TW202105789A - Display panel and method of fabricating the same - Google Patents

Abstract

A display panel including a substrate, a plurality of bonding pads and a plurality of conductive traces is provided. The substrate has a substrate edge, a display region and a peripheral region disposed between the substrate edge and the display region. The bonding pads are arranged in the peripheral region. The conductive traces are electrically connected to the bonding pads. The conductive traces extend between the bonding pads and the substrate edge, and have a plurality of breaks. A method of fabricating the display panel is also provided.

Description

Display panel and manufacturing method thereof

The present invention relates to an electronic device and a manufacturing method thereof, and more particularly to a display panel and a manufacturing method thereof.

Generally speaking, a display panel is composed of a thin film transistor array substrate and a display medium layer disposed on it. In particular, the thin film transistor array substrate can be divided into an active area and a peripheral circuit area. The active area is equipped with a pixel array, and the peripheral circuit area is equipped with multiple conductive traces (or leads) and multiple Bonding pads and test transistors and other components. Usually, after the display panel is manufactured, a series of testing procedures are carried out to confirm whether the display quality of the display panel meets the standard.

Generally, the tested display panel needs to undergo a cutting step to remove the test pads for electrical testing. Because the configuration of these conductive traces (such as trace width and spacing between traces) arranged in the peripheral circuit area will vary due to different product designs (such as pixel resolution). Therefore, during the cutting process, it is often necessary to adjust cutting parameters (such as laser power or depression depth of the cutter wheel) for display panels of different product specifications to ensure that the cutting of the substrate does not cause damage to the display panel. However, as the resolution of the display panel continues to improve, the spacing between the conductive traces used for testing has also been continuously reduced. As a result, after the display panel is removed from the test pads, these conductive traces are likely to occur in the cutting direction. Electrical short circuit.

The present invention provides a display panel with better production yield.

The present invention provides a method for manufacturing a display panel, which has a better cutting yield.

The display panel of the present invention includes a substrate, a plurality of bonding pads, and a plurality of conductive traces. The substrate has an edge of the substrate, a display area, and a peripheral area arranged between the edge of the substrate and the display area. A plurality of bonding pads are arranged in the peripheral area of the substrate. A plurality of conductive traces are electrically connected to the bonding pads. The conductive traces extend between the bonding pads and the edge of the substrate, and have multiple disconnections.

The manufacturing method of the display panel of the present invention includes the step of disconnecting a plurality of conductive traces, electrically separating the plurality of bonding pads of the display panel from the plurality of test pads, and cutting the substrate of the display panel along the cutting line Steps and electrically bonding the flexible circuit board to the bonding pads of the display panel. The bonding pads and the test pads are arranged in the peripheral area of the display panel on at least one side of the substrate, and the conductive traces of the display panel are electrically connected between the bonding pads and the test pads. After the disconnection step is completed, these conductive traces respectively have multiple disconnections. In the step of cutting the substrate, the cutting line is located between the disconnections of the conductive traces and the test pads.

Based on the above, in the manufacturing method of the display panel of an embodiment of the present invention, the uncut display panel is provided with a plurality of disconnects on the conductive traces connecting the plurality of bonding pads and the plurality of test pads. Place. In the step of cutting the substrate, the display panel is cut along the cutting line between the test pads and the bonding pads to remove the test pads. These disconnections through the conductive traces are arranged between the bonding pads and the cutting lines, which can prevent the conductive traces from being electrically short-circuited during the cutting process, which helps to improve the cutting yield of the display panel. Therefore, in the display panel of an embodiment of the present invention, the plurality of conductive traces extending between the edge of the cut substrate and the plurality of bonding pads respectively have these disconnections.

As used herein, "approximately", "approximately", "essentially", or "substantially" includes the stated value and the average value within the acceptable deviation range of the specific value determined by a person of ordinary skill in the art, taking into account all The measurement in question and the specific number of errors associated with the measurement (ie, the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or, for example, within ±30%, ±20%, ±15%, ±10%, ±5%. Furthermore, "about", "approximately", "essentially", or "substantially" used in this article can be based on measurement properties, cutting properties, or other properties to select a more acceptable deviation range or standard deviation. Not one standard deviation applies to all properties.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. It should 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 Intermediate elements can 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. As used herein, "connection" can refer to physical and/or electrical connection. Furthermore, "electrical connection" can mean that there are other components between the two components.

