Disclosure of Invention
The invention provides a display panel with good light-emitting uniformity.
The invention provides a manufacturing method of a display panel, which has high production yield.
The display panel provided by the invention is provided with a display area and a peripheral area surrounding the display area, and comprises an active element array substrate, an isolation structure layer and a light emitting structure layer. The isolation structure layer is configured on the active element array substrate. The isolation structure layer defines a plurality of first grooves, and the first grooves are configured in the display area. The light emitting material layer is disposed on the active device array substrate. The light emitting structure layer includes a first dummy material portion, a second dummy material portion, and a plurality of light emitting material patterns. The plurality of luminescent material patterns are respectively arranged in the plurality of first grooves. The first dummy material portion is disposed in the peripheral region, and the first dummy material portion is located on a first side of the display region. The second dummy material portion is disposed in the peripheral region, and the second dummy material portion is located on a second side of the display region. The first side and the second side are opposite sides of the display area in the first direction. The first material edge of the first dummy material portion farthest from the display area is separated from the first side of the display area by a first distance, the second material edge of the second dummy material portion farthest from the display area is separated from the second side of the display area by a second distance, and the first distance is different from the second distance.
The manufacturing method of the display panel comprises the steps of providing an active element array substrate, forming an isolation structure material layer on the active element array substrate, carrying out an etching step, removing a plurality of parts of the isolation structure material layer overlapped on a display area to form an isolation structure layer defining a plurality of first grooves, and carrying out an ink jet printing process on the active element array substrate. The active element array substrate is provided with a display area and a peripheral area surrounding the display area. The ink-jet printing process comprises the steps of spraying first luminescent material liquid drops in the peripheral area, moving the spray head along the first direction to enable the spray head to enter the display area from the first side of the display area, spraying second luminescent material liquid drops and third luminescent material liquid drops in the display area, continuing to move the spray head along the first direction to enable the spray head to leave the display area from the second side of the display area, and spraying fourth luminescent material liquid drops in the peripheral area. The second luminous material liquid drop and the third luminous material liquid drop are respectively sprayed in two of the first grooves which are nearest to the first side and the second side. The distance between the first and second luminescent material droplets is larger than the distance between the third and fourth luminescent material droplets.
In an embodiment of the invention, the light emitting structure layer of the display panel further includes a third dummy material portion and a fourth dummy material portion. The third dummy material portion is disposed in the peripheral region and located on a third side of the display region. The fourth dummy material portion is disposed in the peripheral region and located on a fourth side of the display region. The third side and the fourth side are opposite sides of the display area in a vertical first direction. The third material edge of the third dummy material portion farthest from the display area is a third distance away from a third side of the display area, the fourth material edge of the fourth dummy material portion farthest from the display area is a fourth distance away from a fourth side of the display area, and the third distance is different from the fourth distance.
In an embodiment of the invention, the light emitting structure layer of the display panel further includes a third dummy material portion and a fourth dummy material portion. The third dummy material portion is disposed in the peripheral region and located on the first side of the display region. The fourth dummy material portion is disposed in the peripheral region and located on the second side of the display region. The third material edge of the third dummy material portion farthest from the display area is spaced a third distance from the first side of the display area, and the fourth material edge of the fourth dummy material portion farthest from the display area is spaced a fourth distance from the second side of the display area. The third distance is less than the fourth distance, and the first distance is greater than the second distance.
In an embodiment of the invention, the isolation structure layer of the display panel is located between the first dummy material portion and the active device array substrate, and the isolation structure layer is located between the second dummy material portion and the active device array substrate.
In an embodiment of the invention, at least one of the first dummy material portion and the second dummy material portion of the display panel partially overlaps the isolation structure layer.
In an embodiment of the invention, the isolation structure layer of the display panel further defines a plurality of second grooves and a plurality of third grooves. The second grooves and the third grooves are arranged in the peripheral area and are respectively positioned on the first side and the second side of the display area. The first dummy material portion is disposed in the plurality of second grooves. The second dummy material portion is disposed in the plurality of third grooves. The widths of the areas occupied by the first grooves, the second grooves and the third grooves in the first direction are substantially equal to each other.
In an embodiment of the invention, the isolation structure layer of the display panel further defines a plurality of second grooves and a plurality of third grooves. The second grooves and the third grooves are arranged in the peripheral area and are respectively positioned on the first side and the second side of the display area. The first dummy material portion is disposed in the plurality of second grooves. The second dummy material portion is disposed in the plurality of third grooves. The width of the vertical projection of the area occupied by each first groove on the active element array substrate in the first direction is smaller than the width of the vertical projection of the area occupied by each second groove and each third groove on the active element array substrate in the first direction.
In an embodiment of the invention, the isolation structure layer of the display panel further defines a second groove surrounding the display area. The second groove is provided with a first groove section and a second groove section which are positioned at two opposite sides of the display area. The vertical projections of the areas occupied by the first groove section and the second groove section on the active element array substrate respectively have a first width and a second width in the first direction, and the first width is greater than the second width.
In an embodiment of the invention, the second groove of the display panel further has a third groove segment and a fourth groove segment located on two opposite sides of the display area in a direction perpendicular to the first direction. The third groove section and the fourth groove section are respectively connected between the first groove section and the second groove section. The vertical projections of the third groove section and the fourth groove section on the active element array substrate have a third width and a fourth width respectively in the direction perpendicular to the first direction, and the third width is greater than the fourth width.
