CN113964156A - AMOLED display device and packaging method and packaging structure of AMOLED display device - Google Patents

Abstract

The invention relates to a packaging method of an AMOLED display device, which comprises the following steps: step one, silk-screening glass paste on the edge of a sealing area of each display unit of a packaging substrate to form an inner ring Frit and silk-screening glass paste on the edge of the sealing area to form an outer ring Frit; step two, carrying out high-temperature curing on the inner ring Frit and the outer ring Frit on the packaging substrate to form sintered glass; coating UV glue on the inner side of the outer ring Frit curing layer to form a closed graph, wherein the inner ring Frit curing layer is arranged on the inner side of the UV glue; bonding the display substrate and the packaging substrate; fifthly, carrying out first laser sintering on the attached display substrate and the attached packaging substrate, wherein the part subjected to the first laser sintering is an outer ring Frit curing layer; step six, carrying out ultraviolet curing on the UV glue to form a UV glue curing layer; and seventhly, performing second laser sintering, wherein the part subjected to the second laser sintering is an inner ring Frit solidified layer. The invention also relates to a packaging structure of the AMOLED display device and the AMOLED display device.

Description

AMOLED display device, and packaging method and packaging structure of AMOLED display device

Technical Field

The present invention relates to the field of packaging light emitting semiconductor devices, and in particular, to an AMOLED display device, and a packaging method and a packaging structure of the AMOLED display device.

Background

An Active Matrix Organic Light Emitting Diode (AMOLED) generally uses an evaporation process to prepare a Light Emitting device such as an Organic Light Emitting Diode (OLED) on a substrate, and since components such as water vapor and oxygen in the air greatly affect the lifetime of the OLED device, the AMOLED needs to be packaged after the evaporation process. The packaging method of the AMOLED includes two types of substrate packaging and Thin Film Encapsulation (TFE).

Thin film packages are usually formed by depositing a plurality of thin films, such as acrylate and silicon dioxide, on a Light Emitting device, such as an Organic Light-Emitting diode (OLED), in an alternating multi-Layer manner by using Atomic Layer Deposition (ALD) or direct Coating (Coating). In order to achieve good effects of blocking ambient gas, water vapor and the like, it is sometimes necessary to add multiple organic and/or inorganic barrier layers in the thin film encapsulation structure.

The substrate packaging means that an adhesive film is filled between a display substrate formed with an OLED device and a packaging substrate, and after the adhesive film is solidified, a closed space is formed between the display substrate and the packaging substrate, so that the packaging effect is achieved. The existing process flow applied to the substrate package of the AMOLED includes: the display substrate is provided with a display area, the display area is provided with a plurality of display units (the display units are provided with OLED devices), the packaging substrate is provided with a sealing area, and the sealing area is provided with a plurality of display unit sealing areas which are in one-to-one correspondence with the display units; coating glass paste (Frit) with a closed figure at the edge of the sealing area of each display unit, and then coating UV glue at the edge of the sealing area to form a closed figure; bonding the display substrate and the packaging substrate; and after the UV glue is integrally cured, performing laser sintering by using glass paste (Frit) so as to encapsulate the OLED device on the display unit. The UV glue is used for temporarily isolating the OLED device from the external environment, and the laser sintering is performed in a conventional environment, so that the laser sintering needs to be completed within the protection validity period of the UV glue.

However, the technical problems of the existing substrate packaging technical scheme are as follows: the UV glue is generally coated at the edge of a sealing area of a packaging substrate in a dispensing manner, if foreign particles are doped in the UV glue, the UV glue is not ideally tightly attached to the surface of the display substrate any more due to the foreign particles between the display substrate and the packaging substrate, namely, a gap between the UV glue and the display substrate is formed around the foreign particles clamped between the display substrate and the packaging substrate, the foreign particles induce a sealed space between the display substrate and the packaging substrate or a cavity and an external environment to be communicated through the gap, the sealing atmosphere is damaged, and even the subsequent Frit laser sintering failure can be caused.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides the packaging method of the AMOLED display device, which is improved based on the existing substrate packaging process, the AMOLED display device is ensured to prevent the erosion of the external severe atmosphere to the OLED device before laser sintering on the premise of not increasing the process difficulty, and the method can obviously prolong the effective protection time of UV glue to the closed space or cavity between the display substrate and the packaging substrate.