In addition, relative terms such as "lower" or "bottom" and "upper" or "top" can be used herein to describe the relationship between one element and another element, as shown in the figure. It should be understood that relative terms are intended to include different orientations of the device in addition to the orientation shown in the figures. For example, if the device in one figure is turned over, elements described as being on the "lower" side of other elements will be oriented on the "upper" side of the other elements. Therefore, the exemplary term "lower" may include an orientation of "lower" and "upper," depending on the specific orientation of the drawing. Similarly, if the device in one figure is turned over, elements described as "below" or "below" other elements will be oriented "above" the other elements. Thus, the exemplary terms "above" or "below" can include an orientation of above and below.

Reference will now be made in detail to the exemplary embodiments of the present invention, and examples of the exemplary embodiments are illustrated in the accompanying drawings. Whenever possible, the same component symbols are used in the drawings and descriptions to indicate the same or similar parts.

FIG. 1 is a schematic top view of a motherboard of a display panel according to an embodiment of the invention. 2A to 2D are schematic top views of a manufacturing process of a display panel according to an embodiment of the invention. 3A and 3B are respectively enlarged schematic diagrams of a partial area of the display panel of FIGS. 2A and 2B. Specifically, FIG. 3A corresponds to the partial area I of FIG. 2A, and FIG. 3B corresponds to the partial area II of FIG. 2B. For the sake of clarity, FIG. 1 omits the illustration of the conductive trace CL and the signal line SL in FIG. 2A.

2D, in this embodiment, the display panel 10C includes a substrate 100, a plurality of bonding pads BP, and a plurality of conductive traces CL". The substrate 100 has a substrate edge 100e, a display area DR, and is disposed on the substrate edge 100e and the display The peripheral area PR between the areas DR. A plurality of bonding pads BP are arranged along a direction in the peripheral area PR of the substrate 100. In this embodiment, the direction may be the extending direction of the substrate edge 100e, but it is not Limit. Multiple conductive traces CL" are electrically connected to multiple bonding pads BP, respectively. More specifically, the conductive traces CL" located in the peripheral region PR extend between the edge 100e of the substrate and the connection pads BP. It is worth noting that the conductive traces CL" have multiple disconnections CLb, and These disconnections CLb are located between the substrate edge 100e and the plurality of bonding pads BP. Through the above-mentioned configuration of the disconnection CLb, the conductive traces CL" can be prevented from being electrically short-circuited during the cutting process, which helps to improve the cutting yield of the display panel 10C.

Furthermore, the display panel 10C may further include a counter substrate (not shown) and a display medium layer (not shown) disposed between the substrate 100 and the counter substrate. In this embodiment, the display medium layer includes, for example, a plurality of liquid crystal molecules. In other words, the display panel 10C of this embodiment may be a liquid crystal display panel, but the invention is not limited to this. According to other embodiments, the display medium layer may also include a plurality of light emitting structures. That is, the display panel may also be an organic light emitting diode (OLED) panel, a micro light emitting diode (micro-LED) panel, or a sub-millimeter light emitting diode (mini light emitting diode) panel. emitting diode; mini-LED). In this embodiment, the substrate 100 and the counter substrate of the display panel 10C are, for example, flexible substrates, but not limited to this.

It should be understood that, in this embodiment, a flexible printed circuit board (FPCB) 200 may be further provided on one side of the substrate edge 100e of the substrate 100, and the flexible printed circuit board 200 is electrically connected to these joints. Pad BP. In this embodiment, the flexible circuit board 200 is, for example, a transmission circuit board adopting a chip on film (COF) package. In other words, the flexible circuit board 200 may be a package structure with a driving chip and a transmission line, but the invention is not limited to this. In other embodiments, the flexible circuit board 200 may also be a transmission circuit board formed by using tape automated bonding (TAB) technology. In another embodiment, the flexible circuit board 200 may not have a driver chip.