In an embodiment of the invention, the display panel further includes a plurality of first electrodes and dummy conductive patterns. The plurality of first electrodes are respectively arranged in the plurality of first grooves, and each first electrode is positioned between the active element array substrate and the plurality of luminescent material patterns. The dummy conductive pattern is arranged in the peripheral area and is positioned between the active element array substrate and at least one of the first dummy material part and the second dummy material part.
In an embodiment of the invention, the dummy conductive pattern of the display panel and the plurality of first electrodes belong to a same conductive layer.
In an embodiment of the invention, the display panel further includes a flexible circuit board bonded to the peripheral region of the active device array substrate. The first distance is greater than the second distance, and the flexible circuit board and the second dummy material portion are located on a second side of the display area.
In an embodiment of the invention, the first dummy material portion and the second dummy material portion of the display panel each include a hole injection layer, a hole transport layer, a red light emitting layer, a green light emitting layer, a blue light emitting layer, or a stacked layer of a combination thereof.
In an embodiment of the invention, each of the plurality of light emitting material patterns of the display panel includes a hole injection layer, a hole transport layer and a light emitting layer which are sequentially stacked.
In an embodiment of the invention, the method for manufacturing the display panel further includes performing a drying and baking step to solidify the first luminescent material liquid drop into the first dummy material portion and solidify the fourth luminescent material liquid drop into the second dummy material portion. The first material edge of the first dummy material portion farthest from the display area is separated from the first side of the display area by a first distance, the second material edge of the second dummy material portion farthest from the display area is separated from the second side of the display area by a second distance, and the first distance is different from the second distance. The first side and the second side are opposite sides of the display area in the first direction.
In an embodiment of the invention, the etching step of the manufacturing method of the display panel further includes removing two portions of the isolation structure material layer overlapping the peripheral region to form the second recess and the third recess. The first luminescent material liquid drop and the fourth luminescent material liquid drop are respectively sprayed in the second groove and the third groove. The widths of the areas occupied by the first, second and third grooves in the first direction are substantially equal.
In an embodiment of the invention, the etching step of the manufacturing method of the display panel further includes removing a portion of the isolation structure material layer overlapping the peripheral region to form the second groove. The first luminescent material liquid is sprayed in the second groove in a dripping mode. The width of the area occupied by the second groove in the first direction is larger than the width of the area occupied by each of the plurality of first grooves in the first direction.
In an embodiment of the invention, the method of manufacturing a display panel further includes forming a conductive pattern layer on the active device array substrate. The conductive pattern layer includes a plurality of first electrodes and dummy conductive patterns spaced apart from each other. The first electrodes are respectively arranged in the first grooves. The dummy conductive pattern is disposed in the peripheral region. The second and third light-emitting material droplets are respectively sprayed on two of the plurality of first electrodes, and the first and fourth light-emitting material droplets are sprayed on the dummy conductive pattern.
In view of the above, in the display panel according to the embodiment of the invention, the first dummy material portion and the second dummy material portion are disposed on the peripheral area, and the two dummy material portions are respectively located on the first side and the second side of the display area. That is, the distribution width of the dummy material portions at the first side of the display area is different from the distribution width of the dummy material portions at the second side of the display area. Therefore, the film thickness uniformity of the light-emitting material layer arranged in the display area is promoted, better light-emitting uniformity is achieved, and the production yield is improved.
In the method of manufacturing a display panel according to the embodiment of the invention, the step of forming the first dummy material portion by the droplets of the light emitting material sprayed on the first side of the display area is earlier than the step of forming the second dummy material portion by the droplets of the light emitting material sprayed on the second side of the display area. In addition, the embodiment of the invention adjusts the spraying step so that the distance between the first material edge of the first dummy material part farthest from the display area and the first side is different from the distance between the second material edge of the second dummy material part farthest from the display area and the second side.
In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.
Detailed Description
As used herein, "about", "approximately", "essentially", or "substantially" includes the stated value and the average value within an acceptable range of deviation of the specified value as determined by one of ordinary skill in the art, taking into account the measurement in question and the specified amount of error associated with the measurement (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or within, for example, ± 30%, ± 20%, ± 15%, ± 10%, ± 5%. Further, as used herein, "about", "approximately", "essentially", or "substantially" may be selected with respect to measured properties, cutting properties, or other properties, to select a more acceptable range of deviation or standard deviation, and not to apply one standard deviation to all properties.
In the drawings, the thickness of layers, films, panels, regions, etc. have been exaggerated for clarity. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. As used herein, "connected" may refer to physical and/or electrical connections. Further, "electrically connected" may mean that there are additional elements between the two elements.
Furthermore, relative terms, such as "lower" or "bottom" and "upper" or "top," may be used herein to describe one element's relationship to another element, as illustrated. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in one of the figures is turned over, elements described as being on the "lower" side of other elements would then be oriented on "upper" sides of the other elements. Thus, the exemplary term "lower" can include both an orientation of "lower" and "upper," depending on the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as "below" or "beneath" other elements would then be oriented "above" the other elements. Thus, the exemplary terms "above" or "below" may include both an orientation of above and below.
Exemplary embodiments are described herein with reference to cross-sectional views that are schematic illustrations of idealized embodiments. Thus, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or (and/or) tolerances, are to be expected. Thus, the embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region shown or described as flat may generally have rough and/or nonlinear features. Further, the acute angles shown may be rounded. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the claims.
Unless defined otherwise, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present invention and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the description to refer to the same or like parts.
