Display module and detection method thereof

Abstract

This application discloses a display module and its testing method. The display module includes: a display substrate, which includes a display area and a bonding area located on at least one side of the display area. The bonding area includes multiple test pads. A driver chip is bonded to the bonding area and located on the side of the multiple test pads closer to the display area. One end of a flexible circuit board is bonded to the bonding area and located on the side of the multiple test pads away from the display area. Multiple metal traces are disposed on the display substrate for transmitting the power supply voltage provided by the flexible circuit board to the driver chip via the multiple test pads, and then to the display area via the driver chip. By setting multiple test pads with specific connection relationships on the display substrate between the driver chip and the flexible circuit board, and sequentially applying test voltages to some of the test pads, the lighting status of the display area is observed, allowing for rapid localization of the root cause of abnormal phenomena such as black screen and abnormal display in the display module.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a display module and its testing method. Background Technology

[0002] With the continuous development of display technology, organic light-emitting diode (OLED) display products have good application prospects in wearable devices, industrial security, medical and other industries due to their advantages such as high resolution, low power consumption, small size and light weight.

[0003] OLED display modules typically include components such as a display substrate, a driver chip (DDIC), and a flexible printed circuit board (FPC). Power and signals are usually transmitted to the pixel circuitry of the display substrate through connectors, the flexible printed circuit board, bonding pads from the flexible printed circuit board to the display substrate, bonding pads from the display substrate to the driver chip, the driver chip, and bonding pads from the driver chip to the display substrate, ultimately driving the display area to emit light and display the image.

[0004] However, current OLED display modules suffer from the problem of difficulty in pinpointing the root cause of black screens or abnormal display. Because power and signals pass serially through multiple connection points, it is impossible to quickly locate the specific module causing the fault when a black screen or display abnormality occurs. Summary of the Invention

[0005] This application provides a display module and its detection method to solve the technical problem that it is difficult to quickly locate the root cause of black screen and abnormal display in existing display modules.

[0006] A first aspect of this application provides a display module, including: The display substrate includes a display area and a bonding area located on at least one side of the display area; the bonding area includes a plurality of test pads. The driver chip is bonded to the bonding area and located on the side of the plurality of test pads closest to the display area; A flexible circuit board, one end of which is bonded to the bonding area and located on the side of the plurality of test pads away from the display area; Multiple metal traces are disposed on the display substrate to transmit the power supply voltage provided by the flexible circuit board to the driver chip via the multiple test pads, and then to the display area via the driver chip.

[0007] In some embodiments, the plurality of test pads includes: a first test pad, a second test pad, a third test pad, and a fourth test pad; One end of the first test pad is electrically connected to the first bonding pad located in the bonding area of ​​the flexible circuit board, and the other end is electrically connected to the second bonding pad on the driver chip. One end of the second test pad is electrically connected to the third bonding pad on the driver chip, and the other end is floating; the second bonding pad and the third bonding pad are electrically connected. One end of the third test pad is electrically connected to the fourth bonding pad of the flexible circuit board located in the bonding area, and the other end is electrically connected to the fifth bonding pad on the driver chip. One end of the fourth test pad is electrically connected to the sixth bonding pad on the driver chip, and the other end is floating; the fifth bonding pad and the sixth bonding pad are electrically connected.

[0008] In some embodiments, the display substrate further includes a substrate and a transition metal layer on the side furthest from the substrate; The plurality of test pads are disposed on the same layer as the transition metal layer.

[0009] In some embodiments, the display substrate further includes an anode layer; the plurality of test pads are disposed in the same layer as the anode layer.

[0010] In some embodiments, the display substrate further includes an encapsulation layer; the encapsulation layer completely covers the plurality of test pads.

[0011] In some embodiments, the display substrate further includes a pixel circuit and a fifth test pad; the pixel circuit includes a front transistor, one end of the fifth test pad is electrically connected to the gate of the front transistor, and the other end is floating.

[0012] A second aspect of this application provides a method for detecting a display module as described in any of the preceding claims, comprising: Test voltages are sequentially applied to portions of the multiple test pads in the display substrate. The location of the fault is determined based on the lighting results of the display area in the display substrate.