On the other hand, the display panel 10C further includes a plurality of signal lines SL, and the signal lines SL are disposed in the display area DR and extend to the peripheral area PR to electrically connect the plurality of bonding pads BP. For example, the display area DR of the display panel 10C may be provided with a plurality of pixel structures (not shown), and these pixel structures are electrically connected to the signal lines SL, respectively. In other words, the driving signal from the flexible circuit board 200 can be transmitted to the pixel structure of the display area DR through the transfer of the bonding pad BP and the signal line SL, so as to achieve the effect of displaying an image. The manufacturing process of the display panel 10C will be exemplarily described below.

1 and FIGS. 2A to 2D, the manufacturing method of the display panel 10C includes: cutting a motherboard 1 to obtain a plurality of display panels 10. In this embodiment, the motherboard 1 has a plurality of display panels 10 arranged in an array. That is, the display panels 10 are arranged in multiple rows and multiple rows in the direction X and the direction Y, but not limited to this. In other embodiments, in order to optimize the utilization of the motherboard, these display panels may also have different sizes and are not arranged on the motherboard in an array arrangement. For example, in this embodiment, the cutting process of the mother board 1 is based on mechanical cutting (such as fixed cutter cutting, rotary cutter cutting, or fixed cutter cutting, etc.) along multiple cutting lines C1. It is performed with multiple cutting lines C2, and the extending direction of the cutting line C1 intersects the extending direction of the cutting line C2, but the present invention is not limited to this. In other embodiments, the cutting process of the mother board 1 may also be performed by non-mechanical cutting (for example, laser cutting).

The display panel 10 cut from the motherboard 1 has a plurality of test pads TP, and these test pads TP are disposed on at least one side of the substrate 100S of the display panel 10. In this embodiment, the substrate 100S of the display panel 10 has a side 100Se corresponding to the cutting line C2, and the test pads TP are located between the side 100Se of the substrate 100S and the plurality of bonding pads BP, but not This is limited. 2A and 3A, the manufacturing method of the display panel 10C further includes: forming a plurality of conductive traces CL between the plurality of bonding pads BP and the plurality of test pads TP. The conductive trace CL is electrically connected between a corresponding bonding pad BP and a corresponding test pad TP. However, the present invention is not limited to this. According to other embodiments, the conductive traces may also be electrically connected between the corresponding plurality of bonding pads BP and the corresponding one of the test pads TP.

Furthermore, the conductive trace CL has an extension section 121, a connection portion 122 and an extension section 123, and the connection portion 122 is electrically connected between the extension section 121 and the extension section 123. For example, in this embodiment, the connecting portion 122 of the conductive trace CL has a width W1 in the direction X, and the extension 123 (or extension 121) of the conductive trace CL has a width W2 in the direction X, and the width W1 is smaller than width W2, but the invention is not limited to this. In a preferred embodiment, the ratio of the width W1 of the connecting portion 122 of the conductive trace CL to the width W2 of the extension section 123 is less than 0.5. It should be noted that, in this embodiment, the width of the extension 121 and the extension 123 of the conductive trace CL in the direction X can be selectively the same, but it is not limited thereto. In other embodiments, the widths of the two extension sections of the conductive trace in the direction X may also be different, and both are greater than the width W1 of the connecting portion 122.

Please continue to refer to FIG. 2A, after the cutting step of the mother board 1 is completed, the inspection step of the display panel 10 is performed. For example, the detection step of the display panel 10 includes abutting a plurality of probe pins of the test machine to a plurality of test pads TP of the display panel 10, and applying at least between the test pads TP. A voltage signal for electrical and/or reliability testing. In this embodiment, the at least one voltage signal may be a DC voltage signal provided by the power supply PS1 of the testing machine, but it is not limited to this. It should be noted that the electrical connection between the power supply PS1 and the plurality of test pads TP in FIG. 2A is only for illustrative purposes, and the present invention is not limited by the content of the drawings.

