KR20110050985A - Organic electro-luminescence device - Google Patents

Abstract

PURPOSE: An organic electroluminescent device is provided to maximize heat dissipation by effectively discharging heat from an OLED to the outside through a heat radiation member comprised of a heat radiation pad and a cover film on the rear of the OLED. CONSTITUTION: A heat radiation member(200) is comprised of a heat radiation pad(210) and a cover film(220) for protecting the heat radiation pad. Each edge of the heat radiation pad has a cut structure. The heat radiation pad is attached to the rear of an OLED through a conductive adhesive tape. A cover film surrounds the heat radiation pad and is attached to the adhesive materials.

Description

Organic electroluminescent device

The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device having a heat dissipation member for dissipating an organic light emitting display device.

Until recently, cathode ray tubes (CRT) have been mainly used as display devices. However, in recent years, flat panel such as plasma display panel (PDP), liquid crystal display device (LCD), organic electro-luminescence device (OLED), which can replace CRT Display devices are widely researched and used.

Among the flat panel display devices as described above, the organic light emitting display device (hereinafter referred to as OLED) is a self-light emitting device, and since the backlight used in the liquid crystal display device which is a non-light emitting device is not necessary, a light weight can be achieved.

In addition, the viewing angle and contrast ratio are superior to the liquid crystal display device, and it is advantageous in terms of power consumption. It is also possible to drive DC low voltage, has a fast response speed, and the internal components are solid, so it is strong against external shock and has a wide temperature range. It has advantages.

In particular, since the manufacturing process is simple, there is an advantage that can reduce the production cost more than the conventional liquid crystal display device.

OLEDs having these characteristics are largely divided into a passive matrix type and an active matrix type. The passive matrix type constitutes a device in a matrix form while crossing signal lines, whereas an active matrix type is a pixel. The thin film transistor, which is a switching element that turns on / off, and the driving thin film transistor which transmits current and the capacitor which maintains voltage for one frame are positioned per pixel.

In recent years, the passive matrix type has many limited elements such as resolution, power consumption, and lifespan. Accordingly, active matrix type OLEDs capable of realizing high resolution and large screens have been actively studied.

1 is a schematic cross-sectional view of a general active matrix OLED, and the OLED is a bottom emission method.

As shown, the OLED 10 is usually composed of a first substrate 1 made of glass, and a second substrate 2 facing the first substrate 1, and the first and second substrates 1. , 2) are spaced apart from each other, and the edges thereof are encapsulated and bonded through a seal pattern 20.

In detail, the driving thin film transistor DTr is formed in each pixel region P on the first substrate 1, and the first electrode 11 constituting the organic light emitting diode E, The organic light emitting layer 13 and the second electrode 15 are sequentially formed. The first electrode 11 is electrically connected to the driving thin film transistor DTr.

In this case, the first electrode 11 may be made of a transparent conductive material, and the second electrode 15 may be made of an opaque conductive material. Accordingly, the light emitted from the organic light emitting layer 13 is emitted toward the first electrode 11.

In addition, a moisture absorbent 17 is formed on the inner surface of the second substrate 2 to remove moisture penetrated from the outside.

On the other hand, the OLED 10 has a disadvantage in that the life is drastically reduced by heat generated during driving and deterioration of the driving thin film transistor DTr.

Recently, in order to solve such disadvantages, it has been proposed to configure a fan (not shown) or a heat pipe (not shown) in the apparatus for modularizing the OLED 10, but such a heat dissipation mechanism has been proposed to some extent. Although the effect of the price ratio is insignificant, the heat dissipation structure and its installation has a complex problem.

In addition, such a heat dissipation structure causes a problem that goes against the trend of light weight and thickness of the OLED 10, in particular in the case of the flexible OLED (10) such a problem becomes more prominent.

The present invention is to solve the above problems, the first object is to effectively radiate the OLED.

It is also a second object to provide a lightweight and thin OLED.

In order to achieve the above object, the present invention provides an organic electroluminescent device comprising a display surface for displaying an image and a rear surface opposite to the display surface, the adhesive material on the back of the organic electroluminescent device A heat dissipation pad attached thereto, wherein the heat dissipation pad has a structure in which each corner portion is cut; The organic light emitting device includes a cover film surrounding the heat dissipation pad and having an edge bonded to the adhesive material.

