Undercut structure measurement method and undercut structure measurement system

Abstract

Embodiments of the present application provide a kind of undercut structure measurement method and undercut structure measurement system, it is related to display field, to accurately measure the width of undercut area in undercut structure in line. Undercut structure measurement method includes: applying vibration to the carrying substrate of carrying substrate with to be measured substrate, wherein, to be measured substrate includes undercut structure, undercut structure has undercut slot, undercut structure includes solid area and undercut area, undercut slot is located in undercut area;Control light source emits detection light towards to be measured substrate, and the relative position relationship between control light source and carrying substrate is changed, to make detection light scan to be measured substrate along first path, wherein, first path at least passes through the first edge of undercut structure and first boundary, first boundary is the boundary of undercut area and solid area, and first boundary is opposite to first edge;Control probe receives the detection light reflected back by to be measured substrate;According to the path of reflection light spot received by probe, the width of undercut area is obtained.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a method and system for measuring undercut structures. Background Technology

[0002] To increase the screen-to-body ratio of display panels, holes are typically made in the display area to house optical components such as cameras. Undercut structures are then placed around the holes to isolate the light-emitting layer, preventing moisture from seeping into the display area and adversely affecting the devices within.

[0003] Among them, the structural parameters of the undercut structure have a decisive influence on the blocking effect of the light-emitting functional layer. Therefore, how to accurately measure the structural parameters of the undercut structure in a timely manner on the production line has become an urgent technical problem to be solved. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a method and system for measuring undercut structures, for accurately measuring the width of the undercut area in an undercut structure on a production line.

[0005] On one hand, embodiments of the present invention provide a method for measuring undercut structures, including: Vibration is applied to a substrate carrying a substrate to be tested, wherein the substrate to be tested includes an undercut structure, the undercut structure has an undercut groove, the undercut structure includes a solid area and an undercut area, and the undercut groove is located in the undercut area; The light source is controlled to emit detection light toward the substrate under test, and the relative positional relationship between the light source and the substrate is controlled to change so that the detection light scans the substrate under test along a first path. The first path passes through at least the first edge and the first boundary of the undercut structure. The first boundary is the boundary between the undercut area and the solid area, and the first boundary is opposite to the first edge. The detector is controlled to receive the detection light reflected back from the substrate under test; The width of the undercut region is obtained based on the path of the reflected light spot received by the detector.

[0006] On the other hand, embodiments of the present invention provide an undercut structure measurement system for measuring the width of the undercut region in an undercut structure using the above-described undercut structure measurement method, including: A carrier substrate is used to support the substrate under test during measurement. The substrate under test includes an undercut structure with an undercut groove. The undercut structure includes a solid area and an undercut area, and the undercut groove is located in the undercut area. A vibration device used to apply vibration to a substrate during measurement; A light source is used to emit detection light toward the substrate under test during measurement and move relative to the carrier substrate so that the detection light scans the substrate under test along a first path, wherein the first path passes through at least the first edge and the first boundary of the undercut structure, the first boundary being the boundary between the undercut area and the solid area, and the first boundary being opposite to the first edge. A detector is used to receive the detection light reflected back from the substrate under test during measurement; An electronic device, connected to a detector, is used to obtain the width of the undercut region based on the path of the reflected light spot received by the detector.

[0007] One of the above technical solutions has the following beneficial effects: Based on the structural differences in different regions of the undercut structure, this invention allows for accurate measurement of the width of the undercut region by applying vibration to the substrate and guiding the detection light's scanning path through the first edge and the first boundary. This is achieved by analyzing the changes in the path of the reflected light spot received by the detector at different time points. For example, in one embodiment, the position of the reflected light spot on the detector when the detection light reaches the first boundary is obtained based on the path changes between the first and second reflected light spots. Similarly, the position of the reflected light spot on the detector when the detection light reaches the first edge is obtained based on the path changes between the second and third reflected light spots. The distance between the first boundary and the first edge, and thus the width of the undercut region in the undercut structure, can be calculated based on the distance between these two positions.

[0008] Therefore, by using the undercut structure measurement method provided in this embodiment of the invention, the width of the undercut area in the undercut structure can be accurately measured on the production line in a timely manner, thereby monitoring whether the width specification of the undercut structure is compliant in the first time, without having to wait for offline slicing. This can avoid waste in subsequent process steps, and also prevent defective products from entering the market, thus avoiding quality problems when the display panel is put into use later. Attached Figure Description

