined time, the laser is irradiated along the second path by the second laser head to generate the frit pattern. It is characterized in that the two zones are melted.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic perspective view of a laser irradiation apparatus according to an embodiment of the present invention.

Referring to FIG. 1, in the laser irradiation apparatus according to the present invention, the first substrate 12b and the second substrate 12a are mounted on the substrate stage 11 in the chamber 10. A mask 13 is provided on the second substrate 12a, and a transmissive portion 13a for transmitting a laser is formed on the mask 13.

The predetermined surface of the second substrate 12a to which the laser is irradiated corresponding to the transmission portion 13a becomes the sealing portion 12c.

In this case, the first substrate is a substrate having a plurality of light emitting parts, and the second substrate refers to a sealing member bonded to correspond to the first substrate.

The frit pattern 14 is coated on the opposite surface of the sealing portion 12c of the second substrate 12a.

In the exemplary embodiment of the present invention, at least two laser heads 16 are provided in a group, and each of the laser heads is supported by the laser head guide 17, and the substrates 12a, The upper part of 12b) is mounted to be movable.

In FIG. 1, two laser heads are provided, but the laser head is not limited thereto. In addition, the pair of laser heads may be formed on the same line, or may be formed spaced apart from each other by a predetermined interval, it is shown in Figure 1 formed on the same line.

In addition, one area of each of the laser head guides 17 includes a first CCD for measuring positions of the substrates 12a and 12b and the mask 13. The substrates 12a, At least one first alignment portion 15 for aligning 12b) with the mask 13 is mounted. Accordingly, the first alignment unit 15 aligns the shape of the sealing unit 12c so that the patterned mask 13 and the substrates 12a and 12b coincide with each other.

In addition, one area of the laser heads 16 includes a second CCD for measuring positions of the substrates 12a and 12b and the laser head 16, and the substrates 12a, 12b) and a second alignment portion 18 for aligning the laser head 16 are mounted. Thus, the second alignment portion 18 aligns the moving position of the laser head 16 with the sealing portion 12c.

A temperature control unit (not shown) for adjusting the temperature inside the chamber with a temperature sensor is further provided at a position corresponding to the second alignment unit 18 of the laser head 16.

In addition, the substrate stage 11 is formed to be at least larger than the substrates 12a and 12b to support the substrates 12a and 12b, and the mask 13 corresponds to the pattern of the sealing portion 12c. The permeation | transmission part 13a to be formed is formed.

Although not shown in the drawing, a monitoring camera is installed in the chamber 10 where laser sealing is performed, and thus, a failure rate of the organic light emitting display device can be reduced by monitoring the sealing process.

The laser irradiation apparatus according to the embodiment of the present invention is characterized in that at least two laser heads are provided, through which the laser head is at least two or more of the frit pattern when melting the frit pattern by the laser irradiation Irradiation of the laser along a path may prevent the frit pattern from being incompletely melted.

FIG. 2 is a cross-sectional view of a flat panel display manufactured by the laser irradiation apparatus of FIG. 1.

However, in the exemplary embodiment of the present invention, the flat panel display will be described as an organic electroluminescent display as an example, but the flat panel display according to the present invention is not necessarily limited thereto.

Referring to FIG. 2, a flat panel display device 100 according to an embodiment of the present invention may include a substrate 110 on which a plurality of light emitting elements 112 are formed; A sealing member 120 positioned on the substrate so as to face one surface of the substrate 110 on which the light emitting element 112 is formed; It is configured to include a frit pattern 130 for bonding the substrate and the sealing member.

That is, a plurality of flat panel display devices are formed by bonding the first substrate and the second substrate of FIG. 1, and the flat panel display device illustrated in FIG. 2 is one of the plurality of flat panel display devices formed through FIG. 1.

At this time, the frit pattern 130 is formed along the edge surface of the sealing member 120, and is bonded to the substrate and then melted and cured to bond the substrate 110 and the sealing member 120 together. In the embodiment of the present invention, when the frit pattern 130 is melted, the frit pattern is incompletely melted by irradiating a laser along at least two paths by the laser irradiation apparatus described above with reference to FIG. 1. It is characterized by that it is prevented.

