Patent Publication Number: US-11663958-B2

Title: Display substrate and mother substrate for display substrate

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2021-0126461, filed on Sep. 24, 2021, the entire content of which is incorporated by reference herein. 
     BACKGROUND 
     1. Field 
     Aspects of embodiments of the present disclosure relate to a display substrate, and a mother substrate for a display substrate. 
     2. Discussion of the Background 
     In order to manufacture a display device, a display substrate is formed, and an array test is performed on the display substrate. The array test is a process of confirming whether transistors formed on the display substrate are normally formed. Recently, a circuit structure of a pixel circuit is becoming more complicated in order to realize a high-resolution display device, and thus, an array test of the pixel circuit that may be performed more accurately may be desired. 
     The above information disclosed in this Background section is for enhancement of understanding of the background of the present disclosure, and therefore, it may contain information that does not constitute prior art. 
     SUMMARY 
     One or more embodiments of the present disclosure are directed to a display substrate capable of an array test for transistors. 
     One or more embodiments of the present disclosure are directed to a mother substrate for a display substrate capable of an array test for transistors. 
     According to one or more embodiments of the present disclosure, a display substrate includes: a pixel circuit including: a switching transistor connected between a first terminal of a compensation capacitor and a data line; and a pixel transistor connected between a second terminal of the compensation capacitor and a first voltage line, the pixel transistor being configured to receive a test voltage; and a test transistor including: a test gate terminal configured to receive a test signal; a test source terminal electrically connected to the first voltage line; and a test drain terminal electrically connected to the data line. 
     In an embodiment, when a voltage level of the test voltage changes, a voltage level of a voltage received by the test source terminal may change. 
     In an embodiment, a voltage level of the test voltage may be greater than a voltage level of a first voltage of the first voltage line. 
     In an embodiment, the pixel transistor may include a first transistor including a source terminal connected to a first node, and a drain terminal connected to the first voltage line through a second node. The test voltage may include a second voltage, and the test source terminal may be configured to receive the second voltage through the first node, the second node, and the first voltage line. 
     In an embodiment, the pixel transistor may further include: a sixth transistor connected to the first node; a seventh transistor connected to the sixth transistor; and a ninth transistor connected between the second node and the first voltage line. 
     In an embodiment, the pixel transistor may further include: a third transistor connected to the first node; and a fourth transistor connected to the third transistor. The test voltage may further include a third voltage, and the test source terminal may be configured to receive the third voltage through the fourth transistor, the third transistor, the first node, the second node, and the first voltage line. 
     In an embodiment, the pixel transistor may further include an eighth transistor connected to the second node. The test voltage may further include a fourth voltage, and the test source terminal may be configured to receive the fourth voltage through the eighth transistor, the second node, and the first voltage line. 
     In an embodiment, the display substrate may further include a first voltage bus connected to the first voltage line, and the test source terminal may be directly connected to the first voltage bus. 
     In an embodiment, the first voltage bus may be located between the pixel circuit and the test transistor. 
     In an embodiment, the pixel transistor may include a first transistor including a source terminal connected to a first node, and a drain terminal connected to the first voltage line through a second node. The test voltage may include a second voltage, and the test source terminal may be configured to receive the second voltage through the second node, the first node, and the first voltage line. 
     In an embodiment, the pixel transistor may further include: a third transistor connected to the first node; and a fourth transistor connected to the third transistor. The test voltage may further include a third voltage, and the test source terminal may be configured to receive the third voltage through the fourth transistor, the third transistor, the first node, and the first voltage line. 
     In an embodiment, the pixel transistor may further include an eighth transistor connected to the second node. The test voltage may further include a fourth voltage, and the test source terminal may be configured to receive the fourth voltage through the eighth transistor, the second node, the first node, and the first voltage line. 
     In an embodiment, the pixel transistor may include a first transistor including a source terminal connected to the first voltage line through a first node, and a drain terminal connected to a second node. The test voltage may include a second voltage, and the test source terminal may be configured to receive the second voltage through the second node, the first node, and the first voltage line. 
     In an embodiment, the pixel transistor may further include: a sixth transistor connected to the first node; and a seventh transistor connected to the sixth transistor. The test voltage may further include a third voltage, and the test source terminal may be configured to receive the third voltage through the seventh transistor, the sixth transistor, the first node, and the first voltage line. 
     In an embodiment, the pixel transistor may further include an eighth transistor connected to the second node. The test voltage may further include a fourth voltage, and the test source terminal may be configured to receive the fourth voltage through the eighth transistor, the second node, the first node, and the first voltage line. 
     According to one or more embodiments of the present disclosure, a mother substrate includes: a cutting line; a display substrate located within the cutting line; and a test transistor located outside the cutting line. The display substrate includes a pixel circuit including: a switching transistor connected between a first terminal of a compensation capacitor and a data line; and a pixel transistor connected between a second terminal of the compensation capacitor and a first voltage line, the pixel transistor being configured to receive a test voltage. The test transistor includes: a test gate terminal configured to receive a test signal; a test source terminal electrically connected to the first voltage line; and a test drain terminal electrically connected to the data line. 
     In an embodiment, the test transistor may be electrically connected to the pixel circuit through a bridge pattern. 
     In an embodiment, the bridge pattern may include a conductive metal oxide. 
     According to one or more embodiments of the present disclosure, a display substrate may include a pixel circuit and a test transistor. The pixel circuit may include a compensation capacitor and a pixel transistor. The pixel transistor may be disconnected from a data line by the compensation capacitor. The test transistor may be electrically connected to the pixel transistor and the data line. Accordingly, it may be possible to perform the array test for the pixel transistor that is disconnected from the data line by the compensation capacitor. 
     It is to be understood that both the foregoing general description and the following detailed description are provided as examples, and are intended to provide some examples of the aspects and features of the present disclosure as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects and features of the present disclosure will be more clearly understood from the following detailed description of the illustrative, non-limiting embodiments with reference to the accompanying drawings. 
         FIG.  1    is a block diagram illustrating a display substrate according to an embodiment. 
         FIG.  2    is a plan view illustrating the display substrate of  FIG.  1   . 
         FIG.  3    is an enlarged view of the area A of  FIG.  2   . 
         FIG.  4    is a circuit diagram illustrating the display substrate of  FIG.  1   . 
         FIGS.  5 - 7    are circuit diagrams illustrating the display substrate of  FIG.  4   . 
         FIG.  8    is a cross-sectional view illustrating the display substrate of  FIG.  1   . 
         FIG.  9    is a circuit diagram illustrating a display substrate according to another embodiment. 
         FIG.  10    is a cross-sectional view illustrating the display substrate of  FIG.  9   . 
         FIG.  11    is a block diagram illustrating a display substrate according to another embodiment. 
         FIG.  12    is a circuit diagram illustrating the display substrate of  FIG.  11   . 
         FIGS.  13 - 15    are circuit diagrams illustrating the display substrate of  FIG.  12   . 
         FIG.  16    is a block diagram illustrating a display substrate according to another embodiment. 
         FIG.  17    is a circuit diagram illustrating the display substrate of  FIG.  16   . 
         FIGS.  18 - 20    are circuit diagrams illustrating the display substrate of  FIG.  17   . 