[0013] In some embodiments, the step of sequentially applying a test voltage to a portion of the test pads of a plurality of test pads in the display substrate specifically includes: A first power supply voltage is applied to the second test pad, and a second power supply voltage is applied to the fourth test pad; If the lighting result of the display area is abnormal, the fault location is determined to be within the pixel circuit of the display area; If the lighting result of the display area is normal, then the first power supply voltage is applied to the first test pad and the second power supply voltage is applied to the third test pad. If the lighting result of the display area is abnormal, the fault location is determined to be inside the driver chip; If the lighting result of the display area is normal, power is supplied to the display module through the connector on the flexible circuit board; If the lighting result of the display area is abnormal, the fault location is determined to be within the flexible circuit board.

[0014] In some embodiments, the display module further includes a pixel circuit disposed within the display area, the pixel circuit including a driving transistor, a front transistor and a light-emitting diode, the front transistor being connected between the driving transistor and the light-emitting diode; The display module further includes a fifth test pad, which is electrically connected to the gate of the front transistor; The step of sequentially applying test voltages to a portion of the multiple test pads in the display substrate further includes: An enable voltage is applied to the fifth test pad to enable the preamplifier transistor.

[0015] The beneficial effects of this application are as follows: This application provides a display module and its testing method. The display module includes: a display substrate, which includes a display area and a bonding area located on at least one side of the display area. The bonding area includes multiple test pads. A driver chip is bonded to the bonding area and located on the side of the multiple test pads closer to the display area. One end of a flexible circuit board is bonded to the bonding area and located on the side of the multiple test pads away from the display area. Multiple metal traces are disposed on the display substrate for transmitting the power supply voltage provided by the flexible circuit board to the driver chip via the multiple test pads, and then to the display area via the driver chip. This application achieves rapid localization of the root cause of abnormal phenomena such as black screen and abnormal display by setting multiple test pads with specific connection relationships on the display substrate between the driver chip and the flexible circuit board, sequentially applying test voltages to some of the test pads, and observing the lighting status of the display area. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the display module provided in the embodiments of this application; Figure 2 This is a schematic diagram of a display substrate provided in an embodiment of this application; Figure 3 Another schematic diagram of the structure of the display substrate provided in the embodiments of this application; Figure 4 Another schematic diagram of the structure of the display substrate provided in the embodiments of this application; Figure 5 This is a schematic diagram of a pixel circuit provided in an embodiment of this application; Figure 6 This is yet another schematic diagram of the pixel circuit provided in an embodiment of this application; Figure 7 This is a flowchart of a method for detecting a display substrate provided in an embodiment of this application. Detailed Implementation

[0018] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the application will be further described below in conjunction with the accompanying drawings and embodiments. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the figures denote the same or similar structures, and therefore repeated descriptions of them will be omitted. Terms describing position and direction described in this application are illustrative based on the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this application. The accompanying drawings of this application are for illustrating relative positional relationships only and do not represent actual scale.

[0019] like Figure 1 As shown, a display module typically includes components such as a display substrate 1, a driver chip 2 (DDIC), and a flexible printed circuit board 3 (FPC). Power and signals are typically transmitted through connector 31, flexible printed circuit board 3, bonding pads from flexible printed circuit board 3 to display substrate 1, bonding pads from display substrate 1 to driver chip 2, driver chip 2, and bonding pads from driver chip 2 to display substrate 1, ultimately reaching the pixel circuit of display substrate 1 to drive the display area AA to emit light. However, current display modules suffer from the problem of difficulty in locating the root cause of black screen or abnormal display. Because power and signals are transmitted serially through the aforementioned multiple connection points, when a black screen or display abnormality occurs, it is impossible to quickly pinpoint the specific module where the fault occurs.

[0020] In view of this, embodiments of this application provide a display module to solve the technical problem that it is difficult to quickly locate the root cause of black screen and abnormal display in existing display modules.