Each light emitting device 112 formed on the substrate 110 may be an organic electroluminescent device.

Accordingly, the light emitting device 112 may be provided as a pair of electrodes facing each other and an organic layer disposed between the electrodes and including at least an organic light emitting layer. In this case, the organic electroluminescent unit may be applied whether the driving scheme is a passive matrix or an active matrix.

The organic EL device 112 is disposed such that an anode electrode for supplying holes and a cathode electrode for supplying electrons are opposed to each other, and between the anode electrode and the cathode electrode. It is composed of an organic layer disposed in the light emitting.

In general, the anode electrode is formed on the substrate 110, the organic layer is formed thereon, and the cathode electrode is formed on the organic layer, but is not necessarily limited thereto, the position of the anode electrode and the cathode electrode may be reversed. Do.

When the image is a rear emitting type implemented toward the substrate 110, the anode electrode may be formed as a transparent electrode, and the cathode electrode may be formed as a reflective electrode. In the case of a front emitting type in which an image is formed on the opposite side of the substrate 110, the anode electrode may be formed as a reflective electrode, and the cathode electrode may be formed as a transmissive electrode.

The anode electrode and the cathode electrode may be formed in a predetermined pattern, in the case of the active emission type, the cathode electrode may be deposited on the entire surface. However, the present invention is not necessarily limited thereto and may be patterned.

The organic layer disposed between the anode electrode and the cathode electrode may be a low molecular or high molecular organic layer. When the low molecular organic layer is used, a hole injection layer (HIL), a hole transport layer (HTL), and an organic light emitting layer may be used. (EML: Emission Layer), Electron Injection Layer (EIL), Electron Transport Layer (ETL), etc. may be formed by stacking in a single or complex structure, and the usable organic material may be copper phthalocyanine ( CuPc: copperphthalocyanine), N, N-di (naphthalen-1-yl) -N, N'-diphenyl-benzidine (N, N'-Di (naphthalene-1-yl) -N, N'-diphenylbenzidine: NPB ), Tris-8-hydroxyquinoline aluminum (Alq3) and the like can be variously applied. These low molecular weight organic layers can be formed by vacuum deposition.

In the case of the polymer organic layer, the structure may include a hole transporting layer (HTL) and a light emitting layer (EML). In this case, PEDOT is used as the hole transporting layer, and polyvinylvinylene (PPV) and polyfluorene are used as the light emitting layer. Polymer organic materials such as (Polyfluorene) are used and can be formed by screen printing or inkjet printing.

In such an organic layer, at least the light emitting layer EML may be patterned for each pixel of red (R), green (G), and blue (B) colors to implement a full color.

In the organic electroluminescent device 112, as anode and cathode voltages are applied to the anode electrode and the cathode electrode, holes injected from the anode electrode are moved to the light emitting layer, and electrons are injected from the cathode electrode to the light emitting layer, In this light emitting layer, electrons and holes recombine to generate excitons, and as the excitons change from the excited state to the ground state, fluorescent molecules in the light emitting layer emit light to form an image. In the case of a full color organic light emitting display device, a full color is realized by including pixels emitting three colors of red (R), green (G), and blue (B).

In addition, in the case of the sealing member 120 facing the substrate 110 on which the light emitting device 112 is formed, the frit pattern 130 is formed along the edge region of the sealing member 120 as shown.

The frit pattern 130 is melted by a laser. In the present invention, when the frit pattern 130 is melted, the frit pattern 130 is prevented from being incompletely melted by irradiating a laser along at least two paths. It is characterized by.

Hereinafter, a method of manufacturing an organic light emitting display device using the laser irradiation device of the present invention will be described with reference to FIG. 1.

First, a first substrate 12b including a plurality of light emitting parts having at least one light emitting element formed on the substrate stage 11 in the chamber 10, and a light emitting part forming region of the first substrate 12b. A second substrate 12a and a mask 13 as sealing members joined to the region are provided.