[0009] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of a display panel provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of an undercut structure provided in an embodiment of the present invention; Figure 3This is another schematic diagram of the undercut structure provided in an embodiment of the present invention; Figure 4 This is a flowchart of an undercut structure measurement method provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structural process of the undercut structure measurement method provided in an embodiment of the present invention; Figure 6 This is a top view of the undercut structure provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the path of the reflected light spot received by the detector when the supporting substrate is not vibrating, according to an embodiment of the present invention. Figure 8 This is a schematic diagram of a path of the reflected light spot received by the detector under the condition of vibration of the supporting substrate, provided in an embodiment of the present invention. Figure 9 This is a flowchart of an undercut structure measurement method provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of the position data of the reflected light spot in a coordinate system provided in an embodiment of the present invention. Figure 11 This is another schematic diagram illustrating the correspondence provided in an embodiment of the present invention; Figure 12 This is a schematic diagram of another structural process of the undercut structure measurement method provided in an embodiment of the present invention; Figure 13 A comparative schematic diagram of the first correspondence provided in an embodiment of the present invention; Figure 14 This is a schematic diagram of another structural process of the undercut structure measurement method provided in the embodiment of the present invention; Figure 15 This is another schematic diagram illustrating the correspondence provided in the embodiments of the present invention; Figure 16 This is a schematic diagram of the transmission direction of the detection light provided in an embodiment of the present invention; Figure 17 This is a schematic diagram of a bottom-cut structure measurement system provided in an embodiment of the present invention. Detailed Implementation

[0011] To better understand the technical solution of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0012] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0013] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0014] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0015] Before describing the technical solutions provided in the embodiments of the present invention, the present invention first introduces the film layer structure of the display panel in order to understand the structure and function of the undercut structure involved in the embodiments of the present invention.

[0016] like Figure 1 As shown, Figure 1 This is a schematic diagram of a display panel provided in an embodiment of the present invention. The display panel has an opening area 1, an encapsulation area 2 surrounding the opening area 1, and a display area 3 surrounding the encapsulation area 2.

[0017] The display panel also includes a substrate 4 and a circuit layer 5 and a light-emitting device layer 6 stacked on the substrate 4. The circuit layer 5 includes a semiconductor layer 7, a gate insulating layer 8, a first metal layer 9, a first interlayer dielectric layer 10, a second metal layer 11, and a planarization layer 12. The light-emitting device layer 6 includes an anode layer 13, a pixel definition layer 14, a light-emitting functional layer 15, and a cathode layer 16. The light-emitting functional layer 16 may include film structures such as a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer. When the light-emitting devices in the display panel emit white light and the light-emitting layer is a continuous, full-surface film structure, the light-emitting functional layer 16 may also include a light-emitting layer.

[0018] The encapsulation area 2 includes an undercut structure 17. In one configuration, such as... Figure 2 As shown, Figure 2 This is a schematic diagram of an undercut structure 17 provided in an embodiment of the present invention. The undercut structure 17 can be T-shaped. The undercut structure 17 includes a first film layer 19 and a second film layer 20 located on the side of the first film layer 19 facing away from the substrate 4. One side of the first film layer 19 has a side-cut groove 18, such that the width of the first film layer 19 is smaller than the width of the second film layer 20. Alternatively, in another configuration, such as... Figure 3 As shown, Figure 3This is another schematic diagram of the undercut structure 17 provided in an embodiment of the present invention. The undercut structure 17 can also be I-shaped. The undercut structure 17 includes a first film layer 19, a second film layer 20 located on the side of the first film layer 19 facing away from the substrate 4, and a third film layer 21 located on the side of the first film layer 19 close to the substrate 4. One side of the first film layer 19 has a side-etched undercut groove 18, such that the width of the first film layer 19 is smaller than the width of the second film layer 20 and the third film layer 21. Any of the first film layer 19, the second film layer 20, and the third film layer 21 can be formed using the same patterning process as a film layer in the display area.

[0019] Based on the above structure, see 2 and Figure 3 The undercut structure 17 includes a solid area 22 and an undercut area 23, with an undercut groove 18 located in the undercut area 23. Currently, display panels have strict specifications for the width of the undercut area 23 in the undercut structure 17. If the width of the undercut area 23 is too small, the undercut structure 17 will not be able to function as a barrier, allowing the light-emitting functional layer 16 to continue extending to the edge of the opening area 1 at the undercut structure 17. On the other hand, if the width of the undercut area 23 is too large, it will cause problems such as warping of the second film layer 20 in subsequent processes and cracking of the photoresist during vacuum drying, affecting the photolithography pattern. Therefore, it is extremely important to be able to measure the width of the undercut area 23 in a timely manner on the production line.

[0020] Therefore, embodiments of the present invention provide a method for measuring undercut structures, such as... Figures 4-6 As shown, Figure 4 This is a flowchart of an undercut structure measurement method provided in an embodiment of the present invention. Figure 5 This is a schematic diagram of the structural process of the undercut structure measurement method provided in an embodiment of the present invention. Figure 6 This is a top view of the undercut structure 17 provided in an embodiment of the present invention. The method for measuring the undercut structure includes: Step S1: Vibration is applied to the carrier substrate 25 carrying the substrate 24 to be tested, wherein the substrate 24 to be tested includes an undercut structure 17, the undercut structure 17 has an undercut groove 18, the undercut structure 17 includes a solid area 22 and an undercut area 23, and the undercut groove 18 is located in the undercut area 23.