The AMOLED display device provided by the invention comprises a display substrate and a packaging substrate. The display substrate is provided with a display area, a plurality of display units are arranged in the display area, and the display units are provided with light-emitting devices; the packaging substrate is provided with a sealing area, and the sealing area is provided with a plurality of display unit sealing areas which are in one-to-one correspondence with the display units.

In one aspect, the present invention provides a method for packaging an AMOLED display device, the method comprising the steps of:

forming an inner ring Frit by silk-screening glass paste (Frit) at the edge of a sealing area of each display unit of the packaging substrate, and forming an outer ring Frit by silk-screening glass paste (Frit) at the edge of the sealing area, wherein the inner ring Frit and the outer ring Frit are both closed figures;

carrying out high-temperature curing on the inner ring Frit and the outer ring Frit on the packaging substrate to form sintered glass, wherein the outer ring Frit is cured to form an outer ring Frit cured layer, and the inner ring Frit is cured to form an inner ring Frit cured layer;

coating UV glue on the inner side of the outer ring Frit curing layer to form a closed figure, wherein the inner ring Frit curing layer is arranged on the inner side of the UV glue;

the display substrate and the packaging substrate are attached, the display area and the sealing area are arranged oppositely at the moment, and because the outer ring Frit and the inner ring Frit at the edge of the packaging substrate are both solidified to form the fusion glass, a gap is formed between the attached display substrate and the packaging substrate, the outer ring Frit curing layer and the inner ring Frit curing layer both play a supporting role, and an accommodating space is formed between each display unit and the corresponding sealing area of the display unit and is used for accommodating the light-emitting device;

carrying out first laser sintering on the attached display substrate and the attached packaging substrate, wherein the first laser sintering part is an outer ring Frit curing layer, and the display substrate and the packaging substrate are firmly adhered together through the first laser sintering;

after the first laser sintering is finished, ultraviolet curing is carried out on the UV glue between the display substrate and the packaging substrate to form a UV glue curing layer;

after the UV glue is cured, a second laser sintering is carried out, and the part of the second laser sintering is an inner circle Frit cured layer, so that each display unit is independently sealed.

Preferably, the outer rim Frit on the package substrate is located 2 to 6mm from the edge of the package substrate, and the thickness of the Frit glass formed after the outer rim Frit and the inner rim Frit are cured is 4 to 11 μm.

And the inner ring Frit and the outer ring Frit on the packaging substrate are subjected to simultaneous screen printing or separate screen printing.

Wherein, a Frit of one circle or more than one circle can be silk-screened at the edge of the sealing area of the package substrate.

Preferably, the distance between the UV glue and the outer ring Frit curing layer is 1-2 mm, so that the UV glue is prevented from being damaged when the subsequent outer ring Frit curing layer is subjected to laser sintering.

The process of bonding the display substrate and the packaging substrate and the process of first laser sintering are carried out in a nitrogen environment or a vacuum environment, and the ultraviolet curing process and the second laser sintering process can be carried out in a conventional environment.

In another aspect, the present invention provides a package structure of an AMOLED display device, including:

the display device comprises a display substrate, a light-emitting component and a light-emitting component, wherein the display substrate is provided with an upper surface and a lower surface opposite to the upper surface, a display area is arranged on the upper surface of the display substrate, a plurality of display units are arranged in the display area, and the display units are provided with the light-emitting component;

the packaging substrate is provided with a bottom surface and a top surface opposite to the bottom surface, a sealing area is arranged on the bottom surface of the packaging substrate and corresponds to the display area on the display substrate, and a plurality of display unit sealing areas which correspond to the display units one by one are arranged in the sealing area of the packaging substrate;

an inner Frit cured layer surrounding the display unit sealing region of the encapsulation substrate such that each of the display units is independently sealed; and

the edge of display substrate and packaging substrate all seals through outer lane Frit cured layer and UV glues cured layer, and UV glues cured layer and encloses the display area, and outer lane Frit cured layer encloses UV glues cured layer.

