Thin film packaging layer coated display panel and display device

A display panel includes a substrate, an organic light emitting structure, a first electrode, a light extraction layer, a protection layer, and a thin film packaging layer, which are stacked in sequence. The organic light emitting structure, the first electrode, the light extraction layer and the protection layer are coated by the thin film packaging layer. The light extraction layer is located between the protection layer and the first electrode, and completely isolates the protection layer and the first electrode.

TECHNICAL FIELD

The present disclosure relates to a display technology, for example, a display panel and a display device.

BACKGROUND

An organic light emitting diode (OLED) display panel is a self-luminous display panel. Since the OLED display panel has the advantages such as lightness, high brightness, low power consumption, wide viewing angle, high response speed, and wide operating temperature range, the OLED display panel has increasingly being used in various high performance display fields. The thin film packaging method is often used in the related art to ensure that the organic light emitting structure is not corroded by moisture and oxygen in the external environment. Currently the thin film packaging technology generally employs a multilayer film structure in which an organic layer and an inorganic layer alternate. However, it is found by the inventor that employing the thin film packaging method in the related art often arises the problem of packaging failure.

SUMMARY

Provided is a display panel and a display device, so as to prevent a protection layer from corroding an electrode to affect the charge injection and fail the packaging, and improve the display performance of the display panel.

In one aspect, provided is a display panel, including a substrate, an organic light emitting structure, a first electrode, a light extraction layer, a protection layer, and a thin film packaging layer, which are stacked in sequence.

The organic light emitting structure, the first electrode, the light extraction layer and the protection layer are coated by the thin film packaging layer. The light extraction layer is located between the protection layer and the first electrode, and completely isolates the protection layer and the first electrode.

In one embodiment, along a direction parallel to a surface of the substrate, a distance between an edge of the light extraction layer and an edge of the thin film packaging layer is a first distance; a distance between an edge of the first electrode and the edge of the thin film packaging layer is a second distance; a distance between an edge of the protection layer and the edge of the thin film packaging layer is a third distance. The first distance is less than or equal to the second distance.

In one embodiment, the third distance is equal to the first distance.

Or, the third distance is equal to the second distance.

Or, the first distance is equal to the second distance and equal to the third distance.

Or, the third distance is less than the first distance, and the first distance is less than the second distance.

In one embodiment, the first distance is less than the second distance. The third distance is greater than the first distance, and less than the second distance.

In one embodiment, the first distance is equal to the second distance, and the third distance is less than the first distance.

In one embodiment, the first distance, the second distance and the third distance satisfy at least one of the following.

A minimum distance among the first distance, the second distance, and the third distance is greater than or equal to 100 micron, and less than or equal to 500 micron.

A maximum distance among the first distance, the second distance, and the third distance is less than or equal to 1 mm.

In one embodiment, a difference value between the second distance and the first distance is less than or equal to 900 micron.

In one embodiment, the difference value between the second distance and the first distance is less than or equal to 200 micron.

In one embodiment, a material adopted by the protection layer is lithium fluoride.

In one embodiment, a light transmittance of the first electrode is greater than 80%.

In one embodiment, a material of the first electrode comprises at least one of the following: a mixture of magnesium and silver, indium tin oxide, indium zinc oxide, silver-doped indium tin oxide, or sliver-doped indium zinc oxide.

In one embodiment, the display panel is a top-emitting active-matrix organic light emitting diode (AMOLED) display panel, and the first electrode is a negative electrode.

In one embodiment, the first electrode is a planar electrode.

In one embodiment, the display panel is a bottom-emitting AMOLED display panel or a passive matrix organic light emitting diode (PMOLED) display panel.

In one embodiment, the display panel is the PMOLED display panel, and the first electrode is a strip negative electrode.

In one embodiment, provided is a display device, including a display panel of any embodiment of the present disclosure.

DETAILED DESCRIPTION

The thin film packaging structure often results in the packaging failure. In the study, the inventor has found that the reason for such problem is that the thin film packaging structure usually includes an inorganic layer and an organic layer which are stacked in alternating manner. The inorganic layer functions to block water oxygen, and the common materials are SiNx, SiOx, SiOxNy, Al2O3and TiO2. The inorganic layer usually employs the preparation methods such as plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), pulsed laser deposition (PLD), or sputter. In order to avoid damage to the organic light emitting structure by ions in the preparation stage of inorganic layer, a protection layer is usually arranged between the thin film packaging structure and an electrode of the display panel. However, the protection layer material commonly used has the ions with a relatively high activity. Illustratively, the protection layer mostly employs a lithium fluoride material; the fluoride ion is relatively active, and easy to react with the electrode material of the display panel, consequently the electrode is corroded, the charge injection is affect and the product packaging is failed.

