( 12 ) United States Patent Chen ( 54 ) ENCAPSULATION STRUCTURES OF OLED ENCAPSULATION METHODS, AND OLEDS es ( 71 ) Applicant : Shenzhen China Star Optoelectronics Technology Co., Ltd., Shenzhen, Guangdong ( CN ) ( 72 ) Inventor : Lixuan Chen, Guangdong ( CN ) ( 73 ) Assignee : Shenzhen China Star Optoelectronics Technology Co., Ltd, Shenzhen, THOUTLULUULLITTUR US009905806B2 ( 10 ) Patent No. : US 9, 905, 806 B2 ( 45 ) Date of Patent : Feb. 27, 2018 con una s190 songs ( 52 ) U. S. Cl. CPC....... HOIL 51 / 5268 ( 2013. 01 ) ; HOIL 23 / 291 ( 2013. 01 ) ; HOIL 23 / 293 ( 2013. 01 ) ; HOIL 23 / 3135 ( 2013. 01 ); HOIL 51 / 56 ( 2013. 01 ); HOIL 2251 / 5369 ( 2013. 01 ) ( 58 ) Field of Classification Search CPC. HO1L 23 / 291 ; HO1L 23 / 293 ; HO1L 23 / 3135 ; HO1L 51 / 5268 ; HO1L 51 / 56 See application file for complete search history. Guangdong ( CN ) ( 56 ) References Cited ( * ) Notice : Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U. S. C. 154 ( b ) by 202 days. ( 21 ) Appl. No.: 14 / 914, 656 ( 22 ) PCT Filed : ( 86 ) PCT No. : $ 371 ( c ) ( 1 ), ( 2 ) Date : Jan. 21, 2016 PCT / CN2016 / 071543 Feb. 26, 2016 ( 87 ) PCT Pub. No. : WO2017 / 096696 PCT Pub. Date : Jun. 15, 2017 ( 65 ) Prior Publication Data US 2018 / 0034004 A1 Feb. 1, 2018 ( 30 ) Foreign Application Priority Data Dec. 9, 2015 ( CN )............. 2015 1 0900239 ( 51 ) Int. CI. HOIL 51 / 52 HOIL 23 / 31 HOIL 23 / 29 HOIL 51 / 56 U. S. PATENT DOCUMENTS 7. 952, 105 B2 2011 Cok 2007 / 0114925 A1 * 5 / 2007 Cok HOIL 51 / 5268 313 / 512 2007 / 0267966 A1 * 11 / 2007 Numajiri... B32B 7 / 02 313 / 502 ( Continued ) Primary Examiner Allan R Wilson ( 74 ) Attorney, Agent, or Firm Andrew C. Cheng ( 57 ) ABSTRACT A OLED encapsulation structure includes : a first encapsu lation layer ; a second encapsulation arranged on one side of the first encapsulation layer ; and scattering particles formed between the first encapsulation layer and the second encap sulation layer, and the scattering particles are configured to scatter incident lights. In addition, an encapsulation method of OLEDs and the OLEDs having the encapsulation struc ture are disclosed. The scattering particles are formed within the cathode encapsulation layer. The scattering particles may generate the scattering effect for the ambient lights or the stray lights to reduce the reflection of the light beams by the cathode. Thus, the brightness and the clearness of the OLED may be enhanced. ( 2006. 01 ) ( 2006. 01 ) 2006 01 ( 2006. 01 ) 1 Claim, 3 Drawing Sheets 20 100 22 23 21
( 56 ) References Cited U. S. PATENT DOCUMENTS 2008 / 0169758 Al * 7 / 2008 Cok............ HOIL 51 / 5262 313 / 506 2008 0272367 A1 11 2008 Cok 2012 / 0155093 A1 6 / 2012 Yamada 16 / 2012 Yarachitzka. 2013 / 0105770 A1 * 5 / 2013 Pschenitzka...... HOIL 31 / 0232 257 / 40 2017 / 0062765 Al * 3 / 2017 Yang............. HO1L 51 / 5268 * cited by examiner US 9, 905, 806 B2 Page 2. HOLL - 257149
U. S. Patent Feb. 27, 2018 Sheet 1 of 3 US 9, 905, 806 B2 ' 22 23 21 " 100. FIG. 1
U. S. Patent Feb. 27, 2018 Sheet 2 of 3 US 9, 905, 806 B2 21 ( ool o o o o o / oo oo oo o /???????????????????????????????? po oo ooo???????? o o o o o o o FIG. 2
U. S. Patent Feb. 27, 2018 Sheet 3 of 3 US 9, 905, 806 B2 Forming a first encapsulation layer on a surface of a cathode of the OLED Forming scattering particles on a surface of the first encapsulation layer L S01 S01 Forming a second encapsulation layer on the first encapsulation layer to cover the scattering particles FIG. 3 S03
ENCAPSULATION STRUCTURES OF OLED, ENCAPSULATION METHODS, AND OLEDS BACKGROUND OF THE INVENTION US 9, 905, 806 B2 In another aspect, an encapsulation method of OLEDs includes : forming a first encapsulation layer on a surface of a cathode of the OLED ; forming scattering particles on a surface of the first encapsulation layer, and forming a second 5 encapsulation layer on the first encapsulation layer to cover 1. Field of the Invention the scattering particles. Wherein the scattering particles are made by any one of The present disclosure relates to display technology, and the following methods : adopting a fast film - formation more particularly to an