In another aspect, the invention further provides an AMOLED display device including the package structure.

Compared with the prior art, the technical scheme of the invention has at least the following beneficial effects:

1. when the AMOLED display device needs to be thinned, the sealing glue (such as UV glue) is filled at the edge between the display substrate and the package substrate after the AMOLED display device is attached to the display substrate, and the package method of the AMOLED display device provided by the invention enables the display substrate and the package substrate to be well bonded and sealed, thereby avoiding the problem that the sealing gap is caused because the sealing glue is only attached to the edge of the substrate in the prior art. When the display substrate and the packaging substrate are attached and then are subjected to acidification and thinning treatment, the surface of the substrate is corroded by acid, and the acid cannot enter the corroded part between the two substrates because the surface of the substrate is well sealed, so that the problems of fragment and the like are avoided, and the product quality is improved;

2. according to the packaging method of the AMOLED display device, provided by the invention, the outer ring Frit is utilized, so that even if the UV glue contains pores caused by foreign particles, the atmosphere environment between the display substrate and the packaging substrate can be kept unchanged, and the failure probability of the subsequent laser sintering of the inner ring Frit can be effectively reduced, so that the performance and the yield of the product are improved;

3. the packaging method of the AMOLED display device provided by the invention ensures that the light emitting device on the display unit of the inner ring Frit is not damaged by the external environment before laser sintering by utilizing the outer ring Frit;

4. among the prior art, package substrate and display substrate laminating back in nitrogen gas environment or vacuum environment, the UV glues and glues package substrate and display substrate temporarily, then glues UV under normal atmospheric environment and solidifies, and this prior art has two great hidden dangers: (1) the UV glue is easily damaged by carrying the attached packaging substrate and the attached display substrate before the UV glue is cured, so that the light-emitting device is damaged by the external environment. The energy of water and oxygen blocked by the un-cured UV glue is poor; (2) the time interval required to be controlled from the UV glue curing to the completion of the Frit laser sintering is short, and the AMOLED display device packaging method provided by the invention can overcome the two hidden dangers.

The following description will be given with reference to specific examples.

Drawings

The figures further illustrate the invention, but the examples in the figures do not constitute any limitation of the invention.

Fig. 1 is a schematic structural diagram of a package substrate according to an embodiment of the invention.

Fig. 2 is a schematic structural view illustrating a display substrate and a package substrate bonded together according to an embodiment of the present invention.

Wherein the reference numerals are: 1. a package substrate; 11. a display unit sealing region; 12. an outer ring Frit cured layer; curing the UV glue layer; 14. the Frit layer of the inner ring; 2. a display substrate; 21. a display unit.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, a top view of a package substrate (cover glass)1 for packaging an Active-matrix organic light emitting diode (AMOLED) display device, although the display substrate 2 is not shown in fig. 1, it should be understood that a display substrate (e.g., LTPS substrate, etc.) 2 corresponding to the package substrate 1 will be bonded, or attached or covered with the package substrate 1, so as to bond and mechanically combine/connect the package substrate 1 and the display substrate 2 together. The purpose of the present invention is to provide an Organic Light Emitting Diode (OLED) device in a gap between the package substrate 1 and the display substrate 2 for sealing and packaging, which will be described in detail below.

First, a display substrate 2 prepared with display units to be bonded (or bonded) is provided, the display substrate 2 has an upper surface and a lower surface opposite to the upper surface, and a display area (not shown in the drawing) is disposed on the upper surface of the display substrate, a plurality of display units 21 are disposed in the display area, and light emitting devices (not shown in the drawing) are disposed on the display units 21.

Providing a package substrate 1 bonded (or bonded) to the display substrate 2 based on the display substrate 2, wherein the package substrate 1 has a top surface (i.e. a side of the package substrate 1 facing away from the viewer shown in fig. 1) and a lower surface opposite to the top surface (i.e. a side of the package substrate 1 facing toward the viewer shown in fig. 1), and a sealing region is disposed on the package substrate 1 corresponding to the display region on the display substrate 2 for sealing the display regions after the bonding (or bonding) process; similarly, a plurality of display unit sealing regions 11 corresponding to the display units 21 are disposed on the bottom surface of the package substrate 1, and the display unit sealing regions correspond to the display units 21 one by one, so that each display unit is individually sealed after the subsequent bonding (or bonding) process and the sealing process.