In this case, the cover film may include a size of the heat radiation pad, a thickness of the heat radiation pad, and an adhesive width bonded to the adhesive material, and each corner portion of the cover film has at least an adhesive width bonded to the adhesive material. 2 to 3 mm.

The edge of the cover film has an adhesive width of at least 2 to 3 mm to be bonded to the adhesive material, and the cut structure is an isosceles triangle structure.

The heat dissipation pad may include a heat transfer filler in a resin composition such as epoxy, and the heat transfer filler may be graphite, aluminum (Al), copper (Cu), nickel (Ni), silver (Ag), or the like. One of the metal particles, the cover film is PTFE (poly tetra fluoroethylene) film, flame retardant PVC (poly vinyl chloride) film, flame retardant polyester (poly ether) film, PEI (poly cthylene imide) film, silicon film, silicone Rubber film, fluorine resin film, insulation film, Teflon film PVC (poly vinyl chloride) protective film, PE (polyethylene) film, PO (poly olefin) film is one of the selected.

The adhesive material may be a conductive adhesive tape including a metal epoxy, and the organic light emitting diode may include first and second substrates facing each other, and an inner surface of the first substrate may include a switching thin film transistor and a driving thin film transistor. An organic electroluminescent diode is formed and encapsulated through the second substrate.

As described above, by attaching a heat dissipation member consisting of a heat dissipation pad and a cover film on the back of the OLED is not implemented according to the present invention, by releasing the high temperature heat generated from the OLED to the outside to maximize the heat dissipation effect It can be effected.

In particular, by forming each corner portion of the heat dissipation pad to be cut structure, thereby improving the adhesion area between the cover film and the OLED back, there is an effect to further improve the adhesive force between the heat dissipation pad and the OLED back.

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

2 is a cross-sectional view schematically showing an OLED according to an embodiment of the present invention.

Meanwhile, the OLED 100 is divided into a top emission type and a bottom emission type according to the transmitted direction of emitted light. Hereinafter, the bottom emission method will be described as an example.

As shown, the bottom emission type OLED 100 according to the present invention includes a first substrate 101 having a driving and switching thin film transistor DTr (not shown), an organic light emitting diode E, and a first substrate ( Comprising a second substrate 102 for encapsulation facing the 101, the first and second substrates 101, 102 are spaced apart from each other, the edge portion thereof through a seal pattern (120) Encapsulated and cemented.

In addition, a moisture absorbent 118 is formed on the inner surface of the second substrate 102 to remove moisture penetrated from the outside.

Here, the semiconductor layer 103 is formed on the first substrate 101. The semiconductor layer 103 is made of silicon, and a central portion thereof has a high concentration of impurities on both sides of the active region 103a and the active region 103a. The doped source and drain regions 103b and 103c are formed.

The gate insulating layer 105 is formed on the semiconductor layer 103.

A gate electrode 107 and a gate wiring extending in one direction are formed on the gate insulating layer 105 in correspondence with the active region 103a of the semiconductor layer 103.

In addition, a first interlayer insulating film 109a is formed on the entire surface of the gate electrode 107 and the gate wiring (not shown). At this time, the first interlayer insulating film 109a and the gate insulating film 105 below are formed in an active region ( 103a) first and second semiconductor layer contact holes 116 exposing the source and drain regions 103b and 103c located on both sides thereof, respectively.

Next, an upper portion of the first interlayer insulating layer 109a including the first and second semiconductor layer contact holes 116 is spaced apart from each other and exposed through the first and second semiconductor layer contact holes 116. Source and drain electrodes 110a and 110b are formed in contact with 103b and 103c, respectively.

At this time, the semiconductor layer 103 including the source and drain electrodes 110a and 110b and the source and drain regions 103b and 103c in contact with the electrodes 110a and 110b and the gate insulating layer formed on the semiconductor layer 103. The 105 and the gate electrode 107 form a driving thin film transistor DTr.

Although not shown in the drawing, a data line (not shown) defining the pixel area P is formed to cross the gate line (not shown). The switching thin film transistor (not shown) has the same structure as the driving thin film transistor DTr and is connected to the driving thin film transistor DTr.

