CN1588012A - Packaging inspection method for organic electroluminescence diode panel - Google Patents

Abstract

A method for detecting OLED (Organic Light Emitting Diode) panel includes providing a packaged OLED panel including a substrate, an OLED, a desiccant and a packaging structure, the OLED being formed on a lower surface of the substrate, the packaging structure being combined with the lower surface to package the OLED and the desiccant in a sealed space formed by the substrate and the packaging structure; secondly, shooting an image of the OLED panel to obtain a drying agent image; then calculating the area of the desiccant image; finally, whether the drying agent is expanded or not is judged according to the size of the area value, and whether the OLED panel is packaged badly and moisture enters is known.

Description

Packaging inspection method for organic electroluminescence diode panel

technical field

The present invention relates to a packaging and testing method for an OLED (Organic Light Emitting Diode, organic electroluminescence diode) panel, in particular to a method for packaging and testing an OLED panel by using a CCD (Charged Couple Device, light-sensitive coupling component).

Background technique

OLED (organic light emitting diode, organic light emitting diode) panel is a display component with high brightness, high response speed, thin and short, full color, no viewing angle difference and no backlight, so it has taken the lead in replacing TN (twisted Nematic) and STN (Super Twisted Nematic) liquid crystal panel market, and will further pose a threat to the market for small-sized TFT-LCD, and will be used in portable information products such as mobile phones, personal digital assistants, and even notebook computers on the display screen.

FIG. 1A shows an OLED panel. At present, most OLED panels 10 are small in size (less than 8 mm), and their thickness is less than 3 mm. FIG. 1B is a side sectional view of the OLED panel in FIG. 1 . In the OLED panel 10, an organic electroluminescent diode 14 is formed on the lower surface of a glass substrate 12, and the organic electroluminescent diode 14 includes an upper electrode 141, a hole injection layer 142, and an organic layer 143 from top to bottom. , an electron injection layer 144 and a lower electrode 145; the upper and lower electrodes 141, 145 can provide a voltage, so that the hole injection layer 144 and the electron injection layer 142 provide holes and electrons respectively, and these holes and electrons are formed in the organic layer 143 After the combination, the generated electric energy will cause the organic molecules in the organic layer 143 to be excited to the excited state, and then the organic molecules in the excited state will return to the ground state by generating light to release energy, which is the light emission of the OLED panel 10 principle. Of course, there is also the prior art in which the hole injection layer 142 and the electron injection layer 144 are reversed, and the difference is only the electrical exchange of the upper and lower electrodes 141 and 145 .

Because the organic layer 143 in the organic electroluminescent diode 14 is quite sensitive to moisture, a small amount of moisture can seriously damage the organic layer 143, so in the manufacturing process of the OLED panel 10, an encapsulation step—usually In a high-concentration nitrogen environment, a package structure 16 is used to combine under the glass substrate 12, so that the glass substrate 12 and the package structure 16 form a closed space, so that the organic electroluminescent diode 14 is packaged therein; thus, the OLED The organic electroluminescent diodes 14 in the panel 10 are isolated from the outside moisture. In addition, a desiccant 18 is usually provided on the upper surface of the packaging structure 16 to ensure an anhydrous state in the sealed space formed by the packaging structure 16 and the glass substrate 12 . Wherein, the sidewall 161 of the package structure 16 has a predetermined height, so as to prevent the desiccant 18 from contacting the organic electroluminescent diode 14 and affecting the light-emitting characteristics and performance of the organic electroluminescent diode 14 .

Please refer to FIG. 1C , which is a side cross-sectional view of another conventional OLED panel. Compared with FIG. 1A , the encapsulation structure 16 of the OLED panel 11 in FIG. 1B is a flat plate structure, which may be a glass plate or a plastic plate. The sidewall 161 of the packaging structure 16 in FIG. 1A is replaced by a sealant 19 to achieve the purpose of packaging and providing a predetermined height.