         FIG.  21    is a block diagram illustrating a display substrate according to another embodiment. 
         FIG.  22    is a circuit diagram illustrating the display substrate of  FIG.  21   . 
         FIGS.  23 - 25    are circuit diagrams illustrating the display substrate of  FIG.  22   . 
         FIG.  26    is a plan view illustrating a mother substrate for a display substrate according to an embodiment. 
         FIG.  27    is a plan view illustrating a display substrate included in the mother substrate of  FIG.  26   . 
         FIG.  28    is an enlarged view of the area B of  FIG.  26   . 
         FIG.  29    is a plan view illustrating a mother substrate for a display substrate according to another embodiment. 
         FIG.  30    is a plan view illustrating a display substrate included in the mother substrate of  FIG.  29   . 
         FIG.  31    is an enlarged view of the area C of  FIG.  29   . 
         FIG.  32    is a plan view illustrating a mother substrate for a display substrate according to another embodiment. 
         FIG.  33    is a plan view illustrating a display substrate included in the mother substrate of  FIG.  32   . 
         FIG.  34    is an enlarged view of the area D of  FIG.  32   . 
         FIG.  35    is a plan view illustrating a mother substrate for a display substrate according to another embodiment. 
         FIG.  36    is a plan view illustrating a display substrate included in the mother substrate of  FIG.  35   . 
         FIG.  37    is an enlarged view of the area E of  FIG.  35   . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments will be described in more detail with reference to the accompanying drawings, in which like reference numbers refer to like elements throughout. The present disclosure, however, may be embodied in various different forms, and should not be construed as being limited to only the illustrated embodiments herein. Rather, these embodiments are provided as examples so that this disclosure will be thorough and complete, and will fully convey the aspects and features of the present disclosure to those skilled in the art. Accordingly, processes, elements, and techniques that are not necessary to those having ordinary skill in the art for a complete understanding of the aspects and features of the present disclosure may not be described. Unless otherwise noted, like reference numerals denote like elements throughout the attached drawings and the written description, and thus, redundant description thereof may not be repeated. 
     When a certain embodiment may be implemented differently, a specific process order may be different from the described order. For example, two consecutively described processes may be performed at the same or substantially at the same time, or may be performed in an order opposite to the described order. 
     In the drawings, the relative sizes of elements, layers, and regions may be exaggerated and/or simplified for clarity. Spatially relative terms, such as “beneath,” “below,” “lower,” “under,” “above,” “upper,” and the like, may be used herein for ease of explanation to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or in operation, in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” or “under” other elements or features would then be oriented “above” the other elements or features. Thus, the example terms “below” and “under” can encompass both an orientation of above and below. The device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein should be interpreted accordingly. 
     It will be understood that, although the terms “first,” “second,” “third,” etc., may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section described below could be termed a second element, component, region, layer or section, without departing from the spirit and scope of the present disclosure. 
     It will be understood that when an element or layer is referred to as being “on,” “connected to,” or “coupled to” another element or layer, it can be directly on, connected to, or coupled to the other element or layer, or one or more intervening elements or layers may be present. Similarly, when a layer, an area, or an element is referred to as being “electrically connected” to another layer, area, or element, it may be directly electrically connected to the other layer, area, or element, and/or may be indirectly electrically connected with one or more intervening layers, areas, or elements therebetween. In addition, it will also be understood that when an element or layer is referred to as being “between” two elements or layers, it can be the only element or layer between the two elements or layers, or one or more intervening elements or layers may also be present. 
     The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a” and “an” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” “including,” “has,” “have,” and “having,” when used in this specification, specify the presence of the stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. For example, the expression “A and/or B” denotes A, B, or A and B. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, the expression “at least one of a, b, or c” indicates only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof. 
     As used herein, the term “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent variations in measured or calculated values that would be recognized by those of ordinary skill in the art. Further, the use of “may” when describing embodiments of the present disclosure refers to “one or more embodiments of the present disclosure.” As used herein, the terms “use,” “using,” and “used” may be considered synonymous with the terms “utilize,” “utilizing,” and “utilized,” respectively. 
     Unless otherwise defined, 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 the present disclosure 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/or the present specification, and should not be interpreted in an idealized or overly formal sense, unless expressly so defined herein. 
       FIG.  1    is a block diagram illustrating a display substrate according to an embodiment. 
     Referring to  FIG.  1   , a display substrate  1000  according to an embodiment of the present disclosure may include a display panel  100 , a gate driver  200 , an emission driver  300 , a data driver  400 , a controller  500 , a voltage provider  600 , a test part  700 , and a test signal provider  800 . 
     The display panel  100  may include at least one pixel circuit  110 . The pixel circuit  110  may be electrically connected to the gate driver  200 , the emission driver  300 , the data driver  400 , the voltage provider  600 , and the test part  700 . Accordingly, the pixel circuit  110  may receive a gate signal GS, an emission signal ES, a data voltage VDATA, a first voltage V 1 , and a test voltage DCV. In addition, the pixel circuit  110  may transmit a test source voltage V 1 ′ to the test part  700 . 
     The gate driver  200  may receive a gate control signal GCTRL from the controller  500 . The gate driver  200  may generate the gate signal GS based on the gate control signal GCTRL. The gate signal GS may be provided to the pixel circuit  110  through a gate line. 
     The emission driver  300  may receive an emission control signal ECTRL from the controller  500 . The emission driver  300  may generate the emission signal ES based on the emission control signal ECTRL. The emission signal ES may be provided to the pixel circuit  110  through an emission line. 
     The data driver  400  may receive a data control signal DCTRL and output image data ODAT from the controller  500 . The data driver  400  may generate the data voltage VDATA based on the data control signal DCTRL and the output image data ODAT. The data voltage VDATA may be provided to the pixel circuit  110  through a data line. 
     The controller  500  may receive a control signal CTRL and input image data DAT from an external device (e.g., a graphics processing unit (GPU)). The controller  500  may generate the gate control signal GCTRL, the emission control signal ECTRL, the data control signal DCTRL, and the output image data ODAT based on the control signal CTRL and the input image data IDAT. 
     The voltage provider  600  may provide the first voltage V 1  and the test voltage DCV to the pixel circuit  110 . In an embodiment, the test voltage DCV may include a second voltage V 2 , a third voltage V 3 , and a fourth voltage V 4 . The voltage provider  600  may change voltage levels of the first to fourth voltages V 1 , V 2 , V 3 , and V 4 . In an embodiment, all of the first to fourth voltages V 1 , V 2 , V 3 , and V 4  provided from the voltage provider  600  may be DC voltages. 
     The test part  700  may include at least one test transistor. In an embodiment, the test transistor may be connected between the pixel circuit  110  and the data line. The test transistor may receive the test source voltage V 1 ′ from the pixel circuit  110 . The test part  700  may perform an array test of the pixel circuit  110  based on the test source voltage V 1 ′. 
     The test signal provider  800  may provide a test signal TGS to the test part  700 . The test signal TGS may turn the test transistor on or off. 
       FIG.  2    is a plan view illustrating the display substrate of  FIG.  1   .  FIG.  3    is an enlarged view of the area A of  FIG.  2   . 