encapsulation structure of organic method to damage film - formation quality of the first encap light - emitting diodes ( OLEDs ), an encapsulation method, 10 sulation layer such that the surface of the first encapsulation and the OLEDs having the encapsulation structure. layer includes an island - shaped structure to form the scat tering particles ; heating up plurality of heating points of 2. Discussion of the Related Art the first encapsulation layer, a location of each of the heating points corresponds to one scattering particle such that mate OLEDs may include an anode, a cathode and a light 15 rials in a rim of the heating point shrink down to the heating emitting layer. The cathode may be made by metallic point to form the scattering particles ; adopting a manufac materials, such as Al, and the anode may be made by turing method of sphere - inorganic - nano particles to generate materials such as ITO. The electron and the hole are respec the scattering particles, mixing the scattering particles into tively injected via the cathode and the anode such that solvent, coating the solvent on the surface of the first excitons are formed on the organic light emitting layer such 20 encapsulation layer, and applying a baking process to vapor that the light emitting layer is activated to emit the lights. ize the solvent to form the scattering particles on the surface Currently, most of the OLEDs adopt anode light emitting of the first encapsulation layer ; and adopting a high preci structure and the cathode operates as the reflective layer, sion masking sheet to etch the surface of the first encapsu which causes the ambient lights or the internal scattering lation layer to form the scattering particles. lights are reflected after radiating on the cathode. Especially, 25 In view of the above, the scattering particles are formed most of the cathode are metal and thus the reflective rate is within the cathode encapsulation layer. The scattering par high, and thus the contrastness and the clearness of the ticles may generate the scattering effect for the ambient OLED is reduced. lights or the stray lights to reduce the reflection of the light beams by the cathode. Thus, the brightness and the clearness SUMMARY 30 of the OLED may be enhanced. In order to overcome the above problems, it is necessary BRIEF DESCRIPTION OF THE DRAWINGS to provide an encapsulation structure of OLEDs, an encap sulation method, and the OLEDs having the encapsulation FIG. 1 is a schematic view of the OLED in accordance structure for enhancing the contrastness and the clearness. 35 with one embodiment. In one aspect, an encapsulation structure of OLEDs FIG. 2 is a top view of the first encapsulation layer of the includes : a first encapsulation layer ; a second encapsulation OLED of FIG. 1. arranged on one side of the first encapsulation layer ; and FIG. 3 is a flowchart of the encapsulation method of scattering particles formed between the first encapsulation OLEDs in accordance with one embodiment. layer and the second encapsulation layer, and the scattering 40 particles are configured to scatter incident lights. DETAILED DESCRIPTION OF THE Wherein the first encapsulation layer is a polymer film. EMBODIMENTS Wherein the first encapsulation layer is made by one of Fluorinated Polymers, Parylene, Cyclotene, and Polyacry Embodiments of the invention will now be described lates. 45 more fully hereinafter with reference to the accompanying Wherein the second encapsulation layer is made by drawings, in which embodiments of the invention are ceramics. shown Wherein the diffusion particles are spherical, hemi - FIG. 1 is a schematic view of the OLED in accordance spheric, ellipsoidal, or arc - shaped. with one embodiment. The OLED 100 includes a cathode 10 In another aspect, an OLED includes : a cathode and a 50 and an encapsulation structure 20 formed on the surface of OLED encapsulation structure, the OLEDs are formed on a the cathode 10. It can be understood that FIG. 1 only shows surface of the cathode, the OLED encapsulation structure an example, the OLED 100 may include, but not limited to, includes : a first encapsulation layer, a