In the process of mass production of OLED panels, the above-mentioned encapsulation steps usually use a large piece of glass substrate to cooperate with a large piece of encapsulation board including multiple opening grooves to encapsulate multiple organic electroluminescent diodes at the same time. FIG. 2 shows a fabrication example of sixteen OLED panels. The sixteen organic electroluminescence diodes 14 are formed on the lower surface of the large glass substrate 22 in an array distribution mode; then, a large piece of packaging board 26 is used to combine with the large glass substrate 22 to complete sixteen Encapsulation of the organic electroluminescent diode 14 . Wherein, the large package board 24 includes sixteen opening grooves 261 . Then, the combined large piece of glass substrate 22 and large piece of packaging plate 26 are cut to obtain OLED panels 10 one by one as shown in FIG. 1A . The above-mentioned prior art of cutting into sixteen OLED panels is merely a list, and in the actual manufacturing process, the number of OLED panels may be adjusted due to implementation conditions.

As mentioned earlier, the encapsulation step of the OLED panel is a very important step in the whole process, because if the encapsulation is not correct, the moisture intruding into the OLED panel 10 will cause the key light-emitting layer in the organic electroluminescent diode 14 - the organic light-emitting layer The damage of the layer 143; therefore, the encapsulation step greatly affects the yield rate of OLED panel products.

However, at present, in most OLED panel manufacturing processes, there is no automatic inspection method for the quality of the packaging step. Modular steps, such as the installation of flexible circuit boards, or the installation of housings and other steps. It was not until the final modularization of the OLED panel was completed that the defective OLED panels with poor quality or manufacturing failure were screened out during the quality management test before delivery; The reason for the failure is that the encapsulation step is not accurate, which makes the moisture intrude into the inside of the OLED panel and cause damage. In this way, these OLED panels that have been damaged as early as the packaging step are still undergoing subsequent modular steps, which is undoubtedly a waste of process time, and at the same time increases some unnecessary waste of material costs, such as The flexible circuit boards and casings applied to these damaged OLED panels are unnecessary waste of material costs.

To sum up the above, what the prior art lacks is an OLED panel packaging and testing method, and an automated OLED panel packaging and testing method; so that during the OLED panel manufacturing process, it is possible to react in real time to abnormalities in the packaging steps , in order to adjust the conditions of the process when a large number of OLED panels have packaging abnormalities, so as to avoid continuous occurrence of a large number of packaging abnormalities. In addition, the prior art lacks a packaging inspection method for OLED panels, so as to prevent abnormal packaging or damaged OLED panels from flowing into subsequent modular steps, resulting in waste of process time and cost.

Contents of the invention

The main purpose of the present invention is to provide a detection method for an OLED panel to detect the encapsulation of the OLED panel.

Another object of the present invention is to provide an automatic detection method to facilitate the mass production process of OLED panels.

Another object of the present invention is to screen out poorly encapsulated OLED panels in real time, so as to prevent these OLED panels from entering the modularization process.

Another object of the present invention is to avoid the waste of subsequent process time and material cost caused by the damaged OLED panel.

The invention provides a detection method of an OLED panel, which is used to detect the encapsulation of an OLED panel. The method comprises the following steps:

Firstly, a packaged OLED panel is provided, which includes a substrate, an organic electroluminescent diode, a desiccant, and a packaging structure. The organic electroluminescent diode is formed on the lower surface of the substrate, and the packaging structure is combined on the above-mentioned lower surface. surface, so that the organic electroluminescent diode and the desiccant are encapsulated in a closed space formed by the substrate and the encapsulation structure.

Second, images are captured on the OLED panel to obtain a desiccant image and a non-desiccant image.

Next, define the boundary between the desiccant image and the non-desiccant image.

Afterwards, the area value of the range within the boundary is calculated to obtain the area value of the desiccant image.