     Referring to  FIG.  2   , the gate driver  200  may be located on a left side of the display panel  100 , and the emission driver  300  may be located on a right side of the display panel  100 . The gate line GL may extend in a first direction D 1 , and may transmit the gate signal GS to the pixel circuit  110 . The emission line EML may extend in the first direction D 1 , and may transmit the emission signal ES to the pixel circuit  110 . 
     The data driver  400  may be located on a lower side of the display panel  100 , and a pad part PD may be located on a lower side of the data driver  400 . The data line VDL may extend in a second direction D 2  crossing (e.g., perpendicular to or substantially perpendicular to) the first direction D 1 , and may transmit the data voltage VDATA to the pixel circuit  110 . The pad part PD may be electrically connected to a printed circuit board. A first voltage line VL 1 , a second voltage line VL 2 , a third voltage line VL 3 , and a fourth voltage line VL 4  may be connected to the pad part PD, and may transmit the first voltage V 1 , the second voltage V 2 , the third voltage V 3 , and the fourth voltage V 4 , respectively, to the pixel circuit  110 . 
     The test part  700  may be located on an upper side of the display panel  100 . 
     However, the positions of the components described above are not limited thereto. For example, the test part  700  may be located on the lower side of the display panel  100 . 
     In an embodiment, the display substrate  1000  may further include a first voltage bus BUS 1  and a second voltage bus BUS 2 . The first voltage bus BUS 1  may be disposed between the test part  700  and the display panel  100 . The first voltage bus BUS 1  may be connected to (e.g., may be directly connected to) the first voltage line VL 1 , and may be connected to (e.g., may be directly connected to) the test transistor. The second voltage bus BUS 2  may be disposed between the pad part PD and the display panel  100 . The first voltage bus BUS 1  and the second voltage bus BUS 2  may prevent or substantially prevent a voltage drop of the first voltage V 1 . 
     Referring to  FIG.  3   , the test transistor T-TR may include a test gate terminal  701 , a test source terminal  702 , and a test drain terminal  703 . The test gate terminal  701  may be connected to the test signal provider  800 . The test source terminal  702  may be connected to (e.g., may be directly connected to) the first voltage bus BUS 1  through a contact hole. The test drain terminal  703  may be connected to the data line VDL through a connection pattern CP. The test transistor T-TR may be turned on or off in response to the test signal TGS provided to the test gate terminal  701 . In addition, the test source voltage V 1 ′ may be provided to the test source terminal  702 . Accordingly, the test part  700  including the test transistor T-TR may perform the array test. 
       FIG.  4    is a circuit diagram illustrating the display substrate of  FIG.  1   . 
     Referring to  FIG.  4   , the display substrate  1000  may include the pixel circuit  110  and the test transistor T-TR. The pixel circuit  110  may include a compensation capacitor CST, a holding capacitor CHD, a second transistor T 2 , a fifth transistor T 5 , and a pixel transistor P-TR. 
     In an embodiment, the pixel transistor P-TR may refer to a transistor for receiving the test voltage DCV. For example, the pixel transistor P-TR may include a first transistor T 1 , a third transistor T 3 , a fourth transistor T 4 , a sixth transistor T 6 , a seventh transistor T 7 , an eighth transistor T 8 , and a ninth transistor T 9 . 
     In an embodiment, the first to ninth transistors T 1 , T 2 , T 3 , T 4 , T 5 , T 6 , T 7 , T 8 , and T 9  may be PMOS transistors. In addition, the test transistor T-TR may be a PMOS transistor. However, the present disclosure is not limited thereto. 
     The gate signal GS may include a first gate signal GW, a second gate signal GC, and a third gate signal GI. The emission signal ES may include a first emission signal EM 1 , a second emission signal EM 2 , and a third emission signal EB. 
     In an embodiment, the test voltage DCV may include the second voltage V 2 , the third voltage V 3 , and the fourth voltage V 4 . 
     The holding capacitor CHD may include a first terminal and a second terminal. The first terminal may receive the first voltage V 1 . The second terminal may be connected to the compensation capacitor CST. The holding capacitor CHD may maintain or substantially maintain a voltage level of the data voltage VDATA. 
     The compensation capacitor CST may include a first terminal C 1  and a second terminal C 2 . The first terminal C 1  may be connected to the second transistor T 2 . The second terminal C 2  may be connected to a gate terminal of the first transistor T 1 . The compensation capacitor CST may compensate a threshold voltage of the first transistor T 1 . 
     The second transistor T 2  may include a gate terminal, a first terminal, and a second terminal. The gate terminal may receive the first gate signal GW. The first terminal may receive the data voltage VDATA. The second terminal may be connected to the first terminal C 1  of the compensation capacitor CST. The second transistor T 2  may transfer the data voltage VDATA to the compensation capacitor CST. For example, the second transistor T 2  may be referred to as a switching transistor T 2 . In other words, the switching transistor T 2  may be connected between the first terminal C 1  of the compensation capacitor CST and the data line VDL. 
     The fifth transistor T 5  may include a gate terminal, a first terminal, and a second terminal. The gate terminal may receive the second gate signal GC. The first terminal may be connected to the first terminal C 1  of the compensation capacitor CST. The second terminal may receive a reference voltage VREF. 
     The pixel transistor P-TR may receive the test voltage DCV. In addition, the pixel transistor P-TR may be connected between the second terminal C 2  of the compensation capacitor CST and the first voltage line VL 1 . 
     The first transistor T 1  may include a gate terminal, a source terminal, and a drain terminal. The gate terminal may be connected to the second terminal C 2  of the compensation transistor CST. The source terminal may be connected to a first node N 1 . The drain terminal may receive the first voltage V 1  through a second node N 2 . In other words, the drain terminal may be connected to the first voltage line VL 1  through the second node N 2 . The first transistor T 1  may generate a driving current based on a voltage difference between the second node N 2  and the gate terminal of the first transistor T 1 . 
     The third transistor T 3  may include a gate terminal, a first terminal, and a second terminal. The gate terminal may receive the second gate signal GC. The first terminal may be connected to the second terminal C 2  of the compensation capacitor CST. The second terminal may be connected to the first node N 1 . In other words, the third transistor T 3  may be connected between the gate terminal and the source terminal of the first transistor T 1  to diode-connect the first transistor T 1 . The third transistor T 3  may compensate for a threshold voltage of the first transistor T 1 . 
     The fourth transistor T 4  may include a gate terminal, a first terminal, and a second terminal. The gate terminal may receive the third gate signal GI. The first terminal may be connected to the second terminal C 2  of the compensation capacitor CST. The second terminal may receive the third voltage V 3 . The fourth transistor T 4  may initialize the gate terminal of the first transistor T 1  to the third voltage V 3 . 
     The sixth transistor T 6  may include a gate terminal, a first terminal, and a second terminal. The gate terminal may receive the second emission signal EM 2 . The first terminal may be connected to the first node N 1 . The second terminal may be connected to the seventh transistor T 7 . The sixth transistor T 6  may transmit the driving current to a light emitting diode LED. 