The embodiment provides a packaging method of an AMOLED display device, which comprises the following steps:

firstly, silk-screening glass paste (Frit) at the edge of a sealing area 11 of each display unit of a packaging substrate 1 to form an inner ring Frit and silk-screening glass paste (Frit) at the edge of the sealing area to form an outer ring Frit, wherein the inner ring Frit and the outer ring Frit are both closed figures;

step two, performing high-temperature curing on the inner ring Frit and the outer ring Frit on the packaging substrate 1 to form sintered glass, forming an outer ring Frit cured layer 12 after the outer ring Frit is cured, and forming an inner ring Frit cured layer 14 after the inner ring Frit is cured;

step three, coating UV glue on the inner side of the outer ring Frit curing layer 12 to form a closed figure, wherein the inner ring Frit curing layer 14 is arranged on the inner side of the UV glue;

step four, as shown in fig. 2, attaching the display substrate 2 to the package substrate 1, where the display area and the sealing area are disposed opposite to each other, and because the outer rim Frit and the inner rim Frit at the edge of the package substrate 1 are both cured to form Frit glass, a gap is formed between the attached display substrate 2 and the package substrate 1, both the outer rim Frit cured layer 12 and the inner rim Frit cured layer 14 play a supporting role, and a receiving space is formed between the display unit 21 and the corresponding display unit sealing area 11 for receiving a light emitting device;

fifthly, performing first laser sintering on the attached display substrate 2 and the attached packaging substrate 1, wherein the first laser sintering part is an outer ring Frit curing layer 12, and firmly bonding the display substrate 2 and the packaging substrate 1 together through the first laser sintering;

sixthly, after the first laser sintering is completed, ultraviolet curing is carried out on the UV glue between the display substrate 2 and the packaging substrate 1 to form a UV glue curing layer 13;

and step seven, after the UV adhesive is cured, carrying out second laser sintering, wherein the part of the second laser sintering is the inner-ring Frit cured layer 14, so that each display unit 21 is independently sealed.

The materials used by the AMOLED display device for evaporation are extremely sensitive to external environmental factors such as water, oxygen and the like, and the materials need to perform a packaging process with excellent sealing property immediately after evaporation, so that the external environmental factors such as water, oxygen and the like can not erode each sensitive material part of the device. Referring to fig. 1, it is required to screen-print a glass paste (Frit) on an edge of each display unit sealing region 11 of the package substrate 1 to form an inner ring Frit and screen-print a glass paste (Frit) on an edge of the sealing region to form an outer ring Frit, where the inner ring Frit and the outer ring Frit are both in a closed figure (such as a closed shape like a ring, a square, a circle, etc.; it should be noted that the drawings of the present embodiment illustrate a ring, but it should not be understood that the technical solution in the present embodiment is limited). The UV glue applied between the outer rim Frit cured layer 12 and the inner rim Frit cured layer 14 also has a closed pattern (such as a closed shape like a ring, a square, or a circle; it should be noted that the figures of the present embodiment illustrate a ring shape, but it should not be understood as a limitation to the technical solution of the present embodiment) to surround the inner rim Frit cured layer 14, that is, the display unit sealing area 11 surrounded by the inner rim Frit cured layer 14 is surrounded, and the UV glue is used as an inner frame sealant to seal the space area therein. The purpose of forming the outer ring Frit cured layer 12 after the outer ring Frit cured and the inner ring Frit cured layer 14 after the inner ring Frit cured is to temporarily hold the display substrate 2 and the package substrate 1 to prevent them from being excessively attached and also to maintain a closed atmosphere in the gap between the display substrate 2 and the package substrate 1, where the ultraviolet cured UV glue serves as an inner frame sealant to physically support the display substrate 2 and the package substrate 1 and also to seal a space region between the display substrate 2 and the package substrate 1 and located in the display unit sealing region 11.

