CN1328936C - Method of forming encapsulation protection structure - Google Patents

Abstract

The invention discloses a method for forming an encapsulation protection structure of an organic light emitting element (organic EL element) applied to an Organic Light Emitting Display (OLED), which can be completed in the same reaction cavity. Which comprises the following steps: placing an organic light-emitting element in a plasma reaction chamber; forming a first buffer layer on the organic light emitting element; forming a first protective layer on the first buffer layer; forming a second buffer layer on the first protective layer; and forming a second protective layer on the second buffer layer.

Description

Method of forming encapsulation protection structure

technical field

The invention relates to a method for forming an encapsulation protection structure of an organic light-emitting element (organic EL element), in particular to a method for forming an encapsulation protection structure applied to an organic light-emitting display (OLED).

Background technique

With the advent of the information age, the display has become a necessary component of electrical equipment, such as notebook computers, mobile phones, information appliances (IA) and personal digital assistants (PDA), etc., most of which require display components. Generally speaking, lightness, thinness, and power saving are the basic requirements for displays, but limited by viewing angle, response speed, brightness, image quality, and temperature stability. In the new generation of display technology, organic light-emitting display components ( Organic Light Emitting Device (OLED) has become a product actively researched and developed by technicians in the field due to its good characteristics such as self-luminescence (no need to use backlight), wide viewing angle, fast response speed, simple manufacturing process, and low power consumption. .

Since the development history of organic light-emitting displays is not long enough, the current technology still faces some problems to be broken through. In particular, moisture and oxygen in the atmosphere can easily cause cathode oxidation of organic light-emitting display elements (referred to as organic EL elements) and organic compound interface peeling, which makes organic EL elements very easy to produce dark spots (darkspot), which not only reduces the display The good rate and the brightness emitted, but also shorten the life of the display. In order to avoid the above-mentioned defects, the traditional technologies mostly use metal packaging cans or glass packaging cans for packaging protection to prevent the electrode layer materials and organic layer materials in the organic light-emitting display element from contacting the external environment. However, metal packaging cans have disadvantages such as heavy weight and easy oxidation in manufacture, and glass packaging cans have disadvantages such as difficult processing, fragility, large volume and heavy weight. Moreover, the adhesion between metal and glass is poor, and the flatness of the component bonding is high, and the packaging is very easy to cause peeling due to uneven stress. Moreover, with the trend of using plastic substrates to make organic EL components, it may not be possible in the future. The protective structure is then encapsulated in metal or glass. Therefore, in order to make organic EL elements lighter and thinner, and to adapt to the development of full plasticization of organic EL elements in the future, the high-density packaging protection structure plating method should be the focus of actively strengthening research and development.

Please refer to FIG. 1 , which is a schematic cross-sectional view of an existing organic EL element packaging structure. As shown in FIG. 1 , an organic EL element 10 generally includes a substrate 101 , a first conductive layer 102 , a multilayer structure of organic luminescent material 103 , and a second conductive layer 104 . Among them, the substrate 101 is usually a glass substrate or a metal substrate, the first conductive layer 102 is an indium tin oxide (ITO) conductive transparent film or an indium zinc oxide (IZO) thin film, and the second conductive layer 104 can be a metal or a metal compound or an oxide film. Indium tin (ITO) conductive transparent film or indium zinc oxide (IZO) film, etc., in order to block the electrode layer material and organic layer material in the organic light-emitting display element from contacting the external environment, it is necessary to form a package protection structure 11 on the organic EL element 10 Above, the following are the necessary steps to form a packaging protection structure for traditional organic EL elements:

First, polymer materials such as acrylic acid (ester) precursors are plated on the organic EL element 10 by means of thermal sublimation, and the polymers are polymerized to form a first buffer layer 111 by means of light irradiation, and the first buffer layer 111 is formed by sputtering (sputtering) or chemical vapor deposition (CVD) method, form the first protective layer (passivation) 112 with inorganic or ceramic materials in the reaction chamber, the protective layer is completely filled on the first buffer layer 111, and the substrate 101 is returned to high The molecular deposition chamber is used to form a second buffer layer 113 on the first protection layer 112 . Next, the entire substrate 101 is transported back into the reaction chamber made of inorganic or ceramic materials to form a second passivation layer (passivation) 114 on the second buffer layer 113 , and then repeatedly fabricate a multi-layer structure as required.