second encapsulation an anode and a light emitting layer between the cathode 10 arranged on one side of the first encapsulation layer ; and and the anode. The anode may be made by ITO materials scattering particles formed between the first encapsulation 55 and the light emitting layer is the organic material layer, layer and the second encapsulation layer, and the scattering such as polymer. The light emitting layer emits the lights particles are configured to scatter incident lights. after a predetermined voltage is applied between the anode Wherein the first encapsulation layer is a polymer film. and the cathode 10. The lights of the RGB colors generated Wherein the first encapsulation layer is made by one of by the light emitting layer may be controlled in accordance Fluorinated Polymers, Parylene, Cyclotene, and Polyacry - 60 with the materials of the light emitting layer. In the embodi lates. ment, the OLED 100 is a top emission OLED. Wherein the second encapsulation layer is made by The cathode 10 is a metallic material layer. Specifically, ceramics. the cathode 10 may be one of the Al, Ag, Li, Mg, In, or an Wherein the diffusion particles are spherical, hemi - alloy of several metals. spheric, ellipsoidal, or arc - shaped. 65 The encapsulation structure 20 seals the OLED 100 to Wherein the cathode is one of the Al, Ag, Li, Mg, In, or prevent the OLED 100 from being affected by impurity such an alloy of several metals. as water or air.
US 9, 905, 806 B2 The encapsulation structure 20 is of a translucent struc scattering particle such that the materials in a rim of the ture. The encapsulation structure 20 includes a first encap - heating point shrink down to the heating point to form the sulation layer 21, a second encapsulation layer 22, and a scattering particles. plurality of diffusion particles 23 between the first encap - A manufacturing method of sphere - inorganic - nano par sulation layer 21 and the second encapsulation layer 22. 5 ticles is adopted to generate the scattering particles, and the The first encapsulation layer 21 is formed on the surface scattering particles are mixed into solvent. The solvent is of the cathode 10. In the embodiment, the first encapsulation coated on the surface of the first encapsulation layer. in the layer 21 is a polymer film. Specifically, the first encapsula end, the solvent is vaporized by baking, and the scattering tion layer 21 may be made by one of Fluorinated Polymers, particles are formed on the surface of the first encapsulation Parylene, Cyclotene, and Polyacrylates. 10 layer. The second encapsulation layer 22 is formed on one side high precision masking sheet is adopted to etch the of the first encapsulation layer 21 facing away the cathode surface of the first encapsulation layer to form the scattering 10. The second encapsulation layer 22 may be made by the particles. same or different material with the first encapsulation layer 16 In step S3, a second encapsulation layer is formed on the 21. In the embodiment, the second encapsulation layer 22 surface of the first encapsulation layer to cover the scattering may be made by ceramics. particles. The diffusion particles 23 are configured to change the The second encapsulation may be made by the same direction of incident lights so as to scatter the incident lights. materials and the same method with the first encapsulation The diffusion particles 23 may be formed on the first 20 layer, or may be made by other appropriate materials and encapsulation layer 21 or on the second encapsulation layer other methods. 