CN1265472C - an organic light emitting diode - Google Patents

Abstract

The invention provides an organic light-emitting diode, which comprises a lower substrate, an upper substrate, a groove and a sealing material, wherein the lower substrate comprises a lower electrode, an organic film and an upper electrode which are sequentially arranged on the surface of a preset area of the lower electrode, the upper substrate comprises at least one groove for preventing the sealing material from overflowing into the preset area relative to the surface of the lower substrate, and the sealing material is positioned on a glue dispensing area of the lower substrate and used for bonding the upper substrate and the lower substrate.

Description

an organic light emitting diode

technical field

The present invention relates to an organic light emitting element, in particular to an organic light emitting diode (OLED) which can avoid sealing materials from affecting normal light emission.

Background technique

Among the flat-panel displays, although the organic light-emitting diode display started late, it has the advantages of self-illumination, no viewing angle limitation, high response speed, power saving, full-color, simple structure, and wide operating temperature range. Gradually attract attention in the field of small and medium-sized portable displays.

Please refer to FIG. 1 , which is a schematic cross-sectional view of a conventional organic light emitting diode 10 . As shown in Figure 1, the existing organic light emitting diode 10 mainly includes a transparent glass substrate 12, a transparent conductive layer 14 is arranged on the surface of the glass substrate 12, and is used as an anode of the organic light emitting diode 10, and an organic thin film 16 is arranged on the transparent A surface of a predetermined area of the conductive layer 14 and a metal layer 18 are disposed on the surface of the organic film 16 to serve as a cathode of the OLED 10 .

The transparent conductive layer 14 includes materials such as indium tin oxide (ITO) or indium zinc oxide (IZO), and the organic thin film 16 further includes a hole transport layer (HTL) 20, a light emitting layer An emitting layer (EML) 22 and an electron transport layer (EHL) 24 are disposed on the transparent conductive layer 14 in sequence. Wherein, the organic thin film 16 is made by thermal evaporation (thermal evaporation), the hole transport layer 20 includes a diamine compound, and the metal layer 18 includes a low-power metal or alloy, such as magnesium. , aluminum metal or lithium/silver alloy, etc. In addition, in actual application, a hole injection layer (hole injection layer, HIL) (not shown in FIG. 1 ) (not shown in FIG. An electron injection layer (election injection layer, EIL) (not shown in Fig. 1) is added between 18 and electron transport layer 24, is used for improving the problem of organic thin film 16 and anode/cathode junction, in order to electron or hole injection Organic film 16. Furthermore, it is also possible to choose to use a light-emitting layer with electron-transport capability, or a hole-transport layer with light-emitting capability, so as to reduce the use of organic thin films and simplify the process.

When a direct current (DC) voltage is applied to the organic light emitting diode 10, electrons will pass from the metal layer 18 (cathode) to the electron conducting layer 24, and holes will pass from the transparent conductive layer 14 (anode) to the hole conducting layer 20 respectively. Injected into the light-emitting layer 22, at this time, due to the potential difference caused by the external electric field, the electrons and holes will move in the light-emitting layer 22 and recombine to form electron-hole pairs in the light-emitting layer 22, and make the light-emitting layer The organic light-emitting molecules in 22 are in an excited state, and when the excitons return to the ground state by releasing energy, a certain proportion of the energy (that is, the quantum efficiency of light emission) will be released in the form of photons, and pass through The glass substrate 12 emits light downwards, which is the principle of electroluminescence of the OLED 10 .

However, the organic film 16 and the metal layer 18 are very sensitive to moisture and oxygen, so once moisture or oxygen contacts the organic film 16 and the metal layer 18, the metal layer 18 will be oxidized and the interface between the organic film 16 and the electrode will be peeled off. This phenomenon causes the organic light-emitting element to produce dark spots (darkspot), which will not only significantly reduce the display quality, but also reduce the brightness of the display and shorten the life of the display. Therefore, with the gradual development of organic light-emitting diode displays, when packaging, the packaging materials used not only need to have better wear resistance and high thermal conductivity, but also need to have a lower moisture vapor transmission rate to effectively isolate The contact between the organic thin film material and the external environment further increases the lifespan of the organic light-emitting element.