[0021] The film structure of the substrate under test 24 can be the film structure that the display panel has when the light-emitting functional layer 16 is not formed. For the sake of simplification, the accompanying drawings of this embodiment of the invention only show the undercut structure 17 and the substrate 4 in the substrate under test 24.

[0022] As mentioned above, the undercut structure 17 can be T-shaped or I-shaped. When the undercut structure 17 is T-shaped, the solid area 22 is the region in the undercut structure 17 where the first film layer 19 and the second film layer 20 coexist, and the undercut area 23 is the region where only the second film layer 20 coexists. When the undercut structure 17 is I-shaped, the solid area 22 is the region in the undercut structure 17 where the first film layer 19, the second film layer 20, and the third film layer 21 coexist, and the undercut area 23 is the region where only the second film layer 20 and the third film layer 21 coexist. The accompanying drawings of this embodiment are schematic diagrams using a T-shaped undercut structure 17 as an example.

[0023] Step S2: Control the light source 26 to emit detection light toward the substrate 24 under test, and control the relative positional relationship between the light source 26 and the carrier substrate 25 to change, so that the detection light scans the substrate 24 under test along the first path k. The first path k passes through at least the first boundary 28 and the first edge 27 of the undercut structure 17. The first boundary 28 is the boundary between the undercut region 23 and the solid region 22, and the first boundary 28 is opposite to the first edge 27.

[0024] In this embodiment of the invention, controlling the relative positional relationship between the light source 26 and the carrier substrate 25 can be such that the position of the carrier substrate 25 remains unchanged, while the light source 26 moves at a constant speed and continuously in a direction parallel to the plane of the carrier substrate 25; or, the position of the light source 26 remains unchanged, while the carrier substrate 25 moves at a constant speed and continuously in a direction parallel to the plane of the carrier substrate 25.

[0025] Step S3: Control the detector 29 to receive the detection light reflected back from the substrate 24 under test. The surface of the detector 29 can be parallel to the surface of the supporting substrate 25.

[0026] Step S4: Obtain the width D of the undercut region 23 based on the path of the reflected light spot 30 received by the detector 29.

[0027] Taking the change in the relative position between the light source 26 and the carrier substrate 25 while keeping the position of the detector 29 constant as an example, if no vibration is applied to the carrier substrate 25, when the detection light emitted by the light source 26 scans the substrate 24 under test along the first path k, as... Figure 7 As shown, Figure 7 This is a schematic diagram of a path of the reflected light spot 30 received by the detector 29 when the carrier substrate 25 is not vibrating, according to an embodiment of the present invention. At different time points, the reflected light spot 30 formed by the detection light reflected back from the substrate under test 24 will be displaced along the first straight line L on the detector 29. However, if vibration is applied to the carrier substrate 25, when the detection light emitted by the light source 26 scans the substrate under test 24 along the first path k, as... Figure 8 As shown, Figure 8This is a schematic diagram of the path of the reflected light spot 30 received by the detector 29 under the vibration state of the carrier substrate 25 provided in the embodiment of the present invention. Since the carrier substrate 25 will drive the substrate under test 24 to vibrate, the reflected light spot 30 formed by the detection light reflected back by the substrate under test 24 will fluctuate up and down near the first straight line L at different time points, and the reflected light spot 30 will no longer be displaced on the straight line.

[0028] For clarity, in this embodiment of the invention, the reflected light spot 30 formed by the detection light reflected from the portion of the undercut structure 17 located in the solid region 22 is defined as the first reflected light spot 301, the reflected light spot 30 formed by the detection light reflected from the portion of the undercut structure 17 located in the undercut region 23 is defined as the second reflected light spot 302, and the reflected light spot 30 formed by the detection light reflected from the substrate 4 is defined as the third reflected light spot 303.

[0029] Furthermore, when vibration is applied to the substrate 25, since the undercut structure 17 has a side-cut groove 18 at the undercut area 23, the vibration amplitude of the part of the undercut structure 17 located in the undercut area 23 will be significantly greater than the vibration amplitude of the part located in the solid area 22.

[0030] So, combining Figure 5 and Figure 8 When the detection light emitted by the light source 26 scans the solid region 22 of the undercut structure 17, the first reflected light spot 301 formed by the detection light reflected back from the undercut structure 17 vibrates only slightly in that region. Therefore, the first reflected light spot 301 fluctuates slightly up and down near the first straight line L. At this time, the displacement of the first reflected light spot 301 is small and its turning frequency is low. However, when the detection light emitted by the light source 26 scans the undercut region 23, the second reflected light spot 302 formed by the detection light reflected back from the undercut structure 17 vibrates significantly in that region. Therefore, the second reflected light spot 302 fluctuates significantly up and down near the first straight line L. At this time, the displacement of the second reflected light spot 302 is large and its turning frequency is high.