After the detection step of the display panel 10 is completed, as shown in FIG. 2B and FIG. 3B, a step of disconnecting a plurality of conductive traces CL is performed to electrically separate the bonding pads BP from the test pads TP. It is worth noting that after the disconnection step of the conductive trace CL is completed, the conductive trace CL' with the disconnection CLb is formed. For example, the disconnection step of the conductive trace CL can be performed by the aforementioned testing machine. The difference is that the two ends (for example, the high potential end and the low potential end) of the power supply PS2 (or the power supply PS1) of the test machine are electrically connected to the bonding pad BP and the test pad TP, respectively. Since the width W2 of the connecting portion 122 of the conductive trace CL is smaller than the width W1 of the extending portion 123 (or the width of the extending portion 121), the resistance value of the connecting portion 122 is greater than the resistance value of the extending portion 123 (or the width of the extending portion 121). resistance). Therefore, when the power supply PS2 is enabled and a current Ic is applied between the bonding pad BP and the test pad TP, the current Ic flowing through the conductive trace CL will generate more heat energy when passing through the connecting portion 122, resulting in The temperature of the connecting portion 122 increases and exceeds its melting point. At this time, the connecting portion 122 of the conductive trace CL will be disconnected and form a disconnection CLb. For example, the ratio of the current Ic value used in the disconnection step to the current value used in the detection can be between 1 and 5, but is not limited to this.

It is worth noting that the conductive trace CL' formed after the conductive trace CL is disconnected also has an end 1211 and an end 1231 that define the disconnection CLb. The end 1211 and the end 1231 are respectively connected to the extension section 121 and the extension section 123. In this embodiment, the end 1211 of the conductive trace CL' has a width W1' in the direction X, and the width W1' of the end 1211 (or the width of the end 1231 in the direction X) is smaller than that of the extension 123 in the direction X. The width W2 in X (or the width of the extension 121 in the direction X).

Referring to FIGS. 2C and 3B, after the disconnection step of the conductive trace CL is completed, the cutting step of the substrate 100S is performed along the cutting line C3 to obtain the display panel 10C. It is worth noting that the cutting line C3 is located between the multiple disconnections CLb of the multiple conductive traces CL' and the multiple test pads TP, or the multiple connecting portions 122 of the multiple conductive traces CL are located Between the cutting line C3 and the plurality of bonding pads BP (as shown in FIG. 3A). For example, there is a shortest distance d between the plurality of disconnections CLb of the plurality of conductive traces CL' and the cutting line C3, and the shortest distance d may be greater than or equal to 50 microns, but the present invention is not limited thereto. In other words, the cutting line C3 can be arranged from a position at least 50 micrometers away from the disconnection CLb to the area between the test pads TP. Accordingly, the adjustment margin of the cutting process of the substrate 100S can be increased. From another point of view, these disconnections CLb of the conductive trace CL' are arranged between the bonding pad BP and the test pad TP, which can prevent the conductive trace CL' from being electrically short-circuited during the cutting process. Helps improve the cutting yield of the display panel.

Referring to FIG. 2D, the cut conductive trace CL" extends between the substrate edge 100e of the substrate 100 and the bonding pad BP, and has a disconnection CLb. It is worth noting that due to the above-mentioned configuration of the cutting line C3 ( As shown in FIG. 2C), the shortest distance d between the substrate edge 100e of the cut substrate 100 and the plurality of breaks CLb can be greater than or equal to 50 microns, but not limited to this. Further, when the substrate is completed After the 100S cutting step, the flexible circuit board 200 can be electrically bonded to a plurality of bonding pads BP. For example, the flexible circuit board 200 can have a plurality of pins, and the flexible circuit board 200 can pass through these pins. The thermal compression bonding with the plurality of bonding pads BP electrically connects the plurality of signal lines SL on the substrate 100.

Other embodiments will be listed below to describe the disclosure in detail, wherein the same components will be marked with the same symbols, and the description of the same technical content will be omitted. For the omitted parts, please refer to the foregoing embodiments, and will not be repeated hereafter.

4 is a schematic top view of a partial area of a display panel according to another embodiment of the invention. FIG. 5 is a schematic cross-sectional view of the display panel of FIG. 4. In particular, for the sake of clarity, FIG. 4 omits the illustration of the insulating layer 110 in FIG. 5. 4 and 5, the main difference between the display panel 11 of this embodiment and the display panel 10 of FIG. 3A lies in the composition of conductive traces. Specifically, the conductive trace CL-A of the display panel 11 has an extension section 121A and an extension section 123A that are structurally separated from each other, and a connecting portion 122A electrically connected between the extension section 121A and the extension section 123A. In this embodiment, the step of forming a plurality of conductive traces CL-A may optionally include forming an insulating layer 110 between the extension section and the connecting portion 122A. In other words, the connecting portion 122A and the extension section of the conductive trace CL-A may belong to different film layers.