The UV glue should be as close as possible to the peripheral edge of the package substrate 1 so as to reserve a larger intermediate space to avoid affecting the AMOLED device, but meanwhile, in order to prevent the laser from damaging the UV glue during the first laser sintering, a gap with a proper width should be left between the UV glue and the outer rim Frit cured layer 12, and preferably, the distance between the UV glue and the outer rim Frit cured layer 12 is 1-2 mm.

If undesirable foreign particles (particles) are blown into the package substrate 1 or fall on the package substrate 1 for various reasons at a position where the UV paste is originally applied, once the UV paste is continuously applied in the presence of the foreign particles, the UV paste curing layer 13 is no longer perfectly adhered to the display substrate 2 and the package substrate 1 due to the foreign particles. The foreign particles clamped between the UV glue curing layer 13 and the package substrate 1 can physically support the local UV glue curing layer 13 area above the top of the package substrate, and form a gap between the UV glue curing layer 13 and the package substrate 1 near the periphery of the side wall of the foreign particles, the foreign particles induce the communication between the enclosed space or chamber inside the UV glue curing layer 13 and the external environment through the gap, the accommodating space formed between the display unit 21 and the corresponding display unit sealing area 11 is no longer enclosed, resulting in the poor adhesion of the UV glue curing layer 13 and the damage of the sealing atmosphere.

Similarly, if an undesirable particle of foreign matter is blown into the display substrate 2 or falls on a position on the display substrate 2 where the UV glue is originally required to be contacted for various reasons, or the coated UV glue contains the particle of foreign matter, the UV glue curing layer 13 is poorly bonded, and the sealing atmosphere is damaged, so that the subsequent Laser sealing (Laser sealing) fails, and even the light emitting device reacts with external water, oxygen, and the like, so that the AMOLED display device is discarded.

The packaging method of the AMOLED display device provided by the invention effectively avoids the defects, the bonded display substrate 2 and the packaging substrate 1 are subjected to first laser sintering, so that the outer rim Frit curing layer 12 is bonded with the display substrate 2 and the packaging substrate 1 and plays a role in sealing (namely, the inner side of the outer rim Frit curing layer 12 is isolated from the external atmosphere environment, so that structures such as UV glue, the inner rim Frit curing layer 14, a light-emitting device and the like are in a sealed environment), at the moment, even if foreign particles exist in the UV glue, the sealing performance between the display substrate 2 and the packaging substrate 1 is not influenced, and then, after the inner rim Frit curing layer 14 seals each display unit independently, a cutting process is carried out, so that the preparation process of a panel (panel) of the display device is completed.

As shown in fig. 2, the edge of the display substrate 2 and the edge of the package substrate 1 are sintered and bonded by the first laser sintering process at the outer Frit cured layer 12, even if there are foreign particles, a predetermined sealed chamber between the display substrate 2 and the package substrate 1 is still a sealed environment, and the external moisture atmosphere does not intrude into the sealed space, in other words, the damage caused by the foreign particles is suppressed. In this way, the second laser sintering of the Frit cured layer 14 on the inner ring is performed without worrying about the damaging effect of water vapor, which is not achieved by the prior art.

It is obvious that in the present invention, by the cooperation between the outer Frit cured layer 12 and the UV glue cured layer 13, the outer Frit cured layer 12 can prevent the voids caused by the foreign particles, and the UV glue cured layer 13 is used in the sealed atmosphere environment between the display area and the sealing area, which can bring about a plurality of advantages, such as: the light-emitting device is prevented from being invaded by water and oxygen or losing efficacy due to the failure of the outer ring Frit curing layer 12 or the UV glue curing layer 13; and the degree of influence of the failure of the second laser sintering performed by the inner ring Frit cured layer 14 can be strongly reduced, and the range of the negative influence can be controlled in the vicinity of the foreign matter.