[0021] like Figure 1As shown in the embodiment of this application, a display module includes: a display substrate 1, which includes a display area AA and a bonding area BA located on at least one side of the display area AA. The bonding area BA includes multiple test pads 4. A driver chip 2 is bonded to the bonding area BA and located on the side of the multiple test pads 4 close to the display area AA. One end of a flexible circuit board 3 is bonded to the bonding area BA and located on the side of the multiple test pads 4 away from the display area AA. Multiple metal traces 5 are disposed on the display substrate 1 for transmitting the power supply voltage provided by the flexible circuit board 3 to the driver chip 2 via the multiple test pads 4, and then to the display area AA via the driver chip 2. This application achieves rapid localization of the root cause of abnormal phenomena such as black screen and abnormal display by setting multiple test pads 4 with specific connection relationships on the display substrate 1 between the driver chip 2 and the flexible circuit board 3, sequentially applying test voltages to some of the test pads 4, and observing the lighting status of the display area AA. By applying test voltages to multiple test pads 4, it is possible to effectively distinguish whether the fault occurs in the flexible circuit board 3, the driver chip 2, or the pixel circuit of the display area AA, which significantly improves the efficiency of fault diagnosis and reduces the difficulty and time cost of detection.

[0022] In some embodiments, such as Figure 1As shown, the multiple test pads 4 include: a first test pad 41, a second test pad 42, a third test pad 43, and a fourth test pad 44. One end of the first test pad 41 is electrically connected to the first bonding pad 61 located in the bonding area BA of the flexible circuit board 3, and the other end is electrically connected to the second bonding pad 62 on the driver chip 2. One end of the second test pad 42 is electrically connected to the third bonding pad 63 on the driver chip 2, and the other end is floating. The second bonding pad 62 and the third bonding pad 63 are electrically connected through internal circuit A. One end of the third test pad 43 is electrically connected to the fourth bonding pad 64 located in the bonding area BA of the flexible circuit board 3, and the other end is electrically connected to the fifth bonding pad 65 on the driver chip 2. One end of the fourth test pad 44 is electrically connected to the sixth bonding pad 66 on the driver chip 2, and the other end is floating. The fifth bonding pad 65 and the sixth bonding pad 66 are electrically connected through internal circuit B. This application establishes multiple test pads 4 with specific connections on the display substrate 1 between the driver chip 2 and the flexible circuit board 3. By sequentially applying test voltages to some of the test pads 4 and observing the illumination status of the display area AA, the root cause of abnormal phenomena such as black screen and abnormal display in the display module can be quickly located. By applying test voltages to the second test pad 42 and the fourth test pad 44, it can be determined whether the fault occurs in the pixel circuit of the display area AA; by applying test voltages to the first test pad 41 and the third test pad 43, it can be determined whether the fault occurs in the driver chip 2; by applying test voltages to the connector 31 to test the circuit of the display module, it can be determined whether the fault occurs in the flexible circuit board 3. Therefore, by applying test voltages to multiple test pads 4, it is possible to effectively distinguish whether the fault occurs in the flexible circuit board 3, the driver chip 2, or the pixel circuit of the display area AA, significantly improving the efficiency of fault diagnosis and reducing the difficulty and time cost of detection.

[0023] In some embodiments, such as Figure 2 As shown, the display substrate 1 also includes a substrate 11 and a transition metal layer 12 on the side furthest from the substrate 11. Multiple test pads 4 are disposed on the same layer as the transition metal layer 12. Figure 3 for Figure 2 In the cross-sectional view along the MN direction, the lower surfaces of multiple test pads 4 are connected to the upper surface of the metal traces 5 through multiple tungsten vias 7, and the tungsten vias 7 corresponding to a single test pad 4 are arranged in an array. By fabricating multiple test pads 4 in the same layer as the transition metal layer 12, no additional photomask or deposition process is required, which is compatible with existing processes and avoids the cost increase caused by structural improvements.

[0024] In some embodiments, such as Figure 2 As shown, the display substrate 1 also includes an anode layer 13, which is located on the side of the transition metal layer 12 away from the substrate 11. Multiple test pads 4 are disposed on the same layer as the anode layer 13. Figure 4 for Figure 2 In the cross-sectional view along the MN direction, the lower surfaces of multiple test pads 4 are connected to the upper surface of the metal traces 5 through multiple tungsten vias 7, and the tungsten vias 7 corresponding to a single test pad 4 are arranged in an array. By fabricating multiple test pads 4 in the same layer as the anode layer 13, no additional photomask or deposition process is required, which is compatible with existing processes and avoids the cost increase caused by structural improvements.

