OLED encapsulating structure and manufacturing method thereof

• US 10,446,790 B2
• Filed: 11/30/2017
• Issued: 10/15/2019
• Est. Priority Date: 11/01/2017
• Status: Active Grant

• Current Assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co., Ltd.
• Original Assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co., Ltd.
• Inventors: Li, Wenjie
• Primary Examiner(s): Hoang, Quoc D
• Application Number:
  US15/741,909
• Publication Number:
  US 20190131567A1
• Time in Patent Office: 684 Days
• CPC Class Codes: H10K 50/841 Self-supporting sealing arrangements
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass

Abstract

The present application provides an encapsulation method for an OLED and an encapsulation structure of an OLED. In the encapsulation method for an OLED of the present application, by disposing the UV light absorbing layer on the surface of the OLED device, in one aspect, the UV light absorbing layer has a low UV transmittance. Therefore, UV light can be blocked from being directed to the TFT during UV curing of the encapsulation material and the sealant to reduce or eliminate the influence of UV light on the TFT; on the other hand, the UV light absorbing layer has high visible light transmittance and therefore does not reduce the light intensity of the OLED device. The encapsulation structure of the OLED of the present application is fabricated by the above encapsulation method. The TFT has excellent electrical performance and the OLED device thereof has strong light intensity.

Claims

1. An encapsulation method for an OLED, comprising the following steps:

step S1;

providing a TFT substrate, fabricating an OLED device on the TFT substrate;

forming a first passivation layer covering an outer surface of the OLED device;

step S2;

forming an UV light absorbing layer covering an outer surface of the first passivation layer, the UV light absorbing layer comprising an organic resin and inorganic particles having UV light absorbing property dispersed in the organic resin, and the UV light absorbing layer is transparent;

step S3;

providing an encapsulation cover, coating a sealant on a periphery of the encapsulation cover corresponding to the OLED device, and disposing an encapsulation material in a region surrounded by the sealant on the encapsulation cover;

step S4;

aligning the encapsulation cover and the TFT substrate, the sealant being adhered to the TFT substrate and the encapsulation cover respectively, and forming a sealed space between the TFT substrate and the encapsulation cover, the encapsulation material filled in the sealed space;

wherein the step S2 further comprises;

forming a second passivation layer covering the UV light absorption layer on the outer surface of the UV light absorption layer; and

wherein the first passivation layer and the second passivation layer comprise silicon nitride.

2. The encapsulation method for the OLED according to claim 1, wherein an UV light transmittance of the UV light absorption layer is less than 5%, and a transmittance of the visible light is more than 80%, the UV light absorbing layer has a thickness of 1 μ

m to 10 μ

m, a content of the inorganic particles in the UV light absorbing layer is 0.1 vol % to 1.0 vol %, the inorganic particles have a particle size of 1 nm to 150 nm.

3. The encapsulation method for the OLED according to claim 1, wherein the organic resin comprises one or more of polyurethane, acrylic resin and epoxy resin, the inorganic particles comprise one or more of metal oxide particles and metal oxide modified particles, the metal oxide particles comprise one or more of titanium oxide particles, zinc oxide particles, and cerium oxide particles, and the metal oxide modified particles comprises one or more of titanium oxide modified particles, zinc oxide modified particles, and cerium oxide modified particles.

4. The encapsulation method for the OLED according to claim 1, wherein the method for forming the UV light absorbing layer comprises dispersing the inorganic particles in a solution of an organic resin precursor to prepare a UV light absorbing solution, forming a film of the UV light absorbing layer on the outer surface of the first passivation layer by the UV light absorbing solution by adapting a solution film casting process, curing to form the UV light absorbing layer, the solution film casting process comprises one or more of spin coating, one drop filling, ink jet printing, tape casting, and nozzle printing.

5. An encapsulation method for an OLED, comprising the following steps:

step S1;

providing a TFT substrate, fabricating an OLED device on the TFT substrate;

forming a first passivation layer covering an outer surface of the OLED device;

step S2;

forming an UV light absorbing layer covering an outer surface of the first passivation layer, the UV light absorbing layer comprising an organic resin and inorganic particles having UV light absorbing property dispersed in the organic resin, and the UV light absorbing layer is transparent;

step S3;

providing an encapsulation cover, coating a sealant on a periphery of the encapsulation cover corresponding to the OLED device, and disposing an encapsulation material in a region surrounded by the sealant on the encapsulation cover;

step S4;

aligning the encapsulation cover and the TFT substrate, the sealant being adhered to the TFT substrate and the encapsulation cover respectively, and forming a sealed space between the TFT substrate and the encapsulation cover, the encapsulation material filled in the sealed space;

wherein an UV light transmittance of the UV light absorption layer is less than 5%, and a transmittance of the visible light is more than 80%, the UV light absorbing layer has a thickness of 1 μ

m to 10 μ

m, a content of the inorganic particles in the UV light absorbing layer is 0.1 vol % to 1.0 vol %, and the inorganic particles have a particle size of 1 nm to 150 nm;

wherein the organic resin comprises one or more of polyurethane, acrylic resin and epoxy resin, the inorganic particles comprises one or more of metal oxide particles and metal oxide modified particles, the metal oxide particles comprises one or more of titanium oxide particles, zinc oxide particles, and cerium oxide particles, and the metal oxide modified particles comprises one or more of titanium oxide modified particles, zinc oxide modified particles, and cerium oxide modified particles;

wherein the method for forming the UV light absorbing layer comprises dispersing the inorganic particles in a solution of an organic resin precursor to prepare a UV light absorbing solution, forming a film of the UV light absorbing layer on the outer surface of the first passivation layer by the UV light absorbing solution by adapting a solution film casting process, curing to form the UV light absorbing layer, the solution film casting process comprises one or more of spin coating, one drop filling, ink jet printing, tape casting, and nozzle printing;

wherein the step S2 further comprises;

forming a second passivation layer covering the UV light absorption layer on the outer surface of the UV light absorption layer; and

wherein the first passivation layer and the second passivation layer comprise silicon nitride.