Accordingly, provided is a display panel, including a substrate, an organic light emitting structure, a first electrode, a light extraction layer, a protection layer, and a thin film packaging layer, which are stacked in sequence.

The organic light emitting structure, the first electrode, the light extraction layer and the protection layer are coated by the thin film packaging layer. The light extraction layer is located between the protection layer and the first electrode, and completely isolates the protection layer and the first electrode.

By arranging the light extraction layer located between the protection layer and the first electrode and completely isolating the protection layer and the first electrode, the protection layer does not contact the first electrode; the light extraction layer functions to block the relatively active ions in the protection layer, thereby effectively preventing the protection layer from corroding the first electrode to affect the charge injection and fail the packaging, and improving the display performance of the display panel. Moreover, the solution of the present disclosure only designs the existing film layer in the panel, no another film layer needs to be added, which ensures that the display panel has a relatively small thickness, and conforms to the development trending of the display panel being lighter and thinner.

Hereinafter the present disclosure will be further described in detail in conjunction with accompanying drawings and embodiments.

A display panel is provided by one embodiment of the present disclosure.FIG. 1is a schematic diagram illustrating a display panel provided by one embodiment. Referring toFIG. 1, the display panel includes a substrate10o, an organic light emitting structure20, a first electrode21, a light extraction layer30, a protection layer40and a thin film packaging layer50, which are stacked in sequence.

The organic light emitting structure20, the first electrode21, the light extraction layer30and the protection layer40are coated by the thin film packaging layer50.

Along a direction parallel to a surface of the substrate10, a distance between an edge of the light extraction layer30and an edge of the thin film packaging layer50is a first distance D1, a distance between an edge of the first electrode21and the edge of the thin film packaging layer50is a second distance D2. The first distance D1is less than or equal to the second distance D2.

The substrate10is an array substrate driving the organic light emitting structure20to emit light, and includes a display area and a non-display area. An area corresponding to the display area is provided with the organic light emitting structure20, to realize the display of an image. An area corresponding to the non-display area does not display the image. The display panel may further include a second electrode (not shown in the drawings). The second electrode is arranged on one side of the organic light emitting structure20facing away the first electrode21. The first electrode21may be a negative electrode, and the second electrode may be a positive electrode. Under the action of electrical signal applied by the first electrode21and the second electrode, the organic light emitting structure20emits the light with corresponding color. The light extraction layer30has a relatively high refractive index and a small absorption coefficient for improving the light extraction efficiency of the organic light emitting structure20. The thin film packaging layer50covers the organic light emitting structure20, and protects the organic light emitting structure20from the external moisture, the oxygen, and the like.

In addition, a material of the first electrode21is mostly a material of which a light transmittance is greater than 80% or greater than 90%, for example a mixture of magnesium and silver, indium tin oxide, indium zinc oxide, silver-doped indium tin oxide, or sliver-doped indium zinc oxide. The material of the first electrode21may be a metal material having a relatively large light transmittance such as aluminum. The fluoride ions in the protection layer40are easy to react with the first electrode21, thereby corroding the first electrode21, affecting the charge injection and failing the product package.

By arranging the first distance D less than or equal to the second distance D2, the first electrode21is completely covered by the light extraction layer30, thereby completely isolating the protection layer40and the first electrode21. The relatively active ions in the protection layer40are blocked, thereby effectively preventing the protection layer40from corroding the first electrode21to affect the charge injection and fail the packaging, and improving the display performance of the display panel.

In one embodiment, along the direction parallel to the surface of the substrate10, a distance between an edge of the protection layer40and the edge of the thin film packaging layer50is a third distance D3. When the first distance D1is equal to the second distance D2, the third distance D3may be arranged to be less than or equal to the first distance D1. When the first distance D1is less than the second distance D2, the third distance D3only needs to be less than or equal to the second distance D2, for example, the third distance D3may be arranged to be greater than the first distance D1and less than the second distance D2. The following is described with accompanying drawings.

In one embodiment, referring toFIG. 1, the third distance D3is equal to the first distance D1. Namely, sizes of the protection layer40and the light extraction layer30are the same. On one hand, the light extraction layer30can completely block the protection layer40in a direction perpendicular to the substrate10, thereby preferably preventing the active ions in the protection layer40from reaching the first electrode21through a surface of the first electrode21parallel to the substrate10along the direction perpendicular to the substrate10(namely, reaching the first electrode21through a first path41inFIG. 1), thereby the effectively preventing the protection layer40from corroding the first electrode21to affect the charge injection and fail the packaging, and improving the display performance of the display panel. On the other hand, the sizes of the protection layer40and the light extraction layer30are the same, so that the protection layer40and the light extraction layer30may be fabricated by a same mask, which reduces the fabrication cost of the display panel.