In the process of manufacturing the packaging protection structure 11, since the entire substrate 101 must be reciprocated between the reaction chamber for making the protective layer and the thermal sublimation chamber for making the buffer layer, the manufacturing process is relatively complicated. ) type components, it is necessary to consider whether the light will affect the organic material.

Therefore, how to design a package protection structure with a simpler manufacturing process and lower cost for organic EL elements is indeed a topic that should be studied at present.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for forming a packaging protection structure for organic EL elements, which can complete the manufacturing process of the packaging protection structure in the same reaction chamber, and can be applied to glass substrates, metal substrates and Organic light-emitting elements on plastic substrates, and make the passivation layer of organic light-emitting elements (organic EL elements) lighter, thinner and denser.

Accordingly, the method for forming an encapsulation protection structure applied to an organic light-emitting display (OLED) provided by the present invention includes: placing an organic light-emitting element in a plasma reaction chamber, and using a plasma-enhanced chemical vapor deposition (PECVD) method A first buffer layer (buffer layer) is formed on the light-emitting element without curing the polymer precursor by light; a first passivation layer is formed on the first buffer layer; forming a second buffer layer; and forming a second passivation layer on the second buffer layer. Wherein, the first buffer layer, the first protection layer, the second buffer layer and the second protection layer are all formed by plasma polymerization in the same plasma reaction chamber.

According to the concept of the present invention, wherein the plasma polymerization method can be chemical vapor deposition methods such as plasma enhanced chemical vapor deposition (PECVD) or high density plasma chemical vapor deposition (HDPCVD) or induced combined plasma chemical vapor deposition (ICPCVD).

According to the concept of the present invention, when forming the buffer layer and the protective layer, a surface treatment step or a self-cleaning step of the organic element or the buffer layer or the protective layer may be performed according to the process requirements.

According to the concept of the present invention, the first protective layer and the second protective layer are made of a diamond-like carbon film (Diamond-like Carbon) material.

According to the concept of the present invention, wherein the first buffer layer and the second buffer layer are polymer films formed from polymer precursors, and the polymer precursors can be selected from styrene (Styrene), acetylene (Acetylene), ethylene (Ethylene) or toluene (Methylbenzene, C ₆ H ₅ CH ₃ ) to form polymer films such as polymer diamond-like carbon films (Polymer like Diamond-like Carbon).

According to the concept of the present invention, the organic light emitting element can be a passive organic light emitting element or an active organic light emitting element. And it can be a downward-emitting active organic light-emitting element or an upward-emitting active organic light-emitting element.

According to the concept of the present invention, the organic light emitting element includes: a substrate; a first conductive layer formed on the substrate; a multilayer structure of organic light emitting material formed on the first conductive layer; a multilayer structure formed on the organic light emitting material the second conductive layer on the structure.

According to the concept of the present invention, the substrate may be a glass substrate or a plastic substrate.

Description of drawings

FIG. 1 is a schematic cross-sectional view of an existing organic EL element packaging structure;

2A to 2D are flowcharts of a method for forming a package protection structure according to a preferred embodiment of the present invention.

Explanation of reference signs

Organic EL element 10 substrate 101

First conductive layer 102 Multilayer structure of organic luminescent material 103

Second conductive layer 104 Encapsulation protection structure 11

First buffer layer 111 First protective layer 112

Second buffer layer 113 Second protection layer 114

Organic Light Emitting Components 20 Encapsulation Protection Structure 21

First buffer layer 211 First protective layer 212

Second buffer layer 213 Second protection layer 214

Detailed ways

The method for forming an encapsulation protection structure provided by the invention is applied to an organic light-emitting element (organic EL element). Organic light-emitting elements are roughly divided into two types: passive type and active type. Although the passive type organic light-emitting element is used as an embodiment to further illustrate the technical solution of the present invention, other organic light-emitting elements, for example, emit light downward or All active organic light-emitting elements that emit light on the top are applicable. In addition, there is no limitation on the substrate of the organic light emitting element, either a glass substrate or a plastic substrate can be applied to the technical solution of the present invention.