Then, the frit 14 in a solid state is coated on the edge region of the second substrate 12a. At this time, when the heat applied to the glass material is sharply dropped to produce the frit 14 to be used, the frit 14 in the form of a glass powder is produced. In general, the frit 14 includes an oxide powder in the glass powder. do. Then, an organic substance is added to the frit 14 containing the oxide powder to make a gel paste, and then fired in a range of 300 ° C to 500 ° C. When the frit 14 is fired, the organic substance is extinguished in the air, and the gel paste is cured to exist as the solid frit 14.

Subsequently, the first substrate 12b and the second substrate 12a are bonded to each other, the mask 13 is positioned on a frit pattern formed on the second substrate 12a, and the laser head guide 17 is disposed thereon. The frit pattern and the mask 13 are aligned through the first CCD of the first alignment unit 15 attached to one region of the substrate.

Finally, at least two or more laser heads 16 moving on the mask 13 by the laser head guide 17 irradiate the laser with an intensity in the range of about 25 kW to 50 kW, thereby providing the frit pattern 14. Is melted and the frit pattern in the molten state is cured to bond the first substrate 12b and the second substrate 12a together.

In melting the frit pattern, an embodiment of the present invention prevents the frit pattern from being incompletely melted by irradiating a laser along at least two paths of the frit pattern.

3A and 3B are diagrams showing energy waveforms of a laser irradiated when melting a frit pattern.

3A illustrates a case where the frit pattern is melted using a single laser head, and FIG. 3B illustrates a case where the frit pattern is melted using a pair of laser heads.

First, as shown in FIG. 3A, when using a single laser head, the energy waveform of the laser including the point at which the laser is irradiated may include an energy region E capable of melting the frit pattern 130. It is smaller than the panel width of the formed frit pattern 130.

Therefore, when the laser is irradiated along the center portion of the frit pattern 130, the energy of the laser does not reach the edge region of the frit pattern 130, so that incomplete melting may occur. In this case, incomplete melting occurs. Oxygen or moisture may penetrate, causing separation between the light emitting layer and the electrode provided in the light emitting unit, and causing a problem such as generating a bad pixel.

In order to overcome this, an embodiment of the present invention is provided with a plurality of laser heads during melting of the frit pattern 130 in irradiating a laser having an energy waveform shown in FIG. 3A as shown in FIG. 3B. The laser may be irradiated along two or more paths, and thus the entire frit pattern 130 may be included in the energy region E of the laser to overcome the problems described above with reference to FIG. 3A. do. That is, the frit pattern can be prevented from incomplete melting.

For example, when irradiating a laser along two paths, the entire frit pattern 130 is applied to the effective energy region E of the laser by irradiating along a quarter point and a third quarter point of the frit pattern 130. It can be included.

When the laser is irradiated along at least two paths as described above, the frit pattern 130 melted by the laser irradiation may have at least one inflection point in the region where it is bonded with the substrate as shown in the enlarged portion of FIG. 2. It is formed to have A).

4A to 4D are cross-sectional views illustrating a manufacturing process of a flat panel display device according to an exemplary embodiment of the present invention.

First, as illustrated in FIG. 4A, a plurality of light emitting devices 112 are formed on one surface of the substrate 110.

Here, each light emitting device 112 formed on the substrate 110 may be an organic electroluminescent device, and the detailed configuration thereof is the same as described above with reference to FIG.

Next, as shown in FIG. 4B, the sealing member 12 is prepared to face one surface of the substrate 110 on which the light emitting device is formed.

The sealing member 120 may be a glass substrate, but is not necessarily limited thereto, and may be a plastic or metal cap.

Next, as shown in FIG. 4C, the frit pattern 130 is applied to the surface of the sealing member 120 facing the substrate 110, and the frit pattern 130 is applied after the frit pattern 130 is applied. The sealing member 120 is bonded to the substrate 110 to be bonded to the substrate 110.

Finally, referring to FIG. 4D, a laser is irradiated along at least two paths of the frit pattern 130 to melt the frit pattern 130 and thereby the substrate 110 and the sealing member 120. ) Is coalesced.

That is, when the frit pattern 130 is melted, the entire frit pattern 130 is included in the energy region of the laser beam by irradiating the laser along at least two paths by the laser irradiation apparatus illustrated in FIG. 1. As a result, an incomplete melting portion can be prevented.