[0031] When the detection light's scanning path passes through the first edge 27, at two adjacent time points before and after reaching the first edge 27, the detection light at one time point is reflected by the undercut structure 17 onto the detector 29, while at the other time point, the detection light is reflected by the substrate 4 onto the detector 29. Since the vertical distance between the substrate 4 and the light source 26 is greater than the vertical distance between the undercut structure 17 and the light source 26, the displacement of the reflected light spot 30 at these two time points will change abruptly. For example, see... Figure 5 and Figure 8There will be a large displacement between the third reflected spot 303 and the second reflected spot 302.

[0032] In summary, based on the structural differences of the undercut structure 17 in different regions, this embodiment of the invention, by applying vibration to the supporting substrate 25 and causing the scanning path of the detection light to pass through the first edge 27 and the first boundary 28, can accurately measure the width of the undercut region 23 according to the changes in the path of the reflected light spot 30 received by the detector 29 at different time points. For example, in one embodiment, the position point of the reflected light spot 30 on the detector 29 when the detection light scans to the first boundary 28 is obtained according to the path change between the first reflected light spot 301 and the second reflected light spot 302, and the position point of the reflected light spot 30 on the detector 29 when the detection light scans to the first edge 27 is obtained according to the path change between the second reflected light spot 302 and the third reflected light spot 303. Then, the distance between the first boundary 28 and the first edge 27 can be calculated based on the distance between these two position points, which is to say, the width of the undercut region 23 in the undercut structure 17 can be calculated.

[0033] Therefore, by using the undercut structure measurement method provided in this embodiment of the invention, the width of the undercut area 23 in the undercut structure 17 can be accurately measured on the production line in a timely manner, thereby monitoring whether the width specification of the undercut structure 17 is compliant in the first time, without having to wait for offline slicing. This can avoid the waste of subsequent process steps, and also prevent defective products from entering the market, thus avoiding quality problems when the display panel is put into use later.

[0034] In one feasible implementation, combined with Figure 11 ,like Figure 9 and Figure 10 As shown, Figure 9 This is a flowchart of an undercut structure measurement method provided in an embodiment of the present invention. Figure 10 This is a schematic diagram of the position data of the reflected light spot in a coordinate system provided in an embodiment of the present invention. Step S4 may specifically include: Step S41: Based on the position data X of the reflected light spot 30 received by the detector 29 at each time point, obtain the first correspondence A between the position data X and time, where the position data X is the abscissa of the reflected light spot 30 in the coordinate system of the detector 29.

[0035] The aforementioned coordinate system can be understood as a coordinate system constructed on the surface of the detector 29, and the direction of its horizontal axis can be regarded as the direction of the aforementioned first straight line L. In this embodiment of the invention, the direction of the horizontal axis in the coordinate system can be related to the direction of the first path k. For example, when the first path k is perpendicular to the first edge 27, the horizontal axis can also be perpendicular to the first edge 27.

[0036] Step S42: Obtain the first time point t1 and the second time point t2 according to the first correspondence relationship A, wherein the first time point t1 is the time point when the detection light scans the first boundary 28, and the second time point is the time point when the detection light scans the first edge 27.

[0037] Step S43: Obtain the width of the undercut region 23 based on the first time point t1 and the second time point t2.

[0038] Based on the foregoing analysis, considering the differences in vibration amplitude at different positions of the undercut structure 17, when the detection light emitted by the light source 26 scans the solid area 22, the path fluctuation amplitude of the first reflected light spot 301 reflected back by the undercut structure 17 is relatively small. When the detection light emitted by the light source 26 scans the undercut area 23, the path fluctuation amplitude of the second reflected light spot 302 reflected back by the undercut structure 17 is relatively small. Therefore, the time point at which the fluctuation amplitude of the reflected light spot 30 path changes significantly according to the first correspondence relationship A is the first time point t1 when the detection light scans the first boundary 28. When the detection light scans to the first edge 27, there will be a large displacement between the third reflected light spot 303 and the second reflected light spot 302 at adjacent time points. Therefore, the time point at which the displacement of the reflected light spot 30 path changes significantly according to the first correspondence relationship A is the second time point when the detection light scans the first edge 27. The width of the undercut region 23 can then be obtained based on the first time point t1 and the second time point t2. For example, the width of the undercut region 23 can be calculated by using the time difference between the first time point t1 and the second time point t2 and the relative stepping speed between the light source 26 and the carrier substrate 25.

[0039] In one feasible implementation, combined with Figure 5 When the relative positional relationship between the light source 26 and the carrier substrate 25 changes, the position of the detector 29 remains unchanged. For example, when the carrier substrate 25 remains stationary and the light source 26 moves, the positional relationship between the detector 29 and the light source 26 will also change because the position of the detector 29 remains unchanged.