22. In the embodiment, the diffusion particles 23 are formed in the embodiment, the second encapsulation layer is on the first encapsulation layer 21, and the diffusion particles made by ceramics, and the ceramics are deposited on the 23 are made by the same materials with the first encapsu - surface of the first encapsulation layer. lation layer 21. Also referring to FIG. 2, the diffusion 25 The OLED encapsulation method forms the scattering particles 23 are of spherical - shaped, and the diffusion par - particles within the cathode encapsulation layer. The scat ticles 23 are uniformly distributed on the surface of the first tering particles may generate the scattering effect for the encapsulation layer 21. It can be understood that, in other ambient lights or the stray lights to reduce the reflection of embodiments, the diffusion particles 23 may be spherical, the light beams by the cathode. Thus, the brightness and the hemispheric, ellipsoidal, or arc - shaped. The distribution of 30 clearness of the OLED may be enhanced. the diffusion particles 23 may be regular or irregular in It is believed that the present embodiments and their accordance with demands. advantages will be understood from the foregoing descrip Due to the diffusion particles 23, the ambient lights or the tion, and it will be apparent that various changes may be stray lights may be scattered to reduce the reflection of the 36 made thereto without departing from the spirit and scope of light beams by the cathode. Thus, the contrastness and the the invention or sacrificing all of its material advantages, the clearness of the OLED 100 may be enhanced. examples hereinbefore described merely being preferred or FIG. 3 is a flowchart of the encapsulation method of exemplary embodiments of the invention. OLEDs in accordance with one embodiment. The method includes the following steps. 40 What is claimed is : In step S01, the first encapsulation layer is formed on the 1. An encapsulation method of OLEDs, comprising : surface of the cathode of the OLED. forming a first encapsulation layer on a surface of a The first encapsulation layer may be made by Physical cathode of the OLED ; Vapor Deposition ( PVD ), Chemical Vapor Deposition forming scattering particles on a surface of the first ( CVD ), Atomic Layer Deposition ( ALD ) or other appropri - 45 encapsulation layer ; ate methods. forming a second encapsulation layer on the first encap Specifically, in the embodiment, the OLED is arranged sulation layer to cover the scattering particles, and within a vacuum chamber such that the mother liquid of the materials of the first encapsulation layer may be quickly wherein the scattering particles are made by any one of vapored into the air. The air is directed into the vacuum 50 the following methods : chamber such that the air is condensed, in a liquid form, on adopting a fast film - formation method to damage film the surface of the cathode of the OLED. The liquid conden formation quality of the first encapsulation layer such sates on the surface of the cathode are solidified to form a that the surface of the first encapsulation layer com solid coating, that is, the first encapsulation layer. The prises an island - shaped structure to form the scattering solidification may be conducted by ultraviolet rays. The 55 particles ; mother liquid may be one of Fluorinated Polymers, heating up a plurality of heating points of the first encap Parylene, Cyclotene, Polyacrylates. sulation layer, a location of each of the heating points In step S02, the scattering particles are formed on the corresponds to one scattering particle such that mate surface of the first encapsulation layer. rials in a rim of the heating point shrink down to the Specifically, the scattering particles are formed by one of 60 heating point to form the scattering particles ; the following methods. adopting a manufacturing method of sphere - inorganic A fast film - forming method is adopted to damage the nano particles to generate the scattering particles, mix film - formation quality of the first encapsulation layer. As ing the scattering particles into solvent, coating the such, the surface of the first encapsulation layer may include solvent on the surface of the first encapsulation layer, an island - shaped structure to form the scattering particles ; 65 and applying a baking process to vaporize the solvent The first encapsulation layer is heated via multiple points. to form the scattering particles on the surface of the first The location of each of the heating points corresponds to one encapsulation layer ; and
adopting a high precision masking sheet to etch the surface of the first encapsulation layer to form the scattering particles. * * * * US 9, 905, 806 B2