[0025] In some embodiments, such as Figures 2 to 4 As shown, the display substrate 1 also includes an encapsulation layer 14. (As indicated...) Figure 3 and Figure 4 As shown, multiple test pads 4 are in contact with the package layer 14, and the package layer 14 completely covers the multiple test pads 4, ensuring that none of the test pads 4 are exposed, thereby avoiding the risk of ESD damage.

[0026] In the display substrate provided in the embodiments of this application, such as Figure 2 As shown, it may also include: a barrier layer 15, a first insulating layer 161, a second insulating layer 162, a first passivation layer 171, a second passivation layer 172, a first planarization layer 181, a second planarization layer 182, a third planarization layer 183, a pixel defining layer 19, a first intermediate layer 1101, a second intermediate layer 1102, a light-shielding layer 111, etc. Other essential components of the display substrate are understood by those skilled in the art and will not be described in detail here.

[0027] In practice, Figure 5 This invention relates to a pixel circuit without a preamplifier between the driving transistor T1 and the light-emitting diode EL in the display substrate 1. In conventional lighting methods for the display substrate 1, a grayscale voltage is typically input to the data line (DATA) to control the on-state of the driving transistor T1, thereby adjusting the brightness of the light-emitting diode EL. Alternatively, the display substrate 1 can also be lit in another way, where all transistors are forcibly turned on; simply applying a power supply voltage between ELVDD and Vcom will allow the light-emitting diode EL to light up normally. Based on this principle, this application, by applying corresponding test voltages sequentially to specific test pads and observing the lighting results of the display area AA, quickly locates the location of faults such as black screen and abnormal display. This detection method covers various fault scenarios from the flexible circuit board 3 and the driving chip 2 to the interior of the display area AA, and features simple operation, accurate positioning, and strong applicability.

[0028] In some embodiments, the display substrate 1 further includes, for example, Figure 6The pixel circuit and the fifth test pad are shown. A preamplifier transistor T2 is located between the driving transistor T1 and the light-emitting diode EL in the pixel circuit. One end of the fifth test pad is electrically connected to the gate G of the preamplifier transistor T2, while the other end is floating. When the display module exhibits abnormal phenomena such as a black screen or abnormal display, the voltage required to turn on the preamplifier transistor T2 needs to be provided to the fifth test pad. The pixel circuit adds a preamplifier transistor T2 between the driving transistor T1 and the light-emitting diode EL. If the preamplifier transistor T2 is in the off state, the light-emitting diode EL will not light up regardless of whether the subsequent circuits are normal, making fault location more complex. This application, by setting a fifth test pad and electrically connecting it to the gate G of the preamplifier transistor T2, can apply an on-state voltage to the preamplifier transistor T2 during testing, forcing it to conduct, thereby enabling the light-emitting diode EL to light up normally. This effectively solves the problem that the preamplifier transistor T2 may block the current path, avoiding misjudging the fault source due to an abnormality in the preamplifier transistor T2. Meanwhile, the fifth test pad has the same structure as the aforementioned multiple test pads 4, and can be fabricated in the same layer as the existing transition metal layer 12 and anode layer 13, thus not increasing the process complexity.

[0029] Based on the same inventive concept, embodiments of this application also provide a method for detecting a display module, such as... Figure 7 As shown, it includes: S701. Test voltage is sequentially applied to some of the test pads of multiple test pads in the display substrate; S702. Determine the location of the fault based on the lighting results of the display area in the display substrate.

[0030] This application achieves rapid localization of the root cause of abnormal phenomena such as black screen and abnormal display in the display module by sequentially applying test voltages to some test pads of multiple test pads in the display substrate and observing the lighting status of the display area AA. By applying test voltages to multiple test pads, it is possible to effectively distinguish whether the fault occurs in the flexible circuit board 3, the driver chip 2, or the pixel circuit of the display area AA, significantly improving fault diagnosis efficiency and reducing detection difficulty and time cost.

[0031] To better understand the technical solution of the detection method in this application, it is described in detail below.