Fig. 1 is a schematic top view of a display panel 10 according to a first embodiment of the invention. Fig. 2A to 2F are schematic cross-sectional views illustrating a manufacturing process of the display panel 10 of fig. 1. FIGS. 2A to 2F correspond to the sectional line A-A 'and the sectional line B-B' of FIG. 1. It should be noted that, for the sake of clarity, fig. 1 only illustrates the substrate 110, the isolation structure layer 181, the light emitting structure layer 200 and the flexible circuit board 250 of the display panel 10, and other possible components included in the display panel 10 will be illustrated in fig. 2A to 2F. As shown in fig. 1, the display panel 10 has a display area DA and a peripheral area PA surrounding the display area DA. The isolation structure layer 181 defines a plurality of first grooves in the display area DA, the plurality of first grooves includes, for example, the groove 181a and the groove 181b, and defines a plurality of second grooves and a plurality of third grooves in the peripheral area PA, the plurality of second grooves includes, for example, the groove 181c, and the plurality of third grooves includes, for example, the groove 181d, wherein when the display panel 10 displays, the areas where the groove 181a and the groove 181b in the display area DA are located can emit light to present a picture. The following will exemplarily describe a manufacturing flow of the display panel 10 shown in fig. 1.
Referring to fig. 2A, first, an active device array substrate 100 is provided, wherein the active device array substrate 100 includes a substrate 110, a buffer layer 120, an active device T, a gate insulating layer 130, an interlayer insulating layer 140, an insulating layer 150, and a planarization layer 160. The active device T is disposed on the substrate 110 and has a gate G, a source S, a drain D, and a semiconductor pattern SC. The gate insulating layer 130 is disposed between the semiconductor pattern SC and the gate electrode G. For example, in the present embodiment, the gate G of the active device T may be selectively disposed above the semiconductor pattern SC to form a top-gate thin film transistor (top-gate TFT), but the invention is not limited thereto. According to other embodiments, the gate G of the active device T may also be disposed under the semiconductor pattern SC, i.e., the gate G is located between the semiconductor pattern SC and the substrate 110, so as to form a bottom-gate thin film transistor (bottom-gate TFT). The buffer layer 120 is disposed between the substrate 110 and the active device T. In addition, the active devices T are used to drive the display layer (e.g., the light emitting structure layer 200) to display the image, and therefore, it can be understood that the active devices T are all located in the display area DA of fig. 1, and the peripheral area PA may have no active devices T.
In this embodiment, the semiconductor pattern SC may include a source region SR, a lightly doped source region LSR, a channel region CH, a lightly doped drain region LDR and a drain region DR, the lightly doped source region LSR is located between the source region SR and the channel region CH, the lightly doped drain region LDR is located between the channel region CH and the drain region DR, and the gate G overlaps the channel region CH of the semiconductor pattern SC, but the invention is not limited thereto. According to other embodiments, the semiconductor pattern SC may include only the source region SR, the channel region CH, and the drain region DR.
The interlayer insulating layer 140 is disposed on the gate insulating layer 130 and covers the gate G of the active device T. The source S and the drain D of the active device T are disposed on the interlayer insulating layer 140 and respectively overlap two different regions of the semiconductor pattern SC. In detail, the source S and the drain D of the active device T penetrate the interlayer insulating layer 140 and the gate insulating layer 130 to electrically connect the source region SR and the drain region DR of the semiconductor pattern SC, respectively.
In the present embodiment, the material of the semiconductor pattern SC is, for example, a Low Temperature Polysilicon (LTPS) semiconductor, that is, the active device T may be a low temperature polysilicon thin film transistor (LTPS TFT). However, the invention is not limited thereto, and in other embodiments, the active device T may be an Amorphous Silicon thin film Transistor (a-Si TFT), a microcrystalline Silicon thin film Transistor (micro-Si TFT), or a Metal Oxide Transistor (Metal Oxide Transistor).
The insulating layer 150 covers the source S and the drain D of the active device T and a portion of the surface of the interlayer insulating layer 140, and optionally has an opening 150a overlapping the drain D of the active device T. The planarization layer 160 covers the insulation layer 150 and a portion of the surface of the drain D.
The gate G, the source S, the drain D, the gate insulating layer 130, the interlayer insulating layer 140, the insulating layer 150 and the planarization layer 160 can be respectively implemented by any gate, any source, any drain, any gate insulating layer, any interlayer insulating layer, any insulating layer and any planarization layer for a display panel, which are well known to those skilled in the art, and the gate G, the source S, the drain D, the gate insulating layer 130, the interlayer insulating layer 140, the insulating layer 150 and the planarization layer 160 can be respectively formed by any method well known to those skilled in the art, which is not described herein again.
As shown in fig. 2A, a plurality of first electrodes 171 are formed on the active device array substrate 100, and the first electrodes 171 are arranged in the display area DA. The first electrodes 171 are disposed on the planarization layer 160 and electrically connected to the drains D of the active devices T respectively through the planarization layer 160. Specifically, although only one active device T is illustrated in fig. 2A for clarity of the drawing, a plurality of active devices T may be formed on the substrate 110, and each of the first electrodes 171 may be correspondingly connected to one of the active devices T. In some embodiments, the first electrode 171 is, for example, a light-transmissive electrode, and the material of the light-transmissive electrode includes metal oxides, such as: indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, or other suitable oxide, or a stack of at least two of the foregoing, but the invention is not limited thereto. In other embodiments, the first electrode 171 may also be a reflective electrode, and the material of the reflective electrode includes a metal, an alloy, a nitride of a metal material, an oxide of a metal material, an oxynitride of a metal material, or other suitable materials, or a stacked layer of a metal material and other conductive materials.