[0040] Based on this, such as Figure 11 As shown, Figure 11 This is another schematic diagram of the correspondence provided in the embodiments of the present invention. Step S42 may specifically include: Step S421: Zero out the location point data X in the first correspondence A to obtain zeroed data Xv×t, and obtain the second correspondence B between the zeroed data Xv×t and time.

[0041] Specifically, the zeroing data can be obtained according to the formula Xv×t, where X is the position point data X in the first correspondence A, v is the relative step speed between the light source 26 and the carrier substrate 25, and t is the interval between the time point corresponding to the position point data X and the initial time point. It can be understood that if the initial time point is regarded as 0, then t is directly the time point corresponding to the position point data X.

[0042] Step S422: Take the absolute value of the zeroed data Xv×t and continuously find the maximum value to obtain the first data Max(|Xv×t|), and obtain the third correspondence C between the first data Max(|Xv×t|) and time.

[0043] Step S424: Obtain the first time point t1 and the second time point t2 based on the derivative relationship obtained by differentiating the third correspondence relation C. Specifically, the first derivative relation D1 can be obtained by taking the first derivative of the third correspondence relation C, and / or the second derivative relation D2 can be obtained by taking the second derivative of the third correspondence relation C. The first derivative relation D1 and the second derivative relation D2 will have two inflection points, and the time points corresponding to these two inflection points are the first time point t1 and the second time point t2.

[0044] When the light source 26 moves at a uniform and continuous speed, the arrangement of position data X corresponding to different time points in the first correspondence relationship A is very dense. If the first time point t1 and the second time point t2 are directly judged based on the fluctuation difference of the position data X, the judgment of the time point may be inaccurate, especially the judgment of the first time point t1. However, in this embodiment of the invention, a series of subsequent transformations are performed on the first correspondence relationship A to obtain the derivative relationship corresponding to the first correspondence relationship A. The amplitude difference at the first time point t1 and the second time point t2 in this type of first derivative relationship D1 or second derivative relationship D2 is very obvious. Therefore, judging the first time point t1 and the second time point t2 based on the derivative relationship will make the judgment more accurate, and thus the measurement of the undercut region 23 in the undercut structure 17 will be more accurate.

[0045] Alternatively, in another feasible implementation, such as Figure 12 As shown, Figure 12This is a schematic diagram of another structural flow of the undercut structure measurement method provided in an embodiment of the present invention. When the relative positional relationship between the light source 26 and the support substrate 25 changes, the relative positional relationship between the detector 29 and the support substrate 25 changes synchronously with the relative positional relationship between the light source 26 and the support substrate 25. For example, when the support substrate 25 remains stationary, the light source 26 moves in a uniform and continuous stepping motion, and the detector 29 also moves in a uniform and continuous stepping motion to keep the positional relationship between the detector 29 and the light source 26 unchanged. At this time, the light source 26 and the detector 29 can be fixed on the same support so that they maintain the same moving speed.

[0046] Based on this, step S42 may specifically include: Step S421': Take the absolute value of the position point data X in the first correspondence relationship A and continuously find the maximum value to obtain the second data Max(|X|), and obtain the fourth correspondence relationship between the second data Max(|X|) and time.

[0047] Step S422': Obtain the first time point t1 and the second time point t2 based on the derivative relationship obtained by differentiating the fourth correspondence relation. Specifically, the first derivative relationship can be obtained by taking the first derivative of the third correspondence relation C and / or the second derivative relationship can be obtained by taking the second derivative of the third correspondence relation C, and then the first time point t1 and the second time point t2 can be obtained based on the first derivative relationship and / or the second derivative relationship.

[0048] Similar to the aforementioned concept, this setup also involves a series of transformations to obtain the derivative relationship corresponding to the first correspondence relationship A, and then the first time point t1 and the second time point t2 are determined more accurately based on the derivative relationship.

[0049] However, as Figure 13 As shown, Figure 13This is a comparative schematic diagram of the first correspondence A provided in an embodiment of the present invention. In the configuration where the position of the detector 29 remains unchanged, when the detection light scans the undercut structure 17, the displacement of the position point of the detector 29 illuminated by the detection light reflected back from the undercut structure 17 at different time points changes forward continuously. That is, the horizontal coordinates corresponding to the first reflected light spot 301 and the second reflected light spot 302 in the coordinate system change forward continuously. However, in the configuration where the detector 29 moves, when the detection light scans to the undercut structure 17, the detection light reflected back from the undercut structure 17 at different time points will continuously illuminate a certain point near the detector 29. Therefore, the horizontal coordinates corresponding to the first reflected light spot 301 and the second reflected light spot 302 in the coordinate system only fluctuate back and forth around a certain coordinate point, and do not change forward continuously. However, the fluctuation amplitude of the first reflected light spot 301 near the horizontal coordinate is small, while the fluctuation amplitude of the second reflected light spot 302 near the horizontal coordinate is large, until the detection light scans to the first edge 27, at which point the horizontal coordinate of the third reflected light spot 303 will undergo a sudden forward change. Therefore, in the setting method where the detector 29 moves, it is not necessary to zero out the position point data X in the first correspondence relationship A. Instead, the fourth correspondence relationship can be obtained by taking the absolute value of the position point data X in the first correspondence relationship A and continuously finding the maximum value.