Finally, it is determined whether the desiccant has swelled based on the value of the area, and thus it can be known whether the OLED panel is poorly packaged to cause moisture intrusion.

As mentioned above, after the OLED panel package detection method of the present invention captures the image of the package structure, the rest of the subsequent steps can be completed by using a computer with software; therefore, what the present invention provides is not only a set of automatic detection methods, but also very It is easy to integrate into the mass production process of OLED panels.

Based on the above, the present invention provides an OLED panel packaging and testing method, which is an automatic testing method, and is beneficial to mass production of OLED panels. According to the present invention, poorly packaged OLED panels can be screened out in real time, preventing these damaged OLED panels from entering subsequent modular steps, and improving the process time and materials caused by these damaged OLED panels in the prior art Waste of cost.

Description of drawings

Figure 1A shows an OLED panel;

FIG. 1B is a side sectional view of an existing OLED panel;

FIG. 1C is a side sectional view of another conventional OLED panel;

Figure 2 shows a large substrate and packaging board to package a plurality of organic electroluminescent diodes;

FIG. 3A is a side sectional view of an OLED panel with inaccurate packaging;

3B is a bottom view of the OLED panel of FIG. 3A;

4A is a side sectional view of a well-packaged OLED panel;

FIG. 4B is a bottom view of the AOLED panel in FIG. 4;

Fig. 5 represents the image to be tested;

Fig. 6 is a flow chart of the steps of the OLED panel packaging detection method of the present invention; and

FIG. 7 shows that the images of individual OLD panels are taken in turn by photosensitive electronic components for large packaging boards.

Description of figure number

OLED Panel 10, 11 Glass Substrate 12

Organic Electroluminescent Diode 14 Top Electrode 141

Hole Injection Layer 142 Organic Layer 143

Electron Injection Layer 144 Bottom Electrode 145

Package Structure 16 Sidewall 161

Desiccant 18 Frame glue 19

Large glass substrate 22 Large packaging board 26

Opening groove 261 OLED panel 30, 40

Image to be tested 30P Organic electroluminescent diode 34

Upper Electrode 341 Hole Injection Layer 342

Organic layer 343 Electron injection layer 344

Lower electrode 345 glass substrate 32

Package Structure 36 Non-Desiccant Image 36P

Boundary 37 Desiccant 38

Desiccant (volume expansion) 381 Desiccant image 38P

Opening gap 39 Area unit 39P

Photosensitive electronic components 71 Large substrates 72

Large package board 76 desiccant 78

Detailed ways

Please refer to FIG. 3A. FIG. 3A shows a side cross-sectional view of an OLED panel with incomplete packaging. The OLED panel 30 that has been packaged includes an organic electroluminescence diode 34 formed on the lower surface of a substrate 32, and includes a packaging structure 36 combined on the The lower surface of the substrate 32 is used to encapsulate the organic electroluminescence diode 34 . A desiccant 38 is disposed in the closed space formed by the substrate 32 and the encapsulation structure 36 . In the embodiment shown in FIG. 3A , the desiccant 38 is disposed on the upper surface of the encapsulation structure 36 .

Wherein, the materials of the substrate 32 and the encapsulation structure 36 can be, for example, glass, polymer materials, or organic materials, or inorganic materials (such as silicon materials) of general semiconductor substrates are also another feasible material. The end-view OLED panel 30 uses the substrate 32 or the packaging structure as the light-emitting surface, and the material of the light-emitting surface must be selected as a light-transmitting material. In addition, the organic electroluminescent diode 34 emits light in all directions, so it may also be a double-sided light emitting type. In this case, the materials of the substrate 32 and the packaging structure 36 must be transparent.

The organic electroluminescence diode 34 includes an upper electrode 341 , a hole injection layer 342 , an organic layer 343 , an electron injection layer 344 and a lower electrode 345 from top to bottom. As shown in FIG. 3A , when the packaging of the OLED panel 30 is inaccurate, an opening slit 39 may be formed at its side end, so that water vapor can enter the inside of the OLED panel 30 through the opening slit 39, and cause organic electroluminescent diodes 34 Damage to the critical light emitting layer - the organic layer 343 .