[0032] In some embodiments, such as Figure 1 The testing method for the display module shown is as follows: Test voltages are sequentially applied to a portion of the test pads 4 of multiple test pads in the display substrate 1, specifically including: A first power supply voltage ELVDD is applied to the second test pad 42, and a second power supply voltage Vcom is applied to the fourth test pad 44. Since the second test pad 42 is directly shorted to the third bonding pad 63, and the fourth test pad 44 is directly shorted to the sixth bonding pad 66, no fault will usually occur. Therefore, if the lighting result of the display area AA is abnormal, the fault location is determined to be within the pixel circuit of the display area AA.

[0033] If the illumination result of display area AA is normal, it means that there is no fault in the pixel circuit within display area AA. Then, the first power supply voltage ELVDD is applied to the first test pad 41, and the second power supply voltage Vcom is applied to the third test pad 43. If the illumination result of display area AA is abnormal, the fault location is determined to be within the driver chip 2, i.e., at least one of the following connections is faulty: from the first test pad 41 to the second bonding pad 62, from the second bonding pad 62 to internal circuit A, from internal circuit A to the third bonding pad 63, from the third test pad 43 to the fifth bonding pad 65, from the fifth bonding pad 65 to internal circuit B, and from internal circuit B to the sixth bonding pad 66. Since the first test pad 41 and the second bonding pad 62 are directly shorted, and the third test pad 43 and the fifth bonding pad 65 are also directly shorted, faults are not usually observed. Therefore, the fault location is determined to be within the driver chip 2.

[0034] If the lighting result of display area AA is normal, it means that there are no faults in both the driver chip 2 and display area AA, and power is supplied to the display module through connector 31 on the flexible circuit board 3. If the lighting result of display area AA is abnormal, the fault location is determined to be within the flexible circuit board 3, that is, at least one of the following: connector 31 to flexible circuit board 3, flexible circuit board 3 to bonding pads on display substrate 1, display substrate 1 to bonding pads on flexible circuit board 3, first bonding pad 61 to first test pad 41, and fourth bonding pad 64 to third test pad. Since the first bonding pad 61 and the first test pad 41 are directly shorted, and the fourth bonding pad 64 and the third test pad 43 are directly shorted, no faults usually occur. Therefore, the fault location is determined to be within the flexible circuit board 3.

[0035] In some embodiments, such as Figure 6 As shown, the display module also includes a pixel circuit disposed in the display area AA. The pixel circuit includes a driving transistor T1, a front transistor T2 and a light-emitting diode EL. The front transistor T2 is connected between the driving transistor T1 and the light-emitting diode EL.

[0036] The display module also includes a fifth test pad, which is electrically connected to the gate G of the front transistor T2.

[0037] The method further includes sequentially applying test voltages to a portion of the test pads of a plurality of test pads in the display substrate 1, and includes: An enable voltage is applied to the fifth test pad to turn on the preamplifier transistor T2. When the display module experiences a black screen or abnormal display, the voltage required to turn on the preamplifier transistor T2 needs to be provided to the fifth test pad. The pixel circuit adds a preamplifier transistor T2 between the driver transistor T1 and the light-emitting diode EL. If the preamplifier transistor T2 is in the off state, the light-emitting diode EL will not light up regardless of whether the subsequent circuitry is normal, making fault location more complex. This application addresses this issue by setting a fifth test pad and electrically connecting it to the gate G of the preamplifier transistor T2. During testing, an enable voltage can be applied to the preamplifier transistor T2, forcing it to conduct, thereby enabling the light-emitting diode EL to light up normally. This effectively solves the problem that the preamplifier transistor T2 might block the current path, avoiding misdiagnosis of the fault source due to an abnormality in the preamplifier transistor T2.

[0038] In summary, this application provides a display module and its testing method. The display module includes: a display substrate 1, which includes a display area AA and a bonding area BA located on at least one side of the display area AA. The bonding area BA includes multiple test pads 4. A driver chip 2 is bonded to the bonding area BA and located on the side of the multiple test pads 4 closest to the display area AA. One end of a flexible circuit board 3 is bonded to the bonding area BA and located on the side of the multiple test pads 4 furthest from the display area AA. Multiple metal traces 5 are disposed on the display substrate 1 to transmit the power supply voltage provided by the flexible circuit board 3 to the driver chip 2 via the multiple test pads 4, and then to the display area AA via the driver chip 2. By setting multiple test pads 4 with specific connection relationships on the display substrate 1 between the driver chip 2 and the flexible circuit board 3, this application allows for the sequential application of test voltages to some of the test pads 4, and by observing the lighting status of the display area AA, it enables rapid localization of the root cause of abnormal phenomena such as black screen and abnormal display in the display module. By applying test voltages to multiple test pads 4, it is possible to effectively distinguish whether the fault occurs in the flexible circuit board 3, the driver chip 2, or the pixel circuit of the display area AA, which significantly improves the efficiency of fault diagnosis and reduces the difficulty and time cost of detection.