Referring to fig. 2B, an isolation structure material layer 180 is formed on the active device array substrate 100. The isolation structure layer 180 covers the first electrode 171 and a portion of the surface of the planarization layer 160. Referring to fig. 2C, after the isolation structure material layer 180 is formed, a patterning step is performed to remove portions of the isolation structure material layer 180 overlapping the display area DA to form an isolation structure layer 181 of the display panel 10 and a plurality of first grooves (e.g., the grooves 181a and the grooves 181b) defined by the isolation structure layer 181. The patterning step of the embodiment may further optionally include removing a plurality of portions of the isolation structure material layer 180 overlapping the peripheral region PA to form a plurality of second recesses (e.g., the recess 181c) and a plurality of third recesses (e.g., the recess 181d), but the invention is not limited thereto.
In view of the above, the vertical projection of the area occupied by each of the groove 181a (or the groove 181b), the groove 181c, and the groove 181d on the active device array substrate 100 has a width W1, a width W2, and a width W3 in the direction z, and the width W2 of the groove 181c and the width W3 of the groove 181d may be selectively substantially equal to the width W1 of the groove 181a (or the groove 181 b). In the embodiment, the grooves 181c and 181d in the peripheral region PA may extend through the isolation structure layer 181 and expose a portion of the surface of the planarization layer 160, and the grooves 181a and 181b in the display region DA may also extend through the isolation structure layer 181 and expose a portion of the surface of the first electrode 171.
As shown in fig. 1, the plurality of grooves may be arranged on the substrate 110 in an array, and the plurality of grooves includes, for example, the grooves 181a, the grooves 181b, the grooves 181c, and the grooves 181 d. The grooves 181a and 181b are disposed in the display area DA and are the first grooves nearest to the first side DA-a and the second side DA-b of the display area DA, respectively. The grooves 181c and the grooves 181d are disposed in the peripheral region PA and are respectively located on the first side DA-a and the second side DA-b of the display area DA, wherein the grooves 181c are the second grooves located farthest from the first side DA-a of the display area DA among the grooves located on the first side DA-a of the display area DA, and the grooves 181d are the third grooves located farthest from the second side DA-b of the display area DA among the grooves located on the second side DA-b of the display area DA. Specifically, all of the grooves 181a and 181b are located in the display area DA and all of the grooves 181c and 181d are not located in the display area DA. The vertical projection area of the substrate 110 occupied by each groove may be substantially the same selectively, but the invention is not limited thereto.
After the patterning step is completed, an ink-jet printing process is performed, and droplets to be formed into the light-emitting structure are sequentially sprayed in the plurality of grooves. For example, referring to fig. 1, the inkjet printing process may start from one corner of the display panel 10, first traverse the width of the display panel 10 along the process path P1 and drop droplets into the grooves on the process path P1, and then perform the same process along the process path P2 until all the grooves on the display panel 10 are filled with droplets after traversing the width of the display panel 10 along the process path Pn and dropping droplets into the grooves on the process path Pn. In the present embodiment, the directions of the two adjacent process paths (e.g., the process path P1 and the process path P2) are the same, but in other embodiments, the directions of the two adjacent process paths may be opposite.
In other words, referring to fig. 2D, the inkjet printing process of the embodiment is to spray the first, second, third and fourth light-emitting material droplets LD1, LD2, LD3 and LD4 in the groove 181c, the groove 181a, the groove 181b and the groove 181D in sequence, for example. Specifically, in the ink-jet printing process, the head HD carrying the liquid droplets is first sprayed in the recess 181 c; then moving the nozzle HD along the direction z to enable the nozzle HD to enter the display area DA from the first side DA-a of the display area DA, and spraying in the groove 181a and the groove 181 b; then, the nozzle HD is moved continuously along the direction z, so that the nozzle HD leaves the display area DA from the second side DA-b of the display area DA and enters the peripheral area PA, and then spraying is performed in the groove 181 d. That is, the peripheral area PA between the first side DA-a of the display area DA and the edge of the active device array substrate 100 can be regarded as a pre-spraying area, and the area is sprayed with droplets preferentially in the same process path. Meanwhile, the peripheral area PA between the second side DA-b of the display area DA and the edge of the active device array substrate 100 may be regarded as a tail spraying area, which is finally sprayed with droplets in the same process path.
As can be seen from fig. 2D, a distance L1 between the first and second light emitting material droplets LD1 and LD2 is greater than a distance L2 between the third and fourth light emitting material droplets LD3 and LD 4. In other words, the areas of the light-emitting material droplets sprayed in the pre-spraying region and the tail-end spraying region are different, that is, the light-emitting material droplets sprayed in the peripheral region PA are asymmetrically distributed with respect to the display region DA. Specifically, before the nozzle HD moves into the display area DA, the light-emitting material droplets are sprayed in the peripheral area PA, and after the light-emitting material droplets are stably sprayed, the light-emitting material droplets enter the display area DA for spraying. Thus, the uniformity of the film formation of the light-emitting structure material in the display area DA after drying is improved. It should be noted that, in the present embodiment, the numbers of the grooves 181c and the grooves 181d which are located on the process path P1 and arranged along the direction z are exemplarily illustrated as four and two, respectively, and the invention is not limited thereto.
In the present embodiment, the materials of the first, second, third and fourth light-emitting material droplets LD1, LD2, LD3 and LD4 may selectively include a light-emitting structure material and a solvent, wherein the light-emitting structure material includes a hole injection material, a hole transport material, a light-emitting material, an electron transport material and an electron injection material, and the solvent is a liquid that can be used to uniformly disperse the light-emitting structure material and has volatility.