In addition, the switching and driving thin film transistor (DTr) shows, as an example, a top gate type in which the semiconductor layer 103 is formed of a polysilicon semiconductor layer. As a variation thereof, amorphous and pure impurities are used. It may be formed of a bottom gate type made of silicon.

A second interlayer insulating film 109b having a drain contact hole 117 exposing the drain electrode 110b is formed over the source and drain electrodes 110a and 110b.

In addition, the first electrode 111 constituting the organic light emitting diode E, the organic light emitting layer 113, and the second electrode 115 are sequentially disposed in an area that substantially displays an image on the second interlayer insulating film 109b. It is formed.

The first and second electrodes 111 and 115 and the organic light emitting layer 113 formed therebetween form an organic light emitting diode (E).

The first electrode 111 is connected to the drain electrode 110b of the driving thin film transistor DTr, and the first electrode 111 is formed for each pixel region P, and the first electrode for each pixel region P is formed. A bank 119 is positioned in the non-pixel region NA between the electrodes 111.

That is, the bank 119 is formed in a matrix type having a lattice structure as a whole, and the first electrode 111 is separated by pixel region P with the bank 119 as a boundary portion for each pixel region P. FIG. It is formed into a structure.

In this case, the first electrode 111 may be formed of indium tin oxide (ITO), which is a material having a relatively high work function value to serve as an anode electrode.

In addition, the second electrode 115 is made of aluminum (Al) or aluminum alloy (AlNd), which is a metal material having a relatively low work function in order to serve as a cathode.

Therefore, the light emitted from the organic light emitting layer 113 is driven by the bottom emission method emitted toward the first electrode 111.

In addition, the organic light emitting layer 113 may be formed of a single layer made of a light emitting material, and in order to increase the light emitting efficiency, a hole injection layer, a hole transporting layer, an emitting material layer, an electron It may also consist of multiple layers of an electron transporting layer and an electron injection layer.

When a predetermined voltage is applied to the first electrode 111 and the second electrode 115 according to the selected color signal, the OLED 100 may be formed from holes and second electrodes 115 injected from the first electrode 111. The applied electrons are transported to the organic light emitting layer 113 to form excitons, and when these excitons transition from the excited state to the ground state, light is generated and emitted in the form of visible light.

At this time, since the emitted light passes through the transparent first electrode 111 to the outside, the OLED 100 implements an arbitrary image.

In such a case, the outer surface of the first substrate 101 becomes the display surface. Accordingly, the heat dissipation member 200 is attached to the outer surface of the second substrate 102 to serve to dissipate heat generated from the OLED 100.

That is, the temperature of the OLED 100 is increased to about 80 to 90 ° C. by the heat generated with the deterioration of the driving thin film transistor DTr during driving. Due to such a high temperature, the lifetime of the OLED 100 is drastically reduced.

Therefore, by providing the heat dissipation member 200 on one surface (hereinafter referred to as the rear surface of the OLED) in which the image of the OLED 100 is not implemented, heat dissipation generated from the OLED 100 is radiated so that the lifetime of the OLED 100 is extended. This is to prevent the problem of rapidly decreasing.

Here, the heat dissipation member 200 is composed of a heat dissipation pad 210 and a cover film 220 to protect the heat dissipation pad 210, the heat dissipation member 200 is the OLED (100) through the conductive adhesive tape 130 It is attached to the back of).

As a result, the high temperature heat generated by the OLED 100 is effectively radiated to the outside through the heat radiating member 200. This will be described in more detail with reference to FIG. 3.

3 is a cross-sectional view schematically showing a movement path of heat generated from an OLED according to an OLED heat dissipation design.

As shown, the heat dissipation member 200 is attached to the rear surface where the image of the OLED 100 is not implemented through the conductive adhesive tape 130. Looking at this in more detail, the heat dissipation member on the rear surface of the OLED 100 is shown. The heat dissipation pad 210 of the 200 is attached through the conductive adhesive tape 130, and the cover film 220 is disposed on the outside of the heat dissipation pad 210 to prevent the heat dissipation pad 200 from being contaminated. It is attached to the heat radiation pad 210 so as to completely cover the (210).