FIG. 4A shows a well-packaged OLED panel 40 for comparison with FIG. 3A. The present invention utilizes the property that the desiccant is easy to absorb water and expands after absorbing water, so as to detect whether the OLED panel is packaged incorrectly so that water vapor intrudes. Because a desiccant (381, 38) is provided in each OLED panel (30, 40), and the desiccant is selected from a material that is very easy to absorb water, so as to desiccate the organic layer 343 before moisture damages the organic layer 343. Moisture absorbs to protect the organic layer 343; and the OLED panel 30 with incomplete encapsulation has an opening gap 39 to allow the water vapor to continuously enter it. Therefore, in the OLED panel 30 with indefinite encapsulation, before the organic layer 343 is damaged by moisture, The desiccant 38 will absorb moisture as much as possible according to its own water absorption capacity, resulting in the volume expansion of the desiccant 381 as shown in FIG. 3A . Compared with the well-packaged OLED panel 40 in FIG. 38 is unexpanded. Therefore, the present invention utilizes the swelling condition of the desiccant to determine the encapsulation condition of the OLED panel.

Please refer to FIG. 3B and FIG. 4B , FIG. 3B is a bottom view of the AOLED panel in FIG. 3 , and FIG. 4B is a bottom view of the OLED panel in FIG. 4A . Compared with the OLED panel 30 in FIG. 3B , the OLED panel 40 in FIG. 4B has a good combination of the encapsulation structure 36 and the substrate 32 , so the desiccant 38 inside the OLED panel 40 will not absorb water and swell. And because the packaging structure 36 is transparent or translucent, the desiccant 381 and 38 can be seen from the bottom of the OLED panels 30 and 40; A dark desiccant image is seen below the bottom of the panel. Therefore, by inspecting the areas of the desiccants 381 and 38 from the bottom of the OLED panel, the expansion conditions can be known.

In order to make the above-mentioned method of utilizing the area of the detection desiccant to judge the encapsulation of the OLED panel to be an automated program to integrate into the mass production process of the OLED panel, the present invention can utilize CCD or CMOS (Complementary Metal OxideSemiconductor Complementary metal oxide semiconductor) and other photosensitive electronic components, at a fixed shooting distance, to capture images of OLED panels, the same mass-produced OLED panels will have the same size, so as long as the shooting conditions are the same, the captured images Images will also have a consistent size.

From the lower surface of the encapsulation structure 36 in FIG. 3A, an image is captured on the OLED panel 30. An image to be tested 30P captured is shown in FIG. The non-desiccant image 36P of the desiccant image 38P, the non-desiccant image 36P corresponds to the portion of the package structure 36 in FIG. 3A that is not attached with the desiccant 381 . As mentioned above, the present invention uses photosensitive electronic components (such as CCD or CMOS) to capture images, so the obtained image 30P to be tested is directly in digital format, which is convenient for subsequent direct use of computer with software to calculate the desiccant image therein 38P area. Of course, if a traditional negative camera is used, the developed photo can also be scanned for subsequent area value calculation steps.

After obtaining the test image 30P in digital format, software can be used to define its boundary 37 by utilizing the difference in color contrast between the desiccant image 38P and the non-desiccant image 36P. For example, image software (developed by the manufacturer) can be used in implementation; image software is used to cut the image to be tested 30P into a plurality of small-area area units 39P, as shown in FIG. The color contrasts of area cells 39P are compared to define boundary 37 . For example, when the difference between the color contrast of the two area units 39P is greater than a certain set value (for example, when the contrast is set to be greater than 50), then the area unit 39P with higher contrast is defined as a part of the boundary 37; certainly, in In another embodiment, the area unit 39P with low contrast can also be used as a part of the boundary 37 , or both of the two area units 39P can be defined as a part of the boundary 37 . Using the above steps, the boundary 37 surrounding the desiccant image 38P can be clearly defined.