Referring to fig. 2E, a drying and baking step is then performed to volatilize and remove the solvent dropped or injected into the light emitting material droplets of each groove, and the light emitting structure material is cured to form a corresponding light emitting material layer 190. The thickness of the luminescent material layer 190 may gradually increase from the center toward the edge, that is, the luminescent material layer 190 has a thickness at a portion near the edge of the groove greater than a thickness at a portion far from the edge of the groove.
As shown in fig. 2F, the display panel 10 has a light emitting structure layer 200 formed on the active device array substrate 100. The light emitting structure layer 200 includes a plurality of light emitting material patterns 210, and the light emitting material patterns 210 are respectively formed in a plurality of first grooves (e.g., the grooves 181a and 181b) in the display area DA. In the present embodiment, each of the light emitting material patterns 210 may include a hole injection layer 191, a hole transport layer 192, a light emitting layer 193, and an electron transport layer 194 sequentially stacked on the active device array substrate 100. In addition, the light emitting structure layer 200 further includes a first dummy material portion 211 and a second dummy material portion 212, wherein the first dummy material portion 211 may be selectively formed in a plurality of second recesses (e.g., the recess 181c), and the second dummy material portion 212 may be selectively formed in a plurality of third recesses (e.g., the recess 181d), in other words, the first dummy material portion 211 and the second dummy material portion 212 are respectively disposed on the first side DA-a and the second side DA-b of the display area DA.
In view of the above, each of the first dummy material portion 211 and the second dummy material portion 212 may optionally include a hole injection layer 191, a hole transport layer 192, a light emitting layer 193, and an electron transport layer 194 sequentially stacked on the active device array substrate 100, but the invention is not limited thereto, and in some embodiments, the first dummy material portion 211 and the second dummy material portion 212 may also be stacked layers of the hole injection layer 191 and the hole transport layer 192, respectively. In other embodiments, the first dummy material portion 211 and the second dummy material portion 212 may also be stacked layers of the hole injection layer 191, the hole transport layer 192, and the plurality of light emitting layers 193, respectively, wherein the plurality of light emitting layers 193 includes, for example, a red light emitting layer, a blue light emitting layer, and a green light emitting layer.
In this embodiment, the formation of the hole injection layer 191, the hole transport layer 192, and the light emitting layer 193 may include firstly dropping or injecting the corresponding light emitting structure material into the plurality of grooves defined by the isolation structure layer 181 by means of ink jetting, and then drying and curing the dropped or injected material to form the corresponding film. For example, the inkjet printing process includes dropping the first, second and fourth light emitting material droplets LD1, LD2 and LD4, which each include a hole injection layer material, into the grooves 181c, 181a and 181d, respectively, and then drying and curing the dropped materials to form the hole injection layers 191 corresponding to the first, second and third dummy material portions 211, 210 and 212, respectively. It should be noted that the present invention is not limited to the kind and the number of the luminescent material layers formed by the inkjet printing process, and any person skilled in the art can adjust the number of the luminescent material layers suitable for forming the film by the inkjet printing method according to the process characteristics and the requirements of the luminescent material.
In particular, in the manufacturing process of the display panel 10, the inkjet printing step of the hole transport layer 192 is performed after the hole injection layer 191 is cured, and the inkjet printing step of the light emitting layer 193 is performed after the hole transport layer 192 is cured. In this way, the thickness of each of the hole injection layer 191, the hole transport layer 192, and the light emitting layer 193 can be controlled by the step of inkjet printing, and the materials of the hole injection layer 191, the hole transport layer 192, and the light emitting layer 193 do not mix with each other during the inkjet printing. In addition, the stack of the hole injection layer 191, the hole transport layer 192 and the light emitting layer 193 is only for illustrative purposes, and in other embodiments, any adjacent two of the hole injection layer 191, the hole transport layer 192 and the light emitting layer 193 may optionally include one or more other layers therebetween.
As shown in fig. 1 and 2F, in the present embodiment, the first material edge 211a of the first dummy material portion 211 farthest from the display area DA is separated from the first side DA-a of the display area DA by a first distance d1, the second material edge 212a of the second dummy material portion 212 farthest from the display area DA is separated from the second side DA-b of the display area DA by a second distance d2, and the first distance d1 is greater than the second distance d 2. In addition, the light emitting structure layer 200 may further optionally include a third dummy material portion 213 and a fourth dummy material portion 214, where the third dummy material portion 213 and the fourth dummy material portion 214 are disposed in the peripheral region PA and located on a third side DA-c and a fourth side DA-d of the display area DA, respectively, where the third side DA-c and the fourth side DA-d are opposite sides of the display area DA in the vertical direction z. For example, the third material edge 213a of the third dummy material portion 213 farthest from the display area is separated from the third side DA-c of the display area DA by a third distance d3, the fourth material edge 214a of the fourth dummy material portion 214 farthest from the display area is separated from the fourth side DA-d of the display area DA by a fourth distance d4, and the third distance d3 may be selectively greater than the fourth distance d4, but the disclosure is not limited thereto.
On the other hand, after the inkjet printing process and the drying and baking step, an electron transporting layer 194 may be formed on the light emitting layer 193 by, for example, thermal evaporation (thermal evaporation) to complete the multi-layered light emitting structure 200. In some embodiments, the electron transport layer 194 can also be formed on the light emitting layer 193 by ink jet printing similar to that of fig. 2D and 2E. Next, a second electrode 172 is formed on the isolation structure layer 181 and the light emitting structure 200, and the second electrode 172 covers the isolation structure layer 181 and the light emitting structure 200. In detail, in the present embodiment, the second electrode 172 may continuously extend from above the isolation structure layer 181 to above the light emitting structure 200 in compliance with the sidewall of the isolation structure layer 181 and cover the light emitting structure 200. In particular, in some embodiments, the second electrode 172 may be formed in the same manner as the electron transport layer 194 on the light emitting structure 200, such as thermal evaporation. The second electrode 172 may have a substantially uniform film thickness.