For example, when two laser heads 16 are provided as shown in FIG. 1 to irradiate a laser along two paths, one quarter and three quarters of the frit patterns 14 and 130 are provided. By irradiating the laser along the point, the entire frit pattern can be included in the effective energy region of the laser.

However, in this case, the melting method of the frit pattern may vary slightly depending on whether the pair of laser heads 16 are located on the same line or spaced apart from each other by a predetermined interval.

That is, when the pair of laser heads are located on the same line, the laser is irradiated through the pair of laser heads at the same time as the laser is irradiated along the two paths to melt the frit pattern. When the pair of laser heads are spaced apart by a predetermined interval, the first laser head is irradiated with a laser along the first path to melt the first region of the frit pattern first, and then, after a predetermined time, the second path is moved by the second laser head. Accordingly, the laser is irradiated to melt the second region of the frit pattern to melt the entire frit pattern.

When melting of the entire frit pattern is completed through the above process, the frit pattern is cured, thereby completely bonding the substrate and the sealing member.

According to the present invention as described above, there is an advantage in that a frit sealing structure having a high sealing effect can be obtained by irradiating a laser along at least two paths and melting the frit in bonding the substrate and the sealing member.

In addition, since the frit is completely sealed, the light emitting part can be completely isolated from the external environment, and thus, a separate desiccant or the like is not required, and as a result, the life of the flat panel display device can be further improved.

The above detailed description and drawings are merely exemplary of the present invention, but are used only for the purpose of illustrating the present invention and are not intended to limit the scope of the present invention as defined in the meaning or claims.

Accordingly, those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical protection scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (12)

A laser irradiation apparatus comprising a first substrate, a second substrate, and a mask on a substrate stage, wherein the frit pattern formed in a predetermined region of the second substrate is melted. At least two laser heads provided adjacent to each other such that the laser is irradiated along at least two paths on the frit pattern; A laser head guide supporting the laser head, the laser head moving the frit pattern region; At least one first alignment unit attached to one region of the laser head guide, the first CCD configured to measure positions of the substrate and the mask, and for aligning the substrate and the mask; And And a second alignment unit attached to one region of the laser head to measure a position of the substrate and the laser head, and a second alignment unit for aligning the substrate and the laser head. Device. The method of claim 1, The laser irradiation apparatus, characterized in that provided in a pair of the laser head. The method of claim 2, And the pair of laser heads are positioned on the same line or spaced apart from each other by a predetermined interval. The method of claim 1, And the first substrate is a substrate on which a plurality of light emitting parts are formed, and the second substrate is a sealing member facing one surface of the first substrate on which the light emitting parts are formed. The method of claim 4, wherein And the light emitting unit is an organic electroluminescent unit including an organic electroluminescent element. The method of claim 5, And the organic electroluminescent device comprises a pair of electrodes facing each other and an organic layer disposed between the electrodes and including at least an organic light emitting layer. The method of claim 1, And a frit pattern melted by the laser irradiation has at least one inflection point in the region bonded to the first substrate. Forming a plurality of light emitting devices on one surface of the substrate; Preparing a sealing member to face one surface of the substrate; Applying a frit pattern to one surface of the sealing member facing the substrate, and bonding the frit pattern to the substrate; The frit pattern is melted by irradiating a laser simultaneously or at predetermined time intervals along each path along at least two paths to the frit pattern, and the substrate and the sealing member are bonded by curing the melted frit pattern. Flat panel display manufacturing method characterized in that it comprises a step. The method of claim 8, The light emitting device is a flat panel display device characterized in that the organic electroluminescent device. The method of claim 8, And when the laser is irradiated along two paths of the frit pattern, the laser is irradiated along one quarter and three quarters of the frit pattern. The method of claim 10, And when the laser is irradiated along the two paths, a pair of laser heads located on the same line are simultaneously driven to melt the frit pattern. The method of claim 10, When the laser is irradiated along the two paths, a pair of laser heads spaced apart from each other by a predetermined distance is driven so that the first laser head is irradiated with the laser along the first path to melt the first region of the frit pattern first. And a laser is irradiated along the second path by the second laser head after a lapse of time to melt the second region of the frit pattern.

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