Please refer to FIGS. 2A to 2D , which are flowcharts of a method for forming a package protection structure according to a preferred embodiment of the present invention. As shown in FIG. 2A, first, a passive organic light-emitting element 20 is placed in a plasma reaction chamber (not shown), and a first buffer layer 211 is formed on the organic light-emitting element 20, and then as shown in FIG. 2B As shown, the first protection layer 212 is filled and formed on the first buffer layer 211 by means of plasma polymerization. Next, as shown in FIG. 2C , in the same plasma reaction chamber, the second buffer layer 213 is formed on the first protection layer 212 by plasma polymerlization again. After that, as shown in FIG. 2D , the second protection layer 214 is formed again by plasma polymerization, and the fabrication of the buffer layer and the protection layer can be repeated if necessary. If patterning is required, a shadow mask can be used to block the parts that do not need to be plated (not shown), thus completing the entire manufacturing process of the package protection structure 21 .

In the manufacturing process of the encapsulation protection structure 21, the plasma polymerization method used in the present invention is plasma enhanced chemical vapor deposition (PECVD), with methane (CH ₄ ) or toluene (Methylbenzene, C ₆ H ₅ CH ₃ ) Or C ₄ F ₈ etc. as the main reaction gas, in the plasma reaction chamber, form the first protective layer 212 and the second protective layer 214, the material used is diamond-like carbon (Diamond-like Carbon), in addition, in In the manufacturing process, if necessary, different parameters can be adjusted according to requirements, such as doping certain metal materials, such as titanium (Ti), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten ( W), ruthenium (Ru), iron (Fe), cobalt (Co), nickel (Ni), aluminum (Al), copper (Cu), gold (Au), silver (Ag), etc., or doped with some non- Metal materials, such as silicon (Si) atoms, etc., or III-V group elements in the periodic table, etc. Of course, other plasma polymerization methods can also be applied to the technical solution of the present invention, such as high-density plasma chemical vapor deposition (HDPCVD) and the like. In addition, the materials used in the present invention to form the first buffer layer 211 and the second buffer layer 213 can use a polymer precursor (precursor) as a reaction gas, wherein the polymer precursor can be selected from, for example, styrene (Styrene), acetylene (Acetylene), ethylene (Ethylene) or toluene (Methylbenzene, C ₆ H ₅ CH ₃ ) or one of C ₄ F ₈ to form a polymer film, such as a polymer diamond-like carbon film (Polymer likeDiamond- like Carbon), etc., so that the first buffer layer 211 and the second buffer layer 213 can be formed in the same plasma reaction chamber as the first protective layer 212 and the second protective layer 214. Of course, if necessary, another buffer layer (not shown) can be formed on the second protective layer 214, and then another protective layer (not shown) can be added, so that the organic light-emitting element 20 can be separated from the external environment. further isolation.

The technical solution of the present invention is mainly to sequentially form the first buffer layer 211, the first protective layer 212, the second buffer layer 213 and the The second protective layer 214 . In this way, the traditional disadvantage that the organic light-emitting element 20 must be transported back and forth between different reaction chambers to form the package protection structure can be overcome. In addition, if it is desired to improve the cleanliness of the package protection structure, before each plasma polymerization process, the inside of the reaction chamber can be cleaned first (self-clean), so that the cleanliness of the package protection structure can be ensured.