In this embodiment, the second electrode 172 is, for example, a light-transmissive electrode, and the material of the light-transmissive electrode includes metal oxides, for example: indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, or other suitable oxide, or a stack of at least two of the foregoing, but the invention is not limited thereto. In other embodiments, the second electrode 172 may also be a reflective electrode, and the material of the reflective electrode includes a metal, an alloy, a nitride of a metal material, an oxide of a metal material, an oxynitride of a metal material, or other suitable materials, or a stack of a metal material and other conductive materials. In this way, the display panel 10 of the present embodiment is completed.
Referring to fig. 1, the display panel 10 may further include a flexible circuit board 250 bonded to the peripheral area PA of the display panel 10. It should be noted that the number of the flexible circuit boards 250 of the present embodiment is exemplarily illustrated by four, which does not represent that the present invention is limited thereto. In the present embodiment, the plurality of flexible circuit boards 250 may be respectively disposed on the second side DA-b and the fourth side DA-d of the display area DA. In detail, the substrate 110 has an edge 110a, an edge 110b, an edge 110c and an edge 110d respectively located on the first side DA-a, the second side DA-b, the third side DA-c and the fourth side DA-d of the display area DA, wherein the edge 110a and the edge 110b are two opposite edges of the substrate 110 in the direction z, and the edge 110c and the edge 110d are two opposite edges of the substrate 110 in the vertical direction z.
In response, a first spacing S1 exists between the edge 110a of the substrate 110 and the first material edge 211a of the first dummy material portion 211, a second spacing S2 exists between the edge 110b of the substrate 110 and the second material edge 212a of the second dummy material portion 212, and the first spacing S1 is greater than the second spacing S2. A third spacing S3 is provided between the edge 110c of the substrate 110 and the third material edge 213a of the third dummy material portion 213, a fourth spacing S4 is provided between the edge 110d of the substrate 110 and the fourth material edge 214a of the fourth dummy material portion 214, and the third spacing S3 may be selectively smaller than the fourth spacing S4, but the invention is not limited thereto. In other words, the flexible circuit board 250 is bonded to an area covered by fewer dummy material portions in the peripheral area PA (e.g., the peripheral area PA in which the second dummy material portions 212 and the fourth dummy material portions 214 are arranged).
As shown in fig. 1 and fig. 2F, the display panel 10 includes an active device array substrate 100, an isolation structure layer 181, a first electrode 171, a light emitting structure layer 200, and a second electrode 172. The isolation structure layer 181 defines a plurality of grooves in the display panel 10, and the light emitting structure layer 200 is filled in each groove. The light emitting structure layer 200 includes a plurality of light emitting material patterns 210, a first dummy material portion 211, and a second dummy material portion 212. The plurality of grooves includes, for example, grooves 181a, 181b, 181c, and 181 d. The light emitting material patterns 210 filled in the grooves 181a and 181b are sandwiched between the first electrode 171 and the second electrode 172 and can emit light by being driven by the active device T to serve as a display device. Therefore, the areas where the grooves 181a and 181b are located can be regarded as the display area DA. Neither the first dummy material portion 211 nor the second dummy material portion 212 filled in the recesses 181c and 181d is used as a display element. Therefore, the areas where the grooves 181c and 181d are located can be regarded as the peripheral area PA, and the grooves 181c and 181d are respectively located on two opposite sides of the display area DA. Here, the edge of the display area DA is defined by the outer edge of the light emitting material pattern 210 located at the outermost periphery, for example, and may also be the boundary between the light emitting material pattern 210 located at the outermost periphery and the adjacent first dummy material portion 211 or the second dummy material portion 212.
In addition, since the light emitting layer 193 in the light emitting structure layer 200 can be made of an organic light emitting material, the display panel 10 is substantially an organic light emitting display panel. In the present embodiment, one of the first electrode 171 and the second electrode 172 is a light transmissive electrode layer, and the other may be a light transmissive electrode layer or a reflective electrode layer. The light emitting structure 200 includes a hole injection layer 191, a hole transport layer 192, a light emitting layer 193, and an electron transport layer 194 sequentially stacked on the first electrode 171. The display panel 10 of the present embodiment is, for example, a top emission (top emission) type display panel. However, the present invention is not limited thereto, and according to other embodiments, the display panel 10 may also be a bottom emission (bottom emission) type display panel.
Fig. 3 is a schematic cross-sectional view of a display panel 11 according to a second embodiment of the invention. Referring to fig. 3, the difference between the display panel 11 of the present embodiment and the display panel 10 of fig. 2F is: the display panel 11 may further optionally include a plurality of dummy conductive patterns 175. Each dummy conductive pattern 175 is disposed in the plurality of grooves in the peripheral region PA. In the embodiment, a portion of the dummy conductive pattern 175 may be selectively disposed between the first dummy material portion 211 and the active device array substrate 100, and another portion of the dummy conductive pattern 175 may be selectively disposed between the second dummy material portion 212 and the active device array substrate 100, but the invention is not limited thereto. In other embodiments, the dummy conductive pattern 175 may be disposed only between the second dummy material portion 212 and the active device array substrate 100.