Please refer to FIG. 1 again. The packaging process of the existing organic light emitting diode 10 mainly uses a sealing material 26, such as a binder composed of a polymer glue, to bond a glass or metal packaging cover 28. On top of the glass substrate 12 , dry nitrogen gas is sealed in the hollow portion therebetween, so as to complete the packaging of the OLED 10 . In addition, a desiccant can be additionally arranged in the OLED 10 to absorb moisture entering due to poor sealing, so as to avoid the aforementioned moisture phenomenon on the organic thin film 16 of the OLED 10 .

Although the glass or metal packaging cover 28 provides a good insulation effect for oxygen and moisture, the sealing material 26 must be used in an appropriate amount during the packaging pressing process. Because if too much sealing material 26 is used in order to achieve a better sealing effect, then when the package cover 28 is bonded to the glass substrate 12, it is easy to cause the uneven distribution of the sealing material 26 or the poor control of the pressing pressure. However, excessive sealing material 26 is squeezed out, so that the excess sealing material 26 contacts the organic film 16, causing the organic film 16 to fail to emit light normally, and affecting the normal operation of the organic light emitting diode 10. Therefore, in the existing package In the process, the amount of sealing material 26 is usually reduced to avoid the above problems. However, if the sealing material 26 is too small, the sealing effect between the packaging cover 28 and the glass substrate 12 may be poor, so that moisture and oxygen may easily invade the organic light emitting diode 10, and even cause uneven bonding effect. A case where the glass substrate 12 is easily peeled off. In addition, as shown in FIG. 1, in order to improve the bonding effect between the package cover 28 and the glass substrate 12, the surface of the existing package cover 28 will be subjected to surface treatment such as sandblasting or etching to roughen the surface. , so as to increase the bonding area, but this will affect the luminous quality, so the encapsulation cap 28 with a rough surface cannot be applied to a top emission OLED (TOLED) structure.

Contents of the invention

The main purpose of the present invention is to provide a structure of an organic light-emitting element to avoid the above-mentioned problems.

The preferred embodiment of the present invention discloses an organic light emitting diode (organic light emitting diode, OLED), which includes a lower substrate, a lower electrode is arranged on the upper surface of the lower substrate, an organic thin film is arranged on the lower electrode, an upper An electrode is arranged on the organic thin film, and a spot glue area is arranged on the lower electrode or the lower substrate outside the region where the organic thin film is arranged, and the upper surface of the lower electrode or the lower substrate includes at least one first A groove, an upper substrate is parallel to the lower substrate, and the lower surface of the upper substrate includes at least one second groove (ditch) formed in the upper substrate, and a sealing material (sealing material), located on the The spot glue area of the lower substrate is used to bond the upper substrate and the lower substrate. Wherein the first and second grooves are used to prevent the sealing material from overflowing into the area occupied by the organic film, so as to prevent the sealing material from affecting the normal operation of the OLED.

According to the present invention, there is also provided an organic light-emitting element, the organic light-emitting element includes at least two organic light-emitting diodes, the organic light-emitting element includes: a lower substrate, including at least two element regions, and a cutting region located on the lower substrate Between two adjacent element regions on the upper surface, a lower electrode is arranged on each element region, an organic thin film is arranged on the lower electrode and an active region of the element region, and an upper electrode is arranged on the On the organic thin film; an upper substrate parallel to the lower substrate, and the lower surface of the upper substrate includes at least two first regions corresponding to the element region of the lower substrate, and at least one second region corresponds to the lower substrate The cutting area, and a plurality of first trenches are located in each first area of the upper substrate; and a sealing material is located on the lower substrate or the glue spot area of the lower electrode and outside each active area, for sticking The upper substrate and the lower substrate are connected, wherein the first groove is used to prevent the sealing material from overflowing into the cutting area and each active area of the lower substrate, thereby affecting the normal operation of each organic light emitting diode.

Since the organic light emitting diode of the present invention is provided with a groove in the upper substrate, when the amount of sealing material used to bond the upper and lower substrates is too much, the excess sealing material will flow into the groove to prevent the sealing material from contacting organic thin film, which affects the normal operation of organic light-emitting diodes.

Description of drawings

1 is a schematic cross-sectional view of an existing organic light emitting diode;

2 is a schematic cross-sectional view of an organic light emitting diode according to a first embodiment of the present invention; and

FIG. 3 is a schematic cross-sectional view of an organic light emitting device according to a second embodiment of the present invention.