[0050] Furthermore, the undercut structure measurement method also includes: comparing the amplitude of the derivative relationship with the preset amplitude to determine whether the undercut structure 17 has collapsed in the undercut zone 23.

[0051] See Figure 14 If the undercut structure 17 collapses in the undercut region 23 after its formation, it may affect the blocking effect of the undercut structure 17 on the light-emitting functional layer 16. For example, if the undercut structure 17 collapses significantly in the undercut region 23, the light-emitting functional layer 16 will extend continuously into the solid region 22 at the collapsed portion, making it impossible to effectively block the light-emitting functional layer 16.

[0052] like Figure 14 and Figure 15 As shown, Figure 14 This is a schematic diagram of another structural process of the undercut structure measurement method provided in an embodiment of the present invention. Figure 15This is another schematic diagram illustrating the correspondence provided in this embodiment of the invention. When the undercut structure 17 collapses in the undercut region 23, when the detection light scans to the undercut region 23, the reflected light spot 30, after being reflected by the undercut structure 17, can have a large displacement. This causes a difference between the path of the second reflected light spot 302 when the undercut structure 17 collapses and the path of the second reflected light spot 302 when the undercut structure 17 has not collapsed, thus causing a difference in the first correspondence A. After the first correspondence A changes when the undercut structure 17 collapses, the amplitudes of the subsequent first and second derivative relationships will increase. Therefore, by comparing the magnitude of the derivative relationship with the preset amplitude, it is possible to accurately determine whether the undercut structure 17 has collapsed in the undercut region 23, thereby enabling a more comprehensive detection of the structural features of the undercut structure 17.

[0053] Furthermore, the degree of collapse of the undercut structure 17 will result in different degrees of displacement of the second reflected light spot 302, which in turn will lead to different degrees of change in the amplitude of the derivative relationship obtained after subsequent conversion. Therefore, in this embodiment of the invention, the degree of collapse of the undercut structure 17 in the undercut region 23 can be further determined based on the difference between the amplitude of the derivative relationship and the preset amplitude, thereby allowing for further judgment on the partitioning performance of the undercut structure 17.

[0054] In one feasible implementation, combined with Figure 6 and Figure 10 The first path k and the horizontal axis in the coordinate system are both perpendicular to the first edge 27. At this point, step S43 may specifically include: according to... Calculate the width D of the undercut region 23, where v is the relative stepping speed between the light source 26 and the carrier substrate 25. For example, when the carrier substrate 25 is stationary and the light source 26 moves in a stepping motion, v is the stepping speed of the light source 26, t1 is the first time point, and t2 is the second time point.

[0055] The time difference between the first time point t1 and the second time point t2 multiplied by the relative step speed v is the distance difference between the position point data X corresponding to the first second reflected light spot 302 and the position point data X corresponding to the last second reflected light spot 302. Since the first path k and the horizontal axis in the coordinate system are both perpendicular to the first edge 27, this distance difference is the width of the undercut area 23 in the undercut structure 17.

[0056] Furthermore, in this embodiment of the invention, the measurement accuracy is equal to the product of the vibration period and the relative step speed v. The smaller the vibration period and the greater the relative step speed v, the greater the measurement accuracy. Therefore, the measurement accuracy can be controlled by adjusting the magnitude of the vibration period and the relative step speed v.

[0057] Alternatively, in another feasible implementation, combined with Figure 6 and Figure 10 The first path k and the horizontal axis in the coordinate system are both perpendicular to the first edge 27. At this point, step S43 may specifically include: the process of obtaining the width of the undercut region 23 based on the first time point t1 and the second time point t2 includes: based on... Calculate the width D of the undercut region 23, where x1 is the position data X corresponding to the first time point t1, and x2 is the position data X corresponding to the second time point t2.

[0058] In this configuration, the difference between the position data X corresponding to the first time point t1 and the position data X corresponding to the second time point t2 is the distance difference between the position data X corresponding to the first second reflected light spot 302 and the position data X corresponding to the last second reflected light spot 302. Since the first path k and the horizontal axis in the coordinate system are both perpendicular to the first edge 27, this distance difference is the width of the undercut region 23 in the undercut structure 17. This configuration eliminates the need to obtain the relative stepping speed v between the light source 26 and the supporting substrate 25, making the calculation simpler.

[0059] In one feasible implementation, see Figure 5 When the relative positional relationship between the light source 26 and the carrier substrate 25 changes, the position of the carrier substrate 25 remains unchanged, while the light source 26 moves, so that the substrate under test 24 only vibrates up and down and does not move in the horizontal direction, thus the carrier substrate 25 has higher bearing stability on the substrate under test 24.