In addition to the above method of comparing the color contrast of two adjacent area units 39P, the boundary 37 can also be defined by comparing the color value or other image values of two adjacent area units 39P.

After the boundary 37 is defined, the step of calculating the area value of the desiccant image 38P according to the present invention is carried out. As shown in FIG. 39P, calculate the number of area units 39P within this range, and calculate the sum of these area units 39P to obtain the area value of the desiccant image 38P. For example, in one embodiment of the present invention, the area unit 39P is a square of 0.05mm×0.05mm, and there are 252,800 area units 39p included in the boundary 37, so the area value of the desiccant image 38P is 632mm ² .

From the area value of the desiccant image 38P, it can be determined whether the desiccant 381 has expanded. In practice, the measured area value is compared with a preset standard area value. The standard area value comes from, for example, the well-packaged OLED panel 40 shown in FIG. 4B . A standard area value can be obtained by performing the above-mentioned steps of defining the boundary and calculating the area value of the desiccant image on the well-packaged OLED panel. When comparing the area value of the desiccant image with the standard area value, in one embodiment, the OLED panel whose desiccant image area value is greater than the standard area value is determined to be abnormal in packaging; and in another embodiment, it can also be The desiccant image area value is subtracted from the standard area value, and when the difference is greater than one standard deviation, the OLED panel is judged to be packaged abnormally; otherwise, when the desiccant image area value is less than the standard area value, or both When the difference is less than the standard deviation value, it is determined that the desiccant is not expanded, and the OLED panel is normally packaged. Taking an embodiment of the present invention as an example, the standard area value is 555 mm ² , and the standard deviation value is 30 mm ² .

The above description of the present invention is summarized in FIG. 6 . FIG. 6 is a flow chart of the steps of the OLED panel packaging inspection method of the present invention. The present invention can be better understood from FIG. 6 and the following description.

Step 601: Provide one OLED panel that has been packaged.

Step 602: Capture images on the OLED panel to obtain a desiccant image and a non-desiccant image.

Step 603: Define the boundary between the desiccant image and the non-desiccant image.

Step 604: Calculate the area of the range within the boundary to obtain the area value of the desiccant image.

Step 605: Determine whether the desiccant has swelled based on the area value of the image of the desiccant, so as to know whether the OLED panel is poorly packaged to cause moisture intrusion.

It is worth mentioning that, after the OLED panel packaging and testing method of the present invention captures the image of the OLED panel in step 602, the subsequent steps 603 to 605 can all be completed in a computer with software; therefore, the present invention not only provides a A set of automated detection methods, and it is very easy to integrate into the mass production process of OLED panels.

In consideration of making the OLED panel manufacturing process smoother, the present invention may also have the following implementation method: please refer to FIG. Organic electroluminescent diodes, and a plurality of uncut OLED panels can be defined by these organic electroluminescent diodes, and the desiccant 78 in individual OLED panels can be seen from the lower surface of the large packaging plate 76 . Another implementation method of the present invention is to use the photosensitive electronic component 71 (such as: CCD or CMOS) to capture the images of individual OLED panels in turn before multiple OLED panels are cut, and make the images of individual OLED panels perform the above step 603 respectively. Go to the detection method of step 605. In this way, the OLED panel packaging inspection method of the present invention can be completed in a shorter time. In this way, this embodiment refers to the inspection method performed before the OLED panel has been packaged but not cut into other OLED panels that have also been packaged. And the continuous detection method of detecting another OLED panel is continued after one OLED panel is detected.

