TWI418236B - Sealing method - Google Patents

Description

Packaging method

The present invention relates to a packaging method, and more particularly to a method of packaging an organic light emitting device.

The development and application of organic light-emitting display (OLED) has attracted attention recently; compared with the existing liquid crystal display devices, the organic light-emitting display device has the advantages of large angle of view, high contrast, fast response speed, wide operating temperature, etc. Advantage. The organic light-emitting material and/or electrode material used in the organic light-emitting display device is easily degraded or oxidized by the influence of moisture, oxygen, and therefore, packaging of components is a very important part in manufacturing an organic light-emitting display device.

In general, an organic light emitting display device includes an array substrate (lower substrate), an organic light emitting display element formed on the array substrate, and a package cover (upper substrate). When encapsulating, a seal surrounding the organic light emitting display element is formed between the array substrate and the package cover to seal the organic light emitting display element in the enclosed space. Although the seal can withstand the external moisture and oxygen entering the enclosed space, the moisture and oxygen present in the enclosed space will continue to damage the organic light-emitting display element during the packaging process.

Therefore, there is a need in the related art to provide a simpler packaging method for an organic light emitting display device.

SUMMARY OF THE INVENTION The Summary of the Disclosure is intended to provide a basic understanding of the present disclosure. This Summary is not an extensive overview of the disclosure, and is not intended to be an One of the objects of the present invention is to provide a packaging method. When the light-emitting element is encapsulated by this method, the organic light-emitting material or the electrode in the light-emitting element is not easily damaged, and proper physical and chemical protection can be provided for the light-emitting element.

According to a particular embodiment of the invention, the above method comprises the following steps. An array substrate is provided, wherein the array substrate has an effective display area, and at least one light emitting element is disposed in the effective display area. A package cover is provided and a sealing structure is formed on the package cover, wherein the sealing structure corresponds to the effective display area and substantially surrounds the effective display area. Sealant is filled in the sealing structure. A first curing process is performed to partially cure the sealant and the sealant has a viscosity of 10,000-60,000 cps. The package cover is bonded to the array substrate such that the light emitting elements are located within the sealed structure. A second curing process is performed to further cure the sealant.

The present invention also proposes another packaging method suitable for mass production of a plurality of display devices. When the light-emitting element is encapsulated by this method, the organic light-emitting material or the electrode in the light-emitting element is not easily damaged, and proper physical and chemical protection can be provided for the light-emitting element.

According to a particular embodiment of the invention, the above method comprises the following steps. An array substrate is provided. The array substrate includes a plurality of sub-array substrates, each of the sub-array substrates has an effective display area, and at least one light-emitting element is disposed in each of the effective display areas. A package cover is provided. The glass paste is coated on one surface of the package cover plate, and the glass paste is sintered to form a plurality of accommodating regions, and each of the accommodating regions corresponds to and is larger than each of the effective display regions. A frame of glue is applied around the accommodating areas. A sealant is applied to the accommodating regions. A first curing process is performed to partially cure the sealant and seal the adhesive to a first viscosity, the first viscosity being 10,000-60,000 cps. The package cover is opposite to the array substrate such that each of the effective display areas is located in a corresponding accommodating area, and the frame is cured. A second curing process is performed to further cure the sealant.

The basic spirit and other objects of the present invention, as well as the technical means and implementations of the present invention, will be readily apparent to those skilled in the art of the invention.

The description of the embodiments of the present invention is intended to be illustrative and not restrictive. The features of various specific embodiments, as well as the method steps and sequences thereof, are constructed and manipulated in the embodiments. However, other specific embodiments may be utilized to achieve the same or equivalent function and sequence of steps.

In view of the deficiencies mentioned in the prior art, the present invention proposes a packaging method. One of the principles and spirit of this packaging method is to cure the sealant in two stages; that is, the first curing process is performed to partially cure the sealant, and then the array substrate and package are performed. After the pair of cover plates is completed, a second curing process is performed to further cure the sealant.

The term "cure" as used herein refers to a case where a cross-linking reaction occurs between polymer chains of a polymer material, and this curing process causes the hardness of the material to increase and the viscosity value to become high. Specifically, the term "completely cured" generally refers to the case where the viscosity of the polymer material does not substantially increase; and the "partial cure" is before the viscosity of the material reaches the fully cured viscosity. . That is, in the case of partial curing, the viscosity value of the material can be further increased by starting the crosslinking reaction again. When it is conceivable, the viscosity value of the partially cured and fully cured polymer material usually depends on the characteristics of the material itself.