Because the purpose of manufacturing the encapsulation protection structure (passivation) 21 is to completely isolate the organic layer material and electrode layer material in the organic light emitting element 20 from the external environment, the materials used must also effectively discharge the Therefore, it is best to use a material with high density and good thermal conductivity for the material of the packaging protection structure. Compared with the organic materials or ceramic materials commonly used at present, the diamond-like carbon film (DLC) used in the present invention has better wear resistance and high thermal conductivity, and has lower water penetration to moisture at the same time. Transmittance, and with the different preparation methods, doping impurities and parameters, the characteristics of diamond-like carbon can be from a soft polymer film with extremely small stress to a hard or extremely hard amorphous diamond-like carbon film, and its color It can range from brown to transparent. Therefore, the encapsulation and protection structure formed by the diamond-like carbon material of the present invention can effectively isolate the contact between the organic light-emitting element and the external environment. In addition, the outermost layer of the encapsulation protection structure 21 of the present invention is the second protection layer 214 formed of diamond-like carbon material, which can also increase the abrasion resistance of the organic light emitting element 20 and make the life of the organic light emitting element 20 longer.

In summary, the technical solution of the present invention is to use the plasma polymerization method and the diamond-like carbon material to form the first protective layer and the second protective layer, and to use the plasma polymerization method and the polymer precursor material between the two protective layers. A buffer layer is formed in the same plasma reaction chamber to absorb the stress between the first protective layer and the second protective layer, so that the entire encapsulation protection structure (passivation) can be made in the same reaction chamber, which overcomes the traditional organic light-emitting element The disadvantage of repeatedly transporting between the reaction chambers simplifies the manufacturing steps, reduces the manufacturing cost, and can effectively isolate the organic light-emitting element from contact with the external environment. In addition, the passivation layer of diamond-like carbon material has high density, good electrical insulation performance, good thermal conductivity, good wear resistance, high hardness, and good corrosion resistance, all of which meet the requirements of the passivation layer. Therefore, the technical solution of the present invention is a practical, novel and progressive technical solution for the manufacturing process of the encapsulation and protection structure of the organic light-emitting element.

Alterations and modifications made by those skilled in the art within the concept and protection scope of the present invention will fall within the protection scope of the appended claims.

Claims (9)

1. method that is applied to the formation packaging protection structure of organic light emitting display, this method comprises the steps:

In a plasma reaction cavity, place an organic illuminating element;

On described organic illuminating element, form one first resilient coating;

On described first resilient coating, form one first protective layer;

On described first protective layer, form one second resilient coating; And

On described second resilient coating, form one second protective layer,

Described formation first resilient coating, first protective layer, second resilient coating and second protective layer carry out with the plasma polymerization method in described plasma reaction chamber.

2. the method for formation packaging protection structure as claimed in claim 1 wherein, repeats to make described resilient coating and protective layer, and described resilient coating and protective layer formation order can be adjusted.

3. the method for formation packaging protection structure as claimed in claim 1; wherein, described plasma polymerization method comprises plasma reinforced chemical vapour deposition method, high density plasma chemical vapor deposition method and induces in conjunction with one of plasma chemical vapor deposition process.

4. the method for formation packaging protection structure as claimed in claim 1 wherein, comprises a surface treatment or a cleaning step.

5. the method for formation packaging protection structure as claimed in claim 1, wherein, described first protective layer and second protective layer are formed by the diamond-like-carbon membrane material.

6. the method for formation packaging protection structure as claimed in claim 1, wherein, described first resilient coating and second resilient coating comprise the macromolecule membrane that forms with the macromolecule precursor.

7. the method for formation packaging protection structure as claimed in claim 6, wherein, described macromolecule precursor is selected from styrene, acetylene, ethene or toluene or C ₄F ₈One of.

8. the method for formation packaging protection structure as claimed in claim 1, wherein, described organic illuminating element is a kind of passive type organic illuminating element or active organic light-emitting element.

9. the method for formation packaging protection structure as claimed in claim 1, wherein, described organic illuminating element comprises:

One substrate;

One is formed at first conductive layer on the described substrate;

One is formed at the luminous organic material sandwich construction on described first conductive layer; And

One is formed at second conductive layer on the described luminous organic material sandwich construction.