For example, in this embodiment, the insulating layer 110 covers the extension 121A and the extension 123A of the conductive trace CL-A, the connecting portion 122A of the conductive trace CL-A is disposed on the insulating layer 110, and the connecting portion 122A The two ends of the hole pass through the insulating layer 110 to electrically connect the extension section 121A and the extension section 123A, respectively. However, the present invention is not limited to this. In other unshown embodiments, the connecting portion of the conductive trace may also be disposed between the insulating layer 110 and the substrate 100S, and the two extension sections respectively penetrate the insulating layer 110 to be electrically connected. Connecting part.

It is worth mentioning that in this embodiment, the resistance value of the two extension sections of the conductive trace CL-A may be smaller than the resistance value of the connecting portion 122A. Therefore, in the disconnection step of the conductive trace CL-A, the current flowing through the conductive trace CL-A will generate more heat energy when passing through the connecting portion 122A, causing the temperature of the connecting portion 122A to rise and exceed its melting point. . At this time, the connecting portion 122A of the conductive trace CL-A will be disconnected and form a disconnection (not shown). The arrangement of the disconnection can prevent the conductive trace CL-A from being electrically short-circuited during the subsequent cutting process, which helps to improve the cutting yield of the display panel 11.

FIG. 6 is a schematic top view of a partial area of a display panel according to another embodiment of the present invention. Please refer to FIG. 6, the difference between the display panel 12 of this embodiment and the display panel 10 of FIG. 3A lies in the configuration of the connecting portions of the conductive traces. Specifically, the plurality of connecting portions 122B of the plurality of conductive traces CL-B of the display panel 12 are staggered from each other in the arrangement direction (for example, direction X) of the bonding pads BP. In other words, the connecting portion 122B of any one of the plurality of conductive traces CL-B can overlap the extension 121B or extension 123B of the adjacent conductive trace CL-B in the direction X.

It should be understood that the multiple disconnections formed by the conductive traces CL-B after the disconnection step is completed are also staggered in the direction X (not shown). It is worth mentioning that through the dislocation relationship of the plurality of connecting portions 122B of the plurality of conductive traces CL-B, the heat generated when the current passes through the connecting portions 122B can be dispersed, which helps to further ensure that the bonding pads BP are in The substrate 100S is electrically independent after the cutting step is completed.

In summary, in the manufacturing method of the display panel of an embodiment of the present invention, the uncut display panel is provided with a plurality of conductive traces connecting the plurality of bonding pads and the plurality of test pads. Disconnect. In the step of cutting the substrate, the display panel is cut along the cutting line between the test pads and the bonding pads to remove the test pads. These disconnections through the conductive traces are arranged between the bonding pads and the cutting lines, which can prevent the conductive traces from being electrically short-circuited during the cutting process, which helps to improve the cutting yield of the display panel. Therefore, in the display panel of an embodiment of the present invention, the plurality of conductive traces extending between the edge of the cut substrate and the plurality of bonding pads respectively have these disconnections.

1: Motherboard 10, 10C, 11, 12: display panel 100, 100S: substrate 100Se: side 100e: edge of substrate 110: Insulation layer 121, 121A, 121B, 123, 123A, 123B: extension section 1211, 1231: end 122, 122A, 122B: connecting part 200: flexible circuit board BP: Bonding pad C1, C2, C3: cutting line CL, CL-A, CL-B, CL’, CL”: conductive trace CLb: Break DR: display area d: distance Ic: current PR: Peripheral area PS1, PS2: power supply SL: signal line TP: Test pad W1, W1’, W2: width X, Y: direction I, II: area

FIG. 1 is a schematic top view of a motherboard of a display panel according to an embodiment of the invention. 2A to 2D are schematic top views of a manufacturing process of a display panel according to an embodiment of the invention. 3A and 3B are respectively enlarged schematic diagrams of a partial area of the display panel of FIGS. 2A and 2B. 4 is a schematic top view of a partial area of a display panel according to another embodiment of the invention. FIG. 5 is a schematic cross-sectional view of the display panel of FIG. 4. FIG. 6 is a schematic top view of a partial area of a display panel according to another embodiment of the present invention.