The reference signs in the accompanying drawings are explained as follows:

10 Organic Light Emitting Diodes 12 Transparent Glass Substrate

14 transparent conductive layer 16 organic film

18 metal layer 20 hole transport layer

22 Light emitting layer 24 Electron transport layer

26 Sealing material 28 Glass or metal package cover

50 Organic Light Emitting Diodes 52 Substrates

54 transparent conductive layer 56 organic film

58 metal layers 60 package protection structure

62 Sealing material 64 Hole injection layer

66 hole transport layer 68 light emitting layer

70 Electron transport layer 72 Electron injection layer

74 groove 76 excess sealing material

80 Organic Light Emitting Components 82 Substrates

84 transparent conductive layer 86 organic film

88 metal layer 90 package cover

92 grooves 94 packaging materials

96 excess packaging material

Detailed ways

Please refer to FIG. 2 , which is a schematic cross-sectional view of an organic light emitting diode 50 according to a first embodiment of the present invention. As shown in Figure 2, the organic light emitting diode 50 of the present invention mainly includes a substrate 52, a transparent conductive layer 54 used as an anode is arranged on the surface of the substrate 52, and an organic thin film 56 is arranged on a predetermined portion of the transparent conductive layer 54. region (that is, the active region of the OLED 50 ), and a metal layer 58 serving as a cathode is disposed on the organic thin film 56 . In addition, the organic light emitting diode 50 further includes a packaging substrate, which is arranged in parallel on the substrate 52, and is used as a packaging protection structure 60 for the organic light emitting diode 50. A sealing material 62 on the glue) area to bond the encapsulation protection structure 60 to the substrate 52, so as to prevent the organic thin film 56 and the metal layer 58 from being exposed to the external environment, and the present invention can also be arranged in the organic light emitting diode 50 A desiccant (not shown in FIG. 2 ) is used to prevent the organic film 56 of the OLED 50 from being wet and the metal layer 58 from being oxidized.

In a preferred embodiment of the present invention, the substrate 52 is a glass substrate, the transparent conductive layer 54 includes materials such as indium tin oxide or indium zinc oxide, and the organic film 56 includes a hole injection layer 64, a hole transport layer 66, a The light-emitting layer 68, an electron-transporting layer 70, and an electron-injecting layer 72 are sequentially disposed on the transparent conductive layer 54, and the metal layer 58 includes low-power metals or alloys, such as aluminum-magnesium alloys, aluminum-lithium alloys, or aluminum/fluorine aluminum, and the package protection structure 60 includes a glass substrate, a glass container or a metal can, and the sealing material 62 is epoxy. As mentioned above, the hole injection layer 64 and the electron injection layer 72 can be optional structures depending on the product process requirements.

It should be noted that the package protection structure 60 of the present invention has an annular groove (ditch) on the surface opposite to the substrate 52, that is, two grooves (ditch) 74 shown in the cross-sectional structure of FIG. 2, and the groove 74 Correspondingly located in the middle between the glue dispensing area and the predetermined area of the substrate 52, so when the organic light emitting diode 50 of the present invention is in the packaging step, even if too much sealing material 62 is used on the glue dispensing area, these redundant sealing The material 76 will flow into the groove 74 and will not contact the organic film 56 and affect the normal operation of the OLED 50 . In addition, in a preferred embodiment of the present invention, the cross-sectional shape of the groove 74 is approximately a rectangle, and the depth of the groove 74 is less than half of the thickness of the package protection structure 60, so as not to affect the mechanical strength of the package protection structure 60, however The present invention is not limited thereto. The cross-sectional shape of the groove 74 may have a polygonal shape, such as U-shape or various inclination angles, so as to facilitate the inflow of excess sealing material 76, and the number of grooves 74 may also be based on process requirements. be increased or decreased. Furthermore, the present invention can also form a groove (not shown in FIG. It can also flow into the groove to avoid contact with the organic film 56 , and the depth of the groove is smaller than the thickness of the substrate 52 or the transparent conductive layer 54 .

Next, please refer to FIG. 3 . FIG. 3 is a schematic cross-sectional view of an organic light emitting device 80 according to a second embodiment of the present invention. As shown in FIG. 3 , the organic light emitting device 80 of the present invention is mainly included in a substrate 82 , and the surface of the substrate 82 includes at least two device regions A and at least one cutting region B between two adjacent device regions A. Wherein, each device area A is used to form an OLED, and the cutting area B is used to separate each OLED, or a location for cutting after the organic light emitting device 80 is fabricated.