Among the prior art, the base plate edge cutting unevenness, two base plate laminatings have the deviation, when the marginal point joint limit is glued, do not have the gap between two base plates, the joint limit is glued and is only attached to the base plate edge, and sealed breach can not avoid appearing, when using acid corrosion glass surface in the attenuate process, appear easily sealed not well and cause acid to get into between two base plates and corrode inside to cause the bad problem of quality. According to the technical scheme provided by the invention, the inner ring Frit is formed by silk-screening glass paste (Frit) at the edge of the sealing area 11 of each display unit of the packaging substrate 1, and the outer ring Frit is formed by silk-screening glass paste (Frit) at the edge of the sealing area, so that a gap is formed between the packaging substrate 1 and the display substrate 2, edge sealing glue can not only be attached to the edge of the substrate but also can enter the substrate, the two substrates are well bonded and sealed, and a sealing gap is avoided.

Correspondingly, the invention further provides an encapsulation structure of the AMOLED display device, which includes the edge sealing structure described in fig. 2, and the edge sealing structure may refer to the description of fig. 2, and is not described herein again.

It should be noted that, in the field of flat panel display, display products that are subjected to acidification and thinning, such as various AMOLED products that need to be thinned, may be applicable to the solution of the present invention.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (8)

1. A packaging method of an AMOLED display device comprises a packaging substrate and a display substrate, wherein a display area is arranged on the display substrate, a plurality of display units are arranged in the display area, light-emitting devices are arranged on the display units, a sealing area is arranged on the packaging substrate, and a plurality of display unit sealing areas which are in one-to-one correspondence with the display units are arranged in the sealing area, and the packaging method is characterized by comprising the following steps:

step one, silk-screening glass paste on the edge of a sealing area of each display unit of the packaging substrate to form an inner ring Frit and silk-screening glass paste on the edge of the sealing area to form an outer ring Frit, wherein the inner ring Frit and the outer ring Frit are both closed figures;

step two, carrying out high-temperature curing on the inner ring Frit and the outer ring Frit on the packaging substrate to form sintered glass, wherein the outer ring Frit is cured to form an outer ring Frit cured layer, and the inner ring Frit is cured to form an inner ring Frit cured layer;

coating UV glue on the inner side of the outer ring Frit curing layer to form a closed figure, wherein the inner ring Frit curing layer is arranged on the inner side of the UV glue;

bonding the display substrate and the packaging substrate, wherein an accommodating space is formed between each display unit and the corresponding display unit sealing area and used for accommodating the light-emitting device;

fifthly, performing first laser sintering on the attached display substrate and the attached packaging substrate, wherein the first laser sintering part is the outer ring Frit curing layer;

step six, carrying out ultraviolet curing on the UV glue to form a UV glue curing layer;

and seventhly, performing second laser sintering, wherein the part subjected to the second laser sintering is the inner ring Frit cured layer.

2. The method of packaging of claim 1, wherein: the distance between the position of the outer ring Frit and the edge of the packaging substrate is 2-6 mm.

3. The method of packaging of claim 1, wherein: the thickness of the outer ring Frit cured layer and the thickness of the inner ring Frit cured layer are 4-11 μm.

4. The method of packaging of claim 1, wherein: and the inner ring Frit and the outer ring Frit on the packaging substrate are subjected to simultaneous screen printing or separate screen printing.

5. The method of packaging of claim 1, wherein: the UV glue is 1-2 mm away from the outer ring Frit cured layer.

6. The encapsulation method according to any one of claims 1 to 5, wherein: the process of bonding the display substrate and the packaging substrate and the process of first laser sintering are carried out in a nitrogen environment or a vacuum environment.

7. A package structure of an AMOLED display device, comprising:

the display device comprises a display substrate, a light-emitting diode and a light-emitting diode, wherein a display area is arranged on the display substrate, a plurality of display units are arranged in the display area, and the light-emitting diode is arranged on each display unit;

the packaging substrate is provided with a sealing area corresponding to the display area on the display substrate, and the sealing area of the packaging substrate is provided with a plurality of display unit sealing areas corresponding to the display units one by one;

an inner Frit cured layer surrounding the display unit sealing region of the encapsulation substrate;

the UV glue curing layer surrounds the display area;

the outer ring Frit cured layer surrounds the UV glue cured layer.

8. An AMOLED display device comprising the package structure of claim 7.

Images