Here, the heat dissipation pad 210 may be provided in a form in which a heat transfer filler is contained in a resin composition such as epoxy, for example, formed by depositing graphite on the resin composition under high vacuum by vacuum deposition or sputtering. It is preferable.

At this time, when the heat transfer filler is formed of a graphite material, the heat radiation pad 210 preferably has a structure in which a layer of graphite layers are laminated, and the layered graphite layer is formed by foaming graphite having a flake structure and rolling at high pressure. 210 is formed.

At this time, since the heat dissipation pad 210 made of graphite becomes black, the heat absorption rate is increased, and thus the heat dissipation pad 210 has high thermal conductivity.

Therefore, the heat transferred to the heat radiation pad 210 is effectively spread to the heat radiation pad 210 as a whole.

Alternatively, in addition to graphite, it may be formed of metal particles such as aluminum (Al), copper (Cu), nickel (Ni), silver (Ag), or a rubber-based or acrylic-based material.

In this case, when the heat radiation pad 210 is formed of aluminum (Al), it is preferable that the aluminum has a purity of 99.5%, and through an anodizing treatment, a black oxide film is preferably formed on the surface. .

In addition, the cover film 220 may be provided with various kinds of PTFE (poly tetra fluoroethylene) series, flame retardant PVC (poly vinyl chloride) film, flame retardant polyester (poly ether) film, PEI (poly cthylene imide) film, Silicone film, silicone rubber film, fluororesin film, insulation film, Teflon film PVC (poly vinyl chloride) protective film, PE (polyethylene) film, PO (poly olefin) film and the like are used.

In addition, the conductive adhesive tape 130 may include a metal epoxy, for example, silver (Ag) epoxy, and the conductive adhesive tape 130 may be adhesive and have high thermal conductivity.

Therefore, a large amount of heat generated while the OLED 100 is driven is transferred to the heat radiation pad 210 through the adhesive tape 130 having the conductive property, and the heat radiation pad 210 has excellent thermal conductivity, so the heat radiation pad 210 is excellent. The high temperature heat transmitted to the heat dissipation pad is effectively diffused to the entire heat dissipation pad 210.

The high temperature heat diffused throughout the heat dissipation pad 210 is increased in contact with the outside air, thereby quickly and efficiently dissipating the high temperature heat generated from the OLED 100 to the outside.

Due to this, in the past, the heat generated in the OLED 100 was 80 ~ 90 ℃ or more, the temperature of the OLED 100 is lowered to 55 ~ 60 ℃ through the heat radiation pad 210 of the present invention.

Therefore, it is possible to prevent the problem that the life of the OLED 100 is drastically reduced.

On the other hand, the cover film 220 serves to further improve the adhesive force between the heat radiation pad 210 and the back of the OLED 100, that is, the cover film 220 is formed larger than the size of the heat radiation pad 210 At the same time, the edge of the cover film 220 is completely covered with the conductive adhesive tape 130, thereby further improving the adhesion between the heat radiation pad 210 and the back surface of the OLED 100.

That is, the heat dissipation pad 210 is first fixed through the OLED 100 rear surface and the conductive adhesive tape 130 and secondly fixed by the cover film 220.

4A to 4B are cross-sectional views and plan views schematically illustrating sizes of a cover film and a heat radiation pad.

As shown, the cover film 220 is provided to completely surround the heat radiation pad 210, including the side of the heat radiation pad 210, the edge of the cover film 220 is a conductive adhesive tape on the back of the OLED (100) And 130.

Therefore, the heat dissipation pad 210 is first fixed to the back of the OLED 100 through the conductive adhesive tape 130 and at the same time through the adhesion of the cover film 220 and the conductive adhesive tape 130 surrounding the heat dissipation pad 210. The OLED 100 is fixed to the rear side of the OLED, and the adhesion between the OLED 100 rear surface and the heat dissipation pad 210 is further improved.

In this case, the cover film 220 is formed so as to have a larger size as much as each edge d2 than the heat radiation pad 210, in order to completely surround the heat radiation pad 210.

Here, d2 corresponds to the thickness w1 of the heat dissipation pad 210, which is completely covered by the cover film 220 to the side surface formed by the thickness w1 of the heat dissipation pad 210, and then the cover film 220. The edge of is to be bonded to the conductive adhesive tape 130 on the back of the OLED (100).