Each device region A includes a conductive layer 84 disposed on the surface of the device region A, used as an anode, an organic thin film 86 disposed on an active region of the device region A, and a metal layer 88 disposed on the organic thin film 86 surface, used as a cathode. In addition, the organic light-emitting device 80 of the present invention further includes a packaging cover 90, which is disposed on the substrate 82 in parallel, and the surface of the packaging cover 90 opposite to the substrate 82 includes at least two components whose first regions C correspond to the substrate 82. Area A, at least one second area D corresponds to the cutting area D of the substrate 82, and a plurality of grooves 92 are respectively located in each first area C of the package cover 90, and a sealing material 94 is located between the sealing cover 90 and the substrate The adhesive area outside each active area between 82 is used for bonding the sealing cover 90 and the substrate 82 . The groove 92 is used to prevent the sealing material 94 from overflowing into the cutting area B of the substrate 82 and into each active region of the substrate 82, causing the organic thin film 86 to fail to emit light normally, thereby affecting the normal operation of each organic light emitting diode. operate. As previously mentioned, the present invention can also form a groove (not shown in FIG. 3 ) similar to the sealing cover 90 in the substrate 82 or the transparent conductive layer 84 between the dispensing area and the active area, so that redundant sealing The material 96 can also flow into the groove to avoid contact with the organic film 86 , and the depth of the groove is smaller than the thickness of the substrate 82 or the transparent conductive layer 84 .

In a preferred embodiment of the present invention, the depth of the groove 92 is less than half of the thickness of the package cover 90, so as not to affect the mechanical strength of the package cover 90, and the width of the cutting area B is greater than twice the width of the groove 92, to avoid affecting the mechanical strength of the package cover 90. It is convenient to perform the cutting process of the organic light emitting element 80 . In addition, in the preferred embodiment of the present invention, a passive organic light-emitting element (passive matrix OLED, PMOLED) is used as an illustration, but the present invention is not limited thereto. The encapsulation protection structure with grooves of the present invention, It can also be applied to various components that require sealing materials for packaging and whose structure must avoid moisture, such as active matrix OLED (AMOLED) or top emission OLED (TOLED) )middle.

Compared with the prior art, since the packaging cover of the organic light-emitting diode of the present invention is provided with a plurality of grooves, when the amount of sealing material used to bond the upper and lower substrates is too much, the excess sealing material will flow into the In the groove, to prevent the sealing material from contacting the organic film, which will affect the normal operation of the organic light-emitting diode, so in the present invention, the problem of uneven adhesion caused by too little sealing material can be obtained. The lower substrate has good adhesion and tightness. Moreover, the surface of the packaging cover of the present invention is a smooth surface, rather than a rough surface. Therefore, if the present invention selects a transparent glass jar or a transparent glass substrate as the packaging cover, then the entire transparent organic light emitting diode is also suitable for top-emitting or double-sided LEDs. Surface-emitting organic light-emitting diode displays.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications according to the claims of the present invention shall fall within the scope of the patent of the present invention.

Claims (25)

1. Organic Light Emitting Diode, this Organic Light Emitting Diode includes:

One infrabasal plate, one bottom electrode is located at the upper surface of this infrabasal plate, one organic film is located on this bottom electrode, one top electrode is located on this organic film, and some glue zone is located on this bottom electrode or the infrabasal plate and is being provided with outside the zone of this organic film, and the upper surface of this bottom electrode or infrabasal plate comprises at least one first groove;

One upper substrate is parallel to this infrabasal plate, and the lower surface of this upper substrate includes at least one second groove that is formed in this upper substrate; And

One encapsulant is positioned on this glue application region territory of this infrabasal plate, be used for boning this upper substrate and this infrabasal plate,

Wherein this first groove and this second groove are used for avoiding the sealing material to overflow in the zone that is occupied by this organic film and influence the normal running of this Organic Light Emitting Diode.

2. Organic Light Emitting Diode as claimed in claim 1, wherein this infrabasal plate is a glass substrate, a plastic base or a metal substrate.

3. Organic Light Emitting Diode as claimed in claim 1, wherein this upper substrate comprises a glass substrate, a glass jar or a metal can.

4. Organic Light Emitting Diode as claimed in claim 1, wherein this bottom electrode comprises tin indium oxide or indium zinc oxide, is used for being used as the anode of this Organic Light Emitting Diode.

5. Organic Light Emitting Diode as claimed in claim 1, wherein this top electrode includes the alloy material of magnesium metal, aluminum metal, lithium metal or magnesium, aluminium and lithium, is used for being used as the negative electrode of this Organic Light Emitting Diode.