For example, in the present embodiment, the manufacturing method of the display panel 11 may further optionally include forming a conductive pattern layer on the active device array substrate 100, where the conductive pattern layer includes a plurality of first electrodes 171 and a plurality of dummy conductive patterns 175 spaced apart from each other. In other words, the dummy conductive pattern 175 and the first electrode 171 may be selectively belong to the same conductive layer, but the invention is not limited thereto. In other embodiments, the dummy conductive pattern 175 and the first electrode 171 may belong to different conductive layers. In the inkjet printing process, the first and fourth light emitting material droplets LD1 and LD4 are sprayed on the corresponding dummy conductive patterns 175, and the second and third light emitting material droplets LD2 and LD3 are sprayed on the corresponding first electrodes 171. The difference between the dummy conductive pattern 175 and the first electrode 171 is that the dummy conductive pattern 175 is not connected to any active device and the first electrode 171 is connected to the corresponding active device T. Therefore, the light emitting structure layer formed after the light emitting material droplets on the first electrode 171 are dried can emit light under driving to realize a display function.
Fig. 4 is a schematic cross-sectional view of a display panel 12 according to a third embodiment of the invention. Referring to fig. 4, the difference between the display panel 12 of the present embodiment and the display panel 10 of fig. 2F is: the width W4 and the width W5 of the vertical projection of the area occupied by the second groove (e.g., the groove 181c-1) and the third groove (e.g., the groove 181d-1) of the display panel 12 on the active device array substrate 100 in the direction z can be selectively larger than the width W1 of the vertical projection of the area occupied by the first groove (e.g., the groove 181a and the groove 181b) on the active device array substrate 100 in the direction z. In addition, the width W4 of the groove 181c-1 may be selectively greater than the width W5 of the groove 181d-1, but the invention is not limited thereto. In addition, the pitch of the heads of the droplets of the light emitting material may correspond to the pitch of the grooves in the display area DA during the manufacturing process, and the widths of the grooves 181c-1 and the grooves 181d-1 may be greater than the pitch of the grooves in the display area DA. Therefore, several nozzles can fill the luminescent material droplets in the recesses 181c-1 and 181d-1, and the luminescent material droplets in the recesses 181a and 181b can be discharged by different nozzles.
Fig. 5 is a schematic top view of a display panel 20 according to a fourth embodiment of the invention. Fig. 6 is a schematic cross-sectional view of the display panel 20 of fig. 5. FIG. 6 corresponds to the section line C-C 'and the section line D-D' of FIG. 5. It should be noted that, for the sake of clarity, fig. 5 only illustrates the substrate 110, the isolation structure layer 181-1, the light emitting structure layer 200 and the flexible circuit board 250 of the display panel 20, and other possible components included in the display panel 20 will be illustrated in fig. 5.
Referring to fig. 5 and fig. 6, the difference between the display panel 20 of the present embodiment and the display panel 10 of fig. 1 is: the isolation structure layer 181-1 of the display panel 20 defines a groove 181e surrounding the display area DA in the peripheral area PA. The groove 181e has a first groove section 181e-1 and a second groove section 181e-2 located on two opposite sides of the display area DA in the direction z, and a width W6 of a vertical projection of an area occupied by the first groove section 181e-1 on the active device array substrate 100 in the direction z is greater than a width W7 of an area occupied by the second groove section 181e-2 on the active device array substrate 100 in the direction z. In addition, in the embodiment, the groove 181e further has a third groove segment 181e-3 and a fourth groove segment 181e-4 located on two opposite sides of the display area DA in the vertical direction z, and a width W8 of a vertical projection of an area occupied by the third groove segment 181e-3 on the active device array substrate 100 in the vertical direction z may be selectively greater than a width W9 of an area occupied by the fourth groove segment 181e-4 on the active device array substrate 100 in the vertical direction z. That is, the groove 181e in the peripheral area PA is an annular groove surrounding the display area DA, and the sections on different sides of the annular groove have different widths. In the manufacturing process, when the light emitting structure layer is to be manufactured by an inkjet process, the nozzle of the inkjet device may firstly drip the droplets of the light emitting material from the wider section of the groove 181e and then enter the display area DA for the drip-injection step.
Fig. 7 is a schematic top view of a display panel 30 according to a fifth embodiment of the invention. Fig. 8 is a schematic cross-sectional view of the display panel 30 of fig. 7. FIG. 8 corresponds to section lines E-E 'and F-F' of FIG. 7. It should be noted that, for the sake of clarity, fig. 7 only illustrates the substrate 110, the isolation structure layer 181-2, the light emitting structure layer 200A and the flexible circuit board 250 of the display panel 30, and other possible components included in the display panel 30 will be illustrated in fig. 8.
Referring to fig. 7 and 8, the difference between the display panel 30 of the present embodiment and the display panel 10 of fig. 1 is: in the display panel 30 of the present embodiment, the first dummy material portion 211 and the second dummy material portion 212 are disposed on the upper surface 181s of the isolation structure layer 181-2, in other words, the isolation structure layer 181-2 is located between the first dummy material portion 211 and the active device array substrate 100, and the isolation structure layer 181-2 is located between the second dummy material portion 212 and the active device array substrate 100. In addition, in this embodiment, the third dummy material portion 213 and the fourth dummy material portion 214 may be disposed on the isolation structure layer 181-2, and the third dummy material portion 213 and the fourth dummy material portion 214 are respectively connected between the first dummy material portion 211 and the second dummy material portion 212. That is, the light emitting structure layer 200A of the display panel 30 has a dummy material portion surrounding the display area DA in the peripheral area PA, and the isolation structure layer 181-2 may not be patterned with a plurality of grooves but continuously extend along a circular path surrounding the display area DA in the peripheral area PA, such that the arrangement surfaces of the first dummy material portion 211, the second dummy material portion 212, the third dummy material portion 213, and the fourth dummy material portion 214 are all higher than the arrangement surface of the light emitting material pattern 210.