     The seventh transistor T 7  may include a gate terminal, a first terminal, and a second terminal. The gate terminal may receive the third emission signal EB. The first terminal may be connected to the sixth transistor T 6 . The second terminal may receive the second voltage V 2 . The seventh transistor T 7  may initialize the light emitting diode LED to the second voltage V 2 . 
     The eighth transistor T 8  may include a gate terminal, a first terminal, and a second terminal. The gate terminal may receive the third emission signal EB. The first terminal may be connected to the second node N 2 . The second terminal may receive the fourth voltage V 4 . The eighth transistor T 8  may suppress hysteresis of the first transistor T 1 . 
     The ninth transistor T 9  may include a gate terminal, a first terminal, and a second terminal. The gate terminal may receive the first emission signal EM 1 . The first terminal may receive the first voltage V 1 . The second terminal may be connected to the second node N 2 . In other words, the ninth transistor T 9  may be connected between the second node N 2  and the first voltage line VL 1 . The ninth transistor T 9  may transfer the first voltage V 1  to the second node N 2 . 
     The test transistor T-TR may include the test gate terminal  701 , the test source terminal  702 , and the test drain terminal  703 . The test gate terminal  701  may receive the test signal TGS. The test source terminal  702  may be connected to the first voltage line VL 1 . The test drain terminal  703  may be connected to the data line VDL. 
     The array test may be performed on the pixel circuit  110 . The array test may be performed using the data line VDL. The array test may be performed while the second transistor T 2  and the fifth transistor T 5  change the voltage level of the reference voltage VREF. 
     In the pixel circuit  110 , the pixel transistor P-TR may be electrically disconnected (e.g., electrically insulated) from the data line VDL by the compensation capacitor CST. In other words, the test voltage DCV provided to the pixel transistor P-TR is not transferred to the data line VDL due to a capacitance formed in the compensation capacitor CST, as there is no DC current flow path between the data line VDL and the pixel transistor P-TR through the compensation capacitor CST. Accordingly, it may be impossible to perform the array test on the pixel transistor P-TR in the pixel circuit  110 . 
     However, in the case of the display substrate  1000 , the array test of the pixel transistor P-TR may be performed through the test transistor T-TR, which may be formed outside the pixel circuit  110 . In other words, the array test may be performed on the pixel transistor P-TR that is disconnected from the data line VDL by the compensation capacitor CST. This will be described in more detail below. 
       FIGS.  5  through  7    are circuit diagrams illustrating the display substrate of  FIG.  4   . 
     Referring to  FIG.  5   , the array test for the seventh transistor T 7 , the sixth transistor T 6 , the first transistor T 1 , and the ninth transistor T 9  may be performed using the second voltage V 2 . In other words, the second voltage V 2  may be transferred to the test source terminal  702  through the seventh transistor T 7 , the sixth transistor T 6 , the first node N 1 , the first transistor T 1 , the second node N 2 , the ninth transistor T 9 , and the first voltage line VL 1 . 
     In an embodiment, the voltage level of the second voltage V 2  may be greater than the voltage level of the first voltage V 1 . Accordingly, the test source voltage V 1 ′ may be transferred to the test source terminal  702 . For example, the test source voltage V 1 ′ may correspond to a voltage difference between the second voltage V 2  and the first voltage V 1 . In other words, when the voltage level of the second voltage V 2  is changed, the voltage level of the test source voltage V 1 ′ provided to the test source terminal  702  may be changed. 
     Referring to  FIG.  6   , the array test for the fourth transistor T 4 , the third transistor T 3 , the first transistor T 1 , and the ninth transistor T 9  may be performed using the third voltage V 3 . In other words, the third voltage V 3  may be transferred to the test source terminal  702  through the fourth transistor T 4 , the third transistor T 3 , the first node N 1 , the first transistor T 1 , the second node N 2 , the ninth transistor T 9 , and the first voltage line VL 1 . 
     In an embodiment, the voltage level of the third voltage V 3  may be greater than the voltage level of the first voltage V 1 . Accordingly, the test source voltage V 1 ′ may be transferred to the test source terminal  702 . For example, the test source voltage V 1 ′ may correspond to a voltage difference between the third voltage V 3  and the first voltage V 1 . 
     Referring to  FIG.  7   , the array test for the eighth transistor T 8  and the ninth transistor T 9  may be performed using the fourth voltage V 4 . In other words, the fourth voltage V 4  may be transferred to the test source terminal  702  through the eighth transistor T 8 , the second node N 2 , the ninth transistor T 9 , and the first voltage line VL 1 . 
     In an embodiment, the voltage level of the fourth voltage V 4  may be greater than the voltage level of the first voltage V 1 . Accordingly, the test source voltage V 1 ′ may be transferred to the test source terminal  702 . For example, the test source voltage V 1 ′ may correspond to a voltage difference between the fourth voltage V 4  and the first voltage V 1 . 
       FIG.  8    is a cross-sectional view illustrating the display substrate of  FIG.  1   . 
     Referring to  FIG.  8   , the display substrate  1000  may include a substrate SUB, an active pattern ACT, a first insulating layer IL 1 , a first gate electrode GAT 1 , a second insulating layer IL 2 , a second gate electrode GAT 2 , a third insulating layer IL 3 , a source electrode SE, a first drain electrode DE 1 , a fourth insulating layer IL 4 , a second drain electrode DE 2 , and a fifth insulating layer IL 5 . 
     The substrate SUB may include a transparent or opaque material. For example, the substrate SUB may include glass, quartz, plastic, or the like. 
     The active pattern ACT may include a semiconductor material. For example, the active pattern ACT may include an oxide semiconductor material, a silicon semiconductor material, or the like. The silicon semiconductor material may include amorphous silicon, polycrystalline silicon, or the like. 
     The first insulating layer IL 1  may cover the active pattern ACT, and may be disposed on the substrate SUB. The first insulating layer IL 1  may include an organic insulating material, an inorganic insulating material, or the like. For example, the first insulating layer IL 1  may include silicon oxide, silicon nitride, silicon oxynitride, or the like. 
     The first gate electrode GAT 1  may be disposed on the first insulating layer IL 1 , and may overlap with the first active pattern ACT. The first gate electrode GAT 1  may be formed of a metal, an alloy, a conductive metal oxide, a transparent conductive material, or the like. Examples of the material that may be used as the first gate electrode GAT 1  may include silver (“Ag”), an alloy containing silver, molybdenum (“Mo”), an alloy containing molybdenum, aluminum (“Al”), an alloy containing aluminum, aluminum nitride (“AlN”), tungsten (“W”), tungsten nitride (“WN”), copper (“Cu”), nickel (“Ni”), chromium (“Cr”), chromium nitride (“CrN”), titanium (“Ti”), tantalum (“Ta”), platinum (“Pt”), scandium (“Sc”), indium tin oxide (“ITO”), indium zinc oxide (“IZO”), or the like. These materials may be used alone or in any suitable combinations with each other. 
     The second insulating layer IL 2  may cover the first gate electrode GAT 1 , and may be disposed on the first insulating layer IL 1 . The second insulating layer IL 2  may include an organic insulating material, an inorganic insulating material, or the like. 