When the light-emitting element is packaged by this method, since the specific gravity of the solvent contained in the partially cured sealant is low (compared to before uncured), the probability of the organic solvent being damaged to the light-emitting element can be reduced.

Moreover, the fully cured sealant has better mechanical strength, and the physical protection can not only support the package cover to avoid the generation of Newton's ring, but also enhance the strength of the package and the reliability of the packaged organic light-emitting display device. . The packaged finished product is often subjected to pressure from the outside during subsequent processes and when the final product is in use. If the package cover is stressed and touches the internal light-emitting component, the luminous efficiency and service life of the product may be impaired. For example, when the polarizer is attached or when the user touches the touch screen, pressure is applied to the outer surface of the package cover. Therefore, the formation of a sealant having a higher hardness and viscosity according to the method proposed herein can avoid or reduce the probability of occurrence of the above problems.

Another advantage of using multi-stage curing is that the partially cured sealant (compared to a fully cured sealant) has better fluidity, so that the sealant and the light-emitting element have better conformality. In this way, the sealant can cover the upper surface and the side surface of the light-emitting element more completely, thereby better blocking water and oxygen existing in the closed space, and providing better chemical protection to the light-emitting element.

A packaging method according to an embodiment of the present invention will be described below with reference to process diagrams of FIGS. 1A through 1F.

First, an array substrate 100 is provided. The array substrate 100 has an effective display area 105, as shown in FIG. 1A, and at least one light-emitting element 140 has been formed in the effective display area 105 (as shown in FIG. 1F).

The array substrate 100 described herein can be any suitable substrate, such as a flexible (flexible) or rigid substrate, a transparent or opaque substrate. For example, the materials of the array substrate 100 include, but are not limited to, thermoplastic or thermoset materials, glass and/or thin layers of metal. The light-emitting element 140 may be, for example, an organic light-emitting diode element, a polymer light-emitting diode element, or other various types of light-emitting elements.

In addition, a package cover 110 is provided, and a sealing structure 120 is formed on the package cover 110. As shown in FIG. 1B, the sealing structure 120 corresponds to the effective display area 105 and substantially surrounds the effective display area 105. Specifically, the sealing structure 120 can define an accommodating area 125, and the accommodating area 125 defines an area larger than the effective display area 105.

Materials used to form the sealing structure 120 include, but are not limited to, glass frit or other adhesive materials such as UV glue. For example, the glass paste can be applied to a surface of the package cover 110 by screen printing, spraying, or other suitable technique; then, the glass paste is sintered to obtain the sealing structure 120. By way of illustration and not limitation, the glass cover coated cover sheet 110 can be placed in an oven for baking such that the glass paste forms the sealing structure 120.

The method proposed in the specific embodiment will be described later by taking a glass paste as an example. It will be understood that the specific composition of the glass paste is not limited herein as long as the slurry is melted to form a solid, thereby providing a desired adhesion and water-blocking gas (oxygen).

After the sealing structure 120 is formed, the sealant 130 is filled in the sealing structure 120 as shown in FIG. 1C.

For example, the sealant 130 can be filled into the sealing structure 120 using screen printing, spraying, or other suitable technique.

As an illustration and not limitation, the sealant 130 can be a photosensitive material or a thermally sensitive material. Specifically, the photosensitive material may be a photocurable resin such as an ultraviolet curable resin or a visible light curable resin; and the heat sensitive material may be a thermoset resin. The sealant 130 may comprise one or more materials selected from the group consisting of epoxy resins, acrylic resins, and urethane resins. In a preferred case, the transmittance of the sealant 130 to visible light should be higher than 90% so as not to affect the luminous efficiency of the light-emitting element.

The material suitable for the array substrate 100 can also be used as the package cover 110, and the material of the package cover 110 can be the same as or different from the array substrate 100.

After the sealant 130 is filled, a first curing process is performed to partially cure the sealant 130, and at this time, the partially cured sealant 130 has a viscosity of 10,000 to 60,000 cps. For example, the partially cured sealant 130 at this time may have a viscosity (ie, a first viscosity) of about 10,000, 20,000, 30,000, 40,000, 50,000, or 60,000 cps. In the preferred case, the height of the partially cured sealant 130 is less than or equal to the height of the sealing structure 120 formed by the dried glass paste.

After the first curing process, the package cover 110 is bonded to the array substrate. Specifically, the package cover 110 and the array substrate 100 are disposed opposite to each other, and the effective display area 105 corresponds to the accommodating area 125, so that the light-emitting elements (not shown) are disposed on the package cover 110 and the array substrate 100. Between the accommodating regions 125 defined by the sealing structure 120, as shown in FIG. 1D.