Fig. 9 is a schematic cross-sectional view of a display panel 31 according to a sixth embodiment of the invention. Referring to fig. 9, the difference between the display panel 31 of the present embodiment and the display panel 30 of fig. 8 is: the first dummy material portion 211 of the display panel 31 partially overlaps the isolation structure layer 181-3, that is, a portion of the first dummy material portion 211 that does not overlap the isolation structure layer 181-3 in a direction perpendicular to the substrate 110 directly covers a portion of the surface of the planarization layer 160. In some embodiments, the second dummy material portion 212 may also partially overlap the isolation structure layer.
Fig. 10 is a schematic cross-sectional view of a display panel 32 according to a seventh embodiment of the invention. Referring to fig. 10, the difference between the display panel 32 of the present embodiment and the display panel 30 of fig. 8 is: the first dummy material portion 211 and the second dummy material portion 212 of the light emitting structure layer 200A in the peripheral region PA of the display panel 32 are directly covered on the planarization layer 160, and the first dummy material portion 211 and the second dummy material portion 212 are disposed between the outer contour of the isolation structure layer 181-4 and the edge of the active device array substrate 100.
Fig. 11 is a schematic top view of a display panel 40 according to an eighth embodiment of the invention. It should be noted that, for the sake of clarity, fig. 11 only illustrates the substrate 110, the isolation structure layer 181-5, the light emitting structure layer 200B and the flexible circuit board 250 of the display panel 40. Referring to fig. 11, the difference between the display panel 40 of the present embodiment and the display panel 10 of fig. 1 is: the third dummy material portion 213 and the fourth dummy material portion 214 of the display panel 40 are disposed on the first side DA-a and the second side DA-b of the display area DA, respectively. The third material edge 213a of the third dummy material portion 213 is spaced apart from the first side DA-a of the display area DA by a third distance d3-1, the fourth material edge 214a of the fourth dummy material portion 214 is spaced apart from the second side DA-b of the display area DA by a fourth distance d4-1, and the third distance d3-1 is less than the fourth distance d 4-1.
From another point of view, in the inkjet printing process of the display panel 40, the directions of two adjacent process paths (e.g., the process path P1 and the process path P2) are opposite to each other, that is, the inkjet printing process of the display panel 40 drops droplets in the plurality of grooves in a back-and-forth spraying manner. In detail, the inkjet printing process may start from a corner of the display panel 40, first move the nozzle HD in the direction z to traverse the width of the display panel 40 and drop the liquid droplets in the grooves on the process path P1, then move the nozzle HD in the direction opposite to the direction z and perform the same process until the nozzle HD is moved in the direction opposite to the direction z to traverse the width of the display panel 40 and drop the liquid droplets in the grooves on the process path Pn, and then fill all the grooves on the display panel 40 with the liquid droplets.
In addition, in the present embodiment, the light emitting structure layer 200B further includes a fifth dummy material portion 215 and a sixth dummy material portion 216. The fifth dummy material portion 215 and the sixth dummy material portion 216 are disposed in the peripheral region PA and are respectively located on the third side DA-c and the fourth side DA-d of the display region DA. The fifth material edge 215a of the fifth dummy material portion 215 farthest from the display area DA is separated from the third side DA-c of the display area DA by a fifth distance d5, the sixth material edge 216a of the sixth dummy material portion 216 farthest from the display area DA is separated from the fourth side DA-d of the display area DA by a sixth distance d6, and the fifth distance d5 and the sixth distance d6 may be substantially equal. For example, the fifth distance d5 and the sixth distance d6 may be selectively smaller than the first distance d1 and the fourth distance d4-1, so that the plurality of flexible circuit boards 250 may be selectively disposed on the third side DA-c and the fourth side DA-d of the display area DA, i.e., the area covered by less dummy material portions in the peripheral area PA, but the invention is not limited thereto.
In summary, in the display panel according to the embodiment of the invention, the first dummy material portion and the second dummy material portion are disposed on the peripheral area, the two dummy material portions are respectively located on the first side and the second side of the display area, and a distance between an edge of the first material of the first dummy material portion farthest from the display area and the first side is different from a distance between an edge of the second material of the second dummy material portion farthest from the display area and the second side. Therefore, the film thickness uniformity of the light-emitting material layer arranged in the display area is promoted, and better light-emitting uniformity is achieved. In addition, in the method for manufacturing a display panel according to the embodiment of the invention, the light-emitting material droplets are sprayed into the display area after being sprayed in advance on the peripheral area, and on the same process path, one side of the display area where the light-emitting material droplets are sprayed earlier is a first side, and one side of the display area where the light-emitting material droplets are sprayed later and opposite to the first side is a second side. In the peripheral area, a distance between a luminescent material droplet sprayed farthest from the display area among the luminescent material droplets between the first side and the edge of the display panel and the first side is greater than a distance between a luminescent material droplet sprayed farthest from the display area among the luminescent material droplets between the second side and the edge of the display panel and the second side. That is to say, the pre-spraying area for spraying the droplets of the light-emitting material on the peripheral area before entering the display area is larger, and the droplets are sprayed on the display area after the parameters of the droplets are stabilized in advance for the ink-spraying process, which is helpful for improving the condition that the spraying amount of the droplets of the light-emitting material sprayed on the display area is not uniform, so as to improve the uniformity of the film thickness of the light-emitting material layer in the display area and further improve the production yield.
Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.