     The second gate electrode GAT 2  may be disposed on the second insulating layer IL 2 , and may overlap with the first gate electrode GAT 1 . The second gate electrode GAT 2  may be formed of a metal, an alloy, a conductive metal oxide, a transparent conductive material, or the like. 
     The third insulating layer IL 3  may cover the second gate electrode GAT 2 , and may be disposed on the second insulating layer IL 2 . The third insulating layer IL 3  may include an organic insulating material, an inorganic insulating material, or the like. 
     The source electrode SE and the first drain electrode DE 1  may be disposed on the third insulating layer IL 3 , and may contact the active pattern ACT. The source electrode SE and the first drain electrode DE 1  may be formed of a metal, an alloy, a conductive metal oxide, a transparent conductive material, or the like. 
     The fourth insulating layer IL 4  may cover the source electrode SE and the first drain electrode DE 1 , and may be disposed on the third insulating layer IL 3 . The fourth insulating layer IL 4  may include an organic insulating material, an inorganic insulating material, or the like. For example, the fourth insulating layer IL 4  may include a photoresist, polyacrylic resin, polyimide resin, acrylic resin, or the like. 
     The second drain electrode DE 2  may be disposed on the fourth insulating layer IL 4 , and may contact the first drain electrode DE 1 . The second drain electrode DE 2  may be formed of a metal, an alloy, a conductive metal oxide, a transparent conductive material, or the like. 
     The fifth insulating layer IL 5  may cover the second drain electrode DE 2 , and may be disposed on the fourth insulating layer IL 4 . The fifth insulating layer IL 5  may include an organic insulating material, an inorganic insulating material, or the like. 
     The test source terminal  702  and the test drain terminal  703  of the test transistor T-TR may be formed together with (e.g., concurrently or simultaneously with) the active pattern ACT. 
     The test gate terminal  701  may be formed together with (e.g., concurrently or simultaneously with) the first gate electrode GAT 1 . 
     The first voltage bus BUS 1  and the connection pattern CP may be formed together with (e.g., concurrently or simultaneously with) the source electrode SE and the first drain electrode DE 1 . The first voltage bus BUS 1  may contact the test source terminal  702 , and the connection pattern CP may contact the test drain terminal  703 . 
     The data line VDL may be integrally formed with the second drain electrode DE 2 , and may contact the connection pattern CP. 
       FIG.  9    is a circuit diagram illustrating a display substrate according to another embodiment. 
     Referring to  FIG.  9   , a display substrate  1000 ′ according to another embodiment may be the same or substantially the same as (or similar to) the display substrate  1000  described above, except that a third transistor T 3 , a fourth transistor T 4 , and a test transistor T-TR′ thereof may be different. Accordingly, the differences therebetween may be mainly described hereinafter, and redundant description thereof may be simplified or may not be repeated. 
     In an embodiment, the third transistor T 3 , the fourth transistor T 4 , and the test transistor T-TR′ may be NMOS transistors. In addition, the first, second, fifth, sixth, seventh, eighth, and ninth transistors T 1 , T 2 , T 5 , T 6 , T 7 , T 8 , and T 9  may be PMOS transistors. 
       FIG.  10    is a cross-sectional view illustrating the display substrate of  FIG.  9   . 
     Referring to  FIG.  10   , the display substrate  1000 ′ may include the substrate SUB, a first active pattern ACT 1 , the first insulating layer IL 1 , the first gate electrode GAT 1 , the second insulating layer IL 2 , the second gate electrode GAT 2 , the third insulating layer IL 3 , a second active pattern ACT 2 , a fourth insulating layer IL 4 , a third gate electrode GAT 3 , a fifth insulating layer IL 5 , a first source electrode SE 1 , a first drain electrode DE 1 , a second source electrode SE 2 , a third drain electrode DE 3 , a sixth insulating layer IL 6 , the second drain electrode DE 2 , and a seventh insulating layer IL 7 . 
     The first active pattern ACT 1  may include amorphous silicon, polycrystalline silicon, or the like. 
     The second active pattern ACT 2  may be disposed on the third insulating layer IL 3 , and may include a semiconductor material. For example, the second active pattern ACT 2  may include an oxide semiconductor material. Examples of the oxide semiconductor material may include IGZO (InGaZnO), ITZO (InSnZnO), and the like. 
     The third gate electrode GAT 3  may be disposed on the fourth insulating layer IL 4 , and may overlap with the second active pattern ACT 2 . The third gate electrode GAT 3  may be formed of a metal, an alloy, a conductive metal oxide, a transparent conductive material, or the like. 
     The second source electrode SE 2  and the third drain electrode DE 3  may be disposed on the fifth insulating layer IL 5 , and may contact the second active pattern ACT 2 . The second source electrode SE 2  and the third drain electrode DE 3  may be formed of a metal, an alloy, a conductive metal oxide, a transparent conductive material, or the like. 
     The test source terminal  702 ′ and the test drain terminal  703 ′ of the test transistor T-TR′ may be formed together with (e.g., concurrently or simultaneously with) the second active pattern ACT 2 . 
     The test gate terminal  701 ′ may be formed together with (e.g., concurrently or simultaneously with) the third gate electrode GAT 3 . 
     The first voltage bus BUS 1  and the connection pattern CP may be formed together with (e.g., concurrently or simultaneously with) the second source electrode SE 2  and the third drain electrode DE 3 . The data line VDL may be integrally formed with the second drain electrode DE 2 , and may contact the connection pattern CP. 
     As the test transistor T-TR′ is formed of an oxide semiconductor, a current leakage phenomenon of the test transistor T-TR′ may be prevented or reduced. 
       FIG.  11    is a block diagram illustrating a display substrate according to another embodiment. 
     Referring to  FIG.  11   , a display substrate  2000  according to another embodiment may include a display panel  100 , a gate driver  200 , an emission driver  300 , a data driver  400 , a controller  500 , a voltage provider  600 , a test part  710 , and a test signal provider  800 . The display panel  100  may include at least one pixel circuit  110 . 
     The display substrate  2000  may be the same or substantially the same as (or similar to) the display substrate  1000  described above, except that a connection structure between the pixel circuit  110  and the test part  710  may be different. Accordingly, the differences therebetween may be mainly described hereinafter, and redundant description thereof may be simplified or may not be repeated. 
       FIG.  12    is a circuit diagram illustrating the display substrate of  FIG.  11   . 
     Referring to  FIG.  12   , the display substrate  2000  may include the pixel circuit  110  and a test transistor T-TR. The pixel circuit  110  may include the compensation capacitor CST, the holding capacitor CHD, the second transistor T 2 , the fifth transistor T 5 , and the pixel transistor P-TR. However, the circuit structure of the pixel circuit  110  may be the same or substantially the same as the circuit structure of the pixel circuit  110  described above with reference to  FIG.  4   . 
     In an embodiment, the test voltage DCV may include the first voltage V 1 , the third voltage V 3 , and the fourth voltage V 4 . 
     The test transistor T-TR may include a test gate terminal  711 , a test source terminal  712 , and a test drain terminal  713 . The test gate terminal  711  may receive the test signal TGS. The test source terminal  712  may be connected to the second voltage line VL 2  to receive the second voltage V 2 . The test drain terminal  713  may be connected to the data line VDL. 