Thereafter, the package cover 110 and the array substrate 100 are paired, and the sealing structure 120 is irradiated with a light beam as shown in FIG. 1E, so that the glass paste therein is at least partially melted to be in contact with the package cover 110 and the array substrate 100. connection.

Although this step is performed using laser radiation (e.g., infrared laser) in Fig. 1E, other beams (e.g., infrared rays) may be used to practice the embodiment. Further, the light beam may be irradiated from the array substrate 100 or the package cover 110 or even from the above two directions to the sealing structure 120. In practice, the wavelength, diameter and/or power of the beam can be adjusted as needed.

After the above bonding step is completed, a second curing process is performed to further cure the sealant 130. In one embodiment, the second curing process is performed to further increase the viscosity of the sealant 130, for example, to above 60,000 cps. In various embodiments, the viscosity of the sealant 130 (ie, the second viscosity) may range from about 60,000 to 10 ¹⁵ cps, and may also be about 10 ⁵ -10 ¹² cps or may be about 10 ⁸ -10. ¹⁰ cps. In a preferred embodiment, the composition of the sealant 130 can be adjusted such that the viscosity of the fully cured sealant 130 is close to the viscosity of the solid (about 10 ¹⁵ cps). In another embodiment, the step of performing the second curing process further cures the sealant 130 to a curing rate of 85% or more. Here, the curing rate is defined as the ratio of the monomer consumed by the sealant to the monomer of the sealed collagen when the curing reaction is performed. Embodiments, for example, after performing a curing reaction, measuring the amount corresponding to the wavelength of the representative monomer of the sealant by infrared spectroscopy, that is, the amount of the monomer consumed in the curing reaction, and the infrared spectrum before the curing reaction can be known. The curing rate can be obtained by dividing the amount of the monomer measured therein. In one embodiment, the composition of the sealant 130 is, for example, an epoxy resin.

Generally, the method of performing the first curing process and the second curing process described above depends on the type of the sealant 130. Specifically, when the sealant 130 is an ultraviolet curable resin, the first curing process and the second curing process may be respectively an ultraviolet light irradiation process. Alternatively, when the sealant 130 is a visible light curable resin, the first curing process and the second curing process may each be a visible light irradiation process. Alternatively, when the sealant 130 is a thermosetting resin, the first curing process and the second curing process may each be a thermal process.

It will be appreciated that the degree of cure of the sealant 130 can be adjusted by controlling the relevant parameters of the curing process. For example, the sealant 130 can be partially or fully cured by controlling factors such as the concentration of the constituents of the sealant 130 (such as a resin material, a light or a thermal initiator), the light intensity, or the heating temperature. Taking the ultraviolet light irradiation process as an example, the ultraviolet light energy used in the first curing process may be about 1000-6000 mJ/cm ² ; and in the second curing process, the ultraviolet light energy used may be about 1000-6000 mJ. /cm ² .

In this way, the display device 150 as shown in FIG. 1F can be obtained. The structure shown in Fig. 1F is a cross-sectional view taken along line 1F-1F of Fig. 1E. It can be found that in the FIG. 1F, the sealant 130 covers the upper surface and the side surface of the light-emitting element 140; this is because only the sealant 130 is partially cured before the bonding step, and thus the sealant 130 (and completely The cured sealant 130 has a relatively better fluidity, and thus the upper surface of the partially cured sealant 130 and the light-emitting element 140 has better conformality with the side surface.

Further, although the sealant 130 illustrated in FIG. 1F is not in contact with the sealing structure 120, the invention is not limited thereto. For example, the sealant 130 may be filled in the entire accommodating area 125 and in contact with the sealing structure 120.

The method described above with reference to Figs. 1A to 1E is only one basic embodiment of the method proposed by the present invention, and the present invention is not limited thereto. It is conceivable for those having ordinary knowledge in the art to which the present invention pertains, and the order of the steps described above may be adjusted without departing from the meaning of the text, and even multiple steps may be performed simultaneously. For example, the two steps of providing the array substrate and providing the package cover may be performed simultaneously; or the array substrate may be prepared after the sealing structure is formed on the package cover.

In addition, the above methods do not exclude other steps without departing from the spirit and scope of the invention. For example, the above method may further comprise a method of forming an additional frame.

Please refer to FIG. 1G. Specifically, before the package cover 110 is bonded to the array substrate 100, the photoresist may be coated on the package cover 110 to form a sealant surrounding the receiving area 125 of the sealing structure 120. After the package cover 110 is bonded to the array substrate 130, an illumination process is performed to cure the sealant 135 to form the above-mentioned plastic frame (not shown).