[0060] In one feasible implementation, since the laser has good collimation, it can detect slight changes in the reflection angle. Therefore, in this embodiment of the invention, the detection light emitted by the light source can be a laser, which can make the path of the reflected light spot 30 formed on the detector 29 more accurate and further improve the measurement accuracy.

[0061] In one feasible implementation, such as Figure 16 As shown, Figure 16 This is a schematic diagram of the transmission direction of the detection light provided in an embodiment of the present invention. The angle ɵ between the detection light emitted by the light source 26 and the normal direction F is greater than 45°, and the normal direction F is perpendicular to the plane where the carrier substrate 25 is located.

[0062] When the angle between the detection light emitted by the light source 26 and the normal direction F is too small, the reflection angle of the detection light after being reflected by the undercut structure 17 or the substrate 4 will also be very small. In this case, in order for the reflected detection light to be transmitted to the detector 29, the detector 29 needs to be very close to the light source 26. Therefore, when a measurement method with a fixed position for the detector 29 is used, the detector 29 will greatly limit the moving distance of the light source 26. Therefore, by designing the angle between the detection light and the normal direction F to be greater than 45°, the limitation on the setting position of the detector 29 can be reduced, thereby reducing the limitation on the moving distance of the light source 26. Moreover, increasing the angle between the detection light and the normal direction F will also amplify the degree of displacement change of the reflected light spot 30 caused by vibration, so as to make a more accurate judgment on the first time point t1 and the second time point t2. For example, the larger the angle between the detection light and the normal direction F, the greater the degree of displacement change of the third reflected light spot 303, so that the second time point t2 can be judged more accurately.

[0063] In one feasible implementation, see again Figure 16 The vertical distance h between the detector 29 and the undercut structure 17 is greater than 20cm, so that the vertical distance between the detector 29 and the undercut structure 17 is large. This can also amplify the degree of displacement change of the reflected light spot 30 caused by the vibration, so as to accurately determine the first time point t1 and the second time point t2.

[0064] In one feasible implementation, combined with Figure 5 and Figure 6 The first path k passes through the first boundary 28 and then the first edge 27. In this way, as the detection light scans from the solid area 22 to the undercut area 23 and then to the substrate 4, the reflected light reflected back by the undercut structure 17 and the substrate 4 can continuously enter the detector 29. Each time point corresponds to a position point data X of the reflected light spot 30, making the position point data continuous and the measurement accuracy higher.

[0065] Of course, in other optional embodiments of the present invention, the first path k may first pass through the first edge 27 and then through the first boundary 28. The specific measurement method is similar to the aforementioned method and will not be repeated here.

[0066] In one feasible implementation, see again Figure 5 The vibration direction of the carrier substrate 25 is the normal direction F, which is perpendicular to the plane on which the carrier substrate 25 is located. This allows the carrier substrate 25 to drive the undercut structure 17 to vibrate up and down, controlling the vertical distance between the surface of the undercut structure 17 away from the carrier substrate 25 and the light source 26 to change, causing the reflection path of the detection light at different time points to change, and thus causing the displacement of the path of the reflected light spot 30 to fluctuate.

[0067] Based on the same inventive concept, this embodiment of the invention also provides an undercut structure measurement system, which is used to measure the width of the undercut region 23 in the undercut structure 17 using the above-described undercut structure measurement method. For example... Figure 17 As shown, Figure 17 This is a schematic diagram of an undercut structure measurement system provided in an embodiment of the present invention. The undercut structure measurement system includes a support substrate 25, a vibration device 31, a light source 26, a detector 29, and an electronic device 32.

[0068] The carrier substrate 25 carries the substrate 24 under test during measurement. The substrate 24 includes an undercut structure 17 with an undercut groove 18. The undercut structure 17 includes a solid region 22 and an undercut region 23, with the undercut groove 18 located in the undercut region 23. A vibration device 31 applies vibration to the carrier substrate 25 during measurement. A light source 26 emits detection light towards the substrate 24 under test during measurement and moves relative to the carrier substrate 25, causing the detection light to scan the substrate 24 along a first path k. The first path k passes at least through a first boundary 28 and a first edge 27 of the undercut structure 17. The first boundary 28 is the boundary between the undercut region 23 and the solid region 22, and the first boundary 28 is opposite to the first edge 27. A detector 29 receives the detection light reflected back from the substrate 24 under test during measurement. An electronic device 32 is connected to the detector 29 and obtains the width of the undercut region 23 based on the path of the reflected light spot 30 received by the detector 29.

[0069] The functions of the above-mentioned structures have been described in detail in the above embodiments, and will not be repeated here.