6. Organic Light Emitting Diode as claimed in claim 1, wherein this organic film includes a hole transmission layer in addition and is positioned on this bottom electrode, and a luminescent layer is positioned on this hole transmission layer, and an electron transfer layer is positioned on this luminescent layer.

7. Organic Light Emitting Diode as claimed in claim 6, other includes a hole injection layer between this bottom electrode and this hole transmission layer.

8. Organic Light Emitting Diode as claimed in claim 6, other includes an electron injecting layer between this electron transfer layer and this top electrode.

9. Organic Light Emitting Diode as claimed in claim 1, wherein the sealing material comprises epoxy resin.

10. Organic Light Emitting Diode as claimed in claim 1, the wherein zone between this zone of occupying corresponding to this glue application region territory and by this organic film of this second groove, and the degree of depth of this second groove is less than half of the thickness of this upper substrate.

11. Organic Light Emitting Diode as claimed in claim 1, wherein this first groove is between this glue application region territory and this zone of being occupied by this organic film, and the degree of depth of this first groove is less than the thickness of this bottom electrode or infrabasal plate.

12. Organic Light Emitting Diode as claimed in claim 1, other includes a drier and is located in this Organic Light Emitting Diode, in order to this organic film of avoiding this Organic Light Emitting Diode moist phenomenon takes place.

13. an organic illuminating element, this organic illuminating element includes at least two Organic Light Emitting Diodes, and this organic illuminating element includes:

One infrabasal plate, include at least a two element zone and a cutting zone on the upper surface of this infrabasal plate between two adjacent these element areas, be equipped with a bottom electrode on each element area, one organic film is located on this bottom electrode and on an active region of this element area, and a top electrode is located on this organic film;

One upper substrate, be parallel to this infrabasal plate, and the lower surface of this upper substrate comprises at least two first areas with respect to this element area of this infrabasal plate, and at least one second area corresponds to this cutting zone of this infrabasal plate, and a plurality of first groove is arranged in each first area of this upper substrate; And

One encapsulant is positioned on some glue zone of this infrabasal plate or bottom electrode and outside each active region, be used for boning this upper substrate and this infrabasal plate,

Wherein said first groove is used for avoiding the sealing material to be spilled in this cutting zone of this infrabasal plate and each active region and influences the normal running of each Organic Light Emitting Diode.

14. organic illuminating element as claimed in claim 13, wherein this infrabasal plate is a glass substrate, a plastic base or a metal substrate.

15. organic illuminating element as claimed in claim 13, wherein this upper substrate comprises a glass substrate, a glass jar or a metal can.

16. organic illuminating element as claimed in claim 13, wherein each bottom electrode includes tin indium oxide or indium zinc oxide, is used for being used as the anode of each Organic Light Emitting Diode.

17. organic illuminating element as claimed in claim 13, wherein each top electrode includes the alloy material of magnesium metal, aluminum metal, lithium metal or magnesium, aluminium and lithium, is used for being used as the negative electrode of each Organic Light Emitting Diode.

18. organic illuminating element as claimed in claim 13, wherein each organic film includes that a hole transmission layer is positioned on this bottom electrode, a luminescent layer is positioned on this hole transmission layer, and an electron transfer layer is positioned on this luminescent layer.

19. organic illuminating element as claimed in claim 18, other comprises the multilayer hole injection layer, and each hole injection layer lays respectively between each bottom electrode and each hole transmission layer.

20. organic illuminating element as claimed in claim 18, other comprises the multilayer electronic implanted layer, and each electron injecting layer lays respectively between each electron transfer layer and each top electrode.

21. organic illuminating element as claimed in claim 13, wherein the sealing material comprises epoxy resin.

22. organic illuminating element as claimed in claim 13, wherein said first groove to should the glue application region territory and this active region between the zone, and the degree of depth of described first groove is less than half of the thickness of this upper substrate.

23. organic illuminating element as claimed in claim 13, wherein this organic illuminating element comprises in addition that at least one second groove is positioned at this bottom electrode or infrabasal plate and between this glue application region territory and this active region, and the degree of depth of this second groove is less than the thickness of this bottom electrode or infrabasal plate.

24. organic illuminating element as claimed in claim 13, wherein the width of this cutting zone is greater than the twice of the width of each first groove.

25. organic illuminating element as claimed in claim 13, other comprises that a drier is located in this organic illuminating element, in order to this organic film of avoiding each Organic Light Emitting Diode moist phenomenon takes place.

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