In addition, referring toFIG. 1, while the third distance D3is arranged to be equal to the first distance D1, the first distance D1is arranged to be less than the second distance D2. At this moment, the light extraction layer30completely coats the first electrode21, which can not only preferably prevent the active ions in the protection layer40from reaching the first electrode21along the first path41, but also preferably prevent the active ions in the protection layer40from reaching the first electrode21along a side surface of the first electrode21perpendicular to the substrate10(namely reaching the first electrode21along a second path42), thereby better preventing the protection layer40from corroding the first electrode21to affect the charge injection and fail the packaging, and improving the display performance of the display panel.

FIG. 2is a schematic diagram illustrating another display panel provided by one embodiment. In one embodiment, referring toFIG. 2, the third distance D3is equal to the second distance D2.

In one embodiment, by arranging the third distance D3equal to the second distance D2, namely, the sizes of the protection layer40and the first electrode21are the same, on one hand, while the protection layer40has a relatively small size, the protection layer40is ensured to protect the organic light emitting structure20from damage during the formation stage of the inorganic layer. In addition, by arranging the protection layer40having a relatively small size, the probability that the active ions in the protection layer40corrode the first electrode21is reduced. On the other hand, since the first distance D1is less than or equal to the second distance D2, the third distance D3is greater than or equal to the first distance D1, namely, the size of the protection layer40is less than or equal to the size of the light extraction layer30. The light extraction layer30can completely block the protection layer40from the first electrode21, which can preferably prevent the active ions in the protection layer40from reaching the first electrode21along the first path41.

In addition, referring toFIG. 2, while the third distance D3is equal to the second distance D2, the third distance D3may be arranged to be greater than the first distance D1, at this moment, the light extraction layer30completely coats the first electrode21, which can not only preferably prevent the active ions in the protection layer40from reaching the first electrode21along the first path41, but also preferably prevent the active ions in the protection layer40from reaching the first electrode21along the second path42, thereby better preventing the protection layer40from corroding the first electrode21to affect the charge injection and fail the packaging, and improving the display performance of the display panel.

FIG. 3is a schematic diagram illustrating still another display panel provided by one embodiment. In one embodiment, referring toFIG. 3, the first distance D1is equal to the second distance D2and the third distance D3.

In this way, the sizes of the first electrode21, the light extraction layer30and the protection layer40are the same, which can preferably prevent the active ions in the protection layer40from reaching the first electrode21along the first path41. Moreover, the first electrode21, the light extraction layer30and the protection layer40may be fabricated by a same mask, which reduces the fabrication cost of the display panel.

FIG. 4is a schematic diagram illustrating still another display panel provided by one embodiment. In one embodiment, referring toFIG. 4, the distance between the edge of the protection layer40and the edge of the thin film packaging layer50is the third distance D3. The third distance D3is less than the first distance D1, and the first distance D1is less than the second distance D2.

In one embodiment, referring toFIG. 4, the first distance D1is less than the second distance D2, namely, the light extraction layer30coats the organic light emitting structure20. The third distance D3is less than the first distance D1, namely, the protection layer40coats the light extraction layer30. In this way, the protection layer40can fully prevent the organic light emitting structure20from damage during the preparation stage of the inorganic layer, and the light extraction layer30can also prevent the active ions in the protection layer40from corroding the first electrode21through the first path41and the second path42, which can improve the display performance of the display panel.

In one embodiment, referring toFIG. 1toFIG. 4, a border width D, of the display panel, D2+D4+D5. D4is a distance between the edge of the thin film packaging layer50and an edge of the substrate10. D5is a distance between the edge of the organic light emitting structure20and the edge of the first electrode21. Since the sizes of the organic light emitting structure20and the first electrode21are constant, D5is constant. D4is a size reserved for the cutting of the display panel during the fabrication stage of the display panel, thus D4is constant. In order to ensure the thin film packaging effect, a minimum distance between the edges of the first electrode21, the light extraction layer30and the protection layer40and the edge of the thin film packaging layer50may be arranged to be a set value a. InFIG. 1, the border width D=D1+(D2−D1)+D4+D5=a+(D2−D1)+D4+D5, and D2>D1=D3. InFIG. 2, the border width D=D1+(D2−D1)+D4+D5=a+(D2−D1)+D4+D5, and D2=D3>D1. InFIG. 3, the border width D=D=D1+D4+D5=a+D4+D5, and D2=D3=D. InFIG. 4, the border width D=D3+(D2−D3)+D4+D5=a+(D2−D1)+(D1-D3)+D4+D5, and D2>D1>D3. Thus, the display panel provided by the solution shown inFIG. 3has a narrowest border, the display panel provided by the solution shown inFIG. 2andFIG. 1has a relatively narrow border, and the display panel provided by the solution shown inFIG. 4has a widest border.