The photosensitive adhesive may be an ultraviolet curing type or a visible light curing type material; for an ultraviolet curing type material, it may be cured by ultraviolet light having a wavelength of about 200 to 400 nm; and for a visible light curing type material, a wavelength of about 400 to 700 nm may be used. The visible light will cure it. The photoresist used herein may have the same or different composition as the sealant 130 described above. In one embodiment, the wavelength of light used to cure the photoresist is about 254-365 nm.

Optionally, the step of filling the sealant 130 with the sealant 120 and forming the sealant may be performed sequentially or simultaneously. In addition, the process of curing the sealant may be performed sequentially or simultaneously with the second curing process described above.

The methods described in Figures 1A through 1G are equally applicable to mass production processes. Generally, in mass production, an array of a plurality of sub-array substrates is provided on an array substrate. Accordingly, the present invention provides another packaging method suitable for mass production of a plurality of display devices 150. This packaging method also has the advantages of the method of the invention described above.

Hereinafter, a packaging method according to an embodiment of the present invention will be described with reference to a process diagram of FIGS. 2A to 2E. The details of the steps and components used herein are similar to those described above with reference to Figures 1A through 1F; for the sake of brevity, these similar details are not repeated below.

First, the array substrate 200 is provided. As shown in FIG. 2A, the array substrate 200 includes a plurality of sub-array substrates 202 (ie, regions defined by broken lines in FIG. 2A), each sub-array substrate 202 has an effective display area 205, and each effective display area At least one light-emitting element is disposed in the interior (for the sake of simplicity of the drawing, not shown in the drawing).

A package cover 210 as shown in FIG. 2B is provided. The glass paste 220 is coated on one surface of the package cover 210, and the glass paste 220 is sintered to form a plurality of accommodating regions 225, and each of the accommodating regions 225 corresponds to and is larger than each of the above effective display regions. 205.

A frame glue 235 is applied around the accommodating area 225, as shown in FIG. 2C.

In FIG. 2D, sealant 230 is applied to the accommodating regions 225, respectively. Thereafter, a first curing process is performed to partially cure the sealant 230 to a first viscosity, the first viscosity being 10,000-60,000 cps. When the method is practiced, the steps of applying the sealant 230 to the frame 235 can be performed simultaneously or separately. In an optional embodiment, the height of the partially cured sealant 230 is less than or equal to the height of the glass paste 220.

The package cover 210 is disposed opposite to the array substrate 200 as shown in FIG. 2E such that each of the effective display regions 205 is located in the corresponding receiving region 225. For example, a beam of light (such as the laser radiation shown in FIG. 2E) can be applied to the glass paste 220 to at least partially melt the glass paste 220 to be coupled to the package cover 210 and the array substrate 200.

Although this step is performed using laser radiation (e.g., infrared laser) in Fig. 2E, other beams (e.g., infrared rays) may be used to practice the embodiment. Further, the light beam may be irradiated to the glass paste 220 from the direction of the array substrate 200 or the package cover 210 or even from the above two directions. In practice, the wavelength, diameter and/or power of the beam can be adjusted as needed.

The illuminating process may be performed to cure the frame 235 before or after the step of applying the laser beam as described above. In a preferred embodiment, the illumination process is performed prior to the step of applying the laser beam to pre-engage the package cover 210 with the array substrate 200 using the bezel 235. Further, a second curing process is performed to further cure the sealant 230. In one embodiment, the second curing process is performed to further increase the viscosity of the sealant 230 to above 60,000 cps. Specifically, a second curing process is performed to cure the sealant 250 to a second viscosity of 60,000 to ^{10 15} cps. The second curing process described herein and the curing process of the plastic frame 235 described above may be performed simultaneously or separately. In an exemplary embodiment, if the sealant 235 is also an ultraviolet curable material, the above-described step of applying a laser beam may be performed first, and then an ultraviolet light irradiation process is simultaneously performed to simultaneously cure the sealant 235 and the sealant 230. In another embodiment, the step of performing the second curing process further cures the sealant 130 to a curing rate of 85% or more.

After the sealing method proposed herein is implemented, the packaged product can be cut into individual components, and subsequent cleaning, processing, and assembly processes can be performed to obtain individual display devices, such as the display shown in FIG. Device 150.

Although the embodiments of the present invention are disclosed in the above embodiments, the present invention is not intended to limit the invention, and the present invention may be practiced without departing from the spirit and scope of the invention. Various changes and modifications may be made thereto, and the scope of the invention is defined by the scope of the appended claims.