Thus, the size of the cover film 220 is formed so as to have a size that can be adhered to the conductive adhesive tape 130 in a portion of the cover film 220 in a size that completely covers the side of the heat radiation pad 210.

At this time, the cover film 220 and the conductive adhesive tape 130 is preferably bonded to have an adhesive width (s1) of at least 2 to 3mm, which is the cover film 220 when the adhesive width (s1) is 2 to 3mm or less. This is because the cover film 220 may be lifted due to a decrease in adhesive strength between the sheet and the conductive adhesive tape 130.

Therefore, when the size of the heat dissipation pad 210 is d1 and is provided with a thickness of w1, the size of the cover film 220 covers four edge sides of the heat dissipation pad 210 on d1 which is the size of the heat dissipation pad 210. In order to add a size of (4 × w1), the cover film 220 and the conductive adhesive tape 130 to have a size of 2 ~ 3mm plus the minimum adhesive width (s1).

(Size (d2) of the cover film 220 = heat radiation pad 210 size (d1) + four edge side thicknesses (4 x w1) of the heat radiation pad 210 + cover film 220 and the conductive adhesive tape 130) Adhesive width (s1 = 2 to 3 mm)

For example, when the width × length of the heat radiation pad 210 is 347 × 201 mm, and the thickness w1 of the heat radiation pad 210 is 0.2 mm, the width × length of the cover film 220 is 351.2 × 203.2 mm. By forming the size of the cover film 220 completely covers the side of the heat dissipation pad 210, the edge of the cover film 220 is bonded with the conductive adhesive tape 130, thereby covering the heat dissipation pad 210 The second fixing is performed on the rear surface of the OLED (100 of FIG. 3) through 220.

On the other hand, the heat radiation pad 210 according to the embodiment of the present invention is characterized in that each corner portion is formed in a cut (cutting) structure.

Even if the cover film 220 is configured in such a size as to completely cover the side surface of the heat dissipation pad 210, the cover film 220 may be completely covered up to each corner of the heat dissipation pad 210 having a predetermined thickness through the cover film 220. none.

Particularly, each corner portion of the cover film 220 corresponding to the edge portion of the heat radiation pad 210 is not bonded to the conductive adhesive tape 130 on the back surface of the OLED (100 of FIG. 3), or even if the minimum adhesion width ( s1) may not be secured, causing the edge portion of the cover film 220 to be lifted.

Due to this, the edge portion of the heat radiation pad 210 is contaminated, or the edge portion of the heat radiation pad 210 is lifted up from the OLED (100 in FIG. 3), whereby high temperature heat generated from the OLED (100 in FIG. 3) is emitted from the OLED (FIG. In the corner portion of 100 of 3 will cause a problem that is not emitted to the outside.

Thus, according to the present invention, as the edge portion of the heat dissipation pad 210 is formed in a cut (cutting) structure, each edge portion of the cover film 220 is bonded to the conductive adhesive tape 130 and at least the minimum adhesive width (s1) or more. By doing so, this problem is prevented.

That is, the present invention forms a cut structure of each corner of the heat dissipation pad 210, in which the cut size of the cutting structure of each edge of the heat dissipation pad 210 is the cover film 220 and the conductive adhesive. It is preferable to have a structure in which the adhesive width bonded to the tape 130 is cut within a range having a minimum adhesive width s1 or more.

Therefore, the edge portion of the cover film 220 corresponding to each edge portion of the heat dissipation pad 210 will have an adhesive width s2 by the conductive adhesive tape 130 and s2 defined in the drawing.

In this case, the adhesive width s2 of the corner portion of the cover film 220 that is bonded to the conductive adhesive tape 210 is greater than the four edges of the cover film 220 that are bonded to the conductive adhesive tape 130. Is formed.

Therefore, it can be seen that the corner portion bonded to the conductive adhesive tape 130 of the cover film 220 has a minimum adhesive width (s1) or more in which adhesion deterioration does not occur.

In addition, the adhesive width of s2 is a size corresponding to the cut edge of the heat radiation pad 210.