10C: Display panel

100: substrate

100e: edge of substrate

200: flexible circuit board

BP: Bonding pad

CL”: Conductive trace

CLb: Break

DR: display area

d: distance

PR: Peripheral area

SL: signal line

Claims (20)

A display panel including: A substrate having an edge of the substrate, a display area, and a peripheral area arranged between the edge of the substrate and the display area; A plurality of bonding pads arranged in the peripheral area of the substrate; and A plurality of conductive traces are electrically connected to the bonding pads, and the conductive traces extend between the bonding pads and the edge of the substrate and have a plurality of disconnections. The display panel according to claim 1, wherein the bonding pads are arranged on the substrate along a first direction, and the disconnections of the conductive traces are staggered with each other in the first direction. The display panel according to claim 1, further comprising a flexible circuit board disposed on one side of the substrate edge of the substrate and electrically bonded to the bonding pads. The display panel of claim 1, wherein each of the conductive traces has two extension sections that are structurally separated from each other and a connection portion electrically connected between the extension sections, and the conductive traces The connection part is provided with these disconnections. The display panel according to claim 4, wherein the resistance value of the extension sections of the conductive traces is smaller than the resistance value of the connection parts of the conductive traces. The display panel according to claim 1, wherein the shortest distance between the edge of the substrate and the disconnections of the substrate is greater than or equal to 50 microns. The display panel according to claim 1, wherein each of the conductive traces has two extension sections and two ends, the ends respectively connected to the extension sections define the disconnection, and the ends are at a first Each has a first width in one direction, the extension sections have a second width in the first direction, and the first width is smaller than the second width. The display panel according to claim 7, wherein the ratio of the first width to the second width is less than 0.5. The display panel according to claim 1, wherein the substrate is a flexible substrate. A method for manufacturing a display panel, wherein the display panel has a substrate, a peripheral area provided on at least one side of the substrate, a plurality of bonding pads and a plurality of test pads provided in the peripheral area, and electrically connected to the A plurality of conductive traces between the bonding pads and the test pads, the manufacturing method of the display panel includes: Performing a disconnection step of the conductive traces to electrically separate the bonding pads from the test pads, wherein after the disconnection step is completed, the conductive traces have a plurality of disconnections; Performing a cutting step of the substrate along a cutting line, wherein the cutting line is located between the disconnections of the conductive traces and the test pads; and A flexible circuit board is electrically connected to the bonding pads. The manufacturing method of the display panel according to claim 10 further includes: The conductive traces are formed between the bonding pads and the test pads, wherein each of the conductive traces has two extension sections and a connection portion electrically connected to the extension sections, and the connection The part is located between the cutting line and the bonding pads. The method for manufacturing a display panel according to claim 11, wherein the step of disconnecting the conductive traces includes: A current is applied between the bonding pads and the test pads, so that the connecting portions of the conductive traces form the disconnections. The manufacturing method of the display panel according to claim 11, wherein the connecting portions of the conductive traces are staggered with each other in the arrangement direction of the bonding pads. The method for manufacturing a display panel according to claim 11, wherein the connecting portion has a first width in a first direction, the extension sections have a second width in the first direction, and the first The width is smaller than the second width. The manufacturing method of the display panel according to claim 14, wherein the ratio of the first width to the second width is less than 0.5. The method for manufacturing a display panel according to claim 11, wherein the step of forming the conductive traces includes: An insulating layer is formed, wherein the insulating layer is located between the extension sections and the connection portions. The manufacturing method of the display panel according to claim 16, wherein the resistance value of the extension sections of the conductive traces is smaller than the resistance value of the connection parts of the conductive traces. The manufacturing method of the display panel according to claim 10 further includes: Cutting a motherboard to obtain the display panel, wherein the test pads are located on at least one side of the display panel. The manufacturing method of the display panel as described in claim 18 further includes: After the cutting step of the motherboard is completed, a detection step of the display panel is performed, wherein the detection step includes applying at least one voltage signal between the test pads. The method for manufacturing a display panel according to claim 10, wherein the shortest distance between the cutting line and the disconnections of the conductive traces is greater than or equal to 50 microns.

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