It should be noted that, in the description of the above-mentioned embodiment, the OLED panel of the type shown in FIG. 1B is taken as an example to clarify the spirit and detailed steps of the present invention. The invention is equally applicable to OLED panels of the type shown in Figure 1C, as well as other equivalent OLED panels. In addition, although the present invention is illustrated by an embodiment in which the desiccant is disposed at the center of the upper surface of the package structure, those familiar with the technical field of the present invention should be able to easily know that the change of the desiccant position does not damage the spirit of the present invention. For example, the desiccant can be placed around the closed space formed by the substrate and the packaging structure, or if the area of the substrate allows, the desiccant can even be placed on the lower surface of the substrate where it does not affect the light output of the organic electroluminescent diode. Regardless of the change in its setting position, the present invention captures images of the desiccant for the same batch of OLED panel products under the same photographic conditions to determine whether it swells.

Based on the above, the present invention provides an OLED panel packaging and testing method, which is an automatic testing method, and is beneficial to mass production of OLED panels. According to the present invention, poorly packaged OLED panels can be screened out in real time, preventing these damaged OLED panels from entering subsequent modular steps, and improving the process time and materials caused by these damaged OLED panels in the prior art Waste of cost.

Claims (9)

1. the detection method of an organic electric exciting light-emitting diode panel, is characterized in that this method comprises the following steps: in order to detect the encapsulation situation of an organic electric exciting light-emitting diode panel

Provide and finish one of encapsulation organic electric exciting light-emitting diode panel, it comprises a substrate, an organic electric exciting light-emitting diode, a drying agent and an encapsulating structure, this organic electric exciting light-emitting diode is formed at this base lower surface, and this encapsulating structure is combined in above-mentioned this lower surface, this organic electric exciting light-emitting diode and this drying agent are packaged in the confined space that this substrate and this encapsulating structure constituted;

To this organic electric exciting light-emitting diode panel picked-up image, obtaining a drying agent image, and a non-drying agent image;

Define the border of this drying agent image and this non-drying agent image;

Calculate the area value of the scope in this border; And

By the size of this area value, whether expand to judge this drying agent, learn thus whether this organic electric exciting light-emitting diode panel encapsulates bad and cause aqueous vapor to be invaded.

2. the detection method of organic electric exciting light-emitting diode panel as claimed in claim 1 is characterized in that, comes this organic electric exciting light-emitting diode panel picked-up image with the sensitization electronic original part.

3. the detection method of organic electric exciting light-emitting diode panel as claimed in claim 1, it is characterized in that, judge the step whether this drying agent has expanded, is the area value with this drying agent image, compare with a standard area value, whether expand to judge this drying agent.

4. the detection method of organic electric exciting light-emitting diode panel as claimed in claim 3 is characterized in that, when the area value of this drying agent image greater than this standard area value, and both differences judge that then this drying agent is for expanding during greater than a standard deviation value.

5. the detection method of organic electric exciting light-emitting diode panel as claimed in claim 3 is characterized in that, when the area value of this drying agent image less than this standard area value, or both differences judge that then this drying agent is to expand during less than a standard deviation value.

6. the detection method of organic electric exciting light-emitting diode panel as claimed in claim 1 is characterized in that, utilizes color contrast different of this drying agent image and this non-drying agent image, to define this border.

7. the detection method of organic electric exciting light-emitting diode panel as claimed in claim 1 is characterized in that, utilizes color lightness different of this drying agent image and this non-drying agent image, to define this border.

8. the detection method of organic electric exciting light-emitting diode panel as claimed in claim 1, it is characterized in that, described detection method, be meant in this organic electric exciting light-emitting diode panel and finished encapsulation, cut the preceding performed detection method of processing procedure but Shang Weiyu also finishes other organic electric exciting light-emitting diode panel of encapsulation.

9. the detection method of organic electric exciting light-emitting diode panel as claimed in claim 8, it is characterized in that, described detection method is to continue to carry out the continuous detecting method that detects another organic electric exciting light-emitting diode panel after having detected an organic electric exciting light-emitting diode panel.

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