100, 200. . . Array substrate

105, 205. . . Effective display area

110, 210. . . Package cover

120, 220. . . Sealing structure

125, 225. . . Included area

130, 230. . . Sealant

135, 235. . . Frame glue

140. . . Light-emitting element

150. . . Display device

The above and other objects, features, advantages and embodiments of the present invention will become more apparent and understood.

1A to 1E are schematic views of a process for illustrating a process of packaging according to an embodiment of the present invention;

1F is a schematic view showing a display device according to an embodiment of the present invention, and the structure shown in the drawing is a cross-sectional view taken along line 1F-1F of FIG. 1E;

1G is a process schematic diagram illustrating an optional process step of a packaging method in accordance with an embodiment of the present invention;

2A through 2E are process diagrams illustrating the process steps of a packaging method in accordance with another embodiment of the present invention.

100. . . Array substrate

110. . . Package cover

120. . . Sealing structure

125. . . Included area

130. . . Sealant

140. . . Light-emitting element

150. . . Display device

Claims (18)

A packaging method includes: providing an array substrate, wherein the array substrate has an effective display area, and the effective display area is provided with at least one light emitting element; providing a package cover plate and forming a seal on the package cover plate a structure, wherein the sealing structure corresponds to the effective display area and substantially surrounds the effective display area; filling a sealant in the sealing structure; performing a first curing process to partially cure the sealant and the sealant The viscosity is a first viscosity, wherein the first viscosity is 10,000-60,000 cps; the package cover is bonded to the array substrate such that the effective display area is located in the sealing structure; and a second curing process is performed In order to further cure the sealant. The method of claim 1, wherein the step of performing the second curing process further cures the sealant to a curing rate of 85% or more. The method of claim 1, wherein the step of performing the second curing process further cures the sealant to a second viscosity, the second viscosity being 60,000-10 ¹⁵ cps. The method of claim 1, wherein the step of forming the sealing structure comprises: coating a surface of one of the package covers with a glass paste, and sintering the glass paste to form a surface on the surface. The area is set, and the accommodating area is larger than the effective display area. The method of claim 4, wherein the partially cured sealant has a height less than or equal to the sintered glass paste after the first curing process. The method of claim 4, wherein the step of bonding the package cover to the array substrate comprises: aligning the package cover with the array substrate such that the at least one illuminating component is located And placing a laser beam on the glass paste to at least partially melt the glass paste to be coupled to the package cover and the array substrate. The method of claim 4, further comprising: before performing the step of bonding the package cover to the array substrate, applying a photoresist to the package cover to form a surrounding One of the accommodating regions; and after performing the step of bonding the package cover to the array substrate, an illuminating process is performed to cure the sealant. The method of claim 7, wherein the sealant is cured at a wavelength of 254-365 nm. The method of claim 7, wherein the sealing compound is filled in the sealing structure simultaneously with the step of forming the sealant. The method of claim 1, wherein the sealant is an ultraviolet curable resin, and the first curing process is an ultraviolet light irradiation process and the energy used is 1000-6000 mJ/cm ² . The method of claim 10, wherein the second curing process is an ultraviolet light irradiation process, and the energy used is 1000-6000 mJ/cm 2 . The method of claim 1, wherein the sealant is a photosensitive material, and the first curing process and the second curing process are a light-receiving process. The method of claim 1, wherein the sealant is a heat sensitive material, and the first curing process and the second curing process are hot processes. A package method includes: providing an array substrate, wherein the array substrate comprises a plurality of sub-array substrates, each of the sub-array substrates has an effective display area, and each of the effective display areas is provided with at least one light-emitting element; Encapsulating a cover plate; coating a surface of one of the package covers with a glass paste, and sintering the glass paste to form a plurality of accommodating regions, and each accommodating region corresponds to each of the effective display regions And a larger than each of the effective display regions; coating a seal around one of the accommodating regions; applying a sealant in the accommodating regions; performing a first curing process to partially cure the sealant to a first viscosity, wherein the first viscosity is 10,000-60,000 cps; the package cover is paired with the array substrate such that each of the effective display regions is located in the corresponding receiving region, and the sealant is Curing; and performing a second curing process to further cure the sealant. The method of claim 14, wherein the step of performing the second curing process further cures the sealant to a curing rate of 85% or more. The method of claim 14, wherein the step of performing the second curing process further cures to a second viscosity, the second viscosity being 60,000-10 ¹⁵ cps. The method of claim 14, further comprising: applying a laser beam to the sintered glass paste to at least partially melt the sintered glass paste to form a package cover and the array substrate connection. The method of claim 14, wherein the partially cured sealant has a height less than or equal to the glass paste after the first curing process.