     In the case of the display substrate  2000 , the array test of the pixel transistor P-TR may be performed through the test transistor T-TR, which may be formed outside the pixel circuit  110 . In other words, the array test may be performed on the pixel transistor P-TR that is disconnected from the data line VDL by the compensation capacitor CST. This will be described in more detail below. 
       FIGS.  13  through  15    are circuit diagrams illustrating the display substrate of  FIG.  12   . 
     Referring to  FIG.  13   , the array test for the ninth transistor T 9 , the first transistor T 1 , the sixth transistor T 6 , and the seventh transistor T 7  may be performed using the first voltage V 1 . In other words, the first voltage V 1  may be transferred to the test source terminal  712  through the ninth transistor T 9 , the second node N 2 , the first transistor T 1 , the first node N 1 , the sixth transistor T 6 , the seventh transistor T 7 , and the second voltage line VL 2 . 
     In an embodiment, the voltage level of the first voltage V 1  may be greater than the voltage level of the second voltage V 2 . Accordingly, the test source voltage V 2 ′ may be transferred to the test source terminal  712 . For example, the test source voltage V 2 ′ may correspond to a voltage difference between the first voltage V 1  and the second voltage V 2 . 
     Referring to  FIG.  14   , the array test for the fourth transistor T 4 , the third transistor T 3 , the sixth transistor T 6 , and the seventh transistor T 7  may be performed using the third voltage V 3 . In other words, the third voltage V 3  may be transferred to the test source terminal  712  through the fourth transistor T 4 , the third transistor T 3 , the first node N 1 , the sixth transistor T 6 , the seventh transistor T 7 , and the second voltage line VL 2 . 
     In an embodiment, the voltage level of the third voltage V 3  may be greater than the voltage level of the second voltage V 2 . Accordingly, the test source voltage V 2 ′ may be transferred to the test source terminal  712 . For example, the test source voltage V 2 ′ may correspond to a voltage difference between the third voltage V 3  and the second voltage V 2 . 
     Referring to  FIG.  15   , the array test for the eighth transistor T 8 , the first transistor T 1 , the sixth transistor T 6 , and the seventh transistor T 7  may be performed using the fourth voltage V 4 . In other words, the fourth voltage V 4  may be transferred to the test source terminal  712  through the eighth transistor T 8 , the second node N 2 , the first transistor T 1 , the first node N 1 , the sixth transistor T 6 , the seventh transistor T 7 , and the second voltage line VL 2 . 
     In an embodiment, the voltage level of the fourth voltage V 4  may be greater than the voltage level of the second voltage V 2 . Accordingly, the test source voltage V 2 ′ may be transferred to the test source terminal  712 . For example, the test source voltage V 2 ′ may correspond to a voltage difference between the fourth voltage V 4  and the second voltage V 2 . 
       FIG.  16    is a block diagram illustrating a display substrate according to another embodiment. 
     Referring to  FIG.  16   , a display substrate  3000  according to another embodiment may include a display panel  100 , a gate driver  200 , an emission driver  300 , a data driver  400 , a controller  500 , a voltage provider  600 , a test part  720 , and a test signal provider  800 . The display panel  100  may include at least one pixel circuit  110 . 
     The display substrate  3000  may be the same or substantially the same as (or similar to) the display substrate  1000  described above, except that a connection structure between the pixel circuit  110  and the test part  720  may be different. Accordingly, the differences therebetween may be mainly described hereinafter, and redundant description thereof may be simplified or may not be repeated. 
       FIG.  17    is a circuit diagram illustrating the display substrate of  FIG.  16   . 
     Referring to  FIG.  17   , the display substrate  3000  may include the pixel circuit  110  and a test transistor T-TR. The pixel circuit  110  may include the compensation capacitor CST, the holding capacitor CHD, the second transistor T 2 , the fifth transistor T 5 , and the pixel transistor P-TR. However, the circuit structure of the pixel circuit  110  may be the same or substantially the same as the circuit structure of the pixel circuit  110  described above with reference to  FIG.  4   . 
     In an embodiment, the test voltage DCV may include the first voltage V 1 , the second voltage V 2 , and the fourth voltage V 4 . 
     The test transistor T-TR may include a test gate terminal  721 , a test source terminal  722 , and a test drain terminal  723 . The test gate terminal  721  may receive the test signal TGS. The test source terminal  722  may be connected to the third voltage line VL 3  to receive the third voltage V 3 . The test drain terminal  723  may be connected to the data line VDL. 
     In the case of the display substrate  3000 , the array test of the pixel transistor P-TR may be performed through the test transistor T-TR, which may be formed outside the pixel circuit  110 . In other words, the array test may be performed on the pixel transistor P-TR that is disconnected from the data line VDL by the compensation capacitor CST. This will be described in more detail below. 
       FIGS.  18  through  20    are circuit diagrams illustrating the display substrate of  FIG.  17   . 
     Referring to  FIG.  18   , the array test for the ninth transistor T 9 , the first transistor T 1 , the third transistor T 3 , and the fourth transistor T 4  may be performed using the first voltage V 1 . In other words, the first voltage V 1  may be transferred to the test source terminal  722  through the ninth transistor T 9 , the second node N 2 , the first transistor T 1 , the first node N 1 , the third transistor T 3 , the fourth transistor T 4 , and the third voltage line VL 3 . 
     In an embodiment, the voltage level of the first voltage V 1  may be greater than the voltage level of the third voltage V 3 . Accordingly, the test source voltage V 3 ′ may be transferred to the test source terminal  722 . For example, the test source voltage V 3 ′ may correspond to a voltage difference between the first voltage V 1  and the third voltage V 3 . 
     Referring to  FIG.  19   , the array test for the seventh transistor T 7 , the sixth transistor T 6 , the third transistor T 3 , and the fourth transistor T 4  may be performed using the second voltage V 2 . In other words, the second voltage V 2  may be transferred to the test source terminal  722  through the seventh transistor T 7 , the sixth transistor T 6 , the first node N 1 , the third transistor T 3 , the fourth transistor T 4 , and the third voltage line VL 3 . 
     In an embodiment, the voltage level of the second voltage V 2  may be greater than the voltage level of the third voltage V 3 . Accordingly, the test source voltage V 3 ′ may be transferred to the test source terminal  722 . For example, the test source voltage V 3 ′ may correspond to a voltage difference between the second voltage V 2  and the third voltage V 3 . 
     Referring to  FIG.  20   , the array test for the eighth transistor T 8 , the first transistor T 1 , the third transistor T 3 , and the fourth transistor T 4  may be performed using the fourth voltage V 4 . In other words, the fourth voltage V 4  may be transferred to the test source terminal  722  through the eighth transistor T 8 , the second node N 2 , the first transistor T 1 , the first node N 1 , the third transistor T 3 , the fourth transistor T 4 , and the third voltage line VL 3 . 
     In an embodiment, the voltage level of the fourth voltage V 4  may be greater than the voltage level of the third voltage V 3 . Accordingly, the test source voltage V 3 ′ may be transferred to the test source terminal  722 . For example, the test source voltage V 3 ′ may correspond to a voltage difference between the fourth voltage V 4  and the third voltage V 3 . 