In one embodiment, along the direction parallel to the substrate10, the minimum distance among the first distance D1between the edge of the light extraction layer30and the edge of the thin film packaging layer50, the second distance D2between the edge of the first electrode21and the thin film packaging layer50, and the third distance D3between the edge of the protection layer40and the edge of the thin film packaging layer50is greater than or equal to 100 micron, and less than or equal to 500 micron. The maximum distance among the first distance D1, the second distance D2and the third distance D3is less than or equal to 1 mm.

In one embodiment, the minimum distance among the first distance D1, the second distance D2, and the third distance D3is equal to a width of the thin film packaging layer50at a position of a border of the display panel along the direction parallel to the surface of the substrate10. By arranging the minimum distance among the first distance D1, the second distance D2and the third distance D3greater than or equal to 100 micron, the thin film packaging layer50is ensured to have a suitable width at the position of the border, so that the water and oxygen resistance can be realized at the boundary of the thin film packaging layer, thereby ensuring that the display panel has a better thin film packaging effect. In addition, in this way, the preparation process of the organic layer and the inorganic layer in the thin film packaging layer can be better adapted, and the process difficulty is reduced, thereby reducing the preparation cost of the display panel. By arranging the minimum distance among the first distance D1, the second distance D2and the third distance D3is less than or equal to 500 micron, the display panel is ensured to have a relatively small border.

In addition, as can be seen in conjunction withFIG. 1toFIG. 4, the border width D of the display panel D is equal to a sum of D4, D5, and the maximum value among D1, D2and D3. Therefore, by arranging the maximum distance among D1, D2and D3less than or equal to 1 mm, the display panel is ensured to have a relatively small border.

Moreover, the specific value of the minimum distance among the first distance D1, the second distance D2, and the third distance D3is not specifically limited in the present embodiment, and may be set according to the specific sizes of the different display panels and the specific process of the thin film packaging layer50, for example, may set to be 150 micron, 200 micron, 250 micron, 300 micron, 350 micron or 400 micron. The specific value of the maximum distance among the first distance D1, the second distance D2and the third distance D3is also not specifically limited in the present embodiment, for example, may be set to be 500 micron, 600 micron, 700 micron, 800 micron or 900 micron.

In one embodiment, a difference value between the second distance D2and the first distance D1is less than or equal to 900 micron. In one embodiment, a difference value between the second distance D2and the first distance D1is less than or equal to 200 micron.

In one embodiment, the difference value between the second distance D2and the first distance D1may be set according to the specific size of the display panel. For the display panel having a smaller size, the difference value between the second distance D2and the first distance D1may be arranged to be less than or equal to 200 micron, so that the display panel is ensured to have a smaller border on the premise that the light extraction layer30is ensured to preferably protect the first electrode21from being corroded by the protection layer40. For the display panel having a larger size, the difference value between the second distance D2and the first distance D1may be arranged to be less than or equal to 900 micron, thereby reducing the process difficulty.

In addition, the specific value of the difference value between the second distance D2and the first distance D is not specifically limited in the present embodiment, and may be set according to the specific sizes of the different display panels, for example, may be arranged to be 10 micron, 20 micron, 50 micron, 100 micron, 150 micron, 300 micron, 400 micron, 500 micron, 600 micron, 700 micron or 800 micron, or the like.

In one embodiment, the display panel of the present embodiment is a top-emitting active-matrix organic light emitting diode (AMOLED) display panel. The first electrode21is the negative electrode.

In one embodiment, the first electrode21of the top-emitting AMOLED display panel adopts a planar electrode, which is easier to be corroded by the relatively active ions in the protection layer40. By adopting the solution of the present disclosure, the protection layer40can be effectively prevented from corroding the first electrode21to affect the charge injection and fail the packaging, and the display performance of the display panel is improved.

The display panel of the present embodiment is not limited to the top-emitting AMOLED display panel, and is also applicable to other display panels having the problem that the electrode is easy to be corroded by the protection layer. For example, the display panel may also be a bottom-emitting AMOLED display panel, or a passive matrix organic light emitting diode (PMOLED) display panel, or the like. A shape of the first electrode21may be adjusted according to the structural requirements of the display panel. For example, in the PMOLED display panel, the first electrode is a strip negative electrode.

A display device is further provided by the present embodiment.FIG. 5is a schematic diagram illustrating a display device provided by one embodiment. Referring toFIG. 5, the display device100includes the display panel200provided by any embodiment of the present disclosure. The display device100may be a mobile phone, a tablet computer, a virtual reality (VR) display product, a wearable product such as a smart wristband and a smart watch, or an in-vehicle display product, or the like.