[0070] Based on the foregoing analysis, the undercut structure measurement system can accurately measure the width of the undercut area 23 on the production line in a timely manner, so as to monitor whether the width specification of the undercut structure 17 is compliant in the first instance, thereby avoiding waste in subsequent process steps and preventing defective products from entering the market.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for measuring undercut structures, characterized in that, include: Vibration is applied to a carrier substrate on which a substrate to be tested is supported. The substrate to be tested includes an undercut structure with an undercut groove. The undercut structure includes a solid area and an undercut area, and the undercut groove is located in the undercut area. The vibration direction of the carrier substrate is the normal direction, which is perpendicular to the plane on which the carrier substrate is located. The light source is controlled to emit detection light toward the substrate under test, and the relative positional relationship between the light source and the carrier substrate is controlled to change, so that the detection light scans the substrate under test along a first path, wherein the first path passes through at least the first boundary and the first edge of the undercut structure, the first boundary being the boundary between the undercut area and the solid area, and the first boundary being opposite to the first edge; The detector is controlled to receive the detection light reflected back from the substrate under test; The width of the undercut region is obtained based on the path of the reflected light spot received by the detector; The process of obtaining the width of the undercut region based on the path of the reflected light spot received by the detector includes: obtaining a first correspondence between the position point data and time based on the position point data of the reflected light spot received by the detector at various time points, wherein the position point data is the abscissa of the reflected light spot on the coordinate system of the detector; obtaining a first time point and a second time point based on the first correspondence, wherein the first time point is the time point when the detection light scans the first boundary, and the second time point is the time point when the detection light scans the first edge; and obtaining the width of the undercut region based on the first time point and the second time point. in, When the relative positional relationship between the light source and the carrier substrate changes, the position of the detector remains unchanged; the process of obtaining the first time point and the second time point according to the first correspondence includes: performing zeroing processing on the position point data in the first correspondence to obtain zeroed data, and obtaining a second correspondence between the zeroed data and time; taking the absolute value of the zeroed data and continuously finding the maximum value to obtain first data, and obtaining a third correspondence between the first data and time; obtaining the first time point and the second time point according to the derivative relationship obtained by differentiating the third correspondence; or, When the relative positional relationship between the light source and the carrier substrate changes, the relative positional relationship between the detector and the carrier substrate changes synchronously with the relative positional relationship between the light source and the carrier substrate; the process of obtaining the first time point and the second time point according to the first correspondence includes: taking the absolute value of the position point data in the first correspondence and continuously finding the maximum value to obtain the second data, and obtaining the fourth correspondence between the second data and time; obtaining the first time point and the second time point according to the derivative relationship obtained by differentiating the fourth correspondence; The undercut structure measurement method also includes: The magnitude of the derivative relationship is compared with a preset magnitude to determine whether the undercut structure has collapsed in the undercut region.

2. The undercut structure measurement method according to claim 1, characterized in that, The first path and the horizontal axis of the coordinate system are both perpendicular to the first edge; The process of obtaining the width of the undercut region based on the first time point and the second time point includes: based on Calculate the width D of the undercut region, where v is the relative stepping speed between the light source and the carrier substrate, t1 is the first time point, and t2 is the second time point.

3. The undercut structure measurement method according to claim 1, characterized in that, The first path and the horizontal axis of the coordinate system are both perpendicular to the first edge; The process of obtaining the width of the undercut region based on the first time point and the second time point includes: based on Calculate the width D of the undercut region, where x1 is the position point data corresponding to the first time point and x2 is the position point data corresponding to the second time point.

4. The method for measuring undercut structures according to claim 1, characterized in that, When the relative positional relationship between the light source and the carrier substrate changes, the position of the carrier substrate remains unchanged, while the light source moves.

5. The method for measuring undercut structures according to claim 1, characterized in that, The detection light is a laser.

6. The method for measuring undercut structures according to claim 1, characterized in that, The angle between the detection light emitted by the light source and the normal direction is greater than 45°, and the normal direction is perpendicular to the plane of the substrate.

7. The method for measuring undercut structures according to claim 1, characterized in that, The vertical distance between the detector and the undercut structure is greater than 20cm.

8. The method for measuring undercut structures according to claim 1, characterized in that, The first path first passes through the first boundary and then passes through the first edge.

9. A measurement system for undercut structures, characterized in that, Measuring the width of the undercut region in an undercut structure using the undercut structure measurement method as described in claim 1, comprising: A carrier substrate is used to support a substrate under test during measurement, wherein the substrate under test includes an undercut structure having an undercut groove, the undercut structure including a solid area and an undercut area, and the undercut groove is located in the undercut area; A vibration device for applying vibration to the carrier substrate during measurement; A light source is used to emit detection light toward the substrate under test during measurement and move relative to the carrier substrate so that the detection light scans the substrate under test along a first path, wherein the first path passes at least through a first boundary and a first edge of the undercut structure, the first boundary being the boundary between the undercut area and the solid area, and the first boundary being opposite to the first edge; A detector is used to receive the detection light reflected back from the substrate under test during measurement; An electronic device, connected to the detector, is used to obtain the width of the undercut region based on the path of the reflected light spot received by the detector.

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