       FIG.  21    is a block diagram illustrating a display substrate according to another embodiment. 
     Referring to  FIG.  21   , a display substrate  4000  according to another embodiment may include a display panel  100 , a gate driver  200 , an emission driver  300 , a data driver  400 , a controller  500 , a voltage provider  600 , a test part  730 , and a test signal provider  800 . The display panel  100  may include at least one pixel circuit  110 . 
     The display substrate  4000  may be the same or substantially the same as (or similar to) the display substrate  1000  described above, except that a connection structure between the pixel circuit  110  and the test part  730  may be different. Accordingly, the differences therebetween may be mainly described hereinafter, and redundant description thereof may be simplified or may not be repeated. 
       FIG.  22    is a circuit diagram illustrating the display substrate of  FIG.  21   . 
     Referring to  FIG.  22   , the display substrate  4000  may include the pixel circuit  110  and a test transistor T-TR. The pixel circuit  110  may include the compensation capacitor CST, the holding capacitor CHD, the second transistor T 2 , the fifth transistor T 5 , and the pixel transistor P-TR. However, the circuit structure of the pixel circuit  110  may be the same or substantially the same as the circuit structure of the pixel circuit  110  described above with reference to  FIG.  4   . 
     In an embodiment, the test voltage DCV may include the first voltage V 1 , the second voltage V 2 , and the third voltage V 3 . 
     The test transistor T-TR may include a test gate terminal  731 , a test source terminal  732 , and a test drain terminal  733 . The test gate terminal  731  may receive the test signal TGS. The test source terminal  732  may be connected to the fourth voltage line VL 4  to receive the fourth voltage V 4 . The test drain terminal  733  may be connected to the data line VDL. 
     In the case of the display substrate  4000 , the array test of the pixel transistor P-TR may be performed through the test transistor T-TR, which may be formed outside the pixel circuit  110 . In other words, the array test may be performed on the pixel transistor P-TR that is disconnected from the data line VDL by the compensation capacitor CST. This will be described in more detail below. 
       FIGS.  23  through  25    are circuit diagrams illustrating the display substrate of  FIG.  22   . 
     Referring to  FIG.  23   , the array test for the ninth transistor T 9  and the eighth transistor T 8  may be performed using the first voltage V 1 . In other words, the first voltage V 1  may be transferred to the test source terminal  732  through the ninth transistor T 9 , the second node N 2 , the eighth transistor T 8 , and the fourth voltage line VL 4 . 
     In an embodiment, the voltage level of the first voltage V 1  may be greater than the voltage level of the fourth voltage V 4 . Accordingly, the test source voltage V 4 ′ may be transferred to the test source terminal  732 . For example, the test source voltage V 4 ′ may correspond to a voltage difference between the first voltage V 1  and the fourth voltage V 4 . 
     Referring to  FIG.  24   , the array test for the seventh transistor T 7 , the sixth transistor T 6 , the first transistor T 1 , and the eighth transistor T 8  may be performed using the second voltage V 2 . In other words, the second voltage V 2  may be transferred to the test source terminal  732  through the seventh transistor T 7 , the sixth transistor T 6 , the first node N 1 , the first transistor T 1 , the second node N 2 , the eighth transistor T 8 , and the fourth voltage line VL 4 . 
     In an embodiment, the voltage level of the second voltage V 2  may be greater than the voltage level of the fourth voltage V 4 . Accordingly, the test source voltage V 4 ′ may be transferred to the test source terminal  732 . For example, the test source voltage V 4 ′ may correspond to a voltage difference between the second voltage V 2  and the fourth voltage V 4 . 
     Referring to  FIG.  25   , the array test for the fourth transistor T 4 , the third transistor T 3 , the first transistor T 1 , and the eighth transistor T 8  may be performed using the third voltage V 3 . In other words, the third voltage V 3  may be transferred to the test source terminal  732  through the fourth transistor T 4 , the third transistor T 3 , the first node N 1 , the first transistor T 1 , the second node N 2 , the eighth transistor T 8 , and the fourth voltage line VL 4 . 
     In an embodiment, the voltage level of the third voltage V 3  may be greater than the voltage level of the fourth voltage V 4 . Accordingly, the test source voltage V 4 ′ may be transferred to the test source terminal  732 . For example, the test source voltage V 4 ′ may correspond to a voltage difference between the third voltage V 3  and the fourth voltage V 4 . 
       FIG.  26    is a plan view illustrating a mother substrate for a display substrate according to an embodiment. 
     Referring to  FIG.  26   , a mother substrate  1000 M for a display substrate according to an embodiment may include a display substrate  1100 , a test part  700 M, and a test signal provider  800 M. 
     The mother substrate  1000 M for a display substrate may include a plurality of display substrates. After the array test is performed on the display substrates, the display substrates may be manufactured by cutting the display substrates. 
     In order to perform an array test on the display substrates, a test part and a test signal provider may be provided for each of the display substrates. 
     In an embodiment, the display substrate  1100  may be formed within (e.g., inside) a cutting line CL. The test part  700 M and the test signal provider  800 M may be formed outside the cutting line CL. The test part  700 M may be electrically connected to the display substrate  1100  through a bridge pattern BR. 
       FIG.  27    is a plan view illustrating a display substrate included in the mother substrate of  FIG.  26   . 
     Referring to  FIG.  27   , the display substrate  1100  may include a display panel  100 , a gate driver  200 , an emission driver  300 , and a data driver  400 . However, the display substrate  1100  may be the same or substantially the same as the display substrate  1000  described above with reference to  FIG.  2   , except that the test part and the test signal provider are not included. In other words, as the test part  700 M and the test signal provider  800 M are formed outside the cutting line CL, the test part  700 M and the test signal provider  800 M may not be formed within (e.g., inside) the display substrate  1100 . 
       FIG.  28    is an enlarged view of the area B of  FIG.  26   . 
     Referring to  FIG.  28   , a test transistor T-TR included in the test part  700 M may include a test gate terminal  701 M, a test source terminal  702 M, and a test drain terminal  703 M. The test gate terminal  701 M may be connected to the test signal provider  800 M. The test source terminal  702 M may be connected to the first voltage bus BUS 1  through a first bridge pattern BR 1 . The test drain terminal  703 M may be connected to the data line VDL through a connection pattern CP and a second bridge pattern BR 2 . The test transistor T-TR may be turned on or off in response to a test signal provided to the test gate terminal  701 M. Accordingly, the test part  700 M including the test transistor T-TR may perform the array test. 
     In an embodiment, the first bridge pattern BR 1  and the second bridge pattern BR 2  may be formed of a metal, an alloy, a conductive metal oxide, a transparent conductive material, or the like. Examples of the materials that may be used as the first and second bridge patterns BR 1  and BR 2  may include silver (“Ag”), an alloy containing silver, molybdenum (“Mo”), an alloy containing molybdenum. aluminum (“Al”), an alloy containing aluminum, aluminum nitride (“AlN”), tungsten (“W”), tungsten nitride (“WN”), copper (“Cu”), nickel (“Ni”), chromium (“Cr”), chromium nitride (“CrN”), titanium (“Ti”), tantalum (“Ta”), platinum (“Pt”), scandium (“Sc”), indium tin oxide (“ITO”), indium zinc oxide (“IZO”), and/or the like. These materials may be used alone or in combination with each other. 