At this time, the edge of the heat radiation pad 210 is preferably cut in two sides (a) of the same isosceles triangular structure, as described above, when cutting the edge of the heat radiation pad 210 in an isosceles triangular structure, the cover The film 220 and the conductive adhesive tape 130 are about 2.5 times wider than the adhesive width of s1 to which the edge of the cover film 220 and the conductive adhesive tape 130 are bonded.

For example, when the edge of the cover film 220 and the adhesive width (s1) to which the conductive adhesive tape 130 is bonded is 3mm, when the edge of the heat radiation pad is formed in a cut structure, the edge of the cover film 220 The part is that the adhesive width (s2) to be bonded to the conductive adhesive tape 130 is 7.5mm.

Therefore, the cover film 220 is not completely wrapped around the edge of the heat radiation pad 210, the edge of the cover film 220 is not adhered to the conductive adhesive tape 130, the edge of the heat radiation pad 210 is contaminated, It is possible to prevent the problems caused by the OLED (100 in FIG. 3).

As described above, the OLED (100 of FIG. 3) of the present invention has a heat radiating member (200) consisting of a heat dissipation pad 210 and a cover film 220 on the back of the OLED (100 of FIG. By attaching, it is possible to effectively release the high temperature heat generated from the OLED (100 in Figure 3) to the outside to maximize the heat radiation effect.

In addition, in the OLED (100 of FIG. 3) according to the present invention, the heat dissipation structure and the installation are simple by using the heat dissipation member 200 having a simple structure, and an existing fan or heat pipe is used. It is excellent in heat dissipation effect compared to constructing, and it can maintain light weight and thin shape.

In particular, by forming each corner portion of the heat dissipation pad 210 in a cut structure, thereby improving the adhesion area between the cover film 220 and the back of the OLED (100 in FIG. 3), the heat dissipation pad 210 and the OLED (FIG. 3, 100) further improves the adhesion to the back.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

1 is a schematic cross-sectional view of a typical active matrix type OLED.

2 is a cross-sectional view schematically showing an OLED according to an embodiment of the present invention.

3 is a cross-sectional view schematically showing a movement path of heat generated from an OLED according to an OLED heat dissipation design.

Figures 4a to 4b is a cross-sectional view and a plan view schematically showing the size of the cover film and the heat radiation pad.

Claims (10)

In the organic light emitting device comprising a display surface for displaying an image and a back surface opposite to the display surface, A heat dissipation pad attached to a rear surface of the organic light emitting diode through an adhesive material, the heat dissipation pad having a cut structure at each corner thereof; A cover film surrounding the heat dissipation pad and having an edge bonded to the adhesive material Organic electroluminescent device comprising a. The method of claim 1, The cover film is an organic light emitting device having a size including the size of the heat radiation pad, the thickness of the heat radiation pad, and the adhesive width bonded to the adhesive material. The method of claim 2, Each corner portion of the cover film is an organic light emitting device having an adhesive width of at least 2 ~ 3mm to be bonded to the adhesive material. The method of claim 2, The edge of the cover film is an organic light emitting display device having an adhesive width of at least 2 to 3mm to be bonded to the adhesive material. The method of claim 1, The cut structure is an organic light emitting device having an isosceles triangle structure. The method of claim 1, The heat dissipation pad is an organic light emitting device having a structure containing a heat transfer filler in a resin composition such as epoxy. The method of claim 6, The heat transfer filler is an organic electroluminescent device selected from metal particles such as graphite, aluminum (Al), copper (Cu), nickel (Ni), silver (Ag) and the like. The method of claim 1, The cover film is PTFE (poly tetra fluoroethylene) film, flame retardant PVC (poly vinyl chloride) film, flame retardant polyester (poly ether) film, PEI (poly cthylene imide) film, silicon film, silicon rubber film, fluororesin film, Insulating film, Teflon film PVC (poly vinyl chloride) protective film, PE (polyethylene) film, PO (poly olefin) film selected organic light emitting device is one of the film. The method of claim 1, The adhesive material is an organic light emitting device that is a conductive adhesive tape containing a metal epoxy. The method of claim 1, The organic light emitting device includes a first and a second substrate facing each other, A switching thin film transistor, a driving thin film transistor, and an organic light emitting diode are formed on an inner surface of the first substrate. An organic light emitting display device encapsulated through the second substrate.

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