[0039] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0040] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A display module, characterized by include: The display substrate includes a display area and a bonding area located on at least one side of the display area; The bonding area includes multiple test pads; The driver chip is bonded to the bonding area and located on the side of the plurality of test pads closest to the display area; A flexible circuit board, one end of which is bonded to the bonding area and located on the side of the plurality of test pads away from the display area; Multiple metal traces are disposed on the display substrate to transmit the power supply voltage provided by the flexible circuit board to the driver chip via the multiple test pads, and then to the display area via the driver chip.

2. The display module of claim 1, wherein, The plurality of test pads includes: a first test pad, a second test pad, a third test pad, and a fourth test pad; One end of the first test pad is electrically connected to the first bonding pad located in the bonding area of ​​the flexible circuit board, and the other end is electrically connected to the second bonding pad on the driver chip. One end of the second test pad is electrically connected to the third bonding pad on the driver chip, and the other end is floating; the second bonding pad and the third bonding pad are electrically connected. One end of the third test pad is electrically connected to the fourth bonding pad of the flexible circuit board located in the bonding area, and the other end is electrically connected to the fifth bonding pad on the driver chip. One end of the fourth test pad is electrically connected to the sixth bonding pad on the driver chip, and the other end is floating; the fifth bonding pad and the sixth bonding pad are electrically connected.

3. The display module of claim 2, wherein the display module is configured to be mounted to a display module mounting surface of a display module mounting structure. The display substrate also includes a substrate and a transition metal layer on the side furthest from the substrate; The plurality of test pads are disposed on the same layer as the transition metal layer.

4. The display module of claim 2, wherein the display module is configured to be mounted on a display stand. The display substrate further includes an anode layer; the plurality of test pads are disposed on the same layer as the anode layer.

5. The display module of claim 3 or 4, wherein the display module is configured to be mounted to a display device by means of the first and second mounting means. The display substrate further includes an encapsulation layer; the encapsulation layer completely covers the plurality of test pads.

6. The display module of claim 5, wherein the display module is configured to be mounted to a display module mounting surface of a display module mounting structure. The display substrate further includes a pixel circuit and a fifth test pad; the pixel circuit includes a front transistor, one end of the fifth test pad is electrically connected to the gate of the front transistor, and the other end is floating.

7. A method of detecting a display module as claimed in any one of claims 1 to 6, characterized in that include: Test voltages are sequentially applied to portions of the multiple test pads in the display substrate. The location of the fault is determined based on the lighting results of the display area in the display substrate.

8. The detection method of claim 7, wherein, The step of sequentially applying test voltages to a portion of the multiple test pads in the display substrate specifically includes: A first power supply voltage is applied to the second test pad, and a second power supply voltage is applied to the fourth test pad; If the lighting result of the display area is abnormal, the fault location is determined to be within the pixel circuit of the display area; If the lighting result of the display area is normal, then the first power supply voltage is applied to the first test pad and the second power supply voltage is applied to the third test pad. If the lighting result of the display area is abnormal, the fault location is determined to be inside the driver chip; If the lighting result of the display area is normal, power is supplied to the display module through the connector on the flexible circuit board; If the lighting result of the display area is abnormal, the fault location is determined to be within the flexible circuit board.

9. The detection method of claim 7, wherein, The display module further includes a pixel circuit disposed in the display area. The pixel circuit includes a driving transistor, a front transistor, and a light-emitting diode. The front transistor is connected between the driving transistor and the light-emitting diode. The display module further includes a fifth test pad, which is electrically connected to the gate of the front transistor; The step of sequentially applying test voltages to a portion of the multiple test pads in the display substrate further includes: An enable voltage is applied to the fifth test pad to enable the preamplifier transistor.

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