     In an embodiment, when the first and second bridge patterns BR 1  and BR 2  are formed of a conductive metal oxide (e.g., indium tin oxide (“ITO”), indium zinc oxide (“IZO”), and/or the like), the first and second bridge patterns BR 1  and BR 2  may be resistant to corrosion. Accordingly, even when the first and second bridge patterns BR 1  and BR 2  are cut along (e.g., on) the cutting line CL, the first and second bridge patterns BR 1  and BR 2  may not be corroded. 
     In an embodiment, the first and second bridge patterns BR 1  and BR 2  may include an oxide semiconductor material. Examples of the oxide semiconductor material may include IGZO (InGaZnO), ITZO (InSnZnO), and/or the like. 
     In addition, in order to prevent or substantially prevent a short circuit between the first bridge pattern BR 1  and the second bridge pattern BR 2  during the cutting process, the first bridge pattern BR 1  and the second bridge pattern BR 2  may be covered by an insulating layer. 
       FIG.  29    is a plan view illustrating a mother substrate for a display substrate according to another embodiment. 
     Referring to  FIG.  29   , a mother substrate  2000 M for a display substrate according to another embodiment may include a display substrate  2100 , a test part  710 M, and an test signal provider  800 M. 
     In an embodiment, the display substrate  2100  may be formed within (e.g., inside) the cutting line CL. The test part  710 M and the test signal provider  800 M may be formed outside the cutting line CL. The test part  710 M may be electrically connected to the display substrate  2100  through a bridge pattern BR. 
       FIG.  30    is a plan view illustrating a display substrate included in the mother substrate of  FIG.  29   . 
     Referring to  FIG.  30   , the display substrate  2100  may include a display panel  100 , a gate driver  200 , an emission driver  300 , and a data driver  400 . However, the display substrate  2100  may be the same or substantially the same as the display substrate  1100  described above with reference to  FIG.  27   , except for a first voltage line VL 1  and a second voltage line VL 2  may be different. In an embodiment, the first voltage line VL 1  may not extend to the cutting line CL, and the second voltage line VL 2  may extend to the cutting line CL. 
       FIG.  31    is an enlarged view of the area C of  FIG.  29   . 
     Referring to  FIG.  31   , the test transistor T-TR included in the test part  710 M may include a test gate terminal  711 M, a test source terminal  712 M, and a test drain terminal  713 M. The test gate terminal  711 M may be connected to the test signal provider  800 M. The test source terminal  712 M may be connected to the second voltage line VL 2  through a first bridge pattern BR 1 . The test drain terminal  713 M may be connected to the data line VDL through a connection pattern CP and a second bridge pattern BR 2 . The test transistor T-TR may be turned on or off in response to a test signal provided to the test gate terminal  711 M. Accordingly, the test part  710 M including the test transistor T-TR may perform the array test. 
       FIG.  32    is a plan view illustrating a mother substrate for a display substrate according to another embodiment. 
     Referring to  FIG.  32   , a mother substrate  3000 M for a display substrate according to another embodiment may include a display substrate  3100 , a test part  720 M, and a test signal provider  800 M. 
     In an embodiment, the display substrate  3100  may be formed within (e.g., inside) the cutting line CL. The test part  720 M and the test signal provider  800 M may be formed outside the cutting line CL. The test part  720 M may be electrically connected to the display substrate  3100  through a bridge pattern BR. 
       FIG.  33    is a plan view illustrating a display substrate included in the mother substrate of  FIG.  32   . 
     Referring to  FIG.  33   , the display substrate  3100  may include a display panel  100 , a gate driver  200 , an emission driver  300 , and a data driver  400 . However, the display substrate  3100  may be the same or substantially the same as the display substrate  1100  described above with reference to  FIG.  27   , except for a first voltage line VL 1  and a third voltage line VL 3  may be different. In an embodiment, the first voltage line VL 1  may not extend to the cutting line CL, and the third voltage line VL 3  may extend to the cutting line CL. 
       FIG.  34    is an enlarged view of the area D of  FIG.  32   . 
     Referring to  FIG.  34   , a test transistor T-TR included in the test part  720 M may include a test gate terminal  721 M, a test source terminal  722 M, and a test drain terminal  723 M. The test gate terminal  721 M may be connected to the test signal provider  800 M. The test source terminal  722 M may be connected to the third voltage line VL 3  through a first bridge pattern BR 1 . The test drain terminal  723 M may be connected to the data line VDL through a connection pattern CP and a second bridge pattern BR 2 . The test transistor T-TR may be turned on or off in response to a test signal provided to the test gate terminal  721 M. Accordingly, the test part  720 M including the test transistor T-TR may perform the array test. 
       FIG.  35    is a plan view illustrating a mother substrate for a display substrate according to another embodiment. 
     Referring to  FIG.  35   , a mother substrate  4000 M for a display substrate according to another embodiment may include a display substrate  4100 , a test part  730 M, and a test signal provider  800 M. 
     In an embodiment, the display substrate  4100  may be formed within (e.g., inside) the cutting line CL. The test part  730 M and the test signal provider  800 M may be formed outside the cutting line CL. The test part  730 M may be electrically connected to the display substrate  4100  through a bridge pattern BR. 
       FIG.  36    is a plan view illustrating a display substrate included in the mother substrate of  FIG.  35   . 
     Referring to  FIG.  36   , the display substrate  4100  may include a display panel  100 , a gate driver  200 , an emission driver  300 , and a data driver  400 . However, the display substrate  4100  may be the same or substantially the same as the display substrate  1100  described above with reference to  FIG.  27   , except for a first voltage line VL 1  and a fourth voltage line VL 4  may be different. In an embodiment, the first voltage line VL 1  may not extend to the cutting line CL, and the fourth voltage line VL 4  may extend to the cutting line CL. 
       FIG.  37    is an enlarged view of the area E of  FIG.  35   . 
     Referring to  FIG.  37   , a test transistor T-TR included in the test part  730 M may include a test gate terminal  731 M, a test source terminal  732 M, and a test drain terminal  733 M. The test gate terminal  731 M may be connected to the test signal provider  800 M. The test source terminal  732 M may be connected to the fourth voltage line VL 4  through a first bridge pattern BR 1 . The test drain terminal  733 M may be connected to the data line VDL through a connection pattern CP and a second bridge pattern BR 2 . The test transistor T-TR may be turned on or off in response to a test signal provided to the test gate terminal  731 M. Accordingly, the test part  730 M including the test transistor T-TR may perform the array test. 
     Although some embodiments have been described, those skilled in the art will readily appreciate that various modifications are possible in the embodiments without departing from the spirit and scope of the present disclosure. It will be understood that descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments, unless otherwise described. Thus, as would be apparent to one of ordinary skill in the art, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Therefore, it is to be understood that the foregoing is illustrative of various example embodiments and is not to be construed as limited to the specific embodiments disclosed herein, and that various modifications to the disclosed embodiments, as well as other example embodiments, are intended to be included within the spirit and scope of the present disclosure as defined in the appended claims, and their equivalents.